TW202004233A - Polarizing member and head-up display device provided with same - Google Patents

Abstract

Provided is a polarizing member for a HUD device that not only has excellent surface hardness but also prevents discoloration by light resistance. A polarizing member (18) according to the present invention comprises a polarizing plate (34) including a polarizer and being made of a dyed polarizing material, a first support plate (30) bonded to a front surface of the polarizing plate (34) via an adhesive layer (32), a second support plate (38) bonded to a rear surface of the polarizing plate (34) via an adhesive layer (36), and an ultraviolet absorption layer (B) and a hard coat layer (C) that have natural light transmittances at a wavelength of 380 nm of 10% or less, the ultraviolet absorption layer (B) and the hard coat layer (C) being provided on the surface of at least one of the first support plate (30) and the second support plate (38).

Description

Polarizing component and head-up display device with polarizing component

The present invention relates to a polarizing member and a head-up display device provided with the polarizing member.

A head-up display device (hereinafter referred to as a HUD device) has been used, which displays an image on a display such as a display, reflects the image to a mirror, and reflects it on a glass or the like as a virtual image. The HUD device is used to display the message and the like in accordance with the user's normal field of vision. The HUD device has various application examples such as cars that display information such as vehicle speed on the windshield.

In a HUD device such as a vehicle, a light-transmitting cover is provided so that dust and waste do not enter through the projection port, which projects an image from the device body to a projection section such as glass. As the light-transmitting cover, a polycarbonate plate is used. Here, in order to shield the sunlight incident from the outside without reducing the brightness of the light emitted from the screen, it is proposed to provide the cover with a polarization characteristic. In addition, a structure in which a hard coating layer is laminated on a support plate, that is, polycarbonate has been disclosed.

[Problems to be solved by the invention] However, when the hard coat layer is directly laminated on the support plate, that is, polycarbonate, the surface hardness as a desired physical characteristic is insufficient. In particular, when applied to a vehicle-mounted HUD device, insufficient surface hardness may be a problem.

In addition, the external light will cause the polycarbonate itself to change color, so there will be a problem that the light transmittance becomes lower and affects the image.

In view of the above problems, an object of the present invention is to provide a polarizing member that can be used as a transparent cover of a HUD device and has excellent surface hardness and light resistance.

[Technical means for solving problems] It has been found that by forming a layer structure having ultraviolet absorption characteristics and hard coating characteristics on the surface of the polarizing plate, it not only serves as the surface hardness required for a head-up display cover, but also suppresses the discoloration of the support plate due to external light. Complete the present invention.

That is, one aspect of the present invention is a polarizing member including: a polarizing plate having a polarizing plate and using a dye-based polarizing material; a first support plate that is bonded to the polarizing plate through an adhesive layer The surface of the second support plate, which is attached to the back surface of the polarizing plate via an adhesive layer; and, on the surface of at least one of the first support plate or the second support plate, is provided with an ultraviolet absorbing layer and hard In the coating layer, the transmittance of the ultraviolet absorption layer to natural light with a wavelength of 380 nm is 10% or less.

Here, the film thickness of the ultraviolet absorbing layer and the hard coat layer may be 40 μm or more and 70 μm or less.

In addition, an adhesion layer may be provided between the surface of the first support plate or the second support plate, and the ultraviolet absorption layer or the hard coat layer, and the film thickness of the adhesion layer may be 5 μm or more and 20 μm or less .

In addition, another aspect of the present invention is a polarizing member including: a polarizing plate having a polarizing plate and using a dye-based polarizing material; and a first supporting plate bonded to the polarizing plate via an adhesive layer The surface of the second support plate, which is attached to the back surface of the polarizing plate via an adhesive layer; and, on the surface of at least one of the first support plate or the second support plate, a hard coating layer is provided, The hard coat layer contains an ultraviolet absorber, and the penetration rate of natural light with a wavelength of 380 nm to the ultraviolet absorber is 10% or less.

Here, the film thickness of the hard coat layer may be 40 μm or more and 70 μm or less.

In addition, an adhesion layer may be provided between at least one surface of the first support plate or the second support plate and the hard coat layer, and the film thickness of the adhesion layer may be 5 μm or more and 20 μm or less.

In addition, the first support plate and/or the second support plate may include a flame retardant plastic plate.

In addition, the linear polarized light transmittance can be made 60% or more and 95% or less.

In addition, the polarizing member can be used for a head-up display. The head-up display is arranged such that the polarization direction becomes parallel to the polarized light output from the display and penetrates the polarizing member, and the virtual image of the transmitted image is projected as a projection image.

In addition, another aspect of the present invention is a head-up display comprising: the above-mentioned polarizing member; a display for outputting an image; and, a housing for accommodating the above-mentioned display; wherein the above-mentioned polarizing member is used as a light-transmitting cover, The light-transmitting cover is used to penetrate the image output from the display to the outside of the housing.

According to the present invention, it is possible to provide a polarizing member for a HUD device and a head-up display using the polarizing member, which not only have excellent surface hardness, but also suppress discoloration by light resistance

As shown in FIGS. 1 and 2, the HUD device 100 in the embodiment of the present invention includes the following structures: a housing 10, a display 12, a plane mirror 14, a concave mirror 16, a polarizing member (polarizing cover) 18 and Projecture 20.

The housing 10 accommodates components such as the display 12, the flat mirror 14, and the concave mirror 16 that constitute the HUD device 100. The casing 10 is made of a material having mechanical strength such as plastic or metal.

The display 12 is a device for outputting an image to be projected by the HUD device 100. The display 12 is constituted by a liquid crystal display (LCD) or the like. The image light emitted from the display 12 is linearly polarized.

The flat mirror 14 is provided to reflect the image light emitted from the display 12 to the concave mirror 16. The concave mirror 16 is provided to reflect the image light arriving from the plane mirror 14 to the projection unit 20. After the concave mirror 16 magnifies the image light at a desired magnification, it projects toward the projection unit 20.

The polarizing member (polarizing cover) 18 is a translucent plate-shaped member that is attached to the opening portion, and the opening portion is provided in the housing 10. The polarizing member 18 is provided as a light-transmitting cover so that the image light reflected by the concave mirror 16 penetrates the outside of the housing 10 and dust and waste do not enter the inside of the housing 10. The configuration of the polarizing member 18 will be described later.

The projection unit 20 receives the image light arriving from the concave mirror 16 and projects the virtual image as a projection image. In order to ensure the normal vision of the user, the projection unit 20 may use a half mirror or a holographic element. In addition, the projection portion 20 may be configured so that the mounting angle and the mounting position relative to the housing 10 can be changed. Thereby, the position and angle of the projection unit 20 can be adjusted so that the projected image can be easily seen according to the user's line of sight.

The polarizing member 18 includes a polarizing plate 34 having a polarizing plate. FIG. 3 shows a cross-sectional structure of an example of the polarizing member 18. In this embodiment, the polarizing member 18 is configured as follows: the first supporting plate 30, the adhesive layer 32, the polarizing plate 34, the adhesive layer 36, the second supporting plate 38, the adhesive layer A, and the ultraviolet absorption Layer B and hard coat layer C are laminated.

In addition, as shown in FIG. 4, the polarizing member 18 may be configured as follows: the adhesive layer A is not provided, and the first support plate 30, the adhesive layer 32, the polarizing plate 34, the adhesive layer 36, the first The second supporting plate 38, the ultraviolet absorbing layer B, and the hard coat layer C are laminated.

[Polarizer] The polarizing plate 34 is a layer containing a polarizer that allows only light polarized in a specific direction to pass through. The polarizing plate 34 can be arbitrarily selected, but it may be, for example, a dye-based polarizing plate, which is formed by dyeing a polyvinyl alcohol (PVA) film with a dichroic dye.

For the PVA film, as an example, VF-PS#7500 (trade name) manufactured by Kuraray Co., Ltd. can be applied. For a PVA film, for example, a film with a thickness of 75 μm before stretching is stretched until it becomes about 30 μm after stretching. The polarizing plate 34 is formed on one side of the PVA film.

The polarizing plate 34 can be composed of a dye-based material. The dye-based material may be a dichroic dye. As a dichroic dye, when a dichroic dye such as an azo compound, an anthraquinone compound, a tetrazine compound or a salt thereof is used, the optical properties are durable under high temperature conditions or high temperature and high humidity conditions It has excellent properties and no color change during molding. It is not only easy to adjust the hue (hue), but also has no yellowing caused by iodine, so it is preferable. Because the polarization degree is high and the durability is excellent, the azo compound is better.

As the azo-based compound dye, the following dyes can be exemplified.

(式中，R₁ 表示氫原子、低級烷基、低級烷氧基、羥基、磺酸基、或羧基，R₂ ～R₅ 各自獨立表示氫原子、低級烷基、低級烷氧基、或乙醯氨基，X表示可具有取代基之苯甲醯胺基、可具有取代基之苯胺基、可具有取代基之苯偶氮基、或可具有取代基之萘酚三唑(naphthotriazole)基，m表示1或2，n表示0或1。)(1) The azo compound represented by the chemical formula (1) or its salt disclosed in Japanese Patent Publication WO2009/057676(A1).

(In the formula, R ₁ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a hydroxyl group, a sulfonic acid group, or a carboxyl group, and R ₂ to R ₅ each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, or B Acylamino, X represents a benzylamino group that may have a substituent, an anilino group that may have a substituent, a benzene azo group that may have a substituent, or a naphthotriazole group that may have a substituent, m Means 1 or 2, n means 0 or 1.)

(式中，A表示具有取代基之苯基或具有1～3個磺酸基之萘基，X表示-N=N-或-NHCO-。R₁ ～R₄ 各自獨立表示氫原子、低級烷基、或低級烷氧基，m=1～3，n=0或1。)(2) The azo compound represented by the chemical formula (2) or a salt thereof disclosed in Japanese Patent Publication WO2007/145210(A1).

(In the formula, A represents a phenyl group having a substituent or a naphthyl group having 1 to 3 sulfonic acid groups, X represents -N=N- or -NHCO-. R ₁ to R ₄ each independently represent a hydrogen atom, a lower alkane Base, or lower alkoxy, m=1 to 3, n=0 or 1.)

(式中，R₁ 表示磺酸基、羧基、或低級烷氧基，R₂ 表示磺酸基、羧基、低級烷基、或低級烷氧基。不過，排除R₁ 、R₂ 皆為磺酸基的情況。R₃ ～R₆ 各自獨立表示氫原子、低級烷基、或低級烷氧基，R₇ 、R₈ 各自獨立表示氫原子、胺基、羥基、磺酸基、或羧基。)(3) The triazo dye represented by the chemical formula (3) disclosed in the public table WO2006/057214(A1).

(In the formula, R ₁ represents a sulfonic acid group, a carboxyl group, or a lower alkoxy group, and R ₂ represents a sulfonic acid group, a carboxyl group, a lower alkyl group, or a lower alkoxy group. However, excluding R ₁ and R ₂ are both sulfonic acids R ₃ to R ₆ each independently represent a hydrogen atom, a lower alkyl group, or a lower alkoxy group, and R ₇ and R ₈ each independently represent a hydrogen atom, an amine group, a hydroxyl group, a sulfonic acid group, or a carboxyl group.)

(式中，M表示選自銅、鎳、鋅及鐵之過渡金屬；A¹ 表示可取代之苯基或可取代之萘基；B¹ 表示可取代之1-或2-萘酚殘基，該萘酚的羥基位於偶氮基的鄰位，並與由M表示之過渡金屬錯合；R¹ 及R² 各自獨立表示氫、低級烷基、低級烷氧基、羧基、磺酸基(sulfo)、胺磺醯基、N-烷基胺磺醯基、胺基、醯化胺基(acylamino)、硝基、或鹵素。)(4) The metal-containing disazo compound represented by the chemical formula (4) disclosed in Japanese Patent Laid-Open No. 2004-251963 or a salt thereof.

(In the formula, M represents a transition metal selected from copper, nickel, zinc and iron; A ¹ represents a substituted phenyl or a substituted naphthyl; B ¹ represents a substituted 1- or 2-naphthol residue, The hydroxyl group of the naphthol is located at the ortho position of the azo group and is complexed with the transition metal represented by M; R ¹ and R ² each independently represent hydrogen, lower alkyl, lower alkoxy, carboxyl, and sulfo ), sulfamoyl, N-alkyl sulfamoyl, amine, acylamino, nitro, or halogen.)

(式中，A² 及B² 各自獨立表示可取代之苯基或可取代之萘基；R³ 及R⁴ 各自獨立表示氫、低級烷基、低級烷氧基、羧基、磺酸基(sulfo)、胺磺醯基、N-烷基胺磺醯基、胺基、醯化胺基(acylamino)、硝基、或鹵素；m表示0或1。)(5) The triazo compound represented by the chemical formula (5).

(In the formula, A ² and B ² each independently represent a substituted phenyl or a substituted naphthyl; R ³ and R ⁴ each independently represent hydrogen, lower alkyl, lower alkoxy, carboxyl, and sulfo ), sulfamoyl, N-alkyl sulfamoyl, amine, acylamino, nitro, or halogen; m represents 0 or 1.)

(式中，A表示經甲基取代之苯基或萘基，R表示胺基、甲胺基、乙胺基、或苯胺基。)(6) Japanese Patent Laid-Open No. 3-12606 discloses a water-soluble compound represented by the chemical formula (6) or its copper salt compound.

(In the formula, A represents a phenyl group or naphthyl group substituted with a methyl group, and R represents an amine group, a methylamino group, an ethylamino group, or an anilino group.)

(7) Japanese Patent Laid-Open No. 2-61988 discloses a water-soluble disazo compound represented by the chemical formula (7) or its copper salt compound.

(8) Others, for example, CIDirect Yellow 12, CIDirect Yellow 28, CIDirect Yellow 44, CIDirect Yellow 142, CIDirect Orange 26, CIDirect Orange 39, CIDirect Orange 71, CIDirect Orange 107, CIDirect Red 2, CIDirect Red 31, CIDirect Red 79, CIDirect Red 81, CIDirect Red 117, CIDirect Red 247, CIDirect Green 80, CIDirect Green 59, CIDirect Blue 71, CIDirect Blue 78, CIDirect Blue 168, CIDirect Blue 202, CIDirect Violet 9, CIDirect Violet 51, CIDirect Brown 106, CIDirect Brown 223, etc. Furthermore, it is preferable that two or more of these dyes are blended and dyed to PVA in such a way as to compensate for the polarization characteristics of each wavelength in the visible light region, thereby creating a neutral gray hue.

In addition, as for commercially available dyes, Kayafect Violet P Liquid (manufactured by Nippon Kayaku Co., Ltd.), Kayafect Yellow Y and Kayafect Orange G, Kayafect Blue KW, and Kayafect Blue Liquid 400 can be cited.

In addition, the polarizing plate 34 may have a structure in which a polarizing film obtained by the above-mentioned manufacturing method is bonded to a substrate. The base material is a component that becomes a protective layer of the polarizing plate 34. The substrate can be arbitrarily selected, but for example, a triacetylcellulose (TAC) film, an acrylic film, a cyclic olefin-based film, or the like can be used. As an example, P960GL manufactured by TacBright, etc. can be applied. The thickness of the base material is not limited to this, and may be made 20 μm or more and 200 μm or less. In order to obtain a polarizing plate with little optical change to heat and humidity and suppress shrinkage and warpage, it is preferable to provide a base material on both sides of the polarizing film.

[Adhesive layer] The adhesive layer 32 is a layer for bonding the polarizing plate 34 and the first support plate 30. In addition, the adhesive layer 36 is a layer for bonding the polarizing plate 34 and the second support plate 38. The adhesive or adhesive used for the adhesive layer 32 and the adhesive layer 36 is not particularly limited, and may be a flame retardant adhesive. In addition, when a force such as thermal stress acts between the polarizing plate 34 and the first supporting plate 30, or the polarizing plate 34 and the second supporting plate 38, the adhesive layer 32 and the adhesive layer 36 can be used to absorb (buffer) the Forceful material. The adhesive used for the adhesive layer is not particularly limited, and examples thereof include adhesives prepared by blending isocyanate-based compounds, epoxy compounds, and the like with polyvinyl alcohol-based resins, urethane resins, and the like. Components; or, adhesive components such as acrylic resins and polyester resins. For example, for the adhesive layer 32 and the adhesive layer 36, a polyvinyl alcohol-based adhesive or adhesive can be used. The film thickness of the adhesive layer 32 and the adhesive layer 36 can be made 1 μm or less.

In addition, by applying the adhesive layer 32 and the adhesive layer 36, the polarizing mask 18 having lower flammability than in the past can be provided. In particular, by using a polyvinyl alcohol-based adhesive as the adhesive layer 32 and the adhesive layer 36, flammability can be reduced. In addition, by making the film thicknesses of the adhesive layer 32 and the adhesive layer 36 to 1 μm or less, the flammability can be further reduced.

In addition, the adhesive layer A is a layer for bonding the ultraviolet absorption layer B and the hard coat layer C to the surface of the first support plate 30. The adhesive used for the adhesive layer A is not particularly limited, but examples thereof include adhesives prepared by blending isocyanate compounds, epoxy compounds, and the like with polyvinyl alcohol resins, urethane resins, and the like. Adhesive component; or, acrylic resin, polyester resin and other adhesive components. For example, for the adhesive layer A, acrylic resin is preferably used.

The thickness of the adhesive layer A is not particularly limited, and can be set to a normal thickness in consideration of physical properties. The thickness of the adhesive layer A is preferably, for example, 5 μm or more and 50 μm or less, and more preferably 5 μm or more and 20 μm or less.

The method for forming the adhesive layer 32, the adhesive layer 36, and the adhesive layer A is not particularly limited. For example, it can be set as follows: In the solid component of the acrylic or polyester adhesive The adhesive composition diluted with solvents such as toluene or methyl ethyl ketone (MEK) is applied to the object to be adhered and further laminated to make the applied adhesive composition hardening. In addition, the droplet method can be applied.

[Support Board] The first support plate 30 and the second support plate 38 are members for mechanically supporting the polarizing member 18. That is, the first support plate 30 is attached to the surface of the polarizing plate 34 via the adhesive layer 32. In addition, the second support plate 38 is attached to the back surface of the polarizing plate 34 via the adhesive layer 36.

The first support plate 30 and the second support plate 38 may include flame retardant plastic plates. That is, by configuring the first support plate 30 and the second support plate 38 to be made of flame-retardant plastic plates, it is possible to realize a HUD device 100 that is suitable for being mounted on a polarizing member 18 that requires flame retardancy Specifications of cars, etc.

For example, the first support plate 30 and the second support plate 38 may be polycarbonate (PC) plates, acrylic resin plates, cellulose plates, nylon plates, or the like. The acrylic resin plate can be, for example, polymethyl methacrylate (PMMA) or the like. In addition, the first support plate 30 and the second support plate 38 may be made of non-combustible materials. In consideration of the mechanical strength of the polarizing member 18, the first support plate 30 and the second support plate 38 can each have a thickness of 50 μm or more.

In addition, for the first support plate 30 and the second support plate 38, a material in which at least one of metal, halogen, and phosphorus is mixed in polycarbonate (PC) or coated to be flame retardant can be used. In consideration of price, coloring, characteristics of polycarbonate (PC), and environmental impact, bromine can be used as the halogen. When at least one of metal, halogen, and phosphorus is mixed in polycarbonate (PC), the selected raw material may be kneaded to polycarbonate (PC).

In addition, the first support plate 30 and the second support plate 38 may have a structure in which a plurality of layers are stacked instead of a single layer. For example, a structure may be adopted in which the main board is a polycarbonate (PC) board and an acrylic resin board is laminated thereon as a sub-board.

Here, in order not to deform the imaging after passing through the polarizing member 18, the first support plate 30 and the second support plate 38 may use a flat surface support plate. In addition, the first support plate 30 and the second support plate 38 may use the following support plate: a low phase in which the transmitted light does not cause a phase difference in a manner that does not interfere with the light (polarized light) after passing through the polarizing member 18 Poor support board.

Furthermore, on the first support plate 30 and the second support plate 38, in order to protect the surface, a hard coat (Hard Coat, HC), an anti-glare layer (Anti-Glare, AG), and an anti-reflection layer (Anti-Reflection , AR), Low-Reflection (LR) and other protective layers.

However, in order to suppress the bending of the polarizing member 18, when the sub-plate or the protective layer is provided, it may have a vertically symmetric structure along the film thickness direction of the polarizing member 18.

When the polarizing member 18 is mounted on the HUD device 100, it can be arranged in such a manner that the polarization direction of the light (linearly polarized light) output from the display 12 and passing through the polarizing member 18 becomes parallel to the polarizing plate 34 of the polarizing member 18 Polarization direction.

With this, it is possible to provide a polarizing member 18 that can largely block light (sunlight, etc.) incident on the polarizing member 18 from outside the HUD device 100 and can transmit most of the light output from the display 12. Therefore, it is possible to realize a HUD device 100 whose visibility of an image is improved.

In addition, by using the first support plate 30 and the second support plate 38 to support the front and back surfaces of the polarizing plate 34, the mechanical strength of the polarizing member 18 can be improved.

Further, by sandwiching the polarizing plate 34 between the first support plate 30 and the second support plate 38 so as to be symmetrical in the film thickness direction from the front side and the back side, it is possible to suppress the application of thermal stress to the polarizing member 18 Warpage. That is, when the polarizing member 18 is heated by the light from the display 12 or the sunlight from the outside, the stress generated at the interface between the surface side of the polarizing plate 34 and the first support plate 30 and the polarized light The stress generated at the interface between the back surface side of the plate 34 and the second support plate 38 is balanced, whereby warpage (bending) and deformation occurring in the polarizing member 18 can be suppressed. Such a configuration will be an advantageous effect particularly in the HUD device 100 for in-vehicles requiring heat resistance.

[Ultraviolet absorption layer] The polarizing member 18 is provided with an ultraviolet absorbing layer B and a hard coat layer C on the surface of the first support plate 30. The ultraviolet absorption layer B is provided to suppress the discoloration of the first support plate 30 caused by ultraviolet light and to suppress the deterioration of the display performance of the HUD device 100.

The ultraviolet absorption layer B refers to a layer that absorbs light of a wavelength of 400 nm or less, and includes not only a layer formed of a material having ultraviolet absorption but also a layer formed by including an ultraviolet absorber in a resin film or the like. In addition, a configuration in which an ultraviolet absorber is added to the hard coat layer C to be described later may be adopted.

The ultraviolet absorbing layer B may be a single layer or a multilayer of two or more layers, and the method of laminating each layer is not particularly limited. For example, the first support plate 30 and the ultraviolet absorption layer B may be laminated via an adhesive or an adhesive, and the ultraviolet absorption layer B may be placed on the first support plate 30 without using an additional medium. In addition, it may be carried out by a method of coextrusion of the resin used to form the first support plate 30 and the resin used to form the ultraviolet absorption layer B, or it may be applied for coating on the first support plate 30 Method for forming the resin of the ultraviolet absorption layer B.

The ultraviolet absorber used in the ultraviolet absorption layer B is preferably one that has excellent absorption performance for ultraviolet light with a wavelength of 380 nm or less and has little absorption of visible light with a wavelength of 400 nm or more. Specifically, for the ultraviolet absorbing layer B containing an ultraviolet absorbing agent, natural light having a wavelength of 380 nm has a transmittance of 10% or less to the ultraviolet absorbing layer B, preferably 5.0% or less, more preferably 3.0% or less, and particularly preferably Below 1.0%. The transmittance of light with a wavelength of 380 nm or less generally depends on the content of the ultraviolet absorber. Therefore, a large amount of this content will cause the transmittance to decrease, and can bring about a long-term light resistance effect to ultraviolet rays included in external light. When the transmittance of light with a wavelength of 380 nm exceeds 5.0%, ultraviolet light with a wavelength of 380 nm or less cannot be completely absorbed, and the ultraviolet light will penetrate to the first support plate 30, causing discoloration and deterioration (yellowing deterioration, etc.). When the transmittance of light with a wavelength of 380 nm is 1.0% or less, ultraviolet light with a wavelength of 380 nm or less is almost completely absorbed, and therefore it is possible to delay the discoloration and deterioration (yellowing deterioration, etc.) of the first support plate 30.

In addition, the transmittance of natural light having a wavelength of 400 nm or more in the ultraviolet absorption layer B is preferably 70% or more, and more preferably 90% or more. That is, by having a transmittance of 70% or more at a wavelength of 400 nm, it is possible to suppress the discoloration and deterioration of the ultraviolet absorption layer B (for example, color yellowing). In addition, by having a high transmittance in the entire visible light region, even if laminated as a polarizing member, the optical characteristics are not likely to be lowered.

Examples of the ultraviolet absorber include oxybenzophenone-based compounds, benzotriazole-based compounds, salicylate ester-based compounds, and diphenyl ketone-based compounds. Organic ultraviolet absorbers such as cyanoacrylate compounds and nickel complex salt compounds. These materials can be used alone or in combination. The blending ratio of the ultraviolet absorber in the resin film described later differs depending on the resin film-forming material used, but it is preferably 0.1% by weight or more and 20% by weight or less, and more preferably 0.5% by weight or more and 10% by weight the following. When the blending amount is less than 0.1% by weight, the transmittance at a wavelength of 380 nm or less cannot be sufficiently reduced, and long-term light resistance cannot be obtained. When the blending amount exceeds 20% by weight, the ultraviolet absorbing layer B may bleed out (a phenomenon in which the additives float on the surface of the film), and further, the bleed may be a defect in appearance.

The resin film-forming material is not particularly limited if it has high light permeability, and examples thereof include cellulose ester resins, olefin resins, (meth)acrylic resins, polyester resins, and polycarbonate resins. Resins, vinyl acetate-based resins, polyarylate-based resins, styrene-based resins, polyamide-based resins, polyphenol-based resins, polyimide-based resins, norbornene-based resins, gelatin-based resins, Polyvinyl alcohol-based resins, etc. and mixtures and copolymers thereof.

Specific examples of the cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. In addition, such copolymers and those obtained by modifying a part of hydroxyl groups with other kinds of substituents can also be mentioned. Among them, particularly preferred is cellulose triacetate. As cellulose triacetate, a large number of products are commercially available, which is advantageous in terms of ease of acquisition and cost. In particular, commercially available protective films for liquid crystal polarizers can be suitably used by adding a moderate ultraviolet absorber in order to prevent dyes or PVA films from being decomposed by ultraviolet rays and dimensional changes.

The accumulation of a resin layer or a resin film on the polarizing member 18 causes an asymmetric structure with the polarizing plate 34 as the center. Therefore, when exposed to a high-temperature environment, it is necessary to suppress the warping (curling) of the polarizing member 18. As the main factor of warpage, the difference in dimensional change accompanying the thermal expansion of each resin material can be cited. The general resin material has the property of monotonous expansion proportional to temperature. Therefore, from the viewpoint of suppressing warpage of the polarizing member 18 due to lamination, it is preferable to use a resin material having a smaller coefficient of thermal expansion. In addition, even when only a resin layer or a resin film is laminated on one side of the polarizing member 18, it is possible to combine supports of different thicknesses in such a manner that the thickness of the layer having a polarizer (PVA layer) is equivalent to vertical symmetry The polarizing member 18 is formed by a plate or the like so as to have a vertically symmetric structure along the film thickness direction. Further, a resin layer or a resin film of the same thickness is deposited on the opposite side of the polarizing plate 34 to form a symmetrical structure with the polarizing plate 34 as the center.

Cellulose triacetate, which has the same thermal expansion properties as general resins, but has the property that the water content in the resin decreases with increasing temperature, causing drying and shrinking together, and can be preferably used as a resin material It has little dimensional change due to temperature fluctuation due to the balance of expansion and contraction.

In addition, the cellulose triacetate film has excellent transparency in the resin-based film, and therefore has an advantage that even if it is laminated as the polarizing member 18, the optical characteristics are not likely to deteriorate. Further, the cellulose triacetate film has higher compression hardness properties than polycarbonate-based resin and (meth)acrylate-based resin films. Therefore, in the configuration provided with the hard coat layer C described later, high hardness can be easily obtained. This is because the hardness of the hard coat layer C provided together with the resin film depends on the physical properties of the resin film as the base. In addition, as a hard coating agent for resin-based films, commercially available ultraviolet curable resins such as polyfunctional (meth)acrylates can be applied, and the adhesion between the hard coating layer C and the film can be easily established.

Examples of commercially available products of cellulose triacetate include FUJITAC (registered trademark) TD80 (manufactured by FUJIFILM Corporation), FUJITAC (registered trademark) TD80UF (manufactured by FUJIFILM Corporation), FUJITAC (registered trademark) TD80UZ (FUJIFILM Corporation) System), FUJITAC (registered trademark) TD40UZ (manufactured by FUJIFILM Corporation), KC8UX2M, KC4UY, KC6UAW (manufactured by Konica Minolta Opto Device Co., Ltd.), etc.

Specific examples of (meth)acrylate-based resins include poly(meth)acrylates such as polymethyl methacrylate, methyl methacrylate-(meth)acrylic acid copolymers, and methyl methacrylate. -(Meth)acrylate copolymer, methyl methacrylate-acrylate-(meth)acrylic acid copolymer, methyl(meth)acrylate-styrene copolymer (MS resin, etc.), having alicyclic hydrocarbon group Polymers (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-norbornene (meth)acrylate copolymer). Preferably, polyalkyl (meth)acrylate (C1-6), such as polymethyl (meth)acrylate, is mentioned. As the (meth)acrylic resin, methacrylic acid having methyl methacrylate as the main component (50% by weight or more and 100% by weight or less, preferably 70% by weight or more and 100% by weight or less) can be preferably used. Methyl ester resin.

[Hard coating] The hard coat layer C has the function of improving the surface hardness of the film, and is provided for the purpose of preventing surface scratches and the like. The hard coat layer C is more preferably a value indicating H or harder in the pencil hardness test specified in JIS K 5600-5-4. When this hard coat layer C is formed, in the manufacturing process or the final product, for example, even when the surface is wiped with a cloth or the like to remove surface dirt, there is an advantage that scratches are less likely to occur.

The material used to form the hard coat layer C is generally hardened by heat or light. For example, organic hard coating materials such as organic polysiloxane-based, melamine, epoxy-based, acrylic, urethane acrylate-based, and inorganic hard coating materials such as silicon dioxide can be cited.

The film thickness of the ultraviolet absorbing layer B and the hard coat layer C differs depending on the performance required for each of the ultraviolet absorbability and the hard coat layer property, so it cannot be generalized, but it can be set to 0.1 μm or more and 200 μm or less. When the film thickness is less than 0.1 μm, sufficient surface hardness cannot be obtained. In addition, in order to obtain long-term light resistance, it is necessary to add more ultraviolet absorbers per part by weight of the resin. When the film thickness exceeds 200 μm, the total thickness of the polarizing member 18 may increase, so that double reflection (a phenomenon of double display of projected images) may occur in the image projected from the HUD device. In addition, in the film forming method described later, there is a possibility that it becomes difficult to obtain smooth surface properties. In addition, the inherent strain (also referred to as "undulation") of the polarizing member 18 affects the quality of the projected image, so the ultraviolet absorbing layer B and the hard coat layer C can have a smooth surface. Therefore, from the viewpoints of ease of coating and suppression of ultraviolet penetration, it is more preferably 1 μm or more and 100 μm or less, still more preferably 10 μm or more and 80 μm or less, and particularly preferably 40 μm or more and 70 μm. the following. As a result, the ultraviolet absorption layer B and the hard coat layer C can suppress the increase in the total thickness of the polarizing member 18, while having excellent surface hardness and ultraviolet absorption, and having both smooth surface properties.

In addition, when the composite layer of the ultraviolet absorption layer B and the hard coat layer C is formed, it is more desirable that the total film thickness of each layer falls within the above range.

The film-forming method of the hard coat layer C, which can use known methods such as a roll coating method, a dipping method, a gravure coating method, a bar coating method, a spin coating method, a spray coating method, a printing method, etc. method. In addition, the method of forming the composite layer of the ultraviolet absorbing layer B and the hard coat layer C is not particularly limited, but for example, the following method can be applied: direct coating on the ultraviolet absorbing layer B or the first support plate 30 to constitute the hard coating Method of layer C resin, method of lamination with adhesive or adhesive.

[Optical characteristics of polarizing parts] The transmittance of the polarizing member 18 can be set by the balance between the shading effect of external light such as sunlight and the amount of polarized light emitted from the liquid crystal (luminance of the emitted light). In order to balance the aforementioned effects, the natural light transmittance of the polarizing member 18 is preferably 30% or more and 50% or less, more preferably 35% or more and 45% or less, and particularly preferably 37.5% or more and 42.5% or less. That is, the light transmittance of the linearly polarized light of the polarizing member 18 corresponding thereto is preferably 60% or more and 95% or less, more preferably 70% or more and 90% or less, and particularly preferably 75% or more and 85 %the following. When the natural light transmittance is less than 30%, the shading effect of external light such as sunlight becomes higher, the amount of light emitted from the display device is blocked, and there is a possibility that sufficient display brightness may not be obtained. Conversely, when the natural light transmittance exceeds 50%, higher display brightness can be obtained, but the shielding effect of external light will be reduced.

…(1)Natural light transmittance can be measured by V-7100 manufactured by JASCO Corporation or U-4100 (model) manufactured by Hitachi, Ltd. (Hitachi, Ltd.). Specifically, a polarizing plate is produced, and the transmittance when using one polarizing plate is defined as the single transmittance Ys, and the transmittance when the two polarizing plates are overlapped in such a manner that the absorption axis direction becomes the same It is set to the parallel bit transmittance Yp, and the transmittance when the two polarizing plates are overlapped with the absorption axis perpendicular is set to the vertical bit transmittance Yc. Each transmittance is obtained by calculating the spectral transmittance τλ at a specific wavelength interval dλ (here, 5 nm) in the wavelength region of 380 to 700 nm, and is calculated by the mathematical formula (1). In the mathematical formula (1), Pλ represents the spectral distribution of standard light (C light source), yλ represents the color-matching function of the 2-degree field of view, and τλ represents the spectral transmittance. [Mathematical formula (1)]

…(1)

…(2)The light transmittance of linear polarized light is that the absolute polarized light is incident on the polarizing plate so that the vibration direction of the absolute polarized light is perpendicular to the absorption axis direction of the polarizing plate of the present invention (the absolute polarizing plate and the absorption axis of the polarizing plate Is parallel) to determine the obtained penetration and expressed as absolute parallel penetration Ky. Here, the absolute parallel transmission rate Ky can be obtained by substituting the above-obtained monomer transmission rate Ys and vertical transmission rate Yc into the mathematical formula (2). In addition, the absolute parallel transmittance Ky corresponds to the design of the display device and the waveform characteristics of the polarizing plate, and the transmittance at a predetermined wavelength such as 380 to 700 nm can be obtained only, or it can be expressed by the average value of the predetermined wavelength range . [Mathematical formula (2)]

…(2)

[Application example 1] When a car driver wears polarized sunglasses, the polarization axis of the sunglasses may be inconsistent with the polarization axis of the display image projected and reflected from the HUD device and become invisible. Therefore, in the embodiment of the present invention, for example, a phase difference plate is provided between the optical paths of the plane mirror 14 and the concave mirror 16 so that the optical axis of polarized light rays projected from the display device is shifted by 1 to 30° with respect to the optical axis To solve the visibility problem.

Here, the phase difference plate is preferably, for example, a phase difference film bonded to a glass plate via an adhesive layer. In addition, examples of the retardation film include a retardation film formed by laminating a λ/2 retardation film or two λ/4 retardation films.

[Application example 2] By providing a heat insulating layer on the polarizing member 18 of the present invention to block infrared rays (heat rays) from sunlight, it is possible to alleviate the temperature rise inside the HUD device caused by sunlight. The heat insulating layer is a layer containing a material having a characteristic of blocking (non-transmitting) infrared rays, and is roughly classified into an absorption type that absorbs infrared rays and a reflection type that reflects infrared rays. It is desirable to apply any aspect of the absorption type or the reflection type to the polarizing member 18, which has less coloration in the visible light region and is excellent in transparency. The heat insulating layer may be constituted by making the adhesive layer constituting the polarizing member 18 include a material having heat insulating properties, or may be provided by forming a film having a heat insulating material on the surface of any film constituting the polarizing member 18 .

(Example) Hereinafter, the present invention will be further specifically described by examples, but the scope of application of the present invention is not limited to the examples.

[Example 1] On both sides of the polarizing plate 34 (Polatechno Co., Ltd.'s dye-based polarizing plate EHC-125U (film thickness 215 μm)), polycarbonate (LEXAN8010VMC made by SABIC) was used as the first A support board 30 and a second support board 38 are bonded by using acrylic adhesive as the adhesive layer 32 and the adhesive layer 36. Further, on the surface of the first support plate 30, a cellulose triacetate film (KC6UAW manufactured by Konica Minolta Opto Device Co., Ltd.) coated with an acrylic resin with a thickness of 5 μm was bonded via an acrylic resin. The adhesive is adhered to produce the polarizing member 18. In addition, to the cellulose triacetate film used, as an ultraviolet absorber, 2.0% of a benzotriazole-based compound was added, so that the natural light transmittance at a wavelength of 380 nm was 2.6%.

The natural light transmittance of the polarizing member 18 in Example 1 is calculated by Mathematical Formula 1 to be 40%, and can block about 60% of sunlight. In addition, the light transmittance of the linearly polarized light of the polarizing member 18 is calculated by Mathematical Formula 2 to be 78%, and the light from the liquid crystal can transmit 78%.

[Example 2] Instead of TAC film (KC6UAW manufactured by Konica Minolta Opto Device Co., Ltd.), use polymethyl methacrylate (PMMA) with 2.0% benzotriazole compound as ultraviolet absorber, and The method of co-extrusion of the polycarbonate resin of the first support plate 30 was used for lamination, and the polarizing member 18 was produced in the same manner as in Example 1 except for the above.

[Comparative Example 1] Instead of a TAC film (KC6UAW manufactured by Konica Minolta Opto Device Co., Ltd.) coated with an acrylic resin, a hard coating layer C is formed on the surface of the first support plate 30 by using an acrylic resin with a thickness of 5 μm. Except for the above, a polarizing member was produced in the same manner as in Example 1.

[test results] With respect to the polarizing members obtained in Example 1 and Comparative Example 1, the pencil hardness test and the light resistance test were performed by the following methods and conditions.

>Pencil hardness test> The pencil hardness evaluation described in JIS K 5600-5-4 (1999) was performed. After conditioning the hard coat layer C at a temperature of 25°C and a relative humidity of 60% for 2 hours, use HB to 4H test pencils specified in JIS S 6006 (2007) under a load of 4.9 N to measure the scratches with each pencil The number of scratches that did not occur at five times was determined using the following criteria. ○: When scratched 5 times with a pencil, the number of scratches occurred is 0 to 2 times. ×: When scratched 5 times with a pencil, the number of scratches occurred was 3 or more, which was outside the allowable range. [Table 1]

From Table 1, it can be confirmed that the polarizing member 18 of Example 1 shows a value that is harder than the pencil hardness H. In contrast, the polarizing member of Comparative Example 1 has only the degree of pencil hardness B.

>Light resistance test> Subsequently, using a xenon arc aging test machine Ci4000 manufactured by Atlas Co., Ltd., in an environment with a temperature of 65° C. in the bath, the ultraviolet light of 300 to 400 nm was measured under the condition of an intensity of 60 W/m ² Natural light transmittance (%) after 240 hours, 500 hours, and 600 hours of irradiation from the side of the hard coat layer C. The result of the polarizing member 18 obtained in Example 1 is shown in FIG. 5, and the result of the polarizing member obtained in Comparative Example 1 is shown in FIG. 6.

As shown in FIG. 5, the natural light transmittance of the polarizing member 18 of Example 1 is maintained at around 40% from the initial to after 600 hours have passed, and there is almost no change. Compared with this, as shown in FIG. 6, the initial value of the natural light transmittance of the polarizing member of Comparative Example 1 in the wavelength region of 400 nm is about 30%, but it drops to about 10% after 600 hours . That is, it is presumed that the polarizing member of Comparative Example 1 is exposed to ultraviolet light for a long time, and the first support plate 30 is discolored, and accordingly, the natural light transmittance decreases.

According to the above, by using the polarizing member of the present invention as the polarizing cover for the HUD device 100, it is possible to provide the HUD device 100 with excellent surface hardness and high reliability in light resistance even when used in a vehicle.

10‧‧‧Housing 12‧‧‧Monitor 14‧‧‧Plane Mirror 16‧‧‧Concave mirror 18‧‧‧Polarizer (polarizer) 20‧‧‧Projection Department 30‧‧‧ First support board 32‧‧‧adhesive layer 34‧‧‧ Polarizer 36‧‧‧adhesive layer 38‧‧‧Second support board 100‧‧‧Head-up display device A‧‧‧adhesive layer B‧‧‧UV absorption layer C‧‧‧hard coating

FIG. 1 is a diagram showing the structure of a head-up display device in an embodiment of the present invention. FIG. 2 is a diagram showing the structure of a head-up display device in another embodiment of the present invention. FIG. 3 is a diagram showing the configuration of a polarizing member in an embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a polarizing member in another embodiment of the present invention. FIG. 5 is a graph showing the measurement results of the natural light transmittance of the polarizing member according to Example 1 as a function of time. FIG. 6 is a graph showing the measurement result of the natural light transmittance of the polarizing member in Comparative Example 1 with time.

Domestic storage information (please note in order of storage institution, date, number) no

Overseas hosting information (please note in order of hosting country, institution, date, number) no

10‧‧‧Housing

12‧‧‧Monitor

14‧‧‧Plane Mirror

16‧‧‧Concave mirror

18‧‧‧Polarizer (polarizer)

20‧‧‧Projection Department

100‧‧‧Head-up display device

Claims (10)

A polarizing component with: A polarizing plate, which has a polarizer, and uses a dye-based polarizing material; a first support plate, which is attached to the surface of the polarizing plate via an adhesive layer; and, a second support plate, which is sandwiched by an adhesive layer It is attached to the back surface of the polarizing plate; and at least one surface of the first supporting plate or the second supporting plate is provided with an ultraviolet absorbing layer and a hard coat layer, and natural light with a wavelength of 380 nm is applied to the ultraviolet absorbing layer. The penetration rate is below 10%. The polarizing member according to claim 1, wherein the film thickness of the ultraviolet absorption layer and the hard coat layer is 40 μm or more and 70 μm or less. The polarizing member according to claim 1 or 2, wherein an adhesive layer is provided between the surface of the first support plate or the second support plate and the ultraviolet absorption layer or the hard coating layer, The thickness of the adhesive layer is 5 μm or more and 20 μm or less. A polarizing component with: A polarizing plate, which has a polarizer, and uses a dye-based polarizing material; a first support plate, which is attached to the surface of the polarizing plate via an adhesive layer; and, a second support plate, which is sandwiched by an adhesive layer It is attached to the back of the polarizing plate; and at least one of the surface of the first supporting plate or the second supporting plate is provided with a hard coat layer, the hard coat layer includes an ultraviolet absorber, and a natural light of 380 nm The penetration rate of the ultraviolet absorber is 10% or less. The polarizing member according to claim 4, wherein the film thickness of the hard coat layer is 40 μm or more and 70 μm or less. The polarizing member according to claim 4 or 5, wherein an adhesive layer is provided between at least one surface of the first support plate or the second support plate and the hard coat layer, The thickness of the adhesive layer is 5 μm or more and 20 μm or less. The polarizing member according to claim 1, wherein the first support plate and/or the second support plate include a flame retardant plastic plate. The polarizing member according to claim 1, wherein the linear polarized light has a light transmittance of 60% or more and 95% or less. The polarizing member according to claim 1, wherein the polarizing member is used for a head-up display, and the head-up display is configured such that the polarization direction becomes parallel to the polarized light output from the display and penetrates the polarizing member, and The virtual image projection of the image is used as the projection image. A head-up display with: The polarizing component described in claim 1; A display for outputting images; and, A housing for accommodating the aforementioned display; Among them, the polarizing member is used as a light-transmitting cover for transmitting the image output from the display to the outside of the housing.

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