JP5076604B2 - Reflective polarizing plate and liquid crystal display device using the same - Google Patents

Description

  The present invention relates to a polarizing plate used for various display devices. More specifically, the present invention relates to a polarizing plate generally referred to as a reflection type that transmits one of polarization components orthogonal to each other and reflects the other, and a liquid crystal display device using the same.

A liquid crystal cell incorporated in a liquid crystal display device includes a liquid crystal layer and two polarizing plates arranged so as to sandwich the liquid crystal layer. This polarizing plate is a sheet that utilizes absorption anisotropy obtained by adsorbing iodine to a polymer sheet and then orienting it by stretching, and has a component parallel to the absorption axis of light incident on the polarizing plate. It absorbs light and expresses polarization characteristics by transmitting light of a component orthogonal thereto. In principle, such an absorption-type polarizing plate has a transmittance that does not exceed 50% when non-polarized light such as natural light is incident. Therefore, it is considered that it is effective to use the absorbed components in order to improve the luminance while the power consumption of the liquid crystal display device is required.

  In this regard, it has been proposed to install a polarization separation sheet that reflects polarized light components absorbed by the polarizing plate constituting the liquid crystal cell, a so-called reflective polarizing plate, at a position closer to the light source than the liquid crystal cell.

  Examples of the reflective polarizing plate include a multilayer laminated type, a circularly polarized light separating type, and a wire grid type.

The multilayer laminate type is a type in which multiple layers of refractive index isotropic layers and refractive index anisotropic layers are alternately laminated. This type of polarizing plate is designed so that there is no difference in the refractive index of each layer in one direction in the sheet plane, and one polarization component is transmitted by increasing the difference in refractive index of each layer in the direction perpendicular to it. And reflects a polarized light component orthogonal thereto, and functions as a reflective polarizing plate (Patent Document 1).
The circularly polarized light separation type is a polarizing plate using circular dichroism that is manifested by a cholesteric liquid crystal layer. The cholesteric liquid crystal layer can selectively reflect right-handed or left-handed circularly polarized light according to the direction of the spiral, as the liquid crystal molecules draw a spiral in the film thickness direction, and the cholesteric liquid crystal layer and the λ / 4 wavelength plate By combining these, it functions as a reflective polarizing plate (Patent Document 2).

The wire grid type is a polarizing plate having a structure in which thin metal lines are arranged in parallel. This type of polarizing plate functions as a reflective polarizing plate by transmitting polarized light that vibrates perpendicular to the metal line and reflecting polarized light that vibrates in parallel (Patent Documents 3, 4, and 5).
Special table 2003-511729 gazette JP 2002-90533 A US Pat. No. 6,122,103 JP-A-2005-195824 JP 7-294730 A

  However, in the case of a multilayer laminate type, in order to express polarization characteristics in a wide band, it is necessary to bond a plurality of sheets whose lamination ratio and film thickness are adjusted according to the wavelength. In addition, since the optical path length changes depending on the incident angle of light, the polarization characteristic has an angle dependency.

  In the case of the circularly polarized light separation type, it is difficult to uniformly form the cholesteric liquid crystal layer in the plane, and it is necessary to bond a plurality of layers having different helical pitches in order to exhibit polarization characteristics in a wide band.

  On the other hand, in the case of the wire grid type, the required polarization characteristics are obtained by forming a metal line with a constant pitch that is miniaturized to about the wavelength to be applied instead of a complicated configuration as in the above two examples. I can do it. As a specific method, as in Patent Document 3, a resist pattern is formed on a metal thin film provided on the surface of a glass substrate using electron beam lithography, and lift-off and dry etching are performed based on the pattern. There is an example in which a polarizing plate provided with a metal pattern is formed. However, since the obtained polarizing plate is made of glass, the weight is heavy, and there is a problem that the impact resistance and the flexibility are inferior. On the other hand, there is an example in which a metal pattern is formed on a film substrate by the same method as in Patent Document 3 as in Patent Document 4, but these are excellent in terms of weight reduction, impact resistance, and flexibility. In the process of providing a metal thin film, the low molecular weight component contained in the film substrate is generated as an outgas, so that the crystal form of the metal thin film is disturbed. As a result, the optical properties (particularly, transmittance, reflection) Rate and optical loss) are insufficient, and there is a drawback in that sufficient light utilization efficiency cannot be obtained when incorporated in a liquid crystal display device.

  Further, as in Patent Document 5, resin-like irregularities are formed on the surface of an inorganic transparent base material such as glass using a mold, and metal deposition is performed obliquely on the irregular surfaces, thereby selecting the position selectively. There is an example in which a polarizing plate is formed by providing a metal pattern, but the obtained polarizing plate is heavy because the base material is glass, is inferior in impact resistance and flexibility, and further in the process of metal deposition The low molecular weight component contained in the surface irregularities is generated as outgas, which disturbs the crystal form of the metal pattern. As a result, the optical properties (particularly, transmittance, reflectance, and optical loss) of the polarizing plate are insufficient. Thus, there has been a drawback that sufficient light utilization efficiency cannot be obtained when it is incorporated into a liquid crystal display device.

  Therefore, the present invention overcomes the problems of the prior art, has a sufficient performance as a reflective polarizing plate, is a lightweight and easy to handle polarizing plate, and further exhibits a high brightness improvement effect using this polarizing plate. Provided is a liquid crystal display device.

  The present invention employs the following means in order to solve such problems. That is, the reflective polarizing plate of the present invention has a resin layer having a polystyrene-reduced molecular weight of 5,000 or less, defined by a method described later, having a content W of 5% by weight or less, and a gap on the resin layer. And a plurality of linear metal layers (hereinafter referred to as linear metal layers).

The liquid crystal display device (1) of the present invention is a liquid crystal display device in which at least a surface light source, a reflective polarizing plate of the present invention, and a liquid crystal cell are arranged in this order, and the liquid crystal cell includes a liquid crystal layer, The direction of the polarization axis of polarized light having a polarizing plate (A) and a polarizing plate (B) arranged so as to sandwich the liquid crystal layer and transmitting through the polarizing plate (B) on the surface light source side constituting the liquid crystal cell And the direction of the polarization axis of the polarized light transmitted through the reflective polarizing plate match , and the reflective polarizing plate is installed so that the linear metal layer faces the liquid crystal cell . It is characterized by.

The liquid crystal display device (2) of the present invention is a liquid crystal display device comprising a surface light source and a liquid crystal cell, and the liquid crystal cell includes a liquid crystal layer and a polarizing plate (A) disposed so as to sandwich the liquid crystal layer. and a polarizing plate (B), the surface light source side polarizing plate (B) is Ri reflective polarizer der of the present invention, and the reflection type polarizing plate, the linear metal layer opposite said liquid crystal layer It is installed so as to be characterized Rukoto.

  According to the present invention, the reflective polarizing plate has excellent performance such as high optical characteristics (high transmittance, high reflectance, high polarization degree, high light utilization efficiency), is lightweight, and has excellent handleability. A reflective polarizing plate can be manufactured, and a high-luminance display can be obtained by incorporating the manufactured reflective polarizing plate into a liquid crystal display device or the like.

  As a result of intensive investigations on a reflective polarizing plate having high optical characteristics (high transmittance, high reflectance, high polarization degree, high light utilization efficiency), light weight and excellent handling properties, Investigating that the above-mentioned problems can be solved at once by configuring a reflective polarizing plate with a resin layer made of a controlled resin and a plurality of linear metal layers formed on the resin layer at intervals. did. That is, according to such a reflective polarizing plate, a high-brightness liquid crystal display device has been successfully provided.

The reflective polarizing plate of the present invention includes a resin layer 1 having a content W of a component having a molecular weight of 5,000 or less in terms of polystyrene defined by the following (Procedure 1) to (Procedure 5) of 5% by weight or less, It is characterized by comprising a plurality of linear metal layers 2 formed at intervals on the resin layer.
(Procedure 1): The surface layer of the resin layer 1 is scraped off (weight is set to W1 (g)).
(Procedure 2): The surface layer scraped in (Procedure 1) is dissolved in chloroform, separated into an insoluble material and a solution, and the insoluble material is dried (the weight of the insoluble material is W2 (g)).
(Procedure 3): The solvent of the solution obtained in (Procedure 2) is removed to obtain a residue.
(Procedure 4): The residue obtained in (Procedure 3) is obtained by a gel permeation chromatograph (hereinafter referred to as GPC) to obtain a polystyrene-equivalent molecular weight curve, and the polystyrene-equivalent molecular weight contained in the residue is 5 from the molecular weight curve. A ratio R (% by weight) of 1,000 or less is obtained.
(Procedure 5): The content W of a component having a molecular weight of 5,000 or less in terms of polystyrene in the resin layer is determined by the following formula (1).
-Content W (weight%) = (W1-W2) x R / W1 (1).

  That is, in the reflective polarizing plate of the present invention, the content W of the component having a molecular weight of 5,000 or less in terms of polystyrene contained in the resin layer is 5 wt% or less, and a linear metal layer is further formed on the resin layer. The above-mentioned effects will be described below.

  The resin layer 1 used in the conventional reflective polarizing plate usually contains a large amount of low molecular weight organic components such as unreacted substances, additives and oligomers, and these low molecular weight organic components are present on the surface of the resin layer 1. In the process of forming the metal layer, it is easily released as outgas. When outgas is generated from the resin layer 1 in the formation process of the metal layer, the metal is deposited on the resin layer 1 while taking out the outgas. Sex is reduced. If it becomes so, the metal layer 2 will come to absorb light and the reflective characteristic as a reflective polarizing plate, a polarizing characteristic, and light utilization efficiency will fall. Furthermore, after forming a linear resin pattern (hereinafter referred to as a linear resin pattern 10) on the surface of the resin layer 1 by a method as will be described later, selective to a specific location of the linear resin pattern 10 Even when the linear metal layer 2 is formed, if the resin layer 1 contains a large amount of low molecular weight organic components, it is difficult to form a pattern with high accuracy in the linear resin pattern forming step. Even when the linear resin pattern can be formed with high accuracy, when the linear metal layer 2 is selectively formed on the pattern, metal atoms that approach the pattern vicinity are emitted from the resin layer 1 with directionality. Colliding with the outgas to be scattered and scattering, the selective formability of the linear metal layer 2 is lowered. In that case, the transmission characteristic and polarization separation characteristic as a reflective polarizing plate are deteriorated, and the long-term shape retention property of the linear resin pattern is lowered. Therefore, in the reflection type polarizing plate using the conventional resin layer, sufficient optical characteristics cannot be obtained.

On the other hand, like the reflective polarizing plate of the present invention, the content W of the low molecular weight component contained in the resin layer 1 is controlled to be 5 wt% or less, and the linear metal layer 2 is formed on the resin layer 1. If formed, it is possible to suppress the generation of outgas mainly composed of low molecular weight organic components contained in the resin layer 1 in the step of forming the metal layer 2. As a result, the metal layer 2 can be stably formed on the resin layer 1, and the crystallinity of the metal layer can be improved. From the above, it becomes possible to form a dense and highly crystalline linear metal layer 2 on the resin layer 1, and to improve reflection characteristics, polarization characteristics, and light utilization efficiency as a reflective polarizing plate. . Further, even when the linear resin pattern 10 is formed on the surface of the resin layer 1 by a method as will be described later, and the linear metal layer 2 is selectively formed at a specific location of the linear resin pattern, the metal Since the collision probability between atoms and outgas decreases, the selective formation of the metal layer can be improved, and the transmission characteristics and polarization characteristics as a reflective polarizing plate can be improved. Furthermore, by controlling the low molecular weight component, the long-term shape retention of the linear resin pattern 10 is increased, and the long-term durability is also achieved in terms of optical characteristics. As a result, it is possible to obtain a reflective polarizing plate having high optical characteristics (high transmittance, high reflectance, high polarization degree, high light utilization efficiency) that has not been available in the past. It is possible to obtain a luminance display device.
A method for obtaining the content W of components having a molecular weight of 5,000 or less in terms of polystyrene contained in the resin layer 1 will be described in detail below.

  In (Procedure 1), the range of 1 μm or less in depth from the outermost surface of the resin layer 1 is scraped and the weight is measured to obtain W1 (g). Further, when the resin layer 1 has a structure in which the resin layer 1 is laminated on a material different from that of the resin layer 1 and the thickness of the resin layer 1 is 1 μm or less, only the resin layer 1 is scraped and the weight thereof is measured. (G) is obtained.

  In (Procedure 2), using the solvent in which the resin layer obtained in (Procedure 1) is most soluble among the solvents in which the standard substance is dissolved, the solvent is dissolved in 100 parts by weight or more of solvent with respect to 1 part by weight of the resin. . In addition, when making it melt | dissolve, heating, ultrasonic irradiation, etc. are performed suitably. If the solution thus obtained contains a component insoluble in the solvent, the insoluble component is removed by filtration through a filter, centrifugation, decantation, etc., and the resulting insoluble material is heated or vacuum dried. Then, after evaporating the residual solvent, W2 (g) is obtained by measuring its weight. When the residue is dried by heating, the drying temperature is Tg1 or more and the decomposition temperature or less of the residue.

  In (Procedure 3), the solvent is removed from the solution from which insolubles have been removed in (Procedure 2) using an evaporator or the like, and the residue is obtained.

In (Procedure 4), the molecular weight distribution of the residue obtained in (Procedure 3) is measured by GPC, and from the molecular weight curve obtained by obtaining a polystyrene-equivalent molecular weight curve, the polystyrene equivalent contained in the residue A ratio R (% by weight) having a molecular weight of 5,000 or less is determined. The measurement conditions of GPC at this time are arbitrarily determined, but in this procedure 4, the molecular weight distribution is measured using a column having a theoretical plate number of 14,000 and a flow rate of 1.0 mL / min.
As a measurement procedure, first, a mixed sample of standard monodisperse polystyrene having a known molecular weight is dissolved in a solvent in which the surface layer obtained in (Procedure 1) can be dissolved, among the solvents in which the standard substance dissolves, and the solution is used. Measurement is performed by GPC under the same conditions, and the elution time of each molecular weight component is determined. At this time, the elution time is the elution time with the maximum value at the peak corresponding to each molecular weight component. Using the obtained elution time and molecular weight, a plot is made with elution time on the horizontal axis and molecular weight on the vertical axis, and a calibration curve is created. Next, dissolve the residue obtained in (Procedure 3) to the same concentration in the same solvent, perform GPC measurement using the solution, and superimpose the obtained result on the calibration curve. The relative molecular weight (polystyrene equivalent molecular weight) and the weight fraction (dW / dlogM) at each elution time are determined. Next, a molecular weight distribution curve is obtained by plotting the molecular weight in terms of polystyrene on the horizontal axis and the weight fraction on the vertical axis. From the obtained molecular weight distribution curve, the integrated value It of the entire molecular weight distribution and the polystyrene equivalent molecular weight of 5 are obtained. An integral value Im of a peak area of 1,000 or less is obtained, and a ratio R (weight%) having a polystyrene-equivalent molecular weight of 5,000 or less contained in the residue is obtained by the following formula (2).
R (%) = Im / It × 100 (2)
In (Procedure 5), the weight W1 (g) of the scraped resin layer 1 and the weight W2 (g) of the insoluble matter obtained in the above (Procedure 1) to (Procedure 4) are converted to polystyrene contained in the residue. From the ratio R (% by weight) having a molecular weight of 5,000 or less, the content W of a component having a molecular weight of 5,000 or less in terms of polystyrene contained in the resin layer 1 can be determined by the following formula (1).
-Content W (weight%) = (W1-W2) x R / W1 (1).

  In the reflective polarizing plate of the present invention, the resin layer 1 has a content W of a component having a polystyrene-equivalent molecular weight of 5,000 or less defined by the above (Procedure 1) to (Procedure 5) of 5% by weight or less. Although it is characterized, the content W thereof is preferably 3.0% by weight or less, more preferably 1.0% by weight or less. When the content W of the component having a molecular weight of 5,000 or less in terms of polystyrene exceeds 5% by weight, the resin layer 1 contains a large amount of low molecular weight components. Therefore, in the step of forming the linear metal layer 2, the resin layer 1 Therefore, a low molecular weight organic component is generated as outgas, and as a result, the crystallinity of the metal layer is lowered, and sufficient polarization characteristics may not be obtained. Further, when the linear resin pattern 10 is formed on the surface of the resin layer 1 by a method as described later, and the linear metal layer 2 is selectively formed at a specific location of the pattern, a highly accurate linear shape Even if it becomes difficult to mold the resin pattern or the linear resin pattern 10 can be molded with high accuracy, the selective formability is reduced when the linear metal layer 2 is formed on the resin layer, and the reflection type This is not preferable because transmission characteristics and polarization separation characteristics as a polarizing plate are deteriorated and long-term durability of optical characteristics is deteriorated. In the reflective polarizing plate of the present invention, by setting the content W of the component having a polystyrene-equivalent molecular weight of 5,000 or less in the resin layer 1 to 5% by weight or less, high optical properties (high transmittance, high reflectance, high A reflective polarizing plate having a degree of polarization and high light utilization efficiency can be obtained.

In the reflective polarizing plate of the present invention, the thermal decomposition starting temperature Td of the resin layer 1 is preferably 150 ° C. or higher. The thermal decomposition start temperature Td here is obtained by measuring the weight change of the resin layer obtained by scraping in the above (procedure 1) when heated at a rate of 10 ° C./min from room temperature. From the obtained weight loss curve, the thermal decomposition onset temperature Td was obtained from the point where the extended straight line of the baseline intersects the tangent of the weight-reduced portion due to thermal decomposition, more preferably 200 ° C. or more, and further preferably Is 250 ° C. When the thermal decomposition start temperature Td of the resin layer 1 is less than 150 ° C., the resin layer 1 undergoes thermal decomposition in the step of forming the linear metal layer 2 and releases a low molecular weight organic component as outgas. As a result, the crystallinity of the metal layer is lowered, and sufficient polarization characteristics cannot be obtained. Further, when a linear resin pattern 10 is formed on the surface of the resin layer 1 by a method as will be described later, and the linear metal layer 2 is selectively formed at a specific location of the pattern, the metal is selectively formed. As a result, the transmission characteristics as a reflective polarizing plate and the polarization separation characteristics are deteriorated. In the reflective polarizing plate of the present invention, by setting the thermal decomposition start temperature Td of the resin layer 1 to 150 ° C. or higher, the metallicity of the linear metal layer 2 can be kept high, and as a result, high optical properties ( A reflective polarizing plate having high transmittance, high reflectance, high degree of polarization, and high light utilization efficiency can be obtained.
In the reflective polarizing plate of the present invention, the resin layer 1 is preferably made of a resin composition containing, as a main component, any one of a thermoplastic resin, a photocurable resin, a thermosetting resin, or a mixture thereof. Here, a composition exceeding 50% by weight in the resin is defined as a main component.

  Examples of the thermoplastic resin include, for example, polyethylene terephthalate, polyethylene-2, 6-naphthalate, polypropylene terephthalate, polyester resins such as polybutylene terephthalate, acrylic resins such as polymethyl methacrylate, polyethylene, polypropylene, polymethylpentene, Polyolefin resins such as alicyclic polyolefin resins, polyamide resins, polycarbonates, polystyrenes, polyethers, polyester amides, polyether esters, polyvinyl chloride, polyvinyl alcohol and copolymers containing these as components, or mixtures thereof These thermoplastic resins can be mentioned.

  Examples of the photocurable resin include a compound having at least one radical polymerizable property in the molecule, a compound having a cationic polymerizable property, and the like. Examples of the compound having radical polymerizability include a compound that undergoes polymerization or crosslinking reaction by irradiation with active energy rays in the presence of a polymerization initiator that generates radicals by active energy rays. Examples thereof include those containing at least one ethylenically unsaturated bond in the structural unit, those containing a polyfunctional vinyl monomer in addition to a monofunctional vinyl monomer, and oligomers, polymers and mixtures thereof. Examples of the compound having at least one cationic polymerizability in the molecule include compounds selected from one or more compounds selected from a compound having an oxirane ring, a compound having an oxetane ring, and a vinyl ether compound.

  Examples of the thermosetting resin include an acrylic resin, an epoxy resin, an unsaturated polyester resin, a phenol resin, a urea / melamine resin, a polyurethane resin, a silicone resin, and the like. A mixture of the above can be used.

  A polymerization initiator is blended with the photocurable resin and the thermosetting resin. In the case of the photocurable resin, a photopolymerization initiator that generates radical species or cationic species by irradiation with active energy rays is used in accordance with the photosensitive wavelength and the polymerization type, and in the case of the thermosetting resin, a process temperature is used. It is preferable to use a thermal polymerization initiator suitable for the above.

  These resins are preferably those which are transparent in the wavelength used, that is, in the visible light region of 400 to 800 nm when used in a liquid crystal display device, and do not show an absorption peak at a specific wavelength. Moreover, the thing which does not scatter a light ray substantially is preferable, and it is preferable that it is about 30% or less by the haze value when it is set as the flat sheet form of a film thickness of 100 micrometers. More preferably, the haze is 20% or less, and still more preferably the haze is 10% or less.

  Here, in the reflective polarizing plate of the present invention, when the resin layer 1 contains a thermoplastic resin as a main component, the thermoplastic resin may have a polystyrene-equivalent weight average molecular weight Mw by GPC measurement of 10,000 or more. preferable. The polystyrene-reduced weight average molecular weight Mw of the thermoplastic resin here is a value obtained by GPC measurement using monodisperse polystyrene as a standard substance, and specifically by the following (Procedure 6) to (Procedure 9). This is the value obtained.

(Procedure 6): A mixed sample such as monodisperse polystyrene of a standard substance having a known molecular weight is dissolved in a solvent in which both the standard substance and the thermoplastic resin to be measured are dissolved, and measurement is performed by GPC using the solution. The elution time of each molecular weight component is obtained (Note that the measurement conditions of GPC at this time can be determined arbitrarily, but in this procedure 6, a column with a theoretical plate number of 14,000 is used, and the flow rate is 1.0 mL / min. In some cases, the molecular weight distribution is measured.)
At this time, the elution time is the elution time with the maximum value at the peak corresponding to each molecular weight component.

  (Procedure 7): Using the obtained elution time and molecular weight, plot the elution time on the horizontal axis and the molecular weight on the vertical axis to create a calibration curve.

  (Procedure 8): A solution having the same concentration as in (Procedure 6) was prepared using a thermoplastic resin, and GPC measurement was performed using the solution under the same conditions as in (Procedure 6). The relative molecular weight (polystyrene equivalent molecular weight) and the weight fraction (dW / dlogM) at each elution time are obtained by superimposing with the calibration curve obtained in (Procedure 7).

(Procedure 9): A polystyrene-converted weight average molecular weight Mw is determined by the following formula (3).
Mw = Σ (Ni · Mi ² ) / Σ (Ni · Mi) (3)
Here, Mi is the molecular weight of the i-th elution position of the GPC curve obtained via the molecular weight calibration curve, and Ni is the number of molecules of the molecular weight Mi.

  In this measurement, if the thermoplastic resin contains organic fine particles, inorganic fine particles, metals, metal salts, other additives and other components that are insoluble in the solvent, it is insoluble by filtration with a filter or centrifugation. It is a value measured by preparing a solvent solution of the resin after removing the components. If there is a possibility that the resin composition contains additives such as plasticizers, surfactants, dyes, etc., after removing insoluble components, reprecipitation method, recrystallization method, chromatography method, extraction It is a value obtained by preparing a solvent solution of the resin composition again after removing the insoluble additive as described above by a method or the like. More preferably, the polystyrene equivalent weight average molecular weight Mw is 15,000 or more, and further preferably 20,000 or more. If the polystyrene-equivalent weight average molecular weight Mw is less than 10,000, the resin layer 1 contains a large amount of low molecular weight components. Therefore, in the step of forming the linear metal layer 2, low molecular weight organic components are outgassed from the resin layer 1. As a result, the crystallinity of the metal layer is lowered, and sufficient polarization characteristics may not be obtained.

  Further, when a linear resin pattern is formed on the surface of the resin layer 1 by a method as will be described later, and the linear metal layer 2 is selectively formed at a specific location of the pattern, a highly accurate linear resin is used. Even if it becomes difficult to mold the pattern or the linear resin pattern 10 can be molded with high accuracy, the selective formability is reduced when the linear metal layer 2 is formed on the substrate, This is not preferable because transmission characteristics and polarization separation characteristics as a reflective polarizing plate are deteriorated and long-term durability of optical characteristics is deteriorated. In the reflective polarizing plate of the present invention, when the resin layer 1 contains a thermoplastic resin as a main component, the polystyrene-converted weight average molecular weight Mw of the thermoplastic resin is set to 10,000 or more so that high optical properties (high transmittance) are obtained. Ratio, high reflectivity, high degree of polarization, high light utilization efficiency) and long-term stability of optical characteristics.

  Moreover, in the reflective polarizing plate in this invention, when it has the linear resin pattern 10 on the surface of the resin layer 1 by the method which is mentioned later, as an upper limit of the polystyrene conversion weight average molecular weight Mw of the resin layer 1, It is preferably 100,000 or less, more preferably 90,000 or less, and particularly preferably 80,000 or less. When the polystyrene-equivalent weight average molecular weight Mw exceeds 100,000, it becomes difficult to form the linear resin pattern 10, and when the linear metal layer 2 is selectively formed on the pattern, the metal selective formability is increased. As a result, the transmission characteristics and polarization separation characteristics of the reflective polarizing plate are deteriorated, which is not preferable. When the resin layer 1 of the present invention has the linear resin pattern 10 on the surface of the resin layer 1, by setting the upper limit of the polystyrene-equivalent weight average molecular weight Mw of the resin layer 1 to 100,000 or less, high optical characteristics A reflective polarizing plate (high transmittance, high reflectance, high degree of polarization, high light utilization efficiency) can be obtained.

In the reflective polarizing plate of the present invention, when the resin layer 1 is mainly composed of a thermoplastic resin, the thermoplastic resin is calculated from the polystyrene-converted weight average molecular weight Mw and polystyrene-converted number average molecular weight Mn by GPC. The dispersity Mw / Mn is preferably 3.0 or less. The polydispersity Mw / Mn here is a value calculated by the following equation (4) based on the results measured in the above (procedure 6) to (procedure 8).
Mn = Σ (Ni · Mi) / ΣNi (4)
Here, Mi is the molecular weight of the i-th elution position of the GPC curve obtained via the molecular weight calibration curve, and Ni is the number of molecules of the molecular weight Mi.

  More preferably, the polydispersity Mw / Mn is 2.5 or less, more preferably 2.0 or less. At this time, the theoretical lower limit of the polydispersity Mw / Mn is 1.0. In this case, it means complete monodispersion. As the polydispersity Mw / Mn is larger, components having different molecular weights (particularly, This means that a large amount of low molecular weight side component) is contained. That is, the closer the polydispersity Mw / Mn is to 1, the more uniform the molecular weight.

  When the polydispersity Mw / Mn exceeds 3.0, since many low molecular weight components are contained, a low molecular weight organic component is generated as an outgas from the resin layer 1 in the step of forming the linear metal layer 2. As a result, the crystallinity of the metal layer is lowered, and sufficient polarization characteristics may not be obtained. Further, even when the linear resin pattern 10 is formed on the surface of the resin layer 1 by a method as described later, and the linear metal layer 2 is selectively formed at a specific location of the pattern, the linear resin pattern Even if it becomes difficult to mold 10 with high accuracy or the linear resin pattern 10 can be molded with high accuracy, the selective formability is high when the linear metal layer 2 is formed on the substrate. This is not preferable because the transmission characteristics and polarization separation characteristics as a reflective polarizing plate are deteriorated, and the long-term durability of optical characteristics is deteriorated. In the reflective polarizing plate of the present invention, when the resin layer 1 contains a thermoplastic resin as a main component, the polydispersity Mw / Mn of the thermoplastic resin is set to 3.0 or less, so that high optical characteristics (high transmission) A reflective polarizing plate having a high reflectance, a high reflectance, a high degree of polarization, and a high light utilization efficiency.

Further, in the reflective polarizing plate of the present invention, as described later, when the resin layer 1 has a linear resin pattern 10 on the surface and the resin layer is mainly composed of a thermoplastic resin, the thermoplastic resin. The polydispersity Mz / Mw calculated from the polystyrene-converted Z-average molecular weight Mz and polystyrene-converted weight-average molecular weight Mw by GPC is preferably 2.0 or less. The polystyrene-reduced Z average molecular weight Mz here is a value calculated by the following formula (5) based on the results measured in the above (procedure 6) to (procedure 8).
Mz = Σ (Ni · Mi ³ ) / Σ (Ni · Mi ² ) (5)
Here, Mi is the molecular weight of the i-th elution position of the GPC curve obtained via the molecular weight calibration curve, and Ni is the number of molecules of the molecular weight Mi.

  More preferably, the polydispersity Mz / Mw is 1.9 or less, more preferably 1.7 or less. Here, the theoretical lower limit value of the polydispersity Mz / Mw is 1.0, which means complete monodispersion. As the polydispersity Mz / Mw increases, components having different molecular weights (particularly, higher This means that a large amount of molecular weight component) is contained. That is, the closer the polydispersity Mz / Mw is to 1, the more uniform the molecular weight.

  When the polydispersity Mz / Mw exceeds 2.0, since a large amount of high molecular weight components are contained, it becomes difficult to form the linear resin pattern 10 and the linear metal layer is selectively formed on the base material. When forming 2 selectively, the metal selective formability is lowered, and as a result, the transmission characteristics and polarization separation characteristics as a reflective polarizing plate are lowered, which is not preferable. In the reflective polarizing plate of the present invention, when the resin layer 1 contains a thermoplastic resin as the main component and the linear resin pattern 10 is provided on the surface of the resin layer 1, the polydispersity Mz / Mw is 2. By setting it to 0 or less, a reflective polarizing plate having high optical characteristics (high transmittance, high reflectance, high polarization degree, high light utilization efficiency) can be obtained.

  Here, in the reflective polarizing plate of the present invention, when the resin layer 1 is mainly composed of a thermoplastic resin, the content W of the component having a molecular weight of 5,000 or less in terms of polystyrene is 5% by weight or less, and the weight average in terms of polystyrene. It is preferable to carry out the polymerization while controlling the molecular weight Mw to be 10,000 or more, the polydispersity Mw / Mn to be 3.0 or less, and the Mz / Mw to be 2.0 or less. Can also be made within the range by applying a preparative GPC method, a reprecipitation method, a recrystallization method, an extraction method or the like. Specifically, in the case of the preparative GPC method, first, based on the above (Procedure 6), a mixed sample solution such as monodisperse polystyrene is measured as a standard sample, and the elution time and the molecular weight of the peak top at each peak are measured. Create a calibration curve. Subsequently, based on the above (Procedure 7), the resin layer of the thermoplastic resin is measured, and the relative molecular weight (polystyrene equivalent molecular weight) and the time during which each molecular weight component is eluted can be obtained from the calibration curve. Next, based on the elution time of each molecular weight component, the collection of the fraction by GPC is completed when the component content W of 5,000 polystyrene equivalent molecular weight is eluted, and the fraction obtained is After concentrating with an evaporator or the like, the residual solvent can be volatilized by heat drying or vacuum drying. At this time, when the fraction is heated and dried, the drying temperature is set to be not less than the glass transition temperature Tg of the resin and not more than the thermal decomposition start temperature Td.

  Next, in the case of the reprecipitation method, a poor solvent for the thermoplastic resin is gradually added to a solution obtained by dissolving the thermoplastic resin in a small amount of a good solvent. Then, since it precipitates in order from the high molecular weight component and precipitates, the addition of the poor solvent is terminated at the stage where the component having a molecular weight of 5,000 in terms of polystyrene is precipitated, and the obtained precipitate is filtered or centrifuged. After separation by decantation filtration, decantation, etc., the resulting precipitate can be obtained by subjecting the residual solvent to volatilization by heat drying or vacuum drying. At this time, when the precipitate is dried by heating, the drying temperature is set to be not less than the glass transition temperature Tg of the resin and not more than the thermal decomposition start temperature Td.

  In the case of the recrystallization method, a solvent having a large temperature dependency of the solubility of the thermoplastic resin is used, and the thermoplastic resin is dissolved in the solvent while being heated and then cooled. Then, it precipitates as a crystal | crystallization sequentially from a high molecular weight component, and precipitates. On the other hand, since the low molecular weight component remains dissolved in the solvent, the deposited precipitate is separated by filtration, centrifugation, decantation filtration, decantation, etc., and then the obtained precipitate is dried by heating or vacuum. It can be obtained by drying and volatilizing the residual solvent. At this time, when the precipitate is dried by heating, the drying temperature is set to be not less than the glass transition temperature Tg of the resin and not more than the thermal decomposition start temperature Td.

  In the case of the extraction method, a solvent that is not mixed with the solvent is added to a solution obtained by dissolving the thermoplastic resin in a good solvent, and the mixture is stirred and allowed to stand. Then, when separating into two phases, the high molecular weight component remains dissolved in the good solvent, but the low molecular weight component moves to the other solvent. After separating this, from the resulting solution, the obtained fraction can be obtained by concentrating with an evaporator or the like, followed by heat drying or vacuum drying to volatilize the residual solvent. At this time, when the fraction is heated and dried, the drying temperature is set to be not less than the glass transition temperature Tg of the resin and not more than the thermal decomposition start temperature Td.

  In the reflective polarizing plate of the present invention, when the resin layer 1 is mainly composed of a thermosetting resin and / or a photocurable resin, the content W of the component having a molecular weight of 5,000 or less in terms of polystyrene is 5% by weight. It is preferable to cause the crosslinking reaction to be controlled to be not more than 5%, but even if it is 5% by weight or more, it is possible to further irradiate light after the resin layer 1 is produced, or to perform heat treatment, Low molecular weight components can be removed by advancing the cross-linking reaction or by maintaining for a long time in a reduced-pressure atmosphere.

  Further, in the reflective polarizing plate of the present invention, when the resin layer 1 and the resin layer 1 on which the linear resin pattern 10 is formed by a method described later are mainly composed of a thermoplastic resin, the glass transition temperature thereof. As for Tg, it is preferable that the glass transition temperature Tg in the temperature rising process (temperature rising rate: 10 ° C./min) obtained by differential scanning calorimetry (hereinafter referred to as DSC) is 70 to 160 ° C. Here, the glass transition temperature Tg is a value obtained by a method according to JIS K-7121 (1999), and is a glass in a differential scanning calorimetry chart obtained when scanning at a heating rate of 10 ° C./min. It is a value obtained from the point where the straight line equidistant in the vertical axis direction from the extended straight line of each baseline intersects with the curved line of the step-like change part accompanying the glass transition in the step-like change part accompanying the transition. . More preferably, the glass transition temperature Tg is in the range of 100 to 160 ° C, more preferably 110 to 150 ° C. If the glass transition temperature Tg is less than 70 ° C., the resin layer itself or the linear resin pattern 10 provided on the surface of the resin layer 1 is deformed by the thermal load in the formation process of the linear metal layer 2, or reflective polarization The heat resistance as a plate is lowered, and the long-term stability of optical characteristics is lacking. When the temperature exceeds 160 ° C., it is difficult to form a highly accurate shape when forming the linear resin pattern 10, and it is difficult to obtain sufficient optical characteristics even if the linear metal layer 2 is formed thereon. Therefore, it is not preferable. In the reflective polarizing plate of the present invention, when the resin layer 1 and the resin layer 1 provided with the linear resin pattern 10 by a method as described later have a thermoplastic resin as a main component, the glass transition temperature Tg is 70. By setting the temperature to ˜160 ° C., it is possible to achieve both good pattern formability and pattern shape retention during the linear metal layer 2 formation step, and as a result, a reflective polarizing plate with high optical characteristics can be obtained. it can.

  Further, in the reflective polarizing plate of the present invention, the resin layer 1 and the resin layer 1 on which the linear resin pattern 10 is formed by the method described later are mainly thermosetting resin or photocurable resin. In this case, the glass transition temperature Tg may be outside the range of 70 to 160 ° C. In that case, the thermal decomposition start temperature Td of the thermosetting resin or the crosslinked product of the photocurable resin is preferably It is preferable that the temperature is 150 ° C or higher, more preferably 200 ° C or higher, and most preferably 250 ° C. If the thermal decomposition start temperature Td of the thermosetting resin or the crosslinked product of the photocurable resin is less than 150 ° C., the resin layer or the linear resin pattern 10 is deformed in the process of forming the linear metal layer 2. In addition to this, low molecular weight organic components are released as outgas during the formation process of the linear metal layer 2 and the crystal arrangement of the metal layer is disturbed to reduce its metallicity, resulting in a decrease in optical properties. Therefore, it is not preferable. In the reflective polarizing plate of the present invention, when the resin layer 1 and the resin layer 1 provided with the linear resin pattern 10 by a method as described later are thermosetting resin or photocurable resin as a main component, By setting the thermal decomposition start temperature Td to 150 ° C. or higher, the metallicity of the linear metal layer 2 can be kept high, and a reflective polarizing plate having high optical characteristics can be obtained.

In the reflective polarizing plate of the present invention, when the resin layer 1 and the resin layer 1 provided with the linear resin pattern 10 by a method as described later are thermoplastic resins, the photoelastic coefficient k at 25 ° C. However, it is preferably 50 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 40 × 10 ⁻¹² Pa ⁻¹ or less, and most preferably 30 × 10 ⁻¹² Pa ⁻¹ or less.

Here, the photoelastic coefficient k means that a resin is formed into a sheet by a known method such as melt film formation or solution film formation, and the sheet is applied with no tension to a sheet having a thickness d (nm) in an atmosphere of 25 ° C. and 65 RH%. When the phase difference Γ1 (nm) and the phase difference generated when the tension F (Pa) is applied is Γ2 (nm),
K = (Γ2-Γ1) / (d × F)
It is a value defined by. The phase difference Γ was measured using a polarizing microscope equipped with crossed Nicols and sodium D line (wavelength 589 nm) as a light source in a state where a tension of 1 kg / mm ² (9.81 × 106 Pa) was applied to the film. In an atmosphere at 25 ° C.

When the photoelastic coefficient k is larger than 50 × 10 ⁻¹² Pa ⁻¹ , optical distortion remains when the linear resin pattern 10 is processed on the surface of the resin layer 1 and the resin layer 1, and the linear metal layer 2 is further formed. Even if it is provided as a reflective polarizing plate, it is not preferable because optical characteristics change in a plane and uneven color tone may occur. In the reflective polarizing plate of the present invention, when the resin layer 1 and the resin layer 1 provided with the linear resin pattern 10 by the method described later are thermoplastic resins, the photoelastic coefficient k at 25 ° C. is 50. By setting it to 10 × 10 ⁻¹² Pa ⁻¹ or less, it is possible to form a linear concavo-convex structure without remaining optical distortion during processing. As a result, a linear metal layer 2 is formed to obtain a reflective polarizing plate. Sometimes, uniform optical characteristics can be obtained in the plane.

  It is also preferable to add various components to these resins as necessary. As such additives, for example, surfactants, crosslinking agents, ultraviolet absorbers, light stabilizers, heat stabilizers, plasticizers, viscosity modifiers, antioxidants, antistatic agents and the like can be preferably used.

  Here, in the reflective polarizing plate of the present invention, the resin layer 1 preferably has linear resin patterns 10 arranged in parallel on the surface of the resin layer 1 as shown in FIG. The effect will be described below.

  First, the first feature is that the birefringence is developed by forming the linear resin pattern 10. When the linear resin pattern 10 having periodic unevenness with a pitch equal to or less than the incident wavelength is formed, anisotropy of refractive index, that is, birefringence is manifested in the pattern longitudinal direction and the direction orthogonal thereto. Here, it is possible to control the birefringence of the resin layer 1 by appropriately setting the width, pitch, height, and refractive index of the material alone of the convex portions 11 constituting the pattern.

  The liquid crystal display device that can be suitably mounted with the reflective polarizing plate of the present invention incorporates a surface light source, but the light emitted from the surface light source is reflected at the interface such as a light guide plate or a prism sheet. Due to the influence of a member utilizing refraction, there may be a bias in the polarization state rather than a complete non-polarization state. Therefore, even if a reflective polarizing plate is arranged on the surface light source side of the liquid crystal cell, if this biased direction does not match the polarization axis transmitted by the reflective polarizing plate, there are many reflective components. As a result, the light use efficiency does not increase.

  Therefore, the polarization state biased by the birefringence of the resin layer 1 is eliminated by causing the resin layer 1 to exhibit birefringence like the reflective polarizing plate of the present invention and making light incident from the resin layer 1 side. , Can increase the light utilization efficiency. For example, when the widths, pitches, and materials of the convex portions 11 constituting the pattern are the same, the polarization state can be further eliminated by increasing the height of the convex portions 11. In order to utilize birefringence, a structure in which the linear metal layer 2 is formed only around the convex portion 11 of the linear resin pattern 10 is preferable. In this case, it is also preferable that not only the linear resin pattern 10 portion but also the entire resin layer 1 has birefringence.

  The second feature is that metal patterning is easy. Details will be described in the section of the manufacturing method, but by forming a pattern on the surface of the resin layer 1 in advance without using a complicated process of resist patterning and etching using a semiconductor manufacturing process or the like, It becomes possible to easily form the linear metal layer 2 corresponding to the pattern shape.

  A third feature is that the formed linear metal layer 2 has high mechanical strength. Since the reflective polarizing plate produced by resist patterning and etching processing using a semiconductor manufacturing process or the like has a thin metal wire formed on a flat surface, an interface between the linear metal layer 2 and the resin layer 1 is formed. The area is slight, the metal pattern is weak against external force, and easily collapses and peels off. On the other hand, in the reflective polarizing plate of the present invention, since the linear metal layer 2 is formed on the linear resin pattern 10 formed on the surface of the resin layer 1, the interface between the linear metal layer 2 and the resin layer 1 is used. In addition to improving the adhesiveness of the linear metal layer 2, the pattern protrusion 11 has an effect of reinforcing the linear metal layer 2, and the strength against external force can be increased.

  As described above, the presence of the linear resin pattern 10 on the surface of the resin layer 1 makes it possible to form a reflective polarizing plate having high optical characteristics and mechanical strength by an easy process.

  In FIG. 1, an example of the shape of the resin layer 1 in which the linear resin pattern 10 which comprises the reflective polarizing plate of this invention was formed is shown. Fig.1 (a) is sectional drawing of the resin layer 1 which has the linear resin pattern 10 containing the convex part 11 with a rectangular cross section on one surface. In the figure, the pitch p, width w, and height h of the convex portion 11 are shown. The width w in the present invention is the length in the direction in which the unevenness is repeated, and is a half of the height h of the convex portion 11, that is, a height of h / 2 from one surface of the resin layer (the bottom surface of the concave portion 12). This means the length in a plane parallel to the surface of the resin layer 1. FIG.1 (b) has illustrated the perspective view of the resin layer 1 which has the parallel linear resin pattern 10 in which the convex part 11 is formed periodically.

  Fig.1 (a) and FIG.2 (a)-(e) have shown the example of the preferable cross-sectional shape of the resin layer 1 which comprises the reflective polarizing plate of this invention. As the cross-sectional shape of the convex portion 11, for example, a rectangle (FIG. 1 (a)), a trapezoid (FIG. 2 (a)), or a corner or side thereof having a curved shape (FIG. 2 (b) (c) ), Waveforms (FIG. 2 (d)), triangles (FIG. 2 (e)), and the like, but not limited thereto, and preferably used if the linear resin pattern 10 is formed in the plane. Can do. Moreover, between the adjacent convex parts 11, a flat part may be formed like FIG.1 (a) and FIG.2 (a)-(c), and it is like FIG.2 (d) (e). The flat portion does not have to be formed. Among these, the convex section 11 having a rectangular or trapezoidal cross section, or a convex section 11 having a curved shape at the corners or side surfaces thereof, and adjacent convex sections 11 are not connected to each other at the bottom (for example, FIG. 1A and FIGS. 2A to 2C are preferable because high optical anisotropy is exhibited after the linear metal layer 2 is formed.

  Here, with respect to the linear resin pattern 10 formed on the surface of the resin layer 1, the bottoms of the adjacent convex portions 11 are not connected as shown in FIGS. 1 (a), 2 (a), 2 (b), and 2 (c). In the case of a shape, the linear metal layer 2 can be easily formed only around the convex portion 11 and is preferable. Even when the cross-sectional shape as shown in FIG. 2 (d) is corrugated, it is possible to form the linear metal layer 2 only around the convex portion 11, but there are many slopes and the portion where the linear metal layer 2 is formed It is difficult to control because it spreads easily.

  In the reflective polarizing plate of the present invention, the linear resin pattern 10 has lines, that is, convex portions 11 formed in parallel as shown in FIG. 1 (b). It does not have to be parallel. Each line is preferably a straight line that most easily exhibits optical anisotropy in the plane, but may be a curved line or a broken line as long as adjacent lines do not contact each other. Similarly, it is preferably a continuous straight line in order to easily develop optical anisotropy, but may be a broken line as long as the length is at least equal to the wavelength to be applied.

  In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 is preferably formed not only on one side of the resin layer 1 but also on both sides. When forming on both sides of the resin layer 1, it is preferable to form the linear resin pattern 10 so that the longitudinal direction of the linear resin pattern 10 is parallel on the front and back. In this case, the linear metal layer 2 is formed only on one side of the linear resin pattern formed on both sides of the resin layer 1, or the linear metal layer 2 is formed on the resin pattern on both sides. Although it does not matter, a reflective polarizing plate with a higher degree of polarization can be obtained by forming the linear metal layer 2 on the linear resin patterns on both sides.

  In the reflective polarizing plate of the present invention, the size of the convex portion 11 in the cross section perpendicular to the longitudinal direction of the linear resin pattern 10 formed on the surface of the resin layer 1 is appropriately selected depending on the wavelength region of the applied light. For example, in order to apply to the wavelength region of near-infrared / infrared light having a wavelength of 800 to 4000 nm, the pitch p = 50 to 800 nm, the width w = 20 to 780 nm, and the wavelength region of visible light having a wavelength of 400 to 800 nm. In order to apply to the above, it is preferable to form with a pitch p = 50 to 400 nm and a width w = 20 to 380 nm. By forming the linear resin pattern 10 on the resin layer 1 with this dimension and further forming the linear metal layer 2, high polarization characteristics are expressed in the wavelength region of light applied to each pitch p and width w. A reflective polarizing plate can be obtained.

  In particular, when applied to the wavelength region of visible light, if the pitch p exceeds 400 nm, the degree of polarization on the short wavelength side in the visible light region is not preferable. Moreover, when the pitch p is less than 50 nm, not only is it difficult to form the linear resin pattern 10 on the surface of the resin layer 1, but also the linear metal layer 2 is formed along the linear resin pattern 10. Is not preferable because it becomes difficult. When applied to the wavelength region of visible light, the range of the pitch p is more preferably 70 to 200 nm, still more preferably 80 to 160 nm, and particularly preferably 80 to 140 nm.

  Further, when applied to the wavelength region of visible light, when the width w is narrower than 20 nm, not only is molding difficult, but even if molding is possible, the mechanical strength is low and the linear resin pattern 10 is collapsed. It is not preferable because it tends to occur. When the width w is larger than 780 nm when applied to the wavelength region of the near infrared light region and larger than 380 nm when applied to the wavelength region of visible light, the linear metal layer 2 is formed on the linear resin pattern 10. When formed, it is difficult to form the metal layer in a shape reflected in the pattern shape, and even if the metal layer can be formed, the aperture ratio becomes very low and the light transmittance is low. It is not preferable. The width w is more preferably 20 to 300 nm, most preferably 20 to 200 nm, and more preferably 20 to 150 nm when applied to the wavelength region of near-infrared light. Most preferably, it is 25-100 nm.

  In the reflective polarizing plate of the present invention, the pitch p and the width w of the linear resin pattern 10 formed on the surface of the resin layer 1 are preferably constant in order to keep the polarization characteristics uniform in the plane. Various pitches and widths may be mixed within the range. In addition, when a polarizing plate is manufactured in a shape that is applied to the visible light region, polarization characteristics can be expressed not only in the visible light region but also in the near infrared region and the infrared region, which are longer wavelengths. It can also be used as a reflective polarizing plate.

  In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 has a polarization characteristic depending on the height h of the convex portion 11 in the cross section perpendicular to the longitudinal direction, and the incident angle of light. May depend on. The height h of the convex portion 11 of the linear resin pattern 10 is preferably 10 to 800 nm when applied to the near infrared light wavelength region, and 10 to 400 nm when applied to the visible light wavelength region. . When applied to the wavelength region of near infrared light, more preferably 20 to 600 nm, most preferably 30 to 400 nm, and when applied to the wavelength region of visible light, more preferably 20 to 300 nm, most preferably 30 to 300 nm. If the height h of the convex portion 11 exceeds 400 nm, the degree of polarization may change depending on the incident angle of light, which is not preferable. On the other hand, it is not preferable that the height h is less than 10 nm because sufficient optical anisotropy may not be obtained even if the linear metal layer 2 is formed along the height h. In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 applies the height h of the convex portion 11 in the cross section perpendicular to the longitudinal direction to the wavelength region of near infrared light. 10 to 800 nm when applied to the wavelength region of visible light, and 10 to 400 nm when applied to the wavelength range of visible light, so that uniform polarization characteristics can be obtained without depending on the incident angle of light. It can be suitably used for required applications. However, when the reflective polarizing plate of the present invention is used in a narrow viewing angle range, for example, in the case of an optical element using only the normal direction or a display device using only the front direction, the incident angle of light is considered. Therefore, the height h may exceed the above range.

  In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 has a ratio (h / w) of the height h to the width w of the convex portion 11 in a cross section perpendicular to the longitudinal direction. , Preferably in the range of 0.5-5. More preferably, it is 1-5, More preferably, it is 2-5. When the ratio h / w is less than 0.5, it becomes difficult to selectively form the linear metal layer 2 and the structural anisotropy cannot be sufficiently exhibited, and sufficient polarization characteristics are obtained. Since it may not be possible, it is not preferable. On the other hand, when the ratio h / w exceeds 5, formation of the linear resin pattern 10 becomes difficult, and it may be meandering and falling or breaking, and uneven polarization characteristics may appear in the plane. . In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 has a ratio h / w of the height h to the width w of the convex portion 11 in a cross section perpendicular to the longitudinal direction of 0. By setting it as 5-5, it can be set as the polarizing plate which has a high polarization characteristic and mechanical strength, and was excellent in the in-plane uniformity of those characteristics.

  Further, in the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 has a height h of the convex portion 11 and a width between the convex portions 11 in a cross section perpendicular to the longitudinal direction, that is, The ratio h / (pw) to the width (pw) of the recess 12 is preferably in the range of 1-5. More preferably, the ratio h / (p-w) is 1.2 to 5, more preferably 1.3 to 5. If the ratio h / (pw) exceeds 5, it is not preferable because the formation of the linear resin pattern 10 becomes difficult, and if it is less than 1, it becomes difficult to selectively form the linear metal layer 2, and the structure This is not preferable because sufficient anisotropy cannot be exhibited and sufficient polarization characteristics may not be obtained. In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 is a ratio of the height 11 of the convex portion 11 to the width (p−w) of the concave portion 12 in a cross section perpendicular to the longitudinal direction. By setting h / (p-w) to 1 to 5, the selective formability of the linear metal layer 2 is increased, and the formation of the linear metal layer 2 only around the convex portion 11 is particularly easy and high. A polarizing plate having polarization characteristics can be obtained.

  In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 has a ratio (w / p) between the width w and the pitch p of the protrusions 11 in a cross section perpendicular to the longitudinal direction. Is preferably in the range of 0.1 to 0.5. More preferably, the ratio w / p is 0.1 to 0.45, and still more preferably 0.1 to 0.40. When the ratio w / p exceeds 0.5, a sufficient aperture ratio cannot be ensured after the linear metal layer 2 is formed, which is not preferable because the transmittance decreases. On the other hand, if the ratio w / p is less than 0.1, a sufficient degree of polarization cannot be obtained even if the linear metal layer 2 is formed. In the reflective polarizing plate of the present invention, the linear resin pattern 10 formed on the surface of the resin layer 1 has a ratio w / p of the width w to the pitch p of the convex portion 11 in the cross section perpendicular to the longitudinal direction of 0.1. By setting it to -0.5, when the linear metal layer 2 is formed, it can be set as the reflective polarizing plate which makes high polarization degree and transmittance compatible.

  In the reflective polarizing plate of the present invention, the resin layer 1 is preferably laminated with a support composed of an organic or inorganic material. By adopting a laminated structure, the planarity of the resin layer 1 can be improved when the resin layer 1 is flat while ensuring the mechanical strength and heat resistance of the support, and a linear resin is formed on the surface of the resin layer 1. In the case of forming the pattern 10, it is preferable because a material that can be easily shaped can be used for the resin layer 1. Note that the layer serving as the support may be a single layer or a multi-layered structure.

  Here, in the case where the linear resin pattern 10 is formed on the surface of the resin layer 1, the material that can be easily shaped used for the resin layer 1 is the above-described thermoplastic resin, photocurable resin, or thermosetting resin. That means. As will be described later, in order to shape the linear resin pattern 10 on the surface of the resin layer 1 from the viewpoint of productivity and the like, a mold transfer method is preferable, but by using these resins, a higher definition pattern can be formed. Is preferable.

  In addition, as a layer serving as a support, inorganic substrates such as glass and metal, polyester resins, acrylic resins such as polymethyl methacrylate, polyolefin resins such as alicyclic polyolefin, resin substrates typified by polycarbonate, etc. Various materials can be used. When an inorganic base material such as glass or metal is used as a support, a polarizing plate excellent in flatness, mechanical strength, and heat resistance can be obtained. Moreover, when a flexible resin base material represented by polyester resin, acrylic resin, polyolefin resin, polycarbonate, or the like is used, further flexibility, weight reduction, thinning, and handling can be imparted. Therefore, it is more preferable. Among the above materials, a thermoplastic resin sheet containing a polyester resin as a main component is preferable, and in order to improve mechanical strength and heat resistance, a uniaxially stretched or biaxially stretched polyester resin sheet is particularly preferable. . The use of a biaxially stretched polyester resin sheet is the most preferable support because it can achieve thinning, flexibility and weight reduction while ensuring mechanical strength and heat resistance. In particular, compared with glass which is an inorganic base material, it has excellent impact resistance when thinned. Further, since birefringence develops in the sheet by stretching, it is preferable because the polarization state of incident light can be eliminated and the luminance of a liquid crystal display device can be improved as described above. As the polyester resin used here, a polyester resin such as polyethylene terephthalate, polyethylene-2,6-naphthalate, or a copolymer with other components based on these is preferably used. In addition, a resin composition containing this polyester resin as a main component and other compatible or / and incompatible components added is also preferably used.

  In the reflective polarizing plate of the present invention, when the resin layer 1 has a laminated structure with the support, the difference Δn = the refractive index n1 of the resin layer 1 including the linear resin pattern 10 and the refractive index n2 of the support. It is preferable to make | n1-n2 | as small as possible, preferably the refractive index difference Δn is 0 to 0.15, more preferably 0 to 0.10, still more preferably 0 to 0.06, and most preferably 0 to 0. .03. When the refractive index difference Δn is outside the range of 0 to 0.15, the refractive index difference between the resin layer 1 and the support, the height h of the linear uneven structure, and the linear resin formed on the surface of the resin layer 1 Thin film interference due to an interval (hereinafter referred to as film thickness) h ′ from the lowermost concave portion of the pattern 10 to the surface on which the linear resin pattern 10 is not formed becomes large. The light that should be reflected and reused by the thin film interference is deactivated. In particular, when light is incident from the support side, the influence appears remarkably and the reflectance is greatly reduced. As a result, the light use efficiency as the reflective polarizing plate is lowered, and the brightness improvement effect cannot be sufficiently obtained when it is incorporated in a liquid crystal display device. In addition, this decrease in light utilization efficiency may vary depending on the wavelength of light, and the color of the liquid crystal display device may appear uneven depending on the in-plane observation location and observation angle, which may reduce color uniformity. Therefore, it is not preferable.

  In the reflective polarizing plate of the present invention, the difference Δn = | n1−n2 | between the refractive index n1 of the resin layer 1 including the linear resin pattern 10 and the refractive index n2 of the support is set to 0 to 0.15. Thus, a reflective polarizing plate having good color uniformity and excellent light utilization efficiency can be obtained. Specifically, when a biaxially stretched polyester film is used as the support, the refractive index n1 of the resin layer 1 is preferably 1.58 to 1.7, more preferably 1.60 to 1.68. In order to achieve the refractive index n1, the molecular skeleton of the resin includes an alicyclic group such as cyclohexane, isobornyl, and adamantane, an aromatic ring such as benzene, naphthalene, anthracene, pyrene, biphenyl, and bisphenol, bromine, and chlorine. It can be obtained by introducing a halogen atom such as iodine, sulfur or the like. Among these, it is preferable to introduce an alicyclic group or an aromatic group from the viewpoint of environmental problems.

  In the reflective polarizing plate of the present invention, the film thickness h ′ from the bottom of the concave portion of the linear resin pattern 10 formed on the surface of the resin layer 1 to the surface on the side where the linear resin pattern 10 is not formed is 1. -1000 micrometers is preferable, More preferably, it is 1-500 micrometers, More preferably, it is 1-200 micrometers.

  When the resin layer 1 has a laminated structure with the support, the film thickness h ′ from the bottom of the concave portion of the resin layer 1 having the linear resin pattern 10 to the interface between the resin layer 1 and the support is 0. ˜2 μm is preferable, more preferably 0 to 1 μm, and still more preferably 0 to 500 nm. In this case, the thickness of the support is not particularly limited, but from the viewpoint of mechanical strength and thinning, for example, 0.1 to 3 mm in the case of an inorganic base material, and 50 μm to 3 mm in the case of a resin base material. Is preferred.

  In the reflective polarizing plate of the present invention, when the linear metal layer 2 is formed only on one side of the resin layer 1, air and the resin layer 1 are formed on the surface of the resin layer 1 on the side where the linear metal layer 2 is not formed. It is preferable that an antireflection layer for preventing reflection of light generated due to a difference in refractive index at the interface with the substrate is formed. By forming the antireflection layer, reflection occurring at the interface between the air on the side where the linear metal layer 2 is not formed and the resin layer 1 can be suppressed, and the utilization efficiency of light rays can be further increased. The antireflection layer may be formed of a material having a property of preventing reflection to exhibit the antireflection function, or the antireflection function may be exhibited by forming the layer in a specific shape.

  In the reflective polarizing plate of the present invention, the use of a material exhibiting light diffusibility as the support is a preferable configuration in that functional integration between the reflective polarizing plate and the light diffusing plate can be achieved. In order to develop light diffusibility, for example, particles or the like are dispersed inside the support, a surface on which the linear resin pattern 10 is not formed is coated with a material containing fine particles, or an uneven shape is formed. This can be achieved by shaping. In the case where light diffusibility is imparted to the resin layer 1 itself by dispersing particles or the like inside the resin layer 1, an isotropic light diffusing effect can be exhibited mainly. When the light diffusion layer is provided on the surface where the resin pattern 10 is not formed, the shape of the surface can be arbitrarily designed, and therefore any light diffusibility can be easily controlled in addition to the isotropic diffusivity. .

  In the reflective polarizing plate of the present invention, it is also preferable to give the support a function of a quarter wave plate. In the case of a laminated structure of the resin layer 1 and a support having the function of a quarter wavelength plate, the light incident from the support side is polarized and separated by the linear metal layer 2 provided on the resin layer 1. The linearly polarized light reflected by the metal layer 2 returns to the support again. Then, the linearly polarized light is converted into circularly polarized light in the support body, returned to the surface light source, and further reflected in the surface light source, so that light containing a large amount of circularly polarized light in the reverse direction (however, the polarization state is partially eliminated) And return to the support again. When this reversely circularly polarized light passes through the support, it is converted from circularly polarized light to linearly polarized light that passes through the linear metal layer 2 and passes therethrough. Therefore, the light utilization efficiency can be increased as a reflective polarizing plate.

  Further, as the support, a material exhibiting light absorption or a material exhibiting light reflectivity can be used. In that case, it can be used as a polarization reflector that reflects a specific polarization component.

  The reflective polarizing plate of the present invention is characterized in that a plurality of linear metal layers 2 formed at intervals are formed on the surface of the resin layer 1. Accordingly, a reflective polarizing plate capable of transmitting one polarized light and reflecting the other polarized light can be obtained.

  About the reflective polarizing plate of this invention, the form of the linear metal layer 2 is demonstrated using FIGS.

  FIG. 3 shows an example of a cross-sectional shape in which the linear metal layer 2 is partially formed on the resin layer 1 having a flat surface. As a cross-sectional shape of the linear metal layer 2, for example, a rectangle (FIG. 3 (a)), a trapezoid (FIG. 3 (b)), a triangle (FIG. 3 (c)) or corners and side surfaces thereof are curved. (FIGS. 3 (d) to (f)) and the like, but are not limited thereto, and can be preferably used if the linear metal layer 2 is partially formed in the plane. FIG. 3G shows a perspective view of the resin layer 1 having the cross-sectional shape of FIG. 3A, and the linear metal layer 2 is linearly formed on the surface of the resin layer 1. Represents.

  Moreover, FIG. 4 has shown the example of the aspect by which the linear metal layer 2 is partially formed on the linear resin pattern 10 which has the convex part 11 whose cross section is a rectangle. For example, when the linear metal layer 2 is formed on the top of the convex part 11 of the linear resin pattern 10 (FIG. 4A), it is formed between the adjacent convex parts 11, that is, in the concave part 12 (FIG. 4). (B)), when formed on the side surface of the convex portion 11 (FIG. 4C), when formed around the convex portion 11 (FIG. 4D), or a combination thereof (FIG. 4). A preferable example is the case of (e)). FIG. 4 (f) shows a perspective view of the resin layer 1 having the cross-sectional shape of FIG. 4 (a), and the linear metal layer 2 is linear along the linear resin pattern 10 of the resin layer 1. This shows how it is formed.

  In the reflective polarizing plate of the present invention, the thickness H of the linear metal layer 2 is preferably 10 to 200 nm. Here, the film thickness H of the linear metal layer 2 is a thickness measured in the height direction of the resin layer 1 convex portion 11 and is a film thickness that satisfies at least a part of the resin layer 1 in the above range. The linear metal layer 2 should just be formed. The film thickness H of the linear metal layer 2 is more preferably 30 to 200 nm, still more preferably 50 to 200 nm. If the film thickness H is less than 10 nm, a sufficient degree of polarization cannot be obtained, and if it exceeds 200 nm, the formation of the linear metal layer 2 becomes difficult, which is not preferable. In the reflective polarizing plate of the present invention, a reflective polarizing plate having a high degree of polarization can be easily formed by setting the thickness of the linear metal layer 2 to 10 to 200 nm.

  In the reflective polarizing plate of the present invention, the dimensions and the like in the cross section perpendicular to the longitudinal direction of the linear metal layer 2 are appropriately selected depending on the wavelength region of light to be applied. For example, in order to apply to the near infrared / infrared wavelength range of wavelength 800 to 4000 nm, pitch P = 50 to 800 nm, width W = 20 to 780 nm, and visible wavelength range of wavelength 400 to 800 nm. Therefore, it is preferable to form with a pitch P = 50 to 400 nm and a width W = 20 to 380 nm. By forming the linear metal layer 2 of this size, it is possible to provide a reflective polarizing plate that exhibits high polarization characteristics in the wavelength region of light to be applied.

  In particular, when applied to the wavelength region of visible light, if the pitch P exceeds 400 nm, the degree of polarization in the short wavelength region of visible light decreases, which is not preferable. On the other hand, when the pitch P is less than 50 nm, it is difficult to form the linear metal layer 2, which is not preferable. The pitch P is more preferably 70 to 200 nm, still more preferably 80 to 160 nm, and particularly preferably 80 to 140 nm.

  In addition, when the width W of the linear metal layer 2 is smaller than 20 nm, not only is formation difficult, but even if it can be formed, it may not function as the linear metal layer 2, which is not preferable. In addition, the width W is larger than the pitch 780 nm when applied to the wavelength region of the near-infrared light region, and the pitch P is larger than 380 nm when applied to the wavelength region of visible light. Considering this range, the aperture ratio becomes very low and the light transmittance becomes low, which is not preferable. Accordingly, the width W is more preferably 20 to 300 nm, most preferably 20 to 200 nm when applied to the near infrared wavelength region, and more preferably 20 to 200 nm when applied to the visible wavelength region. Is 20 to 150 nm, most preferably 25 to 100 nm.

  The pitch P and the width W are preferably constant in order to maintain the uniformity of polarization characteristics in the plane, but various pitches and widths may be mixed within the range. In addition, when a reflective polarizing plate is manufactured in a shape applicable to the visible light region, polarization characteristics can be expressed not only in the visible light region but also in the near infrared region and infrared region, which have longer wavelengths. Alternatively, it can be used as a reflective polarizing plate for infrared rays.

  Here, in the reflective polarizing plate of the present invention, when the linear resin pattern 10 is formed on the surface of the resin layer 1, the linear metal layer 2 is used to obtain high light utilization efficiency and high transmittance. It is preferable that it is formed only around the convex portion 11 (for example, FIG. 4A, FIG. 4C to FIG. 4E), and in particular, it is formed at the top of the convex portion 11 as shown in FIG. Is preferable in terms of high transmittance and high degree of polarization. In this case, the total height of the film thickness H of the linear metal layer 2 formed on the convex portion 11 and the height h of the convex portion 11 is more preferably 400 nm or less. If the combined height exceeds 400 nm, the polarization characteristics may depend on the incident angle of light, which is not preferable. In the reflective polarizing plate of the present invention, by adding the thickness H of the linear metal layer 2 formed on the convex portion 11 and the height h of the convex portion 11 to 400 nm or less, A uniform polarization characteristic can be obtained without depending on the incident angle.

  In the reflective polarizing plate of the present invention, the total width TW of the linear metal layer 2 and the convex portion 11 is a ratio with the pitch p of the convex portion 11, that is, TW / p is 0.1 to 0.7. Preferably there is. Here, the total width TW and the pitch p necessary for calculating this ratio are the same so that the length of the linear metal layer 2 is parallel to the surface of the resin layer 1 and in the direction in which the unevenness is repeated. It shall be measured in a plane. More preferably, TW / p is 0.2 to 0.6, and still more preferably 0.3 to 0.6. When this ratio exceeds 0.7, the light utilization efficiency and the transmittance are lowered, which is not preferable. Moreover, since less than 0.1 cannot obtain sufficient polarization degree, it is not preferable. In the reflective polarizing plate of the present invention, by setting the ratio TW / p of the total width TW and pitch of the linear metal layer 2 and the convex portion 11 to 0.1 to 0.7, both a high degree of polarization and transmittance are achieved. can do.

  In the reflective polarizing plate of the present invention, the linear metal layer 2 contains “a layer made of a highly reflective metal” and / or “a highly reflective metal particle and / or a particle coated with a highly reflective metal”. It is preferable to be a “layer”. Moreover, the layer in which these were mixed may be sufficient, and the laminated structure may be sufficient.

  Here, the “layer made of a highly reflective metal” is a linear metal layer 2 made of a single metal or an alloy made of a plurality of metals, and preferably has a single layer or a laminated structure of two or more layers made of different materials. Used. In the case of a laminated structure of two or more layers made of different materials, at least one layer may be a layer made of a highly reflective metal. For example, a metal oxide having low reflectivity is laminated on the surface of the linear metal layer 2. May be. In particular, when a highly reflective metal that easily oxidizes is used, it is preferable to previously form a layer made of an oxide of the metal on the surface of the linear metal layer 2 as a protective layer to improve the stability over time.

  In addition, the particle diameter of the highly reflective metal particle and the particle coated with the highly reflective metal included in the “layer containing the highly reflective metal particle and / or the particle coated with the highly reflective metal” has a particle diameter. It is preferable that it is 1-100 nm, More preferably, it is 1-50 nm. The particle diameter here refers to the median diameter d50. Metal particles having a particle size of 100 nm or less are preferable because the fusion temperature is lowered, so that, for example, the particles start to be connected even at a low temperature heat treatment at 200 to 300 ° C., and the characteristics as a metal are exhibited and the light reflectivity is improved. Further, it is more preferable that the particle diameter is 50 nm or less because the particles are fused by heat treatment at a lower temperature for a shorter time. The shape of these particles is not particularly limited, and any shape can be preferably used. The inner layer particles coated with the highly reflective metal are preferably used without particular limitation, for example, crosslinked resin particles such as acrylic resin, inorganic particles such as silica and alumina, and the like. These highly reflective metal particles, particles coated with highly reflective metal particles are particles alone or a combination of particles and a dispersant, and further, a thermoplastic resin, a photocurable resin, which becomes a particle, a dispersant and a binder, By combining with any one of thermosetting resins or a resin composition mainly composed of a mixture thereof, “a layer containing highly reflective metal particles and / or particles coated with highly reflective metal” Is preferably formed.

  In the reflective polarizing plate of the present invention, the highly reflective metal preferably contains a group metal composed of aluminum, chromium, silver, copper, nickel, platinum and gold. More preferably, these groups of metals are the main components. Here, the main component means a case where the content of the metal in the linear metal layer 2 exceeds 50% by weight. Moreover, high reflectivity is to show a high reflectance in the wavelength region of the light to be used, specifically, formed on a borosilicate glass (BK-7) having a smooth surface with a thickness of 100 nm, It means that the reflectance when entering from the linear metal layer 2 side is 75% or more over the entire wavelength region to be applied. More preferably, it is 80% or more, More preferably, it is 85% or more. When a metal having a reflectance of less than 75% is used as the linear metal layer 2, the optical loss increases and sufficient light utilization efficiency cannot be obtained, or the degree of polarization decreases even if the optical loss is small. This is not preferable. In the reflective polarizing plate of the present invention, by using the linear metal layer 2 having a reflectance of 75% or more, not only the light utilization efficiency can be increased, but also a high degree of polarization can be obtained. Among the metals, aluminum, chromium, and silver are more preferable because of high reflectance over the entire visible light region.

  The reflective polarizing plate of the present invention has the above-described configuration, and its features include high transmittance, high reflectance, and high degree of polarization. Specifically, it is preferable that the transmittance measured from the resin layer 1 side is 30% or more, the reflectance is 30% or more, and the degree of polarization measured from the linear metal layer 2 side is 90% or more. More preferably, the transmittance is 35% or more, the reflectance is 35% or more, the degree of polarization is 95% or more, more preferably the transmittance is 35% or more, the reflectance is 40% or more, and the degree of polarization is 99% or more.

  The reflective polarizing plate of the present invention can be produced by the following method.

First, when the resin layer 1 is flat, it can be manufactured in the order of the following steps (a-1) to (a-4).
Process (a-1): The process of producing the resin layer 1 (base material formation process)
Step (a-2): Step of forming a metal layer on the surface of the resin layer 1 (metal layer forming step)
Step (a-3): Step of forming a resist pattern on the metal layer (resist pattern forming step)
Step (a-4): Step of removing the metal layer partially (selective removal step)
Moreover, when forming the linear resin pattern 10 on the surface of the resin layer 1, although the formation by the said manufacturing method is also possible, it manufactures in order of the following process (b-1)-process (b-4). This is preferable in that the number of steps is small and the productivity is excellent.
Process (b-1): The process of producing the resin layer 1 (base material production process)
Step (b-2): Step of forming the linear resin pattern 10 on the surface of the resin layer 1 (pattern formation step)
Step (b-3): Step of forming the linear metal layer 2 on the linear resin pattern 10 produced in the step (b-2) (linear metal layer forming step)
Details of each step will be described below.

<Process (a-1), process (b-1): Base material preparation process>
In the reflective polarizing plate manufacturing method of the present invention, the resin layer 1 can be formed, for example, by heating and melting the material forming the resin layer 1 in an extruder and extruding it onto a cast drum cooled from a die to form a sheet. A processing method (melt cast method) can be used. Further, the material for forming the resin layer 1 is dissolved in a solvent, and the solution is extruded from a die onto a support such as a cast drum or an endless belt to form a film, and then the solvent is dried and removed from the film layer. A method of processing into a sheet (solution casting method) or the like can also be used.

  In addition, as a method of laminating the resin layer 1 on the support, for example, in the case of thermoplastic resins having different materials for forming the resin layer 1 and the support, the respective materials are melted using two extruders. The resin layer 1 and the support are simultaneously formed by extruding from the die so that the respective materials are laminated in the extrusion path, and receiving it with a cooled cast drum and processing it into a sheet (coextrusion). Method), a method in which the material of the resin layer 1 is put into an extruder on a support made of a single film and laminated on the support by melt extrusion (melt laminating method), the resin layer 1 and the support A single film is prepared separately, and a method of thermocompression bonding with a heated group of rolls (thermal lamination method), a method of bonding through an adhesive (adhesion method), a material of the resin layer 1 is dissolved in a solvent, Support solution It can be used a method (coating method) of coating on the body.

  Moreover, when the material of the resin layer 1 is a photocurable resin or a thermosetting resin, among the above methods, an adhesion method and a coating method are preferably used.

  As the support, a support formed with an application layer such as an easy-adhesion layer is preferably used in terms of adhesive strength with the resin layer 1. In this case, as a resin constituting the coating layer, for example, polyester resin, polyamide resin, polystyrene resin, polyurethane resin, polyolefin resin, acrylic resin, phenol resin, epoxy resin, melamine resin, silicon resin, etc. A thermoplastic resin and a mixture thereof are appropriately selected and used. When a biaxially stretched polyester film is used as a support, a polyester resin is mainly used from the viewpoint of adhesiveness. . The main component here means that, among the thermoplastic resins constituting the coating layer, the polyester resin preferably consists of 50% by weight or more, more preferably 60% by weight or more, and most preferably 70% by weight or more. It is shown.

  Moreover, it is preferable to contain a crosslinking agent in a coating layer at points, such as an adhesive improvement of a support body and a coating layer, prevention of blocking resistance. As such a crosslinking agent, a resin or a compound that undergoes a crosslinking reaction with a functional group present in the resin constituting the coating layer, for example, a hydroxyl group, a carboxyl group, a glycidyl group, an amide group, or the like is preferably used. It is possible to use alkylolated urea-based, melamine-based, acrylamide-based, polyamide-based resins and epoxy compounds, isocyanate compounds, coupling agents, aziridine compounds, oxazoline compounds, and mixtures thereof. The type and content of the crosslinking agent are appropriately selected depending on the support, the resin layer 1, the resin constituting the coating layer, the type of the crosslinking agent, and the like. The range is 0.01 to 50 parts by weight, and more preferably 0.2 to 30 parts by weight. Moreover, it is also preferable to promote the crosslinking reaction by using a catalyst in combination with such a crosslinking agent. In addition, as a crosslinking reaction system, any of a heating system, an electromagnetic wave irradiation system, a moisture absorption system, etc. may be used, but usually a method by heating is preferably used.

  The coating layer preferably contains fine particles for improving the slipperiness of the coating layer and for blocking resistance. For example, inorganic fine particles or organic fine particles can be used. Examples of the inorganic fine particles include gold, silver, copper, platinum, palladium, rhenium, vanadium, osmium, cobalt, iron, zinc, ruthenium, praseodymium, chromium, nickel, aluminum, tin, zinc, titanium, tantalum, zirconium, Metal oxides such as antimony, indium, yttrium, lanthanium, etc., metal oxides such as zinc oxide, titanium oxide, cesium oxide, antimony oxide, tin oxide, indium tin oxide, yttrium oxide, lanthanum oxide, zirconium oxide, aluminum oxide, silicon oxide Metal fluoride such as lithium fluoride, magnesium fluoride, aluminum fluoride, cryolite, metal phosphate such as calcium phosphate, carbonate such as calcium carbonate, sulfate such as barium sulfate, other talc and kaolin, etc. The It is possible to have. In addition to the crosslinked fine particles such as crosslinked styrene and crosslinked acrylic, the organic fine particles are also incompatible with the thermoplastic resin that constitutes the coating layer, but the thermoplastic resin that is finely dispersed to form a sea-island structure is also used as the fine particles. It can also be used. Examples of the shape of the fine particles include a spherical shape, a spheroid shape, a flat shape, a bead shape, a plate shape, and a needle shape, but are not particularly limited. The average particle size of such fine particles is preferably 0.05 to 15 μm from the viewpoint of dispersibility, slipperiness and blocking resistance, and more preferably 0.1 to 10 μm. Moreover, the addition amount of such fine particles is arbitrary, but is usually preferably 0.1 to 50 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the resin solid content.

  Moreover, various additives can be added to the coating layer as necessary within a range where the effect is not lost. Examples of additives that can be added and blended include, for example, dispersants, dyes, fluorescent brighteners, antioxidants, weathering agents, antistatic agents, polymerization inhibitors, thickeners, antifoaming agents, and UV absorption. Agents, leveling agents, pH adjusters, salts and the like can be used.

  As a method for forming the coating layer on the support, a means for dissolving / dispersing the material constituting the coating layer in a solvent and coating and drying the coating liquid on the support is preferably used. In this case, the solvent to be used is arbitrary, but it is preferable to use water as a main component from the viewpoint of safety. In that case, a small amount of an organic solvent that dissolves in water may be added in order to improve applicability and solubility. Examples of such organic solvents include aliphatic or alicyclic alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, and n-butyl alcohol, diols such as ethylene glycol, propylene glycol, and diethylene glycol, methyl cellosorb, Diol derivatives such as ethyl cellosolve propylene glycol monomethyl ether, ethers such as dioxane and tetrahydrofuran, esters such as methyl acetate, ethyl acetate and amyl acetate, ketones such as acetone and methyl ethyl ketone, amides such as N-methylpyrrolidone Etc. and mixtures thereof may be used, but are not limited to these.

  Examples of the method of coating the coating layer on the support include an in-line coating method that is applied during film formation of the support and an off-line coating method that is applied to the original film after film formation. However, the in-line coating method is preferably used because it is efficient because it can be formed simultaneously with the film formation of the support and the adhesion of the coating layer to the support is high. Further, when coating, corona treatment or the like is preferably performed on the surface of the support from the viewpoint of improving the wettability of the coating solution onto the support and improving the adhesive strength.

  In addition, when a uniaxially or biaxially stretched film substrate is selected as the support, the resin layer 1 can be formed as a method for forming the resin layer 1 in addition to the above-described melt lamination method, thermal lamination method, coating method, and the like. Is made of a thermoplastic resin, the materials of the resin layer 1 and the polyester material for forming the support are melted using two extruders, and the respective materials are laminated in the extrusion path. A method (co-extrusion biaxial stretching method) in which the sheet is discharged from the die and formed into a sheet shape on a cooled cast drum, followed by biaxial stretching and heat treatment is also preferably performed.

The biaxial stretching method may be either a sequential biaxial stretching method in which stretching in the longitudinal direction and the width direction is separated or a simultaneous biaxial stretching method in which stretching in the longitudinal direction and the width direction is performed simultaneously. Absent.
The heat treatment temperature Ta in the heat treatment step is preferably Tm2>Ta> Tm1 when the melting point (or softening point) of the resin layer 1 is Tm1 and the melting point of the support is Tm2. By performing heat treatment in this temperature range, the support can be heat-fixed to give mechanical strength, and at the same time, the resin layer 1 can be melted and homogenized to give easy moldability.

<Process (b-2): Pattern formation process>
The linear resin pattern 10 is formed on the surface of at least one side of the resin layer 1 using the sheet obtained in the step (b-1).

  In the method for producing a reflective polarizing plate of the present invention, as a method for forming the linear resin pattern 10, photolithography and etching methods used in a semiconductor manufacturing process or the like can be used, but these are complicated processes. Therefore, shaping by the mold transfer method is preferable in terms of productivity and cost. That is, the linear resin pattern 10 is formed on the surface of the resin layer 1 by mold transfer using heating / pressurization or electromagnetic wave irradiation. In the method using heating / pressing, as shown in FIG. 5 (a), a mold shape is formed on the surface of the resin layer 1 by stacking the base material and the mold 50, heating and pressing, and releasing. Is transcribed. At this time, it is preferable that at least the surface of the resin layer 1 is made of a thermoplastic resin or a thermosetting resin. In the method using electromagnetic wave irradiation, as shown in FIG. 5 (b), the mold 50 is directly filled with a photocurable resin, or the support is coated with a photocurable resin, and the coated surface is coated with gold. By pressing against the mold 50, the resin is filled and electromagnetic wave irradiation is performed, the resin is cured, and the mold 50 shape is transferred by releasing. It is preferable that at least the resin layer 1 is made of a resin that is cured by electromagnetic waves such as ultraviolet rays, visible light, and electron beams.

  In the production method of the reflective polarizing plate of the present invention, the method for producing the mold 50 used for forming the linear resin pattern 10 is not particularly limited, but the dimensions of the reflective polarizing plate of the present invention are not particularly limited. In view of the above, it is preferable that the resist layer formed on the mold material is patterned using an X-ray, an electron beam, an ultraviolet ray, an ultraviolet laser, or the like, and then manufactured through a process such as etching.

  As the material of the mold 50, various materials such as glass, silicon, stainless steel (SUS), or nickel (Ni) can be used. Although not particularly limited, from the viewpoint of workability of the mold 50, silicon is used. Metal materials such as stainless steel (SUS) and nickel (Ni) are preferable from the viewpoint of glass, glass, releasability and durability.

The mold 50 may use the above-described materials as they are, but the surface of the mold 50 is treated with a surface treatment agent so that the molded product can be easily released after the mold is transferred, thereby providing easy slipping. Is preferred. The contact angle of the surface layer of the mold 50 after the surface treatment is preferably 80 ° or more, more preferably 100 ° or more.
As a surface treatment method of the mold 50, a method of chemically bonding a surface treatment agent to the surface of the mold 50 (chemical adsorption method) or a method of physically adsorbing the surface treatment agent to the surface of the mold 50 (physical adsorption method). ) Etc. can be used. Among these, the surface treatment is preferably performed by a chemical adsorption method from the viewpoint of repeated durability of the surface treatment effect and prevention of contamination of the molded product.

  As a preferable example of the surface treatment agent used in the chemical adsorption method, a fluorine-based silane coupling agent can be used. As a surface treatment method using this, first, gold is obtained by ultrasonic treatment in an organic solvent (acetone, ethanol, etc.) or boiling in a solution of an acid such as sulfuric acid or a peroxide such as hydrogen peroxide. After cleaning the surface of the mold 50, a method of immersing in a solution in which a fluorinated silane coupling agent is dissolved in a fluorinated solvent (wet method), a method of depositing on the surface of the mold 50 by vacuum deposition (dry method), etc. Can be used. In the case of a wet method, it is also preferable to heat the solution during immersion. It is also preferable to heat the solution during immersion. Moreover, it is also preferable to heat-process after immersion.

  An example of a method for forming the linear resin pattern 10 on the surface of the resin layer 1 using the mold 50 will be described with reference to FIG.

  Fig.5 (a) shows the example in the case of metal mold shaping using heating and pressurization. Only the resin layer 1 made of a thermoplastic resin, or the sheet material 40 that is a laminate of the resin layer 1 and a support is heated to a temperature range between the glass transition temperature Tg and the melting point Tm of the resin layer 1 ( 5 (a-1)), the surface of the sheet material 40 on the resin layer 1 side and the mold 50 are brought close to each other, pressed as it is with a predetermined pressure, and held for a predetermined time (FIG. 5 (a-2)). Next, the temperature is lowered while maintaining the pressed state, and finally the pressing pressure is released to release the sheet from the mold 50 (FIG. 5 (a-3)).

  When mold shaping is performed using heating and pressurization, the heating temperature and the press temperature T1 are preferably in the range of Tg to Tg + 60 ° C. If the heating temperature and the press temperature T1 are less than Tg, the resin layer 1 made of thermoplastic resin is not sufficiently softened, so that the uneven shape of the mold 50 is difficult to be transferred when pressed, and the pressure required for molding Becomes very high. Further, if the heating temperature and the press temperature T1 exceed Tg + 60 ° C., it is inefficient in energy, and the difference in volume variation between the mold 50 and the resin layer 1 becomes too large during heating / cooling, and the sheet becomes Even if the mold 50 is bitten into the mold 50 and cannot be released, it is not preferable because the pattern accuracy is lowered or the pattern is partially lost. By setting the heating temperature and the press temperature (T1) to Tg to (Tg + 60 ° C.), it is possible to achieve both good moldability and mold release properties.

  Further, in the case of mold shaping using heating and pressurization, the pressing pressure is appropriately adjusted depending on the elastic modulus of the resin layer 1 constituting the sheet material 40 at the pressing temperature T1, but is preferably 0.00. 5 to 50 MPa, more preferably 1 to 30 MPa. If the pressing pressure is less than 0.5 MPa, the resin is not sufficiently filled into the mold 50 and the pattern accuracy is lowered. On the other hand, if the pressure exceeds 50 MPa, the load becomes too large, so that the load on the mold 50 is large and the unevenness of the mold 50 is deformed. By setting the pressing pressure to 0.5 to 50 MPa, good transferability can be obtained.

  Further, in the case of mold forming using heating and pressurization, the press pressure holding time is appropriately adjusted according to the elastic modulus of the resin layer 1 constituting the sheet material 40 and the molding pressure at the press temperature T1. In the case of a flat plate press, 10 seconds to 10 minutes are preferable. If the press pressure holding time is less than 10 seconds, resin filling into the mold 50 becomes insufficient, resulting in a decrease in pattern accuracy and in-plane uniformity. On the other hand, if it exceeds 10 minutes, deterioration due to thermal decomposition of the resin occurs and the mechanical strength of the molded product may be lowered, which is not preferable. By setting the press pressure holding time to 10 seconds to 10 minutes, both good transferability and mechanical strength of the molded product can be achieved. However, in the case of roll-to-roll molding, the press pressure holding time may be 10 seconds or less.

  Further, in the case of mold forming using heating and pressurization, the press pressure release temperature T2 is preferably within the temperature range of (Tg-10 ° C) to (Tg + 30 ° C) and lower than the press temperature T1. More preferably, they are (Tg-10 degreeC)-(Tg + 20 degreeC). If it is less than Tg-10 ° C., the deformation of the resin at the time of pressing remains as a residual stress, and even if the pattern collapses at the time of mold release or can be released from the mold, the thermal stability of the molded product is lowered, which is not preferable. . On the other hand, if it exceeds Tg + 30 ° C., the fluidity of the resin is still high when the pressure is released, and this is not preferable because the pattern is deformed and the transfer accuracy is lowered. By setting the press pressure release temperature T2 to (Tg−10 ° C.) to (Tg + 30 ° C.), it is possible to achieve both good transferability and releasability.

  Further, in the case of mold shaping using heating and pressurization, the mold release temperature T3 is preferably within a temperature range of 20 ° C. to T2 ° C., more preferably within a temperature range of 20 ° C. to Tg ° C. . If the mold release temperature T3 exceeds T2, the fluidity of the resin at the time of mold release is high, or the surface is softened and has adhesiveness, and the pattern is deformed at the time of mold release and the accuracy is lowered. This is not preferable. By setting the mold release temperature to 20 ° C. to T2 ° C., the mold can be released with good pattern accuracy.

  FIG.5 (b) shows the example in the case of metal mold shaping using electromagnetic wave irradiation. The sheet material 40, which is only the resin layer 1 made of a photocurable resin, or a laminate of the resin layer 1 and a support, and the mold 50 having irregularities that are reversed from the pattern to be transferred, The surface on the resin layer 1 side and the mold 50 are brought close to each other (FIG. 5 (b-1)), pressed as it is at a predetermined pressure, and then irradiated with electromagnetic waves from either the mold 50 side or the sheet 40 side. Is cured (FIG. 5B-2). Next, the press pressure is released to release the sheet material 40 from the mold 50 (FIG. 5 (a-3)).

  In the case of shaping by mold transfer using electromagnetic wave irradiation, the press pressure depends on the viscosity of the material to be shaped at the shaping temperature, but is preferably 0.05 to 10 MPa, more preferably 0.1. ~ 5 MPa. If the pressing pressure is less than 0.05 MPa, the filling of the resin into the mold 50 is insufficient and the pattern accuracy is lowered, which is not preferable. On the other hand, if the pressure exceeds 10 MPa, the load is excessively large, so that the load on the mold 50 is large and the unevenness of the mold 50 is deformed. By setting the press pressure to 0.05 to 10 MPa, good transferability can be obtained.

In the case of shaping by mold transfer using electromagnetic wave irradiation, the amount of electromagnetic wave irradiation is 10 to 5000 mJ / cm ² , although it depends on the light absorption rate at the wavelength at which integrated energy irradiation is performed. If the amount of electromagnetic wave irradiation is less than 10 mJ / cm ² , the resin will be insufficiently cured and the pattern accuracy will be reduced, or the strength will be insufficient and the mold will break due to mold release stress. It is not preferable. On the other hand, if it exceeds 5000 mJ / cm ² , the resin is excessively cured and may shrink and curl may occur, which is not preferable. By setting the irradiation amount of electromagnetic waves to 10 to 5000 mJ / cm ² , both good transferability and mechanical strength of the molded product can be achieved.

In the case of shaping by mold transfer using electromagnetic wave irradiation, the temperature during the series of steps is not particularly limited, but the press temperature is from room temperature to 200 ° C., more preferably from room temperature to 150 ° C., most preferably from room temperature to 120 ° C. When the press temperature is higher than 200 ° C., the fluidity of the resin becomes so high that it flows before pressing, or the resin hardens before pressing, and the molding becomes insufficient. Moreover, the mold release temperature T3 is good below the glass transition temperature Tg of the resin layer 1 which consists of photocurable resin, More preferably, it is Tg-10 degreeC, Most preferably, it is Tg-20 degreeC. If T3 exceeds Tg, the flowability of the resin at the time of mold release is high, the surface is softened and has adhesiveness, and the pattern is likely to be deformed at the time of mold release, resulting in a decrease in accuracy. This is not preferable. By making temperature T3 at the time of mold release below the glass transition temperature Tg of the resin layer 1 which consists of photocurable resin, it can mold release with a sufficient pattern precision.
In the case of shaping by mold transfer using electromagnetic wave irradiation, the degree of curing of the resin can be further improved by performing heat treatment on the resin layer 1 formed with the mold and forming the linear resin pattern 2. it can. As the method, at least one of the mold 50 or the resin layer 1 is heated when the mold 50 is pressed, the mold 50 or the resin layer is cured before being released by electromagnetic wave irradiation to cure the resin. Any one of a method of heating at least one of 1 and a method of heat-treating the patterned resin layer 1 after releasing the mold can be suitably used. Among them, the method of heating at least one of the mold 50 or the resin layer 1 at the time of mold pressing is preferably performed because the number of steps can be reduced. Further, in order to further increase the degree of curing, these may be combined.
In the reflective polarizing plate manufacturing method of the present invention, the pattern forming method includes the above-mentioned method. In addition to the method of pressing a lithographic plate as shown in FIG. A roll-to-roll continuous molding may be used in which a roll-shaped mold is used to form a roll-shaped sheet to obtain a roll-shaped molded body. Roll-to-roll continuous forming is superior to the lithographic press method in terms of productivity.

<Step (a-2): Metal layer forming step, Step (b-3): Linear metal layer forming step>
When the resin layer 1 is flat, the linear metal layer 2 is formed on the entire surface of the resin layer formed by the step (a-1). When the linear resin pattern 10 is provided on the surface of the resin layer 1, a plurality of the linear resin patterns 10 are formed at intervals on the linear resin pattern 10 formed on at least one surface of the resin layer 1 by the step (b-2). A linear metal layer can be formed to form the reflective polarizing plate of the present invention.

  In the method for producing a reflective polarizing plate of the present invention, as a method for forming the linear metal layer 2, a dry method such as a vapor deposition method or a sputtering method, a wet method such as a coating method or a plating method is preferably used.

  When the linear resin pattern 10 is provided on the surface of the resin layer 1, for a dry method such as a vapor deposition method and a sputtering method, an arrangement angle of a metal source (hereinafter referred to as a vapor deposition angle) with respect to the normal direction of the resin layer 1 surface. ) Can be formed only in the vicinity of the convex portion 11 of the linear resin pattern 10, which is an effective means for forming the linear metal layer 2 in a position-selective manner. For example, as shown in FIG. 6, vapor deposition or sputtering is preferably performed from a direction oblique to the normal direction of the resin layer 1 and a direction perpendicular to the longitudinal direction of the linear resin pattern 10.

  Next, the coating method is to form a linear metal layer 2 by applying a coating containing metal particles or particles coated with metal onto the resin layer 1, and the coating thickness and the polarity of the solvent The linear metal layer 2 can be partially formed by controlling the coating conditions.

  Examples of the plating method include an electroplating method in which metal is electrically deposited (electrodeposited) on the solid surface using an external power source, and an electroless plating method in which the linear metal layer 2 is chemically reduced and deposited. It is done. As for the plating method, the plating is grown after the linear metal layer 2 is formed on the resin layer 1 by vapor deposition or the like, or the plating is grown after coating fine particles serving as a catalyst such as silver or palladium on the resin layer 1. For example. In the case where the surface of the resin layer 1 has the linear resin pattern 10, for example, after filling the recess 12 of the linear resin pattern 10 with metal particles serving as a catalyst, electroless plating is performed, so that only the recess 12 is lined. A metal layer 2 is formed.

  When the linear metal layer 2 is provided on the surface of the resin layer 1 having the linear resin pattern 10, the formation position of the linear metal layer 2 is easy to control, and the metallicity of the linear metal layer 2 to be formed is From the viewpoint of high, dry methods such as vapor deposition and sputtering are more preferably used.

  Examples of the method for forming the linear metal layer 2 by the dry method include resistance heating deposition, electron beam deposition, induction heating deposition, and vacuum deposition methods such as plasma and ion beam assist methods, reactive sputtering methods, ion Sputtering methods such as beam sputtering method ECR (electron cyclotron) sputtering method, physical vapor deposition method such as ion plating method (PVD method), chemical vapor deposition method using heat, light, plasma, etc. (CVD method) ), Etc. Among these, an electron beam vapor deposition method and a method in which various assist methods are combined with the electron beam method are preferable in that a dense film having high metallicity can be formed with high selectivity.

In the formation of the metal layer or the linear metal layer 2 by the vacuum deposition method, the degree of vacuum in the system is preferably 8.0 × 10 ⁻⁴ Pa or less, more preferably 1.0 × 10 ⁻⁴ Pa or less. More preferably, it is 5.0 * 10 < ^-5 > Pa or less. In the reflective polarizing plate manufacturing method of the present invention, by setting the degree of vacuum at the time of vapor deposition to 8.0 × 10 ⁻⁴ Pa or less, it becomes easy to selectively form a dense film. A reflective polarizing plate can be obtained.
In the formation of the metal layer or the linear metal layer 2 by the vacuum deposition method, the deposition rate is preferably 2 Å / sec or more, more preferably 5 Å / sec or more, and further preferably 10 Å / sec or more. In the manufacturing method of the reflective polarizing plate of the present invention, by setting the deposition rate to 2 Å / sec or more, it becomes easy to selectively form a dense film, and as a result, a reflective polarizing plate with high optical characteristics can be obtained. Can do.

  In the manufacturing method of the reflective polarizing plate of the present invention, the deposition angle θ may be any angle when the resin layer 1 is flat, but when the linear resin pattern 10 is provided on the surface of the resin layer 1. Depending on the uneven shape of the resin layer 1, preferably, as shown in FIG. 6, the metal deposition direction M1 is parallel to the normal line L3 of the surface of the resin layer 1 and the surface of the resin layer 1, and the linear resin pattern It is preferable to be included in a plane composed of a line L2 perpendicular to the longitudinal direction L1.

In the case of having the linear resin pattern 10 on the surface of the resin layer 1, the metal deposition direction M 1 is parallel to the normal line L 3 of the surface of the resin layer 1 and perpendicular to the longitudinal direction of the linear resin pattern 10. The vapor deposition angle θ (°) is preferably tan θ ≧ (p−w) / h when included in the plane composed of the straight line L2. More preferably, tan (θ-5 °) ≧ (p−w) / h, and further preferably, the deposition angle tan (θ−10 °) ≧ (p−w) / h or more. If the vapor deposition angle θ (°) is less than tan θ ≧ (p−w) / h, it is difficult to selectively form the linear metal layer 2 and the optical characteristics may be deteriorated. In the manufacturing method of the reflective polarizing plate of the present invention, by setting the deposition angle θ to tan θ ≧ (p−w) / h, it becomes possible to selectively deposit metal, and as a result, reflection with high optical characteristics. A mold polarizing plate can be obtained.
In the method for producing a reflective polarizing plate of the present invention, the distance between the resin layer 1 and the metal vapor deposition source should be far, preferably 15 cm or more, more preferably 20 cm or more. In the method for producing a reflective polarizing plate of the present invention, by setting the distance between the resin layer 1 and the metal vapor deposition source to 15 cm or more, the optical characteristics within the polarizing plate surface are likely to be uniform.

<Process (a-3): Resist pattern formation process>
When the resin layer 1 is flat, a resist pattern is formed on the metal layer formed in the step (a-2).

As a method, first, a thin film made of a material containing a compound that can be crosslinked or decomposed by electromagnetic wave irradiation is formed on a metal layer, and a method such as exposure using a photomask, electron beam drawing, or interference exposure is applied to the thin film. To be partially crosslinked or decomposed. Subsequently, it can form by selectively dissolving an exposed part or a non-exposed part using a solvent.
As another method, the resist pattern can also be formed by mold transfer using heating / pressurization or electromagnetic wave irradiation as mentioned in the step (b-2). Specifically, a thin film of a material having thermoplasticity or a material that can be cross-linked by heating or electromagnetic wave irradiation is formed on the metal layer, and gold is formed on the formed thin film by the same method as in step (b-2). It can be formed by transferring the mold shape.

  Here, when the resist pattern is formed by mold transfer, since the resin generally remains on the bottom surface of the formed concave and convex portion, the metal layer is unnecessary in the subsequent (a-4) selective removal step. It is difficult to remove the part. For this reason, it is also preferable to remove the resin remaining in the recesses using a known method such as dry etching or wet etching to partially expose the metal layer.

  The resist pattern thus formed can be used in the subsequent (a-4) selective removal step. It is also preferable to form another metal pattern on the metal layer by performing lift-off based on the resist pattern. In this case, compared with the case where the resist pattern is used as it is, (a-4) the removal selectivity in the selective removal step can be improved, and as a result, a reflective polarizing plate with high optical characteristics can be formed. Is called.

<Step (a-4): Selective removal step>
When the resin layer 1 is flat, the metal layer is partially formed based on the resist pattern formed on the metal layer in the step (a-3) (or the metal pattern formed by lifting off based on the resist pattern). By removing, the target reflective polarizing plate can be formed.

  As the method, a dry etching method, a wet etching method, a sand blasting method, or the like can be used. Among these, the dry etching method is preferable in that the metal layer can be removed with high selectivity. The gas used for dry etching is appropriately selected according to the material of the metal layer and the resist pattern (or a metal pattern formed by lifting off based on the resist pattern).

  The reflective polarizing plate of the present invention is formed by the above-described process, but the surface of the formed pattern and the pattern are formed in order to increase the mechanical strength of the formed pattern and to impart friction resistance to the surface. A protective film made of a transparent resin, a metal oxide film, or the like may be formed over the entire surface, or the concave portions between the formed patterns may be filled with the transparent resin. The transparent resin is not particularly limited, and a thermoplastic resin, a thermosetting resin, a photocurable resin, or the like can be suitably used. Further, the metal oxide is not particularly limited as long as it is transparent. In addition, another film such as a protective film is preferably bonded to the surface of the reflective polarizing plate of the present invention.

Moreover, arbitrary layers, such as an antistatic layer, an antireflection layer, and a hard-coat layer, can be formed on the non-formation surface side of the pattern of the reflective polarizing plate of the present invention. Moreover, it can also be set as the function integrated high performance sheet | seat which has many functions by bonding with the film etc. which have another function.
The reflective polarizing plate of the present invention has a polarization separation function of transmitting a polarization component in a certain uniaxial direction and reflecting a polarization component in a direction perpendicular to the polarization component. However, as an example of the application, particularly when incorporated in a liquid crystal display device, the effect of improving the luminance is exhibited. This mechanism will be described.

  The configuration of the liquid crystal display device is roughly divided into a surface light source 700 and a liquid crystal cell 800.

  FIG. 7 shows an example of a liquid crystal display device using a sidelight type surface light source as the light source 700. In FIG. 7, a diffusion sheet 500 is disposed on the upper surface side of the light guide plate 300, and a prism sheet 600 is disposed thereon. A reflection sheet 400 is disposed on the lower surface side of the light guide plate 300, and a fluorescent tube 200 is disposed on the side surface of the light guide plate 300. Light emitted from the fluorescent tube 200 enters the light guide plate 300 from the side surface of the light guide plate 300, and exits upward from the upper surface of the light guide plate 300 through the diffusion sheet 500 and the prism sheet 600. In addition, it is not restricted to the said structural example, You may use what gave various processes, such as a dot and a prism shape, to the front and back of the light-guide plate 300, or may install two or more fluorescent tubes 200, Instead of the fluorescent tube 200, a light emitting diode (LED) may be used. Furthermore, regarding the light diffusion sheet 500 and the prism sheet 600, various members and configurations are preferably used, such as when only one of them is used or when a plurality of sheets are used.

FIG. 8 shows an example of a liquid crystal display device using a direct type surface light source as the light source 700. In FIG. 8, a plurality of linear fluorescent tubes 200 are arranged inside a housing 410 in which a reflection sheet 400 is spread, a diffusion plate 310 is disposed above the fluorescent tube 200, and a light diffusion sheet 500 and a prism sheet are disposed above the diffusion plate 310. 600 is arranged in order. Also in the case of a direct type surface light source, various members and structures can be adopted as various components. For example, the shape of the fluorescent tube is not limited to a linear shape, and a light emitting diode (LED) may be used instead of the fluorescent tube 200. As for the diffusion plate, the light diffusion sheet, and the prism sheet, various members and configurations can be used as described above.
As the surface light source 700, not only the above surface light source but also any surface light source can be used.

And the reflective polarizing plate 100 of this invention and the liquid crystal cell 800 are laminated | stacked in order on the upper side of the light source 700 of the above surface light sources.
The liquid crystal cell 800 includes two polarizing plates 810 and 830, a liquid crystal layer 820 provided between the two polarizing plates 810 and 830, and the like. The polarizing plates 810 and 830 used in the liquid crystal cell 800 are polarizing plates that are generally referred to as absorption types, and a polarizing component in a direction orthogonal to the transmission axis is absorbed. Therefore, the theoretical light utilization efficiency is 50%.

  However, by disposing the reflective polarizing plate 100 of the present invention closer to the light source than the liquid crystal cell, polarized light that cannot be transmitted can be reflected to the surface light source unit 700 side. The reflected polarized light can be returned to the liquid crystal cell 800 side again after the polarization state is canceled in the surface light source unit 700. Therefore, the luminance can be improved by increasing the light use efficiency. That is, the reflective polarizing plate 100 is installed between the liquid crystal cell 800 and the surface light source 700 so that the direction of the polarization axis coincides with the lower polarizing plate 810 disposed on the surface light source 700 side of the liquid crystal cell 800. Thus, the polarization component that has been absorbed by the lower polarizing plate 810 conventionally can be reflected back to the surface light source 700 side, and the light can be reused. By repeating this cycle, it becomes possible to increase the light use efficiency and improve the luminance as compared with the conventional surface light source that can use only 50% of the total light rays. Here, the angle of intersection between the direction of the polarization axis of the reflective polarizing plate 100 of the present invention and the direction of the polarization axis of the lower polarizing plate 810 is preferably 5 ° or less, because a sufficient effect can be obtained. 0 ° in which the directions match is more preferable because the brightness improvement effect is most manifested.

  Moreover, when installing the reflective polarizing plate of this invention in a liquid crystal display device, it is preferable to install the linear metal layer 2 formation surface toward the liquid crystal cell 800 side. By installing in this way, even when a resin having birefringence is used for the resin layer 1, a high-brightness liquid crystal display device can be obtained without impairing polarization characteristics, which is preferable. However, when an isotropic resin is used as the resin layer 1, not limited to the above, either surface may be disposed on the liquid crystal cell 800 side.

Further, when the polarization degree p of the reflective polarizing plate of the present invention is 90% or more, more preferably 95% or more, and still more preferably 99% or more, as shown in FIGS. 9 and 10, It is also preferable to use the liquid crystal cell 800 as a substitute for the lower polarizing plate 810. In this case, compared with the case where a conventional absorption polarizing plate is used, not only can the liquid crystal display device have a high brightness, but also a thinner than the conventional absorption polarizing plate, because light can be reused. This is also preferable from the viewpoint of thinning.
Also when the reflective polarizing plate of the present invention is used as an alternative to the lower polarizing plate 810 of the liquid crystal cell 800, it is preferable that the surface on which the linear metal layer 2 is formed faces the liquid crystal cell 800 side. By installing in this way, even when a resin having birefringence is used for the resin layer 1, the polarization characteristics are not impaired, which is preferable. However, when an isotropic resin is used as the resin layer 1, not limited to the above, either surface may be disposed on the liquid crystal cell 800 side.
As described above, by incorporating the reflective polarizing plate of the present invention in a liquid crystal display device, the light utilization efficiency is improved, and a liquid crystal display device with higher luminance than that of a conventional liquid crystal display device can be obtained.
The liquid crystal display device of the present invention can be suitably used for mobile phones, electronic notebooks, notebook PCs, monitors, TVs, various display media, and the like.

[Characteristic evaluation method]
A. Component content W of polystyrene conversion molecular weight 5,000 or less, polystyrene conversion weight average molecular weight Mw, polystyrene conversion number average molecular weight Mn, polystyrene conversion Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / Mw
The surface of the resin layer 1 was scraped with a cutter, and its weight W1 was measured. Next, the scraped surface layer was dissolved in chloroform, filtered through a membrane filter having a pore size of 0.45 μm, separated into insoluble matter and solution, and the weight W2 of the insoluble matter obtained by vacuum drying overnight was measured. . The solution was prepared by concentrating the solvent with an evaporator and adding chloroform to the resulting residue so that the solution concentration was 0.2% by weight. In addition, a mixed sample of monodisperse standard polystyrene was dissolved in chloroform so as to have a concentration of 0.2% by weight.

  The detector is a differential refractive index detector RI (RI-71 type, sensitivity 64) manufactured by Showa Denko KK, the column is TSKgel GMHHR-M (φ7.8 mm × 30 cm, theoretical plate number) manufactured by Tosoh Corporation. By measuring with a gel permeation chromatograph GPC (8) manufactured by Tosoh Corporation with two 14,000 plates), the relative molecular weight (equivalent to polystyrene) of the resin on the surface layer of the resin base material Molecular weight) and its weight fraction (dW / dlogM), a molecular weight distribution curve was prepared, polystyrene-converted weight average molecular weight Mw, polystyrene-converted number average molecular weight Mn, polystyrene-converted Z-average molecular weight Mz were determined, and polydispersity Mw / Mn and polydispersity Mz / Mw were calculated. Note that chloroform was used for the moving bed, the flow rate was 1.0 mL / min, the column temperature was 23 ° C. ± 2 ° C., and the injection amount was 0.200 mL.

Further, from the molecular weight curve obtained by GPC, the peak area It of the entire molecular weight distribution and the peak area Im of 5,000 or less in terms of polystyrene are obtained, and the polystyrene equivalent molecular weight contained in the residue by the following formula (2). A ratio R of 5,000 or less was determined.
R (%) = Im / It × 100 (2).

Next, using the obtained W1, W2, and R, the content W of the component having a polystyrene-equivalent molecular weight of 5,000 or less contained in the resin layer 1 was determined by the following formula (1).
-Content W (weight%) = (W1-W2) x R / W1 (1).

B. Glass transition temperature Tg
The surface of the resin layer 1 was scraped off with a cutter, and measured according to JIS K7121 (1999) using a differential scanning calorimeter “Robot DSC-RDC220” manufactured by Seiko Denshi Kogyo Co., Ltd. A disk session “SSC / 5200” was used for data analysis. 5 mg of a chip or a sheet was weighed in a sample pan, and scanned at a rate of temperature increase of 10 ° C./min. As for the glass transition temperature Tg, in the step-like change portion accompanying the glass transition in the differential scanning calorimetry (1stRUN) chart, the extended straight line of each base line and the tangent line of the step-like change portion accompanying the glass transition intersect. Obtained from the point. When the resin substrate was a laminate, the glass transition temperature Tg of the resin substrate on the side where the linear metal layer 2 was provided was determined.

C. Thermal decomposition start temperature Td
The surface of the resin layer 1 was scraped off with a cutter, and measured according to JIS K7120 (1987) using a thermogravimetric measuring device TGA-50 manufactured by Shimadzu Corporation. A thermal analysis system TA-50 was used for data analysis. 10 mg of a chip or a sheet was weighed into a sample pan, and scanned at a nitrogen gas flow rate of 50 ml / min and a heating rate of 10 ° C./min. From the obtained weight loss curve, the thermal decomposition onset temperature Td was determined at the point where the straight line extending the base line and the tangent line of the weight reduced portion due to thermal decomposition intersect.

D. Cross-sectional observation About the reflective polarizing plate produced in each of the examples and comparative examples, a cross section perpendicular to the longitudinal direction of the linear metal layer 2 was cut out, and platinum-palladium was deposited, and then field emission scanning type manufactured by JEOL Ltd. A photograph was taken with an electron microscope “JSM-6700F”, and a cross-section was observed at 50000 times. From the obtained cross-sectional observation image, the dimensions (pitch p (nm), width w (nm), height h (nm)) of the convex portions 11 constituting the linear resin pattern 10 and the film thickness of the linear metal layer 2 are obtained. (Nm) and the total width TW (nm) of the linear metal layer 2 and the convex part 11 were measured. When the resin layer 1 is flat, at any five locations, when the linear resin pattern 10 is formed on the surface of the resin layer 1, the convex portion of the portions where the linear metal layer 2 is formed. The thickness when measured in the normal direction of the resin layer 1 was determined at five arbitrary locations on the part 11, and the average value thereof was determined. Moreover, about the pitch and width | variety of the linear metal layer 2, it measured in five arbitrary places in the direction parallel to the surface of the resin layer 1, and calculated | required the average value. In addition, the total width TW of the linear metal layer 2 and the convex part 11 in case the linear resin pattern 10 is formed on the surface of the resin layer 1 calculated | required the average value in five arbitrary places.

E. Transmittance, degree of polarization About the reflective polarizing plate produced in each example / comparative example, using a cell gap inspection device RETS-1100 (manufactured by Otsuka Electronics Co., Ltd.), in a polarizing plate characteristic evaluation mode, with a measurement diameter of 2 mm. The transmittance and the degree of polarization in the wavelength range of 400 to 800 nm were measured. Note that the measurement was performed such that the linear metal layer 2 was opposed to the light source side of the measuring apparatus, and the light incident angle was 0 °.
About the obtained optical characteristic, it determined as follows.

1) Transmittance Using transmittance at a wavelength of 550 nm, the determination was made as follows.
・ If 35% or more: A,
・ If it is 32% or more and less than 35%: B
・ In the case of 30% or more and less than 32%: C
・ If less than 30%: D
A or B is good, and A is the best.

Further, the wavelength dependency of the transmittance was determined as follows by comparing the transmittance at 450 nm, 550 nm, and 650 nm and using the difference between the maximum value and the minimum value of the transmittance.
・ If less than 20%: A
・ If 20% or more and less than 30%: B
・ If 30% or more: C
A or B is good, and A is the best.

2) Degree of polarization Using the degree of polarization at a wavelength of 550 nm, the determination was made as follows.
・ If 99% or more: A
・ 95% or more and less than 99%: B
・ 90% or more and less than 95%: C
・ If less than 90%: D
A or B is good, and A is the best.

The wavelength dependence of the degree of polarization was determined as follows by comparing the degree of polarization at 450 nm, 550 nm, and 650 nm and using the difference between the maximum value and the minimum value of the degree of polarization.
・ If less than 10%: A
・ In the case of 10% or more and less than 15%: B
・ If 15% or more: C
A or B is good, and A is the best.

F. Total light absolute reflectance For the reflective polarizing plates produced in each of the examples and comparative examples, a spectrophotometer UV-3150 type (manufactured by Shimadzu Corporation) equipped with a large polarizer ASSY was used, and the wavelength was 400 to 800 nm. In the range, the reflectance (maximum reflectance) of the polarization component having the maximum reflectance and the reflectance (minimum reflectance) Hs of the polarization component perpendicular to the reflectance were measured at a light incident angle of 5 °. By applying the obtained absolute reflectances Hp and Hs to the following formula, the total light absolute reflectance was obtained.
Total light absolute reflectance (%) = (Hp + Hs) / 2
In addition, the measurement was implemented about the case where it installed so that the linear metal layer 2 might oppose the light source side of a measuring apparatus, and when it installed so that the resin layer 1 might oppose.

About the obtained optical characteristic, it determined as follows using the total light absolute reflectance in wavelength 550nm.
・ If 40% or more: A
・ If it is 35% or more and less than 40%: B
・ In the case of 30% or more and less than 35%: C
・ If less than 30%: D
A or B is good, and A is the best.

Further, the wavelength dependence of the absolute reflectance was determined as follows by comparing the absolute reflectance at 450 nm, 550 nm, and 650 nm and using the difference between the maximum value and the minimum value of the transmittance.
・ If less than 15%: A
・ In case of 15% or more and less than 25%: B
・ When 25% or more: C
A or B is good, and A is the best.

G. Luminance G-1. Luminance (1)
Light diffusion sheet “GM3” (manufactured by Kimoto Co., Ltd.) on the upper side of the light guide plate of 1.5-inch size LED sidelight type backlight (2 LED type, “ESR” (supplied by Sumitomo 3M Co., Ltd.) as a reflector) ) And prism sheet BEFIII (manufactured by Sumitomo 3M Co., Ltd.), a sidelight type surface light source was assembled, a voltage of 6 V was applied to turn on the LED, and the surface light source was started up in a dark room. Next, the reflective polarizing plates of the respective examples and comparative examples are stacked on the prism sheet, and further the absorbing polarizing plate (LN-1825T, manufactured by Polatechno Co., Ltd.) is aligned thereon so that the directions of the transmission axes coincide. The center luminance L11 was measured at a viewing angle of 0.1 ° using a color luminance meter BM-7 / FAST (manufactured by Topcon Corporation). Subsequently, only the reflective polarizing plate of each Example and Comparative Example was removed, and the center luminance L10 was measured in the same manner. In addition, the measurement was installed so that the linear metal layer 2 of the reflective polarizing plate of each Example and Comparative Example was opposed to the absorbing polarizing plate. The luminance improvement rate B1 obtained by the following formula was calculated from the luminance L10 when the reflective polarizing plate of each example and comparative example was not inserted, and the luminance L11 when inserted.
Brightness improvement rate B1 (%) = 100 × (L11−L10) / L10.

The luminance improvement rate B1 was determined as follows.
・ If 15% or more: A
・ In the case of 10% or more and less than 15%: B
・ In the case of 5% or more and less than 10%: C
・ If less than 5%: D
A or B is good, and A is the best.

G-2. Luminance (2)
Light diffusion sheet “GM3” (manufactured by Kimoto Co., Ltd.) on the upper side of the light guide plate of 1.5-inch size LED sidelight type backlight (2 LED type, “ESR” (supplied by Sumitomo 3M Co., Ltd.) as a reflector) ) And a prism sheet BEFIII (manufactured by Sumitomo 3M Co., Ltd.) to assemble a sidelight type surface light source, and on the lower side, the reflective polarizing plate of the present invention (linear metal layer on the liquid crystal cell side) The liquid crystal cell provided with an iodine type polarizing plate on the upper side was stacked, and the LED and the liquid crystal cell were started up in a dark room. The entire surface of the liquid crystal screen was displayed in white, and the central luminance L21 after 10 minutes of lighting was measured with a color luminance meter BM-7 / FAST (manufactured by Topcon Corporation) at a viewing angle of 0.1 °. Next, using the same surface light source, liquid crystal cells provided with iodine-type polarizing plates on both lower sides were overlapped, and similarly, the central luminance L20 during white display on the entire screen was measured. The luminance improvement rate B2 obtained by the following formula was calculated from the luminance L20 using an iodine-type polarizing plate as the lower polarizing plate and the luminance L21 when using the reflective polarizing plate of the present invention.
Brightness improvement rate B2 (%) = 100 × (L21−L20) / L20.

The luminance improvement rate B2 was determined as follows.
・ If 20% or more: A
・ If 15% or more and less than 20%: B
・ In the case of 10% or more and less than 15%: C
・ If less than 10%: D
A or B is good, and A is the best.

H. Heat resistance Each of the reflective polarizing plates prepared in each Example and Comparative Example was heat-treated for 10 minutes in an ESPEC high performance clean oven PVHC-331 heated to 115 ° C. About the reflective polarizing plate after a test, the transmittance | permeability, the polarization degree, the total light absolute reflectance, and the brightness | luminance were measured based on the above-mentioned E term, F term, and G term.

〔Example〕
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not necessarily limited to these.

  The method of removing (sorting) components having a polystyrene-equivalent molecular weight of 5,000 or less by GPC was as follows: Shodex K2003 (φ20 mm × 300 mm) 1 as an RI detector (RID-10A) column manufactured by Shimadzu Corporation. This was carried out using a preparative chromatograph (LC-6A) manufactured by Shimadzu Corporation equipped with two Shodex K2002 (φ20 mm × 300 mm). Chloroform was used for the moving bed, the flow rate was 3.0 mL / min, the column temperature was 45 ° C., and the injection amount of resin at one time: 60 mg.

(Solution adjustment)
The resin composition and the standard dispersion monodisperse polystyrene were dissolved in chloroform so that the resin composition concentration in the solution was 5% by weight, and the solution was filtered through a membrane filter having a pore diameter of 0.45 μm.
Using the obtained solution, first, a monodispersed polystyrene standard sample was measured, and the elution time of each molecular weight component was determined. At this time, the elution time is the elution time with the maximum value at the peak corresponding to each molecular weight component. Using the obtained elution time and molecular weight, a plot was made with the elution time on the horizontal axis and the molecular weight on the vertical axis to create a calibration curve. Subsequently, the resin composition solution is measured, and the obtained result is overlapped with a constituent curve to obtain a differential distribution value d (weight W) / dLog (polystyrene equivalent weight average molecular weight Mw) of the resin composition. The time for elution of a component with a polystyrene equivalent molecular weight of 5,000 or more of the resin composition was determined, and based on that time, the component was fractionated into a component with a polystyrene equivalent molecular weight of 5,000 or more and a component with a polystyrene equivalent molecular weight of 5,000 or more. .
Among the fractionated components, components having a molecular weight of 5,000 or more in terms of polystyrene are concentrated by an evaporator and then vacuum-dried to volatilize the residual solvent, thereby removing components having a molecular weight of 5,000 or less in terms of polystyrene (sorting). A prepared resin was produced.

Example 1
Dissolved in toluene at 60 ° C. so that 10% by weight of polyester copolymerized with cyclohexanedicarboxylic acid as dicarboxylic acid component, 80 mol% of 9,9′-bis (4-hydroxyethoxyphenyl) fluorene and 20 mol% of ethylene glycol as diol component Isopropyl alcohol was added to the resulting solution with stirring by 90 parts by weight. After the addition, the stirring was stopped, and the resin composition that had been precipitated was allowed to stand for a while to precipitate, the supernatant of the resulting solution was removed by decantation, and the remaining solid was washed with isopropyl alcohol, then 80 The solid was obtained by vacuum drying at 4 ° C. for 4 hours.
The obtained solid was vacuum dried at 80 ° C. for 4 hours, then melted at 280 ° C. in an extruder, extruded from a die onto a 20 ° C. cast drum, and cooled to obtain a sheet having a thickness of 150 μm. .

  The surface of the obtained sheet is scraped off with a cutter, and its glass transition temperature Tg, thermal decomposition start temperature Td, polystyrene-converted weight average molecular weight Mw, polystyrene-converted number average molecular weight Mn, polystyrene-converted Z average molecular weight Mz, polydispersity Mw / Mn The component content W of polydispersity Mz / Mw and Mw = 5,000 or less was determined.

The results are shown in Table 1. Next, on this sheet surface, aluminum having a purity of 99.999% was used as an evaporation source, under a condition of a degree of vacuum of 3.4 × 10 ⁻⁵ Pa, a deposition rate of 10 Å / sec, and a distance between the deposition source and the substrate of 25 cm. Then, aluminum was electron beam evaporated from the normal direction of the substrate surface to form a metal layer having a thickness of 100 nm.

"Adekaoptomer" (registered trademark) KRM-2199 (Asahi Denka Kogyo Co., Ltd.) 10 parts by weight, Aron Oxetane OXT-221 (Toa Gosei Co., Ltd.) 1 part by weight, "Adekaoptomer" (Registered trademark) SP170 (manufactured by Asahi Denka Kogyo Co., Ltd.) A coating liquid consisting of 0.25 parts by weight is applied to the surface provided with the surface shape of the following mold 1 with a spin coater (10 at 1st-500 rpm). Second, 30 seconds at 2nd-2,000 rpm), the above-mentioned base material was overlaid on the upper surface of the coating film so that the metal layer was on the coating film side, and pressure was applied from the film side with a roller to cause adhesion. Next, a total of 1,000 mJ / cm ² of ultraviolet rays was irradiated from the film surface side while maintaining this state, and then the mold was released.
"Mold 1"
Material: Nickel Pitch: 150 nm, Convex width: 90 nm, Convex height: 130 nm
Recess cross-sectional shape: rectangular shape.

When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section obtained by substantially inverting the mold shape was obtained on the aluminum layer (see Table 1).
"Resin pattern shape on aluminum layer"
Pitch p: 150 nm, width w: 60 nm, height h: 129 nm, recess bottom thickness: 100 nm.

Next, the remaining film at the bottom of the recess is removed by a dry etching method using oxygen (O ₂ ) gas to form a resin pattern on the aluminum layer, and then the exposed aluminum layer between the resin patterns is carbon tetrachloride ( A linear metal layer was formed by selective removal by a dry etching method using CCl ₄ ) gas. Finally, the remaining resin layer was removed by a dry etching method using oxygen (O ₂ ) gas to obtain a sample.

  When the form of the obtained sample is observed, the form of the substrate surface and the linear metal layer is as shown in FIG. 3 (d), the pitch between the linear metal layers is 150 nm, and the total width TW of the protrusions. Was 70 nm. The film thickness of the linear metal layer was 100 nm.

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. It was found that by separating the resin composition used for the resin layer by the reprecipitation method, sufficient characteristics as a reflective polarizing plate were obtained and a high brightness enhancement effect was exhibited. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

(Example 2)
A sheet having a thickness of 400 μm was produced in the same manner as in Example 1. This base material and the following mold 1 are overlapped and installed in a vacuum chamber, and after reaching a degree of vacuum of 50 Pa or less, preheating is performed at 165 ° C. for 1 minute, and pressing is performed at a pressing temperature of 165 ° C. and a pressing pressure of 15 MPa for 5 minutes. Then, after cooling to 135 ° C., the pressure was released, and after cooling to 30 ° C., the substrate and the mold were released.
"Mold 1"
Material: Nickel Pitch: 150 nm, Convex width: 90 nm, Convex height: 130 nm
Recess cross-sectional shape: rectangular shape.

When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section almost inverted from the mold shape was obtained as follows (see Table 2).
"Linear resin pattern on substrate surface"
Pitch p: 150 nm, width w: 58 nm, height h: 129 nm.

Next, on the linear resin pattern side of this base material, aluminum having a purity of 99.999% was used as the evaporation source, the degree of vacuum was 3.4 × 10 ⁻⁵ Pa, the deposition rate was 10 Å / sec, and the distance between the deposition source and the substrate. Under the condition of a distance of 25 cm, aluminum is deposited by electron beam evaporation at a film thickness of 50 nm from an oblique direction perpendicular to the longitudinal direction of the linear resin pattern and inclined by 45 ° from the normal direction of the substrate surface, and the linear metal layer is formed. Formed.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 70 nm. The film thickness of the linear metal layer was 45 nm at the top of the convex portion (see Table 2).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. As in Example 1, the resin separated by reprecipitation is made into a sheet, and a linear resin pattern is provided on the surface of the sheet, and a metal layer is formed on the convex portion of the pattern. As a result, it was found that a high luminance improvement effect was exhibited. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

(Example 3)
Dissolved in toluene at 60 ° C. so that 10% by weight of polyester copolymerized with cyclohexanedicarboxylic acid as dicarboxylic acid component, 80 mol% of 9,9′-bis (4-hydroxyethoxyphenyl) fluorene and 20 mol% of ethylene glycol as diol component A sheet having a film thickness of 400 μm was prepared in the same manner as in Example 1 except that 80 parts by weight of isopropyl alcohol was stirred into the solution obtained, and the glass transition temperature Tg of the sheet surface, the thermal decomposition start temperature Td, Polystyrene-converted weight average molecular weight Mw, polystyrene-converted number average molecular weight Mn, polystyrene-converted Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / Mw, and component content W of Mw = 5,000 or less were determined.

Next, in the same manner as in Example 2, a mold was pressed against the surface of the obtained sheet to form a linear resin pattern.
When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section almost inverted from the mold shape was formed as follows (see Table 2).
"Linear resin pattern on substrate surface"
Pitch p: 150 nm, width w: 58 nm, height h: 128 nm.

Next, a linear metal layer was formed in the same manner as in Example 2.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 70 nm. The film thickness of the linear metal layer was 46 nm at the top of the convex portion (see Table 2).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. Similar to Example 1, even when the addition amount of the poor solvent was changed when fractionating the resin composition by reprecipitation, sufficient characteristics were obtained as a reflective polarizing plate, and a high luminance enhancement effect was obtained. It was found to express. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

( Reference Example 1 )
Polyester obtained by copolymerizing 80 mol% of cyclohexanedicarboxylic acid as a dicarboxylic acid component, 80 mol% of 9,9'-bis (4-hydroxyethoxyphenyl) fluorene and 20 mol% of ethylene glycol as a diol component, and using polystyrene GPC for molecular weight 5, 000 or less components were removed to obtain a solid. Glass transition temperature Tg, thermal decomposition start temperature Td, polystyrene equivalent weight average molecular weight Mw, polystyrene equivalent number average molecular weight Mn, polystyrene equivalent Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / The component content W of Mw and Mw = 5,000 or less was determined.

  The solid matter was dissolved in a solution of cyclohexanone / methyl ethyl ketone / toluene = 1.5 / 1.5 / 1 at 35 ° C. to a concentration of 20% by weight. The resulting solution was coated on a 100 μm thick polyester film “Lumirror” (registered trademark) U46 (manufactured by Toray Industries, Inc.) using (# 30) and dried at 140 ° C. for 30 minutes to obtain a dry film. A laminate having a surface layer with a thickness of 5 μm was produced.

A linear resin pattern was formed in the same manner as in Example 2 except that a mold was pressed against the surface layer side of the obtained laminate.
When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section almost inverted from the mold shape was obtained as follows (see Table 2).
"Linear resin pattern on substrate surface"
Pitch p: 150 nm, width w: 58 nm, height h: 128 nm.

Next, a linear metal layer was formed in the same manner as in Example 2.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 70 nm. The film thickness of the linear metal layer was 45 nm at the top of the convex portion (see Table 2).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. Even when the resin composition used for the resin layer is separated by the GPC method and the obtained solid is dissolved in a solvent and applied to the support, the resin layer is formed as in Example 2. It was found that sufficient characteristics as a plate were obtained and a high brightness enhancement effect was exhibited. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

( Reference Example 2 )
Polyester obtained by copolymerizing 80 mol% of cyclohexanedicarboxylic acid as a dicarboxylic acid component, 80 mol% of 9,9'-bis (4-hydroxyethoxyphenyl) fluorene and 20 mol% of ethylene glycol as a diol component, and using polystyrene GPC for molecular weight 5, 000 or less components were removed to obtain a solid. Glass transition temperature Tg, thermal decomposition start temperature Td, polystyrene equivalent weight average molecular weight Mw, polystyrene equivalent number average molecular weight Mn, polystyrene equivalent Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / The component content W of Mw and Mw = 5,000 or less was determined.

  Next, the obtained solid was dissolved in 80 parts by weight of a cyclohexanone / methyl ethyl ketone / toluene = 1/1/1 solution, and the solution was placed on a glass substrate 1737 (made by Corning) having a thickness of 0.6 mm by a slit die coater. And dried at 140 ° C. for 30 minutes to produce a laminate having a surface layer with a dry film thickness of 8 μm.

A linear resin pattern was formed in the same manner as in Example 2 except that a mold was pressed against the surface layer side of the obtained laminate.
When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section almost inverted from the mold shape was obtained as follows (see Table 2).
"Linear resin pattern of substrate"
Pitch p: 150 nm, width w: 59 nm, height h: 128 nm.

Next, a linear metal layer was formed in the same manner as in Example 2.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 70 nm. The film thickness of the linear metal layer was 44 nm at the top of the convex portion (see Table 2).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. It was found that even when an inorganic material was used for the layer to be the support, sufficient characteristics as a reflective polarizing plate were obtained as in Example 2, and a high luminance enhancement effect was exhibited. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

( Reference Example 3 )
A linear resin pattern was formed in the same manner as in Example 4 except that the following mold 2 was used as the mold.
"Mold 2"
Material: Nickel pitch: 130 nm, convex width: 80 nm, convex height: 130 nm
Recess cross-sectional shape: rectangular shape.

When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section substantially inverted from the mold shape was obtained as follows (see Table 1).
"Linear resin pattern on substrate surface"
Pitch p: 130 nm, width w: 49 nm, height h: 127 nm.

Next, a linear metal layer was formed in the same manner as in Example 2.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 65 nm. The film thickness of the linear metal layer was 43 nm at the top of the convex portion (see Table 2).

In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. By reducing the pitch and width of the linear resin pattern, it is possible to obtain characteristics superior to those of Examples 2 and 3 and Reference Examples 1 and 2 as a reflective polarizing plate, and to exhibit a higher brightness enhancement effect. all right. In addition, it was found that even though the shape of the linear resin pattern became fine, the optical characteristics did not deteriorate after the heat test, and the heat resistance was good.

( Reference Example 4 )
A linear resin pattern was formed in the same manner as in Reference Example 1 except that the following mold 3 was used as the mold.
"Mold 3"
Material: Nickel pitch: 120 nm, convex width: 75 nm, convex height: 120 nm
Recess cross-sectional shape: rectangular shape.

When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section substantially inverted from the mold shape was obtained as follows (see Table 1).
"Linear resin pattern of substrate"
Pitch p: 120 nm, width w: 43 nm, height h: 116 nm.

Next, a linear metal layer was formed in the same manner as in Example 2 except that the deposited aluminum film thickness was 45 nm (see Table 2).
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 58 nm. The film thickness of the linear metal layer was 41 nm at the top of the convex portion (see Table 2).

Table 3 shows the transmittance, the degree of polarization, the absolute reflectance, and the wavelength dependency, luminance improvement rate, and heat resistance evaluation results of the obtained sample. By making the pitch and width of the linear resin pattern smaller, it is possible to obtain characteristics superior to those of Examples 2 and 3 and Reference Examples 1 and 2 as a reflective polarizing plate, and to exhibit a higher brightness enhancement effect. I understood. In addition, it was found that even though the shape of the linear resin pattern became finer, the optical characteristics did not deteriorate after the heat resistance test, and the heat resistance was good.

(Example 4 )
The same procedure as in Example 1 was used except that cyclohexanedicarboxylic acid was used as the dicarboxylic acid component, and 9,9′-bis (4-hydroxyethoxyphenyl) fluorene 50 mol% and ethylene glycol 50 mol% copolymerized polyester were used as the diol component. Reprecipitation gave a solid. Using this solid material, a sheet having a thickness of 400 μm was prepared in the same manner as in Example 1. The glass transition temperature Tg and thermal decomposition start temperature Td of the surface layer of the sheet, and the weight average weight of the obtained solid material in terms of polystyrene Molecular weight Mw, polystyrene conversion number average molecular weight Mn, polystyrene conversion Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / Mw, and component content W of Mw = 5000 or less were determined.
Using the obtained sheet base material, a linear resin pattern was formed in the same manner as in Example 2 except that the press temperature was 135 ° C. and the press release temperature was 105 ° C.

When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section almost inverted from the mold shape was obtained as follows (see Table 2).
"Linear resin pattern on substrate surface"
Pitch p: 150 nm, width w: 58 nm, height h: 128 nm.

Next, a linear metal layer was formed in the same manner as in Example 2.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 71 nm. The film thickness of the linear metal layer was 45 nm at the top of the convex portion (see Table 1).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. Even when the Tg of the resin composition used for the resin layer was different, it was found that by separating by the reprecipitation method, sufficient characteristics as a reflective polarizing plate were obtained and a high luminance enhancement effect was exhibited.

( Reference Example 5 )
Cyclohexanedicarboxylic acid as the dicarboxylic acid component, 9,9'-bis (4-hydroxyethoxyphenyl) fluorene as the diol component, 50% by mol of polyester copolymerized with 50% by mol of ethylene glycol, and polystyrene equivalent molecular weight of 5,5 using preparative GPC 000 or less components were removed to obtain a solid. Glass transition temperature Tg, thermal decomposition start temperature Td, polystyrene equivalent weight average molecular weight Mw, polystyrene equivalent number average molecular weight Mn, polystyrene equivalent Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / The component content W of Mw and Mw = 5,000 or less was determined.
Next, to prepare a laminate in the same manner as in Reference Example 1, 135 ° C. The press temperature, except that the press release temperature was at 105 ℃ the same manner as in Reference Example 1, the linear resin pattern Formed.

When the shape of the base material released from the mold was observed, it was confirmed that a linear resin pattern having a cross section almost inverted from the mold shape was obtained as follows (see Table 2).
"Linear resin pattern on substrate surface"
Pitch p: 150 nm, width w: 59 nm, height h: 129 nm.

Next, a linear metal layer was formed in the same manner as in Example 2.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 70 nm. The film thickness of the linear metal layer was 45 nm at the top of the convex portion (see Table 1).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. It was found that by separating the resin composition used for the resin layer by GPC, sufficient characteristics as a reflective polarizing plate were obtained and a high brightness enhancement effect was exhibited. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

( Reference Example 6 )
The following photocurable resin composition was applied to a film thickness of 5 μm on a biaxially stretched polyethylene terephthalate sheet “Lumirror” (registered trademark) U10 (manufactured by Toray Industries, Inc.) having a film thickness of 100 μm, and then the coating layer and Examples The same mold (mold 1) as in No. 1 was superposed and exposed to 600 mJ / cm ² with an ultra-high pressure mercury lamp from the substrate side, and the substrate and the mold were released.
"Photocurable resin composition"
Adeka optomer (registered trademark) KRM-2199 (Asahi Denka Kogyo Co., Ltd.) 10 parts by weight Aron Oxetane (registered trademark) OXT-221 (manufactured by Toagosei Co., Ltd.) 1 part by weight Adeka optomer (registered trademark) SP170 (Asahi Denka Kogyo Co., Ltd.) 0.25 parts by weight.

When the shape of the base material released from the mold was observed, a linear resin pattern having a cross section substantially inverted from the mold shape was obtained as follows (see Table 1).
"Linear resin pattern on substrate surface"
Pitch p: 150 nm, width w: 57 nm, height h: 127 nm.

  After maintaining in a vacuum atmosphere at 30 ° C. for 24 hours, the surface of the base material was scraped off, and a component content W of thermal decomposition starting temperature Td and Mw = 5,000 or less was determined.

Next, a linear metal layer was formed on the linear resin pattern of the substrate by the same method as in Example 1.
When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4E, and the total width TW of the convex part was 71 nm. The film thickness of the linear metal layer was 45 nm at the top of the convex portion (see Table 2).

  In addition, Table 3 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. Even if the resin composition used for the resin layer is a photo-curing resin, sufficient characteristics as a reflective polarizing plate can be obtained by holding it in a vacuum atmosphere and removing low molecular weight components, and a high brightness improvement effect can be obtained. It was found to express. It was also found that the optical characteristics did not deteriorate after the heat test, and that the heat resistance was good.

(Comparative Example 1)
A polyester having the same composition as in Example 1 was prepared in the same manner as in Example 1 except that it was used as it was without reprecipitation or sorting by GPC, and a glass transition on the surface of the sheet was produced. Temperature Tg, thermal decomposition start temperature Td, polystyrene equivalent weight average molecular weight Mw, polystyrene equivalent number average molecular weight Mn, polystyrene equivalent Z average molecular weight Mz, polydispersity Mw / Mn, polydispersity Mz / Mw, Mw = 5,000 or less The component content W of was determined.

Next, a sample was produced in the same manner as in Example 1.
When the form of the obtained sample is observed, the form of the linear metal layer is as shown in FIG. 3D, the pitch between the linear metal layers is 150 nm, and the total width TW of the convex part is 70 nm. It was. The film thickness of the linear metal layer was 100 nm at the top of the convex portion (see Table 1).

  In addition, Table 2 shows the evaluation results of the transmittance, polarization degree, absolute reflectance, wavelength dependency, luminance improvement rate, and heat resistance of the obtained sample. As is clear from comparison with Example 1, when the resin composition forming the resin layer contains a large amount of low molecular weight components having a polystyrene-equivalent molecular weight Mw = 5,000 or less, the optical properties as a reflective polarizing plate are obtained. Insufficient brightness improvement effect was not obtained.

(Comparative Example 2)
Samples were prepared in the same manner as in Reference Example 1 except that the polyester of Reference Example 1 was used as it was without reprecipitation or fractionation by GPC.

  When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4 (e). Table 2 shows the results of measuring the total width TW of the protrusions and the thickness of the linear metal layer.

Table 3 shows the transmittance, the degree of polarization, the absolute reflectance, and the wavelength dependency, luminance improvement rate, and heat resistance evaluation results of the obtained sample. As is clear when compared with Reference Example 1 , when the resin composition forming the resin layer contains a large amount of low molecular weight components having a molecular weight of polystyrene equivalent Mw of 5,000 or less, the optical properties as a reflective polarizing plate are obtained. Insufficient brightness improvement effect was not obtained. Moreover, after the heat test, the optical characteristics were reduced and it was found that the heat resistance was insufficient.

(Comparative Example 3)
Samples were prepared in the same manner as in Reference Example 5 except that the polyester of Reference Example 5 was used as it was without reprecipitation or fractionation by GPC.

  When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4 (e). Table 2 shows the results of measuring the total width TW of the protrusions and the thickness of the linear metal layer.

Table 3 shows the transmittance, the degree of polarization, the absolute reflectance, and the wavelength dependency, luminance improvement rate, and heat resistance evaluation results of the obtained sample. As is clear from comparison with Reference Example 5 , when the resin composition forming the resin layer contains a large amount of low molecular weight components having a polystyrene-equivalent molecular weight Mw = 5,000 or less, the optical properties are insufficient as a reflective polarizing plate. Thus, a sufficient brightness improvement effect was not obtained. Moreover, after the heat test, the optical characteristics were reduced and it was found that the heat resistance was insufficient.

(Comparative Example 4)
In Reference Example 6 , a sample was prepared in the same manner as in Reference Example 6 except that the linear resin pattern was not held in a vacuum atmosphere at 30 ° C. for 24 hours.

  When the form of the obtained sample was observed, the form of the linear metal layer was as shown in FIG. 4 (e). Table 3 shows the results of measuring the total width TW of the protrusions and the film thickness of the linear metal layer.

Table 2 shows the transmittance, the degree of polarization, the absolute reflectance, and the wavelength dependency, luminance improvement rate, and heat resistance evaluation results of the obtained sample. As is clear when compared with Reference Example 6 , when the photocurable resin forming the resin layer contains many low molecular weight components having a molecular weight Mw of 5,000 or less in terms of polystyrene, the optical properties are insufficient as a reflective polarizing plate. Thus, a sufficient brightness improvement effect was not obtained. Moreover, after the heat test, the optical characteristics were reduced and it was found that the heat resistance was insufficient.

It is a figure which shows typically the preferable shape of the resin layer which has a linear resin pattern on the surface which comprises the reflective polarizing plate of this invention. It is a figure which shows typically the preferable cross-sectional shape of the resin layer which has a linear resin pattern on the surface which comprises the reflective polarizing plate of this invention. It is a figure which shows typically the preferable shape of the reflective polarizing plate (resin layer with a flat surface) of this invention. It is a figure which shows typically the preferable shape of the reflective polarizing plate (resin layer which has a linear resin pattern on the surface) of this invention. In the reflective polarizing plate manufacturing method of the present invention, the step of forming a linear resin pattern is schematically exemplified. In the reflective polarizing plate manufacturing method of the present invention, the metal deposition angle in the metal layer forming step is schematically exemplified. It is a figure which shows typically the structure of the liquid crystal display device (1) (side light type) incorporating the reflective polarizing plate of this invention. It is a figure which shows typically the structure of the liquid crystal display device (1) (direct type) incorporating the reflective polarizing plate of this invention. It is a figure which shows typically the structure of the liquid crystal display device (2) (side light type) incorporating the reflective polarizing plate of this invention. It is a figure which shows typically the structure of the liquid crystal display device (2) (direct type) incorporating the reflective polarizing plate of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin layer 2 Linear metal layer 10 Linear resin pattern 11 Convex part of linear resin pattern
12 Linear resin pattern concave portion 22 Surface layer 40 on concave portion Linear resin pattern forming sheet 50 Mold 51 Mold convex portion 52 Mold concave portion 100 Reflective polarizing plate 200 of the present invention Fluorescent tube
300 Light guide plate 310 Diffuser plate 400 Reflective sheet 410 Case 500 Light diffusion sheet 600 Prism sheet 700 Surface light source 800 Liquid crystal cell 810 Lower polarizing plate 820 Liquid crystal layer 830 Upper polarizing plate P Pitch of linear metal layer W Width of linear metal layer H The thickness of the linear metal layer p The pitch of the convex portions of the linear resin pattern w The width h of the convex portions of the linear resin pattern The height h ′ of the convex portions of the linear resin pattern The height of the resin layer having the linear resin pattern Film thickness TW from bottom of recess to interface between resin layer and support Total width L1 of linear metal layer 2 and projection 11 Line parallel to the surface of the resin layer and parallel to the longitudinal direction of the linear resin pattern L2 Line parallel to the surface of the resin layer and perpendicular to the longitudinal direction of the linear resin pattern L3 Normal line of the resin layer surface M1 Metal deposition direction θ Angle formed by the normal L3 of the resin layer surface and the metal deposition direction M1

The reflective polarizing plate of the present invention is suitable as an optical member for improving the luminance of various display devices, particularly a liquid crystal display device.
Further, a liquid crystal display device equipped with the reflective polarizing plate of the present invention can be a high-brightness liquid crystal display device as compared with a conventional liquid crystal display device, and can be a mobile phone, an electronic notebook, a notebook PC, a monitor, It can be suitably used for a TV, various display media, and the like.

Claims (11)

A resin layer having a polystyrene-reduced molecular weight of 5,000 or less, defined by the following (Procedure 1) to (Procedure 5), having a content W of 5% by weight or less, and a plurality of the resin layers are formed on the resin layer at intervals. A reflective polarizing plate composed of a linear metal layer (hereinafter referred to as a linear metal layer).
(Procedure 1): The surface layer of the resin layer 1 is scraped off (weight is set to W1 (g)).
(Procedure 2): The surface layer scraped in (Procedure 1) is dissolved in chloroform, separated into an insoluble material and a solution, and the insoluble material is dried (the weight of the insoluble material is W2 (g)).
(Procedure 3): The solvent of the solution obtained in (Procedure 2) is removed to obtain a residue.
(Procedure 4): The residue obtained in (Procedure 3) is obtained by a gel permeation chromatograph (hereinafter referred to as GPC) to obtain a polystyrene-equivalent molecular weight curve, and the polystyrene-equivalent molecular weight contained in the residue is 5 from the molecular weight curve. A ratio R (% by weight) of 1,000 or less is obtained.
(Procedure 5): The content W of a component having a molecular weight of 5,000 or less in terms of polystyrene in the resin layer is determined by the following formula (1).
-Content W (weight%) = (W1-W2) x R / W1 (1). The resin layer contains a thermoplastic resin as a main component, and the polystyrene equivalent weight average molecular weight Mw by GPC of the thermoplastic resin is 10,000 or more, and the polystyrene equivalent weight average molecular weight Mw and polystyrene equivalent number average molecular weight Mn by GPC. The reflective polarizing plate according to claim 1, wherein the polydispersity Mw / Mn calculated from is 3.0 or less. The reflective polarizing plate according to claim 1, wherein the linear metal layer has a film thickness H of 10 to 200 nm, a pitch P = 50 to 400 nm, and a width W = 20 to 380 nm. . The reflective polarizing plate according to any one of claims 1 to 3, wherein the linear metal layer is mainly composed of at least one metal selected from the group consisting of aluminum, silver, chromium, and gold. On the surface of the resin layer, linear resin patterns (hereinafter referred to as linear resin patterns) arranged in parallel are formed, and convex portions in a cross section perpendicular to the longitudinal direction of the linear resin pattern are formed. The shape is pitch p = 50 to 400 nm, width w = 20 to 380 nm, and height h = 10 to 400 nm, and the ratio (h / w) of height h to width w of the linear resin pattern is 0. The reflective polarizing plate according to any one of claims 1 to 4, wherein the reflective polarizing plate is 5 to 5. The resin layer has a thermoplastic resin as a main component, and the polystyrene equivalent weight average molecular weight Mw by GPC of the thermoplastic resin is 10,000 to 100,000, and the polystyrene equivalent Z average molecular weight Mz and polystyrene equivalent weight by GPC. The reflective polarizing plate according to claim 5, wherein the polydispersity Mz / Mw calculated from the average molecular weight Mw is 2.0 or less. The reflective polarizing plate according to claim 5, wherein the linear metal layer is formed on a top of a convex portion of the linear resin pattern. The reflective polarizing plate according to claim 5, wherein the resin layer is made of a polyester resin having an alicyclic group. The reflective polarizing plate according to claim 5, wherein the resin layer is laminated with a support layer, and the support layer is a biaxially stretched polyester film. A liquid crystal display device in which at least a surface light source, the reflective polarizing plate according to claim 1, and a liquid crystal cell are arranged in this order, the liquid crystal cell including a liquid crystal layer and the liquid crystal layer A polarizing plate (A) and a polarizing plate (B) arranged so as to sandwich the liquid crystal cell, the direction of the polarization axis of the polarized light transmitted through the polarizing plate (B) on the surface light source side constituting the liquid crystal cell, and the reflection A liquid crystal display device in which the direction of the polarization axis of the polarized light passing through the polarizing plate coincides, and the reflective polarizing plate is installed so that the linear metal layer faces the liquid crystal cell. A liquid crystal display device comprising a surface light source and a liquid crystal cell, the liquid crystal cell having a liquid crystal layer, a polarizing plate (A) and a polarizing plate (B) disposed so as to sandwich the liquid crystal layer, The polarizing plate (B) on the surface light source side is the reflective polarizing plate according to any one of claims 1 to 9, and the reflective polarizing plate is arranged so that the linear metal layer faces the liquid crystal layer. The installed liquid crystal display device.

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