TW202219138A - Method for producing phase difference layer-equipped polarizing plate - Google Patents

Abstract

Provided is a simple and efficient method for producing a phase difference layer-equipped polarizing plate in which warp is suppressed. Through an embodiment of the present invention, there is provided a method for producing a phase difference layer-equipped polarizing plate having a polarizer, a protective layer positioned on one side of the polarizer, and a phase difference layer positioned on the other side of the polarizer. This production method includes: humidifying an intermediate layered body in which a water-absorbent film is temporarily adhered to the phase difference layer side of the phase difference layer-equipped polarizing plate, while roll-conveying the intermediate body; and storing the humidified intermediate layered body for at least 12 hours, the moisture permeability of the protective layer at 40 DEG C and 92% RH being 100 g/m2.24 h or less, and the phase difference layer being an aligned solidified layer of a liquid crystal compound.

Description

Manufacturing method of polarizing plate with retardation layer

The present invention relates to a manufacturing method of a polarizing plate with retardation layer.

Image display devices represented by liquid crystal display devices and electroluminescence (EL) display devices (eg, organic EL display devices, inorganic EL display devices) are rapidly spreading. In image display devices, polarizing plates and retardation plates are typically used. In practical use, a polarizing plate with a retardation layer in which a polarizing plate and a retardation plate are integrated is widely used (for example, Patent Document 1). In recent years, the industry is studying the possibility of bending, flexing, folding, and winding the image display device, and it is expected to reduce the thickness of the image display device. And the expectation for the thinning of the polarizing plate with retardation layer also follows. However, the thin polarizing plate with retardation layer has the problem of easy warpage. In particular, in the polarizing plate with retardation layer, which only has a protective layer with low moisture permeability on one side of the polarizing element and includes a retardation layer, that is, an alignment cured layer of a liquid crystal compound, the problem of warpage is more serious. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3325560

[Problems to be Solved by Invention]

The present invention is made to solve the above-mentioned problems, and its main object is to provide a simple and efficient method for producing a polarizing plate with a retardation layer with suppressed warpage. [Technical means to solve problems]

According to an embodiment of the present invention, there is provided a method for manufacturing a polarizing plate with a retardation layer, wherein the polarizing plate with a retardation layer includes a polarizing element, a protective layer arranged on one side of the polarizing element, and a polarizing plate arranged on the polarizing element. The retardation layer on the other side of the polarizing element. The manufacturing method comprises the steps of: carrying out a humidification process while carrying out a roller conveyance to an intermediate layered body temporarily adhering a water-absorbent film on the retardation layer side of a polarizing plate with a retardation layer; The body is stored for more than 12 hours; wherein, the moisture permeability of the protective layer at 40°C and 92%RH is less than 100 g/m ² ·24h, and the retardation layer is an alignment cured layer of liquid crystal compound. In one embodiment, the water absorption rate of the water-absorbing film is 2% or more. In one embodiment, the water-absorbent film is a triacetoxycellulose film. In one embodiment, the thickness of the water-absorbent film is 40 μm or more. In one embodiment, the water-absorbing film has a water vapor transmission rate of 300 g/m ² ·24h or more at 40° C. and 92% RH. In one Embodiment, the said humidification process is performed in the environment of the temperature of 34 degrees C or less and the water vapor amount of 13.8 g/m ³ or more. In one embodiment, the humidification time in the humidification treatment is 5 minutes or more. In one embodiment, the storage time of the above-mentioned humidified intermediate laminate is 24 hours or more. In one embodiment, the storage of the above-mentioned humidified intermediate layered body is performed in an environment where the temperature is 34° C. or lower. In one embodiment, the above-mentioned manufacturing method further includes: peeling and removing the above-mentioned water-absorbent film from the above-mentioned intermediate layered body after the above-mentioned storage. In one embodiment, the water vapor transmission rate of the retardation layer at 40° C. and 92% RH is 300 g/m ² ·24h or more. In one embodiment, the retardation layer is a single layer, the Re(550) of the retardation layer is 100 nm to 190 nm, and the Re(450)/Re(550) of the retardation layer is 0.8 or more and less than 1 The angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizing element is 40°˜50°. In one embodiment, the polarizing plate with the retardation layer further has another retardation layer outside the retardation layer, and the refractive index characteristic of the other retardation layer shows the relationship of nz>nx=ny. In one embodiment, the retardation layer has a laminated structure of the alignment cured layer of the first liquid crystal compound and the alignment cured layer of the second liquid crystal compound; the Re(550) of the alignment cured layer of the first liquid crystal compound is 200 nm～300 nm, the angle formed between the retardation axis and the absorption axis of the polarizing element is 10°～20°; the Re(550) of the alignment cured layer of the second liquid crystal compound is 100 nm～190 nm, and the retardation axis is 10°～20° The angle formed by the absorption axis of the polarizing element is 70°˜80°. In one embodiment, the total thickness of the polarizing plate with the retardation layer is 45 μm or less. [Effect of invention]

According to an embodiment of the present invention, in the manufacturing method of a polarizing plate with retardation layer, a specific humidification process is performed on an intermediate layered body to which a specific water-absorbing film is temporarily adhered, and the humidified intermediate layered body is stored. The polarizing plate with a retardation layer in which warpage is suppressed can be manufactured simply and efficiently by specifying the time.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Definition of Terms and Symbols) Definitions of terms and symbols in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index becomes the largest (ie, the slow axis direction), and "ny" is the in-plane refraction in the direction orthogonal to the slow axis (ie, the advance axis direction) ratio, "nz" is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane retardation measured by light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured by light with a wavelength of 550 nm at 23°C. Re(λ) is obtained by the formula: Re(λ)=(nx−ny)×d when the thickness of the layer (film) is d (nm). (3) Phase difference in thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured by light of wavelength λ nm at 23°C. For example, "Rth(550)" is the retardation in the thickness direction measured by light with a wavelength of 550 nm at 23°C. Rth(λ) is obtained by the formula: Rth(λ)=(nx−nz)×d when the thickness of the layer (film) is d (nm). (4) Nz coefficient The Nz coefficient is obtained by Nz=Rth/Re. (5) Angle When referring to an angle in this specification, the angle includes both clockwise and counterclockwise with respect to the reference direction. So, for example, "45°" means ±45°.

A. Outline of the structure of the polarizing plate with retardation layer obtained by the manufacturing method of the embodiment of the present invention FIG. 1 is a schematic cross-sectional view showing an example of a polarizing plate with a retardation layer obtained by a manufacturing method according to an embodiment of the present invention. The polarizing plate 100 with retardation layer in the illustrated example includes a polarizing element 11 , a protective layer 12 disposed on one side of the polarizing element 11 (representatively, the visible side), and a protective layer 12 disposed on the other side of the polarizing element 11 . retardation layer 20 . That is, the polarizing plate 100 with the retardation layer has the protective layer 12 only on the visible side of the polarizing element 11 (the side opposite to the retardation layer 20 ). In such a polarizing plate with a retardation layer, the effect (described later) by the embodiment of the present invention can be remarkable. In practice, an adhesive layer (not shown) is provided on the opposite side of the retardation layer 20 to the polarizer 11 (that is, as the outermost layer on the opposite side to the visible side), so that the polarizing plate with the retardation layer can be attached on the image display panel. Preferably, a release film (not shown) is temporarily adhered to the surface of the adhesive layer until the polarizing plate with the retardation layer is put into use. By temporarily adhering the release film, the adhesive layer can be protected, and the roll of the polarizing plate with the retardation layer can be formed. In addition, in this specification, the laminated body of a polarizing element and a protective layer may be called a polarizing plate.

In the embodiment of the present invention, the moisture permeability of the protective layer 12 at 40° C. and 92% RH (hereinafter, simply referred to as moisture permeability) is 100 g/m ² ·24h or less. In the polarizing plate with retardation layer provided with the protective layer having such moisture permeability only on one side of the polarizing element, the effect (as described later) brought about by the embodiment of the present invention can become remarkable. The moisture permeability of the protective layer is preferably 80 g/m ² · 24h or less, more preferably 60 g/m ² · 24h or less. The lower limit of the moisture permeability may be, for example, 5 g/m ² ·24h.

In the embodiment of the present invention, the retardation layer 20 is an alignment cured layer (liquid crystal alignment cured layer) of a liquid crystal compound. By using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be significantly larger than that of a non-liquid crystal material, so that the thickness of the retardation layer required to obtain the desired in-plane retardation can be significantly increased. become smaller. Therefore, the polarizing plate with the retardation layer can be significantly reduced in thickness. For such a retardation layer-attached polarizing plate, the effects (described later) brought about by the embodiment of the present invention can become remarkable. The so-called "alignment cured layer" in this specification refers to a layer in which the liquid crystal compound is aligned in a specific direction within the layer and its alignment state is fixed. In addition, "alignment hardening layer" includes the concept of the alignment hardening layer obtained by hardening a liquid crystal monomer as mentioned later. In the retardation layer 20, the rod-shaped liquid crystal compound is typically aligned (horizontal alignment) in a state of being arranged in the slow axis direction of the retardation layer. The retardation layer 20 may be a single layer as shown in FIG. 1 , or may have a laminated structure of two or more layers as shown in FIG. 2 .

The moisture permeability of the retardation layer is preferably 300 g/m ²・24h or more, more preferably 300 g/m ²・24h～1000 g/m ²・24h, and more preferably 400 g/m ²・24h～800 g/m ² ·24h. The difference between the moisture permeability of the protective layer and the moisture permeability of the retardation layer is preferably 200 g/m ² · 24h or more, more preferably 250 g/m ² · 24h～750 g/m ² · 24h.

The total thickness of the polarizing plate with the retardation layer (the total thickness of the polarizing element, the protective layer, the retardation layer, and the bonding layer of the laminate) is preferably 45 μm or less, more preferably 40 μm or less, and more preferably is 35 μm or less. The total thickness of the polarizing plate with the retardation layer may be, for example, 25 μm or more. Furthermore, in a polarizing plate with a retardation layer, the ratio of the thickness of the polarizing plate (polarizing element and protective layer) to the thickness of the retardation layer (polarizing plate/retardation layer; hereinafter, sometimes abbreviated as "thickness ratio") Preferably it is 5 or more, More preferably, it is 5-16, More preferably, it is 5-14. Only one side of the polarizer has a protective layer, the retardation layer is an alignment cured layer of a liquid crystal compound, and the thickness of the polarizer is relatively thin as will be described later, so that such a thickness ratio can be achieved.

The polarizing plate with retardation layer can further include other optical functional layers. The type, characteristic, number, combination, arrangement position, etc. of the optical function layer which can be provided in the polarizing plate with retardation layer can be appropriately set depending on the purpose. For example, the polarizing plate with the retardation layer can further have a conductive layer or an isotropic substrate with a conductive layer (not shown). The conductive layer or the isotropic substrate with the conductive layer is typically provided on the outer side of the retardation layer 20 (the opposite side to the polarizing plate 10 ). The conductive layer or the isotropic base material with the conductive layer can be representatively any layer provided as needed, and it can also be omitted. Furthermore, when a conductive layer or an isotropic substrate with a conductive layer is provided, the polarizer with retardation layer can be applied to a so-called internal touch panel type input display device, which is used for image display. A touch sensor is assembled between the unit (eg, organic EL unit) and the polarizer. For another example, the polarizing plate with the retardation layer may further contain other retardation layers. The optical properties (for example, refractive index properties, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, and the like of other retardation layers can be appropriately set depending on the purpose. Further/or, the surface of the protective layer 12 may be provided with a layer (representatively, a λ/4 plate, an ultra-polarized light plate that imparts (elliptically) polarized light function) to improve the visibility of the case where the polarized sunglasses are visually recognized. high retardation layer). By adopting such a configuration, even when the display screen is visually recognized through a polarized lens such as polarized sunglasses, excellent visibility can be achieved. Therefore, the polarizing plate with the retardation layer can also be preferably applied to an image display device that can be used outdoors.

Hereinafter, the manufacturing method of the polarizing plate with a retardation layer according to the embodiment of the present invention will be described, and then, the constituent elements of the polarizing plate with a retardation layer will be described.

B. Manufacturing method of polarizing plate with retardation layer The manufacturing method of the polarizing plate with retardation layer according to the embodiment of the present invention includes: rolling the intermediate layered body temporarily adhering the water-absorbent film on the retardation layer side of the polarizing plate with retardation layer One side is humidified; the humidified intermediate layered product is stored for more than 12 hours. Hereinafter, each step in the manufacturing method of the polarizing plate with retardation layer is demonstrated in order.

B-1. Production of polarizing plate The polarizing plate can be produced by any appropriate method. Specifically, the polarizing plate may include a polarizing element made of a single-layer resin film, or a polarizing element made using a laminate of two or more layers.

B-1-1. Production of a polarizing plate using a polarizing element obtained from a single-layer resin film A typical method for producing a polarizer from a single-layer resin film includes dyeing and stretching the resin film with a dichroic substance such as iodine or a dichroic dye. Examples of the resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films. The method may further include insolubilization treatment, swelling treatment, crosslinking treatment, and the like. A polarizing plate can be obtained by laminating a protective layer (protective film) on at least one side of the obtained polarizing element. Such a manufacturing method is well known and used in the industry, so the detailed description is omitted.

B-1-2. Production of a polarizing plate using the polarizing element obtained from the laminate When a laminate is used in the manufacture of polarizers, the laminate may be a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or may be a resin substrate and a PVA-based resin layer. The laminate of the PVA-based resin layer formed on the resin substrate is applied. As an example, the manufacturing method of the polarizing element using the laminated body of the resin base material and the PVA-type resin layer formed in this resin base material is demonstrated. This production method typically includes: coating a PVA-based resin solution on a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and obtaining a laminate of the resin substrate and the PVA-based resin layer body; this laminated body is stretched and dyed to make the PVA-based resin layer into a polarizing element. In such a manufacturing method, it is preferable to form the polyvinyl-alcohol-type resin layer containing a halide and a polyvinyl-alcohol-type resin on one side of a resin base material. The stretching typically involves immersing the layered body in an aqueous solution of boric acid and stretching. Further, the stretching may further include, if necessary, performing in-air stretching of the layered body at a high temperature (eg, 95° C. or higher) before stretching in a boric acid aqueous solution. In addition, in such a production method, it is preferable to perform a drying shrinkage treatment on the layered body, that is, to shrink the layered body by 2% or more in the width direction by heating it while conveying the layered body in the longitudinal direction. This production method typically includes sequentially subjecting the laminate to an air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment. By introducing auxiliary stretching, even in the case of coating PVA on thermoplastic resin, the crystallinity of PVA can be improved, and higher optical properties can be achieved. In addition, by improving the orientation of PVA in advance, problems such as lowering of orientation or dissolution of PVA when immersed in water in the subsequent dyeing step or stretching step can be prevented, and higher optical properties can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, compared with the case where the PVA-based resin layer does not contain a halide, the alignment disorder of the polyvinyl alcohol molecules and the decrease in the alignment property can be suppressed. Thereby, the optical characteristics of the polarizing element obtained by the process step of immersing a laminated body in liquid, such as dyeing process and an underwater extension process, can be improved. Furthermore, optical properties can be improved by shrinking the laminate in the width direction by drying shrinkage treatment. The obtained laminate of resin substrate/polarizing element can be used as it is (that is, the resin substrate can be used as a protective layer of the polarizing element), or the resin substrate can be peeled off from the laminate of resin substrate/polarizing element. The peeling area layer is any suitable protective layer depending on the purpose. Details of the manufacturing method of such a polarizing element are described in, for example, Japanese Patent Laid-Open No. 2012-73580 and Japanese Patent No. 6470455 . All the descriptions of these publications are incorporated herein by reference.

B-2. Formation of retardation layer The method for forming the retardation layer (liquid crystal alignment cured layer) will be briefly described. The liquid crystal alignment cured layer can be formed by performing an alignment treatment on the surface of a specific substrate, applying a coating liquid containing a liquid crystal compound on the surface, and aligning the liquid crystal compound in a manner corresponding to the above alignment treatment direction, the alignment state is fixed. As the alignment process, any appropriate alignment process can be employed. Specifically, mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment may be mentioned. Specific examples of the mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of the physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photo alignment treatment. The processing conditions of the various alignment processes can be arbitrarily appropriate depending on the purpose.

The alignment of the liquid crystal compound is performed according to the kind of the liquid crystal compound, by processing at a temperature at which a liquid crystal phase is exhibited. By performing such a temperature treatment, the liquid crystal compound is in a liquid crystal state, and the liquid crystal compound is aligned according to the direction of the alignment treatment on the surface of the substrate.

The alignment state is fixed in one embodiment by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment.

Specific examples of the liquid crystal compound and details of the formation method of the alignment cured layer are described in Japanese Patent Laid-Open No. 2006-163343. The description of this gazette is incorporated in this specification by reference.

As described above, the liquid crystal alignment cured layer is formed on the substrate.

B-3. Production of polarizing plate with retardation layer By laminating the polarizing plate obtained above and the retardation layer, a polarizing plate with a retardation layer can be obtained. The lamination of the polarizing plate and the retardation layer is typically performed while these are conveyed by roll (that is, by so-called roll-to-roll). The lamination can be typically carried out by transferring the liquid crystal alignment cured layer formed on the base material. When the retardation layer has a laminated structure, each retardation layer can be sequentially laminated (transferred) to the polarizing plate, or the laminated volume layer of the retardation layer can be laminated (transferred) to the polarizing plate. The transfer is typically performed through an active energy ray-curable adhesive. The thickness of the active energy ray hardening adhesive after hardening is preferably 0.4 μm or more, more preferably 0.4 μm to 3.0 μm, and still more preferably 0.6 μm to 1.5 μm.

When the polarizing plate with the retardation layer further includes other optical functional layers (such as conductive layers, other retardation layers), these optical functional layers can be laminated or formed at a specific location by any appropriate method .

The production (lamination) of the polarizing plate with the retardation layer is typically performed in an environment where the amount of water vapor is 11.5 g/m ³ or less. The amount of water vapor in the laminate is preferably 6.0 g/m ³ to 11.5 g/m ³ , more preferably 8.0 g/m ³ to 11.5 g/m ³ . By laminating in an environment where the amount of water vapor is within such a range, the effect of the humidification treatment described later becomes remarkable. Such an amount of water vapor in the laminate can be realized by, for example, changing the relative humidity in accordance with the temperature within a temperature range of 18°C to 25°C. Regarding the amount of water vapor, for example, when the temperature is 18°C, it can be achieved by setting the relative humidity below 65% RH; for example, when the temperature is 20°C, it can be achieved by setting the relative humidity to 55%RH or less; for another example, when the temperature is 23°C, it can be achieved by setting the relative humidity to 45%RH or less. Furthermore, the lower limit of the relative humidity may be, for example, 30% RH.

B-4. Production of intermediate laminates Next, as shown in FIG. 3 , the water absorbent film 150 was temporarily adhered to the retardation layer side of the polarizing plate with the retardation layer obtained above, and the intermediate layered body 200 was produced. The production of the intermediate layered body was performed by roll-to-roll in the same manner as described above. Furthermore, regarding the polarizing plate with retardation layer in the production of the intermediate layered product, the structure of the polarizing plate with retardation layer obtained in the end is the same, but it is essentially an intermediate, so in FIG. 3, the The intermediate object corresponding to the polarizing plate 100 with retardation layer in FIG. 1 is shown with the symbol 100 ′, and the intermediate object corresponding to the polarizing plate 101 with the retardation layer in FIG. 2 is shown with the symbol 101 ′ .

The water absorption rate of the water-absorbing film is preferably 2% or more, more preferably 2% to 20%, and still more preferably 2% to 10%. If the water absorption rate of the water-absorbing film is within such a range, the amount of water that can reach the polarizing element can be adjusted to an appropriate range by humidification and storage after humidification (both described later). In more detail, the water-absorbent film can absorb an appropriate amount of moisture by humidifying treatment and maintain a specific amount of the absorbed moisture. The moisture held in the water-absorbent film can be transferred to the polarizing element during storage. Therefore, the amount of moisture absorbed and retained in the water-absorbing film is adjusted by appropriately setting the conditions of the humidification treatment, and the amount of moisture transferred from the water-absorbing film to the polarizing element is adjusted by appropriately adjusting the storage conditions. Therefore, the moisture content of the polarizing element can be kept in an appropriate range. As a result, the warpage of the polarizing plate with the retardation layer can be significantly suppressed. When the water absorption rate is too low, the suppression of warpage may be insufficient. If the water absorption rate is too high, warpage in the direction orthogonal to the initial direction may occur in the opposite direction and/or in-plane. More specifically, if the humidification treatment is not performed, the polarizing plate with the retardation layer typically has convex warpage on the protective layer side. On the other hand, by performing the humidification treatment, convex warpage occurs on the retardation layer side. As a result, the warpages in the directions opposite to each other cancel each other, so that warpage can be suppressed in the obtained polarizing plate with retardation layer. Therefore, if the water absorption rate is too high, the convex warpage will become too large on the retardation layer side, and in the polarizing plate with the retardation layer obtained, it may protrude in the opposite direction (protrusion on the protective layer side) And/or warpage in a direction orthogonal to the initial direction occurs in the plane.

As a water-absorbent film, any appropriate material may be contained as long as it has the above-mentioned desired water absorption rate. As a material which comprises a water-absorptive film, triacetyl cellulose (TAC) and an acrylic resin are mentioned, for example. Preferred is TAC.

The thickness of the water-absorbent film is preferably 40 μm or more, more preferably 60 μm or more, and still more preferably 70 μm or more. The upper limit of the thickness of the water-absorbent film may be, for example, 200 μm. If the thickness of the water-absorbing film is within such a range, the amount of water that can reach the polarizing element during the humidification treatment can be adjusted to an appropriate range by its synergistic effect with the effect of making the water absorption rate within a specific range. Therefore, the moisture content of the polarizing element can be kept within an appropriate range by storing after humidification. As a result, the warpage of the polarizing plate with the retardation layer can be significantly suppressed.

The moisture permeability of the water-absorbing film is preferably 300 g/m ²・24h or more, more preferably 300 g/m ²・24h～1000 g/m ²・24h, and more preferably 300 g/m ²・24h～800 g/m ² ·24h. If the water vapor permeability of the water absorbent film is within such a range, an appropriate amount of moisture absorbed by the water absorbent film by the humidification treatment and held in the water absorbent film can be transferred to polarized light due to storage after the humidification treatment element. Therefore, the moisture content of the polarizing element can be kept within an appropriate range by storing after humidification. As a result, the warpage of the polarizing plate with the retardation layer can be significantly suppressed.

The production (lamination) of the intermediate layered body can be typically performed under the same environment as the production (lamination) of the polarizing plate with retardation layer.

B-5. Humidification Treatment The intermediate layered body 200 obtained above was subjected to a humidification treatment as shown in FIG. 3 . The humidification treatment is typically performed while the intermediate layered body is conveyed by rollers. The humidification treatment is typically performed in an environment where the temperature is 34° C. or lower and the amount of water vapor is 13.8 g/m ³ or more. The temperature in the humidification treatment is preferably 18°C to 34°C. The amount of water vapor in the humidification treatment is preferably 13.8 g/m ³ to 30 g/m ³ , more preferably 13.8 g/m ³ to 24 g/m ³ . Regarding the amount of water vapor in the humidification treatment, for example, when the temperature is 20°C, it can be achieved by setting the relative humidity to 80% RH or more; for example, when the temperature is 23°C, It can be achieved by setting the relative humidity to be more than 70%RH; for example, when the temperature is 25°C, it can be achieved by setting the relative humidity to be more than 60%RH; for example, when the temperature is 28°C In this case, it can be achieved by setting the relative humidity to be greater than 50% RH. Furthermore, the upper limit of the relative humidity may be, for example, 100% RH. By carrying out the humidification treatment under such conditions, an appropriate amount of moisture can be imparted to the polarizing plate with the retardation layer, and by the synergistic effect with the effect of temporarily adhering the water-absorbing film, the retardation layer can be suppressed from being attached. The warping of the polarizing plate.

The humidification time in the humidification treatment is preferably 5 minutes or more, more preferably 5 minutes to 30 minutes, further preferably 5 minutes to 20 minutes, and particularly preferably 5 minutes to 15 minutes. If the humidification time is 5 minutes or more, the above-mentioned required amount of water absorption can be achieved. Even if the humidification time becomes too long, the effect does not change, so the upper limit of the humidification time can be determined according to the balance between the required moisture absorption and manufacturing efficiency.

The humidification treatment is performed so as to increase the weight per unit volume of the polarizing plate with the retardation layer, for example, by 0.2% or more. The weight increase per unit volume of the polarizing plate with the retardation layer in the humidification treatment is preferably 0.2% to 2.5%, more preferably 0.3% to 2.0%, and still more preferably 0.3% to 1.0%. The increase in weight in the humidification process means that the polarizing plate with the retardation layer absorbs moisture. Therefore, by setting the weight increase in such a range, the polarizing element can absorb a required amount of moisture. As a result, the warpage of the polarizing plate with the retardation layer can be suppressed.

B-6. Storage The humidified intermediate laminate is stored as shown in FIG. 3 . Typically, the intermediate laminate is wound into a roll shape and stored in a roll state. By such storage, the moisture imparted to the intermediate layered body (substantially the water-absorbent film) by the humidification treatment can be transferred to the polarizing element favorably. Thereby, the moisture content of the polarizing element is increased, and as a result, the warpage of the polarizing plate with the retardation layer can be suppressed. The storage time is 12 hours or more as described above, preferably 16 hours or more, more preferably 24 hours or more, and still more preferably 30 hours or more. Even if the storage time becomes too long, the effect will not change. Therefore, the upper limit of the storage time can be determined according to the balance between the required moisture absorption and manufacturing efficiency.

Storage can typically be carried out around room temperature. The temperature during storage is typically 34°C or lower, preferably 30°C or lower, more preferably 20°C to 30°C, and still more preferably 23°C to 27°C. If the storage temperature is too high, the moisture imparted to the polarizing plate with the retardation layer by the humidification treatment (the polarizing plate with the retardation layer is absorbed) may evaporate to the outside, and it is not possible to satisfactorily Transfer to polarizer.

The storage is typically carried out in an environment where the amount of water vapor is 11.5 g/m ³ or less. In other words, the storage system is performed without substantially humidifying the intermediate layered body. By storing in such an environment, moisture can be favorably transferred from the water-absorbing film to the polarizer.

After storage, the water-absorbent film was peeled off from the intermediate layered body as shown in FIG. 3 . In this way, a polarizing plate with a retardation layer can be obtained.

C. Polarizing plate C-1. Polarizing element As can be seen from the above-mentioned manufacturing method, a representative one of the polarizing elements 11 is a resin film containing a dichroic substance (eg, iodine). As the resin film, as described above, hydrophilic polymer films such as polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films can be exemplified.

The thickness of the polarizing element is preferably 15 μm or less, more preferably 1 μm to 12 μm, and still more preferably 3 μm to 12 μm. If the thickness of the polarizing element is within such a range, the polarizing element can be made to absorb a desired amount of moisture well by the humidification treatment as described above.

The polarizing element preferably exhibits absorption dichroism at any wavelength from 380 nm to 780 nm. The single transmittance of the polarizing element is, for example, 41.5% to 46.0%, preferably 42.0% to 46.0%, and preferably 44.5% to 46.0%. The polarization degree of the polarizing element is preferably 97.0% or more, more preferably 99.0% or more, and still more preferably 99.9% or more.

C-2. Protective layer The protective layer 12 can be formed by any appropriate film that can be used as a protective layer of a polarizing element as long as it has the above-mentioned moisture permeability. Specific examples of the material used as the main component of the film include polyester-based, polyvinyl-alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyether-based, and polyamide-based , Polystyrene, cyclic olefin (eg polynorbornene), polyolefin, (meth)acrylic, acetate and other transparent resins. Preferably, the protective layer 12 includes a cyclic olefin-based (eg, polynorbornene-based) resin film.

The polarizing plate with retardation layer obtained by the manufacturing method of the embodiment of the present invention is typically arranged on the viewing side of the image display device, and the protective layer 12 is arranged on the viewing side. Therefore, the protective layer 12 may be subjected to surface treatments such as hard coating treatment, anti-reflection treatment, anti-sticking treatment, and anti-glare treatment as necessary.

The thickness of the protective layer 12 is preferably 5 μm˜80 μm, more preferably 10 μm˜40 μm, and more preferably 15 μm˜35 μm. Furthermore, when the surface treatment is performed, the thickness of the protective layer 12 is the thickness including the thickness of the surface treatment layer.

D. retardation layer As described above, the retardation layer 20 may be a single layer or may have a laminated structure of two or more layers.

When the retardation layer 20 is a single layer, the retardation layer can function as a λ/4 plate in one embodiment. Specifically, the Re(550) of the retardation layer is preferably 100 nm to 180 nm, more preferably 110 nm to 170 nm, and still more preferably 110 nm to 160 nm. The thickness of the retardation layer can be adjusted to obtain the required in-plane retardation for the λ/4 plate. The thickness of the retardation layer may be, for example, 1.0 μm to 2.5 μm. In this embodiment, the angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizing element is preferably 40°-50°, more preferably 42°-48°, and more preferably 44°-46°. When the retardation layer is a single layer, the retardation layer preferably exhibits an inverse wavelength dispersion characteristic in which the retardation value increases with the wavelength of the measurement light. In this embodiment, the polarizing plate with the retardation layer may have another retardation layer (not shown in the figure) on the outer side of the retardation layer 20 (the opposite side to the polarizing element) that exhibits the refractive index characteristic of nz>nx=ny Show).

When the retardation layer 20 has a laminated structure, the retardation layer typically has a two-layer structure of an H layer 21 and a Q layer 22 from the polarizing plate side as shown in FIG. 2 . The H layer can typically function as a λ/2 plate, and the Q layer can typically function as a λ/4 plate. Specifically, the Re(550) of the H layer is preferably 200 nm to 300 nm, more preferably 220 nm to 290 nm, and more preferably 230 nm to 280 nm; the Re(550) of the Q layer is preferably 100 nm to 180 nm, more preferably 110 nm to 170 nm, and still more preferably 110 nm to 150 nm. The thickness of the H layer can be adjusted to obtain the required in-plane retardation for the λ/2 plate. The thickness of the H layer may be, for example, 2.0 μm˜4.0 μm. The thickness of the Q layer can be adjusted to obtain the required in-plane retardation for the λ/4 plate. The thickness of the Q layer may be, for example, 1.0 μm˜2.5 μm. In this embodiment, the angle formed by the retardation axis of the H layer and the absorption axis of the polarizer is preferably 10° to 20°, more preferably 12° to 18°, and more preferably 12° to 16° The angle formed between the retardation axis of the Q layer and the absorption axis of the polarizing element is preferably 70° to 80°, more preferably 72° to 78°, and further preferably 72° to 76°. Furthermore, the arrangement order of the H layer and the Q layer can be reversed from the above, the angle formed by the retardation axis of the H layer and the absorption axis of the polarizer, and the angle formed by the retardation axis of the Q layer and the absorption axis of the polarizer. The above can be reversed. When the retardation layer has a laminated structure, each layer (for example, the H layer and the Q layer) can exhibit an inverse wavelength dispersion characteristic in which the retardation value increases with the wavelength of the measured light, and can also exhibit that the retardation value increases with the wavelength of the measured light. The positive wavelength dispersion characteristic that the wavelength of the measurement light decreases, and the flat wavelength dispersion characteristic that the retardation value hardly changes due to the wavelength of the measurement light.

As for the retardation layer (in the case of having a laminated structure, each layer), the refractive index characteristic typically exhibits the relationship of nx>ny=nz. Furthermore, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where ny and nz are substantially equal. Therefore, the situation of ny>nz or ny<nz may exist within the range which does not impair the effect of this invention. The Nz coefficient of the retardation layer is preferably 0.9 to 1.5, more preferably 0.9 to 1.3.

The retardation layer is a liquid crystal alignment cured layer as described above. As a liquid crystal compound, the liquid crystal compound (nematic liquid crystal) whose liquid crystal phase is a nematic phase is mentioned, for example. As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The expression mechanism of the liquid crystallinity of the liquid crystal compound may be either a lyotropic type or a thermotropic type. The liquid crystal polymer and the liquid crystal monomer may be used alone or in combination.

When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. The reason for this is that the alignment state of the liquid crystal monomer can be fixed by polymerizing or crosslinking (ie, curing) the liquid crystal monomer. After aligning the liquid crystal monomers, for example, by polymerizing or crosslinking the liquid crystal monomers, the above-mentioned alignment state can be fixed. Here, a polymer is formed by polymerization, and a three-dimensional network structure is formed by crosslinking, but these are non-liquid crystalline. Therefore, the formed retardation layer does not change to a liquid crystal phase, a glass phase, or a crystal phase due to, for example, a temperature change peculiar to a liquid crystal compound. As a result, the retardation layer becomes a retardation layer with extremely excellent stability not affected by temperature changes.

The temperature range in which the liquid crystal monomer exhibits liquid crystallinity varies depending on the kind. Specifically, the temperature range is preferably 40°C to 120°C, more preferably 50°C to 100°C, and most preferably 60°C to 90°C.

As the above-mentioned liquid crystal monomer, any appropriate liquid crystal monomer can be used. For example, the polymeric mesogens described in Japanese Patent Publication No. 2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, and GB2280445 can be used. compounds, etc. As a specific example of such a polymerizable mesogen compound, the trade name LC242 of BASF company, the trade name E7 of Merck company, and the trade name LC-Silicon-CC3767 of Wacker-Chem company are mentioned, for example. As the liquid crystal monomer, for example, a nematic liquid crystal monomer is preferable. [Example]

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. In addition, unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight. (1) Warping The polarizing plates with retardation layers obtained in Examples and Comparative Examples were cut out to 140 mm × 70 mm before humidification (before making the intermediate laminate) and after humidification and storage (after peeling off the TAC film). size. At this time, the cutting is performed so that the absorption axis direction of the polarizer becomes the longitudinal direction. When the cut out polarizing plate with retardation layer was placed on a flat surface, the height of the highest part from the flat surface was taken as the warpage amount. Next, the warpage amount of the polarizing plate with the retardation layer cut out after storage was measured in the same manner as above, and the evaluation was performed according to the following criteria based on the change in the warpage amount before humidification and after humidification and storage. . ○: Change in warpage is ±25 mm or less ×: The change in the amount of warpage is greater than ±25 mm In addition, the case where the warpage protruded on the side of the stationary surface was described as "positive (+)", and the case where the warpage protruded on the side opposite to the stationary surface was described as "negative (-)". In addition, the side of the stationary surface is the side of the retardation layer (Q layer).

[Example 1] 1. Production of polarizing plate As the thermoplastic resin substrate, a long strip, Tg of about 75°C, amorphous isophthalic acid-co-polyethylene terephthalate film (thickness: 100 μm) was used. Perform corona treatment. To a PVA system prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetylacetate modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER") at a ratio of 9:1 To 100 parts by weight of the resin, 13 parts by weight of potassium iodide was added, and the obtained in the above-described manner was dissolved in water to prepare an aqueous PVA solution (coating liquid). The above-mentioned PVA aqueous solution was coated on the corona-treated surface of the resin substrate and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained layered body was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130° C. (in-air stretching treatment). Next, the layered body was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (insolubilization treatment). Then, in a dyeing bath with a liquid temperature of 30° C. (with respect to 100 parts by weight of water, an iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7), so as to make the monomer transmittance of the polarizing element finally obtained. (Ts) is immersed for 60 seconds (dyeing process), adjusting density|concentration so that it may become a desired value. Next, it was immersed for 30 seconds in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C (crosslinking treatment). Then, while immersing the layered body in an aqueous solution of boric acid (boric acid concentration 4 wt %, potassium iodide concentration 5 wt %) at a liquid temperature of 70° C., it was placed between rolls with different peripheral speeds in the longitudinal direction (longitudinal direction) so that the This layered body was uniaxially stretched (underwater stretching treatment) so that the total stretching ratio became 5.5 times. Then, the layered body was immersed in a cleaning bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 20°C (cleaning treatment). Then, while drying in the oven maintained at about 90 degreeC, it contacted with the heating roll made of SUS maintained at the surface temperature of about 75 degreeC (drying shrinkage treatment). In this way, a polarizing element with a thickness of about 5 μm was formed on the resin substrate, and a polarizing plate having a composition of resin substrate/polarizing element was obtained.

Furthermore, the HC-COP film was bonded to the surface (the surface opposite to the resin base material) of the obtained polarizing element via an ultraviolet curable adhesive as a visible-side protective layer. Furthermore, the HC-COP film is a film formed by forming an HC (Hard Coating, hard coating) layer (thickness 2 μm) on a cycloolefin resin (COP) film (thickness 25 μm), and the COP film is used as the polarizer side. way to fit. Next, the resin base material was peeled off, and the polarizing plate which has the structure of HC-COP film (visibility side protective layer) / polarizing element was obtained. The moisture permeability of the protective layer on the visual side is 100 g/m ² ·24h.

使用磨擦布對聚對苯二甲酸乙二酯(PET)膜(厚度38 μm)表面進行磨擦，實施配向處理。使配向處理之方向於貼合於偏光板時相對於偏光元件之吸收軸之方向從視認側看為15°方向。藉由棒式塗佈機將上述液晶塗敷液塗敷於該配向處理表面，於90℃下加熱2分鐘使其乾燥，藉此使液晶化合物配向。使用金屬鹵素燈對以上述方式形成之液晶層照射1 mJ/cm ²之光，使該液晶層硬化，藉此於PET膜上形成液晶配向固化層A。液晶配向固化層A之厚度為2.0 μm，面內相位差Re(550)為270 nm。進而，液晶配向固化層A表現出nx＞ny＝nz之折射率特性。將液晶配向固化層A用作H層。 除了變更塗敷厚度，以及使配向處理方向相對於偏光元件之吸收軸之方向從視認側看為75°方向以外，以與上述同樣之方式於PET膜上形成液晶配向固化層B。液晶配向固化層B之厚度為1.0 μm，面內相位差Re(550)為140 nm。進而，液晶配向固化層B表現出nx＞ny＝nz之折射率特性。將液晶配向固化層B用作Q層。 2. Fabrication of polarizing plate with retardation layer 2-1. Fabrication of retardation layer 10 g of polymerizable liquid crystal (manufactured by BASF Corporation: trade name "Paliocolor LC242") exhibiting a nematic liquid crystal phase, obtained from the following Formula) and 3 g of a photopolymerization initiator for the polymerizable liquid crystal compound (manufactured by BASF: trade name "Irgacure 907") were dissolved in 40 g of toluene to prepare a liquid crystal composition (coating liquid). [hua 1]

The surface of the polyethylene terephthalate (PET) film (thickness 38 μm) was rubbed with a rubbing cloth to perform alignment treatment. The direction of the alignment treatment was 15° when viewed from the visible side with respect to the direction of the absorption axis of the polarizer when it was attached to the polarizing plate. The above-mentioned liquid crystal coating liquid was applied to the alignment-treated surface by a bar coater, and the liquid crystal compound was aligned by heating at 90° C. for 2 minutes and drying. The liquid crystal layer formed in the above manner was irradiated with light of 1 mJ/cm ² using a metal halide lamp to harden the liquid crystal layer, thereby forming a liquid crystal alignment cured layer A on the PET film. The thickness of the liquid crystal alignment cured layer A is 2.0 μm, and the in-plane retardation Re(550) is 270 nm. Furthermore, the liquid crystal alignment cured layer A exhibits a refractive index characteristic of nx>ny=nz. The liquid crystal alignment cured layer A was used as the H layer. The liquid crystal alignment cured layer B was formed on the PET film in the same manner as above except that the coating thickness was changed and the alignment treatment direction was 75° from the visible side with respect to the absorption axis of the polarizer. The thickness of the liquid crystal alignment cured layer B is 1.0 μm, and the in-plane retardation Re(550) is 140 nm. Furthermore, the liquid crystal alignment cured layer B exhibits a refractive index characteristic of nx>ny=nz. The liquid crystal alignment cured layer B was used as the Q layer.

2-2. Production of polarizing plate with retardation layer The liquid crystal alignment cured layer A (H layer) and the liquid crystal alignment cured layer B (Q layer) obtained in the above 2-1. were sequentially transferred onto the polarizer surface of the polarizing plate obtained in the above 1.. At this time, the angle formed by the absorption axis of the polarizer and the slow axis of the alignment cured layer A is 15°, and the angle formed by the absorption axis of the polarizer and the slow axis of the alignment cured layer B is 75°. Transfer (lamination). In addition, each transfer (bonding) was performed via an ultraviolet curable adhesive (thickness 1.0 μm). In this way, a polarizing plate with retardation layer having a configuration of protective layer/adhesive/polarizing element/adhesive/retardation layer (H layer)/adhesive/retardation layer (Q layer) was obtained. The total thickness of the polarizing plate with retardation layer is 38 μm. In addition, transfer (bonding) is performed while carrying out roller conveyance.

3. Preparation of Intermediate Laminated TAC film (thickness 70 μm) was temporarily adhered to the surface of the Q layer of the polarizing plate with retardation layer obtained in 2. above through an acrylic adhesive to prepare an intermediate layered body. The production of the intermediate layered body is carried out while carrying out roll conveyance. The water absorption rate of TAC film is 5%, and the moisture permeability is 400 g/m ² ·24h.

4. Humidification Treatment and Storage The intermediate layered body obtained in the above 3. was subjected to a humidification treatment while being transported by a roller. The humidification treatment was performed for 10 minutes at 23°C and 70% RH (water vapor amount: 14.4 g/m ³ ). The humidified polarizing plate with retardation layer was wound into a roll, and the roll was stored at 23° C. and 55% RH (11.3 g/m ³ of water vapor) for 24 hours. The evaluation of the above (1) was performed on the polarizing plate with the retardation layer before the humidification treatment and after the roll storage, respectively. The results are shown in Table 1.

[Example 2] A polarizing plate with a retardation layer was obtained in the same manner as in Example 1, except that the humidification treatment was performed at 20° C. and 80% RH (water vapor amount: 13.8/m ³ ) for 10 minutes. The same evaluation as in Example 1 was performed on the polarizing plate with retardation layer before the humidification treatment and after the roll storage, respectively. The results are shown in Table 1.

[Comparative Example 1] A polarizing plate with a retardation layer was obtained in the same manner as in Example 1, except that the TAC film was not adhered to the humidification treatment and the roll was stored. The same evaluation as in Example 1 was performed on the polarizing plate with retardation layer before the humidification treatment and after the roll storage, respectively. The results are shown in Table 1.

[Comparative Example 2] In the same manner as in Example 1, a polarizing plate with a retardation layer was obtained (the former intermediate layered body was produced). The polarizing plate with the retardation layer was stored on a roll in the same manner as in Example 1 as it was (that is, when neither an intermediate laminate was produced nor a humidification treatment was performed). The same evaluations as in Example 1 were performed on the polarizing plates with retardation layers after the rolls were stored. The results are shown in Table 1.

[Reference Example 1] The long roll of PVA-based resin film with a thickness of 30 μm was uniaxially stretched in the long direction by a roll stretching machine so that the total stretching ratio was 6.0 times, and at the same time, swelling, dyeing, and cross-linking were carried out. and cleaning treatment, and finally, drying treatment was carried out, thereby producing a polarizing element with a thickness of 12 μm. In the same manner as in Example 1, the HC-COP film was attached to one surface of the obtained polarizing element as a protective layer on the visible side. Furthermore, a TAC film (thickness 25 μm) was bonded to the other side of the polarizer via a PVA-based adhesive to obtain a polarizer having a configuration of protective layer (HC-COP film)/polarizer/protective layer (TAC film). The subsequent steps were carried out in the same manner as in Example 1 to obtain a film having a protective layer (HC-COP film)/adhesive/polarizing element/adhesive/protective layer (TAC film)/adhesive/retardation layer (H layer )/adhesive/retardation layer (Q layer) of the polarizing plate with retardation layer. The total thickness of the polarizing plate with retardation layer is 71 μm.

The subsequent steps were carried out in the same manner as in Example 1 to produce an intermediate layered body, and after this intermediate layered body was subjected to a humidification treatment, it was stored in a roll. The same evaluation as in Example 1 was performed on the polarizing plate with retardation layer before the humidification treatment and after the roll storage, respectively. The results are shown in Table 1.

[Table 1] Humidification warping condition Amount of water vapor (g/m ³ ) Before humidification (mm) After storage(mm) Example 1 23℃, 70%RH, 10 minutes 14.4 -40(MD) ±20 Example 2 20℃, 80%RH, 10 minutes 13.8 -40(MD) ±20 Comparative Example 1 23℃, 70%RH, 10 minutes without TAC bonding 14.4 -40(MD) +40(TD) Comparative Example 2 No humidification - -40(MD) -40(MD) Reference Example 1 23℃, 70%RH, 10 minutes 14.4 -20(MD) ±10

[Evaluation] As can be seen from Table 1, regarding the polarizing plate with retardation layer obtained by the examples of the present invention, by performing specific humidification treatment and roll storage on the intermediate laminate to which the water absorbent film is attached, the warping is reduced. The curve is suppressed. Furthermore, according to the reference example, such warpage is a problem peculiar to the retardation layer-attached polarizing plate which has a thin total thickness and has a viewing-side protective layer having a small moisture permeability. [Industrial Availability]

Regarding the polarizing plate with retardation layer obtained by the manufacturing method of the embodiment of the present invention, it can be used as a polarizing plate with retardation layer for image display devices, especially suitable for bending, Or an image display device that can be flexed, folded, or rolled (for such an image display device, a resin substrate is typically used as a substrate). Typical examples of the image display device include a liquid crystal display device, an organic EL display device, and an inorganic EL display device.

11: Polarizing element 12: Protective layer 20: retardation layer 21: retardation layer (H layer) 22: retardation layer (Q layer) 100: polarizer with retardation layer 100': polarizing plate with retardation layer (intermediate) 101: Polarizing plate with retardation layer 101': polarizing plate with retardation layer (intermediate) 150: Absorbent film 200: Intermediate Laminate

FIG. 1 is a schematic cross-sectional view showing an example of a polarizing plate with a retardation layer obtained by a manufacturing method according to an embodiment of the present invention. 2 is a schematic cross-sectional view showing another example of a polarizing plate with a retardation layer obtained by the manufacturing method of the embodiment of the present invention. FIG. 3 is a conceptual diagram for explaining the manufacturing method of the embodiment of the present invention.

100: polarizer with retardation layer

100': polarizing plate with retardation layer (intermediate)

101: Polarizing plate with retardation layer

101': polarizing plate with retardation layer (intermediate)

150: Absorbent film

200: Intermediate Laminate

Claims (15)

A method for manufacturing a polarizing plate with a retardation layer, the above-mentioned polarizing plate with a retardation layer has: a polarizing element, a protective layer arranged on one side of the polarizing element, and a phase difference arranged on the other side of the polarizing element layer, and the above-mentioned manufacturing method includes: carrying out a humidification treatment while carrying out a roller conveyance to an intermediate layered product temporarily adhered to the retardation layer side of the retardation layer-attached polarizing plate; The treated intermediate laminate is stored for more than 12 hours; the moisture permeability of the protective layer at 40°C and 92% RH is less than 100 g/m ² ·24h, and the retardation layer is an alignment cured layer of liquid crystal compound. The manufacturing method of the polarizing plate with retardation layer according to claim 1, wherein the water absorption rate of the water-absorbing film is 2% or more. The method for producing a polarizing plate with a retardation layer according to claim 2, wherein the water-absorbing film is a triacetyl cellulose film. The manufacturing method of the polarizing plate with retardation layer according to claim 3, wherein the thickness of the water-absorbing film is 40 μm or more. The method for manufacturing a polarizing plate with a retardation layer according to claim 4, wherein the moisture permeability of the water-absorbing film at 40° C. and 92% RH is 300 g/m ² ·24h or more. The method for producing a polarizing plate with a retardation layer according to any one of claims 1 to 5, wherein the humidification treatment is performed in an environment with a temperature of 34° C. or lower and an amount of water vapor of 13.8 g/m ³ or more. The method for producing a polarizing plate with a retardation layer according to claim 6, wherein the humidification time in the humidification treatment is 5 minutes or more. The method for manufacturing a polarizing plate with a retardation layer according to any one of claims 1 to 7, wherein the storage time of the above-mentioned humidified intermediate laminate is 24 hours or more. The method for manufacturing a polarizing plate with retardation layer according to any one of claims 1 to 8, wherein the storage of the above-mentioned humidified intermediate laminate is performed in an environment where the temperature is below 34°C. The method for producing a polarizing plate with a retardation layer according to any one of claims 1 to 9, further comprising: peeling and removing the water-absorbing film from the intermediate laminate after the storage. The method for manufacturing a polarizing plate with a retardation layer according to any one of claims 1 to 10, wherein the moisture permeability of the retardation layer at 40° C. and 92% RH is 300 g/m ² ·24h or more. The manufacturing method of a polarizing plate with a retardation layer according to any one of claims 1 to 11, wherein the retardation layer is a single layer, the Re(550) of the retardation layer is 100 nm to 190 nm, and the phase difference Re(450)/Re(550) of the difference layer is 0.8 or more and less than 1, and the angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizer is 40° to 50°. The manufacturing method of the polarizing plate with retardation layer according to claim 12, wherein the polarizing plate with retardation layer further has another retardation layer outside the retardation layer, and the refraction of the other retardation layer The rate characteristic shows a relationship of nz>nx=ny. The manufacturing method of a polarizing plate with a retardation layer as claimed in any one of claims 1 to 11, wherein The retardation layer has a laminated structure of the alignment cured layer of the first liquid crystal compound and the alignment cured layer of the second liquid crystal compound, The Re(550) of the alignment cured layer of the first liquid crystal compound is 200 nm to 300 nm, and the angle formed between the retardation axis and the absorption axis of the polarizing element is 10° to 20°, The Re(550) of the alignment cured layer of the second liquid crystal compound is 100 nm to 190 nm, and the angle formed between the retardation axis and the absorption axis of the polarizer is 70° to 80°. The manufacturing method of the polarizing plate with retardation layer according to any one of claims 1 to 14, wherein the total thickness of the polarizing plate with retardation layer is 45 μm or less.

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