JP2015212819A - Method for manufacturing polarizing element, polarizing element obtained by the method, and display device including the polarizing element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polarizing element, by which a homogeneous polarizing layer having no coating defects can be easily patterned, and influences of water or solvent used in a manufacturing process after a polarizing layer is formed are prevented.SOLUTION: The method for manufacturing a polarizing element comprising a substrate, a polarizing layer and a protective layer includes the following steps: (I) a step of forming the polarizing layer by continuously applying a composition for forming a polarizing layer on the substrate and subsequently forming the protective layer on the polarizing layer by continuously applying a photosensitive resin composition; (II) a step of patterning the polarizing layer and the protective layer by exposure and development with a developer; and (III) a step of heating the patterned protective layer to melt and flow.

Description

  The present invention relates to a polarizing element used in a liquid crystal display device and the like, and more particularly to a polarizing element manufacturing method including a polarizing layer formed on a substrate and a protective layer thereof.

  In an LCD (liquid crystal display), a linearly polarizing plate and a circularly polarizing plate are used to control optical rotation and birefringence in display. Also in OLED (organic EL element), a circularly polarizing plate is used to prevent reflection of external light. Conventionally, in these polarizing plates (polarizing elements), iodine or a dichroic organic dye is dissolved or adsorbed in a polymer material such as polyvinyl alcohol, and the film is stretched into a film in one direction to obtain two colors. A polarizing layer obtained by orienting a functional dye has been widely used. However, the conventional polarizing layer manufactured in this way has problems such as insufficient heat resistance and light resistance depending on the dye and polymer material used, and poor yield of bonding of the polarizing layer when manufacturing a liquid crystal device. there were. In addition, attempts have been made to form a polarizing layer in the cell in order to improve luminance by simplifying the element structure.

  On the other hand, a method of producing a polarizing layer by orienting a dichroic dye by applying a solution containing the dichroic dye on a substrate such as glass or a transparent film while applying a shearing force has been studied. (See Patent Documents 1 to 7).

JP-T 8-511109 JP 2002-277636 A JP 2007-72221 A JP 2007-186428 A JP 2008-69300 A JP-T-2001-504238 JP 2006-48078 A

When a plurality of substrates for liquid crystal cells are cut out from a single substrate base material, a plurality of polarizing layers formed in a predetermined pattern are formed on the substrate, and these are divided and used as a substrate in many cases. . In addition, when used as an In-Cell type liquid crystal display device provided with a polarizing layer on the inner surface side of the substrate, the polarizing layer is formed after each layer previously provided in a liquid crystal cell such as an electrode or a color filter is laminated on the substrate. Then, it is formed in a portion (step structure portion) that is convex with respect to the substrate.
However, when a solution containing a dichroic dye is applied to the entire substrate base material using the methods described in Patent Documents 1 to 7 and the like, it is applied to a portion other than the above-described step structure, that is, a portion that does not require application. become. Accordingly, it is necessary to delete unnecessary portions after application.

  As a method for cutting out a plurality of liquid crystal cell substrates from a single substrate base material, for example, it is also possible to select only the above step structure using an intermittent coating method and apply the polarizing layer forming composition. . However, when the interval between the plurality of step structures provided on the substrate base material is short, it is difficult to control the discharge of the composition for forming a polarizing layer, resulting in coating defects. As a result, there is a problem that an optically homogeneous polarizing layer, and thus an optically homogeneous polarizing element cannot be obtained.

On the other hand, the polarizing layer is easily affected by water and a solvent, and the polarizing layer tends to be damaged. In order to prevent these problems, the polarizing layer has been insolubilized and a protective layer has been conventionally provided, but it has not been sufficient.
Moreover, there also existed a problem that a polarizing layer became easy to peel according to the process after forming a polarizing layer.

  The present invention has been made in order to solve the technical problems as described above. The object of the present invention is to provide a polarizing layer which can be easily patterned without any coating defects and can be easily patterned. An object of the present invention is to provide a method for manufacturing a polarizing element which is not affected by water or a solvent used in the manufacturing process after formation. Moreover, it is providing the manufacturing method of the polarizing element which peeling of a polarizing layer does not generate | occur | produce.

As a result of intensive investigations to achieve the above object, the present inventors have made a protective layer with a photosensitive resin composition on a polarizing layer formed by continuously coating a polarizing layer forming composition on a substrate. It is found that the above-mentioned problem can be solved by patterning the polarizing layer and the protective layer, melt-flowing the unexposed protective layer, and sealing the contour side surface of the polarizing layer by partially exposing and developing The present invention has been completed.
That is, the gist of the present invention is as follows.
[1] A method for producing a polarizing element comprising a substrate, a polarizing layer and a protective layer, comprising the following steps.
(I) A step of continuously applying a composition for forming a polarizing layer on a substrate to form a polarizing layer, and then forming a protective layer by continuously applying a photosensitive resin composition on the polarizing layer.
(II) A step of patterning the polarizing layer and the protective layer by exposure and development with a developer.
(III) A step of melt-flowing the patterned protective layer by heating.
[2] The method for manufacturing a polarizing element according to [1], wherein in the step (II), the polarizing layer includes erosion from the contour portion of the protective layer to the inside.
[3] The method for manufacturing a polarizing element according to [1] or [2], wherein, in the step (III), the side surface of the contour portion of the polarizing layer is sealed with a protective layer.
[4] The method for manufacturing a polarizing element according to any one of [1] to [3], wherein the heating in the step (III) is 90 ° C. or higher and 200 ° C. or lower.
[5] A polarizing element manufactured using the manufacturing method according to any one of [1] to [4].
[6] The polarizing element according to [5], wherein the patterned pattern includes a corner radius with R of 50 μm or more.
[7] An image display device comprising the polarizing element according to [5] or [6].

  According to the method for producing a polarizing element of the present invention, the polarizing layer continuously applied on the substrate can be partitioned together with the formation of the protective layer, and can be protected from subsequent processes. Accordingly, after the polarizing layer is formed, an In-Cell type polarizing element having a process using a solvent for forming an alignment film (N-methylpyrrolidone, etc.) or water as a cleaning solvent is partitioned into a plurality of substrates from one substrate base material. This is useful for cutting out the divided substrate.

It is the schematic showing the state which eroded the polarizing layer in the image development process of this invention. It is the schematic showing the state which made the protective layer melt-flow. It is the schematic showing the corner radius of a pattern. It is a cross-sectional SEM figure of the outline part of the polarizing layer of an Example. It is the figure which piled up the polarizing layer of an Example so that it might become orthogonal and parallel.

Although the typical aspect for implementing this invention is demonstrated concretely below, this invention is not limited to the following aspects, unless the summary is exceeded.
In the present invention, “(meth) acrylic acid” includes both acrylic acid and methacrylic acid, and “(meth) acrylate”, “(meth) acryloyl” and the like have the same meaning. Moreover, what added "(poly)" before the monomer name means this monomer and this polymer.

The present invention is a method for manufacturing a polarizing element including a substrate, a polarizing layer, and a protective layer. The production method has at least the following steps (hereinafter, the following step (I) may be referred to as “(I) step”. Similarly to step (I), “(II) step”, (It may be expressed as “(III) step”). (I) A step of forming a protective layer by continuously applying a photosensitive resin composition on a polarizing layer formed by continuously applying a composition for forming a polarizing layer on a substrate.
(II) A step of patterning the polarizing layer and the protective layer by exposure and development with a developer.
(III) A step of melt-flowing the protective layer patterned in the step (II) by heating.

  The production method of the present invention includes the steps (I) to (III), and is not particularly limited as long as it is performed in the order of step (I) → (II) step → (III) step. Moreover, you may have another process between each process, for example, you may have another process between the (I) process and the (II) process.

(Polarizing element)
The polarizing element of the present invention includes a polarizing layer obtained by continuous coating on a substrate surface and a protective layer provided on the polarizing layer. Further, the polarizing element is not limited to the polarizing layer and the protective layer, and may have other layers for the purpose of improving the polarization performance and improving the mechanical strength.
Moreover, the pattern in this invention represents the shape pattern of the polarizing layer surfaced on the board | substrate, and patterning represents forming a pattern. Moreover, an outline part points out the outer peripheral part of the pattern of a polarizing layer. The patterning in the present invention is intended to define a polarizing layer for cutting out a plurality of liquid crystal cell substrates from one substrate base material, but is not limited to this.

(substrate)
Although it does not specifically limit as a board | substrate of this invention, It is preferable that it is a board | substrate which has favorable surface property, a contact angle characteristic, and a water absorption characteristic. As a base material for forming such a substrate, for example, inorganic materials such as glass; triacetate resin, acrylic resin, polyester resin, polycarbonate resin, polyethylene terephthalate resin, triacetyl cellulose resin, norbornene resin , Polymer materials such as cyclic polyolefin resin, polyimide resin, urethane resin, and the like. These may be used alone or in combination of two or more. In particular, the substrate is preferably a substrate including a polymer base material containing a polymer material.
The water absorption rate of the substrate is usually 5% or less, preferably 3% or less, more preferably 1% or less. If the water absorption is excessively large, the substrate may absorb moisture when the anisotropic polarizing material film is formed by a wet film formation method, and the substrate may be warped, which may easily cause coating defects. In addition, after the polarizing layer is formed by a coating method, the substrate may swell and optical defects may occur. The “water absorption rate” in the present embodiment is a value obtained by measuring the rate of change in weight when immersed in water at 23 ° C. for 4 hours using the test method of ASTM D570.

  An orientation-treated layer or the like can be provided in advance on the surface of the substrate surface on which the polarizing layer is formed from the viewpoint of better orienting an anisotropic polarizing material such as a dye contained in the polarizing layer in a certain direction. About the formation method of an orientation processing layer, it can be based on the well-known method as described in "Liquid Crystal Handbook" (Maruzen Co., Ltd., issued on October 30, 2000) pp. 226-239. Moreover, as a shape of a board | substrate, the film form (sheet-fed form) of a fixed dimension may be sufficient, and a continuous film form (strip | belt shape) may be sufficient. Moreover, as a film thickness of a board | substrate, it is 0.01 mm-3 mm normally, Preferably it is 0.02 mm-2 mm.

  The total light transmittance of the substrate is usually 80% or more, preferably 85% or more, more preferably 90% or more. The “total light transmittance” in the present embodiment is measured using an integrating sphere color measuring device, and is a value obtained by combining diffuse transmission light and parallel light transmission light.

(Process (I))
In the present invention, as the step (I), a polarizing layer forming composition is continuously applied to a substrate to form a polarizing layer, and then a photosensitive resin composition is continuously applied on the polarizing layer to form a protective layer. The process of carrying out.

(Polarizing layer)
The polarizing layer is an optical film having anisotropy in the electromagnetic properties in any two directions selected from a total of three directions in the three-dimensional coordinate system of the thickness direction of the film and any two orthogonal in-plane directions. Examples of the electromagnetic property include optical properties such as absorption and refraction, and electrical properties such as resistance and capacitance. Examples of the film having optical anisotropy such as absorption and refraction include a linearly polarizing layer, a circularly polarizing layer, a retardation film, and a conductive anisotropic film. In addition to the polarizing layer, the isopolarizing layer in the present embodiment can be suitably used as a retardation film and a conductive anisotropic film.

(Polarizing material and polarizing layer forming composition)
The polarizing material used for the polarizing layer of the present invention is not particularly limited as long as the material exhibits the above anisotropy. Moreover, since a polarizing layer is produced on a substrate by wet coating, a composition containing a polarizing material and a solvent (hereinafter sometimes referred to as a polarizing layer forming composition) is preferable.
As an aspect of the composition for forming a polarizing layer, it may be in the form of a solution, a gel, or a state in which a polarizing material is dispersed in a solvent. In addition to these, a binder resin, a monomer, a curing agent, an additive, and the like may be included as necessary.

  The composition for forming a polarizing layer is preferably in a liquid crystal phase as a composition from the viewpoint of forming a polarizing layer formed after the solvent evaporates with a high degree of orientation. In the present embodiment, the state of the liquid crystal phase refers to the state described on pages 1 to 16 of “Basics and Applications of Liquid Crystal” (Shoichi Matsumoto and Ryo Tsunoda, 1991). Say. In particular, the nematic phase described on page 3 is preferred. Any polarizing material may be used as long as it can form a polarizing layer having anisotropy, and examples thereof include a dye and a transparent material.

(Dye)
A dichroic dye is used as the dye of the present invention. The dye is preferably a dye having a liquid crystal phase for alignment control. Here, the dye having a liquid crystal phase means a dye exhibiting lyotropic liquid crystallinity in a solvent. The lyotropic liquid crystalline compound used in the present invention is preferably soluble in water or an organic solvent, and particularly preferably water-soluble, in order to form a polarizing layer by coating. Further preferred are compounds having an inorganic value smaller than the organic value as defined in “Organic Conceptual Diagram—Basics and Applications” (Yoshio Koda, Sankyo Publishing, 1984). Further, in a free state that does not take a salt form, the molecular weight is preferably 200 or more, particularly preferably 300 or more, and preferably 1500 or less, particularly preferably 1200 or less. . The term “water-soluble” means that the compound dissolves in water at room temperature, usually 0.1% by weight or more, preferably 1% by weight or more.
Only 1 type may be used for a pigment | dye and it may use it in combination of 2 or more type.

  Specific examples of the dye include azo dyes, stilbene dyes, cyanine dyes, phthalocyanine dyes, and condensed polycyclic dyes (perylene and oxazine dyes). Among these dyes, azo dyes that can take a high molecular arrangement in the anisotropic polarizing layer are preferable. An azo dye means a dye having at least one azo group. The number of azo groups in one molecule is preferably 2 or more, preferably 6 or less, more preferably 4 or less, from the viewpoint of color tone and production. The dye used in the present invention is not particularly limited, and a known dye can be used.

  Examples of the dye include dyes described in JP-A-2007-272211, JP-A-2007-186428, JP-A-2008-69300, JP-T-2001-504238, JP-A-2006-48078, and the like. Is mentioned.

  The dye in the present embodiment may be used in the form of a free acid, or a part of the acid group may have a salt form. Further, a salt-type dye and a free acid-type dye may be mixed. Moreover, when it is obtained in a salt form at the time of production, it may be used as it is or may be converted into a desired salt form. As the salt-type exchange method, a known method can be arbitrarily used, and examples thereof include the following methods.

1) A strong acid such as hydrochloric acid is added to an aqueous solution of a dye obtained in a salt form, the dye is acidified in the form of a free acid, and then the dye is added with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). A method of neutralizing acidic groups and salt exchange.
2) A method of performing salt exchange in the form of a salting-out cake by adding a large excess of a neutral salt (eg, lithium chloride) having a desired counter ion to an aqueous dye solution obtained in a salt form.
3) An aqueous solution of a dye obtained in a salt form is treated with a strongly acidic cation exchange resin, and the dye is acidified in the form of a free acid, and then an alkali solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). ) To neutralize the acidic group of the dye and perform salt exchange.
4) A method of performing salt exchange by allowing an aqueous solution of a dye obtained in a salt form to act on a strongly acidic cation exchange resin previously treated with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution).

  Whether the acidic group of the dye in the present embodiment is a free acid type or a salt type depends on the pKa of the dye and the pH of the aqueous dye solution. Examples of the salt type include salts of alkali metals such as Na, Li and K, ammonium salts optionally substituted with an alkyl group or hydroxyalkyl group, and salts of organic amines. Examples of the organic amine include a lower alkyl amine having 1 to 6 carbon atoms, a hydroxy substituted lower alkyl amine having 1 to 6 carbon atoms, a carboxy substituted lower alkyl amine having 1 to 6 carbon atoms, and the like. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed. Moreover, in this invention, although a pigment | dye can be used independently, these 2 or more types may be used together, and pigment | dyes other than the said exemplary pigment | dye may be mix | blended and used to such an extent that orientation is not reduced. it can. Thereby, anisotropic dye films having various hues can be produced.

  Examples of blending dyes when blending other dyes include C.I. I. Direct Yellow 12, C.I. I. Direct Yellow 34, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 142, C.I. I. Direct Yellow 132, C.I. I. Acid Yellow 25, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Orange 79, C.I. I. Acid Orange 28, C.I. I. Direct Red 39, C.I. I. Direct Red 79, C.I. I. DirectRed 81, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Acid Red 37, C.I. I. Direct Violet 9, C.I. I. Direct Violet 35, C.I. I. Direct Violet 48, C.I. I. Direct Violet 57, C.I. I. Direct Blue 1, C.I. I. Direct Blue 67, C.I. I. Direct Blue 83, C.I. I. Direct Blue 90, C.I. I. Direct Green 42, C.I. I. Direct Green 51, C.I. I. Direct Green 59 etc. are mentioned.

(Solvent of composition for forming polarizing layer)
As the solvent, water, a water-miscible organic solvent, or a mixture thereof is suitable. Specific examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and glycerin, glycols such as ethylene glycol and diethylene glycol, cellosolves such as methyl cellosolve and ethyl cellosolve, or a mixture of two or more. A solvent is mentioned.

(Concentration of polarizing material in polarizing layer forming composition)
The concentration of the polarizing material in the polarizing layer forming composition is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and preferably 50% by weight or less, although it depends on the film forming conditions. More preferably, it is 30% by weight or less. When the concentration of the polarizing material is within the above range, the viscosity of the composition for forming a polarizing layer capable of applying a uniform thin film is obtained, and the polarizing material tends not to precipitate. In addition, sufficient anisotropy such as a dichroic ratio tends to be obtained in the polarizing layer.

(Additive for composition for forming polarizing layer)
In the composition for forming a polarizing layer, additives such as a surfactant, a leveling agent, a coupling agent, and a pH adjuster can be blended as necessary. Depending on the additive, wettability, applicability and the like may be improved. As the surfactant, any of anionic, cationic and nonionic properties can be used. The concentration of the additive is not particularly limited, but is usually sufficient to obtain the added effect and does not inhibit the molecular orientation, and is usually used as the concentration in the composition for forming an anisotropic polarizing layer. 0.05 wt% or more and 0.5 wt% or less is preferable. In addition, for the purpose of suppressing instability such as salt formation and aggregation of the anisotropic polarizing material in the composition for forming a polarizing layer, a pH adjusting agent such as a known acid / alkali is added to the polarizing layer. It may be added before or after or during the mixing of the constituents of the forming composition. As additives other than those mentioned above, “Additive for Coating”, Edited by J. et al. Known additives described in Bieleman, Willy-VCH (2000) can also be used.

(Applying method of polarizing layer)
The method for applying the polarizing layer of the present invention is not particularly limited as long as it is a continuous application. In the present invention, the term “continuous application” refers to the continuous application of regions to be a plurality of patterns (sections), not intermittent application for each pattern. Even when a plurality of patterns are provided on the substrate, it is not necessary to apply the coating continuously at one time and to divide the coating into a plurality of patterns.
The method for continuously applying the polarizing layer forming composition to form the polarizing layer is not particularly limited. For example, Yuji Harasaki, “Coating Engineering” (Asakura Shoten Co., Ltd., published on March 20, 1971), pages 253-277, supervised by Kunihiro Ichimura, “Creation and Application of Molecular Cooperative Materials” MC Publishing, published on March 3, 1998) The method described on pages 118 to 149, a slot die coating method, a spin coating method, a spray coating method on a substrate having a step structure (which may be previously subjected to orientation treatment), Examples of the coating method include a bar coating method, a roll coating method, a blade coating method, a curtain coating method, a fountain method, and a dip method. Among these, the slot die coating method is preferable because an anisotropic polarizing layer with high uniformity can be obtained.

  There are no particular limitations on the method for supplying the composition for anisotropic dye film, the supply interval, etc., when applying the composition for anisotropic dye film. Especially when the film thickness of the anisotropic dye film is thin because the supply operation of the coating liquid becomes complicated and the coating film thickness may fluctuate when the coating liquid starts and stops. It is desirable to apply while supplying the composition for anisotropic dye film.

The speed at which the composition for anisotropic dye film is applied is usually 1 mm / second or more, preferably 5 mm / second or more. Moreover, it is 1000 mm / sec or less normally, Preferably it is 800 mm / sec or less. It exists in the tendency which can apply | coat uniformly, obtaining the anisotropy of an anisotropic pigment | dye film because a coating speed is the said range.
In addition, as application | coating temperature of the composition for anisotropic dye films, it is 0 degreeC or more and 80 degrees C or less normally, Preferably it is 40 degrees C or less. Moreover, the humidity at the time of application | coating of the composition for anisotropic dye films becomes like this. Preferably it is 10% RH or more, More preferably, it is 30% RH or more, Preferably it is 80 RH% or less.

(Insolubilization)
In the present invention, the polarizing layer may be insolubilized after the polarizing layer is formed on the substrate. The insolubilization of the present invention means a treatment step that suppresses elution from the polarizing layer by lowering the solubility of the dye in the polarizing layer and increases the stability of the polarizing layer. Specifically, for example, a process of replacing ions with a lower valence with ions with a higher valence (for example, replacing a monovalent ion with a multivalent ion).

(Insolubilized solution)
The insolubilization liquid used for the insolubilization of this invention is not specifically limited. For example, JP 2007-241267 A, JP 2009-199075 A, JP 2010-44130 A, JP 2010-197760 A, JP 2011-257489 A, JP 2012-058427 A, etc. The insolubilizing solution described in the above can be used.

  The pH of the insolubilized solution used in the present invention is not particularly limited, but the cation concentration contributing to ion exchange must be a certain concentration or higher from the principle of cation exchange. For this reason, it may be necessary to be more acidic than a certain pH depending on the material. Further, the color tone of the insolubilized liquid is not particularly limited, but basically, it is preferably colorless and light color that does not affect the degree of polarization.

The insolubilizing solution used in the present invention is not particularly limited, and preferably contains an insolubilizing compound and a solvent. The insolubilizing compound and the solvent may be used alone or in combination.
The insolubilizing compound preferably has strong ion selectivity for sulfate ion (SO _3- ), carboxylic acid, and phosphonic acid. Specific examples include inorganic salts such as Mg and Ca, polyamine compounds, and the like. Among these, a polyamine compound is preferable for reducing cracks after insolubilization.

A polyamine compound refers to a compound having two or more amino groups in the molecule. The number of amino groups in one molecule of the polyamine compound is usually 2 or more, and the upper limit is usually 20 or less, preferably 10 or less. When the number of amino groups is in an appropriate range, the polyamine compound diffuses into the polarizing layer and tends to insolubilize the polarizing layer.
Examples of polyamine compounds include aliphatic polyamine compounds and aromatic polyamine compounds. Of these, aliphatic polyamine compounds are preferred.

Specific examples of the aliphatic polyamine compounds include diaminoalkane compounds such as diaminohexane and diaminodecane; diaminocyclohexanes such as 1,4-cyclohexanediamine; diaminocycloalkane compounds such as 4,4′-methylenebiscyclohexylamine; diethylenetriamine And polyethylenepolyamine compounds such as pentaethylenehexamine and bis (hexamethylene) triamine; Among these, a polyethylene polyamine compound is preferable, and bis (hexamethylene) triamine is particularly preferable.
Specific examples of the aromatic polyamine compound include diaminobenzene and xylylenediamine. Of these, diaminobenzene is preferred.

The solvent of the insolubilizing solution is preferably a polar solvent that dissolves ions. Specifically, water, an ionic liquid, etc. are mentioned. Among these, water is preferable from the viewpoints of economy and safety.
The amount of the insolubilizing compound in the insolubilizing liquid is not particularly limited as long as it has ion exchange ability, but can be appropriately adjusted according to the kind of the insolubilizing compound and the solvent, the viscosity of the insolubilizing liquid at 25 ° C, and the like. Preferably, it is 10% or more of the saturation concentration, and more preferably 20% or more of the saturation concentration. Further, it is preferably a saturation concentration (= 100%) or less, more preferably 90% or less of the saturation concentration. By setting it within this range, there is a tendency that unnecessary precipitation of the insolubilized compound can be suppressed and the insolubilization reaction can be performed quickly.

(Insoluble solution additive)
The insolubilizing solution of the present invention may contain additives such as a thickener, a humectant, and a surfactant. Further, the amount of the additive in the insolubilized liquid can be appropriately adjusted according to the kind of the additive, the insolubilizing compound, the solvent, and the like.

  The method for adjusting the insolubilizing liquid of the present invention is not particularly limited. For example, the insolubilized compound may be mixed with a solvent so as to be in the above concentration range, and stirred or the like as necessary to dissolve in the solvent. Moreover, you may mix said solvent used as needed with a solvent so that it may become said concentration range, respectively. The mixing time, order, etc. are also arbitrary.

(Insolubilization method)
The method for insolubilizing the polarizing layer is not particularly limited, and examples include immersion; a method of supplying an insolubilizing solution from above the polarizing layer; spraying; application of curtain coat, roll coat, dipping coat, floating coat, blow-off coat, etc. . The polarizing layer of the present invention is very thin and tends to be peeled off by contact with an object. For this reason, it is preferable to use a method capable of suppressing a decrease in the polarization performance of the anisotropic dye film and defects such as film peeling.

(Cleaning after insolubilization)
The insolubilized polarizing layer is preferably washed. The cleaning method is not particularly limited, and dipping, cleaning with running water supplying a cleaning liquid from above the anisotropic dye film, ultrasonic cleaning, and the like can be used. Moreover, you may add the effect which accelerates | stimulates washing | cleaning, such as rocking | fluctuating at a specific frequency during washing | cleaning. Alternatively, it is possible to perform cleaning by combining a plurality of these methods.
Among the above, dipping is preferable in that it does not apply an unnecessary force that causes peeling or defects of the anisotropic dye film.
The cleaning liquid is not particularly limited, and specifically, pure water, a liquid obtained by adding alcohol such as methanol, ethanol, isopropyl alcohol, or the like to pure water may be used. These may contain additives that control the cleaning properties such as cleaning aids and surfactants in order to enhance the cleaning properties.

The temperature of the cleaning liquid is not particularly limited, but is preferably lower from the viewpoint of suppressing cracking of the polarizing layer, preferably 30 ° C. or lower, more preferably 20 ° C. or lower.
The pH of the cleaning solution may be adjusted to be acidic using an inorganic acid such as sulfuric acid, hydrochloric acid or nitric acid, or an organic acid such as acetic acid, oxalic acid or citric acid in consideration of detergency. Moreover, you may adjust to alkalinity using sodium hydroxide, potassium hydroxide, carbonate, a phosphate, another alkaline compound, etc.

  The method for drying the polarizing layer after washing is not particularly limited, and examples include air drying, air blow drying, vacuum drying, and heat drying. Among these, it is preferable to use air-dried air blow from the viewpoint of suppressing cracking of the polarizing layer. Moreover, you may combine these drying.

(Protective layer)
The protective layer of the present invention is formed for the purpose of protecting the polarizing layer from subsequent processes and stimulation and impact after the device is formed. At the same time, a resist for removing unnecessary portions of the polarizing layer and patterning the resist. Also plays a role as.
The protective layer of the present invention is not particularly limited as long as it is formed by continuously applying a photosensitive resin composition on the polarizing layer, but the one having no optical anisotropy is the performance of the polarizing layer. Is preferable because it does not inhibit the above. The optical anisotropy in the present invention has anisotropy in electromagnetic properties in any two directions selected from a total of three directions in the three-dimensional coordinate system of the thickness direction of the protective layer and any two orthogonal in-plane directions. That is.
Since the protective layer of the present invention does not impair the optical properties of the polarizing layer, the light transmittance at 550 nm when the thickness of the protective layer is 500 nm is preferably 80% or more, more preferably 85% or more. Yes, particularly preferably 90% or more. There is no particular upper limit, and a higher one is preferable.

(Photosensitive resin composition)
The photosensitive resin composition used for forming the protective layer of the present invention is not particularly limited as long as the solubility in a developer is changed by light irradiation. In particular, a negative photosensitive resin composition that cures by causing a crosslinking reaction or a polymerization reaction by irradiation with light is preferable.
For example, a combination of a radical photopolymerization initiator and a radically polymerizable unsaturated group-containing compound, a combination of a photocationic polymerization initiator and a cationically polymerizable group-containing compound such as an epoxy group, oxetanyl group, vinyl group, and the like. A system used in combination is also preferably used.

In the step (III), the photosensitive resin composition of the present invention preferably contains a thermoplastic resin in order to cause the melt flow to seal the side surface of the contour portion of the polarizing layer. Examples of the thermoplastic resin include acrylic resin, novolac resin, urethane resin, polyester, nylon, polyimide, polycarbonate, and derivatives thereof. These resins may be provided with a polymerizable group or a crosslinkable group. Moreover, when developing with an alkali developing solution, it is preferable to give acidic groups, such as a carboxyl group and a hydroxyphenyl group.
In addition, the photosensitive resin composition of the present invention includes a thermal radical polymerization initiator, a thermal cationic polymerization initiator, a sensitizing dye, an accelerator, a thermal polymerization initiator, various curing agents, a thermosetting resin, a leveling agent, and the like. Surfactants, adhesion improvers, organic solvents, and the like.

(Photo radical polymerization initiator)
The radical photopolymerization initiator suitably used for the photosensitive resin composition of the present invention is not particularly limited. For example, metallocene compounds including titanocene compounds described in JP-A-59-152396, JP-A-61-151197, etc .; hexaarylbiimidazole derivatives described in JP-A-2000-56118; Halomethylated oxadiazole derivatives, halomethyl-s-triazine derivatives, N-aryl-α-amino acids such as N-phenylglycine, N-aryl-α-amino acid salts, N-aryl -Radical activators such as -α-amino acid esters, α-aminoalkylphenone derivatives; oxime ester derivatives described in JP-A No. 2000-80068, JP-A No. 2006-36750, and the like.
Among these, oxime ester derivatives or α-aminoalkylphenone derivatives are preferable. These may be used alone or in combination.

Examples of the oxime ester derivatives include oximes and / or ketoxime ester compounds described in JP 2000-80068 A, JP 2006-36750 A, and the like.
Examples of α-aminoalkylphenone derivatives include 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butanone-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 4-dimethylaminoethylbenzoate, 4-dimethylaminoisoamylbenzoe -To, 4-diethylaminoacetophenone, 4-dimethylaminopropiophenone, 2-ethylhexyl-1,4-dimethylaminobenzoate, 2,5-bis (4-diethylaminobenzal) cyclohexanone, 7-diethylamino-3- (4 -Diethylaminobenzoyl) coumarin, 4- (diethylamino) chalcone, etc. It is below.

(Photocationic polymerization initiator)
The photocationic polymerization initiator suitably used for the photosensitive resin composition of the present invention is one that generates a cationic species or a Lewis acid upon irradiation with visible light, ultraviolet light or the like, and initiates a polymerization reaction of a cationically curable component. .
Examples of the photocationic polymerization initiator include onium salts such as aromatic iodonium salts and aromatic sulfonium salts, aromatic diazonium salts, and iron-arene complexes. Among these, aromatic iodonium salts or aromatic sulfonium salts are preferable from the viewpoint of curability.

An aromatic iodonium salt is a compound having a diaryl iodonium cation, and an aromatic sulfonium salt is a compound having a triarylsulfonium cation. These cations are paired with anions (anions) to form a photocationic polymerization initiator.
As anions constituting the photocationic polymerization initiator, hexafluorophosphate anion PF ₆ ⁻ , hexafluoroantimonate anion SbF ₆ ⁻ , pentafluorohydroxyantimonate anion SbF ₅ (OH) ⁻ , hexafluoroarsenate anion AsF ₆ ⁻ , Tetrafluoroborate anion BF ₄ ⁻ , tetrakis (pentafluorophenyl) borate anion B (C ₆ F ₅ ) ₄ ^{− and the} like.

  Specific examples of the aromatic sulfonium salt include CPI-100P, CPI-101A, CPI-200K, CPI-210S, Adeka Optomer SP-150, SP-170, SP-171, etc. of ADEKA. It is done.

  Specific examples of the aromatic iodonium salt include PHOTOINITITOR 2074 of Solvay Japan, IRGACURE 250 of BASF Japan, CI-5102 of Nippon Soda Co., Ltd., WPI-113 and WPI-116 of Wako Pure Chemical Industries.

(Radically polymerizable unsaturated group-containing compound)
The radically polymerizable unsaturated group-containing compound suitably used for the photosensitive resin composition of the present invention is a compound having at least one ethylenically unsaturated group in the molecule. The ethylenically unsaturated group is preferably an allyl group and / or a (meth) acryloyl group from the viewpoint of reactivity.

  Examples of radically polymerizable unsaturated group-containing compounds include esters of unsaturated carboxylic acids and polyhydroxy compounds; urethane (meth) acrylates of hydroxy (meth) acrylate compounds and polyisocyanate compounds; (meth) acrylic acid or And epoxy (meth) acrylates of a hydroxy (meth) acrylate compound and a polyepoxy compound. Specific examples include Aronix series from Toa Gosei Co., Ltd., NK series from Shin Nakamura Chemical Co., Ltd., Blemmer series from Nippon Oil & Fats Co., Ltd., Light acrylate series from Kyoeisha Chemical Co., Ltd., and Biscoat series from Osaka Organic Chemical Co., Ltd.

(Cationically polymerizable group-containing compound)
Examples of the cationic polymerizable group-containing compound include an epoxy group-containing compound, an oxetanyl group-containing compound, and a vinyl group-containing compound. Among them, epoxy resins are preferable, for example, JER series of Mitsubishi Chemical Corporation, Celoxide series of Daicel Corporation, Epototo series of Nippon Steel & Sumikin Chemical Co., Ltd., NC-, XD-, EPPN-, EOCN- of Nippon Kayaku Co., Ltd. Series, EPICLON of DIC, etc. are mentioned.
A vinyl polymer containing a side chain α having an epoxy group can also be particularly preferably used. By containing a vinyl polymer containing a side chain α having an epoxy group, photocurability and development pattern formability when forming a pattern by photolithography, shrinkage reduction during light / thermosetting, flexibility, There is a tendency to achieve excellent film quality with reduced permeability.
Examples of the oxetanyl group-containing compound include OXT series manufactured by Toa Gosei Co., Ltd., OXE-10 and OXE-30 manufactured by Osaka Organic Chemical Co., Ltd., and copolymer resins using them.

  The chemical structure of the vinyl polymer containing the side chain α having an epoxy group is not particularly limited. For example, the vinyl polymer containing the side chain α having an epoxy group and having a repeating unit structure represented by the following general formula (1) Can be mentioned.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group.
X represents a direct bond or a divalent linking group. However, the carbon atom which is not couple | bonded with X of the epoxy group in Formula (1) may couple | bond with X, and may form the ring.

As a bivalent coupling group in X, the alkylene group which may have a substituent is mentioned, for example. The methylene group in the alkylene group may be substituted with at least one bond selected from the group consisting of an unsaturated bond, an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond and a urethane bond. For example, the coupling group containing an ester bond and an amide bond is mentioned.
The number of carbon atoms of the alkylene group is not particularly limited, but is preferably 1 or more from the viewpoint of ease of synthesis, and is preferably 9 or less from the viewpoint of film forming properties, and is 7 or less. Is more preferable and 5 or less is still more preferable.
Examples of the substituent that the alkylene group may have include, for example, a halogen atom, an alkenyl group having 2 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a phenyl group, a mesityl group, a tolyl group, a naphthyl group, and a cyano group. Group, acetyloxy group, C2-C9 alkylcarbonyloxy group, sulfamoyl group, C2-C9 alkylsulfamoyl group, C2-C9 alkylcarbonyl group, phenethyl group, hydroxyethyl group, acetyl An amide group, a dialkylaminoethyl group formed by bonding an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, a trialkylsilyl group having 1 to 8 carbon atoms, a nitro group, an alkylthio group having 1 to 8 carbon atoms, etc. Can be mentioned. Among these, preferably an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxy group having 2 to 8 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, or a halogen atom. is there. From the viewpoint of ease of synthesis, the alkylene group is more preferably unsubstituted.

Among X, from the viewpoint of easy synthesis, an alkylene group interrupted by a direct bond, an ether bond, or an alkylene group interrupted by an ester bond is preferable. Among these, an alkylene group interrupted by an ester bond is more preferable, and a — (C═O) —O—CH ₂ — group is more preferable. The alkylene group interrupted by an ether bond means an alkylene group having an ether bond (—O— bond) between C—C bonds constituting the alkylene group. Similarly, an alkylene group interrupted by an ester bond means an alkylene group having an ether bond (— (C═O) —O— bond) between C—C bonds constituting the alkylene group.

  In order to obtain a vinyl polymer containing the side chain α having an epoxy group, a method using an epoxy group-containing vinyl compound as a polymerization component can be mentioned. Examples of the epoxy group-containing vinyl compound include the following compounds.

  Examples of the epoxy group-containing vinyl compound include allyl glycidyl ether, glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, α-ethylglycidyl (meth) acrylate, α-n-propylglycidyl (meth) acrylate, α-n. -Butyl glycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 6,7-epoxyheptyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, glycidyl ether glycidyl crotonate, glycidyl isocroto Crotonyl glycidyl ether, monoalkyl monoglycidyl itaconate, monoalkyl monoglycidyl fumarate, monoalkyl monoglycidyl maleate, o-vinyl Aliphatic epoxy group-containing compounds such as benzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, epoxy group-containing vinyl compounds, 3,4-epoxycyclohexylmethyl (meth) acrylate, 2- (3,4 -Epoxycyclohexyl) ethyl (meth) acrylate, 2,3-epoxycyclopentylmethyl (meth) acrylate, 7,8-epoxy [tricyclo [5.2.1.0] dec-2-yl] oxymethyl (meth) acrylate And alicyclic epoxy group-containing vinyl compounds.

  One of these may be used alone, or two or more thereof may be used in any combination and ratio. Among these, it is preferable to use an aliphatic epoxy group-containing vinyl compound from the viewpoint of adhesion to the substrate. Furthermore, it is more preferable to use a (meth) acrylate compound, and it is particularly preferable to use glycidyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate glycidyl ether.

  The content ratio of the repeating unit structure derived from the epoxy group-containing vinyl compound (the repeating unit structure represented by the general formula (1)) in the vinyl polymer including the side chain α having an epoxy group is 30 mol% or more. Preferably, it is 40 mol% or more, more preferably 50 mol% or more, and particularly preferably 60 mol% or more. Moreover, it is 100 mol% or less normally, It is preferable that it is 99 mol% or less, It is more preferable that it is 90 mol% or less, It is further more preferable that it is 80 mol% or less, It is especially preferable that it is 70 mol% or less. There is a tendency that exposure sensitivity, electrical reliability, and chemical resistance can be ensured by setting the above lower limit value or more, and there is a tendency that excellent film quality and patterning property during development can be ensured by setting the upper limit value or less. is there.

  The vinyl polymer containing the side chain α having an epoxy group may further have a cyclic aliphatic group. By including the side chain β, there is a tendency that uniform and excellent film quality is obtained.

  The chemical structure of the vinyl polymer containing the side chain β having a cycloaliphatic group is not particularly limited. For example, the repeating unit structure represented by the following general formula (2) containing the side chain β having a cycloaliphatic group Can be included.

In the general formula (2), R ² represents a hydrogen atom or a methyl group.
Y represents a direct bond or a divalent linking group.
R ³ represents a cyclic aliphatic group which may have a substituent.

Examples of the divalent linking group for Y include an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond, a urethane bond, and an alkylene group that may have a substituent. A part of the methylene group of the alkylene group may be substituted with at least one bond selected from the group consisting of an unsaturated bond, an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond and a urethane bond. Examples thereof include a linking group containing an ester bond or an amide bond.
The number of carbon atoms of the alkylene group is not particularly limited, but is preferably 1 or more from the viewpoint of ease of synthesis, and is preferably 9 or less from the viewpoint of film forming properties, and is 7 or less. Is more preferable.

  Examples of the substituent that the alkylene group may have include, for example, a halogen atom, an alkenyl group having 2 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a phenyl group, a mesityl group, a tolyl group, a naphthyl group, and a cyano group. Group, acetyloxy group, C2-C9 alkylcarbonyloxy group, sulfamoyl group, C2-C9 alkylsulfamoyl group, C2-C9 alkylcarbonyl group, phenethyl group, hydroxyethyl group, acetyl An amide group, a dialkylaminoethyl group formed by bonding an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, a trialkylsilyl group having 1 to 8 carbon atoms, a nitro group, an alkylthio group having 1 to 8 carbon atoms, etc. Can be mentioned. Among these, preferably, an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxy group having 2 to 8 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, and a halogen atom. is there. From the viewpoint of ease of synthesis, the alkylene group is preferably unsubstituted.

  Among Y, from the viewpoint of ease of synthesis, a direct bond, an ether bond, an ester bond, an alkylene group interrupted by an ether bond, or an alkylene group interrupted by an ester bond is preferable, and an ester bond is more preferable. In addition, the alkylene group interrupted by the ether bond and the alkylene group interrupted by the ester bond are respectively synonymous with those represented by the general formula (1) X.

The number of carbon atoms of the cyclic aliphatic group in R ³ is not particularly limited, but is preferably 5 or more, more preferably 6 or more, and still more preferably 8 or more from the viewpoint of film strength. Further, from the viewpoint of the reactivity of the vinyl polymer, it is preferably 20 or less, more preferably 15 or less, and further preferably 12 or less.
The cyclic aliphatic group may be monocyclic or polycyclic, but is preferably polycyclic from the viewpoint of film strength.
Specific examples of the cycloaliphatic group include a cyclohexyl group, a dicyclopentanyl group, an adamantyl group, a norbornyl group, a tetracyclodecanyl group, etc. Among these, from the viewpoint of the strength of the film, a dicyclopentanyl group Or an adamantyl group is preferable and a dicyclopentanyl group is more preferable.

In order to obtain a vinyl polymer containing a side chain β having a cycloaliphatic group, it is preferable to use a cycloaliphatic group-containing vinyl compound as a polymerization component. Examples of the cyclic aliphatic group-containing vinyl compound include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyl. Examples include oxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, and the like. It is done. One of these may be used alone, or two or more thereof may be used in any combination and ratio.
Among these, it is preferable to use a polycyclic cycloaliphatic group-containing vinyl compound from the viewpoint of the strength of the film formed, and dicyclopentanyl (meth) acrylate or 2-methyl-2-adamantyl (meth). More preferably, acrylate is used.

  The content ratio of the repeating unit structure derived from these cyclic aliphatic group-containing vinyl compounds (the repeating unit structure represented by the general formula (2)) in the vinyl polymer containing the side chain α having an epoxy group is 1 mol% or more. It is preferably 10 mol% or more, more preferably 20 mol% or more. Moreover, it is preferable that it is 40 mol% or less, It is more preferable that it is 35 mol% or less, It is further more preferable that it is 30 mol% or less. There exists a tendency which can ensure the intensity | strength and electric reliability of the film | membrane which carried out application | coating formation by setting it as the said lower limit or more, and there exists a tendency which can ensure exposure sensitivity by setting it as the said upper limit or less.

  The vinyl polymer containing the side chain α having an epoxy group may contain a side chain γ having a carboxy group or an aromatic hydroxyl group for the purpose of imparting alkali developability.

  The chemical structure of the vinyl polymer including a side chain γ having a carboxy group or an aromatic hydroxyl group is not particularly limited. For example, in the following general formula (3) including a side chain γ having a carboxy group or an aromatic hydroxyl group The thing containing the repeating unit structure represented can be mentioned.

In the general formula (3), R ⁴ represents a hydrogen atom or a methyl group.
Z represents a direct bond or a divalent linking group.
R ⁵ represents a carboxy group or a group having an aromatic hydroxyl group.

Examples of the divalent linking group in Z include an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond, a urethane bond, and an alkylene group that may have a substituent. A part of the methylene group of the alkylene group may be substituted with at least one bond selected from the group consisting of an unsaturated bond, an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond and a urethane bond. Examples thereof include a linking group containing an ester bond or an amide bond.
The number of carbon atoms of the alkylene group is not particularly limited, but is preferably 1 or more from the viewpoint of ease of synthesis, and is preferably 9 or less from the viewpoint of film forming properties, and is 7 or less. Is more preferable.
Examples of the substituent that the alkylene group may have include, for example, a halogen atom, an alkenyl group having 2 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a phenyl group, a mesityl group, a tolyl group, a naphthyl group, and a cyano group. Group, acetyloxy group, C2-C9 alkylcarbonyloxy group, sulfamoyl group, C2-C9 alkylsulfamoyl group, C2-C9 alkylcarbonyl group, phenethyl group, hydroxyethyl group, acetyl An amide group, a dialkylaminoethyl group formed by bonding an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, a trialkylsilyl group having 1 to 8 carbon atoms, a nitro group, an alkylthio group having 1 to 8 carbon atoms, etc. Can be mentioned. Preferred are an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxy group having 2 to 8 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, and a halogen atom. From the viewpoint of ease of synthesis, the alkylene group is preferably unsubstituted.

  Among Z, from the viewpoint of ease of synthesis, a direct bond, an ether bond, an ester bond, an alkylene group interrupted by an ether bond or an alkylene group interrupted by an ester bond is preferable, and a direct bond or an ester bond is more preferable. Preferably, an ester bond is more preferable. In addition, the alkylene group interrupted by the ether bond and the alkylene group interrupted by the ester bond are respectively synonymous with those represented by X in the general formula (1).

Examples of the group containing an aromatic hydroxyl group in R ⁵ include a hydroxyphenyl group, a hydroxycarboxylphenyl group, a dihydroxyphenyl group, a trihydroxyphenyl group, a bromophenyl group, a dibromophenyl group, a hydroxynaphthyl group, a hydroxynitrophenyl group, a hydroxy group. A benzyl group etc. are mentioned. Among R ^5, a hydroxyphenyl group is preferable and a p-hydroxyphenyl group is more preferable from the viewpoints of cost and film formability.

In order to obtain a vinyl polymer containing a side chain γ having a carboxy group or an aromatic hydroxyl group, it is preferable to use a carboxy group-containing vinyl compound or an aromatic hydroxyl group-containing vinyl compound as a polymerization component. One of these may be used alone, or two or more thereof may be used in any combination and ratio.
Examples of the carboxy group-containing vinyl compound include (meth) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid and other unsaturated carboxylic acids.
Examples of the aromatic hydroxyl group-containing vinyl compound include o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, o-hydroxyphenyl (meth) acrylate, m-hydroxyphenyl (meth) acrylate, and p-hydroxyphenyl (meth). An acrylate, N- (4-hydroxyphenyl) (meth) acrylamide, etc. are mentioned.
Among these, from the viewpoint of sufficient alkali developability, it is preferable to use a carboxy group-containing vinyl compound. On the other hand, in order to achieve higher electrical reliability, it is preferable to use an aromatic hydroxyl group-containing vinyl compound. More preferably, (meth) acrylic acid is used as the carboxy group-containing vinyl compound, and p-droxystyrene or p-hydroxyphenyl (meth) acrylate is used as the aromatic hydroxyl group-containing vinyl compound.

  In the case where a carboxyl group or an aromatic hydroxyl group is introduced into a vinyl polymer containing a side chain α having an epoxy group to impart alkali developability, the carboxy group-containing vinyl compound and the aromatic hydroxyl group-containing vinyl compound are repeatedly used. The content ratio of the unit structure (repeating unit structure represented by the general formula (1)) is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol%. Further, it is preferably 40 mol% or less, particularly preferably 35 mol% or less, and further preferably 30 mol% or less. There exists a tendency which becomes easy to ensure alkali developability by setting it as the said lower limit or more, and it becomes easy to ensure the manufacture stability of the vinyl polymer containing the side chain alpha which has an epoxy group by setting it as the said upper limit or less. There is.

  When obtaining a vinyl polymer containing a side chain α having an epoxy group, other vinyl compounds may be used as other copolymerization components in addition to the three kinds of polymerization components. Examples of other vinyl compounds include styryl compounds such as styrene and α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, Hexyl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, benzyl ( (Meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N- (meth) acryloylmorpholine, (meth) acrylonitrile, (meth) acrylamide, N- Chiroru (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, (meth) acrylate compound, vinyl compounds such as vinyl acetate and the like. These can be used in a vinyl polymer containing a side chain α having an epoxy group in an amount less than 50 mol% as a repeating unit structure derived from the vinyl polymer, in any combination and ratio. Among these, it is preferable to use a (meth) acrylate compound from the viewpoint of reactivity.

  The method of polymerizing the epoxy group-containing vinyl compound, the cycloaliphatic group-containing vinyl compound, the carboxy group-containing vinyl compound, the aromatic hydroxyl group-containing vinyl compound, other vinyl compounds, etc. is not limited at all. For example, in an organic solvent Using a radical polymerization initiator, it can be synthesized by a known method such as adding a chain transfer agent as necessary and heating at the activation temperature of the radical polymerization initiator.

  The vinyl polymer containing the side chain α having an epoxy group may be obtained by polymerizing various polymerization components to obtain a polymer, and then adding another functional group to the side chain. For example, a carboxy group-containing compound having an aromatic hydroxyl group is added to a part of the side chain epoxy group to introduce an aromatic hydroxyl group into the side chain, or a vinyl compound containing a carboxy group or a hydroxyl group is copolymerized For example, an isocyanate group-containing compound having a vinyl group may be added to the carboxy group or the hydroxyl group to introduce a double bond into the side chain.

The weight average molecular weight (Mw) of the vinyl polymer containing the side chain α having an epoxy group of the present invention is preferably 3000 or more, more preferably 5000 or more, and further preferably 7000 or more. Moreover, it is preferable that the weight average molecular weight (Mw) of the vinyl polymer containing the side chain (alpha) which has an epoxy group is 100,000 or less, It is more preferable that it is 70000 or less, It is further more preferable that it is 50000 or less. There exists a tendency which can ensure film | membrane strength, such as chemical resistance, by setting it as the said lower limit or more, and there exists a tendency which can ensure the outstanding patterning characteristic by setting it as the said upper limit or less.
In addition, the weight average molecular weight (Mw) in the present invention is a value in terms of polystyrene measured using “Column GPC-804” manufactured by Shimadzu Corporation with “Gel Permeation Chromatograph System LS Solution” manufactured by Shimadzu Corporation. To do.

(Thermoplastic resin)
The thermoplastic resin is not particularly limited as long as it is a resin that softens at the temperature at the time of heating performed in the step (III), but acrylic resin and urethane resin in terms of affinity with other components and solubility in a coating solvent. , Novolak resins and the like are preferable examples. In addition, radical polymerizable unsaturated groups, cationic polymerizable groups, and other crosslinking groups may be introduced into these resins. In such a case, the radical polymerizable unsaturated group-containing compound described above or cationic polymerization may be used. It can also serve as a functional group-containing compound.

As a resin having both a radically polymerizable unsaturated group-containing compound and a thermoplastic resin, for example, Nippon Kayaku's ZAR, ZCR, CCR, etc., Epoac resin, glycidyl (meth) acrylate, etc. were polymerized as a copolymerization component. Examples thereof include resins obtained by ring opening of resins with (meth) acrylic acid or the like.
As a resin having both a cationic polymerizable group-containing compound and a thermoplastic resin, in addition to the vinyl polymer containing the side chain α having the above-described epoxy group, for example, novolaks such as NC, EOCN, XD, EPPN of Nippon Kayaku Co., Ltd. An epoxy resin etc. are mentioned.

  Although the photosensitive resin composition of the present invention is not particularly limited, the above-mentioned photo radical polymerization initiator, photo cationic polymerization initiator, radical polymerizable unsaturated group-containing compound, and vinyl polymer containing an epoxy group-containing side chain α Those containing at least four components are particularly preferred. A preferable range as each content ratio is 0.2% by mass or more and 15% by mass or less of the radical photopolymerization initiator with respect to the total solid content of the photosensitive resin composition. Photocationic polymerization initiator is 0.2 mass% or more and 10 mass% or less. A radically polymerizable unsaturated group containing compound is 5 mass% or more and 70 mass% or less. The vinyl polymer containing the side chain α having an epoxy group is 5% by mass or more and 80% by mass or less.

(Solvent for photosensitive resin composition)
Since the photosensitive resin composition of this invention is apply | coated on a polarizing layer, if it does not have a bad influence with respect to a polarizing layer, it will not specifically limit.
The solvent of the photosensitive resin composition of the present invention preferably contains an organic solvent. The organic solvent may be used alone or in combination of two or more.

Examples of organic solvents include glycol monoalkyl ethers; glycol dialkyl ethers; glycol diacetates; alkyl acetates; ethers; ketones; mono- or polyhydric alcohols; Examples thereof include hydrogens; aromatic hydrocarbons; chain or cyclic esters; alkoxycarboxylic acids; halogenated hydrocarbons; ether ketones; Among these, an organic solvent containing an ether bond and an ester bond, a ketone, and the like are preferable.
Examples of the organic solvent containing an ether bond and an ester bond include ethylene glycol monomethyl ether acetate, propylene glycol momethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate and the like.
Examples of the ketone include methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, acetylacetone and the like.

  When using the organic solvent for the photosensitive resin composition of the present invention, the total solid content is preferably 3% by weight or more, and more preferably 5% by weight or more. Moreover, it is preferable to set it as 30 weight% or less, and it is more preferable to set it as 20 weight% or less. When it is at least the lower limit value, the film thickness tends to be easily controlled, and when it is at most the upper limit value, the pot life of the photosensitive resin composition tends to be easily maintained.

(Preparation of photosensitive resin composition)
The method for preparing the photosensitive resin composition of the present invention is not particularly limited. For example, it can be prepared by dissolving or dispersing each of the above-mentioned components together with an organic solvent and stirring or applying ultrasonic waves. In addition, when preparing a composition, when a radically polymerizable unsaturated group containing compound and / or a cation polymerizable group containing compound are liquid, they are good also as a substitute for an organic solvent.

The photosensitive resin composition of the present invention is prepared by mixing the above-described components together with an organic solvent, followed by filtration using a filter, so that gel components, dust, and traces that may occur during synthesis of insoluble materials, resins, etc. It is preferable to remove metals and the like.
As the filter to be used, for example, Integris Optimizer, CUNO Nanoshield, Zeta Plus EC, or the like can be used. Note that insoluble materials, gel components, dust, trace metals, and the like may cause repellency when forming the protective layer. When there is a defect such as foreign matter or repellency penetrating the protective layer, the developer enters the lower polarizing layer from there and dissolves the polarizing layer. Therefore, it is preferable that the filter eye size is as small as possible. Specifically, it is preferably at least smaller than the thickness of the protective layer.

(Method of applying protective layer)
In the protective layer of the present invention, the photosensitive resin composition can be continuously applied onto the polarizing layer by the method described in the method for applying the polarizing layer. Thereafter, when the photosensitive resin composition contains an organic solvent, it may be dried. Drying can be performed by heating using a heating apparatus such as a clean oven, a hot plate, an infrared ray, a halogen heater, or microwave irradiation. Among these, a clean oven or a hot plate is preferable because the entire film can be easily heated uniformly.
What is necessary is just to select drying conditions suitably according to the kind of organic solvent, the heat resistance of a polarizing layer, etc. It is preferable to dry at a high temperature for a long time because it is easier to obtain stable curability when it is sufficiently dried. On the other hand, the shorter the time required for drying, the higher the productivity and the heating of the polarizing layer and the substrate. It is preferable to dry at a low temperature for a short time from the viewpoint of hardly affecting the above. Therefore, the drying temperature is usually 40 ° C. or higher, preferably 50 ° C. or higher, and is usually 150 ° C. or lower, preferably 130 ° C. or lower.
The drying time is preferably 15 seconds or more, and more preferably 30 seconds or more. Moreover, 5 minutes or less are preferable and 3 minutes or less are more preferable. Drying may be performed by a vacuum drying method, or a heating method and a vacuum drying method may be used in combination.

(Process (II))
The production method of the present invention includes, as the step (II), a step of patterning the polarizing layer and the protective layer by exposure and development with a developer.
In the patterning method by exposure and development, the protective layer formed in (I) is directly drawn by exposure or laser through an exposure mask, and a part of the protective layer is polymerized. Furthermore, the polarizing layer and the protective layer are patterned by performing a developing process for removing the protective layer in the portion that has not undergone the polymerization reaction without being exposed to light by exposure and the polarizing layer located therebelow.
The light source used for exposure is not particularly limited as long as the protective layer can be polymerized. Specifically, for example, a xenon lamp, a halogen lamp, a tungsten lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a fluorescent lamp, a lamp light source such as an LED, an argon ion laser, YAG Examples include laser light sources such as lasers, excimer lasers, nitrogen lasers, helium cadmium lasers, blue-violet semiconductor lasers, and near infrared semiconductor lasers. Here, when using light of a specific wavelength, an optical filter may be used.
Exposure is usually 0.01 mJ / cm ² or more, preferably 0.1 mJ / cm ² or more, more preferably 1 mJ / cm ² or more. Also, typically 1000 mJ / cm ² or less, preferably 800 mJ / cm ² or less, more preferably 500 mJ / cm ² or less.

  The main purpose of the patterning of the present invention is to remove a portion of the polarizing layer that does not require coating when the polarizing layer continuously applied to a large substrate base material is divided into necessary substrate sizes. The shape and size of patterning are not particularly limited. It is also preferable that the patterned pattern includes a corner radius having R of 50 μm or more as shown in FIG. More preferably, R is 55 μm or more, more preferably 60 μm or more. In addition, there is no upper limit of R, and it can be adjusted as appropriate according to the shape of the pattern. However, the display area of the display that is desired to be as large as possible is wasted for the purpose of removing unnecessary portions in the division from the substrate base material. It is necessary to cover without. From this point, although it depends on the size of the display area, it is preferably 5 cm or less, more preferably 2 cm or less, and particularly preferably 5 mm or less. Depending on the polarizing layer or protective layer, the corner polarizing layer or protective layer may be easily peeled off from the base during development. By making R a corner radius in the above range, the defects are greatly improved. It tends to be possible.

(Developer)
The developer of the present invention, as long as it dissolves both the non-exposed portion of the protective layer and the polarizing layer, and does not adversely affect the protective layer of the exposed portion and the polarizing layer located thereunder, such as damage, There is no particular limitation.
The developer of the present invention is appropriately selected according to the characteristics of the polarizing layer used. When the polarizing layer is water-soluble, it is preferable to use a developer containing an organic solvent. On the other hand, when the polarizing layer is insoluble or sparingly soluble by, for example, insolubilizing the polarizing layer, an alkali developer is preferably used.

In the case of using a developer containing an organic solvent, the organic solvent is preferably contained in an amount of 80% by volume or more, and more preferably 90% by volume or more, particularly from the viewpoint of the influence on the polarizing layer and the dissolution rate. Moreover, there is no upper limit and 100 volume% may be sufficient.
In addition to the organic solvent, the developer may contain water, a nonionic surfactant, or the like.
The water contained in the developer is preferably 20% by volume or less, and preferably 10% by volume or less. By not having too much water, the protective layer tends to be developed while suppressing the influence on the polarizing layer.

As the organic solvent used in the developer of the present invention, for example, polar solvents such as alcohols, ethers, esters, ketones, lactams, amides, amines, sulphoxides, and carboxylic acids can be suitably used. Specifically, since the polarizing layer needs to be dissolved so slowly that the protective layer is not whitened, propylene glycol monomethyl ether, ethylene glycol, diethylene glycol monomethyl ether, dimethylformamide, dimethyl sulfoxide, N-methyl Examples include pyrrolidone, methyl glycol acetate, ethyl diglycol acetate, 3-methoxybutanol, methyl isobutyl ketone, methyl ethyl ketone, diethylene glycol mono-n-butyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, glycerin and the like.
The organic solvent used in the developer of the present invention may be used alone or in combination.

  Examples of the alkali developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, and sodium metasilicate; aliphatic secondary amines such as ethylamine and n-propylamine; trimethylamine, Aliphatic tertiary amines such as methyldiethylamine, dimethylethylamine and triethylamine; aromatic tertiary amines such as pyridine, collidine, lutidine and quinoline; alkanolamines such as ethanoldimethylamine, methyldiethanolamine and triethanolamine; tetramethyl Examples include aqueous solutions of alkaline compounds such as quaternary ammonium salts such as ammonium hydroxide and tetraethylammonium hydroxide. These may be used alone or mixed and adjusted, or an alkali developer and a water-soluble organic solvent may be mixed and used.

  In addition, the developer used in the present invention may contain a surfactant, an antifoaming agent, a buffering agent, a complexing agent, and the like. Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters; and alkylbenzene sulfonic acids. Anionic surfactants such as salts, alkylnaphthalene sulfonates, alkyl sulfates, alkyl sulfonates, sulfosuccinic acid ester salts; amphoteric surfactants such as alkylbetaines and amino acids.

(Development method)
There are no particular restrictions on the development method and its conditions. Examples of the development method include immersion development, paddle development, spray development, brush development, and ultrasonic development. Of these, immersion development and spray development are preferred because they are difficult to get smudged, hardly cause damage to the protective layer and the polarizing layer, and are easily developed uniformly. Further, paddle development is preferable in that the amount of developer used can be suppressed.
The development temperature is usually 10 ° C. or higher, preferably 15 ° C. or higher, and usually 50 ° C. or lower, preferably 45 ° C. or lower. After the development, it is preferable to dry it by compressed air or the like as it is or after washing with another solvent. Here, as the other solvent, it is preferable to select a solvent that is mixed with the developer without dissolving the protective layer and the polarizing layer after exposure.

In the development step of the present invention, as shown in FIG. 1, the polarizing layer is preferably eroded from the contour of the protective layer to the inside. Since the protective layer portion outside the contour of the eroded polarizing layer becomes a sufficient margin for the melt flow in the step (III), the protective layer can seal the side surface of the polarizing layer contour portion.
The distance by which the contour portion of the polarizing layer enters from the contour portion of the protective layer to the inside is preferably not less than the thickness of the polarizing layer, and preferably not more than 5 mm. When it is at least the above lower limit, the side surface of the contour portion of the polarizing layer tends to be sufficiently protected from the subsequent process, and when it is at most the above upper limit, the time required for development tends to be suppressed. Since the protective layer of the present invention has a lower dissolution rate in the developer than the polarizing layer, the erosion distance can be adjusted as appropriate by the development time.

(Process (III))
The production method of the present invention includes, as the step (III), a step of melt-flowing the patterned protective layer by heating. As shown in FIG. 2, the protective layer is melt-flowed to seal the side surface of the contour portion of the polarizing layer exposed after development.
The condition of the melt flow method is not particularly limited as long as the protective layer after development is softened and the side surface of the contour portion of the polarizing layer can be sealed. From the viewpoint of heat resistance of the polarizing layer, the heating temperature is preferably 200 ° C. or lower, and particularly preferably 180 ° C. or lower. Moreover, 90 degreeC or more is preferable and 110 degreeC or more is especially preferable in order to further accelerate | stimulate hardening of a protective layer by heating.
The heating time is preferably as short as possible in order to avoid deterioration of the polarizing layer, but is preferably longer for the purpose of further promoting the curing of the protective layer, and is usually 1 minute or more, preferably 10 minutes or more, and usually 120 Min or less, preferably 60 min or less.
A known method can be freely selected as the heating method, and examples thereof include a hot plate, an IR oven, and a convection oven.

(Other processes)
In order to obtain the polarizing element of this invention, you may have a process besides said (I)-(III) process. For example, the process of providing an alignment film on a board | substrate, the process of providing the wettability of a board | substrate, etc. are mentioned.

(Process of providing alignment film on substrate)
In order to improve the orientation of the polarizing layer, an alignment film may be provided on the substrate before the step (I). Specifically, a known method described in “Liquid Crystal Handbook” (Maruzen Co., Ltd., issued on October 30, 2000, pages 226 to 239) can be used.

(Process for imparting wettability to the substrate)
In forming a polarizing layer by coating, wettability may be imparted to the substrate in order to suppress repelling of the composition for forming a polarizing layer. The treatment for imparting wettability and forming the lyophilic portion is not particularly limited, but includes corona treatment, plasma treatment, ultraviolet irradiation (UV ozone) treatment, which is a physical or chemical modification treatment means. Apply surface treatment. At this time, the lyophilic state may be adjusted by adjusting the gas composition and processing time.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist thereof.

<Method for Producing Cationic Polymerizable Group-Containing Resin-1>
In a flask equipped with a reflux condenser, a stirrer, and a nitrogen blowing tube, 47 parts by mass of monomethacrylate having a tricyclodecane skeleton (“FA-513M” manufactured by Hitachi Chemical Co., Ltd.), 61 parts by mass of glycidyl methacrylate, propylene glycol monomethyl 400 parts by mass of ether acetate and 8.0 parts by mass of dimethyl 2,2′-azobis (2-methylpropionate) were charged. After the purged flask was replaced with nitrogen, the liquid temperature was raised to 80 ° C. while stirring, and the reaction was carried out at 80 ° C. for 6 hours. Further, dimethyl 2,2′-azobis (2-methylpropionate) was decomposed at 100 ° C. for 1 hour. Thereafter, propylene glycol monomethyl ether acetate was distilled under reduced pressure at 80 ° C. and concentrated to a solid concentration of about 50% by mass to obtain a cationically polymerizable group-containing compound-1. The weight average molecular weight (Mw) of this resin was about 11,000.
The weight average molecular weight was measured using “Column GPC-804” manufactured by Shimadzu Corporation with “Gel Permeation Chromatograph System LS Solution” manufactured by Shimadzu Corporation.

<Method for Producing Cationic Polymerizable Group-Containing Resin-2>
In a flask equipped with a reflux condenser, a stirrer and a nitrogen blowing tube, 44 parts by mass of dicyclopentanyl methacrylate (“FA-513M” manufactured by Hitachi Chemical Co., Ltd.), 46 parts by mass of glycidyl methacrylate, 11 parts by mass of methacrylic acid, 300 parts by mass of diethylene glycol methyl ethyl ether and 9 parts by mass of dimethyl 2,2′-azobis (2-methylpropionate) were charged. The purged flask was purged with nitrogen, and then the liquid temperature was raised to 80 ° C. while stirring and reacted at 80 ° C. for 6 hours to obtain a cationically polymerizable group-containing resin-2. The resin had a weight average molecular weight (Mw) of about 9,000.

The structure of the repeating unit contained in the cationically polymerizable group-containing resin-2 is as follows.
The content of the repeating unit structure derived from glycidyl methacrylate in the cationically polymerizable group-containing resin-2 is 50 mol%, the content of the repeating unit structure derived from dicyclopentanyl methacrylate is 30 mol%, and is derived from methacrylic acid. The content ratio of the repeating unit was 20 mol%.

<Preparation of photosensitive resin composition-1>
Of the components in Table 1, first, a photocationic polymerization initiator (Irg250), a photoradical polymerization initiator (Irg907), and a thermal radical polymerization initiator (VAm-110) were weighed, and propylene glycol monomethyl ether as an organic solvent was measured there. Acetate (PGMEA) was added and stirred with a magnetic stirrer to completely dissolve.
Next, the components in Table 1 other than the above were added, and stirring was further continued for 10 minutes. Next, it filtered using Integris Optimizer V47 0.02 micrometer FD5A XFR, and obtained the photosensitive resin composition-1.

<Adjustment of photosensitive resin composition-2>
Among the components in Table 2, first, a photocationic polymerization initiator (Irg250), a photoradical polymerization initiator (Irg907), a sensitizer (UVS-1331), and an accelerator (ET-2201) were weighed and organically contained therein. The solvent, propylene glycol monomethyl ether acetate (PGMEA), was added and stirred with a magnetic stirrer to completely dissolve it.
Next, the components in Table 2 other than the above were added and stirring was continued for another 10 minutes. Next, it filtered using the Optimizer V47 0.02 micrometer FD5A XFR of Entegris, and obtained the photosensitive resin composition-2.

<Adjustment of insolubilized liquid 1>
Insoluble solution 1 was prepared by adding 75.6 parts by mass of 6N sulfuric acid to 24.4 parts by mass of bis (hexamethylene) triamine (manufactured by Tokyo Chemical Industry Co., Ltd.) and dissolving with stirring. The viscosity of insolubilized solution 1 was 50 cP.

[Example 1]
A composition 1 for forming a polarizing layer is prepared by stirring and dissolving 20 parts of a lithium salt of a dye represented by the following formula (a) and 1 part of a dye represented by the following formula (b) in 79 parts of water. Prepared.

  An alignment film (polyimide film thickness of about 60 nm) formed on a glass substrate (10 × 10 cm, thickness 0.7 mm) and subjected to a rubbing treatment in a horizontal direction on the end surface was prepared as a substrate. A polarizing layer having a film thickness of about 0.4 μm is formed on this alignment film by applying the polarizing layer forming composition 1 with a die coater (wet film thickness 2 μm, head speed 15 mm / s) and naturally drying. did. In addition, the environmental conditions at the time of application | coating were 23 degreeC and 50RH%.

On the obtained polarizing layer, about 0.5 cc of photosensitive resin composition-1 is dropped, and the rotational speed of the spin coater is adjusted so that the film thickness after the melt flow in step (III) is 500 nm, The coating was performed by rotating for 50 seconds. Thereafter, it was dried by heating on a hot plate at 90 ° C. for 90 seconds to form a protective layer. This sample was exposed through a mask having a negative pattern at a dose of 500 mJ / cm ² using a 3 kW high-pressure mercury lamp.
Next, this sample was developed by immersing in a developer mixed with 95% by volume of propylene glycol monomethyl ether and 5% by volume of water while shaking for 30 seconds. After development, the film was poured with propylene glycol monomethyl ether acetate and then dried with compressed air.
When the sample after development was observed with a microscope, the distance from the contour of the protective layer to the contour of the polarizing layer was about 3 μm.

Next, this sample was heated in an oven at 180 ° C. for 30 minutes to obtain a polarizing element.
When the cross-sectional SEM of the part corresponding to the outline part of a polarizing layer of the obtained polarizing element was observed, as shown in FIG. 4, the protective layer melt-flowed and sealed the outline part side surface of the polarizing layer. Confirmed (50,000 times magnification). In FIG. 4, the contour portion of the protective layer was not seen due to the magnification (magnification 50,000 times), but was interrupted about 3 μm from the contour portion of the polarizing layer.

<Evaluation of polarization characteristics>
The obtained polarizing element was divided in half, and the appearance when the polarizing layers were superposed so as to be orthogonal or parallel was observed. The results are shown in FIG. The portion surrounded by the black line is the portion where the solid patterns of the two plates overlap.
<Evaluation of solvent resistance>
N-methylpyrrolidone was dropped onto the obtained polarizing element, held for 5 minutes after dropping, and then the dripped N-methylpyrrolidone was sucked off. After drying, the state of the protective layer and polarizing layer was observed, and no abnormality was observed. It was.

[Example 2]
A substrate having a polarizing layer formed on the substrate in the same manner as in Example 1 was impregnated in the insolubilizing solution 1 for 5 seconds. After removing the substrate, the substrate was washed with demineralized water, and then the substrate was air-dried to obtain an insolubilized polarizing layer.

About 0.5 cc of photosensitive resin composition-2 is dropped on the insolubilized polarizing layer, and the spin coater is rotated so that the film thickness after the melt flow in step (III) is 1.2 μm. The number was adjusted and applied by rotating for 10 seconds. Thereafter, the film was vacuum-dried for 1 minute, and then heated and dried on a hot plate at 120 ° C. for 90 seconds to form a protective layer. This sample was exposed through a mask having a negative pattern at a dose of 200 mJ / cm ² using a 3 kW high pressure mercury lamp. The mask pattern is a negative pattern in which 18 square patterns of 1 cm × 1 cm are used, and the corner of the pattern is a corner radius with R of 70 μm.
Next, this sample was developed with a 0.04% by weight aqueous potassium hydroxide solution for 60 seconds in a shower type developing machine and washed with water for 20 seconds. After pouring with propylene glycol monomethyl ether acetate, it was dried with compressed air.

  When the sample after development was observed with a microscope, the distance from the contour of the protective layer to the contour of the polarizing layer was about 2.5 μm. In addition, when all four corners (4 × 18 = 72) of the obtained pattern were observed with a microscope (5 times), there was no peeling in the case of the corner radius, but there were 72 of 90 ° angles. In 15 samples, peeling of the polarizing layer and the protective layer was observed.

Next, this sample was heated in an oven at 180 ° C. for 30 minutes to obtain a polarizing element.
When the cross-sectional SEM of the part corresponding to the outline part of a polarizing layer of the obtained polarizing element was observed, it confirmed that the protective layer melt-flowed and sealed the outline part side surface of the polarizing layer.

<Evaluation of polarization characteristics>
Dividing the obtained polarizing element in half and observing the state where each polarizing layer was overlapped so as to be orthogonal or parallel, the damage was not observed in the polarizing layer, it was good Polarization characteristics were observed.

<Evaluation of solvent resistance>
N-methylpyrrolidone was dropped onto the obtained polarizing element, held for 5 minutes after dropping, and then the dripped N-methylpyrrolidone was sucked off. After drying, the state of the protective layer and polarizing layer was observed, and no abnormality was observed. It was.

From the above results, it is possible to perform patterning without damaging the polarizing layer by applying a protective layer formed from a photosensitive resin composition on the polarizing layer and developing the upper and lower layers simultaneously. It was shown that. Further, the side surface of the contoured portion of the polarizing layer exposed after development is sealed by the melt flow of the protective layer, and the polarizing layer is removed from the solvent used in the subsequent steps (the coating solvent for the alignment film for liquid crystal (N-methylpyrrolidone)). It was confirmed that it could be protected.
Further, it was confirmed that the corner R pattern can be satisfactorily patterned without defects even under conditions where a load such as shower development is likely to be applied.

  According to the method for producing a polarizing element of the present invention, the polarizing layer continuously applied on the substrate can be patterned together with the formation of the protective layer, and can be protected from subsequent processes. This is useful for cutting out a divided substrate by partitioning a plurality of In-Cell type polarizing elements having a contact with a forming solvent (N-methylpyrrolidone or the like) and a cleaning step from one substrate base material.

Claims (7)

The manufacturing method of the polarizing element containing a board | substrate, a polarizing layer, and a protective layer which has the following processes.
(I) A step of continuously applying a composition for forming a polarizing layer on a substrate to form a polarizing layer, and then forming a protective layer by continuously applying a photosensitive resin composition on the polarizing layer.
(II) A step of patterning the polarizing layer and the protective layer by exposure and development with a developer.
(III) A step of melt-flowing the patterned protective layer by heating. 2. The method for manufacturing a polarizing element according to claim 1, wherein, in the step (II), the polarizing layer includes erosion from the outline of the protective layer to the inside. 3. The method for manufacturing a polarizing element according to claim 1, wherein in the step (III), the side surface of the contour portion of the polarizing layer is sealed with a protective layer. The manufacturing method of the polarizing element of any one of Claim 1 thru | or 3 whose heating of the said (III) process is 90 to 200 degreeC. The polarizing element manufactured using the manufacturing method of any one of Claims 1 thru | or 4. The polarizing element according to claim 5, wherein the patterned pattern includes a corner radius in which R is 50 μm or more. An image display device comprising the polarizing element according to claim 5.

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