KR20220084268A - An optical laminate comprising a shaping film and a shaping film - Google Patents

Abstract

When an optical laminate is formed in combination with a separate film, excellent luminance and luminance viewing angle can be expressed, and it can contribute to the durability (particularly, humidification durability) of the optical laminate, and also a shaping film excellent in processability. to provide. The shaping film of the present invention is a shaping film comprising a base part and an uneven part formed on one side of the base part, wherein the uneven part has a convex part and a concave part having a cell structure formed by being surrounded by the convex part, The height of the convex portion is 5% to 40% with respect to the thickness of the shaping film, the average area of the concave portion having the cell structure is 5000 μm ² or more, and the wall surface of the convex portion is within 500 μm from the short side of the shaping film exist.

Description

An optical laminate comprising a shaping film and a shaping film

The present invention relates to a shaping film and an optical adhesive laminate including the shaping film.

In recent years, the request|requirement with respect to thickness reduction of an image display apparatus (for example, a liquid crystal display device, an organic electroluminescent display apparatus) and improvement of design (for example, narrow bezel reduction) is becoming very strong. In connection with this, the demand for integration of the optical member and/or optical film used for an image display apparatus and/or integration of a function is also strong. As an example of such integration or integration of functions, it has been proposed to directly bond a shaping film to a predetermined optical member or the like to impart a light-diffusing function. In the light-diffusion film, luminance, luminance viewing angle and workability, and durability (particularly, humidification durability) of an optical laminate including the light-diffusion film are required in some cases, but in a light-diffusion film used by direct bonding, It is difficult to satisfy these characteristics in a good balance.

Japanese Patent Laid-Open No. 2012-118235 Japanese Patent Laid-Open No. 2009-025774

The present invention has been made in order to solve the above conventional problems, and its main purpose is that, when an optical laminate is formed in combination with a separate film, excellent luminance and luminance viewing angle can be expressed, and the durability of the optical laminate is It is to provide a shaping film which can contribute to (particularly, humidification durability) and is excellent in workability.

The shaping film of the present invention is a shaping film comprising a base part and an uneven part formed on one side of the base part, wherein the uneven part has a convex part and a concave part having a cell structure formed by being surrounded by the convex part, The height of the convex portion is 5% to 40% of the thickness of the shaping film, the average area of the concave portion having the cell structure is 5000 μm ² or more, and the wall surface of the convex portion is within 500 μm from the edge of the shaping film this exists

In one embodiment, the said base material part and the said uneven|corrugated part are comprised from copper material.

In another situation of the present invention, an optical laminate is provided. This optical laminate includes the shaping film and a separate film disposed so as to oppose the uneven portions of the shaping film on one side of the shaping film, and the overall cross-sectional area (A) in the uneven portions The ratio (B/A) of the cross-sectional area (B) of the concave portion is 50% or more.

In one embodiment, the optical laminate further comprises an adhesive layer between the shaping film and the star film.

In one embodiment, the portion where the thickness of the adhesive layer is maximum is a position corresponding to the recess of the shaping film.

In one embodiment, the said adhesive layer contains an active energy ray hardening-type adhesive agent.

In one embodiment, the storage elastic modulus in 25 degreeC of the said contact bonding layer is 100 kPa or more.

In one embodiment, the said other film is a polarizer, a wavelength conversion film, a polarization reflection film, glass, or a resin film.

In one embodiment, the said optical laminated body is a polarizing plate.

According to the present invention, by composing the surface with irregularities of a specific shape, excellent luminance and luminance viewing angle can be expressed when an optical laminate is formed in combination with a separate film, and the durability of the optical laminate (particularly, humidity durability) ), and can also provide a molding film excellent in processability.

1 is a schematic cross-sectional view of a shaping film according to an embodiment of the present invention.
2 is a schematic plan view showing a representative example of a planar view shape of a convex portion of an uneven surface in a shaping film according to an embodiment of the present invention.
It is a schematic sectional drawing of the optical laminated body by one Embodiment of this invention.
It is a schematic sectional drawing of the polarizing plate by one Embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described with reference to drawings, this invention is not limited to these embodiment. In addition, the drawings are schematically shown for easy viewing, and the ratios of length, width, and thickness, and the shape and fineness of irregularities are different from the actual ones.

A. shaping film

A-1. full configuration

1 is a schematic cross-sectional view of a shaping film according to an embodiment of the present invention. The shaping film 100 of the example of illustration is equipped with the base material part 10, and the uneven|corrugated part 20 formed in the single side|surface of the base material part 10. The uneven portion 20 has a convex portion 21 and a concave portion 22 . The shaping film of the present invention can function as an optical acid film by attaching the concave-convex portion 20 to a separate film and using it.

2 is a schematic plan view showing a representative example of a planar view shape of a convex portion of an uneven portion in a shaping film according to an embodiment of the present invention. As shown in FIG. 2 , the concave portion 22 may have a cell structure formed while being surrounded by the convex portion 21 (substantially, a wall surface of the convex portion). By forming the recesses having a cell structure, when the shaping film is laminated on a separate film to constitute an optical laminate, it is possible to prevent the penetration of moisture into the optical laminate. In addition, by forming the recessed portion having a cell structure, it is possible to obtain a shaping film capable of cutting with good workability by preventing defects such as cracking and chipping in the cut portion. Moreover, it is not necessary that all of the recesses have a cell structure, and, for example, in the vicinity of the edge of the shaping film, the recesses may be opened toward the edge of the shaping film.

As for the planar view shape of the convex part 21 in an uneven|corrugated part, any suitable shape can be employ|adopted. The planar shape of the convex part 21 may be a shape with regularity (for example, a grid|lattice shape), as shown, for example in FIG. 2, or an irregular shape may be sufficient as it. The pitch of the convex portions (the distance between the convex portions and the convex portions) is preferably 1000 µm or less, more preferably 500 µm or less, and still more preferably 100 µm or less. When the planar shape of the convex portion has regularity, a bias may be formed at an angle of 1 degree to 90 degrees. When the planar shape of the convex portion is an irregular shape, the pitch means an average pitch, and it is preferable that the distribution be 50% or more within ±50% of the average value of the pitch. With this configuration, when the shaping film is laminated on a separate film, the adhesive strength between the shaping film and the separate film is secured, and good display quality can be secured. Moreover, when a shaping|molding film is laminated|stacked on another film and the optical laminated body is comprised, the moisture penetration into the said optical laminated body can be prevented.

The height H of the convex portion 21 is 5% to 40% with respect to the thickness of the shaping film. Within this range, when the shaping film is laminated on a separate film to constitute an optical laminate, only the convex portions of the shaping film (substantially, the upper portion of the convex portions) can be adhered to the separate film. In addition, in this specification, adhesion|attachment of only a convex part may be called "adhesive adhesion" for convenience. By such adhesive adhesion, a substantially low refractive index part is defined by a recessed part (air part or a void part) in the vicinity of a sticking part. As a result, while realizing favorable light-diffusion performance, a luminance viewing angle can be enlarged. Conventionally, in an image display apparatus, a separate film (for example, a polarizer (polarizing plate)) and a light-diffusion film are separate, and as a result, an air layer is interposed between a polarizing plate and a light-diffusion film. The air layer is an obstacle to thinning, while the luminance viewing angle is kept large by retroreflection by the air layer. When the separate film and the light-diffusion film are integrated, thinning and function integration can be realized, but the luminance viewing angle is reduced by the exclusion of the air layer. By forming the low-refractive-index portion in the vicinity of the adhesive portion, light is retroreflected efficiently as in the case where there is an air layer. Therefore, according to embodiment of this invention, while exhibiting desired light-diffusion performance by forming adhesive bonding, a brightness|luminance viewing angle can be maintained large (wide). Moreover, it is advantageous also from a viewpoint of mechanical strength to make the height of a convex part into the said range, and by this, the shape of a recessed part can be maintained preferably and the outstanding light diffusivity and luminance viewing angle can be obtained.

The height H of the convex portion 21 is preferably 10% to 30%, more preferably 10% to 20% with respect to the thickness of the shaping film. If it is such a range, the said effect will become remarkable.

The height H of the convex portion 21 is preferably 2.5 µm to 25 µm, and more preferably 5 µm to 20 µm. If it is such a range, the said effect becomes remarkable.

The average area of the recesses having a cell structure is 5000 µm ² or more. If it is such a range, the shaping film which can implement|achieve the outstanding brightness|luminance viewing angle while suppressing a brightness|luminance fall can be obtained. The average area of the recesses having a cell structure is preferably 5000 µm ² to 50000 µm ² , more preferably 7000 µm ² to 40000 µm ² , and still more preferably 8000 µm ² to 30000 µm ² . If it is such a range, the said effect becomes remarkable and the shaping film excellent in mechanical strength can be obtained. The average area of the recesses having a cell structure can be obtained using image analysis software (free software "ImageJ"). That is, the inside and outside of a recessed part are determined by the threshold value of the binary image of the shaping|molding film surface, and the outer frame of a recessed part is specified. It can be calculated|required by calculating the area within the specified range, and calculating the average value of the calculated area.

In one embodiment, the maximum length in plan view of the concave portion serving as the cell structure is preferably 300 µm or more, more preferably 400 µm or more, and still more preferably 500 µm or more. Within this range, even when the shaping film is cut and used, the shaping film can effectively prevent moisture intrusion and improve durability near the end of the optical laminate. The maximum length of the concave portion as a cell structure means the distance at a location where the distance between the wall surfaces of the convex portions forming the concave portion is the longest.

The area ratio of the concave portion 22 to the total area of the uneven portion in a plan view is preferably 50% or more, preferably 60% or more, and more preferably 70% or more. The upper limit of the area ratio of the concave portion may be, for example, 90%. If the area ratio of the recesses is within this range, good diffusion performance is imparted to the shaping film while maintaining a wide luminance viewing angle, and adhesive strength can be secured when the shaping film is laminated on a separate film.

In the shaping film of this invention, the wall surface of the convex part 21 exists in the area|region within 500 micrometers from the edge of the said shaping film. In the present invention, the convex portion 21 can prevent moisture intrusion into the optical laminate when an optical laminate is formed by laminating a shaping film on a separate film. By forming the wall surface of the convex portion 21 in a region within 500 µm from the edge of the shaping film, moisture intrusion can be effectively prevented and durability near the end of the optical laminate can be improved. Preferably, the wall surface of the convex portion 21 is present in a region within 400 μm from the edge of the shaping film, and more preferably in a region within 300 μm from the edge of the shaping film. . Preferably, the wall surface of the convex portion 21 is present in the entire region within 500 µm (preferably within 400 µm, more preferably within 300 µm) from the edge of the shaping film.

The ratio (B/A) of the cross-sectional area (B) of the concave portion to the cross-sectional area (A) of the entire uneven portion (B/A) is preferably 50% or more, more preferably more than 50%, and still more preferably 60% or more, particularly preferably 70% or more. The upper limit of the ratio (B/A) may be, for example, 90%. When the ratio (B/A) is within this range, good diffusion performance is imparted to the shaping film while maintaining a wide viewing angle of luminance, and adhesive strength can be secured when the shaping film is laminated on a separate film. In addition, the cross-sectional area (A) of the entire uneven portion is the area of the portion surrounded by the line connecting the surface of the convex portion, the line connecting the bottom of the concave portion, and the vertical line at both ends of the film (for reference, the outside of the portion is surrounded by a broken line 1), the cross-sectional area B of the concave portion is the cross-sectional area of each concave portion 22 (the area of the portion surrounded by the line connecting the wall of the adjacent convex portion and the surface of the convex portion and the line connecting the bottom of the concave portion) ) is the sum of

The thickness of the shaping film of the present invention is preferably 25 µm to 250 µm, more preferably 40 µm to 100 µm.

The thickness of the said base part becomes like this. Preferably they are 22.5 micrometers - 225 micrometers, More preferably, they are 30 micrometers - 90 micrometers.

In one embodiment, the shaping film does not contain light diffusing particles. By comprising without including light-diffusing particles, a shaping film excellent in workability can be obtained. More specifically, it is possible to obtain a shaping film that does not easily break during film forming. In addition, when cutting the obtained shaping film, for example, defects such as cracking and chamfering in the cut can be prevented, and the end surface can be cut with good quality. It is one of the achievements of this invention that the brightness|luminance viewing angle was able to be enlarged while realizing the transferred optical acid performance even if light-diffusing particle|grains are not included.

The concavo-convex portion (concave-convex shape) can be formed by any suitable method. The concavo-convex shape can be formed by, for example, a roughening method or a method of imparting concavities and convexities with fine particles. As a specific example of a roughening system, an embossing process and sandblasting are mentioned. The concavo-convex portion (concave-convex shape) can typically be formed by shaping the surface of the melt-extruded film with an embossing roll. Further, the concave-convex shape is transferred by pressing the concave-convex mold to the surface of the film precursor formed from the active energy ray (eg, ultraviolet) curable resin composition, and then the composition is cured to obtain a shaping film. good night.

In one embodiment, a base material part and an uneven|corrugated part are comprised from the same material. Preferably, the base part and the uneven|corrugated part are integrally comprised by the same material.

A-2. construction material

Any suitable resin may be employed as the resin constituting the shaping film. Specific examples of the resin constituting the shaping film include a (meth)acrylic resin, a polyester resin (eg, polyethylene terephthalate (PET)), a cycloolefin resin (eg, norbornene resin), and a cellulose resin. (For example, triacetyl cellulose (TAC)), polyvinyl alcohol-based resin, polycarbonate-based resin, polyamide-based resin, polyimide-based resin, polyethersulfone-based resin, polysulfone-based resin, polystyrene-based resin, polyolefin system resin and acetate type resin are mentioned. These resins may be used independently and may use 2 or more types together. From a viewpoint of an optical characteristic, transparency, and versatility, (meth)acrylic-type resin, polyester-type resin, and cycloolefin-type resin are preferable, and (meth)acrylic-type resin is more preferable. In addition, in this specification, "(meth)acryl" means acryl and/or methacryl.

As (meth)acrylic-type resin, arbitrary suitable (meth)acrylic-type resin can be employ|adopted. In addition, for the simplification of a base material, hereafter, (meth)acrylic-type resin is only called acryl-type resin. Acrylic resin typically contains alkyl (meth)acrylate as a main component as a monomer unit. As the alkyl (meth)acrylate constituting the main skeleton of the acrylic resin, a linear or branched alkyl group having 1 to 18 carbon atoms can be exemplified. These can be used individually or in combination. In addition, you may introduce|transduce arbitrary appropriate copolymerization monomers into acrylic resin by copolymerization. The type, number, copolymerization ratio, etc. of these copolymerization monomers may be appropriately set according to the purpose. The structural component (monomer unit) of the main skeleton of an acrylic resin is mentioned later, referring General formula (2).

The acrylic resin may have at least one preferably selected from a glutalimide unit, a lactone ring unit, a maleic anhydride unit, a maleimide unit, and a glutaric anhydride unit. Acrylic resin which has a lactone ring unit is described in Unexamined-Japanese-Patent No. 2008-181078, for example, description of this publication is taken in in this specification as a reference. The glutalimide unit is preferably represented by the following general formula (1):

In the general formula (1), R ¹ and R ² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ³ is an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a cycloalkyl group having 6 carbon atoms. to 10 aryl groups. In general formula (1), Preferably, R< ¹ > and R< ² > are each independently hydrogen or a methyl group, and R< ³ > is hydrogen, a methyl group, a butyl group, or a cyclohexyl group. More preferably, R ¹ is a methyl group, R ² is hydrogen, and R ³ is a methyl group.

The alkyl (meth)acrylate is typically represented by the following general formula (2):

In the general formula (2), R ⁴ represents a hydrogen atom or a methyl group, and R ⁵ represents a hydrogen atom or an optionally substituted aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms. As a substituent, halogen and a hydroxyl group are mentioned, for example. Specific examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, and (meth)acrylic acid. n-hexyl, (meth)acrylic acid cyclohexyl, (meth)acrylic acid chloromethyl, (meth)acrylic acid 2-chloroethyl, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 3-hydroxypropyl, (meth) 2,3,4,5,6-pentahydroxyhexyl acrylic acid and 2,3,4,5-tetrahydroxypentyl (meth)acrylic acid are mentioned. In the general formula (2), R ⁵ is preferably a hydrogen atom or a methyl group. Accordingly, particularly preferred alkyl (meth)acrylates are methyl acrylate or methyl methacrylate.

The said acrylic resin may contain only a single glutalimide unit, and may contain the some glutalimide unit from which R< ¹ >, R< ² > and R< ³ > in the said General formula (1) differs.

The content rate of the glutalimide unit in the said acrylic resin becomes like this. Preferably it is 2 mol% - 50 mol%, More preferably, it is 2 mol% - 45 mol%, More preferably, it is 2 mol% - 40 mol% , particularly preferably from 2 mol% to 35 mol%, and most preferably from 3 mol% to 30 mol%. When the content ratio is less than 2 mol%, there is a possibility that the effects derived from the glutalimide unit (eg, high optical properties, high mechanical strength, and thickness reduction) may not be sufficiently exhibited. When the content ratio exceeds 50 mol%, for example, there is a possibility that heat resistance and transparency may become insufficient.

The said acrylic resin may contain only a single alkyl (meth)acrylate unit, and may contain the some alkyl (meth)acrylate unit from which ^R4 and R5 ⁱⁿ the said General formula (2) differ. .

The content rate of the alkyl (meth)acrylate unit in the said acrylic resin becomes like this. Preferably it is 50 mol% - 98 mol%, More preferably, it is 55 mol% - 98 mol%, More preferably, it is 60 mol% - 98 mol%. mol%, particularly preferably 65 mol% to 98 mol%, and most preferably 70 mol% to 97 mol%. When the content rate is less than 50 mol%, there is a possibility that the effect (eg, high heat resistance, high transparency) derived from the alkyl (meth)acrylate unit cannot be sufficiently exhibited. When the content is more than 98 mol%, the resin becomes brittle and cracks easily, so that high mechanical strength cannot be sufficiently exhibited, and there is a possibility that the productivity may be deteriorated.

The said acrylic resin may contain units other than a glutalimide unit and an alkyl (meth)acrylate unit.

In one embodiment, the acrylic resin may contain, for example, 0 wt% to 10 wt% of an unsaturated carboxylic acid unit not involved in an intramolecular imidization reaction described later. The content rate of an unsaturated carboxylic acid unit becomes like this. Preferably they are 0 weight% - 5 weight%, More preferably, they are 0 weight% - 1 weight%. Transparency, retention stability, and moisture resistance can be maintained as content is such a range.

In one embodiment, the acrylic resin may contain copolymerizable vinylic monomer units (other vinylic monomeric units) other than the above. As other vinyl monomers, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, allyl glycidyl ether, maleic anhydride, itaconic anhydride, N-methylmaleimide, N-ethylmaleimide , N-cyclohexylmaleimide, aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylvinyl Amine, allylamine, metaallylamine, N-methylallylamine, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acroyl-oxazoline, N-phenylmaleimide, phenylamino methacrylate ethyl, styrene, ?-methylstyrene, p-glycidylstyrene, p-aminostyrene, 2-styryl-oxazoline, and the like. These may be used independently and may be used together. Preferably, they are styrene-type monomers, such as styrene and (alpha)-methylstyrene. The content of the other vinyl monomer units is preferably 0 to 1% by weight, more preferably 0 to 0.1% by weight. If it is such a range, expression of an undesired phase difference and the fall of transparency can be suppressed.

The imidation ratio in the said acrylic resin becomes like this. Preferably it is 2.5 % - 20.0 %. If the imidization ratio is within this range, a resin excellent in heat resistance, transparency and moldability can be obtained, and the occurrence of scorching during film molding and a decrease in mechanical strength can be prevented. In the said acrylic resin, the imidation rate is represented by ratio of a glutalimide unit and an alkyl (meth)acrylate unit. This ratio can be obtained from an NMR spectrum, an IR spectrum, etc. of an acrylic resin, for example. In this embodiment, the imidation rate can be calculated|required by ¹ H-NMR measurement of resin using ¹ HNMR BRUKER Avance III (400 MHz). More specifically, let A be the peak area derived from the O-CH ₃ proton of the alkyl (meth)acrylate in the vicinity of 3.5 to 3.8 ppm, and the peak area derived from the N-CH ₃ proton of glutalimide in the vicinity of 3.0 to 3.3 ppm. It is calculated|required by the following formula, making the area of a peak B.

Imidization rate Im(%)={B/(A+B)}×100

The acrylic resin has a Tg (glass transition temperature) of preferably 110°C or higher, more preferably 115°C or higher, still more preferably 120°C or higher, particularly preferably 125°C or higher, and most preferably 130°C or higher. to be. When Tg is 110 degreeC or more, the polarizing plate containing the shaping|shaping film obtained from such resin tends to be excellent in durability. The upper limit of Tg is preferably 300°C or lower, more preferably 290°C or lower, still more preferably 285°C or lower, particularly preferably 200°C or lower, and most preferably 160°C or lower. When the Tg is within this range, the moldability may be excellent.

The said acrylic resin can be manufactured by the following method, for example. This method copolymerizes (I) an alkyl (meth) acrylate monomer corresponding to an alkyl (meth) acrylate unit represented by the general formula (2), an unsaturated carboxylic acid monomer and/or its precursor monomer to obtain a copolymer (a) to obtain; And, (II) by treating the copolymer (a) with an imidizing agent, the alkyl (meth) acrylate monomer unit and the unsaturated carboxylic acid monomer and/or its precursor monomer unit in the copolymer (a) are immobilized in the molecule. and introducing a glutalimide unit represented by the general formula (1) into the copolymer by performing a deoxidation reaction.

About the detail of the said acrylic resin and its manufacturing method, it describes in Unexamined-Japanese-Patent No. 2018-155812 and Unexamined-Japanese-Patent No. 2018-155813, for example. The description of these publications is incorporated herein by reference.

B. Optical Laminate

B-1. full configuration

It is a schematic sectional drawing of the optical laminated body by one Embodiment of this invention. The optical laminate 200 of the illustrated example includes a shaping film 100 and a separate film 110 disposed on one side of the shaping film 100 . The shaping film 100 and the separate film 110 are laminated so that the uneven portions 20 of the shaping film 100 and the separate film 110 face each other. Typically, the shaping film 100 and the separate film 110 are laminated with the adhesive layer 120 interposed therebetween.

As described above, in the uneven portion 20 of the shaping film 100, the ratio (B/A) of the cross-sectional area (B) of the concave portion to the cross-sectional area (A) of the entire uneven portion (B/A) is preferably 50% or more. , More preferably, it is more than 50%, More preferably, it is 60% or more, Especially preferably, it is 70% or more. The upper limit of the ratio (B/A) may be, for example, 90%. The ratio (B/A) may correspond to the porosity. If it is such a range, while realizing favorable light-diffusion performance, a luminance viewing angle can be enlarged, and the optical laminated body excellent in mechanical strength can be obtained.

B-2. separate film

As the separate film, any suitable film may be employed. As another film, For example, Optical films, such as a polarizer, a wavelength conversion film, and a polarization reflection film; glass (preferably, thin glass); A resin film (for example, a protective film) etc. are mentioned.

In one embodiment, a polarizer is used as another film. In this embodiment, the said shaping film functions as a polarizer protective film, and the said optical laminated body can become a polarizing plate. The details of the polarizing plate will be described later.

B-3. adhesive layer

The adhesive layer is comprised of any suitable adhesive or tackifier. The adhesive layer is typically formed of a water-based adhesive (eg, a vinyl alcohol-based adhesive) or a curable adhesive (eg, an active energy ray-curable adhesive or a heat-curable adhesive).

In one embodiment, the said adhesive layer contains an active energy ray hardening-type adhesive agent. When an adhesive layer is formed using an active energy ray hardening-type adhesive agent, an optical laminated body can be obtained without impairing the uneven|corrugated shape of a shaping film.

Any suitable adhesive can be used as said active energy ray-curable adhesive agent, if it is an adhesive agent which can be hardened by irradiation of an active energy ray. Examples of the active energy ray curing adhesive include an ultraviolet curing adhesive and an electron beam curing adhesive. Specific examples of the curing type of the active energy ray-curable adhesive include a radical curing type, a cation curing type, an anion curing type, and combinations thereof (for example, a hybrid of a radical curing type and a cation curing type).

As the active energy ray-curable adhesive, for example, an adhesive containing a compound (eg, a monomer and/or an oligomer) having a radically polymerizable group such as a (meth)acrylate group or a (meth)acrylamide group as a curing component. can be heard

The specific example of the said active energy ray hardening-type adhesive agent and its hardening method is described in Unexamined-Japanese-Patent No. 2012-144690, for example. The above description is incorporated herein by reference.

As a coating method of the said active energy ray hardening-type adhesive agent, arbitrary suitable methods can be employ|adopted according to the viscosity of an adhesive agent, the thickness of the adhesive layer etc. made desired. As a coating method, application|coating by a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, a die coater, a bar coater, a rod coater etc. is mentioned, for example. Moreover, you may employ|adopt the application|coating by a dipping method.

Any suitable method can be employ|adopted as a hardening method of the said active energy ray hardening-type adhesive agent. Conditions, such as the wavelength of an active energy ray, irradiation amount, etc. can be set to arbitrary suitable conditions according to the kind etc. of the curable compound to be used.

The thickness of the portion at which the thickness of the adhesive layer is maximized is preferably 0.5 µm to 10 µm, more preferably 0.5 µm to 5 µm. If it is such a range, the space|gap by the unevenness|corrugation of a mold film can be formed suitably, and the optical laminated body excellent in mechanical strength can be obtained. In one embodiment, the portion at which the thickness of the adhesive layer is maximized corresponds to the gap between the upper surface of the convex portion of the shaping film (the surface facing the separate film) and the lower surface of the separate film (the surface opposite to the shaping film) can do. In another embodiment, the portion at which the thickness of the adhesive layer is maximized may be a position corresponding to the concave portion of the shaping film (FIG. 4). For example, the adhesive layer may be formed so that it may cover at least a part of the wall surface of the convex part of a shaping film. At this time, the adhesive layer is not formed on the concave surface of the shaping film, but is preferably in a so-called meniscus shape. In this embodiment, while ensuring a space|gap, the optical laminated body excellent in the adhesiveness of a shaping|shaping film and another film can be obtained.

In one embodiment, it is preferable that the thickness T of the adhesive layer formed on the upper surface of the convex part of a shaping film is thinner than the thickness (height) H of the convex part. The ratio (T/H) of the thickness T and the height H of the convex portion is preferably 50% or less, and more preferably 30% or less. If the ratio (T/H) is within such a range, good adhesive bonding can be realized. The lower limit of the ratio (T/H) may be, for example, 10%.

The shaping film has an uneven portion, and the convex portions of the shaping film and a separate film are adhered (ie, adhesively adhered) and laminated. It is preferable that it is also formed. In other words, it is preferable that the adhesive layer covers at least a portion (preferably all) of the surface of the separate film in the recess (void portion) of the shaping film. In this way, deterioration of another film can be prevented. This effect is particularly useful when the separate film is deteriorated by moisture, external air, and the like, and is useful, for example, when the separate film is a polarizer. The thickness of the contact bonding layer in a space|gap part may be constant, and may not be constant. In one embodiment, the adhesive layer of the void portion has a meniscus shape, so that its thickness is not constant. As a method of forming an adhesive layer in a space|gap part, after forming an adhesive precursor layer on a separate film, the method of bonding the said other film and a shaping|molding film is mentioned, for example.

The storage modulus of the adhesive layer at 25°C is preferably 100 kPa or more, more preferably 100 kPa to 3 GPa, and still more preferably 100 kPa to 1 GPa. If it is such a range, the space|gap by the unevenness|corrugation of a shaping film can be formed suitably, and the optical laminated body excellent in mechanical strength can be obtained. In addition, the storage modulus can be calculated|required by dynamic viscoelasticity measurement. Dynamic viscoelasticity measurement uses, for example, "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific for an adhesive sample having a thickness of 2 mm x diameter of 8 mm, deformation mode: torsion, measurement frequency: 1 Hz, temperature increase rate 5°C/min, measurement temperature: It can be carried out at -50°C to 150°C.

B-4. Polarizer

As mentioned above, in one Embodiment, the said optical laminated body is a polarizing plate. 4 is a schematic cross-sectional view of a polarizing plate according to one embodiment of the present invention. The polarizing plate 200a of the illustrated example includes a polarizer 110a and a polarizer protective film 100a laminated on the polarizer 110a via an adhesive layer 120 . The polarizer protective film 100a in this embodiment corresponds to the said shaping film. In addition, the polarizer 110a corresponds to the said other film. The polarizer protective film 100a is arrange|positioned so that the said uneven|corrugated part side may become the polarizer 110a side. The adhesive layer is the same as above. Practically, a separate protective film 140 is disposed on the opposite side to the polarizer protective film 100a. Practically, the pressure-sensitive adhesive layer 150 is provided as the outermost layer, enabling the polarizing plate to be attached to the image display cell. In addition, a separator (not shown) is temporarily attached to the surface of the pressure-sensitive adhesive layer 150 so as to be peelable, to protect the pressure-sensitive adhesive layer until the polarizing plate is actually used, and to enable roll formation. The polarizing plate by embodiment of this invention may be used as a back side polarizing plate of an image display apparatus, and may be used as a visual recognition side polarizing plate. According to embodiment of this invention, since polarizer protective film itself has light-diffusion performance and serves also as a shaping|shaping film, remarkable thickness reduction can be implement|achieved by the synergistic effect with the effect of the exclusion of an air layer.

Any suitable polarizer may be employed as the polarizer. For example, a single-layered resin film may be sufficient as the resin film which forms a polarizer, and the laminated body of two or more layers may be sufficient as it.

As a specific example of the polarizer composed of a single-layer resin film, a polyvinyl alcohol (PVA)-based film, a partially formalized PVA-based film, and a hydrophilic polymer film such as an ethylene/vinyl acetate copolymer-based partially saponified film, iodine, dichroic dye, etc. polyene-based oriented films such as those subjected to dyeing treatment and stretching treatment with a dichroic substance of PVA, dehydration treatment products of PVA and dehydrochloric acid treatment products of polyvinyl chloride. Preferably, since it is excellent in an optical characteristic, the polarizer obtained by dyeing|staining a PVA-type film with iodine and uniaxial stretching is used.

Dyeing with the said iodine is performed by immersing a PVA-type film in the iodine aqueous solution, for example. The draw ratio of the said uniaxial stretching becomes like this. Preferably it is 3 to 7 times. Extending|stretching may be performed after a dyeing process, and may be performed, dyeing|staining. Moreover, after extending|stretching, you may dye|dye. A swelling process, a crosslinking process, a washing process, a drying process, etc. are given to a PVA-type film as needed. For example, by immersing the PVA-based film in water and washing with water before dyeing, it is possible not only to wash the surface of the PVA-based film from stains and anti-blocking agents, but also to swell the PVA-based film to prevent staining and the like.

As a specific example of a polarizer obtained using a laminate, a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and a PVA-based resin layer coated on the resin substrate. The polarizer obtained using a laminated body is mentioned. A polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate is applied, for example, a PVA-based resin solution is applied to the resin substrate, and dried to form a PVA-based resin layer on the resin substrate. to obtain a laminate of a resin substrate and a PVA-based resin layer; It can be produced by; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer. In this embodiment, extending|stretching includes extending|stretching by immersing a laminated body in boric-acid aqueous solution typically. Moreover, extending|stretching can further include air-stretching the laminated body at high temperature (for example, 95 degreeC or more) before extending|stretching in boric acid aqueous solution as needed. The obtained resin substrate/polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), and the resin substrate is peeled from the resin substrate/polarizer laminate, may be used by laminating an appropriate protective layer of The detail of the manufacturing method of such a polarizer is described in Unexamined-Japanese-Patent No. 2012-73580, for example. The above publication is incorporated herein by reference in its entirety.

The thickness of the polarizer is, for example, 1 µm to 80 µm. In one embodiment, the thickness of a polarizer becomes like this. Preferably they are 1 micrometer - 20 micrometers, More preferably, they are 3 micrometers - 15 micrometers.

A polarizer protective film, Preferably, it has optically isotropy substantially. In this specification, "it has substantially optically isotropy" means that the in-plane retardation Re(550) is 0 nm to 10 nm. The in-plane retardation Re(550) is more preferably 0 nm to 5 nm, still more preferably 0 nm to 3 nm, and particularly preferably 0 nm to 2 nm. If Re (550) of the polarizer protective film is within this range, adverse effects on display properties can be prevented when a polarizing plate including the polarizer protective film is applied to an image display device. Moreover, Re(550) is the in-plane retardation of the film measured with the light of wavelength 550nm in 23 degreeC. Re(550) is obtained by the formula: Re(550)=(nx-ny)×d. Here, nx is the refractive index in the direction in which the in-plane refractive index is maximized (ie, the slow axis direction), ny is the refractive index in the direction orthogonal to the slow axis in the plane (ie, the fast axis direction), and d is the thickness of the film (nm).

It is so preferable that the light transmittance in 380 nm in 40 micrometers in thickness of a polarizer protective film is high. Specifically, the light transmittance is preferably 75% or more, more preferably 80% or more, and still more preferably 85% or more. If the light transmittance is within such a range, desired optical properties can be secured. The light transmittance can be measured, for example, by a method according to ASTM-D-1003.

The haze of the polarizer protective film is preferably 50% to 99%, more preferably 70% to 95%.

It is preferable that a polarizer protective film has the following characteristics. Assuming that the light transmittance at 550 nm is 100%, the light transmittance at 450 nm and 650 nm is preferably within ±5% of the difference from the light transmittance at 550 nm, more preferably within ±2%. to be.

Regarding the luminance viewing angle of the polarizer protective film, the luminance half value angle (angle at which the luminance is 50% of the front surface) is preferably 56° (28° on one side) or more, more preferably 60° to 70° (30° on one side) ∼35°). The angle at which the luminance is 25% of the front is preferably 90° (45° on one side) or more, and more preferably 96° to 120° (48° to 60° on one side). ADVANTAGE OF THE INVENTION According to embodiment of this invention, the outstanding diffusion performance can be provided to a polarizer protective film, and a brightness|luminance viewing angle can be maintained widely.

Refractive index ( _nF ) as the whole polarizer protective film becomes like this. Preferably it is 1.3-1.8, More preferably, it is 1.4-1.6. If the refractive index of a polarizer protective film is such a range, in a polarizing plate, the refractive index difference with the low-refractive-index part prescribed|regulated by the point adhesion with a polarizer can be made into a desired range.

The moisture permeability of the polarizer protective film is preferably 300 g/m 2 ·24 hr or less, more preferably 250 g/m 2 · 24 hr or less, still more preferably 200 g/m 2 · 24 hr or less, particularly preferably 150 g/m 2 ·24 hr or less, Most preferably, it is 100 g/m 2 ·24 hr or less. If the moisture permeability of the polarizer protective film is within this range, a polarizing plate having excellent durability and moisture resistance can be obtained.

C. Image display device

The polarizing plate may be applied to an image display device. Accordingly, the present invention also includes an image display device using such a polarizing plate. A liquid crystal display device and an organic electroluminescence (EL) display device are mentioned as a representative example of an image display apparatus. Since the image display apparatus employs a structure well known in the industry, detailed description thereof is omitted.

(Example)

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The measuring method of each characteristic is as follows. In addition, unless otherwise specified, "part" and "%" in Examples are based on weight.

(1) The thickness of the shaping film, notice of the convex part

The cross section of the shaping film obtained in the Example and the comparative example was observed with a scanning electron microscope, and the height of the shaping film and the height of a convex part were measured from the image.

(2) Cell size

The surface of the shaping film obtained in the Example and the comparative example was observed with a scanning electron microscope, and the average area of a recessed part was calculated|required from the image with image analysis software (free software "ImageJ"). More specifically, the inside and outside of the concave portion are determined by the threshold value of the surface binary image, the outer frame of the concave portion is specified, the area within the specified range is calculated, and the average value of the calculated area is calculated, and this is the average area of the concave portion did it with

(3) Distance from the edge of the shaping film to the outermost convex part

The surface of the shaping film obtained in the Example and the comparative example was observed with a scanning electron microscope, and the distance from the edge of the shaping film to the outermost convex part was measured from the image. In addition, the said distance was measured over the whole perimeter of a shaping|molding film, and the maximum value is shown in Table 1.

(4) Adhesion evaluation

After applying an adhesive to the surface of the polarizer at 1 μm, the polarizer and the uneven surface of the shaping film (polarizer protective film) obtained in Examples and Comparative Examples are bonded, and then UV irradiated and the adhesive is cured to cure the shaping film The polarizing plate which consists of (polarizer protective film)/adhesive layer/polarizer was obtained. Then, the microscopic observation of the said polarizing plate was performed, the filling state of a shaping recessed part was confirmed, and the following reference|standard evaluated.

○: Out of 100 recesses (voids), 80 or more are good (60 area% or more of the recesses are not filled with adhesive)

△: 30 to 79 out of 100 concave portions (voids) are good

×: Out of 100 recesses (voids), less than 30 good locations

(5) Humidification durability

It carried out similarly to said (4), and obtained the polarizing plate.

The shaping film (polarizer protective film) and the glass plate of the said polarizing plate were laminated|stacked through the acrylic adhesive. The obtained laminate was left to stand for 500 hours in an environment of a temperature of 60°C and a humidity of 90%. Then, the transmittance|permeability of the laminated body was measured with the absorptiometer with an integrating sphere ("V7100" manufactured by Nippon Bunko Corporation).

With respect to the transmittance before heating and humidification, the case where the transmittance after heating and humidification changed by 10% or more was regarded as fail (x), and the case where the change was less than 10% was regarded as pass (circle).

(6) luminance

It carried out similarly to said (4), and obtained the polarizing plate.

SJ8000 manufactured by LG was disassembled, the liquid crystal panel with a polarizing plate was taken out, and the said light plate was mounted as a backlight side polarizing plate. In addition, about the light-diffusion film provided in the backlight unit of the said product, only the mounting location was cut out and it mounted again. About the mounted product obtained in this way, the brightness|luminance of the front direction was measured using Ezconstrast by the ELDIM company. The measured luminance was shown as a ratio (%) when the front luminance at the time of separating a polarizing plate and a light-diffusion film was set to 100.

(7) Machinability

The shaping films obtained in Examples and Comparative Examples were cut with a lever-type cutter. The case where cracking/scraping occurred in the film edge part after cutting|disconnection from the film edge part toward the center of 300 micrometers or more was made into rejection (x) and the case where it did not generate|occur|produce was made into pass (circle).

<Example 1>

A methacrylic resin (manufactured by Kuraray, product name “Parafit HR-S”) is put into a single screw extruder, melt-extruded at 260° C., and a concave-convex shape is formed on one surface with an embossing roll, and a shaping film (thickness: 50) µm, convex part height: 10 µm, cell size: 15000 µm ² ) was obtained.

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Example 2>

Except having changed the embossing roll, it carried out similarly to Example 1, and obtained the shaping film (thickness: 46 micrometers, convex part height: 5 micrometers, cell size: 5000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Example 3>

A methacrylic resin (manufactured by Kuraray Corporation, product name "Parafit HR-S") was put into a single screw extruder, and melt-extruded at 260°C to obtain a substantially flat film with a thickness of 55 µm. On the surface of this film, 5 parts by weight of a photopolymerization initiator (Ciba Specialty Chemicals, trade name "Irgacure 184") is added to 95 parts by weight of urethane acrylate (manufactured by Shin-Nakamura Kagaku Kogyo Co., Ltd., trade name "NK Oligo U-108A"). After coating the UV curing resin and transferring the concave-convex shape to the coated surface, the UV curing resin was cured to obtain a shaping film (thickness: 55 μm, convex height: 5 μm, cell size: 10000 μm ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Example 4>

Except having changed the metal mold|die used, it carried out similarly to Example 3, and obtained the shaping film (thickness: 55 micrometers, convex part height: 20 micrometers, cell size: 10000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Comparative Example 1>

Except having changed the embossing roll, it carried out similarly to Example 1, and obtained the shaping film (thickness: 42 micrometers, convex part height: 2 micrometers, cell size: 10000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Comparative Example 2>

Except having changed the embossing roll, it carried out similarly to Example 1, and obtained the shaping film (thickness: 40 micrometers, convex part height: 1 micrometer, cell size: 12000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Comparative Example 3>

Except having changed the embossing roll, it carried out similarly to Example 1, and obtained the shaping film (thickness: 50 micrometers, convex part height: 4 micrometers, cell size: 10000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Comparative Example 4>

Except having changed the metal mold|die used, it carried out similarly to Example 3, and obtained the shaping film (thickness: 50 micrometers, convex part height: 25 micrometers, cell size: 11000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Comparative Example 5>

Except having changed the used metal mold|die, it carried out similarly to Example 3, and obtained the shaping film (thickness: 50 micrometers, convex part height: 5 micrometers, cell size: 3000 micrometers ² ).

The obtained shaping films were subjected to the above evaluations (1) to (7). A result is shown in Table 1.

<Comparative Example 6>

Except having changed the metal mold|die used, it carried out similarly to Example 3, and obtained the shaping film (thickness: 233 micrometers, convex part height: 50 micrometers). The shaping film had a prismatic shape and had no cell structure concave portions.

The obtained shaping films were subjected to the above evaluations (1), (5) and (7). A result is shown in Table 1.

<Comparative Example 7>

It carried out similarly to Example 3, it extruded and shape|molded methacryl-type resin, and the film was obtained. On the surface of this film, 5 parts by weight of a photopolymerization initiator (Ciba Specialty Chemicals, trade name "Irgacure 184") is added to 95 parts by weight of urethane acrylate (manufactured by Shin-Nakamura Kagaku Kogyo, trade name "NK Oligo U-108A") A mixture of 100 parts by weight of UV curing resin and 10 parts by weight of particles (silicon particles, manufactured by Momentive, trade name "Tospearl 1110", average particle diameter: 11 μm) was coated with a wire bar. After that, the coating layer was UV cured to A film (thickness: 199 µm, convex part height: 11 µm) was obtained.

The obtained shaping films were subjected to the above evaluations (1), (5) and (7). A result is shown in Table 1.

<Evaluation>

As is evident from Table 1, the polarizing plate comprised using the shaping|molding film of this invention can express outstanding brightness|luminance, and is excellent in humidification durability. In addition, the shaping film of the present invention is excellent in processability.

(Industrial Applicability)

The shaping film of the present invention can be used in various fields as a film capable of imparting a light-diffusing function. For example, the shaping film of the present invention is suitably used for a polarizing plate. The polarizing plate of this invention is used suitably for an image display apparatus. The image display apparatus of the present invention includes portable devices such as a portable information terminal (PDA), a smartphone, a mobile phone, a watch, a digital camera, and a portable game machine; OA equipment such as PC monitors, notebook computers, and photocopiers; household electrical appliances such as video cameras, televisions, and microwaves; In-vehicle devices such as a back monitor, a monitor for a car navigation system, and a car audio system; Display devices such as digital signage and information monitors for commercial stores; security devices such as monitors for monitoring; Nursing care/medical equipment, such as a long-term care monitor and a medical monitor; It can be used for various uses, such as

10: Ministry of Finance
20: recess
21: convex part
100: shaping film
110: separate film
120: adhesive layer
200: optical laminate

Claims (9)

A shaping film comprising a base part and an uneven part formed on one side of the base part,
the concave-convex portion has a convex portion and a concave portion having a cell structure formed by being surrounded by the convex portion;
The height of the convex portion is 5% to 40% with respect to the thickness of the shaping film,
The average area of the recesses having the cell structure is 5000 μm ² or more,
The shaping film, wherein the wall surface of the convex portion is present in a region within 500 μm from the short side of the shaping film. The method of claim 1,
The shaping film, wherein the base material portion and the concave-convex portion are composed of a copper material. The shaping film according to claim 1 or 2;
On one side of the shaping film, a separate film disposed to face the concavo-convex portion of the shaping film is provided;
The optical laminated body whose ratio (B/A) of the cross-sectional area (B) of the recessed part with respect to the whole cross-sectional area (A) in the said uneven|corrugated part is 50 % or more. 4. The method of claim 3,
The optical laminate further comprising an adhesive layer between the shaping film and the separate film. 5. The method of claim 4,
The optical laminate, wherein a portion at which the thickness of the adhesive layer is maximum is a position corresponding to the recess of the shaping film. 6. The method according to claim 4 or 5,
The said adhesive layer contains an active energy ray-curable adhesive agent, The optical laminated body. 7. The method according to any one of claims 4 to 6,
The optical laminated body whose storage modulus in 25 degreeC of the said contact bonding layer is 100 kPa or more. 8. The method according to any one of claims 3 to 7,
The optical laminated body whose said other film is a polarizer, a wavelength conversion film, a polarization reflection film, glass, or a resin film. 9. The method according to any one of claims 3 to 8,
The optical laminate which is a polarizing plate.

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