TW201501937A - Bonded optical element and production method thereof - Google Patents

Abstract

A production method of a laminated optical element of the present invention at least includes: a transport step of transporting a first optical sheet (2A) that is an original fabric for a patterned phase difference film, a second optical sheet (8A) that is an original fabric for a polarizer layer, and a third optical sheet (9A) that is an original fabric for a transparent base material or polarizer film in such a manner that the second optical sheet (8A) is positioned between the first optical sheet (2A) and the third optical sheet (9A); a lamination step of laminating the first optical sheet (2A) and the second optical sheet (8A) through a first photocurable adhesive (7a), and laminating the second optical sheet (8A) and the third optical sheet (9A) through a second photocurable adhesive (7b), to thereby forming the laminated optical sheet (1A).

Description

Bonding optical member and method of manufacturing same

The present invention relates to a bonded optical member and a method of manufacturing the same. The present application claims priority based on Japanese Patent Application No. 2013-124098, filed on Jan. 12, 2013, and Japanese Patent Application No. 2013-202047, filed on Sep. 27, 2013.

An optical film such as a polarizing film or a retardation film constitutes an important optical member of a liquid crystal display device. For example, in a liquid crystal display device, a polarizing film is disposed on each of both sides of a liquid crystal panel.

In addition, in the FPR (Film Patterned Retarder) type 3D liquid crystal display device, the image for the left eye and the right eye are displayed for each pixel column extending left and right in the display region of the liquid crystal panel. The images are interactively woven, and by making these images simultaneously displayed, it is possible to see the 3D image system through the polarized glasses.

In the 3D liquid crystal display device, an FPR film having a plurality of polarization patterns corresponding to a plurality of pixel columns of the liquid crystal panel is further disposed on the polarizing film on the surface side of the liquid crystal panel (see, for example, Patent Document 1).

Further, when the 3D liquid crystal display device is manufactured, the polarizing film is bonded to one side surface (back surface) of the liquid crystal panel, and then the polarizing film is bonded to the other side surface (surface) of the liquid crystal panel. Thereafter, the FPR film was bonded to the polarizing film on the surface side.

However, in the conventional manufacturing method, once the polarizing film is manufactured, the FPR film must be bonded to the polarizing film by the adhesive layer. In this case, not only the members constituting the adhesive layer or the polarizing film are often used, but the thickness of the constituent members is increased, and there is a problem that the panel assembly is prone to parallax or crosstalk.

Therefore, the inventors of the present invention have proposed a bonded optical film (bonding optical member) in which an FPR film (patterned retardation film) and a polarizing film are bonded together by a combination of the FPR film (Japanese Patent Application No. 2012-129748). It is attached to the surface side of the liquid crystal panel. By this invention, while the production steps are simplified, the yield of the product can be further improved.

The FPR film has an optical anisotropic layer in which a photoalignment layer and a liquid crystal layer are sequentially laminated on a long strip-shaped transparent substrate. On the other hand, a conventional polarizing film has a structure in which two retardation films or a transparent substrate sandwich a polarizing plate layer. Therefore, the bonded optical film in which the FPR film and the polarizing film are bonded together is formed on the retardation film or the transparent substrate, and the polarizing plate layer, the liquid crystal layer, the photoalignment layer, and the transparent substrate are sequentially laminated. structure.

In addition, when the optical film is bonded as described above, the first optical sheet which is a raw material of the patterned retardation film, the second optical sheet which is a raw material of the polarizing film, and the material which becomes a material of the retardation film or the transparent substrate Each of the three optical sheets is wound out of the raw material, and the first optical sheet, the second optical sheet, and the second optical sheet are separated by a water-based adhesive while the second optical sheet is sandwiched between the first optical sheet and the third optical sheet. The three optical sheets are bonded to each other to form a bonded optical sheet. Thereafter, the bonded optical sheet is heated and dried to cure the aqueous adhesive.

The aqueous binder is composed of water-based binder water mixed with water and a hydrophilic organic solvent. The water-based adhesive agent may, for example, be a polyvinyl alcohol-based resin adhesive or an aqueous two-liquid urethane-based emulsion adhesive. In addition, examples of the organic solvent-based adhesive include a two-liquid type urethane-based adhesive. On the other hand, examples of the solventless adhesive include a one-liquid urethane-based adhesive.

However, the method of bonding each optical sheet using a conventional water-based adhesive agent causes the water contained in the water-based adhesive to absorb water and expand in each optical sheet. On the other hand, when heating and drying, each optical sheet will be hardened by heating, and dehydration and shrinkage will occur in each optical sheet. Such changes in the respective optical sheets adversely affect the pattern quality of the FPR film.

That is, in order to maintain the pattern quality of the FPR film, it is important to uniformize the width of each of the polarized pattern rows in the distance between the respective polarizing pattern rows. Further, it is important that the total pitch (total pitch) of the plurality of polarizing pattern rows is equal to the size of the display region (effective pixel region) of the liquid crystal panel. Furthermore, the height is required to maintain the straightness of the polarized pattern column. Further, it is not required that the polarizing pattern column is bent and deformed, and the pixel sequence of the liquid crystal panel is overflowed by the polarizing pattern column.

When the FPR film is bonded to the liquid crystal panel, the boundary line of the plurality of polarizing patterns is located between the plurality of pixel columns, and the FPR film is required to be adhered to the liquid crystal display panel with high precision. When the boundary line is beyond the pixel list, there is a cause of crosstalk in which the image of the left and right eyes is mixed into the image of the opposite side. In order to make the respective boundary lines of the plurality of polarizing pattern columns between the plural pixel columns, it is necessary to have a bonding precision of at least ±50 μm, preferably ±20 μm.

Therefore, in order to satisfy these requirements, it is necessary to establish a manufacturing condition capable of maintaining quality in consideration of the pattern quality of the FPR film or the bonding precision of the FPR film. For example, in order to stabilize the pattern quality of the FPR film, it is conceivable to perform heating, drying, or humidity control at 80 ° C or higher before the bonding, from the viewpoints of seasonal temperature changes, environmental management, and condition adjustment.

However, due to such changes, it is necessary to properly adjust the manufacturing conditions, and management becomes cumbersome. In addition, management of each raw material is also necessary, and it is difficult to use it efficiently, and a new problem of so-called productivity reduction occurs. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2012-212033

The present invention has been made in view of such a conventional situation, and an object thereof is to provide a bonded optical member which can further improve productivity and a method for manufacturing the same by maintaining pattern quality and improving bonding precision.

In order to achieve the above object, the bonded optical member of the present invention comprises a patterned retardation film in which a photoalignment layer and a liquid crystal layer are sequentially laminated on a transparent substrate, and the liquid crystal layer is provided by a first photocurable adhesive layer. a polarizing plate layer to be bonded, and a transparent substrate or a retardation film bonded to the polarizing plate layer by a second photocurable adhesive layer, wherein the first photocurable adhesive layer and the second light The curable adhesive layer contains an epoxy compound and a cationic polymerization initiator which are formed by a photocurable adhesive which is cured by cationic polymerization when irradiated with activation energy.

Further, the bonding optical member may have a surface treatment layer provided on a surface of the transparent substrate and a surface on the surface and the opposite side of the liquid crystal layer.

Further, the bonding optical member may have a configuration in which an easy-to-adhere layer is provided on a surface on a side opposite to the first photo-curable adhesive layer of the liquid crystal layer.

Moreover, the method for producing a bonded optical member according to the present invention includes a patterned retardation film in which a photoalignment layer and a liquid crystal layer are sequentially laminated on a transparent substrate, and the liquid crystal layer is provided by a first photocurable adhesive layer. A method of manufacturing a bonded polarizing layer and a transparent substrate or a retardation film bonded to the polarizing layer by a second photocurable adhesive layer, comprising at least the following steps: a transport step a first optical sheet which is a raw material of the patterned retardation film, a second optical sheet which is a raw material of the polarizing layer, and a third optical sheet which is a raw material of the transparent substrate or the retardation film, and The second optical sheet is disposed between the first optical sheet and the third optical sheet; and the coating step applies an epoxy group on a surface facing the second optical sheet of the first optical sheet a first photocurable adhesive of the compound and the cationic polymerization initiator, which is coated with an epoxy group-containing compound and a cationic polymerization initiator on a surface facing the second optical sheet of the third optical sheet. a second photocurable adhesive; the bonding step, bonding the first optical sheet and the second optical sheet by the first photocurable adhesive, and the second photocurable adhesive The second optical sheet is bonded to the third optical sheet to form a bonded optical sheet; and the irradiating step is performed by irradiating the bonded optical sheet with an activation energy to cause the first photocurable adhesive and the second The photocurable adhesive is hardened; the winding step is performed to wind up the bonded optical sheet.

Further, in the transfer step, it is preferable that the ratio of the tension before the bonding of the third optical sheet to the tension before the bonding of the first optical sheet is in the range of 0.60 to 0.80.

Further, the step of bonding the surface protective sheet to the surface of the first optical sheet side of the bonded optical sheet, wherein the ratio of the longitudinal elastic modulus of the bonded optical sheet to the tension before bonding of the surface protective sheet is made The range of 1100 to 1300 is preferred.

Further, before the coating step, an easy-to-treat step of subjecting the surface of the liquid crystal layer side of the first optical sheet to subsequent processing may be included.

It is preferable that the temperature before bonding of the first optical sheet is 30 ° C or lower.

Further, in the coating step, the photocurable adhesive can be applied by a gravure coater.

Further, in the bonding step, the bonding optical sheet can be formed by passing the first optical sheet, the second optical sheet, and the third optical sheet between a pair of nip rolls.

In the irradiation step, the bonded optical sheet is wound around the winding roller, and the activation optical energy is applied, and the bonded optical sheet is wound around the winding roller to make the aforementioned It is preferred that the first optical sheet is located on the inner peripheral side.

Further, in the above irradiation step, it is preferable to use a cooling roll having a cooling mechanism as the winding roller.

Further, it is preferable to irradiate ultraviolet light as an activation energy in the irradiation step.

Moreover, after the winding step, the cutting step of cutting the bonded optical member at a predetermined length may be included while the bonded optical sheet is wound up.

As described above, according to the present invention, it is possible to provide a bonded optical member which can further improve productivity while improving the precision of the bonding, and a method of manufacturing the same.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in the drawings used in the following description, in order to facilitate the understanding of the features, it is convenient to enlarge the feature portions for display, and the dimensional ratios and the like of the respective constituent elements are not limited to being substantially the same. In addition, in the following description, the materials, the dimensions, and the like are exemplified, and the present invention is not limited to the examples, and can be appropriately modified and implemented without departing from the scope of the invention.

In the present embodiment, the bonded optical member and the method for producing the same can be manufactured by laminating an FPR film (patterned retardation film) and a polarizing film (polarizing plate). The case of the optical member is described as an example.

(Bonding optical member) First, as an example of the bonded optical member to which the present invention is applied, for example, the optical film 1 to be bonded as shown in Fig. 1 will be described. Moreover, Fig. 1 is a cross-sectional view showing a schematic configuration of the bonded optical film 1.

As shown in Fig. 1, the bonded optical film 1 is an FPR-integrated polarizing film in which an FPR film 2 (patterned retardation film) and a polarizing film 3 (polarizing plate) are bonded together. Specifically, the laminated optical film 1 is provided with an FPR film 2 in which the light alignment layer 5 and the liquid crystal layer 6 are sequentially laminated on the transparent base film 4, and a liquid crystal layer 6 of the FPR film 2 The polarizer layer 8 to be bonded to the photocurable adhesive layer 7a and the transparent base film 9a or the retardation film 9b which are bonded to the polarizer layer 8 by the second photocurable adhesive layer 7b. Further, the optical alignment layer 5 and the liquid crystal layer 6 constitute the optical anisotropic layer 10.

The transparent base film 4 constituting the FPR film 2 is a base material of the FPR film 2, the light alignment layer 5 controls the alignment of liquid crystal molecules in the liquid crystal layer 6, and the liquid crystal layer 6 forms a plurality of pixel columns corresponding to the liquid crystal panel. The plural of the polarized pattern is listed.

Further, the FPR film 2 is provided on the surface on the side to which the polarizing film 3 is bonded, that is, on the surface opposite to the first photo-curable adhesive layer 7a of the liquid crystal layer, and an easy-adhesion layer (not shown) may be provided. The easy-adhesion layer serves to improve the adhesion (adhesion) of the FPR film 2 to the polarizing film 3.

The components of the easy-adhesion layer are not particularly limited as long as the intended function can be obtained. For example, the component of the easy-adhesion layer may be a resin having a polar group on the skeleton and having a relatively low molecular weight and a relatively low glass transition temperature (polyester resin, urethane resin, acrylic acid). Resin, etc.). Moreover, it is preferable that the polar group of the skeleton is selected such that the resin is hydrophilic or water-dispersible, and examples thereof include a hydrophilic substituent, an ether bond, and a plurality of ether bonds.

Examples of the hydrophilic substituent include a sulfonic acid group, a carboxylic acid group, and a phosphoric acid group. Further, lithium salts, sodium salts, potassium salts, ammonium salts and the like can be mentioned. Examples of the group having an ether bond or a complex ether include a substituent or a structural unit introduced from diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol or the like. In addition, examples of the monomer having such a substituent or a structural unit include a component obtained by introducing a polyester resin, an urethane resin, an acrylic resin, or the like as an easy-adhesion layer. The ingredients.

Further, if necessary, a crosslinking agent, an organic or inorganic filler, a surfactant, a lubricant, or the like may be blended in the easy-adhesion layer.

Further, in the FPR film 2, from the viewpoint of improving the adhesion to the polarizing film 3, it is effective to apply the surface to the surface on which the polarizing film 3 is bonded, that is, the surface formed by the easy-adhesion layer. For the easy subsequent treatment, for example, a surface active treatment such as a corona discharge treatment, a plasma treatment, an ultraviolet irradiation treatment, or a flame (flame) treatment may be mentioned. Further, saponification treatment, primer treatment, anchor coating treatment, and the like.

In the FPR film 2, in order to make the portrait light for the right eye and the portrait light for the left eye to be circularly polarized light that opposes the direction, the polarized light pattern for the left eye and the polarized light for the right eye have different polarization directions. The pattern columns are interactively arranged side by side. For example, in the case of a 42-inch liquid crystal display device, about 1000 polarizing pattern columns are alternately arranged side by side in the width direction of the FPR film (the longitudinal direction of the liquid crystal panel). Further, the width of one of the polarized pattern rows is about 450 to 500 μm.

For the transparent base film 4, for example, a polyolefin system containing a polyvinyl alcohol resin, a polystyrene resin, a (meth) acrylate resin, a cyclic polyolefin resin, or a polypropylene resin can be used. Resin. Further, a triacetyl cellulose (TAC) resin, a polycarbonate resin, a polyarylate resin, a polyamidene resin, a polyamide resin, or the like can be used.

The optical anisotropic layer 10 can be formed by aligning the liquid crystal layer 6 by the light alignment layer 5. Specifically, the optical anisotropic layer 10 can be formed by the following steps: forming a photoalignment layer 5 on the transparent substrate film 4; and irradiating the polarized light on the photoalignment layer 5 using a photomask a step of forming an alignment pattern corresponding to the alignment of the polarizing patterns; forming a coating film containing the polymerizable liquid crystal composition on the photoalignment layer 5, and aligning the polymerizable liquid crystal composition contained in the coating film with the alignment pattern The step of polymerizing the polymerizable liquid crystal composition contained in the coating film to form the liquid crystal layer 6.

A photosensitive resin can be used for the light alignment layer 5. The photosensitive resin may, for example, be a light having an azobenzene structure, a spiropyran structure, a spirobenzopyran structure, or a fulgide structure. A photosensitive resin that is anisotropically irradiated. In addition, examples of the photosensitive resin include a maleimide structure, a chalcone type structure, a cinnamic acid type structure, a 1,2-vinyl structure, and a 1,2-acetylene group. A photosensitive resin which is crosslinked by light irradiation such as a structure.

In the light alignment layer 5, a photosensitive resin which is crosslinked by light irradiation is preferably used. Specifically, a chalcone type structure (structure represented by the following formula (a)), a cinnamic acid type structure (structure represented by the following formula (b)), a maleimide structure, and 1 are used. A photosensitive resin having a 2-vinyl group structure and a 1,2-acetylene structure is preferable, and a photosensitive resin having a chalcone structure or a cinnamic acid structure is more preferable. Regarding the photosensitive resin which can form a crosslinked structure, the amount of energy necessary for the crosslinking reaction is small. Further, since the crosslinking reaction is an irreversible reaction, even when a plurality of times of light irradiation is performed, the alignment control force given by the first exposure can be stably maintained.

[Chemical 1]

Further, in the formulae (a) and (b), "Ar" independently means a phenyl group, a naphthalene group or a phenyl group. "*" indicates the key limbs.

In the photo-alignment layer 5, for example, the above-mentioned photosensitive resin and a monomer having one or more radical polymerizable groups (preferably a vinyl group, a acrylonitrile group, a methacryl group, etc.) can be used as a free A polymerizer, a monomer in which the photosensitive resin and a monomer having two or more amine groups are polymerized with a dicarboxylic acid compound, a monomer in which the photosensitive resin and a monomer having two or more carboxyl groups are polymerized with a diamine compound, etc. .

In addition to the above, a mixture of a photosensitive resin and a monomer may be polymerized by a chain polymerization of an anionic polymerization, a cationic polymerization or the like, a coordination polymerization, a ring-opening polymerization or the like. Among them, those obtained by radically polymerizing a photosensitive resin and a monomer having one or more radical polymerizable groups are preferred.

When a photopolymerizable resin and a monomer having one radical polymerizable group are used as a photo-alignment layer 5 as a radical alignment polymer, the photosensitive resin and the radical polymerizable group are bonded by an alkyl group. The conclusion is better. The carbon number of the alkylene group is preferably 3 or more and 20 or less, more preferably 5 or more and 10 or less. Further, the photosensitive resin and the radical polymerizable group may be bonded by an ester bond (-CO-O- or -O-CO-) or an ether bond (-O-).

The light alignment layer 5 is a copolymer obtained by polymerizing a different photosensitive resin with a plurality of monomers. Further, the photo-alignment layer 5 may contain a constituent component (structural unit) derived from a monomer having no photosensitive resin. In this case, the content of the constituent component (structural unit) of the monomer having the photosensitive resin is preferably 50 mol% or more and 95 mol% or less, more preferably 60 mol% or more and 90 mol% or less. Further preferably, it is 70 mol% or more and 80 mol% or less.

The number average molecular weight of the photosensitive resin contained in the photo-alignment layer 5 is preferably 20,000 or more and 100,000 or less, more preferably 25,000 or more and 80,000 or less, still more preferably 30,000 or more and 50,000 or less. When it is in the above range, the alignment property is further improved when the polymerized liquid crystal composition is aligned in the subsequent step.

In addition, the optical alignment layer 5 can be used, for example, in Japanese Patent No. 4,450,261, Japanese Patent No. 4,011, 652, Japanese Patent Application Publication No. 2010-49230, No. 440490, No. 2007-156439 Material described in Japanese Patent Publication No. 2007-232934. These materials may be used singly or in combination of two or more types.

The liquid crystal layer 6 is preferably one containing two or more kinds of liquid crystal compounds (preferably polymerizable liquid crystals) as a polymerizable liquid crystal composition. Specifically, the polymerizable liquid crystal composition may be a compound containing a functional group represented by the following formula (X) (hereinafter sometimes referred to as "compound (X)"). P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ - ...(X)

In the formula (X), "P ¹¹ " represents a polymerizable group. "A ¹¹ " represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted by a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitro group. The hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the 1 to 6 carbon atom in the carbon number may be substituted by a fluorine atom. "B ¹¹ " represents -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR ¹⁶ -, -NR ¹⁶ -CO-, -CO- , -CS-, or single button. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. "B ¹² " and "B ¹³ " each independently represent -C≡C-, -CH=CH-, -CH ₂ -CH ₂ -, -O-, -S-, -C(=O)-, - C(=O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O )-NR ¹⁶ -, -NR ¹⁶ -C(=O)-, -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O-, -CH=CH-C(=O)- O-, -OC(=O)-CH=CH-, or a single bond. "E ¹¹ " represents an alkanediyl group having 1 to 12 carbon atoms. The hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms. The hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. Further, -CH ₂ - constituting the alkanediyl group may be substituted with -O- or -CO-.

The carbon number of the aromatic hydrocarbon group and the alicyclic hydrocarbon group of A ¹¹ is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and particularly preferably 5 or 6. A ^11- cyclohexane-1,4-diyl and 1,4-phenylene are preferred.

It is preferred that the E ¹¹ is a linear alkanediyl group having 1 to 12 carbon atoms. Further, -CH ₂ - constituting the alkanediyl group may be substituted with -O-. Specifically, examples of E ¹¹ include a methylene group, an ethyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,9-diyl, decane-1,10-diyl a linear alkanediyl group having 1 to 12 carbon atoms such as undecane-1,11-diyl or dodecane-1,12-diyl. Moreover, from E ^11, examples thereof include _{-CH 2 -CH 2 -O-CH 2} -CH 2 -, - CH 2 -CH 2 -O-CH 2 -CH 2 -O-CH 2 -CH 2 -, -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -.

The polymerizable group represented by P ¹¹ is preferably a radical polymerizable group or a cationic polymerizable group at a point where polymerization reactivity, particularly photopolymerization reactivity, is high. In addition, it is easy to manufacture the liquid crystal compound itself, and the polymerizable group is preferably a group represented by the following formula (P-11) to formula (P-15).

[Chemical 2]

Further, in the formulae (P-11) to (P-15), R ¹⁷ to R ²¹ each independently represent an alkyl group having 1 to 6 carbon atoms or a hydrogen atom.

Specific examples of the group represented by the formula (P-11) to the formula (P-15) include a group represented by the following formula (P-16) to formula (P-20).

[Chemical 3]

Based group of formula P ¹¹ (P-14) ~ formula (P-20) represented as preferred, a vinyl group, p-diphenyl vinyl group, an epoxy group or an oxygen cyclobutyl is more preferred. The base propylene methoxy group or methane propylene methoxy group represented by P ¹¹ -B ¹¹ - is more preferably.

The compound (X) may, for example, be a compound represented by the following formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI). P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -B ¹⁶ -E ¹² -B ¹⁷ -P ¹² (I) P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -F ¹¹ (II) P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -E ¹² -B ¹⁷ -P ¹² (III) P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² - B ¹⁴ -A ¹³ -F ¹¹ (IV) P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -E ¹² -B ¹⁷ -P ¹² (V) P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -F ¹¹ ...(VI)

In the formulae (I) to (VI), "A ¹² " to "A ¹⁴ " are synonymous with "A ¹¹ " in the above formula (X). "A ¹⁴ " to "A ¹⁵ " are each synonymous with "B ¹² " in the above formula (X). "B ¹⁷ " is independently synonymous with "B ¹¹ " in the above formula (X). "E ¹² " is synonymous with "E ¹¹ " in the above formula (X). "F ¹¹ " means a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxyl group, or a methylol group. , a mercapto group, a sulfonic acid group (-SO ₃ H), a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom. The -CH ₂ - constituting the alkyl group and the alkoxy group may be substituted with -O-.

Specific examples of the polymerizable liquid crystal composition include "3.8.6 Network" which is a liquid crystal handbook (edited by the Liquid Crystal Handbook Compilation Committee, issued by Maruzen Co., Ltd. on October 30, 2009). "6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material", the compound which has a polymerizable group, and the publication of JP-A-2010-36023, JP-A-2010-270108, JP-A-2011-6360 The polymerizable liquid crystal composition described in JP-A-2011-207765.

Specific examples of the compound (X) include the following formula (I-1) to formula (I-4), formula (II-1) to formula (II-4), and formula (III-1). Formula (III-26), Formula (IV-1) to Formula (IV-19), Formula (V-1) to Formula (V-2), and Formula (VI-1) to Formula (VI-6) compound of.

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemistry 7]

[化8]

[Chemistry 9]

[化10]

[11]

Further, in each of the formulas, "k1" and "k2" each independently represent an integer of 2 to 12. These compounds (X) are preferred from the viewpoints of ease of synthesis or ease of availability.

The liquid crystal layer 6 may contain a polymerization initiator, a polymerization inhibiting agent, a photosensitizer, a leveling agent, a chiral agent, a solvent, and the like in addition to the above polymerizable liquid crystal composition. When the liquid crystal layer 6 contains a polymerizable liquid crystal composition, it is preferred to contain a polymerization initiator.

The polarizer layer 8 constituting the polarizing film 3 transmits a linearly polarized light. The polarizer layer 8 can be usually produced by a step of stretching a polyvinyl alcohol-based resin film as a shaft, and adsorbing a dichroic dye by dyeing a polyvinyl alcohol-based resin film with a dichroic dye. a step of treating a polyvinyl alcohol-based resin film that adsorbs a dichroic dye with an aqueous solution of boric acid; and a step of washing with water after treatment with an aqueous solution of boric acid.

The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. The polyvinyl acetate-based resin may be a copolymer of vinyl acetate and other monomers copolymerizable therewith, in addition to the individual polymer polyvinyl acetate of vinyl acetate. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be denatured. For example, polyvinyl formal or polyvinyl acetal which is denatured with an aldehyde may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually from about 1,000 to 10,000, preferably from about 1,500 to 5,000.

The method for producing the polyvinyl alcohol-based resin film is not particularly limited, and a polyvinyl alcohol-based resin film can be produced by a known method. The thickness of the polyvinyl alcohol-based resin film is, for example, about 10 to 150 μm, preferably about 10 to 100 μm.

One of the axial stretching systems of the polyvinyl alcohol-based resin film can be carried out before dyeing, dyeing, or dyeing the dichroic dye. The one-axis extension is carried out after the dyeing, and the one-axis extension can be carried out before the boric acid treatment or in the boric acid treatment. In addition, one-axis extension can be performed in the plural stages of this.

The one-axis extension may be a method of extending one shaft between rolls having different circumferential speeds, a method of extending one shaft by using a heat roll, or the like. Further, the one-axis extension can be carried out by dry stretching in the air, or by wet stretching in which the polyvinyl alcohol-based resin film is swollen with a solvent such as water. The stretching ratio is usually about 3 to 8 times.

The dyeing system of the polyvinyl alcohol-based resin film through the dichroic dye can be, for example, a method of immersing the polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. Specifically, as the dichroic dye, iodine or a dichroic organic dye can be used. Further, the polyvinyl alcohol-based resin film is preferably subjected to a treatment of immersion in water and swelling after the dyeing treatment.

When iodine is used as the dichroic dye, a method in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing iodine and potassium iodide and dyed is usually used. The iodine content in the aqueous solution is usually from 0.01 to 1 part by weight per 100 parts by weight of water. The content of potassium iodide is usually from 0.5 to 20 parts by weight per 100 parts by weight of potassium iodide. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 °C. Further, the immersion time (dyeing time) of the aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, in the case where a dichroic organic dye is used as the dichroic dye, it is usually used in an aqueous solution containing a water-soluble dichroic organic dye. The content of the dichroic organic dye in the aqueous solution is usually from 0.0001 to 10 parts by weight, preferably from 0.001 to 1 part by weight, per 100 parts by weight of the dichroic organic dye. This aqueous dye solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the aqueous solution of the dichroic organic dye used for dyeing is usually about 20 to 80 °C. Further, the immersion time (dyeing time) of the aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing by the dichroic dye can be carried out by immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid. The content of boric acid in the aqueous solution containing boric acid is usually from 2 to 15 parts by weight, preferably from 5 to 12 parts by weight, per 100 parts by weight of water. When iodine is used as the dichroic dye, it is preferred that the aqueous solution containing boric acid contains potassium iodide. The content of potassium iodide in the aqueous solution containing boric acid is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. The immersion time for the aqueous solution containing boric acid is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, more preferably 200 to 400 seconds. The temperature of the aqueous solution containing boric acid is usually 50 ° C or higher, preferably 50 to 85 ° C, more preferably 60 to 80 ° C.

The polyvinyl alcohol-based resin film after the boric acid treatment is usually subjected to a water washing treatment. The water washing treatment can be carried out, for example, by immersing a boric acid-treated polyvinyl alcohol-based resin film in water. The water temperature in the water washing treatment is usually about 5 to 40 °C. The immersion time is usually about 1 to 120 seconds.

After washing, it is applied to a drying treatment. The drying treatment can be carried out using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100 ° C, preferably 50 to 80 ° C. The drying treatment time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. Through the drying treatment, the moisture content in the polyvinyl alcohol-based resin film is reduced to a practical level. The moisture content is usually about 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the flexibility of the film may be lost, and the film may be damaged or broken after drying. Moreover, when the water content exceeds 20% by weight, thermal stability tends to be insufficient.

As described above, the polarizing film 3 in which the polyvinyl alcohol-based resin film has a dichroic dye adsorption alignment can be produced. The thickness of the obtained polarizing film 3 can be, for example, about 5 to 40 μm.

The polarizing film 3 is continuously produced by flowing a long strip-shaped polyvinyl alcohol-based resin film in a production line.

The transparent base film 9a or the retardation film 9b serves as a base material of the polarizing film 3. Further, the retardation film 9b has a function of giving a phase difference to the passing light. Specifically, the retardation film 9b can be formed by a resin which exhibits excellent transparency and can exhibit an appropriate phase difference by stretching.

The resin is, for example, a polyolefin-based resin containing a polyvinyl alcohol-based resin, a polystyrene-based resin, a (meth)acrylate-based resin, a cyclic polyolefin-based resin, or a polypropylene-based resin. Further, examples thereof include a triethyl fluorene-based cellulose (TAC)-based resin, a polycarbonate-based resin, a polyarylate-based resin, a polyimide-based resin, and a polyamine-based resin. By stretching the film thus obtained in a suitable manner such as one axis or two axes, a retardation film 9b which imparts an appropriate phase difference can be obtained.

The retardation film 9b may be a wavelength plate such as a 1/4 wavelength plate or a 1/2 wavelength plate, or may be a viewing angle compensation film or the like. The thickness of the retardation film 9b is usually about 20 to 200 μm, preferably 20 to 120 μm.

In the case where the viewing angle compensation film is used as the retardation film 9b, it is necessary to consider the mode adopted by the liquid crystal panel. For example, in the case of a vertical alignment (VA) mode liquid crystal panel, a positive type A in which a polymer film having positive intrinsic birefringence is extended by one axis and a refractive index round body has a relationship of nx>ny≒nz can be used. The plate serves as a viewing angle compensation film. Further, a biaxial film in which the refractive index 楕 round body has a relationship of nx > ny > nz can be used, which is applied by lateral stretching or sequential biaxial stretching. Further, a negative C plate having a refractive index 楕 round body having a relationship of nx ≒ ny > nz can be used.

The refractive index in the in-plane slow axis (x-axis) direction of the nx-based film, and the refractive index in the direction of the in-plane phase-in-phase axis (y-axis: the axis orthogonal to the in-plane axis), nz The refractive index in the thickness (z-axis) direction.

In particular, the viewing angle compensation film is preferably a biaxially oriented biaxial film. In the case of using a biaxial viewing angle compensation film, the Nz coefficient which is a standard of the biaxiality is defined by the following formula (4). In addition, the in-plane phase difference 値Ro when the film thickness is d and the phase difference 値R _{th in the} thickness direction are each defined by the following formulas (5) and (6). Nz=(nx-nz)/(nx-ny) (4) R ₀ =(nx-ny)×d (5) R _th =[(nx+ny)/2-nx]×d (6)

Further, the relationship between the Nz coefficient, the in-plane phase difference 値R ₀ , and the phase difference 値R _{th in} the thickness direction by the above formulas (4) to (6) can be expressed by the following formula (7). Nz=R _th /R ₀ +0.5 (7)

In the case where the viewing angle compensation film is used as the retardation film 9b, the in-plane phase difference 値R ₀ is preferably in the range of 30 to 300 nm, more preferably in the range of 50 to 260 nm. Further, the range of the Nz coefficient of 1.1 to 7 is preferably, more preferably, the range of 1.4 to 5. Therefore, it is sufficient to select a suitable optical characteristic in accordance with the viewing angle characteristics required for the liquid crystal display device to be applied.

The first photocurable adhesive layer 7a and the second photocurable adhesive layer 7b are cured by irradiation of activation energy. Among them, ultraviolet rays which are hardened by irradiation of ultraviolet (UV) light as activation energy are also preferably used. Curable resin (UV adhesive).

The ultraviolet curable resin (UV adhesive) is preferably a cationic polymerization initiator containing an epoxy group-containing compound, and is preferably cured by cationic polymerization when irradiated with activation energy (UV light).

Specifically, the first photocurable adhesive layer 7a and the second photocurable adhesive layer 7b are cured by irradiation of active energy, heating, drying, or the like, and can be attached by using sufficient strength. In the case of such an adhesive, for example, a cationically polymerizable compound such as a glycidyl ether epoxy compound, an alicyclic epoxy compound, or an oxetane compound may be blended. A cationically polymerizable photocurable adhesive composition comprising a photocationic polymerization initiator. In addition, a radically polymerizable photocurable adhesive composition obtained by blending a photoradical polymerization initiator with a radically polymerizable compound such as an acrylic compound may be mentioned. In addition, a thermosetting adhesive composition obtained by blending a thermal polymerization initiator, that is, a thermal cation generator or a thermal radical generator, with a cationically polymerizable or radically polymerizable compound may be mentioned.

In the present invention, a cationically polymerizable photocurable adhesive composition comprising an epoxy group-containing compound and a photocationic polymerization initiator is preferably used. The photocurable adhesive composition can be more preferably used without a solvent.

That is, as the photocurable adhesive composition, a photocation-hardenable epoxy compound is used, which has moderate fluidity in a solvent-free manner, and is selected to have a suitable curing strength and a suitable cationic polymerization initiator. The winner is better.

The photocurable adhesive composition can be omitted in the curing step, and it is not necessary to heat and dry the bonded optical sheet, and heat is applied to each of the optical sheets constituting the bonded optical sheet, and dehydration and shrinkage do not occur. Therefore, the pattern quality of the FPR film 2 can be favorably maintained.

Examples of the epoxy group compound to be used in the photocurable adhesive composition include, for example, an aromatic compound having a hydroxyl group or a glycidyl etherate of a chain compound, and a glycidylamine having a compound of an amine group. An epoxide of a chain compound having a CC double bond, an alicyclic epoxy compound bonded to a saturated carbocyclic ring directly or by an alkyl group, and a glycidoxy group or an epoxy group; Or an alicyclic epoxy compound in which a saturated carbocyclic ring is directly bonded to an epoxy group. These epoxy compounds may each be used singly or in combination of plural kinds. Among them, the alicyclic epoxy compound is preferably used because it has excellent cationic polymerizability.

The glycidyl etherate of the aromatic compound or the chain compound having a hydroxyl group can be obtained, for example, by adding a condensation alcohol to epichlorohydrin under basic conditions under the conditions of the hydroxyl group of the aromatic compound or the chain compound. Examples of the resin obtained by polymerizing such a glycidyl ether compound include a bisphenol epoxy resin, a polyaromatic ring epoxy resin, and an alkanediol epoxy resin.

Examples of the constituent unit of the bisphenol type epoxy resin include glycidyl etherate of bisphenol A and oligomers thereof, glycidyl etherate of bisphenol F, and oligomers thereof, and 3,3 ',5,5'-tetramethyl-4,4'-bisphenol glycidyl etherate and oligomers thereof.

Examples of the polyaromatic epoxy resin include, for example, a glycidyl etherate of a phenol novolac resin, a glycidyl etherate of a cresol novolac resin, and a phenol aralkyl group. (Gold aralkyl) a glycidyl etherate of a resin, a glycidyl etherate of a naphthol aralkyl resin, a glycidyl etherate of a phenol dicyclopentadiene resin, or the like. Further, the glycidyl etherate of trisphenols and oligomers thereof are also polyaromatic ring type epoxy resins.

The constituent unit of the alkanediol type epoxy resin may, for example, be a glycidyl etherate of ethylene glycol, a glycidyl etherate of diethylene glycol, or a glycidyl group of 1,4-butanediol. An ether compound, a glycidyl etherate of 1,6-hexanediol, or the like.

The glycidylamine of the compound having an amine group can be obtained by a method of addition condensation of an amine group of the compound with epichlorohydrin under basic conditions. The compound having an amine group may have a hydroxyl group at the same time. Examples of the glycidyl aminate of the compound having an amine group include, for example, a glycidylamine of 1,3-phenylenediamine and an oligomer thereof, and a 1,4-phenylene group. Glycidylamines of amines and oligomers thereof, glycidyl amination of 3-aminophenols and glycidyl etherates, and oligomers thereof, glycidyl amination of 4-aminophenols And glycidyl etherate and oligomers thereof.

The epoxy compound of the chain compound having a CC double bond can be obtained by a method of epoxidizing a CC double bond of the chain compound using a peroxide under basic conditions. Examples of the chain compound having a CC double bond include butadiene, polybutadiene, isoprene, pentadiene, and hexadiene. Further, terpene having a double bond may be used as the epoxy group-forming raw material, and when the acyclic monoterpene is used as an example, linalool or the like may be used. Examples of the peroxide used in the epoxidation include hydrogen peroxide, peracetic acid, t-butyl hydroperoxide, and the like.

The alicyclic epoxy compound bonded to the saturated carbocyclic ring directly or by an alkyl group to a glycidoxy group or an epoxy group may be exemplified by the bisphenols previously shown. A glycidyl etherate of a hydrogenated cyclic polyhydroxy compound obtained by hydrogenating an aromatic ring of an aromatic compound having a hydroxyl group. Further, examples thereof include a glycidyl ether compound of a saturated cyclic compound having a hydroxyl group, an epoxy group compound having a saturated cyclic compound of a vinyl group, and the like.

On the other hand, an alicyclic epoxy compound in which a saturated carbocyclic ring is directly bonded to an epoxy group can be used, for example, by a CC double bond of a non-aromatic cyclic compound having a CC double bond in the ring. The oxide is obtained by a method of epoxidizing under basic conditions. The non-aromatic cyclic compound having a CC double bond in the ring may, for example, be a compound having a cyclopentene ring, a compound having a cyclohexene ring, a cyclopentene ring or a cyclohexene ring, and further having at least 2 A polycyclic compound in which a carbon atom is bonded to form an additional ring. The non-aromatic cyclic compound having a CC double bond in this ring may have an additional CC double bond outside the ring. When exemplifying a non-aromatic cyclic compound having a CC double bond in the ring, there are cyclohexene, 4-vinylcyclohexene, limonene of monocyclic monoterpene, and α-pinene (pinene). )Wait.

The alicyclic epoxy compound in which the saturated carbocyclic ring is directly bonded to the epoxy group may be an alicyclic structure having an epoxy group directly bonded to the above ring, and at least two linked compounds are bonded by a suitable linking group. The so-called linking group includes, for example, a group having an ester bond, an ether bond, an alkyl group bond or the like.

Examples of the alicyclic epoxy group in which a saturated carbocyclic ring directly bonds an epoxy group include the following. 3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 1,2-epoxy-4-vinylcyclohexane, 1,2-epoxy-4 - Epoxyethylcyclohexane, 1,2-epoxy-1-methyl-4-(1-methylepoxyethyl)cyclohexane, 3,4-epoxycyclohexyl Addition of a base (meth) acrylate, 2,2-bis(hydroxymethyl)-1-butanol to 4-epoxyethyl-1,2-epoxycyclohexane, an ethyl group Bis(3,4-epoxycyclohexanecarboxylate), oxydiethylidene bis(3,4-epoxycyclohexanecarboxylate), 1,4-cyclohexanedimethyldicarboxylate (3,4-epoxycyclohexanecarboxylate), 3-(3,4-epoxycyclohexylmethoxycarbonyl)propyl 3,4-epoxycyclohexanecarboxylate, and the like.

The photocurable adhesive composition containing an epoxy compound may further contain a photocurable adhesive composition other than the epoxy compound. The photocurable adhesive composition other than the epoxy compound may, for example, be an oxetane compound or an acrylic compound. Among them, an oxetane compound is preferred because cationic polymerization can increase the rate of hardening.

Examples of the compound having a 4-membered cyclic ether in the molecule of the oxetane compound include the following. 1,4-bis[(3-ethyloxetan-3-yl)methoxymethyl]benzene, 3-ethyl-3-(2-ethylhexyloxymethyl)oxyheterocycle Butane, bis(3-ethyl-3-oxocyclobutanemethyl)ether, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-( Cyclohexyloxymethyl)oxetane, phenol novolac oxetane, 1,3-bis[(3-ethyloxetan-3-yl)methoxy]benzene, and the like.

The photocurable adhesive composition containing an epoxy group compound or an oxetane compound is preferably a solvent-free adhesive composition which is blended with the above, and is preferably not diluted with an organic solvent or the like. . Further, a small amount of a component contained in the photocationic polymerization initiator or the sensitizer constituting the photocurable adhesive composition to be described later is preferably dissolved in an organic solvent, and the organic solvent is removed and dried. That is, it is preferred to use a small amount of a separate powder or liquid.

The photocationic polymerization initiator is irradiated with active energy, for example, ultraviolet rays, so that the cationic species can be imparted with the desired adhesive strength and curing rate in the adhesive composition to which it is incorporated. For example, an diazonium salt, an aromatic iodonium salt, an sulfonium salt such as an aromatic sulfonium salt, and an iron-propene complex may be mentioned. These photocationic polymerization initiators may each be used singly or in combination of plural kinds.

The aromatic diazo compound salt may, for example, be a compound as described below. Benzenediazo compound hexafluoroantimonate, benzenediazonium compound hexafluorophosphate, benzenediazonium compound hexafluoroborate.

As the aromatic iodonium salt, for example, the following compounds can be mentioned. Diphenyliodonium (pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, bis(4-mercaptophenyl)iodonium hexafluorophosphate Salt and so on.

As the aromatic onium salt, for example, the following compounds can be mentioned. Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium (pentafluorophenyl)borate, diphenyl(4-phenylthiophenyl)phosphonium hexafluoroantimonate Salt, 4,4'-bis(diphenylfluorenyl)diphenyl sulfide dihexafluorophosphate, 4,4'-bis[bis(β-hydroxyethoxyphenyl)decyl]diphenyl Thioether bishexafluoroantimonate, 4,4'-bis[bis(β-hydroxyethoxyphenyl)indolyl]diphenyl sulfide dihexafluorophosphate, 7-[di(p-toluene) Sulfhydryl) benzyl]-2-isopropylthioxanthone hexafluoroantimonate, 7-[bis(p-tolylmethyl)indolyl]-2-isopropylthioxanthone oxime (pentafluorobenzene) Borate, 4-phenylcarbonyl-4'-diphenyldecyldiphenyl sulfide hexafluorophosphate, 4-(p-t-butylphenylcarbonyl)-4'-diphenylanthracene Diphenyl sulfide hexafluoroantimonate, 4-(p-t-butylphenylcarbonyl)-4'-di(p-tolylmethyl)indenyl-diphenyl sulfide quinone (pentafluoro Phenyl) borate or the like.

As the iron-propadiene complex, for example, the following compounds can be mentioned. Xylene-cyclopentadienyl iron(II) hexafluoroantimonate, cumene-cyclopentadienyl iron(II) hexafluorophosphate, xylene-cyclopentadienyl iron(II) ginseng Trifluoromethylsulfonyl) methanide (methanide) and the like.

Among these photocationic polymerization initiators, the aromatic sulfonium salt has ultraviolet absorbing properties even in a wavelength region of 300 nm or more, and is excellent in curability, and can provide an adhesive layer having good mechanical strength or adhesion strength. Therefore, it is preferably used.

The compounding amount of the photocationic polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 15 parts by weight, per 100 parts by weight of the total amount of the photocurable adhesive composition. When the compounding amount is less than 0.5 part by weight, the hardening becomes insufficient, and the mechanical strength or the subsequent strength of the adhesive layer is lowered. On the other hand, when the amount is more than 20 parts by weight, the ionic substance in the adhesive layer increases, and the moisture absorption property of the adhesive layer becomes high, and the durability of the obtained polarizing plate can be lowered.

The photocurable adhesive composition may contain a photosensitizer as necessary. By using a photosensitizer, the reactivity is enhanced and the mechanical strength or strength of the adhesive layer is further enhanced. Examples of the photosensitizer include a carbonyl compound, an organic sulfur compound, a persulfide compound, a redox compound, an azo compound, a diazo compound, a halogen compound, and a photoreducible dye.

When exemplified by a carbonyl compound which can be a photosensitizer, there are benzoin methyl ether, benzoin isopropyl ether, and benzene such as α,α-dimethoxy-α-phenylacetophenone. Acridine derivative; anthraquinone compound such as 9,10-dibutoxyfluorene; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4 '-Bis(dimethylamino)benzophenone and benzophenone and its derivatives such as 4,4'-bis(diethylamino)benzophenone; 2-chloroindole and Anthracene derivatives such as 2-methylindole; acridone derivatives such as N-methylacridone and N-butylacridone; α,α-diethoxyacetophenone a class of acetophenone derivatives; thioxanthone derivatives; anthrone derivatives and the like. When an organic sulfur compound which can be a photosensitizer is used, there are thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone. Further, a benzyl compound, an uranium mercapto compound or the like can also be used as a photosensitizer. These light sensitizers may be used singly or in combination of plural kinds.

In the case of the photo-sensitizer, the amount thereof is preferably in the range of 0.1 to 20 parts by weight based on 100 parts by weight of the total amount of the photocurable adhesive composition.

Various additives can be blended in the range of the photocurable adhesive composition without impairing the effect thereof. Examples of the additive include an ion scavenger, an antioxidant, a chain shifting agent, an adhesion-imparting agent, a thermoplastic resin, a filler, a flow regulator, a plasticizer, an antifoaming agent, and the like.

The photocurable adhesive composition may have a coatable viscosity in a suitable manner on the film, but the viscosity at 25 ° C is preferably in the range of 10 to 30,000 mPa·sec, and preferably in the range of 50 to 6,000 mPa·sec. For better. When the viscosity is less than 10 mPa·sec, it is limited to a coatable device, and it is difficult to obtain a homogeneous coating film without unevenness during coating. On the other hand, when the viscosity exceeds 30,000 mPa·sec, the flow becomes difficult, and it is also limited to a coatable device, and it is difficult to obtain a homogeneous coating film having no unevenness. The viscosity is a B which is measured by a B-type viscometer and whose composition is adjusted to 25 ° C at 60 rpm.

For the active energy to be irradiated to the photocurable adhesive composition, for example, X-rays having a wavelength of 1 pm to 10 nm, ultraviolet rays of 10 to 400 nm, visible rays having a wavelength of 400 to 800 nm, or the like can be used. Among them, ultraviolet rays are preferably used from the viewpoints of easiness of handling, ease of preparation of a photocurable adhesive composition, stability thereof, and curing performance.

As the light source of the ultraviolet light, for example, a low-pressure mercury lamp having a light-emitting distribution of a wavelength of 400 nm or less, a medium-pressure mercury lamp, a high-pressure mercury lamp, a super-high lamp, a chemical lamp, a black light, a microwave-excited mercury lamp, a methide lamp, or the like can be used.

The irradiation intensity of the ultraviolet ray is determined depending on the type of the adhesive or the irradiation time, and is not particularly limited. For example, the irradiation intensity in the effective wavelength region in the activation of the initiator is set to be in the range of 0.1 to 300 mW/cm ² . Preferably, it is more preferably set to a range of 1 to 200 mW/cm ² . When the light irradiation intensity of the photocurable adhesive composition is less than 0.1 mW/cm ² , the hardening reaction time becomes long, which is disadvantageous in terms of productivity. On the other hand, when the light irradiation intensity exceeds 300 mW/cm ² , heat generated by the lamp and heat generated during polymerization of the curable adhesive composition may cause yellowing of the photocurable adhesive composition or deterioration of the film. situation.

The irradiation time of the ultraviolet ray is determined depending on the type of the adhesive or the irradiation intensity, and is not particularly limited. For example, the integrated light amount indicated by the product of the irradiation intensity and the irradiation time is set to be in the range of 10 to 5,000 mJ/cm ² . Preferably, it is preferably set in the range of 50 to 1,000 mJ/cm ² . When the integrated light amount of the curable adhesive composition is less than 10 mJ/cm ² , the generation of the active species from the initiator is insufficient, and the hardening of the obtained adhesive layer is insufficient. On the other hand, when the integrated light amount exceeds 5,000 mJ/cm ² , the irradiation time becomes long, which is disadvantageous on the productive surface.

The thickness of the first photocurable adhesive layer 7a and the second photocurable adhesive layer 7b is usually 1 μm or more and 50 μm or less. However, from the viewpoint of thinning the thickness of the bonded optical film 1, 20 μm or less is preferable. Preferably, it is 10 μm or less.

Further, the transparent base film 4 is provided on the surface opposite to the surface on which the optical alignment layer 5 and the liquid crystal layer 6 are laminated, and a surface treatment layer such as a hard coat layer, an antireflection layer, or an antiglare layer may be provided.

Further, before the application of the adhesive, the transparent base film 4, the transparent base film 9a or the retardation film 9b may be subjected to, for example, corona treatment, plasma treatment, ultraviolet irradiation treatment, or electron beam irradiation treatment. Surface activation treatment of the class. Further, each film can be dried and humidity-conditioned as necessary.

Further, a surface protective sheet Pf (protective film) is bonded to the surface of the optical film 1 on the side of the FPR film 2 side. The surface protection sheet Pf protects the surface of the bonded optical film 1 and is detachably provided on the bonded optical film 1.

Specifically, the surface protective sheet Pf is generally used to form a resin layer having adhesion or releasability or an adhesive resin layer on the transparent resin film to impart weak adhesion. For example, as the transparent resin film, a film of a thermoplastic resin such as polyethylene terephthalate, polyethylene naphthalate, polyethylene, or polypropylene may be cited; a film; and a film or the like which extends one or two axes to each other.

Examples of the adhesive and peelable resin layer include an acrylic adhesive, a natural rubber adhesive, a styrene-butadiene copolymer resin adhesive, a polyisobutylene adhesive, and a vinyl ether resin. Adhesive, polyoxyl resin adhesive, etc. In addition, examples of the adhesive resin layer include an ethylene-vinyl acetate copolymer resin.

Among them, in the case of the transparent resin film, polyethylene terephthalate or polyethylene one-axis or biaxially stretched film which is excellent in transparency and homogeneity and is inexpensive is preferable. Moreover, it is preferable to use an acrylic adhesive which is excellent in transparency in the resin layer which adheres and peels.

The thickness of the surface protection sheet Pf is preferably 15 to 75 μm. When the thickness is less than 15 μm, the handleability is poor and the surface protection performance originally required is lowered. On the other hand, when the thickness exceeds 75 μm, the rigidity is too strong, the workability is also poor, and the peel strength is high.

The tensile modulus of the surface protective sheet Pf is preferably 1,000 MPa or more in the longitudinal direction (MD), more preferably 3,000 MPa or more. When the tensile modulus is too small, the handleability is poor, and the tension at the time of bonding with the polypropylene resin film is not satisfied.

The surface protection sheet Pf is attached to the surface thereof, and can be applied, for example, to an antifouling treatment, an antireflection treatment, a hard coating treatment, an antistatic treatment, or the like. Moreover, in order to prevent static electricity from being peeled off, the adhesive layer of the surface protection sheet Pf may contain an antistatic agent or the like.

(Manufacturing Method of Bonding Optical Member) Next, as an example of the manufacturing method of the bonded optical member to which the present invention is applied, for example, the manufacturing apparatus 100 shown in Fig. 2 is used to explain the production of the material to be used as the raw material of the bonded optical film 1. The case of the optical sheet 1A. In addition, FIG. 2 is a schematic view showing a schematic configuration of the manufacturing apparatus 100.

As shown in FIG. 2, the manufacturing apparatus 100 includes a first transport path 101 (first transport means) that transports the first optical sheet 2A that is the raw material of the FPR film 2 while being unwound from the first material roll 20 The second transport path 102 (second transport means) transported while the second optical sheet 8A which is the material of the polarizer layer 8 is unwound from the second material roll 80; the transparent substrate 9a or the phase The third optical sheet 9A of the material of the poor film 9b is transported from the third material roll 90 to the third transport path 103 (third transport means) 103; the first optical sheet 2A and the second optical sheet 8A and the third The optical sheet 9A is bonded to the fourth transport path 104 (fourth transport means) that is bonded to the integrated bonded optical sheet 1A.

The first transfer path 101 is located on the lower side of the manufacturing apparatus 100, and has a pair of first nip rolls 105a, 105b and a plurality of second guide rolls 106a-106d. Among them, the pair of first nip rollers 105a, 105b sandwich the first optical sheet 2A while being rotated in the opposite direction, and the first optical sheet 2A is taken out from the first material roll 20. On the other hand, the plurality of first guide rolls 106a-106d are guided to the first optical sheet 2A by the first nip rolls 105a, 105b while being rotated in the same direction, and are guided to the second optical sheet 8A. Below the opposite position.

The second transfer path 102 is located on the middle side of the manufacturing apparatus 100, and has a pair of second nip rolls 107a, 107b and a second guide roll 108. Among them, the pair of second nip rollers 107a, 107b are rotated in opposite directions while sandwiching the second optical sheet 8A therebetween, and the second optical sheet 8A is taken out from the second material roll 80. On the other hand, the guide roller 108 guides the second optical sheet 8A drawn by the pair of second nip rollers 107a, 107b to the downstream side while rotating in one direction.

The third transport path 103 is located on the upper side of the manufacturing apparatus 100, and has a pair of third nip rolls 109a, 109b and a plurality of second guide rolls 110a-110d. Among them, the pair of third nip rollers 109a and 109b are rotatably reversed from each other while sandwiching the third optical sheet 9A therebetween, and the third optical sheet 9A is taken out from the third material roll 90. On the other hand, the plurality of third guide rolls 110a-110d are guided to the second optical sheet 8A by the third nip rolls 109a, 109b while rotating in the same direction. The opposite position above.

The fourth transfer path 104 is located on the downstream side of the second transfer path 102, and has a pair of fourth nip rolls 111a, 111b and a fourth guide roll 112. In addition, the pair of the fourth nip rollers 111a and 111b are slidably bonded to each other while the optical sheet 1A and the surface protection sheet Pf are sandwiched therebetween, and the surface protective sheet Pf is bonded together. The sheet 1A is taken out to the downstream side. On the other hand, the fourth guide roller 112 guides the bonding sheet 1A to the downstream side while rotating in one direction.

In the manufacturing apparatus 100, each of the optical sheets (the first optical sheet 2A and the third optical sheet 9A) is placed while the first transport path 101, the second transport path 102, and the third transport line 103 are synchronized. The second optical sheet 8A) is transported from the upstream side to the downstream side at the same speed. Moreover, after bonding the first optical sheet 2A, the second optical sheet 8A, and the third optical sheet 9A, the bonded optical sheet 1A is transported downstream by the fourth transport path 104.

Further, on the first transport path 101 and the third transport path 103, a stretching mechanism (not shown) for applying tension to the first optical sheet 2A and the third optical sheet 9A is provided. Further, in the manufacturing apparatus 100, the tension applied to the first optical sheet 2A and the third optical sheet 9A is adjusted by the stretching mechanism of each other, and the first optical sheet is made with respect to the second optical sheet 8A conveyed at the reference speed. The speed adjustment of the 2A and the third optical sheets 9A is made equal, and the speed adjustment system is possible.

Further, in the manufacturing apparatus 100, the first optical sheet 2A and the third optical sheet 9A are bonded to the second optical sheet 8A while controlling the tension applied to the first optical sheet 2A and the third optical sheet 9A. Accordingly, it is possible to adjust the total pitch pattern of the FPR film 2, the linearity of the pitch, and the like.

Further, in the manufacturing apparatus 100, the above-described easy-to-treat processing can be applied to the surface of the first optical sheet 2A on the liquid crystal layer 6 side as an easy-to-step processing step before the coating step described later. According to this, an easy-adhesion layer can be formed on the surface on the side to which the second optical sheet 8A of the first optical sheet 2A is bonded.

The manufacturing apparatus 100 includes a first coating device 113 (first coating means) on a surface facing the second optical sheet 8A of the first optical sheet 2A (hereinafter referred to as an inner surface of the first optical sheet 2A). a UV adhesive (first photocurable adhesive) applied to the first photocurable adhesive layer 7a; and a second coating device 114 (second coating means) to be bonded to the third optical sheet The surface of the second optical sheet 8A of 9A (hereinafter referred to as the inner surface of the third optical sheet 9A) is coated with a UV adhesive which is the second photocurable adhesive layer 7b (second photo-curing property is followed by Agent).

The first coating device 113 has a coating roller 113a that faces the inner surface of the first optical sheet 2A that is conveyed between the guide rollers 106b and 106c of the first conveyance path 101. This coating roll 113a is coated with a photocurable adhesive by a gravure coater. In other words, the first coating device 113 is coated with the roller 113a while the outer circumferential surface of the application roller 113a that rotates in the same direction as the first optical sheet 2A is brought into contact with the inner surface of the first optical sheet 2A. The outer circumference faces the inner surface of the first optical sheet 2A, and the UV adhesive is transferred and applied.

The second coating device 114 has a coating roller 114a that is disposed to face the inner surface of the third optical sheet 9A that is conveyed between the guide rollers 110b and 110c of the third conveyance path 103. The application roller 114a is coated with a photocurable adhesive by a gravure coater in the same manner as the above-described application roller 113a. In other words, the second coating device 114 is in contact with the inner surface of the application roller 114a that rotates in the same direction as the conveyance direction of the third optical sheet 9A, and is coated with the inner surface of the first optical sheet 2A, thereby applying the outer circumference of the coating roller 114a. The UV adhesive is transferred and coated on the inner surface of the first optical sheet 2A.

Further, in the manufacturing apparatus 100, the first coating device 113 is used as the coating step, and the UV adhesive which is the first photocurable adhesive layer 7a is applied to the inner surface of the first optical sheet 2A. Using the second coating device 114, a UV adhesive which is the second photocurable adhesive layer 7b is applied to the inner surface of the third optical sheet 9A.

Further, the first coating device 113 and the second coating device 114 are not limited to the method of applying the above-described gravure coater, and a method of uniformly applying a necessary amount of a UV adhesive may be employed. For example, various coating methods such as a doctor blade, a wire bar, a die coater, a notch coater, and a gravure coater can be employed.

The manufacturing apparatus 100 includes a pair of fifth nip rollers 115a and 115b located at a junction of the first transport path 101, the second transport path 102, and the third transport path 103 for attaching the first optical sheet 1A, The second optical sheet 8A and the third optical sheet 9A.

The pair of fifth nip rollers 115a, 115b sandwich the first optical sheet 2A, the second optical sheet 8A, and the third optical sheet 9A while the first optical sheet 2A and the first optical sheet 2A are reversed. The bonded optical sheet 1A of the second optical sheet 8A sandwiched between the three optical sheets 9A is guided to the fourth transport path 104.

Further, in the manufacturing apparatus 100, as the bonding step, the first optical sheet 1A, the second optical sheet 8A, and the third optical sheet 9A are passed between a pair of fifth nip rollers 115a and 115b. The first optical sheet 1A, the second optical sheet 8A, and the third optical sheet 9A are pressed, and the lower surface of the second optical sheet 8A and the inner surface (upper surface) of the first optical sheet 2A are pasted with a UV adhesive. At the same time, the upper surface of the second optical sheet 8A and the inner surface (lower surface) of the third optical sheet 9A are bonded together by a UV adhesive. Thereby, the first optical sheet, the second optical sheet, and the third optical sheet are bonded together by a UV adhesive to form the bonded optical sheet 1A.

The manufacturing apparatus 100 is equipped with a UV irradiation apparatus 116 (irradiation means), and irradiates the bonding optical sheet 1A of the pair of fifth nip rollers 115a and 115b with UV light L (activated energy).

The UV irradiation device 116 has a take-up roll 117 between a pair of nip rolls 115a, 115b and a guide roll 112, and winds up the bonded optical sheet 1A; and a UV illuminating lamp 118 (light source). The bonded optical sheet 1A of this take-up roll 117 irradiates the UV light L.

The winding roller 117 is a cooling roller having a cooling mechanism, and it is possible to guide the bonding sheet 1A to the downstream side by rotating in one direction while cooling the bonded optical sheet 1A wound on the outer peripheral surface thereof. of. The cooling mechanism can adjust the surface temperature of the cooling roll (winding roll 117) within a range of 10 to 60 °C.

The UV irradiation lamp 118 irradiates the UV light L, which is an activation energy for curing the UV adhesive, in a direction opposite to the portion of the winding roller 117 that is bonded to the optical sheet 1A.

In the manufacturing apparatus 100, the bonding optical sheet wound around the winding roller 114 is placed in the state in which the first optical sheet 2A is located on the inner peripheral side (the third optical sheet 9A is located on the outer peripheral side). 1A illuminates the UV light L. Accordingly, the UV adhesive between the lower surface of the second optical sheet 8A and the inner surface (upper surface) of the first optical sheet 2A, and the upper surface of the second optical sheet 8A and the inner surface of the third optical sheet 9A (below) The bonded UV sheet 1A in which the UV adhesive is hardened is obtained.

The manufacturing apparatus 100 is equipped with the winding roller 119 which winds up the bonding optical sheet 1A after the irradiation process. The take-up roller 119 is located on the downstream side of the fourth nip rolls 111a and 111b, and winds the bonded optical sheet 1A while rotating in one direction.

Further, in the manufacturing apparatus 100, the surface protection sheet Pf wound by the fourth material roll 121 is passed between the fourth nip rolls 111a and 111b by the lower surface side of the bonded optical sheet 1A. Thereby, the surface protection sheet Pf is bonded to the side of the first optical sheet 2A of the bonded optical sheet 1A.

In the manufacturing apparatus 100, as the winding step, the first optical sheet 2A is placed on the inner peripheral side (the third optical sheet 9A is located on the outer peripheral side), and the bonded optical sheet 1A is taken up together with the surface protective sheet Pf. Winding roller 119.

After the winding step, the bonding optical sheet 1A is wound up as a cutting step, and each of the bonded optical films 1 is cut to a predetermined length. Thereby, the bonded optical film 1 shown in Fig. 1 described above can be obtained. Further, the bonded optical film 1 is bonded to the surface side of the liquid crystal panel.

In the above-described irradiation step, the first optical sheet 2A is placed on the inner peripheral side (the third optical sheet 9A is located on the outer peripheral side), and the bonded optical sheet 1A wound around the take-up roll 114 is irradiated with the UV light L. good.

In this case, when the bonded optical film 1 cut out from the bonded optical sheet 1A is peeled off from the surface protective sheet Pf, the transparent base film 9a or the retardation film 9b which is bonded to the surface side of the liquid crystal panel is on the outer side. However, curling (bending) occurs, and the bonding to the liquid crystal panel becomes easy. On the other hand, when the transparent base film 9a or the retardation film 9b is located on the inner side and curled (bent) occurs, it may occur due to the fact that bubbles are likely to enter between the liquid crystal panel and the like. good.

Further, in the manufacturing apparatus 100, the drying furnace 120 is provided, and the first optical sheet 2A is heat-treated in the first transport path 101. The FPR film 2 constituting the first optical sheet 2A is dried in a liquid crystal coating process and is in a state of easily absorbing moisture. According to this, it is preferable that the first optical sheet 2A is not subjected to heat treatment, and is heat-treated or humidity-controlled at 30° C. or lower in order to stabilize the size before bonding to other members.

On the other hand, in the third transport path 103, it is not necessary to heat-treat the third optical sheet 9A. The transparent base film 9a or the retardation film 9b constituting the third optical sheet 9A is formed of a raw material of COP (cycloolefin polymer) or TAC (triethyl fluorenyl cellulose), and these raw materials are considered to be close to each other. Parallel moisture content at the time of purchase, almost no moisture swell or dry shrinkage occurred in the step.

Further, although the manufacturing apparatus 100 is not illustrated, a configuration of a drying furnace that heat-treats the second optical sheet 8A may be provided in the second transport path 102. In this case, the second optical sheet 8A is subjected to heat treatment at 60 ° C or lower or humidity control. Accordingly, the total pitch of the polarizer layer 8 can be adjusted.

As described above, in the manufacturing method of the bonded optical film 1, the first optical sheet 2A coated with the UV adhesive and the third optical sheet 9A coated with the UV adhesive are simultaneously sandwiched with the second optical sheet. In the bonding optical sheet 1A in which the first optical sheet 2A, the second optical sheet 8A, and the third optical sheet 9A are bonded to each other, the UV light L is irradiated to the UV adhesive to cure the UV adhesive. Further, the surface of the UV adhesive to which the first optical sheet 2A is applied may be provided with an easy-adhesion layer.

As a result, in the bonded optical sheet 1A, since no excessive heat is applied, dimensional changes due to shrinkage during heating and drying can be avoided. Further, in the case where a water-based adhesive is used, the size change of the bonded optical sheet 1A due to water absorption is indispensable for heating and drying the bonded optical sheet 1A. On the other hand, in the method of manufacturing the bonded optical film 1 described above, the step of heating and drying the bonded optical sheet 1A is unnecessary, and further improvement in productivity is expected.

Accordingly, according to the present invention, it is possible to provide a laminated optical member which can further improve productivity while manufacturing the desired precision, and a method for manufacturing the same. In particular, in the FPR film 2 (patterned retardation film), it is very effective to apply the present invention because the oscillation of the phase difference pattern is maintained at a precision of 10 μm or the linearity.

Further, in the above-described transfer step, the ratio of the tension before bonding of the third optical sheet 9A to the tension before bonding of the first optical sheet 2A is preferably in the range of 0.60 to 0.80, more preferably 0.63 to 0.78. According to this, the linearity of the first optical sheet 2A and the third optical sheet 9A can be improved.

In other words, the pre-bonding tension of the first optical sheet 2A is made larger than the tension of the third optical sheet 9A before bonding, and the linearity of the bonded optical sheet 1A is maintained, and the liquid crystal panel is suitably fitted. Curl is preferred.

Here, the "pre-bonding tension per unit sectional area" means the tension (unit, for example, "N") experienced by the film to be measured divided by the sectional area of the film, that is, the product of the width and thickness of the film (unit is, for example, "mm ² ") The obtained 値 (the unit is, for example, "N/mm ² ").

The method of adjusting the tension before the bonding is not particularly limited. For example, a method of adjusting the applied torque by the film bonding roller provided in the bonding apparatus, the fed film roller or the pitch roller, and the peripheral speed of the bonding roller can be used. A method in which the peripheral speed of the film roll or the pitch roll is slightly deteriorated to cause tension.

The ratio of the pre-bonding tension of the first optical sheet 2A to the tension of the third optical sheet 9A before bonding is the T1 of the pre-bonding tension per unit sectional area of the tension of the first optical sheet 2A before the bonding. When the pre-bonding tension per unit sectional area of the pre-bonding tension of the three optical sheets 9A is T3, the following formula (1) is satisfied. 0.60≦T1/T3≦0.80 ...(1)

Wherein, to obtain the first optical sheet 2A per unit sectional area of the bonding front tension ^{(T1) [N / mm 2} ] of the third optical sheet 9A per unit sectional area of the bonding front tension (T3) [N When /mm ² ] is changed, the ratio (T1/T3) of the pre-bonding tension (T1) of the first optical sheet 2A to the third optical sheet 9A before the bonding is measured, and the conditions are measured. The linearity [mm] of the bonded optical sheet 1A. The results of sorting out these are shown in Table 1.

Further, regarding the linearity, a straight line connecting the both ends of the first polarizing pattern of the 42-inch size is used as a reference axis, and the amount of polarization of the 1080 polarizing patterns in the vertical direction (TD: Transverse Direction) with respect to the reference axis is measured [ Mm]. Further, a measurement using a secondary measuring machine (trade name: Nikon VMR 10080) manufactured by Nikon Corporation was used. When the linearity is deteriorated, the amount of displacement becomes large, which causes crosstalk (the signals from the left and right eyes are leaked).

As shown in Table 1, when T1/T3 is in the range of 0.60 to 0.80, the linearity of the bonded optical sheet 1A can be improved.

Moreover, in the present invention, the surface bonding sheet Pf is bonded to the surface of the first optical sheet 2A side of the bonded optical sheet 1A. In this case, it is preferable that the ratio G/T4 of the longitudinal elastic modulus G of the bonded optical sheet 1A to the pre-bonding tension T4 of the surface protective sheet Pf is in the range of 1100 to 1300.

When the pre-bonding tension T4 of the surface protection sheet Pf is defined in accordance with the longitudinal elastic modulus G of the bonded optical sheet 1A, the linearity of the bonded optical sheet 1A can be favorably maintained, and a suitable liquid crystal panel can be produced. Curl.

In other words, the longitudinal elastic modulus G (Young's modulus) of the bonded optical sheet 1A and the pre-bonding tension T4 per unit sectional area of the surface protective sheet Pf satisfy the following formula (2). 1100≦G/T4≦1300 ...(2)

In the bonded optical sheet 1A (longitudinal elastic modulus G: about 8000), the pre-bonding tension per unit sectional area of the bonded optical sheet 1A was 6.76 N/mm ² , and the surface protective sheet Pf was cut per unit. When the pre-bonding tension T4 of the area is 6.92 N/mm ² , the longitudinal elastic modulus G of the bonded optical sheet 1A is determined with respect to the pre-bonding tension T4 of the surface protective sheet Pf at the time of making 8.90 N/mm ² . The linearity [mm] of the bonded optical sheet 1A produced under the conditions described above was measured in comparison with G/T4. The results of sorting out these are shown in Table 2.

As shown in Table 2, by setting G/T4 to 1100 or more, the linearity of the bonded optical sheet 1A can be improved. On the other hand, when the G/T4 is more than 1300, the tension of the surface protection sheet Pf is too low, and the bonded optical film 1 cut by the bonded optical sheet 1A cannot maintain the curl state suitable for the above-mentioned bonding. The transfer system has become unstable.

Further, it is preferable that the temperature before bonding of the first optical sheet 2A is 30 ° C or lower, and it is more preferable to form the normal temperature (for example, 25 ° C) without heating.

As described above, it is preferable that the temperature is not applied to the first optical sheet 2A, and the pattern quality imparted to the first optical sheet 2A is prevented from being adversely affected by water swelling or syneresis due to moisture ingress and egress.

In the case where the first optical sheet 2A before bonding is not heated (25 ° C), the total pitch [mm] immediately after the production of the bonded optical sheet 1A is measured in the case of heating (75 ° C), And the total pitch [mm] after 7 days of manufacture of the bonded optical sheet 1A, and the variation amount [mm] of the total pitch was investigated. The evaluation results are shown in Table 3. Further, the total pitch indicates the total 値 of the widths of the 1080 polarizing patterns.

As shown in Table 3, it is understood that the case where the first optical sheet 2A before bonding is not heated is smaller than the amount of change in the total pitch in the case where heating is performed.

(Optical Display Device) Next, a liquid crystal panel P shown in Figs. 3 and 4 will be described as an example of an optical display device using the bonded optical film 1A. Moreover, FIG. 3 is a plan view showing a schematic configuration of the liquid crystal panel P. Fig. 4 is a cross-sectional view showing the liquid crystal panel P due to the A-A cutting line shown in Fig. 3.

As shown in FIGS. 3 and 4, the liquid crystal panel P includes a first substrate P1 that is planarly formed in a rectangular shape, and a second rectangular substrate P2 that is formed to face the first substrate P1 and has a relatively small rectangular shape. The liquid crystal layer P3 is sealed between the first substrate P1 and the second substrate P2. The liquid crystal panel P is formed in a rectangular shape in which the plane is regarded as a shape other than the first substrate P1, and a region which is accommodated inside the outer periphery of the liquid crystal layer P3 in plan view is used as the display region P4.

Further, on the inner side (backlight) side of the liquid crystal panel P, the polarizing film F11 is bonded. On the other hand, on the surface (display surface) side of the liquid crystal panel P, the FPR integrated polarizing film F14 (bonding optical film) in which the polarizing film F12 and the FPR film F13 (patterned retardation film) are bonded together is fit. In the FPR-integrated polarizing film F14, the bonded optical film 1 shown in Fig. 1 described above is used. Further, the liquid crystal panel P to which the thin film (the polarizing film F11 and the FPR integrated polarizing film F14) is bonded is formed by further assembling a driving circuit, a backlight unit, or the like to form a liquid crystal display device.

Further, as for the driving method of the liquid crystal panel P, for example, TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), and IPS (face) can be used. In-Plane Switching, OCB (Optically Compensated Bend), etc., various modes known in the art.

The polarizing film F11 and the FPR-integrated polarizing film F14 are bonded to the liquid crystal panel P by an adhesive layer. Accordingly, these films (the polarizing film F11 and the FPR integrated polarizing film F14) are formed with an adhesive layer in advance.

Specifically, examples of the adhesive for forming the pressure-sensitive adhesive layer include an acrylic polymer, a polyoxymethylene polymer, a polyester, a polyurethane, a polyether, and the like as a base polymer. By. Among them, an acrylic adhesive having an acrylic polymer as a base polymer is excellent in optical transparency, maintains moderate wettability or cohesive force, and is excellent in weather resistance and heat resistance, and is heated or humidified. Under the problem of peeling off or peeling off, it is difficult to occur, and it is suitable for use.

In the acrylic base polymer constituting the acrylic pressure-sensitive adhesive, the ester portion is an alkyl acrylate having an alkyl group having a carbon number of 20 or less such as a methyl group, an ethyl group, a butyl group or a 2-ethylhexyl group, and An acrylic copolymer of a (meth)acrylic monomer having a methyl group or a functional group such as 2-hydroxyethyl (meth)acrylate is suitably used.

When the pressure-sensitive adhesive layer containing the acrylic copolymer is bonded to the liquid crystal panel P, any irregularities may occur, and peeling may occur on the glass substrate, and the resin may be peeled off relatively easily. The acrylic copolymer used for the adhesive layer has a glass transition temperature of 25 ° C or less, more preferably 0 ° C or less. Further, the acrylic copolymer usually has a weight average molecular weight of 100,000 or more.

As the adhesive forming the adhesive layer, a diffusion adhesive having a dispersed light diffusing agent can also be used. The light diffusing agent may be a fine particle having a refractive index different from that of the base polymer constituting the pressure-sensitive adhesive layer, and may be a fine particle or an organic compound (polymer) which is obtained by using an inorganic compound. Microparticles.

In the acrylic base polymer as described above, the base polymer constituting the adhesive layer mostly exhibits a refractive index of about 1.4, and the light diffusing agent may be appropriately selected from those having a refractive index of about 1 to 2. The refractive index difference between the base polymer and the light diffusing agent constituting the pressure-sensitive adhesive layer is usually 0.01 or more, and from the viewpoint of maintaining the brightness or visibility of the liquid crystal display device, 0.01 or more and 0.5 or less is preferable. The fine particles which are used as the light diffusing agent are preferably spherical, and those which are close to monodisperse are preferable. For example, fine particles having an average particle diameter of about 2 to 6 μm are preferably used.

Examples of the fine particles of the inorganic compound include alumina (refractive index of 1.76), cerium oxide (refractive index of 1.45), and the like. Further, examples of the fine particles of the organic compound (polymer) include melamine resin beads (refractive index of 1.57), polymethylmethacrylate beads (refractive index of 1.49), and methyl methacrylate/styrene copolymerization. Resin beads (refractive index 1.50~1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polychlorinated vinyl beads (refractive index 1.46) ), polyoxyxene beads (refractive index 1.46), and the like.

The blending amount of the light diffusing agent can be appropriately determined in consideration of the haze necessary for the adhesive layer to be dispersed, or the brightness of the liquid crystal display device to which it is applied, etc., but usually with respect to the base polymer 100 constituting the adhesive layer. The light diffusing agent is about 3 to 30 parts by weight.

The smog of the adhesive layer dispersed by the light diffusing agent is 20 to 80 from the viewpoint of ensuring the brightness of the liquid crystal display device to which the polarizing plate of the adhesive layer is applied, and at the same time, it is difficult to cause image overflow or bokeh. The range of % is preferred. Here, the haze system is defined as (diffusion transmittance/total light transmittance) × 100 (%), and is measured in accordance with JIS K 7105.

Each component constituting the transparent adhesive or the diffusion adhesive is dissolved in a suitable solvent such as ethyl acetate to form an adhesive composition. However, the components which are insoluble in the solvent such as the light diffusing agent are in a dispersed state. The adhesive composition is applied to a suitable substrate to be dried to form an adhesive layer.

In the method of forming the adhesive layer, for example, a release film is used as a substrate, and an adhesive is applied to the surface of the release film to form an adhesive layer, and the obtained adhesive layer is applied to the film (polarized light). a film F11, an FPR-integrated polarizing film F14), or an adhesive is applied directly to the surface of the film (the polarizing film F11, the FPR integrated polarizing film F14) to form an adhesive layer, and then the release film is attached thereto. Method, etc.

Further, it is also possible to form a double-faced release film type adhesive sheet in which one release film is bonded to the adhesive layer after the adhesive layer is formed on the surface of the release film. Such a double-faced release film type adhesive sheet can be peeled off from the one side of the release film and adhered to the film (polarized film F11, FPR integrated type polarizing film F14).

In the case of a product sold as a two-sided release film type adhesive sheet, there are "LUCIACS" sold by Nitto Denko Co., Ltd., "NON CARRIER" sold by Lintec Co., Ltd., and Nakao processing. The "optical adhesive lens on both sides of the substrate for the use of MMH-F25" sold by the company, the "Optical Adhesive Sheet FS800" sold by Toyo Ink Co., Ltd., and the "Optical Two-Side Tape SK" sold by the Research Chemicals Co., Ltd.

The adhesive layer is aged, for example, at a temperature of 23 ° C and a relative humidity of 65% for about 3 to 20 days, and is sufficiently bonded to the liquid crystal panel P after the reaction of the crosslinking agent is sufficiently performed.

The thickness of the adhesive layer is appropriately determined depending on the adhesion force, etc., and is usually about 1 to 40 μm. In order to obtain a thin polarizing plate, it is preferable to set the thickness of the adhesive layer to about 3 to 25 μm in terms of non-destructive properties such as workability and durability. Further, by setting the thickness of the adhesive layer to such a range, it is possible to maintain the brightness of the visible state of the liquid crystal display device or the oblique view, which makes it difficult to produce a display image overflow or bokeh.

The film having the adhesive layer (the polarizing film F11 and the FPR integrated polarizing film F14) is peeled off from the peeling film in a state in which the shape of the product is bonded to the liquid crystal panel P or the adhesive layer protected by the release film. In the state, the side of the adhesive layer can be made convex and curled. Further, from the viewpoint of preventing the liquid crystal panel P from being bonded to the center portion or the end portion from being damaged by air bubbles or the like, the curl amount is preferably 5 mm or less.

Fig. 5 is a plan view showing the position at which the liquid crystal panel P and the FPR-integrated polarizing film F14 are bonded to each other. As shown in FIG. 5, the pixel of the display region P4 of the liquid crystal panel P is along the long side of the display region P4 (the left-right direction of the liquid crystal panel P), corresponding to red (indicated by the symbol R in FIG. 5), green ( The color filters of the respective colors R, G, and B of the blue (indicated by the symbol G in Fig. 5) and blue (indicated by the symbol B in the figure) are arranged side by side in a periodic manner. Further, the pixels corresponding to the respective colors R, G, and B are arranged side by side in the left-right direction as the pixel column L, and the pixel array L is arranged over the display region P4.

On the other hand, the FPR-integrated polarizing film F14 has a plurality of polarizing pattern rows PA extending over the long sides thereof. The plurality of polarized pattern rows PA are arranged in a plurality of pixel columns L of the liquid crystal panel P, and are arranged in a plurality of positions across the upper and lower sides. Further, each of the polarization pattern rows PA has a polarization pattern row PA for the left eye and a polarization pattern column PA for the right eye which are different from the polarization directions for the left eye and the right eye, and the short sides along the display region P4. (the liquid crystal panel P is in the up and down direction) and alternately arranged side by side. Further, the FPR-integrated polarizing film F14 is placed so that the boundary line K of each of the polarized pattern rows PA is positioned between the pixel columns L of the display region P4, and the liquid crystal panel P is bonded to each other.

In the 3D liquid crystal display device of the FPR system using the liquid crystal panel P, the image for the left and right eyes is alternately woven along each line on the left and right of the pixels of the liquid crystal panel P, and the same can be displayed simultaneously. See the 3D image through polarized glasses.

Further, in the above-described FPR-integrated polarizing film F14, the above-described FPR-integrated polarizing film F14 can be inexpensively reduced in thickness and excellent in reliability.

1‧‧‧Finished optical film
2‧‧‧FPR film
3‧‧‧ polarizing film
4‧‧‧Transparent substrate film
5‧‧‧Light alignment layer
6‧‧‧Liquid layer
7a‧‧‧First photo-curable adhesive layer
7b‧‧‧Second photocurable adhesive layer
8‧‧‧Polarized film
9a‧‧‧Transparent substrate film
9b‧‧‧ phase difference film
Pf‧‧‧Surface protection film
2A‧‧‧First optical film
20‧‧‧First raw material roll
8A‧‧‧Second optical film
80‧‧‧Second raw material roll
9A‧‧‧ Third optical piece
90‧‧‧ third raw material roll
100‧‧‧ manufacturing equipment
101‧‧‧First transfer route
102‧‧‧Second transport route
103‧‧‧ Third transport route
104‧‧‧fourth route
105a, 105b‧‧‧First pressure feed roller
106a-106d‧‧‧First guide roller
107a, 107b‧‧‧second pressure feed roller
108‧‧‧Second guide roller
109a, 109b‧‧‧ third pressure feed roller
110a-110d‧‧‧3rd guide roller
111a, 111b‧‧‧fourth pressure feed roller
112‧‧‧fourth guide roller
113‧‧‧First coating device
113a‧‧‧Application roller
114‧‧‧Second coating device
114a‧‧‧Application roller
115a, 115b‧‧‧Pressing roller
116‧‧‧UV irradiation device
117‧‧‧Retracting roller
118‧‧‧UV illumination lamp
119‧‧‧Winding roller
120‧‧‧ drying oven
121‧‧‧fourth raw material roll
F11‧‧‧ polarizing film
F12‧‧‧ polarizing film
F13‧‧‧FPR film
F14‧‧‧FPR integrated polarizing film
K‧‧‧ boundary line
L‧‧‧UV light
P‧‧‧ LCD panel
P1‧‧‧ first substrate
P2‧‧‧second substrate
P3‧‧‧ liquid crystal layer
P4‧‧‧ display area
PA‧‧‧ polarized pattern column

Fig. 1 is a cross-sectional view showing an example of a bonded optical film to which the present invention is applied. Fig. 2 is a schematic view showing an example of a manufacturing apparatus for bonding an optical film shown in Fig. 1. Fig. 3 is a plan view showing a schematic configuration of a liquid crystal panel. Fig. 4 is a cross-sectional view showing the liquid crystal panel P due to the A-A cutting line shown in Fig. 3. Fig. 5 is a plan view showing the positional alignment of the liquid crystal panel and the FPR-integrated polarizing film.

1‧‧‧Finished optical film

2‧‧‧FPR film

3‧‧‧ polarizing film

4‧‧‧Transparent substrate film

5‧‧‧Light alignment layer

6‧‧‧Liquid layer

7a‧‧‧First photo-curable adhesive layer

7b‧‧‧Second photocurable adhesive layer

8‧‧‧Polarized film

9a‧‧‧Transparent substrate film

9b‧‧‧ phase difference film

Pf‧‧‧Surface protection film

Claims (14)

A bonded optical member comprising a patterned retardation film in which a photoalignment layer and a liquid crystal layer are sequentially laminated on a transparent substrate, and a polarizer bonded to the liquid crystal layer by a first photocurable adhesive layer a layer and a transparent substrate or a retardation film bonded to the polarizer layer by a second photocurable adhesive layer, wherein the first photocurable adhesive layer and the second photocurable adhesive layer An epoxy group-containing compound and a cationic polymerization initiator are formed by a photocurable adhesive which is cured by cationic polymerization when irradiated with an activation energy. The bonded optical member according to claim 1, wherein a surface treatment layer is provided on a surface of the opposite side of the surface of the transparent alignment substrate on which the light alignment layer and the liquid crystal layer are laminated. The bonded optical member according to claim 1 or 2, wherein an easy-contact layer is provided on a side opposite to the first photo-curable adhesive layer of the liquid crystal layer. A method for producing a bonded optical member, comprising: a patterned retardation film in which a photoalignment layer and a liquid crystal layer are sequentially laminated on a transparent substrate; and the liquid crystal layer is attached by a first photocurable adhesive layer a method of manufacturing a bonded polarizing layer and a transparent substrate or a retardation film bonded to the polarizing layer by a second photocurable adhesive layer, comprising at least the following steps: a first optical sheet which is a raw material of the patterned retardation film, a second optical sheet which is a raw material of the polarizer layer, and a third optical sheet which is a raw material of the transparent substrate or the retardation film, so that The second optical sheet is disposed between the first optical sheet and the third optical sheet; and the coating step applies an epoxy group-containing compound on a surface of the first optical sheet opposite to the second optical sheet. a first photocurable adhesive agent of a cationic polymerization initiator, comprising an epoxy group-containing compound and a cationic polymerization on a surface of the third optical sheet opposite to the second optical sheet a second photocurable adhesive of a starting agent; a bonding step of bonding the first optical sheet and the second optical sheet by the first photocurable adhesive, and the second photocurability is followed by And bonding the second optical sheet to the third optical sheet to form a bonded optical sheet; and irradiating the bonding optical sheet with an activation energy to cause the first photocurable adhesive and The second photocurable adhesive is cured; and a winding step of winding the bonded optical sheet. The method of manufacturing a bonded optical member according to claim 4, wherein in the transferring step, a ratio of a pre-bonding tension of the first optical sheet to a tension before bonding of the third optical sheet is made 0.60 to 0.80. range. The method for producing a bonded optical member according to claim 4 or 5, comprising the step of bonding the surface protective sheet to the surface of the first optical sheet side of the bonded optical sheet, wherein the longitudinal elastic modulus of the bonded optical sheet The ratio of the pre-bonding tension to the surface protective sheet is set to be in the range of 1100 to 1300. The method for producing a bonded optical member according to any one of claims 4 to 6, comprising the step of subjecting the surface of the first optical sheet to the liquid crystal layer side to an easy subsequent treatment before the coating step step. The method for producing a bonded optical member according to any one of claims 4 to 7, wherein the temperature of the first optical sheet before bonding is 30° C. or less. The method for producing a bonded optical member according to any one of claims 4 to 8, wherein the photocurable adhesive is applied by a gravure coater in the coating step. The method of manufacturing a bonded optical member according to any one of claims 4 to 9, wherein the first optical sheet, the second optical sheet, and the third optical sheet are passed through the bonding step The bonded optical sheet is formed between the nip rolls. The method for producing a bonded optical member according to any one of claims 4 to 10, wherein, in the irradiating step, the activating optical energy is irradiated in a state where the bonded optical sheet is wound around the winding roller At the same time, when the bonded optical sheet is wound around the winding roller, the first optical sheet is positioned on the inner peripheral side. The method of manufacturing a bonded optical member according to claim 11, wherein in the irradiating step, a cooling roll having a cooling mechanism is used as the take-up roll. The method for producing a bonded optical member according to any one of claims 4 to 12, wherein the ultraviolet light as the activation energy is irradiated in the irradiation step. The method for producing a bonded optical member according to any one of claims 4 to 13, further comprising, after the winding step, winding the bonded optical sheet, and forming the bonding optical at a constant length The cutting step of the member cutting.