KR102524848B1 - A flexible functional film - Google Patents

Abstract

The present invention relates to a flexible functional film, and a flexible functional film according to an embodiment of the present invention includes a first alignment layer formed on a base film; a polarization coating layer formed on the first alignment layer; a separation layer formed on the polarization coating layer; a common electrode layer formed on the separation layer; and a second alignment layer formed on the common electrode layer.
The flexible functional film according to the present invention has the advantage of being able to improve cracking and curling in a high-temperature process while enabling thinning.

Description

Flexible functional film {A FLEXIBLE FUNCTIONAL FILM}

The present invention relates to a liquid crystal display device, and more particularly to a flexible functional film usable for a liquid crystal display device.

As the touch input method has been spotlighted as a next-generation input method, attempts are being made to introduce the touch input method to more various electronic devices. Accordingly, research and development on touch sensors that can be applied to various environments and enable accurate touch recognition are being actively conducted. It is being done.

For example, in the case of electronic devices having touch-type displays, ultra-thin flexible displays that achieve ultra-light weight, low power consumption, and improved portability have been attracting attention as next-generation displays, and development of touch sensors applicable to such displays has been required. A flexible (flexible) display means a display manufactured on a flexible substrate that can be bent, bent, or rolled without loss of characteristics, and technology development is in progress in the form of flexible LCD, flexible OLED, and electronic paper.

In particular, with the recent demand for thinning and lightening of displays, the polarizing plate included in the display is also required to be thinning and lightening. there is.

Korean Patent Publication No. 10-2013-0106664 discloses an example of a flexible LCD. The invention disclosed in exemplified Korean Patent Publication No. 10-2013-0106664 relates to a 'method for manufacturing a flexible liquid crystal display', comprising the steps of attaching a first film layer on a first substrate, the first film layer Forming a thin film transistor (TFT) array on the first substrate; attaching a second film layer on the second substrate; forming a color filter array on the second film layer; forming a liquid crystal layer on the thin film transistor array; bonding the first substrate and the second substrate so that the liquid crystal layer of the first substrate and the color filter array of the second substrate face each other; and separating the second substrate from the first film layer and the second film layer, respectively.

However, the exemplified published invention does not suggest at all that a thin polarizing plate is required, and a film layer is attached to the first substrate and the second substrate, respectively, and a thin film transistor array or color filter array is respectively formed on the film layer. To form a thin film transistor array or color filter array, the film layer may be deformed when applying a high-temperature process (eg, inorganic insulating layer, semiconductor layer (active layer, ohmic contact layer) deposition) for forming a color filter array. there is Furthermore, the steps of forming a thin film transistor array or color filter array on each film layer, forming an alignment film to maintain the initial arrangement of the liquid crystal layer, and bonding the first and second substrates also require high-temperature processes. Since the film layer may be deformed and a plurality of functional films (or layers) must be formed on each film layer through various processes, the process is complicated and there are limitations in improving product production yield.

Republic of Korea Patent Publication No. 10-2013-0106664 (2013.09.30.)

Accordingly, the present invention is an invention invented to solve the above-mentioned problems, and the main object of the present invention is to provide a flexible functional film capable of improving cracking and curling in a high-temperature process,

Furthermore, another object of the present invention is to provide a flexible functional film that can be thinned by providing a polarizer included in the flexible functional film in the form of a coating layer.

According to one embodiment of the present invention for solving the above-described technical problem, a flexible functional film includes a first alignment layer formed on a base film; a polarization coating layer formed on the first alignment layer; a separation layer formed on the polarization coating layer; a common electrode layer formed on the separation layer; and a second alignment layer formed on the common electrode layer.

In addition, a flexible functional film according to another embodiment of the present invention is manufactured by sequentially forming a separation layer, a common electrode layer, and a second alignment layer on a substrate, but one surface of the common electrode layer from which the substrate and the separation layer are separated in the separation process It is characterized in that it is prepared by bonding a first alignment layer formed on a base film and a polarizing coating layer formed on the first alignment layer,

A flexible functional film according to another embodiment of the present invention is manufactured by sequentially forming a separation layer, a common electrode layer, and a second alignment layer on a substrate, but in the separation process, the substrate and the separation layer are separated on one side of the common electrode layer. a first alignment layer formed on the base film; It is characterized in that it is manufactured by adhering the polarization coating layer formed on the first alignment layer,

A flexible functional film according to another embodiment of the present invention is manufactured by sequentially forming a protective layer, a common electrode layer, and a second alignment layer on a substrate, on one side of the protective layer from which the substrate and the separation layer are separated in a separation process a first alignment layer formed on the base film; It is characterized in that it is manufactured by adhering the polarization coating layer formed on the first alignment layer.

The present invention also relates to an image display device including the aforementioned flexible functional film.

According to the above-described means for solving the problems, the flexible functional film according to the embodiment of the present invention has excellent heat resistance because it includes a coated polarizing layer, and thus cracks and curls are suppressed even when a high temperature process is applied, thereby providing an advantage of excellent reliability. there is.

In addition, the present invention also has the advantage of minimizing the overall thickness of the color filter array manufactured by directly forming the coating film layer on the base film.

1 to 4 are cross-sectional views of a flexible functional film and a liquid crystal display that can be manufactured according to various embodiments of the present invention.

Hereinafter, the present invention will be described in more detail.

In the present invention, when a member is said to be located “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

In the present invention, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated.

One aspect of the present invention, the first alignment layer 120 formed on the base film 110 and; a polarization coating layer 130 formed on the first alignment layer 120; a separation layer 140 formed on the polarization coating layer 130; a common electrode layer 150 formed on the separation layer 140; It relates to a flexible functional film comprising a; second alignment layer 160 formed on the common electrode layer 150.

In the present invention, the first alignment layer 120 formed on the base film 110 and the polarization coating layer 130 formed on the first alignment layer 120 may be used interchangeably with "optical film".

In short, the optical film refers to the first alignment layer 120 formed on the substrate and the substrate film 110 and the polarization coating layer 130 formed on the first alignment layer 120, and the optical film When provided in the flexible functional film according to the invention, the polarization coating layer 130 is provided to contact the separation layer 140 .

In the present invention, the "polarizing plate" may be used interchangeably with the polarization coating layer 130 formed on the first alignment layer 120, or the first alignment layer 120 formed on the base film 110 and It may be mixed with the polarization coating layer 130 formed on the first alignment layer 120 .

In the present invention, the optical film includes a base film 110 and a polarization coating layer 130 formed on the base film 110 .

The base film 110 is not limited as long as it maintains transparency and has excellent mechanical strength, thermal stability, moisture barrier properties, isotropy, etc., and the base film 110 includes the first alignment layer 120 and the polarization coating layer 130. It serves as a substrate for coating.

For example, the base film 110 may include polyolefin, cyclic olefin resin, polyvinyl alcohol, polyethylene terephthalate, polyimide, polymethacrylic acid ester, polyacrylic acid ester, cellulose ester, polyethylene naphthalate, polycarbonate, polysulfone; polyethersulfone; It may be made of polyether ketone, polyphenylene sulfide, polyphenylene oxide, and the like.

Specifically, polyethylene terephthalate, polymethacrylic acid ester, polyimide, cellulose ester, cyclic olefin resin, or polycarbonate is preferable from the viewpoint of coatability or transparency of the coating polarization layer on the base film 110 .

The coating polarization layer serves to change incident natural light into a single polarization state (linear polarization state), and is formed on one surface of the base film 110 . In the manufacturing method of the coated polarizing layer, the composition for forming the first alignment layer 120 is coated on one surface of the base film 110 and orientation is imparted to form the first alignment layer, and the first alignment layer is formed on the first alignment layer. It can be prepared by forming a liquid crystal coating layer by applying a composition for forming the polarization coating layer 130 including a liquid crystal compound and a dichroic dye.

The first alignment layer has an alignment regulating force for orienting the dichroic dye and the polymerizable liquid crystal compound in a desired direction. The first orientation layer preferably has solvent resistance that does not dissolve when the coating layer forming composition is applied, and also has heat resistance in removal of the solvent and heat treatment for orienting the dichroic dye.

The first alignment layer may include a groove alignment layer having a concave-convex pattern or a plurality of grooves on its surface, and preferably may be a photo-alignment layer.

The film thickness of the first alignment layer is usually 10 nm to 10000 nm, preferably 10 nm to 1000 nm, and more preferably 10 nm to 500 nm or less. If it is set as the said range, orientation regulating force will fully express.

The first alignment layer 120 may be formed of a composition for forming a photo-alignment layer. Specifically, the first alignment layer 120 may be formed of a composition for forming the first alignment layer 120 containing a polymer or monomer having a photoreactive group and a solvent.

The said photoreactive group refers to the group which shows orientation ability by irradiating light. Specifically, the photoreactive group undergoes a photoreaction that is the origin of orientation ability, such as induction of molecular orientation or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction, by irradiation with light. Among the photoreactive groups, those that undergo a dimerization reaction or a photocrosslinking reaction are preferable in terms of excellent orientation. As the photoreactive group capable of generating the above reaction, those having an unsaturated bond, particularly a double bond are preferable, and carbon-carbon double bonds (C=C bonds), carbon-nitrogen double bonds (C=N bonds), A group having at least one selected from the group consisting of a nitrogen-nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond) is particularly preferred.

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C=N bond include groups having structures such as aromatic Schiff base and aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, and a formazan group, as well as those having azoxybenzene as a basic structure. Examples of the photoreactive group having a C=O bond include a benzophenone group, a coumarin group, an anthraquinone group and a maleimide group. These groups may have substituents such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

Among them, a photoreactive group that undergoes a photodimerization reaction is preferable, and the amount of polarized light irradiation required for photo-alignment is relatively small, and the first alignment layer 120 excellent in thermal stability and stability over time can be easily obtained. and a chalcone group are preferred. As the polymer having a photoreactive group, those having a cinnamoyl group at which the terminal portion of the side chain of the polymer concerned becomes a cinnamic acid structure are particularly preferred.

As a solvent for the composition for forming the first alignment layer 120, it is preferable to dissolve a polymer and a monomer having a photoreactive group. The solvent includes alcohols such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, or propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, gamma butyrolactone, propylene glycol methyl ether acetate or ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, or methyl isobutyl ketone; non-chlorine aliphatic hydrocarbon solvents such as pentane, hexane or heptane; non-chlorine aromatic hydrocarbon solvents such as toluene or xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran or dimethoxyethane; Chlorine solvents, such as chloroform or chlorobenzene, etc. are mentioned. These solvents may be used alone or in combination.

The content of the polymer or monomer having a photoreactive group in the composition for forming the first alignment layer 120 is appropriately determined depending on the type of the polymer or monomer having the photoreactive group or the thickness of the first alignment layer 120 to be produced. It can be adjusted, but it is preferably at least 0.2 parts by weight or more, and the range of 0.3 to 10 parts by weight is particularly preferred. In addition, a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer may be included within a range in which the characteristics of the first alignment layer 120 are not significantly impaired.

The manufacturing method of the first alignment layer 120 is not particularly limited in the present invention, and may be manufactured through a commonly used method. For example, the first alignment layer 120 may be prepared by coating the substrate film 110 using bar coating, gravure coating, die coating, applicator method, flexo method, or the like, and then drying.

The liquid crystal compound is a compound having a polymerizable group and exhibiting liquid crystallinity. In short, the liquid crystal compound may be a polymerizable liquid crystal compound, and in this case, strength is improved and color non-uniformity is reduced. The polymerizable group means a group involved in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group capable of undergoing a polymerization reaction with an active radical or an acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. there is. Especially, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The compound exhibiting liquid crystallinity may be a thermotropic liquid crystal or a lyotropic liquid crystal, and may also be a nematic liquid crystal or smectic liquid crystal in the thermotropic liquid crystal.

The polymerizable liquid crystal compound is preferably a smectic liquid crystal compound, and more preferably a higher order smectic liquid crystal compound from the viewpoint of obtaining higher polarization characteristics. Among them, Smetic B phase, Smetic D phase, Smetic E phase, Smetic F phase, Smetic G phase, Smetic H phase, Smetic I phase, Smetic J phase, Smetic K phase or Smetic A higher order smectic liquid crystal compound that forms an L phase is more preferred, and a higher order smectic liquid crystal compound that forms a smectic B phase, a smectic F phase or a smectic I phase is more preferred.

The liquid crystal compound may be included in an amount of usually 1 to 70 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the total solid content of the composition for forming the polarizing coating layer 130 . When the content ratio of the liquid crystal compound is within the above range, it is preferable because it is possible to suppress a phenomenon in which so-called dripping occurs during coating and non-uniformity occurs in the obtained polarizing coating layer 130 .

The above dichroic dye refers to a dye having a property in which the absorbance in the direction of the major axis of the molecule and the absorbance in the direction of the minor axis of the molecule are different. The dichroic dye preferably has an absorption maximum wavelength (λ _MAX ) in the range of 300 to 700 nm. Examples of such dichroic pigments include acridine pigments, oxazine pigments, cyanine pigments, naphthalene pigments, azo pigments and anthraquinone pigments, and among these, azo pigments are preferable. Azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbenazo dyes, and are preferably bisazo dyes and trisazo dyes. The dichroic dye may be used alone or in combination, but it is preferable to use three or more types in combination. In particular, it is preferable to combine three or more types of azo compounds.

The content of the dichroic dye in the composition for forming the polarizing coating layer 130 is 0.1 part by weight based on 100 parts by weight of the solid content of the composition for forming the polarizing coating layer 130, from the viewpoint of improving the orientation of the dichroic dye. 30 parts by weight or less is preferable, more preferably 0.1 parts by weight or more and 20 parts by weight or less, still more preferably 0.1 parts by weight or more and 10 parts by weight or less, and particularly preferably 0.1 parts by weight or more and 5 parts by weight or less. Here, the solid content refers to the total amount of components excluding the solvent from the composition for forming the polarizing coating layer 130 .

In addition, the composition for forming the polarizing coating layer 130 may further include at least one selected from the group consisting of a solvent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a leveling agent, and a polymerizable non-liquid crystal compound.

The solvent is preferably a solvent capable of completely dissolving the polymerizable liquid crystal compound, and is preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound. Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-containing solvents such as chloroform and chlorobenzene, but are not limited thereto. These solvents may be used alone or in combination.

The content of the solvent is preferably 50 to 98 parts by weight based on 100 parts by weight of the total amount of the composition for forming the polarizing coating layer 130. In other words, based on 100 parts by weight of the solid content in the composition for forming the polarizing coating layer 130, 2 to 50 parts by weight is preferable. When the solid content is 50 parts by weight or less, since the viscosity of the composition for forming the polarizing coating layer 130 is lowered, the thickness of the polarizing coating layer 130 becomes substantially uniform, making it difficult for non-uniformity to occur in the polarizing coating layer 130. tend to lose In addition, this solid content may be determined in consideration of the thickness of the polarization coating layer 130 to be manufactured.

The polymerization initiator is a compound capable of initiating a polymerization reaction of the polymerizable liquid crystal compound or the like. The polymerization initiator is preferably a photopolymerization initiator that generates active radicals by the action of light. Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts. The polymerization initiator is preferably included in the composition for forming the polarizing coating layer 130 when a polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130 . When the polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130, the content of the polymerization initiator in the composition for forming the polarizing coating layer 130 is difficult to disturb the alignment of the polymerizable liquid crystal compound. In, the content of the polymerizable liquid crystal compound is usually 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound.

The sensitizer is preferably a photosensitizer. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (eg, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and anthracene containing an alkoxy group (eg, dibutoxyanthracene, etc.); phenothiazine and rubrene; and the like. The sensitizer is preferably included in the composition for forming a polarizing film when a polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130 . When the polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130, the content of the sensitizer in the composition for forming the polarizing coating layer 130 is based on 100 parts by weight of the polymerizable liquid crystal compound. It is usually 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, but is not limited thereto.

The polymerization inhibitor is hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (for example, butylcatechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical radical scavengers such as; thiophenols; β-naphthylamines and β-naphthols, but are not limited thereto. The polymerization inhibitor is preferably included in the composition for forming the polarizing coating layer 130 when a polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130 . The progression of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor. When the polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130, the content of the sensitizer in the composition for forming the polarizing coating layer 130 is based on 100 parts by weight of the polymerizable liquid crystal compound. It is usually 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 0.5 to 8 parts by weight.

The leveling agent has a function of adjusting the fluidity of the composition for forming the polarizing coating layer 130 to make the coating film of the composition for forming the polarizing coating layer 130 more flat, and examples thereof include a surfactant. Preferred leveling agents include a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component. As the leveling agent containing the polyacrylate compound as a main component, "BYK-350, BYK-352, BYK-353, BYK-354, BYK-355, BYK-358N, BYK-361N, BYK-380, BYK-381 and BYK-392 (manufactured by BYK Chemie), etc. The leveling agent forms the polarizing coating layer 130 when the polymerizable liquid crystal compound is included in the composition for forming the polarizing coating layer 130 The content of the leveling agent in the composition for forming the polarizing coating layer 130 is usually 0.3 parts by weight or more and 5 parts by weight or less based on 100 parts by weight of the polymerizable liquid crystal compound. Preferably they are 0.5 part by weight or more and 3 parts by weight or less.

The optical film, that is, the polarization coating layer 130 coated on the base film 110 and the first alignment layer 120 formed on the base film 110 has a thickness of 50 μm or less, specifically, 35 μm or less, Specifically, it may be 30 μm or less. The thickness may further include the thickness of the adhesive layer or the pressure-sensitive adhesive layer. For example, the thickness of the base film 110, the polarization coating layer 130 coated on the first alignment layer 120 formed on the base film 110, and the adhesive layer or pressure-sensitive adhesive layer formed on the polarization coating layer 130 50 μm or less, specifically 35 μm or less, more specifically may be 30 μm or less.

Conventionally, after stretching a polyvinyl alcohol-based film as a polarizer, a dichroic dye was dyed and used. However, in this case, since cracks occur in high-temperature processes, there are some limitations in applying to thin displays because the thickness must exceed 50㎛, and there are other limitations such as curl problems when the thickness is less than 50㎛. there was

However, since the flexible functional film according to the present invention includes the polarization coating layer 130 formed on the first alignment layer 120 formed on the base film 110, it has a thickness of 50 μm or less, specifically 35 μm or less, more specifically Even if the furnace has a thickness of 30 μm or less, there is an advantage in that cracks do not occur in a high temperature process and curl is improved.

The flexible functional film according to the present invention may be manufactured by the following method, but is not limited thereto.

The separation layer 140 may be formed by first coating a polymer organic film on a carrier substrate, that is, a glass substrate. The separation layer 140 is a layer formed to separate a functional film (common electrode, second alignment layer) formed on the glass substrate from the glass substrate, and may perform an insulating function as well. As a method of applying the separation layer 140, a known coating method such as spin coating, die coating, or spray coating may be used.

The peel force of the separation layer 140 is not particularly limited, but may be, for example, 0.01 to 1 N/25 mm, preferably 0.01 to 0.2 N/25 mm. When the above range is satisfied, it can be easily peeled from the glass substrate without residue, and curl and cracks caused by tension generated during peeling can be reduced.

The thickness of the separation layer 140 is not particularly limited, but may be, for example, 10 to 1,000 nm, preferably 50 to 500 nm. When the above range is satisfied, peel force is stable and a uniform pattern can be formed.

Examples of the material of the separation layer 140 include polyimide-based polymers, polyvinyl alcohol-based polymers, polyamic acid-based polymers, polyamide-based polymers, polyethylene-based polymers, polystyrene-based polymers, polynorbornene-based polymers, and phenylmaleimide copolymers ( It may be made of a polymer such as a phenylmaleimide copolymer)-based polymer or a polyazobenzene-based polymer, and these may be used alone or in combination of two or more.

On the other hand, it is preferable to select and use a material having heat resistance that does not deform even at a high temperature, that is, can maintain flatness, so that the glass substrate can withstand the process temperature at the time of forming the common electrode and the second alignment layer.

As the curing process for forming the separation layer 140, thermal curing or UV curing may be used alone or a combination of thermal curing and UV curing may be used.

A protective layer 170 may be additionally formed on the separation layer 140 . This protective layer 170 is an optional component that can be omitted if necessary. As will be described later, depending on the embodiment, the glass substrate may be separated from the separation layer 140 , and the glass substrate and the separation layer 140 may be separated from the protective layer 170 .

For reference, the protective layer 170 covers and protects a common electrode and a second alignment layer to be described later together with the separation layer 140 . The protective layer 170 may be made of an organic material such as a polymer resin or an inorganic material such as a nitride film or an oxide film, and may be formed of one or more layers.

When the isolation layer 140 (and the protective layer 170) are formed, a common electrode is formed on the protective layer on the isolation layer 140. The common electrode may be formed using an indium tin oxide (ITO) electrode. Formation of such a common electrode is just one example, and it will be apparent to those skilled in the art that it can be formed in various known methods.

When the common electrode is formed, a second alignment layer may be formed on the common electrode. This is because the second alignment layer is applicable to a liquid crystal display device as an example of the flexible functional film according to the embodiment of the present invention. That is, the second alignment layer is formed to align the liquid crystals included in the liquid crystal layer, and is rubbed in a predetermined direction to maintain the initial alignment state of the liquid crystal layer.

When the second alignment layer is formed, the protective film coated on one side of the pressure-sensitive adhesive layer 210 is bonded onto the second alignment layer through a transfer process.

When the protective film is bonded through the transfer process, the glass substrate serving as the carrier substrate and the separation layer 140 are separated, or the glass substrate and the separation layer 140 are separated from the protective layer 170 according to the embodiment. The separation method includes a lift-off or peel-off method, but is not limited thereto.

After separating the glass substrate from the separation layer 140, an optical film coated with an adhesive is attached to one surface. In short, the adhesive is applied to one surface of the coated polarization layer formed on the first alignment layer 120 formed on the base film 110 . Subsequently, when the bonded protective film is removed, a flexible functional film having a cross-sectional structure as shown in (a) of each drawing shown in FIGS. 1 to 4 can be manufactured.

More specifically, (a) of FIG. 1 shows the glass substrate from the separation layer 140 after forming the separation layer 140, the common electrode 150, and the second alignment layer without the protective layer 170 on the glass substrate in the manufacturing process. The cross-sectional structure of the flexible functional film prepared by separating the substrate is exemplified, and FIG. It illustrates the cross-sectional structure of the flexible functional film prepared by separating the glass substrate and the separation layer 140 from. 3(a) illustrates a cross-sectional structure of a flexible functional film prepared by sequentially forming a separation layer 140 and a protective layer 170 on a glass substrate and then separating the glass substrate from the separation layer 140. 4 (a) is a flexible manufactured by separating the glass substrate and the separation layer 140 from the protective layer 170 after sequentially forming the separation layer 140 and the protective layer 170 on the glass substrate The cross-sectional structure of the functional film is illustrated.

As described above, the flexible functional film according to the embodiment of the present invention is a flexible functional film having various types of cross-sectional structures as shown in FIGS. Functional films can be produced. Of course, FIGS. 1 to 4 show a state in which the protective film is removed. The protective film may be removed as needed when the product of the flexible functional film is applied.

As described above, since the flexible functional film according to the embodiment of the present invention is manufactured on a glass substrate, there is no risk of deformation of the base material even when a high-temperature process is applied, and thus a reliable functional film can be manufactured.

Hereinafter, a cross-sectional structure of the flexible functional film manufactured by the above-described manufacturing method when applied to a liquid crystal display device will be further described.

1 to 4 illustrate a cross-section of a flexible functional film and a cross-sectional view of a liquid crystal display, respectively, that can be manufactured according to various embodiments of the present invention.

First, the cross-sectional structure of the flexible functional film manufactured according to one embodiment of the present invention is as shown in (a) of FIG. It is a manufactured film, and the coating polarization layer formed on the first alignment layer 120 formed on the base film 110 is adhered to the position where the glass substrate is removed, and the coating polarization layer is attached to the separation layer 140 If the film is adhered to be in contact with each other, the flexible functional film may be bonded to the color filter 220 and used as one color filter film.

That is, as shown in (b) of FIG. 1, a substrate (glass) or a film 230 having a color filter 220 layer formed on one side of the optical film of the flexible functional film is adhered to form an independent type applicable to a liquid crystal display device or the like. A color filter film (which will be referred to as the color filter array 200 for convenience) can be manufactured.

Furthermore, as shown in (c) of FIG. 1, the above-described color filter array 200 is positioned to face the thin film transistor (TFT) array 300 with the liquid crystal 340 therebetween, and then bonded to the thin film transistor array. It is possible to manufacture a (flexible) liquid crystal display in which the and the color filter array 200 are integrated.

For reference, it is preferable that the third alignment layer 330 for imparting alignment to the liquid crystal 340 is positioned on the thin film transistor array. The second alignment layer and the third alignment layer may be the same or different, but are not limited thereto. As for the third alignment layer, the above-described information regarding the second alignment layer may be applied.

In the same way, the substrate (glass ) 230 or by attaching a film to manufacture a color filter array 200 having a cross-sectional structure as shown in FIGS. 2(b), 3(b), and 4(b),

When each of the color filter arrays 200 manufactured in this way are placed between the liquid crystals 340 and positioned to face the thin film transistor array 300 and bonded, FIGS. 2(c), 5(c), and 6( It is possible to manufacture a liquid crystal display device having a cross-sectional structure as shown in c).

For reference, if the color filter 220 layer is formed on a film and the thin film transistor array 300 is also formed on a flexible film, a flexible liquid crystal display can be manufactured as a result.

As described above, the flexible functional film according to the embodiment of the present invention can be bonded to the substrate or film 230 on which the color filter 220 layer is formed and used as the color filter array 200, and the thin film transistor array 300 and may be bonded with a liquid crystal layer interposed therebetween to form one liquid crystal display device.

In addition, the present invention does not use a separate film layer, and the common electrode and the second alignment layer 160 to be formed between the color filter 220 layer and the liquid crystal 340 of the liquid crystal display are made of functional films. Since it is provided, there is an advantage in that the production yield can be improved by a general liquid crystal display manufacturing method.

In addition, the present invention forms the common electrode and the second alignment layer 160 on a flexible film without using a hard substrate so that it can be used in combination with the substrate or film 230 on which the color filter 220 layer is formed. Therefore, there is an advantage in that the overall thickness of the color filter array 200 can be minimized.

In particular, the present invention can overcome the limitations of the stretched type polarizer by using a coated polarizer formed on the first alignment layer 120 formed on the base film 110 instead of the conventionally used stretched type polarizer. Specifically, the flexible functional film according to the present invention can be applied to a thin film device, but has an advantage in that generation of cracks is suppressed and curling is improved in a process heat-resistant environment.

Another aspect of the present invention relates to an image display device including the aforementioned flexible functional film. Specific examples of the image display device include a liquid crystal display (liquid crystal display device; LCD), an organic EL display (organic EL display device), a liquid crystal projector, a display device for game machines, a display device for portable terminals such as mobile phones, and a display for digital cameras. device, a display device such as a display device for car navigation, and the like, but is not limited thereto.

The above has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. For example, a structure in which a barrier layer for blocking diffusion of moisture or impurities and protecting the stacked functional films during peeling may be additionally formed on the flexible functional film as necessary may be considered. Therefore, the true technical scope of protection of the present invention should be defined only by the appended claims.

Hereinafter, examples (manufacturing examples) will be described in detail in order to specifically describe the present specification. However, the embodiments according to the present specification may be modified in many different forms, and the scope of the present specification is not construed as being limited to the embodiments described below. The embodiments herein are provided to more completely explain the present specification to those skilled in the art. In addition, "%" and "parts" indicating content below are based on weight unless otherwise specified.

flexible Manufacture of functional films

manufacturing example One

(1) 1st alignment layer Preparation of Forming Composition

The composition for forming the first alignment layer was obtained by mixing the following components and stirring the resulting mixture at 80°C for 1 hour. The material for forming the first alignment layer described below was synthesized by the method described in Japanese Unexamined Patent Publication No. 2013-33248.

Photo-Orientable Materials (Part 2):

Solvent (98 parts): o-xylene

(2) Preparation of a composition for forming a polarizing coating layer

A composition for forming a polarizing coating layer was obtained by mixing the following components and stirring at 80° C. for 1 hour. As the dichroic dye, the azo dye described in Examples of Japanese Unexamined Patent Publication No. 2013-101328 was used.

[Polymerizable liquid crystal compound]

75부

Part 75

25부

Part 25

[Dichroic pigment]

2.5부

Part 2.5

2.5부

Part 2.5

2.5부

Part 2.5

[Other Ingredients]

Polymerization initiator; 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by BASF Japan Co., Ltd.) 6 parts

Leveling agent; polyacrylate compound (BYK-361N; manufactured by BYK-Chemistry) 1.2 parts

solvent; 250 parts o-xylene

(3) Manufacture of optical films and flexible functional films

As a base film, a composition for forming a first alignment layer was applied to one side of a 25 μm-thick triacetyl cellulose film (TAC) (Konica Minolta Opto Co., Ltd.) by a bar coating method, and then dried in a drying oven at 100° C. It heat-dried for 2 minutes. Polarization UV irradiation treatment was given to the obtained dry film, and the 1st alignment layer was formed. Thereafter, polarized UV was irradiated at an intensity of 20 mJ/cm ² (based on 313 nm) in a direction of 0° with respect to the coating direction.

Thereafter, the composition for forming a polarizing coating layer was applied on the first alignment layer by a bar coating method, dried by heating in a drying oven at 120° C. for 1 minute, and then cooled to room temperature. An optical film (polarizing plate) was prepared by irradiating the dried film with ultraviolet rays at an exposure amount of 1000 mJ/cm 2 (based on 365 nm) using a UV irradiation device to form a 0.10 μm first alignment layer and a 2.1 μm thick polarizing coating layer. Thereafter, an acrylic adhesive (non-carrier film with a separator film manufactured by Lintec) was applied to the surface of the polarizing coating layer to form an adhesive layer, cut to 10 × 10 cm, and then bonded with glass to prepare a flexible functional film.

manufacturing example 2

An optical film and a flexible functional film were prepared in the same manner as in Preparation Example 1, except that a 40 μm-thick triacetyl cellulose film (TAC) (Konica Minolta Opto Co., Ltd.) was used as the base film.

manufacturing example 3

A polyvinyl alcohol film having an average degree of polymerization of about 2,400 and a degree of saponification of 99.9 mol% or more and having a thickness of 75 μm was immersed in pure water at 30 ° C, and then immersed at 30 ° C in an aqueous solution with a mass ratio of iodine / potassium iodide / water of 0.02/2/100. and iodine staining was performed. Thereafter, boric acid treatment was performed by immersing at 56.5°C in an aqueous solution having a mass ratio of potassium iodide/boric acid/water of 12/5/100. Subsequently, after washing with pure water at 8°C, drying was performed at 65°C to produce a polarizing layer (thickness after stretching: 18 µm) in which iodine was adsorbed and oriented in polyvinyl alcohol. Stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times. The obtained polarizing layer and a 25 μm-thick triacetyl cellulose film (TAC) (Konica Minolta Opto Co., Ltd.) as a base film were bonded with a nip roll through a water-based adhesive. After drying at 60 ℃ for 2 minutes to produce a polarizing plate having a protective film on one side. In addition, the water-based adhesive is 100 parts of water, 3 parts of carboxyl group-modified polyvinyl alcohol (Kurare Forval KL318 manufactured by Kuraray) and 1.5 parts of water-soluble polyamide epoxy resin (Sumirez Resin 650 manufactured by Sumika Chemtex, an aqueous solution having a solid content concentration of 30%). prepared by adding Then, an acrylic adhesive (Non-carrier film with separator film manufactured by Lintec) is applied on the surface of the polarization layer to form an adhesive layer, cut to 10 × 10 cm, and bonded with glass to produce an optical film and a flexible functional film. did

manufacturing example 4

An optical film and a flexible functional film were prepared in the same manner as in Preparation Example 3, except that the base film was bonded with a water-based adhesive using two sheets of cellulose ester film (Konica Minolta Opto Co., Ltd.) having a thickness of 25 μm. .

optical film and flexible Performance evaluation of functional films

The structure and performance of the flexible functional film according to the manufacturing example were evaluated and are shown in Table 1 below.

Preparation Example 1 Preparation Example 2 Preparation Example 3 Production Example 4 structure

Thickness (㎛) 32.2(◎) 47.2(○) 48(○) 73(××) heat crack
(120℃,2hr) ◎ ◎ ×× ○ initial curl ○ ○ ×× ○ Curl after heat resistance ○ ○ ×× ○

(1) Thickness

The thickness of the components in the flexible functional film was measured using a contact film thickness meter (NIKON model: MS-5C), among which a polarizing plate, in short, a base film, a first alignment layer, and a polarizing coating layer formed on the first alignment layer And the thickness of the pressure-sensitive adhesive layer was evaluated according to the following measurement criteria.

◎: less than 40 polarizer thickness, ○: less than 50, ×: less than 60, × ×: 60 or more

(2) Heat-resistant crack

Three optical films prepared according to the preparation example were prepared and put under heat resistance (120 degrees for 2 hours) conditions, and cracks on the polarizing coating layer were observed after the heat resistance test. At this time, the evaluation criteria are as follows.

◎: No cracks

○: presence of cracks of 10 mm or less

×: 1 or more frontal cracks

××: all three front cracks

(3) Curl

After cutting the polarizing plate, that is, the optical film, before bonding the adhesive prepared according to the above examples to a size of 10 cm × 10 cm, and then leaving it at 25 ° C. and 48 RH% for 24 hours, the initial curl was measured as the average height of the four corners from the bottom. Then, after 5 min at 120° C., the heat resistance curl was measured as the average height of the four corners from the bottom at room temperature.

◎: ≤10 mm, ○: ≤ 30 mm, ×: ≤ 50 mm, × ×: > 50 mm

Looking at Table 1, it was found that Preparation Examples 1 and 2 suppressed cracks and curls in a heat-resistant environment despite maintaining thin films, and in the case of Preparation Example 3, the performance of heat-resistant cracks, initial curl, and curl after heat resistance It was found that all of them were not excellent, and in the case of Preparation Example 4, crack prevention was achieved only when the film was thick, and curl suppression was possible due to the polarizer-based upper / lower symmetric structure, but the thin film of the polarizer was not achieved.

110: base film
120: first alignment layer
130: polarization coating layer
140: separation layer
150: common electrode layer
160: second alignment layer
170: protective layer
210: adhesive layer or adhesive layer
220: color filter
230: substrate (glass or film)
310: substrate (glass or film)
320: TFT
330: third alignment layer
340: liquid crystal

Claims (9)

a first alignment layer formed on the base film;
a polarization coating layer formed on the first alignment layer;
an adhesive layer formed on the polarizing coating layer;
a separation layer formed on the pressure-sensitive adhesive layer;
a common electrode layer formed on the separation layer;
A second alignment layer formed on the common electrode layer;
A flexible functional film in which the sum of the thicknesses of the base film, the first alignment layer, the polarizing coating layer, and the pressure-sensitive adhesive layer is 50 μm or less. delete According to claim 1,
Flexible functional film characterized in that it further comprises; a protective layer formed between the separation layer and the common electrode layer. According to claim 1,
The flexible functional film further comprising a substrate or film attached to another surface of the base film and having a color filter layer formed thereon. It is manufactured by sequentially forming a separation layer, a common electrode layer, and a second alignment layer on a substrate, but formed on a polarizing coating layer formed on a first alignment layer formed on a base film on one side of the separation layer from which the substrate is separated in the separation process. It is prepared by bonding an adhesive layer,
A flexible functional film in which the sum of the thicknesses of the base film, the first alignment layer, the polarizing coating layer, and the pressure-sensitive adhesive layer is 50 μm or less. It is manufactured by sequentially forming a separation layer, a common electrode layer, and a second alignment layer on a substrate, but in the separation process, a polarization coating layer formed on the first alignment layer formed on the base film on one side of the common electrode layer from which the substrate and separation layer are separated. It is prepared by adhering the pressure-sensitive adhesive layer formed on the
A flexible functional film in which the sum of the thicknesses of the base film, the first alignment layer, the polarizing coating layer, and the pressure-sensitive adhesive layer is 50 μm or less. It is manufactured by sequentially forming a separation layer, a protective layer, a common electrode layer, and a second alignment layer on a substrate. It is prepared by adhering the pressure-sensitive adhesive layer formed on the formed polarizing coating layer,
A flexible functional film in which the sum of the thicknesses of the base film, the first alignment layer, the polarizing coating layer, and the pressure-sensitive adhesive layer is 50 μm or less. delete An image display device comprising the flexible functional film of claim 1.

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