KR20070042453A - Process for producing optical film - Google Patents

Abstract

Provided are a manufacturing method that can dramatically improve production efficiency and raw material waste when producing a thin optical film made of a liquid crystal material layer without a supporting substrate.

Half-cutting is performed on the laminated film laminated in the order of re-peelable film / cured acrylic resin layer / oriented liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolate film, and then the re-peelable film is peeled off. The manufacturing method of the optical film made into.

Optical film, re-peelable film, cured acrylic resin layer, liquid crystal material layer, half cut

Description

Manufacturing method of optical film {PROCESS FOR PRODUCING OPTICAL FILM}

The present invention relates to a method for producing an optical film useful for various optical elements.

In recent years, in addition to excellent optical performance, higher durability is required for optical films that can be used in liquid crystal displays. In particular, it is required to pass a stringent environmental test that assumes various conditions of use for a mobile device or a vehicle liquid crystal display device such as a cellular phone.

A thin film (film) composed of an alignment layer of a liquid crystal compound, in particular, a film composed of a liquid crystal material immobilized with a nematic structure, a twisted nematic structure, or a nematic hybrid structure, is a device for compensating angle or viewing angle compensation for a liquid crystal display device. In addition, it has excellent performance as a optical optical element, etc., and contributes to high performance and light weight of various display elements. As a manufacturing method of these films, the method of transferring the layer which consists of the liquid crystal substance formed on the orientation board | substrate to the transparent substrate which has a support substrate is proposed (for example, refer patent documents 1-3).

Moreover, as a countermeasure for enduring the severe durability test required for a liquid crystal display element, the manufacturing method of the optical film comprised from the liquid crystal material which does not use a support substrate film for further thinning and weight reduction is also proposed (for example, patent document 4). Reference). According to this manufacturing method, the layer composed of the liquid crystal material oriented on the alignment substrate is transferred to the re-peelable substrate once through an adhesive, and then peeled off such a re-peelable substrate, whereby the layer composed of the liquid crystal material layer rather than the supporting substrate film is formed. An optical film can be manufactured.

[Patent Document 1] Japanese Patent Application Laid-Open No. 4-57017

[Patent Document 2] Japanese Patent Application Laid-Open No. 4-177216

[Patent Document 3] Japanese Patent Laid-Open No. 6-242434

[Patent Document 4] Publication No. 8-278491

In general, when used as a liquid crystal display device, a retardation film or a polarizing plate is further laminated on an optical film composed of a liquid crystal material layer. At this time, in order to fully exhibit the optical performance, without the "roll-to-roll bonding" which continuously bonds MD (flow direction) of long film, the "sheet | seat to sheet | seat which makes and bonds the sheets cut | disconnected by predetermined length to a desired angle. Sheet bonding "is normally carried out. In addition, in order to increase the production efficiency as much as possible, one side of the optical film composed of a liquid crystal material layer is continuously applied in advance to the adhesive layer to be bonded to the liquid crystal display device in the final product, and then cut into a predetermined length, and then the retardation film or The "sheet-to-sheet bonding" process with a polarizing plate is performed.

That is, it is necessary to peel the repeelable substrate after cutting the optical film composed of the liquid crystal material layer / adhesive layer / isolate film formed on the repeelable substrate to a predetermined length. At this time, since the peeling force between the pressure-sensitive adhesive layer and the isolation film is small and easily falls off, even if the releasable substrate is peeled off, it often falls between the pressure-sensitive adhesive layer / isolation film first, resulting in deterioration of work efficiency and waste of raw materials, which has a big problem in productivity. have.

As a result of earnestly considering the present state as described above, the inventors have found that the laminated film laminated in the order of re-peelable film / cured acrylic resin layer / alignment-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolate film in this order. WHEREIN: By peeling a repeelable film after carrying out half cutting, it succeeded in improving productivity dramatically and completed this invention.

That is, the first aspect of the present invention is subjected to half-cutting to the laminated film laminated in the order of re-peelable film / cured acrylic resin layer / alignment-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolation film, and then It is related with the manufacturing method of the optical film characterized by peeling a repeelable film.

The 2nd aspect of this invention relates to the manufacturing method of the optical film as described in the 1st aspect of this invention characterized by performing half cutting so that at least a removable film may be cut | disconnected completely.

The 3rd aspect of this invention relates to the manufacturing method of the optical film as described in the 1st aspect of this invention characterized by performing half cutting so that at least the isolation membrane may be cut | disconnected completely.

According to a fourth aspect of the present invention, the liquid crystal material layer having an orientation-immobilized liquid crystal aligns at a temperature above the liquid crystal transition point, and is composed of a polymer liquid crystal material which becomes a glass state at a temperature below the liquid crystal transition point. It relates to a method for producing the optical film according to the first aspect to the third aspect.

Moreover, the 5th aspect of this invention consists of the layer which bridge | crosslinked the liquid crystal substance holding the reactive group which carried out the liquid crystal aligning the liquid crystal substance layer with which the orientation fixation was carried out, The 1st aspect-3rd aspect of this invention characterized by the above-mentioned. It relates to a method for producing an optical film.

In addition, in the said description, "/" represents the interface of each layer, and it describes likewise below.

Hereinafter, the present invention will be described in detail.

The liquid crystal alignment-immobilized liquid crystal material layer usable in the present invention is a layer immobilized by using a means for immobilizing a liquid crystal material in an alignment state, and is a means for immobilization. A method of fixing in a state, a low molecular or polymer liquid crystal material having a reactive group, and then reacting and immobilizing the reactive group.

Examples of the reactive group include a vinyl group, a (meth) acryloyl group, a vinyloxy group, an epoxy group, an oxetanyl group, a carboxy group, a hydroxyl group, an amino group, an isocyanate group, an acid anhydride group, and the like. The reaction is carried out in a manner appropriate to the group.

The liquid crystal material that can be used for the liquid crystal material layer can be selected from various ranges regardless of the low molecular liquid crystal material or the polymer liquid crystal material, depending on the intended use or production method of the liquid crystal film, but the polymer liquid crystal material is preferred. In addition, the molecular shape of a liquid crystal substance may be rod-shaped or disk-shaped. For example, a discotic liquid crystal compound exhibiting discotic nematic liquid crystal can also be used.

Examples of the liquid crystal phase of the liquid crystal material layer before immobilization include a nematic phase, a twisted nematic phase, a cholesteric phase, a hybrid nematic phase, a hybrid twisted nematic phase, a discotic nematic phase, a smectic phase, and the like.

As the polymer liquid crystal substance, various main chain polymer liquid crystal substances, side chain polymer liquid crystal substances, or a mixture thereof can be used. Examples of the main chain polymer liquid crystal material include polyester, polyamide, polycarbonate, polyimide, polyurethane, polybenzimidazole, polybenzoxazole, polybenzthiazole, polyazomethine and polyesteramide. Examples thereof include polymer liquid crystal substances such as polyesters, polyester carbonates, and polyester imides, or mixtures thereof. Moreover, as a side chain type polymeric liquid crystal substance, the skeleton chain of linear or cyclic structure, such as polyacrylate type, polymethacrylate type, polyvinyl type, polysiloxane type, polyether type, polymalonate type, polyester type, etc. Examples thereof include a polymer liquid crystal material or a mixture thereof in which a mesogen group is bonded as a side chain to the material to be retained. Among these, polyester type | system | group which is a main chain type | mold polymer liquid crystal substance is preferable for a synthesis | combination, or an easy orientation.

As the low molecular liquid crystal substance, saturated benzene carbonates, unsaturated benzene carbonates, biphenyl carbonates, aromatic oxy carbonates, Schiff base types, bis azomethine compounds, azo compounds, azoxy compounds, cyclohexane ester compounds, sterols The compound etc. which added the crosslinking | crosslinked compound to the compound which shows liquid crystallinity, or the compound which shows liquid crystallinity among the said compounds in which the said reactive group was introduce | transduced into the terminal, such as compounds, are mentioned. Moreover, as a discotic liquid crystal compound, a triphenylene system, a truxene system, etc. are mentioned as an example.

Moreover, you may mix | blend the various compound which has a functional group or site | part which can react with the crosslinking reaction by external stimulus, such as heat or light, in a liquid crystal material in the range which does not prevent the expression of liquid crystalline. Examples of the functional group capable of crosslinking reaction include the aforementioned various reactive groups.

Formation of the liquid crystal material layer in which the liquid crystal alignment is fixed is performed by applying a liquid crystal material or a composition containing various compounds added as necessary on the alignment substrate in a molten state, and applying a solution such as the composition on the alignment substrate. The coating film formed by the method or the like and coated on the alignment substrate is formed by fixing the orientation by means of fixing the aforementioned orientation such as light irradiation and / or heat treatment, if necessary, through drying and heat treatment (liquid crystal orientation). do.

The solvent used for the preparation of the solution that can be used in the method for applying the solution is not particularly limited as long as it is a solvent that can dissolve the liquid crystal substance or composition used in the present invention and can be removed under suitable conditions. In general, ketones such as acetone, methyl ethyl ketone and isophorone, ether alcohols such as butoxyethyl alcohol, hexayloxyethyl alcohol and methoxy-2-propanol, glycols such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether Esters such as ethers, ethyl acetate, methoxypropyl acetate, ethyl lactate, phenols such as phenol and chlorophenol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and the like Halide hydrocarbons such as amide, chloroform, tetrachloroethane, dichlorobenzene, and the like, or a mixture thereof, may be preferably used. Moreover, in order to form a uniform coating film on an orientation board | substrate, you may add surfactant, an antifoamer, a leveling agent, etc. to a solution. In addition, for coloring purposes, dichroic dyes or ordinary dyes or pigments and the like may be added within a range that does not prevent the expression of liquid crystalline.

About a coating method, if it is a method of ensuring the uniformity of a coating film, a well-known method can be employ | adopted without being specifically limited. For example, a roll coating method, a die coating method, a dip coating method, a curtain coating method, a spin coating method, etc. can be mentioned. You may put in the solvent removal (drying) process by methods, such as a heater or hot air blowing, after application | coating.

The film thickness in the dry state of the apply | coated film | membrane is 0.1 micrometer-50 micrometers normally, Preferably they are 0.2 micrometer-20 micrometers, More preferably, they are 0.3 micrometer-10 micrometers. Outside this range, it is not preferable because the optical performance of the liquid crystal material layer obtained is insufficient, or the orientation of the liquid crystal material is insufficient.

Subsequently, if necessary, the liquid crystal alignment by heat treatment or the like is formed, followed by fixation of the alignment. The heat treatment is to align the liquid crystal by the self-alignment ability originally possessed by the liquid crystal material by heating in the liquid crystal phase expression temperature range. As the heat treatment conditions, since the optimum conditions or limit values differ depending on the liquid crystal phase behavior temperature (transition temperature) of the liquid crystal material to be used, it cannot be collectively mentioned, but is usually 10 to 300 ° C, preferably 30 to 250 ° C. If the temperature is too low, the liquid crystal alignment may not proceed sufficiently, and at a high temperature, the liquid crystal material may decompose or adversely affect the alignment substrate. The heat treatment time is usually 3 seconds to 60 minutes, preferably 10 seconds to 30 minutes. In the heat treatment time shorter than 3 seconds, the liquid crystal alignment may not be sufficiently completed, and in the heat treatment time exceeding 60 minutes, the productivity is extremely deteriorated, which is not preferable in any case. After the liquid crystal material has completed the liquid crystal alignment by heat treatment or the like, the liquid crystal material layer on the alignment substrate is fixed in such a state by means suitable for the liquid crystal material used.

Examples of the alignment substrate include polyimide, polyamide, polyamideimide, polyphenylene sulfide, polyphenylene oxide, polyether ketone, polyether ether ketone, polyether sulfone, polysulfone, polyethylene terephthalate, polyethylene naphthalate and polya Films, such as a related, polyacetyl cellulose, an epoxy resin, and a phenol resin, are mentioned.

Although some of these films exhibit sufficient orientation ability with respect to the liquid crystal material used in the present invention even if the treatment is not performed in order to express the orientation ability again according to the manufacturing method, the orientation performance is insufficient or the orientation performance is not exhibited. These films are stretched under appropriate heating to perform a so-called rubbing treatment in which the film surface is rubbed in one direction with a rayon cloth or the like, or an alignment film composed of a known alignment agent such as polyimide, polyvinyl alcohol, silane coupling agent, or the like is placed on the film. You may use the film which formed and performed the rubbing process, or the orientation ability was expressed by the four-side evaporation process, such as a silicon oxide, or a suitable combination thereof.

Moreover, as an orientation board | substrate, metal plates, such as aluminum, iron, copper, etc. which have many regular fine grooves on the surface, various glass plates, etc. can also be used.

Here, it is not specifically limited as the orientation processing direction of an orientation substrate film, It can select suitably by performing each said process in arbitrary directions. That is, when handling the liquid crystal film formed on the elongate orientation board | substrate, it is preferable to select a predetermined angle with respect to the MD direction of the elongate continuous film, and to align in a diagonal direction as needed. By the alignment treatment in a predetermined angle direction, when laminating the liquid crystal film in an axial arrangement so that optimal optical properties can be exhibited, bonding (so-called roll-to-roll bonding) in the state of cutting the MD of the long film is possible, or There is an extremely useful advantage in terms of increasing the handling efficiency.

Next, a method of transferring the liquid crystal material layer formed on the alignment substrate film onto the removable film will be described.

Examples of the re-peelable film used in the present invention include olefin resins such as polyethylene, polypropylene, and poly-4-methylpentene-1, polyamide, polyimide, polyamideimide, polyetherimide, polyether ketone, and polyether. Ether ketones, polyethersulfones, polyketonesulfides, polysulfones, polystyrenes, polyphenylenesulfides, polyphenylene oxides, polyethylene terephthalates, polybutylene terephthalates, polyarylates, polyacetals, uniaxially stretched polyesters, polycarbonates And plastic films such as polyvinyl alcohol, polymethyl methacrylate, polyarylate, amorphous polyolefin, norbornene-based resin, triacetyl cellulose or epoxy resin.

Among these plastic films, in particular, as a transparent and optically isotropic film excellent in optical lack testability, poly 4-methylpentene-1, polymethyl methacrylate, polystyrene, polycarbonate, polyethylene terephthalate, polyethersulfone, polyarylate Each film, such as amorphous polyolefin, norbornene-type resin, triacetyl cellulose, or an epoxy resin, can be illustrated.

These plastic films may be coated with a surface treatment agent such as silicon in advance on the surface thereof, or an organic thin film or an inorganic thin film may be formed on the surface thereof. In addition, for the same purpose, the surface of the plastic film may be subjected to chemical treatment such as curing treatment or physical treatment such as corona treatment.

The plastic film may also contain a lubricant or surface modifier in order to adjust the peelability of the releasable film. The lubricant is not particularly limited in kind and amount as long as it does not adversely affect the optical deficiency testability or peelability of the liquid crystal material layer. Specific examples of the lubricant include fine silica, fine alumina and the like, and the index of the added amount may be such that the haze value of the releasable substrate is usually 50% or less, preferably 30% or less. If the amount is too small, the effect of addition is unknown, while if too large, the optical lack testability deteriorates, which is not preferable.

Moreover, you may contain other well-known various additives, such as an antiblocking agent, antioxidant, an antistatic agent, a heat stabilizer, an impact resistance improving agent, etc. as needed.

As for the peeling force of the releasable film, even if it is a releasable film made of the same material, it cannot be collectively determined because it varies depending on the manufacturing method, the surface state, or the leakage property of the adhesive used, but at the interface with the adhesive The peel force of (180 ° peeling, peeling rate of 30 cm / min, measured at room temperature) is usually 0.38 to 12 N / m, preferably 0.38 to 8.0 N / m. When the peeling force is lower than the above value, when the liquid crystal material layer on the alignment substrate is adhered to the releasable film and then the alignment substrate is peeled off, the peeling force is so low that the lifting of the releasable film may be seen, and thus the desired interface. When a good peeling state at is not obtained, the transfer of the liquid crystal material layer to the releasable substrate becomes insufficient, and when the peeling force is too high, when the releasable film is peeled off, breakage of the liquid crystal material layer, Or undesired at the interface with the desired layer.

In addition, the thickness of a repeelable film may also affect peelability, Preferably it is 16-100 micrometers, Especially preferably, it is 25-80 micrometers. If the thickness is too thick, the peeling point may not be stable and the peelability may deteriorate. On the other hand, if the thickness is too thin, the mechanical strength of the film may not be maintained, which may cause difficulty such as tearing during manufacture.

When the liquid crystal material layer formed on the alignment substrate is transferred onto the releasable film as described above, an optically isotropic curable acrylic resin-based adhesive is preferably applied to the surface of the liquid crystal material layer, and then reacted by, for example, light irradiation to cure ( After crosslinking) and adhesion, the alignment substrate is peeled off, thereby easily transferring.

As the curable acrylic resin adhesive used, for example, a known one can be used as the photocurable acrylic adhesive. Specifically, various acrylic oligomers such as polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate and silicone acrylate Or a mixture of these, or a mixture of these and various reactive diluents, such as (meth) acrylic monomers.

In addition, these adhesives may be added various particulates or the like, or a surface modifier, in a range that does not impair the properties thereof.

As said microparticles | fine-particles, the microparticles | fine-particles which differ in refractive index from the compound which comprises an adhesive agent, electroconductive microparticles | fine-particles for improving antistatic performance, and microparticles | fine-particles for abrasion resistance improvement, etc. can be illustrated, More specifically, fine silica , Fine alumina, ITO (indium tin oxide) fine particles, silver fine particles, various synthetic resin fine particles, and the like.

In addition, the surface modifier is not particularly limited so long as it has good compatibility with the adhesive and does not affect the curability of the adhesive or the optical performance after curing, and is an ionic or nonionic water-soluble surfactant, an oil-soluble surfactant, or a polymer interface. An activator, a fluorochemical surfactant, organometallic surfactants, such as silicone, a reactive surfactant, etc. can be used.

Although the hardening method of these curable acrylic resin adhesives is not specifically limited, For example, heat hardening, redox type normal temperature hardening, anaerobic hardening, active line hardening, such as an ultraviolet-ray and an electron beam, etc. are illustrated. A preferable curing method is a photocuring method by active rays, such as an ultraviolet-ray and an electron beam. In the photocuring method, since there is no or little heat generation, the influence on the liquid crystal material layer having its orientation fixed is preferable. It is good to add various well-known photoreaction initiators, and to irradiate light from light sources, such as a metal halide lamp, a high pressure mercury, low pressure mercury, etc., a xenon lamp, an arc lamp, a laser, a synchrotron radiation light source, and to react. As irradiation amount per unit area (1 square centimeter), it is a range of 1-2000mJ normally, Preferably it is 10-1000mJ as integrated irradiation amount. However, the case where the absorption region of a photoreaction initiator and the spectrum of a light source differ remarkably, or the case where the reactive compound itself has the absorption ability of a light source wavelength does not have such a restriction | limiting. In such a case, a method such as mixing a suitable photo sensitizer or two or more kinds of photoreaction initiators having different absorption wavelengths may be employed. The acceleration voltage in the electron beam curing type is usually 10 kV to 200 kV, preferably 50 kV to 100 kV.

Examples of thermal reaction initiators include diacyl oxides such as benzoyl peroxide and lauroyl peroxide, ketone peroxides, peroxy ketals, dialkyl peroxides, peroxyesters, and azobisisobutyronitrile and azo. Azobis, such as bisisovaleronitrile, etc. can be used, The usage-amount is 0.1-10 weight% of resin.

In addition, as a photoinitiator at the time of hardening by an active line, benzoin ether, benzoin ethyl ether, benzyl methyl ketal, hydroxy phenyl ketone, 1, 1- dichloro acetophenone, thioxanthones, or amine use are used together, for example. And benzophenones are exemplified. The amount of these used is preferably 0.1 to 10% by weight of the resin.

In the present invention, a protective layer composed of a cured acrylic resin layer for protecting the surface is formed on the liquid crystal material layer. Such a protective layer can also be formed by the curable acrylic resin layer itself comprised from the photocurable acrylate etc. which hold the optical isotropy mentioned above, or can also be comprised by adhering a curable acrylic resin as an adhesive agent to a translucent film. In any case, the cured acrylic resin layer is formed by applying a curable acrylic oligomer or monomer to the surface and curing them.

As the curable acrylate used, one known as an acrylic adhesive, a curable plastic coating agent, or a plastic hard coating agent can be used, and examples thereof include polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, silicone acrylate, and the like. Examples thereof include various acrylic oligomers or monomers alone, mixtures thereof, or mixtures thereof with various reactive diluents.

Moreover, these adhesive agents can also add various microparticles | fine-particles etc. and a surface modifier in the range which does not impair the characteristic.

As said microparticles | fine-particles, the microparticles | fine-particles which differ in refractive index from the compound which comprises an adhesive agent, electroconductive microparticles | fine-particles for improving antistatic performance, and microparticles | fine-particles for abrasion resistance improvement, etc. can be illustrated, More specifically, fine silica , Fine alumina, ITO (indium tin oxide) fine particles, silver fine particles, various synthetic resin fine particles, and the like.

In addition, the surface modifier is not particularly limited so long as it has good compatibility with the adhesive and does not affect the curability of the adhesive or the optical performance after curing, and is an ionic or nonionic water-soluble surfactant, an oil-soluble surfactant, or a polymer interface. An activator, a fluorine-type surfactant, organometallic surfactants, such as silicone, a reactive surfactant, etc. can be used.

Although the hardening method of these curable acrylates is not specifically limited, What is necessary is just to carry out similarly to hardening of the curable acrylic resin type adhesive agent used at the time of transferring the liquid crystal material layer mentioned above to a removable board | substrate.

By the above method, a laminated film in which a re-peelable film / cured acrylic resin layer / alignment-immobilized liquid crystal material layer / cured acrylic resin layer is laminated in this order is obtained. Here, the thickness of the said cured acrylic resin layer is 0.1 micrometer-50 micrometers, respectively, Preferably they are 0.5 micrometer-20 micrometers, More preferably, they are 1 micrometer-10 micrometers. If the thickness becomes too thin over this range, the protective effect of the liquid crystal material layer is insufficient in the environmental test, and if it is too thick, curing of the cured acrylic resin layer takes time or the product thickness becomes thick, which is not preferable.

Further, in the present invention, it is also possible to form a release layer between the liquid crystal material layer and another layer by using a releasable film in which a release layer that is peelable from the film surface is first formed on the surface of the peelable film. By forming the release layer, a stress-blocking effect is obtained for suppressing the change in appearance of the liquid crystal material layer of the thin film (e.g., a waved form, etc.) during manufacture or during environmental testing. The release layer is not particularly limited, but an optically isotropic transparent layer is preferable, and examples thereof include polymers such as acrylic, methacrylic, nitrocellulose and epoxy compounds, and mixtures thereof. As a film thickness of a release layer, it is 0.3 micrometer or more and 40 micrometers or less, Preferably it is 0.5 micrometer or more and 10 micrometers or less, A glass transition point (Tg) is 20 degreeC or more, Preferably it is the optically isotropic transparent layer or more, and a liquid crystal There is no particular limitation on the material unless the optical properties of the material layer are significantly impaired. The film thickness and the glass transition point are not preferable from the viewpoint of the effect thereof being insufficient or the product becoming too thick outside this range.

In addition, the release layer may perform physical property control by partial crosslinking, plasticizer addition, lubricant addition, or the like by addition of a crosslinking component.

There is no particular limitation on the method of forming the release layer, but for example, a method of coating or extruding a material to be a release layer having the above-described film thickness on a removable film such as polyethylene, polypropylene, polyethylene terephthalate, or the like. And a transfer method in which the layer is brought into close contact with each other via a pressure-sensitive adhesive or an adhesive layer or a transparent protective layer, and then the re-peelable film is peeled off.

In the next step, the pressure-sensitive adhesive so that the re-peelable film / cured acrylic resin layer / orientation-immobilized liquid crystal material layer / cured acrylic resin layer obtained as described above is bonded to the laminated film laminated in this order, in the final product, etc. To give. Because of the good production efficiency, an adhesive is usually applied continuously to a long laminated film. The method of continuously giving an adhesive is not specifically limited, The method of apply | coating an adhesive directly to the cured acrylic resin layer surface of a laminated film, and bonding a separator, or the adhesive layer formed on the long separator first, the cured acrylic of a laminated film The method etc. which continuously bond with a resin layer are mentioned. In general, a plastic film such as polyethylene terephthalate, to which silicone treatment has been applied, is used as a separator to ensure peelability with an adhesive.

In this way, a laminated film is obtained in which a re-peelable film / cured acrylic resin layer / alignment-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolate film is laminated in this order.

Subsequently, the laminated | multilayer film in which the re-peelable film / cured acrylic resin layer / orientation-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolation film which were obtained as mentioned above was laminated | stacked in this order is cut | disconnected.

Examples of the half cutting method include the following two methods.

<Method A> Half-cutting method so that at least a re-peelable film is cut | disconnected completely.

<Method B> Half-cutting method so that at least the isolation membrane is cut | disconnected completely.

Here for method A, if at least the re-peelable film is completely cut and the separator remains at least completely uncut, another cured acrylic resin layer / oriented immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer portion It may or may not be cut about. Preferably only the re-peelable film is half cut and the other part is not cut.

Also, in the case of Method B, if at least the separator is completely cut and the re-peelable film remains at least completely uncut, another cured acrylic resin layer / oriented immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer The part may or may not be cut. In addition, since the re-peelable film can be peeled off even if the cured acrylic resin layer / orientation-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer portion is not necessarily cut, the peeling operation of the re-peelable film It is necessary to pull excessively and cut at the time. Preferably, only the re-peelable film is not cut and other portions are completely cut.

Although the method of peeling a repeelable film is not specifically limited, In the case of Method A, only a repeelable film can be peeled easily, if a cellophane tape etc. are stuck and peeled off at the half cut part of a repeelable film. In addition, in the case of Method B, only the re-peelable film can be easily peeled off when the half-cut separator portion is held and peeled off as it is.

Moreover, the method to make peelability of a repeelable film easier, and to raise work efficiency is demonstrated.

In a long laminated film in which a re-peelable film / cured acrylic resin layer / orientated liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolator is laminated in this order, the re-peelable film is continuously peeled off. It is once attached to a long protective film with better peelability, and is replaced. In this way, a long laminated film is obtained in which a protective film / cured acrylic resin layer / alignment-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolating film is laminated in this order. Here, the protective film serves to prevent damage to the surface of the cured acrylic resin or adhesion of dust or the like upon subsequent handling.

Subsequently, the sheet | seat which cut | disconnected such an attached long elongate laminated | multilayer film to predetermined length is given half cutting as mentioned above. That is, the following two methods are mentioned as a half cutting method.

<Method C> The method of half-cutting at least so that a protective film may be cut | disconnected completely.

<Method D> The method of half-cutting so that at least an isolation film is cut | disconnected completely.

In the case of method C, here, for at least another cured acrylic resin layer / orientation-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer portion, if at least the protective film is completely cut and the separator remains at least completely uncut. It may or may not be cut. Preferably, only the protective film is half cut and other portions are not cut.

Also, in the case of Method D, if at least the separator is completely cut and the protective film remains at least completely uncut, another cured acrylic resin layer / oriented immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer portion It may or may not be cut about. Here, since only the protective film can be peeled off even if the cured acrylic resin layer / orientation-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer portion is not necessarily cut, these layers are pulled out during the peeling operation of the protective film. I need to cut it. Preferably, only a protective film is not cut | disconnected and the other part is in the state cut | disconnected completely.

Although the method of peeling a protective film is not specifically limited, In the case of method C, only a protective film can be peeled easily, if a cellophane tape etc. are stuck and peeled off at the half cut part of a protective film. In addition, in the case of Method D, only the protective film can be easily peeled off when the half-cut separator part is grabbed and peeled off as it is.

Although it does not specifically limit as a protective film used here, What is generally used as a protective film for retardation films or a polarizing plate is mentioned. Examples thereof include a coextruded film of polyethylene and an ethylene vinyl acetate copolymer, a film obtained by applying an acrylic or synthetic rubber pressure-sensitive adhesive to a polyethylene substrate, a polyethylene terephthalate substrate, or a polyolefin substrate. In general, the former coextruded film is more preferable because of less peeling force. As peeling force (180 degree peeling, peeling rate 30cm / min, measured under room temperature) of a protective film, it is normally 0.2-12 N / m, Preferably it is 0.38-8.0 N / m. When peeling force is lower than this value, there exists a possibility that a protective film may peel off during handling, or too high, and it is unpreferable because the possibility of peeling between an adhesive / separation film may peel off before peeling a protective film.

By peeling a re-peelable film or a protective film as mentioned above, the sheet-like optical film which the cured acrylic resin layer / orientation fixation liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolation film laminated | stacked in this order is laminated | stacked. Can be obtained. When the optical film on such a sheet is used as a color compensating plate or a viewing angle compensation for a liquid crystal display device, etc., it is usually laminated with a polarizing plate and, if necessary, an optical film or a polymer stretched film made of a liquid crystal material layer oriented and fixed as a phase difference plate. Etc. can also be laminated. Here, also when laminating a polarizing plate, an optical film which consists of an orientation-immobilized liquid crystal material layer, a polymeric stretched film, etc., it can laminate | stack through a well-known translucent point adhesive agent. As an optical laminated body obtained in this way, it is for example

(1) polarizing plate / point, adhesive layer / cured acrylic resin layer / orientation fixed liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolation film

(2) polarizing plate / point, adhesive layer / polymer stretched film / point, adhesive layer / cured acrylic resin layer / alignment-immobilized liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolation film

(3) polarizing plate / adhesive / adhesive layer / cured acrylic resin layer / alignment fixed liquid crystal material layer / cured acrylic resin layer / adhesive layer / cured acrylic resin layer / alignment fixed liquid crystal material layer / cured acrylic resin layer / adhesive layer / For example, the separator.

A polarizing plate may be used independently of a polarizing film, and may arrange | position the transparent protective layer etc. to the polarizing film single side | surface or both surfaces for the purpose of intensity | strength improvement, moisture resistance improvement, and heat resistance improvement. As a transparent protective layer, what laminated | stacked the transparent plastic film, such as polyester or triacetyl cellulose directly or via an adhesive bond layer, the coating layer of resin, photocurable resin layers, such as an acryl-type or an epoxy type, etc. are mentioned. When these transparent protective layers are coat | covered on both surfaces of a polarizing film, the same transparent protective layer may be arrange | positioned at both surfaces, or a different transparent protective layer may be arrange | positioned.

Examples of the polymer stretched film include monoaxial or biaxially stretched retardation phases composed of cellulose, polycarbonate, polyarylate, polysulfone, polyvinyl alcohol (PVA), polyacrylic, polyethersulfone, cyclic polyolefin, etc. An example is a film. Among these, cyclic polyolefin type uniaxial stretched films, such as a polycarbonate type and a norbornene type, are preferable at the point of ease of manufacture, or the uniformity or optical characteristic of a film.

The optical laminate obtained by bonding the optical film having the alignment-immobilized liquid crystal material layer thus obtained to the polarizing plate can function as a compensating member, an elliptical polarizing plate, and a circular polarizing plate of various liquid crystal display devices according to the optical parameters of the liquid crystal material layer. .

That is, since the liquid crystal material layer constituting the optical laminate, for example, the liquid crystal material layer in which the nematic alignment and the twisted nematic alignment are fixed functions as a retardation plate, the optical laminate using the liquid crystal material layer as a constituent member is an STN type. , TN type, OCB type, HAN type or the like can be used as a compensation plate of a transmissive or reflective liquid crystal display device.

In addition, the nematic hybrid alignment-immobilized liquid crystal material layer can be used as a retardation film or a wave plate using the retardation viewed from the front, and also by the direction of the retardation value (the inclination of the molecular axis in the film thickness direction). It can produce asymmetry and can also use it as a viewing angle improvement member of a TN type liquid crystal display device.

In addition, the liquid crystal material layer having a quarter wave plate function can be used as an antireflection filter of a circular polarizing plate or a reflective liquid crystal display device or an EL display device by combining with a polarizing plate.

Moreover, if the liquid crystal material layer which comprises the said laminated body fixed cholesteric orientation or smectic orientation, the color of reflected light according to the time resulting from the polarization reflective film for brightness improvement, a reflective color filter, and selective reflection performance It can be used for various anti-counterfeiting elements or decorative films causing change.

Supporting by half-cutting the laminated film laminated in order of re-peelable film / cured acrylic resin layer / oriented fixed liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolate film, and then peeling off the re-peelable film, The optical film of a thin film without a board | substrate can be manufactured efficiently.

Example

Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these.

In addition, the liquid crystalline high molecular compound used in the present Example is a liquid crystalline high polymer compound (wherein the numerical value in the lower right of a parenthesis represents mol% of each structural unit of a polymer) represented by following Formula, Nematic orientation is carried out and it becomes glass state below liquid crystal transition temperature. Therefore, the orientation at the time of a liquid crystal can be fixed, and this orientation fixing film is a preferable thing as retardation film for liquid crystal display devices.

Formula 1

<Example 1>

The liquid crystal polymer compound coating solution was applied using a roll coater onto the surface on which the long film of the polyimide as the alignment substrate film was rubbed, dried, heated at 210 ° C. for 20 minutes, and the orientation of the liquid crystal polymer compound was fixed. The liquid crystalline polymer film of was obtained. A commercially available ultraviolet curable acrylic adhesive (UV-3400, manufactured by Dong-A Synthetic Co., Ltd.) was applied to a long liquid crystal polymer film formed on the polyimide using another roll coating machine to form an adhesive layer. Additionally, an oriented substrate film / liquid crystal polymer layer / cured acrylic resin layer 1 / repeelable film was formed by bonding a long, re-peelable, uniaxially stretched polyethylene terephthalate (PET) film onto the adhesive layer and curing the adhesive. A long laminated film was obtained. The obtained long laminated film was peeled off at the interface between the alignment substrate film and the liquid crystalline polymer layer using a roll to obtain a long laminated film composed of a liquid crystalline polymer layer / cured acrylic resin layer 1 / repeelable film. . Next, the ultraviolet curable acrylic adhesive (UV-3400) was apply | coated on the liquid crystalline polymer layer of this laminated | multilayer film using a roll coater. In addition, a long silicone treated PET film is bonded onto the applied adhesive layer and the adhesive is cured to a silicone treated PET film / cured acrylic resin layer 2 / liquid crystalline polymer layer / cured acrylic resin layer 1 / repeelable film. A long laminated film was obtained.

The silicon-treated PET film of the laminated film thus obtained was continuously peeled off using a roll, and then, first, the pressure-sensitive adhesive applied on the long separator was bonded to each other, and the separator / adhesive layer / cured acrylic resin layer 2 / liquid crystalline polymer layer / cured acrylic A long laminated film (A) consisting of a resin layer 1 / repeelable film was obtained.

Subsequently, 10 sheets of such a long laminated film (A) were cut into sheets of A4 size. The corner part was cut half by 1 each so that a removable film might be cut | disconnected using the commercially available half cutter (Half cutter RH24 for TEPRA by King Kujima). When the cellophane tape was peeled off and peeled off on the half-cut re-peelable film surface, the interface between the re-peelable film and the cured acrylic resin layer 1 could be easily peeled off.

<Example 2>

Ten long laminate films (A) obtained in Example 1 were cut into sheets of A4 size. In addition, using the commercially available half cutter, the corner part of each sheet was half cut | disconnected so that a separator may be cut | disconnected similarly to Example 1. When the half cut edges were caught and peeled off as they were, the interface between the repeelable film and the cured acrylic resin layer 1 could be easily peeled off in all ten sheets.

<Example 3>

After peeling the interface of the re-peelable film and the cured acrylic resin layer 1 continuously using a roll, the elongate laminated film (A) obtained in Example 1 was subjected to a long protective film (PAC-2-70G, Saeyeon Co., Ltd.) was bonded to obtain a long laminate film (B) consisting of a separator / adhesive layer / cured acrylic resin layer 2 / liquid crystalline polymer layer / cured acrylic resin layer 1 / protective film.

Ten of such elongate laminated | multilayer film B was cut | disconnected by the sheet | seat of A4 size, and the corner part was cut half by 1 each so that a protective film might be cut | disconnected using the commercially available half cutter like Example 1. When the cellophane tape was affixed and peeled off such a half cut protective film surface, the interface of a protective film and the cured acrylic resin layer 1 could all be peeled easily.

<Example 4>

Ten long laminate films (B) obtained in Example 3 were cut into sheets of A4 size. In the same manner as in Example 1, the corner portions were half cut so that the separator was cut using a commercial half cutter. When the half cut edges were grabbed and peeled off as they were, all 10 sheets could easily peel off the interface between the protective film and the cured acrylic resin layer 1.

Comparative Example 1

The long laminated film (A) obtained in Example 1 was cut into ten sheets of A4 size. Attempts were made to peel off only the re-peelable film by attaching a cellophane tape to the re-peelable film surface at this corner portion, but all 10 sheets were peeled only at the interface between the pressure-sensitive adhesive layer and the separator.

Comparative Example 2

Ten long laminate films (B) obtained in Example 3 were cut into sheets of A4 size. When the cellophane tape was attached to the protective film surface of this corner portion and only the protective film was to be peeled off, five sheets could peel only the protective film, but the remaining five sheets peeled off the interface between the adhesive layer and the separator.

Table 1 summarizes the evaluation results of Examples 1 to 4 and Comparative Examples 1 and 2.

Removable film Half cutting position Peel test of re-peelable film or protective film Example 1 Uniaxially-stretched PET Uniaxially Drawn PET Cutting Easy peeling of uniaxially stretched PET (10 out of 10) Example 2 Uniaxially-stretched PET Separator cutting Easy peeling of uniaxially stretched PET (10 out of 10) Example 3 PAC-2-70G PAC-2-70G cutting Easy peeling of PAC-2-70G (10 of 10) Example 4 PAC-2-70G Separator cutting Easy peeling of PAC-2-70G (10 of 10) Comparative Example 1 Uniaxially-stretched PET radish Uniaxially stretched PET does not peel off (10 out of 10) Comparative Example 2 PAC-2-70G radish Some peel at abnormal interface (5 out of 10)

Claims (5)

Half-cutting is performed on the laminated film laminated in the order of re-peelable film / cured acrylic resin layer / oriented liquid crystal material layer / cured acrylic resin layer / adhesive layer / isolate film, and then peeling off the re-peelable film. Method for producing an optical film, characterized in that. The method of manufacturing an optical film as set forth in claim 1, wherein half cutting is performed so that at least the releasable film is completely cut. The method of manufacturing an optical film as set forth in claim 1, wherein half cutting is performed so that at least the separator is completely cut. The liquid crystal material layer according to any one of claims 1 to 3, wherein the alignment-immobilized liquid crystal material layer is made of a polymer material which is oriented in a liquid crystal at a temperature above the liquid crystal transition point and becomes a glass state at a temperature below the liquid crystal transition point. The manufacturing method of the optical film made into. The method for producing an optical film according to any one of claims 1 to 3, wherein the liquid crystal material layer in which the alignment is immobilized is composed of a layer crosslinked with a liquid crystal material having a liquid crystal oriented reactive group.