WO2021070425A1

WO2021070425A1 - Method for manufacturing film laminate having print layer

Info

Publication number: WO2021070425A1
Application number: PCT/JP2020/024374
Authority: WO
Inventors: 岳仁淵田; 康隆石原
Original assignee: 日東電工株式会社
Priority date: 2019-10-07
Filing date: 2020-06-22
Publication date: 2021-04-15
Also published as: JP6816237B1; JP2021059053A; CN112955320A; TW202122268A; KR20220070380A

Abstract

Provided is a simple method for manufacturing a film laminate (100) having a print layer, the film laminate having high pencil hardness and suppressed curling. This method for manufacturing a film laminate having a print layer includes: forming a hard coat layer (20) on one surface of a base material film (10); forming a print layer (30) on another surface of the base material film; laminating a protective film (40) having a heat shrinkage rate in a conveyance direction of 0.1% or less on the surface of the hard coat layer; and heating and drying the print layer while a protective film is laminated thereon.

Description

Manufacturing method of film laminate with print layer

The present invention relates to a method for producing a film laminate with a print layer.

A decorative film (film with a printing layer) is used as a means of improving the design of various products. For example, as one of the means for improving the design of the image display device (for example, concealing the wiring of the non-display area without using a bezel), the portion corresponding to the non-display area of the front plate (typically, the peripheral portion). ) Is provided with a colored layer, a design layer, a decorative layer, or the like (for example, Patent Documents 1 and 2). However, in order to form the print layer, it is necessary to heat and dry it for a long time, and as a result, there is a problem that the film with the print layer is curled.

Japanese Unexamined Patent Publication No. 2011-194799 JP-A-2017-126003

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is a simple method for producing a film laminate with a print layer having high pencil hardness and suppressed curling. Is to provide.

The method for producing a film laminate with a print layer of the present invention is to form a hard coat layer on one surface of a base film; to form a print layer on the other side of the base film; the hard coat layer. A protective film having a heat shrinkage rate of 0.1% or less in the transport direction is laminated on the surface of the printing layer; and the printed layer is heat-dried with the protective film laminated.
In one embodiment, the printing layer is heat-dried at 40 ° C. or higher for 20 minutes or longer.
In one embodiment, the protective film is laminated by roll-to-roll on the surface of the hard coat layer of the laminate of the base film and the hard coat layer.
In one embodiment, the print layer is formed after laminating the protective film.
In one embodiment, in the manufacturing method, a laminate of the base film, the hard coat layer, and the protective film is formed into a predetermined size and a predetermined size between the lamination of the protective film and the formation of the printing layer. It further includes cutting into shapes.
In one embodiment, the hard coat layer is coated with a coating liquid for forming a hard coat layer containing an active energy ray-curable (meth) acrylate to form a coating layer, and the coating layer is irradiated with active energy rays. It is formed by curing it.
According to another aspect of the present invention, there is provided a method for manufacturing an optical laminate. This manufacturing method includes laminating an optical film on the opposite side of the base film of the film laminate with a printing layer obtained by the above manufacturing method to the hard coat layer.
In one embodiment, the manufacturing method comprises laminating the optical films and then peeling off the protective film.
According to yet another aspect of the present invention, there is provided a method of manufacturing an image display device. This manufacturing method includes laminating an optical film and a film laminate with a print layer obtained by the above manufacturing method on the visual side of an image display cell.
In one embodiment, the manufacturing method comprises laminating the optical film and the film laminate with a print layer and then peeling off the protective film.
Yet another image display device of the present invention includes laminating an optical laminate obtained by the above manufacturing method on the visual side of an image display cell.
In one embodiment, the manufacturing method comprises laminating the optical laminate and then peeling off the protective film.

According to the embodiment of the present invention, in the method for producing a film laminate with a print layer, a high pencil is obtained by heating and drying the print layer in a state where a protective film having a heat shrinkage ratio of a predetermined value or less is laminated in a predetermined direction. A film laminate with a print layer having hardness and suppressed curl can be easily produced. Further, according to the embodiment of the present invention, the protective film is peeled off after the optical film is laminated on the side opposite to the hard coat layer of the base film in the film laminate with the print layer, so that the base film is curled. It can be reliably laminated on the optical film without any problems.

It is the schematic sectional drawing of the film laminated body with a print layer obtained by the manufacturing method of embodiment of this invention. FIG. 5 is a schematic cross-sectional view of an optical laminate including the film laminate with a print layer of FIG.

Hereinafter, typical embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

A. Method for Producing Film Laminate with Print Layer The method for producing a film laminate with print layer according to the embodiment of the present invention is to form a hard coat layer on one surface of the base film; the other surface of the base film. A printing layer is formed on the surface of the hard coat layer; a protective film having a heat shrinkage rate of 0.1% or less in the transport direction is laminated on the surface of the hard coat layer; To heat dry;

A-1. Overall configuration of the obtained film laminate with a print layer In order to facilitate understanding of the manufacturing method, first, the overall configuration and components of the film laminate with a print layer obtained by the manufacturing method will be briefly described. FIG. 1 is a schematic cross-sectional view of a film laminate with a print layer obtained by the production method of the embodiment of the present invention. The film laminate 100 with a print layer of the illustrated example includes a base film 10, a hard coat layer 20 formed on one surface of the base film 10, and a print layer formed on the other side of the base film 10. It has 30 and a protective film 40 laminated on the surface of the hard coat layer 20. The protective film 40 includes a base film (resin film) and an adhesive layer. The protective film 40 is releasably laminated on the surface of the hard coat layer 20 via the pressure-sensitive adhesive layer. If necessary, a hue adjusting layer (not shown) may be provided between the base film 10 and the printing layer 30. Practically, another protective film (sometimes referred to as a process protective film, not shown) may be temporarily attached to the surfaces of the print layer 30 and the base film 10 so as to be peelable.

A-2. Base film The base film 10 can be made of any suitable material. Specific examples of the constituent materials include polyethylene terephthalate resin, polyethylene naphthalate resin, acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyamideimide resin, and polyolefin resin. Examples thereof include (meth) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins and the like. These resins may be used alone or in combination of two or more. Preferably, it is a polyamide-based resin, a polyimide-based resin, a polyamide-imide-based resin, a polyethylene naphthalate-based resin, or a polycarbonate-based resin. This is because it has excellent durability and mechanical strength. More preferably, it is a polyimide resin.

The base film may contain fine particles blended in the above constituent materials. More specifically, the base film may be a so-called nanocomposite film in which nanometer-order fine particles are dispersed in the matrix of the constituent materials. With such a configuration, very good hardness and scratch resistance can be imparted. The average particle size of the fine particles is, for example, about 1 nm to 100 nm. The fine particles are typically composed of inorganic oxides. Preferably, the surface of the fine particles is modified with a predetermined functional group. Examples of the inorganic oxides constituting the fine particles include zirconium oxide, ittoria-added zirconium oxide, lead zirconate, strontium titanate, tin titanate, tin oxide, bismuth oxide, niobium oxide, tantalum oxide, potassium tantalate, and tungsten oxide. , Cerium oxide, lanthanum oxide, gallium oxide and the like, silica, alumina, titanium oxide, zirconium oxide, barium titanate and the like.

The thickness of the base film is preferably 40 μm to 100 μm, more preferably 50 μm to 80 μm. With such a thickness, the balance between thinning, handleability, and mechanical strength is excellent.

The pencil hardness of the base film is preferably B or higher, more preferably F or higher, and even more preferably H or higher.

A-3. Formation of hard coat layer The hard coat layer 20 is typically coated with a coating liquid for forming a hard coat layer to form a coating layer, and the coating layer is irradiated with active energy rays (for example, ultraviolet rays) to be cured. Is formed by The coating liquid for forming a hard coat layer contains an active energy ray-curable (meth) acrylate as a base resin. Examples of the active energy ray-curable (meth) acrylate include an ultraviolet curable (meth) acrylate and an electron beam-curable (meth) acrylate. A UV curable (meth) acrylate is preferred. This is because the hard coat layer can be efficiently formed by a simple processing operation. The UV curable (meth) acrylate contains UV curable monomers, oligomers, polymers and the like. The UV curable (meth) acrylate contains a monomer component and an oligomer component having preferably 2 or more, more preferably 3 to 6 UV polymerization functional groups. Typically, the ultraviolet curable (meth) acrylate contains a photopolymerization initiator. The curing method may be a radical polymerization method or a cationic polymerization method. In one embodiment, an organic-inorganic hybrid material in which silica particles, a polysilsesquioxane compound, or the like is mixed with (meth) acrylate may be used. A constituent material and a method for forming the hard coat layer are described in, for example, Japanese Patent Application Laid-Open No. 2011-237789. The description of this publication is incorporated herein by reference. In addition, in this specification, (meth) acrylate means acrylate and / or methacrylate.

A slide ring material may be blended with the ultraviolet curable (meth) acrylate. Good flexibility can be imparted by blending the slide ring material. Polyrotaxane is a typical example of the slide ring material. Polyrotaxane typically has a structure in which a cyclodextrin (CD) cyclic molecule slides on a linear polyethylene glycol (PEG) main chain. Both ends of the PEG backbone are modified with adamantaneamine to prevent shedding of the CD cyclic molecule. In polyrotaxane, preferably, the CD cyclic molecule is chemically modified to impart an active energy ray-polymerizable group. When a slide ring material is used, a radically polymerizable monomer having a radically polymerizable group is preferably used as the ultraviolet curable (meth) acrylate. Examples of the radically polymerizable group include a (meth) acryloyl group and a (meth) acryloyloxy group. This is because it has excellent compatibility with polyrotaxane and various material selections are possible. When polyrotaxane (substantially a polymerizable group of a CD cyclic molecule) reacts with an ultraviolet curable component of an ultraviolet curable (meth) acrylate and is cured, a hard coat layer in which the cross-linking point is movable even after curing is formed. can get. As a result, the stress at the time of bending can be relaxed, and the bending durability is improved. Polyrotaxane and the curing mechanism are described in, for example, Japanese Patent Application Laid-Open No. 2015-155530. The description of this publication is incorporated herein by reference.

The ultraviolet curable (meth) acrylate may contain nanofibers and / or nanocrystals. Typical examples of nanofibers include cellulose nanofibers, chitin nanofibers, and chitosan nanofibers. By blending these, a hard coat layer having excellent flexibility, pencil hardness, scratch resistance, and abrasion resistance can be obtained while maintaining excellent transparency. The nanofibers and / or nanocrystals (the total when used in combination) can be blended in a proportion of 0.1% to 40% by weight, preferably 0.1% by weight, based on the entire hard coat layer. Nanofibers have an average fiber diameter of, for example, 1 nm to 100 nm, and an average fiber length of, for example, 10 nm to 1000 nm. The hard coat layer containing nanofibers is described in, for example, Japanese Patent Application Laid-Open No. 2012-131201 and Japanese Patent Application Laid-Open No. 2012-171171. The description of this publication is incorporated herein by reference.

The coating liquid may further contain any suitable additive depending on the purpose. Additives include, for example, photopolymerization initiators, leveling agents, blocking inhibitors, dispersion stabilizers, rockers, antioxidants, UV absorbers, defoamers, thickeners, dispersants, surfactants, etc. Examples thereof include catalysts, fillers, lubricants, and antistatic agents. The type, combination, content, etc. of the additives contained can be appropriately set according to the purpose and desired characteristics.

Active energy ray (e.g., ultraviolet) irradiation amount (integrated light quantity) is, for example, ^{150mJ / cm 2 ~ 400mJ / cm} 2. If necessary, the coating layer may be heated before irradiation with active energy rays. The heating temperature is, for example, 70 ° C to 100 ° C. The heating time is, for example, 1 minute to 4 minutes.

The thickness of the formed hard coat layer is preferably 3 μm to 20 μm, and more preferably 3 μm to 15 μm. When the thickness is in such a range, curling can be satisfactorily suppressed, and both excellent surface hardness and flexibility and / or foldability can be achieved at the same time.

A-4. Lamination of Protective Film The protective film 40 can be typically laminated by roll-to-roll on the surface of the hard coat layer of the laminate of the base film / hard coat layer. The larger of the heat shrinkage rate in the first direction and the heat shrinkage rate in the second direction orthogonal to the first direction of the protective film is 0.1% or less, preferably 0.08%. It is less than or equal to, more preferably 0.06% or less, still more preferably 0.05% or less. The smaller the heat shrinkage, the more preferable. The lower limit of the heat shrinkage rate can be, for example, 0.01%. When the heat shrinkage rate is within such a range, curl of the film laminate with a print layer (particularly, curl due to heating at the time of forming the print layer) can be remarkably suppressed. The first direction is typically the transport direction of the protective film.

Regarding the heat shrinkage rate of the protective film, typically, the heat shrinkage rate in the transport direction is larger than the heat shrinkage rate in the direction orthogonal to the transport direction (width direction). Such properties regarding the coefficient of thermal shrinkage in the protective film can be realized by lowering the glass transition temperature or increasing the coefficient of linear expansion.

The protective film can be made of any suitable material that can achieve the heat shrinkage as described above. Specific examples of the constituent materials include polyester resins such as polyethylene terephthalate, cycloolefin resins such as norbornene resins, polyamide resins, polycarbonate resins, and copolymer resins thereof. A polyester resin is preferable, and polyethylene terephthalate is more preferable.

The thickness of the protective film is preferably 30 μm to 140 μm, preferably 35 μm to 135 μm. With such a thickness, curling of the film laminate with a print layer can be remarkably suppressed due to a synergistic effect with the above-mentioned characteristics related to the heat shrinkage rate. As described above, the protective film includes the base film (resin film) and the pressure-sensitive adhesive layer, and the thickness of the protective film is the total thickness of the base film and the pressure-sensitive adhesive layer.

The elastic modulus of the protective film is preferably 2.2 kN / mm ² to 4.8 kN / mm ² . When the elastic modulus of the protective film is within such a range, it can contribute to curl suppression of the film laminate with the print layer. The elastic modulus is measured according to JIS K 6781.

The tensile elongation of the protective film is preferably 90% to 170%. When the tensile elongation of the protective film is within such a range, it has an advantage that it is unlikely to break during transportation. The tensile elongation is measured in accordance with JIS K6781.

A-5. Formation of Print Layer The print layer 30 can typically be formed after laminating the protective film. More specifically, the print layer may be formed after the laminate of the base film / hard coat layer / protective film is cut into a predetermined size and shape. Regarding cutting, for example, when the laminated body is cut into a rectangular shape, the laminated body may be cut into a rectangular shape so that the long side direction (transportation direction) of the laminated body is the long side direction, or the rectangular body is cut into a rectangular shape so as to be the short side direction. You may cut it into.

The print layer can be formed by any suitable printing method using any suitable ink or paint. Specific examples of the printing method include gravure printing, offset printing, silk screen printing, and transfer printing from a transfer sheet.

The ink or paint used typically includes a binder, a colorant, a solvent and any suitable additive that may be used as needed. Examples of the binder include chlorinated polyolefins (for example, chlorinated polyethylene and chlorinated polypropylene), polyester resins, urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, and cellulose resins. .. The binder resin may be used alone or in combination of two or more. In one embodiment, the binder resin is a thermosetting resin. Since the thermosetting resin can be used in a smaller amount than the photopolymerizable resin, the amount of the colorant used (colorant content in the colored layer) can be increased. As a result, especially when forming a black colored layer, it is possible to form a colored layer having a very small total light transmittance and excellent hiding power. In one embodiment, the binder resin is a (meth) acrylic resin, preferably a (meth) acrylic resin containing a polyfunctional monomer (eg, pentaerythritol tri (meth) acrylate) as a copolymerization component. By using a (meth) acrylic resin containing a polyfunctional monomer as a copolymerization component, a printed layer having an appropriate elastic modulus can be formed. In addition, a step is also formed due to the thickness of the print layer, and the step can effectively function to prevent blocking.

As the colorant, any suitable colorant can be used depending on the purpose and the desired color. Specific examples of colorants include inorganic pigments such as titanium white, zinc flower, carbon black, iron black, valve handle, chrome vermilion, ultramarine blue, cobalt blue, yellow lead, and titanium yellow; phthalocyanine blue, induslen blue, and iso. Organic pigments or dyes such as indolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, aniline black; metal pigments composed of scaly foil pieces such as aluminum and brass; scales such as titanium dioxide coated mica and basic lead carbonate. Examples thereof include pearl luster pigments (pearl pigments) composed of shaped foil pieces. When forming a black colored layer, carbon black, iron black, and aniline black are preferably used. In this case, it is preferable to use a colorant in combination. This is because it can absorb visible light over a wide range and evenly to form a non-colored (ie, black) colored layer. For example, in addition to the colorants described above, azo compounds and / or quinone compounds can be used. In one embodiment, the colorant comprises carbon black as a main component and other colorants (eg, azo compounds and / or quinone compounds). According to such a configuration, it is possible to form a colored layer that is not colored and has excellent stability over time. When forming a black colored layer, the colorant can be used in a ratio of preferably 50 parts by weight to 200 parts by weight with respect to 100 parts by weight of the binder resin. In this case, the content ratio of carbon black in the colorant is preferably 80% to 100%. By using a colorant (particularly carbon black) at such a ratio, it is possible to form a colored layer having a very small total light transmittance and excellent stability over time.

The printed layer formed is a colored layer that is colored by printing according to the application and the desired design. Examples of the color of the print layer include black, brown, white, dark blue, red, gold, and silver. The printing layer may be a design layer having a predetermined design, or may be a solid colored layer. The printing layer is preferably a solid colored layer, and more preferably a black colored layer. By using a black colored layer as the print layer, wiring, terminals, a backlight, and other parts can be concealed in a non-display area. That is, the print layer can function as a concealment layer. The print layer can be formed in any suitable pattern depending on the purpose. In one embodiment, the print layer may be formed in a position corresponding to the bezel. With such a configuration, the non-display area can be concealed without using a bezel, so that an image display device that does not use a bezel can be realized. As a result, it is possible to provide an image display device having an extremely excellent appearance with no step on the outermost surface.

The thickness of the printed layer formed is preferably 3 μm to 15 μm. Further, the printed layer has a total light transmittance of preferably 0.01% or less, more preferably 0.008% or less at a thickness of 3 μm to 15 μm. When the total light transmittance is in such a range, the non-display area of the image display device can be well concealed without using the bezel.

As described above, a film laminate with a print layer is produced.

A-6. Heat-drying of the print layer Next, by heat-drying the print layer of the film laminate with the print layer, the final film laminate with the print layer can be obtained. That is, the heat-drying of the print layer is performed in a state where the protective films are laminated. Curling can be remarkably suppressed by heating and drying the print layer in a state where the protective films are laminated. Heat drying is typically performed at 40 ° C. or higher for 20 minutes or longer. The heating temperature is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. The upper limit of the heating temperature can be, for example, 95 ° C. The heating time is preferably 30 minutes or more, more preferably 40 minutes or more, still more preferably 50 minutes or more, and particularly preferably 60 minutes or more. The upper limit of the heating time can be, for example, 90 minutes. If the heating temperature is too high and / or the heating time is too long, the curl of the film laminate with the print layer becomes large, and / or the film laminate with the print layer softens or melts due to heat and breaks. There is. If the heating temperature is too low and / or the heating time is too short, the print layer may not be sufficiently formed.

A-7. Others Practically, a process protection film is temporarily attached to the print layer and the surface of the base film of the obtained film laminate with a print layer so as to be peelable. The film laminate with a print layer to which the process protection film is temporarily attached is used for alignment cutting, pre-shipment inspection, and the like. In practical use, the protective film and the process protective film are peeled off and removed. Typically, the protective film is stripped off (substantially at the end) after the process protective film.

A-8. Characteristics of the obtained film laminate with print layer The film laminate with print layer has a warp amount of 19 mm or less, preferably 15 mm or less, more preferably 10 mm or less after being placed in an environment of 70 ° C. for 60 minutes. It is more preferably 7 mm or less. The smaller the amount of warpage, the more preferable. The lower limit of the amount of warpage can be, for example, 2 mm. According to the embodiment of the present invention, the amount of warpage (curl) can be made very small in the film laminate with a print layer. As a result, the film laminate with the print layer can be reliably and satisfactorily laminated on the optical film or the image display cell.

The visible side surface (substantially the surface of the hard coat layer) of the film laminate with the printing layer has a pencil hardness of preferably 2H or more, more preferably 3H or more, still more preferably 4H or more. When the pencil hardness is in such a range, the film laminate with a print layer can function well as a window film. Pencil hardness can be measured according to JIS K 5400-5-4. Further, the visible surface has scratch resistance that does not cause scratches even if it is rubbed back and forth preferably 300 times, more preferably 500 times, and even more preferably 1000 times under a load of 1000 g. The scratch resistance can be evaluated in the state of scratches when steel wool # 0000 is used and the surface is reciprocated a predetermined number of times under a predetermined load (for example, 500 g / cm ² , 1000 g / cm ^2).

The film laminate with a printing layer has a radius of curvature of 3 mm or less (for example, 3 mm, 2 mm, 1 mm) and has flexibility that allows it to bend preferably 50,000 times, more preferably 100,000 times, and even more preferably 200,000 times. Since the film laminate with a print layer has such flexibility, it is possible to realize an image display device that is bendable or foldable when the film laminate with a print layer is applied to an image display device. The flexibility test is performed by bending with the hard coat layer inside. Specifically, in the flexibility test, a film laminate with a print layer is cut out into a strip of 100 mm × 20 mm and used as a measurement sample, and the test machine (“CL09-typeD01-FMC90” manufactured by Yuasa System Co., Ltd.) is used. Set the measurement sample so that the hard coat layer side is inside the bend, and perform under the following conditions. The evaluation of the flexibility can be judged by visually observing the state of peeling at the bent portion of the sample after the test.
Environmental conditions: 25 ° C, 55% RH
Test speed: 60 rpm

The light transmittance of the film laminate with a print layer (excluding the print layer) is preferably 85% or more, more preferably 87% or more, and further preferably 90% or more. The haze of the film laminate with a print layer (excluding the print layer) is preferably 1.5% or less, more preferably 1.2% or less, and further preferably 1.0% or less. When the light transmittance and / or haze is in such a range, good visibility can be realized when the film laminate with a print layer is applied to an image display device.

The film laminate with a print layer can be suitably used as, for example, a window film of an image display device, a front plate of a car navigation system, and a dust cover of a head-up display system.

B. Optical Laminated A film laminate with a print layer may be formed by laminating optical films to form an optical laminate. FIG. 2 is a schematic cross-sectional view of an optical laminate including the film laminate with a print layer of FIG. The optical laminate 200 of the illustrated example has a film laminate 100 with a print layer and an optical film 120. The optical film 120 is arranged on the side opposite to the hard coat layer 20 of the base film 10 in the film laminate 100 with a print layer. The optical film 120 is typically laminated on the film laminate 100 with a print layer via an adhesive layer 140. The adhesive layer is composed of any suitable adhesive or adhesive depending on the purpose.

The film laminate 100 with a print layer is as described in item A above.

Examples of the optical film 120 include any suitable optical film. The optical film may be a film composed of a single layer or a laminated body. Specific examples of the optical film composed of a single layer include a polarizer and a retardation film. Specific examples of the optical film configured as a laminate include a polarizing plate (typically, a laminate of a polarizing element and a protective film), a conductive film for a touch panel, a surface treatment film, and a single layer thereof. Examples thereof include a laminated body (for example, a circular polarizing plate for antireflection, a polarizing plate with a conductive layer for a touch panel) in which an optical film formed as an optical film and / or an optical film formed as a laminated body is appropriately laminated according to a purpose.

The optical laminate 200 can be produced by laminating the optical film 120 on the side opposite to the hard coat layer 20 of the base film 10 in the film laminate 100 with a print layer. After laminating the optical film 120, the protective film 40 is peeled off.

C. Image Display Device The film laminate with a print layer according to item A and the optical laminate according to item B can be applied to an image display device. Typical examples of the image display device include a liquid crystal display device and an electroluminescence (EL) display device (for example, an organic EL display device and an inorganic EL display device). The image display device typically includes a film laminate with a print layer or an optical laminate on the visual side of the image display cell. The image display device is preferably an organic EL display device. In one embodiment, the image display device has a curved shape (substantially a curved display screen) and / or is bendable or bendable. More preferably, the image display device is foldable.

The image display device can be manufactured by laminating the optical film 120 and the film laminate 100 with a print layer on the visual side of the image display cell (not shown). After laminating the optical film 120 and the film laminate 100 with a print layer, the protective film 40 is peeled off. Alternatively, the image display device can be manufactured by laminating the optical laminate 200 on the visual side of the image display cell (not shown). After laminating the optical laminate 200, the protective film 40 is peeled off.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measurement method of each characteristic is as follows.
(1) Thickness Measured with a micro gauge type thickness gauge manufactured by Mitutoyo. The thickness of the base film / hard coat layer laminate was measured, and the thickness of the hard coat layer was calculated by subtracting the thickness of the base film.
(2) Heat Shrinkage Rate of Protective Film The protective film used in Examples and Comparative Examples was cut into sizes of 100 mm in the long direction and 100 mm in the width direction to prepare test samples. The initial dimensions of this test sample were measured using an image measuring machine "QVA606-PRO_AE10" manufactured by Mitutoyo. The test sample was then heated at 70 ° C. for 60 minutes and then sized again. The heat shrinkage was calculated from the following formula. The dimensional measurement was performed for the dimensions in the direction corresponding to the long direction.
Heat shrinkage rate (%) = {(Initial dimension-Dimension after heating) / (Initial dimension)} x 100
(3) Warpage amount The final (after drying) film laminate with a print layer obtained in Examples and Comparative Examples was allowed to stand on a flat surface, and the heights of the four corners from the flat surface were measured. The height of the corner with the highest height was taken as the amount of warpage.
(4) Pencil hardness With respect to the surface of the hard coat layer formed in Examples and Comparative Examples, the pencil hardness was measured according to the pencil hardness test of JIS K 5600-5-4 (however, the load was 750 g).

<Example 1>
1. 1. Preparation of coating liquid for forming hard coat layer 100 parts by mass of ultraviolet curable polyfunctional acrylate (manufactured by Aika Kogyo Co., Ltd., product name "Z-850-16") as base resin, leveling agent (manufactured by DIC Co., Ltd., product name: GRANDIC) PC-4100) 5 parts by mass and 3 parts by mass of a photopolymerization initiator (manufactured by Ciba Japan, trade name: Irgacure 907) are mixed and diluted with methylisobutylketone so that the solid content concentration becomes 50% by mass. To prepare a coating liquid for forming a hard coat layer.

2. Preparation of protective film In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 90 parts by weight of butyl acrylate (BA), 10 parts by weight of acrylic acid (AA), and 2, as a polymerization initiator. 0.2 parts by weight of 2'-azobisisobutyronitrile and 234 parts by weight of ethyl acetate were charged, nitrogen gas was introduced with gentle stirring, and the liquid temperature in the flask was maintained at around 63 ° C. for about 7 hours polymerization. The reaction was carried out to prepare an acrylic polymer (A) solution (30% by weight). The weight average molecular weight of the acrylic polymer (A) was 600,000, and the Tg was −50 ° C. Acrylic polymer (A) solution (30% by weight) is diluted to 20% by weight with ethyl acetate, and an epoxy-based cross-linking agent (Mitsubishi Gas) is used as a cross-linking agent for 100 parts by weight (solid content) of the acrylic polymer in this solution. 11 parts by weight of TETRAD-C) manufactured by Kagaku Co., Ltd. was added, and the mixture was mixed and stirred for about 1 minute at about 25 ° C. to prepare an acrylic pressure-sensitive adhesive composition.
The acrylic pressure-sensitive adhesive composition is applied to one side of a polyethylene terephthalate (PET) base material (thickness 110 μm) and heated at 140 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 20 μm. A thickness of 130 μm) was produced. The heat shrinkage of the obtained protective film was 0.04%.

3. 3. Preparation of film laminate with print layer A transparent polyimide film (manufactured by KOLON, product name "CPITMC_80", thickness 80 μm) was used as a base film. While transporting this base film in a roll, the coating liquid for forming a hard coat layer was applied to one side thereof to form a coating layer, and the coating layer was heated together with a transparent polyimide film at 90 ° C. for 2 minutes. Next, a hard coat layer was formed by irradiating the coating layer with ultraviolet rays using a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm ^2. The thickness of the formed hard coat layer was 10 μm. Next, on the surface of the hard coat layer of the laminate of the base film / hard coat layer, the above 2. The protective film obtained in 1) was laminated by roll-to-roll to prepare a film laminate. The obtained film laminate was cut into sizes of 100 mm in the long direction and 100 mm in the width direction, and black ink was printed on the peripheral edge thereof by gravure printing to form a flat printing layer (black colored layer). The width of the print layer was 12 mm and the thickness was 10 μm. In this way, a film laminate with a print layer was produced. The formulation of the black ink was as follows: 100 parts of binder resin (acrylic resin: manufactured by Kyoeisha Chemical Co., Ltd., trade name: light acrylate PE-3A), 100 parts of carbon black, solvent for adjusting viscosity ( Methyl ethyl ketone: MEK) 200 parts. These mixtures were subjected to a high dispersion treatment by ultrasonic waves to improve diffusivity.

The obtained film laminate with a print layer (substantially, the print layer) was dried at 70 ° C. for 60 minutes to obtain a final film laminate with a print layer. The obtained film laminate with a print layer was subjected to the evaluations (3) and (4) above. The results are shown in Table 1.

<Example 2>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the film was dried at 60 ° C. for 50 minutes. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 3>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the film was dried at 50 ° C. for 40 minutes. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 4>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the film was dried at 40 ° C. for 30 minutes. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 5>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the base film was changed to another transparent polyimide film (manufactured by KOLON, product name “CPITMC_50”, thickness 50 μm). The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 6>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer was 3 μm. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 7>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer was 8 μm. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 8>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer was 13 μm. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 9>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer was 20 μm. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Example 10>
A film laminate with a print layer in the same manner as in Example 1 except that the protective film was changed to another polyethylene terephthalate film (manufactured by Nitto Denko Corporation, product name "IP300F", thickness 38 μm, heat shrinkage rate 0.07%). Got The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Comparative example 1>
A film laminate with a print layer was prepared in the same manner as in Example 1 except that the protective film was changed to a polyethylene film (manufactured by Toray Film Processing Co., Ltd., product name "Tretec 7832C", thickness 30 μm, heat shrinkage rate 0.87%). Obtained. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Comparative example 2>
A film laminate with a print layer was prepared in the same manner as in Example 5 except that the protective film was changed to a polyethylene film (manufactured by Toray Film Processing Co., Ltd., product name "Tretec 7832C", thickness 30 μm, heat shrinkage rate 0.87%). Obtained. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Comparative example 3>
A film laminate with a print layer was obtained in the same manner as in Example 1 except that the protective film was not laminated. The obtained film laminate with a print layer was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

<Evaluation>
As is clear from Table 1, in the film laminate with the printing layer of the embodiment of the present invention, the amount of warpage (curl) is remarkably suppressed while maintaining high pencil hardness.

The film laminate with a print layer of the present invention can be suitably used as a window film of an image display device. The optical laminate of the present invention can be suitably used as a visible side member of an image display device.

10 Base film 20 Hard coat layer 30 Printing layer 40 Protective film 100 Film laminate with printing layer 120 Optical film 200 Optical laminate

Claims

Forming a hard coat layer on one side of the substrate film;
Forming a print layer on the other side of the substrate film;
Laminating a protective film having a heat shrinkage rate of 0.1% or less in the transport direction on the surface of the hard coat layer; and heating and drying the printed layer with the protective film laminated.
A method for producing a film laminate with a print layer, including.
The manufacturing method according to claim 1, wherein the printing layer is heat-dried at 40 ° C. or higher for 20 minutes or longer.
The production method according to claim 1 or 2, wherein the protective film is laminated by roll-to-roll on the surface of the hard coat layer of the laminate of the base film and the hard coat layer.
The manufacturing method according to any one of claims 1 to 3, wherein the printing layer is formed after laminating the protective film.
4. A claim further comprising cutting a laminate of the base film, the hard coat layer, and the protective film into a predetermined size and a predetermined shape between the lamination of the protective film and the formation of the print layer. The manufacturing method described in.
The hard coat layer is formed by applying a coating liquid for forming a hard coat layer containing an active energy ray-curable (meth) acrylate to form a coating layer, and irradiating the coating layer with active energy rays to cure the coating layer. The production method according to any one of claims 1 to 5.
An optical laminate comprising laminating an optical film on the opposite side of the base film of the film laminate with a print layer obtained by the production method according to any one of claims 1 to 6 to the hard coat layer. Manufacturing method.
The manufacturing method according to claim 7, which comprises laminating the optical films and then peeling off the protective film.
A method for manufacturing an image display device, which comprises laminating an optical film and a film laminate with a print layer obtained by the manufacturing method according to any one of claims 1 to 6 on the visual side of an image display cell.
The manufacturing method according to claim 9, further comprising peeling off the protective film after laminating the optical film and the film laminate with the print layer.
A method for manufacturing an image display device, which comprises laminating an optical laminate obtained by the manufacturing method according to claim 7 or 8 on the visual side of an image display cell.
The manufacturing method according to claim 11, further comprising peeling off the protective film after laminating the optical laminate.