WO2021199402A1 - 積層フィルム、偏光板、表示装置及び偏光板ロールの製造方法 - Google Patents
積層フィルム、偏光板、表示装置及び偏光板ロールの製造方法 Download PDFInfo
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- WO2021199402A1 WO2021199402A1 PCT/JP2020/015182 JP2020015182W WO2021199402A1 WO 2021199402 A1 WO2021199402 A1 WO 2021199402A1 JP 2020015182 W JP2020015182 W JP 2020015182W WO 2021199402 A1 WO2021199402 A1 WO 2021199402A1
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- functional layer
- film
- laminated film
- polarizing plate
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/02—Physical, chemical or physicochemical properties
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/02—Physical, chemical or physicochemical properties
- B32B7/023—Optical properties
Definitions
- the present invention relates to a laminated film, a polarizing plate provided with the laminated film, a display device, and a method for manufacturing a polarizing plate roll. More specifically, the present invention can be handled in the same manner as a conventional polarizing plate protective film even though it is a thin film. Further, the present invention relates to a laminated film or the like having excellent curl controllability during polarizing plate processing and improving the productivity of polarizing plate processing.
- liquid crystal display device Since the liquid crystal display device has low power consumption and can be made thinner, it is widely used as an image display device for televisions (TVs), personal computers (PCs), and the like.
- Patent Document 1 by forming a thin functional film on a base film (also referred to as "carrier film") so as to be peelable, the film is conveyed by a thick laminated film until bonding, and is bonded to a polarizer. Later, a method of removing an unnecessary base film has been proposed.
- Patent Document 1 describes a method of laminating and forming a removable functional film on a base film in order to handle a thin functional film.
- the functional film is produced. Since there is a difference in humidity dependence between the film material and the base film, there is a problem that curling occurs due to moisture absorption during polarizing plate processing or storage environment, and it is difficult to handle in the above-mentioned transportability and bonding. These problems become remarkable especially when the laminated film becomes a thin film.
- the present invention has been made in view of the above problems and situations, and the problem to be solved is that although it is a thin film, it has excellent transportability and can be handled in the same manner as a conventional polarizing plate protective film.
- the present inventor is a laminated film in which a peelable functional layer is laminated on a base film in a process of examining the cause of the above problem in order to solve the above problems, and the base film and the functional layer.
- Each has a thickness in a specific range, and when the humidity expansion coefficient and thickness of the base film and the humidity expansion coefficient and thickness of the functional layer satisfy a specific relational expression, while being a thin film, It has excellent transportability, can be handled in the same way as a conventional polarizing plate protective film, has excellent curl controllability during polarizing plate processing, and has excellent polarizing plate processing productivity (adhesion with a polarizer). It was found that a laminated film with improved) can be obtained.
- the thickness of the functional layer is in the range of 1 to 19 ⁇ m.
- the total thickness of the laminated film is 50 ⁇ m or less.
- the coefficient of thermal expansion of the base film at 23 ° C is CHE 1 (ppm /% RH), the thickness is d 1 ( ⁇ m), and the coefficient of thermal expansion of the functional layer at 23 ° C is CHE 2 (ppm /% RH).
- the retardation value Ro defined by the following formula (i) of the functional layer is in the range of 0 to 20 nm, and the retardation value Rt defined by the following formula (ii) is in the range of -25 to 25 nm.
- n y is the refractive index in the in-plane phase-advancing axis direction of the functional layer
- n z is the refractive index in the thickness direction of the functional layer (refractive index is 23 ° C., wavelength 590 nm under the environment of 55% RH).
- D represents the film thickness (nm).
- the first to fourth items are characterized in that the following formula (2) is satisfied when the content of the residual solvent in the base film is S 1 and the content of the residual solvent in the functional layer is S 2.
- the laminated film according to any one of the items up to the item. Equation (2) 10 ⁇ S 1 ⁇ S 2 ⁇ 1000 (ppm)
- the first to second items are characterized in that the base film is a biaxially stretched polyester film, and the humidity expansion coefficient CHE 1 at 23 ° C. of the polyester film is in the range of 10 to 20 ppm /% RH.
- the laminated film according to any one of items up to item 9.
- a polarizing plate comprising the laminated film according to any one of items 1 to 12.
- a display device comprising the laminated film according to any one of items 1 to 12 or the polarizing plate according to item 13.
- a method for producing a polarizing plate roll wherein the laminated film according to any one of items 1 to 12 is wound while being bonded to at least one surface of a polarizing element.
- Manufacture of a polarizing plate roll which comprises a step of winding the laminated film while adhering the laminated film to the polarizing element so that the order is from the inside of the roll to the polarizing element, the adhesive layer, the functional layer, and the base material fill.
- the present invention although it is a thin film, it has excellent transportability, can be handled in the same manner as a conventional polarizing plate protective film, and further has excellent curl controllability during polarizing plate processing, and is a polarizing plate. It is possible to provide a laminated film having improved processing productivity (adhesion to a polarizer), a high-quality polarizing plate having the same, a display device, and a method for producing a polarizing plate roll.
- laminated body in which a functional layer is arranged on a base film
- the warp / curl of the film to be bonded is a very important factor in order to increase the yield. be. Due to the complexity of the warpage mechanism and the unclear mechanism of its generation, no method of controlling warpage without sacrificing productivity has been investigated so far.
- the present inventors investigated how to predict and further improve the curl prediction formula of the laminated body due to heat.
- the curl of the laminated body in warm water (or under high humidity) is large (1) the difference between the base film and the coefficient of thermal expansion (CHE: Coefficient of Hydroscopic Expansion) of the functional layer, and (2) the base film and the base film. It was found that the ratio of the thickness of the functional layer is greatly affected.
- Equation (a) Curl curvature 1 / R ⁇ 6 ( ⁇ 2- ⁇ 1 ) ( ⁇ T) (1 + m 2 ) / h [3 (1 + m) 2 + (1 + mn) ⁇ m 2 + (mn) -1 ⁇ ]
- ⁇ represents the coefficient of thermal expansion
- ⁇ 1 represents the functional layer
- ⁇ 2 represents the base film, respectively.
- ⁇ T represents the temperature rise range.
- H the thickness of the base film (d 1 ).
- M The thickness ratio (d 1 / d 2 ) of the thickness of the base film (d 1 ) and the thickness of the functional layer (d 2).
- n Represents the coefficient of thermal coefficient (f 1 / f 2 ) when the coefficient of elasticity of the base film (f 1 ) and the coefficient of elasticity of the functional layer (f 2 ).
- the humidity difference ( ⁇ T) can be treated as a constant.
- the thickness ratio m which is the thickness of the base film (d 1 ) / the thickness of the functional layer (d 2 ), is actually the thickness of the functional layer (d 2 ) ⁇ the thickness of the base film (d 2). Since d 1 ), 1 ⁇ m and (1 / m) ⁇ 1.
- the total thickness h is also within a certain numerical range as a thickness that can be handled realistically, and is treated as a constant.
- Equation (a) Curvature 1 / R ⁇ CHE ⁇ (1 + m) / [3 + 3m + m 2 + m -1 ] Assuming that "m -1 ⁇ 0" in the formula (a), the formula (b) becomes Equation (c) Curvature 1 / R ⁇ CHE ⁇ (1 + m) / [3 + 3m + m 2 ] Equation (d) Curvature 1 / R ⁇ CHE ⁇ (1 + m) / 3 (1 + m) 2 Since "m is 1 ⁇ m” in the formula (a), the formula (d) is Equation (e) Curl curvature 1 / R ⁇ CHE ⁇ 1 / (1 + m) Further, in the equation (e), since m is 1 ⁇ m, assuming that "1 + m” is "m”, Equation (f) Curl curvature 1 / R ⁇ CHE / m That is, the curl curva
- the substrate film tends to curl so as to be on the outside, and the central part of the functional layer is the polarizer. It floats from the surface, and the functional layer and the polarizer cannot be sufficiently bonded (see FIG. 1). Further, when the curl is large, it is considered that optical unevenness is likely to occur due to the internal stress on the functional layer.
- the present invention has been made in view of the above circumstances, and is a base material that causes curling while suppressing delamination and deformation of the functional layer during storage of the laminated film under high humidity.
- the humidity expansion coefficient and the thickness of the film and the functional layer so as to satisfy the relationship of the above formula (1), not only excellent curl controllability is obtained during polarizing plate processing, but also the productivity of polarizing plate processing is achieved. It is presumed that a laminated film can be obtained in which (adhesion with a polarizing element) and the occurrence of optical unevenness of the functional layer are suppressed.
- the humidity expansion coefficient of the base film and the functional layer at 23 ° C. is appropriately larger than that of the functional layer, and the thickness ratios of the respective thickness ratios are appropriately designed.
- the functional layer exerts the effect of suppressing the occurrence of wrinkles and optical unevenness.
- Schematic diagram illustrating the mechanism of curling in a high humidity environment when producing a polarizing plate using a peelable film laminate Schematic diagram showing a cross section of the laminated film of the present invention
- Cross-sectional view of polarizing plate with base film Is a cross-sectional view of a polarizing plate from which the base film has been peeled off.
- the laminated film of the present invention is a laminated film in which a peelable functional layer is laminated on a base film, and the thickness of the functional layer is in the range of 1 to 19 ⁇ m, and the total thickness of the laminated film is in the range of 1 to 19 ⁇ m.
- the thickness is 50 ⁇ m or less
- the humidity expansion coefficient of the base film at 23 ° C. is CHE 1 (ppm /% RH)
- the thickness is d 1 ( ⁇ m)
- CHE 2 ppm /% RH
- the thickness is d 2 ( ⁇ m)
- This feature is a technical feature common to or corresponding to the following embodiments.
- the thickness of the functional layer is in the range of 2 to 10 ⁇ m, which suppresses wrinkles and curl deformation of the functional layer which is a thin film.
- the viewpoint of providing a thinner polarizing plate when the base film is peeled off and the functional layer is bonded to the polarizer it is also preferable from the viewpoint of suppressing optical unevenness of the liquid crystal display device using the polarizing plate.
- the total thickness of the laminated film is preferably in the range of 30 to 45 ⁇ m. be.
- the retardation value Ro defined by the formula (i) of the functional layer is in the range of 0 to 20 nm, and the retardation value Rt defined by the formula (ii) is in the range of -25 to 25 nm. This is a preferable range of retardation values from the viewpoint of providing a thin polarizing plate applicable to an IPS mode display device. Further, it is preferable to use the functional layer having such optical characteristics in order to impart a very thin functional layer without affecting the optical characteristics of various films.
- the above formula (2) is satisfied by the base film and the functional layer. It is preferable from the viewpoint of controlling the humidity expansion coefficient (CHE 1 and CHE 2).
- CHE 1 and CHE 2 By permeating the solvent into the base film, a slight mixed layer is formed between the laminated films, and it is not easily peeled off during various processes, and good process suitability can be ensured.
- a mixed solvent the total value of all solvent species is used as an index.
- the boiling point of the main solvent among the residual solvents is 100 ° C. or lower under atmospheric pressure
- the residual solvent is a chlorine-based solvent
- the residual solvent is dichloromethane, among which, the residual. It is preferable to contain dichloromethane and alcohols as a solvent from the viewpoint of ease of handling when preparing and forming a dope for the base film and the functional layer.
- a low boiling point solvent and a chlorine-based solvent having high solubility the drying time after film formation can be shortened. It is presumed that the coating film having a short drying time has lower density than the coating film having a long drying time, and as a result, the permeability of water changes, and CHE 2 can be controlled slightly.
- the main solvent refers to a solvent mixed in a solvent type in the coating liquid in a ratio of more than 50% by mass.
- the base film is a biaxially stretched polyester film, and the humidity expansion coefficient CHE 1 at 23 ° C. of the polyester film is in the range of 10 to 20 ppm /% RH, which is an appropriate humidity expansion coefficient CHE 1. Therefore, it is preferable from the viewpoint of suppressing curling of the entire laminated film. Further, by using a biaxially stretched polyester film, the anisotropy of CHE 1 is eliminated, and the occurrence of unevenness can be suppressed.
- the functional layer may contain a linear polymer material having a carbonyl group in the side chain as the resin to be used, or may contain a polymer material having a cyclic structure in the main chain, such as a humidity expansion coefficient. It is preferable from the viewpoint of controlling the physical characteristics and improving the optical characteristics.
- the polarizing plate of the present invention is provided with the laminated film of the present invention, so that the polarizing plate can be processed by the same polarizing plate processing process as the conventional one without reducing the productivity and without requiring a complicated processing process.
- the display device of the present invention is a preferred embodiment from the viewpoint of obtaining a high-quality display device without light leakage or optical unevenness by providing the laminated film of the present invention or the polarizing plate of the present invention.
- the method for producing a polarizing plate roll of the present invention is a method for producing a polarizing plate roll in which the laminated film of the present invention is wound while being bonded to at least one surface of a polarizing element, and the polarizing element and the function are formed from the inside of the roll. It is characterized by including a step of winding the laminated film while adhering it to the polarizing element so that the layers and the base material fill are in the layer order.
- the base film can also serve as a protective film, leading to a reduction in the number of parts and a simplification of the processing process.
- the laminated film of the present invention is a laminated film in which a peelable functional layer is laminated on a base film, and the thickness of the functional layer is in the range of 1 to 19 ⁇ m, and the total thickness of the laminated film is in the range of 1 to 19 ⁇ m.
- the thickness is 50 ⁇ m or less
- the humidity expansion coefficient of the base film at 23 ° C. is CHE 1 (ppm /% RH)
- the thickness is d 1 ( ⁇ m)
- the humidity expansion coefficient of the functional layer at 23 ° C. Is CHE 2 (ppm /% RH) and the thickness is d 2 ( ⁇ m), the following equation (1) is satisfied. Equation (1) 0.20 ⁇ (CHE 1- CHE 2 ) ⁇ ⁇ (d 2 / d 1 ) ⁇ 2.00
- Humidity expansion coefficient (ppm /% RH) at 23 ° C elongation (cm) / (sample length (cm) x humidity difference) x 10 6
- CHE coefficient of thermal expansion
- stretching (magnification) and heat relaxation may be used at the time of film formation or after film formation.
- stretching magnification
- heat relaxation may be used at the time of film formation or after film formation.
- a dense film is formed and the CHE becomes small
- heat relaxation is performed, a coarse film is easily formed and the CHE becomes large. It may be used as a means for adjusting so as to fall within the range of the formula (1).
- the film-forming material used for the base film and the functional layer is also related to the control of CHE.
- the film-forming material of the functional layer is a linear polymer material having a carbonyl group in the side chain, in addition to controlling CHE, it has an effect of suppressing optical unevenness of the polarizer by providing appropriate moisture permeability. Can also be granted.
- an acrylic resin having low photoelasticity tends to exhibit good characteristics.
- a polymer material for example, a cycloolefin resin
- the film-forming material has a cyclic structure as a main chain has little change in optical characteristics with respect to humidity and is less likely to cause unevenness due to humidity. It is also a preferred embodiment to use a material.
- the value of the above formula (1) of the laminated film is larger than 2.00, the curl is large as described above, and it is practically difficult to bond the laminated film at the time of manufacturing the polarizing plate.
- the value of the formula (1) is 0.20 or less, the base film and the functional layer are difficult to peel off, and a peeling error may occur. Therefore, it is necessary to adjust the CHE and thickness within the range of the formula (1).
- air bubbles may be formed, or creases or wrinkles may be formed when the film is attached to the polarizing element (polyvinyl alcohol film).
- the adhesiveness can be improved by controlling the curl within a specific range.
- the range of the index ( ⁇ (CHE 1- CHE 2 ) ⁇ ⁇ (d 2 / d 1 )) corresponding to the curl is in the range of more than 0.20 and less than 2.00.
- the range of 0.30 to 1.00 is more preferable, and the range of 0.40 to 0.70 is particularly preferable.
- interference fringes may occur.
- the functional layer shrinks when the base film is peeled off after the laminated film of the present invention is attached. At this time, it is considered that minute unevenness of the refractive index occurs at the interface between the polarizer and the functional layer, and the interference unevenness is observed due to this.
- the uneven shrinkage of the polarizer can be made uniform and the uneven interference can be improved.
- the range of the index ( ⁇ (CHE 1- CHE 2 ) ⁇ ⁇ (d 2 / d 1 )) corresponding to the curl is in the range of 0.30 to 1.00.
- the range of 0.40 to 0.70 is preferable, and the range of 0.40 to 0.70 is particularly preferable.
- the value of the formula (1) is 2.00 or more, internal stress remains in the functional layer and optical unevenness is likely to occur.
- the value of the formula (1) is 0.20 or less, there is a problem in the moisture permeability of the functional layer, and uneven drying is likely to occur, and wrinkles due to uneven drying and optical unevenness are observed. There is.
- the humidity expansion coefficient CHE of the entire laminated film is large, for example, the humidity expansion amount of each of the base film and the functional layer is large while the laminated film is stored in a roll state at a high temperature. , The difference in the amount of humidity expansion between them tends to be large. As a result, delamination occurs between the base material layer and the base film, and the functional layer is easily deformed. When delamination occurs, the transport stability of the laminated film tends to decrease, and when the functional layer is deformed, the flatness of the functional layer tends to be impaired, so that the bondability with the polarizer also tends to decrease.
- the coefficient of thermal expansion CHE of the entire laminated film it is preferable to reduce the coefficient of thermal expansion CHE of the entire laminated film, and the amount of humidity expansion of the entire laminated film under high humidity can be reduced. Therefore, the amount of humidity expansion between the base film and the functional layer The difference between the two can be reduced. As a result, peeling and deformation of the functional layer can be suppressed while the laminated film is stored at a high temperature, so that the bondability with the polarizer can be improved without impairing the transport stability of the laminated film. ..
- FIG. 2 shows an example of the layer structure of the laminated film of the present invention.
- the laminated film 1 of the present invention has a base film 2 and a functional layer 3 on the base film 2.
- the base film 2 and the functional layer 3 may be formed by laminating a plurality of layers.
- the functional layer 3 may have another functional layer such as a primer layer (not shown) or a protective layer (not shown) on the front surface or the back surface.
- the base film 2 may have an adhesive layer or an adhesive layer (not shown) on the surface opposite to the functional layer, and the adhesive layer or the adhesive layer is bonded between the base film 2 and the display element. Sometimes it can provide an adhesive function.
- the "peelable functional layer” in the present invention means that the base film and the functional layer are in close contact with each other during normal production or general use and cannot be easily peeled off, but only the functional layer is used during polarizing plate processing. A mode in which the functional layer can be peeled off from the base film by external stress when it is desired to be used.
- the stress when peeling the base film from the functional layer is that in a laminated film cut to a width of 25 mm and a length of 80 mm, the surface of the functional layer opposite to the interface on the base film side is an acrylic adhesive sheet.
- the base film and the functional layer After being bonded and fixed to a glass substrate via Grasp the base film, in an atmosphere of temperature 23 ° C and humidity 60% RH, cross head speed (grasping movement speed) 200 mm / min, 90 ° peeling test (JIS K 6854-1: 1999 "Adhesive-peeling adhesive strength"
- the peeling stress is evaluated by performing the test method-Part 1: 90 degree peeling ", the base film and the functional layer can be peeled off with a stress of 0.05 to 2.00 N / 25 mm.
- the stress is 0.05 N / 25 mm or more, peeling is less likely to occur during the polarizing plate processing process, and it is preferable. If the stress is 2.00 N / 25 mm or less, the polarizing plate is used when the base film is peeled off. It is preferable because it does not break.
- Base film supports the functional layer, and the difference in the coefficient of thermal expansion (
- the base film usually includes a resin film.
- the resin used examples include cellulose ester-based resin, cycloolefin-based resin, polypropylene-based resin, acrylic-based resin, polyester-based resin, polyarylate-based resin, and styrene-based resin or a composite resin thereof. Among them, humidity. It is preferable to use a polyester resin as a resin having an appropriately large expansion coefficient and easy to control the range of the formula (1).
- polyester resins examples include polyester resins (eg, polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), etc.). Etc. are included. Among them, a polyester resin film containing polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is preferable because the humidity expansion coefficient CHE at 23 ° C. of the laminated film can be easily adjusted within the range of the above formula (1).
- PET polyethylene terephthalate
- PBT polytrimethylene terephthalate
- PEN polybutylene terephthalate
- PBN polybutylene naphthalate
- Etc. are included.
- a polyester resin film containing polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is preferable because the humidity expansion coefficient CHE at 23 ° C. of the
- the resin film may be heat-treated (heat-relaxed) or stretch-treated, and is suitably used for controlling CHE as described above.
- the heat treatment temperature is not particularly limited, but can be carried out at (Tg + 60) to (Tg + 180) ° C., where Tg is the glass transition temperature of the resin constituting the resin film.
- the stretching treatment increases the residual stress of the resin film, the humidity expansion coefficient CHE 1 of the resin film and thus the base film can be lowered.
- the stretching treatment is preferably performed, for example, in the biaxial direction of the resin film.
- the stretching treatment can be carried out under any conditions, for example, at a stretching ratio of about 120 to 900%. Whether or not the resin film is stretched can be confirmed by, for example, whether or not there is an in-plane slow layer axis (an axis extending in the direction of maximizing the refractive index).
- the stretching treatment may be performed before laminating the functional layers or after laminating, but it is preferable that the functional layers are stretched before laminating.
- polyester-based resin film (simply referred to as polyester film), and for example, polyethylene terephthalate film TN100 (manufactured by Toyobo Co., Ltd.), MELINEX ST504 (manufactured by Teijin DuPont Film Co., Ltd.) and the like are preferably used. Can be done.
- the base film may further have a release layer provided on the surface of the resin film.
- the release layer can facilitate the release of the functional layer from the base film when the polarizing plate is produced.
- the release layer may contain a known release agent and is not particularly limited.
- Examples of the release agent contained in the release layer include a silicone-based release agent and a non-silicone-based release agent.
- silicone-based release agents include known silicone-based resins.
- non-silicone release agents include long-chain alkyl pendant-type polymers obtained by reacting a long-chain alkyl isocyanate with a polyvinyl alcohol or an ethylene-vinyl alcohol copolymer, and olefin resins (for example, copolymerized polyethylene, cyclic polyolefin, etc.).
- Polymethylpentene polyallylate resins (eg, polycondensates of aromatic dicarboxylic acid components and divalent phenol components), fluororesins (eg, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride).
- PTFE polytetrafluoroethylene
- PVDF polyvinylidene fluoride
- PVF polyvinylene
- PFA polyvinylene
- FEP copolymer of tetrafluoroethylene and hexafluoropropylene
- ETFE copolymer of tetrafluoroethylene and ethylene
- the thickness of the release layer may be as long as it can exhibit the desired peelability, and is not particularly limited, but is preferably 0.1 to 1.0 ⁇ m, for example.
- the coefficient of thermal expansion of the base film itself at 23 ° C. is within the range of 10 to 20 ppm /% RH, warpage is unlikely to occur, which is preferable.
- the base film can follow the fluctuation of the polarizer due to the environmental fluctuation if it is 10 ppm /% RH or more, and as a result, it is presumed that the occurrence of poor appearance can be avoided. Further, if it is 20 ppm /% RH or less, it is presumed that the base film itself can avoid the humidity expansion, and as a result, it is presumed that the occurrence of warpage can be suppressed.
- the total thickness of the laminated film of the present invention is 50 ⁇ m or less, preferably in the range of 30 to 45 ⁇ m.
- the thickness d 1 of the base film is preferably in the range of 15 to 45 ⁇ m, more preferably in the range of 20 to 40 ⁇ m, because it is a thin film but also requires a certain level of strength (waist and rigidity) as a support. Is.
- the base film according to the present invention may contain a plasticizer.
- the plasticizer is not particularly limited, but is preferably a polyhydric alcohol ester plasticizer, a phthalic acid ester plasticizer, a citric acid plasticizer, a fatty acid ester plasticizer, a phosphoric acid ester plasticizer, or a polyvalent carboxylic acid. It is preferably selected from ester-based plasticizers, polyester-based plasticizers, and the like.
- the base film according to the present invention may also contain an ultraviolet absorber.
- the ultraviolet absorber used include benzotriazole-based, 2-hydroxybenzophenone-based, and salicylic acid phenyl ester-based agents.
- the base film according to the present invention may contain an antioxidant.
- Antioxidants are also called anti-deterioration agents.
- the antioxidant has a role of delaying or preventing the decomposition of the base film due to, for example, halogen contained in the residual solvent in the base film or phosphoric acid of the phosphoric acid-based plasticizer, and thus the base material. It is preferably contained in the film.
- a hindered phenolic compound is preferably used, for example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di).
- -T-Butyl-4-hydroxyphenyl) propionate and triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] are preferable.
- the base film according to the present invention preferably contains fine particles.
- Examples of the fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, and hydrated silicic acid. Calcium, aluminum silicate, magnesium silicate and calcium phosphate can be mentioned. Further, fine particles of an organic compound can also be preferably used. Examples of organic compounds include polytetrafluoroethylene, cellulose acetate, polystyrene, polymethylmethacrylate, polyppill methacrylate, polymethylacrylate, polyethylene carbonate, acrylic styrene resin, silicone resin, polycarbonate resin, benzoguanamine resin, and melamine resin.
- Polyester-based powder polyester-based resin, polyamide-based resin, polyimide-based resin, polyfluorinated ethylene-based resin, crushed class of organic polymer compounds such as starch, and polymer compounds synthesized by the suspension polymerization method can be used. can.
- Fine particles containing silicon are preferable in that the turbidity is low, and silicon dioxide is particularly preferable.
- Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 above Nippon Aerosil Co., Ltd.) ) Is commercially available under the trade name of) and can be used.
- Method for producing base film As a method for producing a base film according to the present invention, an ordinary inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method are used.
- the solution casting method and the melt casting method are preferable as the film forming method from the viewpoints of suppressing coloring, suppressing foreign matter defects, suppressing optical defects such as die lines, and the like.
- the temperature in the processing step is low, and therefore, high functionality can be imparted by using various additives.
- the content of the residual solvent in the base film can be controlled in order to adjust CHE 1.
- the “solution casting method” will be described.
- the method for producing the base film according to the present invention is a step of dissolving and dispersing an additive such as a thermoplastic resin and the above-mentioned fine particles in a solvent to prepare a dope (dissolving step; Dope preparation step), casting the dope onto an endless metal support (casting step), drying the cast dope as a web (solvent evaporation step), peeling from the metal support. It is preferable to include a step (peeling step), drying, stretching, a step of holding the width (stretching / width holding / drying step), and a step of winding the finished film into a roll (winding step).
- the solvent used in the dope preparation step of the solution casting method the solvent used for forming the functional layer described later can be appropriately selected and used.
- residual solvent amount The content of the residual solvent in the web at the time of peeling the web (hereinafter, also referred to as "residual solvent amount”) is appropriately adjusted depending on the strength of the drying conditions, the length of the metal support, and the like.
- the amount of residual solvent when the web is peeled from the metal support is preferably 10 to 150% by mass.
- the amount is decided. It is more preferably 10 to 40% by mass or 60 to 130% by mass, and particularly preferably 10 to 30% by mass or 70 to 120% by mass.
- the amount of residual solvent in the base film is defined by the following formula.
- Residual solvent amount (mass%) [(MN) / N] ⁇ 100
- M is the mass of the sample collected at any time during or after the production of the web or film
- N is the mass after heating M at 115 ° C. for 1 hour.
- the residual solvent type is basically the solvent type used, but it can be appropriately measured and identified by a gas chromatography method or the like.
- the film is generally dried by a roll drying method (a method in which the web is alternately passed through a large number of rollers arranged vertically) or a tenter method in which the web is conveyed and dried. Taken. For example, after peeling, the web is dried using a drying device that alternately passes and conveys the web through a plurality of rollers arranged in the drying device, and / or a tenter stretching device that clips and conveys both ends of the web with clips. ..
- the means for drying the web is not particularly limited, and generally it can be performed by hot air, infrared rays, heating rollers, microwaves, etc., but it is preferable to use hot air from the viewpoint of simplicity.
- the web is preferably stretched in at least one direction.
- the orientation of the molecules in the film can be controlled by the stretching treatment.
- the following biaxial stretching eliminates the anisotropy of CHE 1 and suppresses the occurrence of unevenness.
- two axes are sequentially or simultaneously with respect to the longitudinal direction of the web (film forming direction; spreading direction; MD direction) and the direction orthogonal to the web surface, that is, the width direction (TD direction). It can be stretched or uniaxially stretched.
- it is a biaxially stretched film in which biaxial stretching is performed in the casting direction (MD direction) and the width direction (TD direction).
- the stretching operation may be performed in multiple stages.
- simultaneous biaxial stretching may be performed, or biaxial stretching may be performed step by step.
- the simultaneous biaxial stretching includes a case where the drawing is performed in one direction and the other is contracted by relaxing the tension.
- the stretching ratios in the biaxial directions orthogonal to each other are preferably in the range of 0.8 to 1.5 times in the spreading direction and 1.1 to 2.5 times in the width direction, respectively. It is preferable to carry out in the range of 0.8 to 1.2 times in the extending direction and 1.2 to 2.0 times in the width direction.
- the stretching temperature is usually preferably carried out in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the film.
- the stretching temperature is preferably 120 ° C. to 200 ° C., more preferably 120 ° C. to 180 ° C.
- the amount of residual solvent in the web at the time of stretching is preferably 0 to 20% by mass, and more preferably 0 to 15% by mass.
- the method of stretching the web For example, a method of making a difference in peripheral speed between multiple rollers and stretching in the vertical direction using the difference in peripheral speed between the rollers, fixing both ends of the web with clips or pins, and widening the distance between the clips and pins in the direction of travel.
- a method of stretching in the vertical direction, a method of similarly spreading in the horizontal direction and stretching in the horizontal direction, a method of spreading in the vertical and horizontal directions at the same time and stretching in both the vertical and horizontal directions, and the like can be mentioned. Of course, these methods may be used in combination.
- These width holding or lateral stretching in the film forming step is preferably performed by a tenter, and may be a pin tenter or a clip tenter.
- the base film according to the present invention can obtain the same effect even if heat is relaxed in addition to stretching.
- the heat relaxation temperature is usually preferably carried out in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the film.
- the heat relaxation temperature is preferably 120 ° C. to 200 ° C., more preferably 120 ° C. to 180 ° C.
- the film is wound into a roll by the winding process, and the method for winding the film may be a commonly used method, which is a constant torque method, a constant tension method, a taper tension method, and an internal stress. There are certain program tension control methods, etc., and you can use them properly.
- the base film according to the present invention is preferably a long film, specifically, one having a thickness of about 100 m to 10000 m, and usually being provided in a roll form.
- the longer the film length the larger the amount that can be produced in one production, which is preferable. From the viewpoint of transportability and handleability, a compact roll shape is required, so that the total film thickness of the laminated film is preferably thin.
- the functional layer according to the present invention constitutes a polarizing plate by being peeled from a base film and then bonded to a polarizer or bonded to a polarizing element and then peeled to form a polarizing plate. It can function as an optical film such as a plate protective film or a retardation film.
- the thickness of the functional layer according to the present invention is in the range of 1 to 19 ⁇ m, and the thickness of the functional layer in the range of 2 to 10 ⁇ m provides a thin polarizing plate, and at the same time, wrinkles and curl deformation of the functional layer which is a thin film. It is preferable from the viewpoint of suppressing the above.
- the resin used for the functional layer according to the present invention is not particularly limited, but contains a linear polymer material having a carbonyl group in the side chain or having a cyclic structure in the main chain. It is preferable to contain a molecular material in order to control the humidity expansion coefficient. Therefore, the preferred resin may be a cycloolefin resin, a fumaric acid diester resin, a (meth) acrylic resin, a styrene / (meth) acrylate copolymer, or the like.
- the cycloolefin-based resin used for the functional layer is preferably a polymer of a cycloolefin monomer or a copolymer of a cycloolefin monomer and another copolymerizable monomer.
- the cycloolefin monomer is preferably a cycloolefin monomer having a norbornene skeleton, and is a cycloolefin monomer having a structure represented by the following general formula (A-1) or (A-2). More preferably.
- R 1 to R 4 independently represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group.
- p represents an integer of 0 to 2. However, all of R 1 to R 4 do not represent hydrogen atoms at the same time, R 1 and R 2 do not represent hydrogen atoms at the same time, and R 3 and R 4 do not represent hydrogen atoms at the same time. do.
- the hydrocarbon group having 1 to 30 carbon atoms represented by R 1 to R 4 in the general formula (A-1) is preferably, for example, a hydrocarbon group having 1 to 10 carbon atoms, and is preferably a carbon atom. More preferably, it is a hydrocarbon group having a number of 1 to 5.
- the hydrocarbon group having 1 to 30 carbon atoms may further have a linking group containing, for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. Examples of such linking groups include divalent polar groups such as carbonyl groups, imino groups, ether bonds, silyl ether bonds, thioether bonds and the like.
- Examples of the hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group and the like.
- Examples of the polar groups represented by R 1 to R 4 in the general formula (A-1) include a carboxy group, a hydroxy group, an alkoxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amide group and a cyano group. Is included. Of these, a carboxy group, a hydroxy group, an alkoxycarbonyl group and an aryloxycarbonyl group are preferable, and an alkoxycarbonyl group and an aryloxycarbonyl group are preferable from the viewpoint of ensuring solubility during solution film formation.
- P in the general formula (A-1) is preferably 1 or 2 from the viewpoint of increasing the heat resistance of the optical film. This is because when p is 1 or 2, the obtained polymer becomes bulky and the glass transition temperature tends to be improved. In addition, there is an advantage that the curl balance as a laminated body can be easily controlled by being able to respond slightly to humidity.
- R 5 represents an alkylsilyl group having a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms.
- R 6 represents a carboxy group, a hydroxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amide group, a cyano group, or a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom).
- p represents an integer of 0 to 2.
- R 5 in the general formula (A-2) preferably represents a hydrocarbon group having 1 to 5 carbon atoms, and more preferably represents a hydrocarbon group having 1 to 3 carbon atoms.
- R 6 in the general formula (A-2) preferably represents a carboxy group, a hydroxy group, an alkoxycarbonyl group and an aryloxycarbonyl group, and from the viewpoint of ensuring solubility during solution film formation, the alkoxycarbonyl group and aryl Oxycarbonyl groups are more preferred.
- P in the general formula (A-2) preferably represents 1 or 2 from the viewpoint of enhancing the heat resistance of the optical film. This is because when p represents 1 or 2, the obtained polymer becomes bulky and the glass transition temperature tends to improve.
- a cycloolefin monomer having a structure represented by the general formula (A-2) is preferable from the viewpoint of improving the solubility in an organic solvent.
- an organic compound loses its symmetry and thus its crystallinity is lowered, so that its solubility in an organic solvent is improved.
- R 5 and R 6 in the general formula (A-2) are substituted with only the ring-constituting carbon atom on one side with respect to the axis of symmetry of the molecule, the symmetry of the molecule is low, that is, the general formula (A-). Since the cycloolefin monomer having the structure represented by 2) has high solubility, it is suitable for producing an optical film by a solution casting method.
- the content ratio of the cycloolefin monomer having the structure represented by the general formula (A-2) in the polymer of the cycloolefin monomer is the total of all the cycloolefin monomers constituting the cycloolefin resin. For example, it can be 70 mol% or more, preferably 80 mol% or more, and more preferably 100 mol%.
- a cycloolefin monomer having a structure represented by the general formula (A-2) is contained in a certain amount or more, the orientation of the resin is increased, so that the retardation value is likely to increase.
- ring-opening copolymerizable copolymerizable monomers examples include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene and dicyclopentadiene.
- Examples of copolymerizable monomers that can be additionally copolymerized include unsaturated double bond-containing compounds, vinyl-based cyclic hydrocarbon monomers, (meth) acrylates, and the like.
- Examples of unsaturated double bond-containing compounds include olefin compounds having 2 to 12 (preferably 2 to 8) carbon atoms, and examples thereof include ethylene, propylene and butene.
- Examples of vinyl-based cyclic hydrocarbon monomers include vinyl cyclopentene-based monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene.
- Examples of (meth) acrylates include alkyl (meth) acrylates having 1 to 20 carbon atoms such as methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate.
- the content ratio of the cycloolefin monomer in the copolymer of the cycloolefin monomer and the copolymerizable monomer is, for example, 20 to 80 mol% with respect to the total of all the monomers constituting the copolymer. It can be preferably 30 to 70 mol%.
- the cycloolefin-based resin is obtained by polymerizing a cycloolefin monomer having a norbornene skeleton, preferably a cycloolefin monomer having a structure represented by the general formula (A-1) or (A-2). It is a polymer obtained by copolymerization, and examples thereof include the following.
- Ring-opening polymer of cycloolefin monomer 2) Ring-opening copolymer of cycloolefin monomer and copolymerizable copolymer with ring-opening copolymerization 3) Of 1) or 2) above Hydrogenated ring-opened (co) polymer 4) The ring-opened (co) polymer of 1) or 2) above was cyclized by the Friedercrafts reaction, and then hydrogenated (co) polymer 5) Cycloolefin.
- the polymers of 1) to 7) above can be obtained by known methods, for example, the methods described in JP-A-2008-107534 and JP-A-2005-227606.
- the catalyst and solvent used for the ring-opening copolymerization of 2) above those described in paragraphs 0019 to 0024 of JP-A-2008-107534 can be used, for example.
- the catalyst used for hydrogenation of 3) and 6) above for example, those described in paragraphs 0025 to 0028 of JP-A-2008-107534 can be used.
- the catalyst used for the addition polymerization of 5) to 7) above for example, those described in paragraphs 0058 to 0063 of JP-A-2005-227606 can be used.
- the alternating copolymerization reaction of 7) above can be carried out, for example, by the method described in paragraphs 0071 and 0072 of JP-A-2005-227606.
- the polymers of the above 1) to 3) and 5) are preferable, and the polymers of the above 3) and 5) are more preferable.
- the cycloolefin-based resin has a structural unit represented by the following general formula (B-1) in that the glass transition temperature of the obtained cycloolefin-based resin can be increased and the light transmittance can be increased. It is preferable that at least one of the structural units represented by the following general formula (B-2) is contained, and only the structural unit represented by the general formula (B-2) is included, or the general formula (B-1) is used. It is more preferable to include both the structural unit represented and the structural unit represented by the general formula (B-2).
- the structural unit represented by the general formula (B-1) is a structural unit derived from the cycloolefin monomer represented by the above-mentioned general formula (A-1), and is represented by the general formula (B-2).
- the structural unit is a structural unit derived from the cycloolefin monomer represented by the above-mentioned general formula (A-2).
- R 1 ⁇ R 4 and p are respectively the same as R 1 ⁇ R 4 and p of the general formula (A-1).
- R 5 ⁇ R 6 and p are respectively the same as R 5 ⁇ R 6 and p in the general formula (A-2).
- the cycloolefin-based resin according to the present invention may be a commercially available product.
- Examples of commercially available cycloolefin resins include Arton G (eg, G7810, etc.), Arton F, Arton R (eg, R4500, R4900, R5000, etc.) and Arton RX (eg, R4500, R4900, R5000, etc.) manufactured by JSR Corporation.
- Arton G eg, G7810, etc.
- Arton F Arton F
- Arton R eg, R4500, R4900, R5000, etc.
- Arton RX eg, R4500, R4900, R5000, etc. manufactured by JSR Corporation.
- RX4500 etc. is included.
- the intrinsic viscosity [ ⁇ ] inh of the cycloolefin resin is preferably 0.2 to 5 cm 3 / g, more preferably 0.3 to 3 cm 3 / g, as measured at 30 ° C. It is more preferably 4 to 1.5 cm 3 / g.
- the number average molecular weight (Mn) of the cycloolefin resin is preferably 8000 to 100,000, more preferably 10,000 to 80,000, and even more preferably 12,000 to 50,000.
- the weight average molecular weight (Mw) of the cycloolefin resin is preferably 20000 to 300,000, more preferably 30,000 to 250,000, and even more preferably 40,000 to 200,000.
- the number average molecular weight and the weight average molecular weight of the cycloolefin resin can be measured by gel permeation chromatography (GPC) in terms of polystyrene.
- the heat resistance, water resistance, chemical resistance, mechanical properties, and molding processability as a functional layer of the cycloolefin resin are good. It becomes.
- the glass transition temperature (Tg) of the cycloolefin resin is usually 110 ° C. or higher, preferably 110 to 350 ° C., more preferably 120 to 250 ° C., and preferably 120 to 220 ° C. More preferred.
- Tg is 110 ° C. or higher, deformation under high temperature conditions can be easily suppressed.
- Tg is 350 ° C. or lower, the molding process becomes easy, and the deterioration of the resin due to the heat during the molding process is also easily suppressed.
- the content of the cycloolefin resin is preferably 70% by mass or more, and more preferably 80% by mass or more with respect to the functional layer.
- the fumaric acid diester resin used for the functional layer is a fumaric acid diester resin containing a diisopropyl fumarate residue unit and a fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms.
- the alkyl groups having 1 or 2 carbon atoms in the fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms are independent of each other, and examples thereof include a methyl group and an ethyl group. Further, these may be substituted with a halogen group such as fluorine or chlorine; an ether group; an ester group or an amino group.
- a halogen group such as fluorine or chlorine
- an ether group such as an ether group
- an ester group or an amino group examples of the fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms include a dimethyl fumarate residue unit and a diethyl fumarate residue unit. Moreover, these may contain 1 type or 2 or more types.
- fumaric acid diester resin examples include diisopropyl fumarate / dimethyl fumarate copolymer resin and diisopropyl fumarate / diethyl fumarate copolymer resin.
- the fumaric acid diester resin may contain other monomer residue units as long as it does not exceed the scope of the present invention, and examples of the other monomer residue units include styrene residue units.
- styrene residue units such as ⁇ -methylstyrene residue unit; (meth) acrylate residue unit; (meth) methyl acrylate residue unit, (meth) ethyl acrylate residue unit, (meth) butyl acrylate residue unit (Meta) acrylic acid ester residue unit such as residue unit; vinyl ester residue unit such as vinyl acetate residue unit, vinyl propionate residue unit; acrylonitrile residue unit; methacrylonyloryl residue unit; methyl Vinyl ether residue units such as vinyl ether residue unit, ethyl vinyl ether residue unit, butyl vinyl ether residue unit; N-methylmaleimide residue unit, N-cyclohexyl maleimide residue unit, N-phenylmaleimide residue unit, etc.
- -Substituted maleimide residue unit olefin residue unit such as ethylene residue unit and propylene residue unit; or din-butyl fumarate residue unit, bis (2-ethylhexyl) fumarate residue unit and the like.
- olefin residue unit such as ethylene residue unit and propylene residue unit
- din-butyl fumarate residue unit bis (2-ethylhexyl) fumarate residue unit and the like.
- Examples thereof include one or more selected from fumaric acid diester residues other than the fumaric acid diester residue unit, and cinnaceous acid and cinnamic acid ester units.
- the blending ratio of the fumaric acid diester resin used in the present invention is preferably diisopropyl fumarate residue unit 50 to 99 mol% and fumaric acid diester residue unit 1 to 50 mol% having an alkyl group having 1 or 2 carbon atoms. Since the retardation characteristics and strength when used as a retardation film are excellent, the diisopropyl fumarate residue unit is 60 to 95 mol% and the fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms is 5 to 5 to A fumaric acid diester resin consisting of 40 mol% is particularly preferable.
- the fumaric acid diester resin used in the present invention preferably has a standard polystyrene-equivalent number average molecular weight in the range of 50,000 to 250,000 obtained from the elution curve measured by the gel permeation chromatography.
- the (meth) acrylic resin used for the functional layer preferably contains at least a structural unit (U1) derived from methyl methacrylate and a structural unit (U2) derived from phenylmaleimide.
- a (meth) acrylic resin containing a structural unit (U2) derived from phenylmaleimide can reduce the coefficient of thermal expansion CHE 2 of the functional layer.
- the photoelastic coefficient is also small, and there is an advantage that unevenness is unlikely to occur even if moisture absorption and expansion occur.
- the (meth) acrylic resin may further contain other structural units other than the above.
- other structural units include (meth) acrylic acid alkyl esters such as adamantyl acrylate; (meth) acrylic acid cycloalkyl esters such as 2-ethylhexyl acrylate.
- the structural unit (U3) derived from the acrylic acid alkyl ester from the viewpoint of reducing the deterioration of brittleness due to the inclusion of the structural unit (U2) derived from phenylmaleimide.
- the (meth) acrylic resin contains a structural unit (U1) derived from methyl methacrylate, a structural unit (U2) derived from phenylmaleimide, and a structural unit (U3) derived from an acrylic acid alkyl ester. Is more preferable.
- the content of the structural unit (U1) derived from methyl methacrylate is preferably 50 to 95% by mass, preferably 70 to 90% by mass, based on all the structural units constituting the (meth) acrylic resin. Is more preferable.
- the structural unit (U2) derived from phenylmaleimide has a relatively rigid structure, the humidity expansion coefficient CHE2 of the functional layer can be reduced. Further, since the structural unit (U2) derived from phenylmaleimide has a relatively bulky structure, it may have microscopic voids in the resin matrix that can move the rubber particles. Therefore, the rubber particles can be used as the surface layer of the functional layer. It can be easily distributed unevenly in the part.
- the content of the structural unit (U2) derived from phenylmaleimide is preferably 1 to 25% by mass with respect to all the structural units constituting the (meth) acrylic resin.
- the content of the structural unit (U2) derived from phenylmaleimide is 1% by mass or more, the humidity expansion coefficient CHE2 at 23 ° C. of the functional layer can be easily reduced, and when it is 25% by mass or less, the brittleness of the functional layer becomes high. It is not easily damaged excessively.
- the content of the structural unit (U2) derived from phenylmaleimide is more preferably 7 to 15% by mass.
- the structural unit (U3) derived from the acrylic acid alkyl ester can impart appropriate flexibility to the resin, for example, the brittleness due to containing the structural unit (U2) derived from phenylmaleimide can be improved.
- the acrylic acid alkyl ester is preferably an acrylic acid alkyl ester having an alkyl moiety having 1 to 7 carbon atoms, preferably 1 to 5 carbon atoms.
- acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate and the like.
- the content of the structural unit (U3) derived from the acrylic acid alkyl ester is preferably 1 to 25% by mass with respect to all the structural units constituting the (meth) acrylic resin.
- the content of the structural unit (U3) derived from the acrylic acid alkyl ester is 1% by mass or more, appropriate flexibility can be imparted to the (meth) acrylic resin, so that the functional layer does not become too brittle and breaks. Hateful.
- the content of the structural unit (U3) derived from the acrylic acid alkyl ester is 25% by mass or less, the Tg of the functional layer does not become too low, and the coefficient of thermal expansion (CHE 2 ) at 23 ° C. does not become too large.
- the content of the structural unit (U3) derived from the acrylic acid alkyl ester is more preferably 5 to 15% by mass.
- the ratio of the structural unit (U2) derived from phenylmaleimide to the total amount of the structural unit (U2) derived from phenylmaleimide and the structural unit (U3) derived from the acrylic acid alkyl ester shall be 20 to 70% by mass. Is preferable. When the ratio is 20% by mass or more, the tensile elastic modulus G2 of the functional layer is likely to be increased, and when it is 70% by mass or less, the functional layer is not too brittle.
- the glass transition temperature (Tg) of the (meth) acrylic resin is preferably 100 ° C. or higher, more preferably 120 to 150 ° C.
- Tg of the (meth) acrylic resin is within the above range, the heat resistance of the functional layer can be easily increased.
- the weight average molecular weight (Mw) of the (meth) acrylic resin is not particularly limited and can be adjusted according to the purpose.
- the weight average molecular weight of the (meth) acrylic resin is, for example, from the viewpoint of promoting entanglement of resin molecules to increase the toughness of the functional layer and making it difficult to break, and to appropriately increase the CHE ratio and curl to a degree preferable for adhesion. From the viewpoint of facilitating adjustment to the amount, it is preferably 100,000 or more, and more preferably 1 million or more. When the weight average molecular weight of the (meth) acrylic resin is 1 million or more, the toughness of the obtained functional layer can be enhanced.
- the weight average molecular weight of the (meth) acrylic resin is more preferably 1.5 million to 3 million.
- the method for measuring the weight average molecular weight is as described above.
- the styrene / (meth) acrylate copolymer (hereinafter, also referred to as styrene / acrylic resin) has excellent transparency when used as a functional layer. Further, since the coefficient of thermal expansion can be adjusted by the copolymerization ratio of the styrene portion, the curl as a laminated body can be controlled by changing these ratios.
- the styrene / acrylic resin is formed by addition polymerization of at least a styrene monomer and a (meth) acrylic acid ester monomer.
- R 1 represents a hydrogen atom or a methyl group
- R 2 represents an alkyl group having 1 to 24 carbon atoms.
- an acrylic acid ester derivative and a methacrylic acid ester derivative having known side chains and functional groups in the structure of these esters are included.
- styrene monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ⁇ -methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-. Includes tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene and pn-dodecyl styrene.
- (meth) acrylic acid ester monomers examples include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate (2EHA), and stearyl.
- Acrylate monomers such as acrylates, lauryl acrylates and phenyl acrylates; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate.
- Methacrylate esters such as lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate;
- (meth) acrylic acid ester monomer is a general term for "acrylic acid ester monomer” and “methacrylic acid ester monomer”, and one or both of them may be used. means.
- methyl (meth) acrylate means one or both of “methyl acrylate” and “methyl methacrylate”.
- the above (meth) acrylic acid ester monomer may be one kind or more. For example, forming a copolymer using a styrene monomer and two or more kinds of acrylic acid ester monomers, or using a styrene monomer and two or more kinds of methacrylic acid ester monomers to have a common weight. It is possible to form a coalescence and to form a copolymer by using a styrene monomer, an acrylic acid ester monomer and a methacrylic acid ester monomer in combination.
- the weight average molecular weight (Mw) of the styrene / acrylic resin is preferably in the range of 5,000 to 150,000, and more preferably in the range of 10,000 to 70,000 from the viewpoint of easy control of plasticity.
- the styrene / acrylic resin according to the present invention may be a commercially available product, and MS resin "TX320XL” manufactured by Denka Corporation can be mentioned as an example.
- Polyarylate-based resins have excellent toughness when used in functional layers.
- the polyialate-based resin contains at least a structural unit derived from an aromatic dialcohol and a structural unit derived from an aromatic dicarboxylic acid.
- the polyarylate-based resin according to the present invention may be a commercially available product, and examples thereof include PAR resin "U-100” manufactured by Unitika Ltd. and a weight average molecular weight (Mw) of 100,000.
- the functional layer may further contain components other than the above, if necessary.
- other components include rubber particles, the above-mentioned matting agent (fine particles), a plasticizer, an ultraviolet absorber, and the like.
- rubber particles and plasticizers give hydrophobicity to the film and can also be used as a means for controlling the humidity expansion coefficient CHE of the functional layer. Therefore, the curl characteristics of the laminate can be adjusted by appropriately adjusting the material and the amount of addition. Can be controlled. Further, from the viewpoint of imparting toughness (suppleness) to the functional layer, it is preferable to further contain rubber particles.
- the rubber particles are particles containing a rubber-like polymer.
- the rubber-like polymer is a soft crosslinked polymer having a glass transition temperature of 20 ° C. or lower.
- cross-linked polymers include butadiene-based cross-linked polymers, (meth) acrylic-based cross-linked polymers, and organosiloxane-based cross-linked polymers.
- the (meth) acrylic crosslinked polymer is preferable from the viewpoint that the difference in refractive index from the (meth) acrylic resin is small and the transparency of the functional layer is not easily impaired, and the acrylic crosslinked polymer (acrylic rubber-like weight) is preferable. Coalescence) is more preferable.
- the rubber particles are preferably particles containing the acrylic rubber-like polymer (a).
- the acrylic rubber-like polymer (a) is a crosslinked polymer containing a structural unit derived from an acrylic acid ester as a main component. "Included as a main component” means that the content of structural units derived from acrylic acid ester is in the range described later.
- the acrylic rubber-like polymer (a) has a structural unit derived from an acrylic acid ester, a structural unit derived from another monomer copolymerizable therewith, and two or more radically polymerizable groups in one molecule ( It is preferably a crosslinked polymer containing a structural unit derived from a polyfunctional monomer having a non-conjugated reactive double bond).
- Acrylic acid esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, benzyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, acrylic.
- An acrylic acid alkyl ester having 1 to 12 carbon atoms of an alkyl group such as n-octyl acid is preferable.
- the acrylic acid ester may be one kind or two or more kinds.
- the content of the structural unit derived from the acrylic acid ester is preferably 40 to 80% by mass, preferably 50 to 80% by mass, based on all the structural units constituting the acrylic rubber-like polymer (a1). Is more preferable.
- the other copolymerizable monomer is a monomer copolymerizable with the acrylic acid ester other than the polyfunctional monomer. That is, the copolymerizable monomer does not have two or more radically polymerizable groups.
- copolymerizable monomers examples include methacrylic ester such as methyl methacrylate; styrenes such as styrene and methylstyrene; (meth) acrylonitrile; (meth) acrylamide; (meth) acrylic acid. .. Among them, the other copolymerizable monomer preferably contains styrenes.
- the other copolymerizable monomer may be one kind or two or more kinds.
- the content of the structural unit derived from the other copolymerizable monomer is preferably 5 to 55% by mass with respect to all the structural units constituting the acrylic rubber-like polymer (a), and is preferably 10 to 55% by mass. It is more preferably 45% by mass.
- polyfunctional monomers examples include allyl (meth) acrylate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl malate, divinyl adipate, divinylbenzene, ethylene glycol di (meth) acrylate, and diethylene glycol (diethylene glycol).
- meth) acrylates triethylene glycol di (meth) acrylates, trimethylrol propanetri (meth) acrylates, tetromethylol methanetetra (meth) acrylates, dipropylene glycol di (meth) acrylates, polyethylene glycol di (meth) acrylates. ..
- the content of the structural unit derived from the polyfunctional monomer is preferably 0.05 to 10% by mass, preferably 0.1 to 10% by mass, based on the total structural units constituting the acrylic rubber-like polymer (a). More preferably, it is ⁇ 5% by mass.
- the content of the polyfunctional monomer is 0.05% by mass or more, the degree of cross-linking of the obtained acrylic rubber-like polymer (a) is likely to be increased, so that the hardness and rigidity of the obtained functional layer are impaired. If it is not too much and is 10% by mass or less, the toughness of the functional layer is not easily impaired.
- the monomer composition constituting the acrylic rubber-like polymer (a) can be measured by, for example, the peak area ratio detected by thermal decomposition GC-MS.
- the glass transition temperature (Tg) of the rubber-like polymer is preferably 0 ° C. or lower, more preferably ⁇ 10 ° C. or lower.
- Tg glass transition temperature of the rubber-like polymer
- appropriate toughness can be imparted to the film.
- the glass transition temperature (Tg) of the rubbery polymer is measured by the same method as described above.
- the glass transition temperature (Tg) of the rubber-like polymer can be adjusted by the composition of the rubber-like polymer.
- It is preferable to increase the mass ratio of other copolymerizable monomers for example, 3 or more, preferably 4 to 10).
- the particles containing the acrylic rubber-like polymer (a) are the particles made of the acrylic rubber-like polymer (a) or the hard layer made of the hard crosslinked polymer (c) having a glass transition temperature of 20 ° C. or higher. , Particles having a soft layer made of the acrylic rubber-like polymer (a) arranged around the particles (these are also referred to as “elastomers”); the acrylic rubber-like polymer (a).
- the particles may be particles made of an acrylic graft copolymer obtained by polymerizing a mixture of monomers such as a methacrylate ester in at least one stage.
- the particles made of the acrylic graft copolymer may be core-shell type particles having a core portion containing the acrylic rubber-like polymer (a) and a shell portion covering the core portion.
- the core portion contains an acrylic rubber-like polymer (a), and may further contain a hard crosslinked polymer (c), if necessary. That is, the core portion may have a soft layer made of an acrylic rubber-like polymer and a hard layer made of a hard crosslinked polymer (c) arranged inside the soft layer.
- the crosslinked polymer (c) can be a crosslinked polymer containing a methacrylic acid ester as a main component. That is, the crosslinked polymer (c) includes a structural unit derived from a methacrylic acid alkyl ester, a structural unit derived from another monomer copolymerizable therewith, and a structural unit derived from a polyfunctional monomer. It is preferably a crosslinked polymer containing.
- the alkyl methacrylate ester may be the alkyl methacrylate ester described above; the other copolymerizable monomer may be the styrenes or acrylic acid ester described above; the polyfunctional monomer may be. Examples thereof include those similar to those mentioned above as the polyfunctional monomer.
- the content of the structural unit derived from the methacrylic acid alkyl ester can be 40 to 100% by mass with respect to all the structural units constituting the crosslinked polymer (c).
- the content of the structural unit derived from the other copolymerizable monomer can be 60 to 0% by mass with respect to the total structural unit constituting the other crosslinked polymer (c).
- the content of the structural unit derived from the polyfunctional monomer can be 0.01 to 10% by mass with respect to all the structural units constituting the other crosslinked polymer.
- the shell portion contains a methacrylic polymer (b) (another polymer) graft-bonded to the acrylic rubber-like polymer (a) and containing a structural unit derived from a methacrylic acid ester as a main component.
- a methacrylic polymer (b) another polymer
- graft-bonded to the acrylic rubber-like polymer (a) and containing a structural unit derived from a methacrylic acid ester as a main component.
- Including as a main component means that the content of structural units derived from methacrylic acid ester is in the range described later.
- the methacrylic acid ester constituting the methacrylic acid polymer (b) is preferably an alkyl methacrylate ester having 1 to 12 carbon atoms of an alkyl group such as methyl methacrylate.
- the methacrylic acid ester may be one kind or two or more kinds.
- the content of the methacrylic acid ester is preferably 50% by mass or more with respect to all the structural units constituting the methacrylic acid polymer (b).
- the content of the methacrylate ester is 50% by mass or more, compatibility with a methacrylic resin containing a structural unit derived from methyl methacrylate as a main component can be easily obtained.
- the content of the methacrylic acid ester is more preferably 70% by mass or more with respect to all the structural units constituting the methacrylic polymer (b).
- the methacrylic polymer (b) may further contain a structural unit derived from another monomer copolymerizable with the methacrylic ester.
- examples of other copolymerizable monomers are acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate; benzyl (meth) acrylate, dicyclopentanyl (meth) acrylate, A (meth) acrylic monomer having an alicyclic, heterocyclic or aromatic ring such as phenoxyethyl (meth) acrylate (ring-containing (meth) acrylic monomer) is included.
- the content of the structural unit derived from the copolymerizable monomer is preferably 50% by mass or less, preferably 30% by mass or less, based on all the structural units constituting the methacrylic polymer (b). Is more preferable.
- the shape of the rubber particles can be a shape close to a true sphere. That is, the aspect ratio of the rubber particles when observing the cross section or the surface of the functional layer can be about 1 to 2.
- the average particle size of the rubber particles is preferably 100 to 400 nm.
- the average particle size of the rubber particles is 100 nm or more, sufficient toughness and stress relaxation property are easily imparted to the functional layer, and when it is 400 nm or less, the transparency of the functional layer is not easily impaired.
- the average particle size of the rubber particles is more preferably 150 to 300 nm.
- the average particle size of the rubber particles can be calculated by the following method.
- the average particle size of the rubber particles can be measured as the average value of the equivalent circle diameters of 100 particles obtained by SEM or TEM photography of the surface or section of the laminated film.
- the equivalent circle diameter can be obtained by converting the projected area of the particles obtained by photographing into the diameter of a circle having the same area.
- the rubber particles observed by SEM observation and / or TEM observation at a magnification of 5000 times are used for calculating the average particle size.
- the content of the rubber particles is not particularly limited, but is preferably 5 to 40% by mass, more preferably 7 to 30% by mass with respect to the functional layer.
- the humidity expansion coefficient (CHE 2 ) of the functional layer at 23 ° C. is in the range of 1 to 30 ppm /% RH in relation to the preferable humidity expansion coefficient (CHE 1) of the base film. It is preferable from the viewpoint of controlling.
- the humidity expansion coefficient CHE 2 of the transparent functional layer is 1 ppm or more, the effect of facilitating the peeling process after bonding is exhibited, and when it is 30 ppm or less, the occurrence of errors and unevenness during bonding can be suppressed. It exerts its effect. It is more preferably in the range of 3 to 20 ppm /% RH, and even more preferably in the range of 5 to 15 ppm /% RH.
- the functional layer according to the present invention can function as an optical film such as a retardation film by being bonded to a polarizer after being peeled from the base film.
- the in-plane retardation Ro measured in an environment with a measurement wavelength of 590 nm and 23 ° C. and 55% RH is preferably 0 to 10 nm. , 0-5 nm, more preferably.
- the phase difference Rt in the thickness direction of the functional layer is preferably -40 to 40 nm, more preferably -25 to 25 nm.
- Ro and Rt are defined by the following formulas, respectively.
- n x represents the refractive index in the in-plane slow-phase axial direction (the direction in which the refractive index is maximized) of the functional layer.
- n y represents the refractive index in the direction orthogonal to the in-plane slow phase axis of the functional layer.
- n z represents the refractive index of the functional layer in the thickness direction.
- d represents the thickness (nm) of the functional layer.
- the in-plane slow-phase axis of the functional layer can be confirmed by an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axometrics).
- Ro and Rt can be measured by the following methods.
- the functional layer is humidity-controlled for 24 hours in an environment of 23 ° C. and 55% RH.
- the average refractive index of this film is measured with an Abbe refractometer, and the thickness d is measured with a commercially available micrometer.
- the phase difference Ro and Rt of the functional layer can be adjusted, for example, by the type of resin, stretching conditions, and drying conditions. For example, Rt can be lowered by raising the drying temperature.
- the form of the laminated film of the present invention is not particularly limited, but may be band-shaped, for example. That is, it is preferable that the laminated film of the present invention is wound into a roll in a direction orthogonal to the width direction to form a roll.
- the method for producing a laminated film of the present invention includes 1) a step of obtaining a solution for a functional layer, 2) a step of applying the obtained functional layer solution to the surface of a base film, and 3) a step of applying the obtained functional layer solution to the surface of the base film. It has a step of removing the solvent from the solution to form a functional layer.
- Step of obtaining a solution for a functional layer A solution for a functional layer containing the above-mentioned resin and a solvent is prepared.
- the solvent used for the solution for the functional layer is not particularly limited as long as it can disperse or dissolve the resin well.
- the organic solvent used in the present invention alcohols (methanol, ethanol, diol, triol, tetrafluoropropanol, etc.), glycols, cellosolves, ketones (acetone, methylethylketone, etc.), carboxylic acids (girate, acetic acid, etc.) Etc.), carbonates (ethylene carbonate, propylene carbonate, etc.), esters (ethyl acetate, propyl acetate, etc.), ethers (isopropyl ether, THF, etc.), amides (dimethyl sulfoxide, etc.), hydrocarbons (heptane, etc.) , Nitriles (acetate, etc.), aromatics (cyclohexylbenzene, toluene, xylene, chlorobenzene, etc.), alkyl halides (
- the functional layer has a boiling point of 100 ° C. or lower under atmospheric pressure, a chlorine-based solvent as a type, and more specifically, dichloromethane (also referred to as "methylene chloride").
- a chlorine-based solvent as a type
- dichloromethane also referred to as "methylene chloride”
- the solubility is high and the drying speed is high, whereby the film quality of the coating film can be adjusted and the humidity expansion coefficient can be controlled.
- the hydrophilic solvent include ketones and alcohols, but alcohols are preferable. Isopropanol, ethanol, methanol and the like are more preferable, and methanol is most preferable.
- the addition amount is preferably in the range of 1 to 20% by mass, more preferably in the range of 3 to 10% by mass.
- the resin concentration of the solution for the functional layer is preferably, for example, 1.0 to 20% by mass from the viewpoint of facilitating the adjustment of the viscosity to the range described later. Further, from the viewpoint of reducing the amount of shrinkage during drying of the coating film, the resin concentration of the solution for the functional layer is preferably moderately high, more preferably more than 5% by mass and 20% by mass or less, and more than 5% by mass. It is more preferably 15% by mass or less. Further, by adjusting the solution concentration, the time until the film is formed is shortened, and the drying time thereof can also be a means for controlling the CHE of the functional layer. A mixed solvent may be appropriately used for increasing the concentration.
- the viscosity of the solution for the functional layer is not particularly limited as long as it can form a functional layer having a desired thickness, but is preferably 5 to 5000 mPa ⁇ s, for example.
- the viscosity of the solution for the functional layer is 5 cP or more, it is easy to form a functional layer having an appropriate thickness, and when it is 5000 mPa ⁇ s or less, it is possible to suppress the occurrence of thickness unevenness due to the increase in the viscosity of the solution.
- the viscosity of the solution for the functional layer is more preferably 100 to 1000 mPa ⁇ s.
- the viscosity of the solution for the functional layer can be measured with an E-type viscometer at 25 ° C.
- Step of applying the functional layer solution the obtained functional layer solution is applied to the surface of the base film. Specifically, the obtained solution for the functional layer is applied to the surface of the base film.
- the method for applying the solution for the functional layer is not particularly limited, and may be, for example, a known method such as a back roll coating method, a gravure coating method, a spin coating method, a wire bar coating method, or a roll coating method. Above all, the back coat method is preferable from the viewpoint of being able to form a thin and uniform thickness coating film.
- Step 3 Step of forming the functional layer
- the solvent is removed from the solution for the functional layer applied to the base film to form the functional layer.
- the solution for the functional layer applied to the base film is dried. Drying can be performed, for example, by blowing air or heating. Above all, from the viewpoint of facilitating curling of the laminated film, it can be dried by blowing air.
- the density of the functional layer can be controlled, and CHE can be adjusted.
- the drying conditions for example, drying temperature, drying air volume, drying time, etc.
- CHE can be adjusted.
- the drying rate is expressed as the mass of the solvent that evaporates per unit time and unit area.
- the drying rate can usually be adjusted by the drying temperature.
- the drying temperature depends on the solvent type used, but may be, for example, 50 to 200 ° C. ((Tb-50) to (Tb + 50) ° C. with respect to the boiling point Tb of the solvent used. Temperature control is performed in multiple steps. After the drying has progressed to some extent, the drying rate and film quality can be controlled by drying at a higher temperature.
- the laminated film according to the present embodiment may be strip-shaped as described above. Therefore, it is preferable that the method for producing a laminated film according to the present embodiment further includes 4) a step of winding a strip-shaped laminated film into a roll to form a roll.
- Step of winding the laminated film to obtain a roll body The obtained strip-shaped laminated film is wound into a roll shape in a direction orthogonal to the width direction thereof to form a roll body.
- the length of the strip-shaped laminated film is not particularly limited, but may be, for example, about 100 to 10000 m.
- the width of the strip-shaped laminated film is preferably 1 m or more, more preferably 1.3 to 4 m. From the viewpoint of improving the uniformity of the film, it is more preferably 1.6 to 2.5 m.
- the method for producing a laminated film of the present invention can be performed by, for example, the production apparatus shown in FIG.
- FIG. 3 is a schematic view of a manufacturing apparatus B200 for carrying out the method for manufacturing a laminated film according to the present embodiment.
- the manufacturing apparatus B200 includes a supply unit B210, a coating unit B220, a drying unit B230, a cooling unit B240, and a winding unit B250.
- Ba to Bd indicate transport rolls for transporting the base film B110.
- the supply unit B210 has a feeding device (not shown) for feeding out the roll body B201 of the strip-shaped base film B110 wound around the winding core.
- the coating unit B220 is a coating device, and includes a backup roll B221 that holds the base film B110, a coating head B222 that applies a solution for a functional layer to the base film B110 held by the backup roll B221, and a coating head. It has a decompression chamber B223 provided on the upstream side of B222.
- the flow rate of the functional layer solution discharged from the coating head B222 can be adjusted by a pump (not shown).
- the flow rate of the functional layer solution discharged from the coating head B222 is set to an amount capable of stably forming a coating layer having a predetermined thickness when continuously coated under the conditions of the coating head B222 adjusted in advance.
- the decompression chamber B223 is a mechanism for stabilizing the bead (pool of coating liquid) formed between the solution for the functional layer from the coating head B222 and the base film B110 at the time of coating, and the degree of decompression can be adjusted. It has become.
- the decompression chamber B223 is connected to a decompression blower (not shown) so that the inside is decompressed.
- the pressure reducing chamber B223 is in a state where there is no air leakage, and the gap between the pressure reducing chamber B223 and the backup roll is narrowly adjusted so that a stable bead of the coating liquid can be formed.
- the drying unit B230 is a drying device that dries the coating film applied to the surface of the base film B110, and has a drying chamber B231, a drying gas introduction port B232, and a discharge port B233.
- the temperature and air volume of the dry air are appropriately determined depending on the type of the coating film and the type of the base film B110.
- the amount of residual solvent in the coating film after drying can be adjusted.
- the amount of residual solvent in the coating film after drying can be measured by comparing the unit mass of the coating film after drying with the mass after the coating film is sufficiently dried.
- the amount of residual solvent Since the functional layer is obtained by applying a solution for the functional layer, a solvent derived from the solution may remain.
- the amount of residual solvent also serves as a means for controlling the humidity expansion coefficient. It can be controlled by the heating temperature of the roll and the like.
- the humidity expansion coefficient CHE 2 becomes large because the film becomes sparse and the moisture permeates faster in the case of high-speed drying.
- the curl balance of the laminated film can be satisfied by satisfying the following formula (2) when the residual solvent amount of the functional layer is S 1 and the residual solvent amount of the functional layer is S 2. It is preferable from the viewpoint of. Equation (2) 10 ⁇ S 1 ⁇ S 2 ⁇ 1000 (ppm) Specifically, the amount of residual solvent in the functional layer is preferably less than 1000 ppm, more preferably less than 800 ppm, and more preferably less than 500 to 700 ppm in consideration of the curl balance of the laminated film. Further, by selecting a solvent / coating process in which the solvent remains in the base film, the adhesion between the laminates is improved. The amount of residual solvent in the base film is preferably in the range of 10 to 100 ppm.
- the amount of residual solvent in the functional layer and the base film can be measured by headspace gas chromatography.
- a sample is sealed in a container, heated, and the gas in the container is promptly injected into a gas chromatograph with the container filled with volatile components, and mass analysis is performed to identify the compound.
- the volatile components are quantified while doing so.
- the headspace method makes it possible to observe all peaks of volatile components by gas chromatography, and by using an analytical method that utilizes electromagnetic interactions, it is possible to quantify volatile substances and monomers with high accuracy. It can be done at the same time.
- the cooling unit B240 cools the temperature of the base film B110 having the coating film (functional layer B120) obtained by drying in the drying unit B230, and adjusts the temperature to an appropriate temperature.
- the cooling unit B240 has a cooling chamber B241, a cooling air inlet B242, and a cooling air outlet B243.
- the temperature and air volume of the cooling air can be appropriately determined depending on the type of the coating film and the type of the base film B110. Further, even if the cooling unit B240 is not provided, the cooling unit B240 may not be provided if the cooling temperature is appropriate.
- the winding unit B250 is a winding device (not shown) for winding the base film B110 on which the transparent functional layer B120 is formed to obtain the roll body B251.
- the thickness d 2 of the functional layer is usually thinner than the thickness d 1 of the base film.
- the thickness d 2 of the functional layer is preferably in the range of 1 to 19 ⁇ m, and more preferably in the range of 2 to 10 ⁇ m from the viewpoint of thinning the polarizing plate. preferable.
- the polarizing plate has a polarizing element and a laminated film or a functional layer arranged on at least one surface thereof. It is preferable that the polarizer and the laminated film or the functional layer are adhered to each other via an adhesive layer.
- 4A and 4B show an example of the layer structure of the polarizing plate of the present invention, but the present invention is not limited thereto.
- FIG. 4A is a cross-sectional view of a polarizing plate with a base film.
- the functional layer 3 side of the laminated film 1 (base film 2 and functional layer 3) of the present invention is bonded to the polarizer 5 via the adhesive layer 4 to process the polarizing plate 10a.
- the opposing film 6 may be bonded to the surface of the polarizer 5 opposite to the surface to which the laminated film 1 of the present invention is bonded, via the adhesive layer 4.
- the laminated film 1 of the present invention may be bonded to the display element side via an adhesive layer (not shown), or the display element.
- the facing film 6 may be attached to the side via an adhesive layer (not shown).
- the laminated film 1 of the present invention it is preferably the embodiment shown in FIG. 4 (b) below in which the base film 2 is peeled off from the laminated film 1.
- FIG. 4B is a cross-sectional view of a polarizing plate from which the base film has been peeled off.
- the functional layer 3 side of the laminated film 1 (base film 2 and functional layer 3) of the present invention is bonded to the polarizer 5 via the adhesive layer 4 to process the polarizing plate 10b.
- the base film 2 is peeled from the functional layer 3 during or after the polarizing plate processing to process the thin polarizing plate 10b.
- the opposing film 6 may be bonded to the surface of the polarizer 5 opposite to the surface to which the functional layer 3 according to the present invention is bonded, via the adhesive layer 4.
- the functional layer 3 may be attached to the display element side via an adhesive layer (not shown), and the polarizing plate 10b may be displayed.
- the facing film 6 may be attached to the element side via an adhesive layer (not shown).
- Polarizer A polarizing element is an element that allows only light on a plane of polarization in a certain direction to pass through.
- the polarizer can usually be a polyvinyl alcohol-based polarizing film.
- Examples of the polyvinyl alcohol-based polarizing film include a polyvinyl alcohol-based film dyed with iodine and a film dyed with a dichroic dye.
- the polyvinyl alcohol-based polarizing film may be a film obtained by uniaxially stretching a polyvinyl alcohol-based film and then dyeing it with iodine or a bicolor dye (preferably a film further subjected to a durability treatment with a boron compound); polyvinyl.
- An alcohol-based film may be a film that has been dyed with iodine or a bicolor dye and then uniaxially stretched (preferably a film that has been further subjected to a durability treatment with a boron compound).
- the absorption axis of the polarizer is usually parallel to the maximum stretching direction.
- the thickness of the polarizer is preferably 5 to 30 ⁇ m, and more preferably 5 to 20 ⁇ m from the viewpoint of thinning the polarizing plate.
- a base film or functional layer constituting the laminated film of the present invention is arranged on at least one surface of the polarizer. Any of the base film or the functional layer constituting the laminated film can function as a polarizer protective film. In the present embodiment, it is preferable that the functional layer is arranged on one surface of the polarizer and the other protective film is arranged on the other surface.
- the opposing film examples include a cycloolefin resin, a polypropylene resin, an acrylic resin, a polyester resin, a polyarylate resin, a cellulose ester resin, a styrene resin, or a composite resin thereof. Above all, a resin film containing a cycloolefin resin, an acrylic resin and a polyester resin is preferable.
- Adhesive layer is arranged between the functional layer and the polarizer and between the opposing film and the polarizer, respectively.
- the adhesive layer arranged between the functional layer and the polarizer and the adhesive layer arranged between the opposing film and the polarizer may be the same or different.
- the adhesive layer may be a cured product layer of an active energy ray-curable adhesive, or may be a layer obtained from a water-soluble polymer.
- the active energy ray-curable adhesive may be a photoradical polymerizable composition or a photocationic polymerizable composition. Of these, a photocationically polymerizable composition is preferable.
- the photocationic polymerizable composition contains an epoxy compound and a photocationic polymerization initiator.
- a water-soluble polymer for example, via an adhesive made of a vinyl alcohol-based polymer, or at least an adhesive made of a water-soluble cross-linking agent of a vinyl alcohol-based polymer such as boric acid, borosand, glutaaldehyde, melamine, and oxalic acid. It can be carried out.
- Such an adhesive layer is formed as a coating dry layer of an aqueous solution or the like, but when preparing the aqueous solution, other additives or a catalyst such as an acid can be added as needed.
- the permeation of the contained water may cause curling of the laminate, which may reduce the yield of the polarizing plate. It is also one of the objects of the present invention to prevent such process errors.
- the thickness of the adhesive layer is not particularly limited, but is preferably 0.01 to 10 ⁇ m, and more preferably 0.01 to 5 ⁇ m, respectively.
- Adhesive layer is a layer for bonding a polarizing plate to a display element such as a liquid crystal cell, and may be formed on either surface of the polarizing plate, but is a functional layer. It can be placed on the opposite side of the polarizer.
- the pressure-sensitive adhesive layer is preferably a pressure-sensitive adhesive composition containing a base polymer, a prepolymer and / or a cross-linking monomer, a cross-linking agent and a solvent, which is dried and partially cross-linked. That is, at least a part of the pressure-sensitive adhesive composition may be crosslinked.
- the pressure-sensitive adhesive composition examples include an acrylic pressure-sensitive adhesive composition using a (meth) acrylic polymer as a base polymer, a silicone-based pressure-sensitive adhesive composition using a silicone-based polymer as a base polymer, and a rubber-based pressure-sensitive adhesive composition using a rubber as a base polymer.
- a pressure-sensitive adhesive composition is included.
- an acrylic pressure-sensitive adhesive composition is preferable from the viewpoint of transparency, weather resistance, heat resistance, and processability.
- Adhesive compositions include tackifiers, plasticizers, fiberglass, glass beads, metal powders, other fillers, pigments, colorants, fillers, antioxidants, UV absorbers, silane couplings as needed. Various additives such as agents may be further included.
- the thickness of the pressure-sensitive adhesive layer is usually about 3 to 100 ⁇ m, preferably 5 to 50 ⁇ m.
- the surface of the adhesive layer is protected by a release film that has undergone a mold release treatment.
- the release film include a plastic film such as an acrylic film, a polycarbonate film, a polyester film, and a fluororesin film.
- the polarizing plate according to the present embodiment is manufactured through a step of laminating the above-mentioned laminated film on at least one surface of the polarizer and peeling off the base film. sell.
- the laminated film may be bonded to only one surface of the polarizer or both surfaces. From the viewpoint of transmittance, the laminated film is bonded to one surface of the polarizer and the other. It is preferable to attach an opposing film, which is another protective film, to the surface of the surface.
- the base film side of the laminated film of the present invention may be bonded to the polarizing element, or the functional layer side may be bonded.
- the functional layer side is bonded and the base film is used as a protective film, or the base film is peeled off and only the functional layer of the thin film is used.
- the polarization is such that the polarizing element, the functional layer, and the base film are layered in this order from the inside of the roll. It is a preferable method for producing a polarizing plate roll to include a step of winding the laminated film while adhering it to the child. Further, a method in which the base film in the laminated film is peeled off and wound before the laminated film is attached to the polarizer, dried and wound is also a preferable embodiment.
- the polarizing plate according to the present invention is: 1) a step of adhering a functional layer of the laminated film to one surface of a polarizing element (a group arranged on a surface of the functional layer opposite to the polarizing element).
- the material film may be left attached or peeled off if necessary), and 2) a step of attaching an opposing film, which is another protective film, to the other surface of the polarizing element.
- the surface of the functional layer of the laminated film is subjected to surface treatment such as corona treatment as necessary.
- the functional layer of the laminated film is laminated on one surface of the polarizer via an adhesive of a water-soluble polymer.
- an opposing film which is another protective film, is attached to the other surface of the polarizer.
- the surface of the opposing film is subjected to a surface treatment such as a corona treatment, if necessary.
- the opposing film is laminated on the other surface of the polarizer via an adhesive of a water-soluble polymer, and then a stepwise drying treatment is performed in a temperature range of, for example, 50 to 80 ° C.
- the steps 1) and 2) may be performed simultaneously or sequentially. From the viewpoint of increasing production efficiency, it is preferable to perform the steps 1) and 2) at the same time.
- the polarizing plate according to the present embodiment may be band-shaped. Therefore, in the steps 1) and 2), the functional layer of the strip-shaped laminated film, the strip-shaped polarizing element, and the other strip-shaped protective film (opposing film) are each unwound from the roll body, and the roll to It is preferable to perform the polarizing plate processing by laminating with a roll.
- the step of winding the strip-shaped polarizing plate into a roll shape to form a roll body it is preferable to further perform the step of winding the strip-shaped polarizing plate into a roll shape to form a roll body.
- the length and width of the strip-shaped polarizing plate are the same as the length and width of the strip-shaped laminated film in the step 4) of the method for manufacturing a laminated film.
- the polarizing element 5 in the step of winding the laminated film 1 while adhering it to at least one surface of the polarizing element 5, the polarizing element 5, the adhesive layer 4, and the functional layer are formed from the inside of the roll. It is also preferable to form a polarizing plate roll by a step of winding the laminated film 1 while adhering the laminated film 1 to the polarizing element 5 so as to be in the layer order of 3 and the base material fill 2.
- the base film 2 according to the present invention since the base film 2 according to the present invention is arranged on the outside of the polarizing plate roll, it exhibits a function as a protective film and prevents scratches or the like on the functional layer 2 during polarizing plate processing. Or, curling can be suppressed to facilitate handling.
- the opposing film 6 is wound on the surface opposite to the surface on which the laminated film 1 is bonded while being bonded to the polarizing element 5 via the adhesive layer 4, and the polarizing plate roll is rolled. It may be formed.
- the display device includes a display element such as a liquid crystal cell or an organic electroluminescence (also referred to as "EL") element, and a polarizing plate manufactured by the above manufacturing method.
- a display element such as a liquid crystal cell or an organic electroluminescence (also referred to as "EL") element
- EL organic electroluminescence
- the display device according to the present embodiment is preferably a liquid crystal display device having a liquid crystal cell and a polarizing plate manufactured by the above manufacturing method.
- the liquid crystal display device includes a liquid crystal cell, a first polarizing plate arranged on one surface of the liquid crystal cell, and a second polarizing plate arranged on the other surface of the liquid crystal cell. Then, at least one of the first polarizing plate and the second polarizing plate is the polarizing plate according to the present embodiment. It is preferable that the absorption axis of the first polarizer in the first polarizing plate and the absorption axis of the second polarizer in the second polarizing plate are orthogonal to each other (cross Nicol).
- the display modes of the liquid crystal cells are, for example, STN (Super-Twisted Nematic), TN (Twisted Nematic), OCB (Optically Compensated Bend), HAN (Hybridrated Nematic), VA (Vertic), and VA (Vertic). (Patterned Vertical Element)), IPS (In-Plane-Switching), and the like.
- STN Super-Twisted Nematic
- TN Transmission Nematic
- OCB Optically Compensated Bend
- HAN Hybridrated Nematic
- VA Very
- VA Very
- VA Very-Plane-Switching
- the IPS mode is preferable.
- Example 1 Laminated film material [1-1] Base film ⁇ Base film A> Polyethylene terephthalate film (PET film): (TN100 manufactured by Toyobo Co., Ltd., with a release layer containing a non-silicone release agent, thickness 38 ⁇ m)
- PET film Polyethylene terephthalate film
- ⁇ Base film D Polyethylene terephthalate film (PET film) (TN100 manufactured by Toyobo Co., Ltd.) heat-retained and relaxed at 150 ° C for 30 seconds) Thickness 38 ⁇ m) ⁇ Base film E> Triacetyl Cellulose Film (TAC) (Konica Minolta KC4UA, no release layer, thickness 38 ⁇ m) ⁇ Base film F> Cycloolefin film (COP) (JSR ARTON G7810, no release layer, thickness 38 ⁇ m) ⁇ Base film G> High density polyethylene (HDPE) (HIZEX 2200J (manufactured by Prime Polymer Co., Ltd.), thickness 38 ⁇ m)
- TAC Triacetyl Cellulose Film
- COP Cycloolefin film
- the humidity expansion coefficient CHE 1 of the base films A to G at 23 ° C. was measured by the following method.
- COP ZNX330R: ZNX330R manufactured by Zeon Corporation 6.
- A-DCP Tricyclodecanedimethanol diacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 7.
- PSt / polyarylate (mass ratio 5: 5) Mixture: Pst (polystyrene: PS Japan, Mw: 500,000: PS Japan], polyarylate (compound P below) 8.
- PSt Polystyrene (Mw: 500,000: manufactured by PS Japan Corporation) 9.
- TAC Acetyl Cellulose with 2.9 Degree of Acetyl Substitution
- the glass transition temperature (Tg) and weight average molecular weight (Mw) of the resins 1 to 9 were measured by the following methods.
- the glass transition temperature (Tg) of the resin was measured using DSC (Differential Scanning Colorimetry) according to JIS K 7121-2012.
- the weight average molecular weight (Mw) of the resin was measured using gel permeation chromatography (HLC8220GPC manufactured by Tosoh Corporation) and a column (TSK-GEL G6000HXL-G5000HXL-G5000HXL-G4000HXL-G3000HXL series manufactured by Tosoh Corporation). 20 mg ⁇ 0.5 mg of the sample was dissolved in 10 ml of tetrahydrofuran and filtered through a 0.45 mm filter. 100 ml of this solution was injected into a column (temperature 40 ° C.), measured at a detector RI temperature of 40 ° C., and a styrene-converted value was used.
- Deionized water 180 parts by mass Polyoxyethylene lauryl ether phosphoric acid 0.002 parts by mass Boric acid 0.4725 parts by mass Sodium carbonate 0.04725 parts by mass Sodium hydroxide 0.0076 parts by mass
- the internal temperature was set to 80 ° C., and 0.021 parts by mass of potassium persulfate was added as a 2% aqueous solution.
- a mixed solution prepared by adding 0.07 parts by mass of polyoxyethylene lauryl ether phosphoric acid to 21 parts by mass of the mixture (c') was continuously added to the above solution over 63 minutes. Further, the innermost hard polymer (c) was obtained by continuing the polymerization reaction for 60 minutes.
- a soft layer (a layer made of an acrylic rubber-like polymer (a)).
- the glass transition temperature (Tg) of the soft layer was ⁇ 30 ° C.
- the glass transition temperature of the soft layer was calculated by averaging the glass transition temperature of the homopolymer of each monomer constituting the acrylic rubber-like polymer (a) according to the composition ratio.
- the obtained polymer was put into a warm aqueous solution of 3% by mass sodium sulfate for salting out and coagulation. Then, after repeating dehydration and washing, the particles were dried to obtain acrylic graft copolymer particles (rubber particles R1) having a three-layer structure.
- the average particle size of the obtained rubber particles R1 was 200 nm.
- the average particle size of the rubber particles was measured by the following method.
- the dispersed particle size of the rubber particles in the obtained dispersion was measured by a zeta potential / particle size measuring system (ELSZ-2000ZS manufactured by Otsuka Electronics Co., Ltd.).
- ⁇ Preparation of functional layer solution for laminated films 202-205> Functions for laminated films 202 to 205 in the same manner as the functional layer solution for laminated film 201, except that the solvents shown in Table I are changed to cyclopentanone (boiling point 131 ° C.) and dichloromethane (methylene chloride, boiling point 41 ° C.). A layered solution was obtained.
- ⁇ Preparation of functional layer solution for laminated films 228 and 229> The following components were mixed to obtain a solution for the functional layer 228. Toluene (boiling point 110 ° C.): 900 parts by mass Polyarylate (U-100 manufactured by Unitika Ltd.): 100 parts by mass In the functional layer solution for laminated film 229, methylene chloride (boiling point 41 ° C.) is used as a solvent as shown in Table III.
- a functional layer solution for the laminated film 229 was prepared in the same manner as the solution for the functional layer for the laminated film 228 except that it was used.
- a PET film (TN100 manufactured by Toyobo Co., Ltd., base film A) was prepared.
- a solution for the functional layer for the laminated film 201 is applied onto the release layer of the PET film using a die by the back coating method, and then the laminated film is dried in the following drying step to obtain a function having a thickness of 5 ⁇ m.
- a layer was formed to obtain a laminated film 201. 1st step: 1 minute at 40 ° C 2nd step: 1 minute at 70 ° C 3rd step: 1 minute at 100 ° C 4th step: 2 minutes at 130 ° C
- Headspace device HP7694 Head Space Sampler (manufactured by Hewlett-Packard) Temperature conditions: Transfer line 200 ° C, loop temperature 200 ° C Sample volume: 0.8 g / 20 ml vial GC: HP5890 (manufactured by Hewlett-Packard) MS: HP5791 (manufactured by Hewlett-Packard) Column: HP-624 (30m x inner diameter 0.25mm) Oven temperature: Initial temperature 40 ° C (holding time 3 minutes), heating rate 10 ° C / min, reaching temperature 200 ° C (holding time 5 minutes) Measurement mode: SIM (select ion monitor) mode
- Transportability The transport stability of the laminated film was evaluated by confirming the presence or absence of breakage or cracking during roll transport on the line while applying a transport tension of 350 N / m. Then, the transport stability was evaluated based on the following criteria. ⁇ : The functional layer can be transported without breaking ⁇ : Small scratches and cracks occur in the functional layer, but can be transported ⁇ : The functional layer is cracked and broken ⁇ If it is equal to or more than that, it is judged to be good.
- the obtained laminated film was cut into a circle having a diameter of 5 cm and used as a sample.
- the obtained sample was left in a constant temperature and humidity chamber at 23 ° C. and 55% RH for 24 hours. Then, the sample was taken out from the constant temperature and humidity chamber, placed on a flat plate, and 1 / r was obtained from the radius of curvature r (m) having a curve matching the sample using a curvature scale. Then, the curl amount was evaluated based on the following criteria.
- ⁇ : 1 / r is less than 4 ⁇ : 1 / r is 4 or more and less than 8 ⁇ : 1 / r is 8 or more and less than 12 ⁇ : 1 / r is 12 or more and ⁇ or more is judged to be good.
- Adhesiveness with a polarizer evaluation of adhesiveness
- a 60 ⁇ m-thick long polyvinyl alcohol film containing polyvinyl alcohol (hereinafter referred to as “PVA:”) is continuously conveyed via a guide roll and placed in a dyeing bath (30 ° C.) containing iodine and potassium iodide. After immersing and dyeing and stretching 2.5 times, in an acidic bath (60 ° C) to which boric acid and potassium iodide were added, a total of 5 times stretching treatment and cross-linking treatment were performed.
- the obtained iodine-PVA-based polarizer having a thickness of 12 ⁇ m was dried in a dryer at 50 ° C.
- the surface of the laminated film on the adhesive side was subjected to corona discharge treatment at a corona output strength of 2.0 kW and a line speed of 18 m / min, and the water-soluble adhesive prepared above was applied to the corona discharge treated surface.
- the agent solution 1 was coated with a bar coater so that the thickness after drying was about 3 ⁇ m, and then dried at 50 ° C., 60 ° C., and 70 ° C.
- a polarizing plate in this order for 60 seconds to obtain a polarizing plate.
- the prepared polarizing plate is placed on a black cloth that does not allow light to pass through, such as a black curtain, with the surface on which the functional layer is formed facing up, and a three-wavelength fluorescent lamp (manufactured by Matsushita Electric Corporation, National Fluorescent Lamp: FL20SS / ENW / 18). ), And the surface of the polarizing plate was visually observed and evaluated according to the following criteria. ⁇ : 10 samples were observed, but no uneven interference was seen.
- the laminated films 201-208, 211-213, 216-218, 222, 224, and 226-229 of the present invention are evaluated for transportability, underwater curl, adhesiveness, and interference fringes. It can be seen that it is comprehensively superior to the laminated film of the comparative example.
- the numerical value represented by the formula (1) is in the range of 0.30 to 1.00, the adhesiveness is good, and when it is in the range of 0.40 to 0.80, the characteristics of the interference fringes are further improved. There was a tendency to become.
- Example 2 The phase differences of the functional layers of the laminated films 204, 213, 214, 216, 218, 226 and 229 produced in Example 1 were measured by the following methods, respectively, and the results are shown in Table V.
- the retardation Ro and Rt were measured by the following methods. 1) The base film is peeled off from the laminated film, and the functional layer is humidity-controlled for 24 hours in an environment of 23 ° C. and 55% RH. The average refractive index of this layer is measured with an Abbe refractometer, and the thickness d is measured with a commercially available micrometer. 2) The retardation Ro and Rt of the film after humidity control at a measurement wavelength of 590 nm were measured at 23 ° C. and 55% RH using an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter). Measure in the environment.
- Axoscan Axo Scan Mueller Matrix Polarimeter
- Ro and Rt are defined by the following equations, respectively.
- Equation (a): Ro (nx-ny) ⁇ d
- Equation (b): Rt ((nx + ny) /2-nz) ⁇ d
- nx is the refractive index in the in-plane slow phase axis direction of the functional layer
- ny is the refractive index in the direction orthogonal to the in-plane slow phase axis of the functional layer
- nz is the refraction in the thickness direction of the functional layer.
- the rate and d represent the thickness (nm) of the functional layer, respectively.
- the retardation value of the functional layer according to the present invention is in the range of 0 to 20 nm for Ro and in the range of -25 to 25 nm for Rt. Therefore, both of them are IPS mode liquid crystal display devices. It can be seen that it is suitable as a retardation film.
- the present invention although it is a thin film, it has excellent transportability, can be handled in the same manner as a conventional polarizing plate protective film, and further, a laminated film having excellent curl controllability during polarizing plate processing can be obtained. Therefore, it is possible to provide a high-quality polarizing plate and a display device having excellent productivity (adhesion with a polarizer) at the time of polarizing plate processing and having no optical unevenness.
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- General Physics & Mathematics (AREA)
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Abstract
Description
前記機能層の厚さが、1~19μmの範囲内であり、
前記積層フィルムの総厚さが、50μm以下であり、
前記基材フィルムの23℃における湿度膨張係数をCHE1(ppm/%RH)、厚さをd1(μm)、及び前記機能層の23℃における湿度膨張係数をCHE2(ppm/%RH)、厚さをd2(μm)としたとき、下記式(1)の関係を満たすことを特徴とする積層フィルム。
式(1) 0.20<│(CHE1-CHE2)│×(d2/d1)<2.00
式(i) Ro=(nx-ny)×d
式(ii) Rt={(nx+ny)/2-nz}×d
(上記式(i)及び(ii)において、Roは機能層の面内方向のリターデーション値、Rtは機能層の厚さ方向のリターデーション値、nxは機能層の面内の遅相軸方向の屈折率、nyは機能層の面内の進相軸方向の屈折率、nzは機能層の厚さ方向の屈折率(屈折率は23℃、55%RHの環境下、波長590nmで測定)、dはフィルムの厚さ(nm)を表す。)
式(2) 10<S1<S2<1000(ppm)
ロールの内側から偏光子、接着層、機能層及び基材フィルの層順になるように、前記偏光子に前記積層フィルムを貼合しながら巻き取る工程を含むことを特徴とする偏光板ロールの製造方法。
(式中、α:熱膨張係数を表し、α1は機能層及びα2は基材フィルムのそれぞれを表す。ΔT:昇温幅を表す。h:基材フィルムの厚さ(d1)と機能層の厚さ(d2)の合計を表す。m:基材フィルムの厚さ(d1)及び機能層の厚さ(d2)のときの厚さ比(d1/d2)を表す。n:基材フィルムの弾性率(f1)及び機能層の弾性率(f2)のときの弾性率比(f1/f2)を表す。)
1)基材フィルムと機能層の湿度膨張率の差を、そのまま熱膨張率の差と置き換える(α2-α1)=ΔCHEとする。)。
式(b)カール曲率1/R∝ΔCHE×(1+m)/[3+3m+m2+m-1]
式(a)の「m-1≒0」とみなすと、式(b)は、
式(c)カール曲率1/R≒ΔCHE×(1+m)/[3+3m+m2]
式(d)カール曲率1/R≒ΔCHE×(1+m)/3(1+m)2
式(a)の「mは1<<m」であるため、式(d)は、
式(e)カール曲率1/R∝ΔCHE×1/(1+m)
さらに、式(e)は、mは1<<m」であるため「1+m」を「m」とすると、
式(f)カール曲率1/R∝ΔCHE/m
すなわち、カール曲率1/Rは、本発明に係る式(1)の、「│(CHE1-CHE2)│×(d2/d1)」で表すことができるものと推察の上実証実験を行うことで、本発明を見出すに至った。
本発明の積層フィルムは、基材フィルム上に、剥離可能な機能層が積層された積層フィルムであって、前記機能層の厚さが、1~19μmの範囲内であり、前記積層フィルムの総厚さが、50μm以下であり、前記基材フィルムの23℃における湿度膨張係数をCHE1(ppm/%RH)、厚さをd1(μm)、及び前記機能層の23℃における湿度膨張係数をCHE2(ppm/%RH)、厚さをd2(μm)としたとき、下記式(1)の関係を満たすことを特徴とする。
式(1) 0.20<│(CHE1-CHE2)│×(d2/d1)<2.00
フィルム試料を恒温恒湿槽に幅1cm、試料長15cmになるように固定し、一定湿度(約30%RH)まで脱湿し、フィルム長が一定になった後、加湿(約80%RH)すると吸湿により伸び始める。約24時間後吸湿は平衡に達してフィルムの伸びも平衡に達する。この時の伸び量から下式により計算する。この際、雰囲気温度は23℃に一定に保つ。
また、カールの大小によって偏光子(ポリビニルアルコールフィルム)との貼合時に気泡が入ったり、折れ・シワが入ったりする場合がある。
カールが、大きすぎるとTD方向(長尺フィルムの幅手方向)の凹凸が大きくなりすぎて貼合時に空気を巻き込んでしまい気泡を発生させる。逆にカールが小さすぎるとMD方向(長尺フィルムの幅手方向)のカールの影響を受けやすくなりすぎて空気を巻き込んでしまい気泡を発生させる。
本発明では、干渉ムラの観点から、カールと対応する本願の指標(│(CHE1-CHE2)│×(d2/d1))の範囲は、0.30~1.00の範囲が好ましく、0.40~0.70の範囲が特に好ましい。
図2に本発明の積層フィルムの層構成について、その一例を示す。
基材フィルムは、機能層を支持するものであり、基材フィルムと機能層との23℃における湿度膨張係数の差(|(CHE1-CHE2)|)を、上記式(1)を満たすような範囲内に調整できるものであればよく、特に制限されない。基材フィルムは、通常、樹脂フィルムを含む。
本発明の積層フィルムの総厚さは50μm以下であり、好ましくは30~45μmの範囲内である。基材フィルムの厚さd1は、薄膜だがある程度の強度(腰や剛性)も支持体として必要であることから、好ましくは、15~45μmの範囲であり、より好ましくは20~40μmの範囲内である。
〈可塑剤〉
本発明に係る基材フィルムは、可塑剤を含有してもよい。可塑剤としては特に限定されないが、好ましくは、多価アルコールエステル系可塑剤、フタル酸エステル系可塑剤、クエン酸系可塑剤、脂肪酸エステル系可塑剤、リン酸エステル系可塑剤、多価カルボン酸エステル系可塑剤、及びポリエステル系可塑剤等から選択されることが好ましい。
本発明に係る基材フィルムは、紫外線吸収剤を含有することもできる。用いられる紫外線吸収剤としては、ベンゾトリアゾール系、2-ヒドロキシベンゾフェノン系又はサリチル酸フェニルエステル系のもの等が挙げられる。例えば、2-(5-メチル-2-ヒドロキシフェニル)ベンゾトリアゾール、2-[2-ヒドロキシ-3,5-ビス(α,α-ジメチルベンジル)フェニル]-2H-ベンゾトリアゾール、2-(3,5-ジ-t-ブチル-2-ヒドロキシフェニル)ベンゾトリアゾール等のトリアゾール類、2-ヒドロキシ-4-メトキシベンゾフェノン、2-ヒドロキシ-4-オクトキシベンゾフェノン、2,2′-ジヒドロキシ-4-メトキシベンゾフェノン等のベンゾフェノン類を例示することができる。
本発明に係る基材フィルムは、酸化防止剤を含有していてもよい。酸化防止剤は劣化防止剤ともいわれる。
本発明に係る基材フィルムは、微粒子を含有することも好ましい。
本発明に係る基材フィルムの製造方法としては、通常のインフレーション法、T-ダイ法、カレンダー法、切削法、流延法、エマルジョン法、ホットプレス法等の製造法が使用できるが、着色抑制、異物欠点の抑制、ダイラインなどの光学欠点の抑制などの観点から製膜方法は、溶液流延法と溶融流延法が好ましい。溶液流延法であると、加工工程での温度が低く、このため種々の添加剤を用いることによる高機能化を付与することができる。また溶液流延法では、CHE1を調整するために、基材フィルムの残留溶媒の含有量を制御することもできる。
以下、「溶液流延法」について説明する。
溶液流延法により製膜する場合、本発明に係る基材フィルムの製造方法は、熱可塑性樹脂及び上述した微粒子等の添加剤を溶媒に溶解、分散させてドープを調製する工程(溶解工程;ドープ調製工程)、ドープを無限に移行する無端の金属支持体上に流延する工程(流延工程)、流延したドープをウェブとして乾燥する工程(溶媒蒸発工程)、金属支持体から剥離する工程(剥離工程)、乾燥、延伸、幅保持する工程(延伸・幅保持・乾燥工程)、仕上がったフィルムをロール状に巻取る工程(巻き取り工程)を含むことが好ましい。溶液流延法のドープ調製工程に用いる溶媒は、後述する機能層の形成に用いる溶媒を適宜選択して用いることができる。
なお、Mはウェブ又はフィルムを製造中又は製造後の任意の時点で採取した試料の質量で、NはMを115℃で1時間の加熱後の質量である。なお、残留溶媒種は基本的には使用した溶媒種であるが、ガスクロマトグラフィー法などで適宜測定・同定することができる。
本発明に係る機能層は、基材フィルムから剥離された後、偏光子と貼合されて、または偏光子と貼合後に剥離されて 偏光板を構成するものであり、偏光板保護フィルム又は位相差フィルムなどの光学フィルムとして機能しうる。
本発明に係る機能層の用いられる樹脂は、特に制限されないが、カルボニル基を側鎖に有する直鎖状高分子材料を含有すること、又は環状構造を主鎖に有する高分子材料を含有することが、湿度膨張係数を制御する上で好ましい。したがって、好ましい樹脂としては、シクロオレフィン系樹脂、フマル酸ジエステル系樹脂、(メタ)アクリル系樹脂、又はスチレン・(メタ)アクリレート共重合体などでありうる。
機能層に用いられるシクロオレフィン系樹脂は、シクロオレフィン単量体の重合体、又はシクロオレフィン単量体とそれ以外の共重合性単量体との共重合体であることが好ましい。
2)シクロオレフィン単量体と、それと開環共重合可能な共重合性単量体との開環共重合体
3)上記1)又は2)の開環(共)重合体の水素添加物
4)上記1)又は2)の開環(共)重合体をフリーデルクラフツ反応により環化した後、水素添加した(共)重合体
5)シクロオレフィン単量体と、不飽和二重結合含有化合物との飽和共重合体
6)シクロオレフィン単量体のビニル系環状炭化水素単量体との付加共重合体及びその水素添加物
7)シクロオレフィン単量体と、(メタ)アクリレートとの交互共重合体
は一般式(B-1)で表される構造単位と一般式(B-2)で表される構造単位の両方を含むことがより好ましい。一般式(B-1)で表される構造単位は、前述の一般式(A-1)で表されるシクロオレフィン単量体由来の構造単位であり、一般式(B-2)で表される構造単位は、前述の一般式(A-2)で表されるシクロオレフィン単量体由来の構造単位である。
溶媒: メチレンクロライド
カラム: Shodex K806、K805、K803G(昭和電工(株)製を3本接続して使用した)
カラム温度:25℃
試料濃度: 0.1質量%
検出器: RI Model 504(GLサイエンス社製)
ポンプ: L6000(日立製作所(株)製)
流量: 1.0mL/min
校正曲線: 標準ポリスチレンSTK standard ポリスチレン(東ソー(株)製)Mw=500~2800000の範囲内の13サンプルによる校正曲線を使用した。13サンプルは、ほぼ等間隔に用いることが好ましい。
機能層に用いられるフマル酸ジエステル系樹脂は、フマル酸ジイソプロピル残基単位及び炭素数1又は2のアルキル基を有するフマル酸ジエステル残基単位を含むフマル酸ジエステル系樹脂である。
フマル酸ジエステル系樹脂が特に好ましい。
攪拌機、冷却管、窒素導入管および温度計を備えた1Lのオートクレーブに、ヒドロキシプロピルメチルセルロース(信越化学社製、商品名メトローズ60SH-50)2g、蒸留水600g、フマル酸ジイソプロピル330g、フマル酸ジエチル70g、および重合開始剤であるt-ブチルパーオキシピバレート3gを入れ、窒素バブリングを1時間行なった後、400rpmで攪拌しながら50℃で24時間保持することによりラジカル懸濁重合を行なった。室温まで冷却し、生成したポリマー粒子を含む懸濁液をろ別し、蒸留水およびメタノールで洗浄することによりフマル酸ジエステル系樹脂を得た(収率:75%)。
機能層に用いられる(メタ)アクリル系樹脂は、少なくともメタクリル酸メチルに由来する構造単位(U1)と、フェニルマレイミドに由来する構造単位(U2)とを含むことが好ましい。フェニルマレイミドに由来する構造単位(U2)を含む(メタ)アクリル系樹脂は、機能層の湿度膨張係数CHE2を小さくしうる。また光弾性係数も小さくなり、吸湿膨張してもムラの発生が起こりにくいという利点もある。
スチレン・(メタ)アクリレート共重合体(以下、スチレン・アクリル樹脂ともいう。)は、機能層に用いたときに透明性に優れる。また、スチレン部分の共重合比率によって吸湿膨張係数を調整することもできるため、これらの比率を変更することによって積層体としてのカールを制御することができる。
ポリアリレート系樹脂は、機能層に用いたときに靱性に優れる。当該ポリアイレート系樹脂は、少なくとも芳香族ジアルコール由来の構成単位と芳香族ジカルボン酸由来の構成単位とを含む。
機能層は、必要に応じて上記以外の他の成分をさらに含んでもよい。他の成分の例には、ゴム粒子、前述したマット剤(微粒子)、可塑剤、紫外線吸収剤などが含まれる。中でも、ゴム粒子や可塑剤はフィルムに疎水性を与え、機能層の湿度膨張係数CHEを制御する手段としても使用することができるため、適宜材料・添加量を調整することで積層体のカール特性を制御することができる。また機能層に 靱性(しなやかさ)を付与する観点から、ゴム粒子をさらに含むことが好ましい。
ゴム粒子は、ゴム状重合体を含む粒子である。ゴム状重合体は、ガラス転移温度が20℃以下の軟質な架橋重合体である。そのような架橋重合体の例には、ブタジエン系架橋重合体、(メタ)アクリル系架橋重合体、及びオルガノシロキサン系架橋重合体が含まれる。中でも、(メタ)アクリル系樹脂との屈折率差が小さく、機能層の透明性が損なわれにくい観点では、(メタ)アクリル系架橋重合体が好ましく、アクリル系架橋重合体(アクリル系ゴム状重合体)がより好ましい。
アクリル系ゴム状重合体(a)は、アクリル酸エステルに由来する構造単位を主成分として含む架橋重合体である。主成分として含むとは、アクリル酸エステルに由来する構造単位の含有量が後述する範囲となることをいう。アクリル系ゴム状重合体(a)は、アクリル酸エステルに由来する構造単位と、それと共重合可能な他の単量体に由来する構造単位と、1分子中に2以上のラジカル重合性基(非共役な反応性二重結合)を有する多官能性単量体に由来する構造単位とを含む架橋重合体であることが好ましい。
共重合可能な他の単量体は、アクリル酸エステルと共重合可能な単量体のうち、多官能性単量体以外のものである。すなわち、共重合可能な単量体は、2以上のラジカル重合性基を有しない。共重合可能な単量体の例には、メタクリル酸メチルなどのメタクリル酸エステル;スチレン、メチルスチレンなどのスチレン類;(メタ)アクリロニトリル類;(メタ)アクリルアミド類;(メタ)アクリル酸が含まれる。中でも、共重合可能な他の単量体は、スチレン類を含むことが好ましい。共重合可能な他の単量体は、1種類であってもよいし、2種類以上であってもよい。
(コア部)
コア部は、アクリル系ゴム状重合体(a)を含み、必要に応じて硬質な架橋重合体(c)をさらに含んでもよい。すなわち、コア部は、アクリル系ゴム状重合体からなる軟質層と、その内側に配置された硬質な架橋重合体(c)からなる硬質層とを有してもよい。
シェル部は、アクリル系ゴム状重合体(a)にグラフト結合した、メタクリル酸エステルに由来する構造単位を主成分として含むメタクリル系重合体(b)(他の重合体)を含む。主成分として含むとは、メタクリル酸エステルに由来する構造単位の含有量が後述する範囲となることをいう。
〈23℃における湿度膨張係数(CHE2)〉
機能層の23℃における湿度膨張係数(CHE2)は、1~30ppm/%RHの範囲であることが、基材フィルムの好ましい湿度膨張係数(CHE1)との関係から、カールの向きや程度を制御する観点から、好ましい。透機能層の湿度膨張係数CHE2が1ppm以上であると貼合後の剥離プロセスが行いやすくなるという効果を発現し、30ppm以下であると、貼合時のエラーおよびムラの発生を抑制できるという効果を発現する。より好ましくは3~20ppm/%RHの範囲であり、さらに好ましくは5~15ppm/%RHの範囲である。
本発明に係る機能層は、基材フィルムから剥離された後、偏光子と貼り合わされて位相差フィルムなどの光学フィルムとして機能しうる。
機能層は、例えばIPSモード用の位相差フィルムとして用いる観点では、測定波長590nm、23℃55%RHの環境下で測定される面内方向の位相差Roは、0~10nmであることが好ましく、0~5nmであることがより好ましい。機能層の厚さ方向の位相差Rtは、-40~40nmであることが好ましく、-25~25nmであることがより好ましい。
式(b):Rt=((nx+ny)/2-nz)×d
(式中、
nxは、機能層の面内遅相軸方向(屈折率が最大となる方向)の屈折率を表し、
nyは、機能層の面内遅相軸に直交する方向の屈折率を表し、
nzは、機能層の厚さ方向の屈折率を表し、
dは、機能層の厚さ(nm)を表す。)
機能層の面内遅相軸は、自動複屈折率計アクソスキャン(Axo Scan Mueller Matrix Polarimeter:アクソメトリックス社製)により確認することができる。
本発明の積層フィルムの形態は、特に制限されないが、例えば帯状でありうる。すなわち、本発明の積層フィルムは、その幅方向に直交する方向にロール状に巻き取られて、ロール体とすることが好ましい。
[製造方法]
本発明の積層フィルムの製造方法は、1)機能層用溶液を得る工程と、2)得られた機能層溶液を、基材フィルムの表面に付与する工程と、3)付与された機能層用溶液から溶媒を除去して、機能層を形成する工程とを有する。
前述の樹脂と、溶媒とを含む機能層用溶液を調製する。
添加量としては1~20質量%の範囲が好ましく、より好ましくは3~10質量%の範囲である。
次いで、得られた機能層用溶液を、基材フィルムの表面に付与する。具体的には、得られた機能層用溶液を、基材フィルムの表面に塗布する。
次いで、基材フィルムに付与された機能層用溶液から溶媒を除去して、機能層を形成する。
得られた帯状の積層フィルムを、その幅方向に直交する方向にロール状に巻き取り、ロール体とする。
本発明の積層フィルムの製造方法は、例えば図3に示される製造装置によって行うことができる。
機能層は、機能層用溶液を塗布して得られることから、当該溶液に由来する溶媒が残留していることがある。残留溶媒量は、湿度膨張係数の制御手段ともなり、使用溶媒・塗布液濃度、機能層の乾燥に当てる風速、乾燥温度・時間、乾燥室の条件(外気か内気循環か)、塗布時のバックロールの加熱温度等によって制御しうる。
式(2) 10<S1<S2<1000(ppm)
具体的には、機能層の残留溶媒量は、1000ppm未満であることが好ましく、800ppm未満であることがより好ましく、500~700ppm未満であることが、積層フィルムのカールバランスを考慮するとより好ましい。また、基材フィルムにも溶媒が残存するような溶媒・塗布プロセスを選ぶことで、積層体間の密着性が向上する。基材フィルムの残存溶媒量としては10~100ppmの範囲が好ましい。
(厚さ)
機能層の厚さd2は、通常、基材フィルムの厚さd1よりも薄い。具体的には、機能層の厚さd2は、偏光板の薄型化の観点では、具体的には、1~19μmの範囲であることが好ましく、中でも2~10μmの範囲であることがより好ましい。
偏光板は、偏光子と、その少なくとも一方の面に配置された積層フィルム又は機能層とを有する。偏光子と積層フィルム又は機能層とは、接着剤層を介して接着されていることが好ましい。
偏光子は、一定方向の偏波面の光だけを通す素子である。偏光子は、通常、ポリビニルアルコール系偏光フィルムでありうる。ポリビニルアルコール系偏光フィルムの例には、ポリビニルアルコール系フィルムにヨウ素を染色させたものや、二色性染料を染色させたものが含まれる。
偏光子の少なくとも一方の面には、本発明の積層フィルムを構成する基材フィルム又は機能層が配置される。積層フィルムを構成する基材フィルム又は機能層は、いずれも偏光子保護フィルムとして機能しうる。本実施の形態では、偏光子の一方の面に機能層が配置され、他方の面に他の保護フィルムが配置されていることが好ましい。
接着剤層は、機能層と偏光子との間、及び、対向フィルムと偏光子との間にそれぞれ配置されている。機能層と偏光子との間に配置される接着剤層と、対向フィルムと偏光子との間に配置される接着剤層とは、同じであってもよいし、異なってもよい。
粘着剤層は、偏光板を、液晶セルなどの表示素子と貼合するための層であり、偏光板のどちらの面に形成してもよいが、機能層の偏光子とは反対側の面に配置されうる。
本実施の形態に係る偏光板は、偏光子の少なくとも一方の面に、前述の積層フィルムを貼合するとともに、基材フィルムを剥離する工程を経て製造されうる。積層フィルムの貼り合わせは、偏光子の一方の面のみに行ってもよいし、両方の面に行ってもよく、透過率の観点では、偏光子の一方の面に積層フィルムを貼り合わせ、他方の面に他の保護フィルムである対向フィルムを貼り合わせることが好ましい。
偏光子の一方の面に、上記積層フィルムの機能層を、接着剤を介して貼合する。貼り合わされる機能層の表面、又は、偏光子の一方の表面に、必要に応じてコロナ処理などの前処理を施してもよい。
本実施の形態に係る表示装置は、液晶セルや有機エレクトロルミネッセンス(「EL」ともいう。)素子などの表示素子と、上記製造方法で製造された偏光板とを有する。中でも、本実施の形態に係る表示装置は、液晶セルと、上記製造方法で製造された偏光板とを有する液晶表示装置であることが好ましい。
[1]積層フィルムの材料
[1-1]基材フィルム
<基材フィルムA>
ポリエチレンテレフタレートフィルム(PETフィルム):(東洋紡社製TN100、ノンシリコーン系剥離剤を含む離型層あり、厚さ38μm)
ポリエチレンテレフタレートフィルム(PETフィルム)(東洋紡社製TN100)をTD方向に13%延伸させたフィルム(厚さ30μm)
<基材フィルムC>
ポリエチレンテレフタレートフィルム(PETフィルム)(東洋紡社製TN100)をTD方向に30%延伸させたフィルム(厚さ25μm)
ポリエチレンテレフタレートフィルム(PETフィルム)(東洋紡社製TN100)を150℃で30秒間熱保持緩和させたフィルム)厚さ38μm)
<基材フィルムE>
トリアセチルセルロースフィルム(TAC)(コニカミノルタ社製KC4UA、離型層なし、厚さ38μm)
<基材フィルムF>
シクロオレフィンフィルム(COP)(JSR社製ARTON G7810、離型層なし、厚さ38μm)
<基材フィルムG>
高密度ポリエチレン(HDPE)(ハイゼックス 2200J(プライムポリマー社製)、厚さ38μm)
基材フィルムの23℃における湿度膨張係数CHE1は、JIS K7197を参考として測定した。
フィルム試料を恒温恒湿槽に幅1cm、試料長15cmになるように固定し、一定湿度(約30%RH)まで脱湿し、フィルム長が一定になった後、加湿(約80%RH)すると吸湿により伸び始める。約24時間後吸湿は平衡に達してフィルムの伸びも平衡に達する。この時の伸び量から下式により計算した。この際、雰囲気温度は23℃に一定に保った。
23℃における湿度膨張係数(ppm/%RH)=伸び量(cm)/(試料長(cm)×湿度差)×106
(1)材料の準備
<樹脂>
1.COP(G7810):JSR(株)製ARTON G7810、Mw:14万、カルボン酸基を有するシクロオレフィン系樹脂
2.フマル酸樹脂:東ソー社製フマル酸ジエステル系樹脂、数平均分子量12万
3.アクリル:MMA/PMI/MADA共重合体(60/20/20質量比)、Mw:150万、Tg:137℃(なお、略称は、以下を示す。MMA:メタクリル酸メチル、PMI:フェニルマレイミド及びMADA:アクリル酸アダマンチル)
4.ポリアリレート:ユニチカ社製U-100
5.COP(ZNX330R):日本ゼオン社製ZNX330R
6.A-DCP:トリシクロデカンジメタノールジアクリレート(新中村化学工業社製)
7.PSt/ポリアリレート(質量比5:5)混合物:Pst(ポリスチレン:PSジャパン社製、Mw:50万:PSジャパン製]、ポリアリレート(下記化合物P)
8.PSt::ポリスチレン(Mw:50万:PSジャパン社製)
9.TAC:アセチル置換度2.9のアセチルセルロース
樹脂のガラス転移温度(Tg)は、DSC(Differential Scanning Colorimetry:示差走査熱量法)を用いて、JIS K 7121-2012に準拠して測定した。
樹脂の重量平均分子量(Mw)は、ゲル浸透クロマトグラフィー(東ソー社製 HLC8220GPC)、カラム(東ソー社製 TSK-GEL G6000HXL-G5000HXL-G5000HXL-G4000HXL-G3000HXL 直列)を用いて測定した。サンプル20mg±0.5mgをテトラヒドロフラン10mlに溶解し、0.45mmのフィルターで濾過した。この溶液をカラム(温度40℃)に100ml注入し、検出器RI温度40℃で測定し、スチレン換算した値を用いた。
以下の方法で調製したゴム粒子R1を用いた。
ポリオキシエチレンラウリルエーテルリン酸 0.002質量部
ホウ酸 0.4725質量部
炭酸ナトリウム 0.04725質量部
水酸化ナトリウム 0.0076質量部
得られた分散液中のゴム粒子の分散粒径を、ゼータ電位・粒径測定システム(大塚電子株式会社製 ELSZ-2000ZS)で測定した。
<積層フィルム201用機能層溶液の調製>
下記成分を混合して、機能層用溶液201を得た。
COP(G7810): 100質量部
表Iに示される溶媒であるシクロペンタノン(沸点131℃)及びジクロロメタン(塩化メチレン、沸点41℃)に変更した以外は積層フィルム201用機能層溶液と同様にして、積層フィルム202~205用機能層溶液を得た。
下記成分を混合して、機能層用溶液206~215を得た。
塩化メチレン(沸点41℃): 760質量部
メタノール(沸点65℃): 40質量部
COP(G7810): 200質量部
下記成分を混合して、機能層用溶液216を得た。
メチルエチルケトン(MEK:沸点80℃) 900質量部
フマル酸ジエステル樹脂(フマル酸樹脂と表記): 100質量部
下記成分を混合して、機能層用溶液223を得た。
メチルエチルケトン(MEK:沸点80℃) 900質量部
アクリル: 100質量部
下記成分を混合して、機能層用溶液224を得た。
メチルエチルケトン(MEK:沸点80℃) 900質量部
アクリル: 80質量部
ゴム粒子R1: 20質量部
下記成分を混合して、機能層用溶液225を得た。
塩化メチレン(沸点41℃) 900質量部
アクリル: 100質量部
下記成分を混合して、機能層用溶液226を得た。
塩化メチレン(沸点41℃) 800質量部
アクリル: 80質量部
ゴム粒子R1: 20質量部
下記成分を混合して、機能層用溶液227を得た。
塩化メチレン(沸点41℃) 800質量部
アクリル: 160質量部
ゴム粒子R1: 20質量部
下記成分を混合して、機能層用溶液228を得た。
トルエン(沸点110℃): 900質量部
ポリアリレート(ユニチカ社製U-100): 100質量部
積層フィルム229用機能層溶液では、表III記載のように、溶媒として塩化メチレン(沸点41℃)を用いた以外は、積層フィルム228用機能層用溶液と同様にして、積層フィルム229用機能層溶液を調製した。
特開2020-3823号公報の実施例1を参考として、下記成分を混合して、機能層用溶液230を得た。
シクロヘキサン(沸点81℃): 900質量部
COP(ZNX330R) 100質量部
特開2018-45220号公報の実施例3を参考として、下記成分を混合して、積層フィルム231用機能層溶液を得た。
酢酸エチル(EA:沸点77℃) 100質量部
A-DCP 100質量部
イルガキュア127 2質量部
レベリング剤(F-784-F) 0.08質量部
特開2018-45220号公報の実施例3を参考として、下記成分を混合して、積層フィルム232用機能層溶液を得た。
塩化メチレン(沸点41℃) 900質量部
PSt: 70質量部
ポリアリレート樹脂(化合物P) 30質量部
レベリング剤(F-784-F) 0.08質量部
特開2018-41028号公報の実施例3を参考として、下記成分を混合して、積層フィルム233用機能層溶液を得た。
酢酸エチル(EA:沸点77℃): 700質量部
PSt: 98質量部
可塑剤(ポリエステル化合物) 2質量部
レベリング剤(F-784-F) 0.08質量部
下記成分を混合して、機能層用溶液234を得た。
塩化メチレン(沸点41℃): 800質量部
エタノール(沸点78℃): 100質量部
TAC: 90質量部
可塑剤(エチルフタリルエチルグリコレート): 10質量部
<積層フィルム201の作製>
基材フィルムとして、PETフィルム(東洋紡社製TN100、基材フィルムA)を準備した。このPETフィルムの離型層上に、積層フィルム201用機能層用溶液を、バックコート法によりダイを用いて塗布した後、下記の乾燥ステップで積層フィルムの乾燥を行うことで厚さ5μmの機能層を形成し、積層フィルム201を得た。
第1ステップ:40℃で1分
第2ステップ:70℃で1分
第3ステップ:100℃で1分
第4ステップ:130℃で2分
積層フィルム201の作製において、表I~表IIIに示すように、基材フィルムの種類及び厚さ、機能層溶液の種類及び厚さをそれぞれ変更した以外は同様にして、積層フィルム202~234を得た。なお乾燥温度は第4ステップのドライヤー温度のみ変更し、第1、第2、第3ステップの温度は固定とした。
(1)残留溶媒の定性及び定量
得られた積層フィルム中の残留溶媒の定性及び定量は、積層フィルムをそれぞれ基材フィルムと機能層に剥離し、それぞれをヘッドスペースガスクロマトグラフィーにより行った。ヘッドスペースガスクロマトグラフィーでは、試料を容器に封入して加熱し、容器中に揮発成分が充満した状態で速やかに容器中のガスをガスクロマトグラフに注入し、質量分析を行って化合物の同定を行いながら揮発成分の定量を行った。揮発成分の定量は、濃度が既知の試料を用いて検量線を予め作成しておき、測定で得られた揮発成分のピーク面積と検量線とを照合して行った。
ヘッドスペース装置:HP7694 Head Space Sampler(ヒューレットパッカード社製)
温度条件:トランスファーライン200℃、ループ温度200℃
サンプル量:0.8g/20mlバイアル
GC:HP5890(ヒューレットパッカード社製)
MS:HP5971(ヒューレットパッカード社製)
カラム:HP-624(30m×内径0.25mm)
オーブン温度:初期温度40℃(保持時間3分)、昇温速度10℃/分、到達温度200℃(保持時間5分)
測定モード:SIM(セレクトイオンモニター)モード
得られた積層フィルムにおいて、機能層の23℃における湿度膨張係数(CHE2)は、基材フィルムを剥離した試料において、上記基材フィルムの湿度膨張係数(CHE1)と同様の方法で測定した。
積層フィルムの搬送安定性は、搬送張力350N/mを付与しながら、ラインでロール搬送したときの破断や割れの有無を確認することにより評価した。そして、以下の基準に基づいて、搬送安定性を評価した。
〇:機能層は破断することなく、搬送可能
△:機能層に微小な傷と割れが発生するが、搬送可能
×:機能層が割れて、破断する
△以上であれば、良好と判断した。
積層フィルムを35mm(製造時の横方法)×2mm(製造時の縦方向)の帯状に切断し、38℃の温水中に30分間浸漬した時の水中での幅手方向のカール度を測定する。
機能層を塗設する側が凹の場合をプラスとして測定する。
得られた積層フィルムを、直径5cmの円形に切り出し、サンプルとした。得られたサンプルを、23℃55%RHの恒温恒湿室にて24時間放置した。その後、サンプルを恒温恒湿室から取り出し、平板上に置き、曲率スケールを用いて、サンプルと合致するカーブを有する曲率半径r(m)から1/rを求めた。そして、以下の基準に基づいて、カール量を評価した。
◎:1/rが4未満
○:1/rが4以上8未満
△:1/rが8以上12未満
×:1/rが12以上
△以上であれば良好と判断した。
(貼合性の評価)
ポリビニルアルコール(以下、「PVA:という。」)を含有する厚さ60μmの長尺ポリビニルアルコールフィルムを、ガイドロールを介して連続搬送しつつ、ヨウ素とヨウ化カリウム配合の染色浴(30℃)に浸漬して染色処理と2.5倍の延伸処理を施した後、ホウ酸とヨウ化カリウムを添加した酸性浴(60℃)中で、トータルとして5倍となる延伸処理と架橋処理を施し、得られた厚さ12μmのヨウ素-PVA系偏光子を、乾燥機中で50℃、30分間乾燥させて水分率4.9%の偏光子を得た。偏光子は、10cm×10cmにカットした。
ついで次の各成分を混合し、水系接着剤1を調製した。
純水:100質量部
ポリビニルアルコール系樹脂(日本合成化学工業(株)製 商品名「ゴーセファイマーZ200」]:3質量部
水系接着剤1をワイヤーバー(#0)にてPVA偏光子に塗工し、10cm×10cmに加工した本願フィルムを機能層面がPVA面と接着するように、高精度卓上型貼合機HAL-215(三共株式会社製)を用いて枚葉貼合を行った後、基材フィルムを剥離してPVAと機能層の積層体を作製した。
この積層体の貼合工程適性について、下記のように評価した。
(評価ランク)
◎:50枚貼合を行っても気泡の混入、端部の折れ、フィルムの位置ずれ等の発生は見られなかった
〇:20枚貼合を行っても気泡の混入、端部の折れ、フィルムの位置ずれ等の発生は見られなかった
△:10枚貼合を行っても気泡の混入、端部の折れ、フィルムの位置ずれ等の発生は見られなかった
×:10枚貼合を行ったところ、1枚以上気泡の混入、端部の折れ、フィルムの位置ずれ等の発生が見られた
(6)干渉縞
〈偏光板の作製〉
上記作製した積層フィルム201~234を用いて、下記手順にて偏光板を作製した。
ポリビニルアルコールフィルムの厚さ60μmの長尺ポリビニルアルコールフィルムを、ガイドローラーを介して連続搬送しつつ、ヨウ素とヨウ化カリウム配合の染色浴(30℃)に浸漬して染色処理と2.5倍の延伸処理を施した後、ホウ酸とヨウ化カリウムを添加した酸性浴(60℃)中で、トータルとして5倍となる延伸処理と架橋処理を施し、得られた厚さ12μmのヨウ素-PVA系偏光子を、乾燥機中で50℃、30分間乾燥させて水分率4.9%の偏光子を得た。
上記作製した偏光子を、積層フィルム201~234と対向フィルムとして下記光学フィルムを用いて両面から挟持して、下記水溶性接着剤液1を介して、接着し偏光板201~234を作製した。
〈対向フィルム〉
対向フィルムは下記樹脂を含有するフィルムを用いた。
COP(シクロオレフィン):JSR(株)製ARTON G7810
(水溶性接着剤液1の調製)
下記の各成分を混合した後、脱泡して、水溶性接着剤液1を調製した。
株式会社日本触媒製「エポクロス WS-300」 7.5質量部
MENADIONA社製「CROSSLINKER CL-427」
0.1質量部
なお、偏光板作製は、積層フィルムの接着側表面にコロナ出力強度2.0kW、ライン速度18m/分でコロナ放電処理を施し、コロナ放電処理面に、上記調製した水溶性接着剤液1を、乾燥後の厚さが約3μmとなるようにバーコーターで塗工した後、50℃、60℃、70℃でこの順番に60秒ずつ乾燥し、偏光板を得た。
作製した偏光板を暗幕のような光を通さない黒布の上に機能層が形成された面を上にして置き、三波長蛍光灯(松下電器社製、ナショナル蛍光灯:FL20SS・ENW/18)で照らして、偏光板の表面を目視観察し、以下の基準で評価した。
◎:試料10枚を観察したが干渉ムラが見えない。
○:干渉縞が見えない
△:干渉縞がうっすらと見える
×:干渉縞が目立つ
得られた積層フィルム201~234の製造条件を表I、表II及び表IIIに示し、評価結果を表IVに示す。なお、ゴム粒子の含有量は、乾燥後の塗膜(機能層)中の質量%を示す。
実施例1で作製した、積層フィルム204、213、214、216、218、226及び229の機能層の位相差をそれぞれ下記方法で測定し、結果を表Vに示した。
1)積層フィルムから基材フィルムを剥離し、機能層を23℃55%RHの環境下で24時間調湿する。この層の平均屈折率をアッベ屈折計で測定し、厚さdを市販のマイクロメーターを用いて測定する。
2)調湿後のフィルムの、測定波長590nmにおけるリターデーションRo及びRtを、それぞれ自動複屈折率計アクソスキャン(Axo Scan Mueller Matrix Polarimeter:アクソメトリックス社製)を用いて、23℃55%RHの環境下で測定する。
式(a):Ro=(nx-ny)×d
式(b):Rt=((nx+ny)/2-nz)×d
(式中、nxは、機能層の面内遅相軸方向の屈折率、nyは、機能層の面内遅相軸に直交する方向の屈折率、nzは、機能層の厚さ方向の屈折率、及びdは機能層の厚さ(nm)をそれぞれ表す。)
2 基材フィルム
3 機能層
4 接着層
5 偏光子
6 対向フィルム
10、10′ 偏光板
B110 基材フィルム
B120 機能層
B200 製造装置
B210 供給部
B220 塗布部
B230 乾燥部
B240 冷却部
B250 巻き取り部
Claims (15)
- 基材フィルム上に、剥離可能な機能層が積層された積層フィルムであって、
前記機能層の厚さが、1~19μmの範囲内であり、
前記積層フィルムの総厚さが、50μm以下であり、
前記基材フィルムの23℃における湿度膨張係数をCHE1(ppm/%RH)、厚さをd1(μm)、及び前記機能層の23℃における湿度膨張係数をCHE2(ppm/%RH)、厚さをd2(μm)としたとき、下記式(1)の関係を満たすことを特徴とする積層フィルム。
式(1) 0.20<│(CHE1-CHE2)│×(d2/d1)<2.00 - 前記機能層の厚さが、2~10μmの範囲内であることを特徴とする請求項1に記載の積層フィルム。
- 前記積層フィルムの総厚さが、30~45μmの範囲内であることを特徴とする請求項1又は請求項2に記載の積層フィルム。
- 前記機能層の下記式(i)で定義されるリターデーション値Roが0~20nmの範囲内であり、下記式(ii)で定義されるリターデーション値Rtが-25~25nmの範囲内であることを特徴とする請求項1から請求項3までのいずれか一項に記載の積層フィルム。
式(i) Ro=(nx-ny)×d
式(ii) Rt={(nx+ny)/2-nz}×d
(上記式(i)及び(ii)において、Roは機能層の面内方向のリターデーション値、Rtは、機能層の厚さ方向のリターデーション値、nxは機能層の面内の遅相軸方向の屈折率、nyは機能層の面内の進相軸方向の屈折率、nzは機能層の厚さ方向の屈折率(屈折率は23℃、55%RHの環境下、波長590nmで測定)、dはフィルムの厚さ(nm)を表す。) - 前記基材フィルムの残留溶媒の含有量をS1とし、前記機能層の残留溶媒の含有量をS2としたときに、下記式(2)を満たすことを特徴とする請求項1から請求項4までのいずれか一項に記載の積層フィルム。
式(2) 10<S1<S2<1000(ppm) - 前記残留溶媒のうち主たる残留溶媒の沸点が、大気圧下において100℃以下であることを特徴とする請求項5に記載の積層フィルム。
- 前記残留溶媒が、塩素系溶媒であることを特徴とする請求項5又は請求項6に記載の積層フィルム。
- 前記残留溶媒が、ジクロロメタンであることを特徴とする請求項5から請求項7までのいずれか一項に記載の積層フィルム。
- 前記残留溶媒としてジクロロメタン及びアルコール類を含むことを特徴とする請求項5から請求項8までのいずれか一項に記載の積層フィルム。
- 前記基材フィルムが2軸延伸されたポリエステルフィルムであり、当該ポリエステルフィルムの23℃における湿度膨張係数CHE1が、10~20ppm/%RHの範囲内であることを特徴とする請求項1から請求項9までのいずれか一項に記載の積層フィルム。
- 前記機能層が、カルボニル基を側鎖に有する高分子材料を含有することを特徴とする請求項1から請求項10までのいずれか一項に記載の積層フィルム。
- 前記機能層が、環状構造を主鎖に有する高分子材料を含有することを特徴とする請求項1から請求項10までのいずれか一項に記載の積層フィルム。
- 請求項1から請求項12までのいずれか一項に記載の積層フィルムを具備することを特徴とする偏光板。
- 請求項1から請求項12までのいずれか一項に記載の積層フィルム又は請求項13に記載の偏光板を具備することを特徴とする表示装置。
- 請求項1から請求項12までのいずれか一項に記載の積層フィルムを、偏光子の少なくとも一方の面に貼合しながら巻き取る偏光板ロールの製造方法であって、
ロールの内側から偏光子、接着層、機能層及び基材フィルの層順になるように、前記偏光子に前記積層フィルムを貼合しながら巻き取る工程を含むことを特徴とする偏光板ロールの製造方法。
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006293255A (ja) * | 2004-05-18 | 2006-10-26 | Fuji Photo Film Co Ltd | 光学フィルム、光学補償フィルム、偏光板、液晶表示装置、および自発光型表示装置 |
JP2010113315A (ja) * | 2008-10-10 | 2010-05-20 | Jsr Corp | フォトマスク |
JP2016200806A (ja) * | 2015-04-10 | 2016-12-01 | 日東電工株式会社 | 粘着剤層付偏光フィルムセット、液晶パネルおよび液晶表示装置 |
JP2017122888A (ja) * | 2016-01-08 | 2017-07-13 | コニカミノルタ株式会社 | 光学フィルム、光学フィルムの製造方法、偏光板及び画像表示装置 |
JP2017156531A (ja) * | 2016-03-02 | 2017-09-07 | コニカミノルタ株式会社 | 偏光板保護フィルム |
JP2018041028A (ja) * | 2016-09-09 | 2018-03-15 | 富士フイルム株式会社 | 剥離性積層フィルム及び偏光板の製造方法 |
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Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006293255A (ja) * | 2004-05-18 | 2006-10-26 | Fuji Photo Film Co Ltd | 光学フィルム、光学補償フィルム、偏光板、液晶表示装置、および自発光型表示装置 |
JP2010113315A (ja) * | 2008-10-10 | 2010-05-20 | Jsr Corp | フォトマスク |
JP2016200806A (ja) * | 2015-04-10 | 2016-12-01 | 日東電工株式会社 | 粘着剤層付偏光フィルムセット、液晶パネルおよび液晶表示装置 |
JP2017122888A (ja) * | 2016-01-08 | 2017-07-13 | コニカミノルタ株式会社 | 光学フィルム、光学フィルムの製造方法、偏光板及び画像表示装置 |
JP2017156531A (ja) * | 2016-03-02 | 2017-09-07 | コニカミノルタ株式会社 | 偏光板保護フィルム |
JP2018041028A (ja) * | 2016-09-09 | 2018-03-15 | 富士フイルム株式会社 | 剥離性積層フィルム及び偏光板の製造方法 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023037715A1 (ja) * | 2021-09-09 | 2023-03-16 | コニカミノルタ株式会社 | 積層体の製造方法 |
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