JP4335773B2 - Film laminate manufacturing method and manufacturing apparatus used therefor - Google Patents

Description

  The present invention provides a method for producing a film laminate in which another film is provided on at least one surface of the film via an adhesive liquid, a production apparatus used therefor, a film laminate obtained by the production method, and a method obtained by the production method. The present invention relates to a polarizing plate, an optical film including the polarizing plate, and an image display device.

  Conventionally, as a method of laminating a film via an adhesive liquid such as an adhesive or a pressure-sensitive adhesive, generally, a method of laminating after applying an adhesive liquid to a film, or a method of supplying an adhesive liquid between a pair of films and a pair of rolls There is a method of bonding by passing through a pressure bonding means such as a gap (see, for example, Patent Document 1). In the case of using an adhesive liquid having a low viscosity at the time of such bonding, the overflow of the adhesive liquid from the end portion of the film and the outflow, and contamination of the film and the apparatus due to the back of the adhesive liquid have been problems.

  On the other hand, in Patent Document 1, when the supply amount of the adhesive liquid supplied between the polarizer and the protective film becomes excessive, excess adhesive liquid is left and right of the protective film due to roll pressure. It has been pointed out that it flows out from both sides and contaminates the roll and the protective film. For this reason, in the following Patent Document 1, an air weir is formed at the width direction end portion of the protective film by blowing air from at least one end portion in the width direction of the protective film toward the center portion in the width direction. A method for bringing a chemical solution to the center in the width direction is disclosed.

  However, in the above method, since the adhesive liquid at the end part is dried and solidified particularly by the air blowing, the polarizer and the protective film cannot be sufficiently adhered and fixed, and are liable to become uneven. There is a problem.

  Also disclosed is a method of sucking and removing excess adhesive liquid brought to the center in the width direction by an air weir with a suction nozzle provided at the end of the protective film. A water supply nozzle is provided inside the suction nozzle so that the suction port is not closed by the solidification of the adhesive liquid with water supplied from the water supply nozzle.

  However, since the water supply nozzle is provided in the suction nozzle, the structure is complicated.When cleaning or cleaning the water supply nozzle, a cleaning tool is put in the suction nozzle or the water supply nozzle is connected to the suction nozzle. Need to pull out. For this reason, work becomes complicated.

  Further, since the water supply nozzle is provided in the suction nozzle, there is a problem that the suction space in the suction nozzle is reduced and the suction force is reduced. Furthermore, there is also a problem that the water discharged from the water supply nozzle hinders the adhesive liquid sucked into the suction nozzle and cannot perform smooth suction.

As described above, the problem that occurs when air is blown from the end portion is not limited to the method of Patent Document 1 in which the protective film is bonded to both surfaces of the polarizer, and also occurs when the surfaces are bonded one by one by the conventional method. Is.
Japanese Patent Laid-Open No. 11-179871

  The present invention has been made in view of the above-mentioned problems, and when the films are bonded, for example, when the polarizer and the protective film are bonded, the leakage of the adhesive liquid from the bonding surface is not solidified. It aims at providing the manufacturing method of the film laminated body which can be prevented. It is another object of the present invention to provide an apparatus for manufacturing a film laminate that is easy to clean and care and that can prevent the adhesive liquid from leaking from the bonding surface without solidifying. Furthermore, it aims at providing the film laminated body obtained by the said manufacturing method, the polarizing plate which can be utilized to an edge part, an optical film provided with the same, and an image display apparatus.

  In order to solve the above-mentioned conventional problems, the inventors of the present application provide a film laminate production method, a production apparatus used therefor, a film laminate obtained by the production method, a polarizing plate obtained by the production method, and the like. The optical film and the image display device were intensively studied. As a result, the inventors have found that the above-described problems can be solved by adopting the following configuration, and have completed the present invention.

  That is, in order to solve the above-described problems, a method for producing a film laminate according to the present invention is a method for producing a film laminate in which another film is provided on at least one surface of the film, Arranging another film on at least one surface, supplying an adhesive liquid to the bonded portion of the film and the other film, and resisting an adhesive liquid that tends to flow toward at least one end of the film The film and another film are bonded together by pressure bonding while supplying the liquid from at least one end of the film.

  According to the above-described method, the liquid that flows against the adhesive liquid that flows out toward at least one end of the film is supplied, so that the adhesive liquid is prevented from leaking from the end of the film. be able to. As a result, it is possible to prevent the laminating means such as a roll used for laminating the film and the other film, and the other film from being contaminated by the adhesive liquid. Further, since leakage of the adhesive liquid is prevented by the liquid, the adhesive liquid is not dried and solidified unlike when air is blown. Thereby, a film laminate in which a film and another film are securely bonded and fixed can be manufactured.

  Before the film and another film are bonded together, it is preferable to suck and remove the adhesive liquid that tends to flow out toward at least one end of the film or the adhesive liquid diluted with the liquid.

  According to the above method, since the excess adhesive liquid that is not used for bonding is removed by suction, the two can be bonded together with an optimal amount of adhesive liquid for bonding the film to another film. As a result, it becomes possible to produce a film laminate that is uniform in the plane. Further, the adhesive liquid may be removed by suction while being diluted with a liquid. In this case, the adhesive liquid does not solidify. For this reason, suction removal becomes easy.

  When the other film having a width larger than that of the film and having a surplus portion in the width direction is used, it is preferable that the liquid is supplied within the surplus length portion forming range.

  In the case of the above method, the liquid is supplied within the range of the extra length, thereby preventing the adhesive liquid used for bonding the film and another film from being diluted with the liquid.

  When the other film is wider than the film and has a surplus part in the width direction, the surplus part is formed by suction removal of the adhesive liquid or the adhesive liquid diluted with the liquid. It is preferable to carry out within the range.

  With the above method, excess adhesive liquid that is not used for bonding is diluted with liquid and sucked and removed within the formation range of the extra length, so that it is securely fixed to other films at the end of the film. Can be made.

  It is preferable to use the liquid that dissolves the adhesive liquid.

  If the liquid that prevents the leakage of the adhesive liquid dissolves the adhesive liquid, the adhesive liquid that is not used for bonding is diluted with the liquid. As a result, it is possible to suppress the adhesive liquid from solidifying during the removal of the excess adhesive liquid and facilitate the removal.

  It is preferable to use a polarizer as the film and a protective film as the other film.

  Thereby, a non-uniformity in adhesiveness can be produced, and a polarizing plate having a uniform in-plane can be produced.

  Moreover, in order to solve the said subject, the manufacturing apparatus of the film laminated body which concerns on this invention is a manufacturing apparatus of the film laminated body used for manufacture of the film laminated body by which the other film was provided in the at least one surface of the film. An adhesive liquid supply means for supplying an adhesive liquid to a bonding portion between the film and another film disposed on at least one surface of the film, and at least one end from a central portion of the film A liquid supply means for supplying a liquid that resists the adhesive liquid to flow out toward at least one end of the film, and a bonding means for bonding the film and the other film by pressure bonding. And

  Since it has the liquid supply means which supplies the liquid which opposes this with respect to the adhesive liquid which flows out toward at least one edge of another film in the said structure, it is adhesive liquid from the edge of another film. Can be prevented from leaking. As a result, for example, it is possible to reduce contamination of a roll used for bonding between a film used as a bonding means and another film, another film, and the like with the adhesive liquid. Moreover, since leakage of the adhesive liquid is prevented by the liquid, the adhesive liquid does not dry and solidify as when air is blown, and as a result, it is possible to produce a film laminate without undulations. Become.

  It is preferable to have a suction means for sucking and removing an adhesive liquid that tends to flow out toward at least one end of the film or an adhesive liquid diluted with the liquid.

  According to the above-described configuration, the excess adhesive liquid that is not used for bonding is removed by suction while being diluted with the liquid, so that the suction means can be prevented from becoming unusable due to the solidification of the adhesive liquid. In addition, as described above, it is not necessary to provide a water supply nozzle for diluting the adhesive liquid around or inside the portion to be sucked in the suction means, so that the suction force is improved and efficient suction removal is performed. Can be planned. Further, since the suction means is independent of the liquid supply means, it does not require a complicated structure and is excellent in workability such as cleaning and care.

  When the other film is wider than the film and has a surplus length part in the width direction, the delivery part of the liquid supply means is located within the surplus length part forming range. Is preferred.

  With the above configuration, by providing the delivery portion of the liquid supply means so as to be positioned within the range of the extra length portion, it is possible to prevent the adhesive liquid used for bonding the film to another film from being diluted by the liquid. To do.

  When using the other film having a width larger than the film and having a surplus portion in the width direction, the suction portion of the suction means may be located within the surplus length portion forming range. preferable.

  With the above configuration, since the suction part of the suction means is provided so as to be located within the formation range of the extra length part, excess adhesive liquid is removed while diluting with liquid, and as a result, even at the end of the film It can be securely bonded to other films.

  It is preferable that the opening portion in the suction portion is flattened in a predetermined direction, and the suction portion is provided so that the flattening direction of the opening portion and the width direction of the film are substantially parallel.

  With the above configuration, the suction part can be brought close to the bonded portion of the film and the other film, and the adhesive liquid and the liquid can be efficiently sucked.

  It is preferable to use a polarizer as the film and a protective film as the other film.

  By the said structure, the manufacturing apparatus which enables manufacture of a polarizing plate with a nonuniformity in adhesiveness and in-plane uniformity as a film laminated body can be provided.

  In order to solve the above problems, a film laminate according to the present invention is a film laminate in which another film is provided on at least one surface of the film, and the other is provided on at least one surface of the film. A liquid that resists the adhesive liquid that attempts to flow toward at least one end of the other film, and supplies the adhesive liquid to the bonded portion of the film and the other film. While being supplied from at least one end of the film, the film and the other film are bonded together by pressure bonding.

  The film laminate configured as described above supplies a liquid that flows against the adhesive liquid that is about to flow out toward at least one end of the other film, and the adhesive liquid leaks from the end of the other film. It was obtained by preventing That is, it is a film laminated body obtained by the said structure, without other films etc. being contaminated with adhesive liquid. In addition, since leakage of the adhesive liquid is prevented by liquid rather than air, there is no portion made of the adhesive liquid that has been dried and solidified when the film is bonded to another film. Therefore, the film laminate having the above-described structure has no unevenness in adhesiveness, is uniform in the surface, and does not wavy.

  In order to solve the above problems, the polarizing plate according to the present invention is a polarizing plate in which a protective film is provided on at least one surface of the polarizer, and the protective film is provided on at least one surface of the polarizer. An adhesive liquid is supplied to the bonded portion of the polarizer and the protective film, and a liquid that resists the adhesive liquid that tends to flow toward at least one end of the protective film is provided at least on the protective film. While being supplied from one end, the polarizer and the protective film are obtained by bonding together by pressing.

  The polarizing plate configured as described above supplies a liquid that flows against the adhesive liquid that is about to flow out toward at least one end of the protective film, so that the adhesive liquid leaks from the end of the protective film. It was obtained by preventing. That is, it is a polarizing plate obtained by the said structure, without a protective film etc. being contaminated with adhesive liquid. Further, since leakage of the adhesive liquid is prevented by liquid rather than air, there is no portion made by the adhesive liquid that has been dried and solidified in the bonding of the polarizer and the protective film. Therefore, the polarizing plate having the above-described configuration has no unevenness in adhesiveness, is uniform in the surface, and does not wavy.

  In order to solve the above problems, the optical film according to the present invention is characterized in that at least one polarizing plate described above is laminated.

  In order to solve the above problems, the image display device according to the present invention is characterized in that the polarizing plate described above or the optical film described above is provided.

  The present invention has the following effects by the means described above.

  That is, according to the method for producing a film laminate according to the present invention, since the adhesive liquid that is about to leak is prevented by the liquid, the adhesive liquid is not dried and solidified. As a result, it is possible to produce an in-plane uniform film laminate without unevenness in adhesion.

  In addition, according to the film laminate manufacturing apparatus of the present invention, since leakage of the adhesive liquid is prevented by the liquid, for example, a roll used for bonding the film and another film, other films, etc. by the adhesive liquid. There is no contamination. Further, since the suction means can remove the excess adhesive liquid that is not used for bonding while being diluted with a liquid, the suction means can be prevented from becoming unusable due to the solidification of the adhesive liquid. Furthermore, since the suction means is configured independently of the liquid supply means, it does not require a complicated structure and is excellent in workability such as cleaning and care. In addition, in the suction means, it is not necessary to provide a water supply nozzle or the like for diluting the adhesive liquid around or inside the portion to be sucked, so that suction force can be improved and efficient suction removal can be achieved.

  Further, according to the film laminate of the present invention, the adhesive liquid can be attached to another film in such a manner that an appropriate amount of the adhesive liquid is supplied to the end of the film while preventing leakage of the adhesive liquid with the liquid. Since they are combined, there is no unevenness in adhesion, uniform in-plane, and no waviness.

  Further, according to the polarizing plate according to the present invention, the adhesive liquid is bonded to the protective film so that an appropriate amount of the adhesive liquid is supplied even at the end of the polarizer while preventing leakage of the adhesive liquid with the liquid. As a result, there is no unevenness in adhesion, uniform in-plane and no waviness.

  Further, according to the optical film of the present invention, since the in-plane uniform and non-waving polarizing plate is provided, it is possible to provide a film having excellent optical characteristics.

  In addition, according to the image display device of the present invention, since it is provided with a polarizing plate excellent in optical characteristics and in-plane uniform and no waviness, or an optical film excellent in optical characteristics, it provides an excellent display characteristic. can do.

  An embodiment of the present invention will be described below with reference to FIGS. However, parts that are not necessary for the description are omitted, and some parts are illustrated by being enlarged or reduced for easy explanation.

  First, the manufacturing method of the film laminated body which concerns on this invention is demonstrated below using a polarizing plate as an example. FIG. 1 is a perspective view for explaining a method of manufacturing a polarizing plate according to an embodiment of the present invention. FIG. 2 is a side view for explaining the manufacturing method of the polarizing plate. FIG. 3 is an enlarged view of an essential part of FIG. FIG. 4 is a schematic diagram showing the shape of the opening portion of the suction port in the suction nozzle according to the polarizing plate manufacturing apparatus. FIG. 5 is a schematic cross-sectional view schematically showing the polarizing plate according to the present embodiment.

  As shown in FIGS. 1 and 2, first, a protective film (another film) 2 is arranged on both sides of the polarizer (film) 1, and the polarizer 1 is sandwiched between the protective films 2. In this state, the polarizer 1 together with the protective film 2 is conveyed in the vertical direction from the upper side to the lower side in FIG. However, in the present invention, it is not necessarily limited to the case where the polarizer 1 and the protective film 2 are transported in the vertical direction, but can be applied to the case where they are transported in the horizontal direction. Can be changed accordingly.

  The protective film 2 has a surplus length portion 9 in the width direction and has a larger width than the polarizer 1. However, the present invention is not limited to this, and a protective film having the same size as that of the polarizer 1 may be used. Details of the polarizer 1 and the protective film 2 will be described later.

  The adhesive liquid 3 is supplied to the bonded portion of the polarizer 1 and the protective film 2 by an adhesive liquid supply nozzle (adhesive liquid supply means) 11. Adhesive liquid supply nozzles 11 are respectively disposed on both sides of the polarizer 1. A method for supplying the adhesive liquid 3 is not particularly limited, and for example, a dropping method or the like can be employed. The supply position of the adhesive liquid 3 is not particularly limited, and may be determined as necessary. For example, the adhesive liquid 3 may be dropped from the vicinity of the bonded portion and from the vicinity of the center in the width direction. Alternatively, the adhesive liquid 3 may be dropped at a position separated from the bonding portion on the protective film 2 by a predetermined distance, and the adhesive liquid 3 may be poured into the bonding portion. However, in this case, the protective film 2 needs to be inclined at a predetermined angle above the horizontal direction. Further, a plurality of dropping positions may be provided.

  The adhesive liquid 3 supplied to the bonded portion forms a liquid pool 12 over the entire width direction of the polarizer 1 (or protective film 2). The adhesive liquid 3 can be evenly applied to the polarizer 1 and the protective film 2 that have passed through the liquid reservoir 12.

  The supply amount, the supply speed, and the like of the adhesive liquid 3 are appropriately set to optimum values according to the type and viscosity of the adhesive liquid 3 to be used.

  The adhesive which comprises the adhesive liquid 3 is not specifically limited, A conventionally well-known various thing is employable. For example, polyvinyl alcohol-based adhesives, polyurethane-based adhesives, isocyanate-based adhesives, and adhesives composed of the polyvinyl alcohol-based adhesives and water-soluble crosslinking agents such as boric acid, borax, glutaraldehyde, melamine, and oxalic acid. Can be mentioned. In particular, it is preferable to use polyvinyl alcohol in consideration of the best adhesiveness with the polarizer 1. Here, the average degree of polymerization of polyvinyl alcohol is preferably 1000 to 5000, and more preferably 1500 to 4000. The saponification degree is preferably 90 to 100 mol%. As a solvent constituting the adhesive liquid 3, water or the like can be generally exemplified. Moreover, you may mix | blend other additives and catalysts, such as an acid, as needed.

  Further, as the constituent material of the adhesive liquid 3, an adhesive may be used. It does not specifically limit as an adhesive, A conventionally well-known various thing is employable.

  The viscosity of the adhesive liquid is preferably in the range of 1 to 1000 mPa · s, more preferably in the range of 1 to 100 mPa · s. Within the above range, there is an advantage that the effect of the present invention can be easily obtained because it easily flows out to the end of the protective film 2.

  Here, the liquid 6 is supplied from the both end sides of the protective film 2 toward the central portion in the width direction with respect to the adhesive liquid 3 that tends to flow toward both end sides of the protective film 2. The liquid 6 is supplied using a supply nozzle (liquid supply means) 5. The supply nozzles 5 are respectively disposed on the left and right sides of the protective film 2. This is because the polarizer 1 and the protective film 2 are arranged so as to be parallel to the horizontal direction, and the bonded portion is also almost horizontal, so that the excess adhesive liquid 3 flows in the left and right directions. It depends. However, when the polarizer 1 and the protective film 2 are disposed to be inclined to one side, or when a pair of rolls 4 (described later) are disposed to be inclined, a bonded portion is accordingly provided. Is also inclined, the adhesive liquid 3 flows to one side. Therefore, in such a case, it is sufficient to arrange the supply nozzle only on the downstream side of the adhesive liquid 3. By supplying the liquid 6, excess adhesive liquid 3 that tends to flow toward both ends of the protective film 2 is blocked within the range of the extra length portion 9, and leakage of the adhesive liquid 3 is prevented.

  The discharge amount and discharge pressure of the liquid 6 need to be kept within a range in which the flow of the adhesive liquid 3 can be suppressed. This is because if the discharge amount of the liquid 6 is larger than necessary, the adhesive liquid 3 is diluted and the adhesiveness is lowered. Further, the discharge direction of the liquid 6 is not limited to the direction toward the central portion in the width direction, and various changes can be made within a range in which the outflow of the adhesive liquid 3 can be stopped.

  Here, the supply nozzle 5 is provided such that the supply port 7 is positioned inward in the width direction from the left and right ends of the protective film 2, that is, in the formation region of the extra length portion 9. This prevents the liquid 6 from leaking out from the left and right sides of the protective film 2. Further, the liquid 6 is prevented from being supplied to the bonded portion, and the adhesive liquid 3 in the bonded portion is prevented from being diluted. As a result, a sufficient amount of the adhesive liquid 3 can be supplied at both ends of the polarizer 1, and the protective film 2 can be securely bonded and fixed at the ends of the polarizer 1. Enable.

  The liquid 6 is not particularly limited as long as it dissolves the adhesive. Specifically, for example, alcohols such as methanol, ethanol and propyl alcohol, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as methylene chloride and chloroform, etc. Examples of the organic solvent and water.

  In the manufacturing apparatus according to the present embodiment, as shown in FIG. 3, a suction nozzle (for removing excess adhesive liquid 3 that does not contribute to the bonding of the polarizer 1 and the protective film 2 by suction) (Suction means) 8 is provided. As a result, the optimal amount of adhesive liquid for bonding can be supplied to the entire surface reaching the left and right ends of the polarizer 1 without unevenness. As a result, there is no unevenness in in-plane adhesiveness. A uniform polarizing plate is obtained. More specifically, the suction nozzle 8 does not suck the excess adhesive liquid 3 itself, but sucks the adhesive liquid 3 diluted with the liquid 6. This is because, when the adhesive liquid 3 itself is sucked, smooth suction is hindered and the adhesive liquid 3 is eventually solidified to block the suction port 10.

  Here, the suction nozzle 8 is provided so that the suction port 10 is located within the range of the extra length portion 9. This is because suction is performed in a state where the adhesive liquid 3 is diluted with the liquid 6. Further, when the suction port 10 is provided inside the end portion of the polarizer 1, the adhesive liquid 3 is diluted with the liquid 6 at the end portion, so that at least the end portion is not sufficiently bonded to the protective film 2. Because it becomes. In addition, since the suction nozzle 8 is disposed separately from the supply nozzle 5, the structure can be simplified. Therefore, cleaning and care are facilitated.

  The shape of the opening portion of the suction port 10 is preferably flat in a predetermined direction. As such a shape of the opening portion, for example, as shown in FIGS. 4 (a) to 4 (j), an ellipse, a semicircle, a rectangle, a rectangle in which corners are chamfered, a flat rhombus, Various shapes such as a flat cloud shape can be exemplified. Moreover, it is preferable to arrange | position the suction port 10 so that the flat direction of an opening part may become substantially parallel to the width direction. Thereby, the suction port 10 can be brought close to the bonded portion of the polarizer 1 and the protective film 2, and the excess adhesive liquid 13 and liquid 6 can be efficiently sucked and removed.

  Next, the polarizer 1 and the protective film 2 are continuously guided between a pair of rolls (bonding means) 4 while being superposed. Furthermore, the polarizer 1 and the protective film 2 that have passed between the rolls 4 are securely bonded and fixed by the roll pressure. Here, the roll 4 is not particularly limited, and various conventionally known rolls can be employed. However, in order to improve the appearance of the polarizing plate to be produced, a roll having high surface accuracy is preferable. Moreover, it does not specifically limit as a material of the roll 4, For example, a metal or rubber | gum etc. can be illustrated. In addition, as a bonding means, in addition to the roll 4, a flat pressure bonding means may be used.

  As shown in FIG. 5, the polarizing plate (film laminate) 21 according to the present embodiment obtained by the above method has a configuration in which the protective film 2 is laminated on both surfaces of the polarizer 1. Further, both end portions have a structure in which the protective films 2 are bonded to each other by the extra length portion 9.

  The polarizer 1 is manufactured by appropriately performing treatments such as swelling, dyeing, stretching, and crosslinking on a hydrophilic polymer. As the hydrophilic polymer, polyvinyl alcohol is generally used because of the good orientation of iodine or dichroic dye in the dyeing process, but is not particularly limited in the present invention. Specifically, for example, a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, a polyethylene terephthalate film, an ethylene vinyl acetate copolymer film, a polymer film such as a partially saponified film, a cellulose film, etc. Examples thereof include polyethylene-oriented films such as a dehydrated product of alcohol and a dehydrochlorination treatment of polyvinyl chloride.

  When the hydrophilic polymer is stretched, the total stretching ratio is preferably set in the range of 3 to 7 times, more preferably in the range of 4 to 6 times. This is because when the total draw ratio is less than 3 times, it is difficult to obtain a polarizing plate having a high degree of polarization, and when it exceeds 7 times, the film tends to be easily broken. Here, the hydrophilic polymer may be stretched gradually from 3 to 7 times in all steps such as swelling, dyeing, stretching, and crosslinking, and stretched only in any one step. Alternatively, it may be stretched a plurality of times in the same process.

  Further, the thickness of the polarizer 1 is not particularly limited. However, about 5 to 80 μm is common.

  As a material for forming the protective film 2, a polymer film excellent in transparency, mechanical strength, thermal stability, isotropy and the like is preferably used. Specifically, for example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, styrene polymers such as polystyrene and acrylonitrile / styrene copolymer (AS resin), cellulose polymers such as diacetyl cellulose and triacetyl cellulose, and polyethers. Examples include sulfone polymers, polycarbonate polymers, polyamide polymers, polyimide polymers, polyolefin polymers, and acrylic polymers such as polymethyl methacrylate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Examples include polymer blends. Other examples include acrylic, urethane-based, acrylic-urethane-based, epoxy-based, and silicone-based thermosetting or ultraviolet curable resins.

  Moreover, the polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a substitution in the side chain And / or a resin composition containing a non-substituted phenyl and a thermoplastic resin having a nitrile group. A specific example is a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used. Since these films have a small phase difference and a small photoelastic coefficient, problems such as unevenness due to the distortion of the polarizing plate can be eliminated, and since the moisture permeability is small, the humidification durability is excellent.

  As the protective film 2, a film having a phase difference as small as possible is better. In consideration of such viewpoints, polarization characteristics, durability, and the like, it is preferable to use a cellulosic polymer. Furthermore, among the cellulose polymers, triacetyl cellulose is preferable. Moreover, you may use the protective film 2 in which the surface is formed in the fine concavo-convex structure by containing microparticles | fine-particles.

Moreover, it is preferable that the thickness of the protective film 2 is 100 micrometers or less, and it is more preferable that it is 60 micrometers or less. For example, in the case of a thin polarizing plate, triacetyl cellulose (TAC) having a thickness of about 40 μm can be used. In this case, it is known that the curl suppressing effect of the present invention is higher than that of a normal polarizing plate (TAC having a thickness of 80 μm). This is because it is considered that the total thickness (thickness of the polarizing plate) is thin and less susceptible to curling due to fluctuations in moisture of the polarizing plate. The moisture permeability of the protective film 2 is preferably in the range of 400 to 1000 g / m ² 4h. Even if the moisture permeability is out of the above range, the effect of suppressing curling of the present invention is high when a polarizing plate having a protective film having a relatively high moisture permeability is used. The moisture permeability is the number of g of water vapor passing through a sample of 1 m ² in 24 hours with a relative humidity difference of 40 ° C. and 90% according to a moisture permeability test (cup method) of JIS Z0208.

  Moreover, each protective film 2 provided on both surfaces of the polarizer 1 may be formed of the same polymer material, or may be formed of different polymer materials.

  Further, when the protective film 2 is bonded only to one surface of the polarizer 1 and not bonded to the other surface, a process of forming a hard coat layer on the other surface, antireflection treatment, anti-sticking, A treatment for the purpose of diffusion or antiglare may be performed.

  The hard coat treatment is performed for the purpose of preventing scratches on the polarizing plate surface. For example, it can be formed by a method of adding a cured film excellent in hardness, slipping property, etc. with an appropriate ultraviolet curable resin such as acrylic or silicone to the surface of the protective film 2. The antireflection treatment is performed for the purpose of preventing reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. Further, the anti-sticking treatment is performed for the purpose of preventing adhesion with an adjacent layer.

  The anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing plate and hindering the viewing of the light transmitted through the polarizing plate. For example, it can be formed by imparting a fine concavo-convex structure to the surface of the protective film 2 by an appropriate method such as a roughening method by a sandblasting method or an embossing method or a blending method of transparent fine particles. Examples of the fine particles to be included in the formation of the surface fine concavo-convex structure include conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like having an average particle diameter of 0.5 to 20 μm. In some cases, transparent fine particles such as inorganic fine particles, organic fine particles made of a crosslinked or uncrosslinked polymer, and the like are used. When forming the surface fine uneven structure, the amount of fine particles used is generally about 2 to 70 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the transparent resin forming the surface fine uneven structure. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

  The antireflection layer, antisticking layer, hard coat layer, diffusion layer, antiglare layer, and the like can be provided on the protective film 2 itself, and are provided separately from the protective film 2 as an optical function layer. You can also

  The polarizing plate 21 according to the present embodiment can also be used as an optical film (not shown) in which an optical functional layer is laminated depending on the application.

  There is no limitation in particular about the said optical function layer. For example, when an optical functional layer is bonded to the polarizing plate 21 via an adhesive layer, a retardation film (including a 1/2 or 1/4 wavelength film) can be exemplified. These films can use one layer or two or more layers as required. For example, a retardation film can be laminated on the polarizing plate 21 of the present invention and used as an elliptically polarizing plate or a circularly polarizing plate.

  Moreover, when using a viewing angle expansion film as an optical function layer, the polarizing plate of a wide viewing angle is obtained by laminating | stacking on the polarizer 1 through an adhesive layer, for example.

  The reflective polarizing plate is obtained by providing a reflective layer on the polarizing plate 21 and is applied to a reflective liquid crystal display device that reflects and displays incident light from the viewing side (display side). The reflective polarizing plate can be formed by an appropriate method such as attaching a reflective layer made of metal or the like to the protective film 2 on the side opposite to the side on which the birefringent layer is laminated. For example, the foil or vapor deposition film which consists of reflective metals, such as aluminum, is attached to one side of the protective film etc. which carried out the mat | matte treatment as needed. Moreover, what attached the metal reflective layer by appropriate methods, such as a vapor deposition system and a plating system, on the surface fine concavo-convex structure by fine particle content of the said protective film 2 etc. are mentioned. The reflective layer having the fine concavo-convex structure has the advantage that incident light can be diffused by irregular reflection to prevent reflection and irregular reflection, and to suppress uneven brightness. Moreover, the protective film 2 containing fine particles also has an advantage that incident light and its reflected light are diffused when passing through it and light and dark unevenness can be further suppressed. The reflective layer having a fine concavo-convex structure reflecting the surface fine concavo-convex structure of the protective film 2 is used to protect the metal by an appropriate method such as a vapor deposition method such as a vacuum deposition method, an ion plating method, a sputtering method, or a plating method It can be performed by a method of attaching directly to the surface of the film 2 or the like.

  In addition, the reflective polarizing plate may be used as a reflective sheet in which a reflective layer is provided on an appropriate film according to the protective film 2 instead of directly forming the reflective polarizing plate 21 on the protective film 2. it can. In addition, since a reflective layer is normally made of metal, a usage pattern in which the reflective surface is covered with a protective film 2, a polarizing plate, or the like prevents a decrease in reflectance due to oxidation. Furthermore, it is possible to maintain the initial reflectance over a long period of time and to separately laminate the protective film 2 on the reflective layer.

  The transflective polarizing plate can be obtained by using a transflective reflective layer such as a half mirror that reflects and transmits light with the reflective layer. The transflective polarizing plate is usually provided on the back side of the liquid crystal cell. When a transflective liquid crystal display device equipped with such a transflective polarizing plate is used in a bright environment, external light incident from the viewing side (display surface side) is used as display light and used in a dark environment. In that case, light from a backlight or the like is used as display light. Therefore, power consumption can be reduced.

  An elliptically polarizing plate or a circularly polarizing plate in which a retardation film is further laminated on the polarizing plate 21 will be described. As a method of laminating the retardation film on the polarizing plate 21, it is laminated on the polarizing plate 21 via an adhesive layer, or a new adhesive layer is formed on the surface from which the protective film 2 is peeled off, or the protective film is laminated. For example, a method in which layers 2 are adhered and laminated without or without providing an adhesive layer is appropriately used. A retardation film or the like is used when changing linearly polarized light into elliptically polarized light or circularly polarized light, changing elliptically polarized light or circularly polarized light into linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called ¼ wavelength film (also referred to as a λ / 4 plate) is used as a retardation film that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A half-wave film (also referred to as a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

  The elliptically polarizing plate compensates (prevents) coloring (blue or yellow) caused by birefringence of the liquid crystal layer of a liquid crystal display device in STN (Super Twisted Nematic) mode, for example, when displaying black and white without the coloring. Used effectively. Furthermore, the one having a controlled three-dimensional refractive index is preferable because it can compensate (prevent) coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device in which an image is displayed in color, and also has an antireflection function. Specific examples of the retardation film include a birefringent film obtained by stretching a film made of an appropriate polymer such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene, other polyolefins, polyarylate, and polyamide. And an alignment film of a liquid crystal polymer, and a liquid crystal polymer alignment layer supported by a film. The retardation film may have an appropriate retardation according to the purpose of use, such as those for the purpose of compensating for coloration, viewing angle, etc. due to birefringence of various wavelength films and liquid crystal layers, for example. What laminated | stacked retardation film and controlled optical characteristics, such as retardation, may be used.

  The elliptically polarizing plate and the reflective elliptical polarizing plate are obtained by laminating the polarizing plate 21 or the reflective polarizing plate and a retardation film in an appropriate combination. Such an elliptically polarizing plate or the like can also be formed by sequentially laminating them sequentially in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflection type) polarizing plate and a retardation film. An optical film such as a polarizing plate has an advantage that it can improve the production efficiency of a liquid crystal display device and the like because of excellent quality stability and lamination workability.

  The polarizing plate obtained by bonding the polarizing plate 21 and the brightness enhancement film is usually provided on the back side of the liquid crystal cell. The brightness enhancement film reflects a linearly polarized light with a predetermined polarization axis or a circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display device or reflection from the back side, and transmits other light. is there. The polarizing plate in which the brightness enhancement film is laminated on the polarizing plate 21 allows light from a light source such as a backlight to enter to obtain transmitted light in a predetermined polarization state, and reflects light without transmitting the light other than the predetermined polarization state. . Further, the light reflected on the surface of the brightness enhancement film is further inverted through a reflective layer or the like provided on the rear side thereof and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light having a predetermined polarization state. Thus, the luminance can be improved by increasing the amount of light transmitted through the luminance enhancement film and increasing the amount of light that can be used for liquid crystal image display or the like by supplying polarized light that is difficult to be absorbed by the polarizer 1. For example, when light is incident through the polarizer 1 from the back side of the liquid crystal cell by using a backlight or the like without using a brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer 1 is It is almost absorbed by the polarizer 1 and does not pass through the polarizer 1. Specifically, although depending on the characteristics of the polarizer 1 used, approximately 50% of the light is absorbed by the polarizer 1, and the amount of light that can be used for liquid crystal image display or the like is reduced accordingly. Becomes darker. The brightness enhancement film allows light having a polarization direction that is absorbed by the polarizer 1 to be reflected once by the brightness enhancement film without being incident on the polarizer 1, and further through a reflection layer or the like provided on the rear side thereof. Inverting and re-entering the brightness enhancement film is repeated, and only the polarized light whose polarization direction is such that the polarization direction of the light reflected and inverted between the two passes through the polarizer 1 is obtained. Is transmitted and supplied to the polarizer 1. Thereby, light, such as a backlight, can be efficiently used for image display of the liquid crystal display device, and the display screen can be brightened.

  A diffusion plate may be provided between the brightness enhancement film and the reflection layer. The light in the polarization state reflected by the brightness enhancement film travels to the reflection layer or the like, but the installed diffusion plate uniformly diffuses the light passing therethrough and simultaneously cancels the polarization state and becomes a non-polarization state. That is, the diffuser plate returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the natural light state is directed toward the reflection layer and the like, reflected through the reflection layer and the like, and again passes through the diffusion plate and reenters the brightness enhancement film. In this way, by providing a diffuser plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., while maintaining the brightness of the display screen, the display screen display unevenness is reduced and uniform. Can provide a bright screen. By providing such a diffusion plate, the first incident light has a moderate number of reflection repetitions, and a uniform and bright display screen is possible in combination with the diffusion function of the diffusion plate.

  The brightness enhancement film has a characteristic of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of dielectrics or a multilayer laminate of thin film films having different refractive index anisotropies. As shown in the figure, the cholesteric liquid crystal polymer alignment film and the alignment liquid crystal layer supported on the film substrate reflect either left-handed or right-handed circularly polarized light and transmit other light. Appropriate ones such as those shown can be used.

  Therefore, the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis described above is efficient while suppressing the absorption loss due to the polarization plate 21 by allowing the transmitted light to enter the polarization plate 21 with the polarization axis aligned. Can penetrate well. On the other hand, a brightness enhancement film of a type that transmits circularly polarized light, such as a cholesteric liquid crystal layer, can be incident on the polarizer 1 as it is. Furthermore, when it is desired to suppress the absorption loss, it is preferable that the circularly polarized light is linearly polarized through a retardation plate and incident on the polarizing plate 21. Note that circularly polarized light can be converted to linearly polarized light by using a quarter wave plate as the retardation plate.

  A retardation film that functions as a quarter-wave film in a wide wavelength range such as a visible light region exhibits, for example, a retardation layer that functions as a quarter-wave film for light-color light having a wavelength of 550 nm and other retardation characteristics. It is obtained by a method of superposing a retardation layer, for example, a retardation layer functioning as a half-wave film.

  In addition, the cholesteric liquid crystal layer can also be obtained by reflecting circularly polarized light in a wide wavelength range such as the visible light region by combining two or more layers with different reflection wavelengths and having an overlapping structure. Can do. As a result, transmitted circularly polarized light in a wide wavelength range can be obtained.

  Further, the polarizing plate 21 may be formed by laminating the polarizing plate 21 and two or three or more optical function layers, like the above-described polarization separation type polarizing plate. Therefore, a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate in which the above-mentioned reflective polarizing plate or transflective polarizing plate and a retardation film are combined may be used.

  The polarizing plate 21 according to the present invention and the optical film including the polarizing plate 21 can be applied to various image display devices such as a liquid crystal display device and an electroluminescence (EL) display device.

  For example, when applied to a transmissive liquid crystal display device, the liquid crystal display device is configured by providing a liquid crystal cell between a pair of transmissive polarizing plates (or optical films). The transmissive polarizing plate and the liquid crystal cell are bonded with a conventionally known pressure-sensitive adhesive or the like. The front polarizing plate on the display surface side and the rear polarizing plate on the back surface side of the liquid crystal cell may be the same type or different types. When manufacturing a liquid crystal display device, for example, a single layer or an appropriate part such as a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, or a backlight is placed in an appropriate position. Two or more layers can be arranged.

  As a display mode of the liquid crystal display device, a TN (Twisted Nematic) mode, an STN mode, a VA (Vertical Aligned) mode, an OCB (Optically Self-Compensated Birefringence) mode, or the like can be applied.

  The polarizing plate 21 or the optical film of the present invention can also be applied to an organic EL display device. In general, in an organic EL display device, a transparent electrode, an organic light emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light emitter (organic EL light emitter). Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Or, a structure having various combinations such as a laminate of an electron injection layer composed of such a light emitting layer and a perylene derivative, or a laminate of these hole injection layer, light emitting layer, and electron injection layer is known. ing.

  In organic EL display devices, holes and electrons are injected into the organic light-emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by recombination of these holes and electrons excites the fluorescent material. Then, light is emitted on the principle that the excited fluorescent material emits light when returning to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be predicted from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

  In the organic EL display device, it is sufficient that at least one of the electrodes has transparency in order to extract light emitted from the organic light emitting layer. Usually, a transparent electrode formed of indium tin oxide (ITO) or the like is used as the anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually metal electrodes such as Mg—Ag and Al—Li are used.

  In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident from the surface of the transparent substrate at the time of non-light emission, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is again emitted to the surface side of the transparent substrate. The display surface of the organic EL display device looks like a mirror surface.

  In an organic EL display device comprising an organic electroluminescent light emitting device comprising a transparent electrode on the surface side of an organic light emitting layer that emits light upon application of a voltage and a metal electrode on the back side of the organic light emitting layer, the surface of the transparent electrode While providing the polarizing plate 21 on the side, a retardation film can be provided between the transparent electrode and the polarizing plate 21.

  Since the retardation film and the polarizing plate 21 have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization function. In particular, if the retardation film is composed of a ¼ wavelength film and the angle formed by the polarization direction of the polarizing plate 21 and the retardation film is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. it can.

  That is, only the linearly polarized light component of the external light incident on the organic EL display device is transmitted by the polarizing plate 21. This linearly polarized light is generally elliptically polarized light by the retardation film. In particular, when the retardation film is a ¼ wavelength film and the angle between the polarizing directions of the polarizing plate 21 and the retardation film is π / 4, circular polarization is obtained.

  This circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, is again transmitted through the organic thin film, the transparent electrode, and the transparent substrate, and becomes linearly polarized light again on the retardation film. Since this linearly polarized light is orthogonal to the polarization direction of the polarizing plate 21, it cannot be transmitted through the polarizing plate 21. As a result, the mirror surface of the metal electrode can be completely shielded.

(Other matters)
In the above description, the most preferred embodiment of the present invention has been described. However, the present invention is not limited to this embodiment, and various modifications can be made within the scope substantially the same as the technical idea described in the claims of the present invention.

  That is, in the present embodiment, as shown in FIGS. 1 to 3, the mode in which one supply nozzle 5 and one suction nozzle 8 are arranged on each of the left and right sides has been described. However, in the present invention, the number of supply nozzles 5 and suction nozzles 8 is not limited to this. For example, two or more plural films may be disposed on the left and right sides of the protective film 2.

It is a perspective view for demonstrating the manufacturing method of the polarizing plate which concerns on one Embodiment of this invention. It is a side view for demonstrating the manufacturing method of the said polarizing plate. It is the enlarged view to which the principal part of the said FIG. 2 was expanded. It is a schematic diagram which shows the shape of the opening part of a suction opening in the suction nozzle which concerns on the manufacturing apparatus of the said polarizing plate. It is a cross-sectional schematic diagram which shows schematically the polarizing plate which concerns on one Embodiment of this invention.

Explanation of symbols

1 Polarizer (film)
2 Protective film (other films)
3 Adhesive liquid (adhesive liquid)
4 rolls (bonding means)
5 Supply nozzle (liquid supply means)
6 Liquid 7 Supply port 8 Suction nozzle (suction means)
9 Extra length 10 Suction port 11 Adhesive liquid supply nozzle (adhesive liquid supply means)
13 Adhesive liquid (adhesive liquid)
21 Polarizing plate (film laminate)
22 Protective film (other films)

Claims (6)

A method for producing a film laminate in which another film is provided on at least one surface of the film,
On at least one surface of the film, another film having a larger width than the film and having an extra length in the width direction is arranged.
The adhesive liquid is supplied to the bonding portion between the film and the other film, and a liquid that resists the adhesive liquid that tends to flow toward at least one end of the film is within the range of the extra length portion. While sucking and removing the adhesive liquid diluted with the liquid, which is supplied from at least one end of the film and is about to flow out toward at least one end of the film, within the formation range of the extra length portion ,
A method for producing a film laminate, wherein the film and another film are bonded together by pressure bonding. As the liquid, the film production method of the laminate according to claim 1, characterized in that use those dissolving the adhesive fluid. Using a polarizer as the film, and the film production method of the laminate according to claim 1 or 2, characterized by using the protective film as the other film. An apparatus for producing a film laminate used for producing a film laminate in which at least one surface of the film is provided with another film having a width larger than the film and having an extra length in the width direction ,
An adhesive liquid supply means for supplying an adhesive liquid to a bonding portion between the film and another film disposed on at least one surface of the film;
Liquid supply means for supplying a liquid that resists the adhesive liquid that is about to flow out from the center of the film toward at least one end from at least one end of the film , wherein the liquid supply port has the extra length Provided within the formation range of the part ,
A suction means for sucking and removing the adhesive liquid diluted with the liquid, which is about to flow out toward at least one end of the film, within the formation range of the extra length portion, the suction port of the extra length Provided within the formation range of the part,
An apparatus for producing a film laminate, comprising a laminating means for laminating the film and another film by pressure bonding. The opening portion of the suction port is flattened in a predetermined direction, and the suction portion is provided so that the flattening direction of the opening portion and the width direction of the film are substantially parallel to each other. Item 5. The apparatus for producing a film laminate according to Item 4 . The apparatus for producing a film laminate according to claim 4 or 5 , wherein a polarizer is used as the film, and a protective film is used as the other film.

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