TW202118638A - Method for producing multilayer polarizing film - Google Patents

Abstract

The present invention comprises: an adhesive application step wherein an adhesive is applied to a protective film with use of a coating roll; and a stacking step wherein a polarizer and the protective film, to which the adhesive has been applied, are bonded with each other through a nip roll. The protective film is at a temperature within the range of from 20 DEG C to 35 DEG C at the outlet side of the coating roll in the adhesive application step; and the protective film is at a temperature within the range of from 20 DEG C to 35 DEG C at the outlet side of the nip roll in the stacking step.

Description

Manufacturing method of laminated polarizing film

The present invention relates to a method for manufacturing a laminated polarizing film by bonding a polarizer and a protective film through an adhesive.

In the past, the constituent materials of liquid crystal display devices, polarized sunglasses, and the like have used laminated polarizing films containing polarizers. The foregoing laminated polarizing film is, for example, a film containing a polarizing member dyed with a dichroic substance such as iodine and a protective film for protecting the polarizing member. The laminated polarizing film can be obtained, for example, as described in Patent Documents 1 and 2 by bonding a protective film to one or both sides of a polarizer with a specific adhesive. Specifically, Patent Documents 1 and 2 disclose that a polyvinyl alcohol-based resin film is dyed with an iodine solution while being stretched and washed with water to produce a polarizing member, and a protective film is attached to the polarizing member through an adhesive. Thus, a multilayer polarizing film is produced. Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2014-129505 Patent Document 2: Japanese Patent Laid-Open No. 2018-127610

The problem to be solved by the invention However, after the protective film is coated with an adhesive, when the protective film of the adhesive is attached to the polarizing member, the adhesive may excessively infiltrate the protective film. In this case, the adhesive will not harden well. Fear of partial peeling between the layers of the adhesive. In addition, if the adhesive does not soak into the protective film, the adhesive cannot be well adhered to the protective film, and there is a fear of partial peeling between the layers of the adhesive.

The object of the present invention is to provide a method for manufacturing a laminated polarizing film, which is capable of adhering a polarizer and a protective film well through an adhesive.

Means to solve the problem The manufacturing method of the laminated polarizing film of the present invention has: an adhesive coating step, which uses a coating roller to apply the adhesive to the protective film; and, the lamination step, which passes the protective film coated with the adhesive and the polarizer through the sandwich Laminating with a roller; the protective film on the delivery side of the coating roller in the adhesive application step is set in the range of 20°C to 35°C, and the protective film on the delivery side of the nip roller in the lamination step It is set to the range of 20℃~35℃.

In the ideal manufacturing method of the present invention, the protective film is a transparent film having a surface that is easily adhered to the adhesive. In the ideal manufacturing method of the present invention, the protective film is a cellulose triacetate film. The ideal manufacturing method of the present invention is a film with a urethane-based easy-adhesive agent. The ideal manufacturing method of the present invention is an acrylic film with a urethane-based easy-adhesive agent. In the ideal manufacturing method of the present invention, the aforementioned adhesive is an active energy ray curable adhesive. The ideal manufacturing method of the present invention is to coat the aforementioned adhesive with a thickness of 0.1 µm~5 µm on the aforementioned protective film. The ideal manufacturing method of the present invention is that after the protective film is coated with the adhesive, the polarizer is attached to the protective film within 2 to 30 seconds. The ideal manufacturing method of the present invention is to maintain the protective film between the delivery side of the coating roller and the delivery side of the nip roller in the range of 20°C to 35°C.

Invention effect According to the manufacturing method of the present invention, it is possible to manufacture a laminated polarizing film in which the polarizer and the protective film are well bonded through the adhesive.

The form used to implement the invention In this manual, the numerical range shown in "lower limit X to upper limit Y" means that the lower limit X is higher than the upper limit Y and the upper limit Y is lower. When multiple numbers of the aforementioned numerical ranges are individually recorded, any lower limit value and any upper limit value can be selected to set "arbitrary lower limit value ~ arbitrary upper limit value". Each figure is for reference. Please note that the size, scale and shape of the components shown in each figure are sometimes different from the actual objects.

[Laminated Polarizing Film] The laminated polarizing film obtained by the manufacturing method of the present invention has a polarizing member and a protective film attached to at least one side of the polarizing member using an adhesive layer. 1 to 3 show several structural examples of the laminated polarizing film 1 that can be obtained by the manufacturing method of the present invention. In FIG. 1, a laminated polarizing film 1 according to an embodiment of the present invention has a first protective film 12, an adhesive layer 31, a polarizer 11, an adhesive layer 32 and a second protective film 13 laminated in this order. In FIG. 2, the laminated polarizing film 1 of another embodiment of the present invention has a protective film 12, an adhesive layer 31, a polarizing member 11, an adhesive layer 33 and an optional optical film 14 laminated in this order. In FIG. 3, the laminated polarizing film 1 of another embodiment of the present invention is sequentially laminated with a first protective film 12, an adhesive layer 31, a polarizer 11, an adhesive layer 32, a second protective film 13, and an adhesive layer 34. And any optical film 14. However, the laminated polarizing film of the present invention is not limited to the configuration examples shown in FIGS. 1 to 3, and can be appropriately changed. For example, one or more arbitrary other optical films may be further laminated on the laminated polarizing film of each of the above-mentioned structural examples.

＜Polarizers＞ The polarizer refers to an optical element that only transmits light that vibrates in a specific direction (polarized light) and can shield light that vibrates in directions other than the specific direction. The polarizer of the present invention is a soft film shape. Specifically, the polarizer of the present invention is manufactured by the wet process described later. The aforementioned polarizer is composed of a hydrophilic polymer film dyed with a dichroic substance and stretched (for example, a polyvinyl alcohol-based film dyed with a dichroic substance and stretched, etc.).

＜Protective film＞ The protective film is a film provided to protect the polarizer. A colorless and transparent film can be used as the protective film. Colorless and transparent protective films such as cellulose triacetate film (TAC film), acrylic film (film using acrylic polymer), polyethylene terephthalate film, cyclic or norbornene structure can be used Polyolefin film, etc. The protective film is preferably a transparent film having a surface that is easy to bond to an adhesive (especially an active energy ray curable adhesive described later). The aforementioned transparent film with an easily adhesive surface is easy to mix with or penetrate the adhesive on its surface. The transparent film with a surface that is easy to bond to the adhesive includes the following: (a) the film itself is a film formed of a material that has easy bonding to the adhesive, (b) the film itself is to have The adhesive is formed of an easy-adhesive material, and an easy-adhesive film has been applied to the surface of the film. (c) Although the film itself is formed of a material that is difficult to adhere to the adhesive, it has been applied to the surface of the film A film that is easy to bond. The transparent film of (a) mentioned above may be a TAC film or an acrylic film. The transparent film of (b) or (c) mentioned above can be exemplified by any transparent film coated with an easy-adhesive agent on at least one side (protective film with easy-adhesive agent), and a film coated with an easy-adhesive composition (attached) Easy-to-bond film) and so on. The easy-adhesive agent is not particularly limited, and it is preferable to use an easy-adhesive agent containing a urethane-based resin from the viewpoint of excellent adhesion to an active energy ray-curable adhesive. As the easy-adhesion composition is described later, an easy-adhesion composition that can be applied to a polarizing member and the like can be mentioned.

＜Optical film＞ Conventionally well-known materials can be used for arbitrary optical films, for example, a retardation film, an anti-glare film, a brightness enhancement film, a viewing angle improvement film, a transparent conductive film, etc. are mentioned.

＜Adhesive layer＞ The adhesive layer is a cured layer of the adhesive, and is a layer that exists between the two films to bond the two films. 1 to 3, the adhesive layers 31 and 32 of the polarizer 11 and the protective film 12, the adhesive layer 33 of the polarizer 11 and the optical film 14, and the adhesive layer 34 of the protective film 13 and the optical film 14 Each is not particularly limited, and it can be composed of a conventionally known adhesive. Examples of the aforementioned adhesive include solvent-volatile adhesives, two-component reaction type adhesives, active energy ray hardening type adhesives, and the like. Preferably, an active energy ray hardening type adhesive can be used. The active energy ray-curable adhesive is preferably used at least when bonding the polarizer and the protective film. For example, in the case of the laminated polarizing films 1 shown in FIGS. 1 and 3, the adhesive layers 31 and 32 are preferably composed of active energy ray-curable adhesives. In the case of the laminated polarizing film 1 of FIG. 2, the adhesive layer 31 is preferably composed of an active energy ray curable adhesive. The adhesive layers 33 and 34 may be composed of an active energy ray-curable adhesive, or may be composed of other adhesives, and are preferably composed of an active energy ray-curable adhesive. The active energy ray-curable adhesive will be described in detail later.

[Manufacturing equipment for polarizers and manufacturing equipment for laminated polarizing films] The manufacturing device of the polarizing element of the present invention has: a wet processing device, which uses a dyeing treatment solution to dye a long strip-shaped hydrophilic polymer film while stretching, thereby manufacturing a strip-shaped polarizing element; and a drying device , The polarizer obtained by using the aforementioned wet processing device is dried. In addition, the manufacturing device of the laminated polarizing film of the present invention has: a wet processing device, which uses a dyeing treatment solution to dye the long strip-shaped hydrophilic polymer film while stretching, thereby manufacturing a long strip-shaped polarizer; The drying device is to dry the polarizer obtained by the wet processing device; and the laminating device is to bond the polarizer and the protective film.

The aforementioned manufacturing device of the polarizer uses a wet processing device to manufacture a long strip-shaped polarizer from a strip-shaped hydrophilic polymer film, and then uses a drying device to continuously dry the polarizer. That is, the wet processing device and the drying device are arranged on one manufacturing line. The manufacturing device of the aforementioned laminated polarizing film may be a form in which a protective film is continuously attached to the polarizer dried by the aforementioned manufacturing device of the polarizer using a laminating device. Alternatively, the manufacturing device of the aforementioned laminated polarizing film can also be in the form of temporarily winding the polarizer dried by the aforementioned manufacturing device of the polarizer into a roll shape and pulling out the roll-shaped polarizer, and then using a laminating device to attach the protective film . The former form is a form in which a series of steps from manufacturing a polarizer to a protective film to obtain a laminated polarizing film are carried out on a manufacturing line; while the latter form is a form in which the manufacturing of polarizers is carried out on a manufacturing line and will be The step of attaching a protective film to the polarizer to obtain a laminated polarizing film is performed on another manufacturing line. The manufacturing apparatus of the laminated polarizing film of the present invention is preferably in a form in which a series of steps from manufacturing a polarizer to following a protective film to obtain a laminated polarizing film are performed on one manufacturing line. In the manufacturing apparatus of the laminated polarizing film of the above-mentioned form, the manufacturing apparatus and the laminating apparatus of the polarizing member having a wet processing device and a drying device are arranged on one manufacturing line.

FIG. 4 shows an example of the ideal configuration of the manufacturing apparatus 2 of the laminated polarizing film. 4, the manufacturing apparatus 2 of the laminated polarizing film has a wet processing apparatus 4, a drying apparatus 5, and a laminating apparatus 6 in this order from the upstream side. The aforementioned wet processing device 4 has a first roller portion 41, a conveying portion 42, and a processing portion. The first roller portion 41 is wound with a long strip of untreated hydrophilic polymer film 1a, and the conveying portion 42 is It is used to transport the aforementioned hydrophilic polymer film 1a. The aforementioned treatment part treats the untreated hydrophilic polymer film 1a with a dichroic substance so that the hydrophilic polymer film 1a becomes part of the polarizing member 1b. The aforementioned drying device 5 has a conveying unit 51 for conveying the long strip-shaped polarizer 1b, and a heating unit for applying heat to the polarizer 1b to dry the polarizer 1b. The aforementioned laminating device 6 has a conveying part 61, an adhesive application part 64, a bonding part 67, and a chamber 69. The conveying part 61 is used to convey the dried polarizer 1c and the protective film 12. The chamber 69 The adhesive application part 64 and the bonding part 67 are surrounded.

＜Wet processing equipment＞ The wet processing device 4 includes a processing unit that dyes the long strip-shaped hydrophilic polymer film 1a and stretches it with a dyeing processing solution. The wet treatment includes a process of causing a plurality of treatment liquids including a dyeing treatment liquid to act on the hydrophilic polymer film 1a while simultaneously extending the hydrophilic polymer film 1a. The wet processing device is known in the past, and the wet processing device 4 of the present invention may also adopt a conventionally known structure. The aforementioned treatment section has, for example, a swelling treatment tank 4A, a dyeing treatment tank 4B, a cross-linking treatment tank 4C, an elongation treatment tank 4D, and a washing treatment tank 4E in this order from the upstream side. The conveying section 42 of the wet processing device 4 has a plurality of guide rollers and the like, and draws out the long strip-shaped hydrophilic polymer film 1a wound on the first roller section 41 and conveys it to the aforementioned processing section. The blank arrow in Fig. 4 indicates the traveling direction (conveying direction) of the film being conveyed.

The hydrophilic polymer film 1a has a long strip shape. In this specification, the long strip shape refers to a rectangular shape in which the length in the longitudinal direction is much larger than the length in the width direction (the width direction is the direction orthogonal to the longitudinal direction). The length in the longitudinal direction of the long strip shape is, for example, 10 m or more, and preferably 50 m or more. The aforementioned hydrophilic polymer film 1a is not particularly limited, and conventionally known films can be used. Specifically, the hydrophilic polymer film 1a includes, for example, polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, polyethylene terephthalate (PET) films, and ethylene-vinyl acetate copolymers. System films, such partially saponified films, etc. Furthermore, in addition to these, polyene-oriented films such as dehydrated PVA or dehydrochloric acid-treated polyvinyl chloride, and stretch-oriented polyethylene-based films can also be used. Among them, in view of the good dyeability due to the dichroic substance, the PVA-based polymer film is preferred. The raw material polymer of the aforementioned PVA-based polymer film can include, for example, a polymer that is saponified after polymerization of vinyl acetate, and copolymerizable monomers such as unsaturated carboxylic acid or unsaturated sulfonic acid in a small amount relative to vinyl acetate. Into polymers and so on. The degree of polymerization of the aforementioned PVA-based polymer is not particularly limited, but from the viewpoint of solubility in water, etc., it is preferably 500 to 10,000, and more preferably 1,000 to 6,000. In addition, the degree of saponification of the aforementioned PVA-based polymer is preferably 75 mol% or more, and more preferably 98 mol% to 100 mol%. The thickness of the untreated hydrophilic polymer film 1a is not particularly limited, and is, for example, 15 μm to 110 μm.

The swelling treatment tank 4A is a treatment tank containing a swelling treatment liquid. The swelling treatment liquid can swell the hydrophilic polymer film 1a. For the aforementioned swelling treatment liquid, for example, water can be used. In addition, an appropriate amount of iodine compounds such as glycerin or potassium iodide may be added to the water and the resulting water may be made into a swelling treatment liquid. When glycerin is added, its concentration is preferably 5% by weight or less, and when iodine compounds such as potassium iodide are added, its concentration is preferably 10% by weight or less.

The dyeing treatment tank 4B is a treatment tank containing a dyeing treatment liquid. The dyeing treatment liquid can dye the hydrophilic polymer film 1a. The aforementioned dyeing treatment solution may include a solution containing a dichroic substance as an active ingredient. Examples of dichroic substances include iodine and organic dyes. It is preferable to use a solution in which iodine has been dissolved in a solvent for the aforementioned dyeing treatment liquid. Water is generally used as the aforementioned solvent, and an organic solvent compatible with water can also be added. The concentration of iodine in the dyeing treatment solution is not particularly limited, and is preferably 0.01% by weight to 10% by weight, and is preferably in the range of 0.02% by weight to 7% by weight, more preferably 0.025% by weight to 5% by weight. In order to further improve the dyeing efficiency, an iodine compound can also be added to the dyeing treatment solution as required. Iodine compounds are compounds containing iodine and elements other than iodine in the molecule. Examples include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, and iodine. Calcium fluoride, tin iodide, titanium iodide, etc.

The cross-linking treatment tank 4C is a treatment tank containing a cross-linking treatment liquid. The crosslinking treatment liquid can crosslink the dyed hydrophilic polymer film 1a. The aforementioned crosslinking treatment liquid may use a solution containing a boron compound as an active ingredient. For example, as the crosslinking treatment liquid, a solution obtained by dissolving a boron compound in a solvent can be used. Water is generally used as the aforementioned solvent, and an organic solvent compatible with water can also be added. Examples of boron compounds include boric acid and borax. The concentration of the boron compound in the cross-linking treatment solution is not particularly limited, and is preferably 1% to 10% by weight, preferably 2% to 7% by weight, more preferably 2% to 6% by weight. In addition, from the viewpoint of obtaining a polarizer with uniform optical characteristics, an iodine compound may be added to the aforementioned cross-linking treatment liquid as required.

The extension treatment tank 4D is a treatment tank containing an extension treatment liquid. The extension treatment liquid is not particularly limited, and, for example, a solution containing a boron compound as an active ingredient can be used. As the extension treatment liquid, for example, a solution in which a boron compound and various metal salts, zinc compounds, etc. are dissolved in a solvent can be used as required. Water is generally used as the aforementioned solvent, and an organic solvent compatible with water can also be added. The concentration of the boron compound in the extension treatment solution is not particularly limited, and is preferably 1% by weight to 10% by weight, and more preferably 2% by weight to 7% by weight. From the viewpoint of inhibiting the elution of iodine adsorbed on the film, an iodine compound can also be added to the aforementioned stretching treatment solution as required.

The washing treatment tank 4E is a treatment tank containing a washing treatment liquid. The washing treatment liquid can wash the stretched hydrophilic polymer film 1a. The washing treatment liquid is a treatment liquid for washing treatment liquids such as a dyeing treatment liquid or a cross-linking treatment liquid attached to the hydrophilic polymer film 1a. The aforementioned washing treatment liquid can typically use water such as ion-exchange water, distilled water, and pure water. In addition, in the example of the drawing, the processing section has a swelling treatment tank 4A, a dyeing treatment tank 4B, a cross-linking treatment tank 4C, an elongation treatment tank 4D, and a washing treatment tank 4E. On the condition that it has a dyeing treatment tank 4B, One or two treatment tanks can also be omitted. On the other hand, the aforementioned processing unit may further have an adjustment processing tank (not shown). The adjustment treatment tank contains a treatment tank for the adjustment treatment liquid. Although this adjustment treatment tank is not shown in FIG. 5, it can be installed between the aforementioned cross-linking treatment tank 4C and the stretching treatment tank 4D, or between the stretching treatment tank 4D and the washing treatment tank 4E. The aforementioned adjustment treatment liquid is a solution for adjusting the color of the film to be equal, and a solution containing an iodine compound as an active ingredient can be used.

＜Drying device＞ The drying device 5 is installed on the downstream side of the aforementioned wet processing device 4 and on the upstream side of the laminating device 6. In the illustrated example, the drying device 5 is installed on the downstream side of the washing treatment tank 4E. There can be one drying device 5, or two or more drying devices can be arranged side by side in the conveying direction of the polarizer. In the illustrated example, for example, one drying device 5 is installed on the transport path of the polarizer. The drying device 5 has a conveying portion 51 and a heating portion. The conveying portion 51 has a guide roller for conveying the long strip-shaped polarizer 1b manufactured by the wet processing device 4, and the heating portion uses the conveying portion 51 The polarizer 1b conveyed in the longitudinal direction (MD direction) is dried by applying heat. The heating unit has, for example, a chamber 52 and a heat source (not shown). The chamber 52 has a space 53 capable of conveying a polarizer inside. As the heat source, for example, warm wind can be used. The inner wall of the aforementioned chamber 52 is provided with a duct (not shown) for transmitting warm air. The air (warm air) heated by a heat source not shown is sent out into the space 53 of the chamber 52 through the aforementioned duct. The polarizer 1 b that enters the space 53 from the slit-shaped inlet on the upstream side of the chamber 52 is dried by a heat source, and then is transported to the outside of the chamber 52 from the slit-shaped outlet on the downstream side of the chamber 52.

＜Laminating device＞ The conveying unit 61 of the laminating device 6 has guide rollers and the like. The conveying part 61 conveys the long strip-shaped polarizer 1 c dried by the drying device 5 to the bonding part 67. In addition, the aforementioned conveying section 61 conveys the long strip-shaped protective film 12 and the like to the bonding section 67. The manufacturing apparatus 2 of the laminated polarizing film of the schematic example is capable of laminating the first protective film 12 and the second protective film 13 on the two areas of the polarizer 1c, respectively. According to this device, a laminated polarizing film 1 having a layer configuration of the first protective film 12/adhesive layer 31/polarizer 11/adhesive layer 32/second protective film 13 as shown in FIG. 1 can be obtained.

The manufacturing device 2 has a second roller portion 62 and a third roller portion 63. The second roller portion 62 is wound with a long strip-shaped first protective film 12, and the third roller portion 63 is wound with a long strip. Strip-shaped second protective film 13. The first protective film 12 of the second roller portion 62 and the second protective film 13 of the third roller portion 63 are independently transported by the transport portion 61 from the roller portions 62 and 63 to the bonding portion 67, respectively.

The adhesive application section 64 has an application roller 641. The application roller 641 of the adhesive application part 64 applies the adhesive to the film. The adhesive application part 64 is arranged on the upstream side of the bonding part 67. In the laminating device 6 of the illustrated example, the adhesive application portion 64 is respectively arranged on the one-sided side of the first protective film 12 and the one-sided side of the second protective film 13. The adhesive layer can be formed by applying an adhesive on one side of the first protective film 12 by one adhesive application portion 64, and the adhesive can be applied to the second protective film by the other adhesive application portion 64 The adhesive layer is formed on one side of the film 13. In addition, if necessary, the adhesive application portion may also be arranged on one side of the polarizer 1c and the other side of the polarizer 1c (not shown). When the adhesive application part (not shown) is provided, an adhesive can be applied to one side of the polarizer 1c and the other side of the polarizer 1c to form an adhesive layer. In addition, the adhesive application portions respectively arranged on one side of the polarizing member 1c and the other side of the polarizing member 1c can also be used to apply the easily bonding composition described later.

The adhesive application part 64 has, for example, a gravure roller 641 which is a coating roller, a container 642 storing the adhesive, and a doctor blade 643. In addition, a back roller can also be provided as required. The backing roller is arranged to face the gravure roller 641 while sandwiching the film. The gravure roller 641 is formed with a plurality of grooves (recesses into which the adhesive can be placed) on the surface. The gravure roller 641 rotates around its axis in such a way that its surface contacts the adhesive 65 stored in the container 642 (the direction of rotation of the gravure roller 641 is indicated by an arrow). With the rotation, the surface of the gravure roller 641 containing the grooves will adhere to the adhesive 65, and the excess adhesive 65 will be scraped by the doctor blade 643 into the container 642. When the gravure roller 641 with the adhesive in the groove is in contact with the film, the adhesive 65 in the groove is transferred to one side of the first protective film 12 and the second protective film 13. In this manner, the adhesive 65 is applied from the gravure roll 641 to the single side of the first protective film 12 and the second protective film 13 in a full-page form.

The adhesive for bonding the polarizer 1c to the first protective film 12 and the second protective film 13 is not particularly limited, but it is preferable to use an active energy ray curable adhesive as described above. As the active energy ray-curable adhesive, conventionally known materials can be used. Active energy ray curable adhesives generally include active energy ray curable components and polymerization initiators, and various additives may be included as required. The active energy ray curable components can be roughly classified into electron beam curable properties, ultraviolet curable properties, and visible light curable properties. In addition, the active energy ray curable component can be roughly classified into a radical polymerizable compound and a cation polymerizable compound from the viewpoint of the curing mechanism.

系化合物等。Examples of the radically polymerizable compound include compounds having a radically polymerizable functional group having carbon-carbon double bonds such as a (meth)acryloyl group and a vinyl group. In addition, either a monofunctional radical polymerizable compound or a bifunctional or more polyfunctional radical polymerizable compound can be used. Moreover, these radically polymerizable compounds can be used individually by 1 type or in combination of 2 or more types. The aforementioned radically polymerizable compound is preferably a compound having a (meth)acrylic acid group, and examples include (meth)acrylic acid amine derivatives having a (meth)acrylic acid group, and (meth)acrylic acid Base (meth)acrylate and so on. When a radical polymerizable compound is used as an active energy ray-curable adhesive, the polymerization initiator can be appropriately selected in accordance with the active energy ray. When the adhesive is cured by ultraviolet or visible light, a polymerization initiator that cracks by ultraviolet or visible light can be used. The polymerization initiator includes, for example, benzophenone-based compounds, aromatic ketone compounds, acetophenone-based compounds, aromatic ketal-based compounds, aromatic sulfochlorine-based compounds, and 9-oxysulfur 𠮿

Department of compounds and so on.

Examples of the cationically polymerizable compound include a monofunctional cationically polymerizable compound having one cationically polymerizable functional group in the molecule, and a multifunctional cationically polymerizable compound having two or more cationically polymerizable functional groups in the molecule. Examples of the cationically polymerizable functional group include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of the cationic polymerizable compound having an epoxy group include aliphatic epoxy compounds, alicyclic epoxy compounds, and aromatic epoxy compounds. The cationic polymerizable compound having an oxetanyl group includes 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methyl Oxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane and the like. Examples of the cationic polymerizable compound having a vinyl ether group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, and the like. When a cationic polymerizable compound is used as an active energy ray curable adhesive, a cationic polymerization initiator can be blended. The cationic polymerization initiator generates cationic species or Lewis acid by irradiating active energy rays such as visible rays, ultraviolet rays, and electron beams, and starts polymerization reaction with epoxy groups of the cationic polymerizable compound. As the cationic polymerization initiator, a photoacid generator and a photobase generator can be used.

As a preferable active energy ray-curable adhesive agent, for example, an adhesive agent having an SP value as shown below can be used. That is, a preferable active energy ray curable adhesive contains active energy ray curable compounds (A), (B), and (C) as curable components. Specifically, when the total amount of the adhesive is 100% by weight, the SP value of 0.0-15.0% by weight is 29.0 (MJ/m ³ ) ^1/2 to 32.0 (MJ/m ³ ) ^1/2 active energy ray hardening type Compound (A), 20.0 to 80.0% by weight SP value of 18.0 (MJ/m ³ ) ^1/2 or more and less than 21.0 (MJ/m ³ ) ^1/2 active energy ray hardening compound (B), and 10.0-80.0% by weight of the active energy ray hardening compound (C) with an SP value of 21.0 (MJ/m ³ ) ^1/2 to 26.0 (MJ/m ³ ) ^1/2. In addition, in the present invention, the "total amount of adhesive" means the total amount of various initiators or additives added to each active energy ray hardening compound.

Here, the algorithm of SP value (solubility parameter) in the present invention will be described below. (Algorithm of solubility parameter (SP value)) In the present invention, the solubility parameter (SP value) of the active energy ray hardening compound can use Fedors' algorithm [refer to "Polymer Engineering and Science (Polymer Eng. & Sci.)", Volume 14, No. 2 (1974) , Pages 148~154], that is, use the following mathematical formula (but Δei is attributed to the evaporation energy of the atom or group at 25°C, and Δvi is the molar volume at 25°C).

[Math 1]

The Δei and Δvi in the above mathematical formula show the fixed values assigned to the i atoms and groups in the main molecule, respectively. In addition, representative examples of the numerical values of Δe and Δv given to atoms or groups are listed in Table 1 below.

[Table 1]

Active energy ray curable compound (A) as long as it has a radical polymerizable group such as a (meth)acrylate group and has an SP value of 29.0 (MJ/m ³ ) ^1/2 ~ 32.0 (MJ/m ³ ) ^1/2 The compound can be used without restriction. Specific examples of the active energy ray hardening compound (A) include hydroxyethyl acrylamide (SP value 29.5), N-methylol acrylamide (SP value 31.5), and the like. In addition, in this specification, (meth)acrylate means an acrylate group and/or a methacrylate group.

Active energy ray curable compound (B) as long as it has a radical polymerizable group such as a (meth)acrylate group and has an SP value of 18.0 (MJ/m ³ ) ^1/2 or more and less than 21.0 (MJ/m ³ ) ^1/2 of the compound can be used without restriction. Specific examples of the active energy ray hardening compound (B) include tripropylene glycol diacrylate (SP value 19.0), 1,9-nonanediol diacrylate (SP value 19.2), tricyclodecane dimethanol diacrylate Ester (SP value 20.3), cyclic trimethylolpropane formal acrylate (SP value 19.1), dioxanediol diacrylate (SP value 19.4), EO modified diglycerol tetraacrylate (SP value 20.9) Wait. In addition, the active energy ray hardening type compound (B) can also be suitably used commercially available, for example, ARONIX M-220 (manufactured by Toagosei Co., Ltd., SP value 19.0), LIGHT ACRYLATE 1,9ND-A (Kyoeisha Chemical Co., Ltd.) Manufacture, SP value 19.2), LIGHT ACRYLATE DGE-4A (manufactured by Kyoeisha Chemical Co., SP value 20.9), LIGHT ACRYLATE DCP-A (manufactured by Kyoeisha Chemical Co., SP value 20.3), SR-531 (manufactured by Sartomer) , SP value 19.1), CD-536 (manufactured by SARTOMER, SP value 19.4) and so on.

Active energy ray curable compound (C) as long as it has a radical polymerizable group such as a (meth)acrylate group and has an SP value of 21.0 (MJ/m ³ ) ^1/2 to 26.0 (MJ/m ³ ) ^1/2 The compound can be used without restriction. Specific examples of the active energy ray hardening compound (C) include acrylomethrin (SP value 22.9), N-methoxymethacrylamide (SP value 22.9), N-ethoxymethyl Acrylic amide (SP value 22.3) and so on. In addition, the active energy ray hardening type compound (C) can also be suitably used commercially, and examples include ACMO (manufactured by Koto Co., Ltd., SP value 22.9), Wasmer 2MA (manufactured by Kasano Kosan Co., Ltd., SP value 22.9), and Wasmer EMA (Manufactured by Kasano Kosan Co., Ltd., SP value 22.3), Wasmer 3MA (manufactured by Kasano Kosan Co., Ltd., SP value 22.4), ARONIX M-5300 (manufactured by Toagosei Co., Ltd., SP value 23.4), etc.

Bing Xixi C _ae another group equivalent, in the present invention, the active energy ray curable adhesive of the represented by the following formula (X) if it is more than 140, curing shrinkage can be suppressed when the active energy ray curable adhesive is cured. Therefore, the adhesion with the polarizer can be improved, which is better. Formula (X): C _ae =1/Σ(W _N /N _ae ) In the aforementioned formula (X), W _N is the mass fraction of the active energy ray hardening compound N in the adhesive, and _Nae is the active energy ray The acryl equivalent of hardening compound N. In addition, in the present invention, when the acryl equivalent of the active energy ray-curable adhesive is more than a predetermined value, the reason why the adhesive force of the obtained adhesive layer can be improved can be inferred as follows.

The higher the acryl equivalent of the active energy ray curable adhesive, the higher the active energy ray is applied to the adhesive to cure it, it has the effect of suppressing volume shrinkage due to the formation of covalent bonds. Thereby, the stress remaining at the interface between the adhesive layer and the adherend can be relieved, and as a result, the adhesive force of the adhesive layer can be improved.

The Bing Xixi C _ae group equivalent of 155 or more preferred, more preferably 165 or more. In addition, in the present invention, the acryl equivalent is defined as follows. (Acrylic acid equivalent) = (Molecular weight of acrylic monomer)/(Number of (meth)acrylic acid monomers contained in 1 molecule of acrylic monomer)

In addition to active energy ray-curing compounds (A), (B) and (C) as curable components, active energy ray-curing adhesives may also contain acrylic oligomers formed by polymerization of (meth)acrylic monomers. Polymer (D). By containing component (D) in the active energy ray-curable adhesive, the volume shrinkage can be reduced when the adhesive is irradiated with active energy ray to harden, and the adhesion of the adhesive layer to the polarizer and transparent protective film can be reduced. The interface stress of the body. As a result, it is possible to suppress the deterioration of the adhesiveness between the adhesive layer and the adherend. In order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the adhesive preferably contains 3.0% by weight or more of the acrylic oligomer (D), and more preferably contains 5.0% by weight or more. On the other hand, if the content of the acrylic oligomer (D) in the adhesive is too large, the reaction rate when the adhesive is irradiated with active energy rays is drastically reduced, which may cause poor curing. Therefore, the content of the acrylic oligomer (D) in the adhesive is preferably 25% by weight or less, preferably 15% by weight or less.

Considering the workability and uniformity during coating, the active energy ray-curable adhesive is better with low viscosity, so the acrylic oligomer (D) formed by polymerization of (meth)acrylic monomer also has low viscosity Better. As an acrylic oligomer with low viscosity and capable of preventing the hardening and shrinkage of the adhesive layer, the weight average molecular weight (Mw) is preferably 15,000 or less, more preferably 10,000 or less, and particularly preferably 5,000 or less. On the other hand, in order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the weight average molecular weight (Mw) of the acrylic oligomer (D) is preferably 500 or more, more preferably 1000 or more, and particularly preferably 1500 or more. Specific examples of the (meth)acrylic monomer constituting the acrylic oligomer (D) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, Isopropyl (meth)acrylate, 2-methyl-2-nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylic acid Secondary butyl ester, tertiary butyl (meth)acrylate, n-pentyl (meth)acrylate, tertiary pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-dimethyl acrylate Butyl (meth)acrylate, n-hexyl (meth)acrylate, cetyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4- (Meth)acrylic acid (carbon number 1-20) alkyl esters such as methyl-2-propylpentyl (meth)acrylate and N-octadecyl (meth)acrylate; and, for example, cycloalkyl (Meth)acrylate (for example, cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, etc.), aralkyl (meth)acrylate (for example, benzyl (meth)acrylate, etc.), Polycyclic (meth)acrylates (e.g. 2-isobornyl (meth)acrylate, 2-norbornylmethyl (meth)acrylate, 5-norbornen-2-yl-methyl(methyl) )Acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, etc.), hydroxyl-containing (meth)acrylates (e.g. hydroxyethyl (meth)acrylate, (meth)acrylic acid) 2-hydroxypropyl ester, 2,3-dihydroxypropylmethyl-butyl (meth)methacrylate, etc.), (meth)acrylates containing alkoxy or phenoxy groups ((methyl) ) 2-methoxyethyl acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate Ester, ethyl carbitol (meth)acrylate, phenoxyethyl (meth)acrylate, etc.), epoxy group-containing (meth)acrylates (for example, glycidyl (meth)acrylate, etc.) ), halogen-containing (meth)acrylates (e.g. 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2-trifluoroethylethyl (meth)acrylate, (methyl) ) Tetrafluoropropyl acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptafluorodecyl (meth)acrylate, etc.), alkylamino (meth)acrylate Esters (for example, dimethylaminoethyl (meth)acrylate, etc.) and the like. These (meth)acrylates can be used individually or in combination of 2 or more types. Specific examples of the aforementioned acrylic oligomer (D) include "ARUFON" manufactured by Toagosei Co., Ltd., "ACTFLOW" manufactured by Soken Chemical Co., Ltd., and "JONCRYL" manufactured by BASF JAPAN.

The active energy ray hardening adhesive preferably contains a radical polymerization initiator (E) with hydrogen abstraction. With the aforementioned structure, the adhesion to the adherend can be significantly improved, especially even in a high-humidity environment or a non-dry state. This reason has not been clarified, but it can be presumed to be the following reason. If there is a radical polymerization initiator (E) with hydrogen abstraction in the active energy ray hardening type adhesive, the active energy ray hardening type compound is polymerized to form the base polymer constituting the adhesive layer while Free radicals are generated by abstracting hydrogen from active energy ray hardening compounds such as methylene groups. Then, the methylene group that generates free radicals will react with the hydroxyl group of the polarizing member such as PVA to form a covalent bond between the adhesive layer and the polarizing member. As a result, it can be inferred that even in a non-dried state, the adhesiveness of the adhesive layer will still be significantly improved.

系自由基聚合起始劑、二苯基酮系自由基聚合起始劑等。作為9-氧硫𠮿

系自由基聚合起始劑，可舉例如下述通式(1)所示化合物。In the present invention, the radical polymerization initiator (E) having a hydrogen abstraction effect can be, for example, 9-oxysulfur 𠮿

It is a radical polymerization initiator, a benzophenone-based radical polymerization initiator, etc. As 9-oxysulfur 𠮿

The radical polymerization initiator includes, for example, a compound represented by the following general formula (1).

[Chemical formula 1]

In the formula, R ³ and R ⁴ represent -H, -CH ₂ CH ₃ , -iPr or Cl, and R ³ and R ⁴ may be the same or different from each other.

尤佳。Compared with the case of using a photopolymerization initiator having high sensitivity to light of 380 nm or more, the adhesiveness is better when the compound represented by the general formula (1) is used. The photopolymerization initiator with high sensitivity to light above 380 nm will be described later. Among the compounds represented by the general formula (1), R ³ and R ⁴ are -CH ₂ CH ₃ diethyl 9-oxythio𠮿

Especially good.

The photopolymerization initiator of the general formula (1) can be polymerized by long-wavelength light that can transmit a transparent protective film with UV absorbing energy, so that the adhesive can be cured even through the UV absorbing film. Specifically, for example, even in the case of a transparent protective film such as cellulose triacetate-polarizer-cellulose triacetate having UV absorbing energy in the two-area layers, when the photopolymerization initiator of the general formula (1) is contained, Then the agent can harden.

When the total amount of the adhesive is 100% by weight, the composition ratio of the radical polymerization initiator (E) with hydrogen abstraction in the adhesive, especially the composition ratio of the compound represented by the general formula (1), is preferably 0.1 ~10% by weight, preferably 0.2 to 5% by weight.

In addition, it is advisable to add a polymerization initiation aid as required. The polymerization initiation aid may include, for example, triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylamine benzoic acid, methyl 4-dimethylamine benzoate, 4-dimethylamine benzoic acid Ethyl, isoamyl 4-dimethylaminobenzoate, etc., and ethyl 4-dimethylaminobenzoate is particularly preferred. When the polymerization initiation aid is used, its addition amount is generally 0-5 wt% when the total amount of the adhesive is 100 wt%, preferably 0-4 wt%, and optimally 0-3 wt%.

In addition, a known photopolymerization initiator may be used in combination as required. The transparent protective film with UV absorption energy does not transmit light below 380nm, so it is better to use a photopolymerization initiator with high sensitivity to light above 380nm. Specifically, for example, 2-methyl-1-(4-methylthiophenyl)-2-morpholinylpropan-1-one, 2-benzyl-2-dimethylamino-1- (4-Mopholinylphenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-methyl) Folin) phenyl)-1-butanone, 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzyl) )-Phenylphosphine oxide, bis(Η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) Titanium etc.

In particular, the photopolymerization initiator preferably contains a compound represented by the following general formula (2) in addition to the photopolymerization initiator of the general formula (1).

[Chemical formula 2]

In the formula, R ⁵ , R ⁶ and R ⁷ represent -H, -CH ₃ , -CH ₂ CH ₃ , -iPr or Cl, and R ⁵ , R ⁶ and R ⁷ may be the same or different from each other. By combining the photopolymerization initiators of the above general formula (1) and general formula (2), the photosensitization reaction of them promotes the efficiency of the reaction, and the adhesiveness of the adhesive layer is particularly improved.

Among the above-mentioned active energy ray hardening adhesives, it is more preferable to contain an active energy ray hardening compound having an active methylene group together with the radical polymerization initiator (E) having a hydrogen abstraction effect. According to this configuration, the adhesiveness of the adhesive layer can be further improved.

The active energy ray hardening compound having active methylene group is a compound having active double bond groups such as (meth)acryloyl group at the end or in the molecule, and active methylene group. Examples of the active methylene group include acetylacetoxy, alkoxypropanedioxin, or cyanoacetoxy. Specific examples of active energy ray-curable compounds having active methylene groups include 2-acetylacetoxyethyl (meth)acrylate, 2-acetylacetoxypropyl (meth)acrylic acid Acetyl acetoxy alkyl (meth) acrylates such as 2-acetoxy acetoxy-1-methyl ethyl (meth) acrylate; 2-ethoxypropanedioicoxy ethyl Methyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, N-(2-cyanoacetoxyethyl)acrylamide, N-(2-propaneacetate Oxybutyl) acrylamide, N-(4-acetylacetoxymethylbenzyl) acrylamide, N-(2-acetylacetamide ethyl) acrylamide, and the like. In addition, the SP value of the active energy ray curable compound having an active methylene group is not particularly limited, and any compound can be used.

On the delivery side of the application roller 641 of the adhesive application portion 64 of the first protective film 12 and the second protective film 13, temperature measurement mechanisms 681 and 681 are respectively arranged. The temperature measurement mechanism 681 is arranged in the vicinity of the coating roller 641. The temperature measuring mechanism 681 measures the temperature of the first protective film 12 and the second protective film 13 to which the adhesive is applied. Hereinafter, the first protective film 12 and the second protective film 13 may be collectively referred to as "protective film". The thermometer measuring mechanism 681 can use a thermal imaging camera, a radiation thermometer, etc., for example. The aforementioned thermal imaging camera can use an infrared camera to detect infrared rays radiated from the protective film coated with an adhesive, and analyze the detected infrared image to calculate its temperature. The radiation thermometer can measure the intensity of infrared or visible light radiated from the protective film coated with the adhesive and measure its temperature. The temperature measurement mechanism 681 can measure the temperature of the protective film from the side on which the adhesive is applied, or can measure the temperature of the protective film from the side opposite to the side on which the adhesive is applied. In the example of the drawing, the temperature measuring mechanism 681 is arranged on the side (adhesive layer side) on which the adhesive is applied. At this time, the temperature measurement mechanism 681 strictly measures the temperature of the adhesive layer. However, since the adhesive layer is directly provided on one side of the protective film, the temperature of the adhesive layer is substantially equal to the temperature of the protective film, and it can be said that the aforementioned temperature measuring mechanism 681 measures the temperature of the protective film.

In addition, a cooling mechanism 66 is provided on the transport path of the protective film (the first protective film 12 and the second protective film 13). The cooling mechanism 66 lowers the room temperature in the chamber 69 and lowers the temperature of the protective film. Examples of the cooling mechanism 66 include a cooler that can send cold air, a heat exchanger that can circulate a refrigerant in a pipeline, and the like. The cooling mechanism 66 may be provided in the chamber 69, and its position is not particularly limited. In the illustrated example, the cooling mechanism 66 adopts a cooler. And the cooler (cooling mechanism 66) is arranged in such a way that the cold air from the cooler can be blown to the protective film. In the illustrated example, the cooling mechanism 66 is arranged between the adhesive application portion 64 and the bonding portion 67 and blows cold air to the first protective film 12 and the second protective film 13.

The bonding part 67 is to bond the protective film coated with the adhesive and the polarizing member 1c. The bonding part 67 has nip rollers 671 and 671. The protective film (the first protective film 12 and the second protective film 13) provided with the adhesive layer and the polarizer 1c are inserted through the nip rollers 671 and 671 and pressed. And on the delivery side of the nip rollers 671 and 671, a laminate 1d composed of the first protective film 12/uncured adhesive layer/polarizer 1c/uncured adhesive layer/second protective film 13 is transported. The temperature measuring mechanism 682 is arranged on the delivery side of the nip roller 671 of the bonding part 67. The temperature measuring mechanism 682 measures the temperature of the protective film attached to the polarizer 1c through the adhesive layer. The thermometer measuring mechanism 682 can use a thermal imaging camera, a radiation thermometer, etc., for example. The temperature measurement mechanism 682 may measure the temperature from the side of the first protective film 12 or may measure the temperature from the second protective film 13. In the illustrated example, the temperature measurement mechanism 682 is arranged on the side of the first protective film 12. In addition, a cooling mechanism (not shown) can also be provided on the delivery side of the nip roller 671 as required.

The outer side of the adhesive application portion 64 and the bonding portion 67 is surrounded by the cavity 69. In other words, the adhesive application portion 64 including the temperature measurement mechanism 681 and the cooling mechanism 66 and the bonding portion 67 including the temperature measurement mechanism 682 are arranged in the chamber 69. In addition, slit-shaped inlets and outlets (not shown) are formed on the upstream side and the downstream side of the chamber 69. The polarizer 1c enters the cavity 69 from the entrance on the upstream side of the cavity 69. The laminated body 1d mentioned above is formed in the bonding part 67, and this laminated body 1d will be conveyed out of the chamber 69 from the slit-shaped exit of the chamber 69. As shown in FIG. In the example of the drawing, the second roller portion 62 with the first protective film 12 wrapped around and the third roller portion 63 with the second protective film 13 wrapped around are arranged outside the chamber 69, but the second roller The part 62 and the third roller part 63 may also be arranged in the cavity 69 (not shown).

When an active energy ray curable adhesive is used as the adhesive, the curing device 7 is arranged on the downstream side of the bonding part 67. The curing device 7 has an irradiation device 71 that irradiates the aforementioned layered body 1d with active energy rays. If necessary, the hardening device 7 may also have a cavity 72. When the chamber 72 is provided, the irradiation device 71 is arranged in the chamber 72. The active energy ray of the irradiation device 71 can be appropriately selected according to the curability of the active energy ray-curable adhesive. For example, an irradiating device 71 that can irradiate visible rays of 380 nm to 450 nm can be used. Furthermore, the curing device 7 for irradiating active energy rays is preferably arranged on both sides of the laminated body 1d as shown in FIG. 4, and the active energy rays can be irradiated from both sides of the laminated body 1d. The two irradiation devices 71 and 71 arranged on both sides may be arranged facing each other around the laminated body 1d, or one irradiation device 71 may be arranged on the upstream side and the other irradiation device 71 may be arranged on the downstream side. The laminate 1d entering the chamber 72 from the slit-shaped inlet on the upstream side of the chamber 72 is transported to the chamber from the slit-shaped outlet on the downstream side of the chamber 72 after the adhesive layer is cured by the irradiation device 71 72 outside.

Since the irradiation device 71 irradiates the activation energy ray, the vicinity of the irradiation device 71 tends to become warmer. In this regard, since the cavity 72 surrounding the irradiation device 71 is provided, the high-temperature heat of the curing device 7 does not easily act on the bonding portion 67. Therefore, it is possible to effectively prevent the protective film from becoming too high in the bonding portion 67 (and the adhesive application portion 64).

[Manufacturing method of polarizer and manufacturing method of laminated polarizing film] ＜Manufacturing steps of polarizing parts＞ 4, the untreated hydrophilic polymer film 1a is pulled out from the first roller portion 41, and the aforementioned hydrophilic polymer film 1a is conveyed to the swelling treatment tank 4A by the conveying portion 42. While conveying the hydrophilic polymer film 1a by the guide roller 42 in the swelling treatment tank 4A, the hydrophilic polymer film 1a is immersed in the swelling treatment liquid, thereby swelling the hydrophilic polymer film 1a. The temperature of the aforementioned swelling treatment liquid is not particularly limited, and is, for example, 20°C to 45°C. The time for immersing the hydrophilic polymer film 1a in the swelling treatment liquid is not particularly limited, and is, for example, 5 seconds to 300 seconds. Next, the swollen hydrophilic polymer film 1a is immersed in the dyeing treatment solution in the dyeing treatment tank 4B, whereby the hydrophilic polymer film 1a is dyed with the dichroic substance. The temperature of the aforementioned dyeing treatment liquid is not particularly limited, and is, for example, 20°C to 50°C. The time for immersing the hydrophilic polymer film 1a in the dyeing treatment liquid is not particularly limited, and is, for example, 5 seconds to 300 seconds. The dyed hydrophilic polymer film 1a is immersed in the cross-linking treatment liquid in the cross-linking treatment tank 4C, whereby the dichroic substance of the hydrophilic polymer film 1a is cross-linked. The temperature of the aforementioned cross-linking treatment liquid is not particularly limited. For example, it is 25°C or higher, preferably 40°C to 70°C. The time for immersing the hydrophilic polymer film 1a in the crosslinking treatment liquid is not particularly limited, and is, for example, 5 seconds to 800 seconds.

The hydrophilic polymer film 1a after the aforementioned crosslinking is stretched while being conveyed by the guide roller 42 in the stretching treatment liquid in the stretching treatment tank 4D. The temperature of the extension treatment liquid is not particularly limited, and is, for example, 40°C to 90°C. The stretching magnification can be appropriately set according to the purpose, and the total stretching magnification is, for example, 2 times to 7 times, preferably 4.5 times to 6.8 times. The aforementioned total stretching ratio means the final stretching ratio of the hydrophilic polymer film 1a. The stretched hydrophilic polymer film 1a is immersed in the washing treatment liquid in the washing treatment tank 4E, thereby washing the hydrophilic polymer film 1a. The temperature of the aforementioned cleaning treatment liquid is, for example, 5°C to 50°C. The washing time is, for example, 1 second to 300 seconds. The hydrophilic polymer film after washing will become the polarizing member 1b. The obtained polarizer 1b is then transported to the drying device 5.

＜Drying step＞ The polarizer 1b obtained by the above-mentioned wet treatment contains a lot of water, so it is dried by the drying device 5. Regarding the drying temperature in the drying step, the temperature of the space 53 of the chamber 52 (the temperature of the gas environment in the chamber 52) is set to, for example, 40°C to 100°C, and preferably set to 50°C to 90°C. In addition, when the drying device 5 using warm air is used as described above, the wind speed of the warm air is set to, for example, 1m/sec to 30m/sec, and preferably 2m/sec to 20m/sec.

＜Adhesive application procedure＞ The long strip-shaped polarizer 1 c after the drying is conveyed to the bonding section 67 by the conveying section 61. It is also possible to coat the easy-adhesive composition on both sides of the dried polarizer 1c using an adhesive application part (not shown) such as a gravure roll to form an easy-adhesive layer. By forming the easy-to-bond layer, the adhesion of the protective film to the polarizer can be improved. The aforementioned easy-to-bond composition can include compounds having (meth)acrylic acid groups, acid anhydride group-containing silane coupling agents, acetyl acetyl group-containing silane coupling agents, isocyanuric acid group-containing silane coupling agents, Carboxylic polymers, etc. The thickness of the easy bonding layer is not particularly limited, for example, 0.1μm~5μm.

On the other hand, the long strip-shaped first protective film 12 is drawn out from the second roller portion 62 and is transported to the bonding portion 67 by the transport portion 61. Similarly, the long strip-shaped second protective film 13 is pulled out from the third roller section 63 and is transported to the bonding section 67 by the transport section 61. In each conveying process, an adhesive such as an active energy ray-curable adhesive is applied to one side and the second side of the first protective film 12 by the application roller 641 (e.g., a gravure roller) of the adhesive application section 64, respectively. One side of the protective film 13. By applying an adhesive, an adhesive layer is formed on one side of the first protective film 12 and one side of the second protective film 13, respectively.

The thickness of the adhesive applied to the protective film is not particularly limited, but if it is too small, the adhesive strength will decrease, and if it is too large, the thickness of the laminated polarizing film will be relatively too large. From the above point of view, the thickness of the adhesive applied to the protective film (the first protective film 12 and the second protective film 13) (the coating thickness of the adhesive layer) is preferably 0.1 μm to 5 μm.

In addition, the viscosity of the adhesive during application is not particularly limited, but if it is too small or too large, uneven application of the adhesive may occur. From the said point of view, the viscosity of the adhesive at 25°C should be adjusted to 10mPa·s~50mPa·s, and the viscosity at 25°C should be adjusted to 15mPa·s~45mPa·s. In addition, the aforementioned viscosity can be measured using a viscometer at 25°C. In addition, the conveying speed (line speed) of the polarizing member 1c, the first protective film 12, and the second protective film 13 during coating is not particularly limited, but if it is too fast, uneven adhesion may occur, and if it is too slow Then the production efficiency of the laminated polarizing film will be reduced. From the viewpoint, the conveying speed of the protective film etc. during coating is preferably 15 m/min to 40 m/min, and more preferably 20 m/min to 35 m/min.

The temperature of the protective film on the delivery side of the coating roller 641 (protective film after application of the adhesive) is set within the range of 20°C to 35°C. As described above, the temperature of the protective film is monitored by the temperature measuring mechanism 681 provided on the delivery side of the coating roller 641. And in such a way that the temperature of the protective film is in the range of 20°C to 35°C, the cooling mechanism 66 is used to cool the protective film. For example, according to the measurement of the temperature measurement mechanism 681, when the temperature of the protective film continues to rise, the control device (control program) will increase the cooling performed by the cooling mechanism 66. In addition, according to the measurement of the temperature measurement mechanism 681, when the temperature of the protective film continues to drop, the control device will reduce or stop the cooling by the cooling mechanism 66. By controlling the cooling mechanism 66 in response to the temperature measuring mechanism 681 as described above, the temperature of the protective film on the delivery side of the coating roller 641 can be maintained in the range of 20°C to 35°C.

The temperature of the protective film on the delivery side of the coating roller 641 is measured by the temperature measuring mechanism 681 within 5 seconds after the coating roller 641 is sent out, for example. By measuring within 5 seconds, the temperature of the protective film immediately after application of the adhesive can be measured. Furthermore, by setting the position where the temperature measuring mechanism 681 is installed in consideration of the conveying speed of the protective film, the temperature of the protective film within 5 seconds after being sent from the coating roller 641 can be measured.

＜Layering Steps＞ The protective film (the first protective film 12 and the second protective film 13) on which the aforementioned adhesive layer (uncured adhesive) is formed is transported to the bonding portion 67 together with the polarizer 1c. While making the polarizer 1c face the adhesive layer formed on the first protective film 12, and make the polarizer 1c face the adhesive layer formed on the second protective film 13, at the same time these films are inserted through the nip roller 671, 671 rooms. By passing through the nip rollers 671 and 671, the polarizing member 1c, the protective film 12 and the second protective film 13 are bonded together, and the protective film 12/uncured adhesive layer/polarizing member 1c/uncured adhesive can be obtained Layer/second protective film 13 constituted laminated body 1d. The bonding of the protective film and the polarizing member 1c is preferably performed between 2 seconds and 30 seconds after the protective film is coated with an adhesive. After the adhesive is applied to the protective film, if it does not adhere to the polarizer 1c for too long, there is a risk that the adhesive will excessively penetrate into the protective film, and if the protective film is attached to the protective film just after the adhesive is applied For the polarizer 1c, there is a possibility that the adhesive hardly penetrates the protective film.

The temperature of the protective film on the delivery side of the nip roller 671 (the protective film of the laminate 1d) is set within the range of 20°C to 35°C. As described above, the temperature of the protective film of the laminate 1d is monitored by the temperature measuring mechanism 682 provided on the delivery side of the nip roller 671. And so that the temperature of the protective film of the laminate 1d is in the range of 20°C to 35°C, the cooling mechanism 66 is used to cool the protective film. For example, according to the measurement by the temperature measuring mechanism 682, when the temperature of the protective film of the laminated body 1d continues to rise, the control device (control program) increases the cooling performed by the cooling mechanism 66. In addition, according to the measurement by the temperature measurement mechanism 682, when the temperature of the protective film of the laminated body 1d continues to drop, the control device lowers or stops the cooling by the cooling mechanism 66. By controlling the cooling mechanism 66 in response to the temperature measuring mechanism 682 as described above, the temperature of the protective film on the delivery side of the nip roller 671 can be maintained within the range of 20°C to 35°C. The temperature of the protective film on the delivery side of the nip roller 671 is measured by the temperature measuring mechanism 682 within 5 seconds after delivery from the nip roller 671, for example. By measuring within 5 seconds, the temperature of the protective film just after bonding with the polarizer 1c can be measured. And by setting the position where the temperature measuring mechanism 682 is installed in consideration of the conveying speed of the layered body 1d, the temperature of the protective film within 5 seconds after being sent out from the nip roller 671 can be measured.

In addition, the adhesive application portion 64 and the laminating portion 67 are contained in the cavity 69, so the temperature in the cavity 69 should also be controlled within the range of 20°C to 35°C. By maintaining the chamber 69 in the range of 20°C to 35°C, it is possible to move from the delivery side of the coating roller 641 to the delivery side of the nip roller 671 (from the application of the adhesive to the bonding of the polarizer) The series so far), the protective film is maintained at a temperature range of 20°C to 35°C.

＜Adhesive curing step＞ When using an active energy ray-curable adhesive, by irradiating the laminate 1d with active energy rays using the curing device 7 to cure the active energy ray-curable adhesive, a protective film 12/cured adhesive layer/ A laminated polarizing film 1e composed of a polarizer 1c/adhesive layer after curing/the second protective film 13. In addition, the thickness of the adhesive layer before curing (during application) and the thickness after curing of the adhesive layer composed of the aforementioned active energy ray-curable adhesive are substantially the same. The obtained laminated polarizing film 1e is taken up by the take-up roller part 8 (refer to FIG. 4).

[Effects of the present invention] According to the manufacturing method of the present invention, the protective film on the delivery side of the coating roller in the adhesive coating step is set at 20°C~35°C, and the protective film on the delivery side of the nip roll in the lamination step is set at 20°C~ The range of 35°C. It is also preferable to continuously maintain the protective film between the delivery side of the coating roller and the delivery side of the nip roller in the range of 20°C to 35°C. Therefore, it is possible to obtain a laminated polarizing film in which the polarizer and the protective film are well bonded through the adhesive. In particular, by using a protective film with an easy-to-adhesive surface such as a TAC film, the adhesive will dissolve or penetrate well on the surface of the protective film, and a laminated polarizing film with excellent bonding strength can be obtained.

Specifically, after the protective film is coated with the adhesive, if the temperature of the protective film is too high, the adhesive will excessively infiltrate the protective film, and there is a risk that the compatibility of the adhesive and the protective film may proceed excessively. If the compatibility between the adhesive and the protective film progresses excessively, the cohesive force of the cured adhesive will be insufficient, and the polarizing member and the protective film cannot be firmly bonded through the adhesive. By using the method of the present invention to make the protective film after the adhesive is applied below 35° C., excessive infiltration of the protective film by the adhesive can be prevented. On the other hand, after the protective film is coated with the adhesive, if the temperature of the protective film is too low, the adhesive will not easily penetrate into the protective film, and there is a possibility that the compatibility between the adhesive and the protective film will hardly proceed. If the adhesive and the protective film are almost incompatible, a good compatibility layer will not be formed between the adhesive layer and the protective film, and the polarizer and the protective film cannot be firmly bonded through the adhesive. By making the protective film above 20°C in the manner of the present invention, the adhesive will moderately infiltrate the protective film, and a good compatibility layer is formed between the adhesive layer and the protective film. Therefore, according to the manufacturing method of the present invention, it is possible to obtain a laminated polarizing film in which the polarizer and the protective film are bonded well through the adhesive.

[Uses of laminated polarizing film, etc.] The laminated polarizing film of the present invention is representatively used as an optical film for displays such as liquid crystal display devices or organic display devices. In addition, the laminated polarizing film of the present invention is not limited to the case of being used in the aforementioned display, and can also be used in applications other than the display. Applications other than displays include optical equipment, buildings, medical, food, etc. When the laminated polarizing film is used in optical equipment, the laminated polarizing film can be processed into a polarizing lens, a transparent radio wave shielding film, etc., for example. When the laminated polarizing film is used in electronic components, the laminated polarizing film can be processed into, for example, a film for dimming windows. When the laminated polarizing film is used in the medical and food fields, the laminated polarizing film can be processed into a light-deteriorating film, for example.

Example Hereinafter, examples and comparative examples are described to further detail the present invention. However, the present invention is not limited by the following examples.

系紫外線吸收劑(ADEKA公司製，商品名：T-712)0.62重量份於220℃下混合，而製出樹脂丸粒。使所製得之樹脂丸粒在100.5kPa、100℃下乾燥12小時，再以單軸擠製機在模具溫度270℃下從T型模頭擠出，成形為薄膜狀(厚度160µm)。並且在150℃的氣體環境下將前述成形之薄膜沿其輸送方向延伸(厚度80µm)，接著塗佈含水性胺甲酸酯樹脂之易接著劑後，在150℃的氣體環境下沿與薄膜輸送方向正交之方向延伸，而獲得厚度40µm(透濕度58g/m² /24h)之透明丙烯酸薄膜。[Materials used] <TAC film> A cellulose triacetate film with a thickness of 60 µm (manufactured by Fuji Film Co., Ltd., trade name: TG60UL) is used. <Acrylic film with easy-adhesive agent> 100 parts by weight of the imidized MS resin described in Production Example 1 in Japanese Patent Laid-Open No. 2010-284840 was used with a biaxial kneader.

0.62 parts by weight of an ultraviolet absorber (manufactured by ADEKA, trade name: T-712) was mixed at 220°C to prepare resin pellets. The prepared resin pellets were dried at 100.5kPa and 100°C for 12 hours, and then extruded from a T-die with a uniaxial extruder at a die temperature of 270°C to form a film (thickness 160μm). In addition, the formed film is stretched along its conveying direction (thickness 80µm) under a 150°C gas environment, and then coated with a water-containing urethane resin adhesive, and then conveyed along with the film under a 150°C gas environment Extend in the orthogonal direction to obtain a transparent acrylic film with a thickness of 40 µm (with a moisture permeability of 58 g/m ² /24h).

(日本化藥公司製，商品名：KAYACURE DETX-S)予以混合且攪拌3小時，藉此獲得了活性能量線硬化型接著劑A。 該活性能量線硬化型接著劑A在25℃下之黏度為38mPa・s。 ＜活性能量線硬化型接著劑B＞ 將47.5重量%之丙烯醯基嗎福林(KJ Chemicals Corporation製，商品名：ACMO)、47.5重量%之三丙二醇二丙烯酸酯(東亞合成公司製，商品名：ARONIX M-220)、3重量%之2-甲-1-(4-甲基硫基苯基)-2-嗎福林基丙-1-酮(IGM Resins公司製，商品名：OMNIRAD 907)及2重量%之2,4-二乙基9-氧硫𠮿

(日本化藥公司製，商品名：KAYACURE DETX-S)予以混合且攪拌3小時，藉此獲得了活性能量線硬化型接著劑B。 該活性能量線硬化型接著劑A在25℃下之黏度為16mPa・s。 ＜易接著組成物＞ 將70重量%之丙烯醯基嗎福林(KJ Chemicals Corporation製，商品名：ACMO)、2重量%之3-乙烯基苯基硼酸及28重量%之水予以混合且攪拌3小時，藉此獲得了易接著組成物。<Active Energy Ray Curing Adhesive A> 10% by weight of hydroxyethyl acrylamide (manufactured by KJ Chemicals Corporation, trade name: HEAA) and 30% by weight of acrylamide (manufactured by KJ Chemicals Corporation, product Name: ACMO), 37% by weight of tripropylene glycol diacrylate (manufactured by Toagosei Co., Ltd., trade name: ARONIX M-220), 3% by weight of tetra-n-butyl titanate (manufactured by Matsumoto Fine Chemical Co. Ltd., product Name: TA-21), 5 wt% of ω-carboxy-dicaprolactone monoacrylate (manufactured by Toagosei Co., Ltd., trade name: ARONIX M-5300), 10 wt% of epoxy-modified acrylic oligomer (Manufactured by Toagosei Co., Ltd., trade name: ARUFON UP-1190), 3% by weight of 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-one (IGM Resins Manufactured by the company, trade name: OMNIRAD 907) and 2% by weight of 2,4-diethyl 9-oxysulfur 𠮿

(Nippon Kayaku Co., Ltd., trade name: KAYACURE DETX-S) was mixed and stirred for 3 hours, thereby obtaining an active energy ray hardening adhesive A. The active energy ray hardening adhesive A has a viscosity of 38mPa·s at 25°C. <Active Energy Ray Curing Adhesive B> 47.5 wt% of propylene mopholine (manufactured by KJ Chemicals Corporation, trade name: ACMO) and 47.5 wt% of tripropylene glycol diacrylate (manufactured by Toagosei Co., Ltd., trade name) : ARONIX M-220), 3% by weight of 2-methyl-1-(4-methylthiophenyl)-2-morpholinylpropan-1-one (manufactured by IGM Resins, trade name: OMNIRAD 907 ) And 2% by weight of 2,4-diethyl 9-oxysulfur 𠮿

(Manufactured by Nippon Kayaku Co., Ltd., trade name: KAYACURE DETX-S) was mixed and stirred for 3 hours, thereby obtaining an active energy ray hardening adhesive B. The active energy ray hardening adhesive A has a viscosity of 16mPa·s at 25°C. <Easy bonding composition> Mix and stir 70% by weight of propylene mopholine (manufactured by KJ Chemicals Corporation, trade name: ACMO), 2% by weight of 3-vinylphenylboronic acid, and 28% by weight of water In 3 hours, an easy-to-bond composition was obtained by this.

[Method of Measuring Viscosity] The viscosities of the active energy ray-curable adhesives A and B were measured at 25°C with an E-type rotary viscometer (manufactured by Toki Sangyo Co., Ltd.).

[Manufacturing device used] Utilize a manufacturing device (the manufacturing device shown in Figure 4) of a laminated polarizing film with a wet processing device, a drying device, a laminating device, and a curing device. The manufacturing device 2 (refer to FIG. 4) is equipped with commercially available thermal imaging cameras as the temperature measuring mechanisms 681 and 682, and further equipped with a cooler as the cooling mechanism 66.

[Example 1] The cooler was set so that the room temperature in the chamber 69 surrounding the adhesive application portion 64 and the bonding portion 67 reached 22°C. After setting the inside of the chamber 69 to the aforementioned room temperature, a polarizer is produced and dried in the following manner, and then a first protective film and a second protective film are attached to both sides of the polarizer to produce a laminated polarizing film. In Example 1, both the first protective film and the second protective film used TAC films.

＜Manufacturing steps of polarizing parts＞ Using the wet processing device of the above manufacturing device, a polyvinyl alcohol film (thickness 45µm, width 3000mm) with an average degree of polymerization of 2400 and a degree of saponification of 99.9 mol% was immersed in warm water at 30°C for 60 seconds to swell. Next, it was immersed in a 0.3% aqueous solution of iodine/potassium iodide (weight ratio=0.5/8), and the film was dyed while extending it to 3.5 times. Then, it was stretched in a borate aqueous solution at 65° C. so that the total stretch magnification reached 6 times, and then washed with water, thereby fabricating a long strip-shaped polarizer. ＜Drying steps of polarized parts＞ Next, the polarizer is transported to a drying device to be dried. The wind speed of the warm air of the drying device is set to 3m/sec, the temperature of the gas environment in the chamber is set to about 60°C, and the polarizer is transported at a transport speed of 25m/min.

<Adhesive application step, layering step, and adhesive curing step> Next, while conveying the dried polarizer to the bonding part at a speed of 25m/min, the active energy ray-curable adhesive A was applied to both sides of the polarizer in a full pattern with a gravure roller to form Apply an adhesive layer with a thickness of 1.0 µm. At the same time, while conveying the first protective film and the second protective film (both TAC films) at a speed of 25m/min, the active energy ray-curable adhesive A was applied to the first protective film in a full pattern with a gravure roller. One side of the film and one side of the second protective film form an adhesive layer with a coating thickness of 1.0 µm. The adhesive layer of the first protective film is superimposed on the adhesive layer of one side of the polarizing member, and the adhesive layer of the second protective film is laminated on the other side of the polarizing member to pass through the bonding part 67 Nip rolls to obtain a laminate of the first protective film/uncured adhesive layer/polarizer/uncured adhesive layer/second protective film, and irradiate light with a wavelength of 380nm~450nm from both sides of the laminate to make the adhesive The layer is hardened to continuously produce a multilayer polarizing film.

The temperature of the second protective film immediately after application of the adhesive is measured by a thermal imaging camera arranged on the delivery side of the gravure roll. The aforementioned temperature was measured at a position about 2 seconds after the second protective film was sent out from the gravure roll. In addition, the temperature of the second protective film of the laminate is measured by a thermal imaging camera arranged on the delivery side of the nip roller. The aforementioned temperature was measured at a position about 2 seconds after the laminate was sent out from the gravure roll. Table 2 lists the temperature of the protective film immediately after applying the adhesive and the temperature of the protective film immediately after forming the laminate (the temperature of the protective film immediately after bonding). However, the values in Table 2 are based on an average value of 10 seconds from the time when the room temperature in the chamber 69 is approximately stable at the set temperature after the device is operated.

[Example 2] A laminated polarizing film was produced in the same manner as in Example 1, except that the room temperature in the chamber 69 surrounding the adhesive application portion 64 and the bonding portion 67 was set to 29°C. Table 2 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Example 2.

[Example 3] A laminated polarizing film was produced in the same manner as in Example 1 except for the following: (without applying active energy ray-curable adhesive) the dried polarizer was transported at a speed of 25m/min while using The gravure roll coats the easy-adhesive composition on both sides of the full plate and air-dried to form an easy-adhesive layer with a thickness of 0.2μm, and then transport it to the bonding part of the device; replace the active energy ray hardening adhesive A uses the active energy ray-curable adhesive B; and, the room temperature in the chamber 69 surrounding the adhesive application portion 64 and the bonding portion 67 is set to be 24°C. Table 2 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Example 3.

[Example 4] A laminated polarizing film was produced in the same manner as in Example 1 except for the following: (without applying active energy ray-curable adhesive) the dried polarizer was transported at a speed of 25m/min while using The gravure roll coats the easy-adhesive composition on both sides of the full plate and air-dried to form an easy-adhesive layer with a thickness of 0.2μm, and then transport it to the bonding part of the device; replace the active energy ray hardening adhesive A uses the active energy ray-curable adhesive B; and, the room temperature in the chamber 69 surrounding the adhesive application portion 64 and the bonding portion 67 is set to 27°C. Table 2 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Example 4.

[Example 5] The first protective film and the second protective film both use an acrylic film with an easy-to-adhesive agent, and the room temperature in the chamber 69 set to surround the adhesive application part 64 and the bonding part 67 is 22°C. In the same manner as in Example 1, a multilayer polarizing film was produced. In addition, an active energy ray curable adhesive was coated on the easy-adhesive side of the acrylic film (this point is the same in Example 6, Comparative Examples 4 and 5). Table 2 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Example 5.

[Example 6] The first protective film and the second protective film both use an acrylic film with an easy-adhesive agent, and the room temperature in the chamber 69 that is set to surround the adhesive application part 64 and the bonding part 67 is 28°C. In the same manner as in Example 1, a multilayer polarizing film was produced. Table 2 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Example 6.

[Comparative Example 1] Except that the room temperature in the chamber 69 surrounding the adhesive application part 64 and the bonding part 67 was set to 36 degreeC, it carried out similarly to Example 1, and produced the laminated polarizing film. Table 3 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Comparative Example 1.

[Comparative Example 2] A laminated polarizing film was produced in the same manner as in Example 1, except that the room temperature in the cavity 69 surrounding the adhesive application portion 64 and the bonding portion 67 was set to 18°C. Table 3 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Comparative Example 2.

[Comparative Example 3] A laminated polarizing film was produced in the same manner as in Example 1 except for the following: (without applying active energy ray-curable adhesive) the dried polarizer was transported at a speed of 25m/min while using The gravure roll coats the easy-adhesive composition on both sides of the full plate and air-dried to form an easy-adhesive layer with a thickness of 0.2μm, and then transport it to the bonding part of the device; replace the active energy ray hardening adhesive A uses an active energy ray-curable adhesive B; and, the room temperature in the chamber 69 surrounding the adhesive application part 64 and the bonding part 67 is set to 37°C. Table 3 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Comparative Example 3.

[Comparative Example 4] The first protective film and the second protective film both use an acrylic film with an easy-adhesive agent, and the room temperature in the chamber 69 set to surround the adhesive application part 64 and the laminating part 67 is 36°C. In the same manner as in Example 1, a multilayer polarizing film was produced. Table 3 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Comparative Example 4.

[Comparative Example 5] The first protective film and the second protective film both use an acrylic film with an easy-to-adhesive agent, and the room temperature in the chamber 69 set to surround the adhesive application part 64 and the laminating part 67 is 17°C. In the same manner as in Example 1, a multilayer polarizing film was produced. Table 3 lists the temperature of the protective film immediately after application of the adhesive and the temperature of the protective film immediately after forming the laminate of Comparative Example 5.

[Table 2]

[table 3]

[Peel strength test] The laminated polarizing film was cut into a size of 200 mm parallel to the extension direction of the polarizer and 15 mm in the direction orthogonal to it, to prepare a sample piece. After making a cut with a utility knife between the first protective film and the layer of the polarizer of the sample piece, the second protective film side of the laminated polarizing film is attached to the glass plate. Using a TENSILON tester (manufactured by Shimadzu Corporation, product name: AG-1 10KN), the first protective film and the polarizer were peeled in a 90-degree direction (speed 1000 mm/min), and the initial peel strength (N/15 mm) was measured. In the same way, after making a sample piece with cut marks between the layers of the second protective film and the polarizer, the first protective film side was attached to the glass plate, and the second protective film and the polarizer were peeled off in the same manner , Determine the initial peel strength (N/15mm). And the results are shown in Table 2 and Table 3. The "○" in the evaluation column of Table 2 and Table 3 means that the initial peel strength is 0.5N/15mm or more, and "×" means that it is less than 0.5N/15mm.

1,1e: multilayer polarizing film 11, 1b, 1c: Polarizer 1a: Hydrophilic polymer film 1d: layered body 12: Protective film (1st protective film) 13: The second protective film 14: Optical film 2: Manufacturing device for laminated polarizing film 31, 32, 33, 34: Adhesive layer 4: Wet treatment device 41: The first roller part 42: Conveying part (guide roller) 4A: Swelling treatment tank 4B: Dyeing treatment tank 4C: Cross-linking treatment tank 4D: Extended processing tank 4E: Washing treatment tank 5: Drying device 51, 61: Conveying Department 52, 69, 72: Chamber 53: Space 6: Laminating device 62: The second roller part 63: The third roller part 64: Adhesive coating part 641: Coating roller (gravure roller) 642: container 643: Scraper 65: Adhesive 66: Cooling mechanism 67: Fitting Department 671: nip roller 681,682: Thermometer measurement mechanism 7: Hardening device 71: Irradiation device 8: Coiling drum section

Fig. 1 is a cross-sectional view of a laminated polarizing film according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of a laminated polarizing film according to another embodiment of the present invention. Fig. 3 is a cross-sectional view of a laminated polarizing film according to another embodiment of the present invention. Fig. 4 is a schematic diagram showing the manufacturing apparatus of the laminated polarizing film of the present invention.

1a: Hydrophilic polymer film

1b, 1c: Polarizing parts

1d: layered body

1e: Multilayer polarizing film

12: Protective film (1st protective film)

13: The second protective film

2: Manufacturing device for laminated polarizing film

4: Wet treatment device

41: The first roller part

42: Conveying part (guide roller)

4A: Swelling treatment tank

4B: Dyeing treatment tank

4C: Cross-linking treatment tank

4D: Extended processing tank

4E: Washing treatment tank

5: Drying device

51, 61: Conveying Department

52, 69, 72: Chamber

53: Space

6: Laminating device

62: The second roller part

63: The third roller part

64: Adhesive coating part

641: Coating roller (gravure roller)

642: container

643: Scraper

65: Adhesive

66: Cooling mechanism

67: Fitting Department

671: nip roller

681,682: Thermometer measurement mechanism

7: Hardening device

71: Irradiation device

8: Coiling drum section

Claims (9)

A manufacturing method of laminated polarizing film has the following steps: The adhesive coating step is to apply the adhesive to the protective film using a coating roller; and In the laminating step, the protective film coated with the adhesive and the polarizer are pasted by a nip roller; In the adhesive coating step, the protective film on the delivery side of the coating roller is set in the range of 20°C to 35°C; In the lamination step, the protective film on the delivery side of the nip roll is set in the range of 20°C to 35°C. The method for manufacturing a laminated polarizing film of claim 1, wherein the protective film is a transparent film having a surface that is easily adhered to the adhesive. The method for manufacturing a laminated polarizing film according to claim 1 or 2, wherein the protective film is a cellulose triacetate film. The method for manufacturing a laminated polarizing film according to claim 1 or 2, wherein the protective film is a film with a urethane-based easy-adhesive agent. The method for manufacturing a laminated polarizing film of claim 1 or 2, wherein the protective film is an acrylic film with a urethane-based easy-adhesive agent. The method for manufacturing a laminated polarizing film of claim 1 or 2, wherein the aforementioned adhesive is an active energy ray hardening type adhesive. Such as the manufacturing method of the laminated polarizing film of claim 1 or 2, which coats the aforementioned adhesive on the aforementioned protective film with a thickness of 0.1 µm~5 µm. According to the manufacturing method of the laminated polarizing film of claim 1 or 2, after the adhesive is applied to the protective film, the polarizing member is attached to the protective film within 2 to 30 seconds. According to the manufacturing method of the laminated polarizing film of claim 1 or 2, the protective film between the delivery side of the coating roller and the delivery side of the nip roller is maintained in the range of 20°C to 35°C.

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