TWI709479B - Manufacturing method of polarizer, polarizer, polarizer and image display device - Google Patents

Abstract

The present invention provides a method for manufacturing a polarizer capable of realizing multi-functionalization and high-functionalization of electronic devices such as image display devices, which can form a desired shape of a non-polarizing portion with high accuracy. The manufacturing method of the polarizer of the present invention includes the following steps: one side of the polarizer transmits an adhesive layered surface protection film with a thickness of less than 10 μm, and a polarized light having an exposed portion exposing at least a part of the polarizer is produced on one side of the polarizer Thin film laminate; contact the exposed portion of the polarizing film laminate with an alkaline solution; and removing the surface protection film from the polarizing film laminate.

Description

Manufacturing method of polarizer, polarizer, polarizer and image display device Technical field

The present invention relates to a manufacturing method of a polarizer. In more detail, the present invention relates to a method for manufacturing a polarizer with a non-polarizing portion.

Background technique

Video display devices such as mobile phones and notebook computers (PCs) are equipped with internal electronic components such as cameras. For the purpose of improving the camera performance of such an image display device, various reviews have been conducted (for example, Patent Documents 1 to 7). However, due to the rapid spread of smartphones and touch panel-type information processing devices, it is desired to further improve the performance of cameras. In addition, in order to cope with the diversification and high performance of the shape of the image display device, a polarizing plate with partial polarization performance is required. In order to fulfill these requirements in industrial and commercial areas, it is hoped to manufacture image display devices and/or their parts at an allowable cost. There are still various issues that need to be reviewed to establish such a technology.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2011-81315

Patent Document 2: Japanese Patent Application Publication No. 2007-241314

Patent Document 3: US Patent Application Publication No. 2004/0212555 Specification

Patent Document 4: Korean Published Patent No. 10-2012-0118205

Patent Document 5: Korean Patent No. 10-1293210

Patent Document 6: JP 2012-137738 A

Patent Document 7: JP 2014-211548 A

Summary of the invention

The present invention is made to solve the above-mentioned conventional problems, and its main purpose is to provide a method of manufacturing a polarizer that can realize multi-function and high-functioning of electronic devices such as image display devices, which can form desired high precision The shape of the non-polarizing part.

The manufacturing method of the polarizer of the present invention includes the following steps: one side of the polarizer transmits an adhesive layered surface protection film with a thickness of less than 10 μm, and a polarized light having an exposed portion exposing at least a part of the polarizer is produced on one side of the polarizer Thin film laminate; contact the exposed portion of the polarizing film laminate with an alkaline solution; and removing the surface protection film from the polarizing film laminate.

In one embodiment, the step of contacting the exposed portion with an alkaline solution includes immersing the polarizing film laminate in an alkaline solution.

In one embodiment, the adhesive layer contains acrylic resin.

In one embodiment, the manufacturing method further includes the step of contacting the exposed portion of the polarizing film laminate with an acid solution.

In one embodiment, the step of contacting the exposed portion with an acid solution includes immersing the polarizing film laminate in an acid solution.

In one embodiment, the step of contacting the exposed portion with an alkaline solution includes immersing the polarizing film laminate in an alkaline solution, and the step of contacting the exposed portion with an acid solution includes immersing the polarizing film laminate in Acidic solution.

In one embodiment, the above-mentioned polarizing film laminate has an elongated shape.

Another aspect of the present invention is to make a polarizer. The polarizer is made by the above manufacturing method.

Another aspect of the present invention is to produce a polarizing plate. The polarizing plate includes the above-mentioned polarizing member.

Another aspect of the present invention is to provide an image display device. The image display device includes the above-mentioned polarizing plate.

The polarizing film laminated system used in the manufacturing method of the present invention transmits an adhesive laminated surface protective film with a thickness of less than 10 μm on one side of the polarizer. By using such a polarizing film laminate, it is possible to accurately form a non-polarized portion of a desired shape.

1,10‧‧‧Polarizer

2‧‧‧Non-polarized part

20‧‧‧Protective film

30,50‧‧‧Surface protection film

51‧‧‧Exposed part

60‧‧‧Adhesive layer

71‧‧‧through hole

100‧‧‧Polarizing film laminate

a,b‧‧‧The approximate circle distance between the non-polarized part and the non-polarized part

Fig. 1 is a schematic cross-sectional view of a polarizing film laminate used in an embodiment of the present invention.

Figure 2A illustrates a surface protection film used in an embodiment of the present invention A schematic plan view of an example of the through hole arrangement pattern of.

2B is a schematic plan view illustrating another example of the through hole arrangement pattern of the surface protection film used in an embodiment of the present invention.

2C is a schematic plan view illustrating another example of the through hole arrangement pattern of the surface protective film used in an embodiment of the present invention.

Fig. 3A is a schematic diagram illustrating the measurement method of hole roughness. It shows that when the boundary (solid line) between the polarizer 1 and the non-polarized portion 2 is outside the approximate circle (broken line) of the non-polarized portion, the distance a between the non-polarized portion and the non-polarized portion is approximated to the circle.

Fig. 3B is a schematic diagram illustrating the measurement method of hole roughness. It shows that when the boundary (solid line) between the polarizer 1 and the non-polarized portion 2 is located inside the non-polarized portion approximate circle (dotted line), the distance b between the non-polarized portion and the non-polarized portion approximate circle.

The form used to implement the invention

Hereinafter, one embodiment of the present invention will be described, but the present invention is not limited to this embodiment.

A. Manufacturing method of polarizing parts

The manufacturing method of the polarizer of the present invention includes the following steps: pass an adhesive layered surface protection film with a thickness of less than 10 μm on one side of the polarizer, and produce a polarizer with an exposed portion exposing at least a part of the polarizer on one side of the polarizer Thin film laminate; contact the exposed portion of the polarizing film laminate with an alkaline solution; and removing the surface protection film from the polarizing film laminate. By using a polarizing film laminate having an exposed part, only a desired part of the polarizer (that is, the part exposed from the exposed part) can be brought into contact with the alkaline solution. By contacting the polarizer and alkaline solution, the content of the contact part can be reduced The content of dichroic substance, so it can form a non-polarized part with dichroic substance content lower than other parts.

In addition, in the manufacturing method of the present invention, a polarizing film laminate in which a polarizer and a surface protective film are laminated through an adhesive having a thickness of 10 μm or less is used. By making the thickness of the adhesive layer 10μm or less, the surface tension of the adhesive can prevent bubbles from adhering to the exposed part. As a result, the alkaline solution sufficiently contacts the entire exposed portion, and a desired shape of the non-polarized portion can be formed with high accuracy. In addition, the polarizing member before forming the non-polarizing portion is strictly an intermediate of the polarizing member having the non-polarizing portion manufactured by the manufacturing method of the present invention, but it is only referred to as the polarizing member in this specification. As long as those with ordinary knowledge in the relevant technical field have read the description of this specification, they can easily understand that "polarizer" means an intermediate or a polarizer with a non-polarizing portion manufactured by the manufacturing method of the present invention.

A-1. Production of polarizing film laminate

A surface protective film with a thickness of 10 μm or less was laminated on one side of the polarizer to produce a polarizing film laminate. The polarizing film laminate used in the present invention has an exposed portion exposing at least a part of the polarizer on one of the above-mentioned sides.

Fig. 1 is a schematic cross-sectional view of a polarizing film laminate used in an embodiment of the present invention. In this embodiment, a polarizing plate having a structure of a polarizer/protective film is used. The polarizing film laminate 100 is a laminate of a surface protection film 50 on the surface of the polarizer 10 of the laminate of the polarizer 10/protective film 20 that penetrates the adhesive layer 60 with a thickness of 10 μm or less. The surface protection film 50 has a through hole 71. The polarizing film laminate 100 has a polarizer exposed through a through hole 71 10 of the exposed part 51. The surface protection film 50 is releasably laminated on the polarizing plate (substantially the polarizing member 10). In addition, of course, the same procedure can also be applied to polarizers having forms other than the polarizer form (for example, a single resin film polarizer, a resin substrate/polarizer laminate).

In one embodiment, the polarizing film laminate 100 may further laminate another surface protection film (surface protection film 30 in FIG. 1) on the surface where the surface protection film 50 with through holes is not laminated. Hereinafter, the surface protection film 50 with through holes is also referred to as the first surface protection film, and the surface protection film 30 laminated on the side of the surface protection film with through holes that is not laminated on the polarizing film laminate 100 is also referred to as the second surface protection film.

The representative polarizing film laminate is elongated. The elongated polarizing film laminate can be produced, for example, by laminating a elongated surface protection film having through holes arranged at predetermined intervals along the elongate direction and/or width direction and a elongated polarizer. By using the long polarizing film laminate, for example, the step of contacting with an alkaline solution and the step of contacting with other processing liquids (for example, the step of contacting with an acid solution) can be continuously performed by immersion. As a result, the productivity of the polarizer can be further improved. In addition, the elongated polarizing film laminate may have many exposed portions. In such a case, it is also possible to make the alkaline solution sufficiently contact each exposed portion, so that the non-polarized portion of the desired shape can be formed with high accuracy.

In addition, by using a polarizing film laminate, a polarizing element having a non-polarizing portion can be produced by a pattern corresponding to the pattern of the exposed portion, so that the non-polarizing portion can be precisely controlled and arranged on the entire elongated polarizer. As a result, the strip-shaped polarizer cuts the polarized light of a predetermined size as the final product It can significantly control the quality variation of each final product. Moreover, since such a non-polarizing part is selectively and easily formed at the position of the through hole, no complicated device or operation is required. In addition, according to this embodiment, the position of the non-polarizing part can be set according to the size of the polarizing member that is cut and mounted on the image display device as the final product and the position of the camera part of the image display device, so that a predetermined size can be obtained The yield when polarizing parts is excellent.

A-1-1. Polarizing parts

The polarizer is represented by a resin film containing a dichroic substance. The resin film system is, for example, a polyvinyl alcohol-based resin (hereinafter referred to as "PVA-based resin") film. Examples of the dichroic substance include iodine and organic dyes. These dichroic substances may be used alone or in combination of two or more kinds. Among them, iodine is preferred. This is because, as described later, the iodine complex can be reduced by contact with an alkaline solution to reduce the iodine content, and as a result, a non-polarized portion having characteristics suitable for use as part of a camera can be formed.

Any appropriate resin can be used for the resin forming the above-mentioned resin film. It is better to use PVA resin. Examples of PVA-based resins include polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Polyvinyl alcohol can be prepared by saponifying polyvinyl acetate. The ethylene-vinyl alcohol copolymer can be prepared by saponifying an ethylene-vinyl acetate copolymer. The degree of saponification of the PVA-based resin is usually 85 mol% or more and less than 100 mol%, and preferably 95.0 mol% to 99.95 mol%, and 99.0 mol% to 99.93 mol% is more preferable. The degree of saponification can be determined in accordance with JIS K 6726-1994. By using the PVA-based resin with such a degree of saponification, a polarizer with excellent durability can be produced. When the saponification is too high, there is a risk of gelation.

The average degree of polymerization of the PVA-based resin can be appropriately selected according to the purpose. The average degree of polymerization is usually 1,000 to 10,000, preferably 1200 to 4500, and more preferably 1500 to 4300. In addition, the average degree of polymerization can be determined in accordance with JIS K 6726-1994.

The thickness of the polarizer (resin film) can be set to any appropriate value. The thickness is preferably 30 μm or less, preferably 25 μm or less, more preferably 20 μm or less, and particularly preferably less than 10 μm. On the other hand, the thickness is preferably 0.5 μm or more, and more preferably 1 μm or more. If it is such a thickness, by contacting with an alkaline solution, the non-polarizing part can be formed well. In addition, the time of contact with alkaline solutions can be shortened. In addition, the thickness of the part in contact with the alkaline solution may be thinner than other parts. By using a thin resin film, the difference in thickness between the part that is in contact with the alkaline solution and the part that is not in contact with the alkaline solution can be reduced, so that it can be well bonded with other components such as protective films.

The resin film is preferably subjected to various treatments such as swelling treatment, stretching treatment, the above-mentioned dichroic substance dyeing treatment, cross-linking treatment, washing treatment, drying treatment, etc., so that it can function as a polarizer. When various treatments are performed, the resin film may be a resin layer formed on the substrate. The laminate of the substrate and the resin layer can be produced, for example, by a method of applying a coating solution containing the above-mentioned resin film forming material on the substrate, a method of laminating a resin film on the substrate, or the like.

The above-mentioned dyeing treatment is performed, for example, by immersing a resin film in a dyeing liquid. An aqueous iodine solution should be used for the dyeing solution. The blending amount of iodine is preferably 0.04 parts by weight to 5.0 parts by weight relative to 100 parts by weight of water. Since the solubility of iodine in water can be improved, it is ideal to blend iodide in an aqueous iodine solution. Potassium iodide should be used as iodide. Relative to 100 parts by weight of water, the doping of iodide The total amount is preferably 0.3 parts by weight to 15 parts by weight.

In the above-mentioned stretching treatment, the resin film represents uniaxial stretching from 3 to 7 times. In addition, the extending direction may correspond to the direction of the absorption axis of the manufactured polarizer.

A-1-2. Surface protection film

The surface protection film 50 is provided with a through hole 71 corresponding to the portion of the polarizer that is not in contact with the alkaline solution (that is, corresponds to the exposed portion 51 of the polarizing film laminate).

The top view shape of the through hole of the surface protection film can be any suitable shape according to the purpose. Specific examples include, for example, a circle, an oval, a square, a rectangle, and a rhombus. As described above, according to the manufacturing method of the present invention, it is possible to prevent the polarizer exposed from the exposed part from being in contact with the alkaline solution due to the adhesion of bubbles, so that even the more complicated shape (for example, star) and/or small The exposed part of the size can also form the non-polarized part of the desired shape.

The through holes of the surface protection film can be, for example, mechanically punched (for example, punching, engraving knife punching, plotter, waterjet) or removed (for example, laser ablation or chemical dissolution) the predetermined part of the surface protection film To form.

The arrangement pattern (formation pattern) of the through holes can be appropriately set according to the purpose. 2A is a schematic plan view illustrating an example of the through hole arrangement pattern of the surface protection film, FIG. 2B is a schematic plan view illustrating another example of the through hole arrangement pattern, and FIG. 2C is a schematic plan view illustrating another example of the through hole arrangement pattern. For example, as shown in FIG. 2A, the through holes 71 may be arranged at substantially equal intervals along the longitudinal direction and the width direction of the surface protective film 50. In addition, "arranged at substantially equal intervals along the longitudinal direction and width direction" means that the longitudinal direction The interval is equal interval, and the interval in the width direction is equal interval, and the interval in the longitudinal direction and the interval in the width direction are not necessarily equal. For example, when the interval in the longitudinal direction is L1, and the interval in the width direction is L2, L1=L2 or L1≠L2 may be possible. Alternatively, the through holes may be arranged at substantially equal intervals along the longitudinal direction, and at different intervals along the width direction; may be arranged at different intervals along the longitudinal direction, and arranged at substantially equal intervals along the width direction (all not shown) ). When the through holes are arranged at different intervals in the longitudinal direction or the width direction, the intervals between adjacent through holes may all be different, or only a part (the specific interval between adjacent through holes) may be different. In addition, it is also possible to define a plurality of areas along the longitudinal direction of the surface protective film, and to set the interval of the through holes in the longitudinal direction and/or the width direction in each area.

In addition, in one embodiment, the through holes 71 are arranged such that, as shown in FIG. 2A, the straight line connecting the through holes adjacent in the longitudinal direction is substantially parallel to the longitudinal direction, and is connected in the width direction. The straight lines of the adjacent through holes are substantially parallel to the width direction. In another embodiment, the through-hole 71 is arranged such that, as shown in FIG. 2B, the straight line connecting the through-holes adjacent in the longitudinal direction is substantially parallel to the longitudinal direction, and connects adjacent in the width direction. The straight line of the through hole has a predetermined angle θ _W with respect to the width direction. In another embodiment, the through holes 71 are arranged such that, as shown in FIG. 2C, a straight line connecting adjacent through holes in the longitudinal direction has a predetermined angle θ _L with respect to the longitudinal direction, and is connected in the width direction The straight lines of adjacent through holes have a predetermined angle θ _W with respect to the width direction. θ _L and/or θ _W should exceed 0° and be below ±10°. Here, "±" means that the relative reference direction (length direction or width direction) includes either clockwise rotation or counterclockwise rotation.

The embodiments shown in Figs. 2B and 2C have the following advantages. When using a long-length polarizing film laminate, the non-polarized portion can be formed in a desired pattern (a pattern corresponding to the arrangement pattern of the through hole) while being conveyed by a roller. As a result, it is possible to precisely control the arrangement pattern on the entire elongated polarizer to form a non-polarizing portion. Here, in order to improve the display characteristics of the image display device, it is sometimes necessary to displace the absorption axis of the polarizer with respect to the long side or short side of the device by approximately 10°. Since the absorption axis of the polarizer is in the longitudinal direction or the width direction, by forming the non-polarized portion of the pattern as shown in FIG. 2B and FIG. 2C, in this case, the entire elongated polarizer can be unified The positional relationship between the non-polarized portion and the absorption axis is controlled, so that the final product with excellent axis accuracy (hence, excellent optical characteristics) can be obtained. Therefore, the direction of the absorption axis of the single-piece polarizer that is cut (for example, cut and punched in the longitudinal direction and/or the width direction) can be precisely controlled at a desired angle, and each polarized light can be significantly suppressed The unevenness of the absorption axis of the piece. In addition, the arrangement pattern of the through holes is of course not limited to the illustrated example. For example, the through holes 71 may also be arranged such that a line connecting adjacent through holes in the longitudinal direction has a predetermined angle θ _L with respect to the longitudinal direction, and a line connecting adjacent through holes in the width direction is relative to the width The directions are substantially parallel. In addition, it is also possible to define a plurality of areas along the longitudinal direction of the surface protective film 50, and set θ _L and/or θ _W in each area.

The surface protection film is preferably a film with high hardness (for example, elastic modulus). This is because it can prevent the deformation of the through holes, especially when used as a long strip of polarizing film laminate, it can prevent the through holes during transportation and/or pasting Deformed. Examples of surface protection film forming materials include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, and polyamide resins. , Polycarbonate resins, copolymer resins of these resins, etc. Among them, ester resins (especially polyethylene terephthalate resins) are preferred. If it is such a material, the modulus of elasticity is very high, which can prevent the deformation of the through hole, and when used as a long strip of polarizing film laminate, it is difficult to deform the through hole even if tension is applied during transportation and/or pasting. The advantages.

The thickness of the surface protection film can be set to any appropriate value. For example, when used as a long-length polarizing film laminate, it has the advantage that the through holes are hard to deform even if tension is applied during transportation and/or pasting. The thickness of the surface protection film is, for example, 30 μm to 150 μm.

The elastic modulus of the surface protection film is preferably 2.2kN/mm ² to 4.8kN/mm ² . If the elastic modulus of the surface protection film is within this range, deformation of the through hole can be prevented. Especially when used as a long strip of polarizing film laminate, it is difficult to penetrate the hole even if tension is applied during transportation and/or pasting. The advantages of deformation. In addition, the modulus of elasticity is measured in accordance with JIS K 6781.

The stretch degree of the surface protection film is preferably 90% to 170%. If the stretching degree of the surface protection film is within such a range, when used as a long strip of polarizing film laminate, it has the advantage of not being easily broken during transportation. In addition, the degree of stretch is measured in accordance with JIS K 6781.

A-1-3. Adhesive layer

The thickness of the adhesive layer 60 is 10 μm or less, and preferably 5 μm or less. Make When using a polarizing film laminate and contacting an alkaline solution, air bubbles adhere to the surface protection film of the exposed portion, and the alkaline solution may not sufficiently contact the exposed portion. When the size of the exposed portion is small or the shape of the exposed portion is complicated, the effect is significant, and there is a possibility that the non-polarized portion of the desired shape cannot be formed. With the thickness of the adhesive layer within such a range, the surface tension of the adhesive can prevent bubbles from adhering to the exposed portion. As a result, the alkaline solution can sufficiently contact the exposed portion, and a polarizer having a non-polarizing portion of a desired shape can be obtained.

The adhesive layer can be formed using any appropriate composition. The composition for forming an adhesive layer contains, for example, a resin component and any appropriate additives. Any appropriate resin can be used as the base resin of the adhesive, and a resin with a glass transition temperature Tg of 0°C or less is preferred. Specifically, acrylic resins, silicone resins, and urethane resins can be given as examples. From the viewpoint of maintaining the laminated state of the surface protective film and the polarizer even with a thickness of 10 μm or less, acrylic resin is ideal.

The acrylic resin is preferably an acrylic polymer containing at least one acrylate and/or methacrylate (hereinafter, also referred to as (meth)acrylate) having an alkyl group having 1 to 14 carbon atoms. The above-mentioned acrylic polymer preferably contains 50% by weight to 100% by weight of (meth)acrylate having an alkyl group having 1 to 14 carbon atoms as a monomer component.

Examples of (meth)acrylates having an alkyl group having 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylic acid. Tertiary butyl ester, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate Ester, n-nonyl (meth)acrylate, (meth) Isononyl acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-decyl (meth)acrylate Tetraester etc. These (meth)acrylates may be used alone or in combination of two or more kinds.

Among them, it preferably contains butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, N-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, (meth) (Meth)acrylates having an alkyl group having 4 to 14 carbon atoms, such as n-tridecyl acrylate and n-tetradecyl (meth)acrylate. By including the (meth)acrylate having an alkyl group with a carbon number of 4 to 14, the adhesive force can be easily controlled, so it has excellent re-peelability.

The above-mentioned acrylic polymer may contain any appropriate other monomer components in addition to the (meth)acrylate having an alkyl group having 1 to 14 carbon atoms. Other monomer components can include, for example: sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, cyano group-containing monomers, vinyl esters, aromatic vinyl compounds, and other monomers that can help improve cohesion and heat resistance Ingredients, carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, amine group-containing monomers, amine group-containing monomers, epoxy group-containing monomers, N-acryloyl morpholine, vinyl ethers Such as a monomer component having a functional group that improves adhesion or functions as a crosslinking base point. The other monomer components may be used alone or in combination of two or more.

Examples of sulfonic acid group-containing monomers include: styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamide propanesulfonic acid, Sulfopropyl (meth)acrylate, (meth)acryloxynaphthalenesulfonic acid and the like. With The phosphoric acid-based monomer can be exemplified by 2-hydroxyethyl allyl phosphate. The cyano group-containing monomer can be exemplified by acrylonitrile. Vinyl esters can be exemplified by ethyl acetate. The aromatic vinyl compound can be exemplified by styrene.

Examples of carboxylic acid group-containing monomers include: (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxyheptyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, Crotonic acid and so on. Examples of the acid anhydride group-containing monomer include maleic anhydride and itaconic anhydride. Examples of hydroxyl-containing monomers include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and (meth)acrylic acid- 6-hydroxyhexyl ester, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate,-12-hydroxydodecyl (meth)acrylate, (4-hydroxymethyl) Hexyl)-methacrylate, N-methylol (meth)acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monoethylene Ether etc. The amine group-containing monomer can be exemplified by acrylamide and diethyl acrylamide. Examples of the amine group-containing monomer include N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate and allyl glycidyl ether. Vinyl ethers can be exemplified by ethyl vinyl ether.

For example, from the viewpoint of easy adjustment of adhesive force, other monomer components can be used to make the Tg of the obtained polymer below 0°C. In addition, the Tg of the polymer is preferably above -100°C, for example.

The weight average molecular weight of the acrylic polymer is, for example, 100,000 or more.

The above-mentioned acrylic polymer can be produced by any suitable polymerization method. Examples include: solution polymerization, emulsion polymerization, bulk polymerization, suspension Polymerization is generally used as a method of synthesizing acrylic polymers.

The composition for forming an adhesive layer may contain other resins than the aforementioned base resin as a resin component. Examples of other resins include polyether resin, modified polyether resin, and epoxy resin. When other resins are contained, the content of other resins is preferably 20% by weight or less.

The composition for forming an adhesive layer may contain any appropriate additives in addition to the resin component. Examples include: cross-linking agents, coupling agents, adhesion imparting agents, surface lubricants, leveling agents, surfactants, antistatic agents, sliding properties improvers, wettability improvers, antioxidants, corrosion inhibitors, light stabilizers Agents, ultraviolet absorbers, polymerization inhibitors, cross-linking accelerators, cross-linking catalysts, inorganic or organic fillers, metal powders, pigments and other powders, particles, foils, etc.

Any appropriate crosslinking agent can be used as the crosslinking agent. Examples include isocyanate compounds, epoxy compounds, propylene compounds, and melamine compounds. The crosslinking agent may be used alone or in combination of two or more kinds.

Relative to 100 parts by weight of the resin component, the content of the crosslinking agent is preferably 0.1 parts by weight to 15 parts by weight, and more preferably 2 parts by weight to 10 parts by weight.

The adhesive layer can be formed by any appropriate method. Specific examples include a method of coating the composition for forming an adhesive on the surface protection film and drying, and a method of forming an adhesive layer on a separator and transferring the adhesive layer onto the surface protection film. Examples of coating methods include roll coating methods such as reverse coating and gravure coating, spin coating methods, screen coating methods, spray knife coating methods, dip coating methods, and spray coating methods.

In one embodiment, the first surface protection film is an adhesive sheet having an adhesive layer with a thickness of 10 μm or less. The first surface protection film of this embodiment is a laminate having a resin film used as the above-mentioned surface protection film and an adhesive layer provided on one side of the resin film, and has through holes penetrating the resin film and the adhesive layer . When the first surface protection film is an adhesive sheet, the strip polarizer and the strip first surface protection film can be pasted in a roll-to-roll manner, so that the manufacturing efficiency can be further improved. In this embodiment, the separator is temporarily adhered to the adhesive so as to be peelable.

The separator has a function as a protective material for protecting the adhesive layer until it is actually used. The separator can be, for example, a plastic (for example, polyethylene terephthalate (PET)) coated with a release agent such as a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl acrylate release agent. ), polyethylene, polypropylene) film, non-woven fabric or paper, etc. The thickness of the partition can be any appropriate thickness according to the purpose. The thickness of the separator is, for example, 10 μm to 100 μm. The separator can be laminated on the laminate of the resin film and the adhesive layer used as the surface protection film, or the adhesive layer can be formed on the separator and the laminated volume layer of the separator and the adhesive layer can be used as a surface protection film On the resin film used.

In the polarizing film laminate 100, as described above, the second surface protection film 30 may be further laminated on the side where the first surface protection film 50 is not arranged. The second surface protection film may be the same film as the first surface protection film 50 except that no through holes are provided. In addition, the second surface protection film can also be flexible (e.g., polyolefin (e.g., polyethylene) film). For example, low modulus of elasticity) film. By using the second surface protection film, the polarizing plate (polarizer/protective film) can be further properly protected in the step of contacting with the alkaline solution. As a result, the step of contacting the polarizer with the alkaline solution can be performed better.

A-2. Steps of contact with alkaline solution

Next, the alkaline solution is brought into contact with the exposed part of the polarizing film laminate. By contacting the alkaline solution, the content of the dichroic substance in the exposed part can be reduced, so the non-polarizing part can be formed by reducing the content of the dichroic substance. In addition, the polarizer used in the polarizing film laminate is preferably a polarizer containing iodine as described above. When the polarizer contains iodine as a dichroic substance, by contacting the exposed part of the polarizer and the alkaline solution, the iodine content of the exposed part can be reduced. As a result, the non-polarized part can be selectively formed only in the exposed part. Therefore, it is possible to selectively form the non-polarized portion on the predetermined portion of the polarizer without complicated operations and with very high manufacturing efficiency. In addition, when iodine remains in the polarizer, even if the iodine complex is destroyed to form a non-polarized portion, the iodine complex will be formed again with the use of the polarizer, and the non-polarized portion may not have the desired characteristics. In the present invention, the iodine itself can be removed by a polarizer (essentially a non-polarizing part). As a result, it is possible to prevent the characteristics of the non-polarizing portion from changing with the use of the polarizer.

Any appropriate means can be used for the step of contacting the alkaline solution with the polarizing film laminate. Examples include dipping, dripping, coating, spraying, and the like. As described above, by using the first surface protection film (and, if necessary, the second surface protection film), the iodine content of the polarizing member can be reduced in the part other than the exposed part of the polarizing film laminate. A non-polarized portion is formed in the desired portion. Specifically, by combining polarizing film laminates When immersed in an alkaline solution, only the exposed part of the polarizing film laminate is in contact with the alkaline solution.

The formation of the non-polarizing portion by the alkaline solution will be described in more detail below. After contacting the exposed part of the polarizing film laminate, the alkaline solution penetrates into the exposed part (specifically, the polarizer). The iodine complex contained in the polarizer is reduced by the alkali contained in the alkaline solution to become iodine. By reducing the iodine complex to iodide ions, the polarization performance of the polarizer exposed from the exposed part is substantially eliminated, and a non-polarizing part is formed in the exposed part. In addition, by reducing the iodine complex, the transmittance of the exposed part can be improved. Iodine, which becomes iodide ion, moves from the exposed part to the solvent of the alkaline solution. As a result, iodide ions are removed from the polarizer together with the alkaline solution. In this way, the non-polarized portion can be selectively formed in the predetermined portion of the polarizer, and the non-polarized portion will be stable without changing with time. In addition, by adjusting the material, thickness and mechanical properties of the first surface protection film, the concentration of the alkaline solution, and the immersion time of the polarizing film laminate in the alkaline solution, it is possible to prevent the alkaline solution from penetrating into an undesirable part (As a result, a non-polarized portion is formed in an undesired portion).

Any appropriate alkaline compound can be used for the alkaline compound contained in the alkaline solution. Examples of basic compounds include: alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, inorganic alkali metal salts such as sodium carbonate, and organic Alkali metal salts, ammonia water, etc. The alkaline compound contained in the alkaline solution is preferably an alkali metal hydroxide, and sodium hydroxide, potassium hydroxide, and lithium hydroxide are more preferred. By using an alkaline solution containing an alkali metal hydroxide, the iodine complex can be ionized efficiently, so that the non-polarized portion can be formed more simply. The alkali Sexual compounds may be used alone or in combination of two or more kinds.

Any appropriate solvent can be used as the solvent of the above alkaline solution. Specifically, for example, alcohols such as water, ethanol, and methanol, ethers, benzene, chloroform, and mixed solvents of these solvents can be mentioned. Since iodide ions can move well into the solvent and can easily remove iodide ions, the solvent is preferably water or alcohol.

The concentration of the above alkaline solution is, for example, 0.01N to 5N, and preferably 0.05N to 3N, and more preferably 0.1N to 2.5N. If the concentration of the alkaline solution is within such a range, the iodine content inside the polarizer can be efficiently reduced, and the iodine complex compound can be prevented from ionizing in parts other than the exposed portion.

The liquid temperature of the above alkaline solution is, for example, 20°C to 50°C. The contact time between the polarizing film laminate (essentially the exposed part of the polarizer) and the alkaline solution can be set according to the thickness of the polarizer, the type of alkaline compound contained in the alkaline solution used, and the concentration of the alkaline compound, for example , 5 seconds to 30 minutes.

After the alkaline solution is in contact with the exposed part of the polarizer (after forming the non-polarizing part), it can be removed by any appropriate means as needed. Specific examples of the method of removing the alkaline solution include, for example, wiping removal with a rag or the like, suction removal, natural drying, heat drying, air drying, reduced-pressure drying, and washing. The drying temperature when the alkaline solution is removed by drying is, for example, 20°C to 100°C.

A-3. Removal steps of surface protective film

After necessary steps, the surface protective film can be removed from the polarized film laminate. As mentioned above, the surface protection film is releasably attached to the surface of the polarizer through the adhesive layer. Therefore, make the polarization with non-polarized light part

After the steps required by the light element, it can be easily removed from the surface of the polarizer.

A-4. Other steps

The manufacturing method of the non-polarized portion having the non-polarized portion of the present invention may further include the step of making a polarizing film laminate, the step of contacting the exposed portion of the polarizing film laminate with an alkaline solution, and the step of removing the surface protective film. Any appropriate step. For other steps, the step of contacting with the acid solution and the washing step can be cited as examples.

A-4-1. Steps in contact with acidic solution

The manufacturing method of the present invention may further include a step of contacting the exposed portion of the polarizing film laminate with an acid solution. By further including the step of contacting with an acidic solution, the non-polarized portion of the desired size and shape can be maintained more stably (especially in a humidified environment). The step of contacting with the acidic solution can be performed after the step of contacting with the alkaline solution, for example.

Any appropriate acidic compound can be used for the acidic compound contained in the acidic solution. Examples of acidic compounds include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrogen fluoride, and boric acid, and organic acids such as formic acid, oxalic acid, citric acid, acetic acid, and benzoic acid. The concentration of the acidic solution is, for example, 0.01N to 5N, and preferably 0.05N to 3N, and more preferably 0.1N to 2.5N.

The solvent used for the acidic solution, the liquid temperature of the acidic solution, the contact time with the acidic solution, and the contact method can be the same conditions as those used in the alkaline solution contacting step described in A-2 above.

The step of contacting with the acid solution is preferably carried out before the step of peeling off the above-mentioned surface protection film (specifically, in the state of the polarizing film laminate). It can be in contact with alkaline solution by working in the state of polarizing film laminate The step of continuously carrying out the step of contacting with the acidic solution.

A-4-2. Washing steps

The manufacturing method of the present invention may further include a washing step. The washing step can be performed only once or multiple times. The washing step can be performed at any appropriate stage of the manufacturing step of the polarizer having the non-polarizing portion. For example, after washing the polarizer in contact with the alkaline solution with any suitable liquid, the step of contacting with the acid solution can be carried out, or after the step of contacting with the alkaline solution and the step of contacting with the acid solution, any Wash steps with appropriate liquids.

Any appropriate liquid can be used for the cleaning liquid. Examples include pure water, alcohols such as methanol and ethanol, acidic aqueous solutions, and mixed solvents of these liquids. In addition, the temperature of the liquid used can be set to any appropriate temperature.

B. Polarizing parts with non-polarizing parts

The polarizer manufactured by the method of the present invention can have a non-polarized portion of a desired shape and size formed with high precision. Therefore, the polarizer of the present invention can have excellent performance and design.

The polarizing member with the non-polarizing part, for example, can be used in an image display device with a camera. This is because even when the non-polarized portion of a smaller size is formed, the camera can fully exert its camera function, and the appearance of the obtained image display device is also good.

As long as the top view shape of the non-polarized portion does not adversely affect the camera performance of the image display device, any appropriate shape can be adopted. In addition, the transmittance of the non-polarized part (for example, measured at 23°C with light with a wavelength of 550nm The transmittance) is preferably 50% or more, more preferably 60% or more, more preferably 75% or more, and particularly preferably 90% or more. With such a transmittance, the desired transparency as a non-polarizing part can be ensured. As a result, when the polarizing element is arranged in such a way that the non-polarizing part corresponds to the camera part of the image display device, it is possible to prevent the adverse effect on the photographing performance of the camera.

The non-polarized part is the part with less dichroic substance content than other parts of the polarizer (parts with polarizing properties). The content of the dichroic substance contained in the non-polarizing portion is preferably 1.0% by weight or less, preferably 0.5% by weight or less, and more preferably 0.2% by weight or less. In addition, the lower limit of the content of the dichroic substance in the non-polarizing part is usually below the detection limit value. If the content of the dichroic substance in the non-polarized portion is within such a range, not only can the non-polarized portion be imparted with the desired transparency, but when the non-polarized portion is used as the part of the camera corresponding to the image display device, the brightness and hue are both From the aspect of point of view, very excellent photographic performance can also be achieved. In addition, when iodine is used as a dichroic substance, the iodine content of the non-polarized part is the value obtained by the X-ray intensity measured by fluorescent X-ray analysis using a calibration curve prepared in advance using a standard sample.

The difference between the content of the dichroic substance contained in the part other than the non-polarized part (part with polarizing properties) of the polarizer and the content of the dichroic substance contained in the non-polarized part is preferably 0.5% by weight or more, and more preferably 1% by weight or more . Since the difference between the content of the dichroic substance contained in the part other than the non-polarized part and the content of the dichroic substance contained in the non-polarized part is within such a range, the non-polarized part can have sufficient transparency, for example, it can be used ideally The non-polarized part serves as the camera part corresponding to the image display.

C. Polarizing parts

Practically, a polarizer can be provided to make a polarizing plate. The polarizer has a polarizer and a protective film disposed on at least one side of the polarizer. Practically, the polarizing plate has an adhesive layer as the outermost layer. The representative adhesive layer becomes the outermost layer on the side of the image display device. The separator is temporarily adhered to the adhesive layer in a peelable manner.

The forming material of the protective film includes, for example, cellulose resins such as diacetyl cellulose and triacetyl cellulose, (meth)acrylic resins, cycloolefin resins, olefin resins such as polypropylene, and polymer Ester resins such as ethylene phthalate resins, polyamide resins, polycarbonate resins, copolymer resins of these resins, etc. The thickness of the protective film is preferably 10 μm to 100 μm. The representative protective film is laminated on the polarizer through the adhesive layer (specifically, the adhesive layer and the adhesive layer). The representative adhesive layer is formed of a PVA-based adhesive or an activated energy beam curing type adhesive. The representative adhesive layer is formed of acrylic adhesive.

The polarizing plate may further have any appropriate optical function layer according to the purpose. Representative examples of optical functional layers include retardation films (optical compensation films) and surface treatment layers. In addition, the above-mentioned protective film may also have an optical compensation function (specifically, it may have an appropriate refractive index ellipsoid, in-plane retardation, and thickness direction retardation according to the purpose).

The surface treatment layer can be arranged on the viewing side of the polarizer. Representative examples of surface treatment layers include rod coatings, anti-reflection layers, and anti-glare layers.

D. Image display device

The image display device of the present invention has the above-mentioned polarizer. Examples of image display devices include liquid crystal display devices and organic EL devices. Specifically, LCD The display device has a liquid crystal panel, and the liquid crystal panel includes a liquid crystal cell and the above-mentioned polarizers arranged on one or both sides of the liquid crystal cell. The organic EL device has an organic EL panel in which the polarizer is arranged on the viewing side. The polarizer can be configured such that the non-polarizing part corresponds to the camera part of the mounted image display device.

Example

Hereinafter, the present invention will be specifically explained through examples, but the present invention is not limited to these examples.

[Production example 1] Production of surface protective film 1 with adhesive layer

Mix 100 parts by weight of acrylic resin (acrylic polymer with a weight average molecular weight of 600,000 formed by a composition ratio of butyl acrylate/acrylic acid = 95/5) and 5 parts by weight of epoxy crosslinking agent (MITSUBISH GAS CHEMICAL (Stock) system, trade name: TETRAD-C), to prepare acrylic adhesive 1.

On a long strip (width 1200mm, length 43m) 38μm thick PET film (manufactured by MITSUBISH CHEMICAL POLYESTER FILM (stock), trade name: Diafoil T100C), coated with acrylic adhesive to make the thickness after drying 10μm , Form an adhesive layer. The separator is pasted on the formed adhesive layer to prepare an adhesive sheet. On the prepared adhesive sheet, use a pinnacle knife to form 1,000 circular holes with a diameter of 2 mm. The small holes were formed at an interval of 250 mm in length and 400 mm in width to produce a surface protective film 1 with an adhesive layer.

[Production example 2] Production of surface protective film 2 with adhesive layer Make

Except that the thickness of the adhesive layer was 5 μm, a surface protection film 2 having an adhesive layer was produced in the same manner as in Production Example 1.

[Production example 3] Production of surface protective film C1 with adhesive layer

Except that the thickness of the adhesive layer was 30 μm, a surface protective film C1 having an adhesive layer was produced in the same manner as in Production Example 1.

[Production example 4] Production of surface protective film C2 with adhesive layer

Except that the thickness of the adhesive layer was 20 μm, a surface protective film C2 having an adhesive layer was produced in the same manner as in Production Example 1.

[Production Example 5] Production of surface protective film C3 with adhesive layer

Except that the thickness of the adhesive layer was 15 μm, a surface protective film C3 having an adhesive layer was produced in the same manner as in Production Example 1.

[Production Example 6] Production of surface protective film 3 with adhesive layer

Mix 100 parts by weight of acrylic resin (acrylic polymer with a weight average molecular weight of 500,000 formed by the composition ratio of 2-ethylhexyl acrylate/2-hydroxyethyl acrylate = 96/4), and 4 parts by weight of isocyanate Coupling agent (manufactured by NIPPON POLYURETHANE INDUSTRY (Stock), trade name: CORONATE HX) to prepare acrylic adhesive 2.

A long strip (1200mm in width, 43m in length) of 38μm thick PET film (manufactured by Toyobo Co., Ltd., trade name: E5000) is coated with acrylic The acid-based adhesive makes the thickness after drying 10μm to form an adhesive layer. The separator is pasted on the formed adhesive layer to prepare an adhesive sheet. On the prepared adhesive sheet, use a sharp knife to form 1,000 circular holes with a diameter of 2 mm. The small holes were formed at an interval of 250 mm in length and 400 mm in width to produce a surface protective film 3 with an adhesive layer.

[Production example 7] Production of surface protective film 4 with adhesive layer

Except that the thickness of the adhesive layer was 5 μm, a surface protection film 4 having an adhesive layer was produced in the same manner as in Production Example 6.

[Production Example 8] Production of surface protective film C4 with adhesive layer

Except that the thickness of the adhesive layer was 30 μm, a surface protective film C4 having an adhesive layer was produced in the same manner as in Production Example 6.

[Production Example 9] Production of surface protective film C5 with adhesive layer

Except that the thickness of the adhesive layer was 20 μm, a surface protective film C5 having an adhesive layer was produced in the same manner as in Production Example 6.

[Production Example 10] Production of surface protective film C6 with adhesive layer

Except that the thickness of the adhesive layer was 15 μm, a surface protective film C6 having an adhesive layer was produced in the same manner as in Production Example 6.

[Production Example 11] Production of surface protective film 5 with adhesive layer

In addition to making the diameter of the small hole formed on the adhesive sheet 4mm, the In Example 1, a surface protective film 5 with an adhesive layer was produced in the same manner.

[Production Example 12] Production of surface protective film 6 with adhesive layer

A surface protective film 6 having an adhesive layer was produced in the same manner as in Production Example 2 except that the diameter of the small holes formed in the adhesive sheet was 4 mm.

[Production Example 13] Production of surface protective film C7 with adhesive layer

A surface protective film C7 having an adhesive layer was produced in the same manner as in Production Example 3 except that the diameter of the small hole formed in the adhesive sheet was 4 mm.

[Production Example 14] Production of surface protective film C8 with adhesive layer

Except that the diameter of the small hole formed in the adhesive sheet was 4 mm, a surface protective film C8 having an adhesive layer was produced in the same manner as in Production Example 4.

[Production Example 15] Production of surface protective film C9 with adhesive layer

A surface protective film C9 having an adhesive layer was produced in the same manner as in Production Example 5, except that the diameter of the small holes formed in the adhesive sheet was 4 mm.

[Production Example 16] Production of surface protective film 7 with adhesive layer

A surface protective film 7 having an adhesive layer was produced in the same manner as in Production Example 6, except that the diameter of the small holes formed in the adhesive sheet was 4 mm.

[Production Example 17] Production of surface protective film 8 with adhesive layer

In addition to making the diameter of the small hole formed on the adhesive sheet 4mm, the In Example 7, a surface protective film 8 having an adhesive layer was produced in the same manner.

[Production Example 18] Production of surface protective film C10 with adhesive layer

Except that the diameter of the small holes formed in the adhesive sheet was 4 mm, a surface protection film C10 having an adhesive layer was produced in the same manner as in Production Example 8.

[Production Example 19] Production of surface protective film C11 with adhesive layer

A surface protective film C11 having an adhesive layer was produced in the same manner as in Production Example 9 except that the diameter of the small hole formed in the adhesive sheet was 4 mm.

[Production Example 20] Production of surface protective film C12 with adhesive layer

A surface protective film C12 having an adhesive layer was produced in the same manner as in Production Example 10 except that the diameter of the small hole formed in the adhesive sheet was 4 mm.

<Example 1>

A long strip of amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100μm) with a water absorption rate of 0.75% and a Tg of 75°C is used as the substrate. On one surface of the substrate, corona treatment is performed, and on the corona treatment surface, it is coated and dried at 25°C and contains polyvinyl alcohol in a ratio of 9:1 (polymerization degree 4200, saponification degree 99.2 mol%) And an aqueous solution of acetyl acetyl modified PVA (polymerization degree 1200, acetyl acetyl modified degree 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z200"), A PVA-based resin layer with a thickness of 11 μm was formed to form a laminate.

Make the resulting laminate in an oven at 120℃ between rollers with different peripheral speeds The free end is uniaxially extended to 2.0 times in the longitudinal direction (long side direction) (assisted extension in air).

Next, the layered body was immersed in an insolubilization bath (a boric acid aqueous solution prepared by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 30°C for 30 seconds (insolubilization treatment).

Next, while adjusting the iodine concentration and the immersion time, the polarizer was immersed in a dyeing bath at a liquid temperature of 30°C so that the polarizing plate had a predetermined transmittance. In this embodiment, it is immersed in an aqueous solution of iodine prepared by mixing 0.2 parts by weight of iodine and 1.5 parts by weight of potassium iodide with respect to 100 parts by weight of water for 60 seconds (dyeing treatment).

Next, immerse in a cross-linking bath (with respect to 100 parts by weight of water, 3 parts by weight of potassium iodide, and 3 parts by weight of boric acid to prepare a boric acid aqueous solution) for 30 seconds (cross-linking Joint processing).

Then, the layered body was immersed in an aqueous solution of boric acid (an aqueous solution prepared by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 70°C. Uniaxial stretching is carried out in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds, so that the total stretching ratio is 5.5 times (underwater stretching).

Then, the layered body was immersed in a washing bath (an aqueous solution prepared by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water with a liquid temperature of 30°C) (washing treatment).

Next, on the surface of the PVA resin layer of the laminate, a PVA resin aqueous solution (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., brand name "GOHSEFIMER (registered trademark) Z-200", resin concentration: 3 weight %) and paste a protective film (thickness 25μm), and then heat it in an oven maintained at 60°C for 5 minutes. Then, the substrate was peeled off from the PVA-based resin layer, and a polarizing plate (width: 1200 mm, length 43 m) having a polarizer with a transmittance of 42.3% and a thickness of 5 μm was produced.

Next, on the side surface of the polarizer of the obtained polarizer, the surface protective film 1 with the adhesive layer of the separator was pasted through the adhesive layer to obtain a laminate. The resulting laminate was immersed in an alkaline solution (aqueous sodium hydroxide solution, 1 mol/L (1N)) at room temperature for 8 seconds and 0.1 mol/L (0.1N) hydrochloric acid for 30 seconds. Then, it was dried at 60° C., and the PET film was peeled off to prepare a polarizing plate including a polarizer having a transparent portion.

[Examples 2 to 8]

A polarizing plate including a polarizer having a transparent part was produced in the same manner as in Example 1, except that the surface protective films having an adhesive layer described in Table 1 were used.

(Comparative Examples 1 to 12)

A polarizing plate including a polarizer having a transparent part was produced in the same manner as in Example 1, except that the surface protective films having an adhesive layer described in Table 1 were used.

The transmittance and iodine content of the transparent part of the polarizer formed in each Example and Comparative Example were measured by the following methods.

1. Transmittance (Ts)

Measure with a spectrophotometer (manufactured by Murakami Color Technology Research Institute Co., Ltd., product name "DOT-3"). The transmittance (T) is the Y value after the visual sensitivity is corrected by the 2 degree field of view (C light source) of JIS Z 8701-1982.

2. Iodine content

The iodine content of the transparent part of the polarizer was obtained by fluorescence X-ray analysis. Specifically, from the X-ray intensity measured under the following conditions, the iodine content of the polarizer is obtained by using a calibration curve prepared in advance using a standard sample.

Analysis device: Rigaku Denki Kogyo's fluorescent X-ray analysis device (XRF) product name "ZSX100e"

On the cathode: rhodium

Spectroscopic crystal: lithium fluoride

Excitation light energy: 40kV-90mA

Iodine measuring line: I-LA

Quantitative method: FP method

2θ angle peak: 103.078deg (iodine)

Measuring time: 40 seconds

The transparent part of the polarizer prepared in each of the Examples and Comparative Examples has a transmittance of more than 90% and an iodine content of less than 1% by weight. These transparent parts can function as non-polarizing parts.

[Evaluation method]

The shape conformity of each transparent part formed on the polarizing plate was measured by the following method. Among the 1000 transparent parts on the polarizer, the ratio of the shape conformity of more than 0.05 is defined as ◎ if the degree of conformity is 40% or less, ○ if it is 50% or less, and × if it exceeds 60%. The results are shown in Table 1.

[Shape Integration Degree]

The ultra-high-speed flexible video display system (manufactured by KEYENCE, trade name: XG7700) was used to perform the preparations in Examples 1 to 8 and Comparative Examples 1 to 12 The edge of the non-polarized part of the polarizer is detected, and the approximate circle of the non-polarized part is obtained. Measure the distance between the approximate circle of the non-polarized portion (the dotted line in Figs. 3A and 3B) and the boundary of the polarizer 1 and the non-polarized portion 2 (the solid line in Figs. 3A and 3B) every 2° to obtain the total A distance of 180 points. As far as the measurement point is concerned, when the boundary between the polarizer 1 and the non-polarized portion 2 is outside the approximate circle of the non-polarized portion (that is, in the case of FIG. 3A), the distance a between the non-polarized portion 2 and the approximate circle of the non-polarized portion is measured, and When the boundary between the polarizer 1 and the non-polarized portion 2 is located inside the approximate circle of the non-polarized portion (ie, in the case of FIG. 3B), the distance b between the non-polarized portion 2 and the approximate circle of the non-polarized portion is measured. Calculate the sum of the maximum value of distance a and the maximum value of distance b as the hole roughness. The calculated hole roughness value is divided by the diameter of the small holes formed in the PET film (Examples 1 to 4 and Comparative Examples 1 to 3 and 7 to 9: 2mm, Examples 5 to 8 and Comparative Examples 4 to 6 and 10 to 12: 4mm) to obtain the value of the degree of shape integration.

Examples 1 to 8 using polarizing film laminates with an adhesive layer having a thickness of 10 μm or less produced polarizers having non-polarizing portions corresponding to the shape of the small holes formed on the PET film with high yield. If it is a polarizing element having such a non-polarizing portion, for example, when the non-polarizing portion is used in a way that the non-polarizing portion corresponds to the part of the camera portion of the image display device, the alignment processability can be improved, and therefore the camera can be well aligned. Even in Examples 1 to 4 in which the small holes provided in the surface protection film are as small as 2 mm, a polarizer having a non-polarizing portion close to the shape of the small hole formed on the PET film can be produced.

Industrial availability

The polarizer made by the method of the present invention is suitable for wisdom Video display devices (liquid crystal display devices, organic EL devices) with cameras such as mobile phones such as mobile phones, notebook PCs, and tablet PCs.

10: Polarizing parts

20: Protective film

30, 50: Surface protection film

51: Exposed

60: Adhesive layer

71: Through hole

100: Polarized film laminate

Claims (10)

A manufacturing method of a polarizer with a non-polarizing part, comprising the following steps: pass an adhesive layered surface protection film with a thickness of less than 10μm on one side of the polarizer, and make at least a part of the polarizer exposed on one side of the polarizer The exposed part of the polarizing film laminate; contacting the exposed part of the polarizing film laminate with an alkaline solution; and removing the surface protection film from the polarizing film laminate. The method for manufacturing a polarizer according to claim 1, wherein the step of contacting the exposed portion with an alkaline solution includes immersing the polarizing film laminate in an alkaline solution. The method for manufacturing a polarizing member according to claim 1, wherein the adhesive layer contains acrylic resin. The method for manufacturing a polarizer of claim 1, which further includes the step of contacting the exposed portion of the aforementioned polarizing film laminate with an acid solution. The method for manufacturing a polarizing member according to claim 4, wherein the step of contacting the exposed portion with an acid solution includes immersing the polarizing film laminate in an acid solution. The method for manufacturing a polarizing member according to claim 5, wherein the step of contacting the exposed portion with an alkaline solution includes immersing the polarizing film laminate in an alkaline solution, and the step of contacting the exposed portion with an acid solution includes The polarizing film laminate is immersed in an acid solution. Such as the manufacturing method of the polarizing element of any one of claims 1 to 6, wherein the aforementioned The polarizing film laminate is elongated. A polarizer is produced by the method of any one of Claims 1 to 7. A polarizing plate having the polarizing element as claimed in claim 8. An image display device having the polarizing plate as claimed in claim 9.

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