KR20110042481A - Cutting method of optical film laminate - Google Patents

Abstract

PURPOSE: A cutting method of an optical film laminate is provided to reduce cracks and delamination occurred when an optical film laminate is cut by optimizing the angle range of a blade. CONSTITUTION: A cutting method of an optical film laminate is as follows. An optical film laminate is a polarizing plate with polarizer protective films. The optical film laminate is cut using a cutting blade(20). The thickness of the polarizing plate is less than 150 micrometer. The tensile modulus of the optical film laminate is 9~12 Giga-Pascal. The angle of the blade of the cutting blade is 10~30.

Description

CUTTING METHOD OF OPTICAL FILM LAMINATE}

The present invention relates to a method for cutting an optical film laminate that can improve the quality of the cut surface by suppressing the occurrence of cracks and lamination during the cutting process of the optical film laminate.

The optical film laminate is obtained by laminating two or more optical films via an adhesive or an adhesive, and typical examples thereof include a polarizing plate.

The polarizing plate is an essential member of a liquid crystal display device (LCD), and is used to protect both sides of the polyvinyl alcohol polarizer and the polarizer, which are stretched in a certain direction and adsorbed and oriented with an iodine compound or a dichroic polarizer. It comprises a laminated polarizer protective film. In more detail, a conventional polarizing plate has a polarizer protective film having a thickness of 50 to 90 μm laminated on both sides of a polarizer having an elongation ratio of 5 to 6.5 times, and thus exhibits a tensile modulus of less than 9 GPa, mostly 4.5 to 6 GPa.

Such a polarizing plate is cut into a predetermined shape or dimension from a disc on a long sheet, bonded to a liquid crystal panel, and mounted. However, a problem may occur in that the quality of the cut surface is deteriorated due to cracking or delamination. Crack is a phenomenon that the polarizer does not withstand the shear stress and the resulting deformation caused by the blade cutting the polarizer, and cracks occur partially. Delamination is another optical film adjacent to any optical film constituting the polarizer. It shows the phenomenon that interlayer peeling occurs at the bonding surface of.

On the other hand, in recent years, the demand for higher performance and thinning of the liquid crystal display device has been further increased. Accordingly, the draw ratio of the polarizer constituting the polarizing plate is higher, and the thickness of the optical film is becoming thinner and the width is wider. The tensile modulus of elasticity of the film is increasing. In addition, as the production speed was increased, the occurrence of cracks and laminations during cutting was greatly increased.

In order to solve this problem, the optical film laminate, that is, to polish the cut surface of the polarizing plate, there is a problem that the productivity is reduced by increasing the amount of polishing and the number of polishing due to the increase of cracks and lamination phenomenon.

Japanese Laid-Open Patent Publication No. 2009-113123 discloses a method for solving the problem of cracking and lamination of a polarizing plate, in particular a polarizing plate having a hard coating layer having a pencil hardness of 4H or more, by adjusting the angle of incidence of a blade during cutting of the polarizing plate. However, this method did not solve the crack or delamination phenomenon generated during cutting of the polarizing plate having a high tensile modulus of elasticity.

The present inventors have intensively studied to solve the problems of the prior art, and as a result of cutting various optical film laminates, especially laminates having high tensile modulus of elasticity, the angle of the blade of the cutting knife (θ) When adjusting the thickness, cutting speed and the like with the cutting knife, it was confirmed that it is possible to improve the cutting processing quality by suppressing the cracks and the lamination phenomenon generated in the cutting surface, to complete the present invention based on this.

Accordingly, an object of the present invention is to provide a method for cutting an optical film laminate that can suppress the occurrence of cracks and lamination.

In order to achieve the above object, the present invention is a method for cutting an optical film laminate having a tensile modulus of elasticity of 9 to 12 GPa, using the cutting knife having a blade angle (θ) of 10 to 30 ° It provides a cutting method of an optical film laminate, characterized in that for cutting.

According to the present invention, there is a significant reduction in cracks and delamination phenomena generated during cutting of various optical film laminates, such as polarizing plates having a high draw ratio, a thin thickness, a wide width, and a high tensile modulus of elasticity. Can improve the cutting quality, and can reduce the amount of polishing and the number of times of the cutting surface to improve the productivity.

The present invention relates to a method for cutting an optical film laminate that can improve the quality of the cut surface by suppressing the occurrence of cracks and lamination during the cutting process of the optical film laminate.

Hereinafter, the present invention will be described in more detail.

The cutting method of the optical film laminate of the present invention is a method of cutting an optical film laminate having a tensile modulus of 9 to 12 GPa, wherein the optical film laminate using a cutting knife having an angle? Of 10 to 30 °. It characterized in that the cutting.

As used herein, the term “optical film laminate” means that two or more optical films, for example, polarizers (polarizing films), retardation films, various protective films, and the like are laminated via an adhesive or an adhesive.

In this invention, a polarizing plate is demonstrated as an example as an optical film laminated body.

The polarizing plate which is an optical film laminate according to an embodiment of the present invention may have a structure in which a polarizer protective film is laminated on one or both surfaces of the polarizer. Preferably, as including a polarizer protective film laminated on both sides of the polarizer, it is particularly preferable that the polarizing plate having a thickness of at least one of the polarizer protective film is 40㎛ or less and the total thickness is 150㎛ or less.

In addition, the polarizing plate which is an optical film laminate according to an embodiment of the present invention, as shown in Figure 1, the surface protective film 11, polarizer protective film 12, polarizer 13, polarizer protective film 14, The pressure-sensitive adhesive layer 15 and the release film 16 may be laminated in order.

The surface protection film 11 is a film for protecting the outermost layer of the polarizing plate, the pressure-sensitive adhesive layer may be formed on the base film. As a base film for surface protection films, Polycarbonate film; Polyester-based films such as polyethylene terephthalate; Polyether sulfone-based film; Polyolefin film, such as a polyolefin film which has a polyethylene, a polypropylene, a cyclo system, or norbornene structure, an ethylene propylene copolymer, etc. can be used. In addition, the pressure-sensitive adhesive layer may be formed of a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive resin commonly used in the art. As the pressure-sensitive adhesive resin using an acrylic pressure-sensitive adhesive resin, that is, a copolymer of an acrylic monomer having an alkyl group having 1 to 14 carbon atoms and a monomer having a crosslinkable functional group, has a low adhesive force to the adherend, and thus has excellent re-peelability. desirable.

As the polarizer 13, one in which the dichroic dye is adsorbed and oriented on a film made of polyvinyl alcohol-based resin can be used. As a polyvinyl alcohol-type resin which comprises a polarizer, the copolymer of polyvinyl acetate which is a homopolymer of vinyl acetate, and vinyl acetate and the other monomer copolymerizable with this can be used. In this case, examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, and acrylamides having an ammonium group. The thickness of the polarizer is not particularly limited and can be produced in a conventional thickness.

The polarizer protective films 12 and 14 are preferably those having excellent transparency, mechanical strength, thermal stability, moisture shielding, isotropy, and the like, and for example, polyester type such as polyethylene terephthalate, polyethylene isophthalate, and polybutylene terephthalate. film; Cellulose films such as diacetyl cellulose and triacetyl cellulose; Polycarbonate film; Acrylic films such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene films such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin-based films such as polyethylene, polypropylene, cyclo- or polyolefin-based films having a norbornene structure, and ethylene propylene copolymers; Polyimide film; Polyether sulfone-based film; A sulfone film etc. can be used, The thickness of these is also not specifically limited. Among them, a triacetyl cellulose film is mainly used.

In addition, a functional coating layer, such as a hard coating layer, an antireflection layer, a low reflection layer, an antiglare layer, an antistatic layer, may be further formed on a surface which is not bonded to the polarizer of the polarizer protective film 12.

The pressure-sensitive adhesive layer 15 may be formed of a pressure-sensitive adhesive composition commonly used in the art, which includes a pressure-sensitive adhesive resin and a crosslinking agent as a layer for bonding to a liquid crystal cell.

As the pressure-sensitive adhesive resin, an acrylic copolymer, natural rubber, styrene-isoprene-styrene (SIS) block copolymer, styrene-butadiene-styrene (SBS) block copolymer, styrene-ethylene butylene-styrene (SEBS) block copolymer, Conventional polymers such as styrene-butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber and silicone rubber can be used, and acrylic copolymers can be preferably used.

As an acryl-type copolymer, the copolymer of the monomer which has a crosslinkable functional group with the (meth) acrylate monomer of C1-C14 of an alkyl group can be used. In this case, (meth) acrylate means both acrylate and methacrylate.

Specific examples of the (meth) acrylate monomer having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t- Butyl (meth) acrylate, isobutyl (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, n-tridecyl (meth) Acrylate, n-tetradecyl (meth) acrylate, etc. are mentioned. The (meth) acrylate monomer having 1 to 14 carbon atoms is preferably included at 50 to 99% by weight based on the total monomer content (100% by weight) of the acrylic copolymer.

The monomer having a crosslinkable functional group reacts with a crosslinking agent to impart cohesion force or adhesive strength by chemical bonding so that cohesive force breakdown of the pressure sensitive adhesive does not occur under high temperature or high humidity conditions. For example, a sulfonic acid group-containing monomer and a phosphate group-containing monomer , Cyano group-containing monomers, vinyl esters, aromatic vinyl compounds, carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxy group-containing monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, epoxy group-containing monomers, ether group-containing monomers Etc. can be used and these can be used individually or in combination of 2 or more types. The monomer having a crosslinkable functional group is preferably included in 1 to 50% by weight relative to the total monomer content (100% by weight) of the copolymer.

The crosslinking agent is used to reinforce the cohesive force of the pressure-sensitive adhesive by appropriately crosslinking the acrylic copolymer, and an isocyanate compound, an epoxy compound, a melamine resin, an aziridine compound, or the like can be used, and preferably an isocyanate compound or an epoxy compound is used. It is good. These can be used individually or in combination of 2 or more types. In addition, an ultraviolet curable polyfunctional (meth) acrylate type monomer can also be used as a crosslinking agent. The crosslinking agent is preferably included in an amount of 0.01 to 15 parts by weight based on 100 parts by weight of the pressure sensitive adhesive resin (based on the solid content), and in the case of an ultraviolet curable polyfunctional (meth) acrylate-based monomer, 0.1 to 30 parts by weight.

In addition, the pressure-sensitive adhesive composition may further include additives such as tackifier resins, antioxidants, corrosion inhibitors, leveling agents, surface lubricants, dyes, pigments, antifoaming agents, fillers, light stabilizers or antistatic agents.

The method of laminating the pressure-sensitive adhesive layer on the polarizing plate is not particularly limited as long as it is a method commonly used in the art. For example, the pressure-sensitive adhesive composition on the polarizer protective film may be directly applied in a suitable development method by using a flow casting method and a coating method such as an air knife, gravure, reverse roll, kiss roll, spray or blade method to be dried and laminated. Can be. In addition, after the pressure-sensitive adhesive layer is formed on the release film or the silicone-coated release film described below by forming the pressure-sensitive adhesive layer, the pressure-sensitive adhesive sheet may be laminated on the polarizer protective film using a roll pressing device. . Under the present circumstances, when an ultraviolet curable polyfunctional (meth) acrylate monomer is included as a crosslinking agent in an adhesive composition, it is preferable to perform an ultraviolet irradiation process.

The release film 16 is a film for protecting the pressure-sensitive adhesive layer 15, and the type is not particularly limited as long as it is a film commonly used in the art. Specific examples include polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethylacrylic Polyolefin type films, such as a rate copolymer and an ethylene-vinyl alcohol copolymer; Polyester-based films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Polyamide films such as polyacrylate, polystyrene, nylon 6 and partially aromatic polyamide; Polyvinyl chloride film; Polyvinylidene chloride film; Or polycarbonate films. Such a film may be one whose surface is properly released by a compound such as silicone or fluorine.

In the polarizing plate having the structure as described above, the draw ratio of the polarizer is usually 5 to 6.5 times, the thickness of the polarizer protective film is 50 to 90㎛, the tensile modulus of the polarizing plate is less than 9GPa, mostly 4.5 to 6GPa. If the elongation ratio of the polarizer is less than 5 times, the polarizer does not show brittleness and the tensile modulus of elasticity of the polarizer is also maintained at about 4 GPa, so that cracks and delamination are hardly generated during cutting, but the optical performance is low, resulting in high contrast ratio products. Difficult to obtain In addition, when the draw ratio of a polarizer exceeds 6.5 times, a polarizer is cut | disconnected in an extending process, and mass production is difficult. In addition, when the thickness of the polarizer protective film is in the above range, the polarizer protective film during the cutting process to protect the polarizer with a bulk effect, the occurrence of cracks and lamination phenomenon is reduced. However, recently, as high optical performance and thinning of the polarizing plate are required, a film having a thickness of 40 μm or less is required as a polarizer protective film laminated on at least one side of the polarizer.

Therefore, in the polarizing plate of the present invention, a polarizer protective film having a thickness of 50 to 80 μm is laminated on one side of the polarizer having an elongation ratio of 5 to 6.5 times and a thickness of 30 μm or less, and a polarizer having a thickness of 40 μm or less on the other side of the polarizer. As a protective film is laminated, it is preferable that the total thickness of the polarizing plate is 150 μm or less and the tensile modulus of elasticity is 9 to 12 GPa.

When the polarizing plate of the present invention having such a structure is cut and processed in the same manner as in the polarizing plate having a tensile modulus of elasticity of less than 9 GPa as described above, there is a problem in that cracks and laminations occur frequently.

In particular, the cutting method of the present invention is a method of cutting a polarizing plate having a tensile modulus of elasticity of 9 to 12 GPa, and is characterized by optimizing the angle (θ) of the cutting blade and the thickness of the cutting blade, cutting speed, and the like. have.

2 shows a cutting process of a polarizing plate according to an embodiment of the present invention. As shown in FIG. 2, the cutting of the polarizing plate is performed by placing the cutting knife on the upper portion of the polarizing plate such that the blade is positioned in the vertical direction with respect to the polarizing plate, and then directly cutting the blade vertically to cut it at once. When using such a method, a polarizing plate can be easily cut | disconnected, without a problem, such as the adhesive omission which was laminated | stacked on the polarizing plate.

In addition, Figure 3 shows a cutting knife according to an embodiment of the present invention. As shown in Figure 3, the cutting knife 20 used for cutting the polarizing plate of the present invention is composed of a body (A) and a blade (B) portion, the blade (B) on the basis of the center line (L) It is preferable that the shape is symmetrical on both sides. The angle θ of the blade means an angle formed by one blade of the blade B from the end of the blade B with respect to the center line L. In addition, the thickness T of the blade B means the total thickness of the blade | wing which has made both symmetry.

In particular, in the cutting process of the polarizing plate of the present invention, an important factor in suppressing cracks and lamination is the angle (θ) of the cutting blade, and together with the thickness and cutting speed of the cutting blade. have.

It is preferable that the angle (theta) of a blade is 10-30 degrees, More preferably, it is 15-26 degrees. If the angle θ of the blade is less than 10 °, it is difficult to exhibit sufficient strength of the cutting knife, and if it exceeds 30 °, cracks and lamination may be generated.

Moreover, it is preferable that the thickness T of a blade is 0.3-1.5 mm, More preferably, it is 0.5-1 mm, Most preferably, it is 0.5-0.7 mm. If the thickness (T) of the blade is less than 0.3 mm, the amount of deformation transmitted to the polarizing plate is small, which is advantageous for suppressing cracks and lamination, but in the case of mass production, the strength of the blade may be weak. In addition, when the thickness T exceeds 1.5 mm, the amount of deformation of the polarizing plate is increased during cutting of the polarizing plate, thereby increasing the frequency of cracking and lamination.

Moreover, it is preferable that cutting speed is 4-10 mm / sec, More preferably, it is 5-8 mm / sec. If the cutting speed is less than 4 mm / sec, the speed is too slow to increase the occurrence of cracks and lamination. If the cutting speed is more than 10 mm / sec, the cutting speed is difficult to control, and an expensive motor for controlling the speed and The same equipment or control system is required.

In particular, in this invention, it is most preferable that the angle (theta) of a blade is 15 degrees, the thickness T of a blade is 0.5 mm, and a cutting speed is 5-8 mm / sec.

In the case of using the cutting method as described above, in cutting and processing various optical film laminates as well as polarizing plates having a high tensile modulus of elasticity of 9 to 12 GPa, the cutting process is performed by suppressing cracks and lamination occurring at the cutting surface. Quality can be improved.

The present invention provides various optical film laminates including a polarizing plate having excellent quality at the cut surface, cut using the cutting method.

In addition, the present invention provides a liquid crystal display device having the polarizing plate and various optical film laminates.

In the present invention, since the liquid crystal display device is well known to those skilled in the art of the present invention, a detailed description of each configuration is omitted.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

[Example]

Preparation Example 1 Polarizing Plate I Manufacturing

(1) Preparation of polarizer

The transparent unstretched PVA film (PS, KURARAY) having a degree of saponification of 99.9% or more was swelled by immersion in a swelling tank filled with deionized water at 30 ° C. for 3 minutes, and then 0.4% by weight of iodine and 1.2% by weight of potassium iodide were contained. It was immersed in an aqueous solution for dyeing at 30 ° C. for 4 minutes for dyeing and uniaxially stretched in the advancing direction (MD) of the film. Subsequently, the PVA film was uniaxially stretched in the advancing direction (MD) of the film while immersing in a 58 ° C. aqueous solution for crosslinking containing 11.0% by weight of potassium iodide and 3.5% by weight of boric acid for 3 minutes, and the wet drawing was performed so that the total draw ratio was 5.5 times. . The PVA film, which has been dyed, crosslinked and stretched, was dried in an oven at 60 ° C. for 5 minutes to prepare a polarizer.

(2) Preparation of Polarizing Plate

A polarizer (thickness: 30 μm or less) was bonded to one side of a triacetyl cellulose (TAC) film having a thickness of 80 μm, and a 40 μm triacetyl cellulose (TAC) film was bonded to another side to prepare a polarizing plate. It was.

The tensile modulus of elasticity of the prepared polarizing plate was 9.6 GPa.

Preparation Example 2 Preparation of Polarizing Plate II

Prepared in the same manner as in Preparation Example 1, but (1) stretched so that the total draw ratio is 5.0 times in the manufacturing of the polarizer.

The tensile modulus of elasticity of the prepared polarizing plate was 9 GPa.

Preparation Example 3: Polarizing Plate III Preparation

Prepared in the same manner as in Preparation Example 1, but (1) stretched so that the total draw ratio is 6.0 times in the manufacturing of the polarizer.

The tensile modulus of elasticity of the prepared polarizing plate was 11.1 GPa.

Preparation Example 4 Polarizing Plate IV Preparation

Manufactured in the same manner as in Preparation Example 1, (2) when manufacturing a polarizing plate is bonded to a triacetyl cellulose (TAC) film of 80㎛ thickness on one side of the polarizer, 53㎛ triacetylcellulose (TAC) film on the other side It bonded together and manufactured the polarizing plate.

The tensile modulus of elasticity of the prepared polarizing plate was 8.7 GPa.

Preparation Example 5 Polarizing Plate V Preparation

Prepared in the same manner as in Preparation Example 1, (2) to prepare a polarizing plate by bonding a triacetyl cellulose (TAC) film having a thickness of 80㎛ on both sides of the polarizer in the manufacture of the polarizing plate.

The tensile modulus of elasticity of the prepared polarizing plate was 8.1 GPa.

Example 1

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 5 mm / sec using a super cutter having an angle θ of the blade at 15 ° and a thickness of 0.7 mm.

Example 2

The polarizing plate I manufactured in Production Example 1 was cut at a cutting speed of 8 mm / sec using a super cutter having an angle θ of the blade at 15 ° and a thickness of 0.7 mm.

Example 3

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 5 mm / sec using a super cutter having an angle θ of a blade of 26 ° and a thickness of 0.7 mm.

Example 4

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 8 mm / sec using a super cutter having an angle θ of a blade of 26 ° and a thickness of 0.7 mm.

Example 5

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 5 mm / sec using a super cutter having an angle θ of the blade at 15 ° and a thickness of 0.5 mm.

Example 6

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 8 mm / sec using a super cutter having an angle θ of the blade at 15 ° and a thickness of 0.5 mm.

Example 7

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 5 mm / sec using a super cutter having an angle θ of a blade of 26 ° and a thickness of 0.5 mm.

Example 8

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 8 mm / sec using a super cutter having an angle θ of a blade of 26 ° and a thickness of 0.5 mm.

Example 9

Polarizing plate II manufactured in Production Example 2 was cut at a cutting speed of 5 mm / sec using a super cutter having an angle θ of the blade at 15 ° and a thickness of 0.7 mm.

Example 10

The polarizing plate III manufactured in Production Example 3 was cut at a cutting speed of 5 mm / sec using a super cutter having an angle θ of the blade at 15 ° and a thickness of 0.7 mm.

Comparative Example 1

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of 43 degrees and a thickness of 1 mm.

Comparative Example 2

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of a blade of 26 ° and a thickness of 1 mm.

Comparative Example 3

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of 43 degrees and a thickness of 0.7 mm.

Comparative Example 4

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 3 mm / sec using a super cutter having an angle θ of 43 degrees and a thickness of 0.7 mm.

Comparative Example 5

The polarizing plate I manufactured in Production Example 1 was cut at a cutting speed of 3 mm / sec using a super cutter having an angle θ of 26 degrees and a thickness of 0.7 mm.

Comparative Example 6

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of 43 degrees and a thickness of 0.5 mm.

Comparative Example 7

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of 26 degrees and a thickness of 0.5 mm.

Comparative Example 8

The polarizing plate I prepared in Production Example 1 was cut at a cutting speed of 3 mm / sec using a super cutter having an angle θ of a blade of 26 ° and a thickness of 0.5 mm.

Reference Example 1

The polarizing plate IV manufactured in Production Example 4 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of 43 degrees and a thickness of 1 mm.

Reference Example 2

The polarizing plate V prepared in Production Example 5 was cut at a cutting speed of 1.7 mm / sec using a super cutter having an angle θ of 43 degrees and a thickness of 1 mm.

Test Example

The physical properties of the polarizing plates prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

(1) Tensile modulus of elasticity (GPa)

Measuring instrument: SHIMAZHU's AUTOGRAPH AG-X 1KN

Test piece: 50 mm × 5 mm

-The modulus of elasticity was measured five times in a 10 to 20 MPa section and expressed as the average value.

(2) Crack and Delamination Generation Length (㎛)

-Measuring instrument: OLYMPUS MX-61 optical microscope

-Measurement method: The number and length of occurrence of cracks and delamination in 100mm section was measured, and the average value thereof was calculated by Equation 1 below. At this time, the occurrence length of the lamination took the maximum length that the lamination occurred and penetrated into the flat plane.

Crack and Delamination Occurrence Length (㎛) = (Total Crack Occurrence Length + Total Delamination Occurrence Length) / (Number of Crack Occurrences + Number of Delamination Occurrences)

division Polarizer
Kinds Polarizer
thickness
(Μm) Tensile Modulus
(GPa) knife
Angle
(°) knife
thickness
(Mm) cut
speed
(Mm / sec) Cracks and
Delamination occurrence length
(Μm) Example 1 I 150 or less 9.6 15 0.7 5 54 Example 2 I 150 or less 9.6 15 0.7 8 38 Example 3 I 150 or less 9.6 26 0.7 5 83 Example 4 I 150 or less 9.6 26 0.7 8 65 Example 5 I 150 or less 9.6 15 0.5 5 7 Example 6 I 150 or less 9.6 15 0.5 8 4 Example 7 I 150 or less 9.6 26 0.5 5 20 Example 8 I 150 or less 9.6 26 0.5 8 20 Example 9 Ⅱ 150 or less 9 15 0.7 5 32 Example 10 Ⅲ 150 or less 11.1 15 0.7 5 89 Comparative Example 1 I 150 or less 9.6 43 One 1.7 320 Comparative Example 2 I 150 or less 9.6 26 One 1.7 190 Comparative Example 3 I 150 or less 9.6 43 0.7 1.7 210 Comparative Example 4 I 150 or less 9.6 43 0.7 3 140 Comparative Example 5 I 150 or less 9.6 26 0.7 3 120 Comparative Example 6 I 150 or less 9.6 43 0.5 1.7 180 Comparative Example 7 I 150 or less 9.6 26 0.5 1.7 130 Comparative Example 8 I 150 or less 9.6 26 0.5 3 110 Reference Example 1 Ⅳ 163 or less 8.7 43 One 1.7 84 Reference Example 2 Ⅴ 190 or less 8.1 43 One 1.7 5

As shown in Table 1, Examples 1 to 10 of the polarizing plate having a tensile modulus of elasticity of 9 to 12 GPa according to the present invention is cut by adjusting the thickness and cutting speed of the blade to a specific range together with the angle (θ) of the blade. When compared with the comparative example it was possible to control the crack and the generation length of the lamination is less than 100㎛, it was confirmed that the cutting surface can be improved through a simple grinding. As shown in Reference Examples 1 and 2, it was found that exhibiting an effect of suppressing cracks and delamination phenomena equal to or higher than that in the case of cutting a polarizing plate having a conventional tensile modulus of elasticity by the conventional method.

As described above, the present invention can greatly reduce the occurrence of cracks and lamination phenomenon when cutting the polarizing plate and various optical film laminates having a high tensile modulus of elasticity value, it is expected to improve the cutting quality and productivity.

1 is a cross-sectional view showing a polarizing plate according to an embodiment of the present invention,

2 is a perspective view of a polarizing plate cut according to an embodiment of the present invention;

3 is a front view of the polarizing plate cutting knife according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: polarizing plate 11: surface protective film

12, 14: polarizer protective film 13: polarizer

15: adhesive layer 16: release film

20: cutting knife

Claims (6)

As a method of cutting an optical film laminate having a tensile modulus of elasticity of 9 to 12 GPa, A method for cutting an optical film laminate, characterized in that the optical film laminate is cut using a cutting knife having an angle? Of 10 to 30 degrees. The method according to claim 1, The optical film laminate is a polarizing plate comprising a polarizer protective film laminated on both sides of the polarizer, the thickness of at least one of the polarizer protective film is 40㎛ or less and the total thickness of the polarizer is 150㎛ or less. Cutting method. The method according to claim 1, The angle (θ) of the blade is a cutting method of the optical film laminate is 15 to 26 °. The method according to claim 1, The thickness of the blade is 0.3 to 1.5mm cutting method of the optical film laminate. The method according to claim 1, Cutting speed of the blade is 4 to 10mm / sec cutting method of the optical film laminate. The method according to claim 1, The angle (θ) of the blade is 15 °, the thickness is 0.5 mm, the cutting speed of the blade is 5 to 8 mm / sec cutting method of the optical film laminate.

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