TW202413078A - optical laminate - Google Patents

Abstract

The present invention provides an optical laminate including a surface protection film and a polarizing plate, which has excellent hue and brightness unevenness inspection performance even through the surface protection film. The optical laminate of the embodiment of the present invention includes a surface protection film and an optical component, the surface protection film has a substrate and an adhesive layer, the optical component has a polarizing plate, the front phase difference R0 of the surface protection film is R0≦2500 nm or R0≧3000 nm, and the angle between the absorption axis of the polarizing plate and the slow axis of the substrate of the surface protection film is less than 30°.

Description

Optical laminate

The present invention relates to an optical multilayer body.

Surface protection films are provided on the surfaces of optical devices such as displays and camera devices, electronic devices, and films or glass materials that are components of such devices for the purpose of protecting the surface or imparting impact resistance. Surface protection films are typically those that are temporarily adhered to the device before use such as assembly, processing, and transportation of the device and then peeled off before the device is used (those used as engineering materials), and those that are also attached to the surface of the device when the device is used (those for the purpose of permanent adhesion) (for example, refer to Patent Document 1).

The surface protection film used as an engineering material and the surface protection film used for permanent bonding are both provided with an adhesive layer on the main surface of the film substrate, and are adhered to the surface of the adherend as the protection object through the adhesive layer (for example, refer to patent document 2).

Conventionally, optical components including polarizing plates such as liquid crystal display devices are generally inspected to evaluate hue and brightness unevenness. However, in the past, when an optical laminate having a surface protective film attached to an optical component including a polarizing plate is inspected for hue and brightness unevenness through the surface protective film, it is sometimes impossible to perform a proper inspection due to the anisotropy of the surface protective film. [Prior Art Literature] [Patent Literature]

[Patent document 1] Japanese Patent No. 3518677 [Patent document 2] Japanese Patent No. 6249617

[The problem the invention is trying to solve]

The problem of the present invention is to provide an optical laminate including a surface protection film and a polarizing plate, which has excellent hue and brightness unevenness inspection performance even through the surface protection film. [Technical means for solving the problem]

[1] The optical multilayer of the embodiment of the present invention comprises a surface protection film and an optical component, wherein the surface protection film has a substrate and an adhesive layer, and the optical component has a polarizing plate, the front phase difference R0 of the surface protection film is R0≦2500 nm or R0≧3000 nm, and the angle between the absorption axis of the polarizing plate and the slow axis of the substrate of the surface protection film is less than 30°. [2] The optical multilayer as described in [1] above, wherein the RGB standard deviation of the optical multilayer can be less than 9.50. [3] The optical multilayer as described in [1] or [2] above, wherein the dispersion entropy _SCD of the optical multilayer can be greater than 2.52× ^10-14 . [Effects of the Invention]

According to the present invention, an optical laminate including a surface protection film and a polarizing plate can be provided, which has excellent inspection performance for color and brightness unevenness even through the surface protection film.

The "mass" in this manual may be replaced by the "weight" which is a commonly used unit of weight. Conversely, the "weight" in this manual may be replaced by the "mass" which is a commonly used SI unit of weight.

In this specification, the angle "formed by the slow axis and the longitudinal direction (MD direction)" means the angle formed in the counterclockwise direction with respect to the longitudinal direction (MD direction).

In this specification, “(meth)acrylic acid” means “acrylic acid and/or methacrylic acid”, “(meth)acrylate” means “acrylate and/or methacrylate”, “(meth)allyl” means “allyl and/or methallyl”, and “(meth)acrolein” means “acrolein and/or methacrolein”.

The optical laminate of the embodiment of the present invention comprises a surface protection film and an optical component. The surface protection film has a substrate and an adhesive layer. The optical component has a polarizing plate.

FIG. 1 shows an embodiment of the optical laminate of the present invention. The optical laminate 1000 includes a surface protection film 100 and an optical component 200. The surface protection film 100 has a substrate 10 and an adhesive layer 20.

The optical laminate of the embodiment of the present invention only needs to include a surface protection film and an optical component, and may also include any other appropriate layers within the scope that does not impair the effect of the present invention.

Examples of such other layers include glass, displays, cameras, lenses, and (semi) mirrors.

The optical layered body of the embodiment of the present invention may also contain any appropriate additives within the scope that does not impair the effect of the present invention.

Examples of such additives include antioxidants, ultraviolet absorbers, light stabilizers, nucleating agents, fillers, pigments, surfactants, and antistatic agents.

The total thickness of the optical laminate of the embodiment of the present invention can be any appropriate thickness according to the type of optical component. Typically, the total thickness of the optical laminate of the embodiment of the present invention is preferably 10 μm to 1000 μm, more preferably 25 μm to 800 μm, further preferably 30 μm to 800 μm, further preferably 40 μm to 700 μm, further preferably 40 μm to 600 μm, particularly preferably 50 μm to 500 μm, and most preferably 100 μm to 500 μm.

In the optical multilayer of the embodiment of the present invention, the angle formed by the absorption axis of the polarizing plate and the slow axis of the substrate possessed by the surface protection film is 30° or less. If the angle formed by the absorption axis of the polarizing plate and the slow axis of the substrate possessed by the surface protection film is within this range, the effect of the present invention can be further demonstrated. In terms of further demonstrating the effect of the present invention, the angle formed by the absorption axis of the polarizing plate and the slow axis of the substrate possessed by the surface protection film is preferably 25° or less, more preferably 20° or less, further preferably 15° or less, further preferably 10° or less, further preferably 5° or less, particularly preferably 2° or less, and most preferably 1° or less. Furthermore, the "angle formed by the absorption axis of the polarizing plate and the slow axis of the substrate possessed by the surface protection film" in the present invention refers to the angle of less than 90° among the four angles formed by the intersection of the absorption axis of the polarizing plate and the slow axis of the substrate possessed by the surface protection film.

The smaller the RGB standard deviation of the optical multilayer of the embodiment of the present invention, the better, preferably 9.50 or less, more preferably 9.40 or less, further preferably 9.30 or less, further preferably 9.20 or less, further preferably 9.17 or less, further preferably 9.14 or less, particularly preferably 9.11 or less, and most preferably 9.10 or less. By the RGB standard deviation being within the above range, the effect of the present invention can be further demonstrated.

The larger the dispersion entropy S _CD of the optical multilayer of the embodiment of the present invention, the better, preferably 2.52×10 ^-14 or more, more preferably 2.53×10 ^-14 or more, further preferably 2.54×10 ^-14 or more, and particularly preferably 2.55×10 ^-14 or more. When the dispersion entropy S _CD is within the above range, the effect of the present invention can be further demonstrated.

In the optical laminate of the embodiment of the present invention, the RGB standard deviation/dispersion entropy S _CD is preferably 3.50×10 ¹⁴ ～3.80×10 ¹⁴ , more preferably 3.52×10 ¹⁴ ～3.70×10 ¹⁴ , further preferably 3.53×10 ¹⁴ ～3.65×10 ¹⁴ , particularly preferably 3.53×10 ¹⁴ ～3.60×10 ¹⁴ , and most preferably 3.53×10 ¹⁴ ～3.57×10 ¹⁴ . When the RGB standard deviation/dispersion entropy S _CD is within the above range, the effect of the present invention can be further demonstrated.

≪≪Surface protection film≫≫ Surface protection film usually has a base material and an adhesive layer.

The surface protection film may also have any other appropriate layers in addition to the substrate and the adhesive layer within the scope that does not impair the effects of the present invention.

Such other layers include, for example, an easy-adhesion layer, an easy-slip layer, an anti-adhesion layer, an anti-static layer, an anti-reflection layer, and an anti-oligomer layer.

In the surface protection film of the embodiment of the present invention, a peeling pad may be provided on the surface of the adhesive layer opposite to the substrate for the purpose of protecting the adhesive layer. The peeling pad is usually peeled off when the surface protection film of the embodiment of the present invention is used.

The surface protection film may also contain any appropriate additives within the scope that does not impair the effects of the present invention.

Examples of such additives include antioxidants, ultraviolet absorbers, light stabilizers, nucleating agents, fillers, pigments, surfactants, and antistatic agents.

As shown in FIG. 1 , in one embodiment of a surface protection film, the surface protection film 100 includes a substrate 10 and an adhesive layer 20 .

The front phase difference R0 of the surface protection film is preferably R0≦2500 nm or R0≧3000 nm, more preferably R0≦2500 nm or R0≧4000 nm, further preferably R0≦2300 nm or R0≧4500 nm, further preferably R0≦2100 nm or R0≧5000 nm, further preferably R0≦1900 nm or R0≧5500 nm, particularly preferably R0≦1700 nm or R0≧5500 nm, and most preferably R0≦1700 nm or R0≧6000 nm. By adjusting the in-plane phase difference of the surface protection film to the above range, the effect of the present invention can be further demonstrated. Furthermore, in the description of the present invention, the preferred range of the above-mentioned front phase difference R0 is specified, for example, in the form of "R0≦2500 nm or R0≧3000 nm" in segments with combinations below or above the specified value, but the above-mentioned preferred range of the front phase difference R0 is not limited to the specified combinations, for example, it can also be a combination of the range of "R0≦1900 nm" and the range of "R0≧4500 nm" ("R0≦1900 nm or R0≧4500 nm"). In addition, regarding the provisions described in sections with a combination of below or above a specified value, for example, when the provision is "R0≦2500 nm or R0≧3000 nm", it means "R0≦2500 nm" or "R0≧3000 nm". Furthermore, regarding the measurement of the front phase difference R0 of the surface protection film of the embodiment of the present invention, when a peeling pad is provided in advance on the surface of the adhesive layer of the surface protection film on the opposite side to the substrate, the measurement is performed after the peeling pad is peeled off.

When the front phase difference R0 of the surface protection film is R0≦2500 nm, the lower limit value is as small as possible, but in practice it is preferably above 100 nm due to factors such as material selection.

When the front phase difference R0 of the surface protection film is R0≧3000 nm, the upper limit value is as large as possible, but in practice it is preferably below 30000 nm due to factors such as material selection.

≪Base material≫ The base material may be a base material composed of one layer or a base material composed of a layered structure of two or more layers.

The thickness of the substrate can be any appropriate thickness within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the thickness of the substrate is preferably 5 μm to 1000 μm, more preferably 10 μm to 800 μm, further preferably 20 μm to 600 μm, and particularly preferably 30 μm to 400 μm.

The front phase difference R0 of the substrate is preferably R0≦2500 nm or R0≧3000 nm, more preferably R0≦2500 nm or R0≧4000 nm, further preferably R0≦2300 nm or R0≧4500 nm, further preferably R0≦2100 nm or R0≧5000 nm, further preferably R0≦1900 nm or R0≧5500 nm, particularly preferably R0≦1700 nm or R0≧5500 nm, and most preferably R0≦1700 nm or R0≧6000 nm. By adopting such a substrate, the effect of the present invention can be further demonstrated. Furthermore, in the description of the present invention, the preferred range of the above-mentioned front phase difference R0 is specified, for example, in the form of "R0≦2500 nm or R0≧3000 nm" in combination of below or above the specified value, but the above-mentioned preferred range of the front phase difference R0 is not limited to the specified combination, for example, it can also be a combination of the range of "R0≦1900 nm" and the range of "R0≧4500 nm" ("R0≦1900 nm or R0≧4500 nm"). Furthermore, regarding regulations that are described in sections with a combination of values below or above a prescribed value, for example, when the regulation reads “R0≦2500 nm or R0≧3000 nm”, it means “R0≦2500 nm” or “R0≧3000 nm” as stated.

When the front phase difference R0 of the substrate is R0≦2500 nm, the lower limit value is as small as possible, but in practice it is preferably above 100 nm due to factors such as material selection.

When the front phase difference R0 of the substrate is R0≧3000 nm, the upper limit value is as large as possible. However, in practice, it is preferably below 30000 nm due to factors such as material selection.

As a method for obtaining a substrate having a front phase difference R0 within the above range, any appropriate method can be adopted within the range that does not impair the effect of the present invention. Such methods include, for example, a method of stretching a substrate made of plastic, a method of using a super birefringent film, a method of laminating a substrate made of plastic with two or more layers, and a method of using a crystalline PET (polyethylene terephthalate) substrate having a front phase difference R0 of R0≦2600 nm.

As the material of the substrate, any appropriate material can be used within the scope of not damaging the effect of the present invention. In terms of further demonstrating the effect of the present invention, such material is preferably exemplified by plastic.

As the plastic, any appropriate plastic can be used within the scope of not impairing the effect of the present invention. In terms of further demonstrating the effect of the present invention, such plastic is preferably exemplified by a thermoplastic resin.

Examples of thermoplastic resins include polyester, acrylic resin, urethane resin, polycarbonate, triacetyl cellulose (TAC), polyolefins (olefin homopolymers, copolymers of olefins and other monomers), polyamide (nylon), wholly aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyvinyl acetate, and cyclic olefin polymers.

In terms of further demonstrating the effects of the present invention, the thermoplastic resin is preferably polyester. Examples of polyester include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT). In terms of further demonstrating the effects of the present invention, polyethylene terephthalate (PET) is preferred.

<One preferred embodiment A of the substrate> One preferred embodiment A of the substrate is a stretched thermoplastic resin substrate. Hereinafter, the thermoplastic resin substrate used for stretching is sometimes referred to as a "thermoplastic resin substrate", and the stretched thermoplastic resin substrate is sometimes referred to as a "stretched thermoplastic resin substrate".

The thickness of the stretched thermoplastic resin substrate of embodiment A can be any appropriate thickness within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the thickness of the stretched thermoplastic resin substrate is preferably 1 μm to 100 μm, more preferably 2 μm to 80 μm, further preferably 3 μm to 70 μm, and particularly preferably 5 μm to 60 μm.

The front phase difference R0 of the stretched thermoplastic resin substrate is preferably R0≦2500 nm, more preferably R0≦2100 nm, further preferably R0≦1700 nm, further preferably R0≦1300 nm, further preferably R0≦1000 nm, particularly preferably R0≦800 nm, and most preferably R0≦700 nm. If the front phase difference R0 of the stretched thermoplastic resin substrate is within the above range, the effect of the present invention can be further demonstrated.

The lower limit of the front phase difference R0 of the stretched thermoplastic resin substrate is as small as possible, but in practice it is preferably above 100 nm due to factors such as material selection.

In order to further demonstrate the effects of the present invention, the thermoplastic resin substrate preferably has a water absorption rate within a specified range. The water absorption rate of the thermoplastic resin substrate is preferably 0.2% or more, and more preferably 0.3% or more. The thermoplastic resin substrate with such a water absorption rate can absorb water during the following underwater stretching, and the water acts like a plasticizer and plasticizes. As a result, the stretching stress can be greatly reduced, and the stretching can be performed at a high rate. The stretchability of the thermoplastic resin substrate can be better than the following aerial stretching. If such a thermoplastic resin substrate is stretched, it can become a substrate with excellent optical properties, so that the effects of the present invention can be further demonstrated. On the other hand, the water absorption rate of the thermoplastic resin substrate is preferably 3.0% or less, and more preferably 1.0% or less. The thermoplastic resin substrate having such a water absorption rate has excellent dimensional stability, so that it is possible to prevent the appearance of the stretched thermoplastic resin substrate from being deteriorated after stretching the thermoplastic resin substrate, and to prevent the substrate from being broken in the following underwater stretching step. The water absorption rate is a value obtained in accordance with JIS K 7209.

In order to further demonstrate the effects of the present invention, the thermoplastic resin substrate preferably has a glass transition temperature (Tg) within a specified range. The glass transition temperature (Tg) of the thermoplastic resin substrate is preferably below 170°C. By using such a thermoplastic resin substrate, excellent elongation can be exhibited. Furthermore, considering the smooth plasticization of the thermoplastic resin substrate using water and the elongation in water, the glass transition temperature (Tg) of the thermoplastic resin substrate is preferably below 120°C. On the other hand, the glass transition temperature (Tg) of the thermoplastic resin substrate is preferably above 60°C. By using such a thermoplastic resin substrate, deformation of the thermoplastic resin substrate (for example, the generation of bumps, sagging, or wrinkles) and other undesirable conditions can be prevented. The glass transition temperature (Tg) is a value obtained according to JIS K 7121.

As the material of the thermoplastic resin substrate, in order to further demonstrate the effects of the present invention, it is preferred that the water absorption rate and glass transition temperature of the thermoplastic resin substrate be within the above ranges. The water absorption rate can be adjusted by, for example, introducing a modifying group into the material. The glass transition temperature can be adjusted by, for example, introducing a modifying group into the material, or using a crystallized material and heating it.

As the material of the thermoplastic resin substrate, in terms of further demonstrating the effects of the present invention, preferably, for example, a polyethylene terephthalate (PET) resin is used, more preferably, an amorphous (non-crystallizable) polyethylene terephthalate (PET) resin is used, and further preferably, an amorphous (non-crystallizable) polyethylene terephthalate (PET) resin is used. Specific examples of amorphous polyethylene terephthalate (PET) resins include copolymers further including isophthalic acid as a dicarboxylic acid, or copolymers further including cyclohexanedimethanol as a diol.

In order to further demonstrate the effects of the present invention, the thickness of the thermoplastic resin substrate (thickness before stretching) is preferably 10 μm to 500 μm, more preferably 20 μm to 400 μm, further preferably 30 μm to 300 μm, and particularly preferably 50 μm to 200 μm.

A typical stretching method for thermoplastic resin substrates is underwater stretching (wet stretching) using a water bath as a stretching bath. By adopting underwater stretching, if the thermoplastic resin substrate has the above-mentioned water absorption rate, water can play a role like a plasticizer and plasticize. As a result, the stretching stress can be greatly reduced, and stretching can be performed at a high rate. The stretchability of the thermoplastic resin substrate can be better than the following aerial stretching. Therefore, since a substrate with excellent optical properties is obtained, the effect of the present invention can be further demonstrated. In addition, by adopting underwater stretching, stretching can be performed at a high rate at a temperature lower than the glass transition temperature of the thermoplastic resin substrate.

The extending direction of the thermoplastic resin substrate is preferably the lateral direction (short side direction) of the long strip-shaped thermoplastic resin substrate.

As a stretching method for underwater stretching, any appropriate method can be adopted within the scope that does not impair the effect of the present invention. Such stretching methods include fixed end stretching and free end stretching (for example, a method of uniaxial stretching by passing the laminate between rollers with different circumferential speeds). Stretching can be performed in one stage or in multiple stages. In the case of multiple stages, the stretching ratio (maximum stretching ratio) is the product of the stretching ratios of each stage.

The stretching temperature (liquid temperature of the stretching bath) of the stretching in water can be any appropriate temperature within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, it is preferably 30°C or higher, more preferably 40°C to 90°C, further preferably 45°C to 85°C, and particularly preferably 50°C to 80°C. If the temperature of the stretching bath is too low, even if the thermoplastic resin substrate is plasticized by water, there is a risk that stretching cannot be performed well.

The extension time in water can be any appropriate time within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, it is preferably 15 seconds to 5 minutes.

The maximum stretching ratio of underwater stretching is preferably 5.0 times or more relative to the original length of the thermoplastic resin substrate. In this specification, "maximum stretching ratio" refers to the stretching ratio before the substrate breaks. The stretching ratio at which the substrate breaks is confirmed separately, and "maximum stretching ratio" refers to a value 0.2 lower than this value. In addition, when underwater stretching is performed, the maximum stretching ratio will be higher than when stretching is performed only by dry stretching.

As a stretching method for the thermoplastic resin substrate, aerial stretching (dry stretching) can be combined with the above-mentioned underwater stretching. Any appropriate stretching method can be adopted for aerial stretching within the scope that does not damage the effect of the present invention. By combining aerial stretching with underwater stretching, the stretching can be performed while suppressing the orientation of the thermoplastic resin substrate. As the orientation of the thermoplastic resin substrate increases, the stretching tension increases, making it difficult to perform stable stretching or the thermoplastic resin substrate breaks. Therefore, by performing stretching while suppressing the orientation of the thermoplastic resin substrate, it is possible to perform stretching at a higher magnification. As a result, a substrate with better optical properties can be obtained, thereby further demonstrating the effect of the present invention.

The stretching method of aerial stretching is the same as the above-mentioned underwater stretching, and can be fixed-end stretching or free-end stretching (for example, a method of making the laminate pass between rollers with different circumferential speeds to perform uniaxial stretching). In addition, the stretching can be performed in one stage or in multiple stages. When it is performed in multiple stages, the stretching ratio is the product of the stretching ratios of each stage. The stretching direction is preferably substantially the same as the stretching direction of the above-mentioned underwater stretching.

The stretching temperature of the air stretching can be any appropriate temperature within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the stretching temperature of the air stretching is preferably 95°C to 150°C.

The extension time of the aerial extension can be any appropriate time within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the extension time of the aerial extension is preferably 15 seconds to 5 minutes.

The stretching ratio of the mid-air stretching can be any appropriate ratio within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the stretching ratio of the mid-air stretching is preferably 3.5 times or less.

When the aerial stretching and the underwater stretching are combined, the maximum stretching ratio is preferably 5.0 times or more, more preferably 5.5 times or more, and further preferably 6.0 times or more relative to the original length of the thermoplastic resin substrate.

The stretched thermoplastic resin substrate of the preferred embodiment A as the substrate may be, for example, the stretched thermoplastic resin substrate described in Japanese Patent Application Publication No. 2012-73580.

<One of the preferred embodiments B of the substrate> One of the preferred embodiments B of the substrate is a super birefringent film substrate.

The thickness of the super birefringent film substrate of embodiment B can be any appropriate thickness within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the thickness of the super birefringent film substrate is preferably 10 μm to 500 μm, more preferably 15 μm to 300 μm, further preferably 25 μm to 200 μm, and particularly preferably 30 μm to 100 μm.

The front phase difference R0 of the super birefringent film substrate is preferably R0≧4000 nm, more preferably R0≧5000 nm, further preferably R0≧6000 nm, further preferably R0≧6500 nm, further preferably R0≧7000 nm, particularly preferably R0≧7500 nm, and most preferably R0≧8000 nm. If the front phase difference R0 of the super birefringent film substrate is within the above range, the effect of the present invention can be further demonstrated.

The upper limit of the front phase difference R0 of the super birefringent film substrate is as large as possible, but in practice it is preferably below 30,000 nm due to factors such as material selection.

As the material of the super birefringent film substrate, any appropriate plastic can be used within the scope of not impairing the effect of the present invention. In terms of further demonstrating the effect of the present invention, such plastic is preferably exemplified by thermoplastic resin.

Examples of thermoplastic resins include polyester, acrylic resin, urethane resin, polycarbonate, triacetyl cellulose (TAC), polyolefin (olefin homopolymer, copolymer of olefin and other monomers), polyamide (nylon), wholly aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyvinyl acetate, and cyclic olefin polymers.

In terms of further demonstrating the effects of the present invention, the thermoplastic resin is preferably polyester. Examples of polyester include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT). In terms of further demonstrating the effects of the present invention, polyethylene terephthalate (PET) is preferred.

The super birefringent film substrate may also be a stretched substrate.

<One preferred embodiment C of the substrate> One preferred embodiment C of the substrate is a laminate of two or more layers of a substrate made of plastic. Hereinafter, a substrate made of plastic will sometimes be referred to as a "plastic substrate".

The thickness of the laminate of embodiment C can be any appropriate thickness within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the thickness of the laminate of embodiment C is preferably 50 μm to 1000 μm, more preferably 100 μm to 800 μm, further preferably 150 μm to 700 μm, and particularly preferably 200 μm to 600 μm.

As described above, the number of layers of the laminate of embodiment C is 2 or more. In order to further demonstrate the effect of the present invention, it is preferably 2 to 20 layers, more preferably 2 to 15 layers, further preferably 2 to 12 layers, and particularly preferably 2 to 10 layers.

The front phase difference R0 of the laminate of embodiment C is preferably R0≧2500 nm, more preferably R0≧3000 nm, further preferably R0≧3500 nm, further preferably R0≧4000 nm, further preferably R0≧4500 nm, particularly preferably R0≧5000 nm, and most preferably R0≧5500 nm. By adopting such a substrate, the effect of the present invention can be further presented. The laminated multiple plastic substrates can all be substrates of different types (different materials), or at least two of them can be substrates of the same type (same material).

As for the upper limit of the front phase difference R0 of the multilayer body of implementation method C, the larger the better. However, in practice, it is preferably below 30000 nm in view of factors such as material selection.

As the material of the plastic substrate that can be used in Embodiment C, any appropriate plastic can be used within the scope that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, such plastic is preferably exemplified by thermoplastic resin.

Examples of thermoplastic resins include polyester, acrylic resin, urethane resin, polycarbonate, triacetyl cellulose (TAC), polyolefin (olefin homopolymer, copolymer of olefin and other monomers), polyamide (nylon), wholly aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyvinyl acetate, and cyclic olefin polymers.

In terms of further demonstrating the effects of the present invention, the thermoplastic resin is preferably polyester. Examples of polyester include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT). In terms of further demonstrating the effects of the present invention, polyethylene terephthalate (PET) is preferred.

The plastic substrate that can be used in embodiment C can be the stretched thermoplastic resin substrate of embodiment A or the super birefringent film substrate of embodiment B.

<One of the preferred embodiments of the substrate D> One of the preferred embodiments of the substrate D is a crystalline PET (polyethylene terephthalate) substrate with a front phase difference R0 of R0≦2600 nm.

The thickness of the crystalline PET substrate of embodiment D can be any appropriate thickness within the range that does not impair the effect of the present invention. In terms of further demonstrating the effect of the present invention, the thickness of the crystalline PET substrate is preferably 10 μm to 500 μm, more preferably 15 μm to 300 μm, further preferably 25 μm to 200 μm, particularly preferably 30 μm to 100 μm, and most preferably 30 μm to 50 μm.

As described above, the front phase difference R0 of the crystalline PET substrate of embodiment D is R0≦2600 nm, preferably R0≦2500 nm, more preferably R0≦2400 nm, further preferably R0≦2300 nm, particularly preferably R0≦2100 nm, and most preferably R0≦1900 nm. If the front phase difference R0 of the crystalline PET substrate is within the above range, the effect of the present invention can be further demonstrated.

The lower limit of the front phase difference R0 of the crystalline PET substrate of implementation method D is as small as possible, but in view of factors such as material selection, it is preferably above 100 nm, more preferably above 500 nm, further preferably above 800 nm, particularly preferably above 1000 nm, and most preferably above 1200 nm.

The crystalline PET substrate may also be a stretched substrate.

As a crystalline PET substrate, in order to further demonstrate the effect of the present invention, the ratio of the tensile strength in the width direction (TD direction) to the tensile strength in the length direction (MD direction) (TD/MD) is preferably 1.2 to 3.3. Furthermore, as described below, the tensile strength is the strength (unit: MPa) when the object to be measured is stretched at a speed of 200 mm/min using a tensile testing machine in accordance with JIS C 2151:2019 so that the object to be measured is cut (broken).

≪Adhesive layer≫ The adhesive layer may be composed of one layer or may be composed of a layered structure of two or more layers.

In order to further demonstrate the effect of the present invention, the thickness of the adhesive layer is preferably 0.5 μm to 150 μm, more preferably 1 μm to 100 μm, further preferably 2 μm to 80 μm, further preferably 3 μm to 50 μm, further preferably 5 μm to 30 μm, further preferably 7 μm to 27 μm, particularly preferably 9 μm to 25 μm, and most preferably 11 μm to 23 μm.

The adhesive constituting the adhesive layer is preferably at least one selected from the group consisting of acrylic adhesives, urethane adhesives, and silicone adhesives.

The adhesive layer is more preferably composed of an acrylic adhesive.

The acrylic adhesive is formed from an acrylic adhesive composition.

Acrylic adhesives can be defined as those formed from an acrylic adhesive composition. The reason for this is that acrylic adhesives are formed by a crosslinking reaction of an acrylic adhesive composition due to heating or ultraviolet irradiation, and therefore acrylic adhesives cannot be directly identified based on their structure. Also, since there are generally unrealistic situations ("impossible and unrealistic situations"), acrylic adhesives are reasonably specified as "objects" by defining "formed from an acrylic adhesive composition".

The peeling force of the acrylic adhesive relative to the acrylic resin sheet at 23°C, relative humidity 50%, at a tensile speed of 300 mm/min and a peeling angle of 180 degrees is preferably 0.01 N/25 mm or more, more preferably 0.03 N/25 mm or more, further preferably 0.05 N/25 mm or more, and particularly preferably 0.07 N/25 mm or more. Furthermore, the preferred range of the upper limit of the above peeling force will vary depending on the purpose of the surface protective film of the optical laminate of the present invention. Typically, in the case of permanent bonding applications (surface protection films for the purpose of permanent bonding), there is no upper limit, the higher the better, and in the case of re-stripping applications (for example, surface protection films used as engineering materials), the upper limit is preferably 5 N/25 mm or less, more preferably 3 N/25 mm or less, and further preferably 1 N/25 mm or less.

The adhesive layer can be formed by any appropriate method. Such methods include, for example, the following methods: applying an adhesive composition that forms an adhesive constituting the adhesive layer on any appropriate substrate, heating or drying as needed, and hardening it as needed to form an adhesive layer on the substrate; applying an adhesive composition that forms an adhesive constituting the adhesive layer on any appropriate film such as a peel-off pad, heating or drying as needed, and hardening it as needed to form an adhesive layer on the film, and attaching any appropriate substrate to the adhesive layer for transfer printing to form an adhesive layer on the substrate.

The method of applying the acrylic adhesive composition may be any appropriate method within the scope of not impairing the effect of the present invention. Such coating methods include, for example, roll coating, gravure roll coating, reverse roll coating, contact roll coating, dip roll coating, rod coating, roll brush coating, spray coating, scraper coating, air knife coating, notch wheel coating, direct coating, and die nozzle coating.

The acrylic adhesive composition can be heated or dried by any appropriate method within the scope that does not impair the effect of the present invention. Such heating or drying methods include, for example, heating to 60°C to 180°C, or aging at room temperature.

The acrylic adhesive composition can be cured by any appropriate method within the scope of not impairing the effect of the present invention. Such curing methods include, for example, heat, ultraviolet irradiation, laser irradiation, α-ray irradiation, β-ray irradiation, γ-ray irradiation, X-ray irradiation, and electron beam irradiation.

In order to further exhibit the effects of the present invention, the acrylic adhesive composition preferably comprises an acrylic polymer and a crosslinking agent.

The acrylic polymer is a base polymer in the field of acrylic adhesives. The acrylic polymer may be only one type or may be two or more types.

The content of the acrylic polymer in the acrylic adhesive composition is preferably 60% to 99.9% by weight, more preferably 65% to 99.9% by weight, further preferably 70% to 99.9% by weight, particularly preferably 75% to 99.9% by weight, and most preferably 80% to 99.9% by weight, based on solid content.

Any appropriate acrylic polymer may be used as long as the effects of the present invention are not impaired.

In order to further exhibit the effects of the present invention, the weight average molecular weight of the acrylic polymer is preferably 300,000 to 2.5 million, more preferably 350,000 to 2 million, further preferably 400,000 to 1.8 million, and particularly preferably 500,000 to 1.5 million.

As the acrylic polymer, in terms of further exhibiting the effects of the present invention, an acrylic polymer formed by polymerization of a composition (M) comprising an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms in the alkyl ester portion (component a), and at least one selected from the group consisting of (meth)acrylates having an OH group and (meth)acrylic acid (component b). Component a and component b may be either one or two or more, respectively, independently.

Examples of the (meth)acrylic acid alkyl esters in which the alkyl group of the alkyl ester part has 4 to 12 carbon atoms include n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. Among them, n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred, and n-butyl acrylate and 2-ethylhexyl acrylate are more preferred in terms of further exhibiting the effects of the present invention.

Examples of (meth)acrylates having an OH group include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and the like. Among them, hydroxyethyl (meth)acrylate is preferred, and hydroxyethyl acrylate is more preferred, in terms of further exhibiting the effects of the present invention.

The (meth)acrylic acid is preferably acrylic acid in that the effects of the present invention can be further exhibited.

The composition (M) may also contain copolymerizable monomers other than the components a and b. The copolymerizable monomers may be only one or may be two or more. Examples of such copolymerizable monomers include: carboxyl group-containing monomers (except (meth)acrylic acid) such as itaconic acid, maleic acid, fumaric acid, crotonic acid, isomethacrylic acid, and anhydrides thereof (for example, monomers containing anhydride groups such as maleic anhydride and itaconic anhydride); (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-hydroxy monomers containing an amide group such as 1,2-dimethylaminoethyl (meth)acrylamide; monomers containing an amine group such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; monomers containing an epoxy group such as glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate; monomers containing a cyano group such as acrylonitrile or methacrylonitrile; N-vinyl-2-pyrrolidone, (meth)acryloyl phenoxylate, N-vinyl piperidone, N-vinyl piperidine, and N-vinyl piperidine; Vinyl monomers containing heterocyclic groups such as vinylpiperidinium, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, and vinyloxazole; monomers containing sulfonic acid groups such as sodium vinylsulfonate; monomers containing phosphoric acid groups such as 2-hydroxyethylacryloyl phosphate; monomers containing imide groups such as cyclohexylmaleimide and isopropylmaleimide; monomers containing isocyanate groups such as 2-methacryloyloxyethyl isocyanate; cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. (Meth)acrylates having alicyclic hydrocarbon groups such as (meth)acrylate, isobutyl (meth)acrylate, etc.; (meth)acrylates having aromatic hydrocarbon groups such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc.; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyl toluene; olefins or dienes such as ethylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ether; vinyl chloride, etc.

Copolymerizable monomers may also be multifunctional monomers. Multifunctional monomers refer to monomers having two or more ethylenic unsaturated groups in one molecule. Any appropriate ethylenic unsaturated group may be used as long as the effect of the present invention is not impaired. Examples of such ethylenic unsaturated groups include free radical polymerizable functional groups such as vinyl, propenyl, isopropenyl, vinyl ether (vinyloxy), and allyl ether (allyloxy). Examples of the multifunctional monomer include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, tetrahydroxymethylmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, etc. Such a multifunctional monomer may be only one kind or two or more kinds.

The copolymerizable monomer may also be an alkoxyalkyl (meth)acrylate. Examples of the alkoxyalkyl (meth)acrylate include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. The alkoxyalkyl (meth)acrylate may be one or more.

In order to further demonstrate the effects of the present invention, the content of the (meth)acrylic acid alkyl ester (component a) in which the alkyl group of the alkyl ester part has 4 to 12 carbon atoms is preferably 30 wt % or more, more preferably 35 wt % to 99 wt %, further preferably 40 wt % to 98 wt %, and particularly preferably 50 wt % to 95 wt % relative to the total amount of monomer components constituting the acrylic polymer (100 wt %).

In order to further demonstrate the effect of the present invention, the content of at least one (component b) selected from the group consisting of (meth)acrylates having an OH group and (meth)acrylic acid is preferably 1 wt % or more, more preferably 1 wt % to 30 wt %, further preferably 2 wt % to 20 wt %, and particularly preferably 3 wt % to 10 wt % relative to the total amount (100 wt %) of monomer components constituting the acrylic polymer.

The composition (M) may contain any other appropriate components within the scope that does not impair the effects of the present invention. Such other components may include, for example, polymerization initiators, chain transfer agents, solvents, etc. The content of these other components may be any appropriate content within the scope that does not impair the effects of the present invention.

The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) according to the type of polymerization reaction. The polymerization initiator may be only one kind or two or more kinds.

Thermal polymerization initiators may be preferably used when obtaining acrylic polymers by solution polymerization. Examples of such thermal polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazoline)] Azo initiators such as 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.); persulfates such as potassium persulfate and ammonium persulfate, peroxide Di(2-ethylhexyl) dicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, di(2-butyl) peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauryl peroxide, dioctyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, Peroxide-based initiators such as dibenzoyl peroxide, tert-butyl peroxyisobutyrate, 1,1-di(tert-hexylperoxy)cyclohexane, tert-butyl hydroperoxide, and hydrogen peroxide; redox-based initiators formed by combining peroxides with reducing agents, such as a combination of persulfate and sodium hydrogen sulfite, and a combination of peroxide and sodium ascorbate; substituted ethane-based initiators such as phenyl-substituted ethane; and aromatic carbonyl compounds.

Photopolymerization initiators may be preferably used when obtaining acrylic polymers by active energy ray polymerization. Examples of photopolymerization initiators include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzoyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, 9-oxysulfonyl chloride-based photopolymerization initiators, and the like. It is a photopolymerization initiator.

Examples of benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether. Examples of acetophenone-based photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-(tert-butyl)dichloroacetophenone. Examples of α-ketoalcohol-based photopolymerization initiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. Examples of aromatic sulfonyl chloride-based photopolymerization initiators include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of benzoin-based photopolymerization initiators include benzoin. Examples of benzoyl-based photopolymerization initiators include benzoyl. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include benzoyl dimethyl ketal. 9-Oxosulfuron Examples of photopolymerization initiators include: 9-sulfuryl sulfide , 2-chloro-9-oxysulfuron , 2-methyl 9-oxosulfuron , 2,4-dimethyl 9-oxosulfuron 、Isopropyl 9-oxysulfide 、2,4-Diisopropyl 9-oxysulfide , dodecyl 9-oxysulfide .

The amount of the polymerization initiator used can be set to any appropriate amount within the range that does not impair the effect of the present invention.

The acrylic adhesive composition may also contain a crosslinking agent. By using a crosslinking agent, the cohesive force of the acrylic adhesive can be increased, and the effect of the present invention can be further demonstrated. The crosslinking agent may be only one kind or may be two or more kinds.

Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, polysiloxane crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyl etherified melamine crosslinking agents, metal chelate crosslinking agents, and peroxide crosslinking agents. In terms of further demonstrating the effect of the present invention, it is preferably at least one crosslinking agent selected from the group consisting of isocyanate crosslinking agents, epoxy crosslinking agents, and peroxide crosslinking agents (component c).

Isocyanate crosslinking agents can be used for compounds having two or more isocyanate groups in one molecule (including isocyanate-regenerated polar groups formed by temporarily protecting isocyanate groups by blocking agents or polymerization). Examples of isocyanate crosslinking agents include aromatic isocyanates such as toluene diisocyanate and xylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; and aliphatic isocyanates such as hexamethylene diisocyanate.

Examples of the isocyanate crosslinking agent include low-order aliphatic polyisocyanates such as butyl diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentyl diisocyanate, cyclohexyl diisocyanate, and isophorone diisocyanate; aromatic diisocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate; trihydroxymethylpropane/toluene diisocyanate trimer adduct (e.g., manufactured by Tosoh Corporation, trade name: Coronate L), trihydroxymethylpropane/hexamethylene diisocyanate trimer adduct (e.g., manufactured by Tosoh Corporation, trade name: Coronate HL), isocyanurate of hexamethylene diisocyanate (e.g., manufactured by Tosoh Co., Ltd., trade name: Coronate HX), etc. isocyanate adducts; trihydroxymethylpropane adducts of xylylenediisocyanate (e.g., manufactured by Mitsui Chemicals Co., Ltd., trade name: Takenate D110N), trihydroxymethylpropane adducts of xylylenediisocyanate (e.g., manufactured by Mitsui Chemicals Co., Ltd., trade name: Takenate D120N), trihydroxymethylpropane adducts of isophorone diisocyanate (e.g., manufactured by Mitsui Chemicals Co., Ltd., trade name: Takenate D140N), trihydroxymethylpropane adducts of hexamethylene diisocyanate (e.g., manufactured by Mitsui Chemicals Co., Ltd., trade name: Takenate D160N), trihydroxymethylpropane adduct of toluene diisocyanate (e.g., Mitsui Chemicals, trade name: Takenate D101E); polyether polyisocyanate, polyester polyisocyanate, and adducts thereof with various polyols; polyisocyanates multifunctionalized by isocyanurate bonding, biuret bonding, allophanate bonding, etc. Among them, aromatic isocyanates and alicyclic isocyanates are preferred in terms of good balance between deformability and cohesion.

Epoxy crosslinking agents can be used for polyfunctional epoxy compounds having two or more epoxy groups in one molecule. Examples of epoxy crosslinking agents include: N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether. , glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trihydroxymethylpropane polyglycidyl ether, adipate diglycidyl ester, phthalate diglycidyl ester, tri(2-hydroxyethyl)isocyanuric acid triglycidyl ester, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, epoxy resin having two or more epoxy groups in the molecule. Commercial products of epoxy crosslinking agents include, for example, the trade names "Tetrad C" and "Tetrad X" manufactured by Mitsubishi Gas Chemical Co., Ltd.

Examples of peroxides include dibenzoyl peroxide, diisopropylbenzene peroxide, di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, di-t-butyl hydroperoxide, t-butyl isopropylbenzene peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(t-butylperoxy)-hexane, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, di(2-ethylhexyl) peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, Di-sec-butyl dicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauryl peroxide, di-n-octyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, t-butyl peroxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-butyl peroxy-2-ethylhexyl carbonate, t-amyl peroxyisopropyl carbonate, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxy-2-hexanoate, t-butyl peroxypivalate, t-hexyl peroxypivalate. Examples of commercially available peroxides include the "Nyper BMT" series and "Nyper BW" series manufactured by NOF Corporation.

The content of the crosslinking agent in the acrylic adhesive composition can be any appropriate content within the range that does not impair the effect of the present invention. For example, in order to further demonstrate the effect of the present invention, the content is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 18 parts by weight, further preferably 0.5 to 15 parts by weight, and particularly preferably 0.5 to 10 parts by weight relative to the solid content (100 parts by weight) of the acrylic polymer.

The acrylic adhesive composition may contain any other appropriate components within the scope that does not impair the effect of the present invention. Such other components include, for example: polymer components other than acrylic polymers, crosslinking promoters, crosslinking catalysts, silane coupling agents, adhesion-imparting resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, etc.), and other components. materials or dyes, etc.), foils, UV absorbers, antioxidants, light stabilizers, nucleating agents, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, anti-corrosion agents, heat-resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc.

≪≪Optical component≫≫ The optical component has a polarizing plate. As long as the optical component has a polarizing plate, it may also include any other appropriate components within the scope that does not impair the effect of the present invention.

Other components include, for example, an adhesive layer and a brightness enhancement film.

The thickness of the optical component can be any appropriate thickness depending on its type. Typically, the thickness of the optical component is preferably 10 μm to 1000 μm, more preferably 30 μm to 800 μm, further preferably 50 μm to 700 μm, particularly preferably 100 μm to 600 μm, and most preferably 100 μm to 500 μm. [Example]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples. Furthermore, the test and evaluation methods in the examples are as follows. Furthermore, when "parts" are recorded, unless otherwise specified, they mean "parts by weight", and when "%" is recorded, unless otherwise specified, they mean "% by weight".

<Determination of tensile strength of substrate> According to JIS C 2151:2019, a tensile testing machine (manufactured by Shimadzu Corporation, product name "Autograph") is used to stretch the substrate of the measurement object in the width direction (TD direction) or the length direction (MD direction) at a speed of 200 mm/min, and the strength of the substrate of the measurement object when it is cut (broken) is measured (unit: MPa).

<Measurement of front phase difference and angle between slow axis and longitudinal direction (MD direction)> The substrate obtained in each manufacturing example or the surface protection film obtained in each embodiment and each comparative example was cut into a size of 210 mm × 300 mm, and the peeling pad of the surface protection film was peeled off from the adhesive layer. The polarization-phase difference measurement system ("AxoScan" manufactured by Axometrics, using software (Multi-order-retardance)) was used to measure the wavelength 590 nm measured the front phase difference and the angle between the slow axis and the longitudinal direction (MD direction) at 12 points in the plane (intersection points of X[mm]＝25, 150, 275, Y[mm]＝15, 75, 135, 195), and calculated the average value of the 12 points. Furthermore, as shown in Figure 2, the angle between the slow axis and the longitudinal direction (MD direction) means the angle θ between the slow axis and the longitudinal direction (MD direction) in the counterclockwise direction when the longitudinal direction (MD direction) is set to 0° with the longitudinal direction (MD direction) as the reference.

<Iridescence unevenness> The peelable pad is peeled off from the surface protection film, and the adhesive layer of the surface protection film is bonded to the polarizing plate (a) (manufactured by Nitto Denko, trade name "SEG1423DU") so that the angles formed by the slow axis of the substrate of the surface protection film and the absorption axis of the polarizing plate (a) (manufactured by Nitto Denko, trade name "SEG1423DU") are 90° or less, i.e., the axis offset is 0°, 15°, 30°, and 45°. Next, another polarizing plate (b) (manufactured by Nitto Denko, trade name "SEG1423DU") is arranged on the substrate side of the surface protection film so as to form orthogonal polarization with the polarizing plate bonded to the surface protection film. Fluorescent light was irradiated from the bottom side of the polarizing plate (b), and the transmitted light was visually observed to evaluate the degree of rainbow unevenness at polar angles of 0° to 85° and azimuth angles of 0° to 360° according to the following criteria. ◎: No rainbow unevenness was observed at any polar angle or azimuth angle. ○: Slight rainbow unevenness was observed at specific polar angles and azimuth angles. △: Strong rainbow unevenness was observed. ×: Strong rainbow unevenness was observed.

<Measurement of hue and brightness> A polarizing plate (manufactured by Nitto Denko, trade name "SEG1423DU") was cut into a size of 180 mm x 250 mm, and was bonded to a brightness enhancement film (manufactured by 3M Japan Products, trade name "APF-V3") in such a way that the absorption axis of the polarizing plate and the reflection axis of the brightness enhancement film were aligned to produce a polarizing plate with a brightness enhancement film. The peeling pad was peeled off from the surface protective film, and the adhesive layer of the surface protective film was bonded to the brightness enhancement film side of the polarizing plate with a brightness enhancement film in such a way that the angle formed by the slow axis of the substrate of the surface protective film and the absorption axis of the polarizing plate with a brightness enhancement film was 0°, 15°, 30°, or 45°. In order to make the axis offset as uniform as possible within the plane, it is necessary to control the unevenness of the axis angle of the slow axis of the substrate of the surface protection film within the plane. Therefore, the substrate of the surface protection film uses the maximum value of the axis angle of the slow axis within the plane - the minimum value of the axis angle of the slow axis within the plane is less than 1.15°. The surface protection film, the polarizing plate with the brightness enhancement film, and the measuring device are set on the backlight device in sequence. The hue and brightness are measured by a 2D spectroradiometer ("SR-5000HS" manufactured by TOPCON TECHNOHOUSE Co., Ltd., using the XYZ mode) with the distance between the sample and the detection camera set to 590 mm. In addition, the same measurement is also performed on the polarizing plate with only the brightness enhancement film attached without the surface protection film. Furthermore, the backlight device used is composed of (corner column sheet/diffuser plate/light guide plate [edge-type LED]/reflector plate), the average value of the in-plane brightness Y is 9500 cd/ ^m2 ~10000 cd/ ^m2 , the W of the backlight device is (chromaticity coordinate x=0.28~0.31, chromaticity coordinate y=0.27~0.32), RGB is R (631 nm) (chromaticity coordinate x=0.62~0.72, chromaticity coordinate y=0.22~0.32), G (535 nm) (chromaticity coordinate x=0.18~0.26, chromaticity coordinate y=0.62~0.78), B (450 nm) (chromaticity coordinate x=0.08~0.18, chromaticity coordinate y=0.01~0.12).

<RGB standard deviation> The RGB standard deviation is calculated from (1) the data of each RGB of the polarizing plate only and (2) the data of each RGB of the surface protection film + polarizing plate obtained in the above <Hue and brightness measurement>. The following evaluation is performed during the calculation. First, when calculating the difference between (1) and (2), due to the axis offset, there is a part where the surface protection film is not attached to the polarizing plate, so the values of X: 200 px to 800 px, Y: 100 px to 600 px in the sample surface X: 0 px to 910 px (200 mm), Y: 0 px to 730 px (160 mm) are used. Then, the standard deviation of each RGB is calculated, and finally the sum of the standard deviations of each RGB is obtained to calculate the RGB standard deviation.

<Dispersion entropy S _CD > The dispersion entropy S CD is calculated from (1) the data of each RGB of the polarizing plate only and (2) the data of each RGB of the surface protection film + polarizing plate obtained in the above <Measurement of hue and brightness _> . The following evaluation is performed when calculating. First, when calculating the difference between the above (1) and the above (2), due to the axis offset, there is a part where the surface protection film is not attached to the polarizing plate, so the value of X: 200 px ~ 800 px, Y: 100 px ~ 600 px in the sample surface X: 0 px ~ 900 px, Y: 0 px ~ 700 px is used. Then, as described below, the dispersion entropy S _CD is defined and calculated. S _CD = _SRCD + _SGCD + _SBCD in the case of R is as follows. S _RCD = k _B lnW k _B : Boltzmann constant X: The sum of the difference between (1) and (2) of R in the range of 200 px to 800 px, Y: 100 px to 600 px plus 255 (The difference between (1) and (2) of R in the range of X: 200 px to 800 px, Y: 100 px to 600 px is in the range of -255 to 255, so in order to handle it as a positive number, 255 is added to it and it is handled as a value of 0 to 510) N _Rn : The sum of the difference between (1) and (2) of R in the frame divided by 10 px × 10 px plus 255 W: The number W = _NR !/(N _R1 , _NR2 , ..., _NRn in each frame) _R1 !, N _R2 !, ..., N _Rn !) Since the calculation is rather complicated, Stirling's formula is used for approximate calculation, and the calculation is performed according to the following formula.

[Mathematical formula 1] In the case of G and B, the dispersion entropy S _CD is calculated in the same manner as R. In the "Dispersion entropy S _CD " and "RGB standard deviation/S _CD " columns in the table, "aEb" (a and b are numerical values) means "a×10 ^b ".

<Evaluation of peeling force relative to acrylic resin sheet> The surface protective film obtained in each embodiment and each comparative example was cut into a size of 25 mm in width and 100 mm in length, the peeling liner self-adhesive layer was peeled off, and the peeling liner was pressed onto an acrylic resin sheet ("Acrylite" manufactured by Mitsubishi Chemical Co., Ltd., thickness: 2 mm, width: 70 mm, length: 100 mm) with a roller pressure of 0.25 MPa and a feed speed of 0.3 m/min. After the sample was placed in an environment with a temperature of 23°C and a relative humidity of 50% for 30 minutes, a peeling test was performed in the environment with a peeling angle of 180° and a tensile speed of 300 mm/min to measure the peeling force relative to the acrylic resin board.

[Production Example 1] ＜Polymerization of acrylic polymer 1＞ 96.2 parts by mass of 2-ethylhexyl acrylate (2EHA) as monomer components, 3.8 parts by mass of hydroxyethyl acrylate (HEA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and 150 parts by mass of ethyl acetate were added to a reaction vessel equipped with a thermometer, a stirrer, a condenser, and a nitrogen inlet pipe, and nitrogen replacement was performed while slowly stirring at 23°C and introducing nitrogen. Thereafter, the polymerization reaction was performed for 6 hours while maintaining the liquid temperature at about 65°C to prepare a solution of acrylic polymer 1 (concentration 40% by mass). The weight average molecular weight of acrylic polymer 1 was 540,000. <Preparation of acrylic adhesive 1> Ethyl acetate was added to the solution of acrylic polymer 1 to dilute it to a concentration of 20% by mass. 4 parts by mass of isocyanurate of hexamethylene diisocyanate ("Coronate HX" manufactured by Tosoh Corporation) as a crosslinking agent and 3 parts by mass of dibutyltin dilaurate (1% by mass ethyl acetate solution) as a crosslinking catalyst were added to 500 parts by mass of the solution (100 parts by mass of solid content) and stirred to prepare acrylic adhesive 1.

[Production Example 2] <Polymerization of acrylic polymer 2> Into a reaction vessel equipped with a thermometer, a stirrer, a condenser, and a nitrogen inlet pipe, 95 parts by mass of butyl acrylate and 5 parts by mass of acrylic acid as monomer components, 0.2 parts by mass of AIBN as a polymerization initiator, and 186 parts by mass of ethyl acetate were added, and nitrogen was introduced while slowly stirring at 23°C to perform nitrogen replacement. Thereafter, the polymerization reaction was carried out for 10 hours while maintaining the liquid temperature at about 63°C to prepare a solution of acrylic polymer B (concentration 35% by mass). The weight average molecular weight of acrylic polymer 2 is 500,000. <Preparation of acrylic adhesive 2> Ethyl acetate was added to the solution of acrylic polymer 2 to dilute it to a concentration of 20% by mass. 0.075 parts by mass of a tetrafunctional epoxy compound ("Tetrad C" manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent was added to 500 parts by mass of the solution (100 parts by mass of solid content) and stirred to prepare an acrylic adhesive 2.

[Production Example 3] <Preparation of substrate (1)> On one side of an amorphous polyethylene terephthalate film (Mitsubishi Chemical Holdings Group, trade name "Novacrea", thickness 100 μm) with a water absorption rate of 0.60% and a Tg of 80°C as a thermoplastic resin substrate, an aqueous solution of a polyvinyl alcohol (PVA) resin (Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosenol (registered trademark) NH-26") with a polymerization degree of 2600 and a saponification degree of 99.9% was applied at 60°C and dried to form a PVA-based resin layer with a thickness of 7 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched to 2 times in the longitudinal direction (length direction) between rollers of different peripheral speeds in an oven at 120°C, then immersed in an insoluble bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 30°C for 30 seconds, and then immersed in a dyeing bath (an iodine aqueous solution obtained by mixing 0.2 parts by weight of iodine with 2 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 30°C for 60 seconds. Seconds, then, immersed in a crosslinking bath at a liquid temperature of 30°C (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide with 100 parts by weight of water and 3 parts by weight of boric acid) for 30 seconds, and then, while the laminate is immersed in a boric acid aqueous solution at a liquid temperature of 60°C (a water solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water and 5 parts by weight of potassium iodide), it is uniaxially stretched in the longitudinal direction (length direction) between rollers with different peripheral speeds. The immersion time in the boric acid aqueous solution is 120 seconds, and the stretching is carried out until the laminate is about to break. After that, the laminate was immersed in a cleaning bath (an aqueous solution obtained by mixing 3 parts by weight of potassium iodide with 100 parts by weight of water), and then dried using hot air at 60°C. In this way, an optical film laminate with a maximum stretch ratio of 6.5 times was obtained, in which a thin polarizing film was formed on a thermoplastic resin substrate. Here, the "maximum stretch ratio" refers to the stretch ratio before the laminate breaks. The stretch ratio at which the laminate breaks was separately confirmed, and the value 0.2 lower than this value was set as the "maximum stretch ratio". Finally, the thermoplastic resin substrate was removed from the obtained optical film laminate by peeling and set as the substrate (1). The thickness of the substrate (1) used is 40 μm, and the front phase difference R0 is 668 nm.

[Production Example 4] <Preparation of substrate (2)> Four substrates (1) obtained in Production Example 3 were layered to produce substrate (2). The layering was performed in such a way that the layering direction of the substrate and the slow axis direction of the substrate were as consistent as possible. The thickness of the substrate (2) used was 242 μm, and the front phase difference R0 was 2769 nm.

[Production Example 5] <Preparation of substrate (3)> Six substrates (1) obtained in Production Example 3 were layered to produce substrate (3). The layering was performed in such a way that the layering direction of the substrate and the slow axis direction of the substrate were as consistent as possible. The thickness of the substrate (3) used was 368 μm, and the front phase difference R0 was 4069 nm.

[Production Example 6] <Preparation of substrate (4)> Nine substrates (1) obtained in Production Example 3 were layered to produce substrate (4). The layering was performed in such a way that the layering direction of the substrate and the slow axis direction of the substrate were as consistent as possible. The thickness of the substrate (4) used was 557 μm, and the front phase difference R0 was 6011 nm.

[Production Example 7] <Preparation of substrate (5)> A super birefringent polyester film (manufactured by Toyobo Co., Ltd., trade name "COSMOSHINE SRF-1", thickness = 80 μm) was used as substrate (5). The front phase difference R0 of the substrate (5) used was 8369 nm.

[Production Example 8] <Preparation of substrate (6)> A crystalline PET film (manufactured by Toray Co., Ltd., trade name "XF60R", thickness = 38 μm) was used as substrate (6). The ratio (TD/MD) of the tensile strength in the width direction (TD direction) of the substrate (6) was 1.38. As the substrate (6) used, five types of substrates (6) with front phase differences R0 of 1438 nm, 1654 nm, 1675 nm, 1827 nm, and 1859 nm were used by changing the position of the main roll split.

[Production Example 9] <Preparation of substrate (7)> A polyester film (manufactured by Mitsubishi Chemical Co., Ltd., trade name "T100C38", thickness = 38 μm) was used as substrate (7). The front phase difference R0 of the substrate (7) used was 755 nm.

[Production Example 10] <Preparation of coating liquid A> 100 parts by mass of vinyl-containing addition-type polysilicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KS-847T", 30% toluene solution), 3 parts by mass of platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "CAT-PL-50T"), 15,000 parts by mass of toluene as a dilution solvent, and 1,500 parts by mass of n-hexane were mixed to prepare coating liquid A (refer to Japanese Patent Publication No. 2015-151473).

[Production Example 11] <Production of Peelable Liner A> After applying the coating liquid A on one side of a 38 μm thick polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Co., Ltd., trade name "T100C38", thickness = 38 μm) using a Mayer bar, the film was heated at 130°C for 1 minute using a hot air dryer to obtain a peelable liner A. The coating amount of the coating liquid A was set to 0.1 g/m ² in terms of solid content. In addition, the coating surface of the coating liquid A was set to the corona-treated surface of the PET film.

[Example 1] The acrylic adhesive 1 obtained in Preparation Example 1 was applied to the surface of a peeling pad A and dried to form an adhesive layer with a thickness of 10 μm on the peeling pad. The substrate (1) obtained in Preparation Example 3 was attached to the obtained adhesive layer to obtain a surface protective film (1) attached to a peeling pad. Next, cut the polarizing plate (manufactured by Nitto Denko, trade name "SEG1423DU") into a size of 180 mm × 250 mm, and laminate it with the brightness enhancement film (manufactured by 3M Japan Products, trade name "APF-V3"), so that the absorption axis of the polarizing plate and the reflection axis of the brightness enhancement film are aligned, thus making a polarizing plate with brightness enhancement film (A). The peelable liner is peeled off from the obtained surface protective film (1) with a peelable liner, and the polarizing plate (A) with a brightness enhancement film is bonded to the adhesive layer of the surface protective film so that the angle between the slow axis of the substrate of the surface protective film (1) and the absorption axis of the polarizing plate is 90° or less, i.e., the axis offset is 0°, thereby obtaining an optical laminate (1). The various evaluation results are shown in Table 1.

[Example 2] Except that the axis offset was changed to 15°, the same method as Example 1 was used to obtain a surface protection film (2) with a peel-off pad and an optical laminate (2). The various evaluation results are shown in Table 1.

[Example 3] Except that the axis offset was changed to 30°, the same method as Example 1 was used to obtain a surface protection film (3) with a peel-off pad and an optical laminate (3). The various evaluation results are shown in Table 1.

[Example 4] The acrylic adhesive 1 obtained in Preparation Example 1 is applied to the surface of the substrate (6) having a front phase difference R0 of 1438 nm obtained in Preparation Example 8 and dried to form an adhesive layer with a thickness of 10 μm on the substrate (6). A peelable liner A is attached to the surface of the obtained adhesive layer on the opposite side to the substrate (6) to obtain a surface protective film (4) with a peelable liner. The peelable liner is peeled off from the obtained surface protective film (4) with the peelable liner, and the polarizing plate (A) with the brightness enhancement film is attached to the adhesive layer in such a manner that the angle between the slow axis of the substrate of the surface protective film and the absorption axis of the polarizing plate is 90° or less, that is, the axis offset is 0°, thereby obtaining an optical laminate (4). The various evaluation results are shown in Table 1.

[Example 5] Except that the axis offset was changed to 15°, the same method as Example 4 was used to obtain a surface protection film (5) with a peel-off pad and an optical laminate (5). The various evaluation results are shown in Table 1.

[Example 6] Except that the axis offset was changed to 30°, the same method as Example 4 was used to obtain a surface protection film (6) with a peel-off pad and an optical laminate (6). The various evaluation results are shown in Table 1.

[Example 7] Except that the acrylic adhesive 2 obtained in Preparation Example 2 was used instead of the acrylic adhesive 1 obtained in Preparation Example 1, the same method as Example 4 was used to obtain a surface protective film (7) with a peel-off pad and an optical laminate (7). The various evaluation results are shown in Table 1.

[Example 8] Except that the substrate (6) with a front phase difference R0 of 1675 nm obtained in Manufacturing Example 8 was used instead of the substrate (6) with a front phase difference R0 of 1438 nm obtained in Manufacturing Example 8, the same method as Example 4 was used to obtain a surface protection film (8) with a peel-off pad and an optical laminate (8). The various evaluation results are shown in Table 1.

[Example 9] Except that the axis offset was changed to 15°, the same method as Example 8 was used to obtain a surface protection film (9) with a peel-off pad and an optical laminate (9). The various evaluation results are shown in Table 1.

[Example 10] Except that the axis offset was changed to 30°, the same method as Example 8 was used to obtain a surface protection film (10) with a peel-off pad and an optical laminate (10). The various evaluation results are shown in Table 1.

[Example 11] Except that the substrate (6) with a front phase difference R0 of 1654 nm obtained in Manufacturing Example 8 was used instead of the substrate (6) with a front phase difference R0 of 1438 nm obtained in Manufacturing Example 8, the same method as Example 4 was used to obtain a surface protection film (11) with a peel-off pad and an optical laminate (11). The various evaluation results are shown in Table 1.

[Example 12] Except that the axis offset was changed to 15°, the same method as Example 11 was used to obtain a surface protection film (12) with a peel-off pad and an optical laminate (12). The various evaluation results are shown in Table 1.

[Example 13] Except that the axis offset was changed to 30°, the same method as Example 11 was used to obtain a surface protection film (13) with a peel-off pad and an optical laminate (13). The various evaluation results are shown in Table 1.

[Example 14] Except that the substrate (6) with a front phase difference R0 of 1859 nm obtained in Example 8 was used instead of the substrate (6) with a front phase difference R0 of 1438 nm obtained in Example 8, the same method as Example 4 was used to obtain a surface protection film (14) with a peel-off pad and an optical laminate (14). The various evaluation results are shown in Table 1.

[Example 15] Except that the axis offset was changed to 15°, the same method as Example 14 was used to obtain a surface protection film (15) and an optical laminate (15) with a peel-off pad. The various evaluation results are shown in Table 1.

[Example 16] Except that the axis offset was changed to 30°, the same method as Example 14 was used to obtain a surface protection film (16) and an optical laminate (16) with a peel-off pad. The various evaluation results are shown in Table 1.

[Example 17] Except that the substrate (6) with a front phase difference R0 of 1827 nm obtained in Manufacturing Example 8 was used instead of the substrate (6) with a front phase difference R0 of 1438 nm obtained in Manufacturing Example 8, the same method as Example 4 was used to obtain a surface protection film (17) with a peel-off pad and an optical laminate (17). The various evaluation results are shown in Table 1.

[Example 18] Except that the axis offset was changed to 15°, the same method as Example 17 was used to obtain a surface protection film (18) and an optical laminate (18) with a peel-off pad. The various evaluation results are shown in Table 1.

[Example 19] Except that the axis offset was changed to 30°, the same method as Example 17 was used to obtain a surface protection film (19) and an optical laminate (19) with a peel-off pad. The various evaluation results are shown in Table 1.

[Example 20] Except that the substrate (3) obtained in Production Example 5 was used instead of the substrate (1) obtained in Production Example 3, the same method as in Example 1 was used to obtain a surface protective film (20) with a peel-off pad and an optical laminate (20). The various evaluation results are shown in Table 1.

[Example 21] Except that the axis offset was changed to 15°, the same method as Example 20 was carried out to obtain a surface protection film (21) with a peel-off pad and an optical laminate (21). The various evaluation results are shown in Table 1.

[Example 22] Except that the axis offset is changed to 30°, the same method as Example 20 is carried out to obtain a surface protection film (22) with a peel-off pad and an optical laminate (22). The various evaluation results are shown in Table 1.

[Example 23] Except that the substrate (4) obtained in Preparation Example 6 was used instead of the substrate (1) obtained in Preparation Example 3, the same method as Example 1 was used to obtain a surface protective film (23) with a peel-off pad and an optical laminate (23). The various evaluation results are shown in Table 1.

[Example 24] Except that the axis offset was changed to 15°, the same method as Example 23 was used to obtain a surface protection film (24) with a peel-off pad and an optical laminate (24). The various evaluation results are shown in Table 1.

[Example 25] Except that the axis offset was changed to 30°, the same method as Example 23 was used to obtain a surface protection film (25) with a peel-off pad and an optical laminate (25). The various evaluation results are shown in Table 1.

[Example 26] Except that the substrate (5) obtained in Production Example 7 was used instead of the substrate (6) with a front phase difference R0 of 1438 nm obtained in Production Example 8, the same method as in Example 4 was used to obtain a surface protection film (26) with a peel-off pad and an optical laminate (26). The various evaluation results are shown in Table 1.

[Example 27] Except that the axis offset was changed to 15°, the same method as Example 26 was used to obtain a surface protection film (27) and an optical laminate (27) with a peel-off pad. The various evaluation results are shown in Table 1.

[Example 28] Except that the axis offset is changed to 30°, the same method as Example 26 is carried out to obtain a surface protection film (28) and an optical laminate (28) with a peel-off pad. The various evaluation results are shown in Table 1.

[Example 29] Except that the acrylic adhesive 2 obtained in Preparation Example 2 was used instead of the acrylic adhesive 1 obtained in Preparation Example 1, the same method as Example 26 was used to obtain a surface protective film (29) with a peel-off pad and an optical laminate (29). The various evaluation results are shown in Table 1.

[Comparative Example 1] Except that the substrate (2) obtained in Production Example 4 was used instead of the substrate (1) obtained in Production Example 3, the same method as in Example 1 was used to obtain a surface protective film (C1) with a peel-off pad and an optical laminate (C1). The various evaluation results are shown in Table 1.

[Comparative Example 2] Except that the axis offset was changed to 15°, the same method as in Comparative Example 1 was used to obtain a surface protection film (C2) and an optical laminate (C2) with a peel-off pad. The various evaluation results are shown in Table 1.

[Comparative Example 3] Except that the axis offset was changed to 30°, the same method as in Comparative Example 1 was used to obtain a surface protection film (C3) and an optical laminate (C3) with a peel-off pad. The various evaluation results are shown in Table 1.

[Comparative Example 4] Except that the axis offset was changed to 45°, the same method as in Comparative Example 1 was used to obtain a surface protection film (C4) and an optical laminate (C4) with a peel-off pad. The various evaluation results are shown in Table 1.

[Comparative Example 5] Except that the axis offset was changed to 45°, the same method as Example 20 was used to obtain a surface protection film (C5) and an optical laminate (C5) with a peel-off pad. The various evaluation results are shown in Table 1.

[Comparative Example 6] Except that the substrate (7) obtained in Production Example 9 was used instead of the substrate (1) obtained in Production Example 3, the same method as in Example 1 was used to obtain a surface protective film (C6) and an optical laminate (C6) with a peel-off pad. The various evaluation results are shown in Table 1.

[Comparative Example 7] Except that the substrate (7) obtained in Manufacturing Example 9 was used instead of the substrate (6) with a front phase difference R0 of 1438 nm obtained in Manufacturing Example 8, the same method as in Example 4 was used to obtain a surface protective film (C7) and an optical laminate (C7) with a peel-off pad. The various evaluation results are shown in Table 1.

[Comparative Example 8] Except that the acrylic adhesive 2 obtained in Production Example 2 was used instead of the acrylic adhesive 1 obtained in Production Example 1, the same method as in Comparative Example 7 was used to obtain a surface protective film (C8) and an optical laminate (C8) with a peel-off pad. The various evaluation results are shown in Table 1.

[Table 1] Example/Comparative Example Substrate Adhesive layer Surface protection film Optical laminate Type Thickness [μm] Front phase difference R0 [nm] Type Application method Thickness [μm] Relative peeling force of acrylic board [N/25 mm] Front phase difference R0 [nm] Average value of the angle between the slow axis and the longitudinal direction (MD direction) [°] The maximum value of the angle between the slow axis and the longitudinal direction (MD direction) in the plane [°] Minimum value of the angle between the slow axis and the longitudinal direction (MD direction) in the plane [°] The maximum and minimum angles between the slow axis and the longitudinal direction (MD direction) [°] Axis offset [°] Rainbow uneven evaluation RGB standard deviation Dispersion entropy S _CD RGB standard deviation/S _CD Embodiment 1 (1) 40 668 1 Transfer 10 0.09 672 88.99 89.18 88.82 0.36 0 ◎ 9.04 2.56E-14 3.53E+14 Embodiment 2 (1) 40 668 1 Transfer 10 0.09 672 88.99 89.18 88.82 0.36 15 ○ 9.31 2.56E-14 3.63E+14 Embodiment 3 (1) 40 668 1 Transfer 10 0.09 672 88.99 89.18 88.82 0.36 30 ○ 9.39 2.54E-14 3.69E+14 Embodiment 4 (6) 38 1438 1 Direct printing 10 0.09 1452 89.77 90.28 89.20 1.08 0 ◎ 9.10 2.57E-14 3.54E+14 Embodiment 5 (6) 38 1438 1 Direct printing 10 0.09 1452 89.77 90.28 89.20 1.08 15 ○ 9.25 2.56E-14 3.61E+14 Embodiment 6 (6) 38 1438 1 Direct printing 10 0.09 1452 89.77 90.28 89.20 1.08 30 ○ 9.31 2.54E-14 3.67E+14 Embodiment 7 (6) 38 1438 2 Direct printing 13 10.5 1449 89.75 90.26 89.18 1.08 0 ◎ 9.11 2.55E-14 3.54E+14 Embodiment 8 (6) 38 1675 1 Direct printing 15 0.09 1688 91.23 91.85 90.71 1.14 0 ◎ 9.08 2.56E-14 3.55E+14 Embodiment 9 (6) 38 1675 1 Direct printing 15 0.09 1688 91.23 91.85 90.71 1.14 15 ○ 9.10 2.57E-14 3.54E+14 Embodiment 10 (6) 38 1675 1 Direct printing 15 0.09 1688 91.23 91.85 90.71 1.14 30 ○ 9.28 2.56E-14 3.63E+14 Embodiment 11 (6) 38 1654 1 Direct printing 20 0.09 1643 90.78 91.21 90.18 1.03 0 ◎ 9.09 2.57E-14 3.54E+14 Embodiment 12 (6) 38 1654 1 Direct printing 20 0.09 1643 90.78 91.21 90.18 1.03 15 ○ 9.13 2.55E-14 3.58E+14 Embodiment 13 (6) 38 1654 1 Direct printing 20 0.09 1643 90.78 91.21 90.18 1.03 30 ○ 9.25 2.55E-14 3.63E+14 Embodiment 14 (6) 38 1859 1 Direct printing 15 0.09 1843 82.65 83.22 82.13 1.09 0 ◎ 9.11 2.57E-14 3.54E+14 Embodiment 15 (6) 38 1859 1 Direct printing 15 0.09 1843 82.65 83.22 82.13 1.09 15 ○ 9.22 2.57E-14 3.59E+14 Embodiment 16 (6) 38 1859 1 Direct printing 15 0.09 1843 82.65 83.22 82.13 1.09 30 ○ 9.34 2.56E-14 3.65E+14 Embodiment 17 (6) 38 1827 1 Direct printing 20 0.09 1804 83.49 83.96 83.04 0.92 0 ◎ 9.13 2.57E-14 3.55E+14 Embodiment 18 (6) 38 1827 1 Direct printing 20 0.09 1804 83.49 83.96 83.04 0.92 15 ○ 9.20 2.54E-14 3.62E+14 Embodiment 19 (6) 38 1827 1 Direct printing 20 0.09 1804 83.49 83.96 83.04 0.92 30 ○ 9.36 2.55E-14 3.67E+14 Embodiment 20 (3) 368 4069 1 Transfer 10 0.09 4074 89.37 89.60 89.09 0.51 0 △ 9.57 2.54E-14 3.76E+14 Embodiment 21 (3) 368 4069 1 Transfer 10 0.09 4074 89.37 89.60 89.09 0.51 15 △ 9.61 2.54E-14 3.78E+14 Embodiment 22 (3) 368 4069 1 Transfer 10 0.09 4074 89.37 89.60 89.09 0.51 30 △ 9.61 2.54E-14 3.78E+14 Embodiment 23 (4) 557 6011 1 Transfer 10 0.09 6039 87.16 87.51 86.36 1.15 0 ◎ 9.17 2.57E-14 3.57E+14 Embodiment 24 (4) 557 6011 1 Transfer 10 0.09 6039 87.16 87.51 86.36 1.15 15 ○ 9.29 2.56E-14 3.64E+14 Embodiment 25 (4) 557 6011 1 Transfer 10 0.09 6039 87.16 87.51 86.36 1.15 30 ○ 9.39 2.54E-14 3.70E+14 Embodiment 26 (5) 80 8369 1 Direct printing 10 0.09 8375 91.81 92.31 91.35 0.96 0 ◎ 9.17 2.57E-14 3.57E+14 Embodiment 27 (5) 80 8369 1 Direct printing 10 0.09 8375 91.81 92.31 91.35 0.96 15 ○ 9.24 2.56E-14 3.61E+14 Embodiment 28 (5) 80 8369 1 Direct printing 10 0.09 8375 91.81 92.31 91.35 0.96 30 ○ 9.31 2.55E-14 3.65E+14 Embodiment 29 (5) 80 8369 2 Direct printing 13 10.5 8378 91.83 92.33 91.37 0.96 0 ◎ 9.17 2.57E-14 3.57E+14 Comparison Example 1 (2) 242 2769 1 Transfer 10 0.09 2705 89.35 89.64 89.04 0.60 0 × 9.25 2.45E-14 3.78E+14 Comparison Example 2 (2) 242 2769 1 Transfer 10 0.09 2705 89.35 89.64 89.04 0.60 15 × 9.40 2.44E-14 3.86E+14 Comparison Example 3 (2) 242 2769 1 Transfer 10 0.09 2705 89.35 89.64 89.04 0.60 30 × 9.46 2.38E-14 3.98E+14 Comparison Example 4 (2) 242 2769 1 Transfer 10 0.09 2705 89.35 89.64 89.04 0.60 45 × 9.66 2.34E-14 4.13E+14 Comparison Example 5 (3) 368 4069 1 Transfer 10 0.09 4074 89.37 89.60 89.09 0.51 45 × 9.87 2.50E-14 3.95E+14 Comparative Example 6 (7) 38 755 1 Transfer 10 0.09 741 100.78 104.19 98.36 5.83 - × 9.60 1.52E-14 6.30E+14 Comparison Example 7 (7) 38 755 1 Direct printing 10 0.09 765 108.20 111.96 104.79 7.17 - × 9.78 1.54E-14 6.37E+14 Comparative Example 8 (7) 38 755 2 Direct printing 13 10.5 763 108.15 111.91 104.74 7.17 - × 9.72 1.53E-14 6.36E+14 [Industrial Availability]

The optical multilayer of the present invention can be used for any appropriate purpose. Preferably, the optical multilayer of the present invention is used in the field of optical components or electronic components.

10: substrate 20: adhesive layer 100: surface protection film 200: optical component 1000: optical laminate θ: angle

FIG1 is a schematic cross-sectional view showing one embodiment of the optical multilayer body of the present invention. FIG2 is a schematic explanatory view for explaining the angle between the slow axis and the longitudinal direction (MD direction).

10: Base material

20: Adhesive layer

100: Surface protection film

200: Optical components

1000:Optical multilayer

Claims (3)

An optical laminate, comprising a surface protection film and an optical component, the surface protection film having a substrate and an adhesive layer, the optical component having a polarizing plate, the front phase difference R0 of the surface protection film being R0≦2500 nm or R0≧3000 nm, the angle between the absorption axis of the polarizing plate and the slow axis of the substrate of the surface protection film being less than 30°. An optical multilayer as claimed in claim 1, wherein the RGB standard deviation of the optical multilayer is less than 9.50. The optical multilayer of claim 1, wherein the dispersion entropy S _CD of the optical multilayer is greater than 2.52×10 ^-14 .