TW202403350A - Surface protection film and optical laminate - Google Patents

Abstract

The invention provides a surface protection film and an optical laminate, the surface protection film is pasted on an optical member, and the inspection performance of hue/brightness unevenness is excellent even through the surface protection film is interposed. Also provided is an optical laminate comprising such a surface protection film. A surface protection film according to an embodiment of the present invention is a surface protection film provided with a substrate and an adhesive layer, wherein the product [sigma] SSA * CVSR0 obtained by multiplying the standard deviation [sigma] SSA of the angle formed between the slow axis of 12 points in plane and the longitudinal direction (MD direction) by the variation coefficient CVSR0 of the front phase difference of 12 points in plane is 0.020 or less.

Description

Surface protective film and optical laminate

The present invention relates to a surface protective film. Furthermore, the present invention provides an optical laminate including such a surface protective film.

Surface protection films are provided on the surfaces of optical equipment such as displays and imaging devices, electronic equipment, and films or glass materials that are components of such equipment for the purpose of protecting the surface or imparting impact resistance. As a typical surface protective film, there are those that are temporarily adhered in the state before use of equipment such as assembly, processing, and transportation, and then peeled off before using the equipment (those used as engineering materials), and those that are used when the equipment is used. The user attaches the device to the surface of the device (for the purpose of permanent adhesion) (for example, refer to Patent Document 1).

Surface protective films used as engineering materials and surface protective films used for permanent adhesion are equipped with an adhesive layer on the main surface of the film base material, and are bonded to the surface of the adherend as the object of protection 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 in which a surface protective film was bonded to an optical member including a polarizing plate was inspected for hue and brightness unevenness through the surface protective film, there were cases where the surface protective film had Anisotropy, etc., making it impossible to perform appropriate inspections. [Prior technical literature] [Patent Document]

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

[Problem to be solved by the invention]

An object of the present invention is to provide a surface protective film that is attached to an optical member and has excellent inspection properties for hue and brightness unevenness even across the surface protective film. Furthermore, another object of the present invention is to provide an optical laminate including such a surface protective film. [Technical means to solve problems]

[1] The surface protective film according to the embodiment of the present invention has a base material and an adhesive layer, and the standard deviation σ SSA of the angle between the slow axis of 12 points in the plane and the longitudinal direction (MD direction) is equal to the standard deviation σ _SSA of the angle between the 12 points in the plane The product σ _SSA × CV _SR0 of the coefficient of variation CV _SR0 of the frontal phase difference is 0.020 or less.

[2] The surface protective film as described in the above [1], wherein the front-side phase difference R0 of the above-mentioned substrate may be R0≦2600 nm or R0≧4100 nm.

[3] The surface protection film according to the above [1] or [2], wherein the material of the above substrate can be polyethylene terephthalate.

[4] The surface protective film according to any one of the above [1] to [3], wherein the adhesive constituting the adhesive layer may be selected from the group consisting of acrylic adhesives, urethane adhesives, and at least one of the group consisting of polysiloxane adhesives.

[5] The optical laminated body according to the embodiment of the present invention includes the surface protective film and the optical member as described in any one of [1] to [4] above.

[6] The optical laminate according to the above [5], wherein the optical member may include a polarizing plate. [Effects of the invention]

According to the present invention, it is possible to provide a surface protective film that is attached to an optical member and has excellent inspection properties for hue and brightness unevenness even across the surface protective film. Furthermore, an optical laminated body containing such a surface protective film can be provided.

When expressed as "mass" in this specification, it can also be replaced by "weight", which is commonly used as a unit of weight. Conversely, when it is expressed as "weight" in this specification, it can also be replaced by the SI system, which is commonly used to express weight. Unit of "mass".

In this specification, the angle in the case of "the angle formed by the slow axis and the longitudinal direction (MD direction)" means the angle formed in the counterclockwise direction with the longitudinal direction (MD direction) as the reference.

In this specification, "(meth)acrylic acid" means "acrylic acid and/or methacrylic acid", and "(meth)acrylate" means "acrylate and/or methacrylic acid ester". "Ester", when expressed as "(meth)allyl" it means "allyl and/or methallyl", when expressed as "(meth)acrolein" it means "acrolein and /or methacrolein".

≪≪Surface protective film≫≫ The surface protective film according to the embodiment of the present invention has a base material and an adhesive layer.

The surface protective film according to the embodiment of the present invention may also have any other appropriate layer other than the base material and the adhesive layer within the scope that does not impair the effects of the present invention.

Examples of such other layers include: an easy-adhesive layer, an easy-slip layer, an anti-adhesion layer, an antistatic layer, an anti-reflective layer, and an anti-oligomer layer.

In the surface protective film according to the embodiment of the present invention, for the purpose of protecting the adhesive layer, a release liner may be provided on the surface of the adhesive layer opposite to the base material. This release liner is usually peeled off when using the surface protective film according to the embodiment of the present invention.

The surface protective film according to the embodiment of the present invention may also contain any appropriate additive 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 the surface protection film of the present invention, the surface protection film 100 includes a base material 10 and an adhesive layer 20 .

In the surface protective film according to the embodiment of the present invention, the product of the standard deviation σ _SSA of the angle between the slow axis and the longitudinal direction (MD direction) at 12 points in the plane and the coefficient of variation CV _SR0 of the frontal phase difference at 12 points in the plane The smaller σ _SSA ×CV _SR0 is, the better. It is preferably 0.020 or less, more preferably 0.015 or less, further preferably 0.012 or less, particularly preferably 0.010 or less, and most preferably 0.008 or less. By adjusting the above-mentioned σ _SSA × CV _SR0 value of the surface protective film to the above-mentioned range, the effects of the present invention can be further exhibited.

In the surface protective film according to the embodiment of the present invention, the standard deviation σ _SSA of the angle between the slow axis at 12 points in the plane and the longitudinal direction (MD direction) is as small as possible, preferably 2.00 or less, and more preferably 1.50. or less, more preferably 1.00 or less, still more preferably 0.90 or less, particularly preferably 0.80 or less, most preferably 0.75 or less. By adjusting the above-mentioned σ _SSA value of the surface protective film to the above-mentioned range, the effects of the present invention can be further exhibited.

In the surface protective film according to the embodiment of the present invention, the coefficient of variation CV _SR0 of the frontal phase difference at 12 points in the plane is as small as possible, preferably 0.050 or less, more preferably 0.040 or less, further preferably 0.035 or less, and particularly preferably is 0.030 or less, and the optimum is 0.25 or less. By adjusting the above-mentioned CV _SRO value of the surface protective film to the above-mentioned range, the effects of the present invention can be further exhibited.

The front-side phase difference R0 of the surface protective film according to the embodiment of the present invention is preferably R0≦2600 nm or R0≧2700 nm, more preferably R0≦2500 nm or R0≧3400 nm, and further preferably R0≦2400 nm or R0 ≧4100 nm, preferably R0≦2300 nm or R0≧4500 nm, further preferably R0≦2200 nm or R0≧5000 nm, further preferably R0≦2100 nm or R0≧5500 nm, especially R0 ≦2000 nm or R0≧6000 nm, the best is R0≦1900 nm or R0≧6000 nm. By adjusting the in-plane phase difference of the surface protective film to the above range, the effects of the present invention can be further exhibited. Furthermore, in the description of the present invention, the above-mentioned preferable range of the front-side phase difference R0 is specified in sections, for example, in the form of "R0≦2600 nm or R0≧2700 nm", with combinations of below the specified value or above the specified value. , but the preferred range of the above-mentioned front-side phase difference R0 is not limited to the combination described. 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 regulations that are stated in combinations of below a specified value or above a specified value, for example, when it is specified as "R0 ≦ 2600 nm or R0 ≧ 2700 nm", it means "R0 ≦ 2600 nm" or "R0≧2700 nm".

Furthermore, regarding the measurement of the front phase difference R0 of the surface protective film according to the embodiment of the present invention and the angle between the slow axis and the longitudinal direction (MD direction), the relationship between the adhesive layer of the surface protective film and the base material is When a release liner is provided on the opposite surface, the measurement is performed after the release liner is peeled off.

When the front-side phase difference R0 of the surface protective film is R0 ≦ 2600 nm, the lower limit value is as small as possible. However, due to factors such as material selection, in reality it is better to be above 100 nm.

When the front-side phase difference R0 of the surface protective film is R0 ≧ 2700 nm, the larger the upper limit, the better. However, due to factors such as material selection, in reality, it is preferably below 30000 nm.

≪Substrate≫ The base material may be one composed of one layer, or may be a base material composed of a laminated structure of two or more layers.

The thickness of the base material can also be any appropriate thickness within the range that does not impair the effects of the present invention. In order to further express the effects of the present invention, the thickness of the base material 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. ~400 μm.

The front-side phase difference R0 of the substrate is preferably R0≦2600 nm or R0≧2700 nm, more preferably R0≦2400 nm or R0≧3400 nm, and more preferably R0≦2300 nm or R0≧4100 nm, even more preferably R0≦2200 nm or R0≧4500 nm, more preferably R0≦2100 nm or R0≧5000 nm, especially R0≦2000 nm or R0≧5500 nm, most preferably R0≦1900 nm or R0≧6000 nm . By using such a base material, the effects of the present invention can be further demonstrated. Furthermore, in the description of the present invention, the above-mentioned preferable range of the front-side phase difference R0 is specified in sections, for example, in the form of "R0≦2600 nm or R0≧2700 nm", with combinations of below the specified value or above the specified value. , but the preferred range of the above-mentioned front-side phase difference R0 is not limited to the combination described. 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 regulations that are stated in combinations of below a specified value or above a specified value, for example, when it is specified as "R0 ≦ 2600 nm or R0 ≧ 2700 nm", it means "R0 ≦ 2600 nm" or "R0≧2700 nm".

When the front-side phase difference R0 of the substrate is R0 ≦ 2600 nm, the lower limit value is as small as possible. However, due to factors such as material selection, in reality it is better to be above 100 nm.

When the front-side phase difference R0 of the substrate is R0 ≧ 2700 nm, the larger the upper limit value, the better. However, due to factors such as material selection, in reality, it is preferably below 30000 nm.

As a method of obtaining a substrate with a front-surface phase difference R0 within the above range, any appropriate method can be used within the scope that does not impair the effects of the present invention. Examples of such methods include: a method of stretching a base material made of plastic, a method of using a super birefringent film, a method of laminating two or more layers of a base material made of plastic, and using a front-surface phase difference R0 to R0 ≦2600 nm crystalline PET (polyethylene terephthalate) substrate method.

As the material of the base material, any appropriate material can be used within the scope that does not impair the effects of the present invention. In terms of further exhibiting the effects of the present invention, a preferred example of such material is plastic.

As the plastic, any appropriate plastic can be used within the scope that does not impair the effects of the present invention. From the perspective of further exhibiting the effects of the present invention, a preferred example of such plastic is 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) material), polyamide (nylon), fully aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyvinyl acetate, cyclic olefin polymers.

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

<One of the preferred embodiments of the base material A> One preferred embodiment A of the base material is an extended thermoplastic resin base material. Hereinafter, the thermoplastic resin base material used for stretching may be simply referred to as "thermoplastic resin base material", and the stretched thermoplastic resin base material may be referred to as "stretched thermoplastic resin base material".

The thickness of the stretched thermoplastic resin base material in Embodiment A can be any appropriate thickness within the range that does not impair the effects of the present invention. In order to further express the effects of the present invention, the thickness of the stretched thermoplastic resin base material is preferably 1 μm to 100 μm, more preferably 2 μm to 80 μm, and still more preferably 3 μm to 70 μm, particularly preferably It is 5 μm～60 μm.

The front-side 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, especially R0≦800 nm, the best is R0≦700 nm. If the front-side phase difference R0 of the stretched thermoplastic resin base material is within the above range, the effects of the present invention can be further exhibited.

The lower limit of the front-side phase difference R0 of the extended thermoplastic resin substrate is as small as possible. However, due to factors such as material selection, in reality it is better to be above 100 nm.

In order to further express the effects of the present invention, the thermoplastic resin base material preferably has a water absorption rate within a predetermined range. The water absorption rate of the thermoplastic resin base material is preferably 0.2% or more, more preferably 0.3% or more. A thermoplastic resin base material with such water absorption can absorb water while extending in water, and the water acts as a plasticizer and is plasticized. As a result, the stretching stress can be significantly reduced, stretching can be performed at a high magnification ratio, and the stretchability of the thermoplastic resin base material can be superior to that of air stretching described below. If such a thermoplastic resin base material is stretched, it can become a base material with excellent optical properties, and therefore the effects of the present invention can be further exhibited. On the other hand, the water absorption rate of the thermoplastic resin base material is preferably 3.0% or less, more preferably 1.0% or less. The thermoplastic resin base material with such water absorption has excellent dimensional stability, so it is possible to prevent undesirable situations such as deterioration of the appearance of the stretched thermoplastic resin base material after stretching the thermoplastic resin base material. In addition, the following water stretching step is performed to prevent substrate breakage. In addition, the water absorption rate is a value obtained based on JIS K 7209.

In order to further express the effects of the present invention, the thermoplastic resin base material preferably has a glass transition temperature (Tg) within a predetermined range. The glass transition temperature (Tg) of the thermoplastic resin base material is preferably 170°C or lower. By using this thermoplastic resin base material, excellent elongation can be achieved. Furthermore, in consideration of smooth plasticization of the thermoplastic resin base material using water and water elongation, the glass transition temperature (Tg) of the thermoplastic resin base material is preferably 120° C. or lower. On the other hand, the glass transition temperature (Tg) of the thermoplastic resin base material is preferably 60°C or higher. By using such a thermoplastic resin base material, it is possible to prevent undesirable situations such as deformation of the thermoplastic resin base material (for example, the occurrence of unevenness, sagging, or wrinkles, etc.). In addition, the glass transition temperature (Tg) is a value calculated based on JIS K 7121.

As a material for the thermoplastic resin base material, in terms of further exhibiting the effects of the present invention, a preferred example is a material in which the water absorption rate and glass transition temperature of the thermoplastic resin base material are within the above ranges. The water absorption rate can be adjusted, for example, by introducing a modifying group into the material. The glass transition temperature can be adjusted, for example, by introducing a modifying group into the material or by using a crystalline material and heating it.

As the material of the thermoplastic resin base material, in terms of further exhibiting the effects of the present invention, polyethylene terephthalate (PET)-based resin is preferably used, and amorphous (non-crystalline) resin is more preferably used. Polyethylene terephthalate (PET) resin that can crystallize), and more preferably, amorphous (not easy to crystallize) polyethylene terephthalate (PET) resin. Specific examples of the amorphous polyethylene terephthalate (PET)-based resin include, for example, a copolymer further containing isophthalic acid as a dicarboxylic acid, or a copolymer further containing cyclohexane as a diol. Alkanedimethanol copolymer.

In order to further express the effects of the present invention, the thickness of the thermoplastic resin base material (thickness before stretching) is preferably 10 μm to 500 μm, more preferably 20 μm to 400 μm, and still more preferably 30 μm to 30 μm. 300 μm, preferably 50 μm～200 μm.

A typical stretching of a thermoplastic resin substrate is underwater stretching (wet stretching) using a water bath as a stretching bath. By using stretching in water, if the thermoplastic resin base material has the above-mentioned water absorption rate, water can act as a plasticizer and be plasticized. As a result, the stretching stress can be significantly reduced, stretching can be performed at a high magnification ratio, and the stretchability of the thermoplastic resin base material can be superior to that of air stretching described below. Therefore, since a base material having excellent optical properties is obtained, the effects of the present invention can be further exhibited. Furthermore, by using water stretching, it is possible to stretch at a high rate at a temperature lower than the glass transition temperature of the thermoplastic resin base material.

The extending direction of the thermoplastic resin base material is preferably the transverse direction (short side direction) of the elongated thermoplastic resin base material.

As an extension method for extending in water, any appropriate method can be used within the scope that does not impair the effects of the present invention. Examples of 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 peripheral speeds). Extension can be carried out in one stage or in multiple stages. When the process is carried out in multiple stages, the stretching ratio (maximum stretching ratio) is the product of the stretching ratios in each stage.

The extension temperature of the extension in water (the liquid temperature of the extension bath) can be any appropriate temperature within the range that does not impair the effects of the present invention. In order to further express the effects of the present invention, the temperature 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, there is a risk that the thermoplastic resin base material may not be stretched satisfactorily even if plasticization of the thermoplastic resin base material using water is considered.

The extension time in water can be any appropriate time within the scope that does not impair the effect of the present invention. In order to further express the effects of the present invention, 15 seconds to 5 minutes is preferred.

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

As the stretching of the thermoplastic resin base material, air stretching (dry stretching) and the above-mentioned underwater stretching can also be combined. Any appropriate extension method can be used for air extension within the scope that does not impair the effects of the present invention. By combining stretching in the air and stretching in water, the alignment of the thermoplastic resin substrate can be suppressed while stretching. As the orientation of the thermoplastic resin base material increases, the stretching tension increases, making it difficult to perform stable stretching or causing the thermoplastic resin base material to break. Therefore, by stretching while suppressing the alignment of the thermoplastic resin base material, it is possible to stretch at a higher magnification. As a result, a base material with more excellent optical properties can be obtained, so that the effects of the present invention can be further exhibited.

The stretching method of in-air stretching is the same as the above-mentioned stretching in water. It can be fixed-end stretching or free-end stretching (for example, a method of uniaxial stretching by passing the laminated body between rollers with different peripheral speeds). In addition, the extension can be performed in one stage or in multiple stages. In the case of multiple stages, the stretch ratio is the product of the stretch ratios of each stage. The extension direction is preferably substantially the same as the above-mentioned extension direction in water.

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

The extension time of the air extension can be any appropriate time within the scope that does not impair the effect of the present invention. In order to further demonstrate the effect of the present invention, the extension time of the air extension is preferably 15 seconds to 5 minutes.

The stretching magnification of air stretching can be any appropriate magnification within the range that does not impair the effect of the present invention. In order to further express the effects of the present invention, the stretching ratio of the air stretching is preferably 3.5 times or less.

The maximum stretching ratio when combining air stretching and underwater stretching is preferably 5.0 times or more, more preferably 5.5 times or more, and still more preferably 6.0 times or more relative to the original length of the thermoplastic resin base material.

As the stretched thermoplastic resin base material of one preferred embodiment A of the base material, for example, the stretched thermoplastic resin base material described in Japanese Patent Application Laid-Open No. 2012-73580 can also be used.

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

The thickness of the super birefringent film base material in Embodiment B can be any appropriate thickness within the range that does not impair the effects of the present invention. In order to further demonstrate the effects of the present invention, the thickness of the super birefringent film base material is preferably 10 μm to 500 μm, more preferably 15 μm to 300 μm, and further preferably 25 μm to 200 μm, especially Preferably, it is 30 μm~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, especially R0≧7500 nm, the best is R0≧8000 nm. If the front-side phase difference R0 of the super-birefringent film substrate is within the above range, the effects of the present invention can be further exhibited.

The larger the upper limit of the front-side phase difference R0 of the superbirefringent film substrate, the better. However, due to factors such as material selection, in reality it is preferably below 30,000 nm.

As the material of the base material of the super birefringent film, any appropriate plastic can be used within the scope that does not impair the effects of the present invention. From the perspective of further exhibiting the effects of the present invention, a preferred example of such plastic is 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) material), polyamide (nylon), fully aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyvinyl acetate, cyclic olefin polymers.

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

The superbirefringent film substrate can also be an extended substrate.

＜One of the preferred embodiments of the base material C＞ One preferred embodiment C of the base material is a laminate of two or more layers of base materials made of plastic. Hereinafter, base materials made of plastic are sometimes referred to as "plastic base materials".

The thickness of the laminate in Embodiment C can be any appropriate thickness within the range that does not impair the effects of the present invention. In order to further express the effects of the present invention, the thickness of the laminated body of Embodiment C is preferably 50 μm to 1000 μm, more preferably 100 μm to 800 μm, and further preferably 150 μm to 700 μm. Particularly preferred is 200 μm to 600 μm.

As described above, the number of layers of the laminated body in Embodiment C is 2 or more. In order to further exhibit the effects of the present invention, 2 to 20 layers are preferred, and 2 to 15 layers are more preferred. Furthermore, 2 to 12 layers are more preferable, and 2 to 10 layers are especially preferable.

The front-side phase difference R0 of the laminated body of Embodiment C is preferably R0≧2500 nm, more preferably R0≧3000 nm, further preferably R0≧3500 nm, further preferably R0≧4000 nm, still more preferably R0≧4500 nm, especially R0≧5000 nm, the best is R0≧5500 nm. By using such a base material, the effects of the present invention can be further demonstrated. The plurality of laminated plastic substrates can all be of different types (different materials), or at least two of the plastic substrates can be of the same type (same materials).

The upper limit of the front-surface phase difference R0 of the laminate in Embodiment C is preferably as large as possible. However, in view of factors such as material selection, in reality, it is preferably 30,000 nm or less.

As the material of the plastic base material that can be used in Embodiment C, any appropriate plastic can be used within the scope that does not impair the effects of the present invention. In terms of further exhibiting the effects of the present invention, a preferred example of such plastic is 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) material), polyamide (nylon), fully aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyvinyl acetate, cyclic olefin polymers.

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

As the plastic base material that can be used in Embodiment C, the stretched thermoplastic resin base material as Embodiment A can be used, or the super birefringent film base material as Embodiment B can be used.

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

The thickness of the crystalline PET base material of Embodiment D can be any appropriate thickness within the range that does not impair the effects of the present invention. In order to further demonstrate the effects of the present invention, the thickness of the crystalline PET base material is preferably 10 μm to 500 μm, more preferably 15 μm to 300 μm, further preferably 25 μm to 200 μm, and particularly preferably It is 30 μm～100 μm, and the optimum is 30 μm～50 μm.

As mentioned above, the front-side phase difference R0 of the crystalline PET substrate of Embodiment D is R0≦2600 nm, preferably R0≦2500 nm, more preferably R0≦2400 nm, and further preferably R0≦2300 nm. Particularly preferred is R0≦2100 nm, and optimal is R0≦1900 nm. If the front-side phase difference R0 of the crystalline PET substrate is within the above range, the effects of the present invention can be further exhibited.

The lower limit of the front-side phase difference R0 of the crystalline PET substrate of embodiment D is as small as possible. However, in view of factors such as material selection, in reality, it is preferably 100 nm or more, more preferably 500 nm or more, and still more preferably It is above 800 nm, preferably above 1000 nm, and most preferably above 1200 nm.

The crystalline PET substrate can also be an extended substrate.

As a crystalline PET base material, in order to further express the effects 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 preferred. It is 1.2~3.3. In addition, as described below, the above-mentioned tensile strength is based on JIS C 2151:2019, and the strength when the measurement object is stretched at a speed of 200 mm/min using a tensile testing machine to cut (break) the measurement object (unit: MPa).

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

In order to further express the effects 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, and still more preferably 3 μm to 50 μm, more preferably 5 μm to 30 μm, more preferably 7 μm to 27 μm, particularly 9 μm to 25 μm, 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 preferably composed of an acrylic adhesive.

The acrylic adhesive is formed from an acrylic adhesive composition.

The acrylic adhesive can be defined as being formed from an acrylic adhesive composition. The reason for this is that the acrylic adhesive becomes an acrylic adhesive when the acrylic adhesive composition undergoes a cross-linking reaction due to heating or ultraviolet irradiation, etc., so the acrylic adhesive cannot be directly identified based on its structure, and, Since there are generally unrealistic situations ("impossible, impractical situations"), acrylic adhesives are reasonably designated as "things" by the provisions of "formed from acrylic adhesive compositions".

When the acrylic adhesive is used in an environment of 23°C and relative humidity of 50%, with a stretching speed of 300 mm/min and a peeling angle of 180 degrees, the peeling force relative to the acrylic resin board is preferably 0.01 N/25 mm or more, preferably more It is 0.03 N/25 mm or more, more preferably 0.05 N/25 mm or more, especially 0.07 N/25 mm or more. Furthermore, the preferable range of the upper limit of the peeling force will vary depending on the use of the surface protective film of the present invention. Typically, in the case of permanent bonding applications (surface protective films with the purpose of permanent bonding), there is no upper limit, and the higher the better, in the case of re-peelable applications (for example, surface protective films used as engineering materials) In this case, the upper limit is preferably 5 N/25 mm or less, more preferably 3 N/25 mm or less, and still more preferably 1 N/25 mm or less.

The adhesive layer can be formed by any suitable method. This method may include, for example, the following method: apply the adhesive composition forming the adhesive constituting the adhesive layer on any appropriate base material, heat or dry it as necessary, and harden it as necessary to form the adhesive composition on the base material. Form an adhesive layer on the material; apply the adhesive composition that forms the adhesive constituting the adhesive layer on any appropriate release liner or other film, heat or dry it as necessary, and harden it as necessary. An adhesive layer is formed on the film, and any appropriate base material is attached to the adhesive layer and transferred, thereby forming an adhesive layer on the base material.

The method of applying the acrylic adhesive composition can be any appropriate method within the scope that does not impair the effects of the present invention. Examples of such coating methods include roll coating, gravure roll coating, reverse roll coating, contact roll coating, dip roll coating, rod coating, and roller brush coating. Method, spray coating method, blade coating method, air knife coating method, notch wheel coating method, direct coating method, die nozzle coating method.

Any appropriate method can be used for heating or drying the acrylic adhesive composition within the scope that does not impair the effects of the present invention. Such heating or drying methods include, for example, heating to 60°C to 180°C, or aging treatment at a temperature around room temperature.

The acrylic adhesive composition can be hardened by any appropriate method within the scope that does not impair the effects of the present invention. Examples of such hardening methods include heat, ultraviolet irradiation, laser light irradiation, alpha ray irradiation, beta ray irradiation, gamma ray irradiation, X-ray irradiation, and electron beam irradiation.

In terms of further exhibiting the effects of the present invention, the acrylic adhesive composition preferably contains an acrylic polymer and a cross-linking agent.

Acrylic polymers can be called base polymers in the field of acrylic adhesives. Only one type of acrylic polymer may be used, or two or more types may be used.

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

As the acrylic polymer, any appropriate acrylic polymer may be used within the scope that does not impair the effects of the present invention.

In order to further express 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 2,000,000, further preferably 400,000 to 1,800,000, especially The best value is 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) containing an alkyl ester moiety is preferred. The alkyl (meth)acrylate (component a) having an alkyl group with a carbon number of 4 to 12, and at least one selected from the group consisting of (meth)acrylate and (meth)acrylic acid having an OH group 1 type (component b). The a component and the b component may be each independently one type, or two or more types.

Examples of (meth)acrylic acid alkyl esters in which the alkyl group of the alkyl ester part has a carbon number of 4 to 12 include: (meth)n-butyl acrylate, (meth)isobutyl acrylate, (methyl) Second butyl acrylate, third butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, (meth)acrylate 2-Ethylhexyl acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, iso(meth)acrylate Decyl ester, undecyl (meth)acrylate, dodecyl (meth)acrylate, etc. Among them, n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred, and n-butyl acrylate, 2-ethylhexyl acrylate.

Examples of the (meth)acrylate having an OH group include (meth)acrylic acid having an OH group such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. ester. Among them, hydroxyethyl (meth)acrylate is preferable, and hydroxyethyl acrylate is more preferable in that the effects of the present invention can be further exhibited.

The (meth)acrylic acid is preferably acrylic acid in terms of further expressing the effects of the present invention.

The composition (M) may contain copolymerizable monomers other than component a and component b. The number of copolymerizable monomers may be only one type, or two or more types. Examples of such copolymerizable monomers include: itaconic acid, maleic acid, fumaric acid, crotonic acid, methacrylic acid, and acid anhydrides thereof (for example, maleic anhydride, itaconic anhydride, and other acid anhydride group-containing monomers). (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-hydroxymethyl(methyl)acrylamide ) Acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, etc. Amino group-containing monomers; (meth)acrylic acid aminoethyl ester, (meth)acrylic acid dimethylaminoethyl ester, (meth)acrylic acid tert-butylaminoethyl ester and other amine group-containing monomers; Monomers containing epoxy groups such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; monomers containing cyano groups such as acrylonitrile or methacrylonitrile; N-vinyl-2- Pyrrolidone, (meth)acrylamide, N-vinyl piperidone, N-vinyl piperidone, N-vinylpyrrole, N-vinylimidazole, vinyl pyridine, vinyl pyrimidine, vinyl Heterocyclic ring-containing vinyl monomers such as ethazole; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphoric acid-containing monomers such as 2-hydroxyethylacrylyl phosphate; cyclohexylmaleimide , isopropyl maleimide and other imide group-containing monomers; 2-methacryloyloxyethyl isocyanate and other isocyanate group-containing monomers; (meth)acrylic acid cyclopentyl, ( Cyclohexyl methacrylate, isopropyl (meth)acrylate and other (meth)acrylates with alicyclic hydrocarbon groups; phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, (Meth)acrylates with aromatic hydrocarbon groups such as benzyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyl toluene; ethylene and butadiene , isoprene, isobutylene and other olefins or dienes; vinyl ethers such as vinyl alkyl ether; vinyl chloride, etc.

The copolymerizable monomer may also be a polyfunctional monomer. Polyfunctional monomers refer to monomers with more than two ethylenically unsaturated groups in one molecule. As the ethylenically unsaturated group, any appropriate ethylenically unsaturated group can be used within the scope that does not impair the effects of the present invention. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as vinyl, propenyl, isopropenyl, vinyl ether (ethyleneoxy), and allyl ether (allyloxy) groups. Examples of the polyfunctional monomer include hexylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, and (poly)propylene glycol. Di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trihydroxy Methylpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, Polyester acrylate, urethane acrylate, etc. Only one type of such polyfunctional monomer may be used, or two or more types may be used.

As the copolymerizable monomer, (meth)acrylic acid alkoxyalkyl ester can also be used. Examples of (meth)acrylic acid alkoxyalkyl esters include: (meth)acrylic acid 2-methoxyethyl ester, (meth)acrylic acid 2-ethoxyethyl ester, (meth)acrylic acid methoxyalkyl ester Triethylene glycol, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, (meth)acrylic acid 4 -Ethoxybutyl ester, etc. Only one type of (meth)acrylic acid alkoxyalkyl ester may be used, or two or more types may be used.

In order to further express the effects of the present invention, the content of alkyl (meth)acrylate (component a) having an alkyl group in the alkyl ester part having a carbon number of 4 to 12 is relative to the content of the acrylic polymer constituting it. The total amount of monomer components (100% by weight) is preferably 30% by weight or more, more preferably 35% by weight to 99% by weight, further preferably 40% by weight to 98% by weight, and particularly preferably 50% by weight to 95% by weight. %.

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

The composition (M) may contain any appropriate other ingredients within the range that does not impair the effects of the present invention. Examples of such other components include polymerization initiators, chain transfer agents, solvents, and the like. The content of these other components can be any appropriate content within the range that does not impair the effects of the present invention.

As the polymerization initiator, a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) can be used depending on the type of polymerization reaction. The polymerization initiator may be only one type or two or more types.

A thermal polymerization initiator may be preferably used when obtaining an acrylic polymer by solution polymerization. Examples of such thermal polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azo Bis(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-imidazolin-2-yl)propane]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.) and other azo initiators; persulfates such as potassium persulfate and ammonium persulfate, peroxide Di(2-ethylhexyl) carbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, di-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, peroxydicarbonate tert-hexyl pivalate, tert-butyl pivalate, dilauryl peroxide, di-n-octyl peroxide, 1,1,3,3-tetramethyl peroxy2-ethylhexanoate Butyl ester, di(4-methylbenzoyl peroxide), dibenzoyl peroxide, tert-butyl peroxyisobutyrate, 1,1-di(tert-hexylperoxy)cyclohexane, Peroxide-based initiators such as tert-butyl hydroperoxide and hydrogen peroxide; the combination of persulfate and sodium bisulfite, the combination of peroxide and sodium ascorbate, etc. are made by combining peroxide and reducing agent Redox initiator; phenyl-substituted ethane and other substituted ethane initiators; aromatic carbonyl compounds.

A photopolymerization initiator may be preferably used when obtaining an acrylic polymer by active energy ray polymerization. Examples of the photopolymerization initiator include: benzoin ether-based photopolymerization initiator, acetophenone-based photopolymerization initiator, α-ketool-based photopolymerization initiator, and aromatic sulfonyl chloride-based photopolymerization initiator. agent, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzoyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, ketal-based photopolymerization initiator Agent, 9-oxosulfide𠮿 It is a photopolymerization initiator.

Examples of benzoin ether photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-dimethoxy-1,2-diphenyl ether. Alkane-1-one, anisole methyl ether, etc. Examples of acetophenone-based photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 1-hydroxycyclohexylphenyl Ketone, 4-phenoxydichloroacetophenone, 4-(tert-butyl)dichloroacetophenone. Examples of the α-ketool photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. . Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalene sulfonyl chloride. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of the benzoin-based photopolymerization initiator include benzoin. Examples of the benzilide-based photopolymerization initiator include benzilide. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoyl benzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, and polyvinyl diphenyl Methyl ketone, alpha-hydroxycyclohexyl phenyl ketone. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. 9-oxysulfur𠮿 Examples of photopolymerization initiators include: 9-oxosulfide , 2-chloro-9-oxosulfide𠮿 , 2-Methyl 9-oxosulfide𠮿 , 2,4-dimethyl 9-oxosulfide𠮿 , isopropyl 9-oxosulfide𠮿 , 2,4-diisopropyl 9-oxosulfide𠮿 , dodecyl 9-oxosulfide𠮿 .

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

The acrylic adhesive composition may also contain a cross-linking agent. By using a cross-linking agent, the cohesive force of the acrylic adhesive can be improved, thereby further exhibiting the effects of the present invention. There may be only one type of cross-linking agent, or two or more types of cross-linking agents.

Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, polysiloxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, and silane-based cross-linking agents. Cross-linking agents such as alkyl etherified melamine-based cross-linking agents, metal chelate-based cross-linking agents, and peroxides are preferably selected from isocyanate-based cross-linking agents in order to further exhibit the effects of the present invention. At least one kind (component c) of the group consisting of an agent, an epoxy cross-linking agent, and a peroxide.

Isocyanate cross-linking agents can be used for compounds having two or more isocyanate groups in one molecule (including isocyanate regenerated polar groups obtained by temporarily protecting isocyanate groups using blocking agents or polymerization). Examples of the isocyanate-based crosslinking agent 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 isocyanate cross-linking agents include lower aliphatic polyisocyanates such as butyl diisocyanate and hexamethylene diisocyanate; cyclopentyl diisocyanate, cyclohexyl diisocyanate, isophorone diisocyanate, etc. Alicyclic isocyanates; aromatic diisocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate; trihydroxy Methylpropane/toluene diisocyanate trimer adduct (for example, manufactured by Tosoh Corporation, trade name: Coronate L), trimethylolpropane/hexamethylene diisocyanate trimer adduct (for example, manufactured by Tosoh Corporation) , trade name: Coronate HL), isocyanate adducts such as the isocyanurate body of hexamethylene diisocyanate (for example, manufactured by Tosoh Co., Ltd., trade name: Coronate HX); trimethylol of xylylene diisocyanate propane adduct (for example, manufactured by Mitsui Chemicals, trade name: Takenate D110N), trimethylolpropane adduct of xylylene diisocyanate (for example, manufactured by Mitsui Chemicals, trade name: Takenate D120N), Trimethylolpropane adduct of isophorone diisocyanate (for example, manufactured by Mitsui Chemicals, trade name: Takenate D140N), trimethylolpropane adduct of hexamethylene diisocyanate (for example, Mitsui Chemicals Manufactured by the company, trade name: Takenate D160N), trimethylolpropane adduct of toluene diisocyanate (for example, manufactured by Mitsui Chemicals Co., Ltd., trade name: Takenate D101E); polyether polyisocyanate, polyester polyisocyanate, and the like Adducts with various polyols; polyisocyanates multi-functionalized through isocyanurate bonding, biuret bonding, allophanate bonding, etc. Among them, aromatic isocyanate and alicyclic isocyanate are preferred in terms of achieving a well-balanced balance between deformability and cohesion.

Epoxy cross-linking agents can be used for polyfunctional epoxy compounds having two or more epoxy groups in one molecule. Examples of epoxy cross-linking agents include: N,N,N',N'-tetraglycidyl m-xylylenediamine, diglycidyl aniline, 1,3-bis(N,N-diglycidyl Aminomethyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether Ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan anhydride polyglycidyl ether, trimethylol Propane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, tris(2-hydroxyethyl)triglycidyl isocyanurate, resorcinol diglycidyl ether, bisphenol -S-diglycidyl ether, epoxy resin with two or more epoxy groups in the molecule. Examples of commercially available epoxy cross-linking agents include trade names "Tetrad C" and "Tetrad X" manufactured by Mitsubishi Gas Chemical Co., Ltd.

Examples of the peroxide include: dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, di-tert-butylperoxy-3,3,5-trimethylcyclohexane alkane, di-tert-butyl hydroperoxide, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2, 5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(tert-butylperoxy)-hexane, α ,α'-Bis(tert-butylperoxy-m-isopropyl)benzene, di(2-ethylhexyl) peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate Ester, di-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauryl peroxide, peroxide Di-n-octyl peroxide, 1,1,3,3-tetramethylbutyl peroxide 2-ethylhexanoate, di(4-methylbenzoyl peroxide), tert-butyl peroxyisobutyrate, 1,1-di(tert-butylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2-ethylhexylperoxy tert-butyl carbonate, peroxy tert-amyl isopropyl carbonate, 3,5,5-trimethylhexanoic acid peroxide, tert-butyl peroxide 2-hexanoate, tert-butyl peroxypivalate, tert-butyl peroxypivalate Trihexyl ester. Examples of commercially available peroxide products include the "Nyper BMT" series and the "Nyper BW" series manufactured by Nippon Oils and Fats Co., Ltd. under the trade names.

The content of the cross-linking agent in the acrylic adhesive composition can be any appropriate content within the range that does not impair the effects of the present invention. The content is preferably 0.01 to 20 parts by weight, and more preferably 0.01 part by weight relative to the solid content (100 parts by weight) of the acrylic polymer in order to further exhibit the effects of the present invention. ~18 parts by weight, more preferably 0.01 ~ 15 parts by weight, particularly preferably 0.05 ~ 10 parts by weight.

The acrylic adhesive composition may contain any appropriate other components within the range that does not impair the effects of the present invention. Examples of such other components include polymer components other than acrylic polymers, cross-linking accelerators, cross-linking catalysts, silane coupling agents, adhesion-imparting resins (rosin derivatives, polyterpene resins, petroleum resins, oils Soluble phenol, etc.), anti-aging agent, inorganic filler, organic filler, metal powder, colorant (pigment or dye, etc.), foil, UV absorber, antioxidant, light stabilizer, nucleating agent, 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 laminated body≫≫ The optical laminated body according to the embodiment of the present invention includes the surface protective film and the optical member according to the embodiment of the present invention.

FIG. 2 shows an embodiment of an optical laminated body of the present invention. The optical laminated body 1000 includes a surface protective film 100 having a base material 10 and an adhesive layer 20 and an optical component 200 .

The optical laminate according to the embodiment of the present invention only needs to include a surface protective film and an optical member, and may include any other appropriate layer within a range that does not impair the effects of the present invention.

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

The total thickness of the optical laminate according to the embodiment of the present invention can be any appropriate thickness depending on the type of optical component. Typically, the total thickness of the optical laminate according to 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. ~700 μm, more preferably 40 μm ~ 600 μm, particularly preferably 50 μm ~ 500 μm, most preferably 100 μm ~ 500 μm.

The optical member preferably has a polarizing plate. As long as the optical member has a polarizing plate, it may also include any other appropriate member within the scope that does not impair the effects of the present invention.

Examples of other members include an adhesive layer and a brightness improving 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, especially 100 μm to 600 μm, and most preferably 100 μm. ~500 μm.

Hereinafter, the present invention will be specifically described using examples, but the present invention is not limited to these examples. In addition, the test and evaluation methods in Examples etc. are as follows. When it is described as "parts", it means "parts by weight" unless otherwise stated, and when it is described as "%", it means "% by weight" unless otherwise stated.

＜Measurement of tensile strength of base material＞ In accordance with JIS C 2151:2019, use a tensile testing machine (manufactured by Shimadzu Corporation, product name "Autograph") to stretch the base of the measurement object in the width direction (TD direction) or length direction (MD direction) at a speed of 200 mm/min. material, and measure the strength (unit: MPa) when the base material of the measurement object is cut (broken).

<Measurement of the frontal phase difference and the angle between the slow axis and the longitudinal direction (MD direction)> The base material obtained in each production example or the surface protective film obtained in each example and each comparative example was cut into a size of 210 mm×300 mm, and the peeling liner of the surface protective 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 of 590 nm at 12 points in the plane (X [mm] = the intersection of 25, 150, 275, Y [mm] = 15, 75, 135, 195) measure the front phase difference and the angle between the slow axis and the length direction (MD direction), and find these 12 The average of the points. Furthermore, as shown in FIG. 3 , the angle between the slow axis and the longitudinal direction (MD direction) means that when the longitudinal direction (MD direction) is used as a reference and the longitudinal direction (MD direction) is set to 0°, the angle between the slow axis and the longitudinal direction (MD direction) is The angle θ formed by the length direction (MD direction) in the counterclockwise direction.

＜Irregular rainbow＞ Peel off the release liner from the surface protective film and make sure that the angle between the slow axis of the base material of the surface protective film and the absorption axis of the polarizing plate (a) (trade name "SEG1423DU" manufactured by Nitto Denko) is 90° or less. The adhesive layer of the surface protective film is bonded to the polarizing plate (a) in such a way that the angle, that is, the axis offset becomes 0°, 15°, 30°, and 45°. Next, another polarizing plate (b) (manufactured by Nitto Denko, trade name "SEG1423DU") is placed on the base material side of the above-mentioned surface protective film so as to form orthogonal polarization with the polarizing plate bonded to the above-mentioned surface protective film. . Irradiate the light of a fluorescent lamp from the lower side of the polarizing plate (b), and visually inspect the transmitted light to determine the rainbow unevenness between the polar angle of 0° to 85° and the azimuth angle of 0° to 360° based on the following standards. Evaluate the degree of occurrence. ◎: No rainbow unevenness was confirmed at any polar angle or azimuth angle. ○: Slightly uneven rainbow is observed at specific polar angles and azimuth angles. △: Strong rainbow unevenness was confirmed. ×: Strong rainbow unevenness was confirmed.

<Measurement of Hue and Brightness> Cut the polarizing plate (manufactured by Nitto Denko, trade name "SEG1423DU") into a size of 180 mm × 250 mm, and increase the brightness by aligning the absorption axis of the polarizing plate with the reflection axis of the brightness improving film. film (manufactured by 3M Japan Products, trade name "APF-V3") to form a polarizing plate with a brightness-enhancing film. Peel off the release liner from the surface protective film. Among the angles formed by the slow axis of the base material of the surface protective film and the absorption axis of the polarizing plate with the brightness enhancement film, the angle below 90°, that is, the axis offset becomes 0°. , 15°, 30°, and 45°, laminate the adhesive layer of the surface protection film to the brightness enhancement film side of the polarizing plate with brightness enhancement film. A surface protective film, a polarizing plate with a brightness enhancement film, and a measuring device were sequentially placed on the backlight device, and a 2D spectroradiometer ("SR-5000HS" manufactured by TOPCON TECHNOHOUSE Co., Ltd., using the XYZ mode) was used to compare the sample with The distance of the detection camera was set to 590 mm and the hue and brightness were measured. In addition, the same measurement was performed on the polarizing plate with only the brightness improvement film attached without the surface protective film. Furthermore, the backlight device used is composed of (corner sheet/diffusion plate/light guide plate [edge type LED]/reflective plate), and the average value of the in-plane brightness Y is 9500 cd/m ² to 10000 cd/m ² , 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).

<The standard deviation σ _SSA of the angle between the slow axis and the longitudinal direction (MD direction) at 12 points in the plane> is determined by the above <Measurement of the frontal phase difference and the angle between the slow axis and the longitudinal direction (MD direction)> The standard deviation σ _SSA is calculated from the angle between the slow axis of the 12 points in the plane and the longitudinal direction (MD direction) obtained by the measurement described in the first section.

<Coefficient of variation CV _SR0 of the frontal phase difference at 12 points in the plane> Surface obtained by the measurement described in the above "Measurement of the frontal phase difference and the angle between the slow axis and the longitudinal direction (MD direction)" Calculate the coefficient of variation CV _SR0 from the frontal phase difference at 12 points.

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

＜Dispersion Entropy S _CD ＞ Obtained from the above ＜Measurement of Hue and Brightness＞ (1) RGB data of polarizing plates with brightness improvement film only, and (2) surface protection film + brightness improvement film The color dispersion entropy S _CD is calculated from the data of each RGB of the polarizing plate. The following evaluation is performed during calculation. First, when calculating the difference between the above (1) and the above (2), there is a part where the surface protective film is not attached to the polarizing plate with the brightness improvement film due to axis deviation, so the X in the sample plane is used: 0 px ~900 px, Y: 0 px ~ 700 px, X: 200 px ~ 800 px, Y: 100 px ~ 600 px. Next, the dispersion entropy S _CD is defined and calculated as follows. S _CD = S _RCD + S _GCD + S _BCD is as follows in the case of R. S _RCD = k _B lnW k _B : Boltzmann constant X: 200 px to 800 px, Y: 100 px to 600 px, the difference between the above (1) and the above (2) plus 255 The difference between the above (1) and the above (2) of R in the range of the total value of R (X: 200 px to 800 px, Y: 100 px to 600 px) is in the range of -255 to 255, so in order to be regarded as a positive number Process, add 255 and process it as a value from 0 to 510) N _Rn : The difference between the above (1) and the above (2) of R in the frame divided by 10 px × 10 px plus the value of 255 Total W: The number of N _R1 , N _R2 ,・・・, and N _Rn in each frame W = N _R !/( _NR1 !, N _R2 !,・・・, N _Rn !) Also, since The calculation is relatively complicated, so 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 also calculated in the same manner as R. In addition, in the "dispersion entropy S _CD " and "RGB standard deviation/S _CD " columns in the table, the case where "aEb" (a and b are numerical values) is written means "a×10 ^b ".

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

[Manufacturing Example 1] <Polymerization of acrylic polymer 1> 96.2 parts by mass of 2-ethylhexyl acrylate (2EHA) and 3.8 parts by mass of hydroxyethyl acrylate (HEA) as monomer components were added to a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction pipe, as a polymerization starter. 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as the starting agent and 150 parts by mass of ethyl acetate were slowly stirred at 23° C. and nitrogen gas was introduced to perform nitrogen replacement. Thereafter, a polymerization reaction was performed for 6 hours while maintaining the liquid temperature at approximately 65° C. to prepare a solution of acrylic polymer 1 (concentration 40% by mass). The weight average molecular weight of acrylic polymer 1 is 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. To 500 parts by mass of this solution (100 parts by mass of solid content), 4 parts by mass of an isocyanurate body of hexamethylene diisocyanate ("Coronate HX" manufactured by Tosoh Corporation) as a cross-linking agent was added. Acrylic adhesive 1 was prepared by adding 3 parts by mass (solid content: 0.03 parts by mass) of dibutyltin dilaurate (1 mass % ethyl acetate solution) as a catalyst and stirring.

[Manufacturing example 2] <Polymerization of acrylic polymer 2> 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 ethyl acetate were added to a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction pipe. 186 parts by mass, the mixture was slowly stirred at 23° C. and nitrogen gas was introduced to perform nitrogen replacement. Thereafter, a polymerization reaction was performed for 10 hours while maintaining the liquid temperature at approximately 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. To 500 parts by mass of this solution (100 parts by mass of solid content), 0.075 parts by mass of a tetrafunctional epoxy compound ("Tetrad C" manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a cross-linking agent was added and stirred to prepare an acrylic system. Adhesive 2.

[Manufacturing Example 3] ＜Preparation of base material (1)＞ On one side of an amorphous polyethylene terephthalate film (manufactured by 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 base material, An aqueous solution of polyvinyl alcohol (PVA) resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosenol (registered trademark) NH-26") with a degree of polymerization of 2600 and a degree of saponification of 99.9% is applied at 60°C and dried. A PVA-based resin layer with a thickness of 7 μm was formed to prepare a laminated body. The obtained laminated body was uniaxially stretched to 2 times in the longitudinal direction (length direction) between rolls with different circumferential speeds in an oven at 120°C, and then placed in an insoluble bath with a liquid temperature of 30°C (100 parts by weight of water). Immerse it in a boric acid aqueous solution prepared by preparing 4 parts by weight of boric acid) for 30 seconds, and then immerse it in a dyeing bath with a liquid temperature of 30° C. (an aqueous iodine solution prepared by preparing 0.2 parts by weight of iodine and 2 parts by weight of potassium iodide with respect to 100 parts by weight of water) ) for 60 seconds, and then immersed in a cross-linking bath (a boric acid aqueous solution prepared by mixing 3 parts by weight of potassium iodide and 3 parts by weight of boric acid to 100 parts by weight of water) with a liquid temperature of 30°C for 30 seconds. While immersing the laminated body in a boric acid aqueous solution with a liquid temperature of 60°C (an aqueous solution obtained by mixing 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water), the laminate was placed in the longitudinal direction (length) between rollers with different peripheral speeds. direction) for uniaxial extension. The immersion time in the boric acid aqueous solution was 120 seconds, and the extension was continued until the laminate was about to break. Thereafter, the laminated body was immersed in a cleaning bath (an aqueous solution prepared by mixing 3 parts by weight of potassium iodide with respect to 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 extension magnification of 6.5 times was obtained, in which a thin polarizing film was formed on a thermoplastic resin base material. Here, the "maximum stretch ratio" refers to the stretch ratio just before the laminated body breaks. The stretch ratio at which the laminated body breaks is separately confirmed, and a value 0.2 lower than this value is set as the "maximum stretch ratio". Finally, the thermoplastic resin base material is taken out from the obtained optical film laminated body by peeling, and it is set as base material (1). The thickness of the substrate (1) used is 40 μm, and the front-side phase difference R0 is 668 nm.

[Manufacturing Example 4] ＜Preparation of base material (2)＞ Four base materials (1) obtained in Production Example 3 were laminated to prepare a base material (2). Laminate in such a way that the lamination direction of the substrate is as consistent as possible with the slow axis direction of the substrate. The thickness of the substrate (2) used is 242 μm, and the front-side phase difference R0 is 2769 nm.

[Manufacturing Example 5] ＜Preparation of base material (3)＞ Six base materials (1) obtained in Production Example 3 were laminated to prepare a base material (3). Laminate in such a way that the lamination direction of the substrate is as consistent as possible with the slow axis direction of the substrate. The thickness of the substrate (3) used is 368 μm, and the front-side phase difference R0 is 4069 nm.

[Manufacturing Example 6] ＜Preparation of base material (4)＞ Nine sheets of the base material (1) obtained in Production Example 3 were laminated to prepare a base material (4). Laminate in such a way that the lamination direction of the substrate is as consistent as possible with the slow axis direction of the substrate. The thickness of the substrate (4) used is 557 μm, and the front-side phase difference R0 is 6011 nm.

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

[Manufacturing Example 8] ＜Preparation of base material (6)＞ A crystalline PET film (manufactured by Toray Co., Ltd., trade name "XF60R", thickness = 38 μm) was used as the base material (6). The ratio (TD/MD) of the tensile strength in the width direction (TD direction) to the tensile strength in the length direction (MD direction) of the base material (6) is 1.38. As the substrates (6) used, five substrates (6) with front-side 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 division.

[Manufacturing Example 9] ＜Preparation of base material (7)＞ A polyester film (manufactured by Mitsubishi Chemical Co., Ltd., trade name "DIAFOIL MRF38", thickness = 38 μm) was used as the base material (7). The front-side phase difference R0 of the substrate (7) used is 2299 nm.

[Manufacturing Example 10] ＜Preparation of base material (8)＞ A polyester film (manufactured by Mitsubishi Chemical Co., Ltd., trade name "T100C38", thickness = 38 μm) was used as the base material (8). The front-side phase difference R0 of the substrate (8) used is 755 nm.

[Manufacturing Example 11] ＜Preparation of coating liquid A＞ 100 parts by mass of vinyl-containing addition-type polysiloxane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KS-847T", 30% toluene solution), platinum catalyst (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "CAT-PL" -50T") 3 parts by mass, 15000 parts by mass of toluene as a dilution solvent, and 1500 parts by mass of n-hexane were mixed to prepare a coating liquid A (see Japanese Patent Laid-Open No. 2015-151473).

[Manufacturing Example 12] <Preparation of Release Liner A> Coating liquid A was applied to a 38-μm-thick polyethylene terephthalate (PET) film (product manufactured by Mitsubishi Chemical Co., Ltd.) using a Meyer rod. Named "T100C38", thickness = 38 μm), and heated at 130°C for 1 minute using a hot air dryer to obtain release liner A. In addition, 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 the corona-treated surface of the PET film.

[Example 1] The acrylic adhesive 1 obtained in Production Example 1 was applied to the surface of the release liner A and dried to form an adhesive layer with a thickness of 10 μm on the release liner. The base material (1) obtained in Production Example 3 was bonded to the obtained adhesive layer to obtain a surface protective film (1) with a release liner. Table 1 shows various evaluation results.

[Example 2] The acrylic adhesive 1 obtained in Production Example 1 was applied to the surface of the base material (6) with a front-side retardation R0 of 1438 nm obtained in Production Example 8, and dried. An adhesive layer with a thickness of 10 μm is formed on it. The release liner A is attached to the surface of the obtained adhesive layer opposite to the base material (6), and a surface protective film (2) with a release liner is obtained. Table 1 shows various evaluation results.

[Example 3] The same procedure as in Example 2 is used except that the substrate (6) with a front-side phase difference R0 of 1675 nm obtained in Production Example 8 is used instead of the substrate (6) with a front-side phase difference R0 of 1438 nm obtained in Production Example 8. Proceed in the same manner to obtain the surface protective film (3) with a release liner. Table 1 shows various evaluation results.

[Example 4] The same procedure as in Example 2 is used except that the substrate (6) with a front-surface phase difference R0 of 1654 nm obtained in Production Example 8 is used instead of the substrate (6) with a front-surface phase difference R0 of 1438 nm obtained in Production Example 8. Proceed in the same manner to obtain the surface protective film (4) with a release liner. Table 1 shows various evaluation results.

[Example 5] The same procedure as in Example 2 is used except that the substrate (6) with a front-surface phase difference R0 of 1859 nm obtained in Production Example 8 is used instead of the substrate (6) with a front-surface phase difference R0 of 1438 nm obtained in Production Example 8. Proceed in the same manner to obtain the surface protective film (5) with a release liner. Table 1 shows various evaluation results.

[Example 6] The same procedure as in Example 2 is used except that the substrate (6) with a front-surface phase difference R0 of 1827 nm obtained in Production Example 8 is used instead of the substrate (6) with a front-surface phase difference R0 of 1438 nm obtained in Production Example 8. Proceed in the same manner to obtain the surface protection film (6) with a release liner. Table 1 shows various evaluation results.

[Example 7] Except using the acrylic adhesive 2 obtained in Production Example 2 instead of the acrylic adhesive 1 obtained in Production Example 1, proceed in the same manner as Example 2 to obtain a surface protective film with a release liner (7 ). Table 1 shows various evaluation results.

[Example 8] Except using the base material (7) obtained in Production Example 9 instead of the base material (1) obtained in Production Example 3, proceed in the same manner as in Example 1 to obtain a surface protective film (8) with a release liner. ). Table 1 shows various evaluation results.

[Example 9] Except using the base material (2) obtained in Production Example 4 instead of the base material (1) obtained in Production Example 3, proceed in the same manner as in Example 1 to obtain a surface protective film with a release liner (9 ). Table 1 shows various evaluation results.

[Example 10] Except using the base material (3) obtained in Production Example 5 instead of the base material (1) obtained in Production Example 3, proceed in the same manner as in Example 1 to obtain a surface protective film (10) with a release liner. ). Table 1 shows various evaluation results.

[Example 11] Except using the base material (4) obtained in Production Example 6 instead of the base material (1) obtained in Production Example 3, proceed in the same manner as in Example 1 to obtain a surface protective film (11) with a release liner. ). Table 1 shows various evaluation results.

[Example 12] Except using the base material (5) obtained in Production Example 7 instead of the base material (1) obtained in Production Example 3, proceed in the same manner as in Example 1 to obtain a surface protective film (12) with a release liner. ). Table 1 shows various evaluation results.

[Example 13] The acrylic adhesive 1 obtained in Production Example 1 was applied to the surface of the base material (5) obtained in Production Example 7 and dried to form an adhesive with a thickness of 10 μm on the base material (5). layer. The release liner A is attached to the surface of the obtained adhesive layer opposite to the base material (5), and a surface protective film (13) with a release liner is obtained. Table 1 shows various evaluation results.

[Example 14] Except using the base material (5) obtained in Production Example 7 instead of the base material (6) obtained in Production Example 8, proceed in the same manner as in Example 7 to obtain a surface protective film with a release liner (14 ). Table 1 shows various evaluation results.

[Comparative example 1] Except that the base material (8) obtained in Production Example 10 was used instead of the base material (1) obtained in Production Example 3, the same manner as in Example 1 was performed to obtain a surface protective film with a release liner (C1 ). Table 1 shows various evaluation results.

[Comparative example 2] Except that the base material (8) obtained in Production Example 10 was used instead of the base material (6) whose front-side phase difference R0 was 1438 nm obtained in Production Example 8, the same manner as in Example 2 was performed to obtain attached peeling. Surface protective film of gasket (C2). Table 1 shows various evaluation results.

[Comparative example 3] Except that the base material (8) obtained in Production Example 10 was used instead of the base material (6) whose front-side phase difference R0 was 1438 nm obtained in Production Example 8, the same manner as in Example 7 was performed to obtain attached peeling. Surface protective film of gasket (C3). Table 1 shows various evaluation results.

[Table 1] Example/Comparative Example base material Adhesive Surface protective film optical laminate Kind Thickness[μm] Frontal phase difference [nm] Kind Application method Thickness[μm] Peeling force relative to acrylic resin plate [N/25 mm] Frontal phase difference [nm] Standard deviation of the angle between the slow axis and the length direction (MD direction) Coefficient of variation of frontal phase difference σ _SSA ×CV _SR0 Rainbow uneven evaluation RGB standard deviation Dispersion entropy S _CD RGB standard deviation/S _CD Example 1 (1) 40 668 1 transfer 10 0.09 672 0.12 0.009 0.0011 ◎ 9.04 2.56E-14 3.53E+14 Example 2 (6) 38 1438 1 Direct printing 10 0.09 1452 0.34 0.024 0.0080 ◎ 9.10 2.57E-14 3.55E+14 Example 3 (6) 38 1675 1 Direct printing 15 0.09 1688 0.50 0.009 0.0045 ◎ 9.08 2.56E-14 3.55E+14 Example 4 (6) 38 1654 1 Direct printing 20 0.09 1643 0.47 0.008 0.0039 ◎ 9.09 2.57E-14 3.54E+14 Example 5 (6) 38 1859 1 Direct printing 15 0.09 1843 0.56 0.010 0.0056 ◎ 9.11 2.57E-14 3.54E+14 Example 6 (6) 38 1827 1 Direct printing 20 0.09 1804 0.49 0.010 0.0049 ◎ 9.13 2.57E-14 3.55E+14 Example 7 (6) 38 1438 2 Direct printing 13 10.5 1449 0.33 0.024 0.0079 ◎ 9.11 2.55E-14 3.54E+14 Example 8 (7) 38 2299 1 transfer 10 0.09 2291 0.71 0.010 0.0070 ◎ 9.21 2.56E-14 3.60E+14 Example 9 (2) 242 2769 1 transfer 10 0.09 2705 0.20 0.008 0.0015 ○ 9.25 2.45E-14 3.77E+14 Example 10 (3) 368 4069 1 transfer 10 0.09 4074 0.13 0.006 0.0008 △ 9.57 2.54E-14 3.76E+14 Example 11 (4) 557 6011 1 transfer 10 0.09 6039 0.31 0.006 0.0019 ◎ 9.17 2.57E-14 3.57E+14 Example 12 (5) 80 8369 1 transfer 10 0.09 8375 0.27 0.006 0.0016 ◎ 9.17 2.57E-14 3.56E+14 Example 13 (5) 80 8369 1 Direct printing 10 0.09 8444 0.22 0.028 0.0061 ◎ 9.17 2.57E-14 3.57E+14 Example 14 (5) 80 8369 2 Direct printing 13 10.5 8440 0.25 0.026 0.0065 ◎ 9.17 2.57E-14 3.57E+14 Comparative example 1 (8) 38 755 1 transfer 10 0.09 741 2.27 0.028 0.0636 × 9.60 1.52E-14 6.30E+14 Comparative example 2 (8) 38 755 1 Direct printing 10 0.09 765 2.22 0.029 0.0642 × 9.78 1.54E-14 6.37E+14 Comparative example 3 (8) 38 755 2 Direct printing 13 10.5 759 2.24 0.029 0.0650 × 9.72 1.53E-14 6.36E+14 [Industrial availability]

The surface protective film and optical laminate of the present invention can be used for any appropriate purpose. The surface protective film and optical laminate of the present invention are preferably used in the fields of optical components or electronic components.

10:Substrate 20: Adhesive layer 100:Surface protective film 200:Optical components 1000: Optical laminated body θ: angle

FIG. 1 is a schematic cross-sectional view showing one embodiment of the surface protective film of the present invention. FIG. 2 is a schematic cross-sectional view showing one embodiment of the optical laminate of the present invention. FIG. 3 is a schematic explanatory diagram illustrating the angle between the slow axis and the longitudinal direction (MD direction).

Claims (6)

A surface protective film having a base material and an adhesive layer, and the standard deviation σ _SSA of the angle between the slow axis at 12 points in the plane and the longitudinal direction (MD direction) and the coefficient of variation of the frontal phase difference at 12 points in the plane The product of CV _SR0 , σ _SSA × CV _SR0, is 0.020 or less. Such as the surface protective film of claim 1, wherein the front-side phase difference R0 of the above-mentioned substrate is R0≦2600 nm or R0≧4100 nm. The surface protection film of claim 1, wherein the material of the above-mentioned base material is polyethylene terephthalate. The surface protective film of claim 1, wherein the adhesive constituting the adhesive layer is at least one selected from the group consisting of acrylic adhesives, urethane adhesives, and polysiloxane adhesives. species. An optical laminate including the surface protective film according to any one of claims 1 to 4 and an optical member. The optical laminated body according to claim 5, wherein the optical member includes a polarizing plate.