JP2001049205A - Surface protecting film and optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface protecting film not peeling from an optical member due to changes in surrounding temperature or humidity, yet peeling easily from the same when necessary without leaving any glue behind, and retaining excellent peelability even after heat treatment such as aging. SOLUTION: A surface protecting film 1 adhesivery covers an optical material 2 thanks to its adhesive layer 12. The adhesive layer 12 is an acrylic polymer containing 10 weight % or more of an alkyl acrylate having an alkyl group containing 12 or more carbons, with 5 weight % or less of the alkyl acrylate remaining unreacted in the adhesive layer 12. An optical member consists of the optical material 2 and the surface protecting film 1 that covers the surface of the optical material 2 using its adhesive layer 12. The adhesive strength of the adhesive layer 12 does not easily increase with the passage of time or easily become whitish thanks to the proper control of residual monomers, and this enables the optical member to bear visual inspection for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface protective film which can be easily peeled off from an optical member even after a liquid crystal panel is formed.

[0002]

BACKGROUND OF THE INVENTION Optical materials such as a polarizing plate and a retardation plate used for forming a liquid crystal panel and an elliptically polarizing plate obtained by laminating them are usually long, which is coated with a surface protective film so that the surface is not damaged. After being formed as an optical member in a state, it is subjected to various processes such as punching, inspection, transportation, panel assembly, etc., and the protective film is peeled off from the optical member when surface protection becomes unnecessary. In such a case, an aging process by heating may be performed in a panel assembling process or the like for the purpose of stabilizing an adhesion state between the optical material and the liquid crystal cell.

However, in the conventional surface protective film, the adhesive force when peeling off the optical member after assembling the liquid crystal panel is strong and the working efficiency is poor. There is a problem that the panel may be damaged. In particular, when the above-mentioned aging treatment is performed, there is a problem that the adhesive force is greatly increased by heating during the treatment and peeling failure is apt to occur.

[0004]

The object of the present invention is to satisfy the property of not peeling off from an optical member due to environmental changes such as temperature and humidity, and at the time of peeling, it can be easily peeled off from an optical member without adhesive residue, and after heat treatment such as aging. Another object of the present invention is to develop a surface protective film that maintains good releasability.

[0005]

The present invention relates to a protective film for adhesively covering the surface of an optical material via an adhesive layer, wherein the adhesive layer contains 10% by weight of an acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms. 5% by weight of the acrylic polymer contained in the adhesive layer, and the remaining amount of the acrylic acid-based alkyl ester in the pressure-sensitive adhesive layer due to unreaction.
The present invention provides a surface protective film characterized by the following, and an optical member obtained by adhesively coating the surface of an optical material with the surface protective film via an adhesive layer.

[0006]

According to the present invention, it is possible to form a pressure-sensitive adhesive layer whose adhesive strength is hardly increased with time by containing the above-mentioned acrylic acid alkyl ester, and satisfy the property of not peeling off from the optical member due to environmental changes such as temperature and humidity. A surface protection film that can be easily peeled off from the optical member without any adhesive residue even after continuing the adhesive state for a long period of time through a hand or a machine and maintains good peelability even after heat treatment such as aging. Obtainable. In addition, by suppressing the residual amount of the acrylic acid-based alkyl ester, the pressure-sensitive adhesive layer is less likely to be clouded, and good appearance inspection properties can be maintained for a long period of time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The surface protective film according to the present invention comprises:
A protective film for adhesively covering the surface of the optical material via an adhesive layer, wherein the adhesive layer is made of an acrylic polymer containing 10% by weight or more of an acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms, and An optical member in which the residual amount of the acrylic acid-based alkyl ester in the adhesive layer due to unreaction is 5% by weight or less, and the optical member is formed by adhesively coating the surface of an optical material with the surface protective film via the adhesive layer. Consists of FIG. 1 shows an example of the optical member. 1 is a surface protective film, 11 is a protective substrate, 12 is an adhesive layer, 2 is an optical material, 21
Is an adhesive layer.

The surface protective film is formed such that an adhesive layer 12 is provided on a protective substrate 11 as shown in the figure and the protective substrate can be peeled off from the optical member together with the adhesive layer. As the protective substrate, an appropriate thin leaf body according to the related art can be used, and there is no particular limitation.

In general, from the viewpoint of inspection and controllability of optical materials by transparency, for example, polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefins A protective substrate made of a film or rubber sheet made of a transparent polymer such as a resin or an acrylic resin, or a laminate thereof is used. The thickness of the protective substrate can be appropriately determined according to the strength and the like, and is generally 500 μm or less, particularly 5 to 300 μm, particularly 10 to 200 μm.
μm.

In forming the pressure-sensitive adhesive layer, an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer is used in view of transparency, weather resistance, heat resistance, and the like. From the viewpoint of long-term stability of peelability, an acrylic polymer containing an acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms in an amount of 10% by weight or more is used as a base polymer.

As the acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms, any suitable one can be used, and there is no particular limitation. Generally, for example, a lauryl group, a tridecyl group, a tetradecyl group, a stearyl group or the like. One or two or more of esters of acrylic acid or methacrylic acid having a linear or branched alkyl group having 12 to 20 carbon atoms such as a group or octadecyl group are used.

[0012] The content of the acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms in the acrylic polymer is 5% from the viewpoint of exhibiting necessary adhesive strength.
It is preferably 0% by weight or less, particularly preferably 40% by weight or less, particularly preferably 12 to 35% by weight. Therefore, at the time of forming the acrylic polymer, one or more copolymerizable monomers other than the ester are used.

The above-mentioned copolymerizable monomer is not particularly limited, and a suitable monomer known for an acrylic pressure-sensitive adhesive can be used. Incidentally, examples thereof include a methyl group or an ethyl group, a propyl group or a butyl group, an amyl group or a hexyl group, a heptyl group or a cyclohexyl group, a 2-ethylhexyl group or an octyl group, a carbon number such as a nonyl group or a decyl group of 11 or less. And especially esters of acrylic acid or methacrylic acid having a linear or branched alkyl group of 2 to 10, especially 4 to 8.

In addition, the adhesive properties are improved by introducing a functional group or a polar group, the cohesion and heat resistance are controlled by controlling the glass transition temperature of the resulting copolymer, and the molecular weight is increased by imparting crosslinking reactivity. For the purpose of modification, etc., acrylic acid and methacrylic acid, carboxyethyl acrylate and carboxypentyl acrylate, carboxyl group-containing monomers such as itaconic acid and maleic acid, fumaric acid and crotonic acid, and acid anhydrides such as maleic anhydride and itaconic anhydride Monomer, hydroxyl group-containing monomers such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and hydroxyhexyl (meth) acrylate can also be used.

Further, (meth) acrylamide, N, N-
Dimethyl (meth) acrylamide, N-butyl (meth)
(N-substituted) amide monomers such as acrylamide and N-methylol (meth) acrylamide; alkylaminoalkyl (meth) acrylates such as aminoethyl (meth) acrylate and N, N-dimethylaminoethyl (meth) acrylate Monomers, alkoxyalkyl (meth) acrylate monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide. A maleimide-based monomer such as the above can also be used.

Further, N-methylitaconimide and N-
Ethyl itaconimide, N-butyl itaconimide or N
-Itaconimide monomers such as octylitaconimide; succinimide monomers such as N- (meth) acryloyloxymethylene succinimide and N- (meth) acryloyl-6-oxyhexamethylene succinimide; vinyl acetate, vinyl propionate, and N-vinylpyrrolidone And methylvinylpyrrolidone, vinylpyridine and vinylpiperidone, vinylpyrimidine and vinylpiperazine, vinylpyrazine and vinylpyrrole, vinylimidazole and vinyloxazole, vinylmorpholine and N-vinylcarboxylic acid amides, styrene and α-methylstyrene, N-vinylcaprolactam Vinyl-based monomers such as those described above can also be used.

In addition, cyanoacrylate monomers such as acrylonitrile and methacrylonitrile, epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate, polyethylene glycol (meth) acrylate and polypropylene glycol (meth) acrylate, (meth) ) Methoxyethylene glycol acrylate or (meth)
Use of glycol-based acrylic ester monomers such as methoxypropylene glycol acrylate, and acrylate-based monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate Can be.

Further, divinylbenzene, butyl diacrylate, hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate and neopentyl glycol di (meth) acrylate ) Multifunctional monomers such as acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate Etc. can also be used.

The acrylic polymer can be prepared by, for example, applying an appropriate method such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method or a suspension polymerization method to a mixture of component monomers. The acrylic polymer which can be preferably used in the present invention has a weight average molecular weight of 100,000 or more, especially 200,000 or more, particularly 300,000 to 2 from the viewpoint of heat resistance and adhesive properties.
One million.

The pressure-sensitive adhesive layer can be subjected to a crosslinking treatment by an appropriate method such as an internal crosslinking method or an external crosslinking method. Generally, an external cross-linking method in which an intermolecular cross-linking agent is blended with an adhesive to perform a cross-linking treatment is employed. Examples of the intermolecular crosslinking agent include a polyfunctional isocyanate crosslinking agent and an epoxy crosslinking agent, a melamine resin crosslinking agent and a metal salt crosslinking agent, a metal chelate crosslinking agent and an amino resin crosslinking agent, and a peroxide crosslinking agent. Any suitable agent such as an agent can be used.

The formation of the surface protective film can be carried out by providing an adhesive layer on the protective substrate by an appropriate method. By the way, as an example, an acrylic pressure-sensitive adhesive liquid of about 10 to 40% by weight is prepared by dissolving or dispersing a base polymer or the like in a solvent composed of a single substance or a mixture of appropriate solvents such as toluene and ethyl acetate, A method in which it is directly attached to the protective substrate by an appropriate developing method such as a casting method or a coating method, or a method in which an adhesive layer is formed on a separator according to the above and transferred to the protective substrate. And so on. The surface of the protective substrate on which the adhesive layer is provided may be subjected to an appropriate surface treatment such as a corona treatment for the purpose of improving the adhesion to the adhesive layer.

The pressure-sensitive adhesive layer may contain, if necessary, appropriate additives such as natural or synthetic resins such as tackifying resins and antioxidants for the purpose of controlling the above properties and adhesive strength. can do. The adhesive layer can also be provided on the protective substrate as a superimposed layer of different compositions or types. The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the adhesive strength, the surface roughness of the optical member, and the like, and is generally 1 to 500 μm, preferably 5 to 200 μm, and particularly preferably 10 to 100 μm.

In the present invention, the adhesive strength to the optical material is 400 gf / 50 mm or less, especially 50 to 350 gf based on a 180 degree peel at a peeling speed of 20 m / min at normal temperature.
/ 50 mm, particularly preferably an adhesive layer adjusted to 100 to 300 gf / 50 mm. It is preferable that the pressure-sensitive adhesive layer contains as little unreacted monomer as possible. If the unreacted monomer remains in the adhesive layer, it becomes cloudy over time and the transparency decreases,
This may hinder the appearance inspection of the optical material.

From the viewpoint of the prevention of white turbidity, the residual amount of the unreacted monomer in the adhesive layer is reduced by 5% based on the acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms.
It is preferable that the content is not more than 4% by weight, especially not more than 4% by weight, especially not more than 3% by weight. Control of the content of the unreacted monomer in the adhesive layer is performed by an appropriate method such as a method of extending the polymerization time of the base polymer, a method of purifying after the polymerization treatment, and a method of drying and removing the remaining monomer in the adhesive layer. Can be. In addition, an antistatic layer may be provided on one or both surfaces of the surface protective film, particularly on the protective substrate, for the purpose of preventing static electricity at the time of peeling.

The optical material to be adhered and coated with the surface protective film is, for example, a polarizing plate, a retardation plate, an elliptically polarizing plate or a reflective polarizing plate obtained by laminating them, a transflective polarizing plate or a reflective elliptically polarizing plate, Any type may be used as appropriate for forming a liquid crystal panel such as a elliptically polarizing plate, and the type is not particularly limited.

Therefore, the polarizing plate may be of a reflection type or a transflective type. Also, the phase difference plate is や or ４
It may have an appropriate purpose, such as a wave plate such as that described above, and viewing angle compensation. In the case of a laminated type optical material such as the above-mentioned elliptically polarizing plate, the lamination may be performed through an appropriate bonding means such as an adhesive layer.

Incidentally, specific examples of the above-mentioned polarizing plate include iodine and / or iodine on a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene / vinyl acetate copolymer-based partially saponified film. Examples thereof include a film obtained by adsorbing a dichroic dye and stretching, a polarizing film made of a polyene oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrochlorinated product of polyvinyl chloride. The polarizing plate may have a transparent protective layer on one or both sides of a polarizing film.

On the other hand, the reflection type polarizing plate is provided with a reflection layer on the polarizing plate, and is used for forming a liquid crystal panel or the like of a type which reflects incident light from the viewing side (display side) to display. In addition, there is an advantage that the incorporation of a light source such as a backlight can be omitted and the thickness of the liquid crystal panel can be easily reduced. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is provided on one surface of the polarizing plate via a transparent protective layer or the like as necessary.

Specific examples of the reflective polarizing plate include a transparent protective layer that has been matted as required, and a reflective layer formed by attaching a foil or a vapor-deposited film made of a reflective metal such as aluminum to one surface of the transparent protective layer. can give. Further, there may be mentioned, for example, those in which fine particles are contained in the transparent protective layer to form a fine surface uneven structure, and a reflective layer having a fine uneven structure is provided thereon. The reflective layer has a reflective surface covered with a transparent protective layer or a polarizing plate. Is more preferable.

The reflective layer having the fine uneven structure described above has an advantage that the incident light is diffused by irregular reflection to prevent directivity and glaring appearance, and to suppress unevenness of brightness and darkness.
Further, the transparent protective layer containing fine particles also has an advantage that the incident light and the reflected light thereof are diffused when transmitting the light and the unevenness of light and darkness can be further suppressed.

The reflection layer having a fine uneven structure reflecting the fine uneven structure on the surface of the transparent protective layer is formed by an appropriate method such as an evaporation method such as a vacuum evaporation method, an ion plating method and a sputtering method, and a plating method. The method can be performed by directly attaching a metal to the surface of the transparent protective layer.

For the formation of the transparent protective layer in the above-mentioned polarizing plate, a polymer or the like having excellent transparency, mechanical strength, heat stability, moisture shielding property and the like is preferably used. Examples of such resins include polyester resins and acetate resins, polyethersulfone resins and polycarbonate resins,
Examples of the resin include a polyamide resin, a polyimide resin, a polyolefin resin, an acrylic resin, and a thermosetting resin such as an acrylic resin, a urethane resin, an acrylic urethane resin, an epoxy resin, or a silicone resin, or an ultraviolet curable resin.

The transparent protective layer may be formed by an appropriate method such as a method of applying a polymer or a method of laminating a film, and the thickness may be appropriately determined. Generally 500 μm
Hereinafter, the thickness is preferably 1 to 300 μm, particularly 5 to 200 μm. The fine particles to be contained in the formation of the transparent protective layer having the fine surface irregularity structure include, for example, an average particle size of 0.5 to 5
Transparent inorganic fine particles of 0 μm silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like, and organic fine particles of a crosslinked or uncrosslinked polymer, etc. Fine particles are used. The amount of fine particles used is 1
The amount is generally 2 to 50 parts by weight, preferably 5 to 25 parts by weight per 00 parts by weight, but is not limited thereto.

On the other hand, as a specific example of the above-mentioned retardation plate, a film made of an appropriate polymer such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene, other polyolefin, polyarylate or polyamide is stretched. Birefringent film or liquid crystal polymer oriented film,
Examples thereof include a film in which an alignment layer of a liquid crystal polymer is supported by a film.

The retardation plate has an appropriate retardation according to the intended use, for example, various wavelength plates, those for the purpose of compensating for coloring due to birefringence of the liquid crystal layer, and for compensating the viewing angle such as expansion of the viewing angle. And an obliquely oriented film having a controlled refractive index in the thickness direction. Further, two or more retardation plates may be laminated to control optical characteristics such as retardation.

The above-mentioned obliquely oriented film can be formed, for example, by applying a heat-shrinkable film to a polymer film and applying a shrinkage force by heating to stretch or / and shrink the polymer film. It can be obtained by a method such as

The optical material may be formed by laminating two or three or more optical layers, such as a laminate of the above-mentioned elliptically polarizing plate, reflection type polarizing plate and retardation plate. Therefore, a reflective elliptically polarizing plate, a transflective elliptically polarizing plate, or a combination of a reflective polarizing plate, a transflective polarizing plate, and a retardation plate may be used.

An optical material in which two or three or more optical layers are laminated can also be formed by a method in which the optical materials are laminated separately in the manufacturing process of a liquid crystal panel or the like. This has the advantage that the stability of quality, the workability of assembling, etc. are excellent and the production efficiency of liquid crystal panels and the like can be improved.

The optical member according to the present invention is one in which one or both of the front and back surfaces of the optical material are adhesively coated with a surface protection film for the purpose of preventing damage or the like. When the surface protective film 1 is provided only on one surface of the optical material 2 as shown in the figure, an adhesive layer 21 for adhering to another member such as a liquid crystal cell can be provided on the surface where the surface protective film 1 is not provided, if necessary.

The above-mentioned pressure-sensitive adhesive layer can be formed with an appropriate pressure-sensitive adhesive according to the related art. Above all, from the viewpoint of prevention of foaming and peeling phenomena due to moisture absorption, deterioration of optical characteristics due to difference in thermal expansion, prevention of liquid crystal cell warpage, and formation of high quality and durable liquid crystal panel, moisture absorption rate It is preferable that the pressure-sensitive adhesive layer is low and has excellent heat resistance.

When the adhesive layer provided on the optical material is exposed on the surface, the adhesive layer may be temporarily attached with a separator 3 as shown in the figure for the purpose of preventing contamination or the like until the adhesive layer is put to practical use. preferable. The separator is formed by, for example, providing a release coating with a suitable release agent such as a silicone-based or long-chain alkyl-based, fluorine-based or molybdenum sulfide on a suitable thin leaf according to the above-described protective substrate or the like. It can be carried out.

Each layer in the optical material and the adhesive layer forming the optical member is made of, for example, an ultraviolet absorbing material such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound, or the like. It may have an ultraviolet absorbing ability by an appropriate method such as a method of treating with an agent.

The surface protective film according to the present invention is bonded to the surface of an optical material to form an optical member, which is bonded to another member such as a liquid crystal cell, and aging for stabilizing the bonded state if necessary. It can be preferably used for forming various devices such as a liquid crystal panel which needs to separate and separate the surface protective film from the optical member after the heat treatment.

[0044]

Example 1 80 parts of isononyl acrylate (parts by weight, the same applies hereinafter), 15 parts of lauryl acrylate and 5 parts of 2-hydroxyethyl acrylate were added to 100 parts of ethyl acetate via 0.5 part of azobisisobutyronitrile. Parts of the acrylic polymer solution obtained by reacting at about 60 ° C. for 10 hours per 100 parts of the solid content of a crosslinking agent (Coronate L, manufactured by Nippon Polyurethane Co., Ltd.)
The resulting syrup was coated on a 35 μm-thick polyester film and dried to form a 25 μm-thick acrylic pressure-sensitive adhesive layer, thereby obtaining a long surface protective film.

Example 2 Stearyl acrylate was replaced with lauryl acrylate.
Use 5 parts and reduce the amount of isononyl acrylate to 70
A surface protective film was obtained in the same manner as in Example 1 except that the above parts were used.

Comparative Example 1 A surface protective film was obtained in the same manner as in Example 1, except that the amount of isononyl acrylate was 95 parts and lauryl acrylate was not used.

Comparative Example 2 A surface protective film was obtained in the same manner as in Example 1, except that an acrylic polymer solution in which the polymerization time was reduced to 3 hours was used.

Evaluation Test The surface protective films obtained in Examples and Comparative Examples were adhered to a long polarizing plate with a laminator via the adhesive layer, and the resultant was adhered to a 50-inch polarizing plate.
An optical member was formed by aging in an autoclave at 5 ° C. and 5 atm for 30 minutes, and subjected to the following test. The polarizing plate has a pressure-sensitive adhesive layer on a surface having no surface protective film.

Adhesive force A test piece cut to a width of 50 mm was formed, and the 180 ° peel value at a peeling speed of 20 m / min was measured through a tensile tester to determine the adhesive force of the surface protective film to the polarizing plate at 23 ° C. Was examined.

Peeling workability A test piece cut into a size of 650 mm in length and 470 mm in width was formed, and the test piece was cut through an adhesive layer of a polarizing plate to a thickness of 0.7 mm.
It was adhered to a glass plate having a length of 700 mm and a width of 500 mm, placed on a table with the glass plate facing down, and the surface protective film was peeled off from its corners, and the peeling workability in that case was examined. In the evaluation, a case where time was required for peeling or a case where the glass plate was lifted at the time of peeling was evaluated as poor, and a case where the glass plate was smoothly peeled without lifting the glass plate was evaluated as good.

Residual amount of monomer The solution obtained when the acrylic polymer was prepared was analyzed by gas chromatography to determine qualitatively and quantitatively the unreacted monomer, and the residual amount of lauryl acrylate or stearyl acrylate was examined.

Transparency The transparency of the pressure-sensitive adhesive layer was visually evaluated.

The results are shown in the following table. Example 1 Example 2 Comparative Example 1 Comparative Example 2 Adhesive force (gf / 50 mm) 250 200 500 240 Peeling workability Good Good Good Good Bad (* 1) Good Good Remaining amount of monomer (% by weight) 1207 Transparency Transparent Transparent Transparent Transparent Opaque (* 2) * 1: Difficult to peel without supporting the glass plate * 2: Cloudy

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an optical member.

[Explanation of symbols]

 1: Surface protective film 11: Protective substrate 12: Adhesive layer 2: Optical material 21: Adhesive layer 3: Separator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Shiki 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Inside Nitto Denko Corporation (72) Inventor Tomomori Masada 1-1-1, Shimohozumi, Ibaraki City, Osaka Prefecture No. 2 Nitto Denko Corporation F term (reference) 2H049 BA02 BA04 BA06 BB23 BB26 BB27 BB28 BB36 BB51 2H091 FA08X FA08Z FA11Z FB02 2K009 AA00 AA12 BB12 BB22 CC14 CC24 CC34 DD01 DD03 DD04 DD07 4J004A

Claims (3)

[Claims] 1. A protective film for adhesively covering the surface of an optical material via an adhesive layer, wherein the adhesive layer contains 10% by weight or more of an acrylic acid alkyl ester having an alkyl group having 12 or more carbon atoms. A surface protective film comprising a polymer, wherein the residual amount of the acrylic acid-based alkyl ester in the pressure-sensitive adhesive layer due to unreaction is 5% by weight or less. 2. An optical member, wherein the surface of an optical material is adhesively coated with the surface protective film according to claim 1 via the adhesive layer. 3. The method according to claim 2, wherein the optical material is a polarizing plate,
An optical member which is a retardation plate, an elliptically polarizing plate, a reflection type polarizing plate, a semi-transmission type polarizing plate, a reflection type elliptically polarizing plate, or a semi-transmission type elliptically polarizing plate.