Surface protective film

Abstract

The invention relates to a surface protective film. The present invention provides an optical surface protective film which has low transmittance of ultraviolet rays, suppresses color change, and has excellent adhesive force stability. The optical surface protective film according to the present invention has a base material formed from a polyester-based resin and an adhesive layer formed from an adhesive composition provided on one surface of the base material, and is characterized in that the b * value of the surface protective film is 2 or less, the transmittance of the surface protective film at a wavelength of 365 nm is 2% or less, and the b * value of the surface protective film at a wavelength of 365 nm is 2% or less. After the adhesive layer has been adhered to glass and heated at 100 DEG C for 30 minutes, the change rate of the adhesive force with respect to the adhesive force before heating is + / -30% or less.

Description

[0001] This application is a divisional application of the Chinese patent application with application date of March 22, 2018 and application number 201810239654.8. Technical Field

[0002] The present invention relates to an optical surface protective film. In particular, the optical surface protective film is useful as an optical surface protective film for protecting the surface of an optical component (for example, a polarizing plate, a wave plate, a phase difference plate, an optical compensation film, a reflective sheet, a brightness enhancement film, a protective glass for a display, etc. used in a liquid crystal display, etc.) and protecting components that are easily degraded by ultraviolet irradiation from the influence of ultraviolet rays. Background Art

[0003] The protective film generally has a structure in which an adhesive layer is provided on a film-like substrate. The protective film is used for the following purpose: by bonding it to an optical member as an adherend via the adhesive layer, the optical member is protected from surface damage and stains during processing, transportation, inspection, etc. For example, a panel of a liquid crystal display is formed by bonding an optical member such as a polarizing plate and a wave plate to a liquid crystal cell via an adhesive layer (Patent Document 1).

[0004] Since the protective film is sometimes subjected to appearance inspection in a state of being bonded to an optical member or the like, it is required to be able to prevent the color tone change (discoloration such as reddening) of the protective film over time.

[0005] In addition, since liquid crystal sealed in a liquid crystal cell used in a panel of a liquid crystal display is degraded by ultraviolet rays, a protective film having an ultraviolet absorbing function is bonded and used to a member such as a polarizing plate bonded to the liquid crystal cell.

[0006] In addition, in recent years, when manufacturing cover glasses for thin smartphones, tablet computers and other mobile terminals, resins that cure by active energy such as ultraviolet rays and heat are used for bonding operations. However, sometimes ultraviolet irradiation is not required, and components that deteriorate due to ultraviolet rays are used. In order to protect such components, protective films containing ultraviolet absorbers are used.

[0007] The protective film used will be peeled off when it is no longer needed. However, when peeling off the protective film affixed to the protective glass used in thin smartphones, etc., it is difficult to easily peel off the protective film because the adhesive strength is increased due to ultraviolet rays, heat, etc., which sometimes causes damage to the protective glass.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2007-304425 Summary of the invention

[0011] Problems to be solved by the invention

[0012] Therefore, the present inventors have conducted intensive studies in view of the above circumstances, and an object of the present invention is to provide an optical surface protection film having low ultraviolet transmittance, suppressed color change, and excellent adhesive stability.

[0013] Means used to solve problems

[0014] That is, the optical surface protection film of the present invention comprises a substrate formed of a polyester resin and an adhesive layer formed of an adhesive composition and provided on one side of the substrate, and the optical surface protection film of the present invention is characterized in that the b* value of the surface protection film is 2 or less, the transmittance of the surface protection film at a wavelength of 365 nm is 2% or less, and after the adhesive layer is attached to glass, the rate of change of the adhesive force after heating at 100° C. for 30 minutes relative to the adhesive force before heating is ±30% or less.

[0015] In the optical surface protection film of the present invention, it is preferred that the pressure-sensitive adhesive composition contain a UV absorber.

[0016] In the optical surface protection film of the present invention, the number of hydroxyl groups in the molecule of the ultraviolet absorber is preferably 3 or less.

[0017] In the optical surface protection film of the present invention, it is preferred that the pressure-sensitive adhesive composition contains a (meth)acrylic polymer and / or a polyurethane polymer as a base polymer.

[0018] In the optical surface protection film of the present invention, the pressure-sensitive adhesive composition preferably contains 0.1 to 20 parts by weight of the ultraviolet absorber based on 100 parts by weight of the base polymer.

[0019] In the optical surface protection film of the present invention, it is preferred that the thickness of the substrate is 6 μm to 100 μm, and the thickness of the pressure-sensitive adhesive layer is 1 μm to 30 μm.

[0020] The present invention is useful because it is possible to obtain an optical surface protective film having low ultraviolet transmittance, suppressed color change, and excellent adhesive stability by using a surface protective film having specific optical characteristics. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described in detail.

[0022] <Overall structure of optical surface protection film>

[0023] The optical surface protection film disclosed herein (hereinafter sometimes referred to as "surface protection film") is a film in which the surface of an adhesive layer in the form of an adhesive tape, an adhesive label, an adhesive film, etc. is protected by a spacer, and is particularly suitable as a surface protection film for protecting the surface of an optical component during processing, inspection, and transportation of an optical component (for example, an optical component used as a component of a liquid crystal display panel such as a polarizing plate, a wave plate, and a protective glass). The adhesive layer in the surface protection film is typically formed continuously, but is not limited to such a form. For example, it may also be an adhesive layer formed into a regular or irregular pattern such as dots or stripes. In addition, the surface protection film disclosed herein may be in a roll form or in a paper form (leaf form).

[0024] <Base material>

[0025] The optical surface protection film of the present invention is characterized in that it has a substrate formed of a polyester resin. The substrate formed of the polyester resin has excellent optical properties and dimensional stability, which are preferred properties as a substrate of a surface protection film.

[0026] As the substrate, a substrate composed of a resin material having a main resin component (main component in the resin component, typically a component accounting for 50% by weight or more) such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, etc. as the polyester resin can be preferably used. As examples of resin materials other than the polyester resin, styrene polymers such as polystyrene and acrylonitrile-styrene copolymer; olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymer; vinyl chloride polymers; amide polymers such as nylon 6, nylon 6,6, and aromatic polyamide can be cited. Other examples of the resin material include imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, etc. The base material may also be a blend of two or more of the above polymers.

[0027] The resin material constituting the substrate may be mixed with various additives such as antioxidants, ultraviolet absorbers, plasticizers, colorants (pigments, dyes, etc.) as needed. For example, known or commonly used surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, primer coating, etc. may be implemented. Such surface treatments may be, for example, treatments for improving the adhesion between the substrate and the adhesive layer (anchoring properties of the adhesive layer).

[0028] As the substrate, a substrate subjected to an antistatic treatment can also be used. By using the substrate, the charging of the surface protection film itself during peeling can be suppressed, so it is preferred. In addition, by subjecting the substrate to an antistatic treatment, the charging of the surface protection film itself can be reduced and a substrate with excellent antistatic ability for the adherend can be obtained. It should be noted that there is no particular limitation as to the method for imparting an antistatic function, and existing known methods can be used, for example: a method of coating an antistatic resin containing an antistatic agent and a resin component, a conductive polymer, and a conductive resin containing a conductive substance; a method of evaporating or plating a conductive substance, and a method of kneading an antistatic agent, etc.

[0029] The thickness of the substrate is preferably 6 to 100 μm, more preferably 10 to 60 μm, and still more preferably 15 to 40 μm. When the thickness of the substrate is within the above range, the adhesion workability to the adherend and the peelability and workability from the adherend are excellent, which is preferred.

[0030] The surface protection film disclosed herein can also be implemented in a manner that includes other layers in addition to the substrate and the adhesive layer. As the other layers, a primer layer (anchoring layer) that improves the anchoring property of the antistatic layer and the adhesive layer can be cited. In addition, for the purpose of protecting the surface of the adhesive layer, a spacer can also be pasted.

[0031] <Adhesive layer>

[0032] The optical surface protective film of the present invention is characterized in that it is formed by providing an adhesive layer formed by an adhesive composition on one side of the substrate. As long as the adhesive layer used in the present invention is formed by an adhesive composition containing an adhesive polymer with adhesiveness, it can be used without particular restrictions. As for the adhesive composition, for example, acrylic adhesives, polyurethane adhesives, synthetic rubber adhesives, natural rubber adhesives, polysiloxane adhesives, polyester adhesives, etc. can be used, wherein, as the base polymer, it is preferred to use an adhesive composition containing a (meth) acrylic polymer and / or a polyurethane polymer.

[0033] <Acrylic adhesive>

[0034] When an acrylic adhesive is used in the adhesive layer, a (meth) acrylic polymer as an adhesive polymer constituting the acrylic adhesive is used as a base polymer, and as a raw monomer constituting the base polymer, a (meth) acrylic monomer having an alkyl group with 1 to 14 carbon atoms can be used as a main monomer. As the (meth) acrylic monomer, one or more than two can be used. By using the (meth) acrylic monomer having an alkyl group with 1 to 14 carbon atoms, it is easy to control the peeling force (adhesive force) to the adherend (protected body) to be low, and a surface protective film with excellent light peelability and re-peelability can be obtained. It should be noted that the (meth) acrylic polymer in the present invention refers to an acrylic polymer and / or a methacrylic polymer, and the (meth) acrylate refers to an acrylate and / or a methacrylate.

[0035] Specific examples of the (meth)acrylic monomer having an alkyl group with 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, and the like.

[0036] Among them, in the surface protection film of the present invention, in particular, (meth)acrylic acid monomers having an alkyl group of 4 to 14 carbon atoms, such as n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate, can be cited as suitable monomers. In particular, by using a (meth)acrylic acid monomer having an alkyl group of 4 to 14 carbon atoms, it is easy to control the peeling force (adhesive force) to the adherend to be low, and the adhesive layer with excellent removability can be obtained.

[0037] In particular, the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms is preferably contained in an amount of 65% by weight or more, more preferably 75% by weight or more, further preferably 85% to 99.9% by weight, and particularly preferably 90% to 99% by weight, relative to 100% by weight of the total amount of monomer components constituting the (meth)acrylic polymer. When the amount is less than 65% by weight, the appropriate wettability of the adhesive composition and the cohesive force of the adhesive layer are deteriorated, which is not preferred.

[0038] In addition, the (meth)acrylic polymer may use a hydroxyl-containing (meth)acrylic monomer as a raw material monomer. The hydroxyl-containing (meth)acrylic monomer may be one or more than one. By using the hydroxyl-containing (meth)acrylic monomer, it is easy to control the crosslinking of the adhesive composition, and further easy to control the balance between the improvement of wettability due to flow and the reduction of peeling force (adhesive force) during peeling.

[0039] Examples of the hydroxyl-containing (meth)acrylic monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate, and N-hydroxymethyl (meth)acrylamide.

[0040] The hydroxyl-containing (meth)acrylic monomer is preferably contained in an amount of 25 wt % or less, more preferably 15 wt % or less, further preferably 0.1 wt % to 10 wt %, and particularly preferably 1 wt % to 5 wt % relative to 100 wt % of the total amount of monomer components constituting the (meth)acrylic polymer. When the amount is within the above range, the balance between the wettability of the adhesive composition and the cohesive force of the obtained adhesive layer can be easily controlled, which is therefore preferred.

[0041] In addition, as other polymerizable monomer components, from the reason of easily achieving a balance in adhesive properties, polymerizable monomers for adjusting the glass transition temperature of the (meth)acrylic polymer so that Tg is 0° C. or lower (usually -100° C. or higher), polymerizable monomers for adjusting releasability, etc. can be used within a range not impairing the effects of the present invention.

[0042] In addition, the (meth) acrylic polymer can use a carboxyl-containing (meth) acrylic monomer as a raw material monomer. By using the carboxyl-containing (meth) acrylic monomer, the adhesive strength increase over time of the adhesive layer (surface protection film) can be suppressed, and the re-peelability, anti-adhesion strength increase and workability are excellent. In addition, not only the cohesive force of the adhesive layer is excellent, but also the shear force is excellent, so it is preferred.

[0043] Examples of the carboxyl group-containing (meth)acrylic monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate.

[0044] The carboxyl group-containing (meth)acrylic monomer is preferably present in an amount of 10% by weight or less, more preferably 0 to 8% by weight, and even more preferably 0 to 6% by weight, relative to 100% by weight of the total amount of monomer components constituting the (meth)acrylic polymer. When the amount is within the above range, the balance between the wettability of the adhesive composition and the cohesive force of the obtained adhesive layer can be easily controlled, which is preferred.

[0045] In addition, the (meth)acrylic polymer may use other polymerizable monomers other than the raw material monomers without particular limitation as long as the characteristics of the present invention are not impaired. For example, as the other polymerizable monomers, components that improve cohesion and heat resistance, such as cyano-containing monomers, vinyl ester monomers, and aromatic vinyl monomers; components that improve peeling strength (adhesion) or have functional groups that act as crosslinking bases, such as amide-containing monomers, imide-containing monomers, amino-containing monomers, epoxy-containing monomers, N-acryloylmorpholine, and vinyl ether monomers, can be appropriately used. Among them, nitrogen-containing monomers such as cyano-containing monomers, amide-containing monomers, imide-containing monomers, amino-containing monomers, and N-acryloylmorpholine are preferably used. By using nitrogen-containing monomers, it is possible to ensure a moderate peeling strength (adhesion strength) without warping, peeling, etc., and further, it is possible to obtain a surface protective film with excellent shearing strength, so it is useful. These polymerizable monomers can be used alone or in combination of two or more.

[0046] Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

[0047] Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinyl pyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide, and diacetone acrylamide.

[0048] Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

[0049] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate.

[0050] Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, and vinyl laurate.

[0051] Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

[0052] Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and allyl glycidyl ether.

[0053] Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, and isobutyl vinyl ether.

[0054] In the present invention, the other polymerizable monomer is preferably 0 to 30 wt %, more preferably 0 to 10 wt %, based on 100 wt % of the total monomer components constituting the (meth)acrylic polymer. The other polymerizable monomer may be appropriately adjusted to obtain desired properties.

[0055] The (meth)acrylic polymer may further contain an alkylene oxide group-containing reactive monomer as a monomer component.

[0056] In addition, from the viewpoint of compatibility with oxyalkylene-containing compounds, the average addition mole number of the oxyalkylene unit of the reactive monomer containing an alkylene oxide group is preferably 1 to 40, more preferably 3 to 40, further preferably 4 to 35, and particularly preferably 5 to 30. When the average addition mole number is 1 or more, there is a tendency to efficiently obtain the effect of reducing the contamination of the adherend (protected body). In addition, when the average addition mole number is greater than 40, the interaction with the oxyalkylene-containing compound is large, and there is a tendency that the viscosity of the adhesive composition increases, making it difficult to apply, and therefore it is not preferred. It should be noted that the end of the oxyalkylene chain may be a hydroxyl group as it is, or may be substituted by other functional groups, etc.

[0057] The reactive monomer containing an alkylene oxide group may be used alone or in combination of two or more thereof. The content of the reactive monomer containing an alkylene oxide group is preferably 0 to 20% by weight, more preferably 0 to 10% by weight, based on the total amount of monomer components of the (meth)acrylic polymer. If the content of the reactive monomer containing an alkylene oxide group is greater than 20% by weight, the staining property to the adherend is deteriorated, which is not preferred.

[0058] Examples of the oxyalkylene unit of the reactive monomer containing an alkylene oxide group include oxyalkylene units having an alkylene group having 1 to 6 carbon atoms, such as oxymethylene, oxyethylene, oxypropylene, oxybutylene, etc. The hydrocarbon group of the oxyalkylene chain may be linear or branched.

[0059] In addition, it is more preferred that the reactive monomer containing an alkylene oxide group is a reactive monomer having an ethylene oxide group. By using a (meth) acrylic polymer containing a reactive monomer having an ethylene oxide group as a base polymer, the compatibility of the base polymer with the oxyalkylene-containing compound is improved, and the bleeding to the adherend is appropriately suppressed, so that a low-staining adhesive composition can be obtained.

[0060] Examples of the alkylene oxide group-containing reactive monomer include (meth)acrylic acid alkylene oxide adducts and reactive surfactants having a reactive substituent such as an acryloyl group, a methacryloyl group, or an allyl group in the molecule.

[0061] Specific examples of the (meth)acrylic acid alkylene oxide adduct include polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol-polypropylene glycol (meth)acrylate, polyethylene glycol-polybutylene glycol (meth)acrylate, polypropylene glycol-polybutylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, ethoxy polyethylene glycol (meth)acrylate, butoxy polyethylene glycol (meth)acrylate, octyloxy polyethylene glycol (meth)acrylate, dodecyloxy polyethylene glycol (meth)acrylate, octadecyloxy polyethylene glycol (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, methoxy polypropylene glycol (meth)acrylate, octyloxy polyethylene glycol-polypropylene glycol (meth)acrylate, and the like.

[0062] Specific examples of the reactive surfactant include anionic reactive surfactants, nonionic reactive surfactants, and cationic reactive surfactants having a (meth)acryloyl group or an allyl group.

[0063] The weight average molecular weight (Mw) of the (meth) acrylic polymer is preferably 100,000 to 5 million, more preferably 200,000 to 4 million, further preferably 300,000 to 3 million, and most preferably 300,000 to 1.2 million. When the weight average molecular weight is less than 100,000, there is a tendency for adhesive residue to be generated due to the reduced cohesive force of the obtained adhesive layer. On the other hand, when the weight average molecular weight is greater than 5 million, the fluidity of the polymer is reduced, and there is a tendency for insufficient wetting of the adherend (for example, a polarizing plate) and a cause of ridges between the adherend and the adhesive layer of the surface protective film. It should be noted that the weight average molecular weight refers to the molecular weight obtained by measuring using GPC (gel permeation chromatograph).

[0064] In addition, the glass transition temperature (Tg) of the (meth) acrylic polymer is preferably below 0°C, more preferably below -10°C (usually above -100°C). When the glass transition temperature is greater than 0°C, the polymer is difficult to flow, for example, there is a tendency that the wetting of the polarizing plate as an optical component is insufficient, and it becomes the cause of the bulge between the polarizing plate and the adhesive layer of the surface protective film. In particular, by adjusting the glass transition temperature to below -70°C, it is easy to obtain an adhesive layer with excellent wettability and light peelability to the polarizing plate. It should be noted that the glass transition temperature of the (meth) acrylic polymer can be adjusted to within the range by appropriately changing the monomer components and composition ratios used.

[0065] The polymerization method of the (meth)acrylic polymer is not particularly limited, and the polymerization can be carried out by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc., but solution polymerization is a more preferred method from the viewpoint of workability, low contamination to the adherend (protected body), etc. In addition, the obtained polymer may be any one of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, etc.

[0066] <Polyurethane adhesive>

[0067] When a polyurethane adhesive is used in the adhesive layer, any suitable polyurethane adhesive may be used. As such a polyurethane adhesive, preferably, an adhesive having a base polymer, i.e., a polyurethane polymer, obtained by reacting a polyol with a polyisocyanate compound, may be used. The polyurethane adhesive may include an adhesive containing a polyurethane resin, which is a resin obtained by curing a composition containing a polyol and a polyisocyanate compound.

[0068] The content ratio of the polyurethane resin in the polyurethane adhesive is preferably 40% by weight or more, more preferably 50% by weight or more, further preferably 55% by weight or more, further preferably 60% by weight or more, particularly preferably 65% ​​by weight or more, and most preferably 70% by weight or more as the lower limit, and preferably 99.999% by weight or less, more preferably 99.99% by weight or less, further preferably 99.9% by weight or less, further preferably 99% by weight or less, particularly preferably 95% by weight or less, and most preferably 90% by weight or less as the upper limit. The polyurethane resin may be only one kind or two or more kinds.

[0069] The polyol may be used alone or in combination of two or more.

[0070] As the polyol, any suitable polyol may be used as long as it has two or more OH groups. Examples of such polyols include polyols having two OH groups (diols), polyols having three OH groups (triols), polyols having four OH groups (tetraols), polyols having five OH groups (pentaols), polyols having six OH groups (hexaols), and the like.

[0071] In addition, as the polyol, a polyol (triol) having 3 OH groups can be preferably used. In this way, by using a polyol (triol) having 3 OH groups as a polyol, for example, an adhesive layer with a fast wetting speed can be made, and by combining it with a specific substrate used in the present invention, a surface protective film with a higher detection rate of damage and impurities can be provided. The content ratio of the polyol (triol) having 3 OH groups in the polyol is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, further preferably 80% by weight to 100% by weight, further preferably 90% by weight to 100% by weight, particularly preferably 95% by weight to 100% by weight, and most preferably substantially 100% by weight.

[0072] As the polyol, preferably, a polyol having a number average molecular weight (Mn) of 400 to 20000 may be included. The content ratio of the polyol having a number average molecular weight (Mn) of 400 to 20000 in the polyol is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, further preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, and most preferably substantially 100% by weight.

[0073] In the present invention, as the polyol (triol) having three OH groups, it is preferred to use a triol having a number average molecular weight (Mn) of 7,000 to 20,000, a triol having a number average molecular weight (Mn) of 2,000 to 6,000, and a triol having a number average molecular weight (Mn) of 400 to 1,900 in combination. It is more preferred to use a triol having a number average molecular weight (Mn) of 8,000 to 15,000, a triol having a number average molecular weight (Mn) of 2,000 to 5,000, and a triol having a number average molecular weight (Mn) of 500 to 1,800 in combination. It is further preferred to use a triol having a number average molecular weight (Mn) of 8,000 to 12,000, a triol having a number average molecular weight (Mn) of 2,000 to 4,000, and a triol having a number average molecular weight (Mn) of 500 to 1,500 in combination.

[0074] Examples of the polyol include polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, and castor oil-based polyol.

[0075] The polyester polyol can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

[0076] Examples of the polyol component include ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol.

[0077] Examples of the acid component include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1,4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, and acid anhydrides thereof.

[0078] Examples of the polyether polyol include polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide using water, low molecular weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzenes (catechol, resorcinol, hydroquinone, etc.), etc. as initiators. Specifically, examples include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0079] Examples of the polycaprolactone polyol include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

[0080] Examples of the polycarbonate polyol include: polycarbonate polyols obtained by polycondensing the above polyol components with phosgene; polycarbonate polyols obtained by transesterification condensation of the above polyol components with carbonic acid diesters such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethylbutyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, and dibenzyl carbonate; copolymerized polycarbonate polyols obtained by using two or more of the above polyol components; polycarbonate polyols obtained by esterification of the above various polycarbonate polyols with carboxyl-containing compounds; polycarbonate polyols; polycarbonate polyols obtained by etherification reaction of the above-mentioned various polycarbonate polyols with hydroxyl-containing compounds; polycarbonate polyols obtained by ester exchange reaction of the above-mentioned various polycarbonate polyols with ester compounds; polycarbonate polyols obtained by ester exchange reaction of the above-mentioned various polycarbonate polyols with hydroxyl-containing compounds; polyester polycarbonate polyols obtained by condensation reaction of the above-mentioned various polycarbonate polyols with dicarboxylic acid compounds; copolyether polycarbonate polyols obtained by copolymerization of the above-mentioned various polycarbonate polyols with alkylene oxides, etc.

[0081] Examples of the castor oil-based polyol include castor oil-based polyols obtained by reacting castor oil fatty acids with the above-mentioned polyol components. Specifically, examples of the castor oil-based polyols include castor oil-based polyols obtained by reacting castor oil fatty acids with polypropylene glycol.

[0082] The polyisocyanate compound (polyfunctional isocyanate compound) may be used alone or in combination of two or more.

[0083] As the polyisocyanate compound (polyfunctional isocyanate compound), any suitable polyisocyanate compound that can be used for a urethanization reaction can be adopted. Examples of such polyisocyanate compounds include polyfunctional aliphatic isocyanate compounds, polyfunctional alicyclic isocyanates, and polyfunctional aromatic isocyanate compounds.

[0084] Examples of the polyfunctional aliphatic isocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0085] Examples of the polyfunctional alicyclic isocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.

[0086] Examples of the polyfunctional aromatic diisocyanate compound include phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.

[0087] Examples of the polyisocyanate compound include trimethylolpropane adducts of the various polyfunctional isocyanate compounds described above, biuret forms obtained by reacting with water, trimers having an isocyanurate ring, etc. These may also be used in combination.

[0088] The content ratio of the polyisocyanate compound is preferably 5 to 60 parts by weight, more preferably 10 to 50 parts by weight, and further preferably 15 to 40 parts by weight, relative to 100 parts by weight of the polyol.

[0089] The equivalent ratio of NCO groups to OH groups in the polyol and the polyisocyanate compound is preferably greater than 1.0 and less than or equal to 5.0, more preferably 1.1 to 5.0, further preferably 1.2 to 4.0, particularly preferably 1.5 to 3.5, and most preferably 1.8 to 3.0.

[0090] The polyurethane resin may contain a fatty acid ester that can be used as a wettability additive. By making the polyurethane resin contain a fatty acid ester, the wetting rate can be improved. The fatty acid ester may be only one kind or two or more kinds.

[0091] Relative to 100 parts by weight of the polyol, the content ratio of the fatty acid ester is preferably 5 to 50 parts by weight, more preferably 10 to 45 parts by weight, further preferably 15 to 40 parts by weight, particularly preferably 20 to 35 parts by weight, and most preferably 25 to 30 parts by weight. By adjusting the content ratio of the fatty acid ester to the above range, the wetting speed can be further improved. When the content ratio of the fatty acid ester is too small, the wetting speed may not be fully improved. When the content ratio of the fatty acid ester is too large, there may be problems that are disadvantageous to the cost, the problem of being unable to maintain the adhesive properties, or the problem of the adherend being contaminated.

[0092] The number average molecular weight (Mn) of the fatty acid ester is preferably 200 to 400, more preferably 210 to 395, further preferably 230 to 380, particularly preferably 240 to 360, and most preferably 270 to 340. By adjusting the number average molecular weight (Mn) of the fatty acid ester within the above range, the wetting speed can be further improved. If the number average molecular weight (Mn) of the fatty acid ester is too small, the wetting speed may not be improved even if the amount is large. When the number average molecular weight (Mn) of the fatty acid ester is too large, the curing property of the adhesive during drying becomes poor, which may have an adverse effect not only on the wetting properties but also on other adhesive properties.

[0093] As the fatty acid ester, any suitable fatty acid ester can be adopted within the scope of not damaging the effect of the present invention. As such fatty acid ester, for example, polyoxyethylene bisphenol A laurate, butyl stearate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, glyceryl monobehenate, 2-ethylhexanoic acid hexadecyl ester, isopropyl myristate, isopropyl palmitate, cholesteryl isostearate, lauryl methacrylate, coconut fatty acid methyl ester, methyl laurate, methyl oleate, methyl stearate, myristyl myristate, octyldodecyl myristate, pentaerythritol monooleate, pentaerythritol monostearate, pentaerythritol tetrapalmitate, stearyl stearate, isotridecyl stearate, tri(2-ethylhexanoic acid)glyceryl ester, butyl laurate, octyl oleate, etc.

[0094] The polyurethane resin may contain a leveling agent. The polyurethane resin may contain a leveling agent to prevent uneven appearance caused by orange peel wrinkles. The leveling agent may be one or more.

[0095] As a method for obtaining a polyurethane resin by curing the composition containing a polyol and a polyisocyanate compound, any suitable method can be adopted within the range that does not impair the effect of the present invention, such as a polyurethane reaction method using bulk polymerization, solution polymerization, etc. However, the polyurethane resin obtained by the so-called urethane prepolymer in the past may not show the effect of the present invention, so as a method for obtaining a polyurethane resin by curing the composition containing a polyol and a polyisocyanate compound, a method other than the method of obtaining a polyurethane resin by the urethane prepolymer is preferred.

[0096] <Ultraviolet light absorber>

[0097] In the optical surface protective film of the present invention, the adhesive composition preferably contains an ultraviolet absorber, and the ultraviolet absorber preferably has 3 or less hydroxyl groups in the molecule. By using an ultraviolet absorber, components that are easily degraded by ultraviolet rays can be protected. Furthermore, by using an ultraviolet absorber having 3 or less hydroxyl groups, the adhesive layer has excellent adhesion stability, so it is preferred. It should be noted that it can be inferred that when there are many hydroxyl groups in the molecule of the ultraviolet absorber, the ultraviolet absorber reacts with the crosslinking agent and hinders the curing of the adhesive composition.

[0098] The ultraviolet absorber is not particularly limited, and examples thereof include triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, hydroxybenzophenone ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, etc., and they can be used alone or in combination of two or more. Among them, the mode in which the hydroxyl group in the molecule of the ultraviolet absorber is 3 or less is a more preferred mode.

[0099] As the triazine type ultraviolet absorber having three or less hydroxyl groups in one molecule, specifically, 2,4-bis[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (TinosorbS, manufactured by BASF); 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (TINUVIN 460, manufactured by BASF); 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-hydroxyphenyl and [(C 10 -C 16 (Mainly C 12 -C 13)alkyloxy)methyl] ethylene oxide reaction product (TINUVIN400, manufactured by BASF); 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol), 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine reaction product with 2-ethylhexyl glycidate (TINUVIN405, manufactured by BASF); 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]phenol (TINUVIN1577, manufactured by BASF); 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]phenol (ADK STAB LA46, manufactured by ADEKA); 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (TINUVIN479, manufactured by BASF);

[0100] As the benzotriazole ultraviolet absorber, 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN 928, manufactured by BASF), 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (TINUVIN PS, manufactured by BASF), an ester compound of phenylpropionic acid and 3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 side chain and linear alkyl) (TINUVIN 384-2, manufactured by BASF) can be used; 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN 900, manufactured by BASF); 2-(2H-benzotriazole-2 -yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN928, manufactured by BASF); methyl-3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 reaction product (TINUVIN1130, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-p-cresol (TINUVIN P, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN234, manufactured by BASF); 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-tert-butylphenol (TINUVIN326, manufactured by BASF), (TINUVIN326 FL, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol (TINUVIN328, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN329, manufactured by BASF); methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propanoic acid Reaction product of ester and polyethylene glycol 300 (TINUVIN213, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (TINUVIN571, manufactured by BASF); 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole (Sumisorb250, manufactured by Sumitomo Chemical Industries), etc.

[0101] Examples of the benzophenone-based ultraviolet absorbers (benzophenone-based compounds) and hydroxybenzophenone-based ultraviolet absorbers (hydroxybenzophenone-based compounds) include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (anhydrous salt and trihydrate salt), 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4-dimethoxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone (KEMISORB 111, manufactured by Chemipro Chemicals).

[0102] Examples of the salicylate ultraviolet absorber (salicylate compound) include phenyl 2-acryloxybenzoate, phenyl 2-acryloxy-3-methylbenzoate, phenyl 2-acryloxy-4-methylbenzoate, phenyl 2-acryloxy-5-methylbenzoate, phenyl 2-acryloxy-3-methoxybenzoate, phenyl 2-hydroxybenzoate, phenyl 2-hydroxy-3-methylbenzoate, phenyl 2-hydroxy-4-methylbenzoate, phenyl 2-hydroxy-5-methylbenzoate, phenyl 2-hydroxy-3-methoxybenzoate, phenyl 3,5-di-tert-butyl-4-hydroxybenzoate (TINUVIN 120, manufactured by BASF), and the like.

[0103] Examples of the cyanoacrylate ultraviolet absorber (cyanoacrylate compound) include 2-cyanoacrylate alkyl esters, 2-cyanoacrylate cycloalkyl esters, 2-cyanoacrylate alkoxyalkyl esters, 2-cyanoacrylate alkenyl esters, and 2-cyanoacrylate alkynyl esters.

[0104] The ultraviolet absorber may be used alone or in combination of two or more. The content of the ultraviolet absorber as a whole is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight, and further preferably 1 to 10 parts by weight relative to 100 parts by weight of the base polymer. By setting the content of the ultraviolet absorber to the above range, the ultraviolet absorption function of the adhesive layer can be fully exerted without hindering ultraviolet polymerization, which is preferred.

[0105] <Antioxidants>

[0106] In the optical surface protection film of the present invention, the pressure-sensitive adhesive composition may contain an antioxidant, and examples thereof include radical chain terminators and peroxide decomposers.

[0107] Examples of the radical chain terminator include phenolic antioxidants and amine antioxidants.

[0108] Examples of the peroxide decomposer include sulfur-containing antioxidants and phosphorus-containing antioxidants.

[0109] Examples of the phenolic antioxidant include monophenolic antioxidants, bisphenolic antioxidants, and polymeric phenolic antioxidants.

[0110] Examples of the monophenol antioxidant include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0111] Examples of the bisphenol antioxidant include 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), and 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane.

[0112] Examples of the polymeric phenolic antioxidant include 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis(4'-hydroxy-3'-tert-butylphenyl)butyrate]ethylene glycol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)s-triazine-2,4,6-(1H, 3H, 5H)trione, tocopherol, and pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate].

[0113] Examples of the sulfur-containing antioxidant include dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, and distearyl 3,3'-thiodipropionate.

[0114] Examples of the phosphorus-containing antioxidant include triphenyl phosphite, diphenyl isodecyl phosphite, and phenyl diisodecyl phosphite.

[0115] The antioxidant may be used alone or in combination of two or more. The total content of the antioxidant is preferably 0.01 to 1 part by weight, more preferably 0.1 to 0.8 parts by weight, and further preferably 0.2 to 0.7 parts by weight relative to 100 parts by weight of the base polymer. By setting the content of the antioxidant within the above range, the degradation of the adhesive layer due to oxidation can be fully suppressed, and the adhesive properties are stabilized, which is preferred.

[0116] <Oxyalkylene-containing compounds>

[0117] The adhesive composition used in the present invention may also contain an oxyalkylene-containing compound. By containing an oxyalkylene-containing compound, light peeling properties can be further demonstrated. Examples of the oxyalkylene-containing compound include organopolysiloxanes having oxyalkylene chains and oxyalkylene-containing compounds that do not include organopolysiloxanes.

[0118] <Cross-linking agent>

[0119] In the surface protection film of the present invention, it is preferred that the adhesive composition contains a crosslinking agent. In addition, in the present invention, the adhesive composition can be used to make an adhesive layer. For example, in the case where the adhesive composition is an acrylic adhesive containing the (meth) acrylic polymer, by appropriately adjusting the constituent units, constituent ratios, selection of crosslinking agents, and addition ratios of the (meth) acrylic polymer and crosslinking, an adhesive layer (surface protection film) with better heat resistance can be obtained. In addition, in the case of a polyurethane adhesive containing a polyurethane polymer, by appropriately adjusting the constituent units, constituent ratios, selection of crosslinking agents, and additive ratios of polyols and crosslinking, an adhesive layer (surface protection film) with excellent initial reworkability and excellent adhesion reliability after time can be obtained.

[0120] As the crosslinking agent used in the present invention, isocyanate compounds, epoxy compounds, melamine resins, aziridine derivatives and metal chelate compounds can be used, and in particular, isocyanate compounds and epoxy compounds are preferred. In addition, these compounds can be used alone or in combination of two or more.

[0121] Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimer acid diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), and 1,3-bis(isocyanatomethyl)cyclohexane; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate (XDI); isocyanates such as allophanate bonds, biuret bonds, isocyanurate bonds, uretdione bonds (ウレトジオン bonds), urea bonds, carbodiimide bonds, uretonimine bonds (ウレトニミン bonds), The polyisocyanate modified body after the above-mentioned isocyanate compound is modified by diazinetrione bond etc. For example, the trade names Takenate 300S, Takenate 500, Takenate 600, Takenate D165N, Takenate D178N (the above are manufactured by Mitsui Chemicals), Sumidule T80, Sumidule L, Desmodur N3400 (the above, manufactured by Sumika Bayer Urethane), Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (the above are manufactured by Tosoh Corporation) etc., which are commercially available products, can be cited. These isocyanate compounds can be used alone, or two or more can be mixed and used, and bifunctional isocyanate compounds and trifunctional or more isocyanate compounds can also be used in combination. By using a crosslinking agent in combination, it is possible to take into account both adhesion and resilience resistance (adhesion to curved surfaces), and an adhesive layer (surface protective film) with better adhesion reliability can be obtained.

[0122] Examples of the epoxy compound include N,N,N',N'-tetraglycidyl-meta-xylylenediamine (trade name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.).

[0123] Examples of the melamine-based resin include hexamethylolmelamine, etc. Examples of the aziridine derivative include commercially available products under the trade names of HDU, TAZM, and TAZO (each manufactured by Souhto Pharmaceutical Industries, Ltd.).

[0124] As the metal chelate compound, examples of the metal component include aluminum, iron, tin, titanium, nickel, and the like; and examples of the chelate component include acetylene, methyl acetoacetate, ethyl lactate, and the like.

[0125] For the content of the crosslinking agent used in the present invention, for example, relative to 100 parts by weight of the (meth) acrylic polymer, it is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, further preferably 0.5 to 10 parts by weight, and most preferably 1 to 8 parts by weight. When the content is less than 0.01 parts by weight, the crosslinking formation using the crosslinking agent becomes insufficient, and there is a tendency that the cohesive force of the obtained adhesive layer becomes smaller, and sometimes sufficient heat resistance cannot be obtained, and it becomes the cause of the adhesive residue. On the other hand, when the content is greater than 20 parts by weight, the cohesive force of the polymer is large, the fluidity is reduced, and there is a tendency that the wetting of the adherend (for example, a polarizing plate) is insufficient, which becomes the cause of the bulge between the adherend and the adhesive layer (adhesive composition layer). In addition, these crosslinking agents can be used alone or in combination of two or more. In addition, in the case of a polyurethane adhesive containing the polyurethane polymer, the content of the crosslinking agent is preferably 5 to 30 parts by weight, more preferably 5 to 28 parts by weight, further preferably 5 to 25 parts by weight, and particularly preferably 5 to 23 parts by weight, relative to 100 parts by weight of the polyol. By adjusting the content of the crosslinking agent to the above range, the obtained adhesive layer has not only excellent initial adhesion when attached to an adherend, but also excellent adhesion reliability after a period of time.

[0126] <Cross-linking catalyst>

[0127] The pressure-sensitive adhesive composition may further contain a cross-linking catalyst for more efficiently carrying out the above-mentioned optional cross-linking reaction. As the crosslinking catalyst, for example, tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate (dioctyltin dilaurate); tris(acetylacetonate)iron, tris(hexane-2,4-dione)iron, tris(heptane-2,4-dione)iron, tris(heptane-3,5-dione)iron, tris(5-methylhexane-2,4-dione)iron, tris(octane-2,4-dione)iron, tris(6-methylheptane-2,4-dione)iron, tris(2,6-dimethylheptane-3,5-dione)iron, tris(nonane-2,4-dione)iron, tris(nonane-4,6-dione)iron, tris(2,2,6,6-tetramethylheptane-3,5-dione)iron, tris(tridecane-6,8-dione)iron, tris(tridecane-6,8-dione)iron, tris(isopropylamine) iron, tris(isopropylamine) iron, tris(2,2,6,6-tetramethylheptane-3,5-dione)iron ... ) iron, tris(1-phenylbutane-1,3-dione) iron, tris(hexafluoroacetylacetonate) iron, tris(ethyl acetoacetate) iron, tris(n-propyl acetoacetate) iron, tris(isopropyl acetoacetate) iron, tris(n-butyl acetoacetate) iron, tris(sec-butyl acetoacetate) iron, tris(tert-butyl acetoacetate) iron, tris(methyl propionylacetate) iron, tris(ethyl propionylacetate) iron, tris(n-propyl propionylacetate) iron, tris(isopropyl propionylacetate) iron, tris(n-butyl propionylacetate) iron, tris(sec-butyl propionylacetate) iron, tris(tert-butyl propionylacetate) iron, tris(benzyl acetoacetate) iron, tris(dimethyl malonate) iron, tris(diethyl malonate) iron, trimethoxy iron, triethoxy iron, triisopropoxy iron, ferric chloride, etc. These crosslinking catalysts may be used alone or in combination of two or more.

[0128] The content of the crosslinking catalyst is not particularly limited. For example, relative to 100 parts by weight of the (meth) acrylic polymer, it is preferably set to about 0.0001 parts by weight to about 1 part by weight, and more preferably 0.001 parts by weight to 0.5 parts by weight. When it is within the range, the speed of the crosslinking reaction is fast when the adhesive layer is formed, and the applicable period of the adhesive composition is also prolonged, which is a preferred mode. In addition, it can be only one or more than two. In addition, in the case of a polyurethane adhesive containing the polyurethane polymer, as the content of the crosslinking catalyst, relative to 100 parts by weight of the polyol, it is preferably 0.01 parts by weight to 1 part by weight, and more preferably 0.08 parts by weight to 0.5 parts by weight.

[0129] <Other additives>

[0130] In addition, within the scope of not impairing the effects of the present invention, the adhesive composition may contain other well-known additives, for example, lubricants, colorants, pigments and other powders, solvents, plasticizers, softeners, tackifiers, low molecular weight polymers, surface lubricants, leveling agents, wetting additives, antioxidants, corrosion inhibitors, light stabilizers, heat stabilizers, ultraviolet absorbers, inhibitors, silane coupling agents, antistatic agents, inorganic or organic fillers, metal powders, granules, foils, etc. can be appropriately added according to the intended use.

[0131] <Surface protection film for optical applications>

[0132] The optical surface protective film (surface protective film) of the present invention comprises a substrate comprising a polyester resin and an adhesive layer formed of an adhesive composition and arranged on one side of the substrate. In this case, crosslinking of the adhesive composition is generally performed after coating of the adhesive composition, but the adhesive layer comprising the crosslinked adhesive composition can also be transferred to a substrate, etc.

[0133] In addition, the method for forming the adhesive layer on the substrate is not particularly limited, and for example, it can be prepared in the following manner: the adhesive composition (solution) is applied to the substrate, and the polymerization solvent is dried and removed, thereby forming an adhesive layer on the substrate. Afterwards, it can also be maintained for the purpose of adjusting the component transfer of the adhesive layer or adjusting the cross-linking reaction. In addition, when the adhesive composition is applied to the substrate to prepare the surface protection film, one or more solvents other than the polymerization solvent can be newly added to the adhesive composition so that it can be evenly applied to the substrate.

[0134] In addition, as a method for forming the adhesive layer when manufacturing the surface protection film of the present invention, a known method used in the manufacture of adhesive tapes is used. Specifically, for example, a roll coating method, a gravure coating method, a reverse coating method, a roller brush method, a spray coating method, an air knife coating method, an extrusion coating method using a die coater, etc. can be cited.

[0135] The thickness of the adhesive layer is preferably 1 μm to 30 μm, more preferably 2 μm to 28 μm, and even more preferably 3 μm to 25 μm. When the thickness of the adhesive layer is within the above range, a proper balance between removability and adhesiveness can be easily obtained, which is preferred.

[0136] For the surface protection film of the present invention, the total thickness is preferably 7 μm to 130 μm, more preferably 10 μm to 100 μm, and further preferably 20 μm to 50 μm. Within the above range, the adhesive properties (re-peelability, adhesion, adhesion stability, etc.), workability, and appearance properties are excellent, which is a preferred embodiment. It should be noted that the total thickness refers to the total thickness of all layers including the substrate, adhesive layer, separator and other layers.

[0137] <Spacer>

[0138] The surface protection film of the present invention may be bonded with a separator as needed for the purpose of protecting the surface of the pressure-sensitive adhesive layer.

[0139] As materials constituting the separator, there are paper and plastic films, and plastic films are preferably used from the viewpoint of excellent surface smoothness. As for the film, there is no particular limitation as long as it is a film capable of protecting the adhesive layer, and examples thereof include polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, and the like.

[0140] The thickness of the separator is usually about 5 μm to about 200 μm, preferably about 8 μm to about 100 μm, and more preferably about 10 μm to about 50 μm. The separator may be subjected to demoulding and antifouling treatment using a release agent such as polysiloxane, fluorine-containing, long-chain alkyl or fatty acid amide, silica powder, or antistatic treatment such as coating, kneading, or vapor deposition as needed.

[0141] The surface protection film disclosed herein may be implemented in a form including other layers in addition to the support and the adhesive layer. Examples of the other layers include an antistatic layer and a primer layer (anchor layer) that improves the anchoring property of the adhesive layer.

[0142] <How to use optical surface protection film>

[0143] As for the method of using the optical surface protection film of the present invention, for example, in the process of attaching the adhesive layer surface constituting the optical surface protection film of the present invention to the surface of a part of the printing part of the printed glass and performing ultraviolet curing, an ultraviolet curing resin is applied to the exposed part without attaching the optical surface protection film, so as to prevent the part of the optical surface protection film to which the ultraviolet curing resin is not applied from being deteriorated by ultraviolet rays. By this method of use, components such as the printing part can be protected, and it is desirable to prevent the curing reaction due to ultraviolet irradiation and the deterioration due to ultraviolet irradiation of the components.

[0144] <Optical components>

[0145] In the present invention, the surface of the adhesive layer of the optical surface protective film can be pasted to an optical component to protect the optical component. Even if the surface protective film is pasted and stored on an optical component or the like as an adherend of the adhesive layer and then heated, it can prevent the adhesive force from increasing, and the adhesive force stability is excellent, and the re-peelability is excellent, so it can be used for surface protection purposes (surface protective film) during processing, transportation, and delivery, so it is useful for protecting the surface of the optical component (polarizing plate, etc.). In addition, the color change of the adhesive layer constituting the surface protective film is suppressed, and the ultraviolet transmittance of the entire surface protective film is suppressed to be low, so that the surface protective film can be inspected in a state where it is attached to the optical component, and it can also be used for the purpose of suppressing the curing and deterioration accompanied by ultraviolet irradiation, so it is a preferred method.

[0146] [Example]

[0147] Hereinafter, several embodiments related to the present invention will be described, but it is not intended to limit the present invention to the scope shown in the specific examples. It should be noted that the "parts" and "%" in the following description are weight references unless otherwise specified. In addition, the blending amount (addition amount) in the table is shown.

[0148] In addition, each characteristic in the following description was measured or evaluated by the following method.

[0149] <Measurement of glass transition temperature (Tg) of acrylic polymer>

[0150] The glass transition temperature (Tg) (° C.) was determined from the following formula using the following literature value as the glass transition temperature Tgn (° C.) of a homopolymer formed from each monomer.

[0151] Formula: 1 / (Tg+273)=Σ[Wn / (Tgn+273)]

[0152] (Wherein, Tg (°C) represents the glass transition temperature of the copolymer, Wn (-) represents the weight fraction of each monomer, Tgn (°C) represents the glass transition temperature of the homopolymer formed by each monomer, and n represents the type of each monomer.)

[0153] Literature value:

[0154] 2-Ethylhexyl acrylate (2EHA): -70°C

[0155] 2-Hydroxyethyl acrylate (HEA): -15°C

[0156] In addition, as a literature value, "Synthesis, Design and New Application Development of Acrylic Resins" (published by the Central Business Development Center Publishing Department) was referenced.

[0157] <Measurement of Weight Average Molecular Weight (Mw) of Acrylic Polymer>

[0158] The weight average molecular weight (Mw) of the (meth)acrylic polymer used was measured using a GPC apparatus (HLC-8220GPC) manufactured by Tosoh Corporation. The measurement conditions are as follows.

[0159] Sample concentration: 0.2 wt% (tetrahydrofuran (THF) solution)

[0160] Injection volume: 10 μl

[0161] Eluent: Tetrahydrofuran

[0162] Flow rate: 0.6ml / min

[0163] Measurement temperature: 40℃

[0164] column:

[0165] Sample column: TSKguardcolumn SuperHZ-H (1 column) + TSKgel SuperHZM-H (2 columns)

[0166] Reference column: TSKgel SuperH-RC (1 column)

[0167] Detector: Differential Refractometer (RI)

[0168] In addition, the weight average molecular weight is calculated|required as a polystyrene conversion value. Moreover, when measuring the number average molecular weight (Mn), it is measured similarly to the weight average molecular weight (Mw) without limiting to an acrylic polymer.

[0169] <Determination of b* value>

[0170] The optical surface protective film (surface protective film) of each example was aged at room temperature for 7 days, then cut into a size of 50 mm in width and 50 mm in length, the separator was peeled off from the adhesive layer surface of the surface protective film, and then the "b* value" was measured using a high-speed integrating sphere transmittance meter (manufactured by Murakami Color Technology Research Institute, model "DOT-3C"). It should be noted that the b* value refers to the CIELab value.

[0171] The b* value of the surface protection film is 2 or less, preferably 1.6 or less, and more preferably 1.2 or less. If the b* value is within the range, the change in the color tone of the adhesive layer can be suppressed, and the adhesive layer can be inspected in a state of being attached to an optical component, which is a level that does not cause problems in actual use, and is therefore preferred.

[0172] <Measurement of transmittance>

[0173] For transmittance, a spectrophotometer U-4100 manufactured by Hitachi was used to make light of 300 nm to 400 nm wavelength vertically incident on the substrate surface of the optical surface protection film obtained by the embodiment and the comparative example, and the transmittance (%) was obtained. It should be noted that the transmittance (ultraviolet transmittance) represents the transmittance (%) at a wavelength of 365 nm among the transmittance of light of wavelengths within the range.

[0174] The transmittance is 2% or less, preferably 1.8% or less, and more preferably 1.6% or less. When the transmittance is greater than 2%, the transmittance of ultraviolet rays is high, and curing and degradation due to ultraviolet irradiation cannot be prevented, resulting in problems such as reduced strength of the printed portion, and is therefore not preferred.

[0175] <Initial adhesion (adhesion before heating)>

[0176] The surface protective film of each example was cut into a width of 25 mm, and the adhesive layer side of the optical surface protective film after peeling off the spacer was adhered to the surface of a glass plate (manufactured by Matsunami Glass Industries, Ltd., trade name: Micro SlideGlass S) using a 2 kg roller. The film was then left at room temperature (23°C, 50% RH) for 20 minutes, and then peeled off using a tension and compression testing machine (device name "TG-1kN", manufactured by Minebea) at a peeling angle of 180° and a peeling speed of 0.3 m / min, and the peeling force (adhesion to glass) of the surface protective film was measured as the "initial adhesion (adhesion before heating)" (N / 25 mm).

[0177] Measurement conditions: Temperature: 23±2℃, Humidity: 50±5%RH

[0178] <Adhesion after heating>

[0179] A test piece was prepared in the same manner as the initial adhesion test, and then heated at 100°C for 30 minutes, and then placed at room temperature (23°C, 50% RH) for 1 hour, and then the "adhesion after heating" (N / 25mm) was measured under the same conditions as the initial adhesion test.

[0180] As for the adhesion to glass, the initial (before heating) and the adhesion after heating are preferably 0.2N / 25mm or less, more preferably 0.15N / 25mm or less, and further preferably 0.1N / 25mm or less. When the adhesion is greater than 0.2N / 25mm, the adhesion becomes too high, making it difficult to achieve easy peelability (repeelability). For example, when used as a surface protection film, it is possible that adhesive residue will be generated on the adherend or the substrate will be damaged when it is peeled off later, so it is not preferred.

[0181] <Change rate of adhesive strength before and after heating>

[0182] The change rate of the adhesive force before and after heating was calculated by the following formula.

[0183] (Change rate of adhesive force before and after heating (%)) = 100 × (adhesive force after heating - adhesive force before heating) / (adhesive force before heating)

[0184] The change rate of the adhesive force before and after heating is less than ±30%, preferably less than ±25%, and more preferably less than ±20%. If the change rate is greater than ±30%, it will cause heavy peeling and peeling problems, so it is not preferred.

[0185] [Example 1]

[0186] [Preparation of acrylic polymer]

[0187] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, 200 parts by weight of 2-ethylhexyl acrylate (2EHA), 8 parts by weight of 2-hydroxyethyl acrylate (HEA), 0.4 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 312 parts by weight of ethyl acetate as a solvent were added, and nitrogen was introduced while slowly stirring, and the liquid temperature in the flask was maintained at about 65°C, and a polymerization reaction was performed for 6 hours, thereby preparing an acrylic polymer solution (40% by weight). The weight average molecular weight (Mw) of the acrylic polymer is 540,000, and the glass transition temperature (Tg) is -68°C.

[0188] [Preparation of acrylic adhesive solution]

[0189] The acrylic polymer solution (40 wt %) was diluted to 29 wt % with ethyl acetate, and 4 parts by weight of isocyanurate form of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industries, trade name: Coronate HX, “C / HX” in Table 1) as a crosslinking agent, 0.015 parts by weight of dibutyltin dilaurate (manufactured by Tokyo Fine Chemical, trade name: EMBILIZEROL-1, “OL-1” in Table 1, 0.5 wt % ethyl acetate solution) as a crosslinking catalyst, 2 parts by weight of 2,4-bis[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (trade name: Tinosorb S, manufactured by BASF) as a UV absorber, and 3 parts by weight of acetylacetone as a crosslinking retarder relative to the total solvent were added and stirred to obtain an acrylic adhesive solution (adhesive composition).

[0190] [Production of optical surface protection film]

[0191] The acrylic adhesive solution was applied to the surface opposite to the antistatic treated surface of a polyethylene terephthalate film with an antistatic treated layer (trade name: Diafoil T100G38, manufactured by Mitsubishi Plastics Co., Ltd., thickness 38 μm) as a substrate, and heated at 130° C. for 1 minute to form an adhesive layer with a thickness of 21 μm. Next, the silicone treated surface of a separator (polyethylene terephthalate film with a thickness of 21 μm treated with silicone on one side) was attached to the surface of the adhesive layer to prepare an optical surface protective film.

[0192] <Examples 2 to 5, Comparative Examples 1 to 3>

[0193] Based on the formulation shown in Table 1, an optical surface protection film was produced by the same method as in Example 1.

[0194] <Examples 6 and 7>

[0195] An optical surface protective film was produced in the same manner as in Example 1 based on the formulations shown in Table 1, using a 12 μm thick polyester film (manufactured by Mitsubishi Plastics Corporation, trade name: Diafoil T100G12) instead of the substrate used in Example 1.

[0196] <Examples 8 and 9>

[0197] Instead of the substrate used in Example 1, an optical surface protective film was produced in the same manner as in Example 1 based on the formulation shown in Table 1, using a polyester film having a thickness of 80 μm (manufactured by Toyobo Co., Ltd., trade name: SRF).

[0198] <Example 10>

[0199] [Preparation of polyurethane adhesive solution]

[0200] 85 parts by weight of PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000), 13 parts by weight of SANNIX GP3000 (manufactured by Sanyo Chemical Industries, Ltd., Mn=3000), and 2 parts by weight of SANNIX GP1000 (manufactured by Sanyo Chemical Industries, Ltd., Mn=1000) were used as polyols, 10 parts by weight of Tinuvin 384-2 (manufactured by BASF) as an ultraviolet absorber, 18 parts by weight of a polyfunctional alicyclic isocyanate compound (manufactured by Tosoh, trade name: Coronate HX) as a crosslinking agent, 0.08 parts by weight of a crosslinking catalyst (manufactured by Nippon Chemical Industry Co., Ltd., trade name: Nacem Fe(III)) as a crosslinking catalyst, 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and isopropyl myristate (manufactured by Kao, trade name: Exceparl) as a fatty acid ester as a wetting additive were added. IPM) 30 parts by weight and ethyl acetate 210 parts by weight as a diluent were added and stirred with a disperser to obtain a polyurethane adhesive solution (adhesive composition).

[0201] [Production of optical surface protection film]

[0202] The polyurethane adhesive composition was applied to the surface opposite to the antistatic treated surface of a polyethylene terephthalate film with an antistatic treated layer as a substrate (trade name: Diafoil T100G38, manufactured by Mitsubishi Plastics Co., Ltd., thickness 38 μm), and heated at 130° C. for 1 minute to form a 20 μm thick adhesive layer. Next, the silicone treated surface of a separator (polyethylene terephthalate film with a thickness of 25 μm and silicone treated on one side) was attached to the surface of the adhesive layer to prepare an optical surface protective film.

[0203] The above-mentioned compounding contents, various measurements and evaluation results of the optical surface protection films with separators of Examples and Comparative Examples are shown in Tables 1 and 2. The compounding amounts in Table 1 represent active ingredients.

[0204]

[0205] The details of the abbreviations in Table 1 above are as follows.

[0206] <Base material>

[0207] Diafoil T100G38: Thickness 38μm, manufactured by Mitsubishi Plastics Co., Ltd., trade name: Diafoil T100G38

[0208] Diafoil T100G12: Thickness 12μm, manufactured by Mitsubishi Plastics Co., Ltd., trade name: Diafoil T100G12

[0209] SRF: Thickness 80 μm, manufactured by Toyobo Co., Ltd., trade name: SRF

[0210] <Ultraviolet light absorber>

[0211] Tinosorb S: 2,4-bis[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine, trade name: Tinosorb S, manufactured by BASF, number of hydroxyl groups: 2)

[0212] Tinuvin 571: 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol, manufactured by BASF, trade name: Tinuvin 571, number of hydroxyl groups: 1)

[0213] Tinuvin 384-2: ester compound of phenylpropionic acid and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 side chain and linear alkyl), manufactured by BASF, trade name: Tinuvin 384-2, number of hydroxyl groups: 1)

[0214] Tinuvin 326: 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-tert-butylphenol, manufactured by BASF, trade name: Tinuvin 326, number of hydroxyl groups: 1)

[0215] KEMISORB 111: 2,2'-dihydroxy-4-methoxybenzophenone, manufactured by Chemipro Chemicals Co., Ltd., trade name: KEMISORB 111, number of hydroxyl groups: 2)

[0216] SEESORB 106: 2-Hydroxy-4-methoxybenzophenone, manufactured by SHIPRO Chemicals Co., Ltd., trade name: SEESORB106, number of hydroxyl groups: 4)

[0217] <Antioxidants>

[0218] Irganox 1010: Pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate], manufactured by BASF, trade name: Irganox 1010

[0219] <Wetting additives>

[0220] Isopropyl myristate, manufactured by Kao Corporation, trade name: Exceparl IPM

[0221]

[0222] It can be confirmed from Table 2 that in all the examples, the color change is suppressed, UV curing can be prevented, and the increase in adhesive force after heating can be prevented. On the other hand, in Comparative Example 1, the UV transmittance is slightly high, and the prevention of degradation during UV irradiation is insufficient. In Comparative Example 2, the UV absorber used has many hydroxyl groups, and the rate of change of adhesive force before and after heating is large, resulting in heavy peeling and not suitable for light peeling. In Comparative Example 3, since no UV absorber is used, it can be confirmed that the UV transmittance is very high, which is not suitable for use as a material (component) that is intended to prevent UV curing (absorption).

[0223] Industrial Applicability

[0224] The optical surface protection film disclosed herein is suitable as a surface protection film for protecting an optical member used as a constituent element of a liquid crystal display panel, a plasma display panel (PDP), an organic electroluminescent (EL) display, etc. during manufacture, transportation, etc. of the optical member. In particular, the optical surface protection film is useful as an optical member such as a polarizing plate, a wave plate, a phase difference plate, an optical compensation film, a brightness enhancement film, a light diffusion sheet, a reflective sheet for a liquid crystal display panel, or a member such as a display glass.

Claims

1. An optical component with an optical surface protective film, the optical component having an optical surface protective film having a substrate formed of a polyester resin and an adhesive layer formed of an adhesive composition provided on one side of the substrate, characterized in that: The b* value of the surface protection film is less than 2, The transmittance of the surface protection film at a wavelength of 365 nm is less than 2%. After the adhesive layer is attached to glass, the rate of change in adhesive strength after heating at 100° C. for 30 minutes relative to the adhesive strength before heating is less than ±30%. The optical member is at least one selected from the group consisting of a polarizing plate, a wave plate, a phase difference plate, an optical compensation film, a brightness enhancement film, a light diffusion sheet, a reflection sheet, and display glass.

2. The optical member with an optical surface protective film according to claim 1, wherein: The adhesive composition contains an ultraviolet absorber.

3. The optical member with an optical surface protective film according to claim 2, wherein: The number of hydroxyl groups in the molecule of the ultraviolet absorber is 3 or less.

4. The optical member with an optical surface protective film according to any one of claims 1 to 3, wherein: The adhesive composition contains a (meth)acrylic polymer and / or a polyurethane polymer as a base polymer.

5. The optical member with an optical surface protective film according to claim 4, wherein: The adhesive composition contains 0.1 to 20 parts by weight of the ultraviolet absorber based on 100 parts by weight of the base polymer.

6. The optical member with an optical surface protective film according to any one of claims 1 to 5, wherein: The thickness of the substrate is 6 μm to 100 μm, and the thickness of the adhesive layer is 1 μm to 30 μm.

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