JP2013072067A - Surface protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface protective film that can be favorably used for removing mask ink from the surface of an ITO film, can prevent occurrence of breaking in the ITO film in release operation in removal of the mask ink, and yet can sufficiently remove the mask ink from the ITO film.SOLUTION: The surface protective film is a surface protective film which includes a plastic film and a pressure sensitive adhesive layer formed on one side of the plastic film. The surface energy of the surface of the pressure sensitive adhesive layer is 25.0-50.0 mN/mm and the displacement magnitude of the unloading curve of the surface of the pressure sensitive adhesive layer is 800-5,000 nm.

Description

  The present invention relates to a surface protective film.

  An ITO film used as an electrode of the touch panel is printed with a conductive paste such as a silver paste for forming a conductive circuit. When printing such a conductive paste on an ITO film, a mask ink is coated in advance, and the mask ink is removed after printing.

  Removal of the mask ink from the ITO film is conventionally performed by attaching and peeling an adhesive tape or an adhesive sheet (Patent Document 1).

  However, with the recent thinning of the ITO film, in the removal of the mask ink using the conventional adhesive tape or adhesive sheet, the ITO film is broken during the peeling operation, and the ITO film is damaged. There is a problem of end.

  Moreover, in the conventional adhesive tape and adhesive sheet, when it is going to express favorable peelability for the purpose of solving the said problem, there exists a problem that mask ink cannot fully be removed from an ITO film.

JP 9-265191 A

  An object of the present invention is a surface protective film that can be suitably used for removing mask ink from an ITO film, and can prevent the ITO film from being broken during a peeling operation in removing mask ink. And it is providing the surface protection film which can fully remove mask ink from on ITO film.

The surface protective film of the present invention is
A surface protective film having a plastic film and a pressure-sensitive adhesive layer provided on one side of the plastic film,
The surface energy of the pressure-sensitive adhesive layer is 25.0 mN / mm to 50.0 mN / mm,
The unloading curve displacement amount on the surface of the pressure-sensitive adhesive layer is 800 nm to 5000 nm.

In a preferred embodiment, the surface protective film of the present invention comprises
The pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer to the ITO film is 0.30 N / 20 mm or less at a tensile speed of 0.3 m / min, and 1.60 N / 20 mm or less at a tensile speed of 10 m / min.
The pressure-sensitive adhesive layer has a surface adhesive strength of 0.35 N / 20 mm or more at a tensile speed of 0.3 m / min, with respect to a polyvinyl chloride film having a surface roughness Ra of 0.6 μm to 0.7 μm. 2.30 N / 20 mm or more at a speed of 10 m / min.

  In preferable embodiment, the thickness of the said pressure sensitive adhesive layer is 3.0 micrometers-20.0 micrometers.

  In preferable embodiment, the said pressure sensitive adhesive layer contains (meth) acrylic-type resin.

  In preferable embodiment, the thickness of the said plastic film is 40 micrometers-150 micrometers.

  In a preferred embodiment, the elastic modulus of the plastic film is 100 MPa to 1000 MPa.

  In a preferred embodiment, the plastic film includes at least one selected from soft polyvinyl chloride, polyethylene, and polypropylene.

  In preferable embodiment, the surface protection film of this invention has a peeling process layer on the surface on the opposite side to the said pressure-sensitive adhesive layer of the said plastic film.

  In a preferred embodiment, the surface protective film of the present invention has a release liner on the surface of the pressure-sensitive adhesive layer on the side opposite to the plastic film.

  In a preferred embodiment, the surface protective film of the present invention is used for removing mask ink on an ITO film.

  ADVANTAGE OF THE INVENTION According to this invention, it is a surface protection film which can be used suitably for removal of the mask ink from an ITO film, Comprising: It can prevent that a ITO film breaks at the time of peeling operation in removal of a mask ink. And the surface protection film which can fully remove mask ink from an ITO film can be provided.

≪Surface protection film≫
The surface protective film of the present invention has a plastic film and a pressure-sensitive adhesive layer provided on one side of the plastic film.

  In addition to the plastic film and the pressure-sensitive adhesive layer provided on one side of the plastic film, the surface protective film of the present invention may have any other layer as long as the object of the present invention is not impaired. Such a layer is preferably a release treatment layer provided on the surface opposite to the pressure-sensitive adhesive layer of the plastic film, or a release provided on the surface opposite to the plastic film of the pressure-sensitive adhesive layer. Examples include liners.

  In the surface protective film of the present invention, the surface energy of the pressure sensitive adhesive layer is 25.0 mN / mm to 50.0 mN / mm, preferably 25.5 mN / mm to 45.0 mN / mm, More preferably, it is 26.0 mN / mm-40.0 mN / mm. If the surface energy of the pressure-sensitive pressure-sensitive adhesive layer falls within the above range, moderate light releasability suitable for removal of the mask ink can be exhibited, and the ITO film can be removed during the peeling operation in removing the mask ink. Occurrence of folds can be prevented, and the mask ink can be sufficiently removed from the ITO film.

  In the surface protective film of the present invention, the unloading curve displacement of the surface of the pressure-sensitive adhesive layer is 800 nm to 5000 nm, preferably 800 nm to 3000 nm, more preferably 800 nm to 2000 nm, and further preferably 800 nm. ~ 1000 nm. If the amount of unloading curve displacement on the surface of the pressure-sensitive adhesive layer falls within the above range, a sufficient contact area can be obtained even on a surface with large irregularities such as mask ink. It can be easily peeled from above.

  In the surface protective film of the present invention, the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer to the ITO film is preferably 0.30 N / 20 mm or less, more preferably 0.01 N at a tensile speed of 0.3 m / min. / 20 mm to 0.25 N / 20 mm, and more preferably 0.05 N / 20 mm to 0.20 N / 20 mm. Here, the ITO film preferably has a surface roughness Ra of 0.02 μm to 0.05 μm.

  In the surface protective film of the present invention, the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer to the ITO film is preferably 1.60 N / 20 mm or less, more preferably 0.01 N / 20 mm at a tensile speed of 10 m / min. It is -1.60N / 20mm, More preferably, it is 0.1N / 20mm-1.59N / 20mm. Here, the ITO film preferably has a surface roughness Ra of 0.02 μm to 0.05 μm.

  In the surface protective film of the present invention, more preferably, the pressure-sensitive adhesive layer has an adhesive force on the surface of the ITO film of 0.30 N / 20 mm or less at a tensile speed of 0.3 m / min and a tensile speed of 10 m / min. 1.60 N / 20 mm or less. Here, the ITO film preferably has a surface roughness Ra of 0.02 μm to 0.05 μm.

  If the adhesive force of the surface of the pressure-sensitive adhesive layer to the ITO film is within the above range under the above conditions, it is possible to express moderate light releasability suitable for removing the mask ink, and a peeling operation for removing the mask ink. In this case, the ITO film can be prevented from being folded, and the mask ink can be sufficiently removed from the ITO film.

  The surface protective film of the present invention preferably has an adhesive force on the surface of the pressure-sensitive adhesive layer to a polyvinyl chloride film having a surface roughness Ra of 0.6 μm to 0.7 μm at a tensile speed of 0.3 m / min. Is 0.35 N / 20 mm or more, more preferably 0.35 N / 20 mm to 5.0 N / 20 mm, still more preferably 0.40 N / 20 mm to 3.0 N / 20 mm, and particularly preferably 0.40 N. / 20 mm to 2.0 N / 20 mm.

  The surface protective film of the present invention preferably has an adhesive strength of the surface of the pressure-sensitive pressure-sensitive adhesive layer to a polyvinyl chloride film having a surface roughness Ra of 0.6 μm to 0.7 μm at a tensile speed of 10 m / min. .30 N / 20 mm or more, more preferably 2.30 N / 20 mm to 10.0 N / 20 mm, still more preferably 2.30 N / 20 mm to 8.0 N / 20 mm, and particularly preferably 2.30 N / 20 mm. -6.0N / 20mm.

  More preferably, in the surface protective film of the present invention, the adhesive force of the surface of the pressure-sensitive adhesive layer to the polyvinyl chloride film having a surface roughness Ra of 0.6 μm to 0.7 μm has a tensile speed of 0.3 m / It is 0.35 N / 20 mm or more at min, and 2.30 N / 20 mm or more at a tensile speed of 10 m / min.

  The composition of the mask ink on the ITO film is polyvinyl chloride, and the surface roughness Ra is 0.6 μm to 0.7 μm, so that the surface roughness Ra is 0.6 μm to 0.7 μm. If the adhesive force of the surface of the pressure-sensitive adhesive layer to the film falls within the above range under the above conditions, the mask ink is sufficiently peeled off from the ITO film because the adhesion of the mask ink to the ITO film is sufficiently exceeded. Can do.

<Plastic film>
Any appropriate plastic film can be adopted as the plastic film as long as the effects of the present invention are not impaired.

  The thickness of the plastic film is preferably 40 μm to 150 μm, more preferably 45 μm to 120 μm, still more preferably 50 μm to 100 μm, and particularly preferably 50 μm to 90 μm. When the thickness of a plastic film is less than 40 micrometers, there exists a possibility that the bonding operation | work of the surface protection film of this invention may become difficult. When the thickness of the plastic film is larger than 150 μm, the followability to the edge of the mask ink on the ITO film may be deteriorated.

  The elastic modulus of the plastic film is preferably 100 MPa to 1000 MPa. If the material is selected so that the elastic modulus of the plastic film falls within this range, the effects of the present invention can be sufficiently exhibited. When the elastic modulus of the plastic film is less than 100 MPa, the plastic film is too flexible and the bonding property may be deteriorated. When the elastic modulus of the plastic film is larger than 1000 MPa, the followability to the edge of the mask ink on the ITO film may be deteriorated.

  Any appropriate material can be adopted as the material of the plastic film. Preferred examples of such a material include soft polyvinyl chloride (soft PVC), polyethylene (PE), and polypropylene (PP). This is because these materials have an elastic modulus in the range of 100 MPa to 1000 MPa, and thus have good bonding properties and good followability to the edge of the mask ink on the ITO film. That is, the plastic film is preferably a soft polyvinyl chloride film, a polyethylene film, or a polypropylene film.

  As a material for the plastic film, soft polyvinyl chloride is particularly preferable. When soft polyvinyl chloride is used as the material for the plastic film, the amount of plasticizer bleed on the pressure-sensitive adhesive surface and the pressure-sensitive adhesive surface / plastic film interface is small even if a plasticizer is added to the pressure-sensitive adhesive. It is. On the other hand, when polyethylene or polypropylene is used as the material for the plastic film, the plasticizer bleeds to the pressure-sensitive adhesive surface or the pressure-sensitive adhesive surface / plastic film interface when a plasticizer is added to the pressure-sensitive adhesive. May occur, which may cause throwing destruction (glue residue) and contamination. That is, the plastic film is particularly preferably a soft polyvinyl chloride film.

  The plastic film may contain a plasticizer. The content ratio of the plasticizer in the plastic film is preferably 0.5% by weight to 500% by weight with respect to the material (resin material such as soft polyvinyl chloride, polyethylene, polypropylene) in the plastic film, More preferably, it is 1.0 weight%-40 weight%, More preferably, it is 2.0 weight%-30 weight%. By keeping the content of the plasticizer in the plastic film within the above range, the effect of the present invention can be expressed more effectively. When there is too much content rate of the plasticizer in a plastic film, a plastic film will become soft too much and there exists a possibility that bonding property may fall. When the content ratio of the plasticizer in the plastic film is too small, the plastic film becomes too hard, and the followability to the edge of the mask ink on the ITO film may be lowered.

  Examples of the plasticizer include phthalate ester-based, trimellitic ester-based (Dainippon Ink Co., Ltd., W-700, trimellitic trioctyl, etc.), adipate ester-based (manufactured by J-Plus, D620, dioctyl adipate, diisononyl adipate, etc.), phosphate esters (such as tricresyl phosphate), adipic acid esters, citrate esters (such as acetyl citrate tributyl), sebacic acid esters, aceleic acid esters, maleic acid esters Benzoic acid ester, polyether polyester, epoxy polyester (epoxidized soybean oil, epoxidized linseed oil, etc.), polyester (low molecular polyester comprising carboxylic acid and glycol, etc.) and the like. In the present invention, it is preferable to use an ester plasticizer. Only one type of plasticizer may be used, or two or more types may be used.

<Pressure-sensitive adhesive layer>
Any appropriate pressure-sensitive adhesive layer can be adopted as the pressure-sensitive adhesive layer as long as the effects of the present invention are not impaired.

  The thickness of the pressure sensitive adhesive layer is preferably 3.0 μm to 20.0 μm, more preferably 3.5 μm to 18.0 μm, still more preferably 4.0 μm to 15.0 μm, particularly preferably. 4.5 μm to 13.5 μm. When the thickness of the pressure-sensitive adhesive layer is less than 3.0 μm, the mask ink may not be sufficiently removed from the ITO film. When the thickness of the pressure-sensitive adhesive layer is larger than 20.0 μm, the adhesive force becomes too large, and the ITO film may be easily broken during the peeling operation in removing the mask ink.

  The pressure-sensitive adhesive layer preferably contains a (meth) acrylic resin. By including the (meth) acrylic resin in the pressure-sensitive adhesive layer, it is possible to efficiently achieve both an appropriate adhesive property that can exhibit the effect of the present invention and a sufficient removability of the mask ink from the ITO film. .

  Here, in this specification, “(meth) acryl” means acryl and / or methacryl, and “(meth) acrylate” means acrylate and / or methacrylate.

  When the pressure-sensitive pressure-sensitive adhesive layer contains a (meth) acrylic resin, the content ratio of the (meth) acrylic resin in the pressure-sensitive pressure-sensitive adhesive layer can be appropriately set according to the purpose, but is preferably 50% by weight. More preferably, it is 60 wt% to 98 wt%, more preferably 65 wt% to 95 wt%, particularly preferably 70 wt% to 90 wt%, and most preferably 75 wt% to 85% by weight.

  The said (meth) acrylic-type resin is resin comprised from the monomer component which contains a (meth) acrylic-type monomer as a main monomer. The content ratio of the (meth) acrylic monomer in the monomer component constituting the (meth) acrylic resin is preferably 50% by weight or more, more preferably 70% by weight to 100% by weight, and still more preferably 90% by weight to 100%. % By weight, particularly preferably 95% by weight to 100% by weight. The monomer in the monomer component may be only one type or two or more types.

  As a (meth) acrylic-type monomer, Preferably, (meth) acrylic acid ester and (meth) acrylic acid are mentioned.

  Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic. Isobutyl acid, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, ( 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, Undecyl (meth) acrylate, dodecyl (meth) acrylate, (meth) acrylic Carbon number, such as tridecyl lurate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, lauryl (meth) acrylate (Meth) acrylic acid alkyl ester having an alkyl group of 1-20. Among these (meth) acrylic acid esters, preferably, (meth) acrylic acid alkyl esters having 1 to 12 carbon atoms, more preferably (meth) alkyl groups having 1 to 8 carbon atoms. Acrylic acid alkyl ester. Only one (meth) acrylic acid ester may be used, or two or more may be used.

  The monomer component constituting the (meth) acrylic resin preferably contains at least one selected from a hydroxyl group-containing monomer and a carboxyl group-containing monomer in order to sufficiently exhibit the effects of the present invention. More preferably, it is a hydroxyl group-containing monomer.

  When the monomer component constituting the (meth) acrylic resin contains a hydroxyl group-containing monomer, the content ratio of the hydroxyl group-containing monomer in the monomer component constituting the (meth) acrylic resin is preferably 0.5% by weight. -10% by weight. When the monomer component constituting the (meth) acrylic resin includes a carboxyl group-containing monomer, the content ratio of the carboxyl group-containing monomer in the monomer component constituting the (meth) acrylic resin is preferably 0.01. % By weight to 0.1% by weight. Thus, when the monomer component constituting the (meth) acrylic resin includes at least one selected from a hydroxyl group-containing monomer and a carboxyl group-containing monomer, when a crosslinking agent is used, A crosslinking reaction can be efficiently generated, and the effects of the present invention can be sufficiently exhibited. Furthermore, the content ratio of the hydroxyl group-containing monomer in the monomer component constituting the (meth) acrylic resin and the content ratio of the carboxyl group-containing monomer in the monomer component constituting the (meth) acrylic resin are within the above range. By adjusting so as to be within the range, it is possible to effectively prevent the ITO film from being folded during the peeling operation in removing the mask ink. The content ratio of the hydroxyl group-containing monomer in the monomer component constituting the (meth) acrylic resin and the content ratio of the carboxyl group-containing monomer in the monomer component constituting the (meth) acrylic resin are more than the above range. When the amount is too large, the adhesive force to ITO becomes too large, and the ITO film may be easily broken during the peeling operation in removing the mask ink.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, allyl alcohol, and the like. Only one type of hydroxyl group-containing monomer may be used, or two or more types may be used.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, crotonic acid, maleic acid, fumaric acid, and itaconic acid. Only one type of carboxyl group-containing monomer may be used, or two or more types may be used.

  The pressure sensitive adhesive layer preferably contains a crosslinking agent. When the pressure-sensitive pressure-sensitive adhesive layer contains a cross-linking agent, the content of the cross-linking agent in the pressure-sensitive pressure-sensitive adhesive layer can be appropriately set according to the purpose, but preferably the main resin component (preferably, (meth) acrylic To 0.1 wt% to 10 wt%, more preferably 0.2 wt% to 8.0 wt%, still more preferably 0.5 wt% to 6.0 wt%. Particularly preferred is 1.0% to 5.0% by weight, and most preferred is 1.2% to 4.0% by weight. By keeping the content of the cross-linking agent in the pressure-sensitive adhesive layer within the above range, an appropriate cross-linking reaction can be caused, and the ITO film may be folded during the peeling operation in removing the mask ink. Can be effectively prevented.

  Examples of the crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a metal alkoxide crosslinking agent, a metal chelate crosslinking agent, a metal salt crosslinking agent, and a carbodiimide crosslinking. Agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents and the like. Among these crosslinking agents, an epoxy-based crosslinking agent and an isocyanate-based crosslinking agent are preferable, and an isocyanate-based crosslinking agent is more preferable because the effects of the present invention can be sufficiently exhibited.

  The pressure sensitive adhesive layer may contain a plasticizer. When the pressure-sensitive pressure-sensitive adhesive layer contains a plasticizer, the content of the plasticizer in the pressure-sensitive pressure-sensitive adhesive layer can be appropriately set according to the purpose, but is preferably 10% by weight to 60% by weight, more Preferably, it is 10 to 30% by weight. By keeping the content of the plasticizer in the pressure-sensitive adhesive layer within the above range, the effect of the present invention can be expressed more effectively. When the content ratio of the plasticizer in the pressure-sensitive adhesive layer is more than 60% by weight, the pressure-sensitive adhesive layer becomes too flexible, and there is a possibility that adhesive residue and adherend contamination are likely to occur. In addition, when the elastic modulus of the pressure-sensitive adhesive layer is within the range of 0.01 MPa to 1.0 MPa, it may not be necessary to include a plasticizer.

  Examples of the plasticizer include phthalate ester-based, trimellitic ester-based (Dainippon Ink Co., Ltd., W-700, trimellitic trioctyl, etc.), adipate ester-based (manufactured by J-Plus, D620, dioctyl adipate, diisononyl adipate, etc.), phosphate esters (such as tricresyl phosphate), adipic acid esters, citrate esters (such as acetyl citrate tributyl), sebacic acid esters, aceleic acid esters, maleic acid esters Benzoic acid ester, polyether polyester, epoxy polyester (epoxidized soybean oil, epoxidized linseed oil, etc.), polyester (low molecular polyester comprising carboxylic acid and glycol, etc.) and the like. In the present invention, it is preferable to use an ester plasticizer. Only one type of plasticizer may be used, or two or more types may be used.

  The pressure-sensitive adhesive layer may contain any appropriate catalyst in order to promote a crosslinking reaction or the like. When the pressure-sensitive pressure-sensitive adhesive layer contains a catalyst, the content of the catalyst in the pressure-sensitive pressure-sensitive adhesive layer can be appropriately set according to the purpose, but is preferably 0.01 wt% to 10 wt%. Preferably it is 0.05 weight%-5 weight%. By keeping the content of the catalyst in the pressure-sensitive adhesive layer within the above range, the effect of the present invention can be expressed more effectively.

  Examples of such catalysts include tetraisopropyl titanate, tetra-n-butyl titanate, tin octylate, lead octylate, cobalt octylate, zinc octylate, calcium octylate, lead naphthenate, cobalt naphthenate, and dibutyltindi Organometallic compounds such as acetate, dibutyltin dioctate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin maleate; butylamine, dibutylamine, hexylamine, t-butylamine, ethylenediamine, isophoronediamine, imidazole, lithium hydroxide, potassium hydroxide, Basic compounds such as sodium methylate; p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid, monoalkyl phosphoric acid, dialkyl phosphoric acid, phosphoric acid of β-hydroxyethyl acrylate Ester, monoalkyl phosphite, acidic compounds such as dialkyl phosphite; and the like. Only one type of catalyst may be used, or two or more types of catalysts may be used.

  The pressure-sensitive adhesive layer may contain any appropriate additive as long as the effects of the present invention are not impaired. Examples of such additives include ultraviolet absorbers, fillers, anti-aging agents, tackifiers, pigments, dyes, and silane coupling agents.

<Peeling treatment layer>
The surface protective film of the present invention may have a release treatment layer on the surface of the plastic film opposite to the pressure-sensitive adhesive layer.

  The release treatment layer is preferably formed by subjecting the surface of the plastic film opposite to the pressure-sensitive adhesive layer to a back treatment with a release treatment agent.

  Any appropriate release treatment agent can be adopted as the release treatment agent. Examples of such release treatment agents include silicone release agents, fluorine release agents, long-chain alkyl release agents, low molecular weight polyethylene release agents, low molecular weight polypropylene release agents, rubber polymers, and phosphate ester types. Surfactant etc. are mentioned.

<Release liner>
The surface protective film of the present invention may have a release liner on the surface of the pressure-sensitive adhesive layer on the side opposite to the plastic film.

  Any appropriate separator can be adopted as the release liner. As such a release liner, for example, a base material having a release layer such as a plastic film or paper surface-treated with a release agent such as silicone-based, long-chain alkyl-based, fluorine-based, molybdenum sulfide; polytetrafluoroethylene, Low-adhesive substrate made of a fluoropolymer such as polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene copolymer, chlorofluoroethylene / vinylidene fluoride copolymer; And a low-adhesive substrate made of a nonpolar polymer such as a resin (for example, polyethylene, polypropylene, etc.).

≪Method for producing surface protective film≫
The surface protective film of the present invention can be produced by any appropriate method.

  The surface protective film of the present invention is preferably applied by applying a pressure-sensitive adhesive composition as a material for the pressure-sensitive pressure-sensitive adhesive layer on a plastic film, and drying it by applying any appropriate temperature for any appropriate time. It can be produced by forming a pressure sensitive adhesive layer on a plastic film. At this time, if necessary, a release treatment layer may be formed on the surface opposite to the pressure-sensitive adhesive layer of the plastic film by any appropriate method, or the plastic film of the pressure-sensitive adhesive layer. A release liner may be formed on the opposite surface.

  The pressure-sensitive adhesive composition preferably contains a (meth) acrylic resin, a cross-linking agent, and a catalyst described in the section of <Pressure-sensitive pressure-sensitive adhesive layer> in the section of <Surface protective film>, if necessary. More preferably, a plasticizer is included. Further, it contains any appropriate additive as required.

  Examples of the coating method include a method using a bar coater, a gravure coater, a spin coater, a roll coater, a knife coater, an applicator and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. Parts mean parts by weight.

[Surface energy]
The surface energy of the pressure-sensitive adhesive layer surface was calculated by the following method.
First, the contact angle (θ (°)) of each surface of the pressure-sensitive adhesive layer was measured using water and methylene iodide.
Next, the surface energy (γ _s ) was calculated by the following equation using this measured value and the surface energy value of the contact angle measurement liquid (a known value in the literature).
γ _s = γ _s ^d + γ _s ^p (1)
γ _L = γ _L ^d + γ _L ^p (2)
(1 + cos θ) γ _L = 2 (γ _s ^d γ _L ^d ) ^1/2 +2 (γ _s ^p γ _L ^p ) ^1/2 (3)
However,
γ _s ^d : dispersion component in surface energy of pressure-sensitive adhesive layer γ _s ^p : polar component in surface energy of pressure-sensitive adhesive layer γ _L : surface energy of water or methylene iodide γ _L ^d : water or methylene iodide dispersive component of the surface energy of the gamma _{L ^p:} polar component of the surface energy of water or methylene iodide Incidentally, water and methylene iodide, literature values known surface energy is as follows.
Water: γ _L ^d = 21.8 mJ / m ² , γ _L ^p = 51.0 mJ / m ²
Methylene iodide: γ _L ^d = 49.5 mJ / m ² , γ _L ^p = 1.3 mJ / m ²
The contact angle between water and methylene iodide is approximately 1 μL of water (on the surface of the pressure-sensitive adhesive layer in an environment of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% Rh according to JIS-Z8703. Distilled water) or methylene iodide droplets were dropped, and a surface contact angle meter ("CA-X", manufactured by Kyowa Interface Science Co., Ltd.) was used, and after 30 seconds, the three-point method (using the average value) was used. It was measured.

[Adhesive surface unloading curve displacement evaluation]
With the nanoindenter, the amount of unloading curve displacement on the surface of the pressure-sensitive adhesive layer was measured under the following conditions.
Each measurement sample was cut into about 1 cm square and then fixed to a predetermined holder as a measurement sample.
Measuring device: Nanoindenter (manufactured by Hysitron Inc., “Tribo Scope”)
Working indenter: Berkovich (triangular pyramid type)
Measuring method: Single indentation measurement Measuring temperature: Room temperature (25 ° C)
Indentation depth setting: about 1200nm

[Evaluation of ink removal rate]
A sample cut to a width of 65 mm and a length of 230 mm was affixed to an ITO film with a mask ink under the following conditions, and then allowed to stand at 23 ° C. and 50% RH for 5 hours. The ink was removed. Take a photo of the glue surface and ITO film of the sample after ink removal, print it on A4 paper, cut out each ink application site, measure the total weight and the weight of the ink site applied to the tape adhesive surface, and remove the ink The rate was calculated.
Pasting atmosphere: 23 ° C, 50% RH
Substrate: ITO film with mask ink Bonding conditions: linear pressure 17.5 N / cm, speed 3.0 m / min

[Evaluation of film breakability]
A sample cut to a width of 65 mm and a length of 230 mm was affixed to an ITO film with a mask ink under the following conditions, and then allowed to stand at 23 ° C. and 50% RH for 5 hours. The degree of film folding was confirmed.
Pasting atmosphere: 23 ° C, 50% RH
Substrate: ITO film with mask ink Bonding condition: Linear pressure 17.5 N / cm Speed 3.0 m / min
Evaluation was shown by (circle) or x by the following reference | standard.
○: The film does not bend when the protective film is peeled off.
X: When the protective film is peeled off, the film is bent, and the ITO film is marked with a fold.

[Evaluation of adhesion to ITO film]
About the sample cut | disconnected by width 20mm and length 100mm, the adhesive force was measured on condition of the following.
Measuring device: Instron type tensile tester (manufactured by Shimadzu Corporation, “AUTOGRAPH AG-IS”)
Measurement atmosphere: 23 ° C., 50% RH
Substrate: ITO film with surface roughness Ra = 0.02 to 0.05 μm (ITO surface)
Bonding conditions: linear pressure 17.5 N / cm, speed 3.0 m / min
Measurement conditions: 180 ° peel, 0.3 m / min and 10 m / min

[Evaluation of adhesive strength to PVC film]
About the sample cut | disconnected by width 20mm and length 100mm, the adhesive force was measured on condition of the following.
Measuring device: Instron type tensile tester (manufactured by Shimadzu Corporation, “AUTOGRAPH AG-IS”)
Measurement atmosphere: 23 ° C., 50% RH
Substrate: Polyvinyl chloride (PVC) film with surface roughness Ra = 0.67 μm Bonding conditions: linear pressure 17.5 N / cm, speed 3.0 m / min
Measurement conditions: 180 ° peel, 0.3 m / min and 10 m / min

[Example 1]
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of an adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyltin dilaurate A toluene solution of a pressure-sensitive adhesive consisting of 0.3 part by weight of a system catalyst ("Enabilizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 10 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 1.

[Example 2]
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of an adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyltin dilaurate A toluene solution of a pressure-sensitive adhesive consisting of 0.3 part by weight of a system catalyst ("Enabilizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 5 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 1.

Example 3
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 4.1 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.3 parts by weight of a tin dilaurate catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 13.5 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 1.

Example 4
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 2.34 parts by weight of an isocyanate-based crosslinking agent (aliphatic polyisocyanate resin, “Coronate HX”, manufactured by Nippon Polyurethane), 20 parts by weight of adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.3 parts by weight of a tin dilaurate catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 10 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 1.

Example 5
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3.17 parts by weight of an isocyanate-based crosslinking agent (aliphatic polyisocyanate resin, “Coronate HX”, manufactured by Nippon Polyurethane), 20 parts by weight of adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.3 parts by weight of a tin dilaurate catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 13.5 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 1.

Example 6
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3.17 parts by weight of an isocyanate-based crosslinking agent (aliphatic polyisocyanate resin, “Coronate HX”, manufactured by Nippon Polyurethane), 20 parts by weight of adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.3 parts by weight of a tin dilaurate catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 6.5 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 1.

[Comparative Example 1]
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of acrylic copolymer (Mw = 800,000) composed of butyl acrylate (BA) / acrylonitrile (AN) / acrylic acid (AA) = 85/15 / 2.5 (weight ratio), melamine-based crosslinking Agent (butanol-modified melamine formaldehyde resin, "Super Becamine J-820-60N", manufactured by Nippon Polyurethane) 10 parts by weight, DOP plasticizer (bis (2-ethylhexyl) phthalate, manufactured by J-Plus) 60 parts by weight, paratoluene A toluene solution of an adhesive composed of 0.7 part by weight of sulfonic acid (first grade, manufactured by Kishida Chemical) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 7 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 2.

[Comparative Example 2]
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of an adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyltin dilaurate A toluene solution of a pressure-sensitive adhesive consisting of 0.3 part by weight of a system catalyst ("Enabilizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 15 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 2.

[Comparative Example 3]
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 4.1 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.3 parts by weight of a tin dilaurate catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 15 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 2.

[Comparative Example 4]
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 1.16 parts by weight of an isocyanate-based crosslinking agent (aliphatic polyisocyanate resin, “Coronate HX”, manufactured by Nippon Polyurethane), 20 parts by weight of adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.7 parts by weight of a tin dilaurate-based catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 10 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 2.

[Comparative Example 5]
2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / acrylic acid (AA) / hydroxyethyl acrylate (HEA) = 30/70/5 / 0.2 / 0.8 (weight ratio) 100 parts by weight of an acrylic copolymer composed of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), polystyrene resin (“Toyostyrene H700”, Toyo Styrene Co., Ltd.) A toluene solution of a pressure-sensitive adhesive consisting of 5 parts by weight of a company) and 0.5 parts by weight of a dioctyltin dilaurate catalyst ("Environizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution is applied to one side of a base material layer made of a polyethylene film (thickness 60 μm, elastic modulus 200 MPa), and then dried at 80 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 5 μm on the surface of the polyethylene film. did.
Various evaluation results are shown in Table 2.

[Comparative Example 6]
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / vinyl acetate (VAc) / acrylic acid (AA) = 100/80/5 (weight ratio), an epoxy-based crosslinking agent (“TETRAD-C “Toluene / ethyl acetate / methyl ethyl ketone (MEK) mixed solution of pressure-sensitive adhesive comprising 2.0 parts by weight of Mitsubishi Gas Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution is applied to one side of a base material layer made of a polyethylene film (thickness 60 μm, elastic modulus 200 MPa), and then dried at 80 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 5 μm on the surface of the polyethylene film. did.
Various evaluation results are shown in Table 2.

[Comparative Example 7]
A flexible PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) and 0.7 parts by weight of a fatty acid amide is prepared for 100 parts by weight of a PVC resin having a polymerization degree P = 1050. did. The soft PVC film had a thickness of 70 μm and an elastic modulus of 550 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), Isocyanate-based crosslinking agent (aliphatic polyisocyanate resin, “Coronate HX”, manufactured by Nippon Polyurethane) 3.0 parts by weight, adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation) 20 parts by weight, dioctyl A toluene solution of a pressure-sensitive adhesive consisting of 0.7 parts by weight of a tin dilaurate-based catalyst (“Environizer OL-1”, manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive adhesive layer having a thickness of 10 μm on the surface of the soft PVC film.
Various evaluation results are shown in Table 2.

Example 7
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of an adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyltin dilaurate A toluene solution of a pressure-sensitive adhesive consisting of 0.3 part by weight of a system catalyst ("Enabilizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 10 μm on the surface of the soft PVC film.
Next, 60 parts by weight of a silicone resin (KS-723A, manufactured by Shin-Etsu Chemical Co., Ltd.), 40 parts by weight of a silicone resin (KS-723B, manufactured by Shin-Etsu Chemical Co., Ltd.), 10 parts by weight of a tin-based catalyst (Cat-PS3, manufactured by Shin-Etsu Chemical Co., Ltd.) Parts, acrylic copolymer (MMA (methyl methacrylate) / BA (butyl acrylate) / HEA (hydroxyl ethyl acrylate) = 70/30/10) 100 parts by weight of solution mixed, pressure sensitive adhesive for base material layer It was applied to the opposite surface of the layer and dried, and a release treatment layer having an average thickness of 0.5 μm was provided to produce a surface protective film with a release treatment layer.

Example 8
A soft PVC film containing 27 parts by weight of a DOP plasticizer (bis (2-ethylhexyl phthalate), manufactured by J-Plus) with respect to 100 parts by weight of a PVC resin having a polymerization degree P = 1050 was prepared. The soft PVC film had a thickness of 70 μm and an elastic modulus of 520 MPa.
100 parts by weight of an acrylic copolymer composed of 2-ethylhexyl acrylate (2EHA) / ethyl acrylate (EA) / methyl methacrylate (MMA) / hydroxyethyl acrylate (HEA) = 30/70/5/4 (weight ratio), 3 parts by weight of an isocyanate-based crosslinking agent (aromatic polyisocyanate resin, “Coronate L”, manufactured by Nippon Polyurethane), 20 parts by weight of an adipic acid-based polyester plasticizer (“Polysizer W-360ELS”, manufactured by DIC Corporation), dioctyltin dilaurate A toluene solution of a pressure-sensitive adhesive consisting of 0.3 part by weight of a system catalyst ("Enabilizer OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.) was prepared.
This pressure-sensitive adhesive solution was applied to one side of a base material layer made of a soft PVC film, and then dried at 150 ° C. for 60 seconds to form a pressure-sensitive pressure-sensitive adhesive layer having a thickness of 10 μm on the surface of the soft PVC film.
Next, the sheet | seat which has this pressure sensitive adhesive layer was bonded together to the peeling liner (Diafoil MRF38, product made from Mitsubishi resin), and the surface protection film with a peeling liner was produced.

  As shown in Tables 1 and 2, the surface protective film of the present invention is a surface protective film that can be suitably used for removing the mask ink from the ITO film, and the ITO is used during the peeling operation in removing the mask ink. It can be seen that folding of the film can be prevented, and the mask ink can be sufficiently removed from the ITO film.

  The surface protective film of the present invention can be suitably used for removing mask ink from the ITO film.

Claims (10)

A surface protective film having a plastic film and a pressure-sensitive adhesive layer provided on one side of the plastic film,
The surface energy of the pressure-sensitive adhesive layer is 25.0 mN / mm to 50.0 mN / mm,
The amount of unloading curve displacement on the surface of the pressure-sensitive adhesive layer is 800 nm to 5000 nm.
Surface protective film. The adhesive force of the surface of the pressure-sensitive adhesive layer to the ITO film is 0.30 N / 20 mm or less at a tensile speed of 0.3 m / min, and 1.60 N / 20 mm or less at a tensile speed of 10 m / min,
The pressure-sensitive adhesive layer has a surface adhesive strength of 0.35 N / 20 mm or more at a tensile speed of 0.3 m / min, with respect to a polyvinyl chloride film having a surface roughness Ra of 0.6 μm to 0.7 μm. 2.30 N / 20 mm or more at a speed of 10 m / min,
The surface protective film according to claim 1.   The surface protection film of Claim 1 or 2 whose thickness of the said pressure sensitive adhesive layer is 3.0 micrometers-20.0 micrometers.   The surface protection film in any one of Claim 1 to 3 in which the said pressure sensitive adhesive layer contains (meth) acrylic-type resin.   The surface protective film according to claim 1, wherein the plastic film has a thickness of 40 μm to 150 μm.   The surface protection film according to any one of claims 1 to 5, wherein the elastic modulus of the plastic film is 100 MPa to 1000 MPa.   The surface protection film according to any one of claims 1 to 6, wherein the plastic film contains at least one selected from soft polyvinyl chloride, polyethylene, and polypropylene.   The surface protection film in any one of Claim 1-7 which has a peeling process layer in the surface on the opposite side to the said pressure-sensitive adhesive layer of the said plastic film.   The surface protection film in any one of Claim 1-8 which has a peeling liner in the surface on the opposite side to the said plastic film of the said pressure sensitive adhesive layer.   The surface protective film according to claim 1, which is used for removing mask ink on an ITO film.