JP3996800B2 - Surface protective film and laminate using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a surface protective film for sticking to the surface of a polarizing plate or a retardation plate to protect the polarizing plate / retardation plate. Moreover, it is related with the laminated body to which such a surface protection film was stuck.
[0002]
[Prior art]
  In the manufacturing process of the polarizing plate and the retardation plate, after the surface protective film is stuck to prevent the surface from being stained and scratched, the opposite surface is subjected to adhesive processing (the adhesive processing surface is covered with a release film) It is made to be in a state) and it is cut into a desired size. The layer structure of the laminate is
    "Surface Protective Film / Polarizing Plate / Phase Difference Plate / Adhesive Layer / Peeling Film"
It is. The cut products are handled in a stacked state until they are used in a later process.
[0003]
  The above surface protective film is typically slightly sticky on one side of the base film.Adhesive layerThat is,
    “Base film / Slight adhesive layer”
(A release film is placed over the slightly adhesive layer). Here, the slight pressure-sensitive adhesive layer is a layer for sticking the surface protective film to the polarizing plate / retardation plate, and the slight pressure-sensitive adhesive layer is a surface protective film after achieving the purpose of surface protection. This is because when peeling and removing from the polarizing plate / retardation plate of the liquid crystal display panel, smooth peeling is performed and no adhesive residue is left.
[0004]
  In the laminate having the layer configuration of “surface protective film / polarizing plate / retardation plate / adhesive layer (/ release film)”,
  1. The adhesive protrudes from the cut surface of the cut product and adheres to the surface of the surface protection film. As a result, it interferes with the inspection or causes stickiness during shipment, thereby hindering the handling of the cut product. That there is,
  2. The upper and lower polarizing plates and retardation plates of the stacked product after cutting become sticking to each other due to static electricity, making it difficult to handle, feeling pain due to electrostatic shock when handling manually, and destroying the TFT element when peeling There are things,
  3. When the adhesive attached to the surface of the cut surface protection film is wiped off with a solvent, the appearance of the surface protection film may change. However, it is regarded as a defect of the polarizing plate and retardation plate itself, and the product yield may be reduced.
  4). When marking the polarization angle and phase angle with oil-based ink or pressing the inspection mark on the surface protection film of the cut product, it should be possible to print cleanly without causing repelling,
In addition, when rolled or cut and stacked, other sheets touch the printed surface and the ink does not transfer.
  5. After marking the polarization angle and phase angle with oil-based ink on the surface protection film of the cut product or pressing the inspection mark, the appearance may change when wiped with a solvent. In the inspection process, even if it is a defect of only the surface protection film, it is regarded as a defect of the polarizing plate / retardation plate itself, and the product yield may be reduced, and the marking or inspection mark is wiped off with a solvent. It is difficult to remove or mark (If you cannot remove it later, the product yield will be reduced)
It is easy to cause troubles. Accordingly, it is desired that all these problems be solved.
[0005]
  In order to deal with 1 or 2 of the above problems, for example, the following proposals have been made.
[0006]
(A) In Japanese Patent Application Laid-Open No. 9-113726 according to the applicant's application, the outer surface of a protective film for attaching to the surface of a polarizing plate or a phase plate (retardation plate) is peel strength by a cellophane adhesive tape. Shows a surface protective film formed on a weakly peeled surface of 50 to 400 g / 24 mm (0.49 to 3.92 N / 24 mm). In the publication,
  ・ Weak release surface can be formed by coating with a release agent mainly composed of a polymer having a long-chain alkyl group or a fluoroalkyl group (in the examples, graft polymerization of alkyl carbamate release agent, perfluoroalkyl acrylate) Used release treatment agent),
  ・ Formation of weak release surface is performed by coating with a treatment agent consisting of a mixture of a release treatment agent and an antistatic agent, or by coating with a release treatment agent on a coating layer with an antistatic agent.
Is also described. It also describes that an adhesive layer is provided on the surface of the protective film opposite to the weakly peeled surface, and a release sheet is coated thereon.
[0007]
(B) Japanese Patent Application Laid-Open No. 11-256115 discloses a surface protective film in which an antistatic layer is provided on one side of a polyester film, an antifouling layer is provided on the layer, and a slightly adhesive layer is provided on the opposite side. It is shown. In addition, an antistatic layer is provided on one side of the polyester film,
A surface protective film is shown in which a slightly adhesive layer is provided on the layer and an antifouling layer is provided on the opposite side. Examples of the antifouling layer include a layer mainly composed of a copolymer obtained by long-chain alkylating polyvinyl alcohol or polyethyleneimine with chlorinated alkyloyl or alkyl isocyanate.
[0008]
(C) In JP 2000-26817 A, a surface protective film in which an antistatic layer is provided on one side of a polyester film, an antifouling layer is provided on the layer, and a slightly adhesive layer is provided on the opposite side, A surface protective film is shown in which the antistatic layer contains a conductive polymer obtained by polymerizing thiophene and / or a thiophene derivative. In this gazette, the antifouling layer has an appropriate peeling force, and the adhesive that protrudes from the cut surface makes contact with the surface protective film and hardly adheres to the film. Examples of components to be used include polymers having long alkyl side chains (for example, copolymers obtained by long-chain alkylation of polyvinyl alcohol or polyethyleneimine with chlorinated alkyloyl or alkyl isocyanate), silicone-based or fluorine-based release agents, and the like. In addition, it is preferable to contain a thermoplastic resin (thermoplastic polyester resin, acrylic resin, polyvinyl resin, etc.) or a thermosetting resin (thermosetting acrylic resin, urethane resin, melamine resin, epoxy resin, etc.) as the binder. There is also a description. In the examples, an example in which a stain preventing layer is provided by a mixed coating solution of polyethyleneimine octadecyl carbamate, polyester resin and melamine resin is shown.
[0009]
[Problems to be solved by the invention]
  According to the proposals disclosed in the above publications (a), (b), and (c), it is possible to solve the problems 1 and 2 out of the five problems described above. However, according to these methods, the problems 3, 4 and 5 remain unsolved. For example, it is not always easy to achieve both stain prevention and printability, and it is also easy to achieve both printability and print erasability, printability and solvent resistance while ensuring stain resistance. Furthermore, it is not easy to achieve both printability, print erasability and solvent resistance. In today's day-to-day development, the market demands not only to solve problems 1 and 2, but also to solve problems 3, 4 and 5.
[0010]
  Under such a background, the present invention prevents the adhesive sticking out from the cut surface of the laminate composed of a polarizing plate or a retardation plate having a surface protective film adhered thereto from adhering to the surface of the surface protective film, Even if an adhesive is attached, it can be easily removed.In addition, the appearance of the surface protective film changes when the adhesive attached to the surface of the cut surface protective film is wiped with a solvent. In addition, when the polarization angle and phase angle are marked with oil-based ink on the surface protection film of the cut product or when the inspection mark is pressed, the print can be printed cleanly and the printed ink is transferred to another sheet. Providing a surface protection film that is devised so that the markings and marks can be erased without impairing the appearance of the surface. It is an object to provide a laminate surface protective film is stuck on the surface of the polarizing plate or a retardation plate.
[0011]
[Means for Solving the Problems]
  Surface protective film of the present inventionIs
  An antistatic layer (2) is provided on at least one side of the base film (1), and an antifouling layer (3) containing an antifouling component is provided on the same side as the antistatic layer (2) or on the opposite side. Furthermore, in the antifouling layer (3), the surface protective film (A) having a layer structure in which a slightly adhesive layer (4) is provided on the surface opposite to the installation side,
  The antifouling component contained in the antifouling layer (3)Silicone modification using alkyd resin modified with silicone as base resin and melamine resin as crosslinking agentIt is an amino alkyd resin (x).
[0012]
  In this case,Antifouling component contained in antifouling layer (3)The silicone modifiedConsists of an aminoalkyd resin (x) and a compound (y) having a long-chain alkyl group or a fluoroalkyl groupIt may be a thing.
[0013]
  The laminate of the present invention has a polarizing plate or a retardation plate (B) on the surface,aboveIt has a structure in which the surface protective film (A) is adhered.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention will be described in detail below.
[0015]
<Surface protection film (A)>
(Basic layer structure)
  In the surface protective film of the present invention, an antistatic layer (2) is provided on at least one surface of the base film (1), and the antistatic layer (2) is provided on the same or opposite surface as the antistatic layer (2). The soil layer (3) is provided, and the anti-stain layer (3) has a layer structure in which a fine pressure-sensitive adhesive layer (4) is provided on the surface opposite to the installation side. That is,
  ・ "Anti-fouling layer (3) / Antistatic layer (2) / Base film (1) / Slight adhesive layer (4)",
  ・ "Anti-fouling layer (3) / Base film (1) / Antistatic layer (2) / Slight adhesive layer (4)", or
  ・ "Anti-fouling layer (3) / Antistatic layer (2) / Base film (1) / Antistatic layer (2) / Slight adhesive layer (4)"
It has the following layer structure. Usually, a release film (5) is placed over the slightly adhesive layer.
Hereinafter, each layer will be described in order.
[0016]
(Base film (1))
  As the base film (1), a polyester film (polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, etc.) is preferably used. In addition to the polyester film, other plastics films having the required strength and optical suitability, for example, polyolefin film, polyacetate film, polycarbonate film, polyphenylene sulfide film, polyamide film, ethylene-acetic acid Vinyl copolymer films, polyvinyl chloride films, polyvinylidene chloride films, synthetic rubber films, various liquid crystal polymer films, and the like can be used.
[0017]
  The base film (1) may be an unstretched film or may be uniaxially or biaxially stretched. When using a stretched film, if it is a biaxially stretched film, light interference may occur and diffraction fringes may occur, and it is difficult to visually inspect the polarizing plate because of the interference color. There is a risk. For this reason, it is more preferable to use a uniaxially stretched film having a high retardation value from the viewpoint of the inspection property of the polarizing plate.
[0018]
  The thickness of the base film (1) is not particularly limited, but is often about 6 to 125 μm (preferably about 12 to 50 μm, more preferably about 20 to 40 μm). The base film (1) may be subjected to easy adhesion treatment such as corona discharge treatment or anchor coating treatment, if necessary.
[0019]
(Antistatic layer (2))
  The antistatic layer (2) is formed on one side of the base film (1) by the following method.
  A method of depositing or coating an antistatic component made of metal or metal oxide.
  A method of coating a silicate compound.
  A method of coating a known antistatic agent.
[0020]
  Here, examples of the metal or metal oxide include metals such as aluminum, silicon, copper, silver, gold, and indium, and oxides or composite oxides of these metals. Since it is used for optical applications, a material with good transparency is preferable. From this viewpoint, a vapor deposition layer of indium oxide or silica is suitable.
[0021]
  Silicate compounds are also suitable for this purpose because the antistatic layer (2) to be formed has good transparency.
[0022]
  As the antistatic agent, any of antifouling components in the antifouling layer (3) or known ones can be used as long as they do not inhibit the curing of the below-mentioned fine pressure-sensitive adhesive layer (4).it can.For example, cationic activators, quaternary ammonium salts, pyrinidium salts, primary amines, tertiary amines, pyridine derivatives, stearoamidopropyldimethyl-β-hydroxyethyl ammonium nitrate, stearoamidopropyldimethyl-β -Hydroxyethyl, ammonium, dihydrogen, phosphate, special amine compounds, alkyl phosphates, sodium, alkyl, diphenyl ether, disulfonate, modified aliphatic dimethylethylammonium ethosulphate, anionic activator, polyoxyethylene alkylamine, Polyhydric alcohol derivatives, nonionic activators, alkylamine derivatives, alkyl phosphate amine salts, fatty acid esters, alkyl diethanolamides, polyethylene glycol esters, amphoteric Activators, organoboron compounds, polythiophenes, polyanilines, polypyrroles, functional group-containing polymers, etc. are examples of commercially available antistatic agents.
[0023]
  These antistatic agents are coated on the base film (1) by a known method. Specifically, methods such as gravure coating, Mayer bar coating, air knife coating, and doctor knife coating are employed. The application amount of the antistatic agent is not particularly limited, and may be determined in consideration of the type of antistatic agent and the required antistatic performance.
[0024]
  As described above, the surface on which the antistatic layer (2) is provided may be the surface on the side on which the antifouling layer (3), which is a subsequent step, is provided, or the surface on the opposite side. . However, it is desirable to provide the antistatic layer (2) on the surface on the side where the antifouling layer (3) is provided because the antistatic performance is easily exhibited. If the antistatic layer (2) is placed on the side opposite to the side where the antifouling layer (3) is installed, devise measures such as increasing the amount of antistatic agent applied or improving the antistatic performance. It is desirable to take.
[0025]
  The thickness of the antistatic layer (2) is 0.01-2 g / m on a dry basis in the case of coating with an antistatic agent.²Degree, especially 0.03-1g / m²In many cases.
[0026]
(Anti-fouling layer (3))
  The antifouling layer (3) is a layer containing an antifouling component and is a characteristic layer in the present invention.
[0027]
  Of the present inventionSurface protection film(A)In that case, the antifouling component contained in the antifouling layer (3) isSilicone modification using alkyd resin modified with silicone as base resin and melamine resin as crosslinking agentIt consists of an amino alkyd resin (x).A typical example of such a silicone-modified aminoalkyd resin is “TA31-209E” manufactured by Hitachi Chemical Co., Ltd. used in Examples described later.
[0028]
  hereMelamine resinas,Etherified melamine resin, etc.Can be given. In addition,Typical examples of etherified melamine resins include butyl etherified melamine resins and methyl etherified melamine resins.is there.
[0029]
  Also,The antifouling component contained in the antifouling layer (3)The above silicone modificationConsists of an aminoalkyd resin (x) and a compound (y) having a long-chain alkyl group or a fluoroalkyl groupIt may be a thing.
[0030]
  Where silicone modifiedAs amino alkyd resin (x), AboveThings are used. Examples of the compound (y) having a long-chain alkyl group or a fluoroalkyl group include a long-chain alkyl carbamate of a hydroxyl group-containing polymer, a long-chain alkyl acrylate copolymer, a long-chain alkyl vinyl ester copolymer, and a long-chain alkyl vinyl ether. Examples thereof include a copolymer, a long-chain alkylacrylamide copolymer, a long-chain alkylallyl ester copolymer, a hydroxyl group-containing polymer perfluoroalkyl carbamate, and a perfluoroacrylate copolymer. Here, as long-chain alkyl, if it has 6 or more carbon atoms, it can be used in the present invention. Particularly, alkyl having 12 or more carbon atoms including octadecyl group (especially those having 18 carbon atoms are easily available). It is preferably a group.
[0031]
  About the ratio of both components at this time,Silicone modifiedWhen the total amount of the aminoalkyd resin (x) and the compound (y) having a long-chain alkyl group or fluoroalkyl group is 100% by weight, the ratio of the former (x) is 97 to 5% by weight, and the latter (y) It is desirable that the ratio is 3 to 95% by weight. If the latter (y) is excessive (the former (x) is too small), the solvent resistance may be insufficient, and the appearance of the protective film surface will be removed when the adhesive attached to the protective film surface or ink printed is wiped off. May cause drawbacks. When the latter (y) is too small (excess of the former (x)), other sheets may touch the printed surface when it is printed on the surface of the protective film, rolled up, or stacked with cut products. In some cases, the ink may be transferred (however, the proportion of the latter (y) is less than 3% by weight, and there is a corresponding effect, and it can be used as it is in applications in which printability is not important). A more preferable ratio is 95 to 40% by weight of the former (x) and 5 to 60% by weight of the latter (y), and a particularly preferable ratio is 90 to 50% by weight of the former (x) and the latter (y) is 10 to 50% by weight.
[0032]
  Antifouling components contained in the antifouling layer (3) include, in addition to the above components ((x), or (x) and (y)), silicone and organic, as long as the gist of the present invention is not impaired. A copolymer with a base resin, an alkyd resin, a shellac resin, a silicone resin, and the like may be included.
[0033]
  The antifouling layer (3) is formed by various methods such as gravure coating, Mayer bar coating, air knife coating, and doctor knife coating.
[0034]
  The coating amount is not particularly limited, but considering the performance balance including the peeling performance, it is 0.003-2g / m on a dry basis.²Degree, preferably 0.03 to 1 g / m²Degree, particularly preferably 0.05-0.4 g / m²In many cases.
[0035]
  Here, from the viewpoint of performance of the antifouling layer (3), it should be noted that the antifouling layer (3) is formed so as to have the following performance.
[0036]
-Performance1-
  When 0.1g of ethyl acetate was dropped on the antifouling layer (3) of the surface protective film (A) and air-dried at 23 ° C, the appearance did not change and the adhesive adhered to the antifouling layer (3) The appearance of the antifouling layer (3) did not change when it was wiped off with ethyl acetate, and the antifouling layer (3) was removed when the drawn lines with oil-based ink attached to the antifouling layer (3) were erased with ethyl acetate. Pay attention to the conditions for forming the antifouling layer (3) so that there is no change in the appearance.
[0037]
  If the surface of the surface protective film does not satisfy this performance and changes its appearance, the surface of the surface protective film will become white if the surface is wiped with a cloth or paper soaked with a solvent when the adhesive is attached to the surface of the surface protective film. It becomes a defect in appearance. Further, even if the adhesive-adhered portion is wiped with a cloth or paper without using a solvent, the adhesive cannot be completely removed, and the adhesive remains as a defect in appearance. On the other hand, what satisfies this performance 1 clears the above solvent resistance test even when characters or symbols are printed on the surface of the surface protective film with oil-based ink or a stamp is pressed. If there is, remove the oil-based ink with ethyl acetate and use it as a normal part.
[0038]
-Performance 2-
  Pay attention to the conditions for forming the antifouling layer (3) so that the peel strength of the cellophane adhesive tape on the antifouling layer (3) of the surface protective film (A) is set in the range of 0.49 to 3.92 N / 24 mm. Here, the peel strength is measured by attaching a cellophane adhesive tape having a width of 24 mm to the surface of the antifouling layer (3) of the surface protective film with a roller having a weight of 2 kg and using a tensile tester at a speed of 300 mm / min. It is the strength when pulled in the ° direction. When the peel strength is 0.49 to 3.92 N / 24 mm (preferably 0.98 to 3.43 N / 24 mm), the surface of the surface protective film is less likely to adhere to the surface, and even if it adheres, the cloth soaked with the solvent Can be easily wiped off with paper or paper. When the peel strength exceeds 3.92 N / 24mm, when the laminated laminates are stacked, it is easy for the adhesive to adhere to the surface of the surface protection film, and it can be wiped with cloth or paper soaked with solvent. However, it is difficult to remove the adhesive. On the other hand, when the peel strength is less than 0.49 N / 24 mm, it is difficult to remove the surface protective film because the cellophane adhesive tape is difficult to adhere to the surface protective film when the surface protective film is peeled in the subsequent step.
[0039]
-Performance 3-
  Further, in the second surface protective film, in addition to the above performances 1 and 2, the surface protective film (A) has an antifouling layer (3) surface with oil-based ink (magic (registered trademark) supplement black). Ink-resistant layer (3) so that the ink contact angle is 3 to 10 ° (preferably 6 to 9 °) when 0.03 g of ink is dropped from a height of 10 cm and left to dry at 23 ° C. for 24 hours. ) Pay attention to the conditions of formation. When the ink contact angle exceeds 10 °, when marking the polarization angle or phase angle with oil-based ink or pressing an inspection mark, the ink may be repelled and printing may not be performed cleanly. When the ink contact angle is less than 3 °, the printability is good, but the antifouling property may be deteriorated.
[0040]
(Slight adhesive layer (4))
  The fine pressure-sensitive adhesive layer (4) may be selected from known pressure-sensitive adhesives according to the required characteristics, and the type of the pressure-sensitive adhesive is not particularly limited, and an acrylic one-component or two-component adhesive Various pressure-sensitive adhesives including rubber-based pressure-sensitive adhesives and silicone-based pressure-sensitive adhesives can be used. If it says according to form, a solventless type, a solvent type, an emulsion type, etc. will be mentioned. Since the pressure-sensitive adhesive is used for optical applications, it is preferable that the hue does not change such as yellowing over time.
[0041]
  Among these, a solvent-type acrylic pressure-sensitive adhesive is often used with an acrylic two-component type, and specifically, a monomer (ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc.) that becomes a soft segment, Those obtained by copolymerizing monomers (methyl methacrylate, vinyl acetate, acrylonitrile, styrene, etc.) that become hard segments, or functional group-containing monomers such as acrylic acid, methacrylic acid, hydroxyethyl (meth) acrylate, glycidyl methacrylate, etc. A copolymerized acrylic pressure-sensitive adhesive is preferably used. A two-component type containing an isocyanate curing agent or the like may be used, and after application, dried and cured to cause a crosslinking reaction.
[0042]
  The fine pressure-sensitive adhesive layer (4) is formed by various methods such as gravure coating, Mayer bar coating, air knife coating, doctor knife coating and the like. For the installation of this layer, a method of processing an adhesive on the release film (5) described below, and sticking after heat drying may be employed, or an antistatic layer (2) and an antifouling layer (3) may be employed. A method may be employed in which the pressure-sensitive adhesive is processed on the side of the base film (1) provided with a coating, and the release film (5) is coated after heat drying.
[0043]
  In general, the adhesive strength of the slightly adhesive layer (4) is preferably about 0.098 to 0.294 N / 25 mm for the polarizing plate and the retardation plate. Also, care should be taken to select an adhesive that does not remain on the surface of the polarizing plate or retardation plate when the surface protective film is peeled off.
[0044]
  The thickness of the fine pressure-sensitive adhesive layer (4) is not particularly limited, but is often about 1 to 200 μm, preferably about 5 to 50 μm.
[0045]
(Release film (5))
  A release film (5) is usually coated on the above slightly adhesive layer (4). A representative example of the release film (5) is one obtained by subjecting the surface of the polyester film to a release treatment using a silicone release agent or the like.
[0046]
<Laminate>
  The laminate of the present invention has a configuration in which the surface protective film (A) is adhered to the surface of a polarizing plate (including a polarizing plate serving as a retardation plate) or a retardation plate (B).
[0047]
【Example】
  The following examples further illustrate the invention.
[0048]
<Production of release film>
Example 1
  FIG. 1 is a cross-sectional view showing an example of the surface protective film of the present invention.
[0049]
  As an example of the base film (1), an antistatic agent made of a cationic polymer (“Bondip-P main agent” manufactured by Konishi Co., Ltd.) is applied to one side of a 25 μm-thick biaxially stretched polyester film (polyethylene terephthalate) film. By coating and drying a water-alcohol solution of a mixture obtained by mixing 100 wt. 46.7 with a weight ratio of solids and epoxy resin curing agent ("Bondip-P curing agent" manufactured by Konishi Co., Ltd.) , 0.2 g / m on a dry basis²The antistatic layer (2) was formed.
[0050]
  Then from above,Silicone modifiedAn amino alkyd resin ("TA31-209E" manufactured by Hitachi Chemical Polymer Co., Ltd.) and an acidic catalyst ("Dryer 900" manufactured by Hitachi Chemical Polymer Co., Ltd.) are mixed at a weight ratio of 100: 3 in terms of the solid content. By coating and drying the solution obtained by diluting with a solvent, 0.2 g / m on a dry basis²An antifouling layer (3) was formed.
[0051]
  Next, on the other side of the base film (1), an acrylic solvent type pressure-sensitive adhesive solution made of 2-ethylhexyl acrylate-butyl acrylate-vinyl acetate copolymer is coated and dried on a dry basis. 25g / m²A slightly pressure-sensitive adhesive layer (4) was formed. A release sheet (5) made of a silicone-treated polyester film was coated on the slightly pressure-sensitive adhesive layer (4).
[0052]
  As a result, a surface protective film having a layer structure of “antifouling layer (3) / antistatic layer (2) / base film (1) / slight adhesive layer (4) / release film (5)” is obtained. It was.
[0053]
Example 2
  FIG. 2 is a cross-sectional view showing another example of the surface protective film of the present invention.
[0054]
  An antifouling layer (3) is formed on one side of the base film (1), an antistatic layer (2) is formed on the opposite side of the base film (1), and then a slightly adhesive layer (4) is formed. Except that the release film (5) was coated on the slightly pressure-sensitive adhesive layer (4), the same as in Example 1, “Antifouling layer (3) / Base film (1) / Antistatic layer (2)” A surface protective film having a layer structure of “/ slight adhesive layer (4) / release film (5)” was obtained.
[0055]
Comparative Example 1
  Silicone modifiedInstead of amino alkyd resin, an alkyl carbamate-based release treatment agent (on the other hand, “Pyroyl 1010” manufactured by Yushi Kogyo Co., Ltd.) is coated and dried, so that the dry standard is 0.04 g / m.²Example 1 was repeated except that the antifouling layer (3) was formed.
[0056]
Comparative Example 2
  Silicone modifiedInstead of aminoalkyd resin, polyethyleneimine octadecyl carbamate (“RP-20” manufactured by Nippon Shokubai Co., Ltd.): polyester resin (“Esper 1510” manufactured by Hitachi Chemical Co., Ltd.): Melamine resin (Sanwa Chemical Co., Ltd.) The coating liquid obtained by mixing “Nicalac NS-11”) manufactured by mixing so that the weight ratio of the solid content is 1: 3: 1 is coated and dried, so that the dry standard is 0.3 g / m²Example 1 was repeated except that the antifouling layer (3) was formed.
[0057]
Comparative Example 3
  Example 1 was repeated except that the antistatic layer (2) and the antifouling layer (3) were not provided, and the layer constitution of “base film (1) / slight adhesive layer (4) / release film (5)” was established. A surface protective film was obtained.
[0058]
<Production of laminate>
  The release film (5) is peeled off from the surface protective film with the release film (5) obtained in the above Examples 1 and 2 and Comparative Examples 1 to 3, and the remaining surface protective film is removed from the polarizing plate (or the position). A polarizing plate laminate (or a retardation plate laminate) was prepared by sticking to the surface of the retardation plate (hereinafter referred to as a polarizing plate and a polarizing plate laminate).
[0059]
<Evaluation methods>
  About the sample of the laminate obtained above, the peel strength of the cellophane adhesive tape, solvent resistance, adhesive non-adhesiveness, adhesive wiping property, appearance after wiping, oil-based ink wiping property, appearance after wiping, surface resistance, The peel chargeability was measured or evaluated as follows.
[0060]
・ Peel strength of cellophane adhesive tape:
  A cellophane adhesive tape (“Cello Tape (24 mm width), manufactured by Nichiban Co., Ltd.)” was affixed to the surface of the surface protective film of the polarizing plate laminate using a 2 kg roller so that air bubbles would not enter. The strength when the cellophane adhesive tape was peeled in the direction of 180 ° at a peeling speed of 300 mm / min was measured, and this was taken as the peeling force.
[0061]
・ Solvent resistance:
  0.1 g of ethyl acetate was dropped on the surface of the surface protective film of the polarizing plate laminate, and then the appearance of the sample when air-dried at 23 ° C. was visually observed. Those having no change in appearance were judged to have good solvent resistance.
[0062]
・ Adhesive non-adhesive, adhesive wiping, appearance after wiping:
  When the pressure-sensitive adhesive surface of another polarizing plate laminate was rubbed strongly against the surface of the surface protective film of the polarizing plate laminate, it was visually observed whether the pressure-sensitive adhesive remained on the surface of the surface protective film. . Those having no adhesive remained were judged to have good adhesive non-adhesiveness.
[0063]
  In addition, the pressure-sensitive adhesive of the polarizing plate laminate was taken with a micro spatula, and the surface of the surface protective film was rubbed to forcibly attach the pressure-sensitive adhesive, followed by a non-woven fabric soaked with ethyl acetate ("Bencot" manufactured by Asahi Kasei Kogyo Co., Ltd. M-1 ") and the appearance of the surface of the surface protective film after wiping was observed visually. The adhesive was wiped cleanly, and the adhesive wiping property was good. The surface protective film appearance after the adhesive was wiped was determined to be good after wiping.
[0064]
-Oil-based ink wiping property, appearance after wiping:
  A non-woven fabric (Asahi Kasei Co., Ltd.) impregnated with ethyl acetate on the surface of the surface protective film of the polarizing plate laminate, drawing a line about 1 cm in length with oil-based ink (hereinafter abbreviated as “magic”). When the magic drawing part was wiped off with “Bencott M-1” manufactured by the company, the wiping property of the magic and the change in appearance after wiping were visually observed. The thing that the magic was wiped off was judged to have good wiping properties, and the change in appearance after wiping was judged to be good if the appearance did not change.
[0065]
・ Surface resistance:
  After leaving the polarizing plate laminate for 24 hours under the conditions of 23 ° C. and 50% RH, the surface of the surface protective film surface was measured using a surface resistance meter (“High Lester IP” manufactured by Mitsubishi Yuka Co., Ltd.). Resistance was measured.
[0066]
・ Peeling electrification:
  After leaving the polarizing plate laminate under conditions of 23 ° C. and 50% RH for 24 hours, when the protective film is peeled off at high speed by hand, it is checked whether the protective film clings to the hand and does not cling to the hand. Things were good.
[0067]
  The results are shown in Table 1. In addition, the code | symbol of (circle), (triangle | delta), x (good, a little defect, defect) is also attached | subjected in this order.
[0068]
[Table 1]
  
  Evaluation item Example 1 Example 2 Comparative example 1 Comparative example 2 Comparative example 3
    A 2.65 2.84 1.76 4.21 6.66
    B ○ Good ○ Good × Defect × Defect ○ Good
    C ○ Good ○ Good ○ Good △ Slightly poor × Poor
    D ○ Good ○ Good ○ Good ○ Good × Poor
    E ○ Good ○ Good × Defect × Defect ○ Good
    F ○ Good ○ Good ○ Good ○ Good △ Slightly bad
    G ○ Good ○ Good × Defect × Defect ○ Good
    H 8.2 × 10⁸     Ten¹⁴6.5 × 10 or more⁸    9.8 × 10⁸     Ten¹⁴more than
  I ○ Good ○ Good ○ Good ○ Good × Poor
  (Note) A: Cellophane adhesive tape peeling force (N / 24mm), B: Solvent resistance,
        C: Adhesive non-adhesiveness, D: Adhesive wiping property,
        E: Appearance after wiping adhesive, F: Oil-based ink wiping property,
        G: Appearance after wiping ink, H: Surface resistance (Ω),
        I: Release chargeability
[0069]
(analysis)
  From Table 1, the surface protective films of the examples are cellophane adhesive tape peeling force, solvent resistance, adhesive non-adhesiveness, adhesive wiping property, appearance after wiping off the adhesive, oil-based ink wiping property, and appearance after wiping the ink. It can be seen that the surface resistivity is good in all respects.
[0070]
<Production of release film>
Example 3
  FIG. 1 is a cross-sectional view showing an example of the surface protective film of the present invention.
[0071]
  As an example of the base film (1), on one side of a uniaxially stretched polyester film (polyethylene terephthalate) film having a thickness of 25 μm, an antistatic agent made of a cationic polymer (“Bondip-P main agent” manufactured by Konishi Co., Ltd.) By coating and drying a water-alcohol solution of a mixture obtained by mixing an epoxy resin curing agent (“Bondip-P curing agent” manufactured by Konishi Co., Ltd.) in a weight ratio of 100: 46.7 with a solid content, 0.2 g / m on a dry basis²The antistatic layer (2) was formed.
[0072]
  Then from above,Silicone modifiedA mixture of amino alkyd resin (“TA31-209E” manufactured by Hitachi Chemical Co., Ltd.) and an acidic catalyst (“Dryer 900” manufactured by Hitachi Chemical Polymer Co., Ltd.) in a weight ratio of 100: 3. Diluted with a solvent, and mixed with an alkyl carbamate-based release treatment agent (on the other hand “Pyroyl 1010” manufactured by Yushi Kogyo Co., Ltd.), which is an example of a compound having an alkyl group, at a weight ratio of solids of 85:15 By coating and drying the resulting solution, 0.2 g / m on a dry basis²An antifouling layer (3) was formed.
[0073]
  Next, on the other side of the base film (1), an acrylic solvent type pressure-sensitive adhesive solution made of 2-ethylhexyl acrylate-butyl acrylate-vinyl acetate copolymer is coated and dried on a dry basis. 25g / m²A slightly pressure-sensitive adhesive layer (4) was formed. A release sheet (5) made of a silicone-treated polyester film was coated on the slightly pressure-sensitive adhesive layer (4).
[0074]
  As a result, a surface protective film having a layer structure of “antifouling layer (3) / antistatic layer (2) / base film (1) / slight adhesive layer (4) / release film (5)” is obtained. It was.
[0075]
Reference example 1
  Silicone modifiedInstead of a mixture of an aminoalkyd resin and an acidic catalyst and an alkyl carbamate-based release treatment agent,Silicone modifiedA solution obtained by diluting an amino alkyd resin and an acidic catalyst in a weight ratio of 100: 3 in a solid content ratio with a solvent is coated and dried to obtain 0.2 g / m on a solid basis.²Example 3 was repeated except that the antifouling layer (3) was formed.
[0076]
Comparative Example 4
  Silicone modifiedInstead of a mixture of an aminoalkyd resin and an acidic catalyst, and an alkyl carbamate release treatment agent, an alkyl carbamate release treatment agent (on the other hand, “Pyroyl 1010” manufactured by Yushi Kogyo Co., Ltd.) is coated and dried. 0.004 g / m based on solids²Example 3 was repeated except that the antifouling layer (3) was formed.
[0077]
Comparative Example 5
  Silicone modifiedInstead of a mixture of an aminoalkyd resin and an acidic catalyst and an alkyl carbamate release treatment agent, polyethyleneimine octadecylcarbamate (“RP-20” manufactured by Nippon Shokubai Co., Ltd.): polyester resin (manufactured by Hitachi Chemical Co., Ltd.) “Esper 1510”): a coating solution obtained by mixing melamine resin (“Nikalac NS-11” manufactured by Sanwa Chemical Co., Ltd.) so that the weight ratio of the solids is 1: 3: 1. 0.3g / m on a solid basis by coating and drying²Example 3 was repeated except that the antifouling layer (3) was formed.
[0078]
Comparative Example 6
  Example 3 was repeated except that the antistatic layer (2) and the antifouling layer (3) were not provided, and the layer constitution of “base film (1) / slight adhesive layer (4) / release film (5)” was established. A surface protective film was obtained.
[0079]
<Production of laminate>
  The release film (5) was peeled and removed from the surface protective film with the release film (5) obtained in Example 3, Reference Example 1 and Comparative Examples 4 to 6, and the remaining surface protective film was removed from the polarizing plate ( Or it stuck on the surface of the phase difference plate, and the polarizing plate laminated body (or phase difference plate laminated body) was produced (Hereinafter, it shall represent with a polarizing plate and a polarizing plate laminated body).
[0080]
<Evaluation methods>
  About the sample of the laminate obtained above, the cellophane adhesive tape peel strength, ink contact angle, paintability, solvent resistance, adhesive non-adhesiveness, adhesive wiping property, appearance after wiping, oil-based ink wiping property, wiping off The subsequent appearance and surface resistivity were measured or evaluated as follows. Among these, properties other than the ink contact angle and paintability were measured or evaluated by the method described in the section of Example 1 above.
[0081]
・ Ink contact angle
  Under an environment of 23 ° C. and 55% RH, 0.03 g of magic ink R supplement black was dropped from the height of 10 cm on the surface of the protective film, left for 24 hours for drying, and the contact angle was measured.
[0082]
・ Paintable
  A line having a length of about 1 cm was drawn on the surface of the protective film with magic ink R very thick red, and the state of the ink was visually determined. Those with no repelling were considered good, while those with repelling but capable of printing were considered slightly good.
[0083]
  The results are shown in Table 2. In addition, the code | symbol of (circle), (triangle | delta), x (good, a little defect, defect) is also attached | subjected in this order.
[0084]
[Table 2]
  
  Evaluation Item Example 3 Reference Example 1 Comparative Example 4 Comparative Example 5 Comparative Example 6
    A 2.16 2.65 1.76 4.21 6.66
    J 8 12 7 6 4
    K ○ Good × Poor ○ Good ○ Good ○ Good
    B ○ Good ○ Good × Defect × Defect ○ Good
    C ○ Good ○ Good ○ Good △ Slightly poor × Poor
    D ○ Good ○ Good ○ Good ○ Good × Poor
    E ○ Good ○ Good × Defect × Defect ○ Good
    F ○ Good ○ Good ○ Good ○ Good △ Slightly bad
    G ○ Good ○ Good × Defect × Defect ○ Good
  H 8.2 × Ten ⁸ 8.2 × Ten ⁸ 6.5 × Ten ⁸ 9.8 × Ten ⁸ Ten ¹⁴ more than
  (Note) A: Cellophane adhesive tape peeling force (N / 24mm),
        J: Ink contact angle (°), K: Paintable, B: Solvent resistance,
        C: Adhesive non-adhesiveness, D: Adhesive wiping property,
        E: Appearance after wiping adhesive, F: Oil-based ink wiping property,
        G: Appearance after wiping ink, H: Surface resistance (Ω)
[0085]
Example 4
  Example 3 was repeated except that the antifouling layer (3) in Example 3 was changed as follows. That is, an antistatic layer (2) is formed on the base film (1), and then from above,Silicone modifiedA mixture of amino alkyd resin (“TA31-209E” manufactured by Hitachi Chemical Co., Ltd.) and an acidic catalyst (“Dryer 900” manufactured by Hitachi Chemical Polymer Co., Ltd.) in a weight ratio of 100: 3. Diluted with a solvent, and mixed with a fluoroalkyl carbamate release treatment agent (“FIG” manufactured by Yashara Chemical Co., Ltd.), which is an example of a compound having a fluoroalkyl group, at a weight ratio of solids of 85:15. By coating and drying the resulting solution, 0.2 g / m on a dry basis²An antifouling layer (3) was formed.
[0086]
  In this evaluation, evaluation item A is 2.74, evaluation item B is good, and evaluation item H is
7.9 × 10⁸
Example 3 was the same as in Example 3.
[0087]
【The invention's effect】
  The surface protective film of the present invention is said to protect the surface of the polarizing plate or retardation plate by sticking it to the surface of the polarizing plate or retardation plate to form a polarizing plate laminate or retardation plate laminate. In addition to achieving the original purpose, the following advantageous effects are obtained.
[0088]
  1. Since it has the necessary antistatic properties, the upper and lower polarizing plates and phase difference plates of the stacked product after cutting are stuck to each other due to static electricity, and it is difficult to handle, or the user feels pain due to electrostatic shock when handling it manually. Troubles such as destroying the TFT element during peeling do not occur.
[0089]
  2. Even if stacked cut products are stacked, the adhesive sticks out of the cut surface, making it difficult to adhere to the surface of the surface protection film, which may interfere with inspection or cause stickiness during shipment. The risk of causing troubles is resolved.
[0090]
  3. Moreover, even if the pressure-sensitive adhesive adheres to the surface of the surface protective film, the pressure-sensitive adhesive can be easily removed by wiping with a solvent. And the external appearance of a surface protection film does not change in that case. Therefore, in the subsequent inspection process, even when the defect is only the surface protective film, it is regarded as a defect of the polarizing plate / retardation plate itself, and the product yield does not decrease.
[0091]
  4). When marking the polarization angle or phase angle with oil-based ink or pressing an inspection mark on the cut surface protective film, it is possible to print cleanly without causing repellency. In addition, when the sheet is rolled or cut and stacked, another sheet does not touch the printed surface and the ink is not transferred.
[0092]
  5. When marking the polarization angle or phase angle with oil-based ink on the cut surface protection film or pressing the inspection mark, the marking or mark can be easily removed by wiping with a solvent at a later stage. Can do. Moreover, the appearance does not change when wiped with a solvent.
For this reason, the adhesive remaining portion and the printed portion, which have conventionally been defective products, can be used as normal products, and the product yield is improved.
[0093]
  6). After fulfilling the role as the surface protective film, the surface protective film can be easily peeled off from the laminate with a cellophane adhesive tape.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a surface protective film of the present invention.
FIG. 2 is a cross-sectional view showing another example of the surface protective film of the present invention.
[Explanation of symbols]
  (1) ... base film,
  (2) ... Antistatic layer,
  (3)… Anti-fouling layer,
  (4) ... Slight adhesive layer,
  (5)… Release film

Claims (4)

An antistatic layer (2) is provided on at least one side of the base film (1), and an antifouling layer (3) containing an antifouling component is provided on the same side as the antistatic layer (2) or on the opposite side. Furthermore, in the antifouling layer (3), the surface protective film (A) having a layer structure in which a slightly adhesive layer (4) is provided on the surface opposite to the installation side,
The antifouling component contained in the antifouling layer (3) is a silicone-modified aminoalkyd resin (x) using an alkyd resin modified with silicone as a base resin and a melamine resin as a crosslinking agent. A surface protective film. Claim wherein the antifouling layer is antifouling component contained in (3), characterized in that consists of the silicone-modified amino alkyd resin (x) a compound having a long chain alkyl group or a fluoroalkyl group and (y) 1. The surface protective film according to 1 . When the total amount of the silicone-modified aminoalkyd resin (x) and the compound (y) having a long-chain alkyl group or fluoroalkyl group is 100% by weight, the former (x) is 97 to 5% by weight, and the latter The surface protective film according to claim 2, wherein the proportion of (y) is from 3 to 95% by weight.   A laminate having a structure in which the surface protective film (A) according to claim 1 or 2 is adhered to the surface of a polarizing plate or a retardation plate (B).

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