TWI669383B - Antistatic surface-protective film - Google Patents

Abstract

The present invention provides an antistatic surface protective film that has less pollution to adherends, does not deteriorate over time, and has excellent anti-peel electrostatic properties. This antistatic surface protection film is formed by forming an adhesive layer (2) composed of an adhesive composition on one side of a base film (1) composed of a transparent resin, and laminating the adhesive layer (2) on the surface. The release agent film (5) of the release agent layer (4), the release agent layer (4) contains a release agent containing dimethyl polysiloxane as a main component and an antistatic agent, and the adhesive composition includes: A) At least one of (meth) acrylic acid ester monomers having C4 to C18 alkyl groups and (B) at least one of hydroxyl-containing copolymerizable monomers which do not include a carboxyl-containing copolymerizable monomer. A copolymer acrylic polymer further includes (C) a difunctional or higher isocyanate compound, (D) a crosslinking accelerator, and (E) a keto-enol tautomer compound.

Description

Anti-charge surface protection film

The invention relates to an adhesive composition and a surface protective film. Specifically, it relates to an antistatic surface protective film having antistatic performance. In more detail, the present invention provides a method for producing an antistatic surface protective film that has less contamination to an adherend, does not deteriorate over time (does not deteriorate over time), and has excellent anti-peel electrostatic properties. , And antistatic surface protective film.

Currently, when manufacturing and transporting optical films such as polarizing plates, retardation plates, display lens films, anti-reflection films, hard coating films, transparent conductive films for touch panels, and optical products such as displays, A surface protective film is attached to the surface of the optical film to prevent surface contamination and scratches in subsequent steps. In order to save the labor and time of laminating the surface protective film and then attaching it to improve work efficiency, the appearance inspection of the optical film as a product may sometimes include a surface protective film laminated on the optical film. It is implemented directly in the state.

Conventionally, in order to prevent the adhesion of scratches and dirt during the manufacturing process of an optical product, a surface protection film having an adhesive layer provided on one side of a base film is generally used. The surface protective film is adhered to the optical film with an adhesive layer having a slight adhesive force. The reason why the adhesive layer is set to micro-adhesion is to When the surface protective film is peeled off and removed from the surface of the optical film, it can be easily peeled off, and in order to prevent the adhesive from adhering and remaining on the optical film of the product as an adherend (so-called preventing the occurrence of adhesive residue) The phenomenon.

In recent years, in the production process of a liquid crystal display panel, a peeling static voltage generated when a surface protective film attached to an optical film is peeled off and removed, destroying a driver IC or the like for controlling a display screen of a liquid crystal display panel. Circuit components and the orientation of liquid crystal molecules are damaged. Although these phenomena occur in a small number, they also occur.

In addition, in order to reduce the power consumption of the liquid crystal display panel, the driving voltage of the liquid crystal material tends to decrease, and the breakdown voltage of the driving IC also tends to decrease. Recently, it has been required to control the peeling static voltage within a range of +0.7 kV to -0.7 kV.

Therefore, in order to prevent defects caused by a high peeling static voltage when the surface protective film is peeled off from an optical film as an adherend, a surface protective film has been proposed which uses antistatics to reduce the peeling static voltage. Adhesive layer.

For example, Patent Document 1 discloses a surface protective film using an adhesive composed of an alkyltrimethylammonium salt, a hydroxyl-containing acrylic polymer, and a polyisocyanate.

In addition, Patent Document 2 discloses an adhesive composition composed of an ionic liquid and an acrylic polymer having an acid value of 1.0 or less, and an adhesive sheet using the composition.

In addition, Patent Document 3 discloses an adhesive composition composed of an acrylic polymer, a polyether polyol compound, and an alkali metal salt treated with an anion-adsorbing compound, and a surface protective film using the composition. .

In addition, Patent Document 4 discloses an adhesive composition composed of an ionic liquid, an alkali metal salt, and a polymer having a glass transition temperature of 0 ° C. or lower, and a surface protective film using the composition.

In addition, Patent Documents 5 and 6 disclose the technical content of mixing a polyether-modified polysiloxane with an adhesive layer of a surface protective film.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2005-131957

Patent Document 2: Japanese Patent Application Laid-Open No. 2005-330464

Patent Document 3: Japanese Patent Application Laid-Open No. 2005-314476

Patent Document 4: Japanese Patent Application Laid-Open No. 2006-152235

Patent Document 5: Japanese Patent Application Laid-Open No. 2009-275128

Patent Document 6: Japanese Patent No. 4537450

In the aforementioned Patent Documents 1 to 4, an antistatic agent is added to the inside of the adhesive layer, but the thicker the thickness of the adhesive layer, and the adherend adhered from the adhesive layer to the surface protective film over time The more antistatic dose that moves. In addition, in optical films such as LR (Low Reflective) polarizers and AG (Anti Glare) -LR polarizers, anti-fouling treatment is applied to the surface of the optical film by using a polysiloxane compound or fluoride. When the surface protective film used for the optical film is peeled from the optical film as an adherend, the peeling static voltage becomes high.

In addition, as described in Patent Documents 5 and 6, when the polyether-modified polysiloxane is mixed in the adhesive layer, it is difficult to fine-tune the adhesive force of the surface protective film. In addition, since the polyether-modified silicone is mixed in the adhesive layer, when the conditions for coating and drying the adhesive composition on the base film are changed, the surface of the adhesive layer formed on the surface protective film is changed. The characteristics change subtly. In addition, from the viewpoint of protecting the surface of the optical film, the thickness of the adhesive layer cannot be set to be extremely thin. Therefore, depending on the thickness of the adhesive layer, it is necessary to increase the amount of polyether-modified polysiloxane mixed in the adhesive layer. As a result, it is easy to contaminate the surface of the adherend, the adhesion force with time and the contamination of the adherend. Changed.

In recent years, with the spread of 3D displays (stereoscopic displays), FPR (Film Patterned Retarder) films may be bonded to the surface of optical films such as polarizing plates. After peeling the surface protection film bonded to the surface of an optical film such as a polarizing plate, the FPR film is bonded. However, when the surface of an optical film such as a polarizing plate is contaminated with an adhesive or an antistatic agent used for a surface protective film, there is a problem that it is difficult to adhere the FPR film. Therefore, the surface protection film used for this application is required to have less contamination to an adherend.

On the other hand, in some liquid crystal panel manufacturers, as a method for evaluating the contamination of an adherend by a surface protective film, the following method is adopted: firstly, peel off the surface protective film attached to the optical film such as a polarizing plate, and Re-lamination was performed with air bubbles mixed therein, and the re-laminated article was heat-treated under prescribed conditions, and then the surface protective film was peeled off and the surface of the adherend was observed. In this evaluation method, even if the surface contamination of the adherend is slight, if there is a difference in the surface contamination of the adherend between the part where the air bubbles are mixed and the part in contact with the adhesive of the surface protective film, it will be regarded as air bubbles. Traces (sometimes called "bubble stains" Marks ") remain. Therefore, as a method for evaluating the contamination of the surface of an adherend, it will be a very strict evaluation method. In recent years, even if the result of this strict evaluation method is judged, it is necessary to adhere to the adherend. A surface protective film having no problem with the surface contamination of the body. However, it has been difficult to solve this problem in a surface protective film using a conventional adhesive layer containing an antistatic agent.

Therefore, there is a need for a surface protection film for use in an optical film, which has very little contamination of the adherend and does not change the contamination of the adherend with time (it does not change over time). In addition, a surface protective film that suppresses the peeling static voltage when peeling from the adherend is low.

In order to solve this problem, the present inventors have conducted intensive studies.

In order to reduce contamination of the adherend and also to reduce the change with time of the antistatic performance, it is necessary to reduce the amount of the antistatic agent presumed to be the cause of contaminating the adherend. However, when the amount of the antistatic agent is reduced, the peeling static voltage when the surface protective film is peeled from the adherend becomes high. The present inventors have studied a method of suppressing the peeling static voltage when peeling a surface protective film from an adherend to a relatively low level without increasing the absolute amount of the antistatic agent added. As a result, it was found that instead of adding an antistatic agent to the adhesive composition and mixing to form an adhesive layer, the adhesive composition was coated and dried to laminate the adhesive layer, and then the surface of the adhesive layer was imparted with an appropriate amount of resistance. The electrostatic agent component can suppress the peeling static voltage when peeling the surface protection film from the optical film as an adherend to a relatively low level, and completed the present invention based on the above findings.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide an excellent resistance to adherends that is less contaminated and has no deterioration with time. Antistatic surface protection film with electrostatic properties.

In order to solve the above-mentioned problems, the technical idea of the antistatic surface protective film of the present invention is to apply an appropriate amount of an antistatic agent to the surface of the adhesive layer after applying the adhesive composition and drying the adhesive layer to laminate the adhesive layer. It is possible to suppress the contamination of the adherend to a relatively low level, and to suppress the peeling static voltage when peeled from the optical film as an adherend to a low level.

In order to solve the above-mentioned problems, the present invention provides an antistatic surface protection film, which is manufactured through the following steps (1) to (2) in sequence, step (1): on a substrate made of a resin having transparency The step of forming an adhesive layer composed of an adhesive composition on one side of the film, the adhesive composition including: (A) alkyl (meth) acrylate monomers having C4 to C18 carbon atoms An acrylic polymer comprising, as a copolymerizable monomer group, a copolymer containing at least one of (B) a hydroxyl-containing copolymerizable monomer as a copolymerizable monomer group excluding a carboxyl-containing copolymerizable monomer; further including (C) Difunctional or higher functional isocyanate compound, (D) cross-linking accelerator, and (E) keto-enol tautomer compound, step (2): a release agent layer containing an antistatic agent is laminated on one side of the resin film, and The release film is formed by attaching the release agent layer to the surface of the adhesive layer. The release agent layer is formed by a release agent containing dimethylpolysiloxane as a main component and an antistatic agent. Resin composition to form, the peeling static voltage of the adhesive layer is ± 0 Below .6kV.

The copolymerizable monomer group preferably further contains (F) Polyalkylene glycol mono (meth) acrylate monomer.

In addition, it is preferable that the (D) crosslinking accelerator is at least one selected from the group consisting of an aluminum chelate, a titanium chelate, and an iron chelate, and is acryl-based polymerization of the copolymer. 100 parts by weight, containing 0.001 to 0.5 parts by weight of the (D) crosslinking accelerator, and 0.1 to 300 parts by weight of the (E) keto-enol tautomer compound, and (E) / (D) by weight The serving ratio is 70 ~ 1000.

In addition, the (B) hydroxyl-containing copolymerizable monomer is preferably selected from the group consisting of 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Ester, 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide At least one or more of the compound groups in the composition are 0.1 to 10 parts by weight of the (B) hydroxyl-containing copolymerizable monomer with respect to 100 parts by weight of the acrylic polymer of the copolymer.

In addition, as the copolymerizable monomer group, (F) a polyalkylene glycol mono (meth) acrylate monomer, and (F) a polyalkylene glycol mono (meth) acrylic acid monomer may be contained. The ester monomer is selected from the group consisting of polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylic acid At least one or more of the esters are preferably 0 to 50 parts by weight of the (F) polyalkylene glycol mono (meth) acrylate monomer with respect to 100 parts by weight of the acrylic polymer of the copolymer.

In addition, it is preferable that the difunctional or higher isocyanate compound (C) is produced by reacting a diisocyanate compound with a diol compound as an acyclic aliphatic isocyanate compound as the difunctional isocyanate compound. A compound in which the diisocyanate compound is an aliphatic diisocyanate and is selected from the group consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, One of a group of compounds consisting of lysine diisocyanate; the diol compound is selected from the group consisting of 2-methyl 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and 2-formaldehyde Methyl-2-propyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl- One of the compound groups consisting of 1,3-propanediol monohydroxypivalate, polyethylene glycol, and polypropylene glycol. The trifunctional isocyanate compound is preferably an isocyanurate of hexamethylene diisocyanate, Isophorone diisocyanate compound isocyanurate, adduct of hexamethylene diisocyanate compound, adduct of isophorone diisocyanate compound, biuret of hexamethylene diisocyanate compound, Biuret of isophorone diisocyanate compound, isocyanuric acid of toluene diisocyanate compound , Isocyanurate of xylylene diisocyanate compound, isocyanurate of hydrogenated xylylene diisocyanate compound, addition product of toluene diisocyanate compound, addition product of xylylene diisocyanate compound The adduct of a hydrogenated xylylene diisocyanate compound is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic polymer of the copolymer.

In addition, it is preferable that the (G) HLB value of 7 to 15 in the adhesive composition is 1.0 parts by weight or less (excluding 0 parts by weight) with respect to 100 parts by weight of the acrylic polymer of the copolymer. Polyether modified siloxane compound.

The antistatic agent in the release agent layer is preferably an alkali metal salt.

The antistatic agent in the release agent layer is a Li salt, and is preferably selected from a compound group consisting of Li (CF ₃ SO ₂ ) ₂ N, Li (FSO ₂ ) ₂ N, and LiCF ₃ SO ₃ . At least one or more.

In addition, in order to solve the above-mentioned problems, the present invention provides an antistatic surface protection film comprising an adhesive layer composed of an adhesive composition formed on one side of a substrate film composed of a transparent resin, and On the surface of the adhesive layer, a release agent film obtained by laminating an antistatic agent-containing release agent layer on one side of the resin film is formed by laminating the release agent layer. The adhesive composition includes: A) At least one of the (meth) acrylic acid ester monomers having C4 to C18 alkyl groups and the copolymerizable monomer group that does not include a carboxyl group-containing copolymerizable monomer and (B) a hydroxyl group-containing An acrylic polymer of a copolymer of at least one of comonomers; further comprising (C) a difunctional or higher isocyanate compound, (D) a crosslinking accelerator, and (E) a keto-enol tautomer compound, the foregoing The release agent layer is formed of a resin composition containing a release agent containing dimethylpolysiloxane as a main component and an antistatic agent.

The copolymerizable monomer group preferably further contains (F) a polyalkylene glycol mono (meth) acrylate monomer.

In addition, it is preferable that the (G) HLB value of 7 to 15 in the adhesive composition is 1.0 parts by weight or less (excluding 0 parts by weight) with respect to 100 parts by weight of the acrylic polymer of the copolymer. Polyether modified siloxane compound.

The antistatic agent in the release agent layer is preferably an alkali metal salt.

The antistatic agent in the release agent layer is a Li salt, and is preferably selected from a compound group consisting of Li (CF ₃ SO ₂ ) ₂ N, Li (FSO ₂ ) ₂ N, and LiCF ₃ SO ₃ . At least one or more.

The present invention also provides an optical film to which the above-mentioned antistatic surface protective film is bonded.

In addition, the present invention provides an optical component to which the above-mentioned antistatic surface protective film is bonded.

The antistatic surface protective film of the present invention has less pollution to the adherend, and has no time-varying change to the adherend's low pollution (it will not change with time). In addition, according to the present invention, it is possible to provide an optical film capable of preventing pollution even if the surface of an adherend such as an LR polarizing plate or an AG-LR polarizing plate is subjected to antifouling treatment with a polysiloxane compound, fluoride, or the like. An antistatic surface protective film that suppresses the peeling static voltage that occurs when the antistatic surface protective film is peeled from the adherend, and has no degradation with time and excellent antistatic properties.

The antistatic surface protection film according to the present invention can reliably protect the surface of the film for optics, and thus can improve the production efficiency and the yield.

1‧‧‧ substrate film

2‧‧‧ Adhesive layer

3‧‧‧ resin film

4‧‧‧ peeling agent layer

5‧‧‧ peeling film

7‧‧‧Antistatic agent

8‧‧‧ Adhered body (optical component)

10‧‧‧Anti-static surface protective film

11‧‧‧Antistatic surface protective film after peeling off the film

20‧‧‧ Optical components with antistatic surface protective film

FIG. 1 is a schematic cross-sectional view of an antistatic surface protective film of the present invention.

FIG. 2 is a cross-sectional view showing a state where a release film is peeled from the antistatic surface protection film of the present invention.

FIG. 3 is a cross-sectional view showing an embodiment of an optical component of the present invention.

Hereinafter, the present invention will be described in detail based on embodiments.

FIG. 1 is a schematic cross-sectional view of an antistatic surface protective film of the present invention. This antistatic surface protection film 10 is formed with an adhesive layer 2 on one surface of the transparent base film 1. A release film 5 is laminated on the surface of the adhesive layer 2, and the release film 5 is formed by forming a release agent layer 4 on the surface of the resin film 3.

As the base film 1 used in the antistatic surface protective film 10 of the present invention, a base film made of a resin having transparency and flexibility is used. Thereby, the appearance inspection of an optical component can be performed in the state which bonded the antistatic surface protective film to the optical component as an adherend. As the film made of a transparent resin used as the base film 1, polyethylene terephthalate, polyethylene naphthalate, and polyethylene isophthalate are preferably used. ), Polyester films such as polybutylene terephthalate. The substrate film may have a desired strength and optical compatibility, and a film made of another resin may be used in addition to the polyester film. The base film 1 may be an unstretched film or a film subjected to uniaxial stretching or biaxial stretching. The stretching ratio of the stretched film and the orientation angle in the axial direction of the stretched film accompanying crystallization may be controlled to specific values.

The thickness of the base film 1 used in the antistatic surface protection film 10 of the present invention is not particularly limited. For example, a thickness of about 12 to 100 μm is preferred, and a thickness of about 20 to 50 μm is easy to handle. Therefore, it is more preferable.

In addition, if necessary, an antifouling layer, an antistatic layer, a hard coat layer, or the like for preventing surface contamination may be provided on the opposite side of the surface of the base film 1 on which the adhesive layer 2 is formed. In addition, the surface of the base film 1 may be subjected to adhesion treatment such as surface modification by corona discharge, application of a primer, and the like.

In addition, as for the adhesive layer 2 used in the antistatic surface protective film 10 of the present invention, as long as it is adhered to the surface of the adherend, it can be easily peeled off after use and it is difficult to contaminate the adherend of the adherend. The agent layer is not particularly limited, but an acrylic adhesive layer obtained by crosslinking a (meth) acrylate copolymer is generally used in consideration of durability and the like after bonding to an optical film.

In particular, it is preferable that the main agent of the acrylic adhesive is at least one of (A) alkyl group-containing (meth) acrylic acid ester monomers having C4 to C18 carbon atoms and does not include a carboxyl group as a copolymerizable monomer group. An adhesive layer composed of an acrylic polymer which is a copolymerizable monomer and contains (B) a copolymer of at least one of a hydroxyl group-containing copolymerizable monomer.

The copolymerizable monomer group may further contain (F) a polyalkylene glycol mono (meth) acrylate monomer.

More preferably, the binder is composed of a binder composition consisting of (C) a difunctional or higher isocyanate compound, (D) a cross-linking accelerator, and (E) a keto-enol tautomer compound in addition to the acrylic polymer.剂 层。 The agent layer.

Examples of (A) alkyl (meth) acrylate monomers having C4 to C18 carbon atoms include butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic acid Amyl ester, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (formyl) (Nonyl) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, twelve (meth) acrylate Alkyl ester, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, decyl (meth) acrylate Pentaalkyl, cetyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, myristyl (meth) acrylate, (methyl) ) Isotetradecyl acrylate, cetyl (meth) acrylate, isohexadecyl (meth) acrylate, stearyl (meth) acrylate, isooctadecyl (meth) acrylate Esters, etc.

When the total amount of the acrylic polymer of the copolymer is set to 100 parts by weight, the content of the (meth) acrylic acid ester monomer having a carbon number of C4 to C18 of the (A) alkyl group is preferably 50 to 95 parts by weight.

Examples of the (B) hydroxyl-containing copolymerizable monomer include 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, ( (Meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl methacrylate; N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (Meth) acrylamide containing hydroxyl groups, such as (meth) acrylamide.

Preferably, the above-mentioned hydroxyl-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (methyl) ) 2-hydroxyethyl acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide At least one more.

When the total amount of the acrylic polymer of the copolymer is set to 100 parts by weight, the content of the (B) hydroxyl-containing copolymerizable monomer is preferably 0.1 to 10 parts by weight.

As the (C) difunctional or higher isocyanate compound, any polyisocyanate compound having at least two isocyanate (NCO) groups in one molecule is selected. At least one or two or more of the cyanate ester compounds may be sufficient. Polyisocyanate compounds include classifications of aliphatic isocyanates, aromatic isocyanates, acyclic isocyanates, and alicyclic isocyanates, and the present invention may be any of them. Specific examples of the polyisocyanate compound include aliphatic isocyanate compounds such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and trimethylhexamethylene diisocyanate (TMDI). ; Diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H6XDI), dimethyldiphenylene diisocyanate (TOID), toluene diisocyanate (TDI ) And other aromatic isocyanate compounds.

Examples of the trifunctional or higher isocyanate compound include a biuret modified product or an isocyanurate modified product of a difunctional isocyanate compound (a compound having two NCO groups in one molecule), and trimethylol. Adducts (polyol modified products) of trivalent or higher polyhydric alcohols (compounds having at least three or more OH groups in one molecule) such as propane (TMP) or glycerol.

As the (C) difunctional or higher isocyanate compound, only (C-1) a trifunctional isocyanate compound or only (C-2) a difunctional isocyanate compound can be used. In addition, (C-1) a trifunctional isocyanate compound and (C-2) a difunctional isocyanate compound may be used in combination.

The (C-1) trifunctional isocyanate compound used in the present invention preferably includes at least one or more members selected from the (C-1-1) first aliphatic isocyanate compound group and is selected from (C-1- 2) At least one or more of the second aromatic isocyanate compound group, wherein the (C-1-1) first aliphatic isocyanate compound group is composed of a hexamethylene diisocyanate compound Isocyanurate, isophorone diisocyanate compound isocyanurate, adduct of hexamethylene diisocyanate compound, adduct of isophorone diisocyanate compound, hexamethylene di The biuret of an isocyanate compound and the biuret of an isophorone diisocyanate compound; the (C-1-2) second aromatic isocyanate compound group is an isocyanurate composed of a toluene diisocyanate compound , Isocyanurate of xylylene diisocyanate compound, isocyanurate of hydrogenated xylylene diisocyanate compound, addition product of toluene diisocyanate compound, addition product of xylylene diisocyanate compound , Hydrogenated xylylene diisocyanate compound adduct. The (C-1-1) first aliphatic isocyanate compound group and the (C-1-2) second aromatic isocyanate compound group are preferably used in combination. In the present invention, as the (C-1) trifunctional isocyanate compound, at least one or more selected from the (C-1-1) first aliphatic isocyanate compound group is used in combination and selected from (C-1-2) At least one or more of the second aromatic isocyanate compound group can further improve the balance of the adhesive force in the low-speed peeling region and the high-speed peeling region.

In addition, it is preferable that the (C-1) trifunctional isocyanate compound includes at least one or more members selected from the aforementioned (C-1-1) first aliphatic isocyanate compound group and the member selected from the aforementioned (C-1-2) second The total content of the (C) trifunctional or higher isocyanate compound is at least one or more in the aromatic isocyanate compound group, based on 100 parts by weight of the acrylic polymer of the copolymer. In addition, as a mixture of at least one or more members selected from the (C-1-1) first aliphatic isocyanate compound group and at least one or more members selected from the (C-1-2) second aromatic isocyanate compound group The ratio, calculated by weight ratio, is preferably (C-1-1): (C-1-2) at 10%: 90% ~ 90%: Within 10%.

The (C-2) difunctional isocyanate compound used in the present invention is preferably an acyclic aliphatic isocyanate compound and a compound produced by reacting a diisocyanate compound with a diol compound.

For example, when a diisocyanate compound is represented by the general formula "O = C = NXN = C = O" (where X is a divalent group), and by the general formula "HO-Y-OH" (where Y is a divalent group) When a diol compound represents a diol compound, examples of the compound produced by reacting a diisocyanate compound with a diol compound include compounds represented by the following general formula Z.

[Formula Z] O = C = NX- (NH-CO-OYO-CO-NH-X) _n -N = C = O

Here, n is an integer of 0 or more. When n is 0, the general formula Z is expressed as "O = C = N-X-N = C = O". The difunctional acyclic aliphatic isocyanate compound may include a compound in which n is 0 in the general formula Z (a diisocyanate compound unreacted with respect to a diol compound), and a compound containing n as an integer of 1 or more as an essential component is preferable. . The bifunctional acyclic aliphatic isocyanate compound may be a mixture composed of a plurality of compounds in which n in Formula Z is different.

The diisocyanate compound represented by the general formula "O = C = N-X-N = C = O" is an aliphatic diisocyanate. Preferably, X is an acyclic aliphatic divalent group. The aliphatic diisocyanate is preferably selected from the group consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate. One or two or more of the compound group.

The diol compound represented by the general formula "HO-Y-OH" is aliphatic two alcohol. Preferably, Y is an acyclic aliphatic divalent group. The diol compound is preferably selected from 2-methyl 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and 2-methyl-2-propyl-1,3- Propylene glycol, 2-ethyl-2-butyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate One or two or more compounds in a compound group consisting of polyethylene glycol, polypropylene glycol, and polypropylene glycol.

The weight ratio (C-1 / C-2) of the (C-1) trifunctional isocyanate compound to the (C-2) difunctional isocyanate compound is preferably 1 to 90. It is preferable that it is 0.1-10 weight part with respect to 100 weight part of acrylic polymers of the said copolymer, and the said (C) bifunctional or more isocyanate compound.

In the case where a polyisocyanate compound is used as the crosslinking agent, the (D) crosslinking accelerator may be any substance that functions as a catalyst to function in the reaction (crosslinking reaction) of the copolymer and the crosslinking agent. : Amine compounds such as tertiary amines, metal chelates, organic tin compounds, organic lead compounds, organic zinc compounds and the like. In the present invention, a metal chelate compound or an organic tin compound is preferably used as the crosslinking accelerator.

The metal chelate is a compound in which one or more polydentate ligands L are bonded to a central metal atom M. The metal chelate may or may not have one or more monodentate ligands X bonded to the metal atom M. For example, when the general formula of a metal chelate metal atom M is one represented by M (L) _m (X) _n , m 1, n 0. When m is 2 or more, m Ls may be the same ligand or different ligands. When n is 2 or more, n X may be the same ligand or different ligands.

Examples of the metal atom M include Fe, Ni, Mn, Cr, V, Ti, Ru, Zn, Al, Zr, and Sn.

Examples of the multidentate ligand L include methyl ethyl acetate, ethyl ethyl acetate, ethyl ethyl acetate, oleyl ethyl acetate, lauryl ethyl acetate, stearyl ethyl acetate, and the like. β-ketoesters; β-diketones such as acetoacetone (alias: 2,4-pentanedione), 2,4-hexanedione, benzophenone acetone, and the like. These are keto-enol tautomer compounds, and the polydentate ligand L may also be an enolate (for example, acetamidine acetonate) obtained by deprotonating the enol.

Examples of the monodentate ligand X include a halogen atom such as a chlorine atom and a bromine atom, pentamyl, hexyl, 2-ethylhexyl, octyl, nonyl, decyl, sulfonyl, Alkoxy groups such as stearyl, and alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, and butoxy.

Specific examples of the metal chelate include tris (2,4-pentanedione) iron (III), iron triacetonium acetone, titanium triacetonium acetone, titanium triethyl acetonate ruthenium, zinc diethyl acetonate , Aluminum triacetamone acetone, zirconium tetraacetamone acetone, tris (2,4-hexadione) iron (III), bis (2,4-hexadione) zinc, tris (2,4-hexadione) Titanium, tris (2,4-hexadione) aluminum, tetras (2,4-hexadione) zirconium and the like.

Examples of the organic tin compound include dialkyltin oxides, fatty acid salts of dialkyltin, and fatty acid salts of stannous acids. In the past, dibutyltin compounds have been used in most cases, but in recent years, the toxicity of organic tin compounds has been pointed out. In particular, tributyltin (TBT) contained in dibutyltin compounds is also a cause of concern. From the viewpoint of safety, a long-chain alkyltin compound such as a dioctyltin compound is preferred. Specific examples of the organic tin compound include dioctyltin oxide and dioctyltin dilaurate. Although Sn compounds can also be used temporarily, in view of the tendency to use more safe substances in the future, it is preferable to use gold such as Al, Ti, Fe, etc., which are safer than Sn. Is a chelate.

The (D) crosslinking accelerator in the binder composition of the present invention is preferably at least one or more selected from the group consisting of an aluminum chelate, a titanium chelate, and an iron chelate.

The content of the crosslinking accelerator (D) is preferably 0.001 to 0.5 parts by weight based on 100 parts by weight of the acrylic polymer based on 100 parts by weight of the copolymer.

Examples of (E) keto-enol tautomer compounds include methyl ethyl acetate, ethyl ethyl acetate, octyl ethyl acetate, oleyl ethyl acetate, lauryl ethyl acetate, and ethyl acetate Β-ketoesters such as stearyl acetate; β-diketones such as acetone, 2,4-hexanedione, and benzophenone. In an adhesive composition using a polyisocyanate compound as a cross-linking agent, by blocking the isocyanate group of the cross-linking agent, it is possible to suppress an excessive increase in viscosity or gelation of the adhesive composition after the cross-linking agent is mixed. This phenomenon can extend the shelf life of the adhesive composition.

The content of the (E) keto-enol tautomer compound is preferably 0.1 to 300 parts by weight based on 100 parts by weight of the acrylic polymer of the copolymer.

The (E) keto-enol tautomer compound has the effect of inhibiting the cross-linking as opposed to the (D) crosslinking accelerator. Therefore, it is preferable to appropriately set the (E) keto-enol tautomer compound to (D) ) Proportion of crosslinking accelerator. In order to extend the shelf life of the adhesive composition and improve storage stability, the weight ratio of (E) / (D) is preferably 70 to 1,000.

The acrylic polymer may optionally contain (F) a polyalkylene glycol mono (meth) acrylate monomer as the copolymerizable monomer group. As (F) a polyalkylene glycol mono (meth) acrylate monomer, What is necessary is just a compound in which one of a plurality of hydroxyl groups of a polyalkylene glycol is esterified into a (meth) acrylate. Since the (meth) acrylate group is a polymerizable group, it can be copolymerized with a base polymer. The other hydroxyl group may be in the state of OH, may be an alkyl ether such as methyl ether and diethyl ether, or may be a saturated carboxylic acid ester such as acetate.

Examples of the alkylene group included in the polyalkylene glycol include, but are not limited to, vinyl, propenyl, and butenyl. The polyalkylene glycol may be a copolymer of two or more kinds of polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol. Examples of the polyalkylene glycol copolymer include polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, and polyethylene glycol-polypropylene glycol-polybutylene glycol. The copolymer may be a block copolymer or a random copolymer.

It is preferable that the average number of alkylene oxides constituting the polyalkylene glycol chain in the (F) polyalkylene glycol mono (meth) acrylate monomer is from 3 to 14. The "average repeating number of alkylene oxides" refers to the alkylene in the "polyalkylene glycol chain" part contained in the molecular structure of the (F) polyalkylene glycol mono (meth) acrylate monomer. The average number of oxygenation unit repeats.

The (F) polyalkylene glycol mono (meth) acrylate monomer is preferably selected from the group consisting of polyalkylene glycol mono (meth) acrylate and methoxy polyalkylene glycol (methyl ) At least one or more of acrylate and ethoxy polyalkylene glycol (meth) acrylate.

More specific examples include polyethylene glycol-mono (meth) acrylate, polypropylene glycol-mono (meth) acrylate, polybutylene glycol-mono (meth) acrylate, and polyethylene glycol. -Polypropylene glycol-mono (meth) acrylate, polyethylene glycol-polybutylene Glycol-mono (meth) acrylate, polypropylene glycol-polybutylene glycol-mono (meth) acrylate, polyethylene glycol-polypropylene glycol-polybutylene glycol-mono (meth) acrylate; methoxy Polyethylene glycol- (meth) acrylate, methoxy polypropylene glycol- (meth) acrylate, methoxy polybutylene glycol- (meth) acrylate, methoxy-polyethylene glycol- Polypropylene glycol- (meth) acrylate, methoxy-polyethylene glycol-polybutylene glycol- (meth) acrylate, methoxy-polypropylene glycol-polybutylene glycol- (meth) acrylate, Methoxy-polyethylene glycol-polypropylene glycol-polybutylene glycol- (meth) acrylate; ethoxy polyethylene glycol- (meth) acrylate, ethoxy polypropylene glycol- (meth) acrylic acid Ester, ethoxy polybutylene glycol- (meth) acrylate, ethoxy-polyethylene glycol-polypropylene glycol- (meth) acrylate, ethoxy-polyethylene glycol-polybutylene glycol- (Meth) acrylate, ethoxy-polypropylene glycol-polybutylene glycol- (meth) acrylate, ethoxy-polyethylene glycol-polypropylene glycol-polybutylene glycol- (meth) acrylate, etc. .

When the total amount of the acrylic polymer of the copolymer is set to 100 parts by weight, the content of the (F) polyalkylene glycol mono (meth) acrylate monomer is preferably 0 to 50 parts by weight. The adhesive composition in the adhesive layer of the present invention may not include (F) a polyalkylene glycol mono (meth) acrylate monomer.

The adhesive composition may optionally contain (G) a polyether-modified silicone compound having an HLB value of 7 to 15. The polyether-modified silicone compound is a silicone compound having a polyether group. In addition to the usual silicone unit (-SiR ¹ ₂ -O-), the polyether-modified silicone compound also contains a polyether group ( -SiR ¹ (R ² O (R ³ O) _n R ⁴ ) -O-). Here, R ¹ represents one or two or more alkyl or aryl groups, R ² and R ³ represent one or two or more alkylene groups, R ⁴ represents one or two or more alkyl groups, fluorenyl groups, and the like ( Terminal group). Examples of the polyether group include polyoxyalkylene groups such as a polyoxyethylene group ((C ₂ H ₄ O) _n ) or a polyoxypropylene group ((C ₃ H ₆ O) _n ).

The polyether-modified silicone compound is preferably a polyether-modified silicone compound having a (G) HLB value of 7 to 15. In addition, the content of the polyether-modified silicone compound having a (G) HLB value of 7 to 15 is preferably 0.01 to 1.0 parts by weight, and more preferably 0.1 to 0.5, based on 100 parts by weight of the acrylic polymer of the copolymer. Parts by weight.

HLB refers to a predetermined hydrophilic-lipophilic balance (a ratio of hydrophilicity to lipophilicity) specified in JIS K3211 (surfactant term).

The polyether-modified siloxane compound can be obtained, for example, by a method of grafting an organic compound having an unsaturated bond and a polyoxyalkylene group to a polyorganosiloxane having a silane group by a hydrosilylation reaction. Obtained from the main chain. Specific examples include a dimethylsiloxane-methyl (polyoxyethylene) siloxane copolymer, a dimethylsiloxane-methyl (polyoxyethylene) siloxane-methyl (polyoxyethylene) (Propylene oxide) silicone copolymer, dimethylsiloxane-methyl (polyoxypropylene) silicone copolymer, and the like. The HLB value of the polyether-modified siloxane compound can be adjusted by selecting the ratio of the polyether group to the siloxane group.

By adding a polyether-modified silicone compound having a (G) HLB value of 7 to 15 to the adhesive composition, the adhesive force and reworkability of the adhesive can be improved. When the adhesive composition does not contain a polyether-modified silicone compound, the cost can be made lower.

In addition, as other components, a copolymerizable (meth) acrylic monomer containing an alkylene oxide, a (meth) acrylamide monomer, a dialkyl-substituted acrylamide monomer, Known additives such as surfactants, curing accelerators, plasticizers, fillers, curing inhibitors, processing aids, anti-aging agents, and antioxidants. These can be used alone or in combination Use more than two.

As the copolymer of the main agent used in the binder composition of the present invention, at least one of (A) alkyl (meth) acrylate monomers having C4 to C18 carbon atoms can be used as a copolymerizable monomer The body group is synthesized by copolymerizing at least one selected from (B) a hydroxyl group-containing copolymerizable monomer without including a carboxyl group-containing copolymerizable monomer. The copolymerizable monomer group may further contain (F) a polyalkylene glycol mono (meth) acrylate monomer. The polymerization method of the copolymer is not particularly limited, and an appropriate polymerization method such as solution polymerization or emulsion polymerization can be used.

The adhesive composition of the present invention can be formulated by blending (C) a difunctional or higher-functional isocyanate compound, (D) a cross-linking accelerator, (E) a keto-enol tautomer compound in the copolymer, and optionally Of any additive.

The copolymer is preferably an acrylic polymer, and preferably contains 50 to 100% by weight of a (meth) acrylate monomer or an acrylic monomer such as (meth) acrylic acid or (meth) acrylamide.

Since the aforementioned acrylic polymer does not include a carboxyl-containing copolymerizable monomer as a copolymerizable monomer group, it is effective for improving the crosslinking speed and stabilizing the adhesive force. As a monomer which reacts with (C) a difunctional or more isocyanate compound used as a crosslinking agent, (B) a hydroxyl-containing copolymerizable monomer is preferably used. Examples of the preferable monomer composition of the copolymer include one or more of each of the (A) and (B), one or more of each of the (A) and (B), and (F).

The adhesive force of the adhesive layer formed by cross-linking the adhesive composition is preferably 0.05 to 0.1 N / 25 mm at a low peeling speed of 0.3 m / min. The cohesive force at a separation speed of 30m / min is 1.0N / 25mm or less. As a result, a small change in the adhesive force with the peeling speed can be obtained, and the peeling can be performed quickly even in the case of high-speed peeling. In addition, even when the surface protection film is temporarily peeled for re-adhesion, an excessive force is not required, and it is easy to peel from the adherend.

The surface resistivity of the adhesive layer obtained by crosslinking the adhesive composition is preferably 5.0 × 10 ⁺¹² Ω / □ or less, and the peeling static voltage is “± 0.6 kV or less”. In addition, in the present invention, the term “± 0.6 kV or less” means “0 to −0.6 kV” and “0 to +0.6 kV”, that is, “−0.6 to +0.6 kV”. If the surface resistivity is large, the performance of releasing the static electricity generated by the charging at the time of peeling is poor. Therefore, by making the surface resistivity sufficiently small, it is possible to reduce the static electricity generated when the adhesive layer is separated from the adherend. The peeling static voltage can suppress the influence on the electrical control circuit and the like of the adherend.

The gel fraction of the adhesive layer (crosslinked adhesive) obtained by crosslinking the adhesive composition of the present invention is preferably 95 to 100%. Because the gel fraction is so high, the adhesive force will not become too large at low peel speeds, reducing the phenomenon of dissolution of unpolymerized monomers or oligomers from the copolymer, which can improve reworkability, high temperature / high Durability under wet conditions and suppresses contamination by adherends.

The adhesive film of the present invention is formed by forming an adhesive layer on one or both sides of a resin film, and the adhesive layer is formed by crosslinking the adhesive composition of the present invention. In addition, the surface protection film of the present invention is formed by forming an adhesive layer on one side of a resin film, and the adhesive layer is formed by crosslinking the adhesive composition of the present invention. In the adhesive composition of the present invention, since each of the components (A) to (E) is blended in a good balance, it has excellent antistatic performance, and the adhesive force at a low peeling speed and a high peeling speed. Excellent balance and durability And reprocessability (after drawing on a surface protective film with a ballpoint pen through an adhesive layer, there is no transfer of contamination to an adherend) is also excellent. Therefore, it can be used suitably as a surface protective film use of a polarizing plate.

The thickness of the adhesive layer 2 used in the antistatic surface protection film 10 of the present invention is not particularly limited. For example, the thickness is preferably about 5 to 40 μm, and more preferably about 10 to 30 μm. When the antistatic surface protective film has a peeling strength (adhesive force) of the adherend layer of about 0.03 to 0.3N / 25mm and has a microadhesive adhesive layer 2, the antistatic surface protection is peeled from the adherend. Since it is excellent in handleability at the time of a film, it is preferable. In addition, from the viewpoint of excellent operability when peeling the release film 5 from the antistatic surface protective film 10, the peel force of the release film 5 from the adhesive layer 2 is preferably 0.2 N / 50 mm or less.

The release film 5 used in the antistatic surface protective film 10 of the present invention is formed by forming a release agent layer 4 on one side of the resin film 3, and the release agent layer 4 contains A polysiloxane is a resin composition containing a release agent as a main component and an antistatic agent.

Examples of the resin film 3 include a polyester film, a polyamide film, a polyethylene film, a polypropylene film, and a polyimide film. From the viewpoint of excellent transparency and relatively low cost, a polyester film is particularly preferred. . The resin film may be an unstretched film, or a uniaxially stretched film or a biaxially stretched film. The stretching ratio of the stretched film and the orientation angle in the axial direction of the stretched film accompanying crystallization may be controlled to specific values.

The thickness of the resin film 3 is not particularly limited, and for example, a thickness of about 12 to 100 μm is preferable; a thickness of about 20 to 50 μm is easy to handle, so it is more preferable.

In addition, the surface of the resin film 3 may be subjected to an easy-adhesion treatment such as surface modification by corona discharge, application of a primer, and the like, as necessary.

Examples of the release agent comprising dimethylpolysiloxane as the main component constituting the release agent layer 4 include well-known polysiloxanes such as addition reaction type, condensation reaction type, cation polymerization type, and radical polymerization type. Alkane release agent. Examples of commercially available products of the addition reaction type polysiloxane-based stripping agent include KS-776A, KS-847T, KS-779H, KS-837, KS-778, and KS-830 (Shin-Etsu Chemical Industry Co., Ltd. Manufacturing Co., Ltd.); SRX-211, SRX-345, SRX-357, SD7333, SD7220, SD7223, LTC-300B, LTC-350G, LTC-310 (Dow Corning Toray Co., Ltd. , Ltd.)). As a commercially available product of a condensation reaction type, SRX-290, SYLOFF-23 (made by Dow Corning Toray Co., Ltd.), etc. are mentioned, for example. Examples of commercially available cationic polymerization products include TPR-66501, TPR-6500, UV9300, UV9315, and UV9430 (manufactured by Momentive Performance Materials Inc.), X62-7622 (Shin-Etsu Chemical Industry Co., Ltd.) Co., Ltd.) and so on. As a commercially available product of a radical polymerization type, X62-7205 (made by Shin-Etsu Chemical Industry Co., Ltd.) etc. can be mentioned, for example.

As the antistatic agent constituting the release agent layer 4, it is preferable that the dispersibility of the release agent solution containing dimethylpolysiloxane as a main component is good, and the release agent containing dimethylpolysiloxane as a main component is not hindered. Cured antistatic agent. As such an antistatic agent, an alkali metal salt is preferable.

Examples of the alkali metal salt include metal salts containing lithium, sodium, and potassium. Specifically, for example, by using preferably containing Li ^+, Na ^+, K ⁺ cations comprising ^{Cl -, Br -, I -} , BF 4 -, PF 6 -, SCN -, ClO 4 -, CF 3 SO 3 _{^{-, (FSO 2) 2 N}} -, (CF 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C - anions consisting of a metal salt. Among them, LiBr, LiI, LiBF ₄ , LiPF ₆ , LiSCN, LiClO ₄ , LiCF ₃ SO ₃ , Li (FSO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₂ N, and Li (C ₂ F ₅ SO) are particularly preferably used. ₂ ) Lithium salts (Li salts) such as ₂ N and Li (CF ₃ SO ₂ ) ₃ C. Among them, Li (CF ₃ SO ₂ ) ₂ N (abbreviated as LiTFSI), Li (FSO ₂ ) ₂ N ( abbreviated as LiFSI), LiCF ₃ SO ₃ (abbreviated as LiTF or LiTf). These alkali metal salts may be used alone or in combination of two or more. To stabilize the ionic substance, a compound containing a polyoxyalkylene structure may be added.

The amount of antistatic agent added to the release agent containing dimethyl polysiloxane as the main component varies depending on the type of the antistatic agent and the degree of affinity with the release agent. It is only necessary to set the peeling static voltage required for peeling the antistatic surface protection film, the contamination property of the adherend, the adhesion characteristics, and the like.

There is no particular limitation on the method for mixing the release agent and the antistatic agent containing dimethylpolysiloxane as a main component. Any one of the following mixing methods may be adopted: a method in which an antistatic agent is added to a release agent containing dimethylpolysiloxane as a main component, and then a catalyst for curing the release agent is added and mixed; a method in advance A method of adding an antistatic agent and a curing agent for curing the release agent after diluting the release agent containing dimethyl polysiloxane as a main component by using an organic solvent, and diluting the release agent containing polysiloxane as a main component by using an organic solvent A method in which a catalyst is added and mixed, and then an antistatic agent is added and mixed. In addition, if necessary, an adhesion promoter such as a silane coupling agent, a polyoxyalkylene-containing compound, or the like may be added. Auxiliary antistatic effect material.

There is no particular limitation on the mixing ratio of the release agent containing dimethyl polysiloxane as the main component and the antistatic agent, but the solid content of the release agent containing dimethyl polysiloxane as the main component is solid. The component 100 is preferably an antistatic agent in a ratio of about 5 to 100 in terms of solid content. Relative to the solid content 100 of the release agent containing dimethyl polysiloxane as the main component, if the amount of the antistatic agent added in terms of solid content is less than 5, the transfer amount of the antistatic agent to the surface of the adhesive layer It also becomes less, making it difficult for the adhesive to exert an antistatic function. In addition, with respect to the solid content 100 of the release agent containing dimethyl polysiloxane as the main component, if the amount of the antistatic agent added in terms of solid content exceeds 100, it will result in The release agent based on polysiloxane is also transferred to the surface of the adhesive layer, so the adhesive properties of the adhesive layer may be reduced.

In the present invention, the method of forming the adhesive layer 2 on the base film 1 of the antistatic surface protection film 10 and the method of bonding the release film 5 can be performed by a known method, and are not particularly limited. Specifically, (1) A method of applying the resin composition for forming the adhesive layer 2 on one surface of the base film 1 and drying the adhesive composition to form the adhesive layer, and then bonding the release film 5 to the method. (2) A method of applying the resin composition for forming the adhesive layer 2 on the surface of the release film 5 and drying it to form an adhesive layer, and then bonding the base film 1 and the like. Either method can be used.

When the adhesive layer 2 is formed on the surface of the base film 1, a known method can be used. Specifically, reverse coating, comma blade coating, gravure coating, slit extrusion coating, and Mayer bar can be used. A known coating method such as coating or air knife coating.

Similarly, when the release agent layer 4 is formed on the resin film 3, it can be performed by a well-known method. Specifically, well-known coating methods, such as gravure coating, Mylar bar coating, and air knife coating, can be used.

FIG. 2 is a cross-sectional view showing a state where a release film is peeled from the antistatic surface protection film of the present invention.

By peeling the release film 5 from the antistatic surface protective film 10 shown in FIG. 1, a part of the antistatic agent (reference numeral 7) contained in the release agent layer 4 of the release film 5 is transferred (attached). To the surface of the adhesive layer 2 of the antistatic surface protection film 10. Therefore, in FIG. 2, the antistatic agent transferred to the surface of the adhesive layer 2 of the antistatic surface protective film is schematically shown by the spots of reference numeral 7.

In the antistatic surface protection film of the present invention, when the antistatic surface protection film 11 in a state where the release film is peeled off as shown in FIG. 2 is attached to the adherend, it is transferred to the surface of the adhesive layer 2 The antistatic agent is in contact with the surface of the adherend. This makes it possible to suppress the peeling static voltage when the antistatic surface protective film is peeled from the adherend again.

FIG. 3 is a cross-sectional view showing an embodiment of an optical component of the present invention.

In a state where the release film 5 is peeled from the antistatic surface protection film 10 of the present invention and the adhesive layer 2 is exposed, the adhesive layer 2 is bonded to the optical member 8 as an adherend.

That is, FIG. 3 shows the optical component 20 to which the antistatic surface protective film 10 of the present invention is bonded. Examples of the optical component include optical films such as a polarizing plate, a retardation plate, a lens film, a polarizing plate also serving as a retardation plate, and a polarizing plate also serving as a lens film. This optical component is used as a liquid crystal display device such as a liquid crystal display panel. Components of optical systems and devices such as measuring instruments and various measuring instruments. Examples of the optical component include optical films such as antireflection films, hard coat films, and transparent conductive films for touch panels. In particular, it can be preferably used as a low-reflection-treated polarizing plate (LR-polarizing plate) or an anti-glare low-reflection-processing polarizing plate (AG-LR) bonded to a surface that has been subjected to anti-pollution treatment with a polysiloxane compound, a fluorine compound, or the like. An antistatic surface protective film on the surface of an optical film such as a polarizing plate) to which an antifouling treatment has been applied.

According to the optical member of the present invention, when the antistatic surface protective film 10 is peeled off from the optical member (optical film) as an adherend, the peeling static voltage can be sufficiently suppressed to a low level, so there is no need to worry about it. Destroying circuit components such as a driving IC, a TFT element, and a gate line driving circuit can improve the production efficiency in steps such as manufacturing a liquid crystal display panel and ensure the reliability of the production steps.

[Example]

Hereinafter, the present invention will be further described through examples.

〈Manufacture of adhesive composition〉

[Example 1]

Nitrogen was introduced into a reaction device equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube, thereby replacing the air in the reaction device with nitrogen. Then, 100 parts by weight of 2-ethylhexyl acrylate, 4.5 parts by weight of 8-hydroxyoctyl acrylate, and 10 parts by weight of polypropylene glycol monoacrylate (n = 12) were added to the reaction device. At the same time, 60 parts by weight of a solvent (ethyl acetate) was added. Then, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was dropped over 2 hours and reacted at a temperature of 65 ° C. for 6 hours to obtain an acrylic copolymer solution of Example 1 having a weight average molecular weight of 500,000. To this acrylic copolymer solution, 8.5 parts by weight of acetone and acetone were added and stirred. 2.5 parts by weight of Coronate HX (isocyanurate of a hexamethylene diisocyanate compound) and 0.1 parts by weight of titanium triacetamidine acetone were stirred and mixed to obtain the adhesive composition of Example 1.

[Examples 2 to 6 and Comparative Examples 1 to 3]

Except that each component of the adhesive composition of Example 1 was adjusted as described in Tables 1 and 2, the same operations as in Example 1 were performed to obtain the adhesives of Examples 2 to 6 and Comparative Examples 1 to 3. combination. In Tables 1 and 2, the monomers (copolymerized) contained in the acrylic copolymer are (A), (B), (F), and "carboxyl-containing monomer".

Tables 1 and 2 are tables in which the entire table showing the mixing ratio of each component is divided into two parts, and the values in parentheses represent the weight parts of each component obtained by setting the total amount of group (A) to 100 parts by weight. Value. In addition, the compound names corresponding to the abbreviations of the respective components used in Tables 1 and 2 are shown in Tables 3 and 4. In addition, Coronate ( , Registered trademarks) HX, Coronate HL and Coronate L are trade names of Nippon Polyurethane Industry Co., Ltd., Takenate ( , Registered trademarks) D-140N, D-127N, D-110N are the trade names of Mitsui Chemicals Co., Ltd. In the "antistatic agent" in Table 2 and Table 7 described later, LiTFSI means Li (CF ₃ SO ₂ ) ₂ N, LiFSI means Li (FSO ₂ ) ₂ N, LiTF means LiCF ₃ SO ₃ , and SH8400 means polyether modification Polysiloxane (Product name is SH8400, the main ingredient is Dimethyl, methyl (polyethylene oxide acetate-capped) siloxane), Dow Corning Dongli Co., Ltd. Co., Ltd.).

<Synthesis of Difunctional Isocyanate Compounds>

The difunctional isocyanate compounds of Synthesis Examples 1 and 2 were synthesized by the following method. That is, as shown in Tables 5 and 6, the diisocyanate and the diol compound were mixed at a molar ratio of NCO / OH = 16, reacted at 120 ° C for 3 hours, and then removed under reduced pressure using a thin film evaporation device. Unreacted diisocyanate gives the desired Difunctional isocyanate compound.

〈Manufacture of antistatic surface protection film〉

[Example 1]

5 parts by weight of an addition reaction type polysiloxane (product name is SRX-345, manufactured by Dow Corning Toray Corporation), 0.5 parts by weight of Li (CF ₃ SO ₂ ) ₂ N, and 95 parts by weight of A mixed solvent of toluene and ethyl acetate of 1: 1, and 0.05 parts by weight of a platinum catalyst (product name: SRX-212 Catalyst, manufactured by Dow Corning Toray Co., Ltd.) were mixed together and mixed by stirring. A coating for forming the release agent layer of Example 1. Using a Müller rod, the coating for forming the release agent layer of Example 1 was applied on the surface of a polyethylene terephthalate film having a thickness of 38 μm so that the thickness after drying was 0.2 μm. Then, it was dried in a hot-air loop-type oven at 120 ° C. for 1 minute to obtain the release film of Example 1.

The adhesive composition of Example 1 was applied on the surface of a polyethylene terephthalate film having a thickness of 38 μm so that the thickness after drying was 20 μm. Thereafter, it was dried in a hot-air loop-type oven at 100 ° C for 2 minutes to form an adhesive layer. Then, on the surface of the adhesive layer, a release agent layer (polysiloxane-treated surface) of the release film of Example 1 produced as described above was bonded. The obtained adhesive film was held in an environment at 40 ° C. for 5 days to cure the adhesive, and the antistatic surface protective film of Example 1 was obtained.

[Example 2]

The same procedure as in Example 1 was performed except that the adhesive composition of Example 1 was set to the adhesive composition of Example 2 and the antistatic agent used in the release agent layer was set to LiCF ₃ SO ₃ . The antistatic surface protective film of Example 2.

[Examples 3 to 6]

The adhesive composition of Example 1 was the same as that of Example 1 except that the adhesive composition of Examples 3 to 6 was used, and the antistatic agent used in the release agent layer was set to Li (FSO ₂ ) ₂ N. Operation was carried out to obtain the antistatic surface protective films of Examples 3 to 6.

[Comparative Example 1]

5 parts by weight of an addition reaction type polysiloxane (product name is SRX-345, manufactured by Dow Corning Toray Corporation), 95 parts by weight of a mixed solvent of toluene and ethyl acetate of 1: 1, and 0.05 parts by weight of a platinum catalyst (product name: SRX-212 Catalyst, manufactured by Dow Corning Toray Co., Ltd.) was mixed together and stirred to prepare a coating material for forming a release agent layer of Comparative Example 1. The paint used to form the release agent layer of Comparative Example 1 was applied to the surface of a polyethylene terephthalate film having a thickness of 38 μm using a Meyer bar so that the thickness after drying was 0.2 μm. And hot air loop oven at 120 ℃ Drying was performed for 1 minute, and the release film of Comparative Example 1 was obtained.

The adhesive composition of Comparative Example 1 was applied to the surface of a polyethylene terephthalate film having a thickness of 38 μm so that the thickness after drying was 20 μm, and then baked at 100 ° C. in a hot-air loop. Dry in the oven for 2 minutes to form an adhesive layer. Then, on the surface of the adhesive layer, a release agent layer (polysiloxane-treated surface) of the release film of Comparative Example 1 produced as described above was bonded. The obtained adhesive film was kept in an environment at 40 ° C. for 5 days to cure the adhesive, and an antistatic surface protective film of Comparative Example 1 was obtained.

[Comparative Example 2]

An antistatic surface protective film of Comparative Example 2 was obtained in the same manner as in Comparative Example 1 except that the adhesive composition of Comparative Example 1 was replaced with the adhesive composition of Comparative Example 2.

[Comparative Example 3]

The operation was performed in the same manner as in Example 1 except that the adhesive composition of Example 1 was set to the adhesive composition of Comparative Example 3, and the antistatic agent used in the release agent layer was set to Li (FSO ₂ ) ₂ N. An antistatic surface protective film of Comparative Example 3 was obtained.

Table 7 shows the composition of the release agent layer in the antistatic surface protective films of Examples 1 to 6 and Comparative Examples 1 to 3.

<Test method and evaluation>

After the surface protective films of Examples 1 to 6 and Comparative Examples 1 to 3 were aged at 23 ° C and 50% RH for 7 days, the release film (a silicone resin-coated PET film) was peeled off to cause adhesion. The agent layer was exposed and used as a sample for measuring surface resistivity.

Furthermore, the exposed surface protective film of the adhesive layer was bonded to the surface of the polarizing plate pasted on the liquid crystal cell through the adhesive layer, and after being left for 1 day, it was subjected to autoclave treatment at 50 ° C and 5 atmospheres for 20 minutes. After being left at room temperature for 12 hours, it was used as a sample for measuring the adhesive force, peeling static voltage, and reworkability.

<Adhesion>

Using a tensile tester, the measurement sample obtained above was peeled in a 180 ° direction at a low peel speed (0.3 m / min) and a high peel speed (30 m / min) (a 25 mm wide surface protective film was bonded to polarized light) A sample formed on the surface of a plate), and the peeling strength was measured, and this peeling strength was used as the adhesive force.

<Surface resistivity>

After etching and before bonding to the polarizing plate, peel off the release film (PET film coated with silicone resin) to expose the adhesive layer. Use resistivity meter HirestaUP-HT450 (Mitsubishi Chemical Analysis Technology Co., Ltd. (Mitsubishi Chemical Analytech Co., Ltd.), and the surface resistivity of the adhesive layer was measured.

<Peeling Static Voltage>

Using high-precision electrostatic sensors SK-035 and SK-200 (manufactured by Keyence Corporation), it was measured that the measurement sample obtained above was subjected to a tensile speed of 180 ° at a speed of 30 m / min. The voltage (static voltage) generated by the electrification of the polarizing plate at the time of peeling is the maximum value of the measured value as the peeling static voltage.

<Reworkability>

After drawing on the surface protective film of the measurement sample obtained above with a ballpoint pen (load of 500 g, three times back and forth), the surface protective film was peeled from the polarizing plate, and the surface of the polarizing plate was observed to confirm whether contamination was transferred to the polarizing plate. Evaluation target standard: When the pollution is not transferred to the polarizing plate, it is evaluated as "○"; when it is confirmed that the trace traced by the ball-point pen is at least partially transferred, it is evaluated as "△"; when it is confirmed that the trace traced by the ball-point pen is contaminated and transferred In addition, when the detachment of the adhesive was also confirmed from the surface of the adhesive, it was evaluated as “×”.

The evaluation results are shown in Table 8. Further, the surface resistivity by "mE + n" to represent "m × 10 ^{+ n"} (where, m is an arbitrary real numbers, n-is a positive integer).

From the measurement results shown in Table 8, the following can be understood.

The antistatic surface protection films of Examples 1 to 6 of the present invention have proper adhesion and have no pollution to the surface of the adherend, and the peeling static voltage when peeling the antistatic surface protection film from the adherend is low.

On the other hand, in the antistatic surface protective film of Comparative Example 1 in which a polysiloxane compound and an antistatic agent were added to the adhesive layer, the surface resistivity of the adhesive layer was low and good, but the adhesive force was large. For this reason, the peeling static voltage is high and the reworkability is poor. In addition, in Comparative Example 2, the adhesive may be gelled due to the large amount of the crosslinking accelerator added, and coating may not be performed. In addition, in Comparative Example 3, since a carboxyl group-containing monomer was included, the adhesive force was large and the reworkability was slightly inferior.

That is, in Comparative Examples 1 and 2 in which a polysiloxane compound and an antistatic agent were mixed in an adhesive, it was difficult to satisfy both the reduction of the peeling static voltage and the improvement of the contamination of the adherend. On the other hand, Examples 1 to 6 in which the antistatic agent was added to the release agent layer and the antistatic agent was transferred to the surface of the adhesive layer had the effect of reducing the peeling static voltage with a small amount of addition. The adherend was also not contaminated, and a good antistatic surface protective film was obtained.

[Industrial availability]

The antistatic surface protective film of the present invention can be applied to, for example, optical films such as polarizing plates, retardation plates, and lens films for displays. In addition, in the production steps of various optical components and the like, the optical films can be protected. Components and other surfaces. In particular, when used as an antistatic surface protective film for an optical film such as an LR polarizing plate or an AG-LR polarizing plate whose surface has been subjected to antifouling treatment with a polysiloxane compound, a fluorine compound, or the like, it can be reduced. The amount of static electricity generated when peeling from the adherend.

The antistatic surface protection film of the present invention has less pollution to adherends, does not deteriorate with time, and has excellent anti-peeling electrostatic performance. Therefore, it can improve the yield of production steps and has high industrial application value.

Claims (16)

An antistatic surface protective film is manufactured through the following steps (1) to (2) in order, and step (1): forming a bonding agent on one side of a substrate film made of a transparent resin A step of an adhesive layer composed of a composition, the adhesive composition comprising: (A) an alkyl group containing at least one of (C) to C18 (meth) acrylic acid ester monomers and a copolymerizable monomer The acrylic polymer containing a copolymer of at least one of (B) a hydroxyl group-containing copolymerizable monomer without a carboxyl group-containing copolymerizable monomer, and (C) a difunctional or higher-functional isocyanate compound, (D ) A cross-linking accelerator and (E) a keto-enol tautomer compound, step (2): a release film in which a release agent layer containing an antistatic agent is laminated on one side of a resin film, The step of attaching a release agent layer to the surface of the adhesive layer, the release agent layer is formed by a resin composition containing a release agent containing dimethylpolysiloxane as a main component and an antistatic agent, and is bonded. The peeling static voltage of the agent layer is ± 0.6 kV or less. The antistatic surface protection film according to item 1 of the scope of the patent application, wherein the copolymerizable monomer group further contains (F) a polyalkylene glycol mono (meth) acrylate monomer. The antistatic surface protection film according to item 1 or 2 of the scope of the patent application, wherein the (D) crosslinking accelerator is selected from the group consisting of an aluminum chelate, a titanium chelate, and an iron chelate The content of the (D) cross-linking accelerator is 0.001 to 0.5 parts by weight with respect to 100% by weight or more of the acrylic polymer of the copolymer, and the (E) keto-enol The content of the tautomer compound is 0.1 to 300 parts by weight, and the ratio of (E) / (D) by weight is 70 to 1,000. The antistatic surface protective film according to item 1 or 2 of the scope of the patent application, wherein the (B) hydroxyl-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth) acrylate, (formaldehyde) 6-hydroxyhexyl acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (methyl ) At least one or more of a compound group consisting of acrylamide and N-hydroxyethyl (meth) acrylamide, the (B) containing 100 parts by weight of the acrylic polymer of the copolymer The copolymerizable monomer of the hydroxyl group is 0.1 to 10 parts by weight. The antistatic surface protective film according to item 2 of the scope of patent application, wherein the (F) polyalkylene glycol mono (meth) acrylate monomer is selected from polyalkylene glycol mono (meth) At least one or more of acrylate) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate, with respect to 100 parts by weight of The copolymer is an acrylic polymer, and the (F) polyalkylene glycol mono (meth) acrylate monomer is 0 to 50 parts by weight. The antistatic surface protective film according to item 1 or 2 of the scope of the patent application, wherein, for the (C) difunctional or higher isocyanate compound, the difunctional isocyanate compound is an acyclic aliphatic isocyanate compound and is A compound produced by the reaction of a diisocyanate compound and a diol compound. The diisocyanate compound is an aliphatic diisocyanate and is selected from the group consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, One of a group of compounds consisting of trimethylhexamethylene diisocyanate and lysine diisocyanate, the diol compound is selected from the group consisting of 2-methyl 1,3-propanediol, 2,2-dimethyl -1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 3-methyl-1,5-pentane One of a group of compounds consisting of diol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate, polyethylene glycol, and polypropylene glycol. As the trifunctional isocyanate compound, hexamethylene bis Isocyanurate of isocyanate compound, isophorone diisocyanate compound Cyanurate, adduct of hexamethylene diisocyanate compound, adduct of isophorone diisocyanate compound, biuret of hexamethylene diisocyanate compound, condensation of isophorone diisocyanate compound Addition of diurea, isocyanurate of toluene diisocyanate compound, isocyanurate of xylylene diisocyanate compound, isocyanurate of hydrogenated xylylene diisocyanate compound, addition of toluene diisocyanate compound Product, an adduct of a xylylene diisocyanate compound, and an adduct of a hydrogenated xylylene diisocyanate compound, with respect to 100 parts by weight of the acrylic polymer of the copolymer, the (C) difunctional The above isocyanate compound is 0.1 to 10 parts by weight. The antistatic surface protective film according to item 1 or 2 of the scope of the patent application, wherein the adhesive composition contains 1.0 part by weight or less of 100 parts by weight of the acrylic polymer of the copolymer ( (G) (Excluding the case of 0 parts by weight) (G) A polyether-modified silicone compound having an HLB value of 7 to 15. The antistatic surface protection film according to item 1 or 2 of the scope of the patent application, wherein the antistatic agent in the release agent layer is an alkali metal salt. The antistatic surface protection film according to item 1 or 2 of the scope of the patent application, wherein the antistatic agent in the release agent layer is a Li salt selected from the group consisting of Li (CF ₃ SO ₂ ) ₂ N, Li (FSO ₂ ) ₂ N and at least one of a compound group consisting of LiCF ₃ SO ₃ . An antistatic surface protective film is formed by forming an adhesive layer composed of an adhesive composition on one side of a substrate film composed of a resin having transparency, and on the surface of the adhesive layer, a resin A release agent film in which a release agent layer containing an antistatic agent is laminated on one side of the film, and the release agent layer is bonded together. The adhesive composition includes a carbon atom containing an (A) alkyl group. At least one of (C) to C18 (meth) acrylate monomers and at least one of (B) a copolymerizable monomer containing a hydroxyl group and a copolymerizable monomer group that does not include a carboxyl group-containing copolymerizable monomer An acrylic polymer of a copolymer; further comprising (C) a difunctional or higher isocyanate compound, (D) a crosslinking accelerator, and (E) a keto-enol tautomer compound, the release agent layer is A resin composition containing a release agent containing dimethylpolysiloxane as a main component and an antistatic agent. The antistatic surface protective film according to item 10 of the scope of application for a patent, wherein the copolymerizable monomer group further contains (F) a polyalkylene glycol mono (meth) acrylate monomer. The antistatic surface protective film according to item 10 or 11 of the scope of the patent application, wherein the adhesive composition contains 1.0 part by weight or less of 100 parts by weight of the acrylic polymer of the copolymer ( (G) (Excluding the case of 0 parts by weight) (G) A polyether-modified silicone compound having an HLB value of 7 to 15. The antistatic surface protection film according to item 10 or 11 of the scope of application for a patent, wherein the antistatic agent in the release agent layer is an alkali metal salt. The antistatic surface protection film according to item 10 or 11 of the scope of the patent application, wherein the antistatic agent in the release agent layer is a Li salt selected from the group consisting of Li (CF ₃ SO ₂ ) ₂ N, Li (FSO ₂ ) ₂ N and at least one of a compound group consisting of LiCF ₃ SO ₃ . An optical film is bonded with the antistatic surface protective film described in any one of the claims 1 to 14 of the patent application scope. An optical component is bonded with the antistatic surface protective film described in any one of the claims 1 to 14 of the scope of patent application.