KR102270918B1 - Antistatic surface-protective film - Google Patents

Abstract

The present invention provides an antistatic surface protection film that has little contamination on an adherend, does not deteriorate over time, and has excellent peeling antistatic performance. On one side of the base film 1 made of a resin having transparency, (A) at least one of (meth)acrylic acid ester monomers having C4-C18 alkyl groups and copolymerizable monomers containing a carboxyl group are not included. , (B) consisting of an acrylic polymer of a copolymer containing at least one copolymerizable monomer containing a hydroxyl group, further (C) a bifunctional or more functional isocyanate compound, (D) a crosslinking accelerator, (E) keto A pressure-sensitive adhesive layer (2) made of a pressure-sensitive adhesive composition containing an enol tautomer compound is formed, a release film (5) having a release agent layer (4) laminated is bonded to the surface thereof, and a release agent layer (4) is dimethylpolysiloxane Contains a release agent and an antistatic agent containing as a main component.

Description

Antistatic surface protection film {ANTISTATIC SURFACE-PROTECTIVE FILM}

The present invention relates to a pressure-sensitive adhesive composition and a surface protection film. More specifically, it relates to an antistatic surface protection film having antistatic performance. More specifically, it is to provide a method for producing an antistatic surface protection film and an antistatic surface protection film having little contamination to an adherend, which does not deteriorate over time, and has excellent peeling and antistatic performance.

Optical films such as polarizing plates, retardation plates, display lens films, antireflection films, hard coat films, and transparent conductive films for touch panels, and optical products such as displays using the same are manufactured and transported on the surface of the optical film A surface protection film is pasted together, and preventing the surface contamination and a flaw in a post process is performed. The visual inspection of the optical film which is a product may be performed in the state which pasted the surface protection film to the film for optics in order to reduce the trouble of peeling and bonding a surface protection film again, and to raise work efficiency.

DESCRIPTION OF RELATED ART Conventionally, the surface protection film which formed the adhesive layer on one side of a base film WHEREIN: In the manufacturing process of an optical product, in order to prevent adhesion of a flaw or contamination, it is generally used. A surface protection film is bonded to the film for optics through the adhesive layer of non-adhesive force. The non-adhesive force of the pressure-sensitive adhesive layer enables easy peeling when peeling and removing the used surface protection film from the surface of the optical film, and prevents the adhesive from remaining attached to the optical film of the product as an adherend ( That is, to prevent the generation of the adhesive residue).

In recent years, in the production process of a liquid crystal display panel, circuit components, such as a driver IC for controlling the display screen of a liquid crystal display panel by the peeling electrification voltage which arises when peeling and removing the surface protection film bonded on the optical film. Although this phenomenon of destruction and the phenomenon in which the orientation of a liquid crystal molecule is impaired are few occurrences, it is occurring.

Further, in order to reduce the power consumption of the liquid crystal display panel, the driving voltage of the liquid crystal material is lowered, and accordingly, the breakdown voltage of the driver IC is also lowered. In recent years, it is calculated|required that the peeling electrification voltage shall be in the range of +0.7 kV - 0.7 kV.

For this reason, when peeling a surface protection film from the optical film which is a to-be-adhered body, in order to prevent generation|occurrence|production of the problem by the high peeling electrification voltage, the surface protection using the adhesive layer containing the antistatic agent for suppressing the peeling electrification voltage low. A film is being proposed.

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

Further, Patent Document 2 discloses a pressure-sensitive adhesive composition comprising an ionic liquid and an acrylic polymer having an acid value of 1.0 or less, and pressure-sensitive adhesive sheets using the same.

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

Moreover, the adhesive composition which consists of an ionic liquid, an alkali metal salt, and a polymer with a glass transition temperature of 0 degreeC or less in patent document 4, and the surface protection film using the are disclosed.

Moreover, mixing polyether-modified silicone in the adhesive layer of a surface protection film is disclosed by patent document 5, 6.

Japanese Laid-Open Patent Publication No. 2005-131957 Japanese Laid-Open Patent Publication No. 2005-330464 Japanese Laid-Open Patent Publication No. 2005-314476 Japanese Laid-Open Patent Publication No. 2006-152235 Japanese Patent Laid-Open No. 2009-275128 Japanese Patent Publication No. 4537450

In Patent Documents 1 to 4, an antistatic agent is added to the inside of the pressure-sensitive adhesive layer, but as the thickness of the pressure-sensitive adhesive layer increases, and as time elapses, the pressure-sensitive adhesive layer is applied to the adherend to which the surface protection film is pasted. The amount of the antistatic agent transferred to the adherend increases. In addition, in optical films such as LR (Low Reflective) polarizing plates and AG (Anti Glare)-LR polarizing plates, the surface of the optical film is antifouling treated with a silicone compound or a fluorine compound. The peeling electrification voltage at the time of peeling a protective film from the optical film which is a to-be-adhered body becomes high.

Moreover, when polyether-modified silicone is mixed in the adhesive layer of patent documents 5 and 6, it is difficult to fine-tune the adhesive force of a surface protection film. In addition, since polyether-modified silicone is mixed in the pressure-sensitive adhesive layer, when the conditions for coating and drying the pressure-sensitive adhesive composition on the base film change, the surface properties of the pressure-sensitive adhesive layer with the surface protection film are delicately changed. Moreover, from a viewpoint of protecting the surface of the film for optics, the thickness of an adhesive layer cannot be made extremely thin. For this reason, it is necessary to increase the amount of polyether-modified silicone to be mixed in the pressure-sensitive adhesive layer according to the thickness of the pressure-sensitive adhesive layer. change

In recent years, with the spread of 3D displays (stereoscopic display), there exists a thing which bonded FPR(Film Patterned Retarder) film on the surface of films for optics, such as a polarizing plate. After peeling the surface protection film pasted on the surface of films for optics, such as a polarizing plate, an FPR film is pasted together. However, when the surface of optical films, such as a polarizing plate, is contaminated with the adhesive and antistatic agent used for a surface protection film, there exists a problem that an FPR film is hard to adhere|attach. For this reason, it is calculated|required that there are few contaminations with respect to a to-be-adhered body as for the surface protection film used for the said use.

On the other hand, in some liquid crystal panel manufacturers, as a method for evaluating the staining property of a surface protection film to an adherend, the surface protection film pasted to an optical film such as a polarizing plate is peeled once and re-bonded in a state in which air bubbles are mixed. After heat-processing under predetermined conditions, the method of peeling a surface protection film and observing the surface of a to-be-adhered body is employ|adopted. In this evaluation method, even if the surface contamination of the adherend is very small, if there is a difference in the surface contamination of the adherend between the part where bubbles are mixed and the part where the pressure-sensitive adhesive of the surface protection film is in contact, there is a trace of bubbles (it is sometimes called bubble unevenness) ) remains as For this reason, it becomes a very strict evaluation method as an evaluation method of the contamination with respect to the surface of a to-be-adhered body. In recent years, there has been a demand for a surface protection film that does not have a problem in contamination on the surface of an adherend even as a result of judgment by such a strict evaluation method. However, it was a difficult situation for the surface protection film using the adhesive layer containing the antistatic agent proposed conventionally to solve the said subject.

For this reason, as a surface protection film used for the film for optics, there is very little contamination with respect to a to-be-adhered body, and it is required that the contamination with respect to a to-be-adhered body does not change with time. Moreover, the surface protection film which suppressed the peeling electrification voltage at the time of peeling from a to-be-adhered body low is calculated|required.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to solve this subject.

In order to reduce the amount of contamination on the adherend and also to reduce the change in antistatic performance over time, it is necessary to reduce the amount of the antistatic agent added, which is presumed to be the cause of contamination of the adherend. However, when the addition amount of an antistatic agent is reduced, the peeling electrification voltage at the time of peeling a surface protection film from a to-be-adhered body becomes high. The present inventors investigated the method of suppressing the peeling electrification voltage low at the time of peeling a surface protection film from a to-be-adhered body without increasing the absolute amount of the addition amount of an antistatic agent. As a result, instead of adding and mixing an antistatic agent in the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition is coated and dried to laminate the pressure-sensitive adhesive layer, and then an appropriate amount of an antistatic agent component is applied to the surface of the pressure-sensitive adhesive layer to protect the surface. It discovered that the peeling electrification voltage at the time of peeling a film from the optical film which is a to-be-adhered body can be suppressed low, and completed this invention.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an antistatic surface protection film having little contamination to an adherend, not deteriorated with time, and having excellent peeling and antistatic performance.

In order to solve the above problems, the antistatic surface protection film of the present invention is coated and dried with an adhesive composition to laminate an adhesive layer, and then an appropriate amount of an antistatic agent is applied to the surface of the adhesive layer. It is making it a technical idea to suppress low the peeling electrification voltage at the time of peeling from the optical film which is a to-be-adhered body, suppressing low.

In order to solve the above problems, the present invention provides an antistatic surface protection film, the following steps (1) to (2),

Step (1): on one side of a base film made of a resin having transparency, (A) at least one of (meth)acrylic acid ester monomers having C4-C18 alkyl groups and a carboxyl group as a monomer group copolymerizable with It does not contain a copolymerizable monomer, but (B) consists of an acrylic polymer of a copolymer containing at least one type of copolymerizable monomer containing a hydroxyl group, and further (C) a bifunctional or more functional isocyanate compound, (D) crosslinking A step of forming a pressure-sensitive adhesive layer comprising an accelerator and (E) a pressure-sensitive adhesive composition containing a ketoenol tautomer compound;

Step (2): A release film in which a release agent layer containing an antistatic agent is laminated on one surface of a resin film on the surface of the pressure-sensitive adhesive layer is laminated through the release agent layer in order through a step of bonding, The release agent layer is made of a release agent containing dimethylpolysiloxane as a main component and a resin composition containing an antistatic agent, and provides an antistatic surface protection film, characterized in that the peeling electrification voltage of the pressure-sensitive adhesive layer is ±0.6 kV or less .

Moreover, it is preferable to contain (F) polyalkylene glycol mono(meth)acrylic acid ester monomer further as said copolymerizable monomer group.

In addition, the (D) crosslinking accelerator is at least one selected from the group consisting of an aluminum chelate compound, a titanium chelate compound, and an iron chelate compound, and contains 0.001 to 0.5 parts by weight based on 100 parts by weight of the acrylic polymer of the copolymer. and 0.1 to 300 parts by weight of the (E) ketoenol tautomer compound, and the ratio by weight of (E)/(D) is preferably 70 to 1000.

In addition, (B) the copolymerizable monomer containing a hydroxyl group is 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy At least one selected from the group consisting of hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and N-hydroxyethyl (meth) acrylamide; , It is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the acrylic polymer of the copolymer.

In addition, as the copolymerizable monomer group, (F) with or without a polyalkylene glycol mono (meth) acrylic acid ester monomer, the (F) polyalkylene glycol mono (meth) acrylic acid ester monomer is a poly At least one selected from alkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate, 100 parts by weight of the acrylic polymer of the copolymer It is preferable that it is 0-50 weight part with respect to it.

In addition, as the (C) bifunctional isocyanate compound, the bifunctional isocyanate compound is an acyclic aliphatic isocyanate compound, a compound produced by reacting a diisocyanate compound with a diol compound, and the diisocyanate compound is an aliphatic diisocyanate compound, One selected from the group of compounds consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate, and the diol compound includes 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 - Consists of one selected from the group consisting of pentanediol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate, polyethylene glycol, and polypropylene glycol, and the trifunctional isocyanate compound is hexamethylene di The isocyanurate body of the isocyanate compound, the isocyanurate body of the isophorone diisocyanate compound, the adduct body of the hexamethylene diisocyanate compound, the adduct body of the isophorone diisocyanate compound, the biuret body of the hexamethylene diisocyanate compound, Biuret form of isophorone diisocyanate compound, isocyanurate form of tolylene diisocyanate compound, isocyanurate form of xylylene diisocyanate compound, isocyanurate form of hydrogenated xylylene diisocyanate compound, and tolylene diisocyanate compound It consists of an adduct body, the adduct body of a xylylene diisocyanate compound, and the adduct body of a hydrogenated xylylene diisocyanate compound, It is preferable that it is 0.1-10 weight part with respect to 100 weight part of acrylic polymers of the said copolymer.

In addition, in the pressure-sensitive adhesive composition (G) the polyether-modified siloxane compound having an HLB value of 7 to 15, 1.0 parts by weight or less (excluding the case of 0 parts by weight) based on 100 parts by weight of the acrylic polymer of the copolymer. desirable.

Moreover, it is preferable that the antistatic agent in the said release agent layer is an alkali metal salt.

In addition, it is preferable that the antistatic agent in the release agent layer is a Li salt, and at least one selected from the group consisting of _{Li(CF 3} SO ₂ ) ₂ N, Li(FSO ₂ ) ₂ N, and LiCF ₃ SO _{3 .}

In addition, in order to solve the above problem, the present invention is copolymerizable with (A) at least one (meth)acrylic acid ester monomer having C4 to C18 carbon atoms in the alkyl group on one side of a base film made of a resin having transparency. It does not contain a copolymerizable monomer containing a carboxyl group as a monomer group, but (B) consists of an acrylic polymer of a copolymer containing at least one copolymerizable monomer containing a hydroxyl group, and further (C) a bifunctional or more isocyanate A pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition containing a compound, (D) a crosslinking accelerator, and (E) a ketoenol tautomer compound is formed, and an antistatic agent is applied to one side of the resin film on the surface of the pressure-sensitive adhesive layer. A release film comprising a release agent layer laminated thereon is bonded through the release agent layer, and the release agent layer is formed of a resin composition containing a release agent containing dimethylpolysiloxane as a main component and an antistatic agent. Provides an anti-surface protective film.

Moreover, it is preferable to contain (F) polyalkylene glycol mono(meth)acrylic acid ester monomer further as said copolymerizable monomer group.

In addition, in the pressure-sensitive adhesive composition, (G) a polyether-modified siloxane compound having an HLB value of 7 to 15, 1.0 parts by weight or less (excluding the case of 0 parts by weight) based on 100 parts by weight of the acrylic polymer of the copolymer. it is preferable

Moreover, it is preferable that the antistatic agent in the said release agent layer is an alkali metal salt.

In addition, it is preferable that the antistatic agent in the release agent layer is a Li salt, and at least one selected from the group consisting of _{Li(CF 3} SO ₂ ) ₂ N, Li(FSO ₂ ) ₂ N, and LiCF ₃ SO _{3 .}

Moreover, this invention provides the film for optics in which the said antistatic surface protection film is pasted together.

Moreover, this invention provides the optical component by which the said antistatic surface protection film is pasted together.

The antistatic surface protection film of the present invention has little contamination on the adherend, and the low contamination on the adherend does not change over time. Further, according to the present invention, even when the surface of an adherend, such as an LR polarizing plate or an AG-LR polarizing plate, is an optical film in which the surface of the adherend is antifouling treated with a silicone compound or a fluorine compound, etc., when the antistatic surface protection film is peeled from the adherend It is possible to provide an antistatic surface protection film that can suppress the generated peeling electrification voltage low, does not deteriorate over time, and has excellent peeling antistatic performance.

ADVANTAGE OF THE INVENTION According to the antistatic surface protection film of this invention, the improvement of productivity and the improvement of a yield can be aimed at at the point which can protect the surface of an optical film reliably.

1 is a cross-sectional view showing the concept of the antistatic surface protection film of the present invention.
It is sectional drawing which shows the state which peeled the peeling film from the antistatic surface protection film of this invention.
3 is a cross-sectional view showing one embodiment of the optical component of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on embodiment.

1 is a cross-sectional view showing the concept of the antistatic surface protection film of the present invention. As for this antistatic surface protection film 10, the adhesive layer 2 is formed in the surface of one side of the transparent base film 1. The release film 5 in which the release agent layer 4 was formed in the surface of the resin film 3 is pasted together on the surface of this adhesive layer 2 .

As the base film 1 used for the antistatic surface protection film 10 according to the present invention, a base film made of a resin having transparency and flexibility is used. Thereby, the external appearance inspection of an optical component can be performed in the state which bonded the antistatic surface protection film to the optical component which is a to-be-adhered body. As for the film which consists of resin which has transparency used as the base film 1, Preferably, polyester films, such as a polyethylene terephthalate, a polyethylene naphthalate, a polyethylene isophthalate, and a polybutylene terephthalate, are used. In addition to the polyester film, a film made of another resin can be used as long as it has a required strength and has optical aptitude. An unstretched film may be sufficient as the base film 1, and the uniaxially or biaxially stretched film may be sufficient as it. Moreover, you may control the orientation angle of the axial method formed with the draw ratio of a stretched film and crystallization of a stretched film to a specific value.

Although the thickness of the base film 1 used for the antistatic surface protection film 10 according to the present invention is not particularly limited, for example, a thickness of about 12 to 100 μm is preferable, and a thickness of about 20 to 50 μm. It is easy to handle, and it is more preferable.

In addition, an antifouling layer for preventing surface contamination, an antistatic layer, a scratch preventing hard coat layer, etc. may be formed on the surface opposite to the surface on which the pressure-sensitive adhesive layer 2 is formed of the base film 1 as needed. Moreover, you may give easily adhesion processing, such as surface modification by corona discharge and application|coating of an anchor coat agent, to the surface of the base film 1.

In addition, the pressure-sensitive adhesive layer 2 used in the antistatic surface protection film 10 according to the present invention adheres to the surface of the adherend, is easily peeled off after use, and is particularly difficult to contaminate the adherend. Although not limited, when the durability after bonding to the film for optics, etc. are considered, it is common to use the acrylic adhesive formed by bridge|crosslinking a (meth)acrylate copolymer.

In particular, the main ingredient of the acrylic pressure-sensitive adhesive does not contain a copolymerizable monomer containing (A) at least one (meth)acrylic acid ester monomer having an alkyl group having C4-C18 carbon atoms and a carboxyl group as a copolymerizable monomer group, but (B) a hydroxyl group A pressure-sensitive adhesive layer made of an acrylic polymer of a copolymer containing at least one copolymerizable monomer containing

As the copolymerizable monomer group, it may further include (F) polyalkylene glycol mono (meth) acrylic acid ester monomer.

Further, the pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition containing (C) a bifunctional or more functional isocyanate compound, (D) a crosslinking accelerator, and (E) a ketoenol tautomer compound in addition to the acrylic polymer is preferred.

(A) Examples of (meth)acrylic acid ester monomers having C4 to C18 alkyl group carbon atoms include butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate Acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate , hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, myristyl (meth) acrylate, isomyristyl (meth) acrylate, cetyl (meth) acrylate, iso Cetyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, etc. are mentioned.

When the total of the acrylic polymer of the copolymer is 100 parts by weight, it is preferable to contain (A) the (meth)acrylic acid ester monomer having C4-C18 carbon atoms in the alkyl group in a proportion of 50 to 95 parts by weight.

(B) Examples of the hydroxyl group-containing copolymerizable monomer include 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy Hydroxyalkyl (meth)acrylates, such as ethyl (meth)acrylate, N-hydroxy (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, etc. and hydroxyl group-containing (meth)acrylamides.

8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) ) It is preferable that it is at least 1 sort(s) selected from the compound group which consists of acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide.

When the sum total of the acrylic polymer of a copolymer is 100 weight part, it is preferable to contain the said (B) hydroxyl-containing copolymerizable monomer in the ratio of 0.1-10 weight part.

(C) What is necessary is just to be at least 1 type or 2 or more types chosen from the polyisocyanate compound which has at least 2 or more isocyanate (NCO) groups in 1 molecule as a bifunctional or more than isocyanate compound. Although there exist classifications, such as an aliphatic type isocyanate, an aromatic type isocyanate, an acyclic type isocyanate, and an alicyclic type isocyanate, a polyisocyanate compound may be any. 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), and aromatic isocyanate compounds such as xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H6XDI), dimethyl diphenylene diisocyanate (TOID), and tolylene diisocyanate (TDI).

As the trifunctional or more functional isocyanate compound, a bifunctional isocyanate compound (a compound having two NCO groups in one molecule) of a burette-modified product or an isocyanurate-modified product, trimethylolpropane (TMP) or a polyol (1) having more than trivalence, such as glycerin Adduct body (polyol modified body) etc. with the compound which has at least 3 or more OH groups in a molecule|numerator) are mentioned.

(C) It is also possible to use only the (C-1) trifunctional isocyanate compound or only the (C-2) bifunctional isocyanate compound as a bifunctional or more than bifunctional isocyanate compound. Moreover, it is also possible to use together the (C-1) trifunctional isocyanate compound and the (C-2) bifunctional isocyanate compound.

In addition, as (C-1) trifunctional isocyanate compound used for this invention, the isocyanurate form of a hexamethylene diisocyanate compound, the isocyanurate form of an isophorone diisocyanate compound, and a hexamethylene diisocyanate compound At least one selected from the group of (C-1-1) first aliphatic isocyanate compounds, comprising a duct body, an adduct body of an isophorone diisocyanate compound, a biuret body of a hexamethylene diisocyanate compound, and a biuret body of an isophorone diisocyanate compound More than one species, the isocyanurate form of a tolylene diisocyanate compound, the isocyanurate form of the xylylene diisocyanate compound, the isocyanurate form of the hydrogenated xylylene diisocyanate compound, the adduct form of the tolylene diisocyanate compound, xyl It is preferable to contain at least one or more selected from the group of (C-1-2) second aromatic isocyanate compounds comprising an adduct body of a lylene diisocyanate compound and an adduct body of a hydrogenated xylylene diisocyanate compound. (C-1-1) It is preferable to use together the 1st aliphatic isocyanate compound group and (C-1-2) 2nd aromatic isocyanate compound group. In the present invention, as the (C-1) trifunctional isocyanate compound, (C-1-1) at least one selected from the first aliphatic isocyanate compound group and (C-1-2) from the second aromatic isocyanate compound group By using together the selected at least 1 sort(s), the adhesive force balance of a low-speed peeling area|region and a high-speed peeling area|region can further be improved.

In addition, the (C-1) trifunctional isocyanate compound includes at least one selected from the group of (C-1-1) first aliphatic isocyanate compounds, and (C-1-2) the second group of aromatic isocyanate compounds. Including at least one selected from among, it is preferable that 0.5 to 5.0 parts by weight in total are included with respect to 100 parts by weight of the acrylic polymer of the copolymer. In addition, the mixing ratio of (C-1-1) at least one selected from the first aliphatic isocyanate compound group and (C-1-2) at least one selected from the second aromatic isocyanate compound group is (C- 1-1): (C-1-2) is preferably in the range of 10%:90% to 90%:10% by weight.

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

For example, a diisocyanate compound represented by the formula "O=C=NXN=C=O" (where X is a divalent group) and a diol compound represented by a formula "HO-Y-OH" (where Y is a divalent group) In this case, as a compound produced|generated by making a diisocyanate compound and a diol compound react, the compound represented by following formula (Z) is mentioned, for example.

[Formula Z]

O=C=NX-(NH-CO-OYO-CO-NH-X) _n -N=C=O

Here, n is an integer greater than or equal to 0. When n is 0, the formula Z represents "O=C=N-X-N=C=O". As the bifunctional acyclic aliphatic isocyanate compound, in the formula (Z), a compound in which n is 0 (a diisocyanate compound unreacted with respect to the diol compound) may be included, but it is preferable to include a compound in which n is an integer of 1 or more as an essential component. The bifunctional acyclic aliphatic isocyanate compound may be a mixture composed of a plurality of compounds having different n in the general formula (Z).

The diisocyanate compound represented by the general formula "O=C=N-X-N=C=O" is an aliphatic diisocyanate. X is preferably an acyclic and aliphatic divalent group. As said aliphatic diisocyanate, it is preferable that it consists of 1 type or 2 or more types selected from the compound group which consists of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, and lysine diisocyanate.

The diol compound represented by the general formula "HO-Y-OH" is an aliphatic diol. Y is preferably an acyclic and aliphatic divalent group. Examples of the diol compound include 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-pentanediol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate, from the group of compounds consisting of polyethylene glycol and polypropylene glycol It is preferable that it consists of 1 type or 2 or more types selected.

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

(D) The crosslinking accelerator may be a material that functions as a catalyst for the reaction (crosslinking reaction) of the copolymer and the crosslinking agent when a polyisocyanate compound is used as a crosslinking agent. An amine compound such as a tertiary amine, a metal chelate compound and organometallic compounds such as organotin compounds, organolead compounds, and organozinc compounds. In the present invention, as the crosslinking accelerator, a metal chelate compound or an organotin compound is preferable.

The metal chelate compound is a compound in which one or more polydentate ligands L are bonded to a central metal atom M. The metal chelate compound may or may not have one or more monodentate ligands X bonded to the metal atom M. For example, when the chemical formula of a metal chelate compound having one metal atom M is _{expressed as M(L) m} (X) _n , m≧1, n≧0. When m is 2 or more, the m pieces of L may be the same ligand or different ligands. When n is 2 or more, the n pieces of 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, Sn, and the like.

Examples of the polydentate ligand L include β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate, and acetylacetone (also known as 2,4-pentanedione). and β-diketones such as , 2,4-hexanedione and benzoylacetone. These are ketoenol tautomer compounds, and in the polydentate ligand L, enolates in which the enol is deprotonated (eg, acetylacetonate) may be used.

Examples of the monodentate ligand X include a halogen atom such as a chlorine atom and a bromine atom, a pentanoyl group, a hexanoyl group, a 2-ethylhexanoyl group, an octanoyl group, a nonanoyl group, an acyl oxide such as a decanoyl group, a dodecanoyl group, and an octadecanoyl group. Alkoxy groups, such as a group, a methoxy group, an ethoxy group, n-propoxy group, an isopropoxy group, a butoxy group, etc. are mentioned.

Specific examples of the metal chelate compound include tris(2,4-pentanedionate)iron(III), iron trisacetylacetonate, titanium trisacetylacetonate, ruthenium trisacetylacetonate, zinc bisacetylacetonate, aluminum tris Acetylacetonate, zirconium tetrakisacetylacetonate, tris(2,4-hexanedionate) iron(III), bis(2,4-hexanedionate) zinc, tris(2,4-hexanedionate) titanium, Tris(2,4-hexanedionate)aluminum, tetrakis(2,4-hexanedionate)zirconium, etc. are mentioned.

Examples of the organotin compound include dialkyl tin oxide, fatty acid salt of dialkyl tin, and fatty acid salt of stannous tin. Conventionally, dibutyltin compounds have been widely used, but in recent years, toxicity problems of organotin compounds have been pointed out, and in particular, tributyltin (TBT) contained in dibutyltin compounds is also concerned as an endocrine disrupting substance. From the viewpoint of safety, long-chain alkyltin compounds such as dioctyltin compounds are preferable. Specific examples of the organotin compound include dioctyltin oxide and dioctyltin dilaurate. Although Sn compounds can be used temporarily, in the future, in consideration of the trend requiring the use of materials with higher safety, it is better to use metal chelate compounds such as Al, Ti, Fe, etc., which are safer than Sn. desirable.

The (D) crosslinking accelerator in the pressure-sensitive adhesive composition according to the present invention is preferably at least one selected from the group consisting of an aluminum chelate compound, a titanium chelate compound, and an iron chelate compound.

(D) It is preferable to contain 0.001-0.5 weight part of crosslinking accelerators with respect to 100 weight part of acrylic polymers of a copolymer.

(E) Ketoenol tautomeric compounds include β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate, acetylacetone, 2 and β-diketones such as ,4-hexanedione and benzoylacetone. In the adhesive composition which uses a polyisocyanate compound as a crosslinking agent, by blocking the isocyanate group which a crosslinking agent has, excessive viscosity rise and gelation of the adhesive composition after mixing|blending of a crosslinking agent are suppressed, and the pot life of an adhesive composition can be extended.

(E) The ketoenol tautomer compound is preferably contained in an amount of 0.1 to 300 parts by weight based on 100 parts by weight of the acrylic polymer of the copolymer.

(E) the ketoenol tautomer compound has an effect of inhibiting crosslinking as opposed to (D) the crosslinking accelerator, and (D) the ratio of the (E) ketoenol tautomer compound to the crosslinking accelerator is appropriately set. it is preferable In order to lengthen the pot life of an adhesive composition and to improve storage stability, it is preferable that the weight part ratio of (E)/(D) is 70-1000.

The acrylic polymer may optionally contain (F) polyalkylene glycol mono(meth)acrylic acid ester monomer as the copolymerizable monomer group. (F) As a polyalkylene glycol mono(meth)acrylic acid ester monomer, what is necessary is just a compound in which one hydroxyl group was esterified as (meth)acrylic acid ester among the several hydroxyl groups which polyalkylene glycol has. Since the (meth)acrylic acid ester group becomes a polymerizable group, it can copolymerize with a main polymer. The other hydroxyl group may be OH as it is, and may be an alkyl ether such as methyl ether or ethyl ether, or a saturated carboxylic acid ester such as acetic acid ester.

Although an ethylene group, a propylene group, a butylene group etc. are mentioned as an alkylene group which polyalkylene glycol has, It is not limited to these. Polyalkylene glycol may be a copolymer of 2 or more types of polyalkylene glycol, such as polyethyleneglycol, polypropylene recall, and polybutylene glycol. Examples of the copolymer of polyalkylene glycol include polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, polyethylene glycol-polypropylene glycol-polybutylene glycol, and the like. The copolymer may be a block copolymer or a random copolymer.

(F) It is preferable that the average repeating number of the alkylene oxide which polyalkylene glycol mono(meth)acrylic acid ester monomer comprises a polyalkylene glycol chain|strand is 3-14. "Average number of repetitions of alkylene oxide" is (F) in the portion of the "polyalkylene glycol chain" contained in the molecular structure of the polyalkylene glycol mono (meth) acrylic acid ester monomer, the alkylene oxide unit is repeated is the average number.

(F) Polyalkylene glycol mono (meth) acrylic acid ester monomers include polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, ethoxy polyalkylene glycol (meth) acrylic It is preferable that it is at least 1 type or more selected from the rate.

More specifically, polyethylene glycol - mono (meth) acrylate, polypropylene glycol - mono (meth) acrylate, polybutylene glycol - mono (meth) acrylate, polyethylene glycol - polypropylene glycol - mono (meth) acrylic rate, polyethylene glycol-polybutylene glycol-mono(meth)acrylate, polypropylene glycol-polybutylene glycol-mono(meth)acrylate, polyethylene glycol-polypropylene glycol-polybutylene glycol-mono(meth)acrylic rate; Methoxy polyethylene glycol-(meth)acrylate, methoxypolypropylene glycol-(meth)acrylate, methoxypolybutylene glycol-(meth)acrylate, methoxy-polyethylene glycol-polypropylene glycol-(meth)acryl Rate, 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) acrylate, ethoxy polybutylene glycol - (meth) acrylate, ethoxy - polyethylene glycol - polypropylene glycol - (meth) acrylic rate, ethoxy-polyethylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polypropylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polyethylene glycol-polypropylene glycol-polybutylene Glycol-(meth)acrylate etc. are mentioned.

When the sum total of the acrylic polymer of a copolymer is 100 weight part, it is preferable to contain the said (F) polyalkylene glycol mono(meth)acrylic acid ester monomer in the ratio of 0-50 weight part. The adhesive layer which concerns on this invention WHEREIN: It is not necessary to contain the (F) polyalkylene glycol mono(meth)acrylic acid ester monomer in an adhesive composition.

The pressure-sensitive adhesive composition (G) may optionally contain a polyether-modified siloxane compound having an HLB value of 7 to 15. The polyether-modified siloxane compound is a siloxane compound having a polyether group, and in addition to the usual siloxane unit [-SiR ¹ ₂ -O-], a siloxane unit having a polyether group [-SiR ¹ (R ² O(R ³ O)) _n R ⁴ )-O-]. Here, R ¹ is one or more alkyl or aryl groups, R ² and R ³ are one or two or more alkylene groups, R ⁴ is one or more alkyl or acyl groups (terminal groups) indicates. Examples of the polyether group include polyoxyalkylene groups such as polyoxyethylene group [(C ₂ H ₄ O) _n ] and polyoxypropylene group [(C ₃ H ₆ O) _n ].

The polyether-modified siloxane compound is preferably a polyether-modified siloxane compound having (G) HLB values of 7 to 15. Moreover, it is preferable that 0.01-1.0 weight part of (G) the polyether-modified siloxane compound whose HLB value is 7-15 is contained with respect to 100 weight part of acrylic polymers of a copolymer. More preferably, it is 0.1-0.5 weight part.

HLB is, for example, a hydrophilic-lipophilic balance (hydrophilic-lipophilic ratio) prescribed by JIS K3211 (Terminology of Surfactant) or the like.

The polyether-modified siloxane compound can be obtained by, for example, grafting an organic compound having an unsaturated bond and a polyoxyalkylene group to a polyorganosiloxane main chain having a silicon hydride group by hydrosilylation reaction. Specifically, dimethylsiloxane/methyl (polyoxyethylene) siloxane copolymer, dimethylsiloxane/methyl (polyoxyethylene) siloxane/methyl (polyoxypropylene) siloxane copolymer, dimethylsiloxane/methyl (polyoxypropylene) siloxane polymer, etc. can be heard The HLB value of a polyether modified siloxane compound can be adjusted by selecting the ratio of a polyether group and a siloxane group.

(G) By mix|blending the polyether modified siloxane compound whose HLB value is 7-15 with an adhesive composition, the adhesive force of an adhesive and rework performance can be improved. When an adhesive composition does not contain a polyether modified siloxane compound, it becomes lower cost.

In addition, copolymerizable (meth)acrylic monomers containing alkylene oxide as other components, (meth)acrylamide monomers, dialkyl-substituted acrylamide monomers, surfactants, curing accelerators, plasticizers, fillers, curing retarders, processing aids Well-known additives, such as antioxidant, antioxidant, and antioxidant, can be mix|blended suitably. These are used individually or in combination of 2 or more types.

The copolymer of the main subject used in the pressure-sensitive adhesive composition of the present invention is (A) a copolymerizable monomer containing a carboxyl group as a monomer group copolymerizable with (A) at least one of (meth)acrylic acid ester monomers having C4-C18 alkyl groups. Although it does not contain (B), it can synthesize|combine by copolymerizing at least 1 sort(s) of the copolymerizable monomer containing a hydroxyl group. As the above-mentioned copolymerizable monomer group, (F) polyalkylene glycol mono(meth)acrylic acid ester monomer may be further included. The polymerization method of a copolymer is not specifically limited, Suitable polymerization methods, such as solution polymerization and emulsion polymerization, can be used.

The pressure-sensitive adhesive composition of the present invention can be prepared by blending (C) a bifunctional or more functional isocyanate compound, (D) a crosslinking accelerator, (E) a ketoenol tautomer compound, and further appropriate optional additives to the copolymer. .

It is preferable that the said copolymer is an acrylic polymer, and it is preferable to contain 50 to 100 weight% of acrylic monomers, such as (meth)acrylic acid ester monomer, (meth)acrylic acid, and (meth)acrylamide.

Since the acrylic polymer does not include a copolymerizable monomer containing a carboxyl group as a copolymerizable monomer group, it is effective in improving the crosslinking rate and stabilizing the adhesive force. It is preferable to use the copolymerizable monomer containing the (B) hydroxyl group as a monomer which reacts with the (C) difunctional or more functional isocyanate compound used as a crosslinking agent. As a monomer composition with a preferable said copolymer, 1 or more types from said (A) and said (B), respectively, 1 or more types, respectively from said (A), said (B), and said (F), etc. are mentioned.

The adhesive layer formed by crosslinking the pressure-sensitive adhesive composition preferably has an adhesive force of 0.05 to 0.1 N/25 mm at a low peel rate of 0.3 m/min, and an adhesive force of 1.0 N/25 mm or less at a high peel rate of 30 m/min. . Thereby, the performance with little change in adhesive force also with peeling speed can be acquired, and it becomes possible to peel quickly also by high-speed peeling. Moreover, in order to stick again, also when peeling a surface protection film once, excessive force is not required, and it is easy to peel from a to-be-adhered body.

It is preferable that the surface resistivity of the adhesive layer formed by bridge|crosslinking the said adhesive composition is 5.0x10 ⁺¹² ohm/square or less, and peeling electrification voltage is "±0.6 kV or less." In addition, in this invention, "±0.6kV or less" means 0 to -0.6kV and 0 to +0.6kV, ie, -0.6 to +0.6kV. If the surface resistivity is large, the ability to escape static electricity generated by charging at the time of peeling is lowered. By making the surface resistivity sufficiently small, the peeling electrification voltage caused by static electricity generated when the adhesive layer is peeled from the adherend is reduced. As a result, it is possible to suppress an influence on the electrical control circuit or the like of the adherend.

It is preferable that the gel fraction of the adhesive layer (adhesive after crosslinking) formed by crosslinking the pressure-sensitive adhesive composition of the present invention is 95 to 100%. As described above, when the gel fraction is high, the adhesive force is not excessive at a low peeling rate, the elution of unpolymerized monomers or oligomers from the copolymer is reduced, and the reworkability and durability at high temperature and high humidity are improved, and avoid Contamination of the complex can be suppressed.

The adhesive film of this invention forms the adhesive layer formed by bridge|crosslinking the adhesive composition of this invention on one side or both surfaces of a resin film. Moreover, the surface protection film of this invention is a surface protection film formed by forming in one surface of a resin film the adhesive layer which bridge|crosslinks the adhesive composition of this invention. Since each component of the said (A)-(E) is blended in a well-balanced manner, the adhesive composition of this invention is equipped with the outstanding antistatic performance, and in a low-speed peeling rate and a high-speed peeling rate, it is excellent in the adhesive force balance, and also , the durability performance and the rework performance (the thing with no contamination transfer to the adherend after the surface protection film is overlaid with a ball-point pen through an adhesive layer) is also excellent. For this reason, it can use suitably as a use of the surface protection film of a polarizing plate.

Although the thickness of the adhesive layer 2 used for the antistatic surface protection film 10 which concerns on this invention is not specifically limited, For example, the thickness of about 5-40 micrometers is preferable, and the thickness of about 10-30 micrometers is more preferable. When peeling the antistatic surface protection film from the adherend, the antistatic surface protection film is the pressure-sensitive adhesive layer 2 having a non-adhesive force of about 0.03 to 0.3 N/25 mm in peel strength (adhesion force) of the antistatic surface protection film to the surface of the adherend. It is preferred from the viewpoint of excellent operability. Moreover, since it is excellent in the operability at the time of peeling the peeling film 5 from the antistatic surface protection film 10, it is that the peeling force from the adhesive layer 2 of the peeling film 5 is 0.2 N/50 mm or less. desirable.

In addition, the release film 5 used in the antistatic surface protection film 10 according to the present invention is a resin composition comprising a release agent containing dimethylpolysiloxane as a main component and an antistatic agent on one side of the resin film 3 The used release agent layer 4 is formed.

As the resin film 3, a polyester film, a polyamide film, a polyethylene film, a polypropylene film, a polyimide film, etc. are mentioned, A polyester film is especially preferable at the point which is excellent in transparency and a comparatively cheap price. Do. An unstretched film may be sufficient as the resin film, and the uniaxially or biaxially stretched film may be sufficient as it. Moreover, you may control the orientation angle of the axial method formed with the draw ratio of a stretched film and crystallization of a stretched film to a specific value.

Although the thickness of the resin film 3 is not specifically limited, For example, the thickness of about 12-100 micrometers is preferable, if it is thickness of about 20-50 micrometers, it is easy to handle, and it is more preferable.

Moreover, you may give the surface of the resin film 3 easily adhesion processing, such as surface modification by corona discharge, application|coating of an anchor coat agent, as needed.

As a release agent which has dimethylpolysiloxane as a main component which comprises the release agent layer 4, well-known silicone type release agents, such as an addition reaction type, a condensation reaction type, a cationic polymerization type, and a radical polymerization type, are mentioned. Products marketed as addition reaction type silicone release agents include, for example, KS-776A, KS-847T, KS-779H, KS-837, KS-778, KS-830 (manufactured by Shin-Etsu Chemical Industries, Ltd.), SRX- 211, SRX-345, SRX-357, SD7333, SD7220, SD7223, LTC-300B, LTC-350G, LTC-310 (manufactured by Toray Dow Corning Co., Ltd.) and the like. As a product marketed as a condensation reaction type, SRX-290, SYLOFF-23 (made by Toray Dow Corning Co., Ltd.) etc. are mentioned, for example. Products marketed as cationic polymerization types include, for example, TPR-6501, TPR-6500, UV9300, VU9315, UV9430 (manufactured by Momentive Performance Materials), X62-7622 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Examples of the product marketed as a radical polymerization type include X62-7205 (manufactured by Shin-Etsu Chemical Co., Ltd.).

The antistatic agent constituting the release agent layer 4 preferably has good dispersibility in a release agent solution containing dimethylpolysiloxane as a main component and does not inhibit curing of the release agent containing dimethylpolysiloxane as a main component. As such an antistatic agent, an alkali metal salt is preferable.

As an alkali metal salt, the metal salt which consists of lithium, sodium, and potassium is mentioned. Specifically, for example, a ^{cation composed of Li +} , Na ⁺ , K ⁺ , 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 ^- A metal salt composed of an anion is preferably used 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, Li(C ₂ F ₅ SO _{2 )} Lithium salts (Li salts) such as ) ₂ N, Li(CF ₃ SO ₂ ) _{3 C, in particular, Li(CF 3} SO ₂ ) ₂ N “abbreviated symbol LiTFSI”, Li(FSO ₂ ) ₂ N “abbreviated symbol LiFSI” ', LiCF ₃ SO ₃ "abbreviation symbol LiTF or LiTf" is preferably used. These alkali metal salts may be used independently, and 2 or more types may be mixed and used for them. For stabilization of the ionic substance, a compound containing a polyoxyalkylene structure may be added.

The amount of the antistatic agent added to the release agent containing dimethylpolysiloxane as a main component varies depending on the type of antistatic agent and the degree of affinity with the release agent, but when the antistatic surface protection film is peeled from the adherend, the desired peeling electrification voltage, What is necessary is just to consider the contamination with respect to a complex, adhesive characteristic, etc. and just to set it.

The mixing method of the release agent and antistatic agent which have dimethylpolysiloxane as a main component is not specifically limited. A method of adding and mixing an antistatic agent to a release agent containing dimethylpolysiloxane as a main component, then adding and mixing a catalyst for curing the release agent. After diluting a release agent containing dimethylpolysiloxane as a main component with an organic solvent in advance, an antistatic agent and a catalyst for curing the release agent are added Any method, such as the method of adding and mixing, the method of previously diluting the release agent which has siloxane as a main component in the organic solvent, adding and mixing a catalyst, and adding and mixing an antistatic agent after that may be sufficient. Moreover, you may add materials which assist the antistatic effect, such as a close_contact|adherence improving agent, such as a silane coupling agent, and a compound containing a polyoxyalkylene group, as needed.

Although the mixing ratio of the release agent containing dimethylpolysiloxane as a main component and the antistatic agent is not particularly limited, the ratio of the antistatic agent as a solid content of about 5 to 100 is preferable with respect to the solid content of 100 of the release agent containing dimethylpolysiloxane as a main component. When the added amount of the antistatic agent in terms of solid content is less than a ratio of 5 to 100 solid content of the release agent containing dimethylpolysiloxane as a main component, the amount of the antistatic agent transferred to the surface of the pressure-sensitive adhesive layer also decreases, making it difficult to exert an antistatic function on the pressure-sensitive adhesive. In addition, when the addition amount of the antistatic agent in terms of solid content exceeds a ratio of 100 to 100 of the release agent containing dimethylpolysiloxane as a main component, the release agent containing dimethylpolysiloxane as a main component together with the antistatic agent is also transferred to the surface of the pressure-sensitive adhesive layer, so the pressure-sensitive adhesive There is a possibility that the adhesive properties of the

The method of forming the pressure-sensitive adhesive layer 2 and the method of bonding the release film 5 to the base film 1 of the antistatic surface protection film 10 according to the present invention may be performed by a known method, and is not particularly limited. does not Specifically, (1) a method of bonding the release film 5 together after coating and drying the resin composition for forming the pressure-sensitive adhesive layer 2 on one surface of the base film 1 to form the pressure-sensitive adhesive layer, ( 2) After apply|coating and drying the resin composition for forming the adhesive layer 2 on the surface of the peeling film 5, and forming an adhesive layer, the method of bonding the base film 1 etc. are mentioned, Any method may be used.

In addition, what is necessary is just to form the adhesive layer 2 on the surface of the base film 1 by a well-known method. Specifically, known coating methods such as reverse coating, comma coating, gravure coating, slot die coating, Mayer bar coating, and air knife coating can be used.

In addition, what is necessary is just to form the release agent layer 4 in the resin film 3 similarly by a well-known method. Specifically, known coating methods such as gravure coating, Mayer bar coating, and air knife coating can be used.

It is sectional drawing which shows the state which peeled the peeling film from the antistatic surface protection film of this invention.

By peeling the release film 5 from the antistatic surface protection film 10 shown in FIG. 1 , a part of the antistatic agent (symbol 7) contained in the release agent layer 4 of the release film 5 is removed from the antistatic surface. It is transferred (attached) to the surface of the pressure-sensitive adhesive layer 2 of the protective film 10 . For this reason, in FIG. 2, the antistatic agent transcribe|transferred on the surface of the adhesive layer 2 of an antistatic surface protection film is shown typically by the dot of the code|symbol 7.

In the antistatic surface protection film according to the present invention, in bonding the antistatic surface protection film 11 in a state in which the release film shown in Fig. 2 is peeled off to an adherend, the charge transferred to the surface of the pressure-sensitive adhesive layer 2 is The inhibitor comes into contact with the surface of the adherend. Thereby, the peeling electrification voltage at the time of peeling an antistatic surface protection film from a to-be-adhered body again can be suppressed low.

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

From the antistatic surface protection film 10 of the present invention, the release film 5 is peeled off, and in a state in which the pressure-sensitive adhesive layer 2 is exposed, the pressure-sensitive adhesive layer 2 is interposed therebetween to the optical component 8 as an adherend. are glued together

That is, in FIG. 3, the optical component 20 by which the antistatic surface protection film 10 of this invention was pasted is shown. As an optical component, optical films, such as a polarizing plate, retardation plate, a lens film, a retardation plate combined polarizing plate, and a lens film combined polarizing plate, are mentioned. Such optical components are used as constituent members of liquid crystal display devices such as liquid crystal display panels and optical system devices of various instruments. Moreover, as an optical component, films for optics, such as an antireflection film, a hard coat film, and the transparent conductive film for touch panels, are also mentioned. In particular, the antifouling treatment surface of an optical film, such as a low reflection treatment polarizing plate (LR polarizing plate) or an anti-glare low reflection treatment polarizing plate (AG-LR polarizing plate), whose surface is antifouling with a silicone compound or a fluorine compound, etc. , it can be preferably used as an antistatic surface protection film.

ADVANTAGE OF THE INVENTION According to the optical component of this invention, when peeling and removing the antistatic surface protection film 10 from the optical component (optical film) which is a to-be-adhered body, since peeling electrification voltage can be suppressed low enough, a driver IC, a TFT element, a gate There is no fear of destroying circuit components, such as a line drive circuit, and the production efficiency in the process of manufacturing a liquid crystal display panel etc. can be improved, and the reliability of a production process can be maintained.

Example

Next, the present invention will be described in detail by way of Examples.

<Preparation of the pressure-sensitive adhesive composition>

[Example 1]

Nitrogen gas was introduced into a reaction apparatus equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen introduction tube, and the air in the reaction apparatus was replaced with nitrogen gas. Then, 100 parts by weight of 2-ethylhexyl acrylate, 4.5 parts by weight of 8-hydroxyoctyl acrylate, 10 parts by weight of polypropylene glycol monoacrylate (n=12), and 60 parts by weight of a solvent (ethyl acetate) were added to the reaction apparatus. parts by weight were added. Then, 0.1 weight part of azobisisobutyronitrile was dripped over 2 hours as a polymerization initiator, it was made to react at 65 degreeC for 6 hours, and the acrylic copolymer solution of Example 1 with a weight average molecular weight of 500,000 was obtained. To this acrylic copolymer solution, 8.5 parts by weight of acetylacetone was added and stirred, then 2.5 parts by weight of coronate HX (isocyanurate of hexamethylene diisocyanate compound) and 0.1 parts by weight of titanium trisacetylacetonate were added, It stirred and mixed, and the adhesive composition of Example 1 was obtained.

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

Except having carried out the composition of the adhesive composition of Example 1 as Table 1 and Table 2, respectively, it carried out similarly to Example 1, and obtained the adhesive composition of Examples 2-6 and Comparative Examples 1-3. In Tables 1 and 2, the monomers (copolymerized) contained in the acrylic copolymer are (A), (B), (F) and "carboxyl group-containing monomers".

Tables 1 and 2 divide all tables showing the compounding ratio of each component into two, and the numerical values of parts by weight obtained by calculating the total of all (A) groups as 100 parts by weight are shown in parentheses. In addition, the compound name of the abbreviation of each component used for Table 1 and Table 2 is shown in Table 3 and Table 4. In addition, Coronate (trademark) HX, HL, and L are the brand names of Nippon Polyurethane Industries, Ltd., Takenate (trademark) D-140N, D-127N, D-110N are the brand names of Mitsui Chemicals. In "Antistatic Agent" of Table 2 and Table 7 to be described later, LiTFSI represents Li(CF ₃ SO ₂ ) ₂ N, LiFSI represents Li(FSO ₂ ) ₂ N, LiTF represents LiCF ₃ SO ₃ , SH8400 represents polyether-modified silicone (manufactured by Toray Dow Corning Co., Ltd., product name: SH8400, main components: dimethyl, methyl (polyethylene oxide acetate) siloxane).

<Synthesis of bifunctional isocyanate compound>

The bifunctional isocyanate compound of Synthesis Examples 1 and 2 was synthesized by the following method. As shown in Tables 5 and 6, diisocyanate and diol compound were mixed in a molar ratio of NCO/OH=16, reacted at 120° C. for 3 hours, and then unreacted under reduced pressure using a thin film evaporation device. of diisocyanate was removed, and the target bifunctional isocyanate compound was obtained.

<Production of antistatic surface protection film>

[Example 1]

Addition reaction silicone (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-345) 5 parts by weight, Li(CF ₃ SO ₂ ) ₂ N 0.5 parts by weight, 95 parts by weight of a 1:1 mixed solvent of toluene and ethyl acetate And 0.05 parts by weight of a platinum catalyst (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-212 Catalyst) were mixed and stirred and mixed to prepare a paint forming a release agent layer of Example 1. On the surface of the polyethylene terephthalate film having a thickness of 38 μm, the paint forming the release agent layer of Example 1 was applied with a Meyer bar so that the thickness after drying was 0.2 μm, and dried in a hot air circulation oven at 120° C. for 1 minute, The release film of Example 1 was obtained.

The pressure-sensitive adhesive composition of 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 dried in a hot air circulation oven at 100° C. for 2 minutes to form an adhesive layer. Then, the release agent layer (silicone process surface) of the peeling film of Example 1 produced above was stuck to the surface of this adhesive layer. The obtained adhesive film was heat-retained in 40 degreeC environment for 5 days, the adhesive was hardened, and the antistatic surface protection film of Example 1 was obtained.

[Example 2]

The pressure-sensitive adhesive composition of Example 1 was used as the pressure-sensitive adhesive composition of Example 2, and the antistatic agent used for the release agent layer was LiCF ₃ SO ₃ . Except that, it carried out similarly to Example 1, and obtained the antistatic surface protection film of Example 2.

[Examples 3 to 6]

Example 1 of pressure-sensitive adhesive composition of Examples 3-6, respectively, and the pressure-sensitive adhesive composition, in the same manner as the antistatic agent used for the release agent layer as in Example 1 Li (FSO ₂₎ put up in ₂ N, except in Example 3 to The antistatic surface protection film of 6 was obtained.

[Comparative Example 1]

5 parts by weight of addition reaction silicone (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-345), 95 parts by weight of a 1:1 mixed solvent of toluene and ethyl acetate, and platinum catalyst (manufactured by Toray Dow Corning Co., Ltd., product name) : SRX-212 Catalyst) 0.05 parts by weight was mixed, stirred and mixed, and the paint forming the release agent layer of Comparative Example 1 was prepared. On the surface of the polyethylene terephthalate film having a thickness of 38 μm, the paint forming the release agent layer of Comparative Example 1 was applied with a Meyer bar so that the thickness after drying was 0.2 μm, and dried in a hot air circulation oven at 120° C. for 1 minute, A release film of Comparative Example 1 was obtained.

The pressure-sensitive 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 dried in a hot air circulation oven at 100° C. for 2 minutes to form an adhesive layer. Then, the release agent layer (silicone-treated surface) of the release film of the comparative example 1 produced above was stuck to the surface of this adhesive layer. The obtained adhesive film was heat-retained in 40 degreeC environment for 5 days, the adhesive was hardened, and the antistatic surface protection film of the comparative example 1 was obtained.

[Comparative Example 2]

Except having made the adhesive composition of the comparative example 1 into the adhesive composition of the comparative example 2, it carried out similarly to the comparative example 1, and obtained the antistatic surface protection film of the comparative example 2.

[Comparative Example 3]

Antistatic surface of Comparative Example 3 in the same manner as in Example 1 except that the pressure-sensitive adhesive composition of Example 1 was used as the pressure-sensitive adhesive composition of Comparative Example 3, and the antistatic agent used for the release agent layer was Li(FSO ₂ ) _{2 N} A protective film was obtained.

In Table 7, the composition of the release agent layer in Examples 1-6 and the antistatic surface protection film of Comparative Examples 1-3 is shown.

<Test method and evaluation>

After aging the surface protection films in Examples 1 to 6 and Comparative Examples 1 to 3 in an atmosphere of 23°C and 50%RH for 7 days, the release film (PET film coated with silicone resin) was peeled off, and the pressure-sensitive adhesive layer was What was exposed was made into the measurement sample of surface resistivity.

Further, the surface protection film in which the pressure-sensitive adhesive layer was exposed was bonded to the surface of the polarizing plate pasted on the liquid crystal cell through the pressure-sensitive adhesive layer, left to stand for 1 day, autoclaved at 50° C., 5 atmospheres, 20 minutes, and again at room temperature What was left to stand for 12 hours was made into the measurement sample of adhesive force, peeling electrification voltage, and rework property.

<Adhesive force>

A low-speed peeling rate (0.3 m/min) and a high-speed peeling rate (30 m/min) using a tensile tester in the 180° direction for the measurement sample (25 mm wide surface protection film bonded to the surface of the polarizing plate) obtained above. was peeled, and the measured peel strength was made into adhesive force.

<Surface resistivity>

After aging, before bonding to a polarizing plate, the release film (silicone resin-coated PET film) was peeled to expose the pressure-sensitive adhesive layer, and the resistivity meter Hirestar UP-HT450 (manufactured by Mitsubishi Chemical Analytech) was used to remove the pressure-sensitive adhesive layer. The surface resistivity was measured.

<Peel electrification voltage>

When the measurement sample obtained above is peeled 180° at a tensile speed of 30 m/min, the voltage (charged voltage) generated by the charging of the polarizing plate is measured using high-precision electrostatic sensors SK-035 and SK-200 (manufactured by Keyence Co., Ltd.) and the maximum value of the measured value was taken as the peel electrification voltage.

＜Rework Castle＞

After overwriting the surface protection film of the measurement sample obtained above with a ballpoint pen (load 500 g, 3 reciprocations), the surface protection film was peeled off from the polarizing plate and the surface of the polarizing plate was observed, and it was confirmed that there was no transfer of contamination on the polarizing plate. The evaluation target criteria are “○” when there is no contamination transfer on the polarizing plate, “△” when contamination transfer is confirmed at least in part along the trajectory overwritten with a ballpoint pen, and contamination transfer is confirmed along the trajectory overwritten with a ballpoint pen, and the surface of the adhesive The case where the release of the pressure-sensitive adhesive was also confirmed was evaluated as "x".

Table 8 shows the evaluation results. The surface resistivity was indicated by the way (but, m is an arbitrary real number, n is a positive integer) of the "m × 10 ^{+ n"} in "mE + n".

From the measurement results shown in Table 8, the following are known.

The antistatic surface protection films of Examples 1 to 6 according to the present invention have moderate adhesion, no contamination on the surface of the adherend, and the peeling electrification voltage when the antistatic surface protection film is peeled from the adherend. low.

On the other hand, the antistatic surface protection film of Comparative Example 1 in which a silicone compound and an antistatic agent were added to the pressure-sensitive adhesive layer had a low and good surface resistivity of the pressure-sensitive adhesive layer, but had a high adhesive force, so the peeling electrification voltage was high and reworkability was poor. . Moreover, in Comparative Example 2, perhaps because there was a large amount of the crosslinking accelerator added, the pressure-sensitive adhesive gelled and could not be applied. In Comparative Example 3, since a monomer containing a carboxyl group is included, the adhesive strength is large and the reworkability is high. was a bit far

That is, in Comparative Examples 1 and 2 in which a silicone compound and an antistatic agent were mixed with the pressure-sensitive adhesive, it is difficult to achieve both reduction of the peeling electrification voltage and the contamination property to the adherend. On the other hand, in Examples 1 to 6 in which the antistatic agent was transferred to the surface of the pressure-sensitive adhesive layer after adding the antistatic agent to the release agent layer, there is an effect of reducing the peel electrification voltage with a small amount of addition, so there is no contamination on the adherend and good An antistatic surface protection film was obtained.

The antistatic surface protection film of the present invention is, for example, an optical film such as a polarizing plate, a retardation plate, a display lens film, etc. In the production process of various optical components, etc., in order to protect the surface of the optical component, etc. Can be used. In particular, when used as an antistatic surface protection film for an optical film such as an LR polarizing plate or an AG-LR polarizing plate whose surface is antifouling with a silicone compound or fluorine compound, the amount of static electricity generated when peeling from an adherend is reduced can do.

The antistatic surface protection film of the present invention has little contamination on an adherend, does not deteriorate over time, and has excellent peeling and antistatic performance, so it can improve the yield of the production process, and thus has great industrial use value.

One… Base film, 2... Adhesive layer, 3... resin film, 4... release agent layer, 5... release film, 7... antistatic agent, 8... An adherend (optical component), 10 ... Antistatic surface protection film, 11... The antistatic surface protection film which peeled the peeling film, 20... The optical part which stuck an antistatic surface protection film together.

Claims (3)

An antistatic surface protection film in which an adhesive layer formed by crosslinking an adhesive composition containing an acrylic polymer on one side of a base film made of a resin having transparency is formed, the antistatic surface protection film comprising:
A peeling film for an antistatic surface protection film capable of transferring an antistatic agent to the surface of the pressure-sensitive adhesive layer is pasted together,
The acrylic polymer (A) does not contain a copolymerizable monomer containing a carboxyl group as a monomer group copolymerizable with at least one of (meth)acrylic acid ester monomers having a C4-C18 alkyl group, but (B) a hydroxyl group It is an acrylic polymer of a copolymer obtained by copolymerizing at least one of the copolymerizable monomers contained therein,
The pressure-sensitive adhesive composition further comprises (C) a bifunctional isocyanate compound, (D) a crosslinking accelerator, (E) a ketoenol tautomer compound, and (G) a polyether-modified siloxane compound having an HLB value of 7 to 15 It is made by containing
(D) the crosslinking accelerator is at least one selected from the group consisting of an aluminum chelate compound, a titanium chelate compound, and an iron chelate compound,
The release film for antistatic surface protection film is formed by laminating a release agent layer containing an antistatic agent on one side of a resin film,
The release agent layer is formed by a release agent containing dimethylpolysiloxane and a resin composition containing the antistatic agent,
The antistatic agent included in the release agent layer is transferred only to the surface of the pressure-sensitive adhesive layer,
An antistatic surface protection film, characterized in that no antistatic agent is included in the pressure-sensitive adhesive layer. The method of claim 1,
An antistatic surface protection film characterized in that the antistatic agent in the release agent layer is an alkali metal salt. The optical film formed by bonding the antistatic surface protection film of Claim 1 together.

Images