WO2006137559A1

WO2006137559A1 - Antistatic acrylic pressure-sensitive adhesive

Info

Publication number: WO2006137559A1
Application number: PCT/JP2006/312740
Authority: WO
Inventors: Naotoshi Nakamura; Noboru Kojima; Yasuto Kuwahara; Ichiro Sawatari; Etsuko Yoshinari
Original assignee: Toyo Ink Manufacturing Co., Ltd.
Priority date: 2005-06-24
Filing date: 2006-06-26
Publication date: 2006-12-28
Also published as: HK1120542A1; JPWO2006137559A1; CN101208403B; JP5061898B2; TW200706622A; CN101208403A; KR101198531B1; TWI411654B; KR20080024215A

Abstract

An antistatic acrylic pressure-sensitive adhesive characterized by comprising an acrylic copolymer (A) having a hydroxy group and an alkylene oxide chain in side chains, an ionic compound (B), a hardener (C), and an antioxidant (D). The antistatic pressure-sensitive adhesive is suitable for use as a pressure-sensitive adhesive for pressure-sensitive adhesive films for protecting the surface of an optical member. The pressure-sensitive adhesive solution before incorporation of the hardener has satisfactory storage stability. The antistatic pressure-sensitive adhesive has excellent transparency, is almost colorless, has excellent strippability after application, and is less apt to cause electrification upon stripping.

Description

Specification

Antistatic acrylic adhesive

Technical field

The present invention relates to an antistatic pressure-sensitive adhesive and a protective film for an optical member that carries a pressure-sensitive adhesive layer formed from the antistatic pressure-sensitive adhesive. More specifically, the present invention relates to an adhesive suitable for a surface protective film for mechanically and electrically protecting an adherend surface for a predetermined period. More specifically, the pressure-sensitive adhesive of the present invention is suitably used for forming a surface protective pressure-sensitive adhesive film for optical parts such as liquid crystal panels, plasma displays, polarizing plates, and CRTs (CRTs).

Background art

[0002] Conventionally, the surface of various displays such as word processors, computers, mobile phones, and televisions, or optical parts such as polarizing plates and laminates equivalent thereto, electronic substrates, etc. are usually used for the purpose of surface protection and functionality. A transparent surface protective film (base film) such as polyethylene, polyester, or polypropylene is laminated via an adhesive layer.

[0003] These surface protective adhesive films often finish the role of surface protection after being assembled into a liquid crystal display, for example, and are often peeled off. But surface protective adhesive

RU Furthermore, there may be a problem that the liquid crystal and the electronic circuit are destroyed due to the peeling electrification generated when the surface protective adhesive film is peeled off.

[0004] Accordingly, various measures have been proposed as means for imparting antistatic properties to the surface protective adhesive film. As typical methods, for example, the following three methods can be mentioned.

(1) A method of imparting antistatic properties to the base film itself constituting the surface protective adhesive film,

(2) Method of providing a layer having antistatic performance between the base film constituting the surface protective adhesive film and the adhesive layer, or on the side where the adhesive layer of the base film is not laminated , (3) A method of imparting antistatic properties to the pressure-sensitive adhesive layer constituting the surface protective pressure-sensitive adhesive film.

[0005] The method (1) includes a thermoplastic resin such as polyester or polyethylene, which is a raw material of the base film, and a resin compound such as an organic sulfonate group, metal powder, carbon black, or the like. In this method, a conductive substrate film is obtained by kneading and mixing a conductive filler. In this case, the transparency of the substrate film is lowered or the film is colored.

By the way, it is necessary to continuously inspect the surface protective appearance of the adherend through the adhesive film even while the surface protective adhesive film is adhered to the adherend. Therefore, the substrate film itself is required to be excellent in transparency and optically free from defects.

Therefore, when a surface protective adhesive film using an antistatic agent-containing substrate film is attached to an adherend, there is a problem that the adherend surface becomes visible. Another problem is that the base film is expensive.

[0006] The method (2) has various variations as shown below (for example, Patent Documents 1 to 3;

(2-1) A method of depositing a metal compound on at least one surface of a substrate film, (2-2) A length having a quaternary ammonium salt and a sulfonate group on at least one surface of the substrate film Layers containing various antistatic agents such as ionic surfactants such as chain alkyl compounds, thiophene derivatives, polymers containing nitrogen elements ionized in the main chain, and sulfonate group-modified polystyrene. How to install, etc.

However, since, for example, a light-on surfactant such as a long-chain alkyl compound having a sulfonate group has a relatively low molecular weight, a part of the antistatic agent migrates through the antistatic coating film. There are problems that accumulate at the interface with the material film and shift to the opposite surface of the base film, etc., and that the antistatic property decreases with time!

In addition, since the polymer having a nitrogen element ionized in the main chain, sulfonate group-modified polystyrene, and the like have a relatively high molecular weight, the above problems do not occur. However, in order to obtain good antistatic performance, it is necessary to add a large amount of antistatic agent, and it is not economical because it is necessary to increase the thickness of the antistatic layer. In addition, scrap film that has not become a product (for example, film edges cut and removed in the manufacturing process) is collected for film production. When used as a reclaimed material, the antistatic agent component contained in the reclaimed material is thermally deteriorated during melt film formation, and the reclaimed film is remarkably colored and lacks practicality (recoverability is poor). Such problems arise. In addition, there are disadvantages that the films are difficult to peel off (blocking) and the coating film is easy to be scraped off, and the solution is desired.

[0007] The method (3) is a method of imparting antistatic performance to a peeling interface where static electricity is generated. A method of forming a pressure-sensitive adhesive layer using a resin having antistatic performance, and an antistatic agent-containing method. There is a method of forming an adhesive layer with an adhesive (Patent Document 6).

In the former case, the antistatic performance of the resin itself, which can be paraphrased as conductivity, is insufficient.

In the latter case, examples of the antistatic agent used include various surfactants and conductive powders such as carbon black. However, when a surfactant-containing pressure-sensitive adhesive is used, the surfactant generally tends to concentrate on the surface of the pressure-sensitive adhesive layer, i.e., the bonding interface with the adherend. Very susceptible to That is, water reduces the cohesive force of the pressure-sensitive adhesive layer, and part of the pressure-sensitive adhesive layer tends to remain on the adherend (so-called “glue residue”) when the surface protective pressure-sensitive adhesive film is peeled off. On the other hand, when a conductive pressure-sensitive adhesive containing conductive powder such as carbon black is used, there is a problem that transparency of the pressure-sensitive adhesive layer and the surface protective adhesive film is lowered or the film is colored. .

[0008] The use of an antistatic agent that is excellent in transparency and hardly causes coloring problems is also disclosed.

(For example, Patent Document 7).

However, the invention described in Patent Document 7 is for an electrode pad that is used by being attached to a living body although it relates to a conductive adhesive, and the conductive adhesive described in Patent Document 7 is a surface protective adhesive film. For use, it was hard to use.

[0009] In the case of obtaining a pressure-sensitive adhesive layer in which the resin component in the pressure-sensitive adhesive is crosslinked with a curing agent as in the present invention, the curing agent is used for the purpose of ensuring the pot life of the pressure-sensitive adhesive. It is a common usage form that is separated and blended with a curing agent just before using the adhesive.

(Hereinafter, the pressure-sensitive adhesive solution containing no curing agent is referred to as “main agent”.)

When an alkylene oxide chain is contained in the main agent, there is a problem that the viscosity of the main agent itself increases with time due to radical generation due to decomposition of the alkylene oxide chain. As a result, problems such as poor coating properties of the pressure-sensitive adhesive resulting from this have been regarded as problems, and a solution has been desired.

[0010] By the way, the pressure-sensitive adhesive containing the main agent and the curing agent is applied to various substrates such as a plastic film, dried and cured to form a pressure-sensitive adhesive layer, and then adhered to the adherend. When an alkylene oxide chain is contained in the main agent, the decomposition of the alkylene oxide chain proceeds as time elapses after the main agent and the curing agent react and the adhesive layer is formed. . As the decomposition of the alkylene oxide chain progressed, there was a problem that the conductivity decreased.

Patent Document 1: Japanese Patent Laid-Open No. 7-26223

Patent Document 2: Japanese Patent Laid-Open No. 11-256116

Patent Document 3: Japanese Patent Laid-Open No. 2001-219520

Patent Document 4: Japanese Patent Laid-Open No. 2002-060707

Patent Document 5: JP 2002-275296 A

Patent Document 6: JP-A-1-253482

Patent Document 7: Japanese Patent No. 2718519

Disclosure of the invention

Problems to be solved by the invention

The object of the present invention is to be suitable as a pressure-sensitive adhesive for surface protective adhesive films of optical members such as various displays and polarizing plates, with good storage stability of the main agent, excellent transparency, and mostly coloring. An object of the present invention is to provide an antistatic pressure-sensitive adhesive that has excellent re-peelability and has little peeling charge upon peeling.

Means for solving the problem

As a result of intensive studies, the present inventor has obtained an acrylic copolymer (A), an ionic compound (B), a curing agent (C) and an antioxidant (D) having a hydroxyl group and an alkylene oxide chain in the side chain. As a result of the inclusion, it was found that an antistatic pressure-sensitive adhesive having good storage stability of the main agent and appropriate conductivity was obtained, and the present invention was completed.

That is, the present invention contains an acrylic copolymer (A) having a hydroxyl group and an alkylene oxide chain in the side chain, an ionic compound (B), a curing agent (C), and an antioxidant (D). And an antistatic acrylic pressure-sensitive adhesive characterized by

[0015] A preferable aspect of the acrylic pressure-sensitive adhesive of the present invention is that the alkylene oxide has a caloric number power of ˜16.

[0016] Another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention is U! On the other hand, the alkylene oxide chain is an ethylene oxide chain.

[0017] In another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, the antioxidant (D) is

And at least one selected from the group consisting of phenolic acid antioxidants, phosphite acid antioxidants, and thioether acid antioxidants.

[0018] In another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, the acrylic copolymer (A) has a weight average molecular weight of 50,000 to 1,000,000.

[0019] In another preferred embodiment of the present invention, the ionic compound (B) is an ionic compound (

B) is liquid or solid at room temperature.

[0020] In another preferred embodiment of the present invention, the ionic compound (B) is an alkali metal inorganic salt or alkali metal organic salt.

[0021] Further, according to another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, the acrylic pressure-sensitive adhesive further contains an acrylic copolymer (E) having no alkylene oxide chain.

[0022] Further, in another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, a low molecular weight talyl copolymer having a hydroxyl group and an alkylene oxide chain in the side chain and having a weight average molecular weight of 50,000 to 200,000 (A1 ) And a weight average molecular weight not having an alkylene oxide chain is 200,000

~: Contains LOO 10,000 high molecular weight acrylic copolymer (E1).

[0023] In another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, the ionic compound (A) and (E) are combined with respect to a total of 100 parts by weight of the ionic copolymer (A) and (E). Contains 0.1 to 50 parts by weight of B).

[0024] In another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, the acrylic copolymer (A) is obtained by subjecting a monomer having an alkylene oxide chain to copolymerization. When the total monomer constituting the copolymer (A) is 100% by weight, the monomer having an alkylene oxide chain is 1 to 60% by weight.

[0025] Further, according to another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, an acrylic copolymer is used. When the body (A) is obtained by subjecting a monomer having an alkylene oxide chain to copolymerization, and the total amount of monomers constituting the acrylic copolymers (A) and (E) is 100% by weight, the alkylene oxide monomers having a chain is 1 to 60 weight ^_0/0.

[0026] Furthermore, in another preferred embodiment of the acrylic pressure-sensitive adhesive of the present invention, a curing agent (C) force trifunctional isocyanate compound and Z or polyfunctional epoxy compound are used.

Furthermore, the present invention relates to a protective film for an optical member, characterized in that a pressure-sensitive adhesive layer formed from the above antistatic acrylic pressure-sensitive adhesive is laminated on at least one surface of a plastic film substrate.

The invention's effect

[0028] According to the present invention, an antistatic pressure-sensitive adhesive having good storage stability of the main agent, an appropriate surface resistance, and excellent transparency and removability can be obtained.

Brief Description of Drawings

[0029] [Fig. 1] An antistatic pressure-sensitive adhesive film according to the present invention comprising a PET film substrate and an antistatic acrylic pressure-sensitive adhesive layer carried on one surface of the anti-static acrylic pressure-sensitive adhesive layer by means of an antistatic acrylic pressure-sensitive adhesive layer. It is typical sectional drawing which shows the state stuck on.

FIG. 2 shows a state in which an antistatic pressure-sensitive adhesive film according to the present invention in which an antistatic acrylic pressure-sensitive adhesive layer is provided on both sides of a PET film substrate is attached to a polarizing plate with one antistatic acrylic pressure-sensitive adhesive layer. It is typical sectional drawing.

[FIG. 3] An antistatic adhesive film according to the present invention in which an antistatic coating agent layer is provided on one surface of a PET film substrate and an antistatic acrylic adhesive layer is further supported thereon is used as the antistatic acrylic film. FIG. 5 is a schematic cross-sectional view showing a state where the adhesive layer is attached to the polarizing plate 3.

[FIG. 4] An antistatic adhesive film according to the present invention comprising an antistatic acrylic adhesive layer provided on one surface of a PET film substrate and an antistatic coating agent layer provided on the opposite surface of the antistatic adhesive film according to the present invention. FIG. 5 is a schematic cross-sectional view showing a state of being attached to the polarizing plate 3 with an acrylic pressure-sensitive adhesive layer.

Explanation of symbols

[0030] 1: Plastic film substrate 2: Antistatic acrylic adhesive layer

3: Polarizing plate

4: Antistatic coating agent layer

BEST MODE FOR CARRYING OUT THE INVENTION

[0031] The acrylic copolymer (A) used in the present invention has a hydroxyl group and an alkylene oxide chain. The acrylic monomer (al) having a hydroxyl group and an acrylic monomer having an alkylene oxide chain (a2 ) And, if necessary, other acrylate monomers (a3) copolymerizable with these (ie acrylic monomers (a3) having both hydroxyl groups and alkylene oxide chains and acrylic monomers (a3)) can do.

[0032] The acrylic monomer (al) having a hydroxyl group used in the present invention is an acrylic monomer (al) having a hydroxyl group but having no alkylene oxide chain.

4-Hydroxybutyl (meth) acrylate and glycerol mono (meth) acrylate. In the present invention, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferred.

In the present invention, the purpose of using the acrylic monomer (al) having a hydroxyl group is to ensure the removability while ensuring the adhesive force to the adherend. More specifically, a crosslinked structure is formed by utilizing a reaction between a curing agent (C), such as an isocyanate curing agent, which will be described later used in forming the pressure-sensitive adhesive layer, and these hydroxyl groups, and as described later. By controlling the molecular weight of the acrylic copolymer (A), it is possible to balance the adhesive force and the removability.

[0034] Therefore, when only the acrylic copolymer (A) is used and the acrylic copolymer (E) is not used in combination, 100% by weight of all monomers constituting the acrylic copolymer (A) are used. %, The acrylic monomer (al) having a hydroxyl group is preferably 1 to 30% by weight. More preferably, it is 3 to 10% by weight.

Further, when the acrylic copolymer (A) and the acrylic copolymer (E) are used in combination, the acrylic monomer having a hydroxyl group is assumed when the total monomer constituting (A) and (E) is 100% by weight. The system monomer (al) is preferably 1 to 30% by weight. More preferably, 3-10 weight %.

In any of the above cases, if the acrylic monomer having a hydroxyl group (al) is less than 1% by weight, the degree of cross-linking and cohesion as the pressure-sensitive adhesive layer is insufficient, the adhesive strength becomes too large, and adhesive residue is generated. Since it is easy to do, it is not preferable. If it exceeds 30% by weight, the degree of crosslinking becomes so high that the adhesiveness becomes poor, which is preferable.

[0035] Examples of the acrylic monomer (a2) having an alkylene oxide chain used in the present invention include a monomer having an ethylene oxide chain, a monomer having a propylene oxide chain, and a monomer having both.

As the number of added moles of the alkylene oxide chain, that is, the number of repeating units, 3 to 20 is preferable, 4 to 16 is more preferable, and 6 to 12 is more preferable. When the number of added moles of the alkylene oxide chain is increased, handling during polymerization tends to be complicated, and the crystallinity of the copolymer obtained as a result of the polymerization tends to increase, and the formed pressure-sensitive adhesive layer tends to become hard. On the other hand, when the added mole number of the alkylene oxide chain becomes small, it is necessary to use a large amount of the monomer (a2) in order to obtain the desired conductivity. In such a case, there is a tendency to become gely during polymerization due to the influence of the bifunctional monomer that is produced as a by-product in the production process of the monomer (a2) and contained as an impurity in the monomer (a2).

[0036] Monomers having an ethylene oxide chain include alkoxypolyethylene glycol (meth) acrylate and polyethylene glycol (meth) acrylate, such as methoxy polyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth) acrylate, etc. Is mentioned.

Examples of monomers having a propylene oxide chain include alkoxy polypropylene glycol (meth) acrylates such as methoxy polypropylene glycol (meth) acrylate and ethoxy polypropylene glycol (meth) acrylate, and polypropylene glycol (meth) aterrata 卜. Monkey.

In the present invention, a monomer having an ethylene oxide chain is preferred in consideration of compatibility with the later-described ionic compound (B). In addition, the alkoxy group in which the hydroxyl group at the end of the alkylene oxide chain is blocked with an alkyl group from the viewpoint of not inhibiting the reactivity between the isocyanate-based crosslinking agent and the hydroxyl group derived from the monomer (al) in the main agent. It is preferable that As the acrylic monomer (a2) having an alkylene oxide chain used in the present invention, methoxy polyethylene glycol (meth) acrylate and ethoxy polyethylene glycol (meth) acrylate are particularly preferable.

[0037] The purpose of using the acrylic monomer (a2) having an alkylene oxide chain in the present invention is to form a complex with the ionic compound (B) and the alkylene oxide chain to develop conductivity. Therefore, the role of the alkylene oxide chain is very large, and it also serves as a transfer medium for the ionic compound (B), which merely provides a field for complex formation. In other words, the conductivity in the present invention varies greatly depending on the amount of the ionic compound (B) and the content of the monomer (a2) having an alkylene oxide chain.

[0038] Therefore, when only the acrylic copolymer (A) is used and the acrylic copolymer (E) is not used in combination, the total amount of monomers constituting the acrylic copolymer (A) is 100% by weight. %, The acrylic monomer (a2) having an alkylene oxide chain is preferably 1 to 60% by weight. More preferably, it is 5-50 weight%, and it is still more preferable that it is 8-40 weight%. In addition, when the acrylic copolymer (A) and the acrylic copolymer (E) are used in combination, the alkylene oxide chain is changed when the total monomers constituting (A) and (E) are 100% by weight. The acrylic monomer (a2) is preferably 1 to 60% by weight. More preferably, it is 5-50 weight%, and it is still more preferable that it is 8-40 weight%.

When the amount of the acrylic monomer ( _a2 ) having an alkylene oxide chain is small, the antistatic effect tends to be small. When the amount is large, the crystallinity is high, and the high-speed peelability and antistatic property tend to be poor.

[0039] As the monomer (a3) copolymerizable with the acrylic monomer used in the present invention, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl ( (Meth) acrylate, pentyl (meth) acrylate, 2-ethyl hexyl (meth) acrylate, heptyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, nor (meta ) Atalylate, Decyl (meth) Atalylate, Undecyl (meth) Atalylate, Dodecyl (Meth) Atylate, Tridecyl (Meth) Atylate, Tetradecyl (Meth) Atylate, Pentadecyl (Meth) Atarylate, Hexadecyl (Meta ) Atalylate, heptadecyl (meth) atarylate, Octadecyl (meth) atarylate, Nadeshiru (meth) Atarire And icosyl (meth) acrylate, hencosyl (meth) acrylate, docosyl (meth) acrylate, (meth) acrylic acid, and the like. In the present invention, it is preferable to subject the acrylic monomer (a3) having a carbon number of ˜12 to copolymerization from the viewpoint of ensuring the adhesive properties. More preferred are butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

These may be appropriately selected and used alone or in combination of two or more for the purpose of obtaining desirable physical properties as a pressure-sensitive adhesive.

[0040] The acrylic copolymer (A) obtained by copolymerizing the acrylic monomer (al) having a hydroxyl group, the acrylic monomer (a2) having an alkylene oxide chain, and other monomers (a3), etc. The weight average molecular weight (Mw) is preferably from 50,000 to 1,000,000, more preferably from 50,000 to 200,000, a low molecular weight acrylic copolymer (A1).

[0041] As described in the Background section, the pressure-sensitive adhesive for the protective film for an optical member is required to have an antistatic function, removability and transparency. Therefore, from the viewpoint of the antistatic function, it is preferable that the talyl copolymer (A) contains more alkylene oxide chains.

By the way, some optical members are very thin and fragile, while others are relatively strong. Depending on the type of adherend to which the protective film is applied, the protective film and the adhesive are required. The magnitude of the peel force applied is different.

That is, when the fragile optical member is used as an adherend, the peeling force is preferably 200 gZ25 mm or less so as not to damage the adherend when the protective film is peeled off after the sticking. More preferably, it is 100 gZ25 mm or less.

On the other hand, when a relatively strong optical member is used as an adherend, the peel force can be allowed to be about 1000 gZ25 mm.

In addition, it is always required that the adhesive remains on the adherend when it is peeled regardless of the adherend.

[0042] The peel strength of the pressure sensitive adhesive is greatly influenced by the cohesive strength of the main component itself constituting the pressure sensitive adhesive and the state of crosslinking between the main component and the curing agent (C) described later. In general, the peeling force can be reduced by using a large amount of the curing agent (C) relative to the main component. In general, increasing the molecular weight of the main component increases the cohesion of the main component itself. can do.

[0043] In the pressure-sensitive adhesive of the present invention, when a low peeling force of 200 gZ25 mm or less at the time of peeling is required, the curing agent (C) is used with respect to 100 parts by weight of the main component, that is, the acrylic copolymer (A). Is preferably used in an amount of 1 to 30 parts by weight, more preferably 2 to 20 parts by weight, and even more preferably 3 to 15 parts by weight. From the viewpoint of low peel strength, it is preferable that the curing agent (C) is large. However, if the amount is too large, the cross-linking becomes excessive, and it cannot be peeled off by sliding force.

The acrylic monomer (a2) having an alkylene oxide chain used in the present invention can generally be easily copolymerized with other acrylic monomers (al) and (a3). Is big. Accordingly, if the viewpoint of improving conductivity is to increase the content of alkylene oxide chains, the molecular weight of the resulting acrylic copolymer (A) tends to decrease. When the molecular weight decreases, the cohesive force of the acrylic copolymer (A) itself tends to decrease, and the adhesive tends to remain on the adherend during peeling.

However, in order to secure a low peel strength, when a relatively large amount of the curing agent (C) is used relative to the acrylic copolymer (A) as described above, a densely crosslinked pressure-sensitive adhesive layer can be obtained. Therefore, even when a relatively low molecular weight acrylic copolymer (A1) is used, the adhesive does not remain on the adherend during peeling.

Therefore, when excellent conductivity and low peeling force as described above are required, a larger amount of the acrylic monomer (a2) having an alkylene oxide chain is copolymerized as the acrylate copolymer (A). It is preferable to use a low molecular weight acrylic copolymer (A1) having a weight average molecular weight (Mw) of 50,000 to 200,000.

[0044] In the present invention, a high molecular weight acrylic copolymer (A2) having a weight average molecular weight (Mw) of 200,000 to 1,000,000 may be used as the acrylic copolymer (A). it can. By copolymerizing the acrylic monomer (a2) having an alkylene oxide chain while controlling the chain transfer effect, it is possible to obtain an acrylic copolymer (A2) having a relatively high molecular weight and excellent conductivity. it can.

For example, it can be obtained by using a plurality of polymerization steps (multistage polymerization reaction), reducing the amount of the initiator, or controlling the monomer concentration. In the present invention, multistage polymerization refers to an operation in which a monomer is divided into a plurality of parts and used for polymerization. For example, when all monomers are charged in a reaction vessel and polymerized, or when no monomer is charged in the reaction vessel and all monomers are added dropwise to polymerize, both steps This is a two-stage polymerization in which a part of the monomer is charged in a reaction vessel and polymerized while dropping the remaining monomers. Further, when the remaining monomer is dropped and polymerized in two stages, this is a three-stage polymerization.

Any of these polymerization methods can be selected for the purpose of adjusting the molecular weight of the resulting polymer.

In the present invention, more specifically, a monomer other than (a2) is used with little or no use of an acrylic monomer (a2) having an alkylene oxide chain for copolymerization at the initial stage of polymerization (reaction vessel). After the polymerization is progressed to the extent that it is a main component, the molecular weight of the acrylic copolymer (A2) is increased by subjecting all or most of the acrylic monomer (a2) having an alkylene oxide chain to polymerization. ) Can be obtained.

When such a so-called multistage polymerization method is used, a polymerization initiator can be further used when the main amount of the acryl-based monomer (a2) having an alkylene oxide chain is polymerized.

[0045] It should be noted that the high molecular weight acrylic copolymer (A2) has a larger cohesive force than the low molecular weight acrylic copolymer (A 1), and therefore the amount of the curing agent (C) is reduced. However, it is difficult for adhesive residue to occur during peeling. However, when fine adhesion is required such that the peel force is 100 gZ25 mm or less, preferably 50 gZ25 mm or less, it is preferable to form a dense cross-linked structure in the pressure-sensitive adhesive layer. Accordingly, the curing agent (C) should be used in an amount of about 1 to 30 parts by weight with respect to 100 parts by weight of the high molecular weight acrylic copolymer (A2) as in the case of the low molecular weight acrylic copolymer (A1). I like it.

[0046] Further, in the present invention, an acrylic copolymer (E) having no alkylene oxide chain can be used in combination, and an alkylene oxide chain having a weight average molecular weight (Mw) of 200,000 to 1,000,000 is used. Do not have! /, High molecular weight acrylic copolymer (E1) with weight average molecular weight ( Mw) It is also one of the embodiments of the present invention to use together with a low molecular weight acrylic copolymer (A1) having an alkylene oxide chain of 10,000 to 200,000.

When high molecular weight acrylic copolymer (E1) is used in combination, low molecular weight acrylic copolymer (Al) Z high molecular weight acrylic copolymer (E1) = 5-80 / 20-95 (weight ratio) A certain force S is preferable, and 10 to 60 Z40 to 90 (weight ratio) is more preferable.

As described above, the low molecular weight acrylic copolymer (A1) is excellent in conductivity in many cases, but because of its low cohesive force, it has the power to suppress and prevent adhesive residue and a large amount of curing agent (C). Must be used. By using the high molecular weight acrylic copolymer (E1) in combination with such a low molecular weight acrylic copolymer (A1), the amount of the curing agent (C) used can be reduced. For example, the curing agent (C) should be used in an amount of 0.1 to 20 parts by weight with respect to a total of 100 parts by weight of the low molecular weight acrylic copolymer (A1) and the high molecular weight acrylic copolymer (Ε 1). Preferably, it can be used in an amount of 0.5 to 10 parts by weight. When a peeling force of up to about 1000gZ25mm can be tolerated at the time of peeling, various levels of electrification can be achieved by reducing the curing agent (C) while using the high molecular weight acrylic copolymer (E1) in this way. It can meet the requirements for prevention and removability.

If the curing agent (C) is used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the total of the low molecular weight acrylic copolymer (A1) and the high molecular weight acrylic copolymer (E1), It is possible to obtain an adhesive with peel strength.

[0047] The acrylic copolymer (E) having no alkylene oxide chain used in the present invention is an acrylic copolymer (E), except that an acrylic monomer having an alkylene oxide chain is not subjected to polymerization. It can be obtained as in A).

[0048] In the present invention, when the acrylic copolymer (A) and the acrylic copolymer (E) are used in combination, both are obtained after obtaining (A) and (E), respectively. Alternatively, the acrylic copolymer (A) may be obtained first, and the monomer constituting the acrylic copolymer (E) may be polymerized in the presence of the (A). A copolymer (E) is obtained, and the monomer constituting the acrylic copolymer (A) may be polymerized in the presence of the (E)! /.

[0049] Examples of the ionic compound (B) used in the present invention include any ionic compounds that are liquid or solid at room temperature. Here, room temperature means 25 ° C. In addition, the present invention Examples of the ionic compound (B) used in the method include inorganic salts of alkali metals or organic salts of alkali metals. In addition, so-called surfactants and other salts such as salt-ammonium, salt-aluminum, copper chloride, ferrous chloride, ferric chloride, ammonium sulfate and the like can be mentioned. These may be used singly or in combination, and alkali metal salts, liquid ionic compounds, and solid ionic compounds are preferred, and alkali metal salts and liquid ionic compounds are more preferred.

[0050] Examples of the alkali metal salt used in the present invention include metal salts having lithium, sodium, and potassium strength, and are composed of a cation moiety comprising Li +, Na +, K + and various key-on moieties. Depending on the type of cation part, it can be divided into inorganic salts and organic salts.

[0051] Inorganic salts of alkali metals include sodium chloride, potassium salt, lithium chloride, lithium perchlorate (LiCIO), potassium chlorate, potassium nitrate, sodium nitrate, sodium carbonate.

Four

Um, sodium thiocyanate, LiBr, Lil, LiBF, LiPF, LiSCN and the like.

4 6

From the viewpoints of conductivity and safety, sodium chloride sodium, potassium potassium salt, lithium perchlorate and the like are preferable.

[0052] Examples of alkali metal organic salts include sodium acetate, sodium alginate, sodium lignate sulfonate, sodium toluenesulfonate, LiCF SO, Li (CF SO) N, Li (

3 3 3 2 2

CF SO) IN, Li (C F SO) N, Li (C F SO) IN, Li (CF SO) C, etc.

3 2 2 5 2 2 2 5 2 3 2 3

LiCF SO, Li (CF SO) N, Li (CF SO) IN, Li (C F SO) N ゝ Li (C F SO) 1

3 3 3 2 2 3 2 2 5 2 2 2 5 2

N, Li (CF SO) C, etc. are preferred Li (CF SO) N, Li (CF SO) IN, Li (C F SO

3 2 3 3 2 2 3 2 2 5 2

) Fluorine-containing lithium imide salts such as N, Li (C F SO) IN, especially (perfluoroalkyl)

2 2 5 2

Preferable is a sulfonyl) imidolithium salt.

In the present invention, the liquid ionic compound that can be used as the ionic compound (B) is a compound that exhibits liquid properties at room temperature, and is composed of a cation component and a cation component. ing.

[0054] As the cation component of the ionic compound (B) of the present invention, pyridinium cation, piperidium cation, pyrrolidinium cation, cation having pyrroline skeleton, cation having pyrrole skeleton, imidazolium cation, tetrahydropyrimidium Cation, dihydropyrimidinium cation, pyrazolium cation, virazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphine Examples include home cations.

§ the [0055] ionic compound of the present invention (B) - The on-component is not particularly limited as long as it satisfies that it becomes a liquid ionic compounds, ^{e.g., Cl _, Br ", Γ} , A1C1-, Al CI "

4 2 7

, BF-, PF-, CIO-, NO-, CH COO ", CF COO", CH SO-, CF SO-,

4 6 4 3 3 3 3 3 3 3

(CF SO) N-, (CF SO) C-, AsF-, SbF-, NbF-, TaF-, F (HF)-, (C

3 2 2 3 2 3 6 6 6 6 n

N) N_, C F SO _, (C F SO) N_, C F COO ", (CF SO) (CF CO) N— etc.

2 4 9 3 2 5 2 2 3 7 3 2 3 Used. In particular, a cation component containing a fluorine atom is preferably used because an ionic compound having a low melting point can be obtained.

[0056] Specific examples of the liquid ionic compound used in the present invention are appropriately selected from the combination of the cation component and the cation component, and include, for example, 1 butyl pyridinium tetrafunoleoloborate, 1-Butylpyri-hexahexoleophthalate phosphate, 1-Butyl- 3 Methylpyridi-mu-tetrafluoroborate, 1-Butyl-3 Methylpyridi-mu-trifluoromethanesulfonate, 1-Butyl-3-methylpyridi-umbis (trifluoromethanesulfo- ) Imide, 1-butyl-3-methylpyridumumbis (pentafluoroethanesulfol) imide, 1-hexylpyridyl-tetrafluoroborate, 2-methyl-1-pyrrolinetetrafluoroborate, 1-ethyl 2-phenolindole Tetrafluoroborate, 1,2-dimethylindoleteto Fluoroborate, 1-ethyl carbazol tetrafluoroborate, 1-ethyl trifluoro-3-methyl imidazolium tetrafluoroborate, 1-ethyl -3-methyl imidazolium acetate, 1-ethyl trifluoro-3-methyl imidazolium trifluoroacetate 1-Ethyl 3-methylimidazol heptafluorobutyrate, 1-Ethyl 3-methyl imidazole trifluoromethanesulfonate, 1-Ethyl 3-methylimidazole perfluorobutane sulfonate, 1-Ethyl 3-methylimidazo Ryudicyanamide, 1-ethyl 3-methylimidazolium bis (trifluoromethanesulfurimide), 1-ethyl 3-methylimidazolium bis (pentafluoroethanesulfurimide), 1-ethyl-3-methylimidazolium tris Trifluoromethanesulfo) methide, 1-butyl-3-methylimidazole tetrafluoroborate, 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole trifluoroacetate, 1 —Butyl—3-methylimidazolium hep Tafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazole perfluorobutanesulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethane) (Sulfo-) imide, 1 hexyl 3-methyl imidazolium bromide, 1 mono-hexyl 3-methyl imidazolium chloride, 1 mono-hexyl 3-methyl imidazolium tetrafluoroborate, 1 hex 3-methylimidazole hexafluorophosphate, 1-hexylol 3-methyl imidazolium trifluoromethanesulfonate, 1-octyl 3-methyl imidazolium tetrafluoroborate, 1-octyl 3-methyl imidazole hexafluoro Lophosphate, 1 Hexilous 2, 3 Methyl imidazolium tetrafluoroborate, 1, 2 dimethyl 3 propyl imidazolium bis (trifluoromethanesulfol) imide, 1 Methyl villa Zorium tetrafluoroborate, 3-Methyl virazolium tetrafluoroborate Bromoborate, tetrahexylammo-umbis (trifluoromethanesulfol) imide, diaryldimethylammotetrafluoroborate, diaryldimethylammo-trifluoromethanesulfonate, di Lildimethylammo-umbis (trifluoromethanesulfoyl) imide, diaryldimethylammo-umbis (pentafluoroethanesulfol) imide, N, N diethyl-N-methyl-N- (2-methoxyethyl) ammo -UMTetrafluoroborate, N, N Jetyl N-Methyl N- (2-Methoxyethyl Ammonium trifluoromethane sulfonate, N, N Jetyl N-methyl-N— (2-methoxyethyl) ammo-umbis (trifluoromethanesulfol) imide, N, N Jetyl N-methyl N One (2-methoxyethyl) ) Ammonium bis (pentafluoroethanesulfol) imide, glycidyltrimethylammonium-trifluoromethanesulfonate, glycidyltrimethyl ammonium-umbis (trifluoromethanesulfonyl) imide, glycidyltrimethylammonium Bis (pentafluoroethanesulfol) imide, 1-butylpyridium (trifluoromethanesulfuryl) trifluoroacetamide, 1-butyl 3-methylpyridyl-um (trifluoromethanesulfuryl) trifluoroacetamide, 1 —Ethyl—3-methylimidazolium Trifluoromethanesulfol) trifluoroacetamide, N, N Jetyl N-methyl-N- (2-methoxyethyl) ammonium (trifluoromethanesulfol) trifluoroacetoamide, diallyldimethylammonium (Trifluoromethanesulfol) trifluoroa Cetamide, glycidyltrimethylammonium (trifluoromethanesulfur) trifluoroacetamide, N, N dimethyl-N ethyl-N propylammonum bis (trifluoromethanesulfol) imide, N, N dimethyl-N ethyl-N Butylammo-bisbis (trifluoromethanesulfo) imide, N, N dimethyl-N ethyl N—pentylammo-mubis (trifluoromethanesulfo) imide, N, N dimethyl-N—ethyl-N hexylammo-mubis (trifluoro) (Romethanesulfol) imide, N, N-dimethyl-N-ethyl N-heptylammo-umbis (trifluoromethanesulfurimide), N, N dimethyl-N-ethyl N-norammo-umbis (trifluoromethanesulfurol) ) Imido, N, N Dimethyl-N, N Dipropylammo (Trifluoromethanesulfo) imide, N, N dimethyl-N propyl-N-butylammo-mubis (trifluoromethanesulfol) imide, N, N dimethyl-N-propyl-N pentylammo-mubis (trifluoromethanesulfo) ) -Imide), N, N-dimethyl-N-propyl-N-hexylammo-umbis (trifluoromethanesulfol) imide, N, N-dimethyl-N-propyl-N-heptylammo-umbis (trifluoromethanesulfol) imide, N, N Dimethyl-N-Butyl-N Hexyl Ammum Bis (trifluoromethanesulfol) imide, N, N Dimethyl-N-Butyl-N Heptyl Ammo-umbis (Trifluoromethanesulfol) imide, N, N Dimethyl — N-pentyl--N-hexylammo-umbis (trifluoromethanesulfuryl) ester N, N—Dimethyl-N, N Dihexylammo-umbis (trifluoromethanesulfol) imide, Trimethylheptylammo-umbis (trifluoromethanesulfol) imide, N, N Diethyl N Methyl N Propyl ammo -UMBIS (trifluoromethanesulfol) imide, N, N Jetyl N-methyl-N-pentylammo-UMBIS (trifluoromethanesulfol) imide, N, N Jetyl N-methyl-N heptylammo umbis (trifluoromethane) Sulfo-) imide, N, N Jetyl-N-propyl-N-pentylammo-mubis (trifluoromethanesulfol) imide, triethylpropylammo-mubis (trifluoromethanesulfol) imide, triethylpentylammo- Umbis (trifluoromethanesulfol) imide, Triethyl heptyl ammonium bis (trifluoromethanesulfol) imide, N, N dipropyl mono N-methyl N ethyl ether Mubis (trifnoreolomethanesulphononiole) imide, N, N-dipropinoleyl N-methinole N-pentylammo-mubis (trifluoromethanesulfol) imide, N, N-dipropyl-N-butyl-N- Xylammo-umbis (trifluoromethanesulfol) imide, N, N-dipropyl mono-N, N-dihexylammo-umbis (trifluoromethanesulfol) imide, N, N-dibutyl-N-methyl-N-pentylammo -UMBIS (trifluoromethanesulfol) imide, N, N-dibutyl-N-methyl-N-hexylammo umbis (trifluoromethanesulfol) imide, trioctylmethylammo-umbis (trifluoromethanesulfonyl) Imido, N-methyl-N-ethyl-N-propyl-N-pentylammo-umbis (trifluoro (Romethanesulfol) imide and the like.

[0057] The solid ionic compound that can be used as the ionic compound (B) in the present invention is a combination of the force thione component and the cation component and exhibits a solid property at room temperature.

In the present invention, examples of the surfactant that can be used as the ionic compound (B) include a cationic surfactant and an anionic surfactant.

[0059] Examples of cationic surfactants include alkyl trimethyl ammonium salts, acylamidopropyl trimethyl ammonium methosulfate, alkyl benzyl methyl ammonium salts, choline chloride, polydimethyl (Meth) acrylate copolymer having a quaternary ammonium group such as aminoethyl methacrylate, styrene copolymer having a quaternary ammonium group such as polybutenyl trimethyl ammonium chloride, And diarylamine copolymers having a quaternary ammonium group such as polydiaryldimethylammonium chloride. These compounds can be used alone or in combination of two or more.

[0060] Examples of the anionic surfactant include alkyl sulfonate, alkyl benzene sulfonate, alkyl sulfate ester salt, alkyl ethoxy sulfate ester salt, alkyl phosphate ester salt, and sulfonate group-containing styrene copolymer. Is mentioned. These compounds may be used alone or in admixture of two or more.

[0061] Further, the content of the ionic compound (B) is 100 parts by weight of the acrylic copolymer (A), or when the acrylic copolymer (E) is used in combination, The total content is preferably 100 to 50 parts by weight with respect to 100 parts by weight. More preferably 1-30 parts by weight The 0.1 If less than 1 part by weight, sufficient ionic conductivity cannot be obtained, and even if it contains more than 50 parts by weight of ionic compound (B), almost no improvement in conductivity can be expected, and the adhesive properties are further reduced. Also, it is not preferable because the coating film is likely to be whitened due to a decrease in compatibility with the resin.

[0062] The stability over time of the pressure-sensitive adhesive film using the antistatic acrylic pressure-sensitive adhesive, that is, the protective film for optical members, includes the amount of the ionic compound (B) and the acrylic copolymer (A). The amount of alkylene oxide chain greatly affects.

When the amount of alkylene oxide chains is large, a complex can be formed efficiently with the ionic compound (B). However, when the amount of ionic compounds with a small amount of alkylene oxide chains is large, a complex is formed. The excess ionic compound that cannot be obtained migrates to the surface of the pressure-sensitive adhesive layer, and the whitening phenomenon as described above tends to occur. In addition, the surface resistance over time is likely to increase.

From these viewpoints, it is preferable that the amount of the alkylene oxide chain contained in the pressure-sensitive adhesive layer is increased as much as possible, and a minimum amount of the ionic compound (B) capable of expressing the required conductivity is added.

[0063] In the antistatic acrylic pressure-sensitive adhesive of the present invention, in order to increase the cohesive strength and the degree of crosslinking

The curing agent (C) can be preferably used.

As the curing agent (C) of the present invention, preferably two or more functional groups capable of reacting with a functional group such as a hydroxyl group contained in the acrylic copolymers (A) and (E) are contained in one molecule. What you have is preferred. For example, a known trifunctional isocyanate compound or a known polyfunctional epoxy compound can be suitably used. These can also be used in combination.

[0064] As a known trifunctional isocyanate compound, a known diisocyanate compound is modified with a three-functional polyol component, so that a so-called adduct, diisocyanate compound is water and A reacted burette, diisocyanate compound, or a trimer (isocyanurate) having an isocyanurate ring that also forms a molecular force can be used.

[0065] Examples of known diisocyanate compounds include aromatic diisocyanates, aliphatic diisocyanates, araliphatic diisocyanates, alicyclic diisocyanates, and the like.

[0066] Aromatic diisocyanates include 1,3-phenolic diisocyanate, 4, 4, Ninoresiocyanate, 1,4 Phenylene Diisocyanate, 4, 4, Di-Dimethane Diisocyanate, 2, 4 Tolylene Diisocyanate, 2, 6 Tolylene Diisocyanate, 4, 4, One Toluidine Examples thereof include isocyanate, di-cidin diisocyanate, 4,4′-diphenylenoyl monoterdiisocyanate, and the like.

[0067] Aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2, 3 Examples include butylene diisocyanate, 1,3 butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4 trimethylhexamethylene diisocyanate.

[0068] The aromatic aliphatic diisocyanate includes ω, ω, monodiisocyanate, 1,3 dimethylbenzene, ω, ω, monodiisocyanate, 1,4 dimethylbenzene, ω, ω, monodiisocyanate, 1,4-jetylbenzene. 1, 4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate, and the like.

[0069] The alicyclic diisocyanates include 3-isocyanate methyl-1,3,5,5 trimethylcyclohexenoylisocyanate, 1,3 cyclopentane diisocyanate, 1,3 cyclohexanediiso Cyanate, 1,4-cyclohexanediisocyanate, methyl-2,4 cyclohexanediisocyanate, methyl-2,6 cyclohexanediisocyanate, 4,4, -methylenebis (cyclohexyliso Cyanate), 1,4 bis (isocyanate methyl) cyclohexane, 1,4 bis (isocyanate methyl) cyclohexane, and the like.

[0070] The diisocyanate compounds used in the present invention include 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanate methyl-3, 5, 5-trimethyl. It is preferable to use cyclohexyl isocyanate (also referred to as “isophorone diisocyanate”).

[0071] The known polyfunctional epoxy compound is not particularly limited as long as it is a compound having a plurality of epoxy groups in the molecule. Specific examples of the polyfunctional epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6 hexanediol diglycidyl ether, and bisphenol. Enol ェ -epoxychlorohydrin type epoxy resin, N, N, N, N, monotetraglycidyl 1 m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidyl dilin, N, N-diglycidyl toluidine and the like can be mentioned.

[0072] For the above-mentioned curing agent (C), a trifunctional isocyanate compound and a polyfunctional epoxy compound can be used alone or in combination. When using in applications that emphasize flexibility, it is preferable to use a polyfunctional epoxy compound when heat resistance is required, which preferably uses a trifunctional isocyanate compound.

As described above, when low peel strength of 200 gZ25 mm or less, preferably 100 gZ25 mm or less is required, 1 to 30 parts by weight of the curing agent (C) should be used with respect to 100 parts by weight of the acrylic copolymer (A). It is more preferable to use 2 to 20 parts by weight, and more preferable to use 3 to 15 parts by weight.

In the case of using a polyfunctional epoxy compound, it is preferable that the acrylic copolymer (A) contains acrylic acid or methacrylic acid in order to act as a crosslinking agent more effectively. The content is preferably 0.5 to 5% by weight in the total acrylic monomer. If it is less than 5%, it does not sufficiently act as a crosslinking agent, and if it exceeds 5%, the pot life after the addition of the curing agent (C) tends to be short.

[0073] It is important to use the antioxidant (D) in the antistatic pressure-sensitive adhesive of the present invention.

One of the purposes is to suppress the increase in viscosity of the main agent over time. Another object is to prevent the conductivity of the pressure-sensitive adhesive layer after the reaction between the main agent and the curing agent from decreasing with time.

In the acrylic copolymer (A) of the present invention, a monomer having many alkylene oxide chains is used. When the temperature and room temperature are 50 ° C. or higher in a harsh environment, the acrylic copolymer (A) is not resistant to heat. A stable ether bond portion is decomposed to generate a radical. As a result, the residual monomers remaining in the acrylic copolymer (A) and acrylic copolymer (E) are polymerized over time, resulting in a thickening of the main agent. End up. In the present invention, by using the antioxidant (D), decomposition of the ether bond of the alkylene oxide chain can be suppressed, and an increase in the viscosity of the main agent over time can be suppressed. Furthermore, in the present invention, the use of the antioxidant (D) enables alkylene oxide after the reaction between the main agent and the curing agent. This suppresses the decomposition of the ether bond of the oxide chain and suppresses the deterioration of the conductivity of the adhesive layer over time.

The amount of the antioxidation agent (D) used is preferably 0.01-10.0 parts by weight, more preferably 0.1-0.1 parts by weight per 100 parts by weight of the acrylic copolymer (A). 3. 0 parts by weight. If the amount is less than 0.01 parts by weight, the effect of suppressing the viscosity increase of the main agent is insufficient. If the amount is more than 10.0 parts by weight, contamination of the adherend may be caused by the antioxidant component.

[0074] As the anti-oxidation agent (D) used in the present invention, a known anti-oxidation agent can be used.

[0075] Examples of the known antioxidant (D) include phenolic acid antioxidants, phosphite acid antioxidants, thioether acid antioxidants, and the like. These can be used alone, but in some cases, they can also be used in combination. In the present invention, phenolic acid antioxidants are preferred. Particularly, hindered phenol acid antioxidants are also preferable in terms of heat resistance, weather resistance, and compatibility.

[0076] Examples of phenolic antioxidants include compounds having the following CAS numbers. 2767 6—62—6, 1843—03—4, 85—60—9, 2082—79—3, 6683—19—8, 3644

3—68—2, 90498—90—1 (ADK STAB AO—80), 1709—70—2, 41484—3

5-9, 23128-74- 7, 125643- 61-0, 134701-20-20, 976-56-7, 65 140-91-2, 110553-27-0, 35074-77-2, 40601-76 — 1, 68411—4

6—1, 991—84—4 etc.

Examples of the phosphite-based anti-oxidation agent include compounds having the following CAS numbers. 5266

4—24—1, 3806—34—6, 26741—53—7, 80693—00—1, 126050—54—2 (Adeka Stub HP—10), 31570—04—4, 13003—12—8, 26523— 78—4 etc. As an anti-oxidant agent for the aged tenor system, [66534—05—2, 71982—66—6] (Ade force stub AO—23), 29598—76—3, 10595—72—9 etc. It can be mentioned.

[0077] The antistatic pressure-sensitive adhesive of the present invention can be used in combination with other resin, such as acrylic resin, polyester resin, amino resin, epoxy resin, and polyurethane resin, if necessary. . Depending on the application, tackifiers, talc, calcium carbonate, titanium oxide, etc. You may mix | blend additives, such as a filler, a coloring agent, a ultraviolet absorber, an antifoamer, and a light stabilizer.

[0078] Using the antistatic pressure-sensitive adhesive of the present invention, a pressure-sensitive adhesive sheet is obtained in which a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive and a substrate such as a plastic film, paper, cloth, or foam are laminated. The surface of the pressure-sensitive adhesive layer can be covered with a release sheet.

The pressure-sensitive adhesive sheet can be obtained by applying or impregnating various types of base materials with a pressure-sensitive adhesive and drying and curing it. Alternatively, a pressure-sensitive adhesive is applied onto the release sheet, dried, and various substrates are laminated on the surface of the pressure-sensitive adhesive layer that is being formed, and the hydroxyl group in the pressure-sensitive adhesive and the isocyanate group in the curing agent (C), or It can also be obtained by advancing the reaction between the carboxyl group in the adhesive and the epoxy group in the curing agent (C).

[0079] By applying the pressure-sensitive adhesive of the present invention to a transparent plastic film preferably as a substrate, a surface protective pressure-sensitive adhesive film for an optical member can be suitably obtained.

[0080] Examples of the plastic film include a polychlorinated butyl film, a polyethylene film, a polyethylene terephthalate (PET) film, a polyurethane film, a nylon film, a treated polyolefin film, and an untreated polyolefin film.

[0081] The antistatic pressure-sensitive adhesive of the present invention is preferably applied to a substrate or the like so as to have a thickness of about 2 to 200 m when dried and cured. If it is less than 2 m, the ionic conductivity becomes poor, and if it exceeds 200 m, it becomes difficult to produce and handle the adhesive sheet.

In this way, it is possible to obtain an antistatic pressure-sensitive adhesive film having a pressure-sensitive adhesive layer having a surface resistance of ΙΟ ^ Ω or less.

[0082] By using the antistatic pressure-sensitive adhesive of the present invention and considering its use, required performance, etc., various forms of antistatic pressure-sensitive adhesive films can be obtained.

For example, an antistatic adhesive film for a protective film for a polarizing plate will be described with reference to the drawings.

FIG. 1 shows an antistatic pressure-sensitive adhesive film according to the present invention comprising a PET (polyethylene terephthalate) film substrate 1 and an antistatic acrylic pressure-sensitive adhesive layer 2 held on one surface thereof. FIG. 6 is a schematic cross-sectional view showing a state where the film is attached to the polarizing plate 3.

Figure 2 shows a book with an antistatic acrylic adhesive layer 2 on both sides of a PET film substrate 1. 2 is a schematic cross-sectional view showing a state in which an antistatic pressure-sensitive adhesive film according to the invention is attached to a polarizing plate 3 with one antistatic acrylic pressure-sensitive adhesive layer 2. FIG.

FIG. 3 shows an antistatic pressure-sensitive adhesive film according to the present invention in which an antistatic coating agent layer 4 is provided on one surface of a PET film substrate 1 and an antistatic acrylic pressure-sensitive adhesive layer 2 is further supported thereon. FIG. 3 is a schematic cross-sectional view showing a state where the protective acrylic pressure-sensitive adhesive layer 2 is attached to the polarizing plate 3.

FIG. 4 shows an antistatic pressure-sensitive adhesive film according to the present invention in which an antistatic acrylic pressure-sensitive adhesive layer 2 is provided on one surface of a PET film substrate 1 and an antistatic coating agent layer 4 is provided on the opposite surface. FIG. 3 is a schematic cross-sectional view showing a state where the protective acrylic pressure-sensitive adhesive layer 2 is attached to the polarizing plate 3.

When the adhesive of the present invention is used for a film for protecting the surface of an optical member or an electronic member, an antistatic coating agent layer should be provided as shown in FIGS. 3 and 4 in order to further reduce the peel charge amount. Is also possible.

Also, in applications where functionality is to be imparted to plastic films, as shown in Fig. 2, antistatic acrylic adhesive layers are provided on both sides of the base film, and one antistatic acrylic adhesive layer has functionalities. A film (for example, a retardation film, an optical compensation film, a light diffusion film, an electromagnetic wave shielding film, etc.) can be further bonded.

Considering workability and production cost, the embodiment shown in FIG. 1 is most preferable.

[0083] As shown in FIG. 3 and FIG. 4, it has adhesiveness between the pressure-sensitive adhesive layer and the plastic film substrate, or on the opposite side (top coat), not on the pressure-sensitive adhesive layer side of the plastic film substrate. Examples of the antistatic agent used for forming the antistatic coating layer include metal fillers, quaternary ammonium salt derivatives, surfactants, and conductive resins.

[0084] Examples of the metal filler include metal oxides such as tin oxide, zinc oxide, iron oxide and antimony oxide, metals such as carbon, silver and copper. In consideration of the transparency of the coating film, tin oxide, antimony oxide and the like are preferable.

[0085] As the quaternary ammonium salt derivative, a polymer of a (meth) acrylate monomer having a quaternary ammonium salt, or a copolymer with another (meth) acrylate monomer is used. be able to. [0086] The antistatic coating agent layer preferably has a thickness of 0.1 μm to 50 μm as a coating film, more preferably 1 μm to 20 μm. If it is less than 0.1 m, the antistatic performance cannot be sufficiently exerted, and if it exceeds 50 m, there are problems in cost, coating properties, and the like.

Example

[0087] Synthesis Example 1

An acrylic copolymer (A) having a monomer force with the composition ratio shown in Table 1 was obtained as follows.

That is, using a 4-roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, the reaction kettle was 46% by weight of 2EHA [46 of 68% by weight of “68” in Table 1]. meaning of weight ^_0/0; the same applies hereinafter], 50 wt% of BA, 50 wt% of 2HEA, the total amount of AM90G, acetic acid as solvent Echiru, Azobisuisopuchi port as initiator - tolyl a suitable amount charged, the remaining monomer total amount, A solution prepared by adding an appropriate amount of ethyl acetate and azobisisobutyryl-tolyl was added dropwise over about 1 hour and polymerized at about 80 ° C. for 5 hours under a nitrogen atmosphere. After completion of the reaction, it was cooled and diluted with ethyl acetate. This reaction solution had a solid content of 40% and a viscosity of 13 OOmPa-s, Mw (weight average molecular weight) of 310,000.

[0088] Synthesis example 2

In other words, using a 4-roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, the reaction kettle was 44% by weight of 2EHA, 50% by weight of 2HEA, the total amount of M40G, and ethyl acetate as a solvent. Add an appropriate amount of azobisisobutyl-tolyl as an initiator, add the remaining monomer, ethyl acetate, and azobisisobutyl-tolyl in an appropriate amount, add dropwise over about 1 hour, and then add about 80 ° C under nitrogen atmosphere. For 5 hours. After completion of the reaction, it was cooled and diluted with ethyl acetate. This reaction solution had a solid content of 41%, a viscosity of 1200 mPa's, and Mw (weight average molecular weight) of 350,000.

[0089] Synthesis Example 3

An acrylic copolymer (A) having a monomer force with the composition ratio shown in Table 1 was obtained as follows. In other words, a stirrer, a reflux condenser, nitrogen inlet, thermometer, using a 4 Roff flask equipped with a dropping funnel, 35% by weight of 2EHA to the reaction kettle, 30 wt% of BA, 30 wt ^_0/0 of 2HEA, acetate as a solvent Echiru, Azobisuisopuchi port as initiator - qs tolyl charged, then 42 weight 2EHA ^_0/0, 40 weight 40 weight ^_0/0, 2HEA of BA ^_0/0, 30% by weight of M90G, acetic acid A solution prepared by adding a suitable amount of ethyl and azobisisobutyl-tolyl was added dropwise over about 1 hour and polymerized at about 80 ° C. for 1 hour in a nitrogen atmosphere.

Further, a solution prepared by adding an appropriate amount of tolyl to the remaining monomer, ethyl acetate, and azobisisobuty was added dropwise over about 1 hour and polymerized at about 80 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was cooled and diluted with ethyl acetate and toluene. This reaction solution had a solid content of 40%, a viscosity of 1500 mPa.s, and Mw (weight average molecular weight) of 330,000.

[0090] Synthesis Example 4

In other words, using a 4 Roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer and dropping funnel, the reaction kettle was 40% by weight of 2EHA, 30% by weight of BA, 30% by weight of 2HEA, acetate Echiru, Azobisuisopuchi port as initiator - qs tolyl charged, then, 40 weight 46 weight ^_0/0, BA of 2EHA ^_0/0, 40 weight 2HEA ^_0/0, 20% by weight of M90G, acetic Echiru, A solution prepared by adding an appropriate amount of azobisisobutyl-tolyl was added dropwise over about 1 hour and polymerized at about 80 ° C. for 1 hour in a nitrogen atmosphere.

Thereafter, the remaining monomer, ethyl acetate, and azobisisobuty / t-tolyl were mixed in a suitable amount and added dropwise over about 1 hour and polymerized at about 80 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was cooled and diluted with ethyl acetate and toluene. This reaction solution had a solid content of 40%, a viscosity of 3700 mPa.s, and Mw (weight average molecular weight) of 250,000.

[0091] Synthesis Example 5

In other words, a 4-roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel was used. In the reaction kettle, 74% by weight of 2EHA, 50% by weight of 2HEA, Chill, azobis isopuchi-tolyl as an initiator

A solution prepared by adding a suitable amount of the remaining monomers, ethyl acetate, toluene, and azobisisobuty-tolyl was added dropwise over about 1 hour and polymerized at about 80 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled and diluted with toluene. This reaction solution had a solid content of 41%, a viscosity of 100 OmPa's, and Mw (weight average molecular weight) of 110,000.

[0092] Synthesis Example 6

That is, using a 4-roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, the reaction kettle was 44% by weight of 2EHA, 50% by weight of BA, 50% by weight of 2HEA, 50% by weight, total amount of M40G, ethyl acetate as solvent, azobisisopropylonitrile as initiator,

The remaining monomer, ethyl acetate, and azobisisobuty-tolyl were added in appropriate amounts and added dropwise over about 1 hour, and polymerized at about 80 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, it was cooled and diluted with ethyl acetate. This reaction solution had a solid content of 40%, a viscosity of 2000 mPa's, and Mw (weight average molecular weight) of 320,000.

[0093] Synthesis Example 7

In other words, using 4 Roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, the reaction kettle was 88% by weight of 2EHA, 50% by weight of 2HEA, ethyl acetate as solvent, initiator As azobis isopuchi mouth-tolyl

A solution prepared by adding a suitable amount of the remaining monomers, ethyl acetate, toluene, and azobisisobuty-tolyl was added dropwise over about 1 hour and polymerized at about 80 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled and diluted with toluene. This reaction solution had a solid content of 40%, a viscosity of 400 mPa's, and Mw (weight average molecular weight) of 105,000.

[0094] Synthesis Example 8

Monomer strength with composition ratio shown in Table 1 Construct acrylic copolymer (E) as follows I got it.

In other words, a stirrer, a reflux condenser, nitrogen inlet, thermometer, using a 4 Roff flask equipped with a dropping funnel, 50% by weight of 2EHA to the reaction kettle, 50 wt% of BA, 50 wt ^_0/0 of 2HEA, Add appropriate amount of ethyl acetate as solvent and azobisisobutyl butyl-tolyl as initiator, and add the remaining monomer, ethyl acetate and azobisisobutyl butyl-tolyl as appropriate amount, and add dropwise over about 1 hour under nitrogen atmosphere. Polymerization was carried out at about 80 ° C for 5 hours. After completion of the reaction, it was cooled and diluted with ethyl acetate. This reaction solution had a solid content of 41%, a viscosity of 1700 mPa's, and Mw (weight average molecular weight) of 400,000.

[0095] Synthesis Example 9

A monomer power having a composition ratio shown in Table 1 was formed, and no hydroxyl group was contained. An acrylic copolymer was obtained as follows.

In other words, using a 4 Roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, the reaction kettle was 35% by weight of 2EHA, 30% by weight of BA, ethyl acetate as the solvent, start An appropriate amount of azobisisopetite-tolyl is added as an agent,

Next, 42 weight 2EHA ^_0/0, 40 weight BA ^_0/0, 30 weight ^_0/0 of M90G, acetic Echiru, § Zobisuisopuchi port - tolyl the solution was mixed with an appropriate amount added over about 1 hour dropwise Then, polymerization was performed at about 80 ° C. for 1 hour in a nitrogen atmosphere.

Thereafter, the remaining monomer, ethyl acetate, and azobisisobuty / t-tolyl were added in appropriate amounts and mixed dropwise over about 1 hour and polymerized at about 80 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was cooled and diluted with ethyl acetate and toluene. This reaction solution had a solid content of 40%, a viscosity of 1300 mPa.s, and Mw (weight average molecular weight) of 350,000.

[0096] Synthesis Example 10

Monomer power having the composition ratio shown in Table 1 An acrylic copolymer was obtained in the following manner, without containing the constituted hydroxyl group.

In other words, using a 4-roflasco equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, the reactor was charged with all the monomers, benzene as the solvent, and azobis isopuchi-tolyl as the initiator, Polymerization was performed at about 80 ° C. for 5 hours under a nitrogen atmosphere to obtain a reaction solution having a solid content of 40%.

2 E H A: 2-Ethylhexyl acrylate

B A: Petryl acrylate

2 H E A: 2-hydroxyethyl acrylate

AA: Acrylic acid

AM9 OG: Metoxypolyethyleneglycol acrylate (ethylene oxide 9 mo I)

M23 OG: methoxypolyethylene glycol methacrylate (ethylene oxide 23mo I)

M9 OG: Methoxypolyethylene glycol methacrylate (ethylene oxide 9 mo I)

M40G: Methoxypolyethylene glycol methacrylate (ethylene oxide 4 mo I)

§ s [ [Example 1]

Based on 40 g of the solid content of the acrylic resin solution obtained in Synthesis Example 1, 3 g of lithium perchlorate, “Adekastab AO-80” (antioxidant: 3,9-bis [1,1,1-dimethyl-2- [β- (3-1-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10-tetraoxaspiro [5,5] -undecane; manufactured by Asahi Denka Co., Ltd. 2 g and 10 g of tolylene diisocyanate trimethylolpropane adduct 37% ethyl acetate solution as a curing agent were blended to obtain an adhesive.

The obtained pressure-sensitive adhesive was coated on a release paper to a dry coating thickness of 20 m, dried at 100 ° C for 2 minutes, and then formed into a polyethylene terephthalate film (thickness 38 μm) ) And laminated for 2 days at room temperature in this state to obtain a test adhesive tape. Using the pressure-sensitive adhesive tape, the adhesive strength, surface resistance value, removability and transparency were evaluated according to the following methods. Furthermore, the storage stability of the main component of the adhesive was evaluated.

[0099] <Adhesive strength>

The release paper of the test pressure-sensitive adhesive tape was peeled off, and the exposed pressure-sensitive adhesive layer was attached to a glass plate having a thickness of 2 mm at 23 ° C.-50% RH, and roll-bonded according to JIS Z-0237. After 24 hours, the peel strength (180 degree peel, tensile speed 3 OOmmZ; unit gZ25mm width) was measured with a shopper type peel tester.

[0100] <Surface resistance value>

The release paper of the test pressure-sensitive adhesive tape was peeled off, and the surface resistance value of the exposed pressure-sensitive adhesive layer surface was measured using a surface resistance measurement device (Mitsubishi Chemical Corporation) (Ω Z port).

[0101] <Removability>

Remove the release paper from the test adhesive tape, attach the exposed adhesive layer to the glass plate, and leave it under conditions of 60 ° C-95% RH for 24 hours. 23 ° C--50% RH After cooling, the glass plate force was peeled off, and the adhesive residue on the glass plate was visually evaluated. Specifically, the state after peeling was evaluated according to the following four levels. No adhesive transfer to the adherend ◎

Very little 〇

Partially △

Fully migrated X [0102] <Transparency>

Remove the release paper from the test adhesive tape, attach the exposed adhesive layer to the glass plate, and leave it under conditions of 60 ° C-95% RH for 24 hours. 23 ° C--50% RH After cooling, it was visually evaluated. Colorless and transparent ◎

Very slightly cloudy 〇

Turbidity, aggregates seen △

Not transparent X

[0103] <Storage stability of main agent>

The main component of the pressure-sensitive adhesive (among the blended components, a curing agent was added!) Was placed in a sealed container, and the rate of increase in viscosity after one month was measured in an oven at 50 ° C. Viscosity increase rate is less than 10% ◎

Viscosity increase rate is 10% or more and less than 20% 〇

Viscosity increase rate is 20% or more and less than 50% △

Viscosity increase rate is 50% or more or gelation X

[Examples 2, 3, and 5]

A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that each acrylic resin obtained in Synthesis Examples 2, 3, and 5 was used, and lithium perchlorate was used in an amount of 5 g. evaluated.

[0105] [Example 4]

A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that the acrylic resin obtained in Synthesis Example 4 was used and lithium chloride was used in an amount of 3 g, and evaluation was performed in the same manner as in Example 1.

[Example 6]

Adhesive in the same manner as in Example 1 except that the acrylic resin obtained in Synthesis Example 6 was used and 3 g of N, N, Ν 'Ν'-tetraglycidyl-m-xylenediamine, 5% toluene solution was used as a curing agent. An agent was obtained and evaluated as in Example 1.

[Example 7]

Adhesive in the same manner as in Example 1 except that 50 g of the acrylic resin solution obtained in Synthesis Example 5 and 5 Og of the acrylic resin solution obtained in Synthesis Example 8 were mixed and 5 g of lithium perchlorate was used. And evaluated in the same manner as in Example 1. [Example 8]

A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that the acrylic resin obtained in Synthesis Example 7 was used and lithium perchlorate was used in an amount of lg, and evaluation was performed in the same manner as in Example 1.

[Example 9]

A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that 3 g of lithium perchlorate was used using the acrylic resin obtained in Synthesis Example 7, and evaluation was performed in the same manner as in Example 1.

[0110] [Examples 10 and 11]

Evaluation was performed in the same manner as in Example 1 except that the acrylic resin obtained in Synthesis Examples 5 and 7 was used, lithium perchlorate lg was used, and the test adhesive tape was obtained after 7 days at room temperature.

[0111] [Example 12]

Evaluation was performed in the same manner as in Example 1 except that the acrylic resin obtained in Synthesis Example 7 was used, lithium perchlorate lg was used, and a test adhesive tape was obtained after 30 days at 50 ° C.

[0112] [Example 13]

Instead of lithium perchlorate lg, CIL-314 (manufactured by Nippon Carlit Co., Ltd .: liquid ionic compound; pyridi-um derivative) was used in the same manner as in Example 8 except that 0.5 g was used. Obtained and evaluated in the same manner as in Example 1.

[0113] [Example 14]

A pressure-sensitive adhesive was obtained in the same manner as in Example 8, except that 0.3 g of lithium bis (pentafluoroethanesulfol) imide was used instead of lithium perchlorate lg. Rated 7.

[0114] [Example 15]

Instead of lithium perchlorate lg, PEL-20A (Nippon Carlit Co., Ltd .: Lithium perchlorate Z polyether polyol) Adhesive was obtained in the same manner as in Example 8 except that lg was used. Evaluation was performed in the same manner as in 1.

[0115] [Example 16]

A pressure-sensitive adhesive was obtained in the same manner as in Example 8 except that Elegan C-114 (manufactured by Yuki Oil Co., Ltd .: Cationic surfactant) lg was used instead of lithium perchlorate lg. Example 1 It was evaluated in the same way. [0116] [Example 17]

A pressure-sensitive adhesive was obtained in the same manner as in Example 8 except that 1 g of KS-1262 (manufactured by Kao Corporation: a-on surfactant) was used instead of lithium perchlorate lg. Evaluated.

[0117] [Example 18]

Instead of lithium perchlorate lg, Elegan C-114 (0, manufactured by Yuki Yushi Co., Ltd .: Cationic surfactant) 0.9g and PEL-20A (Nihon Carlit, Inc .: lithium perchlorate Z polyester monopolyol ) Was used in the same manner as in Example 8 except that 0.1 lg was used, and evaluated in the same manner as in Example 1.

[0118] [Example 19]

“Adekastab AO-80” Instead of 0.2 g, Adekastab HP-10 (Asahi Denka Co., Ltd .: Phosphite-based anti-oxidation agent) 0.3 g was used in the same manner as in Example 8 except that 0.3 g was used. An adhesive was obtained and evaluated in the same manner as in Example 1.

[Example 20]

"Adekastab AO-80" Adhesive similar to Example 8 except that 0.2g of Adekastab AO-23 (Asahi Denka Co., Ltd .: thioether antioxidant) was used instead of 0.2g. And evaluated in the same manner as in Example 1.

[0120] [Example 21]

“Adeka Stub AO-80” Instead of 0.2 g, Tinuvin T-123 (Cibas Specialty Chemicals Co., Ltd .: hindered amine acid / antioxidant) 0.2 g was used in the same manner as in Example 8, except that 0.2 g was used. An adhesive was obtained and evaluated in the same manner as in Example 1.

[0121] [Example 22]

“ADK STAB AO—80” Instead of 0.2 g, Ilganox 1010 (Cibas Specialty Chemicals, Inc .: hindered phenolic acid / antioxidant) 0.2 g was used, except that 0.2 g was used. A pressure-sensitive adhesive was obtained and evaluated in the same manner as in Example 1.

[0122] [Example 23]

A pressure-sensitive adhesive was obtained in the same manner as in Example 8 except that ILA2-2 (made by Guangei Chemical Co., Ltd .: solid ionic compound) lg was used instead of lithium perchlorate lg. It was evaluated in the same way. [0123] [Comparative Examples 1 and 4]

Using each acrylic resin obtained in Synthesis Examples 8 and 3, lithium perchlorate and “Adeka Stub”

A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that “AO-80” was used, and evaluated in the same manner as in Example 1.

[0124] [Comparative Example 2]

Using the acrylic resin obtained in Synthesis Example 8, “ADK STAB AO-80” was not used! /, Except that the pressure-sensitive adhesive was obtained in the same manner as in Example 1 and evaluated in the same manner as in Example 1.

[0125] [Comparative Example 3]

A pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that the acrylic resin obtained in Synthesis Example 9 was used, lithium perchlorate was used in an amount of 5 g, and “ADK STAB AO-80” was used. Evaluation was conducted in the same manner as in Example 1.

[0126] [Comparative Example 5]

Using the acrylic resin obtained in Synthesis Example 2, using 5 g of lithium perchlorate and using no curing agent, an adhesive was obtained in the same manner as in Example 1 and evaluated in the same manner as in Example 1. .

[0127] [Comparative Example 6]

The acrylic resin solution obtained in Synthesis Example 10 was desolvated and then dissolved in acetylethylacetone, and 3% by weight of lithium perchlorate was added to the acryl resin solid content and dissolved. This uniform viscous liquid was cast on an aluminum foil and dried at 80 ° C. for about 2 days to completely evaporate the acetone. The obtained resin sheet was laminated on a polyethylene terephthalate film (thickness 38 μm) and evaluated in the same manner as in Example 1.

[0128] [Comparative Example 7]

The test was carried out except that the acrylic resin obtained in Synthesis Example 7 was used, Adeka Stub AO-80 was not used, lithium perchlorate lg was used, and a test adhesive tape was obtained after 7 days at room temperature. A pressure-sensitive adhesive was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1.

[0129] [Comparative Example 8]

Other than having used the acrylic resin obtained in Synthesis Example 7 and not using ADK STAB AO-80, using lithium perchlorate lg, and further allowing 30 days to pass at 50 ° C to obtain a test adhesive tape. Was evaluated in the same manner as in Example 1.

0130

Antistatic pressure-sensitive adhesive of the present invention as ^above:: agent, storage stability of the base resin, the surface resistivity (conductivity Property), transparency and removability.

On the other hand, the pressure-sensitive adhesive shown in Comparative Example 1 has no conductivity because it contains no alkylene oxide chain and ion compound. Since the pressure-sensitive adhesive shown in Comparative Example 2 does not have an alkylene oxide chain, the ionic compound does not dissolve and aggregates, resulting in poor transparency and surface resistance. As shown in Comparative Example 3, the pressure-sensitive adhesive does not contain a hydroxyl group-containing monomer, so that the crosslinking effect by the curing agent cannot be obtained, the removability is poor, and an antioxidant is further contained. The storage stability of the main agent was poor. The pressure-sensitive adhesive shown in Comparative Example 4 had poor conductivity because it did not contain ionic compounds, and further contained antioxidants, so the storage stability of the main agent was poor. Since the adhesive shown in Comparative Example 5 did not use any curing agent, the cohesive force was insufficient and the removability was poor.

In Comparative Example 6, after obtaining the acrylic copolymer (A) as in the present invention, the acrylic copolymer (A) was further crosslinked with a hardener between the release paper and the polyethylene terephthalate film. The acrylic layer is not simply formed on the polyethylene terephthalate film and the curing agent is not used.Therefore, the cohesive force as an adhesive is insufficient and the removability is poor. became.

In addition, the pressure-sensitive adhesives shown in Comparative Examples 7 and 8 did not contain an anti-oxidation agent, so the storage stability of the main agent was poor. When the antioxidant is not contained, the surface resistance value of the adhesive layer after the reaction between the main agent and the curing agent also increases with the passage of time, so the antistatic performance is not stable.

Industrial applicability

The antistatic pressure-sensitive adhesive of the present invention has good storage stability of the main agent, has an appropriate surface resistance value, and is excellent in transparency and removability. For example, it is suitable for forming adhesive films for surface protection of optical parts such as liquid crystal panels, plasma displays, polarizing plates, and CRTs (CRTs). .

As mentioned above, although this invention was demonstrated along the specific aspect, the deformation | transformation and improvement obvious to those skilled in the art are included in the scope of the present invention.

Claims

The scope of the claims

[I] An acrylic copolymer having a hydroxyl group and an alkylene oxide chain in the side chain (A), an ion compound (B), a curing agent (C), and an antioxidant (D) Antistatic acrylic adhesive.

[2] The antistatic acrylic pressure-sensitive adhesive according to claim 1, wherein the added molar power of the alkylene oxide chain is 4 to 16.

[3] The antistatic acrylic pressure-sensitive adhesive according to claim 1 or 2, wherein the alkylene oxide chain is an ethylene oxide chain.

[4] The antioxidant (D) is at least one selected from the group consisting of phenolic acid antioxidants, phosphite acid antioxidants, and ether acid antioxidants. The antistatic acrylic pressure-sensitive adhesive according to claim 1 or 3.

[5] The antistatic acrylic pressure-sensitive adhesive according to claim 1, wherein the acrylic copolymer (A) has a weight average molecular weight of 50,000 to 1,000,000.

[6] The antistatic acrylic pressure-sensitive adhesive according to any one of claims 1 to 5, wherein the ionic compound (B) is liquid or solid at room temperature.

[7] The antistatic acrylic pressure-sensitive adhesive according to any one of claims 1 to 6, wherein the ionic compound (B) is 1S alkali metal inorganic salt or alkali metal organic salt.

[8] The antistatic acrylic pressure-sensitive adhesive according to any one of claims 1 to 7, further comprising an acrylic copolymer (E) having no alkylene oxide chain.

[9] Low molecular weight acrylic copolymer (A1) having a weight average molecular weight of 50,000 to 200,000 having a hydroxyl group and an alkylene oxide chain in the side chain, and a weight average molecular weight not having an alkylene oxide chain of 200,000 to 100 9. The antistatic acrylic pressure-sensitive adhesive according to claim 8, comprising 10,000 high molecular weight acrylic copolymer (E1).

[10] Ionic compound (B) is added to 100 parts by weight of acrylic copolymer (A) and (E) in total.

The antistatic acrylic adhesive according to any one of claims 1 to 9, comprising 1 to 50 parts by weight.

[II] The acrylic copolymer (A) is obtained by subjecting a monomer having an alkylene oxide chain to copolymerization, and the total amount of monomers constituting the acrylic copolymer (A) is 100% by weight. If the, as claim 1, feature that monomers having an alkylene oxide chain is 1 to 60 weight ^_0/0, the teeth 7, an antistatic acrylic adhesive according to any misalignment.

[12] The acrylic copolymer (A) is obtained by subjecting a monomer having an alkylene oxide chain to copolymerization, and all monomers constituting the acrylic copolymers (A) and (E) are 100 The antistatic acrylic pressure-sensitive adhesive according to any one of claims 8 to 10, wherein the amount of the monomer having an alkylene oxide chain is 1 to 60% by weight when the amount is%.

[13] The antistatic acrylic pressure-sensitive adhesive according to any one of [1] to [12], wherein the curing agent (C) is a trifunctional isocyanate compound and Z or a polyfunctional epoxy compound.

[14] A protective film for an optical member, characterized in that an adhesive layer formed from the antistatic acrylic adhesive according to any one of claims 1 to 13 is laminated on at least one surface of a plastic film substrate.