TWI704202B - Adhesive composition and surface-protective film - Google Patents

Abstract

An adhesive composition and a surface protection film are provided. The adhesive composition is used for forming an adhesive layer used as a surface protection film for a polarizing plate. The adhesive layer has excellent antistatic ability, excellent adhestion under both low peeling speed and high peeling speed, a long pot life, and excellent durability and re-workability.

The adhesive composition includes acrylic polymer formed by polymerizing at least one (A) (methyl) acrylic ester monomers containing C₄-C₁₈ alkyl group, at least one (B) copolymerizable monomers containing a hydroxyl group, at least one (C) copolymerizable monomers containing a carboxyl group, and (D) polyalkylene glycol mono (methyl)acrylic ester monomer. The adhesive composition also includes (E) a crosslinking agent and (F) an antistatic agent. The (E) crosslinking agent is a pentamethylene diisocyanate compound containing at least two functional groups, and The (F) antistatic agent is an ionic compound which has a melting point at 25-50 ℃ and is solid at 25℃.

Description

Adhesive composition and surface protective film

The invention relates to an adhesive composition and a surface protective film. In more detail, it relates to a surface for forming a polarizing plate with excellent antistatic properties, excellent balance of adhesion at low and high speed peeling speeds, long pot life, excellent durability and reworkability The adhesive composition of the adhesive layer of the protective film and the surface protective film.

Conventionally, in the production process of optical components such as polarizing plates and phase difference plates that constitute components of liquid crystal displays, a surface protection film for temporarily protecting the surface of the optical component is pasted. The surface protection film is only used in the process of preparing optical components, and when the optical components are assembled to the liquid crystal display, they are peeled and removed from the optical components. The surface protection film for protecting the surface of the optical component is only used in the production process, and therefore is generally called an engineered film.

The surface protection film used in the process of preparing the optical component has an adhesive layer formed on one side of the optically transparent polyethylene terephthalate (PET) resin film, but before bonding to the optical component , The peeling film used to protect the adhesive layer is attached to the adhesive layer.

In addition, optical components such as polarizing plates and retardation plates are bonded with surface protection films to perform display capabilities, hue, contrast, and mixing with liquid crystal display panels. In the inspection of products for optical evaluation such as foreign matter, it is required that no bubbles or foreign matter adhere to the adhesive layer as a required performance for the surface protective film.

In addition, in recent years, when the surface protection film is peeled from the polarizing plate, the phase difference plate and other optical components, the peeling static electricity generated when the adhesive layer is peeled from the adherend may cause the liquid crystal display. The failure of the electrical control circuit requires the adhesive layer to have excellent antistatic properties.

In addition, when bonding the surface protection film to optical components such as polarizing plates and phase difference plates, the surface protection film may be temporarily peeled off for various reasons, and then the surface protection film may be reattached again. At this time, the adhesive layer of the surface protection film is required to have a moderate adhesive force and be easy to peel off from the optical component of the adherend.

In addition, it is also required to not pollute the adherend, that is, no glue residue occurs.

In addition, it is required that the surface protection film can be peeled off quickly when finally peeling off the polarizing plate, the phase difference plate and other optical components. That is, even if it is peeled off at a high speed, it is required that the change in adhesive force due to the peeling speed is small as if it can be peeled off quickly.

As such, in recent years, as the required performance for the adhesive layer constituting the surface protective film, from the viewpoint of ease of use when using the surface protective film, it is required: (1) Obtained at a low-speed peeling speed and a high-speed peeling speed The balance of adhesion, (2) excellent antistatic performance, (3) durability, and (4) reworkability, etc. Here, excellent reworkability means that after drawing on the surface protective film with a ballpoint pen via the adhesive layer, it does not cause contamination transfer to the adherend.

However, as the required performance for the adhesive layer constituting the surface protection film, even if the requirements (1) to (4) above can be satisfied separately, it is necessary to meet the requirements for the adhesive layer of the surface protection film at the same time (1)~ (4) All required performance is a very difficult technical problem.

For example, the following proposals are known for obtaining a balance of adhesive force and preventing the generation of glue residue in (1) a low-speed peeling speed and a high-speed peeling speed.

Adhesive acrylic based on a copolymer of alkyl (meth)acrylate having an alkyl group of 7 or less carbon atoms and a carboxyl group-containing copolymerizable compound as the main component and crosslinking with a crosslinking agent In the agent layer, in the case of long-term adhesion, there is a problem that the adhesive transfers to the side of the adherend or the adhesive force to the adherend is greatly improved over time. In order to avoid this problem, it is known to provide an adhesive layer using a copolymer of an alkyl (meth)acrylate having an alkyl group with 8 to 10 carbon atoms and a copolymerizable compound having an alcoholic hydroxyl group, and crosslinking It is an adhesive layer (Patent Document 1) that has been crosslinked.

In addition, it has also been proposed to provide the following adhesive layer: in the same copolymer as the above, a small amount of (meth)acrylate alkyl ester and carboxyl-containing copolymerizable compound copolymer is added, and the crosslinking agent is used to crosslink it Treated adhesive layer. However, if it is used for surface protection of plastic plates with low surface tension and smooth surface, there will be problems such as peeling due to heating during processing or storage, or it may be carried out at high speed in the manual operation field. The problem of poor repeelability during peeling.

In order to solve this problem, the following adhesive composition has been proposed: a) an alkyl (meth)acrylate having an alkyl group with 8 to 10 carbon atoms as the main component of 100 weight (meth)acrylate alkyl ester Parts, b) 1 to 15 parts by weight of a carboxyl group-containing copolymerizable compound, c) 3 to 100 parts by weight of vinyl ester of aliphatic carboxylic acid having 1 to 5 carbon atoms, and a copolymer of a monomer mixture formed in this The copolymer is added with a crosslinking agent equivalent to or greater than the carboxyl group of component b) (Patent Document 2).

In the adhesive composition described in Patent Document 2, there is no Peeling phenomenon such as warping occurs during storage, and the improvement of the adhesive force with time is small, and the repeelability is excellent. Even if it is stored for a long time, especially under a high temperature atmosphere, it can be peeled off with a small force. At this time, no glue residue is generated on the adherend, and it can be peeled again with a small force even during high-speed peeling.

In addition, for (2) excellent antistatic performance, as a method for imparting antistatic performance to a surface protective film, a method of mixing an antistatic agent on a base film, and the like are disclosed. As antistatic agents, for example, (a) quaternary ammonium salts, pyridinium salts, various cationic antistatic agents having cationic groups such as primary to tertiary amino groups, (b) having sulfonate groups, sulfate groups, Anionic antistatic agents for anionic groups such as phosphate groups and phosphonate groups, (c) amphoteric antistatic agents such as amino acids and aminosulfates, (d) amino alcohols, glycerols, and polyethylene glycols Nonionic antistatic agents such as nonionic antistatic agents, (e) polymer type antistatic agents in which various antistatic agents are polymerized, etc. (Patent Document 3).

In addition, in recent years, it has been proposed to include such an antistatic agent in a base film, or to directly include an adhesive layer instead of coating the surface of the base film.

In addition, with regard to (3) durability, in recent years, the adhesive layer required high temperature and high humidity for the adhesive layer does not increase significantly, that is, the durability is improved. Furthermore, in recent years, in the process of crosslinking the adhesive composition to form an adhesive layer, in order to increase the crosslinking speed, a crosslinking catalyst has been used. Associated with this, new problems such as shortening of the pot life (usable time), disposal of the adhesive composition after the prescribed pot life, and increased economic losses have arisen. Therefore, in order to reduce the production cost, an adhesive composition with a long pot life is required.

In addition, for (4) reworkability, for example, an adhesive composition is proposed, which is based on 100 parts by weight of acrylic resin in acrylic resin 0.0001 to 10 parts by weight of a curing agent of an isocyanate compound and a specific silicate oligomer are added (Patent Document 4).

In Patent Document 4, an alkyl acrylate having an alkyl group with about 2 to 12 carbon atoms or an alkyl group having an alkyl methacrylate with about 4 to 12 carbon atoms or the like is used as a main monomer component, and it may contain, for example, Other functional group-containing monomer components such as carboxyl group-containing monomers. Generally, it is preferable to contain 50% by weight or more of the above-mentioned main monomer, or it is desirable that the content of the functional group-containing monomer component is 0.001 to 50% by weight, preferably 0.001 to 25% by weight, and more preferably 0.01 to 25% by weight %. The adhesive composition described in Patent Document 4 has small changes with time in cohesive force and adhesive force at high temperature or high temperature and high humidity, and exhibits an excellent effect of adhesive force to curved surfaces, and has reworkability.

Generally, if the adhesive layer is made into a soft property, residual glue is likely to occur, and reworkability is likely to decrease. That is, it is difficult to peel off at the time of erroneous bonding, and it is difficult to re-bond. Therefore, it is considered that in order to make it reworkable, it is necessary to cross-link monomers having functional groups such as carboxyl groups in the main agent so that the adhesive layer has a certain hardness.

[Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 63-225677

Patent Document 2: Japanese Patent Application Publication No. 11-256111

Patent Document 3: Japanese Patent Laid-Open No. 11-070629

Patent Document 4: Japanese Patent Application Laid-Open No. 8-199130

Nowadays, in protective films used for polarizing plates such as liquid crystal displays, TAC-based films (triacetyl cellulose-based compounds), acrylic films, etc. are used.

The present invention relates to an adhesive composition and a surface protective film for forming an adhesive layer of a surface protective film for a polarizing plate using such a protective film.

In the prior art, as the required performance for the adhesive layer constituting the surface protection film, it is required to obtain a balance of adhesive force, excellent antistatic performance, durability, and reworkability at low and high peeling speeds. However, even if each required performance can be met separately, it cannot meet all the required performances required by the adhesive layer of the surface protective film.

The present invention was completed in view of the above circumstances, and its technical problem is to provide excellent antistatic properties, excellent balance of adhesion at low and high speed peeling speeds, long pot life, excellent durability and reworkability Adhesive composition and surface protective film for forming the adhesive layer of the surface protective film for polarizing plates.

In order to solve the technical problem, the present invention provides an adhesive composition, which is an adhesive composition containing an acrylic polymer, (E) crosslinking agent, and (F) antistatic agent, characterized in that the acrylic The class polymer is a copolymer copolymerized by the following components: (A) at least one of the (meth)acrylate monomers with C ₄ to C ₁₈ carbon atoms in the alkyl group, and (B) the hydroxyl group-containing At least one of the copolymerized monomers, (C) at least one of the copolymerizable monomers containing a carboxyl group, (D) at least one of the polyalkylene glycol mono(meth)acrylate monomers The (E) crosslinking agent is a pentamethylene diisocyanate compound with more than two functional groups, and the (F) antistatic agent is an ionic compound with a melting point of 25-50°C and a solid at a temperature of 25°C.

The acrylic polymer is preferably composed of 100 parts by weight of at least one of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms relative to the (A) alkyl group, The total amount of at least one or more of the (B) hydroxyl-containing copolymerizable monomers is 0.1 to 10 parts by weight, and the total amount of at least one or more of the (C) carboxyl-containing copolymerizable monomers is 0.05 to 1.0 part by weight, 5-50 parts by weight of the total amount of at least one or more of the (D) polyalkylene glycol mono(meth)acrylate monomers, and (G) a hydroxyl-free nitrogen-containing vinyl group A copolymer in which at least one of the monomers or alkoxy-containing alkyl (meth)acrylate monomers is copolymerized in a total amount of 0.1 to 20 parts by weight. In addition, with respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms in the alkyl group (A), it is preferable to contain the (E) 0.1-10 parts by weight of pentamethylene diisocyanate compound with more than two functional groups of crosslinking agent, (H) cross-linking catalyst 0.001-0.5 parts by weight, (I) keto-enol tautomer compound 0.1-300 parts by weight .

With respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms in the alkyl group (A), the (F) antistatic agent is preferably Containing a total amount of 0.01-5.0 ionic compounds containing a melting point of 25-50 ℃ in the adhesive composition and a solid at a temperature of 25 ℃, copolymerized in the copolymer containing acryloyl ionic compounds Parts by weight. In addition, the (D) polyalkylene glycol mono(meth)acrylate monomer is preferably composed of polyalkylene glycol mono(meth)acrylate, methoxypolyalkylene glycol ( At least one selected from meth)acrylate and ethoxy polyalkylene glycol (meth)acrylate, the average number of repeating units of alkylene oxide (alkylene oxide) constituting the polyalkylene glycol chain It is 3 to 14, and the absorbance in the state of 25% aqueous solution is 0.04 or less.

The (E) crosslinking agent is preferably a trifunctional pentamethylene diisocyanate compound, which is composed of 1,5-pentamethylene diisocyanate, 1,4-pentamethylene diisocyanate, 1,3 -At least one selected from an isocyanurate body, an adduct body, and a biuret body of one or more pentamethylene diisocyanate compounds composed of pentamethylene diisocyanate.

The (H) crosslinking catalyst is preferably a metal chelate. In addition, the weight ratio (I)/(H) of the (H) crosslinking catalyst to the (I) keto-enol tautomer compound is preferably 70 to 1000.

The (B) hydroxyl-containing copolymerizable monomer is preferably composed of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (Meth) 2-hydroxyethyl acrylate, N-hydroxy(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide At least one selected from the compound group.

The (C) carboxyl-containing copolymerizable monomer is preferably composed of (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)propylene Glyoxyethyl hexahydrophthalic acid, 2-(meth)acryloxypropyl hexahydrophthalic acid, 2-(meth)acryloxyethyl phthalic acid, 2- (Meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl maleic acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acrylic acid At least one selected from the group of compounds composed of oxyethyltetrahydrophthalic acid.

With respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms in the alkyl group (A), it is preferable to further contain polyether-modified silicone The alkane compound is 0.01 to 1 part by weight.

Preferably the adhesive layer formed by cross-linking the adhesive composition The gel fraction is 95-100%, the adhesive layer has an adhesion force of 0.04~0.2N/25mm at a low-speed peeling speed of 0.3m/min (m/min), and an adhesion at a high-speed peeling speed of 30m/min The force is 2.0N/25mm or less.

Preferably, the surface resistivity of the adhesive layer formed by crosslinking the adhesive composition is 9.0×10+11Ω/□ or less, and the peeling static voltage is ±0~0.5kV.

In addition, the present invention provides an adhesive film characterized in that an adhesive layer formed by crosslinking the adhesive composition is formed on one or both sides of the resin film.

In addition, the present invention provides a surface protective film composed of the adhesive film and used for the use of a surface protective film for polarizing plates.

It is preferable to perform antistatic treatment and antifouling treatment on one side of the resin film, that is, the side opposite to the side on which the adhesive layer is formed.

According to the present invention, it is possible to provide a polarizing plate with excellent antistatic properties, excellent balance of adhesion at low and high peel speeds, long pot life, excellent durability and reworkability. The adhesive composition of the adhesive layer of the surface protection film and the surface protection film.

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

The adhesive composition of the present invention is an adhesive composition containing an acrylic polymer, (E) a crosslinking agent, and (F) an antistatic agent, and is characterized in that the acrylic polymer is copolymerized with the following components Copolymers: (A) at least one or more of (meth)acrylate monomers with C ₄ to C ₁₈ carbon atoms in the alkyl group, (B) at least one or more of copolymerizable monomers containing hydroxyl groups, (C) at least one or more of the copolymerizable monomers containing carboxyl groups, and (D) at least one or more of the polyalkylene glycol mono(meth)acrylate monomers, wherein the (E) crosslinks The agent is a pentamethylene diisocyanate compound having two or more functional groups, and the (F) antistatic agent is an ionic compound having a melting point of 25-50°C and a solid at a temperature of 25°C.

The acrylic polymer is preferably composed of 100 parts by weight of at least one of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms relative to the (A) alkyl group, The total amount of at least one or more of the (B) hydroxyl-containing copolymerizable monomers is 0.1 to 10 parts by weight, and the total amount of at least one or more of the (C) carboxyl-containing copolymerizable monomers is 0.05 to 1.0 part by weight, 5-50 parts by weight of the total amount of at least one or more of the (D) polyalkylene glycol mono(meth)acrylate monomers, and (G) a hydroxyl-free nitrogen-containing vinyl group A copolymer in which at least one or more of the monomers or alkoxy-containing alkyl (meth)acrylate monomers are copolymerized in a total amount of 0.1 to 20 parts by weight. In addition, with respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms in the alkyl group (A), it is preferable to contain the (E) 0.1-10 parts by weight of pentamethylene diisocyanate compound with more than two functional groups of crosslinking agent, (H) cross-linking catalyst 0.001-0.5 parts by weight, (I) keto-enol tautomer compound 0.1-300 parts by weight .

Examples of (A) alkyl (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms include butyl (meth)acrylate, isobutyl (meth)acrylate, and (meth)acrylic acid Amyl ester, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Yl)nonyl acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate Ester, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate Esters, octadecyl (meth)acrylate, myristyl (meth)acrylate, isomyristyl (meth)acrylate, cetyl (meth)acrylate, isocetyl (meth)acrylate, Stearyl (meth)acrylate, isostearyl (meth)acrylate, etc.

With respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the alkyl group (A), the total amount of acrylic polymer is preferably 105 The ratio of ~200 parts by weight, more preferably the ratio of 110 to 170 parts by weight, and particularly preferably the ratio of 110 to 140 parts by weight.

Examples of (B) hydroxyl-containing copolymerizable monomers include 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, ( Hydroxy(meth)acrylic acid alkyl esters such as 2-hydroxyethyl meth)acrylate, or N-hydroxy(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, N-hydroxyethyl (Meth)acrylamide and other hydroxyl-containing (meth)acrylamides.

Preferably it is composed of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N- At least one selected from the group of compounds consisting of hydroxy (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide.

The total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group is 100 parts by weight, preferably in a ratio of 0.1 to 10 parts by weight (B) The total amount of at least one or more of the hydroxyl-containing copolymerizable monomers is more preferably contained in a ratio of 2 to 8 parts by weight, and particularly preferably contained in a ratio of 2 to 6 parts by weight.

(C) The copolymerizable monomer containing a carboxyl group is preferably (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxy Ethylhexahydrophthalic acid, 2-(meth)acryloxypropylhexahydrophthalic acid, 2-(meth)acryloxyethyl phthalic acid, 2-(methyl) ) Acrylic oxyethyl succinic acid, 2-(meth) acryloxy ethyl maleic acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloxy ethyl At least one selected from the group of compounds composed of tetrahydrophthalic acid.

100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group, preferably in a ratio of 0.05 to 1.0 parts by weight The total amount of at least one or more of the (C) carboxyl group-containing copolymerizable monomers is more preferably contained in a ratio of 0.05 to 0.8 parts by weight, and particularly preferably contained in a ratio of 0.05 to 0.5 parts by weight.

As the (D) polyalkylene glycol mono(meth)acrylate monomer, as long as one of the multiple hydroxyl groups possessed by the polyalkylene glycol is esterified in the form of (meth)acrylate Compound is sufficient. Since the (meth)acrylate group becomes a polymerizable group, it can be copolymerized with the main agent polymer. Other hydroxyl groups may be kept as OH, or may form alkyl ethers such as methyl ether or ethyl ether, saturated carboxylic acid esters such as acetate, and the like.

As an alkylene group which a polyalkylene glycol has, an ethylene group, a propylene group, a butylene group, etc. are mentioned, but it is not limited to these. The polyalkylene glycol may be a copolymer of two or more polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol. Polyalkylene glycol copolymers include polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, polyethylene glycol-polypropylene glycol-polybutylene Diol, etc., the copolymer may be a block copolymer or a random copolymer.

(D) The polyalkylene glycol mono(meth)acrylate monomer preferably has an average number of repeating units of 3-14 of the alkyleneoxy group constituting the polyalkylene glycol chain. The "average number of repeating units of the alkyleneoxy group" refers to the part of the "polyalkylene glycol chain" contained in the molecular structure of the (D) polyalkylene glycol mono(meth)acrylate monomer In the average number of repeating alkyleneoxy units.

The (D) polyalkylene glycol mono(meth)acrylate monomer preferably has an absorbance of 0.04 or less in a 25% aqueous solution state. In addition, the diester component in the monomer is preferably 0.3% or less.

"The diester component in the monomer" refers to the content of polyalkylene glycol di(meth)acrylate contained in (D) polyalkylene glycol mono(meth)acrylate monomer ( weight%).

The "absorbance in the state of a 25% aqueous solution" refers to the absorbance of the aqueous solution in a state where the (D) polyalkylene glycol mono(meth)acrylate monomer is a 25% by weight aqueous solution. That is, (D) polyalkylene glycol mono(meth)acrylate monomer not only has water solubility (relative to water solubility) that can only be 25% aqueous solution, but also needs to have low absorbance under 25% aqueous solution ( Less white turbidity).

In addition, in this specification, the absorbance of a 25% aqueous solution is a value measured by adding the aqueous solution to a quartz cell with an optical path length of 10 mm. This index is used as the degree of hydrophilicity of (D) polyalkylene glycol mono(meth)acrylate monomers. It is used to select monomers with high hydrophilicity that can obtain solutions without white turbidity even at high concentrations. Indexes imported from the body.

(D) Polyalkylene glycol mono(meth)acrylate monomers are preferably polyalkylene glycol mono(meth)acrylates, methoxy polyalkylene glycol (meth) Acrylate, ethoxy polyalkylene glycol (meth) acrylate selected to Less than one kind.

More specifically, polyethylene glycol-mono(meth)acrylate, polypropylene glycol-mono(meth)acrylate, polybutylene glycol-mono(meth)acrylate, polyethylene glycol- Polypropylene glycol-mono(meth)acrylate, polyethylene glycol-polybutylene glycol-mono(meth)acrylate, polypropylene glycol-polybutylene glycol-mono(meth)acrylate, polyethylene glycol- Polypropylene glycol-polybutylene glycol-mono(meth)acrylate; methoxypolyethylene glycol-(meth)acrylate, methoxypolypropylene glycol-(meth)acrylate, methoxypolybutadiene Alcohol-(meth)acrylate, methoxy-polyethylene glycol-polypropylene glycol-(meth)acrylate, methoxy-polyethylene glycol-polybutylene glycol-(meth)acrylate, methyl Oxygen-polypropylene glycol-polybutylene glycol-(meth)acrylate, methoxy-polyethylene glycol-polypropylene glycol-polybutylene glycol-(meth)acrylate; ethoxypolyethylene glycol- (Meth)acrylate, ethoxy polypropylene glycol-(meth)acrylate, ethoxy polybutylene glycol-(meth)acrylate, ethoxy-polyethylene glycol-polypropylene glycol-(methyl) ) Acrylate, ethoxy-polyethylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polypropylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polyethylene Glycol-polypropylene glycol-polybutylene glycol-(meth)acrylate etc.

The total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group is 100 parts by weight, preferably 5-50 parts by weight (D) The total amount of at least one or more of the polyalkylene glycol mono(meth)acrylate monomers is more preferably contained in a proportion of 5-40 parts by weight, and particularly preferably 5-30 parts by weight Contains in the ratio of parts.

In addition to the essential components of (A) to (D), the acrylic polymer may contain (G) a hydroxyl-free nitrogen-containing vinyl monomer or alkoxy-containing (meth)acrylic acid as an optional component At least one of alkyl ester monomers. In (G), make The (G1) nitrogen-containing vinyl monomer includes a vinyl monomer containing an amide bond, a vinyl monomer containing an amino group, and a vinyl monomer having a nitrogen-containing heterocyclic structure. More specifically, N-vinyl-2-pyrrolidone, N-vinylpyrrolidone, methyl vinylpyrrolidone, N-vinylpyridine, N-vinylpyridone, N-vinylpyrimidine, N-vinylpyrrolidone, N-vinylpyrrolidone Pyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N-vinyllaurolactam and other heterocyclic rings with N-vinyl substitution Cyclic nitrogen vinyl compound of structure; N-(meth)acrylomorpholine, N-(meth)acrylic acid, N-(meth)acrylic aziridine, N-(meth)propylene Azetidine, N-(meth)propenylpyrrolidine, N-(meth)propenylpyrrolidine, N-(meth)propenylazacycloheptane, N-(meth)propylene Cyclic nitrogen vinyl compounds with N-(meth)acryloyl substituted heterocyclic structures such as azacyclooctane, etc.; N-cyclohexylmaleimide, N-phenylmaleimide, etc. A cyclic nitrogen vinyl compound having a heterocyclic structure with a nitrogen atom and an ethylenically unsaturated bond in the ring; (meth)acrylamide, N-methyl(meth)acrylamide, N-isopropyl (Meth)acrylamide, N-tert-butyl(meth)acrylamide, etc. unsubstituted or monoalkyl substituted (meth)acrylamide; N,N-dimethyl(meth)propylene Amide, N,N-diethyl(meth)acrylamide, N,N-dipropylacrylamide, N,N-diisopropyl(meth)acrylamide, N,N-di Butyl(meth)acrylamide, N-ethyl-N-methyl(meth)acrylamide, N-methyl-N-propyl(meth)acrylamide, N-methyl-N -Dialkyl substituted (meth)acrylamide such as isopropyl (meth)acrylamide; N,N-dimethylaminomethyl (meth)acrylate, N,N-dimethylaminoethyl (Meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-dimethylaminoisopropyl (meth)acrylate, N,N-dimethylaminobutyl ( Meth)acrylate, N,N-diethylaminomethyl(meth)acrylate, N,N-diethylamino Ethyl (meth)acrylate, N-ethyl-N-methylaminoethyl (meth)acrylate, N-methyl-N-propylaminoethyl (meth)acrylate, N-methyl -N-isopropylaminoethyl (meth)acrylate, N,N-dibutylaminoethyl (meth)acrylate, tert-butylaminoethyl (meth)acrylate and other dialkylamino groups (Meth) acrylate; N,N-dimethylaminopropyl(meth)acrylamide, N,N-diethylaminopropyl(meth)acrylamide, N,N-dipropyl Aminopropyl(meth)acrylamide, N,N-diisopropylaminopropyl(meth)acrylamide, N-ethyl-N-methylaminopropyl(meth)acrylamide, N -Methyl-N-propylaminopropyl(meth)acrylamide, N-methyl-N-isopropylaminopropyl(meth)acrylamide, etc. N,N-dialkyl substituted aminopropyl (Meth)acrylamide; N-vinyl carboxamides such as N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, etc.; N-methoxy Methyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, N,N- (Meth)acrylamides such as methylenebis(meth)acrylamide; unsaturated carboxylic acid nitriles such as (meth)acrylonitrile, etc.

The (G1) nitrogen-containing vinyl monomer preferably does not contain a hydroxyl group, and more preferably does not contain a hydroxyl group and a carboxyl group. As such a monomer, the monomers exemplified above are preferred, such as acrylic monomers containing N,N-dialkyl substituted amino groups or N,N-dialkyl substituted amide groups; N-vinyl-2- N-vinyl substituted lactams such as pyrrolidone, N-vinylcaprolactone, N-vinyl-2-pyridone; N-(meth)acryloylmorpholine or N-(meth)propylene N-(meth)acryloyl substituted cyclic amines such as pyrrolidine.

In (G), examples of (G2) alkoxy-containing alkyl (meth)acrylate monomers include 2-methoxyethyl (meth)acrylate and 2-ethoxyethyl (Meth)acrylate, 2-propoxyethyl (meth)acrylate, 2-isopropoxy Ethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 2-ethoxypropyl (meth)acrylate , 2-propoxypropyl (meth)acrylate, 2-isopropoxypropyl (meth)acrylate, 2-butoxypropyl (meth)acrylate, 3-methoxypropyl Base (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 3-propoxypropyl (meth)acrylate, 3-isopropoxypropyl (meth)acrylate , 3-Butoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 4-ethoxybutyl (meth)acrylate, 4-propoxybutyl (Meth)acrylate, 4-isopropoxybutyl (meth)acrylate, 4-butoxybutyl (meth)acrylate, etc.

These alkoxy group-containing alkyl (meth)acrylate monomers have a structure in which the alkyl group in the alkyl (meth)acrylate is substituted with an alkoxy group.

The total amount of at least one or more of the (meth)acrylate monomers with C ₄ to C ₁₈ carbon atoms of the (A) alkyl group is 100 parts by weight, preferably 0.1-20 parts by weight (G) At least one of a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkoxy-containing alkyl (meth)acrylate monomer, more preferably contained in a ratio of 0.3 to 10 parts by weight, particularly preferably It is contained in a ratio of 0.3-8 parts by weight. (G1) The nitrogen-containing vinyl monomer containing no hydroxyl group and (G2) the alkoxy group-containing alkyl (meth)acrylate monomer can be used individually by 1 type or in combination of 2 or more types.

The (E) crosslinking agent of the acrylic polymer is preferably a pentamethylene diisocyanate compound having two or more functional groups. (E) The crosslinking agent is preferably a bifunctional pentamethylene diisocyanate compound (compound containing two NCO groups in one molecule) or a trifunctional pentamethylene diisocyanate compound. In the present invention, it is particularly preferable that the crosslinking agent (E) is a trifunctional pentamethylene diisocyanate compound, which is composed of 1,5-pentamethylene diisocyanate and 1,4-pentamethylene diisocyanate. Diisocyanate, At least one selected from an isocyanurate body, an adduct body, and a biuret body of one or more pentamethylene diisocyanate compounds composed of 1,3-pentamethylene diisocyanate. Examples of the adduct include trimethylolpropane (TMP) or glycerin and other trivalent or higher polyols (compounds containing at least 3 OH groups per molecule) (polyol modified Body) and so on.

With respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group, the (E) crosslinking agent is preferably 0.1 to The pentamethylene diisocyanate compound (or at least one selected from an isocyanurate body, an adduct body, and a biuret body thereof) having two or more functional groups is contained in a ratio of 10 parts by weight.

In the case of using a polyisocyanate compound as a crosslinking agent, the (H) crosslinking catalyst may function as a catalyst for the reaction (crosslinking reaction) between the copolymer and the crosslinking agent, and tertiary Amine compounds such as amines, metal chelate compounds, organic tin compounds, organic lead compounds, organic zinc compounds and other organic metal compounds.

Examples of tertiary amines include trialkylamines, N,N,N',N'-tetraalkyldiamine, N,N-dialkylamino alcohol, triethylenediamine, morpholine derivatives, and piperazines. Derivatives, etc.

1，n

0。在m為2以上的情況下，m個L可以是相同的配位基，也可以是不同的配位基。在n為2以上的情況下，n個X可以是相同的配位基，也可以是不同的配位基。 As a metal chelate compound, it is a compound in which one or more polydentate ligands L are bonded to the central metal atom M. The metal chelate compound may have one or more monodentate ligands X bonded to the metal atom M, or not. For example, when the general formula of a metal chelate compound with one metal atom M is represented by 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, n Xs 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 methyl acetyl acetate, ethyl acetyl acetate, octyl acetyl acetate, oleyl acetyl acetate, lauryl acetyl acetate, stearyl acetyl acetate, and the like. -Ketoester or β-diketones such as acetone (also called 2,4-pentanedione), 2,4-hexanedione, and benzacetone. They are keto-enol tautomer compounds, and in the polydentate ligand L, they can also be enolates (such as acetone acetonates) in which the enol is deprotonated.

Examples of the monodentate ligand X include halogen atoms such as a chlorine atom and a bromine atom, pentyl, hexyl, 2-ethylhexyl, octyl, nonyl, decyl, and dodecyl Alkoxy groups such as methoxy group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, butoxy group, etc.

Specific examples of the metal chelate compound include tris(2,4-pentanedionyl) iron (III), iron triacetone, titanium triacetone, ruthenium triacetone, and diacetone Zinc, aluminum triacetate, zirconium tetraacetone, tris(2,4-hexanedione) iron(III), bis(2,4-hexanedione) zinc, tris(2,4-hexane) Diketone) titanium, tris(2,4-hexanedione)aluminum, tetra(2,4-hexanedione)zirconium, etc.

Examples of the organotin compound include dialkyltin oxide or fatty acid salt of dialkyltin, and fatty acid salt of divalent tin.

(H) The crosslinking catalyst is preferably a metal chelate compound or an organotin compound. As the metal chelate compound, an aluminum chelate compound, a titanium chelate compound, an iron chelate compound, a tin chelate compound, etc. are preferred. The organotin compound is preferably at least one selected from the group consisting of dioctyltin oxide and dioctyltin dilaurate.

The total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group is 100 parts by weight, preferably in a ratio of 0.001 to 0.5 parts by weight (H) Crosslinking catalyst.

(I) Keto-enol tautomer compounds include methyl acetylacetate, ethyl acetylacetate, octyl acetylacetate, oleyl acetylacetate, lauryl acetylacetate, and acetylacetate. Β-keto esters such as stearyl acetate or β-diketone (I) keto-enol tautomer compounds such as acetone, 2,4-hexanedione, and benzoic acetone are used as polyisocyanate compounds. In the adhesive composition of the linking agent, by blocking the isocyanate group of the crosslinking agent, the excessive viscosity increase or gelation of the adhesive composition after the addition of the crosslinking agent can be suppressed, and the adhesive composition can be prolonged. Applicable period.

(I) The keto-enol tautomer compound is particularly preferably at least one compound selected from the group consisting of acetone and ethyl acetone.

The total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group is 100 parts by weight, preferably 0.1 to 300 parts by weight. (I) Keto-enol tautomer compound, more preferably 1.0-30.0 parts by weight.

(I) The keto-enol tautomer compound has the effect of suppressing cross-linking in contrast to the (H) cross-linking catalyst. Therefore, it is preferable to appropriately set the (I) keto-enol interaction with respect to the (H) cross-linking catalyst. The ratio of the metameric compounds. In order to extend the pot life of the adhesive composition and improve the storage stability, the weight ratio (I)/(H) of the (H) crosslinking catalyst relative to the (I) keto-enol tautomer compound is preferably 70 ~1000.

(F) Antistatic agent is preferably (F1) ionization with a melting point of 25~50°C Compound and/or (F2) an ionic compound containing an acrylic group.

In the present invention, as the (F) antistatic agent, (F1) an ionic compound having a melting point of 25-50° C. is added to the copolymer, and/or (F2) an acryloyl group-containing ionic compound is copolymerized in the copolymer. Since these (F) antistatic agents have a low melting point and have a long-chain alkyl group, it is presumed that they have a high affinity with the acrylic copolymer.

(F) The antistatic agent includes an antistatic agent contained in the adhesive composition and an antistatic agent copolymerized in the copolymer. With respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the (A) alkyl group, the (F) antistatic agent is preferably in a total amount The ratio of 0.01 to 5.0 parts by weight contains (F1) an ionic compound having a melting point of 25-50° C. contained in the adhesive composition and (F2) an acryl group-containing ionic compound copolymerized in the copolymer.

(F1) The ionic compound having a melting point of 25 to 50°C is an ionic compound having a cation and an anion. Examples of the cation include pyridinium cation, imidazolium cation, pyrimidinium cation, thiazolium cation, pyrrolidinium cation, a nitrogen-containing cation, ammonium cation or phosphonium cation, sulfonium cation, the anion is hexafluorophosphate (PF ₆ ^-), thiocyanate (SCN ^-), alkylbenzene sulphonate ^{_{(RC 6 H 4 SO 3 -}} ), perchlorate (ClO ₄ ^-), tetrafluoroborate (BF ₄ ^-), bis (fluorinated sulfonic acyl) (PEI) root (FSI), bis (trifluoromethane sulfonic acyl) (PEI) root (TFSI ), trifluoromethanesulfonate (TF) and other inorganic or organic anion compounds. (F1) An ionic compound with a melting point of 25-50°C is preferably a solid at normal temperature (for example, 25°C). By selecting the chain length of the alkyl group or the position and number of substituents, a melting point of 25~ Compound at 50°C. The cations preferably include quaternary nitrogen-containing cations, 1-alkylpyridinium cations (carbon atoms at positions 2 to 6 may have or may not be substituted.) and other quaternary pyridinium cations, or 1,3-dioxane Quaternary imidazolium cations, such as quaternary imidazolium cations such as quaternary imidazolium cations, such as quaternary ammonium cations such as tetraalkylammonium, etc., may have substituents or unsubstituted carbon atoms at positions 2, 4, and 5

It is preferably contained in a ratio of 0.01 to 5.0 parts by weight relative to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms of the alkyl group (A) (F1) An ionic compound with a melting point of 25-50°C.

(F2) The ionic compound containing an acryloyl group is an ionic compound having a cation and an anion, and the cation is a (meth)acryloxyalkyl trialkylammonium [R ₃ N ⁺ -C _n H _2n -OCOCQ = CH _2, where, Q = H or CH _3, R = alkyl]-containing (meth) Bing Xixi cationic group, hexafluorophosphate anion (PF ₆ ^-), thiocyanate (SCN ^- ), organic sulfonate (RSO ₃ ^-), a perchlorate ClO ₄ ^- compound) of an inorganic or organic anion ^-), tetrafluoroborate (BF ₄ ^-), (PEI) containing the F root (RF ₂ N . Examples of the RF of the F-containing iminium (RF2N ⁻ ) include perfluorocarbon sulfonyl groups such as trifluoromethanesulfonyl and pentafluoroethanesulfonyl or fluorosulfonyl groups. As the root (PEI) containing F include a bis (fluoroalkyl sulfonic acyl) (PEI) root [(FSO _{2) 2} N ^-], bis (trifluoromethane sulfonic acyl) (PEI) root [(CF ₃ SO _{2) 2} N ^-], bis (pentafluoroethane sulfonic acyl) (PEI) root _{[(C 2 F 5 SO 2)} 2 N - ] and the like bis sulfo acyl (PEI) root.

With respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers with C ₄ to C ₁₈ carbon atoms of the alkyl group (A), preferably 0.01 to 5.0 parts by weight In the copolymer (F2) an ionic compound containing an acrylic group is copolymerized.

The specific examples of (F) antistatic agent are not particularly limited, but specific examples of (F1) ionic compounds having a melting point of 25-50°C include 1-octylpyridinium hexafluorophosphate, 1- Nonylpyridinium hexafluorophosphate, 2-methyl-1-dodecylpyridinium hexafluorophosphate, 1-octylpyridinium dodecylbenzenesulfonate, 1-dodecylpyridinium Thiocyanate, 1-dodecylpyridinium dodecylbenzenesulfonate, 4-methyl-1-octylpyridinium hexafluorophosphate, etc. In addition, as a specific example of (F2) acryl group-containing ionic compound, dimethylaminomethyl (meth)acrylate hexafluorophosphate methyl salt [(CH ₃ ) ₃ N ⁺ CH ₂ OCOCQ=CH ₂ ‧PF ₆ ^- where, Q = H or CH _3], dimethylaminoethyl (meth) acrylate, bis (trifluoromethane sulfonic acyl) methyl acyl imide salt ^{_{[(CH 3) 3 N + (}} CH 2 _{) 2 OCOCQ = CH 2 ‧ (} CF 3 SO 2) 2 N -, where, Q = H or CH _3], dimethylaminoethyl methacrylate bis (sulfo acyl fluoro) methyl (PEI) salt ^{_{[(CH 3) 3 N + CH}} 2 OCOCQ = CH 2 ‧ (FSO 2) 2 N -, where, Q = H or CH _3] and the like.

The adhesive composition of the present invention may optionally contain (J) a polyether-modified silicone compound. (J) The polyether-modified silicone compound is a silicone compound having a polyether group, in addition to the usual silicone unit [-SiR ¹ ₂ -O-], it also has a silicone containing a polyether group Unit [-SiR ¹ (R ² O(R ³ O) _n R ⁴ )-O-]. Here, R ¹ represents one or two or more alkyl or aryl groups, R ² and R ³ represent one or two or more alkylene groups, and R ⁴ represents one or two or more alkyl or aryl groups, etc. ( Terminal group). Examples of polyether groups include polyoxyalkylene groups such as polyoxyethylene [(C2H4O)n] or polyoxypropylene [(C3H6O)n].

(J) The polyether-modified silicone compound is preferably a polyether-modified silicone compound with an HLB value of 7-14. In addition, with respect to 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms in the alkyl group (A), it preferably contains 0.01 to 1 part by weight of HLB A polyether modified silicone compound with a value of 7-14. More preferably, it is 0.1 to 0.5 parts by weight. HLB is a hydrophilic-lipophilic balance (hydrophilic-lipophilic ratio) prescribed in, for example, JIS K3211 (surfactant term).

(J) The polyether modified silicone compound is obtained, for example, by the following method Obtained: The organic compound with unsaturated bond and polyoxyalkylene is obtained by grafting the polyorganosiloxane main chain with hydridosilyl group through the hydrosilylation reaction. Specifically, dimethylsiloxane‧methyl(polyoxyethylene)siloxane copolymer, dimethylsiloxane‧methyl(polyoxyethylene)siloxane‧methyl(polyoxyethylene) Propylene) siloxane copolymer, dimethyl siloxane ‧ methyl (polyoxypropylene) siloxane polymer, etc. The HLB value of the polyether modified silicone compound can be adjusted by selecting the ratio of the polyether group to the silicone group.

By adding a polyether-modified silicone compound with an HLB value of 7 to 14 to the adhesive composition, the adhesive force and reworkability of the adhesive can be improved. When the adhesive composition does not contain a polyether-modified silicone compound, the cost is lower.

However, in the present invention, by adding a predetermined amount of (D) polyalkylene glycol mono(meth)acrylate monomer to the adhesive, even if it does not contain silicone compounds such as polyether modified silicone compounds , The hydrophilicity is also improved, so an adhesive layer with excellent antistatic properties can be formed.

Furthermore, as other components, copolymerizable (meth)acrylic monomers containing alkyleneoxy groups, (meth)acrylamide monomers, dialkyl substituted acrylamide monomers, and surfactants can be appropriately added , Curing accelerators, plasticizers, fillers, curing retarders, processing aids, anti-aging agents, antioxidants and other well-known additives. These can be used alone or two or more of them can be used together.

The copolymer used for the main agent of the adhesive composition of the present invention can be obtained by making (A) alkyl group (meth)acrylate monomer with C ₄ to C ₁₈ carbon atoms, (B) hydroxyl group-containing copolymer Copolymerizable monomers, (C) copolymerizable monomers containing carboxyl groups, (D) polyalkylene glycol mono(meth)acrylate monomers, optional components (G) hydroxy-free nitrogen-containing ethylene The base monomer or alkoxy-containing alkyl (meth)acrylate monomer is synthesized by polymerization. The polymerization method of the copolymer is not particularly limited, and suitable polymerization methods such as solution polymerization and emulsion polymerization can be used. The optional monomer (G) can be omitted.

In the case of using (F2) an ionic compound containing an acryloyl group as (F) antistatic agent, the copolymer of the main agent used in the adhesive composition of the present invention can be determined by making (A) the number of carbon atoms of the alkyl group C ₄ ~ C ₁₈ (meth)acrylate monomers, (B) copolymerizable monomers containing hydroxyl groups, (C) copolymerizable monomers containing carboxyl groups, (D) polyalkylene glycol monomers ( Meth) acrylate monomers, optional components (G) nitrogen-containing vinyl monomers without hydroxyl groups or alkoxy-containing alkyl (meth)acrylate monomers, (F2) acryl-containing monomers The ionic compound is synthesized by polymerization. The optional monomer (G) can be omitted.

The adhesive composition of the present invention can also be added by adding (E) crosslinking agent, (H) crosslinking catalyst, (I) keto-enol tautomer compound, and suitable optional additives to the above-mentioned copolymer And preparation. In addition, in the case of polymerizing (F2) an ionic compound containing an acryloyl group in the copolymer of the main agent, (F1) an ionic compound having a melting point of 25 to 50° C. may be further added to the copolymer, or not.

When preparing the copolymer of the main agent, in order to reduce the mixing of moisture into the adhesive composition, it is preferable to perform the polymerization reaction under anhydrous conditions such as solution polymerization using an anhydrous organic solvent. In particular, the (D) polyalkylene glycol mono(meth)acrylate monomer has high hydrophilicity, so it is preferable to use one with a low water content.

In order to prevent the viscosity of the adhesive composition from increasing, the monomers used in the preparation of the copolymer of the main agent preferably reduce the amount of the polyfunctional (difunctional or higher) monomer that can function as a crosslinking agent as much as possible . Especially (D) polyalkylene glycol mono(meth)acrylate monomer, the corresponding diester component is the bis(formaldehyde) of a difunctional monomer Base) acrylate, it is preferable to use one with less diester components.

The copolymer is preferably an acrylic polymer, and preferably contains (meth)acrylate monomer or (meth)acrylic acid in a ratio of 50 to 100 parts by weight relative to 100 parts by weight of the acrylic polymer. Acrylic monomers such as (meth)acrylamides.

In addition, the acid value of the acrylic polymer is preferably 0.01 to 8.0. As a result, it is possible to improve staining properties and improve the performance of preventing glue residue.

Here, "acid value" refers to one of the indexes indicating the content of acid, and it is expressed in mg of potassium hydroxide required to neutralize 1 g of the carboxyl group-containing polymer.

Preferably, the adhesive layer crosslinked by the adhesive composition has an adhesive force of 0.04~0.2N/25mm at a low-speed peeling speed of 0.3m/min, and an adhesive force of 2.0 at a high-speed peeling speed of 30m/min. Below N/25mm. As a result, it is possible to obtain a performance with little change in adhesion due to peeling speed, and it can be peeled off quickly even at high speed. In addition, in order to reattach, even when the surface protective film is temporarily peeled off, it does not require excessive force, and it easily peels off from the adherend.

Preferably, the surface resistivity of the adhesive layer formed by crosslinking the adhesive composition is 9.0×10+11Ω/□ or less, and the peeling static voltage is ±0~0.5kV. In addition, in the present invention, "±0~0.5kV" means 0~-0.5kV and 0~+0.5kV, that is, -0.5~+0.5kV. If the surface resistivity is large, the performance of the escape of static electricity due to charging during peeling is poor. Therefore, by making the surface resistivity very small, the peeling static voltage caused by the static electricity generated when the adhesive layer is peeled from the adherend can be reduced, thereby suppressing the influence on the electrical control circuit of the adherend, etc. .

The gel fraction of the adhesive layer after crosslinking the adhesive composition of the present invention is preferably 95 to 100%. Through the high gel fraction, at low speed In the peeling speed, the adhesive force will not be too large, the elution of unpolymerized monomers or oligomers from the copolymer is reduced, and the reworkability or durability under high temperature and high humidity is improved, and the contamination of the adherend can be suppressed.

The adhesive film of the present invention is formed by forming an adhesive layer formed by crosslinking the adhesive composition of the present invention on one or both sides of a resin film. In addition, the surface protection film of the present invention is a surface protection film formed by forming an adhesive layer crosslinked by the adhesive composition of the present invention on one side of a resin film. Since the adhesive composition of the present invention adds the above-mentioned components (A) to (I) in a good balance, it has excellent antistatic performance, and the balance of adhesive force at low and high peeling speeds Excellent, and durability and reworkability (after drawing on the surface protective film with a ballpoint pen via the adhesive layer, contamination does not transfer to the adherend). Therefore, it is applicable to the use of the adhesive layer of the surface protection film for polarizing plates.

As the base film of the adhesive film of the present invention or the base film of the release film (separator) for protecting the adhesive layer, a resin film such as a polyester film or the like can be used.

In the base film of the adhesive film of the present invention, on the side opposite to the side where the adhesive layer is formed on one side of the resin film, it can be implemented with silicone-based, fluorine-based release agents or coating agents, and two Anti-fouling treatment of silica particles, etc., through antistatic treatment such as coating or mixing of antistatic agents.

In addition, on the surface of the release film that is bonded to the adhesive surface of the adhesive layer, a release treatment can be performed with a silicone-based or fluorine-based release agent.

[Example]

Hereinafter, the present invention will be specifically explained through examples.

<Preparation of acrylic copolymer>

[Example 1]

Nitrogen was introduced into the reaction device equipped with a stirrer, thermometer, reflux cooler, and nitrogen introduction pipe, and the air in the reaction device was replaced with nitrogen. Then, 100 parts by weight of 2-ethylhexyl acrylate, 3.0 parts by weight of 8-hydroxyoctyl acrylate, 0.2 parts by weight of acrylic acid, and polypropylene glycol monoacrylate (the alkylene constituting the polyalkylene glycol chain) were added to the reaction device. The average number of repeating units of the oxy group n=12, the absorbance in a 25% aqueous solution state is 0.03) 10 parts by weight, 5 parts by weight of N-vinylpyrrolidone, and 60 parts by weight of the solvent (ethyl acetate). Then, 0.1 parts by weight of azobisisobutyronitrile as a polymerization initiator was dropped over 2 hours, and reacted at 65° C. for 6 hours to obtain the acrylic copolymer solution used in Example 1 with a weight average molecular weight of 500,000. A part of the acrylic copolymer was used as a measurement sample of the acid value described later.

[Examples 2 to 6 and Comparative Examples 1 to 4]

Except that the monomer composition is as described in (A) to (D), (G) and (F2) of Table 1, in the same manner as the acrylic copolymer solution used in Example 1 above, the The acrylic copolymer solution used in Examples 2 to 6 and Comparative Examples 1 to 4.

<Preparation of Adhesive Composition and Surface Protective Film>

[Example 1]

To the acrylic copolymer solution of Example 1 prepared above, 1.0 part by weight of 1-octylpyridinium hexafluorophosphate and 8.5 parts by weight of acetone were added and stirred, and then the isocyanuric acid of the pentamethylene diisocyanate compound was added. 0.5 parts by weight of ester body and 0.1 parts by weight of titanium triacetone were stirred and mixed to obtain the adhesive composition of Example 1. The adhesive composition is coated on polyterephthalene coated with silicone resin After being applied to the release film composed of ethylene formate (PET) film, the solvent was removed by drying at 90°C to obtain an adhesive sheet having a thickness of 25 μm of the adhesive layer.

Then, transfer the adhesive sheet on the opposite side of the antistatic and antifouling polyethylene terephthalate (PET) film on one side of the antistatic and antifouling treated surface to obtain The surface protection film of Example 1 with a laminated structure of PET film/adhesive layer/release film (PET film coated with silicone resin) after antistatic and antifouling treatment.

[Examples 2 to 6 and Comparative Examples 1 to 4]

Except that the composition of the additives is as described in Table 2 (E), (H), (I), (F2), (J), respectively, it was implemented in the same manner as the surface protective film of Example 1 above. The surface protective films of Examples 2 to 6 and Comparative Examples 1 to 4.

In Table 1 and Table 2, the addition ratio of each component is shown as the value of the weight part calculated|required by the total amount of (A) group enclosed in parenthesis as 100 weight part. Among the (F) antistatic agents, (F2) acryl-containing ionic compounds copolymerized in the copolymer are listed in the column of Table 1, and (F1) added after polymerization at a temperature of 25-50°C The solid ionic compounds at °C are described in the other columns of Table 2.

Moreover, the compound name of the abbreviation of each component used in Table 1 and Table 2 is shown in Table 3 and Table 4. In addition, CORONATE (registered trademark) HX (isocyanurate body of hexamethylene diisocyanate compound (HDI)) is a trade name of Nippon Polyurethane Industry Co., Ltd. The value of "n" in the (D) group of Table 3 is the average number of repeating units of the alkyleneoxy group constituting the polyalkylene glycol chain. The value of "dieester" is the diester component (%) in the monomer. The value of "Absorbance" is the absorbance in a 25% aqueous solution. In addition, the value of "(I)/(H)" in Table 2 represents a weight ratio.

[Table 1]

[table 3]

<Test Method and Evaluation>

After curing the surface protection films of Examples 1 to 6 and Comparative Examples 1 to 4 in an atmosphere of 23°C and 50% RH for 7 days, the release film (PET film coated with silicone resin) was peeled off to expose the adhesive The layer is used as a measurement sample for the gel fraction and surface resistivity of the adhesive layer.

Furthermore, the surface protection film exposing the adhesive layer was pasted on the surface of the polarizing plate attached to the liquid crystal cell via the adhesive layer, and after being left for 1 day, it was subjected to autoclave treatment at 50°C, 5 atmospheres, and 20 minutes , Further placed at room temperature For 12 hours, this was used as a measurement sample for the adhesive force, peeling static voltage, reworkability, and durability of the adhesive layer.

<Gel fraction of adhesive layer>

After the aging is completed, the quality of the adhesive layer separated from the measurement sample before being attached to the polarizing plate is accurately measured, and after immersing in toluene for 24 hours, it is filtered with a 200 mesh metal net. Then, after the filtrate was dried at 100°C for 1 hour, the quality of the residue was accurately measured, and the gel fraction of the adhesive layer (crosslinked adhesive layer) was calculated by the following formula.

Gel fraction of adhesive layer (%) = mass of insoluble part (g)/mass of adhesive layer (g)×100

<Adhesion of the adhesive layer>

The above-obtained measurement sample (made by bonding a 25mm wide surface protective film to the surface of the polarizing plate) was used with a tensile testing machine in the 180° direction at a low-speed peeling speed (0.3m/min) and a high-speed peeling speed ( The peeling was performed at 30 m/min), and the measured peel strength was used as the adhesive force (N/25 mm) of the adhesive layer.

<Surface resistivity of adhesive layer>

After aging, before attaching to the polarizer, peel off the release film (PET film coated with silicone resin) to expose the adhesive layer, and use the resistivity meter Hiresta UP-HT450 (manufactured by Mitsubishi Chemical Analytech) to measure the adhesive layer Surface resistivity (Ω/□).

<Peeling static voltage>

When the measurement sample obtained above was peeled at 180° at a tensile speed of 30m/min, the high-precision electrostatic sensor SK-035, SK-200 (manufactured by Keyence Co., Ltd.) was used to measure the voltage ( Static voltage), the measured value The maximum value is taken as the peeling static voltage (kV).

<Reoperability>

Here, excellent reworkability means that after drawing on the surface protective film with a ballpoint pen via the adhesive layer, there is no transfer of contamination to the adherend.

After drawing on the surface protection film of the measurement sample obtained above with a ballpoint pen (using a scratch test device manufactured by Tester Sangyo Co., Ltd., applying a load of 500 g, reciprocating 3 times), peel the surface protection film from the polarizing plate and observe the polarized light On the surface of the plate, confirm that there is no contamination transfer to the polarizing plate. The criterion for evaluating the reoperability is: if there is no contamination transfer to the polarizing plate, it is evaluated as "○", if at least a part of the contamination transfer along the trace of the ballpoint pen is confirmed, it is evaluated as "△", and the drawing along the ballpoint pen is confirmed Contamination transfer of the track, and the presence of adhesive peeling off the surface of the adhesive layer was confirmed to be evaluated as "×".

<Durability of Adhesive Layer>

The measurement sample obtained above was left in an atmosphere of 60° C. and 90% RH for 250 hours, and then taken out to room temperature. After being left for another 12 hours, the adhesive force was measured to confirm whether there was a significant increase in the initial adhesive force. The criterion for evaluating the durability of the adhesive layer is: the case where the adhesive force after the test is 1.5 times or less of the initial adhesive force is evaluated as "○", and the case exceeding 1.5 times is evaluated as "x".

The evaluation results are shown in Table 5. In addition, the surface resistivity is marked with "m×10 ⁺ⁿ " as "mE+n" (m is an arbitrary real value, and n is a positive integer).

For the surface protection films of Examples 1 to 6, for the adherend of the polarizing plate, the adhesive force at a low-speed peeling speed of 0.3m/min is 0.04~0.2N/25mm, and the adhesive force at a high-speed peeling speed of 30m/min is 2.0N/25mm or less, the surface resistivity is 9.0×10+11Ω/□ or less, and the peeling static voltage is ±0~0.5kV. After drawing with a ballpoint pen on the surface protective film through the adhesive layer, the pollution does not transfer to the surface. The adhesive has excellent durability when placed in an atmosphere of 60°C and 90%RH for 250 hours.

In addition, the adhesive composition used in the surface protective films of Examples 1 to 6 has a weight ratio (I)/(H) of the (H) crosslinking catalyst relative to (I) the keto-enol tautomer compound ) Is 70~1000 (83~500), with an improved pot life of more than 6 hours.

That is, it satisfies all the requirements of (1) achieving a balance of adhesion between low and high peeling speeds, (2) excellent antistatic performance, (3) durability, and (4) reworkability. .

The surface protection film of Comparative Example 1 uses HDI isocyanurate as the crosslinking agent, so the gel fraction of the adhesive layer is a low value. The low-speed peeling speed is 0.3m/min and the high-speed peeling speed is 30m/min. The adhesion is too large, and then the operation And the durability is slightly worse.

In the surface protective film of Comparative Example 2, (D) polyalkylene glycol mono(meth)acrylate monomer was not copolymerized in the acrylic polymer, and HDI isocyanurate was used as the crosslinking agent. Therefore, the gel fraction of the adhesive layer is a low value. The adhesive force at low-speed peeling speeds of 0.3m/min and high-speed peeling speeds of 30m/min is too large, surface resistivity and peeling static voltage are high, and reworkability and durability are slightly difference.

The surface protective film of Comparative Example 3 had too many (C) carboxyl group-containing copolymerizable monomers, used HDI isocyanurate as a crosslinking agent, and did not contain (I) keto-enol tautomer compound ( That is, the weight ratio of (I)/(H) is 0), so the pot life is too short, and the adhesive composition has already been gelled before coating, so it cannot be coated.

In the surface protective film of Comparative Example 4, (B) a copolymerizable monomer containing a hydroxyl group and (C) a copolymerizable monomer containing a carboxyl group were not copolymerized in the acrylic polymer, and the gel fraction of the adhesive layer was 0%, in addition, (D) polyalkylene glycol mono(meth)acrylate monomer has a large absorbance in the state of 25% aqueous solution. The low-speed peeling speed is 0.3m/min and the high-speed peeling speed is 30m/min. Excessive adhesion, poor reworkability and durability. In addition, since the (F) antistatic agent is not included, the surface resistivity and peeling static voltage are increased.

As such, in the surface protection films of Comparative Examples 1 to 4, it is not possible to simultaneously satisfy (1) the balance of adhesion between low and high speed peeling speeds, (2) excellent antistatic performance, and (3) durability. Performance and (4) all required performance of re-operability.

Claims (11)

An adhesive composition, which is an adhesive composition containing an acrylic polymer, (E) a crosslinking agent, and (F) an antistatic agent, characterized in that the acrylic polymer is copolymerized by the following components Copolymers: (A) at least one or more of (meth)acrylate monomers with C ₄ to C ₁₈ carbon atoms in the alkyl group, (B) at least one or more of copolymerizable monomers containing hydroxyl groups, (C) at least one or more of the copolymerizable monomers containing carboxyl groups, and (D) at least one or more of the polyalkylene glycol mono(meth)acrylate monomers, wherein the (E) crosslinks The agent is an isocyanate of more than one pentamethylene diisocyanate compound composed of 1,5-pentamethylene diisocyanate, 1,4-pentamethylene diisocyanate, and 1,3-pentamethylene diisocyanate At least one trifunctional pentamethylene diisocyanate compound selected from cyanurate body, adduct body and biuret body, the (F) antistatic agent is a cyanurate body, an adduct body and a biuret body at a temperature of 25-50℃. It is a solid ionic compound at 25°C. The adhesive composition described in item 1 of the scope of the patent application is characterized in that the acrylic polymer is composed of (methyl) having a carbon number of C ₄ to C ₁₈ relative to the (A) alkyl group. ) 100 parts by weight of at least one of the acrylate monomers, 0.1-10 parts by weight of the total amount of at least one of the (B) hydroxyl-containing copolymerizable monomers, and (C) The total amount of at least one or more of the copolymerizable monomers of the carboxyl group is 0.05 to 1.0 parts by weight, and the total amount of at least one or more of the (D) polyalkylene glycol mono(meth)acrylate monomers is 5 ~50 parts by weight, and (G) a total of 0.1-20 parts by weight of at least one of nitrogen-containing vinyl monomers without hydroxyl groups or alkoxy-containing alkyl (meth)acrylate monomers The copolymer contains 100 parts by weight of the total amount of at least one or more of the (meth)acrylate monomers having C ₄ to C ₁₈ carbon atoms in the alkyl group (A), and contains the (E) cross 0.1-10 parts by weight of linking agent, 0.001-0.5 parts by weight of (H) crosslinking catalyst, and 0.1-300 parts by weight of (I) keto-enol tautomer compound. The adhesive composition described in item 1 or 2 of the scope of the patent application is characterized in that the (A) alkyl group has a C ₄ to C ₁₈ (meth)acrylate monomer with carbon atoms The total amount of at least one or more of 100 parts by weight, the (F) antistatic agent contains the following components in a total amount of 0.01 to 5.0 parts by weight: contained in the adhesive composition with a melting point of 25 to 50°C An ionic compound that is solid at a temperature of 25°C, an ionic compound containing an acrylic acid group copolymerized in the copolymer, and the (D) polyalkylene glycol mono(meth)acrylate monomer is composed of At least one selected from alkylene glycol mono(meth)acrylate, methoxy polyalkylene glycol (meth)acrylate, and ethoxy polyalkylene glycol (meth)acrylate , The average number of repeating units of the alkyleneoxy group constituting the polyalkylene glycol chain is 3 to 14, and the absorbance in the state of a 25% aqueous solution is 0.04 or less. The adhesive composition described in item 2 of the scope of the patent application is characterized in that the (H) crosslinking catalyst is a metal chelate compound, which is less effective than the (I) keto-enol tautomer compound The weight ratio of the (H) crosslinking catalyst is 70-1000 (I)/(H). The adhesive composition described in item 1 or 2 of the scope of the patent application is characterized in that the (B) hydroxyl-containing copolymerizable monomer is composed of 8-hydroxyoctyl (meth)acrylate, (methyl) ) 6-hydroxyhexyl acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N-hydroxy(meth)acrylamide, At least one selected from the group of compounds consisting of N-hydroxymethyl(meth)acrylamide and N-hydroxyethyl(meth)acrylamide, said (C) carboxyl group-containing copolymerizable monomer It is composed of (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-( Meth) acryloxypropyl hexahydrophthalic acid, 2-(meth)acryloxyethyl phthalic acid, 2-(meth)acryloxyethyl succinic acid, 2- (Meth)acryloyloxyethylmaleic acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyltetrahydrophthalic acid At least one selected from among. The adhesive composition described in item 1 or 2 of the scope of the patent application is characterized in that the (A) alkyl group has a C ₄ to C ₁₈ (meth)acrylate monomer with carbon atoms 100 parts by weight of at least one or more of the polyether modified silicone compound further contains 0.01 to 1 part by weight. The adhesive composition described in item 1 or 2 of the scope of patent application is characterized in that the gel fraction of the adhesive layer crosslinked by the adhesive composition is 95-100%, and the adhesive The adhesive force of the agent layer at a low-speed peeling speed of 0.3m/min is 0.04~0.2N/25mm, and the adhesive force at a high-speed peeling speed of 30m/min is less than 2.0N/25mm. The adhesive composition described in item 1 or 2 of the scope of patent application, characterized in that the surface resistivity of the adhesive layer cross-linked by the adhesive composition is 9.0×10 ⁺¹¹ Ω/□ or less , Stripping static voltage is ±0~0.5kV. An adhesive film, characterized in that the adhesive film is formed by the adhesive as described in any one of items 1 to 8 of the scope of patent application by forming on one or both sides of the resin film Adhesive layer formed by cross-linking the composition. A surface protection film, which is composed of the adhesive film as described in item 9 of the scope of patent application, and is used as a surface protection film for polarizing plates. The surface protection film according to the tenth item of the scope of patent application, wherein one surface of the resin film, which is the surface opposite to the side where the adhesive layer is formed, is subjected to antistatic treatment and antifouling treatment .