TWI618768B - Pressure-sensitive adhesive composition and optical element surface protection film - Google Patents

Abstract

The present invention is an adhesive composition containing: a (meth) acrylic acid copolymer, comprising a first constitutional unit represented by the following general formula (1) and a second constitutional unit derived from a monomer having a hydroxyl group; Polyether-modified silicones with hydroxyl groups; and alkali metal salts. In the following general formula (1), R ¹ represents a hydrogen atom or a methyl group, and L represents a divalent linking group composed of at least one selected from the group consisting of an alkylene group, an alkylene group, a carbonyl group, and an oxygen atom. .

Description

Adhesive composition and surface protection film of optical member

The present invention relates to an adhesive composition and a surface protective film for an optical member.

Liquid crystal display devices have been used in various information-related equipment in recent years because they are thin and light and consume less power. For example, a liquid crystal display device is used as a screen display device of a word processor or a notebook computer. Such a liquid crystal display panel is an optical member such as a glass cell (liquid crystal cell) in which liquid crystal is contained as a main part and a polarizing plate and a retardation plate.

These optical members are usually covered with a surface protective film to cover the optical member to form a long optical member laminate, so as to avoid the surface of the optical member during the steps of stamping, inspection, transportation, and assembly of the liquid crystal display panel. Contaminated or damaged. This surface protection film is peeled and removed from the optical member when the surface protection film is no longer needed.

Such a surface protection film is required to adhere to the surface of the member so as not to shift or fall off from the surface during the period when the optical member needs surface protection. At the same time, the surface protection film is required to be highly transparent so as not to cause various inspections such as performance inspections that hinder liquid crystal, and it is required that there is no swelling or tunneling in the adhesive layer and the interface between the adhesive layer and the optical member ), Defects such as peeling. When the surface protective film is peeled from the optical member, it is required that the surface protective film can be easily peeled off without causing damage to the liquid crystal display panel due to the peeling. Disadvantages such as the optical member and the liquid crystal cell, and the peeling of the optical member from the optical member of the liquid crystal cell. In addition, when the surface protective film is peeled off, it is required that no residues from the surface protective film be generated on the optical member, that is, it is required that the contamination property to the adherend (hereinafter simply referred to as "contamination property") is low.

In recent years, for the purpose of improving work efficiency, the peeling speed of the surface protective film tends to increase. As a characteristic of the adhesive, the workability of the surface protective film in high-speed peeling has also been required.

On the other hand, if static electricity is generated when the surface protective film is peeled from the optical member, dirt or dust is adsorbed on the surface of the optical film, which is disadvantageous to the product. In addition, when the surface protection film is peeled off, if a large static electricity occurs, the display member circuit may be damaged. Therefore, when the surface protective film is peeled off, good antistatic properties are required.

In relation to the foregoing, Japanese Patent Application Laid-Open No. 2009-275128 discloses an adhesive containing an acrylic copolymer, a metal salt, and an organopolysiloxane having a polyalkyleneoxy group. This adhesive has less contamination of the adherend, and has less occurrence of static electricity due to peeling and charging.

Also, Japanese Patent Application Laid-Open No. 2002-277634 discloses an adhesive optical film having an adhesive layer containing an acrylic polymer including a monomer unit having a specific structure having a carboxyl group. Cross-linked functional compounds. This adhesive optical film is excellent in reworkability and stress relaxation.

Furthermore, Japanese Patent Application Laid-Open No. 2011-063712 discloses a surface protection film having an adhesive layer formed by adding a silicon-containing compound such as polyether-modified organic polysiloxane to an acrylic adhesive. This surface protection film can suppress the occurrence of static electricity.

However, the adhesives described in Japanese Patent Application Laid-Open No. 2009-275128, Japanese Patent Application Laid-Open No. 2002-277634, and Japanese Patent Application Laid-Open No. 2011-063712 are sometimes difficult to achieve higher levels of both antistatic properties and low pollution. .

An object of the present invention is to provide a high-level adhesive composition having both antistatic properties and low contamination to adherends, and an optical member surface protective film using the same.

The present invention includes the following aspects.

<1> An adhesive composition comprising: a first (meth) acrylic acid copolymer, comprising a first constitutional unit represented by the following general formula (1) and a second constitutional unit derived from a monomer having a hydroxyl group, and Polyether-modified silicone with a hydroxyl group at the end of the ether, and an alkali metal salt.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. L represents a divalent linking group composed of at least one selected from the group consisting of an alkylene group, an arylene group, a carbonyl group, and an oxygen atom.

<2> The adhesive composition according to the aforementioned <1>, wherein L in the general formula (1) is selected from a divalent linking group represented by the following general formula (2a) and the following general formula (2b) At least one of the groups consisting of the divalent linking bases indicated by).

In the general formulae (2a) and (2b), R ²¹ to R ²⁴ each independently represent an alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms. n represents a value from 0 to 10, and m represents a value from 1 to 10.

<3> The adhesive composition according to the above <1> or <2>, wherein the content rate of the first constituent unit in the first (meth) acrylic copolymer is 0.5% by mass to 5% by mass.

<4> The adhesive composition according to any one of <1> to <3>, wherein the content of the polyether-modified silicone is 100 parts by mass relative to the (meth) acrylic copolymer, It is 0.05 to 0.50 parts by mass.

<5> The adhesive composition according to any one of the above <1> to <4>, further comprising a second (meth) acrylic acid copolymer, which contains a constitutional unit having a polyalkyleneoxy group and is larger than the foregoing The molecular weight of the 1st (meth) acrylic acid copolymer is low.

<6> A protective film for the surface of an optical member, comprising: a polyester substrate; and an adhesive layer provided on the polyester substrate and derived from the adhesion as described in any one of the above <1> to <5>剂 组合 物。 Composition.

According to the present invention, it is possible to provide an adhesive composition having both a high level of antistatic properties and low contamination to an adherend, and an optical member surface protective film using the same.

In this specification, the use of a numerical range indicated by "~" means a range that includes numerical values before and after "~" as the minimum and maximum values, respectively. Also in this specification, when referring to the case of the amount of each component in the composition, when a majority of the substances in the composition are present in the composition, unless specifically instructed, it means that it is present in the composition. The total amount of the majority of substances.

Furthermore, (meth) acrylate means at least one of acrylate and methyl acrylate; (Meth) acrylic acid-like (meth) acrylic acid copolymer-like terms have the same meaning.

<Adhesive composition>

The adhesive composition of the present invention contains: a first (meth) acrylic acid copolymer including a first constituent unit represented by the following general formula (1) and a second constituent unit derived from a monomer having a hydroxyl group; and a polyether Polyether-modified silicones with hydroxyl groups at the ends; and alkali metal salts. The said adhesive composition may further contain another component as needed.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. L represents a divalent linking group composed of at least one selected from the group consisting of an alkylene group, an arylene group, a carbonyl group, and an oxygen atom.

The adhesive composition includes a first (meth) acrylic copolymer including a first structural unit having a specific structure having a carboxyl group and a second structural unit derived from a monomer having a hydroxyl group, and a polyether having a hydroxyl group at a polyether terminal. Modified silicone, and alkali metal salt; by this, it is excellent in both antistatic properties and low pollution to the adherend, it also has excellent adhesion and excellent reliability. This adhesive composition can be ideally applied to the surface protective film of an optical member.

This can be estimated as follows, for example. It is considered that the adhesive composition contains polyether-modified silicone and the interaction between the polyether-modified silicone and the alkali metal salt, so that the alkali metal salt can be localized near the surface of the adhesive composition. The composition exhibits excellent antistatic properties. Furthermore, it is thought that the surface resistance value of the adhesive composition is effectively reduced by the interaction between the first (meth) acrylic acid copolymer and the polyether-modified silicone, and the adhesive composition exhibits more excellent antistatic properties. This is believed to be attributable to The 1st (meth) acrylic copolymer has both the 1st structural unit and the 2nd structural unit of a specific structure. In particular, it is considered that a (meth) acrylic copolymer containing a carboxyl-containing structural unit derived from (meth) acrylic acid, etc., is not sufficient unless it is a structural unit containing a first structural unit of a specific structure as a carboxyl group. So effective. Furthermore, it is thought that the polyether-modified silicone has a hydroxyl group at the end of the polyether, and when the adhesive is peeled from the adherend, the constituents of the adhesive composition can be effectively suppressed from remaining on the adherend. The object can exhibit excellent low pollution to the adherend.

[(Meth) acrylic copolymer]

The adhesive composition contains at least one first (meth) acrylic copolymer (hereinafter also referred to as "resin A"), and the first (meth) acrylic copolymer includes the first The structural unit and the second structural unit derived from a monomer having a hydroxyl group. The adhesive composition may further include a (meth) acrylic copolymer different from the 1st (meth) acrylic copolymer, if necessary.

Here, the (meth) acrylic copolymer refers to 50% by mass or more of all monomer components constituting the copolymer (in the case where the monomers constituting the copolymer are simply described as copolymerization components), and preferably 90% by mass or more. It is a copolymer of (meth) acrylic monomers.

(1st (meth) acrylic copolymer)

The 1st (meth) acrylic copolymer contains at least 1 sort (s) of 1st structural unit represented by the said General formula (1). In the first constitutional unit represented by the general formula (1), L represents a divalent linking group composed of at least one selected from the group consisting of an alkylene group, an arylene group, a carbonyl group, and an oxygen atom. The alkylene group in L may be any of linear, branched, and cyclic. When the alkylene group in L is linear or branched, the carbon number of the alkylene group is preferably 1 to 12, more preferably 2 to 10, and even more preferably 2 to 6.

When the alkylene group in L is cyclic, the carbon number of the alkylene group is preferably 3 to 12, more preferably 4 to 8, and still more preferably 5 to 6. For example, when the cyclic alkylene group is cyclohexyl group, the bonding position may be any of the 1st and 4th positions, the 1st and 2nd positions, and the 1st and 3rd positions, and the 1st and 2nd positions are desirable. Bit.

The arylene group in L is preferably 6 to 10 carbon atoms, and more preferably phenylene. Bonding position in arylene There are no special restrictions. For example, when the arylene group is a phenyl group, the bonding position may be any of the 1st and 4th positions, the 1st and 2nd positions, and the 1st and 3rd positions, and the 1st and 2nd positions are desirable.

The alkylene and aryl groups in L may have a substituent. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, a halogen atom, a hydroxyl group, an amino group, a nitro group, and a phenyl group.

The divalent linking group represented by L in the general formula (1) is preferably 2 represented by the following general formula (2a) or (2b) from the viewpoints of antistatic properties and low pollution to adherends. Price link base.

In the general formulae (2a) and (2b), R ²¹ to R ²⁴ each independently represent an alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms. n represents a value from 0 to 10, and m represents a value from 1 to 10.

The alkylene group in R ²¹ to R ²⁴ may be any of linear, branched, and cyclic, preferably linear or branched, and more preferably linear.

The bonding position in the arylene group in R ²¹ to R ²⁴ is not particularly limited. For example, when the arylene group is a phenylene group or a cyclohexyl group, the bonding position may be any of the 1st and 4th positions, the 1st and 2nd positions, and the 1st and the 3rd positions, and the 1st position is desirable. And 2 people.

The alkylene group in R ²¹ and R ²² is preferably 2 to 10 carbon atoms, and more preferably 2 to 6 carbon atoms. The alkylene groups in R ²¹ and R ²² may be the same or different.

The arylene group in R ²¹ and R ²² is preferably a phenylene group or a naphthyl group, and more preferably a phenylene group.

R ²¹ and R ²² in the general formula (2a) are preferably an alkylene group having 1 to 12 carbon atoms, and more preferably 2 carbon atoms in terms of antistatic properties and low pollution to an adherend. An alkylene group of ~ 6, and more preferably a linear or branched alkylene group having 2 to 6 carbon atoms.

n represents a value from 0 to 10. When the first (meth) acrylic acid copolymer contains only one kind of the first structural unit represented by the general formula (1), n is an integer; when the first constituent unit contains two or more kinds, n is an average Value, which is a rational number. n is preferably 0 to 4, more preferably 0 to 2.

R ^{23 is} preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 2 to 6 carbon atoms, and even more preferably an alkylene group having 2 to 4 carbon atoms.

R ^{24 is} preferably a linear or branched alkylene group having 2 to 6 carbon atoms, a cyclic alkylene group having 4 to 8 carbon atoms, or an aromatic group having 6 to 10 carbon atoms, and more preferably Linear or branched alkylene group with 2 to 4 carbon atoms, cyclic alkylene group with 5 to 6 carbon atoms or phenylene group, and more preferably a linear or branched chain with 2 to 4 carbon atoms Branched chain alkylene, cyclohexyl, or phenylene.

m represents a value from 1 to 10. When the first (meth) acrylic acid copolymer contains only one kind of the first structural unit represented by the general formula (1), m is an integer; when the first constituent unit contains two or more kinds, m is an average value. , Which is a rational number. m is preferably 1 to 4, and more preferably 1 to 2.

The content ratio of the first constituent unit in the first (meth) acrylic copolymer is preferably from the viewpoint of antistatic properties and low contamination of the adherend, and 0.5 mass% or more and 5 mass% or less of the total mass, more preferably 0.5 mass% or more and 2 mass% or less, still more preferably 0.5 mass% or more and 1 mass% or less.

When the content rate of the first constituent unit in the first (meth) acrylic copolymer is 0.5% by mass or more with respect to the total mass of the first (meth) acrylic copolymer, the surface resistance of the adhesive-containing composition is reduced. A tendency to obtain more excellent antistatic properties. Moreover, if the content rate of the 1st structural unit in a 1st (meth) acrylic acid copolymer is 5 mass% or less with respect to the total mass of a 1st (meth) acrylic acid copolymer, there exists a possibility of suppressing an adhesive composition. As the viscosity increases over time, a sufficient pot life tends to be obtained.

The first constituent unit in the first (meth) acrylic copolymer may be, for example, a monomer represented by the following general formula (1a) and other monomers constituting the first (meth) acrylic copolymer The copolymerization was carried out together to introduce the first (meth) acrylic acid copolymer.

In the general formula (1a), R ¹ and L are synonymous with R ¹ and L in the general formula (1), respectively.

The monomer represented by the general formula (1a) may be a conventionally produced one, or may be appropriately selected from commercially available monomers. Among the monomers represented by the general formula (1a), L is a monomer represented by the general formula (2a). For example, a (meth) acrylic acid dimer (ideally the average of n in the general formula (2a)) Those having a value of about 0.4), ω-carboxy-polycaprolactone mono (meth) acrylate (preferably, the average value of n in the general formula (2a) is about 1.0), and the like. These monomers can be marketed, for example, "M-5600", "M-5300" (the above are the trade names of Toa Kosei Co., Ltd.).

Moreover, as L in the monomer represented by General formula (1a) is a monomer represented by General formula (2b), a 2- (meth) acryloxyethyl succinic acid, 2- ( (Meth) acryloxyethyl fumaric acid, 2- (meth) acryloxyethyl hexahydrophthalic acid, 2- (meth) acryloxyethyl phthalic acid, and the like. For these monomers, for example, "LIGHT ESTER HO-MS", "LIGHT ACRYLATE HOA-MS (N)", LIGHT ACRYLATE HOA-HH (N) ", and" LIGHT ACRYLATE HOA-MPL (N) "(the above are Kyoeisha Chemical Co., Ltd.) and other marketers.

The 1st (meth) acrylic copolymer contains at least 1 kind of 2nd structural unit derived from the monomer which has a hydroxyl group. The monomer having a hydroxyl group forming the second constituent unit may be a monomer having at least one hydroxyl group and a polymerizable group capable of forming a copolymer with the first constituent unit, and is not particularly limited. Use appropriately in the body.

The method for introducing the second constitutional unit derived from the monomer having a hydroxyl group into the first (meth) acrylic copolymer is not particularly limited. For example, at least one monomer having a hydroxyl group, at least one monomer represented by the aforementioned general formula (1a), and other monomers (ideally at least one type of (meth) acrylic acid) The monomer composition of the alkyl ester) is copolymerized to obtain the first (A) containing the first constitutional unit represented by the general formula (1) and the second constitutional unit derived from the monomer having a hydroxyl group in the molecule. Based) acrylic copolymer.

Examples of the monomer having a hydroxyl group include monomers having a hydroxyl group and an ethylenically unsaturated bonding group. Specific examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (methyl) ) 4-hydroxybutyl acrylate, 3-methyl-3-hydroxybutyl (meth) acrylate, 1,1-dimethyl-3-butyl (meth) acrylate, 1,3 (meth) acrylate -Dimethyl-3-hydroxybutyl, 2,2,4-trimethyl-3-hydroxypentyl (meth) acrylate, 2-ethyl-3-hydroxyhexyl (meth) acrylate, mono ( (Meth) acrylic acid, such as glyceryl methacrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, poly (ethylene glycol-propylene glycol) mono (meth) acrylate, etc. Esters; (meth) acrylamides such as N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamides; unsaturated allyl alcohols, allyl alcohols, etc. Alcohol; etc.

Among them, from the point of good mutual solubility and copolymerizability with other monomers and the point of good cross-linking reaction with the cross-linking agent, the monomer having a hydroxyl group preferably has one hydroxyl group and The (meth) acrylate of an alkyl group having 2 to 6 carbon atoms is more preferably 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate.

The content rate of the second constituent unit derived from the monomer having a hydroxyl group in the first (meth) acrylic copolymer is preferably 0.1% by mass or more and 10.0 in the total mass of the first (meth) acrylic copolymer. Mass% or less, more preferably 2.0 mass% or more and 8.0 mass% or less, and still more preferably 2.0 mass% or more and 5.0 mass% or less. When the content rate of the constituent unit derived from the monomer having a hydroxyl group is equal to or more than the aforementioned lower limit value, there is a tendency that contamination of the adherend is more effectively suppressed. Moreover, when the content rate of the structural unit derived from the monomer which has a hydroxyl group is below the said upper limit, compliance (moisture permeability) tends to be more favorable.

The content ratio of the first constituent unit and the second constituent unit in the first (meth) acrylic copolymer is not particularly limited. From the viewpoint of antistatic properties and low pollution to adherends, the content ratio of the first constituent unit to the second constituent unit in the first (meth) acrylic copolymer (first constituent unit / second Constituent unit), preferably 1/10 to 2/1, more preferably 1/5 to 4/3 on a mass basis.

The total content of the first constituent unit and the second constituent unit in the first (meth) acrylic copolymer is not particularly limited. From the viewpoint of antistatic properties and low pollution to the adherend, the total content of the first constituent unit and the second constituent unit in the first (meth) acrylic copolymer is preferably the first (a 1% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 10% by mass or less, and still more preferably 3% by mass or more and 8% by mass or less of the total mass of the acrylic copolymer.

The first (meth) acrylic copolymer preferably contains, in addition to the first structural unit and the second structural unit, at least one type of third structural unit derived from an alkyl (meth) acrylate.

The alkyl group in the alkyl (meth) acrylate may be linear or branched. The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate is preferably from 1 to 18, more preferably from 2 to 10, from the viewpoint of adhesion.

Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, N-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, (formyl) (N-decyl acrylate), n-dodecyl (meth) acrylate, octadecyl (meth) acrylate, etc., linear or branched (meth) groups having an alkyl group having 1 to 18 carbon atoms Alkyl acrylate and derivatives thereof.

The first (meth) acrylic copolymer may contain only one kind, or may include two or more kinds of third constituent units derived from the alkyl (meth) acrylate, and preferably contains two or more kinds. When the 1st (meth) acrylic acid copolymer contains 2 types of 3rd structural units, it is preferable that one is a (meth) -derived (meth) group which has a linear or branched alkyl group having 1 to 5 carbon atoms. The other structural unit of the alkyl acrylate is a structural unit derived from an alkyl (meth) acrylate having a linear or branched alkyl group having 6 to 18 carbon atoms, and more preferably one is (Meth) acrylic acid having a linear alkyl group having 2 to 5 carbon atoms The other structural unit of an alkyl ester is a structural unit derived from an alkyl (meth) acrylate having a branched chain alkyl group having 6 to 10 carbon atoms.

When the 1st (meth) acrylic copolymer contains a 3rd structural unit, it is preferable that the content rate of a 3rd structural unit is 60 mass%-99.9 mass% of the total mass of a 1 (meth) acrylic copolymer Hereinafter, it is more preferably 72% by mass or more and 99.5% by mass or less, and still more preferably 85% by mass or more and 99% by mass or less. When the content rate of the third constituent unit is equal to or more than the aforementioned lower limit value, the compliance (moisture permeability) tends to be more favorable. In addition, if the content rate of the third constituent unit is equal to or less than the aforementioned upper limit value, the adhesive force during high-speed peeling does not become excessively large, and the workability during high-speed peeling tends to be more excellent.

The 1st (meth) acrylic copolymer may further contain the structural unit other than a 1st structural unit, a 2nd structural unit, and a 3rd structural unit as needed. Examples of monomers forming other constituent units include (meth) acrylates having a cyclic group such as cyclohexyl (meth) acrylate and benzyl (meth) acrylate; vinyl esters of saturated fatty acids such as ethylene formate Esters, vinyl acetate, vinyl propionate, "vinyl versatate" (trade name, vinyl neodecanoate) and other aliphatic vinyl monomers; styrene, α-methylstyrene, ethylene Aromatic vinyl monomers such as methyl toluene; cyano vinyl monomers such as acrylonitrile, methacrylonitrile; dimethyl maleate, di-n-butyl maleate, di-2-ethylhexyl maleate Esters, di-n-octyl maleate, dimethyl fumarate, di-n-butyl fumarate, di-2-ethylhexyl fumarate, di-n-octyl fumarate, etc. Diester of maleic acid; etc.

Furthermore, as a monomer forming another constituent unit, for example, a monomer having at least one functional group in addition to a radical polymerizable group in the molecule, and a monomer forming the first constituent unit And monomers that are different from the monomers that form the second constituent unit (hereinafter also referred to as "functional monomers"). Examples of the functional monomer include a carboxyl group, an amido group, a substituted or unsubstituted amido group, a substituted or unsubstituted amino group, an alkoxy group, an epoxy group, a mercapto group, and a silicon-containing group. Isofunctional monomers. Moreover, as a monomer which forms another structural unit, the monomer which has two or more radically polymerizable groups in a molecule | numerator can also be used.

Specific examples of such functional monomers include (meth) acrylic acid and methylene butane Monomers containing carboxyl groups or anhydride groups, such as acids, maleic anhydride; (meth) acrylamide, diacetoneacrylamide, N-methylol (meth) acrylamide, N-n-butoxymethyl (Meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methyl (meth) acrylamine Amines and other monomers containing substituted or unsubstituted amido groups; aminoethyl (meth) acrylate, dimethylamino ethyl N, N- (meth) acrylate, N, N- (methyl Group) monomers containing substituted or unsubstituted amine groups such as diethylaminoethyl acrylate; 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate , 2-n-butoxyethyl (meth) acrylate, 2-methoxyethoxyethyl (meth) acrylate, 2-ethoxyethoxyethyl (meth) acrylate, (methyl ) 2-n-butoxyethoxyethyl acrylate, methoxypolyethylene glycol mono (meth) acrylate, methoxypolyethylene glycol monomethacrylate and other monomers containing alkoxy groups; (Meth) acrylates containing epoxy groups, such as glycidyl acrylate, glycidyl allyl ether, glycidyl methallyl ether ; Mercapto-containing monomers such as allyl mercaptan; vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, ethylene Triisopropoxysilane, vinyltri-n-butoxysilane, vinyl ginseng (2-methoxyethoxy) silane, vinyl ginseng (2-hydroxymethoxyethoxy) silane, vinyl Triethoxysilane, vinyldiethoxysilanol, vinylethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, vinylmethyldisiloxane Ethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyl Triethoxysilane, 3- (meth) acryloxypropyl ginseng (2-methoxyethoxy) silane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3 -(Meth) acryloxypropyldimethylethoxysilane, 3- (meth) acryloxypropyldimethylmethoxysilane, 2- (meth) acrylamine ethyl triethyl Silicon-containing group Monomers; etc. monomer group.

When the 1st (meth) acrylic copolymer contains other structural units, the content rate of the other structural units is preferably 30% by mass or less, more preferably 20% of the total mass of the 1 (meth) acrylic copolymer. Mass% or less, and more preferably 10 mass% or less. When the content rate of the other constituent units is equal to or lower than the aforementioned upper limit value, there is a tendency that the balance between the adhesion of low-speed peeling and high-speed peeling can be more favorable.

Furthermore, as the other constituent unit of the 1st (meth) acrylic copolymer, if it is derived from When the functional monomer is a constituent unit of a monomer having a carboxyl group, the content rate of the constituent unit derived from the monomer having a carboxyl group is preferably 0.5 in the total mass of the first (meth) acrylic copolymer Mass% or less, more preferably 0.2 mass% or less, and even more preferably not included. If the content rate of the constituent unit derived from the monomer having a carboxyl group is equal to or lower than the aforementioned upper limit value, the antistatic performance tends to be more favorable.

The weight average molecular weight of the 1st (meth) acrylic acid copolymer is not specifically limited. The weight average molecular weight (Mw) of the 1st (meth) acrylic acid copolymer is preferably 200,000 to 1 million, and more preferably 300,000 to 800,000. When the weight average molecular weight (Mw) of the 1st (meth) acrylic acid copolymer is more than the said lower limit, the occurrence of contamination of an adherend can be suppressed more effectively. When the weight average molecular weight (Mw) of the first (meth) acrylic copolymer is equal to or less than the aforementioned upper limit value, the compliance (moisture permeability) tends to be better.

The ratio of the weight average molecular weight (Mw) of the first (meth) acrylic acid copolymer to the number average molecular weight (Mn), that is, the degree of dispersion (Mw / Mn), is preferably 20 or less, more preferably 15 or less, and more It is preferably in the range of 3 to 10. When the value of the degree of dispersion (Mw / Mn) is equal to or less than the upper limit value, there is a tendency that the occurrence of contamination of the adherend can be further suppressed.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the first (meth) acrylic acid copolymer are values measured in accordance with the following methods.

Measurement method of average molecular weight (Mw and Mn):

The measurement was performed in accordance with the following (1) to (3).

(1) A solution of a (meth) acrylic copolymer is applied to a release paper and dried at 100 ° C. for 2 minutes to obtain a film-like (meth) acrylic copolymer.

(2) Using the film-like (meth) acrylic copolymer and tetrahydrofuran obtained in the above (1), a sample solution having a solid content concentration of 0.2% by mass was obtained.

(3) Under the following conditions, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the (meth) acrylic copolymer were measured using gel permeation chromatography (GPC) as standard polystyrene conversion values.

(condition)

GPC: HLC-8220 GPC [Tosoh Corporation]

Column: TSK-GEL GMHXL uses 4

Mobile phase solvent: tetrahydrofuran

Flow rate: 0.6ml / min

Column temperature: 40 ℃

The content rate of the 1st (meth) acrylic acid copolymer in an adhesive composition can be suitably selected according to the objective etc. The content rate of the 1st (meth) acrylic acid copolymer is preferably 80% by mass or more and 99% by mass or less, and more preferably 85% by mass or more and 99% by mass or less of the total solid content of the adhesive composition. It is preferably 90% by mass or more and 98% by mass or less.

In addition, the total solid content means the total mass of the residue after removing volatile components such as solvents from the adhesive composition.

(Second (meth) acrylic copolymer)

The adhesive composition preferably further contains at least one kind of a second (meth) acrylic copolymer (hereinafter also referred to as "resin B"), and the second (meth) acrylic copolymer contains a polyalkyleneoxy group. It is a structural unit and has a lower molecular weight than the first (meth) acrylic copolymer. The adhesive composition contains a second (meth) acrylic copolymer in addition to the first (meth) acrylic copolymer, so that the adhesive composition can have more excellent antistatic properties.

It is considered that the second (meth) acrylic copolymer contains constituent units having a polyalkyleneoxy group and has a molecular weight smaller than that of the first (meth) acrylic copolymer, so that it is easier to move in the adhesive composition. Accordingly, it is considered that the surface resistance value of the adhesive composition can be more effectively reduced, and the antistatic property can be more excellent.

The 2nd (meth) acrylic copolymer contains at least 1 type of structural unit which has a polyalkyleneoxy group. As the polyalkyleneoxy group in the second (meth) acrylic acid copolymer, it is preferable to include an alkyleneoxy group having 2 to 4 carbon atoms as a constituent unit, and it is more preferable to include an alkyleneoxy group having 2 to 3 carbon atoms. Basis as a constituent unit.

The content of the alkyleneoxy group in the polyalkyleneoxy group can be appropriately selected according to the purpose and the like. Stretch From the viewpoint of antistatic properties, the number of alkoxy groups is preferably 20 or more, more preferably 20 to 100, and still more preferably 20 to 50. When the content of the alkoxy group is 20 or more, the adhesive composition can exhibit a more significant antistatic effect by being combined with an alkali metal salt described later. It should be noted that when the content of the alkoxy group is a reasonable number when the second (meth) acrylic acid copolymer contains two or more kinds of constituent units of the alkoxy group, the average is the number of the content.

The terminal portion of the polyalkyleneoxy group in the second (meth) acrylic acid copolymer may be a hydroxyl group or an alkoxy group, and is preferably an alkoxy group from the viewpoint of antistatic properties. When the terminal portion of the polyalkoxy group is an alkoxy group, the carbon number of the alkoxy group is preferably 1 to 10, and more preferably 1 to 5.

The structural unit having a polyalkyleneoxy group may be derived from a monomer having a polyalkyleneoxy group and a polymerizable group, or may be introduced by a polymer reaction to the structural unit having no polyalkyleneoxy group. Polyalkoxylates. From the viewpoint of productivity of the constituent unit having a polyalkyleneoxy group, the constituent unit having a polyalkyleneoxy group is preferably derived from a monomer having a polyalkyleneoxy group and a polymerizable group.

Examples of the monomer having a polyalkyleneoxy group and a polymerizable group include polyethylene glycol (meth) acrylate, methoxypolyethyloxy (meth) acrylate, and ethoxypoly Ethyloxy (meth) acrylate, polypropylene glycol (meth) acrylate, methoxypoly (propyl) oxy (meth) acrylate, ethoxypoly (propyl) oxy (meth) Acrylate, etc. Among them, at least one selected from the group consisting of methoxy poly (ethyl) oxy (meth) acrylate and methoxy poly (propyl) oxy (meth) acrylate is particularly preferred, More preferably, it is selected from the group consisting of methoxy polyethenyloxy (meth) acrylates containing 20 or more ethoxy groups and methoxy polyethenes containing 20 or more in propyloxy groups. At least one member of the group consisting of propyloxy (meth) acrylate.

The second (meth) acrylic copolymer may include only one kind or a combination of two or more kinds of constituent units having a polyalkyleneoxy group.

The content rate of the structural unit having a polyalkyleneoxy group in the second (meth) acrylic acid copolymer is preferably one of the total mass of the second (meth) acrylic acid copolymer from the viewpoint of antistatic properties. 1 quality % To 50% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 20% by mass.

The second (meth) acrylic copolymer preferably contains a structural unit derived from an alkyl (meth) acrylate in addition to the structural unit having a polyalkyleneoxy group.

The alkyl group in the alkyl (meth) acrylate may be linear or branched. The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate is preferably 1 to 18, and more preferably 2 to 10 from the viewpoint of antistatic properties.

Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , N-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, ( (Meth) acrylic acid having linear or branched alkyl groups having 1 to 18 carbon atoms, such as n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, and octadecyl (meth) acrylate Alkyl esters and derivatives thereof.

The 2nd (meth) acrylic copolymer may contain only 1 type, and may also contain the structural unit derived from the alkyl (meth) acrylate.

When the 2nd (meth) acrylic acid copolymer contains the structural unit derived from an alkyl (meth) acrylate, the content rate of the structural unit derived from an alkyl (meth) acrylic acid is the same as that of the 2nd (meth) acrylic acid The total mass of the copolymer is preferably from 40% by mass to 95% by mass, more preferably from 70% by mass to 90% by mass, and even more preferably from 80% by mass to 90% by mass. If the content rate of the structural unit derived from the alkyl (meth) acrylate is equal to or more than the aforementioned lower limit value, there is a tendency that the occurrence of contamination of the adherend is more effectively suppressed. Moreover, if the content rate of the structural unit derived from an alkyl (meth) acrylate is below the said upper limit, the surface resistance of an adhesive composition will fall and the adhesive composition will become more excellent in antistatic property.

The 2nd (meth) acrylic copolymer may contain the structural unit which has a polyalkyleneoxy group and the structural unit other than the structural unit derived from an alkyl (meth) acrylate as needed. As other structural units, for example, the same as other structural units in the 1st (meth) acrylic copolymer is preferable, The same is true.

The molecular weight of the second (meth) acrylic copolymer is not particularly limited as long as it is smaller than the first (meth) acrylic copolymer. The weight average molecular weight (Mw) of the second (meth) acrylic copolymer is preferably 3,000 or more and 100,000 or less, more preferably 5,000 or more and 60,000 or less, and still more preferably 5,000 or more and 20,000 or less. When the weight average molecular weight (Mw) of the 2nd (meth) acrylic copolymer is more than the said lower limit, there exists a tendency for the occurrence of contamination to an adherend to be suppressed more effectively. When the weight average molecular weight (Mw) of the second (meth) acrylic copolymer is equal to or less than the aforementioned upper limit value, the antistatic property tends to be further improved.

The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the second (meth) acrylic copolymer is preferably 10 or less, more preferably 7 or less, and even more preferably 1 Range of ~ 5. When the value of Mw / Mn is equal to or less than the upper limit value, there is a tendency that the occurrence of contamination of the adherend is more effectively suppressed. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the second (meth) acrylic acid copolymer were measured in the same manner as in the case of the first (meth) acrylic acid copolymer.

The ratio of the weight average molecular weight of the second (meth) acrylic acid copolymer to the first (meth) acrylic acid copolymer (second / first) is not particularly limited if it is less than 1. From the viewpoint of antistatic properties, the ratio of the weight average molecular weight of the second (meth) acrylic copolymer to the first (meth) acrylic copolymer is preferably 0.1 or less, and more preferably 0.006 to 0.07.

The content of the second (meth) acrylic copolymer in the adhesive composition can be appropriately selected depending on the purpose and the like. The content of the second (meth) acrylic copolymer is preferably 0.05 to 2.0 parts by mass, and more preferably 0.1 to 1.5 parts by mass based on 100 parts by mass of the first (meth) acrylic copolymer. And more preferably 0.2 mass part to 1.0 mass part. When the content of the second (meth) acrylic copolymer is 0.05 parts by mass or more relative to 100 parts by mass of the first (meth) acrylic copolymer, there is a tendency that a more excellent antistatic effect can be obtained. In addition, if the content of the second (meth) acrylic copolymer is 2.0 parts by mass or less relative to 100 parts by mass of the first (meth) acrylic copolymer, there is a tendency that contamination of the adherend is more effectively suppressed.

The first (meth) acrylic acid copolymer and the second (meth) acrylic acid copolymer (hereinafter, these are also collectively referred to as "copolymers") can be formed by a method capable of forming constituent units included in these copolymers. A mixture of monomers is polymerized to produce it. The polymerization method of the copolymer is not particularly limited, and may be appropriately selected from known methods such as a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method. Among these, in particular, for the consideration that the processing steps in the production of the adhesive composition of the present invention using a copolymer obtained by polymerization are relatively simple and can be implemented in a short time, it is desirable to perform polymerization using a solution polymerization method.

The solution polymerization method can generally be carried out by using a known method such as: putting a predetermined organic solvent, monomer, polymerization initiator, and chain transfer agent as needed in a polymerization tank, in a nitrogen gas stream, organically At the reflux temperature of the solvent, a heating reaction was performed for several hours with stirring.

The weight average molecular weight and dispersion of the first (meth) acrylic acid copolymer and the second (meth) acrylic acid copolymer can be easily determined by the reaction temperature, time, solvent amount, and type and amount of the catalyst. Make adjustments.

Examples of the organic solvent for polymerization used in the polymerization of the first (meth) acrylic acid copolymer and the second (meth) acrylic acid copolymer include benzene, toluene, ethylbenzene, n-propylbenzene, and tertiary butylbenzene. , O-xylene, m-xylene, p-xylene, tetrahydronaphthalene, decahydronaphthalene, aromatic petroleum brain and other aromatic hydrocarbons; n-hexane, n-heptane, n-octane, isooctane, n-decane, Dipentene, petroleum spirit, petroleum naphtha, turpentine and other aliphatic or cycloaliphatic hydrocarbons; ethyl acetate, n-butyl acetate, n-pentyl acetate, 2-hydroxyethyl acetate, 2-butoxy acetate Ester such as ethyl ester, 3-methoxybutyl acetate, methyl benzoate; acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone, methyl cyclohexanone and other ketones Glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and other glycol ethers; Alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutanol, secondary butanol, tertiary butanol; etc. These organic solvents can be used individually by 1 type or in mixture of 2 or more types.

As the aforementioned polymerization initiator, organic peroxides, azo compounds, and the like that can be used in a general solution polymerization method can be used. Examples of organic peroxides include tertiary butyl peroxide Hydrogen, cumene hydroperoxide, dicumyl peroxide, benzamyl peroxide, lauryl peroxide, hexamethylene peroxide, diisopropyl peroxydicarbonate, peroxide Di-2-ethylhexyl oxydicarbonate, tert-butyl peroxytrimethylacetate, 2,2-bis (4,4-di-tert-butylperoxycyclohexyl) propane, 2,2- Bis (4,4-di-tertiary pentylperoxycyclohexyl) propane, 2,2-bis (4,4-di-tertiary octylperoxycyclohexyl) propane, 2,2-bis (4, 4-di-α-cumyl peroxycyclohexyl) propane, 2,2-bis (4,4-di-tert-butylperoxycyclohexyl) butane, 2,2-bis (4,4 -Di-tertiary octylperoxycyclohexyl) butane and the like. As the azo compound, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-4 -Methoxy-2,4-dimethylvaleronitrile and the like.

In the production of the first (meth) acrylic acid copolymer and the second (meth) acrylic acid copolymer, a chain transfer agent is generally not used. However, as long as the purpose and efficacy of the present invention are not impaired, it may be necessary. use. Examples of the chain transfer agent include: cyanoacetic acid; alkyl esters of 1 to 8 carbon atoms of cyanoacetic acid; bromoacetic acid; alkyl esters of 1 to 8 carbon atoms of bromoacetic acid; Aromatic compounds such as hydrazone; p-nitroaniline, n-benzene, dinitrobenzene, p-nitrobenzoic acid, p-nitrophenol, p-nitrotoluene and other aromatic nitro compounds; benzoquinone, 2,3,5,6- Benzoquinone derivatives such as tetramethyl p-benzoquinone; Borane derivatives such as tributylborane; carbon tetrabromide, carbon tetrachloride, 1,1,2,2-tetrabromoethane, tribromoethylene , Trichloroethylene, bromotrichloromethane, tribromomethane, 3-chloro-1-propene and other halogenated hydrocarbons; aldehydes such as chloroaldehyde and furanaldehyde: alkyl mercaptans having 1 to 18 carbon atoms; thiophenol, toluene Aromatic mercaptans such as mercaptans; mercaptoacetic acid, mercaptoacetic acid alkyl esters having 1 to 10 carbons; hydroxyalkyl mercaptans having 1 to 12 carbons; pinene, terpinolene And other terpenes; etc.

The polymerization temperature is generally in the range of about 30 ° C to 180 ° C.

When manufacturing a 1st (meth) acrylic acid copolymer and a 2nd (meth) acrylic acid copolymer, the purification process which refine | purifies the polymer obtained by a polymerization reaction may be provided. When the polymer obtained by the solution polymerization method or the like contains an unreacted monomer by the purification step, the monomer can be removed. The refining step can be appropriately selected from refining methods generally used. For example, purification can be performed by a reprecipitation method using methanol or the like.

[Polyether modified silicone]

The adhesive composition contains at least one type of polyether-modified silicone having a hydroxyl group at the end of the polyether (hereinafter also referred to as "specific polysiloxane compound"). Polyether-modified silicone has excellent antistatic properties by having a hydroxyl group at the end of the polyether, which can effectively inhibit contamination of the adherend.

The specific polysiloxane compound can effectively exhibit antistatic properties by having a hydroxyl group, that is, a polyalkyleneoxy group, at the end of the molecule. The reason is speculated that, for example, a specific polysiloxane compound is concentrated in the vicinity of the surface of the adhesive layer from the adhesive composition, and the polyalkyleneoxy group which interacts with the alkali metal salt is present on the surface of the adhesive layer. As a result, the surface resistance value in the surface of the adhesive layer is reduced.

In general, if the adhesive composition contains a polyether-modified silicone having a hydroxyl group at a polyether terminal as a polysiloxane compound, there is a tendency that the surface resistance of the adhesive composition cannot be sufficiently reduced. . However, in the present invention, the surface resistance value of the adhesive composition can be sufficiently reduced by containing the first (meth) acrylic copolymer containing the first constituent unit represented by the general formula (1). On the other hand, it is difficult to sufficiently reduce the surface resistance value of the adhesive composition by including a (meth) acrylic copolymer derived from a carboxyl group-containing structural unit having (meth) acrylic acid or the like. Furthermore, it is thought that the 1st (meth) acrylic copolymer contains the 2nd structural unit derived from the monomer which has a hydroxyl group, and can reduce the surface resistance value of an adhesive composition more effectively.

The specific polysiloxane compound preferably contains a structural unit derived from a dialkyl siloxane and an alkyl group derived from an alkyl (hydroxy polyalkylene oxide alkane) from the viewpoints of antistatic properties and low pollution to an adherend. Polysiloxane compounds in the structural unit of siloxane) are preferred.

The alkyl group in the dialkylsiloxane is preferably 1 to 4 carbon atoms, and more preferably 1.

The alkylene (hydroxy polyalkyleneoxyalkyl) siloxane has preferably 2 to 4 carbon atoms, and more preferably 2 to 3 carbon atoms. The number of alkoxy groups in the alkyl (hydroxy polyalkyleneoxyalkyl) siloxane is preferably 1 to 100, and more preferably 10 to 100. The alkyl group in the alkyl group (hydroxy polyalkyleneoxyalkyl) siloxane is preferably 1 to 4 carbon atoms.

When a specific polysiloxane compound includes a structural unit derived from a dialkylsiloxane and a structural unit derived from an alkyl (hydroxy polyalkyleneoxyalkyl) siloxane, the Knot The number of constituent units is preferably 100 or less, and more preferably 1 to 80. The content of the structural unit derived from an alkyl (hydroxy polyalkyleneoxyalkyl) siloxane is preferably from 2 to 100, more preferably from 2 to 80.

The specific polysiloxane compound is preferably a polysiloxane compound represented by the following general formula (3) from the viewpoints of adhesiveness, antistatic properties, and low contamination to an adherend.

In the general formula (3), p is a repeating number of a dimethylsiloxane structural unit, and represents a value from 0 to 100. q is a repeating number of a methyl propylene siloxane structure unit having a polyethylenyloxy group, and represents a value of 2 to 100. A is the repeating number of the ethylenoxy structural unit, and each represents a value of 1 to 100. Here, in the case where the compound represented by the general formula (3) is an aggregate of a large number of compounds, p, q, and a are average values of the aggregate of the compounds, and are rational numbers.

The repeating number a of the polyethylenoxy structural unit is a value of 1 to 100, and preferably a value of 10 to 100. If a is 1 or more, there is a tendency that sufficient conductivity can be obtained and antistatic effect can be improved. When a is 100 or less, the mutual solubility with other components constituting the adhesive composition is improved, and the transparency of the adhesive layer tends to be further improved.

The repetition number p of the dimethylsilane structural unit is a value of 0 to 100, and preferably a value of 1 to 80. When p is 0 or more, the antistatic effect tends to be improved. When p is 100 or less, the compatibility with other components constituting the adhesive composition is improved, and the transparency of the adhesive layer tends to be improved.

Furthermore, the repeating number q of the propylene siloxane structure unit is a value from 2 to 100, and preferably a value from 2 to 80. If q is 2 or more, there is a tendency to obtain sufficient conductivity and improve antistatic effect. to. When q is 100 or less, the mutual solubility with other components constituting the adhesive composition is improved, and the transparency of the adhesive layer tends to be improved.

The weight average molecular weight of the specific polysiloxane compound is not particularly limited. For example, the weight average molecular weight of the specific polysiloxane compound may be 5,000 or more and 20,000 or less, and preferably 6,000 or more and 15,000 or less.

In addition, the HLB value of a specific polysiloxane compound is not particularly limited, but from the viewpoint of mutual solubility with the resin, uneven surface distribution, and adhesiveness, it is preferably 5 or more and less than 16, and more preferably 7 Above 15 and below.

The HLB value is a scale indicating the balance between the hydrophilicity and hydrophobicity of a specific polysiloxane compound (surfactant). In the present invention, according to the definition of the Griffin method calculated by the following formula 1, when a specific polysiloxane compound is a commercially available product, its catalogue data is preferably used.

Formula 1 {(Sum of formula amount of hydrophilic group part) / (Molecular weight of surfactant)} × 20

The aforementioned specific polysiloxane compound has a dimethylsiloxane structure unit in the molecule and a methylphenylpropylsiloxane structure unit having a polyethoxy group. These structural units may constitute a block copolymer or a random copolymer.

Specific examples of the specific polysiloxane compound represented by the aforementioned general formula (3) include, for example, "SF-8428", "FZ-2162", and "SH-3773M" [The above is Toray-Dow Corning Silicone ( Share) company system] and so on.

The specific polysiloxane compound may be selected from the aforementioned commercially available products, or an organic compound having an unsaturated bond and a polyethyloxy group may be grafted to a compound having a hydrogenated silane by a hydrosilylation reaction. Dimethyl polysiloxane is obtained from the main chain.

The content of the specific polysiloxane compound in the adhesive composition is preferably 0.05 parts by mass or more and 0.5 parts by mass or less, and more preferably 0.05 parts by mass relative to 100 parts by mass of the first (meth) acrylic copolymer. At least 0.4 parts by mass and more preferably at least 0.05 parts by mass and not more than 0.3 parts by mass.

By setting the content of the specific polysiloxane compound to be equal to or more than the aforementioned lower limit value, the antistatic effect when the surface protective film is peeled off can be obtained more effectively. In addition, by setting the content of the specific polysiloxane compound to be equal to or less than the aforementioned upper limit value, it is possible to suppress the occurrence of contamination (stain) on the adherend, and to suppress white turbidity caused by the decrease in the mutual solubility with the acrylic copolymer .

In addition to the polysiloxane compound represented by the aforementioned general formula (3), the adhesive composition may contain a structure different from that of the general formula (3) and include the same as long as the effect of the present invention is not impaired. Polyethyloxy dimethyl polysiloxane compound.

As a dimethylpolysiloxane compound having a structure different from that of the general formula (3) and containing a polyethylenyloxy group, for example, the polyethylenyloxy terminal is an alkoxy group, a fluorenyloxy group, or the like Compounds that include polyethoxy groups in the main chain or terminal instead of polyethoxy groups in the side chain.

Specific examples include: "BY-16-201", "FZ-77", "FZ-2104", "FZ-2110", "FZ-2203", "FZ-2207", "FZ-2208" , "L-7001", "L-7002", "SF-8427", "SH-3749", "SH-8400" [The above are manufactured by Toray Dow Corning Silicone Co., Ltd.], etc.

In the case where the adhesive composition contains a dimethylpolysiloxane compound having a structure different from the general formula (3) and containing a polyethylenoxy group, the content rate is preferably in a polysiloxane group. The total mass of the alkane compound is 0.05% by mass or less, and more preferably 0.03% by mass or less.

[Alkali metal salt]

The adhesive composition contains at least one alkali metal salt. The alkali gold salt is not particularly limited as long as it is a metal salt using lithium ion (Li ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ), rubidium (Rb ⁺ ) as a cation.

Specifically, the alkali metal salt is preferable to use a Li ^+, Na ^+, K ⁺ cations and ^{Cl -, Br -, I -} , BF 4 -, PF 6 -, SCN -, ClO 4 -, CF 3 SO _{^{3 -, (CF 3 SO 2}} ) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C - anions of the metal salts.

Among them, alkali metal salts are particularly preferred. From the viewpoint of antistatic, LiBr, LiI, LiBF ₄ , LiPF ₆ , LiSCN, LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li ( C ₂ F ₅ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C and other lithium salts.

In particular, the alkali metal salt is preferably LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li ( CF ₃ SO ₂ ) ₃ C and other lithium salts containing fluorine methylsulfonyl are more preferably selected from the group consisting of LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N and Li (C ₂ F ₅ SO ₂ ) At least one member of the group consisting of ₂ N.

These alkali metal salts may be used alone or in combination of two or more.

The content of the alkali metal salt in the adhesive composition is preferably 0.005 parts by mass or more and 0.6 parts by mass or less, more preferably 0.005 parts by mass or more and 0.3 parts by mass or less based on 100 parts by mass of the first (meth) acrylic copolymer. And more preferably 0.01 mass part or more and 0.2 mass part or less.

When the content of the alkali metal salt is 0.005 part by mass or more with respect to 100 parts by mass of the first (meth) acrylic copolymer, sufficient electrostatic characteristics can be obtained. On the other hand, when the content of the alkali metal salt is 0.6 parts by mass or less with respect to 100 parts by mass of the first (meth) acrylic copolymer, a sufficient antistatic effect relative to the content can be obtained.

The mass ratio of the specific polysiloxane compound to the alkali metal salt (specific polysiloxane compound / alkali metal salt) in the adhesive composition is preferably from the viewpoint of antistatic effect and adhesion. 0.1 or more and 5 or less, and more preferably 0.5 or more and 4 or less.

The total content of the specific polysiloxane compound and the alkali metal salt in the adhesive composition is preferably 0.10 part by mass or more and 1.00 part by mass, more preferably 100 parts by mass of the first (meth) acrylic copolymer. 0.10 parts by mass or more and 0.50 parts by mass or less.

[Polyisocyanate compound]

The pressure-sensitive adhesive composition preferably contains at least one polyisocyanate compound in addition to the aforementioned essential components. The polyisocyanate, the first (meth) acrylic copolymer and the specific polysiloxane compound, respectively, have a well-balanced promotion of adhesion by cross-linking reaction and low pollution to the adherend.

Examples of the polyisocyanate compound include aromatic polyisocyanate compounds such as xylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, and methylenephenyl diisocyanate; for example, hexamethylene diisocyanate Aliphatic or alicyclic polyisocyanate compounds such as isocyanate, isophorone diisocyanate, and the hydride of the aromatic polyisocyanate compound; dimers or trimers of their polyisocyanate compounds; these polyisocyanate compounds, and Additions of trimethylolpropane and the like to polyol compounds. Among these polyisocyanate compounds, at least one selected from the group consisting of dimers, trimers, and adducts of hexamethylene diisocyanate and hexamethylene diisocyanate is preferred, and Trimers of hexamethylene diisocyanate are preferred.

These polyisocyanate compounds can be used individually or in mixture of 2 or more types.

As the aforementioned polyisocyanate compound, for example, "CORONATE HX", "CORONATE HL-S", "CORONATE 2234", "AQUANATE 200", "AQUANATE 210" can be suitably used. [The above are manufactured by Japan Polyurethane Co., Ltd. ], "Desmodur N3300", "Desmodur N3400" [The above are manufactured by Sumitomo Bayer Polyurethane Co., Ltd.], "DURANATE E-405-80T", "DURANATE 24A-100", "DURANATE TSE-100" [The above are Asahi Kasei Industries Co., Ltd.], "TAKENATE D-110N", "TAKENATE D-120N", "TAKENATE M-631N", "MT-OLESTER NP1200" [The above is made by Mitsui Takeda Pharmaceutical Co., Ltd.] Marketer.

The content of these polyisocyanate compounds is preferably from 0.1 to 10 parts by mass, and more preferably from 0.5 to 5 parts by mass based on 100 parts by mass of the first (meth) acrylic copolymer.

If necessary, a hardening catalyst such as dibutyltin dilaurate may be further added to the adhesive composition.

The adhesive composition, in addition to the above-mentioned 1st (meth) acrylic acid copolymer, specific polysiloxane compound, and alkali metal salt, may suitably contain a weather resistance stabilizer, a tackifier, and a plasticizer, if necessary. , Softeners, peeling aids, dyes, pigments, inorganic fillers, surfactants, etc.

<Optical member surface protective film>

The optical member surface protective film of the present invention includes a polyester substrate; and an adhesive layer formed from the adhesive composition provided on the polyester substrate.

Since the adhesive layer is derived from the adhesive composition, the adhesive layer can be constituted as an adhesive layer which is excellent in adhesion, suppresses generation of static electricity caused by peeling and charging, and has low pollution to adherends.

The base material used for the surface protection film of the optical member of the present invention is not particularly limited as long as it can form an adhesive layer on the base material.

Examples of the base material include a polyester resin, an acetate resin, a polyether fluorene resin, a polycarbonate resin, a polyamine resin, and Film made of polyimide resin, polyolefin resin, acrylic resin, etc. Among them, from the viewpoint of surface protection performance, the aforementioned substrate is preferably a polyester resin, and in view of practicality, it is particularly preferably a polyethylene terephthalate resin.

The thickness of the substrate can be exemplified as follows: generally, it can be set to 500 μm or less, preferably 5 μm to 300 μm, and more preferably about 10 μm to 200 μm.

An antistatic layer may be provided on one or both sides of the substrate for the purpose of antistatic during peeling. In addition, a corona discharge treatment or the like may be applied to the surface of one side of the base material on which the adhesive layer is provided in order to improve the adhesion with the adhesive layer.

An adhesive layer is provided on the base material from the adhesive composition.

As a method of forming the adhesive layer, for example, the following method can be adopted: the adhesive composition containing a polyisocyanate compound is diluted directly or optionally with an appropriate solvent, and then coated directly on the surface protective base film (substrate) ), The solvent is removed by drying.

In addition, the following method can also be adopted: first, apply a pressure-sensitive adhesive containing a polyisocyanate compound to a release sheet composed of an appropriate film such as a silicone resin or the like that has been subjected to a mold release treatment or a polyester film; The composition is heated and dried to form an adhesive layer, and then the adhesive layer side of the release sheet is pressure-bonded to a surface protective base film (base material), and the adhesive layer is transferred to the protective film.

The aforementioned adhesive layer in the present invention is preferably an adhesive layer obtained by crosslinking the first (meth) acrylic acid copolymer and the specific polysiloxane compound with the polyisocyanate compound contained in the aforementioned adhesive composition. Better. Thereby, the adhesiveness of the adhesive layer and the low pollution to the adherend are further improved.

The conditions for cross-linking the first (meth) acrylic acid copolymer and the specific polysiloxane compound with a polyisocyanate compound are not particularly limited.

The above-mentioned adhesive layer has, for example, sufficient adhesion to a large-sized optical member used for a liquid crystal display screen of 20 inches or more (adhesion at low speed peeling is sufficiently large) and can be easily peeled off at high speed (adhesion at high speed peeling) The force will not increase) and the compliance is good (the cutting end will not roll up in the case of cutting).

That is, the adhesive force of the aforementioned adhesive composition to the 180-degree peeling of the optical member at 23 ° C. is preferably such that the peeling force (peeling force) at a peeling speed of 0.3 m / min (low-speed peeling) is 0.05 N / 25 mm or more. More preferably, it is 0.06N / 25mm or more.

The adhesive force of the aforementioned adhesive composition at the time of low-speed peeling of the optical member is set to 0.05 N / 25 mm or more, thereby suppressing the occurrence of curl or offset.

In addition, if the adhesive force of the adhesive composition to the optical member is increased, workability during high-speed peeling in a large area is reduced. Therefore, the adhesive force at a peeling speed of 30 m / min (high-speed peeling) is preferred. The (peeling force) is less than 1.5 N / 25 mm, and more preferably 1.2 N / 25 mm.

Furthermore, if the static electricity at the time of peeling of the surface protection film is large, the optical member may be damaged. Therefore, the peeling static voltage of the adhesive composition of the present invention when peeling off the anti-glare polarizing plate at 30 m / min. The absolute value of is preferably 0.9 kV or less, more preferably 0.4 kV or less, and still more preferably 0.35 kV or less.

From the viewpoint of preventing static electricity on the film side when the surface protective film is peeled off, the surface resistance value of the adhesive layer is preferably less than 1.0E + 12 (Ω / □) (1.0 × 10 ¹² Ω / □).

The thickness of the adhesive layer formed on the substrate can be appropriately set in accordance with the adhesion force expected from the surface protective film, and the surface roughness of the optical member. The thickness of the adhesive layer formed on the substrate can be exemplified: generally 1 μm to 100 μm, more preferably 5 μm to 50 μm, and even more preferably 15 μm to 30 μm.

The surface protective film for an optical member obtained as described above is laminated on the surface of the optical member to protect the surface of the optical member from being contaminated or damaged. When the optical member is processed or a liquid crystal display panel, the protective film is The state of being laminated on the optical member is supplied to each step of stamping, inspection, transportation, and assembly of the liquid crystal display panel, and heat and pressure treatments such as autoclave treatment and high-temperature ripening treatment are applied as necessary, and When a surface protection is required, it peels and removes from an optical member.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to those examples. In addition, unless otherwise stated, "part" and "%" are quality standards.

(Manufacturing example 1)

-Manufacture of 1st (meth) acrylic copolymer

In a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a reflux cooler, put 20 parts of ethyl acetate and 10 parts of toluene; and in another container, put 50 parts of butyl acrylate (BA) as a monomer. 46 parts of 2-ethylhexyl acrylate (2EHA), 3 parts of 4-hydroxybutyl acrylate (4HBA) as a monomer having a hydroxyl group, and ARONIX M-5300 (M5300) as a monomer represented by the general formula (1a) (Manufactured by Toa Synthesis Co., Ltd.) 1 part, and mixed to make a monomer mixture. 25% of this monomer mixture was added to the reaction vessel, and after replacing the air in the reaction vessel with nitrogen, 0.02 parts of azobisisobutyronitrile (hereinafter referred to as AIBN) was added as a polymerization initiator, with stirring. The temperature of the mixture in the reaction vessel was raised to 70 ° C. in a nitrogen atmosphere to start the initial reaction. After the initial reaction was almost completed, 75% of the remaining monomer mixture and 20 parts of ethyl acetate, 10 parts of toluene, and 0.2 parts of AIBN were added successively, and allowed to react for about 2 hours, and then allowed to react for 2 hours. . Thereafter, 0.25 parts of AIBN was dissolved to A solution of 25 parts of toluene was added dropwise over 1 hour, and the reaction was further allowed to proceed for 1.5 hours. After the reaction was completed, the reaction mixture was diluted with 125 parts of toluene to obtain a 1% (meth) acrylic acid copolymer solution A-1 having a solid content of 35%.

The weight average molecular weight (Mw) of the obtained 1st (meth) acrylic acid copolymer was 530,000, and the degree of dispersion (Mw / Mn) was 8.2.

(Manufacturing example 2)

-Manufacture of 1st (meth) acrylic acid copolymer 2-

In Manufacturing Example 1, except that the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 45 parts, and the blending amount of M5300 was changed to 2 parts, the same procedure as in Manufacturing Example 1 was performed to make the first (Meth) acrylic copolymer solution A-2.

The weight average molecular weight (Mw) of the obtained 1st (meth) acrylic acid copolymer was 520,000, and the degree of dispersion (Mw / Mn) was 8.0.

(Manufacture example 3)

-Manufacture of 1st (meth) acrylic copolymer 3-

In Production Example 1, except that the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 43 parts, and the blending amount of M5300 was changed to 4 parts, the same procedure as in Production Example 1 was carried out to make the first (Meth) acrylic acid copolymer solution A-3.

The weight average molecular weight (Mw) of the obtained 1st (meth) acrylic acid copolymer was 480,000, and the degree of dispersion (Mw / Mn) was 7.7.

(Manufacturing example 4)

-Manufacture of 1st (meth) acrylic copolymer 4-

In Production Example 1, except that one part of LIGHT ACRYLATE HO-AMS (HOAMS, manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of M5300 as the monomer represented by the general formula (1a), it was implemented in the same manner as in Production Example 1. It becomes the 1st (meth) acrylic acid copolymer solution A-4.

The weight average molecular weight (Mw) of the obtained 1st (meth) acrylic acid copolymer was 500,000, and the degree of dispersion (Mw / Mn) was 8.4.

(Manufacturing example 5)

-Manufacture of 1st (meth) acrylic copolymer 5-

Production Example 1 was carried out in the same manner as in Production Example 1 except that the blending amount of butyl acrylate (BA) was changed to 96 parts and the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 0 parts. To prepare a first (meth) acrylic acid copolymer solution A-5.

The weight average molecular weight (Mw) of the obtained 1st (meth) acrylic acid copolymer was 540,000, and the degree of dispersion (Mw / Mn) was 6.9.

(Manufacturing example 6)

-Manufacture of 1st (meth) acrylic copolymer

Production Example 1 was carried out in the same manner as in Production Example 1 except that the blending amount of butyl acrylate (BA) was changed to 0 parts and the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 96 parts. To prepare the first (meth) acrylic acid copolymer solution A-6.

The weight average molecular weight (Mw) of the obtained 1st (meth) acrylic acid copolymer was 410,000, and the degree of dispersion (Mw / Mn) was 8.3.

(Manufacturing example 7)

-Manufacture of (meth) acrylic copolymer C1-

Production Example 1 was carried out in the same manner as in Production Example 1 except that the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 47 parts and M5300 was changed to unblended (0 parts). Methacrylic acid copolymer solution C-1.

The weight average molecular weight (Mw) of the obtained (meth) acrylic copolymer was 530,000, and the degree of dispersion (Mw / Mn) was 8.9.

(Manufacturing example 8)

-Manufacture of (meth) acrylic copolymer C2-

In Production Example 1, except that the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 46.5 parts, and 0.5 part of acrylic acid (AA) was used instead of M5300, it was implemented in the same manner as in Production Example 1 to obtain ( Methacrylic acid copolymer solution C-2.

The weight average molecular weight (Mw) of the obtained (meth) acrylic copolymer was 500,000, and the degree of dispersion (Mw / Mn) was 8.3.

(Manufacturing example 9)

-Manufacture of (meth) acrylic copolymer C3-

In Manufacturing Example 1, except that the blending amount of 2-ethylhexyl acrylate (2EHA) was changed to 46.5 parts, and 0.5 parts of methacrylic acid (MAA) was used instead of M5300, the same procedure as in Manufacturing Example 1 was carried out. It becomes (meth) acrylic copolymer solution C-3.

The weight average molecular weight (Mw) of the obtained (meth) acrylic copolymer was 490,000, and the degree of dispersion (Mw / Mn) was 8.3.

(Manufacturing example 10)

-Manufacture of 2nd (meth) acrylic copolymer

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, a cooler, and a dropping funnel, 90 parts of n-butyl methacrylate (n-BMA) was placed as a methoxy group containing a polyalkyleneoxy monomer. 10 parts of poly (ethylene glycol methacrylate) (average number of repeats of ethoxy groups is 23), 0.8 parts of AIBN as a polymerization initiator, and 400 parts of ethyl acetate, and introduce while slowly stirring The temperature of the liquid in the flask was maintained at 70 ° C. under nitrogen for 6 hours to perform a polymerization reaction to prepare a solution B-1 of the second (meth) acrylic copolymer having a solid content of 20%.

The weight average molecular weight of the 2nd (meth) acrylic acid copolymer obtained was 7,000.

<Example 1>

In a four-necked flask equipped with a stirring blade, a thermometer, a cooler, and a dropping funnel, each of the four (1) (meth) acrylic acid copolymer solution A-1 (resin A in the table) obtained as the solid component was placed in SH-3773M (Toray Dow Corning Co., Ltd. Limited), which is converted into 100 parts of the second (meth) acrylic acid copolymer solution B-1 (Resin B in the table) in terms of solid content, as a specific polysiloxane compound 0.1 part of side chain polyether modified silicone, polyether terminal is hydroxyl), LiCF ₃ SO ₃ (Morida Chemical Industry Co., Ltd., LiTFS) 0.05 part, and the liquid temperature in the flask was kept at 25 ° C The mixture was stirred for 4.0 hours to obtain a (meth) acrylic copolymer mixed solution.

To this was added 2.5 parts of Desmodur N3300 [HMDI trimer type, solid content 100% by weight; manufactured by Sumitomo Bayer Polyurethane Co., Ltd.] as a polyisocyanate compound, Stir well to obtain an adhesive composition for a surface protective film (hereinafter, also simply referred to as "adhesive composition").

This adhesive composition has a sufficient application period.

Using the obtained adhesive composition, a test surface protection film was produced according to the following production method of a test surface protection film, and various physical property tests were performed. The obtained results are shown in Table 1.

(1) Production of surface protective film for testing

On the release paper that has been surface-treated with a silicone-based release agent, the adhesive composition is applied so that the coating amount after the drying is 20 g / m ² , and it is carried out in a hot air circulation dryer at 100 ° C. for 60 seconds. After drying to form an adhesive layer, it is placed on a polyethylene terephthalate (PET) film [trade name; E5001; manufactured by Toyo Industries Co., Ltd.], and the adhesive layer is brought into contact and pressurized After the rolls were pressure-bonded and bonded, they were aged for 10 days in an environment of 23 ° C. and 50% RH to obtain a test surface protection film.

(2) Determination of adhesion

After cutting the test surface protection film prepared in (1) above to 25mm × 150mm, peel the release paper from this surface protection film, and use a desktop laminator to crimp it to the anti-glare treatment. A polarizing film [trade name; SQ-1852AP-AG6; manufactured by Sumitomo Chemical Industries, Ltd.] was used as a test sample.

This test sample was left for 24 hours (conditioning) in an environment of 23 ° C and 50% RH, and the peeling speed was 0.3 m / min (low-speed peeling), and the peeling speed was 30 m / min (high-speed peeling). ) Conditions. The 180 ° peeling force was measured when the surface protective film and the adhesive layer were peeled from the polarizing film in the direction of the long side (150 mm).

(3) Contact angle of water in the adhesive layer (pollution evaluation)

The test surface protection film prepared in the above (1) was left in an environment of 60 ° C. and 90% RH for 48 hours. After being left in an environment of 23 ° C. and 50% RH for another 1 hour, the release film was peeled from the surface protection film for testing to expose the adhesive layer. 2 μl of pure water was dropped on the adhesive layer, and the contact angle of the water was measured using a contact angle measuring device (contact angle meter CA-D, manufactured by Kyowa Interface Chemical Co., Ltd.) after 30 seconds, and the following was evaluated according to the following evaluation criteria. Contamination of things.

~ Evaluation criteria ~

AA: The contact angle is 90 ° or more.

A: The contact angle is 80 ° to 90 °.

B: The contact angle is 50 ° or more and less than 80 °.

C: The contact angle is less than 50 °.

(4) Measurement of surface resistance

The release paper was peeled off from the test surface protective film prepared in (1) above, and the surface resistance value of the surface of the exposed adhesive layer was measured using a surface resistance measuring device (Advantest (share): R12704 RESISTIVITY CHAMBER), and the resistance was evaluated according to the following evaluation criteria Static electricity.

~ Evaluation criteria ~

AA: The surface resistance value does not reach 1.0E + 11 (Ω / □).

A: The surface resistance value is 1.0E + 11 (Ω / □) or more and less than 5.0E + 11 (Ω / □).

B: The surface resistance value is 5.0E + 11 (Ω / □) or more and less than 1.0E + 12 (Ω / □).

C: The surface resistance value is 1.0E + 12 (Ω / □) or more.

(5) Measurement of peeling static voltage

After cutting the surface protection film for test prepared in (1) above to 25mm × 150mm, this surface protection film was crimped to the anti-glare-treated polarizing film using a desktop laminator [trade name; SQ-1852AP-AG6; Sumitomo Chemical Industry Co., Ltd.] as test samples. This sample was left under conditions of 23 ° C. and 50% RH for 24 hours (conditioning treatment), and then peeled at a peeling speed of 180 ° and a peeling speed of 30 m / minute (high-speed peeling conditions). The potential (kV) on the surface of the polarizing plate generated at this time was measured with a potentiometer [KSD-03031, manufactured by Kasuga Electric Co., Ltd.] fixed to a position 10 mm above the surface of the polarizing plate. The measurement was performed under the environment of 23 ° C and 50% RH.

<Example 2 to Example 13>

In Example 1, the components of the surface protective film adhesive composition were changed in the same manner as in Example 1 except that the components used to prepare the surface protective film adhesive composition were changed as shown in Tables 1 and 2, respectively. And perform various physical property tests in the same manner. The obtained results are shown in Tables 1 and 2.

<Comparative Example 1 to Comparative Example 4>

In Example 1, except that the components used to prepare the adhesive composition for surface protection film were changed as shown in Table 2, the production of the adhesive composition for surface protection film was performed in the same manner as in Example 1, and Various physical property tests were performed in the same manner. The obtained results are shown in Table 2.

The abbreviations in Tables 1 and 2 are as follows.

BA: Butyl acrylate; 2EHA: 2-Ethylhexyl acrylate; 4HBA: 4-Hydroxybutyl acrylate; M5300: manufactured by Toa Kosei Co., Ltd .; ARONIX M-5300; 2) Monoacrylate; HOAMS: manufactured by Kyoeisha Chemical Co., Ltd., Light ACRYLATE HOA-MS (N), 2-propenyloxyethyl succinate; AA: acrylic acid; MAA: methacrylic acid; n-BMA : N-butyl methacrylate; MePEGMA: methoxy polyethylene glycol methacrylate (average number of repeats of ethoxy group is 23); N3300: Desmodur N3300 [hexamethylene diisocyanate trimer Body, manufactured by Sumitomo Bayer Polyurethanes Co., Ltd.]; SH-3773M: Toray Dow Corning Co., Ltd., a side chain polyether modified silicone, a polysiloxane compound represented by the general formula (3); FZ-2162 : Toray Dow Corning Co., Ltd., side chain polyether modified silicone, polysiloxane compound represented by general formula (3); SH-8400: Toray Dow Corning Co., Ltd., side chain polyether modified silicon Ketones; AS agent: antistatic agent; LiTFSI: Li (CF ₃ SO ₂ ) ₂ N; LiTFS: LiCF ₃ SO ₃ .

【Table 1】

【Table 2】

As can be seen from Tables 1 and 2, the adhesive composition of the present invention is excellent in adhesion, suppresses generation of static electricity caused by peeling and electrification, and has low pollution to adherends.

[Evaluation of compliance]

The test surface protective film prepared using the adhesive composition prepared in Examples 1 to 13 was cut into a size of 200 mm × 150 mm, and then the release film was peeled off. The conditions were 23 ° C and 50% RH. The adhesive layer was laminated from the central part to the anti-glare-treated polarizing film, and the time to extend the wetting by natural gravity was measured. At this time, in all the samples, the time to complete wetting was not reached until the end. 60 seconds, showing excellent compliance.

[Industrial availability]

According to the present invention, it is possible to provide an adhesive composition having both a high level of antistatic properties and low contamination to an adherend, and an optical member surface protective film using the same.

The disclosure of Japanese Patent Application No. 2012-286049 is incorporated herein by reference in its entirety.

All documents, patent applications, and technical specifications in this specification are incorporated into this specification for reference to the same extent as if the respective documents, patent applications, and technical specifications were incorporated by reference, and were specifically and separately described.

Claims (5)

An adhesive composition comprising: a first (meth) acrylic acid copolymer, comprising a first constituent unit represented by the general formula (1) and a second constituent unit derived from a monomer having a hydroxyl group; and having a hydroxyl group at a polyether terminal Polyether-modified silicone; and an alkali metal salt; the content rate of the first (meth) acrylic acid copolymer is 80% by mass or more and 99% by mass or less of the total solid content of the adhesive composition; the The content of the polyether-modified silicone having a hydroxyl group at the polyether terminal is 0.05 mass part or more and 0.50 mass part or less based on 100 mass parts of the first (meth) acrylic copolymer; the content of the alkali metal salt is relatively 100 parts by mass of the first (meth) acrylic copolymer is 0.005 parts by mass or more and 0.6 parts by mass or less; (In the general formula (1), R ¹ represents a hydrogen atom or a methyl group; L represents a divalent linking group composed of at least one selected from the group consisting of an alkylene group, an alkylene group, a carbonyl group, and an oxygen atom. ). For example, the adhesive composition of the first patent application range, wherein L in the general formula (1) is selected from the group consisting of a divalent linking group represented by the following general formula (2a) and the following general formula (2b) At least one of the groups consisting of a divalent link base; (In the general formulae (2a) and (2b), R ²¹ to R ²⁴ each independently represent an alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms; n represents a value from 0 to 10, and m Represents a value from 1 to 10). For example, the adhesive composition of item 1 or 2 of the patent application scope, wherein the first (meth) acrylic acid The content rate of the first constituent unit in the enoic acid copolymer is 0.5% by mass to 5% by mass. For example, the adhesive composition of the first or second patent application scope further contains a second (meth) acrylic copolymer, which contains a structural unit having a polyalkylene oxide group, and This 1st (meth) acrylic acid copolymer has a low molecular weight. An optical component surface protection film includes a polyester substrate and an adhesive layer, which are disposed on the polyester substrate and are derived from an adhesive composition according to any one of claims 1 to 4 of the scope of patent application.