KR101309824B1 - Adhesive composition, optical member and surface protective film using the same - Google Patents

Abstract

It provides the pressure-sensitive adhesive composition to further relax the curing conditions of the pressure-sensitive adhesive to increase the productivity of the pressure-sensitive adhesive layer, and further improve the productivity and quality of the optical sheet (optical member) and the surface protective film. The said adhesive composition contains 0.05-5 mass parts of crosslinking agents containing 100 mass parts of (1) (meth) acrylic-type polymers, and (2) peroxide, and 0.1-5 mass parts of crosslinking adjuvant containing a benzotriazole compound.

Description

Adhesive composition and optical member and surface protection film using the same {ADHESIVE COMPOSITION, OPTICAL MEMBER AND SURFACE PROTECTIVE FILM USING THE SAME}

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

Recently, the use of flat panel displays (FPDs) such as liquid crystal displays (LCDs), plasma display panels (PDPs), organic EL devices, and the like is expanding. Along with this, development of a pressure-sensitive adhesive used for FPD has been made.

These adhesives can also be used for various purposes, and used as adhesive sites for so-called optical sheets (optical members), or as adhesive sites for surface protection films for the purpose of preventing scratches and dirt in distribution and manufacturing processes. On the other hand, the demand for FPD is only increasing, along with the demand for optical sheets (optical members) and surface protection films.

In order to respond to such an increasing demand, it is desired to further reduce the curing conditions (for example, curing temperature and curing time) of the pressure-sensitive adhesive used herein and to increase the productivity of the pressure-sensitive adhesive layer. And when considering the influence of the heat which affects the sheet | seat or film used as a base material, it can be said that it is preferable to manufacture an adhesion layer and to improve quality on the conditions which reduce hardening temperature and hardening time.

In this way, it is urgent to develop a technology that further alleviates the curing conditions of the pressure-sensitive adhesive that affects the productivity of the optical sheet (optical member) and the surface protective film.

By the way, the technique about the adhesive which can be used for the above uses is disclosed by patent document 1, for example.

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Unexamined Patent Publication No. 2008-063350

This patent document lacks the recognition that the said hardening conditions become a problem. Therefore, according to the technique disclosed in this patent document, when it is going to exhibit the same characteristic (for example, the gel fraction is equivalent and the adhesive force is equivalent) as an adhesive, hardening conditions must be strengthened further.

This invention is made | formed in view of the said situation, and makes it a subject to improve the productivity and quality of an optical sheet (optical member) and a surface protection film further by relieving hardening conditions of an adhesive more, raising productivity of an adhesion layer.

The present inventors earnestly researched in order to solve the said subject. As a result, the adhesive composition which has a crosslinking agent composition which has (1) 0.05-5 mass parts of crosslinking agents containing 100 mass parts of (meth) acrylic-type polymers, and (2) peroxide, and 0.1-5 mass parts of crosslinking adjuvant containing a benzotriazole compound. The above problem is solved by using.

A preferred aspect of the present invention is an adhesive composition wherein the benzotriazole compound is selected from compounds represented by the following formulas (I) to (V):

Provided that R ₁ represents an alkyl group having 1 to 4 carbon atoms or a halogen atom, and when p is 2 to 4, R ₁ may be the same or different;

p is 0-4;

R ₂ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms substituted with alkyl having 1 to 3 carbon atoms, and a carbon atom having 5 to 7 carbon atoms A substituent selected from the group consisting of 7 cycloalkyl-alkyl groups having 1 to 4 carbon atoms;

R ₃ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms substituted with alkyl having 1 to 3 carbon atoms, and a carbon atom having 5 to 7 carbon atoms 7 cycloalkyl-carbon atoms of 1 to 4 alkyl groups, phenyl groups, phenyl-carbon atoms of 1 to 4 alkyl groups, 1 to 3 carbon atoms of 1 to 4 alkyl substituted phenyl groups and 1 to 3 carbon atoms of 1 to 4 A substituent selected from the group consisting of alkyl groups having 1 to 4 carbon atoms substituted with alkyl of;

q is 1-3.

More preferred aspect of the present invention,

The benzotriazole compound is represented by the following formula:

It is an adhesive composition which is at least 1 sort (s) chosen from.

In a more preferred embodiment of the present invention, the peroxide may be di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneo Decanoate, t-hexyl peroxy pivalate, t-butyl peroxy pivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy- It is an adhesive composition which is at least 1 sort (s) chosen from the group which consists of 2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, and t-butyl peroxy butyrate.

More preferred aspect of the present invention,

The (meth) acrylic polymer,

(A) (meth) acrylic acid ester monomer,

(B) a carboxyl group-containing monomer, and

(C) hydroxy group-containing (meth) acrylic monomer

It is an adhesive composition containing at least 1 sort (s).

The curing conditions of the pressure-sensitive adhesive are alleviated more and the productivity of the pressure-sensitive adhesive layer is improved, which leads to the improvement of the productivity and quality of the optical sheet (optical member) or the surface protection film.

The present invention provides an adhesive composition having a crosslinking agent composition having (1) 0.05 to 5 parts by mass of a crosslinking agent containing 100 parts by mass of the (meth) acrylic polymer and (2) a peroxide and 0.1 to 5 parts by mass of a crosslinking aid containing a benzotriazole compound. to be. The present invention is characterized by a configuration in which a specific amount of the crosslinking agent composition is contained in a specific amount of the (meth) acrylic polymer. Because of this configuration, the curing conditions of the pressure-sensitive adhesive is more relaxed, and the productivity of the pressure-sensitive adhesive layer is improved, which leads to the improvement of the productivity and quality of the optical sheet (optical member) or the surface protective film.

Conventionally, the technique of crosslinking with a crosslinking agent containing a peroxide when curing an adhesive is known. In the course of earnest research to complete the present invention, the inventors found that such techniques contribute to shortening of the curing time, but need to be crosslinked and cured at higher temperatures. In other words, it has been found that a large energy is required for heating or that such a heat adversely affects the sheet or film used as the substrate.

In this invention, by using together the crosslinking agent containing a benzotriazole compound in the crosslinking agent containing a peroxide used at the time of crosslinking, heating temperature can be made low, shortening the heating time required for crosslinking. In other words, when comparing the case where the crosslinking agent containing a peroxide is mix | blended with the case where it does not mix with the crosslinking adjuvant containing a benzotriazole compound, the same characteristic (for example, a gel fraction is equivalent and adhesiveness is equivalent) as an adhesive agent, ie When trying to exhibit the same adhesive properties can be crosslinked at a shorter time in the same heating temperature, and at a lower heating temperature in the same time.

The technical idea that the benzotriazole compound in the present invention is used as a crosslinking aid is very innovative. First, the heating time required for crosslinking can be shortened. It is also possible to lower the heating temperature. For this reason, energy required for heating is reduced. This is environmentally friendly. And since the influence of the heat on the sheet | seat and film used as a base material is reduced, the quality of the optical member and surface protection film provided with the adhesion layer formed from an adhesive composition improve. In the case where the "crosslinking agent containing a peroxide" is not blended with the "crosslinking aid containing a benzotriazole compound", the heat resistance and the moist heat resistance may be inferior. However, when blended, the excellent heat resistance and excellent moisture heat resistance are maintained.

The mechanism of the above effects when the benzotriazole compound is used as the crosslinking aid is not clear, but is assumed as follows. That is, when using a peroxide as a crosslinking agent, since radicals generate | occur | produce in the vicinity of a main chain, it is considered that main chains should be close enough to couple | bond (crosslink), and time is required for such a behavior. In the present invention, since the benzotriazole compound is interposed therebetween (crosslinking point) and the benzotriazole compound functions as an adjuvant at the time of peroxide crosslinking, it may be considered that the crosslinking rate is increased. However, such a mechanism is only a guess and, of course, the technical scope of the present invention is not limited thereto.

In view of the above, the present invention also provides a crosslinking agent composition having a crosslinking agent containing a peroxide and a crosslinking aid containing a benzotriazole compound.

EMBODIMENT OF THE INVENTION Below, the adhesive composition of this invention is demonstrated in detail. In the present specification, "(meth) acrylate" is a generic term for acrylate and methacrylate. The compound containing (meth), such as (meth) acrylic acid, is similarly a general term of the compound with "meth" in a name, and the compound without "meth".

(1) (meth) acrylic polymer

The adhesive composition of this invention contains a (meth) acrylic-type polymer.

The (meth) acrylic polymer used in the present invention is not particularly limited but preferably includes the following components. That is, it is preferable that a (meth) acrylic-type polymer contains at least 1 sort (s) of (A) (meth) acrylic acid ester monomer, (B) carboxyl group-containing monomer, and (C) hydroxy group containing (meth) acrylic-type monomer. The (meth) acrylic polymer used in the present invention may be composed of only a single structural unit or may be composed of other structural units. Preferred is the latter case. In that case, each structural unit may be added in either random or block form.

(A) (meth) acrylic acid ester monomer

The (meth) acrylic acid ester monomer (hereinafter also referred to simply as "component (A)") that can be used in the (meth) acrylic polymer of the present invention is an ester of (meth) acrylic acid having no hydroxyl group in the molecule. Specific examples of the (meth) acrylic acid ester monomer are not limited to those described below, but include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n-. Butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, tert-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, tridecyl (meth) acrylate , Stearyl (meth) acrylate, isostearyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, dodecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, Cyclohexyl (meth) acrylic Late, 4-n-butylcyclohexyl (meth) acrylate, 2-ethylhexyl diglycol (meth) acrylate, butoxyethyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (Meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, 2- (2-butoxyethoxy) ethyl (meth) acrylate, 4-butylphenyl (meth) acrylate, Phenyl (meth) acrylate, 2,4,5-tetramethylphenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene oxide monoalkyl ether (meth) acrylate , Polyethylene oxide monoalkyl ether (meth) acrylate, polypropylene oxide monoalkyl ether (meth) acrylate, trifluoroethyl (meth) acrylate, pentadecafluorooxyethyl (meth) acrylate, 2- Chloroethyl (meth) acrylate, 2,3-dibromopropyl (meth) And the like methacrylate, tribromo-phenyl (meth) acrylate. These may be used independently or may be used in combination of 2 or more type.

Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable, and methyl (meth) acrylate and n-butyl (meth ) Acrylate and 2-ethylhexyl (meth) acrylate are more preferable. In particular, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable.

The amount of the (meth) acrylic acid ester monomer is preferably 99.9 to 89.2 parts by mass, more preferably 99.8 to 90.5 parts by mass, and even more preferably 99.7 to 99.3 parts by mass with respect to 100 parts by mass of the total amount of monomers. It is easy to control adhesive physical properties in this range.

(B) carboxyl group-containing monomer

The carboxyl group-containing monomer (hereinafter, also simply referred to as "component (B)") that can be used in the (meth) acrylic polymer of the present invention is an unsaturated monomer having at least one carboxyl group in the molecule. Specific examples of the carboxyl group-containing monomers include, but are not limited to, those described below, (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, crotonic acid, itaconic acid, itaconic anhydride, myristic acid, pal Mittic acid, oleic acid, etc. are mentioned. These may be used independently or may be used in combination of 2 or more type.

Among these, (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, crotonic acid, itaconic acid and itaconic anhydride are preferable, and (meth) acrylic acid is more preferable.

In this invention, it is preferable that the quantity of a carboxyl group-containing monomer is 0-9 mass parts with respect to 100 mass parts of monomer amounts, More preferably, it is 0.1-8 mass parts, More preferably, it is 0.1-6 mass parts. It is easy to balance heat resistance and adhesive force in this range. That is, since a carboxyl group has high polarity and the polymer of a carboxyl group-containing monomer becomes high Tg, heat resistance becomes favorable. However, when too much, the adhesive force may fall and the function as an adhesive may fall.

(C) hydroxy group-containing (meth) acrylic monomer

The hydroxy group-containing (meth) acrylic monomer (hereinafter, simply referred to as "component (C)") that can be used in the (meth) acrylic polymer of the present invention is an acrylic monomer having a hydroxy group in a molecule. Specific examples of the hydroxy group-containing (meth) acrylic monomers include, but are not limited to, those described below, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 1,6-hexanediol mono ( Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropanedi (meth) acrylate, trimethylolethanedi (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4-hydroxycyclohexyl (Meth) acrylate, N-2-hydroxyethyl (meth) acrylamide, cyclohexane dimethanol monoacrylate, etc. are mentioned, Furthermore, alkyl glycidyl ether, allyl glycidyl ether, glycidyl (meth Acrylate etc. Glycidyl group-containing compounds may be mentioned as the (meth) compounds and the like obtained by the addition reaction of acrylic acid. These may be used independently or may be used in combination of 2 or more type.

Among these, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, N-2-hydroxyethyl (meth) acrylamide, and cyclohexane dimethanol monoacrylate are preferable, and 2- Hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and N-2-hydroxyethyl (meth) acrylamide are more preferable. 2-hydroxyethyl (meth) acrylate is particularly preferable.

It is preferable that the usage-amount of a hydroxy group containing acrylic monomer is 0-9 mass parts with respect to 100 mass parts of monomer amounts, More preferably, it is 0.1-8 mass parts, More preferably, it is 0.2-5 mass parts. It is effective in increasing the wettability with the adherend in this range. Although the details are not clear, such wettability is considered to be due to the polarity of the hydroxyl group.

As will be described later, the pressure-sensitive adhesive composition of the present invention is preferably used as an adhesive portion of an optical member or a surface protective film. That is, in this invention, the surface protection film provided with the optical member provided with the adhesion layer formed from the adhesive composition of this invention, and the adhesion layer formed from the adhesive composition of this invention is also provided.

In consideration of using the pressure-sensitive adhesive composition of the present invention for an optical member, it is preferable that the structure of the (meth) acrylic polymer from the viewpoint of durability is essentially including (A) (meth) acrylic acid ester monomer and (B) carboxyl group-containing monomer. Do.

In consideration of using the pressure-sensitive adhesive composition of the present invention in the surface protective film, the structure of the (meth) acrylic polymer from the viewpoint of wettability with the adherend is (A) (meth) acrylic acid ester monomer and (C) hydroxy group-containing (meth) acrylic type It is preferred to include monomers essentially.

As needed, the other monomer copolymerizable with the said component (A)-(C) is used. Other monomers are not particularly limited, and specific examples thereof include acrylic monomers having an epoxy group such as glycidyl (meth) acrylate and methylglycidyl (meth) acrylate; Acrylic type which has amino groups, such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert- butylaminoethyl (meth) acrylate, and methacryloxyethyl trimethylammonium chloride (meth) acrylate Monomers; Acrylic monomer which has amide groups, such as (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, and N, N-methylenebis (meth) acrylamide; Acrylic monomer which has phosphoric acid groups, such as 2-methacryloyl oxyethyl diphenyl phosphate (meth) acrylate, a trimethacryloyloxy ethyl phosphate (meth) acrylate, and a triacryloyloxy ethyl phosphate (meth) acrylate ; Acrylic monomers having sulfonic acid groups such as sodium sulfopropyl (meth) acrylate, sodium 2-sulfoethyl (meth) acrylate and sodium 2-acrylamide-2-methylpropane sulfonate; Acrylic monomer which has urethane groups, such as urethane (meth) acrylate; acrylic vinyl monomers having a phenyl group such as p-tert-butylphenyl (meth) acrylate and o-biphenyl (meth) acrylate; 2-Acetacetoxyethyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethyl) silane, vinyltriacetylsilane, methacryloyloxypropyltrimethoxysilane Vinyl monomers having silane groups such as these; Styrene, chloro styrene, -methyl styrene, vinyltoluene, vinyl chloride, vinyl acetate, vinyl propionate, acrylonitrile, vinylpyridine, etc. are mentioned. Such other monomers may be used alone or in combination of two or more thereof.

Among these other monomers, (meth) acrylamide, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate and 2-acetoxy oxyethyl (meth) acrylate are preferable, and (meth) acrylamide And dimethylaminoethyl (meth) acrylate and 2-acetoxy methoxyethyl (meth) acrylate are more preferable.

It is preferable that it is 0.1-10 mass parts with respect to 100 mass parts of total amounts of components (A)-(C), as for the usage-amount when using another monomer, it is more preferable that it is 0.2-5 mass parts, and it is 0.3-2 mass parts Particularly preferred.

It is preferable that the usage-amount of the said component (A) is not 0 mass part. That is, it is preferable that the structural unit derived from a component (A) is necessarily contained in the (meth) acrylic-type polymer of this invention. Preferably, the total amount of component (A), component (B) and component (C) is 100 parts by mass.

The method for producing the (meth) acrylic polymer of the present invention is not particularly limited, and conventionally known methods such as solution polymerization, emulsion polymerization, suspension polymerization, reverse phase suspension polymerization, thin film polymerization and spray polymerization using a polymerization initiator are known. Method can be used. Examples of polymerization control methods include adiabatic polymerization, temperature controlled polymerization, and isothermal polymerization. In addition to the method of initiating polymerization by a polymerization initiator, a method of initiating polymerization by irradiation with radiation, electron beam, ultraviolet ray, or the like may be employed. Of these, a solution polymerization method using a polymerization initiator is preferable in that the molecular weight can be easily controlled and impurities can also be reduced. For example, ethyl acetate (ethyl acetate), toluene, methyl ethyl ketone, and the like are preferably used in an amount of 60 to 200 parts by mass based on 100 parts by mass of the monomer, and a polymerization initiator is preferably used based on 100 parts by mass of the total amount of monomers. It is obtained by adding 0.01-0.50 mass parts and making it react for 3 to 10 hours, for example by reaction temperature 60-110 degreeC in nitrogen atmosphere. You may add a polymerization initiator in 2 or more times.

Examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile (AIBN), 2,2'-azobis (2-methylbutyronitrile) and azobiscyanovaleric acid; tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethyl hexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, Organic peroxides such as peroxide; Inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. These may be used alone or in combination of two or more.

Preferably the weight average molecular weight (Mw) of the (meth) acrylic-type polymer obtained by copolymerizing each said component is 200,000-2 million, More preferably, it is 400,000-16 million. If the range of the weight average molecular weight (Mw) is within this range, it is effective for durability and reworkability. In the present invention, the weight average molecular weight is a value measured by the method of Table 1 by employing a polystyrene conversion value.

≪ Weight average molecular weight &

It measures by the following measuring method and measurement conditions.

Apparatus: Gel permeation chromatograph GPC (instrument No. GPC-16)
Detector: Differential refractive index detector RI (8020 type sensitivity 32 made by Tosoh Corporation)
Ultraviolet absorption detector UV (Waters company 2487, wavelength 215nm, sensitivity 0.2AUFS
Column: TSKgel GMHXL (2 pieces), G2500HXL (1 piece) manufactured by TOSOH CORPORATION
(S / N M0052, M0051, N0010, 7.8mm × 30cm)
Solvent: tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.)
Flow rate: 1.0mL / min
Column temperature: 23 ° C
Sample: [Concentration] about 0.2%
[Solubility] It was stirred slowly at room temperature.
[Solubility] Solubility (visually confirmed)
Filtration It filtered with a 0.45 micrometer filter.
Injection volume: 0.200 mL
Standard Sample: Monodisperse Polystyrene
Data processing: GPC data processing system

(2) crosslinking agent composition

The adhesive composition of this invention contains a crosslinking agent composition. The crosslinking agent composition used by this invention contains the crosslinking agent containing a peroxide, and the crosslinking adjuvant containing a benzotriazole compound.

As described above, the present invention is characterized in that a "crosslinking agent containing a benzotriazole compound" is used in combination with a "crosslinking agent containing a peroxide" used when crosslinking. Because of this configuration, the heating temperature can be reduced while shortening the heating time required for crosslinking. In other words, when comparing the case where the crosslinking agent containing a peroxide is mix | blended with the case where it does not mix with the crosslinking adjuvant containing a benzotriazole compound, the same characteristic (for example, a gel fraction is equivalent and adhesiveness is equivalent) as an adhesive agent, ie When trying to exhibit the same adhesive properties can be crosslinked at a shorter time in the same heating temperature, and at a lower heating temperature in the same time. That is, the heating time required for crosslinking can be shortened. It is also possible to lower the heating temperature. For this reason, energy required for heating is reduced. This is environmentally friendly. And since the influence of the heat on the sheet | seat and film used as a base material is reduced, the quality of the optical member and surface protection film provided with the adhesion layer formed from an adhesive composition improve.

(Crosslinking agent containing peroxide)

The peroxide used in the crosslinking agent of the present invention can be used as long as it generates radicals by heating to achieve crosslinking of the pressure-sensitive adhesive composition. However, in view of workability and stability, the half-life temperature is preferably 80 ° C to 160 ° C. More preferably, the peroxide which is 90 degreeC-140 degreeC is used. If the half-life temperature is too low for 1 minute, the reaction may occur at the time of preservation before application / drying, resulting in high viscosity, which may make coating impossible. If too high, the temperature during crosslinking reaction may be high, resulting in side reactions or peroxides remaining. As a result, crosslinking may proceed.

The half-life of the peroxide is an indicator of the rate of decomposition of the peroxide and refers to the time at which the peroxide decomposes in half. The decomposition temperature for obtaining the half-life at any time or the half-life time at any temperature is described in the manufacturer's catalog. For example, it is described in the ninth edition of the organic peroxide catalog (May 2003) issued by Nippon Oil Holding Co., Ltd.

Such peroxides include di (2-ethylhexyl) peroxydicarbonate (half life temperature 90.6 ° C for 1 minute), di (4-t-butylcyclohexyl) peroxydicarbonate (92.1 ° C), di-sec-butylperoxydicarbonate ( 92.4 ° C.), t-butylperoxy neodecanoate (103.5 ° C.), t-hexyl peroxy pivalate (109.1 ° C.), t-butyl peroxy pivalate (110.3 ° C.), dilauroyl peroxide (116.4 ° C), di-n-octanoyl peroxide (117.4 ° C), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (124.3 ° C), di (4-methylbenzoyl) peroxide (128.2 ° C.), dibenzoyl peroxide (130.0 ° C.), t-butyl peroxy butyrate (136.1 ° C.), and the like, and di (4-t-butylcyclohexyl) peroxydicarbo having excellent crosslinking reaction efficiency. Nate, dilauroyl peroxide, and dibenzoyl peroxide are used preferably. In particular, di (4-t-butylcyclohexyl) peroxydicarbonate is preferable in view of decomposition temperature.

Although a crosslinking agent may be comprised only by a peroxide and may contain another crosslinking agent, the former is preferable.

In the adhesive composition of this invention, 0.05-5 mass parts of crosslinking agents containing the peroxide which comprises a crosslinking agent composition with respect to 100 mass parts of (meth) acrylic-type polymers are contained. If it is less than 0.05 mass part, crosslinking will become inadequate and a gel fraction will become too low and cannot be used for an adhesive. In addition, since the adhesive is soft, when the adhesive sheet is cut, the glue sticks out too much and there is a problem that the processability is lowered. On the other hand, when it exceeds 5 mass parts, crosslinking will advance too much and a gel fraction will become too high and it cannot use for a use as an adhesive. There is also a problem in that low temperature stability deteriorates. That is, a crystal may precipitate in low temperature and may not be used for a surface protection film or an optical member.

In consideration of using the pressure-sensitive adhesive composition of the present invention for an optical member (particularly a polarizing plate), the crosslinking agent containing a peroxide constituting the crosslinking agent composition is preferably 0.3 parts by mass or more and 4.5 parts by mass or less, more preferably 1.0 parts by mass or more. And 4.0 mass parts or less, More preferably, it is more than 2.0 mass parts and 3.8 mass parts or less. If the compounding quantity of the crosslinking agent containing a peroxide is this range, there exists an effect of realizing the crosslinking degree which expresses favorable heat resistance.

Considering that the pressure-sensitive adhesive composition of the present invention is used for an optical member (particularly hard coat PET), the crosslinking agent containing a peroxide constituting the crosslinking agent composition is preferably 0.3 parts by mass or more and 4.5 parts by mass or less, more preferably 1.0 mass by mass. Or more and 4.0 parts by mass or less, more preferably 1.0 parts by mass or more and 3.8 parts by mass or less. If the compounding quantity of the crosslinking agent containing a peroxide is this range, there exists an effect of realizing the crosslinking degree which expresses favorable heat resistance.

When considering using the adhesive composition of this invention for a surface protection film, Preferably the crosslinking agent containing the peroxide which comprises a crosslinking agent composition is 0.3 mass part or more, 4.5 mass parts or less, More preferably, 1.0 mass part or more and 4.0 mass Or less, more preferably 1.5 parts by mass or more and 3.8 parts by mass or less. If the compounding quantity of the crosslinking agent containing a peroxide is such a range, there exists an effect of reducing adhesive force.

(Crosslinking aid containing a benzotriazole compound)

The benzotriazole compound used in the crosslinking aid of the present invention is not particularly limited as long as it is a compound having a benzotriazole group. Specifically, the following formulas (I) to (V):

The compound etc. which are represented by are mentioned. The compounds of formula (II) are present in isomers and the present invention includes all isomers. “Isomers” include any structural isomers and positional isomers, tautomers, cistran isomers and stereoisomers such as the isomeric and racemic mixtures.

In said Formula (I)-(V), R <_1> represents a C1-C4 alkyl group or halogen atom. Here, the alkyl group having 1 to 4 carbon atoms includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group and tert-butyl group. Halogen atoms include fluorine, chlorine, bromine and iodine atoms. Of these, R ₁ is preferably a methyl group, an ethyl group, a fluorine atom, or a chlorine atom, and more preferably a methyl group or a chlorine atom. Moreover, when two or more R <_1> exists (p is 2-4), these R <_1> may be same or different, respectively. Moreover, p is 0-4, Preferably it is 0-1, More preferably, it is 0. In the formulas (I) to (V), "p is 0" means that the substituent R ₁ does not exist, that is, the substituents R ₁ are all hydrogen atoms.

R ₂ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms substituted with alkyl having 1 to 3 carbon atoms, and a carbon atom having 5 to 7 carbon atoms The substituent selected from the group which consists of an alkyl group (cycloalkylalkylene group) of 1-4 carbon atoms of 7 is shown. The alkyl group having 1 to 12 carbon atoms is not particularly limited, but is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl or heptyl. And linear or branched alkyl groups such as octyl group, nonyl group, decyl group, undecyl group, dodecyl group and 2-ethylhexyl group. The cycloalkyl group having 5 to 7 carbon atoms is not particularly limited, and there are a cyclopentyl group, a cyclohexyl group and a cyclopentyl group, and preferably a cyclopentyl group and a cyclohexyl group. The cycloalkyl group having 5 to 7 carbon atoms substituted with alkyl having 1 to 3 carbon atoms is not particularly limited, but is preferably an alkyl group having 1 to 4 carbon atoms, for example, a methyl group, an ethyl group, or n-propyl. Group, isopropyl group, n-butyl group, isobutyl group, cyclopentyl group and cyclohexyl group substituted with tert-butyl group. Although it does not restrict | limit especially as an alkyl group (cycloalkylalkylene group) of C1-C4 cycloalkyl-C1-C4 carbon atoms, For example, a cyclopentylmethyl group, a cyclohexylmethyl group, a cyclopentyl-1, 1-ethyl group, cyclohexyl -1,1-ethyl group, cyclopentyl-1,2-ethyl group, or cyclohexyl-1,2-ethyl group. Of these, R ₂ is preferably a methyl group, an ethyl group, or a propyl group, and more preferably a methyl group.

R ₃ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms substituted with alkyl having 1 to 3 carbon atoms, and a carbon atom having 5 to 7 carbon atoms 7 cycloalkyl-alkyl group having 1 to 4 carbon atoms (cycloalkylalkylene group), phenyl group, phenyl group having 1 to 4 carbon atoms (phenylalkylene group), substituted with 1 to 3 carbon atoms 1 to 4 alkyl And a substituent selected from the group consisting of a phenyl group and an alkyl group having 1 to 4 carbon atoms substituted with alkyl having 1 to 3 carbon atoms. Wherein an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms substituted with alkyl having 1 to 3 carbon atoms, and a cycloalkyl group having 5 to 7 carbon atoms Since the alkyl group (cycloalkylalkylene group) having 1 to 4 carbon atoms is the same as the definition of the substituent R ₂ , the description is omitted here. In addition, a phenyl group, a phenyl-alkyl group having 1 to 4 carbon atoms (phenylalkylene group), a phenyl group substituted with alkyl having 1 to 3 carbon atoms 1 to 4 carbon atoms and a phenyl group substituted with alkyl having 1 to 3 carbon atoms 1 to 4 carbon atoms The alkyl group having 1 to 4 carbon atoms is not particularly limited, but examples thereof include a phenyl group, benzyl group, 1- or 2-phenylethyl group, 4-methyl or 4-ethylcumyl group, and 4-methylbenzyl group. Of these, R ₃ is preferably a hydrogen atom, a methyl group, an ethyl group, or a propyl group, and more preferably a hydrogen atom.

Or q is 1-3, Preferably it is 1-2, Especially it is preferable.

As a compound which has a benzotriazole group of said Formula (I)-(V), 1,2,3- benzotriazole, 1- (methoxymethyl) -1H-benzotriazole, 1- (formamidemethyl) -1H-benzotriazole, 1- (isocyanomethyl) -1H-benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, tolyltriazole, tolyltriazole Potassium salt, 3- (N-salicyloyl) amino-1,2,4-triazole, 2- (2′-hydroxy-5-methylphenyl) benzotriazole and the like. These may be used alone or in combination, but among these, 1,2,3-benzotriazole, 1- (methoxymethyl) -1H-benzotriazole, 1- ( Formamidemethyl) -1H-benzotriazole and 1- (isocyanomethyl) -1H-benzotriazole are preferred (see formula below).

1,2,3-benzotriazole

1- (methoxymethyl) -1H-benzotriazole

1- (formamidemethyl) -1H-benzotriazole

1- (isocyanomethyl) -1H-benzotriazole

The compound which has a benzotriazole group may be manufactured by synthesis | combination, or a commercial item may be used. As a commercial item, the thing manufactured by Tokyo Chemical Industry Co., Ltd., Seiko Chemical Co., Ltd. shown in the following table | surface can be used.

Although a crosslinking adjuvant may be comprised only by the benzotriazole compound and may contain another crosslinking adjuvant, it is preferable that it is an former.

In the adhesive composition of this invention, 0.1-5 mass parts of crosslinking adjuvant containing the benzotriazole compound which comprises a crosslinking agent composition with respect to 100 mass parts of (meth) acrylic-type polymers is contained. If it is less than 0.1 mass part, there exists a problem that a use effect is not seen. And when it exceeds 5 mass parts, there exists a problem that it precipitates in an adhesion layer.

In consideration of using the pressure-sensitive adhesive composition of the present invention for an optical member (particularly a polarizing plate), the crosslinking aid containing the benzotriazole compound constituting the crosslinking agent composition is preferably 0.3 to 4.0 parts by mass, more preferably 0.4 to 3.0 mass Part, More preferably, it is 0.5-2.5 mass parts. When the compounding quantity of the crosslinking adjuvant containing the benzotriazole compound which comprises a crosslinking agent composition exists in such a range, there exists an effect which acts as a favorable crosslinking adjuvant.

Considering the use of the pressure-sensitive adhesive composition of the present invention for an optical member (particularly hard coat PET), the crosslinking aid containing a benzotriazole compound constituting the crosslinking agent composition is preferably 0.3 to 3.0 parts by mass, more preferably 0.4 to 2.0 mass parts, More preferably, it is 0.3-1.5 mass parts. When the compounding quantity of the crosslinking adjuvant containing the benzotriazole compound which comprises a crosslinking agent composition exists in such a range, there exists an effect which acts as a favorable crosslinking adjuvant.

In consideration of using the pressure-sensitive adhesive composition of the present invention for a surface protective film, the crosslinking aid containing a benzotriazole compound constituting the crosslinking agent composition is preferably 0.3 to 4.0 parts by mass, more preferably 0.4 to 3.0 parts by mass, further Preferably it is 0.5-2.5 mass parts. When the compounding quantity of the crosslinking adjuvant containing the benzotriazole compound which comprises a crosslinking agent composition exists in such a range, there exists an effect which acts as a favorable crosslinking adjuvant.

As described above, the present invention also provides a crosslinking agent composition having a crosslinking agent containing a peroxide and a crosslinking aid containing a benzotriazole compound.

The compounding quantity of the crosslinking agent composition in the adhesive composition of this invention is 0.5-6.0 mass parts with respect to 100 mass parts of (meth) acrylic-type polymers, More preferably, it is 1.0-5.5 mass parts, More preferably, it is 2.0-4.5 mass parts. .

The composition ratio of "crosslinking agent comprising peroxide" and "crosslinking aid comprising benzotriazole compound" in this crosslinking agent composition is "crosslinking agent containing peroxide": "crosslinking aid containing benzotriazole compound" 3:40 to 15: 1, more preferably 1: 3 to 10: 1, and still more preferably 2: 5 to 38: 5.

Moreover, the adhesive composition of this invention may contain a silane coupling agent. By using a silane coupling agent, reactivity can be improved and the mechanical strength and adhesive force of a crosslinked material can be improved. Such silane coupling agents are not particularly limited. Specifically, for example, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane, n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxy Silane, vinyl tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrie Oxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acrylic Roxypropyltrimethoxysilane, N-β- (aminoethyl) -γ-ami Propylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane , γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxy Silane, bis- (3- [triethoxysilyl] propyl) tetrasulfide, (gamma) -isocyanate propyl triethoxysilane, etc. are mentioned.

Furthermore, the silane coupling agent which contains functional groups, such as an epoxy group (glycidoxy group), an amino group, a mercapto group, and a (meth) acryloyl group, and the silane coupling agent containing the functional group which has these functional groups and the reactivity, another coupling agent, poly The compound which has a hydrolyzable silyl group obtained by making isocyanate etc. react with each functional group at arbitrary ratio can also be used.

The silane coupling agent may be synthesized or a commercially available product may be used. Examples of the silane coupling agent include KBM-303, KBM-403, KBE-402, KBM-403, KBE-502, KBE-503, KBM-5103, KBM-573, KBM- KBE-846, and KBE-9007 (manufactured by Shin-Etsu Chemical Co., Ltd.).

Among these silane coupling agents, KBM-303, KBM-403, KBE-402, KBM-403, KBM-5103, KBM-573, KBM-802, KBM-803, KBE-846, KBE-9007 are preferred, and KBM- 403 is more preferable. In addition, the said silane coupling agent may be used independently, or may be used in combination of 2 or more type.

In the present invention, the amount of the silane coupling agent used is not particularly limited. Specifically, the blending amount of the silane coupling agent is preferably 0.01 to 2.0 parts by mass, more preferably 0.03 to 0.8 parts by mass, still more preferably 0.05 to 0.3 parts by mass relative to 100 parts by mass of the (meth) acrylic polymer. If it exists in this range, the outstanding heat resistance and adhesiveness can be exhibited.

As will be described below, for example, a polarizing plate, a hard coat PET, or the like is preferably used as the optical member. Since hard coat PET is hardly affected by heat here, it is preferable not to contain a silane coupling agent in the adhesive composition of this invention. In other words, it is preferable that a silane coupling agent does not exist in the adhesive composition of this invention.

Regarding the polarizing plate, since uniaxially stretched PVA (polyvinyl alcohol) generally contained in the polarizing plate is well influenced by heat, it is preferable to include a silane coupling agent in the pressure-sensitive adhesive composition of the present invention.

When considering using the adhesive composition of this invention for a surface protection film, a silane coupling agent is contained in the adhesive composition of this invention from a viewpoint of suppressing the viewpoint of a change of adhesive force over time, or a cost, and the peelability of a peeling film. It is preferable not to make it. In other words, it is preferable that a silane coupling agent does not exist in the adhesive composition of this invention.

Moreover, the adhesive composition of this invention may contain an adhesive improving agent. When such a component is contained, the adhesiveness to the substrate is increased, so that there is an effect of suppressing or preventing injuries or peeling from the substrate.

Although it does not restrict | limit especially as an adhesion promoter, Isocyanate compound is used preferably. Among these, isocyanate compounds include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate. Especially, an isocyanate compound and an epoxy compound are especially preferable from a viewpoint of obtaining a moderate cohesion force. These compounds may be used independently, or may mix and use 2 or more types.

More specifically, examples of the isocyanate compound include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, cycloaliphatic diisocyanates, cyclohexylene diisocyanate and alicyclic isocyanates such as isophorone diisocyanate. Aromatic diisocyanates such as, 4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylene diisocyanate, trimethylolpropane / tolylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct, and trimethylol Isocyanate adducts, such as the propane / hexamethylene diisocyanate, a trimethylol propane / hexamethylene diisocyanate trimer adduct, and the isocyanurate of hexamethylene diisocyanate, etc. are mentioned.

Also, for example, triallyl isocyanate, dimer acid diisocyanate, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane Diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylenedi isocyanate, xylylene diisocyanate (XDI), tetramethyl xylyl Aromatic diisocyanates such as rendiisocyanate (TMXDI), tolidine diisocyanate (TODI) and 1,5-naphthalene diisocyanate (NDI); Aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, and norbornadiisocyanate methyl (NBDI); Alicyclic diisocyanates such as trans cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI) and H12-MDI (hydrogenated MDI); Carbodiimide-modified diisocyanates of the above diisocyanates; Or you may use these isocyanurate modified diisocyanate etc. Moreover, the adduct of polyol compounds, such as the said isocyanate compound and trimethylol propane, the biuret body and the isocyanurate body of these isocyanate compounds can also be used suitably.

The said isocyanate type compound may synthesize | combine or may use a commercial item. As a commercial item of an isocyanate type hardening | curing agent, coronate L (trademark) (trimethylol propane / tolylene diisocyanate trimer adduct), coronate HL (trimethylol propane / hexamethylene diisocyanate trimer adduct), colo Nate HX (isocyanurate of hexamethylene diisocyanate), coronate 2030, coronate 2031 (above Japan Polyurethane Industry Co., Ltd.), Takenate (registered trademark) D-102, Takenate (registered trademark) D- 110N, Takenate (registered trademark) D-200, Takeate (registered trademark) D-202 (above Mitsui Chemical Polyurethane Co., Ltd.), Duranate (trademark) 24A-100, Duranate (trademark) TPA-100, Dura Nate® TKA-100, Duranate® P301-75E, Duranate® E402-90T, Duranate® E405-80T, Duranate® TSE-100, Duranate® D -101, Duranate (trademark) D-201 (above Asahiga) Say Chemicals Co., Ltd.) etc. are mentioned.

Among these isocyanate-based curing agents, Coronate L (registered trademark), Coronate HL, Takenate (registered trademark) D110N, and Duranate (registered trademark) 24A-100 are preferable, and coronate L and the target (registered trademark) D110N are more preferred. Preferred, and Coronate L® is particularly preferred.

In the adhesive composition of this invention, the usage-amount when using an adhesive improving agent becomes like this. Preferably it is 0.01-3.0 mass parts with respect to 100 mass parts of (meth) acrylic-type polymers, More preferably, it is 0.02-1.5 mass parts, More preferably, it is 0.03- 0.8 parts by mass. In the case of using the adhesion promoter, when the usage amount is within the above range, the drawing force to the substrate of the adhesive (bonding force between the substrate and the adhesive) There is an effect of improvement.

When the pressure-sensitive adhesive composition of the present invention is applied to hard coat PET, hard coat PET is not well influenced by heat, and therefore, it is preferable not to contain the adhesion promoter in the pressure-sensitive adhesive composition of the present invention. In other words, it is preferable that an adhesive improving agent does not exist in the adhesive composition of this invention.

In addition, the pressure-sensitive adhesive composition of the present invention is a curing accelerator, ionic liquid, lithium salt, inorganic filler, softener, antioxidant, antioxidant, stabilizer, tackifying resin, modified resin (polyol resin, phenol resin, acrylic resin, polyester resin, Polyolefin resins, epoxy resins, epoxidized polybutadiene resins, etc.), leveling agents, defoamers, plasticizers, dyes, pigments (colored pigments, sieving pigments, etc.), treatment agents, sunscreen agents, fluorescent brighteners, dispersants, thermal stabilizers, light stabilizers And additives such as ultraviolet absorbers, antistatic agents, lubricants and solvents.

Among these, as a hardening accelerator, dibutyltin dilaurate, JCS-50 (made by Johoku Chemical Co., Ltd.), formate TK-1 (made by Mitsui Chemical Co., Ltd.), etc. are mentioned, for example.

As the ionic liquid, for example, phosphonium ions, pyridinium ions, pyrrolidinium ions, imidazolium ions, guanidinium ions, ammonium ions, isuroronium ions, thiuronium ions, piperidinium ions, pyra Cation components such as zoleium ions and sulfonium ions, halogen ions, nitrate ions, sulfate ions, phosphate ions, perchlorate ions, thiocyanate ions, thiosulfate ions, sulfite ions, tetrafluoroborate ions and hexafluorophosphate The substance which has an anion component, such as an ion, a formate ion, an oxalic acid ion, an acetate ion, a trifluoroacetic acid ion, an alkylsulfonic acid ion, is mentioned.

As antioxidant, dibutylhydroxytoluene (BHT), Irganox (trademark) 1010, Irganox (trademark) 1035FF, Irganox (trademark) 565 (all are Chiba Specialty Chemicals, Inc. make). ), And the like.

Examples of the tackifier resin include rosins such as rosin acid, polymerized rosin acid and rosin acid ester, terpene resins, terpene phenol resins, aromatic hydrocarbon resins, aliphatic saturated hydrocarbon resins, and petroleum resins.

Although the usage-amount of an additive is not restrict | limited especially when using the said additive, For example, it is 0.1-20 mass parts with respect to 100 mass parts of (meth) acrylic-type polymers.

The pressure-sensitive adhesive composition of the present invention can be prepared by mixing each component described above in a batch, mixing each component in turn, or mixing any of a plurality of components, and then mixing the remaining components to stir to make a uniform mixture. Can be. More specifically, it can prepare by stirring with a stirrer etc. for 10 minutes-5 hours, until it becomes warm, it heats at a temperature of 30-40 degreeC, and becomes uniform as needed. In addition, when preparing the pressure-sensitive adhesive composition of the present invention, a crosslinking agent composition should be included, which means that the "crosslinking agent containing a peroxide" and the "crosslinking aid containing a benzotriazole compound" may be mixed together or each component may be mixed in turn. I add it. That is, the "crosslinking agent containing a peroxide" and the "crosslinking aid containing a benzotriazole compound" may be mixed together in the form of a crosslinking agent composition, and the crosslinking aid containing a "crosslinking agent containing a peroxide" and a "benzotriazole compound" may be used. "May be mixed in order to form a crosslinking agent composition. Preferably, the method of mixing in order from a viewpoint of processability is preferable.

The adhesive layer mentioned later is produced (manufacturing) by preparing (manufacturing) and heating an adhesive composition as mentioned above. Since the adhesive composition of this invention is manufactured as mentioned above, the hardening conditions of an adhesive are alleviated more, productivity of an adhesive layer improves, and also leads to the improvement of the productivity and quality of an optical sheet (optical member) or a surface protection film.

(Optical member)

The adhesive composition of this invention can be used for joining various base materials. As a base material which can be used here, glass, a plastic film, paper, a metal foil, etc. are mentioned. Typical inorganic glass is mentioned as glass. Plastics in the plastic film include, for example, polyvinyl chloride resin, polyvinylidene chloride, cellulose resin, acrylic resin, cycloolefin resin, amorphous polyolefin resin, polyethylene, polypropylene, polystyrene, ABS resin, polyamide, Polyester, polycarbonate, polyurethane, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and chlorinated polypropylene. The amorphous polyolefin resin usually has a polymerized unit of a cyclic polyolefin such as norbornene or a polycyclic norbornene monomer, and may be a copolymer of a cyclic olefin and a chain cyclic olefin. Commercially available amorphous polyolefin resins include trade names Aton of JSR Corporation, ZEONEX® of Japan Xeon Corporation, ZEONOR®, APO of Mitsui Chemicals Corporation, and Apel®. In order to form an amorphous polyolefin resin into a film, well-known methods, such as a solvent casting method and a melt extrusion method, are used suitably. Examples of the paper include imitation paper, fine paper, kraft paper, art coated paper, caster coated paper, white rolled paper, parchment paper, water resistant paper, glassine paper and corrugated paper. As metal foil, an aluminum foil etc. are mentioned, for example.

Therefore, this invention also provides the optical member provided with the adhesion layer formed from the adhesive composition of this invention.

As an optical member, a polarizing plate, a hard-coat PET, a retardation plate, the optical film for plasma displays, the film for touch panels, etc. are mentioned preferably, for example. Among these, the adhesive composition of this invention is excellent in the adhesiveness of a polarizing plate and glass. The present invention is, of course, not limited to the above embodiment, and can be used for bonding other members.

The pressure-sensitive adhesive composition of the present invention may be used by directly applying one or both surfaces of the optical member to form an adhesive layer, or may be used by previously forming an adhesive layer on the release film and transferring it to one or both surfaces of the optical member.

Coating of the pressure-sensitive adhesive composition of the present invention may be carried out according to a conventionally known method, for example, natural coater, knife belt coater, floating knife, knife over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, reverse roll, air blade And various coating methods using devices such as a curtain flow coater, a doctor blade, a wire bar, a die coater, a comma coater, a baker applicator, and a gravure coater. And although the coating thickness (thickness after drying) of the adhesive composition of this invention may be selected according to the base material to be used, and a use, 5-30 micrometers is preferable and 15-25 micrometers is more preferable.

The viscosity of the pressure-sensitive adhesive composition of the present invention in the optical member is not particularly limited. However, in consideration of ease of coating, film thickness control of the pressure-sensitive adhesive layer formed of the composition, and the like, the viscosity is preferably 1000 to 8000 mPa · s at 25 ° C., more preferably 3000 to 7500 mPa · s.

When using the adhesive composition of this invention for an optical member, after adhesion processing, it is preferable that the gel fraction of an adhesion layer is 60 to 95% at 23 degreeC and 50% RH, It is more preferable that it is 65 to 92%, 70 to 70 It is more preferable that it is 90%. If it is such a range, punching processing and slit processing can be performed quickly as an optical member provided with an adhesion layer. In order to set a gel fraction as mentioned above, conditions may be suitably selected, such as adjusting the monomer composition of component (A) and the addition amount of each streak to the said range.

As for the adhesive force of the adhesive layer (adhesive composition) in an optical member, about 2.0-15.0 (N / 25mm) is preferable, and about 3.0-12.0 (N / 25mm) is more preferable.

The adhesive layer obtained from the adhesive composition of this invention is formed using the adhesive composition of this invention. As mentioned above, according to the adhesive composition of this invention, heating temperature can be lowered, shortening the heating time required for bridge | crosslinking. In addition, it has moderate adhesive force and adhesion to substrates, and is excellent in corrosion resistance of metals, contamination of adherends, low temperature stability and transparency, and inhibits and prevents foaming under high temperature and high pressure conditions (at the time of autoclave treatment).

(Surface protection film)

The pressure-sensitive adhesive composition of the present invention can be used for bonding various substrates, but it can be suitably used for a surface protective film, particularly a surface protective film for an optical member. Therefore, this invention is a surface protection film provided with the protective film and the adhesion layer formed in at least one surface of the said protective film, The said adhesion layer provides the surface protection film containing the adhesive composition of this invention.

In the present invention, the protective film is not particularly limited, and a known protective film may be used in the same manner. For example, resin films such as polyethylene terephthalate, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyester, polyvinyl chloride, polycarbonate, polyamide, polystyrene, Particularly preferred is polyethylene terephthalate. For example, the protective film may have a thickness of about 15 to 50 mu m.

The formation of the pressure-sensitive adhesive layer in the protective film can be carried out by a method of directly applying the pressure-sensitive adhesive composition of the present invention to a protective film, a method of transferring the pressure-sensitive adhesive composition of the present invention once coated on another substrate (for example, a release liner) .

The method of applying the pressure-sensitive adhesive composition is not particularly limited, and a known method used for manufacturing the pressure-sensitive adhesive tape is used. Specifically, natural coater, knife belt coater, floating knife, roll coat, air knife coat, knife over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, reverse roll, air blade, curtain flow coater, doctor blade, Various coating methods using devices, such as a wire bar, a die coater, a comma coater, a baker applicator, and a gravure coater, are mentioned. Among them, a roll coat, gravure coat, reverse coat, roll brush, spray coat, air knife coat, die coat method is preferably used.

The viscosity of the pressure-sensitive adhesive composition of the present invention is not particularly limited. However, in view of ease of coating, ease of film thickness control of the pressure-sensitive adhesive layer formed from the composition, and the like, the viscosity at 25 ° C is preferably 1000 to 8000 mPa · s, more preferably 3000 to 7500 mPa · s.

The coating thickness (thickness of the pressure-sensitive adhesive layer) of the composition to be formed on the protective film is not particularly limited and may be appropriately selected depending on the intended use. The coating thickness (thickness of the adhesive layer; thickness after drying) of the composition formed on a protective film becomes like this. Preferably it is 3-200 micrometers, More preferably, it is about 10-100 micrometers.

The surface protective film of the present invention can be used for protecting an optical member joined to a flat display panel such as a liquid crystal display panel or a plasma display panel. The optical member includes, for example, a polarizing plate, a retardation plate, a brightness enhancement plate, or an anti-glare sheet. The optical member may be a laminate of two or more optical materials such as a laminate of a polarizing plate and a retardation plate, a laminate of a retardation plate, a laminate of a polarizing plate and a brightness enhancement plate, or an antiglare sheet.

The surface protective film of the present invention can be used not only when the optical member is distributed alone but also when the optical member is bonded to the flat display panel.

When using the adhesive composition of this invention for a surface protection film, it is preferable that the gel fraction of an adhesion layer is 70-100% at 23 degreeC and 50% RH after adhesion processing, It is more preferable that it is 80 to 99%, More preferably, it is 85 to 95%. If it is such a range, a punching process and a slit process can be promptly performed as a surface protection film provided with an adhesion layer. What is necessary is just to select conditions suitably, such as adjusting the addition amount of each component to the said range, in order to set a gel fraction as mentioned above.

In the surface protection film of this invention, about 0.02-1.0 (N / 25mm) is preferable and, as for the adhesive force of the adhesion layer (adhesive composition) formed in the protective film, about 0.05-0.8 (N / 25mm) is more preferable.

The adhesive layer obtained from the adhesive composition of this invention is formed using the adhesive composition of this invention. As mentioned above, according to the adhesive composition of this invention, heating temperature can be lowered, shortening the heating time required for bridge | crosslinking. In addition, it has moderate adhesive force and adhesion to substrates, and is excellent in corrosion resistance of metals, contamination of adherends, low temperature stability and transparency, and inhibits and prevents foaming under high temperature and high pressure conditions (at the time of autoclave treatment).

Example

The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following embodiments.

Solid content and viscosity of the polymer solution obtained by the synthesis example, and the weight average molecular weight of the polymer (A) were measured with the following method.

<Solid matter (dry residue)>

Accurately weigh about 1 g of the polymer solution onto a precisely metered glass dish. After drying at 105 ° C for 1 hour, the temperature is returned to room temperature and the total mass of the glass plate and remaining solid content is precisely measured. The solid content was calculated by the following formula (1), assuming that the total mass of the glass plate and the polymer solution before the mass of the glass plate was X and the mass of the polymer solution was Y, and the total mass of the glass plate and the remaining solid was Z.

(Equation 1)

Solid content (%) = {(Z-X) / (Y-X)} 100

<Viscosity>

The polymer solution put into the glass bottle was temperature-controlled at 25 degreeC, and it measured with the Brookfield viscometer.

1. Optical member

(Polarizer)

(Example 1)

99 parts by mass of n-butyl acrylate (manufactured by Nihon Shokubai Co., Ltd.), 1 part by mass of acrylic acid (manufactured by Nihon Shokubai Co., Ltd.), and 130 parts by mass of ethyl acetate were charged into a flask equipped with a refluxer and a stirrer. Subsequently, it heated up to 65 degreeC, carrying out nitrogen substitution, and 0.075 mass part of azobisisobutyronitrile (AIBN) was added, and it superposed | polymerized for 6 hours, maintaining 65 degreeC. After completion of the polymerization reaction, 270 parts by mass of ethyl acetate was added and diluted to obtain a polymer solution. Solid content (dry residue) of the obtained polymer solution was 17.0 mass%, and the viscosity was 5.0 Pa * s. To 588 parts by mass of the polymer solution (100 parts by mass in terms of solid content of the polymer)

1.0 parts by mass of peroyl TCP (di (4-t-butylcyclohexyl) peroxydicarbonate, manufactured by Nichi Oil Co., Ltd.), which is a crosslinking agent,

2.0 parts by mass of benzotriazole (benzotriazole R manufactured by Seiko Chemical Co., Ltd.), which is a crosslinking aid,

Coronate (registered trademark) L (trimethylolpropane / tolylene diisocyanate trimer adduct), an adhesion improving agent, 0.04 parts by mass (0.03 parts by mass of solid content, 75% of solid content), and

KBM-403 (3-Glycidoxypropylmethyldiethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.), a silane coupling agent, 0.01 parts by mass

Were added in the order described and mixed for 10 minutes at room temperature (25 degreeC), and the solution which the adhesive composition melt | dissolved was obtained.

This solution was applied onto a peeling PET film (MRF38, manufactured by Mitsubishi Resin Co., Ltd., MRF38, thickness: 38 μm) so as to have a thickness of 25 μm. By drying at 130 degreeC for 3 minutes, the adhesion layer was formed, it bonded to the polarizing plate, and the polarizing plate with an adhesion layer was produced.

(Examples 2 to 3)

Except having changed the composition of the adhesive composition in Example 1 as Table 2, the solution which the adhesive composition melt | dissolved was obtained similarly to Example 1. And like Example 1, by drying at 130 degreeC for 3 minutes, the adhesion layer was formed, it bonded to the polarizing plate, and the polarizing plate with an adhesion layer was produced.

(Comparative Examples 1 and 2)

In Example 1, the composition was changed as in Table 2 to obtain a solution in which the pressure-sensitive adhesive composition was dissolved. And,

In Comparative Example 1, an adhesive layer was formed by drying at 130 ° C. for 3 minutes, bonded to a polarizing plate, and a polarizing plate with an adhesive layer was produced.

In Comparative Example 2, the pressure-sensitive adhesive layer was formed by drying at 130 ° C. for 6 minutes, bonded to the polarizing plate, and a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Hard coat PET)

(Example 4)

95 mass parts of n-butyl acrylate (made by Nihon Shokubai Co., Ltd.), 5 mass parts of acrylic acid (made by Nihon Shokubai Co., Ltd.), and 130 mass parts of ethyl acetate were thrown into the flask provided with the reflux machine and the stirrer. Subsequently, it heated up to 65 degreeC, carrying out nitrogen substitution, and 0.075 mass part of azobisisobutyronitrile (AIBN) was added, and it superposed | polymerized for 6 hours, maintaining 65 degreeC. After completion of the polymerization reaction, 270 parts by mass of ethyl acetate was added and diluted to obtain a polymer solution. Solid content of the obtained polymer solution was 17.0 mass%, and the viscosity was 5.0 Pa * s.

To 588 parts by mass of the polymer solution (100 parts by mass in terms of solid content of the polymer),

2.5 parts by mass of peroyl TCP (di (4-t-butylcyclohexyl) peroxydicarbonate, manufactured by Nichi Oil Co., Ltd.), which is a crosslinking agent,

0.5 mass part of benzotriazole (model number benzotriazole R made by Seiko Chemical Co., Ltd.) which is a crosslinking adjuvant,

Were added in the order described and mixed for 10 minutes at room temperature (25 degreeC), and the solution which the adhesive composition melt | dissolved was obtained.

This solution was applied onto a peeling PET film (MRF38, manufactured by Mitsubishi Resin Co., Ltd., MRF38, thickness: 38 μm) so as to have a thickness of 25 μm. The adhesive layer was formed by drying at 130 degreeC for 3 minutes, and it bonded to hard-coat PET (thickness, 100 micrometers), and produced the hard-coat PET with an adhesive layer.

(Example 5)

The solution which the adhesive composition melt | dissolved was obtained like Example 4 except having changed the composition of the adhesive composition in Example 4 as Table 2. And like Example 4, by drying at 130 degreeC for 3 minutes, the adhesion layer was formed, it bonded to the hard coat PET, and the hard coat PET with an adhesion layer was produced.

(Comparative Examples 3 to 4)

In Example 4, the composition was changed as in Table 2 to obtain a solution in which the pressure-sensitive adhesive composition was dissolved. And,

In Comparative Example 3, an adhesive layer was formed by drying at 130 ° C. for 3 minutes, and then bonded to the hard coat PET to prepare a hard coat PET with an adhesive layer.

In Comparative Example 4, an adhesive layer was formed by drying at 130 ° C. for 6 minutes, and then bonded to the hard coat PET to prepare a hard coat PET with an adhesive layer.

About the polarizing plate with adhesion layers of Examples 1-3 and Comparative Examples 1-2 obtained as mentioned above, and the polarizing plate with adhesion layers of Examples 4-5 and Comparative Examples 3-4, each according to the following method The performance was evaluated.

<Heat resistance test>

Cut to 120 mm (polarizing plate MD direction) x 60 mm, it bonded to the glass plate (Glass plate), and autoclaved for 20 minutes on 50 degreeC and 0.49 Mpa (5 kg / cm <^2> ) conditions. Then, the external appearance after leaving to stand for 120 hours in 80 degreeC atmosphere was observed.

In Table 2 below, "good" indicates that foaming, floating and peeling were not observed, and "foaming" indicates that foaming, floating and peeling were observed.

<Humidity Resistance Test>

It cut | disconnected to 120 mm (polarizing plate MD direction) x 60 mm, bonded to the glass plate, and autoclaved for 20 minutes on 50 degreeC and 0.49 MPa (5 kg / cm <^2> ) conditions. Then, the external appearance after leaving to stand for 120 hours in 60 degreeC and 90% RH atmosphere was observed.

In Table 2 below, "good" indicates that foaming, floating and peeling were not observed, and "foaming" indicates that foaming, floating and peeling were observed.

<Adhesive force>

It was cut to a width of 25 mm, bonded to a glass plate, and autoclaved for 20 minutes under conditions of 50 ° C and 0.49 MPa (5 kg / cm ² ). Twenty minutes after bonding, using a tensile tester, the adhesive force was measured in accordance with the adhesive tape and adhesive sheet test method described in JIS Z0237 (2000) at a peel angle of 90 degrees and a peel rate of 0.3 m / min in an atmosphere of 20 ° C. and 50% RH. Measured. af represents interfacial failure and cf represents cohesive failure.

<Gel fraction>

The gel fraction was measured using the polarizing plate which has the adhesion layer produced by each Example and the comparative example, and the polyester film which carried out the peeling process instead of the hard coat PET with adhesion layer. The gel fraction weighed about 0.1 g of the pressure-sensitive adhesive composition which was left in an atmosphere of 23 ° C. and 50% RH, and measured the weight W ₁ (g). This was taken in a sample bottle, and about 30 g of ethyl acetate was added and left standing for 24 hours. After a predetermined time, the contents of the sample bottle were separated by filtration through a 200 mesh stainless steel wire mesh (weight of the film W ₂ (g)), and the total weight W ₃ (g) dried at 90 ° C. for 1 hour. Was measured. The gel fraction was calculated by the following formula 2 from these measured values. The gel fraction was similarly computed also about the following surface protection film.

(Equation 2)

Gel fraction (%) = {(W ₃ -W ₂ ) / W ₁ } × 100

Polarizer Hard Coat PET Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Example 4 Example 5 Comparative Example 3 Comparison 4 cases (Meth) acrylic polymer formulation BA 99 97 97 99 99 95 95 95 95 2EHA AA One 3 3 One One 5 5 5 5 2HEA Dry residue% 17.0 17.0 17.0 17.0 17.0 17.0 17.0 17.0 17.0 Viscosity Pas 5.0 6.5 6.5 5.0 5.0 7.0 7.0 7.0 7.0
Crosslinking agent composition formulation
TCP 1.0 2.5 3.5 1.0 1.0 2.5 2.5 2.5 2.5 Benzotriazole 2.0 1.0 0.5 0.5 1.0 Coronate l 0.03 0.03 0.03 0.03 0.03 KBM 403 0.1 0.1 0.1 0.1 0.1 Heating (dry) condition 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 6 minutes 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 6 minutes Gel fraction (%) 63 73 75 3 65 68 71 5 73 film Pol Pol Pol Pol Pol HCPET HCPET HCPET HCPET Chief
exam Heat resistance Good Good Good firing Good Good Good firing Good Moisture and Heat Resistance Good Good Good firing Good Good Good firing Good Adhesion (N / 25mm) 3.8af 4.5af 5.0af 13.0cf 3.8af 11.5af 10.8af 25.0cf 12.0af

"BA": n-butyl acrylate (made by Nippon Shokubai Co., Ltd.);

"2EHA": 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.);

"2HEA": 2-hydroxyethyl acrylate (manufactured by Nippon Shokubai Co., Ltd.);

"AA": acrylic acid (manufactured by Nippon Shokubai Co., Ltd.);

"Pol": polarizing plate;

`` HCPET '': 100㎛ thick hard coat PET

`` PET '': 25㎛ thick PET

2. Surface protective film

(Example 6)

98 parts by mass of 2-ethylhexyl acrylate (manufactured by Nihon Shokubai Co., Ltd.), 2 parts by mass of 2-hydroxyethyl acrylate (manufactured by Nihon Shokubai Co., Ltd.), and 150 parts by mass of ethyl acetate were added to the flask equipped with a reflux machine and a stirrer. did. Subsequently, it heated to 65 degreeC, carrying out nitrogen substitution, 0.1 mass part of azobisisobutyronitrile (AIBN) was added, superposed | polymerized for 2 hours, maintaining 65 degreeC, 0.2 mass part of azobisisobutyronitrile (AIBN) was added, and 70 degreeC It heated up at and superposed | polymerized for 4 hours. After the completion of the polymerization reaction, 80 parts by mass of ethyl acetate was added and diluted to obtain a polymer solution. Solid content of the obtained polymer solution was 30.0 mass%, and the viscosity was 4.0 Pa * s. To 333 parts by mass of the polymer solution (100 parts by mass in terms of solid content of the polymer),

1.0 parts by mass of peroyl TCP (di (4-t-butylcyclohexyl) peroxydicarbonate, manufactured by Nichi Oil Co., Ltd.), which is a crosslinking agent,

2.0 parts by mass of benzotriazole (benzotriazole R manufactured by Seiko Chemical Co., Ltd.), which is a crosslinking aid,

Coronate (registered trademark) L (trimethylolpropane / tolylene diisocyanate trimer adduct), an adhesion improving agent, was added 0.13 parts by mass (0.1 parts by mass in terms of solid content, 75% in solid content) in the order described. It mixed at room temperature (25 degreeC) for 10 minutes, and obtained the solution which the adhesive composition melt | dissolves.

The solution was dried on a peeled PET film (MRF38, manufactured by Mitsubishi Resin Co., Ltd., MRF38, thickness: 38 μm), and then applied to have a thickness of 25 μm, dried at 130 ° C. for 3 minutes to form an adhesive layer, and then the adhesive layer side was again PET film. (The Toray Corporation make, brand name Lumirror (trademark) S10 # 25, thickness: 25 micrometers) was produced, and the surface protection film with an adhesion layer was produced.

(Examples 7-8)

In Example 6, the composition was changed as in Table 3 to obtain a solution in which the pressure-sensitive adhesive composition was dissolved.

And the adhesive layer was formed by drying at 130 degreeC for 3 minutes similarly to Example 6, and it stuck to PET film, and produced the surface protection film with an adhesive layer.

(Comparative Examples 5-6)

In Example 6, the composition was changed as in Table 3 to obtain a solution in which the pressure-sensitive adhesive composition was dissolved.

In Comparative Example 5, an adhesive layer was formed by drying at 130 ° C. for 3 minutes, and bonded to a PET film to produce a surface protective film having an adhesive layer.

In Comparative Example 6, an adhesive layer was formed by drying at 130 ° C. for 6 minutes, and bonded to a PET film to prepare a surface protective film with an adhesive layer.

Each performance was evaluated according to the following method about the surface protective film with the adhesion layer of Examples 6-8 and Comparative Examples 5-6 obtained as mentioned above.

<Adhesive force>

Twenty minutes after cutting to 25 mm width, bonded to a glass plate, and 20 minutes after bonding using a tensile tester, the adhesive tape and adhesive according to JIS Z0237 (2000) at a peel angle of 90 degrees and a peel rate of 0.3 m / min in an atmosphere of 20 ° C. and 50% RH. Adhesion was measured according to the sheet test method. af represents interfacial failure and cf represents cohesive failure.

Surface protection film Example 6 Example 7 Example 8 Comparative Example 5 Comparative Example 6 (Meth) acrylic polymer formulation
BA 2EHA 98 98 98 98 98 AA 2HEA 2 2 2 2 2 Dry residue% 30.0 30.0 30.0 30.0 30.0 Viscosity Pas 4.0 4.0 4.0 4.0 4.0 Crosslinking agent composition formulation
TCP 1.0 2.5 3.5 3.0 4.0 Benzotriazole 2.0 1.0 0.5 Coronate l 0.1 0.1 0.1 0.1 0.1 Heating (dry) condition 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 3 minutes 130 ° C × 6 minutes Gel fraction (%) 88 90 93 20 90 film PET PET PET PET PET Adhesion (N / 25mm) 0.7af 0.6af 0.5af 3.0cf 0.7af

"BA": n-butyl acrylate (made by Nippon Shokubai Co., Ltd.);

"2EHA": 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.);

"2HEA": 2-hydroxyethyl acrylate (manufactured by Nippon Shokubai Co., Ltd.);

"AA": acrylic acid (manufactured by Nippon Shokubai Co., Ltd.);

"Pol": polarizing plate;

`` HCPET '': 100㎛ thick hard coat PET

`` PET '': 25㎛ thick PET

Claims (11)

(1) 100 mass parts of (meth) acrylic-type polymers;
(2) Crosslinking agent composition containing 0.05-5 mass parts of crosslinking agents containing a peroxide and 0.1-5 mass parts of crosslinking adjuvant containing a benzotriazole compound;
Pressure-sensitive adhesive composition comprising a.
The surface protection film provided with the adhesion layer formed from the adhesive composition of Claim 1.
The surface protective film of claim 2, wherein the adhesive force of the adhesive layer is 0.02 to 1 N / 25 mm.
The surface protective film of claim 2, wherein the pressure-sensitive adhesive composition is attached, and the gel fraction of the pressure-sensitive adhesive layer is 70-100% at 23 ° C. and 50% RH.
The surface protective film of claim 2, wherein the pressure-sensitive adhesive composition has a viscosity of 25 ° C. of 1000 to 8000 mPa · s.
The optical member provided with the adhesion layer formed from the adhesive composition of Claim 1.
The optical member according to claim 6, wherein a content of the crosslinking agent containing the peroxide is more than 2 parts by mass and 3.8 parts by mass or less.
The optical member according to claim 6 or 7, wherein the pressure-sensitive adhesive composition further comprises a silane coupling agent.
The optical member of claim 6, wherein the adhesive force of the adhesive layer is 2 to 15 N / 25 mm.
7. The optical member of claim 6, wherein the pressure-sensitive adhesive composition is attached, and then the gel fraction of the pressure-sensitive adhesive layer at 23 ° C. and 50% RH is 60 to 95%.
The optical member of claim 6, wherein the pressure-sensitive adhesive composition has a viscosity of 25 ° C. of 1000 to 8000 mPa · s.