JP5628081B2 - Pressure-sensitive adhesive sheets for application to metal surfaces and articles having metal surfaces - Google Patents

Description

  The present invention relates to pressure-sensitive adhesive sheets for application to metal surfaces and articles having metal surfaces, and more specifically, does not corrode metal surfaces even when applied directly to metal surfaces, and has excellent adhesive properties. In addition, the present invention relates to a pressure-sensitive adhesive sheet for attaching a metal surface that can be attached to a metal surface with optical characteristics, and an article having a metal surface on which the pressure-sensitive adhesive sheet for attaching a metal surface is used.

  In recent years, optical products such as electronic displays and optical recording discs (optical recording media) such as digital universal discs have become widespread, and there are parts using pressure-sensitive adhesive sheets in the configuration. Many have come to be used. For example, in a plasma display or the like, an electromagnetic wave shielding layer is attached to a front plate, and at this time, an adhesive sheet is directly attached to the electromagnetic wave shielding layer. In addition, in the case of a digital universal disc, the disc (substrate) portion containing data can be read by an optical reader, and this disc has a metal-coated surface, and when these discs are joined, An adhesive may be used (see Patent Document 1).

JP 2003-501296 A

  However, when applying a pressure-sensitive adhesive to such a metal-coated surface, if a conventional pressure-sensitive adhesive is used, corrosion of the metal surface due to acid may occur over time. As described above, when the metal surface is corroded, the original functions such as blocking of electromagnetic waves and optical recording are adversely affected. For example, Japanese Patent Application Laid-Open No. 2003-501296 proposes a pressure-sensitive adhesive that does not substantially corrode a metal layer, but does not describe any conditions for that purpose.

  Japanese Patent Application Laid-Open No. 2002-332468 discloses a pressure-sensitive adhesive composition comprising a copolymer in which a nitrogen-containing monomer is used as a monomer component. However, the pressure-sensitive adhesive composition contains a plasticizer-containing coating. It is a plasticizer-resistant pressure-sensitive adhesive composition that exhibits good adhesive properties to adherends, and no description is given of adhesive properties to adherends having a metal surface.

Therefore, the object of the present invention is to provide pressure sensitivity for metal surface application that does not corrode the metal surface even if applied directly to the metal surface, and can be applied to the metal surface with excellent adhesive properties and optical properties. An object of the present invention is to provide an article having a metal surface in which the pressure-sensitive adhesive sheet and the pressure-sensitive pressure-sensitive adhesive sheet for sticking a metal surface are used.
Another object of the present invention is to provide a pressure-sensitive adhesive sheet for sticking to a metal surface, which is transparent and has good adhesive properties, even when directly attached to a metal surface, and does not change color or change in quality over time, and the metal surface. The object is to provide an article having a metal surface on which pressure-sensitive adhesive sheets for sticking are used.
Still another object of the present invention is to provide pressure-sensitive adhesive sheets for application to metal surfaces that can retain excellent adhesive properties and optical properties even under heating and humidification conditions, and pressure-sensitivity for application to metal surfaces. An object of the present invention is to provide an article having a metal surface on which an adhesive sheet is used.

  As a result of intensive studies to achieve the above-described object, the present inventors have found that when the pressure-sensitive adhesive contains an acid component such as a carboxyl group-containing compound, the metal surface is corroded, and there is simply an acid. It has been found that when a pressure-sensitive adhesive composition having no components is used, peeling may occur due to a decrease in adhesive strength under circumstances where heat or humidity is applied, and adhesion itself may be impossible. Therefore, as a result of further research, the present inventors formed a pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheets with an acrylic pressure-sensitive adhesive having an acrylic polymer based on a specific composition as a base polymer. It has been found that the pressure-sensitive adhesive sheets have good adhesive properties and optical properties, and do not cause corrosion of the metal surface over a long period of time even when directly attached to the metal surface. The present invention has been completed based on these findings.

That is, the present invention is an optical product having a metal thin film layer or pressure-sensitive adhesive sheets for directly sticking to the surface of a metal thin film layer of a member for constituting the optical product, and the total amount of monomer components Containing (meth) acrylic acid ester of 50% by weight or more, nitrogen atom-containing copolymerizable monomer of 10% by weight or more and less than 50% by weight, and containing a carboxyl group-containing copolymerizable monomer It has a metal thin film layer characterized by having a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive having a base polymer of an acrylic polymer composed of an uncopolymerizable monomer component Provided are optical pressure-sensitive adhesive sheets for optical sticking to the surface of a metal thin film layer of an optical product or a member for constituting the optical product.

  It is preferable that the copolymerizable monomer component constituting the acrylic polymer does not further contain an acidic group-containing copolymerizable monomer other than the carboxyl group-containing copolymerizable monomer. The optical product may be an electronic display.

Furthermore, the pressure-sensitive adhesive layer formed with the acrylic pressure-sensitive adhesive is completely irradiated before and after each of the heat treatment at 80 ° C. for 500 hours and the humidification treatment at 60 ° C. and 95% RH for 500 hours. The transmittance is 90% or more before and after each treatment of the heat treatment and humidification treatment, and the haze is 10% or less both before and after each treatment of the heat treatment and humidification treatment. The color difference (ΔE ^* ab) before and after each of the heat treatment and the humidification treatment is preferably 0.5 or less.

Examples of the nitrogen atom-containing copolymerizable monomer include amide group-containing monomers, nitrogen-based heterocycle-containing monomers, cyano group-containing monomers, imide group-containing monomers, and amino group-containing monomers. At least one selected nitrogen atom-containing copolymerizable monomer can be suitably used .

It is preferable that the optical pressure-sensitive adhesive sheet for sticking the surface of the metal thin film layer as an optical product having the metal thin film layer or a member for constituting the optical product is a pressure-sensitive adhesive tape or sheet. Further, the metal material for forming the metal thin film layer may be a metal material containing a non-metal element together with a metal element. Furthermore, the optical pressure-sensitive adhesive sheet for optically sticking the optical product having the metal thin film layer or the metal thin film layer surface of the member for constituting the optical product is the pressure-sensitive adhesive sheet only. The substrate-less double-sided pressure-sensitive adhesive sheet having a configuration formed from Furthermore, the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer may be a solvent-based or photopolymerizable acrylic pressure-sensitive adhesive.
The present invention also relates to a method for producing an optical product having a metal thin film layer, or a pressure-sensitive adhesive sheet for directly sticking to the surface of a metal thin film layer of a member for constituting the optical product. (Meth) acrylic acid ester which is 50% by weight or more with respect to the total amount of body components, and nitrogen atom-containing copolymerizable monomer of 10% by weight or more and less than 50% by weight and a carboxyl group-containing copolymerizable monomer An acrylic pressure-sensitive adhesive having an acrylic polymer composed of a copolymerizable monomer component not containing a body as a base polymer is prepared, and the pressure-sensitive adhesive layer is formed with the acrylic pressure-sensitive adhesive. Provided is a method for producing an optical product having a metal thin film layer, or an optical pressure-sensitive adhesive sheet for application to a surface of a metal thin film layer of a member for constituting the optical product. In this production method, the acrylic polymer may be obtained by a solution polymerization method or a light or radiation polymerization method.

The present invention also relates to an article having a metal surface formed by a metal thin film layer, the optical product having the metal thin film layer directly on the metal surface, or a member for constituting the optical product. Provided is an article having a metal surface formed of a metal thin film layer, characterized in that optical pressure-sensitive adhesive sheets for optical application to the surface of the metal thin film layer are bonded together.
In this specification, in addition to the above-described invention, pressure-sensitive adhesive sheets for directly sticking to a metal surface, and a (meth) acrylic acid ester as a monomer main component and a nitrogen atom-containing copolymer Sensitization by an acrylic pressure-sensitive adhesive comprising an acrylic polymer composed of a copolymerizable monomer component containing a polymerizable monomer and not containing a carboxyl group-containing copolymerizable monomer as a base polymer A pressure-sensitive adhesive sheet for sticking a metal surface, characterized by having a pressure-sensitive adhesive layer, and an article having a metal surface, the pressure-sensitive adhesive for sticking a metal surface directly on a metal surface An article having a metal surface, which is characterized in that sheets are bonded together, will also be described.

  In the present invention, “acrylic” and “methacrylic” may be collectively referred to as “(meth) acrylic”. Therefore, for example, “(meth) acrylic acid” includes acrylic acid and methacrylic acid, and “(meth) acrylic acid ester” includes acrylic acid ester and methacrylic acid ester. For example, “(meth) acrylamide” includes acrylamide and methacrylamide, and “(meth) acrylonitrile” includes acrylonitrile and methacrylonitrile. The same applies to other compound names in which “(meth) acryl” is used.

  According to the pressure-sensitive adhesive sheets for metal surface application of the present invention, the metal surface is not corroded even if applied directly to the metal surface, and it is applied to the metal surface with excellent adhesive properties and optical properties. Can do. Specifically, even when directly attached to a metal surface, discoloration or alteration does not occur over time, and it is transparent and has good adhesive properties. Moreover, excellent adhesive properties and optical properties can be maintained even under heating and humidification conditions.

  The pressure-sensitive adhesive sheet for metal surface sticking of the present invention contains (meth) acrylic acid ester as a monomer main component, a nitrogen atom-containing copolymerizable monomer, and a carboxyl group-containing copolymerizable monomer. It has a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive that uses an acrylic polymer composed of a copolymerizable monomer component not containing a body as a base polymer. As such pressure-sensitive pressure-sensitive adhesive sheets for sticking to metal surfaces, the copolymerizable monomer component constituting the acrylic polymer further contains an acidic group-containing copolymerizable monomer other than a carboxyl group-containing copolymerizable monomer. It is preferable that no monomer is contained. The pressure-sensitive adhesive sheet for metal surface application is a copolymerizable monomer component for (meth) acrylic acid ester as a monomer main component in an acrylic pressure-sensitive adhesive forming a pressure-sensitive adhesive layer. As a nitrogen atom-containing copolymerizable monomer is included and a carboxyl group-containing copolymerizable monomer (preferably, an acidic group-containing copolymerizable monomer) is not included. It can exhibit excellent adhesive properties without causing corrosion, and can also have good optical properties. As described above, in the present invention, an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, but an acrylic polymer as a base polymer of the acrylic pressure-sensitive adhesive is used. As a constituent monomer component (monomer component), a carboxyl group-containing copolymerizable monomer such as (meth) acrylic acid (especially an acidic group-containing copolymerizable monomer) is not used, so the color changes to the metal surface. In addition, since a nitrogen atom-containing copolymerizable monomer is used as a monomer component, excellent adhesive properties and optical properties can be exhibited.

  Examples of the carboxyl group-containing copolymerizable monomer include (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acidic group-containing copolymerizable monomer other than the carboxyl group-containing copolymerizable monomer include, for example, anhydrides of carboxyl group-containing copolymerizable monomers such as maleic anhydride and icotanic anhydride; styrene Contains sulfonic acid groups such as sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid Copolymerizable monomer; phosphate group-containing copolymerizable monomer such as 2-hydroxyethylacryloyl phosphate; In such an acidic group-containing copolymerizable monomer, a carboxyl group-containing copolymerizable monomer such as (meth) acrylic acid can be copolymerized with (meth) acrylic acid ester as the main monomer component. It is widely used as a copolymerizable monomer, and in particular, it is widely used as a modifying monomer for improving the adhesion property to a metal surface.

[(Meth) acrylic acid ester]
(Meth) acrylic acid ester as a main monomer component constituting an acrylic polymer as a base polymer in the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheet for metal surface application As, (meth) acrylic acid alkyl ester can be used suitably. (Meth) acrylic acid esters can be used alone or in combination of two or more.

Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-Methylhexyl acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate , Dodecyl (meth) acrylate, tridecyl (meth) acrylate, (me ) Tetradecyl acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate (meta) ) Acrylic acid C _1-20 alkyl ester [preferably (meth) acrylic acid C _1-18 alkyl ester]. Preferred alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobutyl (meth) acrylate, (meth ) Propyl acrylate, isopropyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate.

  Examples of (meth) acrylic acid esters other than (meth) acrylic acid alkyl esters include, for example, (meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid bornyl, (meth) acrylic acid isobornyl, etc. Aromatic carbonization such as (meth) acrylic acid having a alicyclic hydrocarbon group, phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate Examples thereof include (meth) acrylic acid having a hydrogen group.

  As the (meth) acrylic acid ester, a carboxyl group-free (meth) acrylic acid ester not containing a carboxyl group [in particular, an acidic group-free (meth) acrylic acid ester not containing an acidic group] It is important to be. Further, it is important that the (meth) acrylic acid ester is a nitrogen atom-free (meth) acrylic acid ester that does not contain a nitrogen atom.

[Nitrogen atom-containing copolymerizable monomer]
The nitrogen atom-containing copolymerizable monomer is used as a copolymerizable monomer that can be copolymerized with (meth) acrylic acid ester as a monomer main component. The nitrogen atom-containing copolymerizable monomer is not particularly limited as long as it contains a nitrogen atom and can be copolymerized with the (meth) acrylic acid ester. For example, an amide group-containing monomer , Nitrogen heterocycle-containing monomers, cyano group-containing monomers, imide group-containing monomers, amino group-containing monomers, and the like. The nitrogen atom-containing copolymerizable monomers can be used alone or in combination of two or more. In addition, it is important that the nitrogen atom-containing copolymerizable monomer does not contain a carboxyl group (particularly an acidic group).

  The amide group-containing monomer is not particularly limited as long as it is a copolymerizable monomer having an ethylenically unsaturated bond and an amide group (group having an amide bond). For example, (meth) acrylamide, N-substituted (Meth) acrylamide, amide group-containing (meth) acrylic acid ester and the like can be mentioned. Examples of the N-substituted (meth) acrylamide include N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and Nn-butyl. N-alkyl (meth) acrylamides such as (meth) acrylamide, N-isobutyl (meth) acrylamide, Ns-butyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N-hexyl (meth) acrylamide; N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di (n-butyl) (Meth) acrylamide, N, N-diisobutyl (meth) Kurylamide, N, N-di (s-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide, N, N-dipentyl (meth) acrylamide, N, N-dihexyl (meth) N, N-dialkyl (meth) acrylamides such as acrylamide, N, N-diheptyl (meth) acrylamide, N, N-dioctyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, Hydroxyl group-containing (meth) acrylamides such as N-methylolpropane (meth) acrylamide; alkoxy group-containing (meth) acrylamides such as N-methoxymethyl (meth) acrylamide and N- (n-butoxymethyl) (meth) acrylamide; N , N-Pentaethylene (meth) acryl Amide, and the like. Examples of the amide group-containing (meth) acrylic acid ester include (meth) acrylic acid (N-substituted amide) alkyl such as 2- (dimethylamido) ethyl (meth) acrylate. As the amide group-containing monomer, N, N-dialkyl (meth) acrylamide [in particular, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide] N, N-diisopropyl (meth) acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide] can be preferably used.

  The nitrogen-based heterocyclic ring-containing monomer is not particularly limited as long as it is a copolymerizable monomer having an ethylenically unsaturated bond and a nitrogen-based heterocyclic ring (a heterocyclic ring having a nitrogen atom as a ring constituent element). N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam N-vinyl compounds such as N-vinylpyrrolidone and N-vinylimidazole; N- (meth) acryloyl compounds such as N- (meth) acryloylmorpholine and the like. As the nitrogen-based heterocyclic ring-containing monomer, N- (meth) acryloyl-based compounds [particularly N- (meth) acryloylmorpholine] are suitable.

  The cyano group-containing monomer is not particularly limited as long as it is a copolymerizable monomer having an ethylenically unsaturated bond and a cyano group, and examples thereof include acrylonitrile and methacrylonitrile.

  The imide group-containing monomer is not particularly limited as long as it is a copolymerizable monomer having an ethylenically unsaturated bond and an imino group. For example, maleimide, N-cyclohexylmaleimide, N-isopropylmaleimide, N-lauryl Maleimide monomers such as maleimide and N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylruitacon Itacimide monomers such as imide and N-lauryl itaconimide; N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyocta Methylene sushi Succinimide monomers such as imide, and the like. As the imide group-containing monomer, a maleimide monomer can be suitably used.

  The amino group-containing monomer is not particularly limited as long as it is a copolymerizable monomer having an ethylenically unsaturated bond and an amino group (unsubstituted or substituted amino group). For example, aminomethyl (meth) acrylate , Aminoalkyl (meth) acrylates such as aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, aminoisopropyl (meth) acrylate, and (meth) acrylic acid (N-substituted) aminoalkyl. It is done. Examples of the (meth) acrylic acid (N-substituted) aminoalkyl include (meth) acrylic acid N-alkylaminoalkyl such as N- (t-butyl) aminoethyl (meth) acrylate; (meth) acrylic acid Examples include N, N-dialkylaminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl and N, N-dimethylaminopropyl (meth) acrylate. As the amino group-containing monomer, N, N-dialkylaminoalkyl (meth) acrylate can be preferably used.

  As the nitrogen atom-containing copolymerizable monomer, an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, a cyano group-containing monomer, and an imide group-containing monomer are preferable. Containing monomers and nitrogen-based heterocyclic containing monomers are preferred.

[Copolymerizable monomer for modification]
In the present invention, as a copolymerizable monomer other than a nitrogen atom-containing copolymerizable monomer, a copolymerizable property excluding a carboxyl group-containing copolymerizable monomer (particularly an acidic group-containing copolymerizable monomer). Monomers (sometimes referred to as “modifying copolymerizable monomers”) can be used. By using the modifying copolymerizable monomer, various characteristics of the acrylic pressure-sensitive adhesive, the structure of the polymer, and the like can be controlled. For example, when a copolymerizable monomer for modification having a functional group (polar group such as hydroxyl group) other than a carboxyl group (particularly an acidic group) is used as the copolymerizable monomer for modification, Cross-linking can occur in the polymer. The modifying copolymerizable monomers can be used alone or in combination of two or more.

  Such a modifying copolymerizable monomer does not contain a carboxyl group (particularly an acidic group), or a nitrogen atom and a carboxyl group (particularly an acidic group), and the (meth) acrylic ester Although it will not restrict | limit especially if it is a monomer (copolymerizable monomer) which can be copolymerized with (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 3-hydroxypropyl, (meth) 4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, glycerin dimethacrylate, (meth) acrylic acid Hydroxyl group-containing copolymerizable monomer such as polyethylene glycol and polypropylene glycol (meth) acrylate Epoxy group-containing copolymerizable monomers such as glycidyl (meth) acrylate; methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxy (meth) acrylate Alkoxy group-containing copolymerizable monomers such as polypropylene glycol; Styrene copolymerizable monomers such as styrene and α-methylstyrene; α-olefin copolymerizable monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene An isocyanate group-containing copolymerizable monomer such as 2-methacryloyloxyethyl isocyanate; a vinyl ester copolymerizable monomer such as vinyl acetate and vinyl propionate; a vinyl ether copolymerizable monomer such as vinyl ether ; Tetrahydrofurfuryl (meth) acrylate, etc. Heterocycle-containing (meth) acrylic acid; halogen atom-containing copolymerizable monomer such as fluorine (meth) acrylate; silicon atom-containing copolymerizable monomer such as silicone (meth) acrylate; ethylene glycol di (meth) acrylate , Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl Glycol di (meth) acrylate, hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di (meth) acrylate, a polyfunctional monomer such hexyl di (meth) acrylate.

  As the copolymerizable monomer for modification, a hydroxyl group-containing copolymerizable monomer, a glycidyl group-containing copolymerizable monomer, and a vinyl ester copolymerizable monomer can be suitably used. A hydroxyl group-containing copolymerizable monomer is preferred.

[Acrylic polymer]
The acrylic polymer can be obtained by polymerization of the monomer component [for example, (meth) acrylic acid ester, nitrogen atom-containing copolymerizable monomer, etc.]. That is, the acrylic polymer is an acrylic copolymer in which at least a (meth) acrylic acid ester and a nitrogen atom-containing copolymerizable monomer are used as monomer components. Acrylic polymers can be used alone or in combination of two or more.

  In the acrylic polymer, (meth) acrylic acid ester is used as the main component of the monomer, so the proportion of (meth) acrylic acid ester is 50% by weight or more based on the total amount of monomer components. Is important, and can be selected from the range of, for example, 50 to 99% by weight (preferably 55 to 90% by weight, more preferably 70 to 90% by weight).

  The proportion of the nitrogen atom-containing copolymerizable monomer is important to be less than 50% by weight with respect to the total amount of the monomer components, for example, 5% by weight or more and less than 50% by weight (preferably 10 to 45% by weight, more preferably 10 to 30% by weight). If the ratio of the nitrogen atom-containing copolymerizable monomer is too small (for example, less than 5% by weight), the adhesive property to the metal surface is lowered, and particularly the adhesive strength is high under high temperature and high humidity conditions. The pressure-sensitive adhesive sheet for metal surface sticking is likely to be peeled off from the metal surface.

  Furthermore, the proportion of the copolymerizable monomer for modification is less than 50% by weight (preferably 0.1 to 45% by weight, more preferably 0.1 to 10% by weight) based on the total amount of the monomer components. ) Can be selected from the range.

  As a polymerization method for obtaining an acrylic polymer, for example, a polymerization method (solution polymerization method) performed using a polymerization initiator such as an azo compound (azo initiator) or a peroxide (peroxide initiator) , Emulsion polymerization methods, bulk polymerization methods, etc.), polymerization methods carried out by irradiating light or radiation using a photoinitiator, etc., and polymerization methods carried out using an azo initiator are preferred. In the polymerization initiator, examples of the azo initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2 -Methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-dimethyleneisobutyl) Amidine) dihydrochloride and the like. Examples of the peroxide-based initiator include dibenzoyl peroxide, tert-butyl permaleate, and the like. And the like.

  The amount of the polymerization initiator used is not particularly limited, and is, for example, 0.01 to 2 mol% (preferably 0.02 to 1 mol%) based on the total amount of the monomer components (100 mol%). Degree.

  In the present invention, the acrylic polymer obtained by polymerization using the monomer component may be used after being dried, or may be used after being cured by crosslinking the acrylic polymer. By crosslinking the acrylic polymer, good results can be obtained in durability such as heat resistance in addition to the peelability and adhesiveness of the release liner. The crosslinking method of the acrylic polymer is not particularly limited, and any crosslinking method can be used, but a method using a so-called crosslinking agent is desirable. The acrylic polymer can be crosslinked during or after the formation of the pressure-sensitive adhesive layer.

  As the cross-linking agent, conventionally known ones can be used, but polyisocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, and melamine compounds are preferable, and polyisocyanate compounds are particularly preferable. . A crosslinking agent can be used individually or in mixture of 2 or more types. Examples of polyisocyanate compounds include tolylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, diphenylmethane diisocyanate double product, reaction product of trimethylolpropane and tolylene diisocyanate, trimethylolpropane. And the reaction product of hexamethylene diisocyanate, polyether polyisocyanate, polyester polyisocyanate and the like. The usage-amount of a polyisocyanate type compound is about 0.01-20 weight part (preferably 0.05-15 weight part) with respect to 100 weight part of acrylic polymers, for example.

[Acrylic pressure sensitive adhesive]
The acrylic pressure-sensitive adhesive contains the acrylic polymer as a base polymer. Various additives may be added to the acrylic pressure-sensitive adhesive as required. Examples of such additives include known or commonly used tackifying resins (for example, rosin resins, terpene resins, petroleum resins, coumarone / indene resins, styrene resins, etc.), fillers, colorants (pigment and Dyes, etc.), various known additives such as antioxidants, ultraviolet absorbers, and surfactants. The amount of these additives used may be a normal amount applied to the pressure-sensitive adhesive.

  The acrylic pressure-sensitive adhesive can take any form during the preparation process, but is preferably used in the form of a solvent system, an emulsion system, a hot melt system, a photopolymerization system or the like in terms of handleability. The acrylic pressure-sensitive adhesive can be used alone or in combination of two or more.

[Pressure-sensitive adhesive sheets for metal surfaces]
The pressure-sensitive adhesive sheet for metal surface sticking of the present invention has a pressure-sensitive pressure-sensitive adhesive layer formed by the acrylic pressure-sensitive adhesive (sometimes referred to as “pressure-sensitive adhesive layer for metal surface sticking”). doing. The pressure-sensitive adhesive layer for metal surface sticking may have either a single layer or a laminate. The thickness of the pressure-sensitive pressure-sensitive adhesive layer for sticking to a metal surface is not particularly limited as long as it does not impair high transparency and the like. For example, it is about 1 to 200 μm (preferably 1 to 100 μm, more preferably 1 to 50 μm). You can choose from a range of

  In addition, the formation method in particular of the pressure-sensitive adhesive layer for metal surface sticking is not restrict | limited. For example, using a conventional coater (gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, etc.), the acrylic pressure sensitive adhesive is peeled off on a predetermined surface (for example, peeling) By applying to a release surface of a liner or the surface of a base material, a pressure-sensitive adhesive layer for attaching a metal surface can be formed.

  As a pressure-sensitive adhesive sheet for metal surface sticking, if it has the said pressure-sensitive adhesive layer for metal surface sticking, the structure will not be restrict | limited in particular. Specifically, as pressure-sensitive adhesive sheets for metal surface application, for example, (1) Baseless double-sided pressure-sensitive adhesive sheets having a configuration formed only from a pressure-sensitive adhesive layer for metal surface application, (2 ) Double-sided pressure-sensitive adhesive sheets with a base material having a structure in which a pressure-sensitive adhesive layer for attaching a metal surface is formed on at least one surface of the base material, and adhesive surfaces are formed on both sides of the base material; Examples thereof include a pressure-sensitive adhesive sheet with a base material having a structure in which a pressure-sensitive adhesive layer for attaching a metal surface is formed on one surface of a material.

  In addition, when the pressure sensitive adhesive sheet for metal surface sticking is a double-sided pressure sensitive adhesive sheet with a base material, the pressure sensitive adhesive layer (adhesive layer) formed on both surfaces of the base material is a pressure sensitive adhesive for metal surface sticking. The pressure-sensitive adhesive layer formed on one surface of the substrate may be a pressure-sensitive adhesive layer for metal surface sticking, and the pressure-sensitive adhesive layer formed on the other surface of the substrate May be a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer for metal surface application (sometimes referred to as “pressure-sensitive adhesive layer for non-metal surface application”). When pressure-sensitive adhesive sheets for metal surface application have a pressure-sensitive adhesive layer for non-metal surface application, it is important not to use the pressure-sensitive adhesive layer for non-metal surface application on metal surfaces It is.

  Moreover, the pressure-sensitive adhesive sheet for metal surface sticking may be formed in the form wound by roll shape, and may be formed in the form by which the sheet | seat was laminated | stacked. That is, the pressure-sensitive adhesive sheets for metal surface sticking of the present invention can have forms such as a sheet form and a tape form. Accordingly, the pressure-sensitive adhesive sheets for metal surface application include a pressure-sensitive adhesive tape or a pressure-sensitive adhesive sheet (pressure-sensitive adhesive tape or sheet). In addition, when the pressure sensitive adhesive sheet for metal surface sticking has the form wound by roll shape (when it is a pressure sensitive adhesive tape), for example, a pressure sensitive adhesive layer for metal face sticking etc. The pressure-sensitive adhesive layer can be produced by winding it into a roll while being protected by a release treatment layer formed on the back side of the separator or substrate.

The pressure-sensitive adhesive sheets for metal surface sticking of the present invention can maintain high transparency even when exposed to high temperature and / or high humidity during pretreatment, various manufacturing process stages, product use, and the like. . Specifically, the pressure-sensitive adhesive layer for metal surface application in the pressure-sensitive adhesive sheet for metal surface application includes heat treatment at 80 ° C. for 500 hours and humidification treatment at 60 ° C. and 95% RH for 500 hours. Before and after the treatment, the total light transmittance is 90% or more both before and after the heat treatment and the humidification treatment, and the haze is 10% both before and after the heat treatment and the humidification treatment. In addition, the color difference (ΔE ^* ab) before and after each of the heat treatment and the humidification treatment may be 0.5 or less. If the pressure-sensitive adhesive layer for metal surface sticking has such characteristics, even if it receives heat history due to high heat and / or humidity history due to high humidity, it can effectively retain excellent optical properties. Can do. Specifically, the pressure-sensitive adhesive layer for metal surface sticking maintains its transparency without yellowing even when exposed to high temperatures and high humidity, and has little change in hue. The characteristic can be exhibited.

  Specifically, the pressure-sensitive adhesive layer for metal surface sticking is subjected to heat treatment at 80 ° C. for 500 hours, before each treatment of humidification treatment at 60 ° C. and 95% RH for 500 hours, and the heat treatment and humidification treatment. Both after each of the treatments can have a characteristic that the total light transmittance is 90% or more (preferably 95% or more).

  Further, the pressure-sensitive adhesive layer for metal surface sticking is subjected to heat treatment at 80 ° C. for 500 hours, before each treatment of humidification treatment at 60 ° C. and 95% RH for 500 hours, and each treatment of the heat treatment and humidification treatment. Both of the latter can have a haze property of 10% or less (preferably 5% or less).

Furthermore, the pressure-sensitive adhesive layer for metal surface sticking is subjected to a heat treatment at 80 ° C. for 500 hours, a humidification treatment at 60 ° C. and 95% RH for 500 hours, and each treatment of the heat treatment and the humidification treatment. The color difference (ΔE ^* ab) between and after can be 0.5 or less (0 to 0.5) [preferably 0.3 or less (0 to 0.3)]. That the color difference (ΔE ^* ab) is 0.5 or less means that the color change is at a slightly different level.

In the present invention, the total light transmittance, haze, and color difference (ΔE ^* ab) of the pressure-sensitive adhesive layer for metal surface sticking are values measured by the following measurement methods.
(Measurement method of total light transmittance and haze)
A pressure-sensitive adhesive layer (area: 40 mm × 40 mm) for metal surface application having a thickness of 25 μm was formed, and a slide glass (trade name “Slide Glass Product No. S” was formed on both surfaces of the pressure-sensitive adhesive layer for metal surface application. A sample for evaluation (a product having a layer configuration of glass / metal surface sticking pressure-sensitive adhesive layer / glass) obtained by bonding MATSUNAMI's water-bending type) is used. Measure the total light transmittance (%) and haze (%) of the sample for evaluation according to JIS K7361 and JIS K7136 using a turbidimeter (device name “Hazemeter HM-150” manufactured by Murakami Color Research Laboratory). (Before heat treatment) Thereafter, the evaluation sample was subjected to (a) heat treatment at 80 ° C. for 500 hours and (b) humidification treatment at 60 ° C. and 95% RH for 500 hours. The total light transmittance (%) and haze (%) of the sample are measured (after heat treatment or after humidification treatment).

(Measurement method of color difference (ΔE ^* ab))
For an evaluation sample similar to the evaluation sample (evaluation sample before the heat treatment) prepared by the above-described total light transmittance / haze measurement method, an integrating sphere type spectral transmittance measuring device (device name “DOT-3” Murakami) Using L ^* a ^* b ^* color system, L ^* , a ^* and b ^* are measured (light source: halogen lamp, wavelength: 390 to 730 nm) (before heat treatment). Thereafter, the evaluation sample was subjected to (a) heat treatment at 80 ° C. for 500 hours and (b) humidification treatment at 60 ° C. and 95% RH for 500 hours. Measure L ^* , a ^* , b ^* of the sample (after heat treatment or after humidification treatment).
From the obtained L ^* , a ^* , and b ^* values, the color difference (ΔE ^* ab) before and after each of the heat treatment and the humidification treatment is calculated using the following equation.
ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2
(Here, ΔL ^* means the difference in the value of L ^* before and after the heat treatment and the humidification treatment. Δa ^* is the difference in the value of a ^* before and after the heat treatment and the humidification treatment. Δb ^* means the difference between the values of b ^* before and after the heat treatment and the humidification treatment.)

  The pressure-sensitive adhesive sheet for metal surface application of the present invention is a base material having a structure formed only from the pressure-sensitive adhesive sheet for metal surface application of the above-mentioned configuration (1), that is, the pressure-sensitive adhesive layer for metal surface application. Less double-sided pressure-sensitive adhesive sheets are preferred. Such substrate-less double-sided pressure-sensitive adhesive sheets preferably have a form in which a pressure-sensitive adhesive layer for metal surface application is formed on a release liner.

  The release liner is not particularly limited as long as it is used as a release liner for pressure-sensitive adhesive tapes or sheets, and a known or common release liner can be used. The release liner may be a release surface on both sides, or only one of the surfaces may be a release surface. Therefore, the pressure-sensitive adhesive sheets for metal surface application were laminated on one side of the pressure-sensitive adhesive layer for metal surface application with a release liner having both surfaces as release surfaces and wound in a roll shape. Each release liner may be laminated on each surface of the pressure-sensitive adhesive layer for metal surface sticking by using two release liners that may be formed in a roll shape or having one release surface. Furthermore, it may be formed in a sheet form or a roll form wound in a roll shape as necessary.

  Specific examples of the release liner include, for example, a release treatment agent layer made of a release treatment agent, a release liner base material (for example, paper such as Japanese paper, western paper, glassine paper; fibrous materials such as nonwoven fabric and cloth) Base material by: a release liner formed on the surface of a plastic film such as a polyester film or a metal-deposited plastic film), a plastic film having high peelability itself [eg, polyethylene (linear low density polyethylene, etc.), polo Teflon (Registered Trademark): Ethylene-α-olefin copolymer (block copolymer or random copolymer) such as propylene and ethylene-propylene copolymer, and polyolefin film made of a mixture of these resins; Release liner made of a film made of the Tick film materials (eg, polyolefin resins such as polyethylene-polypropylene, ethylene-α-olefin copolymers such as ethylene-propylene copolymer, Teflon, etc.), various substrates (eg, metal foil, plastic film, etc.) Etc.) and release liners obtained by laminating or coating.

  The release treatment agent is not particularly limited, and examples thereof include known release treatment agents such as silicone release treatment agents, fluorine release treatment agents, and long-chain alkyl release treatment agents. These release treatment agents can be used alone or in combination. In addition, when both surfaces of the release liner are formed of a release treatment agent, the release treatment agents for forming both release surfaces may be the same or different.

  In addition, when the pressure-sensitive adhesive sheet for metal surface sticking has a base material [namely, the double-sided pressure-sensitive adhesive sheet with a base material of the above-mentioned composition (2), and a base material of the above-mentioned composition (3) In the case of pressure-sensitive adhesive sheets], as the substrate, for example, a paper-based substrate such as paper; a fiber-based substrate such as cloth, nonwoven fabric, and net; a metal-based substrate such as metal foil and metal plate; plastic Plastic base materials such as films and sheets; Rubber base materials such as rubber sheets; Foams such as foam sheets and laminates thereof (particularly laminates of plastic base materials and other base materials; A suitable thin leaf body such as a laminate of plastic films (or sheets) can be used. As the substrate, a plastic substrate such as a plastic film or sheet can be suitably used. As a material in such a plastic film or sheet, for example, an α-olefin such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) or the like is used as a monomer component. Olefin resin: Polyester resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); polyvinyl chloride (PVC); vinyl acetate resin; polyphenylene sulfide (PPS); polyamide (Nylon), amide resins such as wholly aromatic polyamide (aramid); polyimide resins; polyether ether ketone (PEEK). These materials can be used alone or in combination of two or more.

  In addition, it is desirable to use what has the outstanding transparency as a base material.

  Although the thickness of a base material is 1-1000 micrometers (preferably 1-500 micrometers, more preferably 3-300 micrometers), for example, it is not limited to these. In addition, the base material may have a single layer form or may have a laminated form.

  In order to improve the adhesion of the surface of the substrate to the pressure-sensitive adhesive layer for metal surface application, etc., conventional surface treatments such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation An oxidation treatment or the like by a chemical or physical method such as a treatment may be performed, or a coating treatment or the like by an undercoat agent or a release agent may be performed.

  Moreover, when the pressure sensitive adhesive sheet for metal surface sticking has a pressure sensitive adhesive layer other than the pressure sensitive adhesive layer for metal surface sticking [that is, double-sided pressure sensitive with a base material of the above-mentioned composition (2)]. When a pressure-sensitive adhesive layer for non-metal surface application is used in the pressure-sensitive adhesive sheets], a pressure-sensitive adhesive layer for non-metal surface application is a known pressure-sensitive adhesive (for example, other acrylic pressure-sensitive adhesive layers). Adhesive, rubber-based pressure-sensitive adhesive, vinyl alkyl ether-based pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, polyester-based pressure-sensitive pressure-sensitive adhesive, polyamide-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, fluorine The pressure-sensitive adhesive layer can be formed by using a known pressure-sensitive adhesive layer forming method. Moreover, the thickness of the pressure-sensitive adhesive layer for non-metal surface sticking is not particularly limited, and can be appropriately selected according to the purpose and usage.

  Since the pressure-sensitive adhesive sheets for metal surface application according to the present invention have the above-described configuration, even when directly applied to a metal surface, the metal surface is not corroded, and excellent adhesive properties and optical properties are provided. Can be attached to a metal surface. Therefore, it can be suitably used as a pressure-sensitive adhesive sheet for directly attaching to a metal surface in an adherend having a metal surface.

[Articles with metal surfaces]
The article having a metal surface of the present invention has a metal surface, and the pressure-sensitive adhesive sheet for metal surface application is at least partially (partially or fully) directly on the metal surface. ) Are pasted together. In an article having such a metal surface, the adherend (sometimes referred to as a “metal surface-containing adherend”) to which the pressure-sensitive adhesive sheet for attaching a metal surface is bonded is at least partially a metal surface. If it has, it will not be restrict | limited in particular. In such a metal surface-containing adherend, the portion where the metal surface is formed is not particularly limited as long as it is a portion where the pressure-sensitive adhesive sheet can be directly attached, and even on the outer surface. It may be an inner surface or the like. When a plurality of metal surfaces are formed on one metal surface-containing adherend, these plurality of metal surfaces may be surfaces formed of the same metal material or formed of different metal materials. It may be a surface.

  The metal surface in the metal surface-containing adherend may be the surface of a metal surface-containing adherend formed of a metal material, or on the surface of a base material (or structure) formed of various materials. It may be the surface of the formed metal layer (in particular, the surface of the metal thin film layer). In any case, the metal surface may be a surface made of a metal material.

  A metal layer such as the metal foil film layer can be formed at a predetermined site on the surface of a base material (or structure) made of various materials. In such a metal layer, the thickness of the metal thin film layer can be appropriately selected according to the type of the metal surface-containing adherend, and may be, for example, 0.1 μm or more. The upper limit of the thickness of the metal foil film layer is not particularly limited as long as it is generally regarded as a thin film layer.

  The metal material for forming the metal surface is not particularly limited. For example, a metal material made of a single metal such as aluminum, silver, gold, copper, iron, titanium, platinum, nickel; a gold alloy (for example, gold-copper) Alloy), copper alloy (eg, copper-zinc alloy (brass), copper-aluminum alloy, etc.), aluminum alloy (eg, aluminum-molybdenum alloy, aluminum-tantalum alloy, aluminum-cobalt alloy, aluminum-chromium alloy, aluminum) -Titanium alloys, aluminum-platinum alloys, etc.), nickel alloys (for example, nickel-chromium alloys, copper-nickel alloys, zinc-nickel alloys, etc.), and metal materials made of various alloys such as stainless steel. A metallic material can be used individually or in combination of 2 or more types.

  Note that the metal material may be a metal material containing only a metal element, or a metal material containing a non-metal element together with a metal element [eg, metal oxide, hydroxide, halide (chloride, etc.). And metal compounds such as oxo acid salts (nitrate, sulfate, phosphate, carbonate, etc.).

  Specifically, as the metal surface-containing adherend, for example, a window material having at least a metal surface, a member for constituting the window material, or an electromagnetic wave shield formed by a metal thin film layer Examples thereof include an optical product having a layer or a member for constituting the optical product. Examples of the optical product having an electromagnetic wave shielding layer include optical devices such as an electronic display (plasma display), optically recordable discs (optical recording discs) such as digital universal discs, and the like.

Examples of the optical recording disk include so-called “DVD” and so-called “CD”. In such an optical recording disk, a DVD includes a so-called “DVD-ROM”, a so-called “DVD-RAM”, a so-called “DVD-R”, a so-called “DVD-RW (so-called“ DVD-RW ⁺ ”, so-called“ DVD-RW ^- including the ")" includes a DVD in the form of a so-called "DVR". The CD includes CDs in the form of so-called “CD-ROM”, so-called “CD-RAM”, so-called “CD-R”, so-called “CD-RW”. In these optical recording disks, the thickness of the metal foil film layer that is an electromagnetic wave shielding layer is generally about 5 to 50 μm, but there are some that are about 100 μm.

  Examples of the present invention will be described below in more detail. However, the present invention is not limited to these examples.

Example 1
In a reaction vessel equipped with a cooling tube, a nitrogen introducing tube, a thermometer, a dropping funnel, and a stirring device, 2,2′-azobisisobutyronitrile as a polymerization initiator: 0.2 part by weight, and ethyl acetate as a solvent: 100 2 parts by weight, 2-ethylhexyl acrylate: 70 parts by weight, N, N-diethylacrylamide: 30 parts by weight, 2-hydroxyethyl acrylate: 1 part by weight as a monomer component, and after carrying out nitrogen reflux for 1 hour, The temperature of the monomer composition solution containing the monomer component in the reaction vessel was raised to 60 ° C., and polymerization was performed in a nitrogen stream for 4 hours. Thereafter, the temperature was raised to 80 ° C. and aging was performed for 2 hours to obtain an acrylic polymer solution. To this acrylic polymer solution, 2 parts by weight (solid content) of trimethylolpropane / tolylene diisocyanate adduct (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.) is added as a crosslinking agent. Product (sometimes referred to as "adhesive A").

  Further, the pressure-sensitive adhesive A was applied onto a release surface of a polyethylene terephthalate film (release liner; thickness 38 μm) that had been subjected to release treatment with a silicone release agent using an applicator, and dried at 130 ° C. for 3 minutes. Thus, an adhesive layer having a thickness of 25 μm was formed. On this pressure-sensitive adhesive layer, a polyethylene terephthalate film (release liner; thickness 38 μm) that had been subjected to a release treatment with a silicone-based release agent was bonded to obtain an adhesive sheet.

(Example 2)
As shown in Table 1, as in Example 1, except that 2-ethylhexyl acrylate: 70 parts by weight, acryloylmorpholine: 30 parts by weight, and 2-hydroxyethyl acrylate: 1 part by weight were used as monomer components. Thus, a pressure-sensitive adhesive composition (sometimes referred to as “pressure-sensitive adhesive B”) was prepared. A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that this pressure-sensitive adhesive B was used.

(Comparative Example 1)
As shown in Table 1, the pressure-sensitive adhesive composition was the same as Example 1 except that 2-ethylhexyl acrylate: 95 parts by weight and 2-hydroxyethyl acrylate: 5 parts by weight were used as monomer components. (It may be referred to as “adhesive C”). A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that this pressure-sensitive adhesive C was used.

(Comparative Example 2)
As shown in Table 1, a pressure-sensitive adhesive composition (“adhesive” was obtained in the same manner as in Example 1 except that 2-ethylhexyl acrylate: 95 parts by weight and acrylic acid: 5 parts by weight were used as monomer components. May be referred to as “agent D”). A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that this pressure-sensitive adhesive D was used.

(Evaluation)
About the adhesive sheet produced in Examples 1-2 and Comparative Examples 1-2, the following corrosivity evaluation method, adhesive force measurement method, total light transmittance and haze measurement method, color difference measurement method, corrosivity, Tackiness and transparency (total light transmittance, haze, color difference) were evaluated. The evaluation results are shown in Table (1).

(Corrosive evaluation method)
Remove the release liner on one side of the pressure-sensitive adhesive sheet and bond it to a transparent polyethylene terephthalate film (thickness: 25 μm), and then peel off the release liner on the other side and apply copper foil (thickness: 80 μm) After the combination, it was stored for 5 days in an atmosphere of 60 ° C. × 95% RH. Thereafter, the surface of the copper foil was visually observed from the polyethylene terephthalate film side to confirm the presence or absence of corrosion on the surface of the copper foil to which the adhesive sheet was bonded.

(Adhesive strength measurement method)
The release liner on one side of the pressure-sensitive adhesive sheet is peeled off, bonded to a polyethylene terephthalate film (thickness: 25 μm), cut into a width of 20 mm and a length of 100 mm, and then the release liner on the other side is peeled off to obtain a copper foil. (Thickness: 80 μm) Bonding was performed. Thirty minutes after being attached to the copper foil, 180 ° peel adhesion was measured. In addition, the measurement conditions for 180 ° peel adhesive strength are peeling angle: 180 °, tensile speed: 300 mm / min, temperature: 23 ° C., humidity: 50% RH, and bonded to a polyethylene terephthalate film from copper foil. The 180 ° peel adhesive strength was measured by peeling off the adhesive sheet.

(Measurement method of total light transmittance and haze)
Cut the adhesive sheet to 40mm x 40mm, peel off the release liner on one side, and stick it to a slide glass (trade name "Slide Glass Part No. S" manufactured by MATSUNAMI Co., Ltd .; water-brush type), heat treatment and humidification A pre-treatment evaluation sample for measurement without treatment was prepared. Thereafter, the release liner on the other side was removed, and the total light transmittance (% ) And haze (%).

  In addition, the adhesive sheet is cut into 40 mm × 40 mm, the release liner on one side is peeled off, and the adhesive sheet is attached to a slide glass (trade name “Slide Glass Part No. S” manufactured by MATSUNAMI; Two evaluation samples were prepared: an evaluation sample for post-heat treatment for measurement after performing and a post-humidification evaluation sample for measurement after performing the humidification treatment. The post-heat treatment evaluation sample was stored for 500 hours in an atmosphere at 80 ° C., while the post-humidification treatment evaluation sample was stored for 500 hours in an atmosphere of 60 ° C. × 95% RH, followed by heat treatment. The release liner on the other side of the post-evaluation sample and the post-humidification treatment evaluation sample was removed, and turbidimeters (device name “Haze Meter HM-150” manufactured by Murakami Color Research Laboratory) were used to make JIS K7361, JIS K7136. According to the above, the total light transmittance (%) and haze (%) were measured.

  In addition, each evaluation sample of the evaluation sample for pretreatment, the evaluation sample for post-heat treatment, and the evaluation sample for post-humidification treatment has a layer configuration of a slide glass / adhesive layer, and the total light transmittance measured. The numerical values of (%) and haze (%) include the total light transmittance (%) and haze (%) of the slide glass.

(Measurement method of color difference)
In the same manner as the measurement method of the total light transmittance and haze, a pre-treatment evaluation sample for measuring the pressure-sensitive adhesive sheet without performing heat treatment and humidification treatment was prepared. Then, the release liner on the other side is removed, and using an integrating sphere type spectral transmittance measuring device (device name “DOT-3” manufactured by Murakami Color Research Laboratory), L ^* a ^* b ^* color system, L ^* , A ^* and b ^* were examined (light source: halogen lamp, wavelength: 390 to 730 nm).

In addition, the pressure-sensitive adhesive sheet is subjected to a heat treatment in the same manner as the total light transmittance and haze measurement method, and the post-heat treatment evaluation sample is measured, and the humidification treatment is performed after the humidification treatment. Two evaluation samples were prepared, including a post-treatment evaluation sample. The post-heat treatment evaluation sample was stored for 500 hours in an atmosphere at 80 ° C., while the post-humidification treatment evaluation sample was stored for 500 hours in an atmosphere of 60 ° C. × 95% RH, followed by heat treatment. The release liner on the other side of the post-evaluation sample and the post-humidification treatment evaluation sample is removed, and in the same manner as the pre-treatment evaluation sample, L ^* , a ^* , b ^{* in the} L ^* a ^* b ^* color system ^. I investigated.

From the obtained values of L ^* , a ^* , and b ^* , the color difference before and after the heat treatment (ΔE ^* ab) and the color difference before and after the humidification treatment (ΔE ^* ab) were calculated using the following equations.
ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2
(Here, ΔL ^* means the difference in the value of L ^* before and after the heat treatment and the humidification treatment. Δa ^* is the difference in the value of a ^* before and after the heat treatment and the humidification treatment. Δb ^* means the difference between the values of b ^* before and after the heat treatment and the humidification treatment.)

  As is clear from Table 1, a nitrogen atom-containing copolymerizable monomer is replaced with an acrylic monomer [(meth) acrylic acid ester etc.] without using a carboxyl group-containing copolymerizable monomer such as acrylic acid. It was confirmed that a pressure-sensitive adhesive sheet having good adhesive properties and optical properties can be obtained without being corroded on the metal surface (particularly the surface of the metal foil film layer).

Claims (12)

An optical product having a metal thin film layer or a pressure-sensitive adhesive sheet for directly sticking to the surface of a metal thin film layer of a member for constituting the optical product, which is 50% by weight based on the total amount of monomer components Copolymerizability containing (meth) acrylic acid ester and nitrogen atom-containing copolymerizable monomer of 10% by weight or more and less than 50% by weight and containing no carboxyl group-containing copolymerizable monomer. An optical product having a metal thin film layer, characterized by having a pressure-sensitive pressure-sensitive adhesive layer made of an acrylic pressure-sensitive pressure-sensitive adhesive having an acrylic polymer composed of a monomer component as a base polymer, or the optical Optical pressure-sensitive adhesive sheets for application to the surface of a metal thin film layer as a member for constituting a product.   2. The metal thin film layer according to claim 1, wherein the copolymerizable monomer component constituting the acrylic polymer does not further contain an acidic group-containing copolymerizable monomer other than the carboxyl group-containing copolymerizable monomer. Optical pressure-sensitive adhesive sheets for sticking to the surface of a metal thin film layer of an optical product having an optical product or a member for constituting the optical product.   3. An optical product having a metal thin film layer according to claim 1 or 2, wherein the optical product is an electronic display, or an optical pressure-sensitive adhesive sheet for attaching a surface of a metal thin film layer of a member for constituting the optical product. The pressure-sensitive adhesive layer formed of the acrylic pressure-sensitive adhesive has a total light transmittance before and after each of the heat treatment at 80 ° C. for 500 hours and the humidification treatment at 60 ° C. and 95% RH for 500 hours. The haze is 90% or more before and after each of the heat treatment and the humidification treatment, and the haze is 10% or less before and after each treatment of the heat treatment and the humidification treatment. The optical product having the metal thin film layer according to any one of claims 1 to 3, wherein the color difference (ΔE ^* ab) before and after each treatment of the humidification treatment is 0.5 or less. Optical pressure-sensitive adhesive sheets for attaching a metal thin film layer surface of a member for the purpose.   The nitrogen atom-containing copolymerizable monomer is selected from an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, a cyano group-containing monomer, an imide group-containing monomer, and an amino group-containing monomer. An optical product having a metal thin film layer according to any one of claims 1 to 4, or a metal of a member for constituting the optical product, wherein the metal product is at least one nitrogen atom-containing copolymerizable monomer. Optical pressure-sensitive adhesive sheets for thin film layer surface application. It is a pressure-sensitive adhesive tape or sheet. Optical sensation for applying an optical product having a metal thin film layer according to any one of claims 1 to 5 or a metal thin film layer surface of a member for constituting the optical product. Pressure-sensitive adhesive sheets. The optical product having the metal thin film layer according to any one of claims 1 to 6 , or the optical product, wherein the metal material for forming the metal thin film layer is a metal material containing a non-metal element together with a metal element. Optical pressure-sensitive pressure-sensitive adhesive sheets for sticking to the surface of a metal thin film layer as a member for constituting the sheet. The optical thin film layer according to any one of claims 1 to 7 , wherein the pressure-sensitive pressure-sensitive adhesive sheets are substrate-less double-sided pressure-sensitive pressure-sensitive adhesive sheets having a configuration formed only from a pressure-sensitive pressure-sensitive adhesive layer. Optical pressure-sensitive adhesive sheets for application to the surface of a metal thin film layer of a product or a member for constituting the optical product. The optical pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is a solvent-based or photopolymerization-type acrylic pressure-sensitive adhesive. 9. The optical film having a metal thin film layer according to any one of claims 1 to 8. Optical pressure-sensitive adhesive sheets for application to the surface of a metal thin film layer of a product or a member for constituting the optical product. An optical product having a metal thin film layer or a method for producing a pressure-sensitive adhesive sheet for directly sticking to the surface of a metal thin film layer of a member for constituting the optical product, the total amount of monomer components Contains 50% by weight or more (meth) acrylic acid ester and nitrogen atom-containing copolymerizable monomer 10% by weight or more and less than 50% by weight and does not contain a carboxyl group-containing copolymerizable monomer An acrylic pressure-sensitive adhesive comprising an acrylic polymer composed of a copolymerizable monomer component as a base polymer is prepared, and a pressure-sensitive adhesive layer is formed from the acrylic pressure-sensitive adhesive. An optical product having a metal thin film layer to be manufactured, or a method for producing an optical pressure-sensitive adhesive sheet for application to a surface of a metal thin film layer of a member for constituting the optical product. The optical product having a metal thin film layer according to claim 10 obtained by a solution polymerization method or a light or radiation polymerization method, or an optical pressure-sensitive adhesive for applying a surface of a metal thin film layer to a member for constituting the optical product. Manufacturing method of adhesive sheets. An optical product having a metal surface formed by a metal thin film layer, the optical product having the metal thin film layer according to any one of claims 1 to 9 directly on the metal surface, or the optical product. An article having a metal surface formed of a metal thin film layer, characterized in that an optical pressure-sensitive adhesive sheet for optical sticking on the surface of the metal thin film layer as a member for constituting a metal is laminated.