JPH0236943A - Laminated material - Google Patents

Abstract

PURPOSE:To obtain a laminated material suitable for obtaining a precoated steel sheet laminated material which is excellent in specular gloss by a method wherein a structure and a composition of each layer constructing the laminated material is made to be within a specific range. CONSTITUTION:A laminate is composed of a polyethylene terephthalate layer and a polyolefin layer. The polyethylene terephthalate layer is 100% or over in surface glossiness and 100 to 200mum in thickness. An opposite surface to a side facing the polyethylene terephthalate layer of the polyolefin layer is an adhesion layer of 0.5 to 25mum in thickness composed of modified polyolefin which is modified with unsaturated carboxylic acid or its anhydride or of polyolefin composition containing modified polyolefin. A polyethylene terephthalate film is preferably a biaxially oriented film from a standpoint of surface glossiness or the like. The modified polyolefin is obtained by graft reaction on polyolefin resin of unsaturated carboxylic acid or its anhydride. Thickness of the laminated material is necessarily 250mum or under from a standpoint of fabrication quality.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a laminate. For more information, please visit Polie/ This invention relates to a laminate with excellent saturation properties.

[Conventional technology]

Painted steel sheets have traditionally been widely used as industrial materials in various fields due to their excellent workability and design, but in recent years there has been a demand for further improving the design. There is an increasing demand to improve the surface gloss of.

One method is to apply an additional layer of clear coating on top of the painted surface of the painted steel plate, but this method gives the surface an apparent gloss, but the gloss is
Without "depth", it is impossible to create a mirror-like design, and
If the clear coat layer is thickened to create depth, there are problems such as the surface hardness decreases, making it more susceptible to scratches, and the coated surface may crack when subjected to secondary processing such as bending.

Therefore, a method of coating a painted steel plate with a transparent high molecular weight plastic film, in particular a method of coating with a biaxially oriented polyethylene terephthalate film (hereinafter referred to as PET film), which has excellent surface gloss and surface hardness, has been devised. P.E.
In order to adhere a polyester film such as T film to a steel plate, it is usually done by special surface treatment, application of an adhesive or primer, or the use of a hot-melt type resin. However, the adhesiveness (adhesive force) between the polyester and the metal plate of the laminate obtained by the above method is not sufficient, and various methods have been proposed to improve this adhesiveness. For example, as an adhesive layer for thermally adhering a metal and a polyester coating layer, ■ A method of using an ionomer resin or an ethylene-methacrylic acid copolymer resin (Japanese Patent Application Laid-open No. 2003-220001-22 or 27), ■ A method of using an ethylene-vinyl acetate copolymer A method using a composition comprising a modified polyolefin resin and
It has been proposed to use a composition in which an ionomer or a modified polyolefin resin is blended with polyester.

[Problem to be solved by the invention]

However, in the above proposed methods ① and ②, the resin used for the adhesive layer has low thermal stability, so it is easy to cause so-called fin sea eyes during the film forming process, etc. In severe cases, a gel with a brownish color may be formed, resulting in the appearance of the resin. Furthermore, since these resins have a low melting point, there is a problem in that when a peg is added to a laminate during secondary processing of the laminate, the adhesive strength between the coating layer and the metal base material decreases. In addition, although method (2) does not have the problem of reduced adhesive strength during primary processing, when forming the composition of the adhesive layer into a film, it must be formed at a high temperature, usually 200"C or higher, in accordance with the melting point of polyester. As a result, there was a problem in that the polyolefin modified by the ionomer contained in the composition was thermally degraded, causing fin sea eyes and significantly deteriorating the appearance.

[Failure to solve the problem]

In view of the above-mentioned problems, the inventors of the present invention have achieved the object and completed the present invention by making a material suitable for the above-mentioned use, specifically, having a specific range of specular gloss and composition. .

That is, the gist of the present invention is a laminate consisting of a polyethylene terephthalate layer and a polyolefin layer, in which the polyethylene terephthalate layer has a surface gloss of 100% or more and a thickness of 70 to 200μ, and the polyolefin layer has a The surface opposite to the side facing the polyethylene terephthalate layer is made of a modified polyolefin modified with an unsaturated carboxylic acid or its anhydride, or a polyolefin composition containing the modified polyolefin, and has a thickness of 0.5
The laminate is characterized by having an adhesive layer of ~25μ.

The present invention will be explained in more detail below.

The polyethylene terephthalate film used in the present invention has a surface gloss with a cross value of 100% or more, preferably 710% or more, as measured by the method of ASTM D-23, and a thickness in the range of 70μ to 200μ.

If the cross value is less than 100%, sufficient specular gloss cannot be imparted to the laminate. In addition, if the thickness is less than 70 μm, the coating layer picks up the irregularities of the base material, resulting in problems such as not being able to achieve the smoothness that is F4 of polyester film, and not being able to achieve the depth of gloss. There is a problem with ease of access. , 200 μm or more, the film is too thick and various problems arise when performing secondary processing such as drawing of the laminate.

The polyethylene terephthalate film is preferably a biaxially stretched film from the viewpoint of surface gloss, strength, etc.

The polyethylene terephthalate (hereinafter abbreviated as PET) refers to both a homopolymer consisting of terephthalic acid and ethylene glycol and a copolymer obtained by copolymerizing terephthalic acid and ethylene glycol with a third component. Such copolymers are known and the third component is usually an aromatic dicarboxylic acid such as isophthalic acid, naphthalene dicarboxylic acid,
Oxycarboxylic acids such as roxybenzoic acid, polyalkylene glycols such as propylene glycol, tetramethylene glycol, neopentyl glycol'l-(7)fulkylene glycol, and polyethylene glycol are used.

The proportion of the third component in the copolymer is usually less than /omol.

The laminate of the present invention is a multilayer film consisting of a PET layer and a polyolefin layer and having a thickness of 23'0μ or less, one side of which is the above-mentioned PET film, and the other side of which is an unsaturated carboxylic acid or its anhydride. Thickness 0.5 to .5 containing modified polyolefin. 2! It consists of at least two or more layers of polyolefin film having an adhesive layer of μ. It is used by being thermally laminated onto the painted surface of a painted steel plate using the adhesive layer.

It is preferable that the haze value of the laminate is 30% or less, as measured by the method of ASTM D-〆003.
If it is higher than %, the color tone of the painted surface of the painted steel sheet will change, which is not preferable.

In order to have a haze value of 30 coefficients or less, the polyolefin (including the raw material of the modified polyolefin) γ resin, which is lower than PET and which constitutes the laminate, needs to be made of a material that provides such a haze.

Examples of such materials include low density polyethylene, medium density polyethylene ethylene-alpha olefin copolymer, ethylene-vinyl acetate copolymer ethylene-(meth)acrylic acid copolymer, and ethylene (meth)acrylic acid ester copolymer. Examples include polymer polypropylene, propylene-α olefin random copolymer, and the like.

On the other hand, materials unsuitable for providing low haze values include high-density polyethylene (especially of high molecular weight), polypropylene block copolymers, and filler-reinforced polyolefins filled with large amounts of inorganic materials.

The thickness of the laminate is 2. Must be less than fOμ250
When μ is exceeded, problems arise in secondary workability, etc., as described above.

The modified polyolefin constituting the adhesive layer of the laminate can be obtained by subjecting a polyolefin resin to a graft reaction with an unsaturated carboxylic acid or its anhydride. There are no particular restrictions on the polyolefin resin as long as it is selected from the polyolefin resins listed above. The polyolefin composition preferably contains 5-25% by weight of a modified polyion 24 modified with an unsaturated carboxylic acid in an amount of 7-3% by weight and 25-j% by weight of a polyolefin resin having a melting point of 100° C. or higher.

The above-mentioned ethylene-α-olefin copolymer mainly contains ethylene, propylene, butene-/, hexene-1
It is a copolymer of α-olefins such as 1-octene-/, ≠-methyl bench roof, and generally has a density of 0.
．． In the present invention, a material having a density of 93 ot/crd or less, more preferably 02 sy/cr/I or less is preferably used in the present invention.

Examples of the unsaturated carboxylic acid or its anhydride include acrylic acid, methacrylic acid, maleic acid, maleic anhydride,
Examples include citraconic acid, citraconic anhydride, itaconic acid, itaconic anhydride, etc. Furthermore, examples of unsaturated carboxylic acids or derivatives of their anhydrides include esterification products of monoepoxy compounds and the above acids, and compounds containing these acids in the molecule. Examples include reaction products of a polymer having a reactive group and an acid. Maleic anhydride is particularly preferably used.

The method for causing the graft reaction with the ethylene-α olefin copolymer may be a solution method or a slurry method, but from an economic standpoint, a melt mixing method is preferable. In the case of the melt mixing method, an unsaturated carboxylic acid or its anhydride and a radical reaction initiator such as an organic peroxide or an azobis compound are added to the raw material ethylene-α-olefin copolymer powder or pellets according to a conventional method. Either by tri-blending using a Henschel mixer or the like, or by dissolving an unsaturated carboxylic acid or its anhydride and an initiator in an organic solvent, the powdered ethylene-α-olefin copolymer is sprayed onto pellets, and mixed with Henschel. Blend using a shell mixer etc. The powder or pellets of the blended ethylene α-olefin copolymer is put into a mixing machine whose system is directly exchanged with nitrogen gas, such as a Banbury mixer, a double screw mixer, etc., at a temperature of 720 to 300°C for a period of time. The above-mentioned modified polyolefin is obtained by melt-kneading for 0.7 to 30 minutes.The amount of the unsaturated carboxylic acid or its anhydride grafted to the above-mentioned modified polyolefin is usually in the range of ethylene-α-olefin copolymer. 0.7-% by weight, preferably in the range 0.7-3% by weight.

If the modified amount of the unsaturated carboxylic acid or its anhydride is less than the lower limit, the adhesion to the metal substrate will be insufficient, and if it exceeds the upper limit, not only will the adhesive force not be effectively applied, but grafting will not occur. There is a problem that as the amount of unsaturated galponic acid or its anhydride component increases, the adhesive strength actually decreases.

Further, the amount of the initiator is 0.7% by weight or less, preferably 0.007 to 0.0j based on the ethylene-α olefin copolymer.
This is within the weight range. The organic peroxides used as the initiator include benzoyl peroxide, acetyl peroxide, di-t-butyl peroxide,
-butyl peroxylaure-1., dicumyl peroxide, α, α'-bis-t-butylveroquine-p-diisopropylbenzene, 2. ! -dimethyl-, 2. ,j
-di-t-butylperoxyhexane,! , j-gee t
-butylperoxyhexyl, t-butylperoxybenzoate. -butyl-g, tI--bis-t-butyl peroxyvalate, octanoyl peroxide,
Examples include p-menthane hydroperoxide, and examples of the azobis compounds include azobisinftyronitrile, co-2,2'-azobis(,2,4t, Hiro-trismethylvaleronitrile), and 2' , 2'-azobis(2-7 cloprobyl propionitrile) nato.

As the adhesive layer in the present invention, a composition in which a polyolefin resin having a melting point of 100° C. or higher is blended with the modified ethylene-α olefin copolymer described above is preferably used.

Here, it is preferable that the melting point of the polyolefin resin is 100°C or higher.If the melting point is lower than 100°C, the polyolefin resin fd, which has a generally low melting point, has poor thermal stability, which may cause deterioration in appearance due to gels and fish eyes as described above.
The finally obtained laminate is sometimes treated with pressurized hot water to clean the surface of the pressed layer, but there are problems such as poor adhesive strength against such treatment.

As the polyolefin resin, polyolefins such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene/kyoden-]-2-combination, etc. are preferably used. Ru.

Modified polyol blended with such polyolefin resin/
In the adhesive layer formed from the fin composition, the blending ratio of modified polyolefin and polyolefin resin is j:P,
to 9. ! ; : between s゛ and the thickness of the adhesive layer is 0. ! When rμm2jμ is preferably /μ~20μ and more preferably il''i!μ~〆lμ, a laminate with particularly strong adhesion between the coating layer and the metal base material is obtained.Among these, when the thickness of the adhesive layer is below the lower limit This makes it difficult to control the thickness and is not practical.

Further, if the blending ratio of the modified polyolefin in the modified polyolefin composition is less than 5%, adhesion to metal profiteers cannot be obtained. The key to obtaining strong adhesion is that the thickness of the adhesive layer made of the composition within the above range is controlled to be below the upper limit of the above thickness. Contrary to the conventional perception that the adhesion is good, on the contrary, the adhesiveness decreases, and when the modified polyolefin composition in the modified polyolefin composition has a ratio of TATA or higher, the adhesion is stable from relatively thin to thick adhesive layers. Although it can produce force, its adhesive strength is insufficient.

The melting point of the polyolefin resin referred to in the present invention is determined from the endothermic peak by differential thermal analysis. When the resin is a mixture of two or more types and there are many endothermic peaks, the endothermic peak resulting from the main component is taken as the melting point of the resin.

In addition, the resin used for the adhesive layer must be stable against heat so as not to cause noisy eyes or gel during film molding. Polymers and copolymers such as ethylene-methacrylic acid copolymers do not meet this requirement.

Although the above-mentioned modified polyolefin composition has a certain degree of thermal stability on its own, it is more preferable that it is stabilized by the addition of an antioxidant, etc. The degree of stabilization is determined by the oxidation reaction measured under the conditions described below. It is preferable that the time (0RT) be stabilized to be at least 1 minute, more preferably at least 1 minute.

The ORT referred to here is measured with a differential scanning calorimeter ([)SC), and its conditions and definitions are as follows.

・Sample: By press-molding the raw material resin, a sheet 1 having a body of ±0.7 in the o and s columns is made, and a 5 mm/yng cut out from it is used as a sample.

Self-appropriate energy...Sample cell/±0. / cc
/ mit+ (7) Divide and let air circulate.

・Temperature increase: Increase the temperature from room temperature to 2 J-, 1''C at <'0'c/ynrn.

・Definition of OR, T ・The time from the completion of temperature rise until the peak of the thermogram of the heat generated by the oxidation reaction appears on the chart ball.

Any known additives may be used to stabilize the modified polyolefin resin, but generally, phenol-based radical promoters and peroxide decomposers such as thioether-based and phosphite-based additives are used. It is effective to use them together.

Examples of the phenolic radical promoter include:
! , O-dicytriphytyl-t-methylphenol, 2
．． ≠-dimethyl-6-tert-butylphenol, 3-tert-butyl-hydroxyanisole, 2. O-Dioctadenru-p-Cresol 1. ,z,tx-shi,
If Le-g-inbonylphenol n-octadecyl-β-(φ'-hydroxy 3
:s'-di-tert-butylphenol) flobionate, styrenated phenol,! , Kudimethyl-6-α
-Methylcyclohexylphenol, g,p'-phyteridene-bis(3-methyl-tert-butylphenol), //. , F'-methylene-bis(2, O-
3rd) methylphenol-methylene-bis (6-thylphenol-methylene-bis),! , 2'-methylene-bis (O-tertiary pterugoethylphenol),
Alkylated bisphenol, 2+O-bis(2'-hydroxy-3'-mtributylruta'-methylbenzyl)
-'l=Meflphenol, tris(2-methyl-≠-hydroxy-J"-tert-butylphenyl)butane, tetrakis-[methylene-(3-tert-tert-phthyl≠-hydroquine-hytrocinnamate) ]Methane, hydroquinone monobenzyl ether, 4, g
'-thiobis(6-tert-butyl-m-ri, resol),
21.2'-thiobis(4t-methyl-ot-tert-butylphenol), bis(,2-hydroxy-3,
j-di-tert-butylphenyl) sulfide, 2.
2'-methylenebis(4L-methyl-ot-α-methylcyclohexylphenol), /,3,! -trimethyl-2,≠,6-tris(3,t-tert-butyl-hiro-hytrooxybenzyl)benzene, co,hiro-bis(
4t--hydroxy-3. r-theta triphthylphenoxy)-6-(+1-octylthio)-/,3,,
5′-triazine, Otsu-(≠-high doyloxy-3
．． ! -tert-butylanilino)-2, goobis(n-
octylthio)-/, 3. ! -triazine, (Hiro-hydroxy-3j-di-tert-butylbenzyl)-dioctadecyl phosphate, phosphorus-alkylated phenol condensate, tetrakis[methylene-3-(3,j-di-tert-butyl-guhydroxyphenyl) ) propionate comethane, etc.

On the other hand, peroxide decomposers include dilauryl thiodipropionate, dilauryl thiodipropionate, stearyl φ lauryl thiodipropionate, dilauryl thiodiisobutyrate, distearyl ethylidene dithiodiglycolate, di-β- Naphthyl ethylidene dithiodiglycolate, triphenyl phosphite, trisnonylphenyl phosphite, diphenyldecyl phosphite, phenyldidecyl phosphite, tridecyl phosphite, trilauryl trithiophosphite, triotadecyl phosphite, cyclic neo Pentanetetryrubis(octadecyl phosphite), tris-(22 μm di-tert-butylphenyl) phosphite,
p, +'-biphenylene diphosphinic acid tetrakis (2
, 4t-di-tert-butylphenyl), mimercaptobenzothiazole, mercaptobenzothiazole, zinc ethyl phenyl dithiocarbamate, dodecyl mercaptan, thiobis(β-naphthol), thiobis(N-phenyl-β-naphthylamine), phenothiazine, tri- Examples include acrylphosphine, Hiroshi, μ'-thiobis(3-methyl-6-tert-butylphenol), and tetramethylthiuram disulfide.

There are no restrictions on the amount of the additive added as long as the above requirements are met, but if the amount added is too large, not only will the effect not be achieved, but the additive may bleed, which may adversely affect adhesive properties. Therefore, care must be taken, and it is usually added between 100 ppm and 1100 OOpp based on the resin.

The laminate of the present invention is composed of a film having a thickness of 230 μm or less that includes the above-mentioned PET layer and adhesive layer on both sides, and is laminated on the painted surface of a painted steel plate via the adhesive layer. When the polyolefin layer of PETi or less of this film becomes a multilayer film including an adhesive layer and a layer made of unmodified polyolefin, the multilayer film may be formed by any known method. Examples include a method of extrusion laminating the modified polyolefin composition as described above, and a method of forming a multilayer film all at once by coextrusion method.

Further, in the case of forming a multilayer film, additives such as a heat stabilizer can be added to the adhesive layer as well as the unmodified polyolefin layer.

Any known method can be used to laminate a polyolefin film and a polyester film, but a common method is to apply corona treatment to a polyolefin film and then laminate it with a polyester film using a dry lamination method. The amount of corona treatment is preferably such that the wetting tension of the adhesive surface of the polyolefin film falls within the range of 0 to so dyne/Cm.

Further, when laminating, it is preferable to use a known anchor coating agent such as a polyurethane type, an alkyl titanate type, a polyethyleneimine type, or an incyanate type as an anchor coat agent.

Further, in the present invention, it is also possible to print a desired pattern on the back side of the polyester film in advance, for example, in order to impart design properties to the laminate.

The laminate obtained as described above is thermally laminated to a painted steel plate via the adhesive layer described above.

The type of coated surface of the painted steel sheet is not particularly limited as long as it has adhesive properties to the adhesive layer described above, but generally polyester-based, epoxy-based, acrylic-based, polyurethane-based, etc. coated surfaces are suitably selected. , the above-mentioned adhesive layer exhibits unprecedented strong adhesion to these painted surfaces. On the other hand, vinyl chloride-based coated surfaces are not suitable because they not only do not exhibit adhesion to the adhesive layer, but also have problems such as generation of thermal decomposition gas from the vinyl chloride during heat treatment for thermal lamination.

The heat lamination method may be any known method, such as a heat press method or a method of pressing onto a preheated metal substrate with a roll, but the present inventors have developed a special method to obtain particularly strong adhesion. It is possible to employ the method disclosed in Japanese Patent Application No. 1997-29931, ie, the method in which the film to be laminated and the metal base material are laminated together, then heated to a temperature higher than the melting point of the adhesive layer, and then rapidly cooled.

The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

Examples/~7 and Comparative Examples/~6 (1) Preparation of modified polyolefin O modified polyolefin A/ Density 0.11 t/c+y! Melt index (M
I)=≠? /10 minutes for ethylene-butene copolymer! 000 ppm of maleic anhydride was mixed and a graft reaction was carried out in a single-screw extruder using an organic peroxide as an initiator.

0 Modified polyolefin A2 Density 0.92'? /ctd, MI=7 Y// for 0 min ethylene-butene copolymer/! ;00ppm
Maleic anhydride was mixed to prepare A/.

(2) Preparation of modified polyolefin composition for adhesive layer A composition having the formulation shown in Table 1 was prepared by kneading it at 770°C using a Banbury mixer.

Note that low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and ethylene-vinyl acetate copolymer (EVA) in the table each have the following physical properties.

LDPE: Density=0. ri229/crd, MI==
23-3, jf/10 min Melting point =/10℃ LLDPE: Density = 0.930 g/7, M =/
O7710 min, melting point =/+26°C EVA: Ethylene-vinyl acetate copolymer with vinyl acetate content of 10% M I =3. j? / / 0 minutes, melting point -26°C Oxidation reaction time (ORT) of the composition obtained in this way
are shown in Table 1.

(3) Molding density of multilayer film 0. A layer of a composition containing 0.03 parts each of Irganox 1010 (trade name) and Irgafuos 76g (trade name) manufactured by Ciba Geigy as a stabilizer in LDPE with a temperature of 2.2 f/crd and an MI of 3.39710. A two-layer film with a thickness of 0μ and a layer made of modified polyolefin was formed at tOoC. After applying corona treatment to the surface opposite to the adhesive layer of this two-layer film so that the surface tension becomes a and 2 dyne/Crn, using a urethane adhesive, the surface gloss cross value is /μθ% and the thickness is 50μ. It was dry laminated with a biaxially stretched PET film.

(4) Laminated with a metal base material Painted white with a polyester paint with a thickness of 0. lt
The galvanized steel plate of the arm is heated to a plate temperature of 200°C, and the multilayer film created as described above is rolled onto the painted surface with the adhesive layer in contact with the painted surface. It was heat-treated again for 30 seconds in an atmosphere of 2-0°C, and then cooled with water to form a laminate.

(5) Evaluation method of laminate O Adhesiveness Conduct Erichsen test according to JIS-47≠g #
The floating in the mold notch was evaluated according to the following ranks.

Rank A No abnormality B Slightly floats C Clearly floats D Large floats E Completely peels d Hot water resistance The test piece obtained as above was treated for 3θ while diving, and the #-shaped notch floated to the above rank. It was evaluated.

The appearance of the film was visually inspected, and surface irregularities caused by fish eyes and gel in the film were rated as ○△x in descending order.

(6) Evaluation results of laminate Shown in Table 2.

Comparative Example 7 The same procedure as in Examples 1 and 2 was carried out, except that the P hood T film having a surface gloss cross value of g% was used.

In this case, the multilayer film had a good haze value, but the surface gloss of the laminate with the painted steel plate was poor, and the image of the surrounding scenery reflected on the surface was blurry. . The evaluation results are shown in Table 2.

Comparative Example-g The same procedure as in Example-/ was carried out except that a PET film having a surface gloss cross value of 732% and a thickness of ♂μ was used.

In this case, although the surface appearance of the laminate with the painted steel plate was good, the image of the surrounding scenery reflected on the surface lacked depth and lacked three-dimensionality. The evaluation results are shown in Table 2.

Comparative Example-2 Density 0.922 in molding the above multilayer film? /
m, M I is density ory s3 instead of 3.5g/10bu DPE? / cr/l, M I is 0.0527
The same procedure as Example f was carried out except that IDPE (10 minutes) was used and a polyester-based brick-colored painted steel plate was used as the painted steel plate.

In this case, the haze value of the multilayer film was extremely poor, and the bright brick color applied to the painted steel plate turned into a dull brick color in the laminate. The evaluation results are shown in Table 2.

Table 2-28 = Table - [Effects of the Invention] When the laminate of the present invention is heat-laminated onto a painted steel plate or the like, it has excellent adhesive properties and is extremely easy to work with, and its surface gloss is excellent and the appearance is improved. It is very effective in practical use.

Claims (1)

[Claims] (1) A laminate consisting of a polyethylene terephthalate layer and a polyolefin layer, where the polyethylene terephthalate layer has a surface gloss of 100% or more and a thickness of 10 to 2
00μ, and the polyolefin layer is made of a modified polyolefin whose surface opposite to the side facing the polyethylene terephthalate layer is modified with an unsaturated carboxylic acid or its anhydride, or a polyolefin composition containing the modified polyolefin. A laminate characterized by having an adhesive layer having a thickness of 0.5 to 25 μm.