KR20160081428A - Security foil - Google Patents

Abstract

The present invention relates to a security film. More specifically, the present invention relates to a security film which exhibits excellent long-term durability and is not easily broken by frequent contact, abrasion, or washing. To this end, the security film includes a base film layer, a release layer, a first protection layer, a relief structure layer, a deposition layer, a second production layer, and an adhesive layer.

Description

Security film {Security foil}

The present invention relates to a security film. And more particularly to a security film usable for gift certificates and banknotes.

It is desirable that security documents such as gift certificates, banknotes and banknotes are damaged by moisture or chemicals during handling, so that they have moisture-proof property and chemical resistance. In particular, the security film applied on the substrate constituting the security document should not be easily damaged even under extreme conditions including frequent contact wear or accidental washing.

In general, the security film applied to security documents includes a hologram film, which is made up of multiple layers.

The holographic film is formed with an aluminum deposition layer on a relief structure layer representing a hologram. At this time, the adhesion between the aluminum deposition layer and the relief structure layer is weak, and when the security film is exposed under the extreme conditions, the aluminum deposition layer is easily detached. Further, in the case of a hologram film for banknotes, a vapor deposition layer removing process for removing a part of the aluminum vapor deposition layer is required depending on the design. In this case, adhesion is important to the portion where the aluminum vapor deposition layer is to be selectively left.

Therefore, it is necessary to research and develop security films to ensure long-term durability so that the security films are not easily damaged by frequent contact and washing.

Korean Published Patent No. 2011-0119890 (2011.11.03)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to improve adhesion between a relief structure layer and a deposition layer in a security film including a hologram. That is, it is an object of the present invention to provide a security film excellent in long-term durability because it is not easily damaged by frequent contact and washing.

In addition, in the deposition layer etching process step performed in some processes, the deposition layer should be selectively left. The present invention aims to provide a security film which is easily removed at a portion where a vapor deposition layer is not to be present, do.

According to an aspect of the present invention, there is provided a security film comprising a base film layer, a release layer, a first protective layer, a relief structure layer, a deposition layer, a second protective layer,

And a adhesion-strengthening layer between the relief structure layer and the deposition layer.

In the security film according to one embodiment of the present invention, the adhesion enhancing layer may include any one or a mixture of two or more selected from a urethane compound, an acrylic compound and an ester compound.

In the security film according to an embodiment of the present invention, the adhesion enhancement layer may have a dry coating thickness of 2 to 10% of the total thickness of the security film. Here, the dry coating thickness means the thickness after coating and drying.

In the security film according to an embodiment of the present invention, the releasing layer is formed by applying a releasing composition comprising a polyurethane resin and a solvent, wherein the coating amount after drying is 0.03 to 0.15 g /

The releasing composition may have a solid content of 0.5 to 3.0% by weight.

In the security film according to an embodiment of the present invention, the polyurethane resin may be any one or more selected from the group consisting of polyurethane, polyether polyurethane and polycarbonate polyurethane.

The security film according to the present invention has an advantage that the adhesion between the relief structure layer and the deposition layer can be improved.

Further, the present invention is advantageous in that it is not easily damaged by abrasion due to frequent contact or washing and has excellent long-term durability.

In addition, the present invention is advantageous in that the deposition layer is selectively left in the process of etching the deposition layer in some processes, and the residual and removal efficiency is excellent.

1 is a cross-sectional view of a security film according to an embodiment of the present invention.

Hereinafter, the security film of the present invention will be described in detail. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Further, it is to be understood that, unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

The security film according to the present invention is characterized in that a base film layer, a release layer, a first protective layer, a relief structure layer, a vapor deposition layer, a second protective layer and an adhesive layer are sequentially formed, and adhesion strength between the relief structure layer and the vapor deposition layer Layer. ≪ / RTI > The adhesion enhancing layer is formed to enhance the adhesion between the relief structure layer and the deposition layer. In addition, the adhesion strengthening layer according to the present invention can further enhance the adhesion strength of the surface of the relief structure layer on which the emboss is formed by performing surface treatment by electric corona discharge, plasma, or the like, Thereby enhancing durability.

The relief structure layer can embody a surface relief type hologram including embossing patterns by embossing. The relief structure layer is formed by coating on the first protective layer.

One aspect of the relief structure layer in the present invention may include polystyrene, polymethyl methacrylate, nitrocellulose, etc. when the first protective layer is a polyester-based compound. Molding of the relief structure layer can be carried out using heat and pressure, or ultraviolet curing may be used and is not necessarily limited thereto. When the relief structure layer is laminated on the first protective layer, the first protective layer may be subjected to surface activation treatment such as corona discharge treatment or plasma treatment.

The thickness of the relief structure layer is not particularly limited, but may be preferably 0.3 to 3 占 퐉.

An adhesion strengthening layer is formed on the relief structure layer. The adhesion-enhancing layer significantly improves the interlayer adhesion between the relief structure layer and the deposition layer, thereby achieving a synergistic effect of the wear resistance and long-term durability of the film.

In the present invention, the adhesion strength between the relief structure layer and the deposition layer may be 50 to 200 gf / mm, preferably 135 gf / mm or more. The interlaminar adhesion is measured by using an adhesion force gauge, and the force in the longitudinal direction when the specimen adhered to the glass surface of 1 cm 2 area is measured is measured. When the above-mentioned range is satisfied, wear resistance and adhesion can be increased and durability can be further improved, which is preferable.

The adhesion enhancing layer includes any one or a mixture of two or more selected from a urethane compound, an acrylic compound and an ester compound.

The urethane-based compound may be a polyurethane resin. The polyurethane resin is not particularly limited, but a water-soluble or water-dispersible polyurethane resin obtained by reacting a diol compound with a diisocyanate compound can be used. Two or more different types of the polyurethane resins may be used.

As the diol compound, a diol compound obtained by polymerization of a heteroalkylene oxide such as ethylene oxide, propylene oxide or ether such as tetrahydrofuran can be used. As one specific example, polyether diols such as polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and polyhexamethylene ether glycol can be used. It is also possible to use polyester diols such as polyethylene adipate, polybutylene adipate, polyneopentyl adipate, polymethyl pentyl adipate, polyethylene / butylene adipate and polyneopentyl / hexyl adipate, polycaprolactone diol, Polycarbonate diol, and the like, but not always limited thereto.

As the isocyanate compound, an aromatic diisocyanate, an alicyclic diisocyanate or an aliphatic diisocyanate can be used. As specific examples, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Xylylene diisocyanate, 1,4-xylene diisocyanate, 1,4-cyclohexane diisocyanate and 4,4-dicyclohexylmethane diisocyanate, tetramethyl diisocyanate, tetramethyl diisocyanate, Isocyanate, hexamethylene diisocyanate, methylcyclohexane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, and the like, but not always limited thereto.

As preferred examples of the polyurethane resin in the present invention, any one or more selected from the group consisting of polyurethane, polyether polyurethane and polycarbonate polyurethane can be used, but not always limited thereto. The polyurethane resin may be a self-emulsifying emulsion or a self-stabilized emulsion, preferably a diol having an acidic group such as a carboxylic acid group or a sulfonic acid group, or a polyhydroxy compound having a low molecular weight may be added. More preferably, a polyurethane resin having a carboxyl group can be used.

In the present invention, the polyurethane resin is, in one embodiment, 10 to 30% by weight of a polyester-based polyol having a weight average molecular weight of 5000 g / mol or less, more preferably 1000 to 2000 g / mol, and aliphatic isocyanate 50 to 70 5 to 15% by weight of a carboxyl group-containing surfactant, and 5 to 15% by weight of triethylamine, followed by urethane reaction. As the aliphatic isocyanate, hexamethylene diisocyanate and the like can be used. As the carboxyl-based surfactant, dimethylpropionic acid or diethylbutionic acid may be used, and preferably an acid vale of 40 to 45 mgKOH / g may be used.

The adhesion reinforcing layer may be formed by coating a water-dispersed polyurethane resin composition comprising a polyurethane resin on a relief structure layer as an embodiment.

The water-dispersible polyurethane resin composition may, in one embodiment, comprise 0.5 to 2.0% by weight of polyurethane resin solids, 0.01 to 0.5% by weight of a silicone-based wetting agent, and a residual amount of water.

In the present invention, the acrylic compound is not particularly limited, but may be an acrylic resin polymerized or copolymerized from a monomer mixture containing an acrylic monomer or a (meth) acrylamide monomer as a main component. (Meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, glycidyl (meth) acrylate, glycidylalkyl (Meth) acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, But is not limited to.

In the present invention, the ester compound is not particularly limited, but polyester resins, monoesters, diesters, polyol esters and the like can be used. Examples of the polyester resin include polyethylene terephthalate, polyethylene naphthalate and polyethylene naphthalate. Examples of the monoester include normal butyl oleate, 2-ethylhexyl oleate, 2-ethylhexyl stearate, 2- Ethylhexyl stearate, butoxyethyl oleate, and the like. Examples of the diesters include dibutyl adipate, diisocyanate adipic acid, diisodecyl adipic acid, azelaic acid di-2-ethylhexyl, azelaic acid iso-octyl, azelaic acid isononyl, Ethylhexyl, sebacic acid diisooctyl, sebacic acid diisononyl, dodecane-2-ethylhexyl, 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-di And diesters of methyl propanoate. Examples of the polyol ester include neopentyl glycol, an ester of a carboxylic acid having 8 to 10 carbon atoms, an ester of trimethylol propane and a carboxylic acid having 8 to 10 carbon atoms, and the like.

In addition, the present invention may comprise an aqueous vinyl polymer which is the reaction product of one or more ethylenically unsaturated monomers. For example, the ethylenically unsaturated monomer may be selected from the group consisting of styrene, isoprene, acrylic acid, methacrylic acid, itaconic acid, crotonic acid,? -Methylstyrene, vinylnaphthalene, vinyltoluene, chloromethylstyrene, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl Acetate, butyl acrylamide, ethyl acrylamide, and the like.

In addition, the present invention can further comprise a setting agent in the aqueous vinyl polymer to prepare a coating composition. These adhesives include Rhoplex SG-30, Rhoplex HG-74P, Rhoplex SG-10M, Ucar 626, Ucar 379G, Aquamac 705, Aquamac 588, and the like, but are not limited thereto.

In the present invention, the adhesion-promoting layer may have a dry coating thickness of 0.5 to 10%, preferably 1 to 5%, based on the total of the relief structure layer and the deposition layer. When the above range is satisfied, it is possible to maximize the interlayer adhesion effect, and it is more preferable that the deposition layer is selectively left in the process of etching the deposition layer in the process of manufacturing the security film.

In the present invention, a deposition layer is formed on the adhesion enhancing layer. At this time, the thickness of the deposition layer is not particularly limited, but may be preferably 100 to 1,000 angstroms. The deposition layer may be a metal deposition layer deposited with a metal such as aluminum, silver, gold, or tin, or a transparent deposition layer deposited with a transparent synthetic resin. The deposition layer may be an aluminum deposition layer.

In the present invention, the base film layer may be formed of any one of a PET (polyethyleneterephthalate) film, a PC (Polycarbonate) film, a PI (polyimide) film and a PEN (polyethylenenaphthalate) film. It is preferable to use a PET film.

In the present invention, the release layer is formed using at least one selected from release agents such as polyurethane series, acrylic series, and cellulose series. The polyurethane based release agent is preferable because it has a high surface energy of 40 to 55 mN / m and a good adhesion to the protective layer. The polyurethane resin is not particularly limited, but it is preferable that the elongation at room temperature (25 DEG C) is 100% or less. When the elongation is 100% or less, excellent cutability and releasability are obtained. The polyurethane resin may be selected from polyurethane, polyether polyurethane and polycarbonate polyurethane.

The release layer comprises a polyurethane resin and a diluting solvent. The release composition having a solid content of 0.5 to 3.0% by weight is applied after drying to a coating weight of 0.03 to 0.15 g / m 2. In this case, the release layer is coated by a gravure coating method, the mesh of the gravure roll is 175 mesh, and the diluting solvent used for the solid content adjustment is isopropyl alcohol and pure water from which the ion component is removed is 4: 6 to 6: 4 is suitable. When coated in the above manner, the solid content of the polyurethane-based releasing composition is preferably in the range of 0.5 to 3.0 wt%, and more preferably 0.8 to 1.5 wt%. If the content of the polyurethane used in the release layer is more than 3% by weight, the cutability becomes poor and it can not be used as a stamping foil. If the content is less than 0.5% by weight, the releasing force is too high, This causes a problem of poor performance. When the solid content is 3 wt%, the coated amount after drying is 0.15 g / m 2, and when the solid content is 0.5 wt%, the coated amount after drying is 0.03 g / m 2.

In the present invention, the first protective layer and the second protective layer may be formed by coating and drying a resin composition for forming a protective layer including an epoxy resin, a curing agent, and a solvent.

The epoxy resin may be at least one selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolac epoxy resin, a cycloaliphatic epoxy resin, a multifunctional amine epoxy resin, a glycidylamine epoxy resin, a dimer acid modified epoxy resin, A urethane-modified epoxy resin, a brominated epoxy resin, a brominated phenoxy epoxy resin, a hydridesided bisphenol A type epoxy resin, and a polyol modified epoxy resin.

The epoxy resin may be at least one selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolac epoxy resin, a cycloaliphatic epoxy resin, a multifunctional amine epoxy resin, a glycidylamine epoxy resin, And may include one or more selected from the group consisting of an epoxy resin, a urethane-modified epoxy resin, a brominated epoxy resin, a brominated phenoxy epoxy resin, a hydridesided bisphenol A type epoxy resin, and a polyol modified epoxy resin. It is not limited.

The epoxy resin may be at least one of a saturated or unsaturated aliphatic compound, an alicyclic compound, an aromatic compound, or a heterocyclic compound, but may preferably be an epoxy resin containing an aromatic functional group in the molecule. For example, an epoxy resin having a glycidylamine moiety derived from meta-xylylenediamine, an epoxy resin having a glycidylamine moiety derived from 1,3-bis (aminomethyl) cyclohexane, An epoxy resin having a glycidyl amine moiety derived from methane, a glycidyl amine moiety derived from para-aminophenol and / or a glycidyl ether moiety, an epoxy resin having a glycidyl ether moiety derived from bisphenol A An epoxy resin having a glycidyl ether moiety derived from bisphenol F, an epoxy resin having a glycidyl ether moiety derived from phenol novolac, and an epoxy resin having a glycidyl ether moiety derived from resorcinol, etc. , Preferably an epoxy resin having a glycidylamine moiety derived from meta-xylylenediamine, 1,3 An epoxy resin having a glycidyl amine moiety derived from bis (aminomethyl) cyclohexane, an epoxy resin having a glycidyl ether moiety derived from bisphenol F, and an epoxy resin having a glycidyl ether moiety derived from resorcinol And resins can be used.

The epoxy resin may be a dimer acid-modified epoxy resin. The dimeric acid-modified epoxy resin improves the adhesive strength to improve the performance of the protective layer, and can exhibit a synergistic effect of mechanical properties such as durability, flexibility, impact resistance and heat resistance of the film. The dimeric acid-modified epoxy resin may be one obtained by reacting at least one carboxyl group in the dimeric acid structure with a polyfunctional epoxy resin.

The curing agent may include any one or two or more amine-based curing agents selected from the group consisting of aliphatic amines, modified amines, aromatic amines, tertiary amines, and polyamine-based compounds.

Preferably, a polyamine-based curing agent can be used. For example, aliphatic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, aliphatic amines having aromatic rings such as meta-xylylenediamine and p-xylylenediamine, aliphatic amines such as 1,3-bis (Aminomethyl) cyclohexane, isophoronediamine, and norbornenediamine, aromatic amines such as diaminodiphenylmethane, metaphenylene diamine, and the like, but are not limited thereto.

The curing agent may be contained in an amount of 70 to 250 parts by weight, preferably 100 to 250 parts by weight, more preferably 150 to 200 parts by weight, based on 100 parts by weight of the epoxy resin. When the content range is satisfied, the curing rate is good and the workability is excellent.

The resin composition for forming a protective layer may have a viscosity of 1,000 to 3,000 cP (25 캜), preferably 1,500 to 2,500 cP (25 캜).

In the present invention, the thicknesses of the first protective layer and the second protective layer may be preferably 0.1 to 10 탆, more preferably 0.5 to 2 탆.

The first and second protective layers may be the same or different in thickness and preferably have the same thickness so as to prevent deformation of other laminated components in the relief structure layer or the security film due to external tension It is better. In addition, the resin material for forming the first protective layer and the second protective layer is preferably the same in terms of dimensional stability and durability.

In the present invention, at least one of the first protective layer and the second protective layer preferably has transparency to such an extent that the relief structure layer can be visually recognized, or the relief structure layer can be colored to such an extent that it can be recognized.

1 is a cross-sectional view of a security film according to an embodiment of the present invention. Referring to FIG. 1, a release layer 20, a first protective layer 30, a relief structure layer 40, The layer 50, the deposition layer 60, the second protective layer 70, and the adhesive layer 80 may be sequentially formed.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

Hereinafter, physical properties were measured by the following methods.

(1) Adhesion (unit: gf / mm)

After the specimens were cut at intervals of 1 cm, adhesion between the aluminum deposition layer and the adhesion strengthening layer was measured by a 180 ° peel method using a friction coefficient meter.

(2) Etching time of the aluminum deposition layer (unit: sec)

A sample (1 cm x 10 cm x 200 m) having an aluminum deposition layer formed on the adhesion enhancing layer according to the example was immersed in an alkali solution (NaOH, 1%) to measure the time during which aluminum was etched.

(4) Optical density

After the deposition layer is formed, 10 points of the deposited film are selected at intervals of 5 cm, and the result is measured with an optical density meter (Gretag Macbeth, IC Film) and the average value is calculated.

(5) Durability evaluation

① Chemical durability

The specimens according to Examples and Comparative Examples were immersed for 30 minutes at 23 ° C in the components shown in the following Table 1 and classified according to the degree of change and the following minimum requirements.

② Physical durability

(ASTM D996), durability (conducted by NBS Crumping Device of IGT brand) and cross-cutter interlaminar adhesive strength test (ASTM D3359) as shown in Table 1 below. In addition, the washability was evaluated by putting a cotton cloth containing the test piece in a general washing machine, and washing the cloth with general detergent (1 g / L) and cold water for 30 minutes. The results are categorized according to the following minimum requirements.

③ Environmental durability

Heat resistance, cold resistance and light resistance were tested under the conditions shown in Table 1 below and classified according to the following minimum requirements.

[Minimum Requirements Legend]

5: No change (less than 5%) 4: Fine change (less than 20%)

3: Significant change (less than 50%) 2: Significant change (more than 50%) 1: Element disappears

(Example 1)

As a base film, a polyethylene terephthalate (PET) film (FQ00, manufactured by KOLON CORPORATION) having a thickness of 12 mu m was used. A security film was prepared by sequentially coating a release layer, a first protective layer, a relief structure layer, a vapor deposition layer, a second protective layer and an adhesive layer on the base film as described below. The properties of the prepared security films were measured and are shown in Table 1.

Release layer: 8.0% by weight of acrylic resin (lubriazole, RA17-1 grade, solid content 25%), 0.225% by weight of wax (wax, montan OP wax, solid content 100%), solvent (toluene: methyl ethyl ketone: (Weight ratio of 5: 3: 2 by weight) to 91.775% by weight and then heated to 60 DEG C using a gravure 180 mesh. The coating amount after drying was 0.03 g / m < 2 >

First protective layer and second protective layer: 150 parts by weight of a curing agent (KPH-F2002, manufactured by KOLON INDUSTRIES CO., LTD.) Was added to 100 parts by weight of an epoxy resin (KEC-2185, 30% by weight (thickness: 0.5 탆).

Relief structure layer: The relief structure layer was coated on the first protection layer, and a relief structure was formed by heat and pressure using an embossing machine (thickness: 2 mu m).

Adhesion enhancing layer: A polyurethane resin prepared by reacting 22.5 wt% of a polyester-based polyol having a weight average molecular weight of 2,000 g / mol, 58.4 wt% of hexamethylene diisocyanate, 9.0 wt% of dimethylpropionic acid, and 10.1 wt% Respectively. A water-dispersed polyurethane coating composition containing 0.5% by weight of the solid content of the polyurethane resin, 0.1% by weight of the silicone-based wetting agent and a residual amount of water was formed by gravure coating to form an adhesion enhancing layer on one side with a dry coating thickness of 35 nm : 30 nm).

Deposition layer: An aluminum deposition layer of 250 ANGSTROM was formed to have an optical density (OD) of 2.2.

Adhesive layer: 30% by weight of Cl-PP (Nippon Paper Chemicals, Superchlon 773H), 60% by weight of acrylic resin (Aekyung Chemical Co., A-111-50 grade) and 10% by weight of silica particles, Lt; 2 > (thickness: 4.5 nm).

(Example 2)

A security film was produced in the same manner as in Example 1, except that the component of the adhesion enhancing layer was changed to acrylic resin. The durability of the manufactured security film was measured and shown in Table 1. The acrylic resin was prepared as follows.

110 parts by weight of ion-exchanged water and 0.9 parts by weight of sodium lauryl sulfate were dissolved in the reaction tank. 134 parts by weight of ion-exchanged water, 4.7 parts by weight of sodium lauryl sulfate, 137 parts by weight of butyl acrylate and 88 parts by weight of methyl methacrylate were added to a separate high-speed stirrer and emulsified. Then, 2.5 parts by weight of an acrylic acid monomer and 2 parts by weight of 2- 5 parts by weight of methacrylate monomer and 3.8 parts by weight of polyethylene glycol acrylate diacrylate were emulsified and stabilized and then charged into a reaction tank and emulsified and polymerized at a temperature of 75 캜 for 4 hours to give a weight average molecular weight of 300,000 g / mol Acrylic resin emulsion was obtained. At this time, 0.2 part by weight of ammonia water, 0.01 part by weight of a defoaming agent (NOPCO NXZ) and 0.08 part by weight of sodium hexametaphosphate were added to 100 parts by weight of the acrylic resin emulsion to prepare a water-dispersible acrylic resin coating composition. A water-dispersed polyurethane coating composition containing 0.5% by weight of the solid content of the polyurethane resin, 0.1% by weight of the silicone-based wetting agent, and a residual amount of water was formed by gravure coating to form an adhesion enhancing layer on one side with a dry coating thickness of 35 nm.

(Example 3)

A security film was produced in the same manner as in Example 1, except that the component of the adhesion-strengthening layer was changed to an ester-based resin. The durability of the manufactured security film was measured and shown in Table 1. The ester-based resin was a coating composition (solid content 50 wt%) mixed with RHOPLEX SG-30 in which a diester of 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropanoate was mixed with RHOPLEX SG- ) Was used to form an adhesion enhancing layer on one side with a dry coating thickness of 35 nm by a gravure coating method.

(Comparative Example 1)

Except that the adhesion reinforcing layer was not provided on the relief structure layer, and instead, the corona treatment (film running speed 2 m / min, corona 1.0 A (Ampere) condition) . The durability of the manufactured security film was measured and shown in Table 1.

(Comparative Example 2)

A security film was prepared in the same manner as in Example 1 except that the adhesion strengthening layer was not provided on the relief structure layer. The durability of the manufactured security film was measured and shown in Table 1.

[Table 1]

10: base film layer 20: release layer 30: first protective layer
40: Relief structure layer 50: Adhesion strengthening layer 60: Deposition layer
70: second protective layer 80: adhesive layer

Claims (4)

A security film in which a base film layer, a release layer, a first protective layer, a relief structure layer, a vapor deposition layer, a second protective layer and an adhesive layer are sequentially formed,
Further comprising an adhesion strengthening layer between the relief structure layer and the deposition layer.
The method according to claim 1,
Wherein the adhesion reinforcing layer comprises any one or a mixture of two or more selected from a urethane compound, an acrylic compound and an ester compound.
The method according to claim 1,
Wherein the releasing layer is formed by applying a releasing composition comprising a polyurethane resin and a solvent, wherein the coating amount after drying is 0.03 to 0.15 g /
Wherein the release composition has a solids content of 0.5 to 3.0 wt%.
The method of claim 3,
Wherein the polyurethane resin is at least one selected from the group consisting of polyurethane, polyether polyurethane, and polycarbonate polyurethane.

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