KR102060804B1 - Multilayer laser marking film and method for manufacturing the same - Google Patents

Abstract

Adhesive layer; A colored base layer having a first color; And a colored coating layer having a second color, wherein the first color and the second color are different colors from each other, and the colored coating layer is a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acryl. Photocurable mixed oligomers including late oligomers; Photoinitiators; Dispersants; And it provides a multi-layer laser marking film comprising a photocured of the coating composition comprising carbon black and a method of manufacturing the same.

Description

Multilayer Laser Marking Film and Manufacturing Method Thereof {MULTILAYER LASER MARKING FILM AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a multilayer film capable of precise laser marking and a method of manufacturing the same.

Various articles have labels for unique identification functions. These labels contain a variety of information about the item and may also perform unique identification functions. Labels used in the automotive industry, for example, may be used to display information about various parts of a vehicle, such as tire pressure or fuel type, or to display unique security information such as, for example, chassis number and vehicle identification number. It is used. In case of theft or accident, these labels allow tracking of the vehicle.

As one kind of method of manufacturing such a label, a method of writing information with a laser is used. Lasers are easy to be used for machining as high power light sources. For example, Korean Patent Publication No. 10-2006-0027501 includes an adhesive label sheet capable of marking a large amount of barcodes in a short time using a laser. Japanese Laid-Open Patent Publication No. 1990-120042 discloses a heat resistant display material having a marked layer having an etching pattern formed by a laser beam on a heat resistant base layer.

Such a label should have physical properties that can be precisely processed by a laser, have excellent adhesion to adherends, and simultaneously implement various physical properties corresponding to a purpose and purpose. Therefore, there is a need for a study to control the properties of the label according to each use and purpose.

One embodiment of the present invention provides a multi-layer laser marking film capable of precise processing through a laser, excellent stability against changes over time, and excellent adhesion to the adherend.

In one embodiment of the invention, the adhesive layer; A colored base layer having a first color; And a colored coating layer having a second color, wherein the first color and the second color are different colors from each other, and the colored coating layer is a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acryl. Photocurable mixed oligomers including late oligomers; Photoinitiators; Dispersants; And it provides a multilayer laser marking film comprising a photocured of the coating composition comprising carbon black.

In another embodiment of the invention, the step of applying a substrate composition on top of one release layer, and laminating another release layer thereon; Curing the substrate composition to form a laminate in which a colored substrate layer having a first color is disposed between two release layers; After removing one release layer from the laminate, the photocurable mixed oligomer, photoinitiator, dispersant comprising a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acrylate oligomer on one surface of the colored substrate layer And transfer coating a coating composition comprising carbon black; Curing the transfer coated coating composition to form a colored coating layer having a second color that is different from the first color; Removing the other release layer from the laminate and applying an adhesive composition to the back surface of the colored substrate layer; And curing the adhesive composition to form an adhesive layer.

The multilayer laser marking film shows excellent stability over time even after being exposed to the outside for a long time after laser marking, and has the advantage of enabling laser marking of precise letters or patterns. In addition, it is possible to fill in a variety of information to be utilized in various industries, excellent adhesion to adherends and excellent security against replication and forgery.

1 is a schematic cross-sectional view of a multilayer laser marking film according to an embodiment of the present invention.
FIG. 2 schematically illustrates a cross section when laser marking is performed on the multilayer laser marking film of FIG. 1.
3 is a schematic cross-sectional view of a multilayer laser marking film according to another embodiment of the present invention.
4 schematically illustrates a method of manufacturing a multilayer laser marking film according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving the same will be apparent with reference to the following embodiments. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms. The present embodiments are merely provided to make the disclosure of the present invention complete, and to fully convey the scope of the invention to those skilled in the art, and the present invention is defined by the scope of the claims. It will be. Like reference numerals refer to like elements throughout.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thicknesses of layers and regions are exaggerated for clarity.

In addition, in this specification, when a part such as a layer, film, region, plate, or the like is said to be "on" or "upper" another part, it is not only when the other part is "right over" but also when there is another part in the middle. Also includes. On the contrary, when a part is "just above" another part, there is no other part in the middle. In addition, when a part such as a layer, a film, an area, or a plate is "below" or "below" another part, it is not only when the part is "below" but also another part in the middle. Include. In contrast, when a part is "just below" another part, there is no other part in the middle.

In one embodiment of the invention, the adhesive layer; A colored base layer having a first color; And a colored coating layer having a second color, wherein the first color and the second color are different colors from each other, and the colored coating layer is a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acryl. Photocurable mixed oligomers including late oligomers; Photoinitiators; Dispersants; And it provides a multilayer laser marking film comprising a photocured of the coating composition comprising carbon black.

1 schematically illustrates a multilayer laser marking film 100 according to an embodiment of the present invention, and specifically, schematically illustrates a cross section thereof.

Referring to FIG. 1, the multilayer laser marking film 100 includes an adhesive layer 10, a colored substrate layer 20, and a colored coating layer 30. For example, the multilayer laser marking film 100 may be formed directly on the adhesive layer 10. A colored substrate layer 20 may be formed on the colored substrate layer 20, and the colored substrate layer 20 may include a multi-layered structure on which the colored coating layer 30 is formed.

The multilayer laser marking film is a film which can be etched by a laser to write various information, and the 'laser marking' means to write information on the film by etching by a laser. Specifically, in the multilayer laser marking film, laser marking may be performed on the colored coating layer.

That is, the multilayer laser marking film has laser marking property, and the laser marking property means a physical property that the colored coating layer is etched by laser irradiation, and the etched portion is removed. As such, the laser irradiated portion of the colored coating layer is etched and removed to interact with the colored substrate layer to write various letters, patterns, and the like.

The colored base layer 20 and the colored coating layer 30 are both colored layers, meaning 'colored' indicates that the base layer or coating layer is not transparent and has a color such as white, black, blue, or the like. . Specifically, the colored base layer 20 has a first color, the colored coating layer 30 has a second color, and the first color and the second color are different colors from each other.

As such, when the colored substrate layer and the colored coating layer have different colors from each other, when the colored coating layer is etched by laser marking, the etched portion may exhibit various colors according to the etching depth.

Specifically, referring to FIG. 2 (a), only the first color of the colored substrate layer 20 may be visually recognized when all of the colored coating layers 30 are etched by laser marking. . In addition, referring to FIG. 2B, when a part of the thickness of the colored coating layer 30 is etched, the colored coating layer 30 remaining without being etched with the first color of the colored base layer 20 is etched. The color in which the second color overlaps may be visually recognized.

The multilayer laser marking film can be written characters or patterns of various colors through the laser marking in this way. For example, the multilayer laser marking film may be used in automobiles, and specifically, may display information about various parts of the vehicle such as tire pressure or fuel type, or may provide unique security information such as chassis number and vehicle identification number. Can be used to indicate.

Multi-layer laser marking film according to an embodiment of the present invention is excellent in chemical resistance and scratch resistance of the surface, and has a physical property capable of precisely marking a letter or pattern of a fairly thin width. Such excellent physical properties of the multilayer laser marking film may be implemented through the adhesive layer, the colored substrate layer, and the colored coating layer.

Specifically, the colored coating layer is a layer that is etched and removed by laser marking, made of a photocured through a photocurable oligomer, including a dispersant and carbon black together with excellent surface properties and laser marking properties.

Specifically, the photocurable oligomer of the coating composition is a mixed oligomer using a mixture of at least two kinds according to the number of functional groups, more specifically, a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acrylate oligomer It is a photocurable mixed oligomer comprising a.

The trifunctional and bifunctional urethane (meth) acrylate oligomers are all oligomers cured by light irradiation, and have excellent chemical resistance as compared with the case where the coating composition includes a resin cured by another curing method such as a thermosetting resin. And scratch resistance can be secured.

Specifically, the tri- and bi-functional urethane (meth) acrylate oligomers include a urethane structure (-CONH-) in a chemical structure, and by including a urethane structure, excellent optical properties and appropriate hardness can be secured.

The photocurable mixed oligomer includes a (meth) acrylate functional group as a photocurable functional group, the trifunctional urethane (meth) acrylate oligomer has three (meth) acrylate functional groups in one molecule, and the bifunctional urethane ( The meta) acrylate oligomer has two (meth) acrylate functional groups in one molecule.

Since the photocurable mixed oligomer includes tri- and bi-functional urethane (meth) acrylate oligomers together, the coating composition can secure physical properties suitable for transfer coating, and the colored coating layer formed therefrom has precise laser marking properties, Chemical resistance and scratch resistance can be secured.

In one embodiment, the photocurable mixed oligomer may be composed of the trifunctional urethane (meth) acrylate oligomer and the bifunctional urethane (meth) acrylate oligomer.

The photocurable mixed oligomer may comprise a trifunctional urethane (meth) acrylate oligomer to a bifunctional urethane (meth) acrylate oligomer in a weight ratio of about 9: 1 to about 8: 2, for example, about 9: 1 to about 8.5: 1.5 by weight. By containing the trifunctional and bifunctional oligomers in such a content ratio, it is possible to effectively prevent agglomeration of carbon black, and to secure properties suitable for transfer coating. If the trifunctional urethane (meth) acrylate oligomer is contained in an excessive amount, the transfer coating properties may be reduced, and when the bifunctional urethane (meth) acrylate oligomer is contained in an excessive amount, chemical resistance and scratch resistance There is a risk of deterioration.

The coating composition for forming the colored coating layer includes a dispersant and carbon black together with the photocurable mixed oligomer. Since the coating composition includes a dispersant and carbon black, the colored coating layer may have an even color distribution as a whole, and the curing and coating processes may be improved in the process of forming the colored coating layer.

The dispersant allows the carbon black to be uniformly dispersed in the coating composition based on the photocurable mixed oligomer, and has a good compatibility with both the photocurable mixed oligomer and the carbon black.

Specifically, the dispersant may include one selected from the group consisting of a polyurethane-based dispersant, an acrylic block copolymer dispersant, a modified polyacrylate-based dispersant, and combinations thereof. By using a dispersant of the kind described above it is possible to evenly disperse the carbon black in the coating composition, it is possible to implement an even color distribution while improving the curing efficiency.

In one embodiment, the dispersant may include an acrylic block copolymer dispersant, in which case it may be more advantageous in terms of compatibility with the photocurable mixed oligomer and carbon black having a predetermined particle size.

Specifically, the acrylic block copolymer may be formed by block copolymerization of mixed monomer components including one selected from the group consisting of acrylonitrile, isoprene, styrene, butadiene, and combinations thereof.

The carbon black is a black pigment, and serves to impart color to the colored coating layer.

Specifically, the carbon black may have a particle diameter of greater than about 0 nm and about 30 nm or less, for example, about 10 nm to about 30 nm. The particle diameter of the carbon black can be derived by measuring the diameter of the projected image when the carbon black is projected with parallel light in a predetermined direction. When the particle diameter of the carbon black satisfies the above range, dispersibility is improved in the colored coating layer, and excellent compatibility with the photocurable mixed oligomer and dispersant may be ensured. For example, when the particle diameter of the carbon black exceeds the above range, the visibility of the colored coating layer may decrease or the appearance may be poor, and when the particle diameter of the carbon black is too small, the coating may be aggregated in the coating composition. Problems may occur that degrade the properties and consequently the surface properties of the colored coating layer.

The coating composition includes a photoinitiator, and the photoinitiator serves as a catalyst for initiating a photocuring reaction by light irradiation.

Although the kind of photoinitiator is not particularly limited, for example, benzophenone-based initiator, alpha-hydroxy ketone initiator, phenylglyoxylate initiator, benzyldimethyl-ketal initiator, alpha-amino ketone initiator, monoacyl It may include one selected from the group consisting of phosphine initiators, bisacrylphosphine initiators, bisacylphosphine initiators, phosphine oxide initiators, metallocene initiators, iodonium salt initiators and combinations thereof.

In one embodiment, the photoinitiator may include a bisacrylphosphine-based initiator, in this case it can be obtained an easy application of the transfer coating method. More specifically, the photoinitiator may include a bisacrylphosphine initiator, but at the same time, may not include an alpha-hydroxyketone initiator. Thus, when the coating composition is coated by a transfer coating method, it may be well coated on one surface of the colored substrate layer by implementing proper adhesion to the release film of the transfer film.

As described above, the coating composition is photocurable through the photocurable mixed oligomer and may not include a thermosetting component. More specifically, the coating composition may not include a thermosetting resin as the base resin component. The coating composition may be excellent in chemical resistance and scratch resistance improvement effect by including only a photocurable resin, without including a thermosetting resin as a base resin.

The coating composition may maximize the effect of simultaneously improving the chemical resistance and precise laser marking processability by including each component in an appropriate content.

Specifically, the coating composition may include about 1 to about 100 parts by weight of the photocurable mixed oligomer, based on 100 parts by weight of solids, for example, about 70 to about 90 parts by weight. Since the photocurable mixed oligomer is contained in the above range, the coating composition may secure a viscosity suitable for coating, and after photocuring, an appropriate hardness may be realized to ensure that the colored coating layer has improved durability with excellent chemical resistance and scratch resistance. can do.

In addition, the coating composition may include about 10 to about 70 parts by weight of the carbon black, based on 100 parts by weight of solids, for example, about 10 to about 20 parts by weight. Since the coating composition includes carbon black in such a content, it is possible to secure excellent dispersibility and high curing efficiency at the same time, and implement a color having a required level of saturation to write clear letters and patterns by laser marking. .

Furthermore, the carbon black has a particle size in the above-described range, and at the same time is used in the content of the above range, thereby greatly improving dispersibility in the coating composition, and as a result, the colored coating layer maximizes the effect of improving the precise workability and curing efficiency. can do.

In addition, the coating composition may include about 1 to 20 parts by weight of the dispersant, for example, about 2 to about 10 parts by weight based on 100 parts by weight of solids. By including the dispersant in the above content range, the coating composition may simultaneously secure excellent dispersibility of the carbon black and high curing efficiency of the coating composition, and may be advantageous in terms of improving dispersibility compared to cost.

Furthermore, the coating composition may maximize the effect of improving the dispersibility and curing efficiency by simultaneously satisfying the carbon black content and the dispersant content of the range, and defects of the coating layer caused by the aggregation of particles and the like during coating. ) Can be effectively prevented.

In addition, the coating composition may include about 1 to about 10 parts by weight of the photoinitiator based on 100 parts by weight of solids. By using the photoinitiator in the above-described content, the photocuring efficiency of the coating composition may be improved and may be cured to have an appropriate degree of curing. If the content of the photoinitiator is excessively exceeding the above range, there is a fear that the photoinitiator remains after curing of the coating composition and changes the gloss when exposed to light, and when the content of the photoinitiator is less than the above range, curing efficiency This may fall.

The coating composition may further include one selected from the group consisting of titanium dioxide (TiO ₂ ), azo-based dyes, and combinations thereof as a pigment in addition to carbon black.

When the coating composition contains at least two or more of the above-described types as pigments, various colors may be realized under different color conditions from the colored base layer according to their natural colors and content ratios. .

Referring to FIG. 1, the multilayer laser marking film 100 may include a colored substrate layer 20 under the colored coating layer 30, and the colored coating layer 30 and the colored substrate layer 20. This may include a structure directly abuts.

The colored substrate layer 20 has an appropriate interface adhesion with the colored coating layer 30 to maintain the overall structure of the film well before laser marking, and precisely remove the colored coating layer 30 during laser marking. Can be.

For example, the interfacial adhesion between the colored substrate layer and the colored coating layer may be 4B or more measured according to a cross cut test at normal pressure and room temperature in accordance with the standard of ASTM D3002 / D3359. For example, it may be 5B or more.

By satisfying the above-mentioned range of the interface adhesion, the multilayer laser marking film can secure improved flowability, and the colored coating layer can be precisely etched and removed by laser marking.

The multilayer laser marking film needs to prevent forgery or tampering when important information is entered. Specifically, the multilayer laser marking film may have 'self-fragmentability'. "Self-fragmentable" means a physical property that the original shape is destroyed and cannot be recycled when an attempt is made to detach or remove the multilayer laser marking film after it is attached to the adherend. Since the multilayer laser marking film has self-fragmentation property, it is impossible to arbitrarily change the unique information written therein, and it is possible to secure a property that cannot be forged or modulated.

In addition, the multilayer laser marking film may have physical properties that do not break when the physical properties such as adhesion, while having a self-fragment. In general, the film having the magnetic crushing property has a problem that the film is torn or broken due to the magnetic crushing property when evaluating physical properties such as adhesion. In particular, in the case of a film having an adhesive layer having a high adhesive force, there is a problem that the measurement of the adhesive force becomes more difficult.

The multilayer laser marking film according to an embodiment of the present invention may include a pressure-sensitive adhesive layer having a high adhesion but may not be torn or broken when evaluating physical properties such as adhesion, and at the same time, a predetermined time is elapsed after being applied to the final article. Later it may have the advantage of exhibiting improved magnetic crushability. Specifically, this advantage of the multilayer laser marking film can be realized through the colored substrate layer and the adhesive layer.

Specifically, the colored substrate layer 20 may include a cured product of a substrate composition including an electron beam (EB) curable oligomer and a pigment. That is, the cured product may be a cured product by an electron beam. Since the colored base layer is formed by electron beam curing, it is easier to control the thickness than by the other curing method, and it is possible to obtain an advantage of easily securing the interface adhesion in relation to the colored coating layer.

Specifically, the electron beam curable oligomer may include, for example, a urethane (meth) acrylate oligomer, an epoxy (meth) acrylate oligomer, or a mixed oligomer thereof.

The urethane (meth) acrylate oligomer used as the electron beam curable oligomer has physical properties that are cured by an electron beam, and the curing method and curing mechanism differ from the photocurable mixed oligomer contained in the coating composition for forming the colored coating layer. . That is, the point of including the urethane structural units with each other may be similar, but have a different chemical structure as a whole, the curing sites are also different.

In one embodiment, the electron beam curable oligomer of the colored substrate layer may be a mixture of a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acrylate oligomer. More specifically, the trifunctional: the bifunctional urethane (meth) acrylate oligomer may be used by mixing in a weight ratio of 9: 1 to 6: 3.

The colored base layer may have a color by including a pigment together with the electron beam curable oligomer, and may implement colors using various pigments under conditions having a different color from the colored coating layer. For example, the pigment may include one selected from the group consisting of titanium dioxide (TiO ₂ ), carbon black, azo dyes, and combinations thereof.

The substrate composition for forming the colored substrate layer may include about 0.1 to about 3 parts by weight of the pigment based on 100 parts by weight of the electron beam curable oligomer. The colored substrate layer has a large influence on the magnetic crushability and structural stiffness of the multilayer laser marking film, and includes a pigment in the above range as compared to the electron beam curable oligomer to properly secure the magnetic crushability and structural stiffness together with the implementation of color. And it can be easily implemented a different color from the colored coating layer.

Referring to FIG. 1, the multilayer laser marking film 100 includes a colored base layer 20 under the colored coating layer 30, and an adhesive layer 10 under the colored base layer 20. It may include. For example, the colored coating layer 30 and the colored base layer 20 may be in direct contact with each other, and the colored base layer 20 and the adhesive layer 10 may be in direct contact with each other.

The multilayer laser marking film is attached to an article related to information contained through laser marking, and may be attached to the article through the adhesive layer 10. The adhesive layer 10 can effectively prevent breakage and tearing during the measurement of adhesion through proper adhesion to the article and appropriate interface adhesion to the colored substrate layer 20, and a predetermined time after application to the final article In the case of elapsed time, improved magnetic crushability can be realized.

Such a pressure-sensitive adhesive layer can be used without limitation, known pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, silicone pressure-sensitive adhesives, acid-free hydroxyl-containing pressure-sensitive adhesives.

For example, the pressure-sensitive adhesive layer may include a photocurable product of an acid-free hydroxyl-containing pressure-sensitive adhesive composition, and specifically, 2-ethylhexylacrylate and hydroxyethylacrylate (Hydroxyethylacrylate). Pressure-sensitive adhesive resin and photocurable monomer derived from And it may include a photocuring of the acrylic pressure-sensitive adhesive composition comprising a photoinitiator.

The pressure-sensitive adhesive composition may be used without limitation, known curing accelerators, plasticizers, dispersants, surfactants, antistatic agents, antifoaming agents, leveling agents and the like to improve physical properties.

The adhesive layer may have an adhesion force of about 1400 gf / cm or more to the adherend, for example, about 1400 gf / cm to about 4000 gf / cm. The multilayer laser marking film may include a pressure-sensitive adhesive layer exhibiting adhesion in the above range, so that the pressure-sensitive adhesive layer and the colored substrate layer may be included together, so that the multilayer laser marking film may be measured without breaking or tearing when measuring physical properties of the adhesive force. In addition, the multilayer laser marking film can improve long term adhesion when applied to the final article through an adhesive layer exhibiting adhesion in the above range.

The multilayer laser marking film has various uses, and may be utilized as a label attached to an automobile, for example, in this case, the adherend may be a metal paint plate for a vehicle, and more specifically, an aluminum automobile It can be applied to the paint plate. In this case, the multilayer laser marking film may implement excellent long-term adhesion and durability through the adhesive layer exhibiting the adhesion of the above range.

3 schematically illustrates a cross section of a multilayer laser marking film 100 ′ according to another embodiment of the invention. Referring to FIG. 3, the multilayer laser marking film 100 ′ may further include a release layer 40 on one or both surfaces of the outermost portion.

Specifically, the release layer 40 may be formed only on one surface of the adhesive layer 10 as shown in (a) of FIG. 3, and one surface of the adhesive layer 10 as shown in (b) of FIG. 3. It may be formed together on one surface of the colored coating layer 30.

The release layer 40 is a layer removed when the multilayer laser marking film is applied to the final article. The release layer 40 formed on one surface of the colored coating layer 30 may be removed before laser marking, or laser marking. It may then be removed. When the release layer 40 is removed after laser marking, the release layer 40 may be formed of a material having transparency to the laser.

The multilayer laser marking film (100, 100 ') is designed to ensure the characteristics of precise laser marking by properly designing the thickness of the layer, to realize the magnetic crushing properties, despite the high adhesion, breakage or tearing when measuring the adhesion A characteristic without a phenomenon can be secured.

For example, the colored substrate layer may have a thickness of about 60 μm to about 150 μm, and the colored coating layer may have a thickness of about 1 μm to about 5 μm. Since the thicknesses of the colored substrate layer and the colored coating layer each satisfy the above ranges, it is possible to implement precise patterns and characters by laser marking the colored coating layer, and the multilayer laser marking film measures adhesion while securing magnetic fracture properties. The breakage or tearing of the city can be effectively prevented.

In addition, the thickness of the adhesive layer is not particularly limited, but may be, for example, about 20 μm to about 50 μm. As the thickness of the adhesive layer satisfies the above range, it is possible to implement adhesiveness at a level capable of securing physical properties capable of measuring adhesion without breakage or tearing, and can be applied to a final article to implement excellent long-term adhesion retention performance. .

In addition, when the multilayer laser marking film includes a release layer, the thickness thereof is not particularly limited. For example, the release layer may have a thickness of about 50 μm to about 125 μm.

In the multilayer laser marking film, the surface roughness Ra of the colored coating layer may be less than about 100 nm. As the surface roughness Ra of the colored coating layer is smaller, precision laser marking property can be secured. The surface roughness (Ra) range of the colored coating layer can be easily implemented by manufacturing a colored coating layer from the coating composition as described above, and further can be easily implemented by transfer coating the coating composition as described below.

In another embodiment of the present invention, a method of manufacturing the multilayer laser marking film is provided. The manufacturing method may be manufactured by, for example, a method schematically illustrated in FIG. 4.

Referring to FIG. 4, in the method of manufacturing the multilayer laser marking film, applying the substrate composition A on one release layer 40 and laminating another release layer 40 thereon. (S100); Curing the substrate composition (A) to form a laminate in which a colored substrate layer 20 having a first color is disposed between the two release layers 40 (S200); After removing one release layer 40 from the laminate, a photocurable comprising trifunctional urethane (meth) acrylate oligomer and bifunctional urethane (meth) acrylate oligomer on one surface of the colored substrate layer 20 Transfer coating the coating composition comprising a mixed oligomer, photoinitiator, dispersant and carbon black (S300); Curing the transfer coating composition (B) to form a colored coating layer (30) having a second color that is different from the first color (S400); Removing the other release layer 40 from the laminate and then applying an adhesive composition (C) to the back surface of the colored substrate layer 20 (S500); Curing the adhesive composition (C) may include forming an adhesive layer 10 (S600).

In the method of manufacturing the multi-layer laser marking film 100, a laminate having a colored substrate layer 20 interposed between two release layers 40 is preferentially formed, thereby manufacturing a colored coating layer and an adhesive layer. It is possible to improve the interfacial adhesion between the layers and to prevent the tearing or breaking of each layer during the process, thereby reducing the defect rate during the process.

The coating composition includes a photocurable mixed oligomer comprising a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acrylate oligomer; Photoinitiators; Dispersants; And carbon black, the details of which are described above.

The coating composition may be coated by a transfer coating method, specifically, prepare a transfer film including some cured product of the coating composition, transfer the transfer film to one surface of the colored substrate layer, and then completely cure the A colored coating layer can be formed. When the coating composition is coated by the transfer coating method, it is possible to minimize the damage of the colored substrate layer than by the direct coating method, and there is an advantage of preventing the deterioration of the overall appearance and function of the multilayer laser marking film.

The transfer film may be prepared by coating the coating composition on top of a separate release film and then partially curing the coating composition. In this case, the coating composition may be coated on the separate release film by using a spin coating method, a bar coating method, or a gravure coating method, and the light having a wavelength of about 250 nm to about 300 nm is about 300 mJ / The transfer film may be prepared by partially curing by irradiation with light energy of 2 cm 2 to about 400 mJ / cm 2.

Subsequently, the manufacturing method includes removing the other release layer 40 from the laminate and then applying the adhesive composition (C) to the other side of the colored substrate layer, ie, the back side, which is revealed by this; And curing the adhesive composition (C) to form an adhesive layer 10.

As described above, the adhesive composition (C) may be an acid-free hydroxyl-containing adhesive composition, and the adhesive layer may be formed by photocuring it.

The manufacturing method of the multilayer laser marking film may further include forming a release layer 40 at the outermost part, in which case, the release layer is one surface of the adhesive layer 10 as shown in FIG. 3. It may be formed only on, or may be formed on each of one surface of the adhesive layer 10 and the colored substrate layer 30, respectively.

The following presents specific embodiments of the present invention. However, the embodiments described below are merely for illustrating or explaining the present invention in detail, and thus the present invention is not limited thereto.

< Production Example >

Production Example  1: Preparation of Substrate Composition

Electron beam curable trifunctional urethane (meth) acrylate oligomer: An electron beam curable bifunctional urethane (meth) acrylate oligomer is mixed at a weight ratio of 8: 2, and titanium dioxide (TiO ₂ ) pigments are used based on 100 parts by weight of the total oligomer. To prepare a base composition comprising 0.5 parts by weight.

Production Example  2: Preparation of Adhesive Composition

A pressure-sensitive adhesive composition comprising 2-ethylhexylacrylate and 2-ethylhexylacrylate and hydroxyethylacrylate, and a monomer and a photoinitiator were prepared.

< Example  And Comparative example >

Example  One

The base composition of Preparation Example 1 was applied to one surface of a polyethylene terephthalate (PET) release layer, and the same PET release layer was laminated thereon. Subsequently, the base composition was cured by electron beam curing to prepare a release layer, a colored substrate layer having a thickness of 100 μm, and a laminate of the release layer.

Then, a trifunctional urethane (meth) acrylate oligomer: a photocurable mixed oligomer comprising a bifunctional urethane (meth) acrylate oligomer in a weight ratio of 9: 1, a bisacrylphosphine-based photoinitiator (BASF, IRG819), acrylo A coating composition comprising an acrylic block copolymer dispersant, which is a block copolymer of nitrile (acrylonitrile), isoprene, styrene, and butadiene, and carbon black in the amounts shown in Table 1 below was prepared, and coated on top of a separate PET release film by a gravure coating method. Thereafter, light having a wavelength of 254 nm was partially cured with light energy of 350 mJ / cm 2 to prepare a transfer film.

Subsequently, one release layer of the laminate was peeled off, and the coating composition was transfer-coated with the transfer film on one surface of the colored substrate layer on which the release layer was peeled off, and light having a wavelength of 254 nm was 350 mJ / cm 2. Photocuring with energy to produce a colored coating layer of 3㎛ thickness.

Subsequently, another release layer of the laminate was peeled off, and a 25 μm thick adhesive layer containing the photocured product of the pressure-sensitive adhesive composition of Preparation Example 2 was formed on the back surface of the colored substrate layer.

As a result, a multilayer laser marking film including a colored coating layer, a colored substrate layer, and an adhesive layer was prepared.

Example  2

The photocurable mixed oligomer of the coating composition is a multilayer in the same manner as in Example 1, except that the trifunctional urethane (meth) acrylate oligomer: bifunctional urethane (meth) acrylate oligomer comprises a weight ratio of 8.5: 1.5. Laser marking films were prepared.

Example  3

The photocurable mixed oligomer of the coating composition was multi-layered in the same manner as in Example 1, except that the trifunctional urethane (meth) acrylate oligomer: bifunctional urethane (meth) acrylate oligomer contained in a weight ratio of 8: 2. Laser marking films were prepared.

Comparative example  One

A multilayer laser marking film was prepared in the same manner as in Example 1, except that the coating composition included a photocurable oligomer composed of only a trifunctional urethane (meth) acrylate oligomer instead of the photocurable mixed oligomer.

Comparative example  2

In place of the coating composition, a thermosetting urethane (meth) acrylate resin having a trifunctional (meth) acrylate group and a hydroxy group, an isocyanate-based thermosetting agent (Asahi Kasei Co., TDI), the same acrylic block copolymer dispersant as in Example 1, and The coating composition including the same carbon black as Example 1 was directly coated on one surface of the colored substrate layer by a gravure coating method, dried at 90 ° C. for 2 minutes, and then colored at 50 ° C. by aging for 48 hours. A multilayer laser marking film was manufactured in the same manner as in Example 1, except that the coating layer was prepared.

Comparative example  3

Instead of the coating composition, the photocurable mixed oligomer of Example 1 and the thermosetting urethane (meth) acrylate resin of Comparative Example 2 in the content of Table 1 below, the same dispersant as Example 1. The dual curable coating composition comprising carbon black and a photoinitiator and the same thermosetting agent as in Comparative Example 2 was directly coated on one surface of the colored substrate layer by a gravure coating method and dried at 90 ° C. for 2 minutes. The same method as in Example 1, except that the first thermal curing by aging at 50 ℃ for 48 hours, and the second photo-curing of light with a wavelength of 254nm at 350mJ / ㎠ light energy to prepare a colored coating layer A multilayer laser marking film was prepared.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Photocurable
Oligomer 3 sensory: 2 sensory
Weight ratio 9: 1 8.5: 1.5 8: 2 3 sensuality only - 9: 1 content 80 80 80 80 40 Thermosetting resin - - - - 80 40 Dispersant 2 2 2 2 2 2 Photoinitiator 8 8 8 8 - 4 Thermosetting agent - - - - 8 4 Carbon black Particle diameter 20 nm 20 nm 20 nm 20 nm 20 nm 20 nm content 10 10 10 10 10 10

In Table 1, the content of each component describes 100 parts by weight based on 100 parts by weight of the solids of each coating composition.

<Evaluation>

Experimental Example  1: evaluation of chemical resistance

About the multilayer laser marking film of the said Example and the said comparative example, after methyl ethyl ketone (MEK) was immersed in the dust-free cloth, it rubbed 10 times on each colored coating layer, and observed whether the colored marking layer peeled off. The results are as shown in Table 2 below, when the colored marking layer did not peel off, it was described as ○, and the peeling off case was described as x.

Experimental Example  2: laser Marking  evaluation

For each multilayer laser marking film of the above examples and comparative examples, each colored coating layer was etched using a laser of 355 nm wavelength at a speed of 1000 mm / s. After etching the colored coating layer, the laser marking property was evaluated by the visibility of the color of the colored substrate layer. If the colored substrate layer is visually recognized as a shape corresponding to the etched shape, it is marked as ○ and is not recognized as the desired shape. In the case indicated by ×. The results are as described in Table 2 below.

Experimental Example  3: warrior Coating  evaluation

For each multi-layer laser marking film of the above Examples and Comparative Examples, the coating composition for forming each colored coating layer is directly coated on top of a 75 μm-thick PET release film, and then cured under appropriate conditions to each colored 3 μm thick color. A coating layer was prepared. Subsequently, the adhesive tape was attached to each colored coating layer and then peeled off to check whether the colored coating layer was peeled off. When peeling neatly, the transfer coating property is excellent, and when it remains without peeling, the transfer coating property is not excellent, and the result is as described in Table 2 below. When the transfer coating method exhibits a degree of transfer coating property, it is described as ○, and when it is impossible to apply the transfer coating method, it is described as ×.

Experimental Example  4: Evaluation of Dispersibility of Carbon Black

For each multilayer laser marking film of the above examples and comparative examples, dispersibility was evaluated for the coating composition for producing each colored coating layer. Specifically, after each coating composition is left at room temperature for 2 days, visual evaluation of whether erosion of carbon black particles occurs in the coating composition is described as '○' when no erosion occurs, and the case where erosion occurs It was described as 'x'. The results are as described in Table 2 below.

Chemical resistance Laser marking Transfer coating Dispersibility of Carbon Black Example 1 ○ ○ ○ ○ Example 2 ○ ○ ○ ○ Example 3 ○ ○ × ○ Comparative Example 1 ○ × × × Comparative Example 2 × ○ ○ ○ Comparative Example 3 × ○ ○ ○

100, 100 ': multilayer laser marking film
10: adhesive layer
20: colored base material layer
30: colored coating layer
40: release layer
A: base material composition
B: coating composition
C: adhesive composition

Claims (16)

Adhesive layer; A colored base layer having a first color; And a colored coating layer having a second color, wherein the first color and the second color are different colors from each other,
The colored coating layer is a photocurable mixed oligomer comprising a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acrylate oligomer; Photoinitiators; Dispersants; And a photocured product of the coating composition comprising carbon black,
The weight ratio of the trifunctional urethane (meth) acrylate oligomer to the bifunctional urethane (meth) acrylate oligomer is from 9: 1 to 8.5: 1.5.
Multilayer Laser Marking Film.
The method of claim 1,
The colored coating layer is etched by laser irradiation, and the laser marking property that the etched portion is removed
Multilayer Laser Marking Film.
The method of claim 1,
The surface roughness (Ra) of the colored coating layer is less than 100nm
Multilayer Laser Marking Film.
delete The method of claim 1,
The dispersant may include one selected from the group consisting of a polyurethane dispersant, an acrylic block copolymer dispersant, a modified polyacrylate dispersant, and a combination thereof.
Multilayer Laser Marking Film.
The method of claim 1,
The carbon black has a particle diameter of more than 0 nm and 30 nm or less.
Multilayer Laser Marking Film.
The method of claim 1,
The photoinitiator is a benzophenone-based initiator, alpha-hydroxy ketone initiator, phenylglyoxylates initiator, benzyldimethyl- ketals initiator, alpha-amino ketone initiator, monoacylphosphine initiator, bisacrylphosphine initiator, bisacyl phosphate It includes one selected from the group consisting of a fins initiator, a phosphine oxide initiator, a metallocene initiator, an iodonium salt initiator and combinations thereof
Multilayer Laser Marking Film.
The method of claim 1,
The photoinitiator includes a bisacrylphosphine initiator and at the same time does not include an alpha-hydroxyketone initiator.
Multilayer Laser Marking Film.
The method of claim 1,
The coating composition comprises 70 to 90 parts by weight of the photocurable mixed oligomer, based on 100 parts by weight of solids
Multilayer Laser Marking Film.
The method of claim 1,
The coating composition comprises 1 to 20 parts by weight of the dispersant, based on 100 parts by weight of solids.
Multilayer Laser Marking Film.
The method of claim 1,
The coating composition comprises 10 to 70 parts by weight of the carbon black, based on 100 parts by weight of solids.
Multilayer Laser Marking Film.
The method of claim 1,
The coating composition comprises 1 to 10 parts by weight of the photoinitiator, based on 100 parts by weight of solids
Multilayer Laser Marking Film.
The method of claim 1,
The colored substrate layer may include an electron beam (EB) curable oligomer; And a cured product of the base composition comprising the pigment.
Multilayer Laser Marking Film.
The method of claim 13,
The base composition comprises 0.1 to 3 parts by weight of the pigment, based on 100 parts by weight of the electron beam curable oligomer.
Multilayer Laser Marking Film.
The method of claim 1,
The adhesive layer has an adhesion force of 1400 gf / cm to 4000 gf / cm for a metal substrate
Multilayer Laser Marking Film.
Applying a substrate composition on top of one release layer and laminating another release layer on top of it;
Curing the substrate composition to form a laminate in which a colored substrate layer having a first color is disposed between two release layers;
After removing one release layer from the laminate, the photocurable mixed oligomer, photoinitiator, dispersant comprising a trifunctional urethane (meth) acrylate oligomer and a bifunctional urethane (meth) acrylate oligomer on one surface of the colored substrate layer And transfer coating a coating composition comprising carbon black;
Curing the transfer coated coating composition to form a colored coating layer having a second color that is different from the first color;
Removing the other release layer from the laminate and applying an adhesive composition to the back surface of the colored substrate layer; And
Curing the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer,
The weight ratio of the trifunctional urethane (meth) acrylate oligomer to the bifunctional urethane (meth) acrylate oligomer is from 9: 1 to 8.5: 1.5.
Method for producing a multilayer laser marking film.

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