JP5208678B2 - Laser printing film - Google Patents

Description

  The present invention relates to a laser printable film.

  2. Description of the Related Art Conventionally, as a method for printing the expiration date, lot number, etc. on a film, a method of applying ink on the outer surface of the film using a thermal printer or an ink jet printer and printing is employed. In this case, since the ink is applied to the outer surface of the film and printed, the case where the printing disappears due to rubbing between the films being transported, the printed ink is erased, the printing is performed again, and the expiration date is altered. There are cases to be done.

In addition, in the case of using a base material made of paper material instead of a film base material made of plastic material, an ink layer formed by applying colored ink on the base material made of paper material is provided with a laser. It is known that the color of a paper material is exposed by irradiating a beam and selectively erasing an ink layer to print a character figure or the like corresponding to an irradiation region of a laser beam.
JP 2005-289401 A JP 2007-322621 A JP 2004-29726 A JP 2007-055110 A JP 2006-069086 A

  In the conventional method of printing by irradiating with a laser beam, there are problems such that the printing is thin and difficult to recognize, and expensive materials are used, resulting in high product costs.

  In addition, in the case of using a base material made of paper material, since the base material is paper material, the ink layer is stably held on the base material made of paper material. It seems that it is possible to print and display character figures corresponding to However, in the case of using a plastic film layer as a base material, unlike in the case of using a paper material as a base material, the lower layer of the ink layer is colored by selectively erasing the ink layer by irradiating a laser beam. The exposure has not been performed in the past because the setting of conditions is too strict to be performed stably.

  The present invention is based on the inventor's earnest consideration, and by providing the first base film and the second base film made of plastic material on both sides, the plastic material film layer is used as the base material. The purpose of the present invention is to irradiate a laser beam to an intermediate layer sandwiched between laminated films, and to perform printing. It is an object of the present invention to provide a film that can be printed at low manufacturing cost and excellent in recognition of printed characters.

  In order to achieve the above object, a laser printing film according to the present invention has an outer surface on the irradiation side irradiated with a laser beam of a predetermined wavelength and an inner surface on the opposite irradiation side opposite to the outer surface. A first base film made of plastic material, a first ink layer formed by applying a first ink to the inner surface of the first base film, and a surface on the counter-irradiation side of the first ink layer; A second ink layer formed by applying a second ink having coloring, and a second base film made of plastic material formed in close contact with the surface of the second ink layer opposite to the irradiation side, When the laser beam is irradiated from the outer side surface of the first base film, the first ink layer can change the quality of the first ink layer so that the second ink layer can be colored according to the irradiated region. The second ink of the first ink layer And having a shielding-reducing reduce the shading degree for.

  According to the configuration of the present invention, since the second base film of the plastic material formed in close contact with the surface opposite to the irradiation side of the second ink layer is provided, the laser beam is irradiated from the outer surface of the first base film. In this case, by changing the quality of the first ink layer and reducing the degree of shading of the first ink layer, the display color of the second ink layer can be seen from the background color of the first ink layer according to the irradiation area. It becomes possible to display a character figure etc. on a laser printing film easily using a laser beam.

Embodiments of the present invention will be described below with reference to the drawings.
A first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, L represents a laser beam, and the laser beam L is irradiated from one surface of the laser printing film 1.

  The laser printing film 1 is a first base of a transparent plastic material having an outer surface 2a on the irradiation side irradiated with a laser beam L of a predetermined wavelength and an inner surface 2b on the opposite side opposite to the outer surface 2a. The material film 2, the first ink layer 4 formed by directly applying the first ink to the inner surface 2b side of the first base film 2, and the surface on the counter-irradiation side of the first ink layer are colored. A second ink layer 6 formed by applying a second ink having a surface and a second base film 12 made of a plastic material formed in close contact with the surface of the second ink layer 6 on the side opposite to the irradiation side. Configured.

  In FIG. 1, the example in which the 2nd base film 12 is comprised from the adhesive layer 8 apply | coated to the 2nd ink layer 6, and the film 10 for sealants laminated | stacked on the adhesive layer 8 is shown. Since the adhesive layer 8 is interposed, the second base film 12 can be adhered to the second ink layer 6 and laminated.

  Moreover, as the 2nd base film 12, it replaces with comprising from the adhesive layer 8 and the film 10 for sealants as shown in FIG. 1, and it is made into a single layer like the 2nd base film 12 shown in FIG. It is also possible to configure. In FIG. 4, the second base film 12 is a molten resin layer formed by applying a molten resin to the second ink layer 6. Since the molten resin is applied to the second ink layer 6, the second base film 12 can be closely adhered to the second ink layer 6 without using an adhesive.

  The predetermined wavelength of the laser beam L is selected so as to be transmissive to the first base film 2 and to be absorbent to the first ink layer 4. The irradiation intensity of the laser beam L is appropriately selected so as not to be too strong or too weak so as to change only the first ink layer 4.

  The first ink layer 4 is formed by dispersing fine aluminum powder in a first ink and applying a silver ink, and has a silver color. Here, the aluminum fine powder dispersed in the first ink plays a main role of light shielding.

  The second ink layer 6 is formed by applying a second ink having a black display color.

  The first ink is not limited to silver, and other colors, for example, a gold first ink can also be used. FIG. 3 shows an example in which the first ink layer 5 is formed with a gold first ink. The gold first ink can be easily obtained by adding an appropriate amount of a yellow pigment to a silver ink liquid in which fine aluminum powder is dispersed. Here, the aluminum fine powder dispersed in the first ink plays a main role of light shielding.

  The second ink layer 6 is formed by applying a second ink having a black display color.

  The laser beam L is condensed and has a minute spot size of, for example, several μm, and is deflection-controlled so as to draw, for example, a character figure through a scanner or the like (not shown). Until the laser printing film 1 is irradiated with the laser beam L, the second ink layer 6 is shielded by the first ink layer 4, and the first ink layer 4 is viewed from the outer surface 2 a side of the first base film 2. The display color of the second ink layer 6 is not exposed. When the laser beam L is irradiated from the outer side surface 2a of the first base film 2, for example, the region of the first ink layer 4 irradiated as a character figure is absorbed by the energy of the laser beam L, and the second The light shielding degree of the first ink layer 4 with respect to the ink layer 6 is reduced, and the first ink layer 4 has a shielding reduction property. As a result, the display color of the second ink layer 6 can be viewed from the outer surface 2a side of the first base film 2 in accordance with the irradiation region of the first ink layer 4, and the character figure can be visually recognized.

  Here, the shielding reduction property generated in the first ink layer 4 will be described. Depending on the irradiation wavelength of the laser beam L, the irradiation intensity, the irradiation time width, the relationship between these and the composition of the first ink layer 4, etc., various factors can be used as the mechanism for the shielding reduction of the first ink layer 4. is assumed.

  For example, as shielding reduction, when the laser beam L is irradiated from the outer surface 2a of the first base film 2, the ink components such as aluminum fine particles in the first ink layer 4 are partially ashed. It is assumed that the light shielding property of the aluminum fine powder is based on diluting.

  Further, as shielding reduction, when the laser beam L is irradiated from the outer surface 2a of the first base film 2, the ink components such as aluminum fine particles in the first ink layer 4 are further refined. It is also assumed that it is based on chemical reaction and transparency.

  Further, as the shielding reduction property, when the laser beam L is irradiated from the outer side surface 2a of the first base film 2, the ink component such as aluminum fine particles in the first ink layer 4 is the beam of the laser beam L. It is assumed that it is based on receiving pressure and disappearing from the irradiation position. In this case, ink components such as aluminum fine particles in the first ink layer 4 that have received the beam pressure of the laser beam L disappear to the boundary portions 4 on both sides of the first ink layer 4 and the second ink layer 6. Or disappearing into the second ink layer 6. According to experimental observation, in consideration of the fact that no change in quality was observed at the position corresponding to the irradiation position of the second ink layer 6, the first ink layer 4 and the second ink layer 6 It can be considered that ink components such as aluminum fine particles in the first ink layer 4 are driven to disappear to the boundary portions on both sides.

  Further, the shielding reduction is such that the ink components such as aluminum fine particles in the first ink layer 4 are driven away to the boundary portions on both sides of the first ink layer 4 and the second ink layer 6 and disappear. Even if not, it may be based on the fact that the central portion of the irradiation position of the laser beam L is compressed toward the peripheral portion and the ink components such as aluminum fine particles in the central portion of the irradiation position become dilute.

  As the various mechanisms described above, it is conceivable that they are combined and mixed.

  In any case, in the present embodiment, when the laser beam L is irradiated from the outer surface 2a of the first base film 2, without affecting the second ink layer 6 such as breaking it, The first ink layer 4 can have the above-described shielding reduction. This is because the second base film 12 is provided in the lower layer of the second ink layer 6, so that the first ink layer 4 and the second ink layer 6 are connected to the first base film 2 and the second base from both sides. The second base film 12 plays a reinforcing role with respect to the second ink layer 6 (or with respect to the first ink layer 4 and the second ink layer 6). The second ink layer 6 (or the first ink layer 4 and the second ink layer 6) can be stably supported by the second base film 12, and the second ink layer 6 (or the first ink layer 4) is supported. It can be considered that the second ink layer 6) is not easily affected by the irradiation pressure of the laser beam L or the heat of irradiation.

  According to the configuration of the present embodiment, when the laser beam L is irradiated from the outer surface 2 a of the first base film 2, shielding reduction occurs in the irradiation region of the first ink layer 4, and the first ink layer 4 Black, which is the display color of the second ink layer 6, is exposed according to the trajectory of the character figure or the like in the irradiated region, and the non-irradiated region of the first ink layer 4 exhibits the surface color silver. As a result, it is possible to recognize the trajectory of a black character graphic or the like that is the display color of the second ink layer 6 from the irradiation surface side of the first base film 2.

Next, a modification of the present embodiment will be described with reference to FIG.
The first ink layer 4 in FIG. 1 is silver ink in which fine aluminum powder is dispersed in the first ink, whereas in FIG. 3, the first ink layer 5 is gold ink. The gold ink is constituted by mixing fine particles of aluminum in the first ink and mixing a yellow pigment in the silver ink.

  According to the configuration shown in FIG. 3, the trajectory of a black character graphic or the like that is the display color of the second ink layer 6 can be displayed on the surface of the first ink layer 5 having a gold surface color.

  Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, when the laser beam L is irradiated between the first base film 2 and the first ink layer 4 from the outer surface 2 a of the first base film 2, the shielding reduction together with the first ink layer 4. An auxiliary ink layer 3 is provided. In the second embodiment shown in FIG. 1 and the like, the first ink layer 4 is formed by directly applying the first ink to the inner surface 2b of the first base film 2, but the second ink In the embodiment, the auxiliary ink layer 3 formed by applying auxiliary ink to the inner surface 2 b of the first base film 2 is provided.

  The auxiliary ink is, for example, a white ink, but the auxiliary ink need not be limited to white. A first ink is applied to the auxiliary ink layer 3 to provide a first ink layer 4. The auxiliary ink layer 3 has a property lower than that of the first ink layer 4 in terms of the ability to shield light, and the auxiliary ink layer 3 is provided with the laser beam L from the outer surface 2a of the first base film 2. In the same manner as the first ink layer 4, the shielding reduction property is exhibited.

  Without providing the first ink layer 4, the auxiliary ink layer 3 is provided directly on the inner surface of the first base film 2, and the second ink layer 6 is shielded alone on the surface opposite to the irradiation side of the auxiliary ink layer 3. When trying to play a role, the auxiliary ink does not have a great shielding ability, so the shielding property of the auxiliary ink layer 3 against the second ink layer 6 is not sufficient. This is because the first ink layer 4 has a shielding property against the second ink layer 6 and the auxiliary ink layer 3 has a surface color selectivity.

  According to the structure of this embodiment, it has the effect which 1st Embodiment has, and also has the following effects. That is, by providing the auxiliary ink layer 3 on the first ink layer 4, the surface color can be variously selected as the color of the auxiliary ink. As a result, the shielding property for the second ink layer 6 and the selectivity of the surface color can be separated, so that the color contrast between the background color and the graphic color can be set variously according to the application. Is possible.

Next, a prototype example of the laser printing film 1 according to this embodiment and printing conditions will be specifically described.
Prototype example 1
First, silver ink (DIC Co., Ltd., univia NT silver K1) as a first ink is applied to a biaxially stretched polypropylene film 20 μm as the first base film 2 to a thickness of about 1 μm (after drying). The ink layer 4 is formed, and then black ink (Finestar R92 S black, manufactured by Toyo Ink Manufacturing Co., Ltd.) as a second ink is applied in a thickness of about 1 μm (after drying) to form the second ink layer 6 Then, the adhesive 8 was applied and bonded to an unstretched polypropylene film 30 μm as the sealant film 10 to prepare the laser printing film 1.

Prototype example 2
Gold ink (DIC Corporation, Univia NT Sun Gold) is applied to a biaxially stretched nylon film 15 μm as the first base film 2 to a thickness of about 1 μm (after drying), and then as a second ink Apply black ink (Toyo Ink Mfg. Co., Ltd., Finestar R92 S Black) to a thickness of about 1 μm (after drying), then apply adhesive 8 and paste with 50 μm of unstretched polyethylene film as sealant film 10 In addition, a laser-printed laminate film was prepared.

  With regard to the above-described prototype examples 1 and 2, laser printing was performed in consideration of the printing conditions and the like described later. In prototype example 1, the display color of the second ink layer 6 was black with the silver first ink layer 4 as the background. For example, character figures such as A, B, C,... Can be drawn clearly. In Prototype Example 2, the display color of the second ink layer 6 is black with the gold first ink layer 5 as the background. Character figures such as A, B, C... Could be drawn clearly.

About laser printing conditions Using the laser printing film 1 of Prototype Example 1, printing was performed with a YVO ₄ laser marker (manufactured by Keyence Corporation, MD-V9900, wavelength 1.06 μm). The printing conditions could be adjusted to achieve optimum printing by mainly adjusting three parameters.

  Here, the three parameters are printing speed (irradiation time), laser output intensity, and laser pulse repetition frequency. The printing speed (irradiation time), laser output intensity, and laser pulse repetition frequency are factors that determine the extent to which the first ink layer 4 is altered. Further, the wavelength of the laser is related to efficiently absorbing the first ink layer 4 without causing the first base film 2 to absorb the laser light.

  By selecting the best combination of the three parameters (printing speed (irradiation time), laser output intensity, laser frequency), clear printing becomes possible. When the combination of parameters is bad and the laser energy to irradiate is small, the contrast ratio of the printed characters will be low, or the printed characters will be thin, so it will not be a print with excellent recognition. In addition, when the laser energy is large, the ink layers 4 and 6 are expanded, film delamination occurs, and the film may break.

About the kind of film There is no restriction | limiting in particular about the kind of film to be used, The various film generally used as a film for packaging can be used.

  If the example of the film to be used is given, the following can be mentioned. As a base film, a biaxially stretched film obtained by biaxially stretching a resin such as polypropylene, polyamide, or polyester, a transparent deposited film obtained by depositing alumina or the like on the biaxially stretched film, or a resin such as polyvinylidene chloride on the biaxially stretched film. And a coextruded film obtained by extruding a high-barrier resin such as an ethylene-vinyl alcohol copolymer resin and a polypropylene resin into a multilayer film. Examples of the sealant film include an unstretched film obtained by forming a film of a resin such as polypropylene or polyethylene without stretching.

About the structure of a film There is no restriction | limiting in particular about the structure of a film, The structure generally used as a film structure for packaging can be used.

If the example of the film structure to be used is given, the following can be mentioned.
Biaxially stretched film / printing / adhesive / unstretched filmBiaxially stretched film / printing / adhesive / biaxially stretched film / adhesive / unstretched film

Laminate Film Laminating Method There is no particular limitation on the method for producing the laminate film, and a laminating method generally used as a packaging laminate film can be used.

  If the example of the bonding method to be used is given, the following can be mentioned. Laminate film with adhesive coated on film, laminated film with another film, molten resin such as polyethylene extruded on film, laminated film with another film stuck together, extruded film with molten resin such as polyethylene laminated Laminated film.

Regarding the configuration of the print layer The configuration of the print layer includes the following combinations.
・ Silver (gold) ink / black (color) ink ・ White ink / silver (gold) ink / black (color) ink

  As the silver ink to be used, an ink used for normal printing can be used. By appropriately selecting the weight ratio of the pigment component (aluminum powder) in the ink, clear printing can be achieved when laser printing is performed. The coating thickness is preferably about 0.3 to 3.0 μm, and the coating thickness can ensure a concealing property that the black (color) ink to be applied following the silver ink cannot be seen through from behind the silver ink. Is preferred. The gold ink to be used is the same as the above silver ink.

  As the black ink to be used, inks used in normal printing can be used. The coating thickness is preferably about 0.3 μm to 3.0 μm, and is preferably a coating thickness that can realize a density at which characters can be recognized when laser printing is performed. Further, instead of the black ink, it is possible to use another color ink having a high contrast ratio with the silver (gold) ink.

  As the white ink to be used, an ink used for normal printing can be used. The coating thickness is preferably about 0.3 μm to 3.0 μm, and ensures a concealing property that the silver (gold) ink to be printed following the white ink cannot be seen from behind the white ink. A coating thickness that can be formed is preferable.

  As described above, according to the embodiment of the present invention, the first base film is provided with the second base film 12 of the plastic material formed in close contact with the surface on the counter-irradiation side of the second ink layer 6. When the laser beam is irradiated from the outer surface of the second ink layer, the display color of the second ink layer 6 is changed according to the irradiation region by changing the first ink layer 4 and reducing the light shielding degree of the first ink layer 4. For example, black can be made visible against background colors such as the first ink layer 4 (for example, silver or gold) or the auxiliary ink layer 3 (for example, white), and a laser printing film using a laser beam 1 can easily display a character figure or the like.

The figure which shows the laser printing film of 1st Embodiment of this invention. The figure which shows the laser printing film of 2nd Embodiment of this invention. The figure which shows the laser printing film of the modification of 1st Embodiment of this invention. The figure which shows the laser printing film of the modification of 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser printing film 2 1st base film 2a Outer surface of 1st base film 2b Inner side of 1st base film 3 Auxiliary ink layer 4 1st ink layer 5 1st ink layer 6 2nd ink layer 8 Adhesive layer 10 Sealant film 12 Second substrate film L Laser beam

Claims (8)

A first base film of plastic material having an outer surface on the irradiation side irradiated with a laser beam of a predetermined wavelength and an inner surface on the opposite side opposite to the outer surface;
A first ink layer formed by applying a first ink to the inner surface of the first base film;
A second ink layer formed by applying a second ink having a display color on the surface opposite to the irradiation side of the first ink layer;
A second base film of a plastic material formed in close contact with the surface on the counter-irradiation side of the second ink layer,
When the laser beam is irradiated from the outer side surface of the first base film, the first ink layer is formed so that the display color of the second ink layer can be displayed according to the irradiation area. Having a shielding reduction property that alters and reduces the degree of light shielding of the first ink layer to the second ink layer;
The first ink layer has silver ink in which fine aluminum powder is dispersed,
The shielding reduction property is based on the fact that the first ink layer is diluted when the laser beam is irradiated from the outer surface of the first base film. A first base film of plastic material having an outer surface on the irradiation side irradiated with a laser beam of a predetermined wavelength and an inner surface on the opposite side opposite to the outer surface;
A first ink layer formed by applying a first ink to the inner surface of the first base film;
A second ink layer formed by applying a second ink having a display color on the surface opposite to the irradiation side of the first ink layer;
A second base film of a plastic material formed in close contact with the surface on the counter-irradiation side of the second ink layer,
When the laser beam is irradiated from the outer side surface of the first base film, the first ink layer is formed so that the display color of the second ink layer can be displayed according to the irradiation area. Having a shielding reduction property that alters and reduces the degree of light shielding of the first ink layer to the second ink layer;
The first ink layer has silver ink in which fine aluminum powder is dispersed,
The shielding reduction property is based on the fact that the first ink layer becomes transparent when the laser beam is irradiated from an outer surface of the first base film. A first base film of plastic material having an outer surface on the irradiation side irradiated with a laser beam of a predetermined wavelength and an inner surface on the opposite side opposite to the outer surface;
A first ink layer formed by applying a first ink to the inner surface of the first base film;
A second ink layer formed by applying a second ink having a display color on the surface opposite to the irradiation side of the first ink layer;
A second base film of a plastic material formed in close contact with the surface on the counter-irradiation side of the second ink layer,
When the laser beam is irradiated from the outer side surface of the first base film, the first ink layer is formed so that the display color of the second ink layer can be displayed according to the irradiation area. Having a shielding reduction property that alters and reduces the degree of light shielding of the first ink layer to the second ink layer;
The first ink layer has silver ink in which fine aluminum powder is dispersed,
In the shielding reduction, when the laser beam is irradiated from the outer surface of the first base film, the central portion of the laser beam irradiation position is compressed toward the peripheral portion of the first ink layer. Laser printing film characterized by that. An auxiliary ink is formed on the inner surface of the first substrate film between the first substrate film and the first ink layer, and the laser beam is irradiated from the outer surface of the first substrate film. 4. The laser printing film according to claim 1, wherein an auxiliary ink layer exhibiting shielding reduction is provided together with the first ink layer. The said 2nd base film consists of the adhesive layer apply | coated to the counter-irradiation side of the said 2nd ink layer, and the film for sealants laminated | stacked on this adhesive layer, The Claim 1 characterized by the above-mentioned. Or the laser printing film of any one of Claim 3. The said 2nd base film is a molten resin layer formed by apply | coating a molten resin to the non-irradiation side of the said 2nd ink layer, Either of Claim 1, 2 or 3 characterized by the above-mentioned. 2. The laser printing film according to item 1. The laser printing film according to any one of claims 1, 2 and 3, wherein the irradiation intensity of the laser beam is selected so as to change only the first ink layer. . The said predetermined wavelength of the said laser beam is selected so that it may have a transmittance | permeability with respect to the said 1st base film, and it has an absorptivity with respect to the said 1st ink layer, The Claim 1 characterized by the above-mentioned. The laser printing film of any one of Claim 2 or Claim 3.

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