JP5699611B2 - Information management method and information management medium - Google Patents

Description

  The present invention relates to an information management method and an information management medium.

  Marking information such as letters, symbols, illustrations, etc. on parts, laminates, etc. covered with resin is widely performed, especially for quality control of products and product classification at production sites such as factories. It is often used for marking production numbers. As the marking information, a method using an inkjet or a method using a laser is generally known.

  Ink marking is often a problem of clogging of ink nozzles, and maintenance is often complicated. On the other hand, marking using a laser has the greatest feature that it can be used without relatively affecting the production process because the marking method is non-contact.

  There are several methods for marking with a laser.

  For example, a character or the like is drawn with a laser beam using a galvanometer or the like (Patent Document 1). In this case, drawing is performed by destroying the surface of the object mainly by heat from laser irradiation. At this time, a continuous wave or a laser with a long pulse width is used, and the laser beam is narrowed down to a thickness of a line that forms a character to be drawn.

  As another example, a character or the like is marked by installing a die (mask) of the character or the like between the laser and the object (Patent Document 2). In this case, the drawing is mainly performed by creating a scratch on the surface due to the laser ablation (damage) effect, or by drawing off the printed layer on the surface.

  As another example, a color developing layer consisting of a color developing agent such as a leuco dye that develops color by absorption of laser light and a color developer is provided on one side of the transparent film, and laser light is irradiated from the film side to draw on the object. A method has been proposed (Patent Document 3).

  As another example, the masking layer and a base layer that appears when the masking layer is removed have a brightness difference that allows the masking layer and the base layer to be easily recognized. A laminate for laser printing has been proposed (Patent Document 4), which is removed by heat generation and destruction, makes the base visible, and can perform desired drawing.

  However, parts and laminates marked with information such as product production control and quality control may be marked with confidential information, in which case the marking part must be removed, concealed, or the marking information erased. There was a problem of having troublesome work. Further, after the marking portion is removed, even if an attempt is made to trace the manufacturing process and quality information of the component and the laminate, the marking information has already been removed or erased, and thus tracing cannot be performed.

Japanese Patent Laid-Open No. 05-077067 JP 05-058024 A Japanese Patent Laid-Open No. 08-025809 JP 2008-100385 A

  In view of the background of the prior art, the present invention solves such problems and is a medium capable of marking production management and quality control information of a factory or the like by laser marking, and the marking of the marked product. An information management method in which the marking information is not easily read by the customer even if it is distributed to the customer without removal, concealment or erasing of the marking information, and can be suitably used for the method. The purpose is to provide information management media.

The present invention employs the following means in order to solve the problems. That is,
At least a part of the surface region is a resin composition, and a concealing layer that is transparent to visible light and opaque to visible light is provided on the information addition part of the article, and the concealing layer contains a near-infrared transmitting pigment. And the near-infrared transparent dye is anthraquinone, quinacridone, azo, diketopyrrolopyrrole, perinone, perylene, benzimidazolone, isoindolinone, isoindoline, phthalocyanine, indigo A thioindigo, dioxazine, azomethine and azomethine azo dyes, and / or a white pigment,
By irradiating the information adding part with an infrared laser,
Information is added by heat-denaturing the resin composition,
An article information management method, comprising: reading information with a near-infrared camera.
As a preferred embodiment,
(1) The thickness of the concealing layer is
5 to 1000 μm,
(2) pre-Symbol white pigment, a white pigment surface is covered by a synthetic resin film, the size of the primary particle diameter of the white pigment is of 20 to 50 nm,
( 3 ) The thermal modification of the resin composition by irradiation with an infrared laser is carbonization.
( 4 ) The resin composition is made of a resin composition containing 20 to 50 mol% of carbon on an atomic basis . Also,
( 5 ) It has a sheet shape, and at least a part of the surface area thereof is constituted by a resin composition, and a concealing layer that is transparent to near infrared rays and is opaque to visible light is provided on the resin composition. The concealing layer contains a near-infrared transmitting dye, and the near-infrared transmitting dye is an anthraquinone, quinacridone, azo, diketopyrrolopyrrole, perinone, perylene, benzimidazolone. Information management medium which is at least one organic dye selected from azomethine, isoindolinone, isoindoline, phthalocyanine, indigo, thioindigo, dioxazine, azomethine and azomethine azo, and / or a white pigment .

  According to the present invention, it is possible to mark production management and quality control information of a factory or the like by laser marking, and the customer does not go through the process of removing, concealing or erasing the marking information of the marked product. The information management method in which the marking information is not easily read by the customer even when it is distributed to the market, and the information management medium that can be suitably used for the method can be provided.

It is a schematic diagram of the cross section around the information addition part of the articles | goods which are the application object of the information management method of this invention. It is a schematic diagram which shows the method of adding information to the information addition part (2) of FIG. It is a schematic diagram which shows the state by which information was added to the information addition part (2) in FIG. It is a figure which shows the state which looked at the information addition part (2) in FIG. 3 with visible light from the outside. It is a figure which shows the state which looked at the information addition part (2) in FIG. 3 through the near-infrared camera from the outside.

  Embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the form shown in the drawings cited for explaining the invention, and implementations other than those shown in the drawings are within the scope of the technique described in this specification. Is also included.

  FIG. 1 is a schematic diagram of a cross section around the information adding portion of an article to which the information management method of the present invention is applied. In FIG. 1, an article (1) (hereinafter sometimes simply referred to as a target article) that is an object of the information management method of the present invention has an information adding section (2) in which at least the surface region (3) is made of a resin composition. In the information management method of the present invention, a concealing layer (4) that is transparent to near infrared rays and is opaque to visible light is provided on the information adding unit (2). Is. Note that the position of the surface (7) of the article in the cross section and the position of the surface (8) of the masking layer in the cross section are indicated by dotted lines (the boundary between the masking layer (4) and the surface region (3) and the masking layer (4)). The surface is indicated by a solid line).

  The information adding unit (2) of the target article (1) in the information management method of the present invention is a part for adding management information related to the target article such as production management and quality control information, and a place where the information adding unit is set The shape and size of the information adding unit can be arbitrarily set at a place where the infrared laser can be irradiated according to the amount, content, purpose, and the like of the information to be added. The surface region (3) is a solid part having a thickness of 5 μm or more in the depth direction from the surface of the article (1) to be subjected to the information management method of the present invention, and at least a part of the surface area (3) is formed from the resin composition. By being configured, when an infrared laser, which will be described later, is irradiated, this is thermally denatured and information can be added. The details of the resin composition used here will be described later.

  And in this invention, it is necessary to provide the concealing layer (4) which is a near-infrared transparent property and a visible light impermeability on the information addition part of the said target article. By providing such a concealing layer (4), when an infrared laser is irradiated and the resin composition underneath is thermally denatured and information is added, the additional information can be read with a near-infrared camera, This additional information can be prevented from being easily read by the customer.

  FIG. 2 is a schematic diagram showing a method of adding information to the information adding unit (2) of FIG. In this invention, it is a figure which shows the method of irradiating a part of information addition part (2) with an infrared laser (5), and adding information, FIG. 3 shows information added to an information addition part (2). It is a schematic diagram which shows the state. FIG. 2 shows a state where the information is added by the part (6) in which the resin composition is thermally denatured by the method of adding information shown in FIG.

  In FIG. 2, the information adding part (2) is provided with a concealing layer (4) on a target article whose surface region (3) is a resin composition, and the concealing layer of the information adding part (2) is provided. By oscillating an infrared laser (5) from the (4) side, focusing on the surface region (3) and irradiating the laser, the surface region (3) is thermally denatured by heat from the infrared laser, The part (6) by which the resin composition was heat-denatured can be produced. In the present invention, the information added as the part (6) in which the resin composition is heat-denatured in the information adding part (2) may be simply referred to as marking information hereinafter.

  Since the article (1 ′) that is the object of the information management method of the present invention has the hiding layer (4), the part (6) in which the resin composition is thermally denatured, that is, the marking information is visually recognized from the outside. (In FIG. 4, the outline (6 ′) indicating the range of the portion where the resin composition is heat-denatured is indicated by a broken line, which is invisible to the naked eye). However, when the article (1 ′) is photographed from the concealing layer side through a near-infrared camera, for example, a CCD camera or a CMOS camera equipped with a visible light cut filter (for example, IR-76 manufactured by FUJIFILM Corporation), It is possible to recognize the marking information (6) recorded in the information adding unit (2) (FIG. 5). This is because when the target article (1 ′) is viewed in the visible light region, the concealing layer (4) makes the marking information (6) recorded in the information adding unit (2) invisible, but the near infrared ray When the target article (1 ′) is viewed with a camera or the like, the near infrared light passes through the concealing layer (4), and the marking information (6) formed by heat denaturation of the information adding unit (2) is near. This is because the image of the marking information (6) can be identified by absorbing infrared rays.

  In the article (1) which is the object of the information management method of the present invention, the surface region (3) of the information adding part (2) is composed of a resin composition, and the region is thermally denatured by laser irradiation. Specifically, any material that is thermally denatured by the heat of the laser light when the surface region (3) is irradiated with the laser light may be used. Preferably, the irradiated portion is carbonized by the heat of the laser light. It is. As such a resin composition, what is necessary is just to contain 20-50 mol% or more of carbon atoms on the basis of the number of atoms. For example, phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyl resin, polyurethane resin, thermosetting polyimide resin, polyolefin resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin, polystyrene Resins, acrylonitrile butadiene (ABS) resins, acrylic resins, and other thermoplastic resins, polyamide resins, polyacetal resins, polycarbonate resins, modified polyferene ether resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polyethylene naphthalate resins, polyphenylene sulfide resins , Polyether sulfone resin, polyether ether ketone resin, polyamide imide resin, etc. and their copolymer resins and acid-modified products, etc. It can be widely used from. Further, a part of the surface region of an inorganic material such as metal or glass may be the resin composition, or a mixture of the inorganic material and the resin composition.

  The thickness of the resin composition in the surface region (3) of the information addition part (2) is not particularly limited, but it is usually 5 μm or more, preferably 10 μm or more, more preferably 20 μm or more. is there. When the thickness of the resin composition is 5 μm or more, the range in which the heat from the laser light is transmitted to the outside of the laser irradiation site can be kept small, so that fine information recording can be performed.

  Next, the masking layer (4) will be described. The hiding layer (4) is a layer having both near-infrared transparent properties and visible light opaque properties.

  In the present invention, the near-infrared-transmitting layer means that the light transmittance is 30% or more, preferably 40% or more in the near-infrared wavelength region of at least 50% of wavelengths from 760 nm to 2500 nm. Preferably, the layer is 50% or more. By having such a near-infrared transmittance, it is possible to read the marking information (6) recorded in the information adding section (2) of the target article (1 ') using a near-infrared camera. Note that the near-infrared camera referred to in the present invention may be any device that can read using near-infrared rays, and examples thereof include a CCD camera and a CMOS camera provided with a visible light cut filter.

  The visible light impermeability referred to in the present invention means that the marking information (6) marked on the information adding part (2) under the concealing layer (4) is not visible through visible light. Specifically, it means that the total light transmittance measured by JIS K7361-1 (1997) is 30% or less, preferably 20% or less, more preferably 10% or less. If the total light transmittance exceeds 30%, the marking information (6) may be seen through by visible light, and the marking information (6) may be legible. If it is 30% or less, the presence itself of the marking information (6) marked on the information adding unit (2) is not noticed.

  The hiding layer (4) preferably contains a near-infrared transparent pigment. The near-infrared transparent dye transmits light with a light transmittance of 30% or more, preferably 40% or more, and more preferably 50% or more in at least a continuous wavelength region of 50% or more of near infrared light having a wavelength of 760 nm to 2500 nm. It is a dye having performance. The “dye” used in the present invention applies both “dye” and “pigment” as long as it can be used within the range of both the near-infrared transparent property and the visible light opaque property. Can do.

  Among them, the near-infrared transmitting dye used in the present invention includes anthraquinone, quinacridone, azo, diketopyrrolopyrrole, perinone, perylene, benzimidazolone, isoindolinone, isoindoline, phthalocyanine. It is preferable to use at least one organic dye selected from a dye, an indigo, a thioindigo, a dioxazine, an azomethine, and an azomethine azo, and / or a white pigment.

  The concealing layer (4) is made of a resin material, one or more dyes selected from red, blue, yellow, and black near-infrared transparent dyes that are the three primary colors, and / or white By appropriately mixing the pigment, a layer having a desired hue and shape can be formed.

  Examples of the organic dye that can be used as a near-infrared transmitting dye in the present invention include azo, anthraquinone, phthalocyanine, perinone, perylene, indigo, thioindigo, dioxazine, quinacridone, and isoindo. Linone, isoindoline, diketopyrrolopyrrole, azomethine, and azomethine azo are preferred.

  The black dye that can be used as the near-infrared transmitting dye in the present invention is preferably an azo, azomethine azo, or perylene-based near-infrared non-absorbing black dye.

  The white pigment used in the present invention is composed of a white pigment and a synthetic resin film coated on the surface of the white pigment. By covering the white pigment with a synthetic resin film, the white pigment is less likely to aggregate and the dispersibility is improved, so that it is considered that near infrared rays are easily transmitted. Moreover, it becomes easy to transmit near-infrared rays by covering with a synthetic resin film. Although it is not certain about this action, it is considered that the synthetic resin film is a substance that easily transmits near infrared rays. In other words, compared to the case where a near-infrared ray is directly irradiated to a dispersion of a white pigment alone, the near-infrared irradiation angle is refracted by the synthetic resin film when the near-infrared ray is irradiated through the synthetic resin film. It is thought that it may become easy to permeate the pigment. As the synthetic resin for forming the synthetic resin film, any synthetic resin can be used. Specifically, vinyl acetate resin, vinyl chloride resin, vinyl acetate-vinyl chloride copolymer resin, (meth) acrylic acid It is preferable to use a copolymer resin, a polyester resin, or the like.

  White pigments include not only commonly used white pigments such as titanium dioxide and zinc white (zinc oxide), but also calcium carbonate, barium sulfate, alumina, silica, clay, activated clay, hydrous silicic acid, anhydrous silicic acid, aluminum powder Further, extender pigments such as stainless steel powder and organic plastic pigment can also be used as white pigments as raw materials for the white pigments of the present invention. These white pigments can be used alone or in combination of two or more. Among these, titanium dioxide is preferable. Titanium dioxide has a rutile type and an anatase type, and any of them may be used in the present invention. It is preferable to use a rutile type having a low photocatalytic action.

  Moreover, it is preferable that the white pigment as a raw material of the white pigment used in the present invention has a primary particle size of 20 to 50 nm. When the primary particle diameter is 20 to 50 nm, the light transmittance can be 30% or more in a wavelength region of at least 50% continuously from a wavelength of 760 nm to 2500 nm which is a near infrared region. If the white pigment has a primary particle diameter of more than 50 nm, the near-infrared transmittance may not continuously be 30% or more at wavelengths from 760 nm to 2500 nm. Moreover, when the primary particle diameter of the white pigment is less than 20 nm, it is difficult to produce a white pigment and it is not practical. Here, the primary particle diameter of the white pigment can be measured using a transmission electron microscope (for example, HT7700 manufactured by Hitachi, Ltd.).

  The method of coating the surface of the white pigment with a synthetic resin film is not limited. For example, the white pigment is dispersed in a synthetic resin such as a heat-melted (meth) acrylic acid copolymer, and then, A method of cooling and solidifying a synthetic resin can be applied. Alternatively, the synthetic resin can be dissolved in a solvent such as esters and ketones, a white pigment can be dispersed therein, and then the solvent can be removed by drying. Although the mass ratio of the white pigment and the synthetic resin film is arbitrary, it is generally preferable that the white pigment / synthetic resin film = 80 parts by mass to 60 parts by mass / 20 parts by mass to 40 parts by mass.

The concealing layer (4) in the information management method of the present invention may contain a near-infrared absorbing dye in addition to the above-mentioned near-infrared transmitting dye. When the hiding layer (4) contains a near-infrared absorbing dye, it is preferably 5 parts by mass or less, preferably 3 parts by mass or less, and more preferably 1 part by mass or less with respect to 100 parts by mass of the resin material. The near infrared absorbing dye is a dye having a maximum absorption peak in the near infrared region. When the near-infrared absorbing pigment is larger than 5 parts by mass with respect to 100 parts by mass of the resin material, the masking layer (4) may not be able to exhibit near-infrared transparency. When the amount is 5 parts by mass or less, the near-infrared transmittance of the masking layer (4) can be maintained. Examples of such a dye include iodo salt of 1-ethyl-4- [5- (1-ethyl-4 (1H) -quinolinylidene) -1,3-pentadienyl] quinolinium, 5,7-dimethyl-3- [3- (5,7-dimethyl-1-phenyl-thiazolo [3,4-a] -1-phenylthiazolo [3,4-a]]-pyridinium perchlorate, N, N-diethyl- N- [4- [1,5,5-tris (4-diethylamino-phenyl-9-2,4-pentadienyldiene] -2,5-cyclehexadiene-1-ylidene] ammonium perchlorate, etc. Cyanine dyes,
N, N-bis (4-dibutylaminophenyl) -N [4- [N, N-bis (4-dibutylaminophenyl) amino]] phenyl] ammonium perchlorate, 2,5-cyclohexadiene-1 , 4-Dilidene-bis [N, N-bis (4-dibutylaminophenyl) ammonium] perchlorate and other aminium dyes; 5-amino-2,3-dicyano-8- (4-ethoxyphenyl-amino ) -1,4-naphthoquinone, 2,3-dicyano-5,8-bis (4-ethoxyphenylamino) -1,4-naphthoquinone, 2,3-dicyano-4- [4- (dimethylamino) phenyl- Imino] -1,4-naphthoquinone and other naphthoquinone dyes; bis (dichlorobenzene-1,2-dithiol) nickel (2: 1) tetrabutylammonium salt, bis (benze) -1,2-dithiol) nickel (2: 1) tetra- (n-butyl) phosphonium salt, bis (1,2-diphenylethylene-1,2-dithiol) nickel, bis (1,2-dicyanoethene- 1,2-dithiol) dithiol dyes such as nickel (2: 1) -n-hexadecyl (trimethyl) ammonium salt,
8-azo-4- (4-diethylamino-2-methylphenyl-imino) -1 (4H) -naphthoquinone (2: 1) quinone complexes such as diperoxides such as copper complexes; 4- (4-diethylaminophenyl) ) -1,2-naphthoquinone (1: 1) naphthoquinone complexes such as diperchlorate of nickel complex; and naphthalocyanine complexes such as tetrakis (t-octyl) naphthalocyanine VO complex.

  The thickness of the masking layer (4) in the information management method of the present invention is preferably 5 μm or more. More preferably, it is 10 micrometers or more, More preferably, it is 20 micrometers or more. When the surface area (3) of the information adding part (2) is thermally denatured with heat by laser light when it is less than 5 μm, it may be difficult to focus on the surface area (3). Even when the surface region (3) can be focused, the shielding layer (4) itself may be thermally denatured by the heat of the laser beam, and as a result, the shielding layer (4) is visible by visible light. ) When viewed from the side, the image of the marking information (6) may be identifiable. If it is 5 μm or more, it is easy to focus the laser beam on the surface region (3), and the marking information (6) can be easily kept invisible with visible light. The thickness of the concealing layer (4) is preferably 1000 μm or less. More preferably, it is 500 micrometers or less, More preferably, it is 300 micrometers or less. If it is larger than 1000 μm, the near-infrared transmittance of the concealing layer may be inferior. Specifically, the near-infrared transmittance is 30% in a continuous infrared wavelength region of 760 nm to 2500 nm of 50% or more. Otherwise, it may be difficult to identify the marking information (6) recorded in the information adding unit (2) of the target article (1 ′) via a near-infrared camera or the like. When the thickness of the masking layer (4) is 1000 μm or less, the marking information (6) can be identified via a near-infrared camera or the like.

  The concealing layer (4) in the information management method of the present invention may be a laminate having two or more layers, and is not limited. For example, a transparent polyester film coated with a paint containing a near-infrared transparent pigment, or a polyester film in which a polyethylene terephthalate resin and a near-infrared transparent pigment are kneaded together with an adhesive or the like Any material can be used as long as it is opaque to visible light and transmits near infrared rays.

  Up to now, the description has been made mainly on the aspect around the information addition part of the article to be managed based on the drawings, but the article information management method of the present invention is formed by forming the periphery of the information addition part as an independent sheet. Can be applied to any object. That is, even for an article that does not have a resin composition in the surface region, at least a part of the surface region is a resin composition using a sheet-shaped substrate, and a near infrared ray is transmitted on the resin composition. Management is possible by applying an information management medium having a concealing layer that is transparent and does not transmit visible light. For example, an adhesive tape type information management medium in which a concealing layer is provided on a resin tape-shaped base material and an adhesive layer is laminated on the surface opposite to the concealing layer, or a resin sheet-shaped base material An adhesive sheet type information management medium in which a concealing layer is provided on the surface, and an adhesive layer and a release sheet are laminated on the surface opposite to the concealing layer, and a shrink label provided with a concealing layer on a shrinkable film Type information management medium. Further, for example, an intermediate layer having a near-infrared transmittance between an object and a concealing layer, specifically, a concealing layer, an air layer, an object laminated in this order, a concealing layer, a transparent polyester layer, Various embodiments can be adopted as long as they are within the scope of the present invention, such as those laminated in the order of objects.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to an Example.
[Method of evaluation]
Each evaluation was performed as follows. Unless otherwise specified, an average value obtained by measuring five different locations was adopted.
(Measurement of primary particle size of white pigment and white pigment)
Using a transmission electron microscope (HT7700, manufactured by Hitachi, Ltd.), observe at a magnification of 100,000 when the diameter is on the order of 10 nm, and at a magnification of 10,000 when the diameter is on the order of 100 nm. , Took a photo. Draw a line that divides the length and width of the field of view of the photograph into four equal parts, and the diameter of nine particles on the intersection (closest to the intersection if there is no particle on the intersection) (the long diameter if the image is not a perfect circle) ) And the average value was taken as the primary particle size. The significant figures were two digits and the third digit was rounded off.
(Visible light impermeability)
Using Nippon Denshoku Industries Co., Ltd. haze meter NDH2000, the total light transmittance of the test piece 1 (after-mentioned) by the single beam method was measured according to JISK7361-1 (1997).
(Near infrared transmission)
The test piece 1 (described later) was used as a sample, and the light transmittance in the near infrared region from 760 nm to 2500 nm was measured using a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation). The continuous wavelength range (a) having a light transmittance of 30% or more was determined, and the ratio of the wavelength range (a) in the range from 760 nm to 2500 nm (the following formula) was calculated as near infrared transmittance.

(Identification of marking information)
(Visibility of visible light region)
The test piece 2 (described later) was observed under a 15,000 Lx (lux) white fluorescent lamp, and whether or not the marking information image could be identified from the test piece 1 side was determined.
(Identity of infrared region)
Near-infrared camera (XEVA-CL-1.7-320-VisNIR manufactured by Xenics) with a filter (IR-76 manufactured by Fuji Film Co., Ltd.) that cuts visible light below 760 nm set in front of the objective lens In the region 590 nm to 2500 nm), photographing was performed from the side of the test piece 2 (described later) on which the test piece 1 (described later) was attached, and whether or not the marking information image was identified was determined.
[Preparation of white pigment]
(White pigment 1)
40 parts by mass of vinyl acetate-vinyl chloride copolymer is heated and melted on a roll disperser, and 60 parts by mass of rutile titanium dioxide having a primary particle diameter of 40 nm is added and dispersed therein, so that the primary particle diameter is 240 nm. A white pigment was obtained.
(White pigment 2)
40 parts by mass of a vinyl acetate-vinyl chloride copolymer is heated and melted on a roll disperser, and 60 parts by mass of rutile titanium dioxide having a primary particle diameter of 300 nm is added and dispersed therein, so that the primary particle diameter is 400 nm. A white pigment was obtained.
[Preparation of printing ink]
Synthetic resins, pigments and organic solvents having the following composition were mixed and mixed and dispersed for 1 hour with a paint disperser to obtain printing inks of respective colors.
(White printing ink 1)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by weight White pigment 1 ... 11.4 parts by weight Cyclohexanone ... 38 parts by weight Ethyl acetate・ 19 parts by mass (white printing ink 2)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by weight White pigment 2 ... 11.4 parts by weight Cyclohexanone ... 38 parts by weight Ethyl acetate・ 19 parts by mass (red printing ink)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by mass Disazo pigment (PIGMENT RED 48: 1) ... 5.7 parts by mass insoluble azo pigment ( Pigment Red 5) ... 5.7 parts by mass Cyclohexanone ... 38 parts by mass Ethyl acetate ... 19 parts by mass (yellow printing ink)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by mass White pigment 1 ... 3.8 parts by mass Disazo pigment (PIGMENT Yellow 12) ... 5.7 parts by mass quinophthalone pigment (PIGMENT Yellow 138) 5.7 parts by mass cyclohexanone 38 parts by mass ethyl acetate 19 parts by mass (blue printing ink)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by mass Phthalocyanine pigment (PIGMENT BLUE 16) ... 11.4 parts by mass Cyclohexanone ... 38 parts by mass 19 parts by mass of ethyl acetate (black printing ink 1)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by mass Perylene pigment (K0084 manufactured by BASF) ... 11.4 parts by mass Cyclohexanone ... 38 parts by mass Part Ethyl acetate ... 19 parts by mass (Black printing ink 2)
Vinyl chloride-vinyl acetate copolymer (NB500 manufactured by Dainichi Seika Kogyo Co., Ltd.) ... 12.6 parts by mass Carbon black pigment (carbon black) ... 11.4 parts by mass Cyclohexanone ... 38 parts by mass 19 parts by mass of ethyl acetate (preparation of test piece 1)
A 12 μm transparent polyester film (Lumirror (R) “S10” manufactured by Toray Industries, Inc.) was used as a base material. Next, the colored printing inks listed in Table 1 were prepared for each Example and Comparative Example, applied on a substrate using a bar coater, dried, and the total thickness in which a 2 μm colored layer and a polyester film were laminated. A laminate having a thickness of 14 μm was prepared and used as test piece 1.
(Preparation of test piece 2)
A white polyester film having a thickness of 100 μm (Lumirror (R) “E20” manufactured by Toray Industries, Inc.) was prepared, and a dry lamination adhesive (Takelac A-515 / Takenate A-3 manufactured by Mitsui Chemicals, Inc.) was applied and dried. Then, an adhesive layer having a thickness of 3 μm was formed. The surface of the colored layer of the test piece 1 prepared above was superimposed on the adhesive layer to obtain a laminate. Next, from the test piece 1 side of the laminate, using a laser marking device (LP-V manufactured by Panasonic Electric Works SUNX Co., Ltd .; fiber laser system), focus on the surface of the white polyester film located at a depth of 17 μm from the surface layer. In addition, laser marking was performed by adjusting the surface layer of the white polyester film so that approximately 4 μm was carbonized. As marking information at this time, “ABC” of 12 points of Gothic body was written, and a test piece 2 was prepared.

  The results are shown in Table 1.

  As is apparent from Table 1, in the state of the test piece 1, Examples 1 to 6 in which the concealing layer satisfies both near-infrared transparency and visible light impermeability, marking information after creating the test piece 2, Although it was impossible to identify with visible light, it was possible to identify with near infrared light. On the other hand, in the state of the test piece 1, the comparative examples 1 to 4 and 6 in which the concealing layer is near-infrared impermeable and visible-light impermeable are incapable of identifying marking information for both visible light and near-infrared light. there were. In Comparative Example 5, the object could not be marked with an infrared laser, the black colored layer of the test piece 1 was thermally denatured, and the colored layer was marked. This is considered to be because the energy of the infrared laser did not pass through the black colored layer, and the energy was absorbed into the black colored layer and thermally denatured. In Comparative Examples 7 to 10 which are visible light transmissive and near infrared transmissive, marking information can be identified for both visible light and near infrared light, and the original function of the concealing layer cannot be achieved. Could not be achieved.

1 article 1 'article (after adding marking information)
2 Information addition part 3 Surface region 4 Concealment layer 5 Infrared laser 6 Part 6 ′ part where resin composition is heat-denatured Contour (dotted line) showing range of part where resin composition is heat-denatured
7 Surface of article in cross section 8 Surface of hiding layer in cross section

Claims (6)

At least a part of the surface region is a resin composition, and a concealing layer that is transparent to visible light and opaque to visible light is provided on the information addition part of the article, and the concealing layer contains a near-infrared transmitting pigment. And the near-infrared transparent dye is anthraquinone, quinacridone, azo, diketopyrrolopyrrole, perinone, perylene, benzimidazolone, isoindolinone, isoindoline, phthalocyanine, indigo A thioindigo, dioxazine, azomethine and azomethine azo dyes, and / or a white pigment,
By irradiating the information adding part with an infrared laser,
Information is added by heat-denaturing the resin composition,
An article information management method, comprising: reading information with a near-infrared camera. The thickness of the concealing layer is
2. The article information management method according to claim 1, wherein the information management method is 5 to 1000 [mu] m. The white pigment is a white pigment surface is covered by a synthetic resin film, the size of the primary particle diameter of the white pigment article how information management according to claim 1 or 2 is of 20~50nm . The method for managing information on an article according to any one of claims 1 to 3 , wherein the thermal modification of the resin composition by irradiation with an infrared laser is carbonization. The information management method for articles according to any one of claims 1 to 4 , wherein the resin composition comprises a resin composition containing 20 to 50 mol% of carbon on an atomic basis. It has a sheet shape, and at least a part of the surface region thereof is composed of a resin composition, and on the resin composition, a concealing layer that is near-infrared transmissive and visible light impermeable is provided , The concealing layer contains a near-infrared transmitting dye, and the near-infrared transmitting dye is anthraquinone, quinacridone, azo, diketopyrrolopyrrole, perinone, perylene, benzimidazolone, An information management medium which is at least one organic dye selected from indolinone, isoindoline, phthalocyanine, indigo, thioindigo, dioxazine, azomethine and azomethine azo, and / or a white pigment .