JP7071882B2 - Composition for laser multicolor printing and molded body for laser multicolor printing - Google Patents

Description

The present invention relates to a composition for laser multicolor printing and a molded body for laser multicolor printing produced by using the composition.

A method of irradiating a molded body with a laser to develop two or more different color tones to print characters, symbols, patterns, and the like is known. Specifically, a technique for developing a single color other than white, black, white and black by laser irradiation (see, for example, Patent Document 1), or creating a coloring layer on the surface of a molded body and irradiating the coloring layer with a laser. A technique for developing a color (see, for example, Patent Document 2) is known.

Japanese Unexamined Patent Publication No. 2006-083242 Special Table 2016-539031 Gazette

However, in the conventional printing method, heat is generated in the kneading step and the molding step of the composition for producing a molded product, and the heat may react with the color-developing agent to color the composition itself. .. Further, as in the technique shown in Patent Document 1, it is difficult to impart a function capable of developing two or more chromatic colors by laser irradiation to the molded product itself, and in order to develop two or more chromatic colors, it is difficult. As in the technique shown in Patent Document 2, it is necessary to separately provide a color-developing layer on the surface of the molded product.

Therefore, in some aspects of the present invention, a composition for laser multicolor printing capable of producing a molded body having a function of developing two or more chromatic colors by laser irradiation without developing a color even after undergoing a kneading step or a molding step. It provides things.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as any of the following aspects.

One aspect of the laser multicolor printing composition according to the present invention is
Polymer (A) and
A laser color former (B1) containing a compound having a lactone skeleton, and
A laser color former (B2) containing a compound having a triarylmethane skeleton, and
Contains.

In one aspect of the laser multicolor printing composition,
With respect to 100 parts by mass of the polymer (A)
The laser color former (B1) is contained in an amount of 0.1 part by mass or more and 15 parts by mass or less.
The laser color former (B2) can be contained in an amount of 0.1 part by mass or more and 15 parts by mass or less.

In any aspect of the laser multicolor printing composition.
The content of the laser color-developing agent ( _B1 ) is MB1 (part by mass), and the laser color-developing agent (B2).
) Can be 0.3 to 3 in _MB1 / _MB2 when the content is _MB2 (part by mass).

In any aspect of the laser multicolor printing composition.
The compound having a lactone skeleton can be a compound having a fluorin skeleton.

In any aspect of the laser multicolor printing composition.
Further, it can contain at least one compound selected from the group consisting of lanthanum hexaboride, tungsten cesium oxide, indium tin oxide (ITO) and antimony trioxide.

In any aspect of the laser multicolor printing composition.
Further, it can contain an organic halide.

One aspect of the molded body for laser multicolor printing according to the present invention is
It is produced by using the composition for laser multicolor printing of any one of the above embodiments.

According to one aspect of the laser multicolor printing composition according to the present invention, a molded product having a function of not developing a color even after undergoing a kneading step or a molding step and capable of developing two or more chromatic colors by laser irradiation is produced. be able to. Further, according to one aspect of the laser multicolor printing composition according to the present invention, it is not necessary to separately form a coloring layer on the surface of the molded body in order to impart a function capable of developing two or more chromatic colors. , The above function can be more easily imparted to the molded body. Further, according to one aspect of the laser multicolor printing composition according to the present invention, it is possible to produce a molded product having a color-developing function necessary for full-color printing.

It is a conceptual diagram for demonstrating an example of a laser printing method. It is a conceptual diagram for demonstrating an example of a laser printing method.

Hereinafter, preferred embodiments of the present invention will be described in detail. It should be noted that the present invention is not limited to the following embodiments, and includes various modifications implemented without changing the gist of the present invention.

In the present specification, the numerical range described by using "-" means that the numerical values described before and after "-" are included as the lower limit value and the upper limit value.

The "laser multicolor printing" in the present invention means to develop at least two or more chromatic colors by laser irradiation, and may include further developing an achromatic color by developing two or more chromatic colors. Further, in the present specification, "developing two or more chromatic colors" means to develop each chromatic color having a difference in hue angle of 45 ° or more. The hue angle refers to the hue angle (h °) defined in the CIELAB color space, and is the hue angle (trade name, manufactured by Gretag) of the image measured using the colorimeter Gretag Spectralino (trade name, manufactured by Gretag). h °).

In the present specification, the "chromatic color" is a color having three dimensions of hue, lightness, and saturation, and examples thereof include red, blue, yellow, green, purple, and blue-green. As used herein, the term "achromatic color" is a color that includes only the dimension of lightness, and includes, for example, white, gray, and black.

1. 1. Laser Multicolor Printing Composition The laser multicolor printing composition according to the present embodiment includes a polymer (A), a laser color former containing a compound having a lactone skeleton (B1), and a compound having a triarylmethane skeleton. Contains a laser color former (B2) and the like. Hereinafter, the laser multicolor printing composition according to this embodiment will be described in detail.

1.1. Polymer (A)
The laser multicolor printing composition according to this embodiment contains the polymer (A). The polymer (A) has a function as a base material of a molded product obtained by molding the composition.

As the polymer (A), known materials can be used, for example, polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycarbonate (PEN). A polyester polymer such as PC); an acrylic polymer such as polymethyl methacrylate (PMMA); a polyacetal (POM) polymer; polystyrene (PS) and the like can be used. Among these, a polyacetal polymer or polystyrene is preferable because a translucent to white opaque molded product having excellent mechanical strength can be obtained. By using a semi-transparent or white opaque molded body, it is possible to clearly print two or more chromatic or achromatic colors.

1.2. Laser Coloring Agent The laser multicolor printing composition according to this embodiment is a laser coloring agent (B1) containing a compound having a lactone skeleton and a laser coloring agent containing a compound having a triarylmethane skeleton (B1) as a laser coloring agent. B2) and. In order to develop the colors of the laser color-developing agent (B1) and the laser color-developing agent (B2), it is necessary to irradiate the laser light with different energies. The compound having a lactone skeleton contained in the laser coloring agent (B1) and the compound having a triarylmethane skeleton contained in the laser coloring agent (B2) are different compounds.

As the laser color former, a leuco dye is preferable. As used herein, the term "leuco dye" refers to a compound having a function of coloring by irradiating with a laser.

1.2.1. Laser color former (B1)
The laser color former (B1) contains a compound having a lactone skeleton. A compound having a lactone skeleton develops a color when the lactone ring contained in the molecule is opened by laser irradiation. Among such compounds having a lactone skeleton, a compound having a fluorane skeleton is preferable.

As commercially available compounds having a lactone skeleton, RED40, BLUE63 (above, manufactured by Yamamoto Chemicals, Inc.), RED500, CVL, BLACK305 (above, manufactured by Yamada Chemical Co., Ltd.) and the like can be preferably used.

The content ratio of the laser color former (B1) is preferably 0.1 part by mass or more and 15 parts by mass or less, and 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymer (A). It is more preferable that there is, and it is particularly preferable that it is 0.3 parts by mass or more and 5 parts by mass or less.

1.2.2. Laser color former (B2)
The laser color former (B2) contains a compound having a triarylmethane skeleton. Examples of the compound having a triarylmethane skeleton include 4,4'-tetramethyldiaminotriphenylmethane, tris (4-dimethylaminophenyl) methane and the like.

As a commercially available compound having a triarylmethane skeleton, leuco malachite green (manufactured by Tokyo Chemical Industry Co., Ltd.), leuco crystal violet (manufactured by Wako Pure Chemical Industries, Ltd.) and the like can be preferably used.

The content ratio of the laser color former (B2) is preferably 0.1 part by mass or more and 15 parts by mass or less, and 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymer (A). It is more preferable that there is, and it is particularly preferable that it is 0.3 parts by mass or more and 5 parts by mass or less.

1.3. Other Additives The laser multicolor printing composition according to the present embodiment may contain other additives in addition to the above-mentioned components depending on the purpose and use. Examples of other additives include color formers, fillers and the like.

1.3.1. Color developer When printing by laser irradiation, the color developer becomes an oxidizing agent by laser irradiation, and has a function of mainly oxidizing the laser coloring agent (B2) to form a double bond to develop a color. As the color developer, it is preferable to use an organic halide. Examples of the organic halide include dibromobenzene, hexabromobenzene, pentabromotoluene, pentabromodiphenyl ether, dichlorobenzene, hexachlorobenzene and the like. These color developeres can be used alone or in admixture of two or more.

The content ratio of the color developer is preferably 0.1 to 15 parts by mass, and more preferably 0.2 to 12 parts by mass with respect to 100 parts by mass of the polymer (A).

1.3.2. Filler The filler has a function of converting electromagnetic rays into heat when printing by laser irradiation, and mainly causing the laser color former (B1) to develop color by heat. Such fillers include metal particles such as aluminum, nickel, gold, silver, copper, iron, stainless steel (SUS); titanium oxide, magnesium oxide, zinc oxide, aluminum oxide, silicon oxide, tin oxide (ITO). , Antimonite oxide, metal oxide particles such as tungsten cesium oxide; carbon black, lanthanum hexaborate and the like. Among these fillers, at least one compound selected from the group consisting of lanthanum hexaboride, tungsten cesium oxide, indium tin oxide (ITO) and antimony trioxide oxide is preferable. These fillers can be used alone or in admixture of two or more.

The content ratio of the filler is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and 0.05 to 1 part by mass with respect to 100 parts by mass of the polymer (A). It is particularly preferable that it is by mass.

1.4. Method for Manufacturing Laser Multicolor Printing Composition The laser multicolor printing composition according to the present embodiment is obtained by, for example, adding each of the above raw material components to a Banbury mixer, a kneader, a roll, or the like and kneading them. Can be manufactured. As a kneading method, each component may be added all at once, or may be kneaded by a multi-stage addition method.

Further, pellets can be prepared from the laser multicolor printing composition produced as described above and used in a step of producing a laser multicolor printing molded body. The pellets for producing such a laser multicolor printing molded body preferably have a content ratio of pellets passing through a three-mesh sieve of 98% by mass or more, preferably 99% by mass, based on the total mass of the pellets. % Or more is more preferable. The content ratio of the pellets that pass through the 5-mesh sieve and do not pass through the 9-mesh sieve is preferably 50% by mass or more, and preferably 70% by mass or more, based on the total mass of the pellets. It is more preferably 85% by mass or more, and particularly preferably 85% by mass or more. The above "mesh" is based on a standard sieving method using a Tyler sieve.

The pellets can be produced by processing the laser multicolor printing composition with an extruder or the like. For example, the thread diameter and its cut length can be appropriately changed by adjusting the die diameter, the take-up speed, and the like using a pelletizer. After that, the pellets can be produced by classifying them with a predetermined sieve.

According to the laser multicolor printing composition according to the present embodiment, it is possible to produce a molded product having a function of developing two or more chromatic colors by laser irradiation without developing a color even after undergoing a kneading step or a molding step. can.

2. 2. Mold for laser multicolor printing The pellets of the above laser multicolor printing composition can be molded by injection molding, extrusion molding, hollow molding, compression molding, film extrusion, sheet extrusion, vacuum molding, foam molding, blow molding, or the like. It is possible to produce a molded product for laser multicolor printing having a predetermined shape.

As for the shape of the molded body for laser multicolor printing, various shaped molded bodies can be selected according to the purpose and application, and if the laser beam can be irradiated, the printed portion is a flat surface, a curved surface, or a corner portion. It may be an uneven surface or the like.

3. 3. Printing Method By irradiating the laser multicolor printing molded body obtained as described above with laser light having two or more different energies, two or more chromatic colors can be developed. That is, the laser color-developing agent (B1) is colored by low-energy laser light irradiation, and the laser color-developing agent (B2) is colored by high-energy laser light irradiation, so that multicolor printing is possible.

In general, the "energy" of a laser beam depends on the irradiation conditions of the laser beam. Specifically, in addition to the type, wavelength, pulse width, frequency, and output of the laser light to be irradiated, the irradiation time, irradiation area, distance and angle from the light source to the laser multicolor printing molding, irradiation method, etc. are changed. Therefore, it is possible to irradiate a laser beam that "has different energies" when irradiating two or more laser beams. For example, laser light having two different energies may be irradiated using laser light having different wavelengths, or laser light having two different energies may be irradiated by changing the irradiation conditions of the laser light having the same wavelength. You may.

As the laser light irradiation method, either a scan method or a mask method may be used. Further, two or more laser beams having different energies may be irradiated at the same time, or may be irradiated one by one.

As the laser light irradiation device, a general laser printing device or the like can be used. In laser printing, one device may irradiate two or more laser beams having different energies, or a plurality of devices may be used. As a device capable of laser printing of two wavelengths, for example, a laser printing system "RSM50D type" or "RSM30D type" manufactured by Roffin Basel can be used.

In the present specification, the numbers indicating the "wavelength" of the laser beam, such as the wavelength of 1064 nm and the wavelength of 532 nm, both mean the central wavelength and usually include an error of about ± 3%.

A convenient way to obtain laser light with two or more different energies is to use laser light of different wavelengths. For example, when laser printing is performed by irradiating two or more laser beams having different wavelengths, the difference in wavelength of each laser beam is preferably 100 nm or more, more preferably 200 nm or more, and particularly preferably 500 nm or more. The upper limit is usually 1,500 nm.

The wavelength of the low-energy laser light used to develop the color of the laser color former (B1) is preferably 700 nm or more and 11000 nm or less, and more preferably 800 nm or more and 1100 nm or less. As such a long-wavelength laser, generally, a YAG laser, a YVO ₄ near-infrared laser (wavelength 1064 nm), a CO2 laser and the like can be preferably used.

The wavelength of the high-energy laser light used to develop the color of the laser color former (B2) is preferably 300 nm or more and less than 700 nm, and more preferably 350 nm or more and 600 nm or less. As such a short-wavelength laser, generally, a YVO ₄ UV laser (wavelength 355 nm), a blue laser (wavelength 455 nm), a green laser (wavelength 532 nm) and the like can be preferably used.

Hereinafter, a specific example of the printing method by laser light irradiation will be described with reference to the drawings, but the multicolor printing method by laser light irradiation is not limited to this. The laser multicolor printing molded body 1 according to the present embodiment is irradiated with laser light having two different energies ([I] in FIG. 1). At this time, the laser light irradiation may be performed simultaneously or separately. Further, depending on the target color, the irradiation position may be different, or overlapping colors may be mixed. The low-energy laser light irradiation part is printed in the color derived from the laser color-developing agent (B1) (3a in FIG. 1), while the high-energy laser light irradiation part is derived from the laser color-developing agent (B2). It is printed in color (3b in FIG. 1) ([II] in FIG. 1). In the above procedure, it is possible to obtain a molded body 2 with multicolor printing printed in two or more different color tones.

Further, by irradiating the laser multicolor printing molded body 1 with low-energy laser light, a color printing portion (3a in FIG. 2) derived from the laser coloring agent (B1) having a wide area is formed. After that, by irradiating the printed portion with a high-energy laser beam, the irradiated portion is mixed with a color derived from the laser coloring agent (B2) and a color derived from the laser coloring agent (B1). The printed portion (3b in FIG. 2) can be formed. In the above procedure, it is possible to obtain a molded body 2a with multicolor printing printed in two or more different color tones.

The molded product with multicolor printing thus produced may be provided with a protective layer on the surface having the printing portion. The material constituting this protective layer may be selected according to the purpose and application, and is not particularly limited.

Molds with multicolor printing are useful for, for example, electrical / electronic applications, automobile applications, general miscellaneous goods applications, building materials, etc., and in particular, automobile parts such as module parts in engine rooms, intake manifolds, underhood parts, radiators, etc. It can be used for cockpit module parts used for parts, instrument panels, etc. Other uses include, for example, electronic components such as personal computers, liquid crystal projectors, mobile devices, and mobile phones.

4. Examples The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples. In addition, "part" and "%" in this Example are based on mass unless otherwise specified.

4.1. Example 1
4.1.1. Preparation of molded body for laser multicolor printing Knead each component of the type and mass part shown in Table 1 with a lab plast mill (manufactured by Toyo Seiki Co., Ltd., model number: 4C150) for 5 minutes at a screw rotation speed of 100 rpm and a cylinder temperature of 200 ° C. To prepare a composition for laser multicolor printing. Then, the obtained laser multicolor printing composition was preheated at 200 ° C. for 5 minutes with a compression press, and then pressure-molded at 30 kgf / cm ² , a circular laser having a diameter of 90 mm and a plate-like laser having a thickness of 1 mm. A molded body for multicolor printing was obtained.

4.1.2. Printing process The surface of the laser multicolor printing molding obtained above is irradiated with a laser with a wavelength of 455 nm under the conditions of a scanning speed of 20 mm / s and an output of 1.8 W (laser irradiation condition A), and the company information of Nippon Coloring Co., Ltd. A 14 mm × 14 mm two-dimensional bar code was printed, and the color of the color of the printed portion and the sharpness of the print were evaluated.

Next, another part of the laser multicolor printing molded body is irradiated with a laser having a wavelength of 455 nm under the conditions of a scanning speed of 15 mm / s and an output of 3.5 W (laser irradiation condition B), and the company information of Nippon Coloring is recorded. A 14 mm × 14 mm two-dimensional bar code was printed, and the color of the printed portion and the sharpness of the print were evaluated.

Furthermore, another part of the molded body for laser multicolor printing was irradiated with a _YVO4 laser having a wavelength of 1064 nm under the conditions of a scanning speed of 25 mm / s and an output of 15 W (laser irradiation condition C), and company information of Nippon Coloring was recorded. A 14 mm × 14 mm two-dimensional bar code was printed, and the color of the printed portion and the sharpness of the print were evaluated. The results are shown in Table 1.

4.1.3. Evaluation method <Clearness of printed part>
The print sharpness was evaluated by visually inspecting the printed portion according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
-If the outline of the print is clear, it is judged to be good and marked as "○".
-If the outline of the print is not clear, it is judged to be defective and marked with "x".

<Fabric color development>
The molded body for laser multicolor printing was visually observed, and the coloring of the fabric color was observed and evaluated according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
-If there is no change in the color tone of the laser multicolor printing molded product as compared with the color tone of the polymer (A), it is judged to be good because there is no deterioration due to the molding process, and it is marked with "○".
-When a change was observed in the color tone of the laser multicolor printing molded body as compared with the color tone of the polymer (A), it was judged to be defective due to deterioration due to the molding process, and was marked with "x".

<Bleed-out property>
The printed part was wiped off with a Bencot, and whether or not the printed part was transferred was evaluated according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
-If transfer to Bencot was not observed, it was judged to be good and marked with "○".
-If transfer to Bencot was observed, it was judged to be defective and marked with "x".

4.2. Examples 2 to 17, Comparative Examples 1 to 4
A laser multicolor printing molded body was prepared in the same manner as in Example 1 except that the laser irradiation conditions were changed in a timely manner and the composition was changed to the composition shown in Table 1 or Table 2, and the printing sharpness was obtained. , The color development of the fabric color and the bleed-out property were evaluated. The results are shown in Table 1 or Table 2.

The abbreviations of the laser irradiation conditions in Table 1 or Table 2 below are as follows.
A: Laser wavelength 455 nm, output 1.8 W / scanning speed 20 mm / s
B: Laser wavelength 455 nm, output 3.5 W / scanning speed 15 mm / s
C: Laser wavelength 1064 nm, output 15 W / scanning speed 25 mm / s
D: Laser wavelength 1064 nm, output 25 W / scanning speed 25 mm / s
E: Laser wavelength 355 nm, output 2 W / scanning speed 600 mm / s
F: Laser wavelength 355 nm, output 2 W / scanning speed 300 mm / s
G: Laser wavelength 532 nm, output 2 W / scanning speed 600 mm / s
H: Laser wavelength 532 nm, output 2 W / scanning speed 300 mm / s

4.3. Example 18
Each component of the type and mass part shown in Table 2 below was melt-kneaded with a twin-screw extruder and then pelletized. The prepared pellets are classified using a sieve, and in 100 parts by mass of the pellets, 98% by mass of pellets that pass through a 3-mesh sieve pass through a 5-mesh sieve and do not pass through a 9-mesh sieve. Is adjusted to 99% by mass, and is injection molded using an injection molding machine (manufactured by JSW, 110H) under the conditions of a cylinder temperature of 200 ° C. and a mold temperature of 60 ° C., length 90 mm × width 50 mm × thickness. A 3 mm laser multicolor printing molded product was produced. The laser multicolor printing molded product thus obtained was evaluated in the same manner as in Example 1.

4.4. Evaluation Results Tables 1 and 2 below show the composition, construction method, and evaluation results of the laser multicolor printing composition for producing a laser multicolor printing molded body in each Example and Comparative Example. In addition, in Comparative Examples 1 to 4, the portion described as "no color development" indicates that the corresponding color did not develop when the laser was irradiated under the above-mentioned laser irradiation conditions A to H.

The names or abbreviations of each component in Table 1 or Table 2 above are as follows.
<Polymer (A)>
-POM: Mitsubishi Engineering Plastics, product name "F20-03", polyacetal resin-PS: PS Japan, product name "HF77", polystyrene <laser color former (B1)>
・ R-40: Product name, manufactured by Yamamoto Chemicals, Inc., 3,3-bis (1-n-butyl-2-methyl-3-indrill) phthalide ・ R-500: Product name, manufactured by Yamada Chemicals, Inc., 9- (N-Ethyl-N-Isopentylamino) Spiro [benzo [a] xanthene-12,3'-phthalide]
BLUE-63: Product name, manufactured by Yamamoto Chemicals, Inc., 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methyl-3-indrill) -4-azaphthalide <laser color former (laser color former) B2)>
・ LMG: Tokyo Chemical Industry Co., Ltd., trade name “Leucoma Malachite Green”, 4,4'-tetramethyldiaminotriphenylmethane ・ LCV: Wako Pure Chemical Industries, Ltd., trade name “Leuko Crystal Violet”, Tris (4- Dimethylaminophenyl) Methane <Other additives>
・ DBB: Wako Pure Chemical Industries, Ltd., trade name “p-dibromobenzene”, color developer ・ PBT: Wako Pure Chemical Industries, Ltd., trade name “pentabromotoluene”, color developer ・ HCB: Wako Pure Chemical Industries, Ltd. Product name "Hexachlorobenzene" manufactured by Wako Pure Chemical Industries, Ltd., color developer / ITO: Wako Pure Chemical Industries, Ltd. product name "E-ITO", indium tin oxide, filler, primary particle diameter 0.03 μm
-Trioxan: Made by Tokyo Chemical Industry Co., Ltd., Product name "1,3,5-Trioxan"

As is clear from the above tables 1 and 2, according to the laser multicolor printing moldings prepared from the laser multicolor printing compositions of Examples 1 to 18, the coloring of the fabric color is suppressed in each case. It was also found that two or more chromatic colors can be developed by irradiating the surface of the molded body with two or more laser beams having different irradiation conditions.

On the other hand, it was found that even if the surface of the molded product prepared from the compositions of Comparative Examples 1 to 4 is irradiated with two or more laser beams having different irradiation conditions, only a single chromatic color can be developed.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method and result, or configurations with the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. Further, the present invention includes a configuration having the same effect as the configuration described in the embodiment or a configuration capable of achieving the same object. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

1 ... Laser multicolor printing molded body, 2.2a ... Multicolor printing molded body, 3a ... Printing section 1, 3b ... Printing section 2

Claims (7)

Polymer (A) and
A laser color former (B1) containing a compound having a lactone skeleton, and
A laser color former (B2) containing a compound having a triarylmethane skeleton, and
Contains ,
The laser color-developing agent (B1) is contained in an amount of 0.1 part by mass or more and 15 parts by mass or less, and the laser color-developing agent (B2) is contained in an amount of 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the polymer (A). Contains less than a part,
When the content of the laser color-developing agent (B1) is _MB1 (parts by mass) and the content of the laser color-developing agent (B2) is _MB2 (parts by mass), _MB1 / _MB2 is 0.3 to 0.3. 3. Laser multicolor printing composition. The laser color-developing agent (B1) is contained in an amount of 0.1 part by mass or more and 10 parts by mass or less, and the laser color-developing agent (B2) is contained in an amount of 0.1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the polymer (A). The composition for laser multicolor printing according to claim 1, which contains a portion or less. Polymer (A) and
A laser color former (B1) containing a compound having a lactone skeleton, and
A laser color former (B2) containing a compound having a triarylmethane skeleton, and
Contains,
The content of the laser color former (B1) is M. _B1 (Mass part), the content of the laser color former (B2) is M _B2 When (mass part), M _B1 / M _B2 A composition for laser multicolor printing for producing pellets for producing a molded body for laser multicolor printing having a value of 0.3 to 3. The composition for laser multicolor printing according to any one of claims 1 to 3, wherein the compound having a lactone skeleton is a compound having a fluorin skeleton. In addition, lanthanum hexaboride, tungsten oxide cesium, indium tin oxide (ITO)
The composition for laser multicolor printing according to any one of claims 1 to 4, which contains at least one compound selected from the group consisting of antimony oxide and tin oxide. The laser multicolor printing composition according to any one of claims 1 to 5, further comprising an organic halide. A molded body for laser multicolor printing produced by using the composition for laser multicolor printing according to any one of claims 1 to 6.

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