JP2002059078A - Print-coated metal plate excellent in light fastness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a print-coated metal plate excellent in light fastness by forming a top coating film with a thermosetting polyester resin specified in molecular weight, glass transition temperature (Tg) and melamine content. SOLUTION: This print-coated metal plate is formed in such a way as to be coated with a clear coating material the main component of which is a thermosetting polyester resin having a number-average molecular weight of 1,000-10,000, a glass transition temperature (Tg) of 20-60 deg.C and a mass ratio of melamine of 2-150 pts.mass based on the total solid resin of 100 pts.mass, and a top coating film 4 provided with a colored pattern by permeating a sublimation dye is applied on a substrate metal plate 1 directly, or through a base coat layer 2, a primer layer 3, and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a full-color advertising signboard,
Used for decorative interior materials, decorative floor materials, decorative surface materials, elevator door materials, home appliance exterior panels, furniture exterior panels, etc., and is a small-lot, multi-product printed metal plate with various printed patterns. About.

[0002]

2. Description of the Related Art When a printed metal plate is manufactured using a sublimable dye, the sublimable dye is printed on the top clear layer of the coated metal plate by a printing method such as offset, silk, gravure, or transfer, and then heated. The sublimation dye penetrates the clear coating film by the treatment. For pattern printing using sublimable dyes,
A method in which a transfer sheet is brought into contact with a coating film of a curable synthetic resin layer and heated (JP-A-51-24313), a printing layer is formed on a coated metal plate by transfer printing using a sublimable dye, A method of forming a top coating film on the surface and then penetrating a sublimable dye from the inside of the coating film by heat treatment (JP-A-54-104907), forming a primer coating film and a colored top coating film on the steel sheet surface. A method of penetrating a heat sublimation ink into a coating film of a prepainted metal plate (Japanese Patent Laid-Open No. 7-31)
No. 931) and a method of infiltrating a sublimation type colorant into an opaque resin layer provided on a metal plate substrate (Japanese Patent Application Laid-Open No. 7-102733).

[0003] In any of the pattern printing methods, a pattern is developed by penetrating a sublimable dye into a top coating film.
However, ordinary sublimable dyes are small-polarity disperse dyes or oily dyes, and are easily degraded by plasticizers, organic chemicals, and the like. It is also a dye that is decomposed by light such as ultraviolet rays and is easily discolored or faded. For this reason, it is difficult to maintain stable colors and patterns in a use environment that is exposed outdoors for a long period of time. Discoloration and fading due to light irradiation can be prevented by adding an ultraviolet absorber to the paint at a ratio of 0.5 to 3% by mass based on the nonvolatile content of the paint.

[0004]

However, the baking conditions of the pre-coated steel sheet used for printing are as follows: the maximum reached plate temperature is 200 to 240 ° C., the holding time is 1 to 2 minutes, and the sublimable dye is applied to the coating film. The transfer condition to be penetrated is 160-190 ° C ×
1 to 4 minutes. That is, the ultraviolet absorber is exposed to the high-temperature atmosphere at least twice until the production of the printed metal plate is completed. Therefore, a benzophenone-based or benzotriazole-based ultraviolet absorber generally used is inferior in heat resistance and sublimation resistance, and the amount of the ultraviolet absorber contained in the coating film is reduced by sublimation. The decrease in the amount of the ultraviolet absorber not only adversely affects the discoloration and fading of the ultraviolet absorber, but also causes the surface of the coating film to become yellowish due to sublimation of the ultraviolet absorber. The yellowing phenomenon becomes more conspicuous as the thickness of a thick original plate becomes stricter in both baking conditions and transfer conditions.

In this regard, Japanese Patent Application Laid-Open No. 9-206678 discloses that a benzotriazole-based or triazine-based ultraviolet absorber having good thermal stability and solubility is added at a ratio of 6 to 18% by mass with respect to the coating nonvolatile matter. are doing. The addition of a benzotriazole- or triazine-based UV absorber is effective for many types of sublimable dyes, but some sublimable dyes, especially those with poor lightfastness, have a level that can be used for outdoor applications. Discoloration and fading cannot be suppressed. Changing to a sublimable dye having better light resistance is also conceivable, but it is not easy to change the sublimable dye in consideration of the suitability for the type of printer used for output and restrictions on the color tone. Incidentally, even if one of the four basic ink colors (cyan, magenta, yellow, and black) used has poor light fastness, it cannot be used for outdoor use.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been devised to solve such a problem, and has been proposed by forming a top coat using a resin having excellent light resistance. It is an object of the present invention to provide a printing-coated metal plate having significantly reduced discoloration and fading of a sublimable dye impregnated in a dye and having improved light fastness.

In order to achieve the object, the printed metal sheet of the present invention has a number average molecular weight of 1,000 to 10,000, a glass transition temperature (Tg) of 20 to 60 ° C., and a ratio of melamine to 20 to 100 parts by mass of resin solid content of 20 to 100 parts by mass. It is formed from a transparent or translucent paint containing a thermosetting polyester resin as a main component, which is 150 parts by mass, and a top coat coated with a colored pattern by infiltration of a sublimable dye is provided on the surface of the metal plate. Features.

As the thermosetting polyester resin, 1,2-benzene-dicarbonyl derived from a dicarboxylic acid monomer and / or a 2,2-dimethyltrimethylene structure derived from a dialcohol monomer have a molecular structure. A partially contained resin is preferable. Preferably, 3 to 22 parts by mass of a triazine-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber may be added to the overcoating film alone or in combination with 3 to 22 parts by mass with respect to 100 parts by mass of the coating nonvolatile matter.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A printed metal plate according to the present invention is provided with a base coat layer 2 and a primer layer 3 on the surface of a base metal plate 1 such as a plated steel plate, a stainless steel plate, an aluminum plate, etc. Transparent or translucent top coat 4
(FIG. 1). As long as there is a top coat 4 on the surface layer, a printed metal plate (a) having a base coat layer 2 provided between the base metal plate 1 and the top coat 4, and further a primer layer 3
Or a printed metal plate (c) in which the top coat 4 is directly provided on the base metal plate 1. In the present specification, the `` overcoat film '' is used in the sense of including the clear coating film, and an aggregate such as silica may be added to the overcoat paint in order to develop a matte appearance. it can. The base coat layer 2 is not limited to white and may have another color tone.

The base coat layer 2 is preferably formed to have a thickness of 10 to 20 μm so as to cover the base metal plate 1 and the primer layer 3. Base coat layer 2 having a thickness of less than 10 μm
In this case, the concealing ability with respect to the base metal plate 1 and the primer layer 3 is weak, and the coating surface has a mixed color tone of the base metal plate 1 and the primer layer 3. Conversely, in the case of a thick base coat layer 2 having a thickness of more than 20 μm, the solvent remaining in the coating film at the time of baking may be rapidly vaporized, and a pinhole-shaped coating defect called “side” may occur.

The top coat 4 is required to be a resin that accepts and dyes the sublimable dye transferred from the transfer sheet. In this regard, the number average molecular weight of 1000 to 100
00, glass transition temperature (Tg) 20 to 60 ° C., ratio of melamine to 20 to 150 parts by mass of resin solid content is 20 to 150.
The thermosetting polyester resin in parts by mass has excellent dyeing properties with respect to the sublimable dye, and also has good storage stability of the obtained image.

A thermosetting polyester resin is a resin synthesized by polycondensation of a dibasic acid and a polyhydric alcohol. The dibasic acid is an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or an acid anhydride thereof, specifically, phthalic anhydride, orthophthalic acid, isophthalic acid, terephthalic acid, maleic acid, maleic anhydride, fumaric acid. , Adipic acid and the like are used alone or in combination of two or more. In order to obtain good light fastness, phthalic anhydride and / or orthophthalic acid which forms a 1,2-benzenedicarbonyl structure after polycondensation is particularly preferable. Adipic acid, which does not contain a phenyl group, is also used as a suitable dibasic acid.

The polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol,
There are propylene glycol, pentyl glycol, neopentyl glycol, trimethylolethane and the like, and these can be used alone or in combination of two or more. In order to obtain good light fastness, it is preferable to use a glycol having a long aliphatic chain such as pentyl glycol, and it is more preferable to use neopentyl glycol which forms a 2,2-dimethyltrimethylene structure after polymerization.

The number average molecular weight of the thermosetting polyester resin used in the present invention is adjusted to 1,000 to 10,000. With a number average molecular weight of less than 1000, the top coat 4
On the other hand, when the number average molecular weight exceeds 10,000, the ratio of the crosslinked portion by melamine decreases, and thus the compound is easily decomposed by ultraviolet irradiation or the like. Melamine used as a curing agent has high light stability by itself, and the light resistance of the resin is improved by mixing it with a polyester resin. The effect of improving light resistance is remarkable with melamine in an amount of 20 parts by mass or more. However, if an excessive amount of melamine in excess of 150 parts by mass is included, the crosslink density becomes too high and the coating film is easily broken during processing. If the glass transition temperature (Tg) is less than 20 ° C., the hardness of the coating film is low and the coating film is easily scratched. Conversely, if the glass transition temperature (Tg) exceeds 60 ° C., the hardness is too high and the workability is significantly deteriorated. I do.

When a transfer sheet preliminarily patterned with a sublimable dye is brought into contact with the base metal plate 1 and heated, the sublimated dye penetrates into the transparent or translucent top coat 4 to dye the sublimable dye. The layer 5 is formed, and a pattern dyed in the thickness direction appears. The transfer sheet can be produced by gravure printing, offset printing, screen printing, or the like. For small lot printing, an electrophotographic method using computer graphics, which does not require a plate making process, an electrostatic recording method, an ink jet method, a thermal transfer method, and the like can be adopted.

The sublimable dye is a dye which can be transferred to the top coat 4 by a phenomenon such as sublimation or volatilization when heated. In the present specification, “sublimation” is used in a sense that also includes volatilization from a liquid phase. As the sublimable dye, for example, a disperse dye such as a quinophthalone derivative, an anthraquinone derivative, or an azo dye is preferably used. A sublimable dye conventionally used for sublimation heat transfer, sublimation transfer printing, and the like is used for printing the overcoat 4 without any particular limitation.

Among the sublimable dyes that can be used, yellow dyes include Kayaset Yellow AG and Kayaset Yellow TDN.
(Nippon Kayaku Co., Ltd.), RTY 52, Dianix Yell
ow5R-E, Dianix Yellow F3G-E, Dianix Brilliant Yell
ow 5G-E (Mitsubishi Chemical Corporation), Blast Yell
ow 8040, DY108 (above, manufactured by Arimoto Chemical Co., Ltd.), Sumik
aron Yellow EFG, Sumikaron Yellow E-4GL (Sumitomo Chemical Co., Ltd.), FORON Brilliant Yellow SGGLPI
(Manufactured by Sand) and PS Yellow GG (manufactured by Mitsui Toatsu Dye Co., Ltd.).

Kayaset Re is a magenta sublimable dye.
d 026, Kayaset Red 130, Kayaset Red B (Nippon Kayaku Co., Ltd.), Oil Red DR-99, Oil Red DK-99
(These are made by Arimoto Chemical Co., Ltd.), Diacelliton Pink B
(Mitsubishi Chemical Co., Ltd.), Sumikaron Red E-FBL (Sumitomo Chemical Co., Ltd.), Latyl Red B (Du Pont), Sud
an Red 7B (BASF), Resolin Red FB, Ceres Red
7B (above, manufactured by Bayer).

The cyan sublimable dyes include Kayalon Fast
Blue FG, Kayalon Blue FR, Kayaset Blue 136, Kayas
et Blue 906 (Nippon Kayaku Co., Ltd.), Oil Blue
63 (manufactured by Arimoto Chemical Co., Ltd.), HSB9, RTB31 (manufactured by Mitsubishi Chemical Corporation), DisperseBlue # 1 (manufactured by Sumitomo Chemical Co., Ltd.), MS Blue 50 (manufactured by Mitsui Toatsu Dye Co., Ltd.), Cere
s Blue GN (Bayer), Duranol Brilliant Blue 2G
(Made by ICI).

The sublimable dye for each color may be used alone or
A mixture of more than one species is used. The black color tone can be obtained by appropriately mixing sublimable dyes for yellow, magenta and cyan colors. As the sublimable dye having a color tone other than yellow, magenta, and cyan, a dye having a sublimation temperature of 60 ° C. or more is preferable. When selecting a sublimable dye, a dye having a high sublimation temperature is preferable because it has a relatively high molecular weight and imparts excellent light resistance and heat resistance to a coating film.

When the transfer sheet is heated while being in contact with the base metal plate 1, the sublimable dye contained in the transfer sheet sublimates, and as shown in FIG.
In the thickness direction. Therefore, the sublimable dye-dyed layer 5 dyed almost uniformly in the thickness direction is formed on the transparent or translucent top coat 4 to obtain a three-dimensional printed pattern. Since the obtained printed pattern is not the one in which the sublimable dye is concentrated only in the surface layer of the top coat 4, the transfer print layer after the design is imparted by thermal transfer without causing print fading due to rubbing or the like. The subsequent step of protecting with a transparent resin is also omitted. In this way, since a required pattern can be easily provided when needed, a small lot production of a design steel sheet provided with various patterns in response to various needs becomes easy. In addition, since it is not necessary to stock design steel plates with a predetermined pattern, inventory burden is reduced. Further, since the dye layer does not exist alone between the transparent or translucent resin layer and the metal layer, delamination as in a conventional laminated steel sheet does not occur.

An ultraviolet absorber can be added to the top coat 4 in order to prevent the discoloration of the sublimable dye due to the transmission of sunlight and ultraviolet rays and to prevent the gloss of the top coat 4 from decreasing. As the ultraviolet absorber, preferably in the air atmosphere,
10 minutes at 300 ° C under heating condition of 5 ° C / min.
Benzotriazole-based or triazine-based materials that result in a weight loss of less than mass% are used. Specifically, the top coat 4
The triazine-based compound alone or the triazine-based compound and the benzotriazole-based compound are added to the top coat 4 in a blending ratio of 3 to 22 parts by mass with respect to 100 parts by mass of the paint nonvolatile content. When 3.0 parts by mass or less of a hindered amine-based light stabilizer is added, light resistance is further improved.

Octyl-3- [3-t-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propinate (TINUVIN 384 manufactured by Ciba Geigy) is used as the benzotriazole-based ultraviolet absorber. , 2- "2-hydroxy-3,5-
Bis (α, α'dimethylbenzyl) phenyl ”-2H-benzotriazole (TINUVIN 900 manufactured by Ciba Geigy), methyl-3- [3-t-butyl-5- (2H-benzotriazol-2-yl)
Condensation product of -4-hydroxyphenyl] propinate and polyethylene glycol (molecular weight: about 300) (TINUVIN 1130 manufactured by Ciba Geigy), 2- [2'-hydroxy-3 '-(3 ", 4", 5 ",
6 "-tetrahydrophthalimidomethyl) -5'-methylphenyl] -benzotriazole (Kyoyaku Co., Ltd. Viosor
b 590).

Examples of the triazine-based ultraviolet absorber include, for example,
2- [4-[(2-hydroxy-3-didecyloxypropyl) -oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine A mixture of 2- [4-[(2-hydroxy-3-tridecyloxypropyl) -oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl-1,3,5-triazine (TINUVIN 400 manufactured by Ciba-Geigy) and the like.

These UV absorbers can be used alone or in combination of two or more. It is preferable that the compounding amount of the ultraviolet absorber is adjusted to 3 to 22% by weight based on 100 parts by mass of the nonvolatile component of the paint. The improvement of light resistance becomes remarkable when 3 parts by mass or more of an ultraviolet absorber is added, but 22% by weight.
If the amount exceeds the above range, the stain resistance, workability, appearance of the coating film, etc. will be degraded. Further, coloring of the coating film due to the ultraviolet absorber is also observed. In order to further improve the light resistance of the transparent or translucent top coat 4, it is preferable to add a hindered amine-based light stabilizer in an amount of 3% by weight or less based on the nonvolatile components of the paint, if necessary. Examples of the hindered amine light stabilizer include the following substances.

Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (SANOL LS770 manufactured by Sankyo), bis
(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (SANOL LS765 manufactured by Sankyo Co., Ltd.), 1- [2- [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] -2,2,6,6-tetramethylpiperidine (SANOLLS2626 manufactured by Sankyo), 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (manufactured by Sankyo)
SANOL LS744), 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4-dione (SANOL LS440 manufactured by Sankyo) , 2- (3,5-di-t-
Bis (1,2,2,6, hydroxybenzyl-2-n-butylmalonate)
6-Pentamethyl-4-piperidyl) (Ciba-Geigy T)
INUVIN 144), bis (2,2,6,6-tetramethyl-4-succinate)
Piperidyl) ester (TINUVIN 78 manufactured by Ciba-Geigy)
0FF), dimethyl succinate and 1- (2-hydroxyethyl) -4-
Polycondensate of hydroxy-2,2,6,6-tetramethylpiperidine (TINUVIN 622LD manufactured by Ciba Geigy), poly [[6- (1,
(1,3,3-tetramethylbutyl) amino-1,3,5-triazine-
2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] (Ciba-Geigy) Made CHIMASSORB 944L
D), N, N'-bis (3-aminopropyl) ethylenediamine
Polycondensate of 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine (Ciba-Geigy) CHIMASSORB 119FL), Screw (1,2,
2,6,6-pentamethyl-4-piperidyl) sebacate (TINUVIN 292, Ciba-Geigy), bis (1-octaoxy-2,
2,6,6-tetramethyl-4-piperidyl) sebacate (TINUVIN 123 manufactured by Ciba-Geigy), HA-70G (manufactured by Sankyo Co., Ltd.), ADK STAB LA-52, ADK STAB LA-57, ADK STAB LA-62, ADK STAB LA- 63, ADK STAB LA-6
7, ADK STAB LA-68, ADK STAB LA-82, ADK STAB LA-87 (made by Asahi Denka Kogyo Co., Ltd.)

These light stabilizers can be used alone or
A mixture of more than one species can be used. Even if the light stabilizer is added in a large amount exceeding 3.0% by weight, the effect of improving the light fastness of the sublimable dye penetrated into the top coat 4 is saturated, and the improvement corresponding to the increase in the amount cannot be seen. The appearance of the coating tends to deteriorate. The light stabilizer is preferably 0.5 to 1.5.
It is blended in the range of weight%.

The transparent or translucent top coat 4 can be applied via the base coat layer 2 (FIG. 1a), via the base coat layer 2 and the primer layer 3 (FIG. 1b), or on the base metal plate 1.
Directly (FIG. 1c). In any case, the color tone of the base metal plate 1 and the base coat layer 2 becomes a ground pattern, and is observed through the dyed resin layer 5. Therefore, a printed metal plate having a unique depth feeling utilizing the texture of the base material can be obtained.

[0029]

Example: Production of a coated steel sheet used as a transfer master sheet A zinc-coated steel sheet having a thickness of 0.5 mm was degreased and surface-adjusted, and then subjected to a coating type chromate treatment to give a dry film thickness of 14 mm.
A white polyester resin paint (manufactured by Nippon Paint Co., Ltd.) was applied at a coating amount of μm, and the maximum temperature reached 220 ° C.
For 1 minute to form a white base coat layer 2. Next, the clear resin coating material was applied to the white base coat layer 2 at an application amount such that the dry film thickness became 18 μm. The clear resin paint has a number average molecular weight of 500 to 20,000,
Glass transition temperature (Tg) 10-80 ° C, resin solid content 10
A polyester resin paint containing 5-70 parts by mass of melamine with respect to 0 parts by mass was used. In this polyester resin coating, one or two selected from adipic acid, orthophthalic acid, isophthalic acid and terephthalic acid were used as dicarboxylic acid monomers. Examples 1 to 9 and 1 of the present invention
In 1, 13, 15, 17 and Comparative Examples 1 to 7, neopentyl glycol was added as a dialcohol-based monomer.

Further, Examples 9 and 19 of the present invention and Comparative Examples 7 and 9
Other than the above, a mixture of a triazine-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber in a ratio of 1: 1 to a clear coating material for the top coat 4 in a ratio of 8: 1 based on the coating non-volatile component was used.
% By mass. Further, 1.5% by mass of a hindered amine light stabilizer was added to all the clear resin paints. A steel sheet coated with clear resin paint is applied at a maximum temperature of 230 ° C.
By heating for minutes, a top coat 4 was formed. Table 1 (Example of the present invention) and Table 2 show the composition of the formed top coat 4.
(Comparative Example)

[0031]

[0032]

Transfer Printing Using a sublimable dye ink prepared from a cyan sublimable dye, a cyan solid pattern was output on output paper by an ink jet printer. The obtained transfer paper was superimposed on the painted surface of the coated steel sheet, and the temperature was 160 ° C. and the pressure was 4 × 10 ⁴ Pa for 15 hours.
It crimped for 0 second. After the completion of the pressure bonding, the transfer paper was peeled from the coated steel sheet. The cyan, magenta, and yellow sublimable dyes that sublimate under substantially the same conditions are compared with each other in light resistance. Since cyan has the lowest light resistance, the composition of the resin is determined based on the light resistance of cyan. Impact on the environment.

Performance Test of Printed Coated Steel Sheet A test piece is cut out from each manufactured printed coated steel sheet and subjected to a light resistance test, a coating film adhesion test, a workability test, a moisture resistance test, a stain resistance test, and a scratch resistance test. Was served. In the light resistance test, the test piece was left for 240 hours in a sunshine carbon arc weather meter set at a test temperature of 63 ° C. under the condition of spraying clear water for 12 minutes during irradiation for 60 minutes. 24
After 0 hour, the color tone of the test piece was measured, and the light resistance was evaluated based on the color difference ΔE from the unirradiated test piece. If the color difference ΔE after 240 hours is 10 or more, the color difference ΔE is not suitable for outdoor use, and for long-term use of 3 years or more, the color difference ΔE is less than 7.
E is desired.

In the coating film adhesion test, the peeling state of the coating film accompanying the peeling of the adhesive tape was observed by a cross-cut Erichsen test (a cross cut specified in JIS G3320 was inserted and extruded by 6 mm). Then, the film where the coating film was completely peeled was marked 1, the one where peeling close to full peeling occurred was scored 2, the one where significant peeling occurred was scored 3, the one where slight peeling occurred was scored 4, and peeling was Those that did not occur were rated as 5, and the coating film adhesion was evaluated on a 5-point scale.

In the workability test, 0 to 6 t in a room at 20 ° C.
(1t when one plate of the same thickness as the test piece is sandwiched) 1
An 80 degree bending process was performed, and the occurrence of cracks in the coating film according to the degree of bending was investigated. ◎ indicates that no cracks occurred in the coating film and ◎ indicates that cracks occurred in the coating film at 0 to 2 t, and ○ indicates that cracks occurred in 3 to 4 t.
The sample in which cracks occurred was evaluated as Δ, and the sample in which cracks occurred at 6 t was evaluated as x. Usually, if the evaluation point is ○ or more, it can be practically used for a precoated steel sheet.

In the moisture resistance test, a wet test set at a test temperature of 49 ° C. was continued for 500 hours in accordance with JIS Z0208. After the test, the coating film was observed, and the sample having no blisters was evaluated as ○, and the sample with blisters detected was evaluated as x, to evaluate the moisture resistance. In the stain resistance test, a red line and a black line were drawn on the coating surface with oil-based ink, and after leaving at 20 ° C. for 24 hours,
The red and black lines were wiped with methanol. A score of 5 was given for a trace that was wiped off without a trace, and a score of 3 was given for a trace that remained slightly.
Stain resistance was evaluated with a score of 1 indicating a marked trace.
Usually, if the red line drawn with oil-based ink has a rating of 2 or more, it can be practically used as a steel sheet for precoating. In the scratch resistance test, in accordance with JIS K5400-8.4,
The surface of the coating film was scratched using a pencil (Mitsubishi Uni Mitsubishi Pencil Co., Ltd.), and the scratch resistance was evaluated at the limit pencil hardness at which no scratch was formed.

As can be seen from the investigation results in Table 3, the printed coated metal sheet according to the present invention exhibited excellent light resistance, coating film adhesion, workability, scratch resistance, stain resistance and moisture resistance. Satisfying the above characteristics. Above all, when orthophthalic acid and / or neopentyl glycol were used as monomers, the light resistance was more excellent.

On the other hand, the printed metal plate of the comparative example was inferior to one or more of light resistance, coating film adhesion, workability, scratch resistance and stain resistance (Table 4). . That is, in Test No. 1 using a polyester resin having a small molecular weight, the coating film adhesion and processability were poor, and conversely, in Test Nos. 2, 7 to 9 using a polyester resin having a large molecular weight, the light resistance was insufficient. . In addition, the glass transition temperature (T
The coating surface of Test No. 3 with low g) was easily scratched, and the workability of Test No. 4 with high glass transition temperature (Tg) was poor. Further, Test No. 5 having a low melamine content was inferior in light resistance and stain resistance, and conversely, Test No. 6 having a high melamine content had a problem in workability.

[0040]

[0041]

[0042]

As described above, the printed metal sheet of the present invention sublimates into a top coat made of a thermosetting polyester resin having a specified molecular weight, glass transition temperature (Tg) and melamine content. The printed pattern is formed by infiltrating the organic dye. Therefore, a printed pattern excellent in light resistance can be obtained, and a clear pattern without discoloration or fading is maintained even in an environment exposed to ultraviolet irradiation for a long time. This printed painted metal sheet is suitable for small-lot multi-product production and has excellent design, full-color advertising signs, decorative interior materials, decorative floor materials,
It is used in a wide range of fields such as decorative surface materials, elevator door materials, skin panels for household appliances, and skin panels for furniture.

[Brief description of the drawings]

FIG. 1 shows a cross section of a surface layer portion of a printed metal plate provided with a printed pattern with a dyeing resin layer 5 according to the present invention, in which a transparent or translucent top coat 4 is provided on a base coat layer 2 (a). Example in which a transparent or translucent top coat 4 is provided on the primer layer 3 and the base coat layer 2 (b), Example in which the transparent or translucent top coat 4 is directly provided on the base metal plate 1 (c)

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 6, 2000 (200.12.
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

The thermosetting polyester resin has a 1,2-benzene-dicarbonyl structure derived from a dicarboxylic acid monomer and / or a 2,2-dimethyltrimethylene structure derived from a dialcohol monomer as one of the molecular structures. The resin contained in the part is preferable. Preferably, 3 to 22 parts by mass of a triazine-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber may be added to the overcoating film alone or in combination with 3 to 22 parts by mass with respect to 100 parts by mass of the coating nonvolatile matter.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

A thermosetting polyester resin is a resin synthesized by polycondensation of a dibasic acid and a polyhydric alcohol. The dibasic acid is an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or an acid anhydride thereof, and specifically, phthalic anhydride, orthophthalic acid, isophthalic acid, terephthalic acid, maleic acid, maleic anhydride, fumaric acid. , Adipic acid and the like are used alone or in combination of two or more. In order to obtain good light resistance, it is preferable that phthalic anhydride and / or orthophthalic acid, which forms a 1,2-benzene-dicarbonyl structure after polycondensation, be contained. Adipic acid, which does not contain a phenyl group, is also used as a suitable dibasic acid.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 15/08 104 B32B 15/08 104Z C09D 167/02 C09D 167/02 (72) Inventor Kazuhiko Takahashi Chiba No.7-1 Takamachi Shinmachi, Ichikawa City Nisshin Steel R & D Co., Ltd. F-term (Reference) 4D075 CB11 DA06 DB01 DB04 DB05 DB06 DB07 DC18 DC38 EA19 EA43 EB32 EB35 EB52 EB53 EB56 EC17 4F100 AA22 AB01B AB03 AH02A AH02A AH03AHA AK44J AL01A BA02 BA04 CA02A CA07A CA13A EJ69 GB08 GB48 GB90 HB00A JA05A JA07A JB13A JL00 JN01A JN28 YY00A YY00H 4J038 DA162 DD051 JB35 KA08 KA12 MA13 MA14 NA03 PC02

Claims (3)

[Claims] 1. A number average molecular weight of 1,000 to 10,000, a glass transition temperature (Tg) of 20 to 60 ° C., and a resin solid content of 100.
A topcoat film formed from a transparent or translucent paint containing a thermosetting polyester resin as a main component, in which the ratio of melamine to 20 parts by mass is 20 to 150 parts by mass, and provided with a colored pattern by infiltration of a sublimable dye is a metal. A printed metal plate with excellent light resistance, which is provided on the surface of the plate. 2. A 1,2 derived from a dicarboxylic acid monomer.
The printed metal plate according to claim 1, wherein a benzene-dicarbonyl structure and / or a 2,2-dimethyltrimethylene structure derived from a dialcohol-based monomer are included in a part of the molecular structure of the thermosetting polyester resin. 3. The printed metal sheet according to claim 1, wherein the triazine-based UV absorber and the benzotriazole-based UV absorber are contained alone or in combination in the top coat.