JPH0741204B2 - Painted metal plate by electron beam curing method and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention applies a composition containing an oligopolyester (meth) acrylate as a main component as a ground coat to a steel sheet and heat-curing it to a printable state to make oligopolyester (meth) acrylate an essential component. After printing the above ink composition, a composition containing oligo (meth) acrylate and polyhydric alcohol (meth) acrylate as essential components is applied as an overprinting varnish, and these three layers can be cured by electron beam. The present invention relates to a coated metal plate having high hardness and excellent stain resistance, and a method for producing the same.

[0002]

2. Description of the Related Art A method for producing a coated metal sheet having high hardness and excellent stain resistance is disclosed in Japanese Patent Publication No. Sho 60 by the present inventors.
It has already been put to practical use as seen in Japanese Patent Publication No.-40169.

However, this coating composition has two (meth) acryloyl groups in one molecule, as can be seen from the publication.
More than one and (meth) acryloyl group equivalent is 500
A composition containing, as an essential component, the following oligopolyester (meth) acrylate and a polyhydric alcohol (meth) acrylate having two or more (meth) acryloyl groups in one molecule and having a (meth) acryloyl group equivalent of 150 or less. And the latter polyhydric alcohol (meth) acrylate is
In general, the viscosity is low and printing on this composition has proven difficult.

In the electron beam curing method, the method of printing on the ground coat is as follows: Japanese Patent Publication No. 54-83
It is found in Japanese Patent Publication No. 83.

According to the present invention, an electron beam curable solvent type paint is applied to the surface of a metal plate and then heated or dried (not heat cured) to remove the solvent in the paint layer, and then The present invention relates to a method of forming a printed pattern of an electron beam curable ink composition on the coating layer, and then irradiating the printed pattern surface with an electron beam to cure the coating layer and the printed pattern layer.

On the electron beam curable solvent type paint (which becomes a solid when the solvent is scattered) in Examples 1 and 3 of this publication, two or more (meth) acryloyl groups are contained in one molecule, and ( (Meth) acryloyl group equivalent is 500 or less oligopolyester (meth) acrylate and contains two or more (meth) acryloyl groups in one molecule, and (meth)
An acryloyl group equivalent was printed with an ink composition containing a polyhydric alcohol (meth) acrylate having an equivalent weight of 150 or less as an essential component, and an additional test was conducted as in Examples, but the hardness was not obtained because the ground coat was soft, and Microscopically, sufficient stain resistance could not be obtained because there was a part that was not printed.

[0007]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a coated steel sheet which is extremely hard (pencil hardness 8H <), has excellent stain resistance and can print a pattern, and a method for producing the same.

[0008]

MEANS FOR SOLVING THE PROBLEMS The present invention includes (1) a bottom layer containing two or more (meth) acryloyl groups in one molecule and having a (meth) acryloyl group equivalent of 4
It has a coating film heat-cured to a solid state or a state close to a solid state, which is composed of a composition containing 00 or less oligopolyester (meth) acrylate as an essential component.
It has a printing layer comprising a composition containing two or more (meth) acryloyl groups in the molecule and an oligopolyester (meth) acrylate having a (meth) acryloyl group equivalent of 500 or less as an essential component, and further as an uppermost layer. Contains two or more (meth) acryloyl groups in one molecule, and (meth)
An essential component is an oligopolyester (meth) acrylate having an acryloyl group equivalent of 500 or less and a polyhydric alcohol (meth) acrylate containing two or more (meth) acryloyl groups in one molecule and having a (meth) acryloyl group equivalent of 150 or less. A coated metal sheet having a coating film comprising the above composition, and these three layers being cured by an electron beam.

(2) Two or more (meth) acryloyl groups are contained in one molecule, and the (meth) acryloyl group equivalent is 4
Two or more (meth) acryloyl groups are contained in one molecule in a coating film that is solid or nearly solid after being coated with a composition containing 00 or less oligopolyester (meth) acrylate as an essential component on a steel sheet and thermally cured. After printing a composition containing the above and an oligopolyester (meth) acrylate having a (meth) acryloyl group equivalent of 500 or less as an essential component, further containing two or more (meth) acryloyl groups in one molecule, and ( (Meth) acryloyl group equivalent is 500 or less oligopolyester (meth) acrylate and contains two or more (meth) acryloyl groups in one molecule, and (meth)
A method for producing a coated metal plate, which comprises coating a composition containing a polyhydric alcohol (meth) acrylate having an acryloyl group equivalent of 150 or less as an essential component and curing these three layers by an electron beam. is there.

[0010]

The present invention can be obtained for the first time when it is produced by combining three layers. The first point is that it is an oligopolyester acrylate (Japanese Patent Publication No. 57-24390) having high hardness and good stain resistance. If the heavy bond equivalent is 400 or less, the steel plate temperature will be 1 without a radical polymerization catalyst.
It has been found that a coating film which can be thermally cured at about 20 ° C to 200 ° C and is in a printable solid state or a state close to a solid state can be obtained.

Here, even without a radical polymerization catalyst,
"Thermal polymerization (thermosetting in the present application) is likely to occur for a monomer in which a double bond ((meth) acryloyl group in the present invention) is directly bonded to an aromatic such as styrene," says Takayuki Otsu. : Radical polymerization (I), P1
7, Kagaku Dojin (1971) ”and the like.

However, the present invention contains two or more (meth) acryloyl groups in one molecule, and (meth)
The chemical structure of oligo polyester (meth) acrylates with an acryloyl group equivalent of 400 or less and monomers such as styrene in which a double bond is directly bonded to an aromatic is completely different, and it is possible to print in a short time as described later. It has never been found to become a state.

In this case, if a radical polymerization catalyst is used,
Naturally, it cures and satisfies the object of the present invention in terms of performance, but the drawback is that when the composition is coated with a coater, polymerization may occur due to heat being applied in the coating circulation system. The storage stability is poor, which is an economical disadvantage.

Also, a composition containing oligopolyester acrylate and polyhydric alcohol acrylate as essential components can be heat-cured without a radical polymerization catalyst, but it is necessary to set the temperature to a high temperature (steel plate temperature 200 ° C. or higher). And
In this case, the latter is scattered, which is disadvantageous in terms of hygiene and cost.

The second point is that oligopolyester acrylate is used as the composition of the ink layer.

Since this is the same as the ground coat layer, it has good adhesion to it, and it has high hardness in addition to being suitable in terms of viscosity in the printing method described later.

A third point is that a composition containing oligopolyester acrylate and polyhydric alcohol acrylate as essential components is used as the overprinting varnish.

It is hard and has a high degree of stain resistance,
High hardness and stain resistance can be obtained.

The oligopolyester acrylate used in the present invention refers to one obtained by esterifying a (meth) acrylic acid with a polyester skeleton in the main chain, and as the one used in the present invention, From the necessity of having a sufficient crosslinked network structure, one having two or more (meth) acryloyl groups in one molecule, more preferably 3
It is desirable to include one or more.

Since the crosslink density must be sufficiently high, the (meth) acryloyl group equivalent is preferably 500 or less, more preferably 400 or less.

In this case, two or more kinds of these oligo (meth) acrylates may be mixed and used as long as they are oligo (meth) acrylates satisfying the requirements of the present invention.

Further details regarding this component will be given. The oligo (meth) acrylate using a polyester skeleton in the main chain is composed of a polyhydric alcohol and a polycarboxylic acid and has a hydroxyl group at the end of the polyester, and this is reacted with (meth) acrylic acid or its derivative. (Meth) acryloyl group is introduced. Further reference will be made here to the synthetic raw materials forming the polyester skeleton.

That is, as the dihydric alcohol, ethylene glycol, propylene glycol, chloropropylene glycol, butanediol (1,3-or 1,4- or 2,3-) in the form of alkylene glycol type, 3
-Methylpentanediol, 2,2-diethylpropanediol, pentamethylene glycol, 1,6-hexanediol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, neopentyl glycol, hexamethylenediol, etc., alicyclic glycol type As 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, etc., as a polyalkylene glycol type, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol 2,2'-bis (4-hydroxyphenyl) propane (also known as bisphenol) Enol A), bis (4-hydroxyphenyl) methane (also known as bisphenol F), 4,
Examples thereof include glycols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to phenols such as 4′-dihydroxyphenyl, hydroquinone and resorcin.

Examples of the trihydric alcohol include alkanetriol type glycerin, trimethylolmethane, trimethylolethane, trimethylolpropane,
1,2,6-hexanetriol, 1,2,3-butanetriol, 1,2,3-pentanetriol, 2-methyl-2,3,4-butanetriol, 2-ethyl-
2,3,4-butanetriol, 2-methyl-1,2,
Alkanetetraols such as 3-butanetriol, 2-ethyl-1,2,3-butanetriol, 2,3,4-hexanetriol, pentamethylene glycol, etc. as erythritol, pentaerythritol, toilet, 1,2,3, 4-pentane tetrol, 2,3
4,5-hexanetetrol, 2,5-dimethyl-2,
3,4,5-hexanetetrol, 1,2,3,5-pentanetetrol, 3-hexene-1,2,5,6-tetrol, 3-hexyne-1,2,5,6-tetrol, etc. , An ether group-containing aliphatic triol, a triol obtained by adding alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) to glycerin, trimethylolpropane, etc., and an ether group-containing aliphatic tetraol, erythritol and pentaerythritol And the like, and tetraol obtained by adding alkylene oxide, and the aromatic triol includes triol obtained by adding alkylene oxide to pyrogallol.

As the carboxylic acid, chain or branched 2
As carboxylic acid, oxalic acid, malonic acid, succinic acid,
Glutaric acid, itaconic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, dotecanoic acid, methyleneglutaric acid, methylmaleic acid, methylsuccinic acid, dodecenylsuccinic acid, etc. as aliphatic dicarboxylic acids, tetrahydrophthalic acid, hexahydrophthalic acid , 6-methyltetrahydrophthalic acid, 6-methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endoisopropylidenetetrahydrophthalic acid, 1,4,5,6,7,7-
Hexachloro-endo-5-norbornene-2,3-dicarboxylic acid (also called het acid), 1,4,5,6,7,7
-Hexabromo-endo-5-norbornene-2,3-
Dicarboxylic acids, cyclohexane, 1,4-dicarboxylic acid and the like, and aromatic dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, tetrabromophthalic acid, and their anhydrides.

Specific examples of some polyester oligomers having two (meth) acryloyl groups are di (meth) acrylate of polyester diol of maleic acid and ethylene glycol,
Di (meth) acrylate of polyester of maleic acid and diethylene glycol, polyester diol di (meth) acrylate of adipic acid and diethylene glycol, di (meth) acrylate of polyester diol of tetrahydrophthalic acid and diethylene glycol, tetrahydrophthalic acid and propylene glycol With polyester diol di (meth) acrylate, tetrahydrophthalic acid and butanediol (1,3-or 1,4
-) Polyester diol di (meth) acrylate with tetrahydrophthalic acid and 1,6-hexanediol polyester diol di (meth) acrylate,
Di (meth) acrylate of polyester diol of tetrahydrophthalic acid and neopentyl glycol, di (meth) acrylate of polyester diol of tetrahydrophthalic acid and 1,4-cyclohexanediol, di (meth) acrylate of phthalic acid and diethylene glycol Examples thereof include (meth) acrylates and di (meth) acrylates of polyester diols of phthalic acid and neopentyl glycol.

Among these polyester oligomers,
Tetrahydrophthalic acid or adipic acid and 3 to 3 carbon atoms
A polyester oligomer having a structure of di (meth) acrylate of polyester diol with 6 alkylene glycols and having a number average molecular weight of 350 to 800 and a number average molecular weight of 180 to 400 per one (meth) acryloyl group is an object of the present invention. In particular, it is particularly suitable.

Further, some of the polyester oligomers having two or more (meth) acryloyl groups will be specifically illustrated. Tetra (meth) acrylate, penta (meth) acrylate of a polyester polyol of adipic acid and pentaerythritol, Hexa (meth) acrylate, tetrahydrophthalic acid and pentaerythritol polyester polyol tetramethacrylate, penta (meth) acrylate, hexa (meth) acrylate, phthalic acid and pentaerythritol polyester polyol tetra (meth) acrylate, penta (Meth) acrylate, hexa (meth) acrylate, tetra (meth) acrylate of polyester polyol of maleic acid and pentaerythritol, penta (meth) acrylate, hex (Meth) acrylate, tetra (meth) acrylate of polyester polyol of adipic acid and trimethylolpropane, penta (meth) acrylate, hexa (meth) acrylate, tetra (meth) of polyester polyol of tetrahydrophthalic acid and trimethylolpropane Acrylate, penta (meth)
Examples thereof include acrylate, hexa (meth) acrylate, tetrahydrophthalic acid and glycerin polyester polyol tetra (meth) acrylate, penta (meth) acrylate, and hexa (meth) acrylate.

Among these polyester oligomers,
Polyester polyol of adipic acid or tetrahydrophthalic acid and trimethylolpropane or pentaerythritol, having a structure of tetra (meth) acrylate, penta (meth) acrylate or hexa (meth) acrylate and having a number average molecular weight of 550 to 2000, (meth) Number average molecular weight per allyloyl group 100-35
Zero polyester oligomers are suitable for the purposes of the present invention.

The polyhydric alcohol acrylate referred to in the present invention is one in which a (meth) acrylic acid is introduced into a hydroxyl group at a terminal of a polyhydric alcohol to introduce a (meth) acryloyl group, and it is combined with an oligo (meth) acrylate. It plays a role in obtaining an extremely high crosslinking density.

For this purpose, one molecule contains two or more (meth) acryloyl groups, and the (meth) acryloyl group equivalent is 150 or less, more preferably about 130 or less.

In this case, a mixture of the above-mentioned polyhydric alcohol (meth) acrylate may be used. The polyhydric alcohol mentioned here means the following.

That is, as the dihydric alcohol, ethylene glycol, propylene glycol, chloropropylene glycol, butanediol (1,3-or 1,4- or 2,3-) in the form of alkylene glycol, 3
-Methylpentanediol, 2,2-diethylpropanediol, pentamethylene glycol, 1,6-hexanediol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, neopentyl glycol, hexamethylenediol, etc., alicyclic glycol type As 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, etc., as a polyalkylene glycol type, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol 2,2'-bis (4-hydroxyphenyl) propane (also known as bisphenol) Enol A), bis (4-hydroxyphenyl) methane (also known as bisphenol F), 4,
Examples thereof include glycols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to phenols such as 4′-dihydroxyphenyl, hydroquinone and resorcin.

As the trihydric or higher alcohol, alkanetriol type glycerin, trimethylolmethane, trimethylolethane, trimethylolpropane,
1,2,6-hexanetriol, 1,2,3-butanetriol, 1,2,3-pentanetriol, 2-methyl-2,3,4-butanetriol, 2-ethyl-
2,3,4-butanetriol, 2-methyl-1,2,
3-butanetriol, 2-ethyl-1,2,3-butanetriol, 2-3,4-hexanetriol, pentamethylene glycol, etc. as alkanetetraols as erythritol, pentaerythritol, dipentaerythritol, toilet, 1, 2,3,4-pentane tetrol, 2,3,4,5-hexane tetrol,
2,5-Dimethyl-2,3,4,5-hexanetetrol, 1,2,3,5-pentanetetrol, 3-hexene-1,2,5,6-tetrol, 3-hexyne-1,
Ether group-containing fatty acids such as triols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to glycerin, trimethylolpropane, etc. as ether group-containing aliphatic triols such as 2,5,6-tetrol Examples of the group tetraol include tetraol obtained by adding alkylene oxide to erythritol or pentaerythritol, and aromatic triol include triol obtained by adding alkylene oxide to pyrogallol.

Of these, those having a (meth) acryloyl group equivalent of 120 or less are particularly preferable as a result.

Although the essential components constituting the present invention have been described above, pigments, solvents, polymers and the like can be added in addition to these, if necessary.

As the pigment, a ground coat and a coloring pigment are required for printing ink.

That is, as the inorganic color pigment, red iron oxide, yellow iron oxide, chrome vermillion, chromium oxide, carbon black, etc., and as the organic color pigment, quinacridone, isoindolinone, indanthrene blue, phthalocyanine blue, phthalocyanine. Green, etc.

Other examples include titanium white, calcium carbonate, barium sulfate, alumina, silica and the like. It is also added to the overprinting varnish as needed.

Examples of the solvent include xylene, butyl acetate, cyclohexanone, methyl cellosolve, ethyl cellosolve, morpholine and olefin solvents.

As the polymer, polyester, acrylic, urethane, epoxy or the like is used, which is sometimes used to improve coating and printing properties. in this case,
If the amount is too large, the performance will be degraded, so an appropriate amount is added.

The ground coat, printing ink and overprinting varnish constituting the present invention have been described above. Next, the manufacturing method will be described.

In the coated metal sheet of the present invention, as the original sheet, a cut sheet or a coiled iron sheet, an electrogalvanized steel sheet, a hot dip galvanized steel sheet, or a chromic acid or phosphoric acid treatment or the like already applied in the steel sheet manufacturing process. A material that has been subjected to chemical conversion treatment, an aluminum plate, a stainless plate, or the like can be used.

Further, it is better to use a primer between this original plate and the layer of the composition of the present invention.

The composition of this primer is epoxy, modified epoxy, epoxy acrylic, polyester,
Anything such as polyester epoxy may be used. As a painting method,
It is a usual method such as natural roll coating or reverse roll coating, and as a curing method, heat, electron beam, ultraviolet ray,
Anything such as far infrared rays may be used. The coating thickness is 1 to 10 μm
Position, preferably 2 to 7 μm.

As the coating method of the ground coat in the present invention, a usual coating method such as roll coating or curtain flow coating is used, and the coating film thickness is about 10 to 50 μm although it depends on the application.

The thermosetting of the ground coat, which is the greatest feature of the present invention, will be described here.

As described above, the ground coat is heat-cured to a printable state without a polymerization catalyst. The present invention has been completed by finding that this is possible.

That is, two or more (meth) acryloyl groups are contained in one molecule, and the (meth) acryloyl group equivalent is 4
The oligo polyester acrylate having a number of 00 or less, and preferably having a (meth) acryloyl group equivalent of 350 or less, is cured to a printable state under the following conditions.

The plate temperature during curing is 120 ° C. to 200 ° C.
It is suitable for this purpose that the time and the time are 20 seconds to 3 minutes.

If the plate temperature is lower than 120 ° C., the reaction is difficult to proceed, and it is difficult to thermally cure to a printable state.

On the other hand, when the plate temperature exceeds 200 ° C., a mixture of a low molecular weight product, a part of oligopolyester acrylate, etc. starts to scatter, which is not suitable.

The coating thickness is about 5 μm to 50 μm.
It is usually performed at about m.

The printing ink containing the above-mentioned oligopolyester (meth) acrylate as an essential component is printed on the ground coat which is heat-cured in the printable state as described above.

In this case, any printing method can be adopted. As the print pattern, for example, abstract patterns, characters,
It may be strip-shaped or any other shape. The thickness of the print layer varies depending on the printing method, but is not particularly limited.

Then, an overprinting varnish consisting of oligo (meth) acrylate and polyhydric alcohol (meth) acrylate is applied.

The coating method may be a printing method such as gravure offset, offset, screen method, or a coating method such as roll coater, curtain flow coater, electrostatic coating or spray coating.

What is important here is that the ground coat layer and the printing ink layer must be completely covered. Therefore, the coating film thickness must be at least about 0.5 μm.

The electron beam irradiation method in the above manufacturing method of the present invention will be described. Known irradiation device,
For example, any of a scanning method, a curtain beam method, a broad beam method, etc. may be used. The required acceleration voltage is selected according to the coating film thickness, and the required current value is selected according to the line speed. Also, the electron beam irradiation atmosphere is replaced with an inert gas or the like.

In the present invention, a protective film made of vinyl chloride, polyethylene, polypropylene or the like may be laminated on the overprinting varnish.

[0061]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

[0062]

Example 1 A. Grand coat: Tetrahydrophthalic acid, trimethylolpropane, and acrylic acid in a condensation molar ratio of about 1: 2:
4 Oligomer (acryloyl group equivalent about 155) 10
200 parts of titanium oxide was added to 0 part to form a paint.

0.7 parts of iron oxide, 0.05 part of quinacridone, 0.15 part of carbon black, and 20 parts of xylene were added to 100 parts of this coating material to form a gray ground coat.

B. Printing ink: tetrahydrophthalic acid,
Oligomer having a condensation molar ratio of trimethylolpropane and acrylic acid of about 1: 2: 4 (acryloyl group equivalent of about 15
5) To 100 parts of cyanine blue, 10 parts of cyanine blue was added to prepare a blue printing ink.

C. Overprinting varnish: Tetrahydrophthalic acid, trimethylolpropane, acrylic acid having a condensation molar ratio of about 1: 2: 4 oligomer (acryloyl group equivalent of about 155) to 100 parts of trimethylolpropane trimethacrylate (acryloyl group). Equivalent about 10
0) 100 parts was added to prepare a colorless and transparent overprinting varnish.

Epoxy primer applied (thickness of 3 μm)
On the ferritic stainless steel plate (0.8 mm thick)
The ground coat A was applied by a curtain flow coater (manufactured by Iwata coating machine) so that the dry coating film had a thickness of 30 μm.

When this was heated in a hot air oven under the condition that the plate temperature was 140 ° C., it became a soft solid. An abstract pattern was printed on this with a gravure offset printing machine.

Further, overprinting varnish C was applied by a gravure offset printing machine so that a dry coating film had a thickness of 5 μm, and then the three layers were simultaneously cured by electron beam irradiation.

The curing conditions are a voltage of 300 KV and a current of 100 m.
A / lm, irradiation dose 9 Mrad, irradiation oxygen concentration 150
It was ppm.

The coated plate was subjected to coating film tests such as a stain resistance / chemical resistance test, a hardness test, and a sliding resistance test. The results are as follows.

(1) Stain resistance Magic ink (red, blue, black), curry, mustard, lipstick, crayon, colored pencil, ink, etc. are applied to the coated plate, 24
After a while, it was easily wiped with a gauze soaked in ethanol. In addition, even if the characters were written with the whiteboard marker manufactured by Pilot Co., Ltd., they could be completely erased with the eraser.

(2) Chemical resistance After immersing in 5% hydrochloric acid, sulfuric acid, acetic acid, nitric acid, caustic soda, methyl ethyl ketone, and acetone for 24 hours and visually observing, no change was observed in the coating film. .

(3) Pencil hardness A test based on JISK5400 showed 9H.
That was all.

(4) Sliding test Eight pieces of gauze were sprinkled on a 1 kg weight (bottom surface 5 × 5 cm ² ), and the coated plate surface was slid 1000 times, but there was no change on the coated surface and the gauze was also colored. I couldn't do it.

(5) Others After being exposed in the tunnel for one year, when it was wiped with a brush for cleaning the tunnel interior plate while sprinkling water, stains were easily removed and no change in the pattern was observed.

[0076]

Comparative Example 1 In Example 1, when the curing conditions for the ground coat were a plate temperature of 90 ° C., the solid state was not obtained and printing was impossible.

[0077]

Comparative Example 2 A coated plate was prepared in the same manner as in Example 1 except that the overprinting varnish was omitted and the other conditions were the same. When this was subjected to the test of Example 1- (4), the gauze was slightly colored after 1000 times of sliding.

[0078]

COMPARATIVE EXAMPLE 3 In Example 1, the condensation molar ratio of tetrahydrophthalic acid, trimethylolpropane and acrylic acid was about 7:14: instead of the ground coat oligomer.
4 oligomer (acryloyl group equivalent weight about 740) was used.

The other composition is exactly the same, and the ground coat A is applied as a dry coating on a ferritic stainless steel plate (0.8 mm thick) coated with an epoxy primer (thickness: 3 μm).
It was applied with a curtain flow coater (manufactured by Iwata Coating Machine Co., Ltd.) so as to have a thickness of 0 μm.

When this was heated in a hot air oven under the condition that the plate temperature was 140 ° C., it did not become solid and printing was impossible.

[0081]

Example 2 Even if the oligomer of Example 1 was replaced by an oligomer having a condensation molar ratio of adipic acid, pentaerythritol, and acrylic acid of about 1: 2: 4 (acryloyl group equivalent: about 120), the performance was improved. It was similar to 1.

[0082]

[Example 3] The heating conditions of the ground coat of Example 1 were changed to
When the plate temperature was set to 120 ° C, printing was possible although there was some tackiness on the coated surface.

Other than that, when a coated plate was prepared under the same conditions and a performance test was conducted, the same performance as that of Example 1 was shown.

[0084]

EFFECTS OF THE INVENTION The coated metal sheet produced according to the present invention has a variety of uses because it has high hardness and high stain resistance as well as characters and pattern printing characteristics.

Examples thereof include tunnel interior plates, walls of underground malls and stations, marker boards, building partitions, office equipment and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B05D 5/00 H 6804-4D 7/14 J B32B 15/08 G C09D 4/00 PDV 5/00 PPF (72) Inventor Shinji Oka 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Co., Ltd. Technology Development Headquarters (72) Inventor Kiyoshi Seto 4013 Nakatsu, Aikawa-cho, Aiko-gun, Kanagawa Dainippon Ellio Co., Ltd. ( 72) Inventor Toshihiro Kano 4013 Nakatsu, Aikawa-cho, Aiko-gun, Kanagawa Prefecture Dainippon Ellio Co., Ltd. (72) Inventor Taku Morimoto 450 Aoto-cho, Midori-ku, Yokohama-shi, Kanagawa The Inktech Co., Ltd. (72) Inventor Mukaiyama Tomoaki 450 Aoto-cho, Midori-ku, Yokohama-shi, Kanagawa The Intec Co., Ltd.

Claims (2)

[Claims] 1. A solid comprising a composition containing, as a lowermost layer, two or more (meth) acryloyl groups in one molecule, and an oligopolyester (meth) acrylate having a (meth) acryloyl group equivalent of 400 or less as an essential component. Alternatively, an oligopolyester having a coating film that is heat-cured in a state close to a solid and containing two or more (meth) acryloyl groups in one molecule as an intermediate layer and having a (meth) acryloyl group equivalent of 500 or less (meth) ) An oligopolyester having a printed layer composed of a composition containing acrylate as an essential component, further containing, as the uppermost layer, two or more (meth) acryloyl groups in one molecule and having a (meth) acryloyl group equivalent of 500 or less ( (Meth) acrylate and two or more (meth) acryloyl groups in one molecule, and (meth) acryloyl group equivalent is 150 or less. A coated metal plate having a coating film comprising a composition containing the polyhydric alcohol (meth) acrylate as an essential component, and having these three layers cured by an electron beam. 2. A (meth) acryloyl group is used in each molecule.
More than one, and (meth) acryloyl group equivalent is 400
The composition containing the following oligopolyester (meth) acrylate as an essential component is applied to a steel sheet and heat-cured to form a solid or near solid state coating film (meth) in one molecule.
Oligopolyester (meth) containing two or more acryloyl groups and having a (meth) acryloyl group equivalent of 500 or less
After printing a composition containing acrylate as an essential component, further containing two or more (meth) acryloyl groups in one molecule,
And a polyhydric alcohol (meth) containing an oligopolyester (meth) acrylate having a (meth) acryloyl group equivalent of 500 or less and two or more (meth) acryloyl groups in one molecule, and having a (meth) acryloyl group equivalent of 150 or less.
A method for producing a coated metal plate, which comprises applying a composition containing acrylate as an essential component and curing these three layers with an electron beam.