JPH0529660B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing a coated metal plate and a coating composition in which the coating film is cured with an electron beam. [Prior art] Generally, paints are soluble in solvents, and the solvent is scattered at room temperature or by heating, or a crosslinking/curing reaction is caused by heating, ultraviolet rays, infrared rays, etc. to make the paint insolubilized to form a cured coating film. shall be. However, with these methods, it is difficult to obtain a product that does not undergo changes such as swelling or discoloration when exposed to any organic solvent, and has sufficient stain resistance against magic ink, whiteboard markers, and the like. As seen in JP-A-49-32488, the present inventors have already applied a paint consisting of an oligo(meth)acrylate system and a polyhydric alcohol (meth)acryloyl system to a metal plate, and applied the coating using an electron beam curing method. By curing the film, we succeeded in obtaining a coated metal plate with high hardness, excellent solvent resistance, and stain resistance. However, with the above resin system, coating methods suitable for industrialization, such as curtain flow coater, spray coater, roll coater, etc.
It was found that the paintability was not sufficient. This tendency is particularly noticeable in curtain flow coater painting. The discovery of the cause led to the present invention. That is, Japanese Patent Application Publication No. 1973-
32488 resin alone does not have sufficient paintability; for example, when using a curtain flow coater, "curtain breakage" and "curtain streaks" occur, making it difficult to produce coated metal sheets with a coating film appearance that is sufficient for practical use. Have difficulty. In order to solve this problem,
I tried adding commonly known paint additives such as surfactants and spreading agents, but although some effects were observed in some cases, they were not sufficient.Also, I tried various changes in the composition of the solvent added during painting, but It was not a fundamental solution. If we carefully consider the cause of this, in the case of oligo(meth)acrylates, even if the upper limit of (meth)acryloyl group equivalent is 500 and the number of (meth)acryloyl groups in one molecule is 6, the molecular weight is approximately
It is 3000. In the case of polyhydric alcohol (meth)acrylates, the molecular weight is even lower. Therefore, it is presumed that the paint has no "stickiness" or "stiffness" and is "smooth". For example, this lack of "stickiness" and "waistiness"
When applying paint to a curtain flow coater,
It is thought that this makes it easier for "curtain torn or curtain streaks" to appear. Furthermore, these oligo(meth)acrylates and polyhydric alcohols (meth)
The viscosity of acrylate varies greatly depending on temperature and amount of added solvent, compared to coating resins used for conventional heat curing, and this makes coating properties more unstable. These problems are caused by the nature of the resin and cannot be solved by using low molecular weight additives or the like. [Structure of the Invention] The inventors of the present invention have finally found a solution after various studies. i.e. oligo(meth)acrylates, polyhydric alcohols (meth)
If a polymer with a molecular weight of 5,000 or more is added to acrylate, the paint will become sticky or stiff, and when applied with a curtain flow coater, spray coater, or roll coater,
This will solve the problems mentioned earlier. In this case, it exhibits a particularly remarkable effect on curtain flow coaters. Here, the polymer to be added will be discussed in more detail. If the molecular weight is 5,000 or more, it is effective against the above-mentioned problems, but those that have a particularly stable effect during coating are solids or close to solids, and their viscosity is 100,000 centipoise. That's all. Furthermore, considering other parameters, resins with an elongation of 50% or more are particularly effective, although this is limited to solid cases. Furthermore, the glass transition point of the resin is preferably lower than 20°C. Based on the above facts, the present inventors,
This was discovered experimentally. If we consider these a little, we find that it is particularly effective when the viscosity and elongation of the resin exceed a certain value, and it is said that it is especially effective in reducing the "stickiness" and "stiffness" that oligo (meth) acrylates and polyhydric alcohol (meth) acrylates lack. It seems that it is given. Furthermore, the fact that it is better for the glass transition point of the resin to be lower than a certain value means that it is better not to include anything "hard" during painting. Here, we will discuss the quantitative relationship between oligo(meth)acrylate, polyhydric alcohol (meth)acrylate, and polymers with a molecular weight of 5000 or more. The above two components are necessary to maintain paint film performance such as excellent stain resistance, chemical resistance, and hardness.Although the polymer itself improves paintability, it has no effect on film performance. This is a negative factor. This is because if the molecule has a large number of (meth)acryloyl groups that are active to electron beams, it will have the same amount as, for example, the oligo(meth)acrylate and polyhydric alcohol (meth)acrylate used in the present invention. If it were, it wouldn't be so negative, but although something like this is theoretically possible, it is impossible to synthesize in practice. Its limits are not clear, but for example, Ford Motor Co., Ltd.
-15630, there are around 3 (meth)acryloyl groups in 1000 molecular weight, and the double bond equivalent is
It is about 330 or more. Here, a quantitative relationship is required. As a result of various studies, the present inventors have discovered that there is a close relationship between the (meth)acryloyl group equivalent and the amount of polymer added. If the average (meth)acryloyl group equivalent of oligo(meth)acrylate and polyhydric alcohol (meth)acrylate is x, and the amount of polymer added is y (%), then x>0, y≧0.1, -2/130x+3≦y≦ -2/130x+12, oligo(meth)acrylate,
It does not impair the excellent stain resistance, chemical resistance, hardness, and properties of polyhydric alcohol (meth)acrylate. Here we will define the excellent stain resistance, chemical resistance, and hardness. Excellent stain resistance means that it can withstand regular test methods such as magic ink, curry, mustard, lipstick,
After applying crayons, colored pencils, ink, whiskey, and other daily necessities, or substances that are often found in stain resistance tests, leave them for 24 hours before applying benzene alcohol, water, or other chemicals that dissolve contaminants, or using cloth or gauze. etc., without leaving any traces, and even if characters or figures are written with a whiteboard marker, they can be erased with an eraser.
Regarding chemical resistance, acids such as 5% hydrochloric acid, acetic acid, sulfuric acid, citric acid, nitric acid, 5% caustic soda,
Alkali such as ammonia, ethanol, benzine, methyl ethyl ketone, acetone, xylene,
After dropping approximately 1 c.c. of ethyl acetate or other organic solvent onto the paint film, placing a cover glass (e.g. a watch glass) over it and leaving it for 24 hours to prevent scattering, no change is observed. It is something. In terms of hardness, it is 7H or higher on the pencil hardness scale. Here, oligo(meth)acrylate will be explained in more detail. As long as the number of meth(acryloyl groups and the equivalent weight of (meth)acryloyl groups are within the range of the present invention), acrylic, epoxy, polyamide, silicone, urethane, and other materials can generally achieve the performance of the present invention in combination with polyhydric alcohol (meth)acrylate. However, considering the combination with polymer, polyester has the most preferable performance.The oligo(meth)acrylate used in the present invention uses a polyester skeleton in the main chain, and esters (meth)acrylic acid to this. The product used in the present invention is one that contains two or more (meth)acryloyl groups in one molecule because of the need to have a sufficient crosslinked network structure, and more preferably It is desirable to have 3 or more.Also, since the crosslinking density must be sufficiently high, the (meth)acryloyl group equivalent is preferably 500 or less, more preferably 400 or less.In this case, the above-mentioned As long as the oligo(meth)acrylate satisfies the requirements of the present invention, two or more of these may be used as a mixture.This component will be described in more detail.Oligo(meth)acrylate using a polyester skeleton in the main chain Acrylate is a polyester made of polyhydric alcohol and polycarboxylic acid with a hydroxyl group at the end, which is reacted with (meth)acrylic acid or its derivatives to introduce (meth)acryloyl groups. Here, we will further discuss the synthetic raw materials forming the polyester skeleton.That is, as dihydric alcohols, alkylene glycol types include ethylene glycol, propylene glycol, chloropropylene glycol,
Butanediol (1,3- or 1,4- or 2,3-), 3-methylpentanediol, 2,
2-diethylpropanediol, pentamethylene glycol, 1,6-hexanediol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, neopentyl glycol,
Alicyclic glycol types such as hexamethylene diol, 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, etc.; polyalkylene glycol types such as diethylene glycol, triethylene glycol, polyethylene glycol, Dipropylene glycol, polypropylene glycol, polytetramethylene glycol polybutadiene diol, etc., as well as aromatic glycol types,
2,2'-bis(4-hydroxyphenylpropane) (also known as bisphenol A), bis(4-hydroxyphenyl)methane (also known as bisphenol F),
Examples include glycols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to phenols such as 4,4'-dihydroxyphenyl, hydroquinone, and resorcinol. 3-4
Examples of the alcohol include glycerin, trimethylolmethane, trimethylolethane, tomethylolpropane, 1,
2,6-hexanetriol 1,2,3-butanetriol, 1,2,3-pentanetriol,
2-methyl-2,3,4-butanetriol, 2
-Methyl-2,3,4-butanetriol, 2-
Methyl-1,2,3-butanetriol, 2-ethyl-1,2,3-butanetriol, 2-3,
4-hexanetriol, pentamethylene glycol, etc., alkanetetraols such as erythritol, pentaerythritrol, toilettetrol, 1,2,3,4pentantetrol, 2,
3,4,5-hexanethetol, 2,5-dimethyl-2,3,4,5-hexanethetol, 1,2,
3,5-pentanetetol, 3-hexane-1,
2,5,6 tetol, 3hexane-1,2,5,
As ether group-containing aliphatic triols such as 6-tetrol, ether group-containing aliphatic tetraols such as triols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to glycerin, trimethylol propane, etc. Etraols obtained by adding alkylene oxide to erythritol, pentaerythritol, etc., and aromatic triols include triols obtained by adding alkylene oxide to pyrogallol. As the carboxylic acid, as a chain or branched divalent carboxylic acid,
Alicyclic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, maleic acid, fumaric acid, adipic acid, sebasacic acid, dodecanoic acid, methylene glutaric acid, methylmaleic acid, methylsuccinic acid, dodecenylsuccinic acid, etc. as, 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 known as Hett's acid), 1,4,5,6,
7,7-hexabromoendo-5-norbornene-2,3-dicarboxylic acid, cyclohexane,
Examples of aromatic dicarboxylic acids include 1,4-dicarboxylic acids, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, tetrapromophthalic acid, and anhydrides thereof. Specific examples of polyester oligomers having two (meth)acryloyl groups include di(meth)acryloyl groups of maleic acid and ethylene glycol;
Acrylate, di(meth)acrylate of polyester with maleic acid and diethylene glycol,
Di(meth)acrylate of polyester diol of adipic acid and diethylene glycol, di(meth)acrylate of polyester diol of tetrahydrophthalic acid and diethylene glycol, di(meth)acrylate of polyester diol of tetrahydrophthalic acid and propylene glycol,
Tetrahydrophthalic acid and butanediol (1,3
- or di(meth)acrylate of polyester diol with 1,4-), di(meth)acrylate of polyester diol with tetrahydrophthalic acid and 1,6-hexanediol, polyester with tetrahydrophthalic acid and neopentyl glycol Di(meth)acrylate of diol, di(meth)acrylate of polyester diol of tetrahydrophthalic acid and 1,4-cyclohexanediol, di(meth)acrylate of polyester diol of phthalic acid and diethylene glycol, phthalic acid and neopentyl glycol and di(meth)acrylates of polyester diols. These polyester oligomers have a di(meth)acrylate structure of a polyester diol of tetrahydrophthalic acid and an alkylene glycol or cycloalkylene glycol having 3 to 6 carbon atoms, and have a number average molecular weight of 350 to 800.
Number average molecular weight per acryloyl group 180-400
The polyester oligomers are particularly suitable for the purposes of the present invention. Further, specific examples of polyester oligomers having two or more (meth)acryloyl groups include tetra(meth)acrylate, penta(meth)acrylate, hexa(meth)acrylate of polyester polyol of adipic acid and pentaerythritol. ) acrylate, tetramethacrylate, penta(meth) of polyester polyol with tetrahydrophthalic acid and pentaerythritol
Acrylate, hexa(meth)acrylate, tetra(meth)acrylate of polyester polyol with phthalic acid and pentaerythritol, penta(meth)acrylate, hexa(meth)acrylate, tetra(meth)acrylate of polyester polyol with maleic acid and pentaerythritol Acrylate, penta(meth)acrylate, hexa(meth)acrylate, tetra(meth)acrylate of polyester polyol with adipic acid and trimethylolpropane, penta(meth)acrylate, hexa(meth)acrylate, tetrahydrophthalic acid and trimethylolpropane Tetra(meth)acrylate of polyester polyol with, penta(meth)acrylate, hexa(meth)acrylate, tetra(meth)acrylate of polyester polyol with tetrahydrophthalic acid and glycerin, penta(meth)acrylate, hexa(meth)acrylate, etc. can be given. Among these polyester oligomers, a polyester polyol with adipic acid or tetrahydrophthalic acid and trimethylolpropane, or pentaerythritol has a structure of tetra(meth)acrylate, penta(meth)acrylate or hexa(meth)acrylate with a number average Polyester oligomers having a molecular weight of 550 to 2000 and a number average molecular weight per (meth)acryloyl group of 100 to 350 are suitable for the purpose of the present invention. The polyhydric alcohol (meth)acrylate referred to in the present invention refers to one in which a (meth)acryloyl group is introduced by reacting the terminal hydroxyl group of a polyhydric alcohol with (meth)acrylic acid, and in combination with an oligo(meth)acrylate. It plays a role in achieving extremely high crosslinking density. For this purpose, one molecule should contain two or more (meth)acryloyl groups, and the (meth)acryloyl group equivalent should be 150 or less, more preferably about 130 or less. In this case, it may be a mixture of two or more polyhydric alcohols and (meth)acrylates. The polyhydric alcohol referred to here refers to the following. That is, as dihydric alcohols, alkylene glycol types include ethylene glycol, propylene glycol, chloropropylene glycol,
Butanediol (1,3- or 1,4- or 2,3-), 3-methylpentadiol, 2,2
-diethylpropanediol, pentamethylene glycol, 1,6-hexanediol, heptamethylene glycol, octamethylene glycol,
Alicyclic glycol types such as nonamethylene glycol, neopentyl glycol, hexamethylene diol, etc., 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, etc., and diethylene glycol as polyalkylene glycol types. , triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol polybutadiene diol, etc. Also, as an aromatic glycol type, 2,2'-bis(4-hydroxyphenylpropane) (also known as bisphenol A) ), bis(4-hydroxyphenyl)methane (also known as bisphenol F), 4,4'-dihydroxyphenyl, hydroquinone, resorcinol, and other phenols to which alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) are added. Examples include glycols obtained by Examples of trihydric or higher alcohols include glycerin, trimethylolmethane, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol 1,
2,3-putanetriol, 1,2,3-pentanetriol, 2-methyl-2,3,4-butanetriol, 2-methyl-2,3,4-butanetriol, 2-methyl-1,2, 3-butanetriol, 2-ethyl-1,2,3-butanetriol, 2-3,4-hexanetriol, pentamethylene glycol, etc., as alkantetraols, erythritol, pentaerythritol, dipentaerythritol, toilette, 1,
2,3,4 pentanetetrol, 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, 3hexene-1,2,
Ether group-containing aliphatic tetraols such as 5,6-tetrol include triols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to glycerin, trimethylolpropane, etc. Examples of the ols include tetraols obtained by adding alkylene oxide to erythritol, pentaerythritol, etc., and aromatic triols include triols obtained by adding alkylene oxide to pyrogallol. Among these, those having a (meth)acryloyl group equivalent of 120 or less are particularly preferred. Furthermore, it is important to note that the addition of a polymer is an essential condition of the present invention, which, as mentioned earlier, results in a decrease in performance. In order to prevent this performance deterioration, in the system where oligo(meth)acrylate and polyhydric alcohol (meth)acrylate are mixed, the average (meth)acryloyl group equivalent must be 100 to
It has been made clear that a range of 200 is particularly preferable in the present invention, where it is essential to add a polymer. Here, we will discuss the blending ratio of oligo(meth)acrylate and polyhydric alcohol (meth)acrylate. Oligo (meth)acrylate/polyhydric alcohol (meth)acrylate = 1/0.5 to 1/10
(weight ratio) is desirable. This is because oligo(meth)acrylate alone does not increase the crosslink density sufficiently, so polyhydric alcohol (meth)acrylate is added to improve the crosslink density, but in order to meet the purpose of the present invention, , it must be added at least 0.5 to 1 oligo(meth)acrylate. Here, the upper limit of polyhydric alcohol (meth)acrylate is 1 to 1 to oligo(meth)acrylate, but if more than this is added and the coating film is cured, the , cracks will increase if the paint film is cracked or scratched. Therefore, it is preferably 10 or less.
The reason why the amount of polyhydric alcohol (meth)acrylate added can be increased compared to the case of JP-A-49-32488 is that the above-mentioned trouble can be alleviated by adding a polymer with a molecular weight of 5000 or more. It is. Next, the polymer having a molecular weight of 5000 or more to be added as the third component in the present invention will be described. As long as the above-mentioned requirements are met, acrylic, polyester, urethane, epoxy, polyamide, melamine, silicone, alkyd, etc., and modified products or combinations thereof may be used.
Acrylic, polyester, and urethane alone or in combination are particularly effective in terms of both coating film performance and paintability. in this case,
It may be a mixture of two or more of the same type of resin. Here, the constituent components of the acrylic polymer will be described, but they are not limited to those exemplified below. For example, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-acrylate
-Butyl, isobutyl acrylate, acrylic acid-
Acrylic acid alkyl esters such as n-amyl, n-hexyl acrylate, and n-octyl acrylate; alkyl acrylic halides such as 2-chloroethyl acrylate and 3-chloropropyl acrylate; and 2-acrylic acid. - Acrylic acid OH-containing esters with OH groups such as hydroxyethyl, 2-hydroxypropyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-methacrylate -butyl,
α-alkyl acrylic acid alkyl esters such as isobutyl methacrylate, n-amyl methacrylate, n-octyl methacrylate, lauryl methacrylate, methyl α-chloroacrylate, α-
α-halogenated acrylic esters such as ethyl chloroacrylate, 2-chloroethyl methacrylate, 3-chloropropyl methacrylate, etc.
-OH of alkylacrylic acid halogenated alkyl esters, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 1-chloro-2-hydroxyethyl methacrylate, etc.
acrylic monomers containing epoxy groups such as α-alkyl acrylic esters and glycidyl acrylates and glycidyl methacrylates,
Monomers having an amino group such as dimethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl mitacrylate, and diethylaminoethyl acrylate are included. As component A of the present invention, it is preferable to use one or more of these acrylic monomers in an amount of 50 mol% or more of the total monomers, and any remaining monomers can be used as long as they can be copolymerized. It is. Next, the constituent components of polyester will be described, but they are not limited thereto. That is, as alcohols, alkylene glycol types include ethylene glycol, propylene glycol, chloropropylene glycol, butanediol (1,3- or 1,4- or 2,3-),
3-methylpentanediol, 2,2-diethylpropanediol, pentamethylene glycol,
Alicyclic glycol types such as 1,6-hexanediol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, neopentyl glycol, hexamethylene diol, 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol , hydrogenated bisphenol A, polyalkylene glycol types such as diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol, polybutadiene diol, etc., and aromatic glycol types such as 2,
2'-bis(4-hydroxyphenylpropane)
(also known as bisphenol A), bis(4-hydroxyphenyl)methane (also known as bisphenol F), 4,
Examples include glycols obtained by adding alkylene oxides (ethylene oxide, propylene oxide, butylene soxide, etc.) to phenols such as 4'-dihydroxyphenyl, hydroquinone, and resorcinol. Furthermore, as alkantriol types, glycerin, trimethylolmethane, trimethylolethane, trimethylolpropane, 1,2,6-
Hexanetriol 1,2,3-butanetriol, 1,2,3-pentanetriol, 2-methyl-2,3,4-butanetriol, 2-methyl-2,3,4-butanetriol, 2-methyl-
1,2,3-butanetriol, 2-ethyl-
Alkanetraols such as 1,2,3-butanetriol, 2-3,4-hexanetriol, pentamethylene glycol, erythritol, pentaerythritol, toilette, 1,
2,3,4 pentanetetrol, 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, 3hexene-1,2,
Ether group-containing aliphatic triols such as 5,6-tetrol, etc., such as triols obtained by adding alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) to glycerin, trimethylolpropane, etc. Tetraols include tetraols obtained by adding alkylene oxide to erythritol, pentaerythritol, etc., and aromatic triols include triols obtained by adding alkylene oxide to pyrogallol. Examples of carboxylic acids include chain or branched divalent carboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, dodecanoic acid,
Methylene glutaric acid, methylmaleic acid, methylsuccinic acid, dodecenylsuccinic acid, etc., as alicyclic dicarboxylic acids, tetrahydrophthalic acid, hexahydrophthalsan, 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 known as Hett's acid),
1,4,5,6,7,7-hexapromoendo-5-norbornene-2,3-dicarboxylic acid, cyclohexane, 1,4-dicarboxylic acid, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, Examples include terephthalic acid, tetrachlorophthalic acid, tetrapromophthalic acid, and anhydrides thereof. Next, let's talk about polyurethane. This may be of any type, such as urethanized oil type, moisture curing type, block type, catalyst curing type, or two-component type. Here, I will talk about isocyanates. Constituent units of aliphatic diisocyanate include ethane, propane, butene, thiodiethyl, pentane, β-methylbutane,
Hexane, ω, ω′ dipropyl ether, thiodipropyl, heptane, 2,2 dimethylpentane,
Fats with cyclic groups such as 3-methoxyhexane, octane, 2,2,4-trimethylpentane, nonane, decane, 3-butoxyhexane, 1,4-butylene glycol dipropyl ether ω, ω′, undecane, dodecane, thiodihexyl, etc. The structural units of group diisocyanates include ω, ω' diisocyanate 1,3 dimethylbenzole, ω, ω' diisocyanate, 1,2 dimethylbenzole, ω,
ω' diisocyanate, 1,2 dimethyl microhexane, ω, ω' diisocyanate 1,4 microhexane, ω, ω' diisocyanate 1,4 diethylbenzole, ω, ω' diisocyanate 1,
4 dimethylnaphthalene, 1-ω-methyl isocyanate-2-ω-η-propylisocyanate-
3,5-dimethylmicrohexane, ω,ω'-diisocyanato-η-propyl-biphenyl,
Examples of aromatic diisocyanates include tolylene diisocyanate, 3,3' bitrylene 4,4' diisocyanate, diphenylmethane 4,4' diisocyanate, 3,3' dimethyldiphenylmethane 4,
4' diisocyanate, 2,4 tolylene diisocyanate dimer, and other aromatic isocyanate structural units include 1,3 phenylene, 1,4 phenylene, 1 methylbenzole 2,4, 1,3 dimethyl benzol 2, 4,1 ethylbenzole 2,4,1 isopropylbenzole, diisopropylbenzole, etc. Naphthalene isocyanate includes naphthalene 1,4,1,1' dinaphthyl 2,2' etc., biphenyl isocyanate includes:
Biphenyl 2,4', 3,3' dimethylbiphenyl 4,4', 2 nitrobiphenyl 4,4', etc. The constituent units of ditriphenylmethane diisocyanate include diphenylmethane 4,4', 2,2' Dimethyldiphenylmethane 4,4', etc., tri- and tetraisocyanate structural units include 1-methylbenzole 2,4,6, 1,3,5-trimethylbenzole 2,4,6, naphthalene 1,3 ,7,
biphenyl 2,4,4', diphenylmethane 2,
4,4',3methyldiphenylmethane4,6,4',
triphenylmethane 4,4′4″, diphenyl 4,
4′ diisocyanate N carbamic acid chloride, etc.
Other isocyanates include organic phosphorus isocyanates, fluorinated isocyanates, sulfonyl isocyanates, and the like. Incidentally, an appropriate molecular group or atomic group may be optionally introduced into the skeleton of these isocyanates, or they may be modified. Next, we will discuss polyols, polyethers, etc. that are reacted or have already reacted with isocyanates. These include RCOOH, H ₂ S, RSH, HCN, HCl,
HOH, HOH, ROH, R(OH) ₂ , NH ₃ , RNH ₂ ,
R( _NH2 ) ₂ , _{RSO2NH2 ,}

[Stain resistance]

Magic ink (red, blue), curry, mustard,
Lipstick, crayons, colored pencils, and ink were applied to the painted board, and after 24 hours, they were wiped off easily with gauze soaked in ethanol, leaving no trace. Also,
Even if I wrote on it with a whiteboard marker made by Pilot Co., Ltd., I could completely erase it with an eraser. [Chemical resistance] Approximately 1 c.c. of 5% hydrochloric acid, acetic acid, sulfuric acid, citric acid, nitric acid, caustic soda, ammonia, etc., as well as ethanol, benzine, methyl ethyl ketone, acetone, xylene, and ethyl acetate, are dropped onto the coating film. After covering the shiso with a watch glass to prevent scattering and leaving it for 24 hours, washing with water and blowing with air, visual judgment was made, but no change was observed in the coating film.
(Pencil hardness) 8H Comparative Example 1 Components A and B were exactly the same as in Example 1, and the composition of component C was the same as in Example 1, but the molecular weight was about 4000.
A mixed resin system (outside the scope of the present invention) was made into a paint and painted in exactly the same manner as in Example 1. However, "curtain breakage" and "streaks" were observed in the curtain film of the curtain flow coater. Comparative Example 2 A coating material was prepared under exactly the same conditions as in Example 1 except for component C. When this was applied to an electrogalvanized steel plate (thickness: 0.6 mm) using a curtain flow coater, the curtain film "curtain breakage" occurred similarly to Comparative Example 1, but even more severely.
“Streaks” etc. were observed. Naturally, the coating film was not good either. Example 2 A Orgoacrylate with a condensation molar ratio of adipic acid, pentaerythritol, and acrylic acid of 1:2:4 (acryloyl group equivalent: 122), B: trimethylolpropane trimethacrylate (methacryloyl group equivalent: 113), C: terephthalic acid, A polyester consisting of sebacic acid and ethylene glycol with a condensation molar ratio of approximately 3:7:10 (number average molecular weight 20,000, glass transition point 6°C, elongation 700%), A, B, and C components under exactly the same conditions as in Example 1. After painting, the painted board was irradiated with an electron beam. The paintability and film performance were exactly the same as in Example 1, except that the hardness was 7H, and the results were excellent. Example 3 A Orgoacrylate (acryloyl group equivalent: 154) in which the condensation molar ratio of terephthalic acid, trimethylolpropane trimethacrylate, and acrylic acid is 1:2:4, B Diethylene glycol dimethacrylate (methacryloyl group equivalent: 121), Example 1 The results were exactly the same as in Example 1. Example 4 In place of Example 2, an oligoacrylate (acryloyl group equivalent: 155) with a condensation molar ratio of tetrahydrophthalic acid, trimethylolpropane, and acrylic acid of 1:2:4 was used, but the results were the same as in Example 1. It was exactly the same. Example 5 Even when half of the component A in Example 1 was replaced with the oligoacrylate in Example 4, the paintability and film performance were the same as in Example 1. Example 6 In Example 1, half the amount of C component was replaced with Example 2.
Even when the C component was replaced, the paintability and film performance were the same as in Example 1.

Claims (1)

[Claims] 1. Contains two or more (meth)acryloyl groups in one molecule, and has a (meth)acryloyl group equivalent of 500
The following oligo(meth)acrylates contain two or more (meth)acryloyl groups in one molecule, and
A paint containing polyhydric alcohol (meth)acrylate with a (meth)acryloyl group equivalent of 150 or less and a polymer with a molecular weight of 5,000 or more and a glass transition point of less than 20°C as essential components is applied to the object to be coated, and the coating is coated with an oxygen concentration of 1 A method for producing a coated metal sheet, characterized by curing it with an electron beam in an inert gas of % or less. 2 Contains two or more (meth)acryloyl groups in one molecule and has a (meth)acryloyl group equivalent of 500
The following oligo(meth)acrylates contain two or more (meth)acryloyl groups in one molecule, and
An electron beam curable coating composition containing as essential components a polyhydric alcohol (meth)acrylate with a (meth)acryloyl group equivalent of 150 or less, and a polymer with a molecular weight of 5,000 or more and a glass transition point of less than 20°C.