JPS61179281A - Production of steel having film stuck thereto by curing with electron beams - Google Patents

Abstract

PURPOSE:To obtain the titled steel having a high bond strength and a high quality with high productivity without causing pollution, by sticking a metal plate and a film together with an adhesive containing as essential ingredients a specific reaction product and a (meth)acrylate compound and curing the adhesive. CONSTITUTION:A metal plate and a plastic film are stuck together with an adhesive comprising, as essential ingredients, (A) 5-95wt% of a reaction product having two or more free SH groups per molecule thereof obtained by adding an alcohol having an SH group to a polyisocyanate compound having two or more isocyanate groups per molecule thereof (e.g. tolylene diisocyanate) and (B) 95-5wt% of an ester of a tricyclodecanedialcohol with a (meth)acrylic acid represented by the given formula (wherein R1 is a 1-12C alkylene; and R2-R3 are each H or CH3) and, optionally, (C) a compound having an ethylenically unsaturated group other than component (B) and/or a compound having at least one SH group per molecule thereof other than component (A). The steel plate is irradiated with electron beams through the film layer to cure the adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a plastic film laminated steel plate by an electron beam curing method.

[Conventional technology]

In the past, various methods have been considered for bonding plastic film and metal plates, but this is one that is currently in use. A typical method is to apply a solvent-based adhesive to a metal plate, use hot air, far infrared rays, near infrared rays, or other heating methods to scatter the solvent and at the same time cause a crosslinking reaction in the adhesive resin. A film is attached to a sticky adhesive under heating.

It is well known that high quality laminated products are produced using heat curing methods. However, in this case, the line speed during production is limited due to the catenary in the heating furnace for coil products, and since solvents are used and combustion exhaust gas from the hot air drying furnace, pollution countermeasures are required. There are problems such as the need to be strictly conducted.

On the other hand, among resin curing methods, electron beam curing has been attracting attention since the early 1960s. The characteristics of this method are: ■ High-speed curing (10-1 to 10-2 seconds);
■The principle is that the oven waste gas is emitted, and a 100% non-volatile resin system can be used to reduce pollution. ■The line cost is low. ■There is no thermal aging of the metal plate because it is not heated. It is said that there is.

However, it is expected that these characteristics may also be disadvantageous when employed as an adhesive curing method in the production of laminated metal plates.

In other words, in the electron beam curing method, the curing reaction proceeds in a very short time and at room temperature, so the internal shrinkage stress of the adhesive layer is extremely large, and in the heat curing method, the internal shrinkage stress is very high. ” effect cannot be expected.For this reason, it has good adhesion to metals, etc., and has a non-volatile content of 10%.
It is expected that it will be difficult to obtain a 0% resin system.

The present inventors have made extensive studies to apply electron beam curable resin systems to the subject matter of the present invention. In this process, known compositions, such as those described in Japanese Patent Publication No. 49-5889, Japanese Patent Publication No. 56-8070, Japanese Patent Publication No. 49-26060, Japanese Patent Application Laid-Open No. 51-100139, etc. I tried additional compositions, but found that they did not adhere well to both plastic film and metal; for example, they adhered well to one but not the other, or they adhered well to both but were not processed properly. This method had disadvantages such as insufficient workability, probably because the adhesive was destroyed, and it did not meet the purpose.

[Problem that the invention seeks to solve]

Therefore, the present inventors investigated adhesive resins with good adhesion to both plastic films and metals, and found that the nonvolatile content was approximately 100%, and the adhesive resin had a high rate of curing (
The present invention has established a method for manufacturing film-bonded steel sheets using an electron beam curing method, which can produce 40n+/min or more) and has good product quality.

[Means to solve the problem]

That is, the present invention provides: (a) a reaction product having two or more free mercapto groups in one molecule, which is obtained by adding a mercapto group-containing alcohol to a polyisocyanate compound having two or more isocyanate groups in one molecule; and (b) In the following general formula, R8 represents a C1-1□ alkylene group, and R2
and R1 each represent H or CHl, contains as a main component a tricyclodecane dialcohol (meth)acrylic acid ester compound represented by the following, and if necessary, (e) an ethylenically unsaturated group-containing compound (however, (excluding component (b) above) and/or (d) a compound having one or more mercapto groups in one molecule (excluding component (a) above). The present invention provides a method for producing a film-bonded steel plate, which comprises bonding a plate and a plastic film together, and then irradiating the adhesive with an electron beam through the film layer to cure the adhesive.

The electron beam curing adhesive, which is an important component of the present invention, will be described in more detail.

As mentioned above, since the purpose of the present invention is to bond metal and plastic film, the adhesive resin must first have adhesive properties, and when the product is processed, Flexibility is also required, and furthermore, water resistance, weather resistance, chemical resistance, heat resistance, etc. are also required in the sense of durability for the adhesive layer of the laminated steel sheet, and from the process point of view of high productivity. In terms of high-speed curing properties and zero pollution, it is required that the nonvolatile content be approximately 100%.

The characteristics of the adhesive in the present invention are that by irradiation with an electron beam,
It is quickly crosslinked and cured mainly by the reaction between the mercapto group (-8H) of component (a) and the ethylenically unsaturated group (-C=CH2) of component (b), so it has good curability and also Since it is made into a linear polymer, it has the advantage of having low shrinkage stress and excellent adhesion and adhesion.

In addition, the adhesive of the present invention has a urethane bond (-NH
Since the adhesive has CO〇-), the cured layer formed from the adhesive is flexible and strong. Furthermore, the hardened layer has excellent durability as mentioned above.

Each component constituting the adhesive composition, which is a component of the present invention, will be explained in more detail below.

Core JK: Obtained by reacting a polyisocyanate compound having two or more isocyanate groups in one molecule with a mercapto group-containing alcohol. (Reaction product having two or more free mercapto groups in one molecule;) The "polyisocyanate compound" used to obtain component (a) above has two or more isocyanate groups in one molecule. Included are polyisocyanates and urethane prepolymers having two or more isocyanate groups in one molecule obtained by reacting the polyisocyanates with polyols having two or more hydroxyl groups in one molecule.

The polyisocyanate having 2 or more, preferably 2 to 3 isocyanate groups in one molecule is any type of polyisocyanate, including aliphatic, cycloaliphatic, aromatic, and aromatic-aliphatic polyisocyanates. For example, tolylene diisocyanate, 4°4'-diphenylmethane diisocyanate, xylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate), 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane 2.4(
- or 2,6) diisocyanate, 1,3-(isocyanatomethyl)cyclohexane, inphorone diisocyanate, trimethylhexamethylene diisocyanate,
guimaric acid diisocyanate, dianisidine diisocyanate, phenyl diisocyanate, halogenated phenyl diisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, propylene diisocyanate, octadecylene diisocyanate), 1.5-7thalene diisocyanate, polymethylene polyphenylene diisocyanate, triphenyl Methane triisocyanate, naphthylene diisocyanate, tolylene diisocyanate polymer, diphenylmethane diisocyanate polymer, hexamethylene diisocyanate polymer, 3-phenyl-2-ethylene diisocyanate, cumene-2,4-diisocyanate, 4
-methoxy-113-phenylene diisocyanate, 4
-ethoxy-1,3-phenylene diisocyanate, 2
．． 4'-diisocyanate diphenyl ether,
5,6-dimethyl-1,3-phenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, benzidine diisocyanate, 9,10-anthracene diisocyanate, 4,4'-diisocyanate pencil, 3,3'-dimethyl-4,4' -diisocyanate diphenylmethane, 2,6-nomerlθ-thyl-4,4'-diisocyanate diphenyl, 3゜3
'-Dimethoxy-4,4'-diisocyanate diphenyl, 1,4-anthracene diisocyanate, phenylene noisocyanate), 2+4+6-F') L/triisocyanate, 2,4.4'-)lyisocyanate diphenyl ether, 1. 4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate,
1.10-decamethylene diisocyanate, 1,3-cyclohexylene diisocyanate-1,4,4'-methylene-bis(cyclohexyl isocyanate), etc., and these can be used alone or in combination of two or more. can. Among these, particularly preferred ones include isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate, 1,6-hexanoisocyanate, and the like.

In addition, examples of polyols having two or more hydroxyl groups in one molecule that can be reacted with the polyisocyanate include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol (molecular weight 4
000 or less), trimethylene glycol, polypropylene glycol (molecular weight 4000 or less), tetramethylene glycol, polytetramethylene glycol (molecular weight 4000 or less), 1,2-butanediol, 1,3-, butanediol , 1,4-butanediol, 1,3-bentanediol, neopentyl glycol, 1,2-hexylene glycol, 1,6-hexanediol, heptanediol, 1゜10-decanediol, cyclohexanediol, 2- Butene-1,4-
Diol, 3-cyclohexene-1,1-dimetatool, 4-methyl-3-cyclohexene-1,1-dimetatool, 3-methylene-1,5-bentanediol, (2
-hydroxyethoxy)-1-propyl, 4-(2
-hydroxyethoxy)-1-butyl, 5-(2-
hydroxyethoxy)-pentanol, 3-(2-hydroxypropoxy)-1-propyl, 4-(2-hydroxypropoxy)-1-butanol, 5-(2-hydroxypropoxy)-i-pentanol, 1-(2-
hydroxyethoxyl)-2-butanol, 1-(2-
Hydroxyethoxy)-2-pentanol, hydrogenated bis7er7-el A1 glycerin, polycaprolactone, 1,
2.6-hexanediol, trimethylolpropane,
Trimethylolethane, pentanetriol, trishydroxymethylami7methane, 3-(2-hydroxyethoxy)-1,2-propanediol, 3-(2-hydroxypropoxy)-1,2-propanediol, 6-
Examples of polyhydric alcohols include (2-hydroxyethoxy)-1,2-hexanediol, pentaerythritol, dipentaerythritol, mannitol, and glucose.

Furthermore, polyether polyols obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to the polyhydric alcohol can also be used as polyols. Furthermore, the above-mentioned polyhydric alcohols include, for example, heptathalic acid, isophthalic acid, terephthalic acid, trimellitic acid, methylcyclohexenetricarboxylic acid, adipic acid, sebacic acid, azelaic acid, tetrahydroheptalic acid, hexahydrophthalic acid, Himic acids, saturated polybasic acids such as succinic acid, dodecynylsuccinic acid, methylglutaric acid, pimelic acid, malonic acid and their anhydrides, and their anhydrides, such as maleic acid, hexamaric acid, chloromaleic acid, dichloromaleic acid, Citraconic acid, mesaconic acid, itaconic acid, tetrahydroheptalic acid, carbic acid, het acid, afnitic acid,
A polyester polyol obtained by reacting a polybasic acid component selected from unsaturated polybasic acids such as glutaconic acid and their anhydrides, or their anhydrides can also be used as the polyol.

Furthermore, in addition to the above, hydroxyl group-containing acrylic 01
Also usable as the polyol are resins, hydroxyl group-containing epoxy resins and epoxy modified resins, hydroxyl group-containing butyral resins, polyvinyl-14 alcohol copolymers, and hydroxyl group-containing polybutadiene resins.

Among these polyols, particularly preferred are ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol (with a molecular fi of 1000 or less), trimethylene glycol, tetramethylene glycol, and polytetramethylene glycol (with a molecular fi of 1000 or less). the following),
1,4-butanediol, 1,5-bentanediol,
Neopentyl glycol, 1,6-hexanediol,
Glycerin polycaprolactone (with a molecular weight of 2,000 or less), a polyhydric alcohol selected from trimethylolpropane, at least one of these polyhydric alcohols and heptalic acid, isophthalic acid, terephthalic acid, adipic acid, tetrahydroctctalic acid, hexahydro At least one polybasic acid selected from phthalic acid and succinic acid has a molecular weight of 5.
000 or less, as well as 3-15 mole propylene oxide adducts of glycerin.

The reaction between a polyisocyanate and a polyol can be carried out by reacting 2 or more moles of polyisocyanate per mole of the polyol according to a conventional method, so that two or more isocyanate groups remain in one molecule of the reaction product. can.

Examples of mercapto group-containing alcohols include mercaptomethanol, mercaptoethanol, and mercaptoprop-7-
and mercaptobutanol. Among these, mercaptoethanol is particularly suitable.

The reaction between a polyisocyanate compound and a mercapto group-containing alcohol is a urethanization reaction between an isocyanate group and a hydroxyl group, and the reaction is carried out using at least 2 moles of the latter per 1 mole of the former, so that one molecule of the reaction product 2 or more, preferably 2 to 6 free mercapto groups (-8
H) is introduced. Note that it is acceptable for unreacted isocyanate groups to remain in the reaction product produced (b) Component 2 In the following general formula, R1 is a C1-12 linear or branched alkylene group. , R2 is H or CI (representing a), and is obtained by esterifying tricyclodecane dialcohol with (meth)acrylic acid.

For example, tricyclodecane dialcohol di(meth)acrylate, tricyclodecane dialcohol di(meth)acrylate, tricyclodecane dialcohol di(meth)acrylate,
Examples include acrylate, tricyclothecandibutyl/di(meth)acrylate, and the like.

Furthermore, tricyclodecane dialcohol to which ethylene oxide, propylene oxide, butylene oxide or ε-caprolactone is added and esterified with (meth)acrylic acid may also be used as component (b).

There is no problem even if the -1-coupled compound (b) contains a very small amount of more acrylate or monomethacrylate of several weight percent or less.

The composition of the present invention contains component (a) and component (b) as essential components, and the composition ratio is based on the total amount of both components, and component (a) is Generally from 5 to 95% by weight, in particular from 30 to 70% by weight, and (l)
) component is generally 95-5% by weight, especially 70-30% by weight.
It is preferable that

The composition of the present invention can be substantially composed of the above-mentioned component (a) and (b) 1f1, but if necessary, the composition of the present invention may further include an ethylenically unsaturated group. Containing compounds (excluding component (l) above) (component (c)) and/or compounds having one or more mercapto groups in one molecule (excluding component (a) above) [(d) )
Components] can be blended to improve physical properties and adjust viscosity.

The ethylenically unsaturated group-containing compound as component (c) includes a conventional moa 7- having a radically polymerizable unsaturated bond,
Oligomers and ethylenically unsaturated group-containing polymers are included, and specific examples include the following.

Examples of such monomers include esters of acrylic acid or methacrylic acid and monohydric alcohols having 1 to 25 carbon atoms, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and acrylic acid. n-butyl, n-butyl methacrylate, 1so-butyl acrylate, 1so-butyl methacrylate, tert-butyl acrylate, tert-methacrylate
Butyl, propyl acrylate, propyl methacrylate,
Hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, stearyl acrylate, methacryl Contains stearyl acid.

Examples of such compounds include vinyl aromatic compounds such as styrene, vinyltoluene, methylstyrene, chlorostyrene, and divinylbenzene; other vinyl compounds such as vinyl acetate, vinyl chloride, vinyl isobutyl ether, methyl vinyl ether, acrylonitrile, and 2-ethylhexyl vinyl ether. Compounds can also be used.

Furthermore, the monomers include carboxyl group-containing monomers such as acrylic acid and methacrylic acid; hydroxyl group-containing moamers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate; butyl isocyanate; Adducts of polyisocyanates such as phenyl isocyanate and the above hydroxyl group-containing monomers; esterification products of phosphoric acid and the above hydroxyl group-containing monomers; unsaturated monomers having nitrogen-containing heterocycles such as vinylpyrrolidone and vinylpyridine can also be used.

Examples of oligomers include diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glyfur dimethacrylate, propylene glycol diacrylate, propylene glyfur dimethacrylate, 1,3-butanediol diacrylate, 1,3
-butanediol dimethacrylate, 1,4-butanediol diacrylate), 1,4-butanediol dimethacrylate, neopentyl glycol diacrylate,
Neopentyl glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol dimethacrylate, pentaerythritol tetraacrylate , tri- or tetravinyl compounds such as pentaerythritol tetramethacrylate; products obtained by reacting adducts of (the above-mentioned polyhydric alcohols) with ethylene oxide with acrylic acid and/or methacrylic acid; A product obtained by reacting an adduct with an oxide with acrylic acid and/or methacrylic acid; a product obtained by reacting an adduct with the alcohol and ε-caprolactone with acrylic acid and/or methacrylic acid: a phosphorus-containing polymerizable inorganic compound Saturated oligomers and the like are included.

The monomers and oligomers mentioned above may be used alone or in combination.
Can be used by mixing more than one species.

Further, as the ethylenically unsaturated group-containing resin, for example, a resin made by condensing (meth)acrylic acid with polyester,
Ethylenically unsaturated group-containing polyurethane resin, ethylenically unsaturated group-containing epoxy resin, ethylenically unsaturated group-containing phosphorus-containing epoxy resin, ethylenically unsaturated group-containing acrylic resin, ethylenically unsaturated group-containing silicone resin, ethylenically unsaturated group-containing silicone resin Examples include melamine resins containing saturated groups.

The blending ratio of component (c) is not strictly limited and can be varied widely depending on the use of the composition of the present invention, but generally the total amount of component (a) and component (b) is Based on the standard, component (c) is 100% by weight or less, preferably 1 to 1% by weight.
It is possible to mix it in a proportion of 25% by weight.

As the component (c), an ethylenically unsaturated group-containing compound having two or more, preferably two to six, polymerizable unsaturated double bonds in one molecule is used alone or in a mixture of two or more. If a monomer having only one double bond in one molecule is used, the amount used should be □ if it is used together with a monomer having two or more double bonds in one molecule. Regardless, it is preferably 10% by weight or less based on the total amount of components (a) and (b).

Ethylenically unsaturated group-containing compounds having two or more polymerizable unsaturated double bonds in one molecule, which are preferably used as component (c), include polyethylene glycol di(
meth)acrylate (with a molecular weight of 5()0 to 1200), polypropylene glycol cy(meth)acrylate (with a molecular weight of 500 to 12()0), 1,4-butanediol cy(meth)acrylate, neopentyl glycol Ester of polyhydric alcohol and acrylic acid such as di(meth)acrylate), 1,6-hexanediol:)(meth)acrylate, trimethylolprobant(meth)acrylate: condensation of (meth)acrylic acid to polyester Examples include ethylenically unsaturated group-containing resins having a number average molecular weight of 400 to 30,000, such as polyurethane resins containing ethylenically unsaturated groups, and acrylic resins containing ethylenically unsaturated groups.

Next, compounds having one or more mercapto groups, preferably 1 to 6 mercapto groups in one molecule, which are used as component (d), include, for example, mercaptometh/ol, mercaptoethanol, mercaptofluorocarbons, etc. Mercaptoalcohols such as mercaptobutanol, 3-mercapto-1゜2-propanediol; mercaptocarboxylic acids such as thioglyfuric acid, mercaptosuccinic acid, and 0-mercaptobenzoic acid; mercapto group-containing polyester resins, mercapto group-containing polyester resins Examples include mercapto F group-containing resins such as polyether resins, mercapto group-containing epoxy resins, mercapto group-containing acrylic resins, and mercapto group-containing polyurethane resins. The blending amounts of these compounds are component (a), (
Based on the total amount of component b) i, component (c) and component (d), an appropriate amount is 20% by weight or less, preferably 1% by weight or less.

The composition of the present invention has the above components (a) and (b) as essential components, and optionally contains the above components (c) and/or (d). Furthermore, the composition may optionally contain a thermal polymerization inhibitor and a coloring agent (pigment or dye) that does not substantially inhibit the curing reaction (radical polymerization) that occurs when irradiated with an electron beam. In addition, a small amount of an organic solvent having a low boiling point (preferably 180° C. or less) may be included.

Examples of thermal polymerization inhibitors that can be incorporated into the composition of the present invention include metal salts of hydroquinone, hydroquinone methyl ether, p-penzoquine, N-nitron diphenylamine, and N-nitron phenylhydroxyamine.
Examples include common radical polymerization inhibitors such as ammonium salt of N-nitrone phenylhydroxyamine and fetchacin.

Here, the line configuration of the present invention will be described.

Cut or filled metal sheets are fed to the line in a conventional manner. If necessary, the metal plate is pre-treated in the pre-treatment process and then enters the adhesive application process, where the adhesive is applied.Of course, if the film is to be laminated on both sides, An adhesive is applied to both sides, and then a film is attached to one or both sides, and the film is immediately put into an electron beam irradiation device, where the adhesive is cured by the electron beam that passes through the film. In addition, in the case of single-sided lamination, the back side may be painted on the opposite side of the film if necessary, and in this case, after the back side paint is applied,
It is also possible to enter an electron beam irradiation device and be cured by electron beams. In this case, it is preferable to perform curing under an inert gas atmosphere.

Furthermore, after passing through these steps, post-heating may be performed as necessary.

The line configurations have been briefly described above, but each will be discussed in more detail.

First, the metal plates used are hot-rolled plates, cold-rolled plates, hot-dipped zinc and zinc alloy plated steel plates, electrolytic zinc and zinc alloy plated steel plates, tinplate, tin-free steel, aluminized steel plates, turn-plated steel plates, and nickel-plated steel plates. Various other alloy-plated steel plates, stainless steel, aluminum plates, copper plates, titanium plates, and other metal plates, and if necessary, chemical conversion treatment, such as phosphate treatment,
Those subjected to chromate treatment, organic chromate treatment, cobalt composite oxide film treatment, nickel displacement plating, and other treatments can be used. These may be treated before passing through this line, or, if necessary, may be carried out in a pretreatment step during the process of the present invention. The method and type of treatment or the thickness of the treatment layer are determined according to the purpose of the present invention,
Each differs depending on the purpose etc.

Next, I will explain how to apply the adhesive.

A single roll coater method is most suitable for this, and examples include a reverse method and a natural method. In this case, in addition to the usual method of applying paint, a gravure method, a gravure offset method, etc., which imitate a printing method, can also be used.

Depending on the case, a knife two-ter spray or a flow coater may be used.

It should be noted that the viscosity of the adhesive, which is a constituent element of the present invention, can vary considerably within compositions of the same invention. In this case, use the above coating method appropriately, or
In the case of high viscosity, measures may be taken to reduce the viscosity to an appropriate viscosity range for coating by heating the roll and adhesive supply device. If the viscosity of the adhesive is about 300 cm, taking into account the heating application, it can be applied sufficiently and uniformly by any of the above-mentioned application methods.

In this case, the appropriate thickness of the adhesive layer is about 1 to 30 microns. However, it goes without saying that the thinner the product, the more cost-effective it is if the product functions as mentioned above are fully demonstrated.According to the experimental experience of the present inventors, the coating thickness is Considering various balances, around several microns is optimal.

For example, if the surface of the film has an uneven pattern as in the case of embossing, care must be taken to ensure that the adhesive is sufficiently applied to the uneven surface. In this case, it is better to apply the adhesive to the metal plate a little thicker than the appropriate coating thickness mentioned above, taking into consideration the smeariness of the embossing.

It is also possible to pre-apply the adhesive to the plastic film.

Next, a plastic film is attached to the adhesive applied to the metal surface, and the adhesive layer is coated with the film fed from the film supply device.

In this case, there are various ideas that can be considered, but a practical method is to cover the bottom of a metal plate coated with adhesive with a film and press it with a lamination roll from the surface of the film. As a matter of course, it is necessary to provide a backup device, such as a backup roll, directly below the previous roll via the laminated steel plate.

In this case, the laminating pressure between the lamination roll and the steel plate to be laminated is important.At first glance, it appears that the roll and the steel plate are in line contact, but in reality they are laminated under pressure, so the roll side is dented and the steel plate is in contact with the lamination roll. Contact will be surface contact. The pressure in this case is about 5 to 1 (13 kg/c+n2) on average, but it varies considerably depending on the line speed, adhesive viscosity, and degree of embossing of the film, and is 1 to 30 kg/cm.
A range of 2nd place is appropriate. This is because high line speeds, high adhesive viscosity, and highly embossed films generally require high pressure; conversely, low line speeds require high pressure If the viscosity is low, the film thickness is thin, or the degree of embossing is small,
Alternatively, if the adhesive has a very high tack, a generally lower pressure may be used.

In any case, in any case, it is necessary to devise a way to prevent air bubbles (oxygen) from being trapped between the adhesive layer and the laminated plastic film as much as possible. The plastic film used here is not particularly limited and is selected depending on the application of the laminated steel plate, but includes polyvinyl chloride, polyacrylic, polyester, polyethylene, polypropylene, fluorine-based, silicon-based, Natural or synthetic rubber, synthetic paper and ponds are used. The thickness of the plastic film to be laminated in this case varies depending on the use, but is usually about 30 to 400 microns. Among these, fluorine-based films have good weather resistance, but there is also a cost issue.
A film with a relatively thin thickness, for example, 40μ, is also used,
A vinyl chloride film having a film thickness of about 50 to 4.11 C1μ is used as it has general-purpose properties including cost.

As mentioned earlier, in some cases, the back side may be coated, but this coating system may be made from the adhesive composition of the present invention, or may be a conventional electron beam curing method that adheres to metal. A mold paint may be applied. In this case, the dry film thickness is usually about 3 to 8 μm, but depending on the application, it is 1 μ to 1 μm.
Some have a diameter of about 20μ. Since corrosion resistance is usually important for the back coating, it is necessary to add anti-rust pigments and the like. The most suitable method for applying this coating is a single-type roll coater, and the coating method may include natural foot or reverse coating, and the coating method may include a gravure method, a gravure offset method, etc.

Next, the electron beam irradiation device for curing the adhesive or back coating of the present invention will be described. This can be used with any known electron beam accelerator, e.g. scanning type, non-scanning type, etc. Currently, as an industrial accelerator, the accelerating voltage ranges from a minimum of 150 KV to several MiV, and any of these can be used. However, what is important here is that when curing the adhesive layer in the case of the present invention, the adhesive is irradiated with an electron beam that has passed through the upper plastic film, so naturally the plastic film layer Absorption of electrons is possible.

Therefore, by taking into account the thickness and specific gravity of the film layer, equipment installation conditions (e.g. distance from the irradiation window to the film), etc., it is necessary to determine the accelerating voltage that will allow the electron beam to sufficiently reach the adhesive layer under the film layer. You need to select a device. The selection method is as follows: Determine the necessary accelerating voltage from the well-known Depth-1)ose curve, which expresses the accelerating voltage and the penetrating power of the electron beam. There are methods such as placing a dosimetry film under the film and comparing it to the case without the plastic film to determine the attenuation rate. If the accelerating voltage is human, the penetration power will be large, but on the other hand, it will be expensive to shield secondary X-rays.

One guideline for selecting the maximum accelerating voltage is that the ratio of the electron beam intensity at the adhesive layer to that at the top layer of the film is 0.6/1. O1 is preferably set to 0, '8/1.0 or more. This is because if the value is less than the above value, e.g. 0.1/1.0, and the adhesive layer is exposed to the dose of 5 M rad required for curing, then the top layer of the film is exposed to a 50 M rad line i, which may cause deterioration of the film, and requires a device with a very high current to obtain the dose necessary for curing the adhesive.

As for the back coating (paint), since the film thickness is usually thin, an acceleration voltage of 150 KV or more is sufficient.

Naturally, if the film thickness becomes large, the above-mentioned consideration must be taken.

Incidentally, the radiation dose necessary for curing the adhesive according to the present invention is 0.1 to 2.0 as the substantial dose that passes through the film.
OM rad, preferably 0.5 to 10 Mrad
Teal.

Next, as mentioned above, post-heating may be performed if necessary, but the purpose of this is that the adhesive and back coating will naturally harden after electron beam irradiation, but the curing reaction will not be due to radical polymerization. Because reactions are the main activity, when viewed microscopically, some molecules of molecules may be in a stable state. There is a possibility that there is internal stress, and this can be ``relaxed''.
This is also related to the above-mentioned stabilization, and as a result, effects such as the possibility of "promoting" the curing reaction can be expected. This method includes immersion in boiling water, application of hot air, infrared rays, far infrared rays, near infrared rays, etc., to raise the temperature of the original plate. At this time, the best range for the plate temperature is between 40℃ and 300℃, but considering the line loss 1 - merit, the plate temperature should be 40℃.
~100°C is optimal.

[Effects of the Invention] The present invention has been described above, but to summarize it once again, the present invention takes advantage of the characteristics of the electron beam curing method, and when combined with the advantages of the adhesive or backside paint, ■High non-volatile content ( (approximately 100%) and can reduce pollution because oven exhaust gas is eliminated or can be reduced; ■ High-speed production possible (40 m/min or more); and Excellent quality.

The adhesive composition that is a component of the present invention is particularly suitable for use in laminating vinyl chloride films.

Manufacturing examples, examples, comparative examples, etc. of adhesives will be described below.

Production Example of Adhesive Composition Production Example 1 550 parts of polycaprolactone with an average molecular weight of 550 and 383 parts of tolylene diisocyanate were added to a four-loaf flask and kept at 80°C for 1 hour while stirring, and then the temperature was lowered to 70°C.
Lower to 0℃. Add to this 0.5 part of hydroquinone and 2
- Add 187 parts of mercaptoethanol, stir while blowing nitrogen gas, and raise the temperature to 80°C.
After holding the mixture for a certain period of time and confirming by a conventional method that almost no free isocyanate groups remained, the mixture was cooled to obtain a reaction product having free mercapto groups.

Then, 50 parts of the reaction product and tricyclo[5,,2
.

Production Example 2 400 parts of Adeka G400 (an adduct of glycerin and propylene oxide with a molecular weight of 400 manufactured by Asahi Denka Co., Ltd.) and 666 parts of isophorone diisocyanate were placed in four Lof flasks.
100°C and kept at 100°C for 2 hours with stirring, then lowered the temperature to 70°C. 0.7 parts of hydroquinone and 234 parts of 2-mercaptoethanol were added to this, and the temperature was raised to 100°C by stirring while blowing nitrogen gas and maintained for 5 hours, until almost no free isocyanate groups remained. After confirming by standard methods that the
This was cooled to obtain a reaction product having a free mercapto group.

Then, 60 parts of the reaction product and tricyclo[5,2,
An electron beam curable adhesive composition was obtained by uniformly mixing 30 parts of 1,0261 DEG dimethadol diacrylate and 10 parts of 1,6-hexanediol diacrylate.

Production Example 3 60 parts of the reaction product having a free mercapto group from Production Example 1, tricyclo[5,2,1,O! , 7] 30 parts of dimethatol diacrylate, 1,6 hex 4. 10 parts of f-rediol diacrylate and 5 parts of 0-mercaptobenzoic acid were uniformly mixed to obtain an electron beam curable adhesive composition.

Production Example 4 In Production Example 1, Trisifu o [5,2,1°026
] 1.6-50 parts of dimethatol diacrylate
An electron beam curable adhesive composition was obtained in the same manner except that 50 parts of hexanediol diacrylate was used.

Production Example 5 Contains an unsaturated group in the same manner as in Production Example 1, using 232 parts of 2-hydroxyethyl acrylate instead of 87 parts of 2-mercaptoethanol and blowing air instead of nitrogen gas. A reaction product was obtained. Then, 50 parts of this reaction product and tricyclo[5.2.1.02z
6] 50 parts of decarbonized dimethator diacrylate was uniformly mixed to obtain an electron beam curable adhesive composition.

Production Example 6 Tricyclo[5.2.1.0"t"]decane dimetatool diacrylate was used as an electron beam curable adhesive composition.

Manufacturing example 7 In Production Example 1, tricyclo[5.2.1.

An electron beam curable adhesive composition was prepared in the same manner except that 50 parts of tricyclo[5.2.1.0"]decane dimethanol dimethacrylate was used in place of 50 parts of decane dimethacrylate. I got it.

Examples and other examples using these adhesives will be described below.

[Example] Example 1 A bar coater was used to apply 6μ of the adhesive composition of Production Example 1 onto the surface of a hot-dip galvanized steel sheet having a thickness of 0.8111 il and treated with Bonderite #3920 (manufactured by Nihon Parkerizing Co., Ltd.). did. Next, add a thickness of 200 mm on top of this.
Roll pressing force of μ semi-rigid vinyl chloride film 10kg
/c1, and an acceleration voltage of 300 KV and an electron beam current of 5011 was applied through the film layer using a scanning electron beam accelerator.
The adhesive layer was cured by irradiating with 41 yl rad at 1A to obtain a film-bonded metal plate.

The obtained film-bonded metal plate was subjected to various performance tests, and the results are shown in Table 1 below.

Examples 2 to 8 and Comparative Examples 1 to 3 Film-bonded metal plates were obtained in the same manner as in Example 1 under the conditions shown in Table 1. The performance test results of this product are shown in Table 1 below.

In addition, these test methods are as follows.

[Test method] (1) 180° peeling: According to JIS K-6744.

(2) Erichsen test: according to JIS K-6744.

Evaluation 54321 Forced peeling ←---→ Natural peeling not possible (3) Solvent resistance: Soaked in air temperature for 5 hours with the ends exposed, taken out, tumbled, visually observed, and rated 1ii.

(4) Heat resistance: After the Erichsen test according to JIS K-6744, the test piece was left in a hot air oven at 150°C for 1 hour, and then taken out to room temperature and allowed to cool. Changes in the processed portion of this test piece are visually observed and evaluated.

(5) Adhesion: Insert a slit and perform a peeling test with cellophane tape.

Claims (1)

[Scope of Claims] (a) A reaction product having two or more free mercapto groups in one molecule, which is obtained by adding a mercapto group-containing alcohol to a polyisocyanate compound having two or more isocyanate groups in one molecule. and (b) Tricyclodecane dialcohol represented by the following general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ In the formula, R_1 represents an alkylene group of C_1 to _1_2, and R_2 and R_3 each represent H or CH_3. Contains a (meth)acrylic acid ester compound as an essential component, and optionally further contains (c) an ethylenically unsaturated group-containing compound (however, the above-mentioned (
b) (excluding component (a)) and (d) a metal plate and a plastic film via an adhesive containing a compound having one or more mercapto groups in one molecule (excluding component (a)). 1. A method for producing a film-bonded metal plate, which comprises curing the adhesive by irradiating the adhesive with an electron beam through the film layer.