JP2906859B2 - Metal foil coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for forming a coating film evenly on a metal foil surface of a resin having a high surface tension and having poor wettability with the metal foil surface so that uneven coating and repelling do not occur. About the method.

[0002]

2. Description of the Related Art Coating methods such as two-coating and high-speed coating are used for resins having poor wettability with the metal foil surface due to high surface tension. The wettability has been improved by the addition of. In addition, degreasing and oxidation treatment of metal foil have been conventionally performed, but there is no fundamental and unified measure. In general, poor coating of a foreign matter mixed type can be prevented by improving the coating environment. Alternatively, even if there is no foreign substance which becomes a core of the stagnation, when a substance having a relatively large surface tension such as mechanical oil is mixed, the viscosity of the resin has been adjusted after reducing the mixed substances as much as possible.

[0003]

However, in recoating or high-speed coating, the repelling of the resin on the surface of the metal foil is not completely eliminated. In addition, increasing the viscosity of the resin or adding a flow control agent causes problems such as deterioration of the composition. In the method such as the oxidation treatment of the metal foil, the cost increase and the deterioration of the material were inevitable. Although the probability of occurrence of a foreign matter-incorporation type coating failure can be reduced, it is difficult to fundamentally solve the problem. The present invention has been made in view of the above points, and a method of uniformly forming a coating film on a resin having a large surface tension and poor coatability on a metal foil surface so that uneven coating and repelling does not occur. It will not be provided.

[0004]

According to the present invention, a resin containing no solvent or containing a small amount of a solvent is applied to the surface of a metal foil, and then a plastic film is immediately adhered thereto. This is achieved by directly applying the resin to the plastic film, bonding the resin-coated film to the surface of the metal foil, and then curing the resin. Hereinafter, the present invention will be described in detail. The resin used in the present invention, which contains no solvent or a small amount of solvent, is a modified polyol, an acrylic resin, a phenol resin, an epoxy resin, a melamine resin, a polyester, a polycarbonate, a polyvinyl chloride, a fluorine, a silicone resin, a poly Any natural or synthetic resin such as sulfone, polyamide, acetal, various elastomers, polyurethane, etc.
It is a liquid resin having a weight fraction of the non-volatile component of 90% or more and a surface tension measured by a surface tensiometer of 20 dyn / cm or more at 25 ° C., particularly 35 dyn having poor wettability.
/ Cm / cm or more is very effective. The resin used in the present invention may optionally contain additives such as a photoinitiator, a sensitizer, a diluent, plasticity, an antioxidant, a filler and a swelling agent. Further, a small amount of a solvent may be added to reduce the viscosity. This coating method has a great effect on metal foils, especially copper foils, but can also be applied to plastics (films), metals (foils), wood, paper, glass, ceramics and the like. The plastic film used in the present invention is not particularly limited as long as the critical surface tension is 60 dyn / cm or less. Polyethylene, vinyl chloride, vinylidene chloride, polypropylene, polybutene, polystyrene, ABS, acryl, polyvinyl acetate, polyvinyl alcohol , Vinyl butyral, polycarbonate, polyacetal, chlorinated polyether, polyvinyl carbazole, polyamide, fluorine, cellulose derivative, PPO,
Films such as polysulfone, polyimide, Teflon, and triacetyl cellulose can be used. There are no particular restrictions on the method of applying the resin on the metal foil,
It is suitable when knife coating and kiss coating produce a thin coating film. Immediately thereafter, the plastic film is laminated without bubbles. The components laminated as described above are cured by heat according to the type of the resin, or by irradiating radiation from a plastic film or a metal foil. As the radiation, active energy rays such as α-rays, β-rays, γ-rays, neutron rays, X-rays, accelerating electron beams, and ultraviolet rays can be used.

[0005]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Examples 1, 2, and 3 Three types of polyethylene glycol diacrylate having a weight average molecular weight of 200, 400, and 600 (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name A-200 (surface tension of 40 dyn / c)
m viscosity 18 cps), -400 (41 dyn / cm,
35 cps), -600 (42 dyn / cm, 70 c)
ps) on an electrolytic copper foil (manufactured by Nihon Denki Co., Ltd., trade name: NDGE-18R) having a thickness of 18 μm and a thickness of 1
Coating so that the thickness is 0 micron, and the thickness is 60
Micron polyethylene film (manufactured by Hitachi Chemical Co., Ltd.
Laminated under the trade name CA-60). These three types of constituents were irradiated with an electron beam by an electron beam irradiation device having an acceleration voltage of 175 KV so that the irradiation dose became 10 Mrad.
Thereafter, the polyethylene film was peeled off, and the surface of the cured resin film was visually observed to evaluate uneven coating and repelling.

Example 4 A-200, 400 and 600 were replaced with the acrylic polymer synthesized in the following polymer production example.
In the same manner as in Nos. 1 to 3, coating unevenness and repelling were evaluated. (Production Example of Polymer) 15 parts of 2-hydroxyethyl methacrylate, 9.5 parts of methyl acrylate, 0.5 part of acrylic acid, 70 parts of polyoxyethylene glycolic acid (ethylene addition mole number 9) 70 parts, β-mercaptopropionic acid After reacting 5 parts, 3 parts of 4,4′-azobis-4-cyanovaleric acid at 70 ° C. for 5 hours under N ₂ , 10 parts of glycidyl methacrylate, 0.01 part of hydroquinone,
0.05 parts of N, N′-dimethyldecylamine was added, and the mixture was reacted at a temperature of 85 ° C. for 5 hours to obtain a polymer having an unsaturated double bond at a terminal or a side chain. The surface tension of this is 44
dyn / cm and viscosity 670 cps.

Example 5 Epoxy acrylate (trade name: EPI-45, manufactured by Idemitsu Petrochemical Co., Ltd.) instead of A-200, 400, 600, etc.
R, surface tension 47 dyn / cm, viscosity 8300 cps)
Was evaluated in the same manner as in Examples 1 to 3 for uneven coating and repelling. Examples 6 and 7 Instead of the polyethylene film for lamination, using a polypropylene film (manufactured by Toray Industries, Inc., trade name: Trefan) and a polyimide film (manufactured by DuPont, trade name: Kapton), In the same way,
The repellency was evaluated.

Comparative Examples 1, 2, and 3 The three oligomers used in Examples 1 to 3 were coated on an electrolytic copper foil in the same manner, without laminating a polyethylene film. 10Mr
The sample was irradiated with an electron beam so as to obtain an ad, and evaluation of uneven coating and repelling was performed in the same manner as in Examples 1 to 3. The evaluation results are summarized in Table 1.

[0009]

[Table 1]

[0010]

As is evident from the results shown in Table 1, according to the present invention, even if the surface tension is large, even if the resin has a poor wettability on the surface of the metal foil, the uniformity and the repelling of the resin are prevented so as not to cause uneven coating and repelling. It is now possible to create a perfect coating.

Claims (6)

(57) [Claims] 1. A metal foil surface having a surface tension of 20 dyn / cm or more.
While applying a liquid resin that is, through the resin
Plastic film with critical surface tension of 60 dyn / cm or less
After laminating, harden the liquid resin,
Thereafter, the plastic film is peeled off . 2. A plastic film having a critical surface tension of not more than 60 dyn / cm is coated with a liquid resin having a surface tension of not less than 20 dyn / cm, and a metal foil is bonded through the resin. A method for forming a coating film on a metal foil, comprising curing a liquid resin and then peeling off the plastic film. 3. The method for forming a coating film on a metal foil according to claim 1, wherein the metal foil is a copper foil. 4. The plastic film is made of polyethylene, polypropylene, polyimide, PET, polytetra
The method for forming a coating film on a metal foil according to any one of claims 1 to 3, wherein the method is made of fluoroethylene or triacetyl cellulose. 5. The metal according to claim 1, wherein the liquid resin is a resin composition containing a radiation-curable polyethylene glycol modified product or a polypropylene glycol modified product having a polymerization degree of 5 or more as a main component. A method for forming a coating film on a foil. 6. The method for forming a coating film on a metal foil according to claim 1, wherein the resin is cured by irradiating radiation from a plastic film or a metal foil.