JPH0699132A - Formation of film on metal foil - Google Patents

Abstract

PURPOSE:To form a uniform film so as not to generate coating irregularity or repellence by coating the surface of a metal foil with a specific resin and laminating a specific film on the coated metal foil or applying a resin to the film to laminate the coated film to the metal foil and subsequently curing the resin. CONSTITUTION:In forming a film on a metal foil, a resin with surface tension of 20dyn/cm or more and containing no solvent or a small amt. of a solvent is applied to the surface of the metal foil and a resin is directly applied to a plastic film with critical surface tension of 60dyn/cm or less and this resin coated film is laminated to the surface of the metal foil and, thereafter, the resin is cured. By this method, a resin inferior in the wettability with the surface of a metal foil because of high surface tension can be applied to the surface of the metal foil as a uniform film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a coating film evenly on a metal foil surface so as to prevent uneven coating and repelling of a resin having a high surface tension and poor wettability with the metal foil surface. Regarding the method.

[0002]

2. Description of the Related Art A coating method such as double coating or high-speed coating is applied to a resin having a high surface tension and poor wettability with the surface of a metal foil. The improvement of the wettability has been achieved by the addition of. In addition, degreasing and oxidation treatment of metal foil have been performed conventionally, but there is no fundamental or unified measure. In general, foreign matter mixed type coating failure can be prevented by improving the coating environment. Alternatively, even if there is no foreign matter that becomes the core of repellency, when a substance having a relatively large surface tension such as machine oil is mixed, the amount of the mixed substance is reduced as much as possible and the viscosity of the resin is adjusted.

[0003]

However, double-coating and high-speed coating cannot eliminate the repellency of the resin on the metal foil surface. Further, there is a problem that the viscosity of the resin is increased and the addition of the flow control agent causes the deterioration of the composition. The cost increase and the deterioration of the material cannot be avoided by the method such as the oxidation treatment of the metal foil. Although it is possible to reduce the occurrence probability of foreign matter-mixed poor coating, it is difficult to solve the problem fundamentally. The present invention has been made in view of such a point, a resin having poor surface wettability due to large surface tension, a method for uniformly forming a coating film so that uneven coating and repellency do not occur. It is intended to be provided.

[0004]

According to the present invention, such an object is to apply a solventless resin or a resin containing a small amount of a solvent to the surface of a metal foil, and then immediately bond a plastic film, or This can be achieved by directly coating the plastic film with the resin, attaching the resin-coated film to the surface of the metal foil, and then curing the resin. The present invention will be described in detail below. The resin used in the present invention, which is solvent-free or contains a small amount of solvent, is a polyol modified product, 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 resin. All natural and synthetic resins such as sulfone, polyamide, acetal, various elastomers, polyurethane,
It is a liquid resin in which the weight fraction of the non-volatile components is 90% or more and the surface tension measured by a surface tensiometer is 20 dyn / cm or more at 25 ° C., but the wettability is particularly poor 35 dyn.
Greatly effective for resins having a thickness of / cm or more. If necessary, the resin used in the present invention may be mixed with additives such as a photoinitiator, a sensitizer, a diluent, a plasticity, an antioxidant, a filler and a swelling agent. A small amount of solvent may be added to reduce the viscosity. The present coating method has a great effect on metal foil, especially copper foil, but can also be applied to plastic (film), metal (foil), wood, paper, glass, ceramic 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, and polyethylene, vinyl chloride, vinylidene chloride, polypropylene, polybutene, polystyrene, ABS, acryl, polyvinyl acetate, polyvinyl alcohol are used. , Vinyl butyral, polycarbonate, polyacetal, chlorinated polyether, polyvinylcarbazole, polyamide, fluorine, cellulose derivative, PPO,
Films of polysulfone, polyimide, Teflon, triacetyl cellulose, etc. can be used. There are no particular restrictions on the method of applying the resin on the metal foil,
Knife coating and kiss coating are suitable for producing a thin coating film. Immediately thereafter, the plastic film is laminated so that air bubbles do not enter. The composition laminated as described above is cured by thermosetting or by irradiating with radiation from a plastic film or a metal foil depending on the type of resin. As the radiation, α, β rays, γ rays, neutron rays, active energy rays such as X rays, accelerated electron rays and ultraviolet rays can be used.

[0005]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Examples 1, 2, 3 Three types of polyethylene glycol diacrylates having a weight average molecular weight of 200, 400, 600 (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name A-200 (surface tension 40 dyn / c
m viscosity 18 cps), -400 (same 41 dyn / cm,
35 cps), -600 (42 dyn / cm, 70 c)
Ps) is applied to an electrolytic copper foil having a thickness of 18 microns (manufactured by Nippon Denki Co., Ltd., trade name NDGE-18R) to give a coating thickness of 1
Coated so that the thickness is 0 micron, and the thickness is 60
Micron polyethylene film (manufactured by Hitachi Chemical Co., Ltd.,
It was laminated with a product name CA-60). These three types of components were irradiated with an electron beam with an electron beam irradiation device having an accelerating voltage of 175 KV so that the irradiation dose was 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 repellency.

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

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

Comparative Examples 1, 2, and 3 The same three kinds of oligomers used in Examples 1 to 3 were coated on an electrolytic copper foil in the same manner, and an oxygen concentration of 100 ppm or less and an irradiation dose of 10 ppm were obtained without laminating a polyethylene film. 10 Mr
Irradiation with an electron beam was performed so as to be ad, and uneven coating and repellency were evaluated in the same manner as in Examples 1 to 3. The evaluation results are summarized in Table 1.

[0009]

[Table 1]

[0010]

As is clear from the results shown in Table 1, according to the present invention, even a resin having a large surface tension and having poor wettability on the surface of the metal foil can be applied uniformly so as to prevent uneven coating and repelling. It is now possible to create a unique coating.

Claims (6)

[Claims] 1. A solvent-free resin having a surface tension of 20 dyn / cm or more or a resin containing a small amount of a solvent is applied to the surface of a metal foil, and a critical surface tension of 60 dyn / cm is immediately applied thereon.
The following plastic film is attached, or after the resin is directly applied to the plastic film, the resin-coated film is attached to the surface of the metal foil,
A method for forming a metal foil coating film, which comprises curing the resin thereafter. 2. The method for forming a metal foil coating film according to claim 1, wherein the metal foil is a copper foil. 3. A plastic film for bonding is polyethylene, polypropylene, polyimide, PE
The method for forming a coating film on a metal foil according to claim 1, which is T, Teflon or triacetyl cellulose. 4. The method for forming a metal foil coating film according to claim 1, wherein the viscosity of the resin containing no solvent or containing a small amount of solvent is 1 to 10,000 cps at 25 ° C. 5. The resin composition containing no solvent or a small amount of solvent is a resin composition containing a polyethylene glycol modified product or a polypropylene glycol modified product having a degree of polymerization of 5 or more as a main component. The method for forming a coating film on a metal foil according to any one of claims. 6. The method for forming a coating film of a metal foil according to claim 1, wherein the resin is cured by irradiating the plastic film or the metal foil with radiation.