# US 4,393,091 A · Method of vacuum depositing a layer on a plastic film substrate

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- Number: US 4,393,091 A
- Document ID: US4393091A
- Status: Granted
- Kind: A
- Application number: 06/272,119
- Filed: 1981-06-10
- Granted: 1983-07-12
- Earliest claimed: 1980-06-10
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Koichi Shinohara; Takashi Fujita
- Web page: https://patentgrep.com/patent/US4393091A

## CPC

- C23C 14/20: on organic substrates
- C23C 14/562: {for coating elongated substrates}
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)

## Abstract

A method of vacuum depositing a layer on a plastic film in which the film is transported so as to pass along a metal surface moving with the film, which surface removes heat from the film, and vacuum depositing the vapor of an evaporant onto the surface of the plastic film while it is in contact with the metal surface. The film is in an electret state when it is located at the metal surface, whereby an electrostatic attractive force is produced between the film and the metal surface, thereby increasing the efficiency of heat conduction between the film and the metal.

## Claims

### Claim 1

A method of vacuum depositing a layer on a plastic film prior to winding the film comprising the steps of:
transporting the film along a metal surface which is movable with the film, said metal surface being grounded and which metal serves to control the temperature of the film in contact therewith by conducting heat away from said film;
rendering said film in an electret state with a surface potential higher than 150 V, prior to or at the same time as the film contacts the metal surface, whereby said film is electrostatically attracted to said metal surface, thereby increasing the efficiency of the heat conduction between the film and the metal surface;
depositing a material on the portion of said film which is opposite the portion in contact with said metal surface; and
neutralizing the surface potential of said film so as to render it into a non-electret state after said deposition step and prior to winding the film.

### Claim 2 (depends on 1)

A method as claimed in claim 1, in which said source material is heated and evaporated by an electron beam bombardment, the energy of said electron being high enough to cause an electron reflected from said source material to be implanted into the film to form a static charge to render the film into an electret state.

### Claim 3 (depends on 1)

A method as claimed in claim 1, in which said metal surface comprises the peripheral surface of a rotary can.

### Claim 4 (depends on 1)

A method as claimed in claim 1, in which said neutralizing is performed by exposing the surface of the film reverse to the deposited layer to a glow discharge.

### Claim 5 (depends on 1)

A method as claimed in claim 1, in which the surface roughness of said metal surface is smaller than 0.1.mu..