DE1036050B - Light-sealing protective strip for roll film - Google Patents

Description

GERMAN

The photographic film wound on camera daylight reels is known to be covered by a light-sealing, the film enclosing the paper strip protected. Bim is such a paper strip mostly made of a two-layer paper of not small thickness and takes a noticeable part of the Aufwiekelraumes in claim. Next is the relative The stiffness of such paper causes the wound material to tear when the closure strip is torn always tends to unravel on its own, causing exposure and fogging Can have a consequence.

Since the spectral sensitivity of the film is usually determined by conventional coloring of the said light-sealing or duplex paper, one is forced to use three or more to manufacture or store different colored papers.

There is also the printing color of the characters or figures on the back of the paper strip have a detrimental effect on the immediately adjacent photographic emulsion exercises, after printing an additional one, from a transparent and photographic one inert substance built up protective layer are applied.

In the roll film of the French patent specification 1 103 446, a particularly thin paper foil is used as the protective paper, but the protective strip which is light-sealing on this foil is used
for roll film

Applicant:

Gevaert Photo-Products NV,
Mortsel, Antwerp (Belgium)

Representative: Dr. W. Müller-Bore, patent attorney,
Braunschweig, Am Bürgerpark 8

Claimed priority:
Belgium from January 27, 1956

Jean Louis Jules de Canniere
and Jan Baptist Verlinden, Mortsel, Antwerp

(Belgium),
have been named as inventors

Sealing is done in combination with a second light-blocking or opaque film made by any known method such as self-adhesive, thermoplastic adhesive

on the

Plastic coated in liquid form is with 30 or intermediate arrangement of an adhesive film, mixed with a light-sealing pigment, attached to transparent film, so that in this case too the characters refer to the color

layer must be printed, which in turn must be covered with a protective layer increasing the thickness again is.

Finally, it was suggested that the edge veil, which extends through the bobbin flange up to the Light penetrating the edges of the roll film is prevented by using a protective strip This transparent plastic film can either consist of a simple or a composite Foil consist of materials whose various properties are printing and / or gluing facilitate.

The essential difference between the inventive and known protective strips including those with simple paper backing

whose width is greater than the inner distance 40 in that on the known 65 to 75 μ thick of the flanges and dös sen edges a transparent thin cover is sharpened by sanding strips of protective paper that they are folded against the inner layer, such as varnish, is placed on a layer of paint, lie against the side of the flange and block the light.
However, these thin edges are fibrous and injurious

bar so that they tear easily.

The invention aims to put together a light-sealing protective strip which in comparison is thinner and more flexible with the previously usual, its production is also easier and

is cheaper to do and which increases the aforementioned 50 protective strips.

This varnishing is done using solutions; this is where the solvents used go mostly lost.

According to the invention, the transparent layer consists of a film about 30 μ thick, and the paper itself is about 60μ thick, so that the plastic serves as a carrier and strength and flexibility of the

Does not have any disadvantages.

A main feature of the invention is that the emulsion layer of the film with a thin transparent plastic film is sealed. This Because the plastic film on the paper strip sticks thermoplastically, no drying is required and any loss of solvents is excluded.

& »580/504

Another feature of the invention is that the above-mentioned conventional paint as well as dtie Signs and numbers in print or in any other way on the adhesive side of either of the above-mentioned transparent ones Plastic film or the opaque film are applied. These characters and / or Colors are clearly legible or visible through the protective film and, as a result of their coverage, cause no chemical emulsion haze.

The light-sealing film can, for example, be a black or other colored pigment paper or be an opaque plastic.

The other film is then a very thin colorless, transparent plastic film, for example made of polyethylene, Cellophane or cellulose acetate. This film can also consist of two or more glued together Be composed of leaves, e.g. B. from a polyethylene and a cellophane sheet.

Preferably the total thickness of the complete strip according to the invention is at most 0.1 mm.

Before gluing, a layer of color is applied to the adhesive side of one of the two foils, in which the digits or characters may be negatively omitted. It is of course also possible to use a colored to use opaque paper and only with colored markings that stand out well To print tones so that the characters are easy to read through the camera window.

Depending on the type of film used, the gluing can either be done by means of an adhesive, whose solvent can escape along one of the films, or it can after a thermoplastic Procedure, e.g. B. the electrical high-frequency bonding can be carried out.

According to a variant of the invention, a thermoplastic film can be produced by pressing, which immediately after leaving the slot is rolled onto an opaque film or otherwise is applied.

The known opaque double-layer paper is thus either two glued together according to the invention thin plastic films or a single plastic film glued to paper Intermediate coloring or overprint replaced. This * 5 measure offers various advantages.

The light-sealing protective strip according to the invention is flexible and a maximum of only 0.1 mm thick. That automatic winding of the roll film is thereby reduced to a great extent. Because you get this strip can be colored as desired, there is no need to store differently colored, opaque papers. because there is no longer any need for a protective backing layer to prevent the emulsion from being affected by printing inks also a procedural step in omission, so that the new protective strip, compared to the known, all in all it is cheaper to manufacture.

The prior sharpening or grinding of the protective strip edges to prevent the edge haze it becomes superfluous if necessary.

Two strips of the same width can be glued together in such a way that their edges do not coincide, and thus has a slightly wider combination compared to normal duplex tape, the edges of which are only a film thick and bend slightly against the reel flanges and the same as well as the sanded edges.

According to another embodiment of the invention, the transparent plastic film is on a something wider, opaque protective film glued, so that also edges with the thickness of a single film arise, which ensure the desired sealing of the wound film against edge haze.

These two embodiments according to the invention make it unnecessary to pass through the edges of the protective strips To make sharpening or the like more flexible, as is necessary with the known duplex tapes.

Claims (7)

Patent claims 1. Light-sealing protective strip for roll film, characterized in that it consists of at least is composed of two thin films glued together, at least one of which consists of opaque material and at least one other a transparent plastic film whose thickness is about half as great as that of the first-mentioned film, with a pigment layer and / or printed characters between these foils or on one or both inner sides the same are attached. 2. Protective strip according to claim 1, characterized in that one of the films is black or other colored, opaque pigment paper, while the side touching the film emulsion Foil made from a flexible, transparent and colored or non-colored plastic consists. 3. Protective strip according to claims 1 and 2, characterized in that the two films with Are connected to each other with the help of a special intermediate adhesive film. 4. Protective strip according to claims 1, 2 and 3, characterized in that its total thickness does not exceed 0.1 mm. 5. Protective strip for roll film according to one of the preceding claims, characterized in that that the adhesive side of one of the ol> narrow foils covered with a pigment or color layer in which the film marks and numbers have been left out. 6. Protective strip for roll film according to one of the preceding claims, characterized in that that one of the two elements of the protective strip consists of a transparent plastic film, which are produced by pressing and immediately afterwards applied to the opaque film, z. B. rolled on, has been. 7. protective strip for roll film according to any one of the preceding claims with attenuated highly elastic edges, characterized in that the edges of the paper carrier are free of one A layer of paint or a transparent film. Considered publications:
French Patent No. 1 103 446. @ 809 580/504 7.58