JPH0218546A - Photographic roll film - Google Patents

Abstract

PURPOSE:To prevent a loading defect at the time of loading of a film into a camera or the rolling defect and loosening of winding in the camera by specifying the thickness, tensile strength in the transverse direction, etc., of the light shielding paper and sealing paper to be wound together with a photographic film on a spool. CONSTITUTION:A narrow part 7 at the front end of the light shielding paper 3 and a tapered part 8 thereof are partly folded at a folding line 6 and the sealing paper 4 for preventing loosening is stuck thereto. Tearing of the sealing paper having a width (b) by holding the turn back part (a) is generally practiced in order to unseal the film at the time of loading of the film to the camera and, therefore, the tensile strength in the transverse direction of the light shielding paper is required to be made higher than the tensile strength in the transverse direction of the sealing paper; however, the light shielding paper loses resilience if the thickness thereof is increased. The rolling defect and the loosening of the winding are then resulted. The overall thickness of the light shielding paper is, therefore, confined to <=95mum and the tear strength thereof to <=2.0kg/cm<2>; further, the tensile strength in the transverse direction thereof is confined to <=3.5kg/cm<2>. The overall thickness of the sealing paper is confined to <=80mum, and the tensile strength in the transverse direction thereof to <=2.5kg/cm<2>. Further, the width size thereof is confined to <=20mm. The purpose is thus attained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a roll film that is rolled together with light-shielding paper and pasted with a seal to prevent it from unraveling, and more particularly relates to a roll film that is rolled with light-shielding paper and pasted with a seal to prevent it from unraveling. This invention relates to a packaging material for roll film that prevents loading defects, transport defects within a camera, and loosening of winding.

[Background of the invention]

As shown in FIG. 1, so-called Brownie type roll films such as 120 size and 220 size have a light-shielding structure that uses light-shielding paper to prevent the film from being exposed to external light. Conventionally, this light-shielding paper has been made of black paper containing carbon. However, as the sensitivity of films has increased in recent years, the light-shielding properties and emulsion resistance of light-shielding papers are required to be even higher than before. In addition, the 220-size long type of Brownie film is one in which light-shielding paper called a leader and a trailer are attached to the leading and trailing ends of the film, respectively, and wound around a spool. A higher light-shielding property is required for the light-shielding paper compared to the 120 size, in which the light-shielding paper is always overlapped and rolled up.

To this end, a method has been adopted in which a backing layer is provided on the back side of the light-shielding paper to prevent the occurrence of pinholes and fluctuations in the width of the paper.

As described above, the main purpose of light-shielding paper is to have light-shielding properties, but it is also important that it be difficult to handle.

First, after setting the roll film in the camera, it is necessary that the unwinding torque is light, or that it is difficult to wind the film in the wrong direction.

To achieve this, the light-shielding paper must be flexible, and it has been said that the easiest and most effective way to impart that flexibility is to reduce the thickness of the light-shielding paper. In addition, by thinning the light-shielding paper, the diameter of the roll film becomes smaller, which increases the tolerance for loose or improper winding, and from a cost perspective, material costs are expected to decrease, improving flexibility and improving flexibility. There will be more points.

[Problem to be solved by the invention]

FIG. 1 is a perspective view of the Brownie film after it has been installed.

A part of the narrow part 7 and the tapered part 8 at the tip of the diagonal paper or the fold line 6
It is folded in, rolled up, and a seal 4 is pasted to prevent it from unraveling.

This paper seal is coated with adhesive 5 on both ends as shown in FIG. This adhesive is usually a real-melt adhesive based on thermoplastic resin, and after heat-welding one end of the sealing paper to the tip of the light-shielding paper, the sealing paper is wrapped once around in a band shape, and the other end is is thermally welded to the surface of the paper seal to prevent the light-shielding paper from unraveling.

When the light-shielding paper 3 and the film (not shown) are wound onto the spool 1 and the end 7 of the light-shielding paper is in the state shown in FIG. 3, it is folded back at the dotted line 6 as shown in FIG. Once the paper has been removed, a seal will be pasted on it, resulting in the state shown in Figure 1.

To load film into the camera, tear the envelope of the film that has been inserted as shown in Figure 1, return it to the state shown in Figure 4, set the film shaft on the supply side of the camera, and then
As shown in FIG. 6, the end 7 of the light-shielding paper is inserted into the slit opening 11 made in the body 10 of an empty spool 9 of the same size as the sprue 1 of the shaft part set on the winding side of the camera.
Insert it, fold it back, send it one screen at a time, take a picture, and then wind it up.

This folding is necessary in order to make it easier for the user to cut the envelope and to prevent it from coming off when the envelope is inserted into the slit 3011 of the spool 9.

Now, the method of opening this roll film varies depending on the user, and in many cases, the folded part of the light-shielding paper shown as a in FIG. 1 is used to tear the band of the sealing paper shown by the width b. However, if the light-shielding paper is torn without tearing the seal, it may be difficult to insert the leading edge of the light-shielding paper into the spool 9 of the camera before taking pictures, or it may be inserted misaligned, resulting in various malfunctions. will occur.

Therefore, when opening the package, the light-shielding paper needs to have a certain degree of strength. However, in order to maintain this strength, it is naturally advantageous to make the light-shielding paper thick rather than thin. This contradicts the thinning of the film for imparting flexibility, and if left as it is, there will be a problem in improving the overall quality of photographic roll films.

In other words, even if the camera is loaded in such a state, it may not be transported correctly and may jam during the process, resulting in poor winding, or may be pulled or wound loosely, resulting in light leakage from the spool flange. This results in poor light shielding for the film. To solve this problem, it is necessary to consider not only the thickness of the light-shielding paper but also the physical properties of the sealing paper.

The object of the present invention is to solve these problems.

[Means to solve the problem]

The purpose of this is to ensure that the total thickness of the light-shielding paper that constitutes the photographic roll film and that is wound around the spool along with the photographic film is 95 μm or less, and that its bursting strength is 2.0 kg/cm.
m2 or less, and the tensile strength in the width direction is 3゜5kg/cm
The total thickness of the sealing paper that is attached to the outer periphery of the light-shielding paper wound on the roll film to prevent it from unwinding is 80 mm or less, and
This is achieved by a photographic roll film having a tensile strength of 2.5 kg/cm or less in the width direction, and a width of 20 mm or less.

That is, the total thickness of the light-shielding paper is 95 μm or less, preferably 7 μm or less.
0 to 95 μm, most preferably 85 to 90 μm,
Tensile strength in the width direction is 3.5 kg/cm or less, preferably 2
．． 5-3.5kg/cm, burst strength 2.0kg/cm
2 or less, the total thickness of the envelope is 80/1 m or less, preferably 50 to 75 μm, and the tensile strength in the width direction is 2.
5 kg/cm or less, preferably 15 to 22 kg/cm, and the width of the seal is 20 mm or less, preferably 15 to 22 kg/cm.
2Q mm.

〔Example〕

The present invention will be explained in more detail below.

The base paper used for the light-shielding paper used in the present invention may be ordinary natural pulp paper, synthetic resin, or synthetic paper using synthetic resin. Natural pulp paper based on pulp is advantageously used. These papers may be made by any of the generally known round net paper making method and fourdrinier paper making method. These base papers mainly composed of natural pulp can contain various polymer compound additives. For example, dry paper strength enhancers include cationized starch, notothionized polyacrylamide, ionized polyacrylamide, carboquine-modified polyvinyl alcohol, gelatin, etc., and sizing agents include fatty acid salts, rosin derivatives, dialkyl ketine timer emulsions, petroleum resins. emulsion,
Ammonium salt of styrene maleic anhydride copolymer alkyl ester, pigments such as clay kaolin, calcium carbonate, barium sulfate, titanium oxide, etc. Wet paper strength enhancers such as melamine resin, urea resin, epoxidized polyamide resin, fixer As agents, polyvalent metal salts such as aluminum sulfate and aluminum chloride, cationically modified polymers such as cationized starch, as pH regulators such as caustic soda, soda carbonate, and hydrochloric acid; as inorganic electrolytes, such as common salt and mirabilite; In addition, dyes, optical brighteners, latex,
Carbon black and the like can be contained in an appropriate combination.

In order to provide physical properties that cannot be obtained with paper alone, resin layers may be laminated.

In addition, examples of thermoplastic resins (hereinafter simply referred to as resins) for processing the back side of the base paper include Japanese Patent Publication No. 5149205, Japanese Patent Application Publication No. 48-22020, Japanese Patent Publication No. 50-67644,
No. 55-140835, No. 58-17434, No. 5
No. 8-186744, No. 59-68238, No. 60-
Low density, medium density, high density, linear low density polyolefins such as polyethylene and polypropylene described in No. 35728 etc., polyahinyls such as ethylene vinyl acetate,
Acrylics such as ethylene ethyl acrylate and ethylene methyl acrylate, rubbers such as styrene-butadiene, single substances such as ionomers, graft polymer polyamides,
Examples include single substances such as polyesters such as polyethylene-terephthalate, blends of two or more types, copolymers, and the like. The above resin may be provided as two or more layers.

When laminating these resins on base paper, an anchoring agent may be used to further improve adhesiveness, and examples of the anchoring agent include organic titanium-based, isocyanate-based, polyethyleneimine-based, and polybutadiene-based.

Means for providing these resins on a paper support can be roughly divided into two methods.

One method is to apply a liquid obtained by dispersing or dissolving a resin in an organic solvent or water onto paper and drying it.

Coating methods include, but are not limited to, a reverse swirl method, a blade method, an air knife method, a rod method, a curtain method, an extrusion method, or a gravure printing method.

The dry thickness of the resin layer obtained by these methods is suitably 1 to 20 μm.

Another method is to heat-melt a resin and apply it to a paper support. The most common coating method is extrusion, but other coating methods may also be used.

The dry film thickness of the resin layer obtained by this method is 5 to 5
0 μm is appropriate.

The most advantageous method in the present invention is the former dispersion or solution coating method. Since this method does not require much consideration of the softening point of the resin to be coated, a wide range of softening points can be selected without being limited, and even resins with high softening points can be coated. However, in the case of the latter hot melt coating, the resin softening point is limited and the melting temperature must be increased for resins with relatively high softening points.
A special coating process is also required. In addition, when considering the adhesion between paper and resin, the former method is generally superior to the latter method.

Furthermore, the effects disclosed in Jitsuma No. 186708/1983 can be easily combined to provide a more comprehensive improvement.

The carbon black used in the resin layer, waste paper, or other layers in the present invention may be produced by any of the furnace, channel, and thermal methods.

In addition, as actual products, for example, Mitsubishi Kasei carbon black #5, #20, #33, #401 #44, #
45, #52, #900, #1000, #2200
B.

Examples include, but are not limited to, #2350#, #2400BXMA8, MAloo, etc.

Is the surface of the light-shielding paper printed with functionally necessary characters or symbols or to increase the product value?The ink used for these printing is selected and generally used as one that is harmless to photosensitive materials. It can be selected from offset printing inks, gravure printing inks or UV inks.

Typical synthetic resins used in these inks are vinyl acetate, nitrified cotton, polyester, polyamide urethane, polyacrylic, and rosin-modified maleic acid.

Ethylene acetate, vinyl ether, urethane vinyl acetate.

Salt and vinegar urethane resin, modified alkyd resin modified phenol resin, alkali-soluble resin (rosin modified maleic acid resin, styrene maleic acid resin, styrene acrylic acid resin, acrylic ester acrylic acid resin, methacrylic ester acrylic acid resin), hydrosol Mold resin (styrene maleic acid resin, styrene acrylic acid resin, σ-methylstyrene acrylic acid resin, acrylic ester acrylic acid resin, methacrylic ester acrylic acid resin), emulsion type resin (styrene resin, styrene acrylic ester resin, acrylic (acrylic acid ester copolymer resin, methacrylic acid ester copolymer resin), and polymers with acrylic unsaturated groups are generally used as resins for UV inks. Typical examples include polyester/acrylic acid ester, Polyester/urethane resin/acrylic ester, epoxy [111/acrylic ester, pentaerythritol triacrylate, trimethylolpropane triacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, hydroxyethyl methacrylate are listed. It will be done.

In addition, commonly known colorants are used in combination with these inks. The coloring agent used is
Various pigments and azo pigments (Azo Lake; Carmiso 6B, Red 2B, Insoluble Azo; Monoazo Yellow (PY-1, -3), Disazo Yellow (P
Y-12, -13, -14, -17, -83), pyrazolo orange (PO-B-34) palcan orange (po
-16).

Condensed azo system; chromophthal yellow (py-93, -95
) Talomophthal red (PR-144, -166), polycyclic pigment (phthalocyanine type; copper phthalocyanine blue (PB-15゜15-1.-15-3), copper phthalocyanine green (PG7), dioxazine type; Dioxazine violet (PV-23), isoindolinone series; isoindolino 7 yellow (PY 109.11
0), thren series; perylene.

Perinone, flavanthrone, thioindigo, lake pigments (malachite green, rhodamine B, rhodamine G,
Victoria Blue B) Also inorganic pigment (oxide).

Titanium dioxide, red iron, sulfate; precipitated barium sulfate, carbonate; precipitated calcium carbonate, silicate: hydrated silicate, anhydrous silicate, metal powder; aluminum powder.

Examples include bronze powder, zinc powder, carbon black, yellow lead, and navy blue. Further, these pigments may be added to the above-mentioned resin layer paper layer etc. as a light-shielding substance.

In addition, oil-soluble dyes, dispersible dyes, etc. are also used.

Other raw materials that make up the ink include various solvents, dispersants, wetting agents, antifoaming agents, and leveling agents as needed.

Additives such as thickeners, stabilizers, crosslinkers, waxes, dryers, etc. are used.

In addition, varnish may be applied to the surface for glossiness and protection of surface printing areas. The types of varnish used at this time include acrylic resin, cellulose resin such as cellulose acetate, urethane resin, epoxy resin, polyester resin, ionomer resin, EEA resin, various polyethylene resins (low density,
Appropriate resins such as high-density polyethylene, linear low-density polyethylene, polypropylene resin, etc. can be used. Also, wax etc. can be used.

Further, the base paper of the envelope used in the present invention is the same as that used for the light-shielding paper, and the printing ink and varnish are also the same.

In addition, thermoplastic adhesives used for paper seals include polyolefin adhesives such as polyethylene and polypropylene, polyhinyl adhesives such as hinyl chloride, acrylic adhesives such as ethylene ethyl acrylate, polyester adhesives, polyamide adhesives, S
Examples include, but are not limited to, rubber-based resins such as BR, cellulose-based resins, ionomer resins, etc. alone, blends of two or more thereof, and copolymers such as EVA.

Experimental Example: A professional ISO roll film was made using the light-shielding paper and sealing paper under the above conditions, and this roll film was loaded into a camera and photographed to detect tears in the light-shielding paper, light leakage, and the like. I checked the condition of the roll.

〔Effect of the invention〕

The evaluation items are as follows.

Tears in the light-shielding paper: Check visually to see if there are any tears in the service section.Light leakage: Photographs were taken using a Mamya RB67 camera, and then exposed to 10,000 lux light for 3 minutes to check for fogging during development.

Check the hardness of the 1st roll with your hands, and the harder the better.

Each sample in the experimental example of the present invention was 100 pieces, and the evaluation criteria were as follows.

0.0/100 △:l/100~5/100 X: 5/100 or more And the evaluation results were like a robe.

As described above, both samples 1 and 2.3 of the roll film produced under the conditions of the present invention obtained good results. However, it can be seen that those that do not meet the conditions of the present invention have defects such as tearing, light leakage, and poor winding.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the Brownie film that has been placed inside. Figure 2 is a top view of the envelope. FIG. 3 is a plan view of the brownie film inside the interior, leaving only the edges of the light-shielding paper. FIG. 4 is a side view of FIG. 3. FIG. 5 is a plan view of the take-up spool at the time of photographing. FIG. 6 is a side sectional view of the state in which the light-shielding paper end is inserted into the slit of the take-up spool. 1.9... Spool flange 3... Light-shielding paper 4... Sealing paper 5... Thermoplastic resin adhesive 6... Folding line 7... End pinching part 8... Taper part

Claims (1)

[Claims] The total thickness of the light-shielding paper that constitutes photographic roll film and is wound around a spool together with photographic film is 95 mm.
μm or less, the burst strength is 2.0 kg/cm^2 or less, and the tensile strength in the width direction is 3.5 kg/cm or less, and it is attached to the outer periphery of the light-shielding paper wound on the roll film. The total thickness of the seal that prevents unraveling is 80 μm or less,
A photographic roll film having a tensile strength in the width direction of 2.5 kg/cm or less and a width dimension of 20 mm or less.