JPH0833619B2 - Bulk roll photosensitive material package - Google Patents

Description

TECHNICAL FIELD The present invention relates to a package in which a light-sensitive material in the form of a bulk roll is hermetically packaged using a cylindrical light-shielding multilayer coextrusion inflation film.

[Conventional technology]

Items such as bulk rolls that lose their quality value when exposed to light are packaged using a packaging bag that completely blocks light. The packaging bag used in this package is required to have sufficient physical strength according to the size and weight of the object to be packaged, that is, tensile strength, tear strength, impact punching strength, etc., in addition to the above-mentioned light-shielding property. Further, when the opening is sealed by heat sealing, heat sealing suitability is required.

In addition, antistatic property is also necessary to prevent electrostatic charge due to friction between the photosensitive material and the packaging bag.

Conventionally, as a laminated film used for a packaging bag of a light-sensitive material such as a bulk roll, a high-pressure branched low-density polyethylene (hereinafter referred to as LDPE) resin film layer and an aluminum foil layer to which a light-shielding substance is added. , A bleached kraft paper layer was sequentially laminated with an LDPE resin melt-extruded adhesive layer.

In addition, for bulky and expensive photosensitive material packages such as bulk rolls, bulk rolls are made by using a light-shielding sheet film laminated with a vacuum-deposited nylon film or polyester film of aluminum having a large Young's modulus and heat resistance. Was wrapped several times like a bamboo shoot and sealed at both ends with tape or a string, or the light-sensitive material was housed in a light-shielding bag made of several layers of black light-shielding fabric with a zipper.

[Problems to be Solved by the Invention]

However, in a package in which a light-shielding sheet film laminated with a vacuum-deposited nylon film or a polyester film of aluminum is wound several times, the light-shielding sheet film is expensive and is used in multiple layers, resulting in high price and light-shielding. It was difficult to produce a hermetically sealed package by one person, because not only the traces of pressing by the winding tip of the flexible sheet film, pressure fog and scratches were generated, but also the workability under a safelight was poor.

Further, in a package which is housed in a black shading cloth bag made of several layers with a zipper, the shading bag made of the black shading cloth is very expensive. If it is used as a light-shielding bag that can not be used for a long time, it is necessary to remove adhering substances and impure contaminants that have invaded the light-shielding bag each time it is used. The workability was poor and it was difficult for one person to manufacture the sealed package.

It was also considered to produce a package by producing a cylindrical film by the inflation film molding method, but with the conventional inflation light-shielding film, the physical strength, flexibility, workability, inflation film moldability, and cylinder of the inflation film are considered. It is possible to obtain a film that satisfies all the properties such as anti-blocking property, light-shielding property, antistatic property, smoothness, etc., which are indispensable properties for producing a film-like film and hermetically packaging a bulky and heavy bulk roll. Therefore, it could not be used for a package of a light-sensitive material which is heavy.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a package of bulk roll photosensitive material at low cost.

[Means for solving the problem]

The present invention has been made in order to achieve the above-mentioned object, and comprises an inner layer containing medium and high density polyethylene resin and L
-A solution is achieved by hermetically packaging using a cylindrical light-shielding multilayer coextrusion inflation film having an outer layer containing an LDPE resin.

That is, the present invention has a melt index of 0.3 g / 10 minutes or more, a density of 0.936 g / cm ³ or more polyethylene resin 0.5
To 70% by weight and 0.01 to 2.0% by weight of antioxidant as an inner layer and a linear low density polyethylene resin film layer as an outer layer, at least 1
Using a multi-layer coextrusion blown film containing 0.05 to 20% by weight of a light-shielding substance in layers or more, a bulk-rolled photosensitive material wound in a cylindrical shape is wrapped into a circular-cylindrical cylinder so that the inner layer is in contact with the photosensitive material. The present invention relates to a bulk roll photosensitive material package.

In the present invention, a cylindrical band-shaped photosensitive material is wrapped with a light-shielding multilayer coextrusion blown film.
The gap between the inflation film and the photosensitive material is not particularly limited, but from the standpoint of eliminating waste of materials and avoiding unnecessary damage of the encapsulated photosensitive material, it is preferable that the cylindrical photosensitive material is as narrow as possible. .

In addition, the light-shielding multilayer co-extrusion blown film has a polyolefin resin film layer as an inner layer and L-
The LDPE resin film layer is located on the outer layer.

The polyolefin resin-based film layer does not need to be composed only of a polyolefin resin, and is made of polyethylene having at least the density of 0.936 g / cm ³ (JISK 6760) or more (hereinafter P
If it contains 0.5 to 70% by weight of resin, polyethylene resin such as other L-LDPE resin and LDPE resin, ethylene-ethyl acrylate (hereinafter referred to as EEA) resin,
An ethylene / vinyl acetate copolymer (hereinafter referred to as EVA) resin or the like, which may be used in the outer layer described below, may be included.

This essential medium / high density PE resin occupies 0.5 to 70% by weight of the polyolefin resin film layer.

The PE resin in the polyolefin resin film layer is 0.
If it is less than 5% by weight, the blocking prevention of the multilayer coextrusion inflation light-shielding film will not be complete, and if it exceeds 70% by weight, the physical strength of the film will be reduced and the inner layers will be slippery, and wrinkles and streaks will occur frequently to cause multilayering. Co-extrusion inflation light-shielding film has a large loss and is difficult to put into practical use.

Among them, the high-density PE resin has a melt index (JISK
6760) (hereinafter referred to as MI) is 0.3g / 10 minutes or more, MI is
Density 0.5 g / 10 minutes or more is preferable ^{0.936g / cm 3 ~0.965g / cm 3} .

When the MI is less than 0.3 g / 10 minutes, the film formability is poor, and the molecules are easily oriented in a large direction in the machine direction, and it is difficult to obtain a film having a good balance of physical strength in the machine direction and in the machine direction. In addition, lump-shaped failures frequently occur and the photosensitive material is easily damaged.

If the density is less than 0.936 g / cm ³ , it is difficult to obtain a polyolefin resin film layer having a high Young's modulus and excellent antiblocking properties.

The ethylene copolymer resin used together with the medium and high density PE resin is preferably used in an amount of 20% by weight or more from the viewpoints of heat seal suitability, physical strength, film moldability and the like.

In addition, a light-shielding substance, an antioxidant, a fatty acid, a fatty acid compound, an antistatic agent, and a lubricant are added to the polyolefin resin film layer in order to prevent blocking and improve moldability, stability, antistatic property, and the like. It is preferable to add an antioxidant.

This light-shielding substance means a substance that can be kneaded or dispersed in each layer and does not transmit visible light, ultraviolet light, and the like.
Examples of the light-shielding substance that can be used in the present invention include various carbon blacks, graphite, iron oxide, zinc oxide, titanium oxide, clay, aluminum powder, aluminum paste, calcium carbonate, mica, barium sulfate, talc,
Examples thereof include cadmium pigments, red iron oxide, cobalt blue, copper phthalmesyanine pigments, monoazo or polyazo pigments, organic pigments such as aniline black, inorganic pigments, and coloring dyes.

Among these, carbon black and metal powder, which have a large light-shielding ability and are inexpensive, are preferable.

Furnace carbon black is particularly preferable in terms of light-shielding ability, economy, ensuring quality of the light-sensitive material, ensuring physical strength of the multi-layer coextrusion inflation light-shielding film, and preventing generation of spots.

The addition amount is preferably 0.05 to 20% by weight from the viewpoint of ensuring the above characteristics.

In addition to carbon black, it is also preferable to add aniline black, graphite, etc., which are light-absorbing and light-shielding substances like carbon black, to the polyolefin resin film layer and / or the L-LDPE resin film layer.

As the antioxidant, various antioxidants disclosed in various documents and patents can be used. However, it is necessary to select the type, grade and amount of the antioxidant depending on the type of the roll-shaped photosensitive material, particularly the photosensitive dye used and the photosensitivity of the photosensitive material.

Typical examples are shown below, but the present invention is not limited to these antioxidants.

The most preferred phenolic antioxidant is n-octadecyl-3 (3 ', 5'-di-t).
-Butyl 4'hydroxyphenyl) propinate, 2,6
Di-t-butyl 4-methylphenol, 2,6 di-t-butyl-p-cresol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-thiobis (3- Methyl 6-t-butylphenol), 4,4′-butylidene bis (3-methyl-6-t-butylphenol), stearyl-β (3,5-di-4-butyl 4-hydroxyphenyl) propionate, 1,1, 3-Tris (2
-Methyl-4-hydroxy-5-t-butylphenyl)
Butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, octadecyl-3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate, tetrakis [methylene-
3 (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and the like, and commercially available products include various Irganox of Ciba-Geigy and Sumilizer BHR, Sumiziz-erBH of Sumitomo Chemical Co., Ltd. -76, SumilizerWX-
R, Sumilizer BP-101 etc.

The phosphite-based antioxidants which are the next preferable antioxidants include trinonylphenylphosphite and triphenylphosphite.

In addition, a collection of data on various antioxidants and plastic additives disclosed on pages 794 to 799 of the Plastic Data Handbook (published by KK Industrial Research Association) (published by KK Chemical Industry Co., Ltd.)
Various antioxidants disclosed on pages 327-329, PLASTICS
AGE ENCYCLOPEDIA Advance edition 1986 (KK Plastic Age Co., Ltd.) Various antioxidants disclosed on pages 211 to 212 are available.

The amount of these antioxidants added varies depending on the type of the light-sensitive material, but in the case of a silver halide photographic light-sensitive material containing a light-sensitive dye, it is 0.01-
Adjust to 2.0% by weight. Preferred representative examples of fatty acids are oleic acid, stearic acid, lauric acid, ricinoleic acid,
These are saturated and unsaturated fatty acids such as naphthenic acid, octylic acid, phthalic acid, adipic acid, sebacic acid, acetylricinoleic acid, and maleic acid. Further, preferable representative examples of the fatty acid compound include oleic acid amide, erucic acid amide, stearic acid amide, bis fatty acid amide, magnesium stearate, calcium stearate, zinc stearate,
Aluminum stearate, barium stearate, calcium laurate, zinc octylate, butyl oleate, butyl stearate and the like.

Antistatic agents include cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, as well as carbon black, metal powders, carbon fibers, metal fibers and graphite. .

As the lubricant, there are various grades of dimethylpolysiloxane and modified products of dimethylpolysiloxane in the silicone type, and oleic acid amide, stearic acid amide, erucic acid amide, bis fatty acid amide and the like in the fatty acid amide type, and alkylamine, There are higher alcohols, paraffins, waxes, higher fatty acids, and the like.

In addition, the L-LDPE resin film layer, which is the outer layer of the light-shielding multi-layer coextrusion inflation film, has the physical strength of the multi-layer co-extrusion inflation light-shielding film while having flexibility as the outermost layer, especially the impact punching strength and tear strength. And the cylindrical multi-layer coextrusion inflation light-shielding film is used to improve workability and prevent pinholes when sealing both ends of the roll-shaped photosensitive material, and to improve the dispersibility of light-shielding substances. It is a layer for doing.

The ethylene copolymer resin contained in the L-LDPE resin-based film layer includes EVA resin, EEA resin, EMA resin, EAA, in addition to L-LDPE resin, which is a copolymer resin of ethylene and α-olefin, which is an essential resin. Resin, ionomer resin, ethylene-
Examples thereof include unsaturated carboxylic acid ester copolymer resins and ethylene-unsaturated carboxylic acid copolymer resins.

When the ethylene copolymer resin is contained in the L-LDPE resin film layer in an amount of 30% by weight or more, LD
One or more kinds of other resins such as PE resin, polypropylene resin and HDPE resin can be kneaded.

The L-LDPE resin is called a third polyethylene resin, and is a low cost, high strength resin that meets the demands of the age of energy saving and resource saving, which has the advantages of both the medium and low pressure method polyethylene resin. This resin has ethylene and 3 to 13 carbon atoms, preferably 4 to 10 carbon atoms by the low pressure method or the high pressure improvement method.
It is a copolymer of a number of α-olefins and is a low to medium density polyethylene resin having a linear straight chain with short branches and an ethylene content of 85 to 99.5 mol%.

As the α-olefin, butene-1, octene-1,
Hexene-1,4-methylpentene-1, heptene-
1, etc. are used, the amount of which is of the order of 0.5 to 15 mol% of the polymer. Density is generally at the Whereas commercial products are low and medium density polyethylene resin about 0.87~0.95g / cm ^3, most common L-LDPE resin 0.90~0.94g / cm ³
Many are within the range.

If a specific example of L-LDPE resin is shown by a trade name, G resin,
TUFLN (UCC Co.), Dow Rex (Dow Chemical Co.), Sclear (Dupont Canada Co.), Marlex (Phillips Co.), NeoZex and UltoZex (Mitsui Petrochemical), Nisseki Linilex (Nippon Petrochemical), NUC Polyethylene- LL, TUFTHENE (Nippon Unicar), Idemitsu Polyethylene L, MORETEC (Idemitsu Petrochemical), Stamirex (DSM) and the like.

This L-LDPE resin-based film layer preferably contains at least one of a light-shielding substance, a fatty acid compound and an antiblocking agent, and a lubricant in order to prevent blocking, oxidation, molding failure, and antistatic.

The antiblocking agent is silica, diatomaceous earth, calcium silicate, aluminum silicate, talc, magnesium silicate, calcium carbonate, higher fatty acid polyvinyl ester, n-octadecyl urea, dicarboxylic acid ester amide and the like.

The light-shielding substance, the fatty acid compound, and the lubricant may be the same as those used for the polyolefin resin film layer.

If necessary, the outermost layer of the surface, L-LD
A metal powder or a white pigment, which is a light-reflecting light-shielding substance, is added to the PE resin-based film layer, and the polyolefin resin-based film layer, which is the innermost layer on the side in contact with the photosensitive material, is a light-absorbing light-shielding substance. Carbon black or aniline black,
It is also preferable to add graphite or the like.

In addition, the polyolefin resin film layer and L-
Various additives can be added to the LDPE resin film layer.

Typical examples of the additives are described below, but the present invention is not limited thereto and can be selected from all known ones.

Further, an intermediate layer may be laminated between the polyolefin resin film layer and the L-LDPE resin film layer to form a laminated film having three or more layers.

The bulk roll-shaped photosensitive material package of the present invention exerts its effect for the first time by the multi-layer coextrusion inflation light-shielding film having the above-mentioned special resin composition, and various rolled films which are silver halide photographic photosensitive materials, various rolled printing papers and Diazo photosensitive material, thermosensitive photosensitive material, photo-fixing type photosensitive material, transfer type photothermographic material, direct positive photosensitive material, photosensitive resin photosensitive material, UV curable photosensitive material, roll-shaped film of magnetic material, roll-shaped It is suitable for short-distance movement of photographic paper, for example, movement from a photosensitive layer coating step to a storage, a cutting step, a packaging step, or the like, or a package for a storage site. The bulk roll here has a diameter of 25 cm, which is heavy and has a large capacity.
As described above, it refers to a packaging material that is transported as a raw material having a length of 50 cm or more or as a wide roll, and is suitable as a packaging material for long-distance transportation of pancakes and the like to domestic and foreign countries.

[Action]

Since the inner layer of the covering material is a polyolefin resin film layer containing an HDPE resin and the outer layer is a light-shielding multilayer coextrusion inflation film extruded with an L-LDPE resin film layer, The film layer does not cause blocking, and since it contains an ethylene copolymer resin and an antioxidant, it has good flexibility, physical strength, antistatic properties and the like. The outer film layer contains a light-shielding substance and a lubricant, so that flexibility, lubricity, light-shielding property, antistatic property,
When forming a multilayer coextrusion blown film having a good physical strength and a light-shielding property, there is little adhesion of the additive to the roller due to bleed-out, so this does not adversely affect the photosensitive material.

Therefore, when covering the light-sensitive material, it is easy to open the light-shielding multilayer co-extrusion inflation film, and since it does not stick to the light-sensitive material, it is easy to wrap and has flexibility, so that the inflation film at the end of the package body is fastened. Can be done firmly.

Further, since the light-sensitive material and the multilayer coextrusion inflation light-shielding film are both concentric cylinders, a well-matched package can be obtained.

〔Example〕

An embodiment of the package according to the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of a package, and FIGS. 2 and 3 are diagrams showing a method of manufacturing the package.

In FIG. 1, reference numeral 15 is a cylindrical photosensitive material. This cylindrical photosensitive material 15 is formed into a cylindrical shape by winding a belt-shaped photosensitive material 13 around a winding core 14 of a hollow shaft, and its end is an adhesive tape.
It is fixed at 16. This cylindrical photosensitive material 15 has its body part wrapped in a concentric cylindrical shape by a cylindrical light-shielding multilayer coextrusion inflation film 6 which is a packaging material, and the multilayer coextrusion inflation film 6 on both sides is wrapped.
The cores are bent in the directions of the cores 14 and 14 and are brought together, and their ends are fastened with a string 20 and sealed.
Then, such a package 21 is suspended by a carriage 17 by a shaft 24 having a core 14 inserted therethrough, and is easily transported to a temporary storage room, a processing plant, or the like.

In order to manufacture the above-mentioned package, as shown in FIG. 2, first, the multi-layer coextrusion inflation film 6 is placed so that the polyolefin resin film layer is on the inside and the L-LDPE resin film layer is on the outside. The column 23 of the winder 22 is fitted. Then, the shaft 24 inserted through the winding core 14 is set on the winding machine 22. The strip-shaped photosensitive material 13 is wound by rotating the winding core 14. After winding the strip-shaped photosensitive material 13 in this manner, the end is fixed with the adhesive tape 16.

Next, as shown in FIG. 3, the multilayer coextrusion inflation film 6 is stretched and moved in the direction of the arrow in the figure to enclose the cylindrical photosensitive material 15.

Then, both sides are covered with the multi-layer coextrusion inflation film 6 by bending it in the direction of the winding core 14 and covering the ends thereof with the cord 20.
The product is fastened and sealed to complete the package.

FIG. 4 is a partially cutaway side view of another embodiment of the package.

The package 21 shown in this figure is one in which the end of the multilayer coextrusion inflation film 6 is pushed into the core 14 and the ear cover 18 is attached from the outside thereof. The package 21 is loaded in the arcuate recess 25 of the carriage 19 and can be easily transported.

Next, an embodiment of a package having a relatively small size will be described with reference to FIGS. 5 and 6.

FIG. 5 is a longitudinal sectional view of the package, and FIG. 6 is a diagram showing a method of manufacturing the package.

The package 21 shown in FIG. 5 is similar to the package 21 shown in FIG. 4 in that the end of the multilayer coextrusion inflation film 6 is pushed into the core 14 and the ear cover 18 is inserted from the outside thereof.
Is attached by fitting the central protrusion. This ear cover 18
Is formed larger than the diameter of the cylindrical photosensitive material 15 because the cylindrical photosensitive material 15 is small.
It effectively protects 15 from outside pressure.

Further, the package 21 can be placed directly, and is further housed in a cardboard box or a cardboard box in order to improve transportability, protect from collision, and improve commercial value.

In order to manufacture such a package 21, as shown in FIG. 6, the cylindrical multi-layer coextrusion inflation light-shielding film 6 and the cylindrical photosensitive material 15 are moved in the direction of the arrow to be encapsulated, and both sides are covered. Bending the multi-layer coextrusion inflation light-shielding film 6 on the surface in the direction of the winding core 14
It is pushed into 14, and further, the central protrusion of the ear cover 18 is pushed into and sealed to form a package.

A method for forming the multi-layer coextrusion inflation light-shielding film used for the package of the present invention will be described with reference to FIGS. 7 to 9.

FIG. 7 is a schematic view of a blown film manufacturing apparatus, and FIGS. 8 and 9 are enlarged sectional views of parts A and B in FIG.

In FIG. 7, the resin forming the polyolefin resin film layer is placed in the extruder 1a, and the resin forming the L-LDPE resin film layer is placed in the extruder 1b, and heated and melted respectively. Next, the polyolefin resin film layer 11 is extruded from the slit inside the ring die 2, and the L-LDPE resin film layer 12 is extruded from the slit outside. At this time, due to the compressed air from the blower pipe 3 and the cooling air from the air ring 4, FIG.
As shown in the figure, a tubular resin film 6 having a polyolefin resin film layer 11 inside and an L-LDPE resin film layer 12 outside is formed.

The tubular resin film 6 rises through the take-up squeeze rolls (nip rolls) 8 · 8 guide rollers 5 ··· 5 and the guide plates 7 · 7, and at this time, the L-LDPE resin film layer 12 is in contact with them. Therefore, the additive does not adhere to the guide rollers 5 ...

Then, the squeeze roll for take-up 8 is folded into a flat plate shape, and as shown in FIG. 9 which is an enlarged cross-sectional view of the B part,
The polyolefin resin film layer 11 is wound by a winder 22 while being in contact with it. Therefore, blocking does not occur between the inner layers.

Next, the experimental results comparing the characteristics of the products I and II of the present invention, the comparative products I, II and III, and the conventional product I will be described.

The product I of the present invention has a circumference of 2700 mm, and the inner layer has a density of 0.954 g / c.
20% by weight of HDPE resin having m ³ , MI of 1.1 g / 10 min and a density of 0.920 g / cm ³ , which is a copolymer resin of ethylene and octene-1,
MI = 2.0g / 10min L-LDPE resin 76.9% by weight, furnace carbon black 3% by weight, antioxidant 0.1% by weight
Is a polyolefin resin film layer having a thickness of 35 μm. 96.75% by weight of L-LDPE resin, which is a copolymer resin of ethylene and 4-methylpentene-1 having a density of 0.920 g / cm ³ and an MI of 2.1 g / 10 min, the furnace carbon black 3% by weight and olein. A thickness consisting of 0.05% by weight of acid amide and 0.2% by weight of synthetic silica as an antiblocking agent.
It is a L-LDPE resin-based film layer of μm.

After cutting the length to 2500 mm using a two-layer coextrusion inflation light-shielding film, before mounting the winding core 14 to the winder 22, the winding core 22 was cylindrically attached to the column 23 of the winder 22 as shown in FIG. After that, a paper core was attached and the X-ray film was wound.

The obtained roll-shaped roentgen film having a width of 1000 mm and a circumference of 2500 mm was covered with the above-mentioned two-layer coextrusion inflation light-shielding film as shown in FIG. 3, and wrapped with two layers at the core as shown in FIG. The end of the coextrusion inflation light-shielding film was completely sealed with the tape 20 to form a package, which was left for 1 week in a product storage with a red light lit while being suspended on a trolley.

 No abnormality was observed in the quality after one week.

Inventive Product II The two-layer coextrusion inflation light-shielding film used in Inventive Product I has an inner layer resin composition of 20% by weight of HDPE resin.
To 2% by weight and the L-LDPE resin was changed from 76.9% by weight to 94.9% by weight, the composition is exactly the same as the product I of the present invention,
Using a two-layer coextrusion inflation light-shielding film having a layered structure, a roll-shaped X-ray film package similar to that of the product I of the present invention was prepared, and a storage test was conducted in the same manner as the product I of the present invention.

 No abnormality was observed in the quality after one week.

Comparative product I: The inner layer had a density of 0.920 g / cm ³ and an MI of 2.0 g / 10
L- which is a copolymer resin of ethylene and octene-1
An L-LDPE resin film layer having a thickness of 35 μm and composed of 97% by weight of LDPE resin and 3% by weight of furnace carbon black. The outer layer is a copolymer resin of ethylene and 4-methylpentene-1 having a density of 0.920 g / cm ³ and an MI of 2.1 g / 10 min L
-LDPE resin 96.75% by weight, furnace carbon black 3% by weight, oleic acid amide 0.05% by weight, synthetic silica 0.2% by weight, a two-layer coextrusion inflation light-shielding property of a L-LDPE resin film layer having a thickness of 35 μm. A package was prepared by the same method as that of the product I of the present invention except that the film was used, and the manufacturing method.

As for the comparative product II layer structure, the inner layer has a density of 0.954 g / cm ³ and an MI of 1.1 g / 10
This is a polyolefin resin film layer having a thickness of 35 μm and composed of 95% by weight of HDPE resin, 3% by weight of furnace carbon black, and 2% by weight of calcium stearate.
L-LDPE, which is a copolymer resin of ethylene and 4-methylpentene-1 whose outer layer has a density of 0.920 g / cm ³ and MI of 2.1 g / 10 min.
Two-layer coextrusion inflation, which is a 35 μm thick L-LDPE resin film layer consisting of 96.75% by weight of resin, 3% by weight of furnace carbon black, 0.05% by weight of oleic acid amide and 0.2% by weight of synthetic silica as an antiblocking agent. A wrapping body was prepared by the same method and manufacturing method as the product I of the invention except that the light-shielding film was used.

COMPARATIVE PRODUCT III The present invention product except that the two-layer coextruded inflation light-shielding film of Comparative Product II is used, except that the two-layer coextrusion inflation light-shielding film has the opposite layer structure and the inner layer is the outer layer and the outer layer is the inner layer. A packaged article was produced by the same method and production method as those of I.

Comparative product IV layer structure is LDPE with a density of 0.923 g / cm ³ and MI of 2.4 g / 10 min.
70 μm thick consisting of 96.95% by weight of resin, 3% by weight of furnace carbon black and 0.05% by weight of oleic acid amide,
A wrapping body was produced by the same method as that of the product I of the present invention except that a light-shielding single inflation film having a circumference of 2700 mm was used.

 The results of each experiment are shown in Table 1.

The evaluation is as follows.

◎… very good ○… excellent ●… possible (within practical limits) ▲… problem (needs improvement) ×… not practical * A anti-blocking property Inflation film made by the above film forming process is wound up. Then, it was cut with a razor to a folding diameter of 330 mm × 220 mm, and it was judged from the ease of opening this cutting opening.

* B film moldability Motor load (current value), bubble stability, frost line position, when the inflation film of the present invention is manufactured using an inflation film molding machine,
It is evaluated by the suitability for production of total inflation film such as fish eyes, spots, film wrinkles, and unevenness of film thickness.

* C White powder generation preventive property Each sample has a die cap of 1 mm, a blow ratio of 2.1, and is prepared using an inflation film molding machine. Judgment by visual inspection * D Physical strength Tear strength required for packaging materials for photosensitive materials (JIS P8
116), impact drilling strength (JIS P8134), burst strength (JIS P8112), and heat seal strength.

* E Wrinkle and streak generation resistance Visual inspection of the appearance of wrinkles and streaks when each sample was created using an inflation film molding machine with a die cap of 1 mm and a blow ratio of 2.1. Judgment from * F Flexibility Judgment from measured values according to JIS P8125 and touch during sealing and packaging work * G Pinhole resistance As described in the examples, using each film, the circumference is 2500 mm and the product width is 1000 mm The roll coated with X-ray emulsion, which is the material, is packaged as shown in Fig. 1 and left for 3 hours under a fluorescent lamp of 1000 lux, then the upper one lap of the X-ray roll film is developed and judged according to the degree of fogging. * H Suitability for sealed packaging Judgment based on the ease of work when a sealed package having the shape of Fig. 1 is produced by one person according to the method for producing a package of the present invention [Effect of the invention] Since the material is a concentric cylindrical package which is formed by using a light-shielding multilayer coextrusion inflation film in which a predetermined polyolefin resin film layer is used as an inner layer and a predetermined L-LDPE resin film layer is used as an outer layer, , The photosensitive material and the coating material are well matched and there is no waste of material. The packaging material does not cause blocking, has antistatic properties, and is flexible and resistant to pinholes, so that the packaging work can be easily performed by one person.

Further, since the packaging material is inexpensive, rich in light-shielding property, and excellent in physical strength, it is possible to obtain a package which is low in cost and excellent in storability and handleability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory front view of a package of the present invention, FIG. 2 and FIG.
FIG. 4 is a perspective view showing a manufacturing method, FIG. 4 is a partially cutaway side view of another package of the present invention, and FIG. 5 is a sectional view of the package of the present invention.
FIG. 6 is a perspective view showing a manufacturing method, FIG. 7 is a schematic view of an inflation film manufacturing apparatus, FIG. 8 is an enlarged sectional view of part A in FIG. 7, and FIG. 9 is an enlarged sectional view of part B in FIG. Is. 6 ... Multi-layer coextrusion inflation light-shielding film 13 ... Photosensitive material, 14 ... Core 15 ... Cylindrical strip-shaped photosensitive material 17 ... Truck, 18 ... Ear cover 19 ... Directly placed cart , 22 …… Winder

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03C 3/00 W

Claims (1)

[Claims] 1. A polyolefin resin film layer containing 0.5 to 70% by weight of a polyethylene resin having a melt index of 0.3 g / 10 minutes or more and a density of 0.936 g / cm ³ or more and 0.01 to 2.0% by weight of an antioxidant as an inner layer. And a light-shielding multilayer coextrusion blown film containing 0.05 to 20% by weight of a light-shielding substance in at least one layer having a linear low-density polyethylene resin film layer as an outer layer Bulk roll-shaped photosensitive material package in which a roll-shaped photosensitive material is wrapped into a concentric cylinder so that the inner layer is in contact with the photosensitive material