JPH0629954B2 - Packaging material for photographic light-sensitive material and packaging method for photographic light-sensitive material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a packaging material suitable for a photographic light-sensitive material and a method for packaging the photographic light-sensitive material.

[Conventional technology]

Various types of packaging materials for photographic light-sensitive materials have been widely put into practical use, and various performances are required according to their use.

A packaging material that completely blocks light is used as a packaging material for a photographic light sensitive material that loses its quality value when exposed to light. In this case, required properties include packaging material slit suitability, gas barrier property, light shielding property, moisture proof property, rigidity, physical strength (breaking strength, tear strength, impact drilling strength, gelbotest strength, abrasion strength, etc.), heat seal suitability ( Heat seal strength, cut seal property, hot tack property, foreign substance seal property, etc.), heat seal strength over time, antistatic property, flatness, and slip property. It is extremely difficult to combine these various properties with a single film material, and conventionally, a very thick, high-pressure branching low-kneading method in which carbon black, a pigment, etc. as shown in FIG. A single layer film of the density polyethylene (hereinafter referred to as LDPE) resin light-shielding film layer 8a, a composite laminate film of an LDPE resin film and a flexible sheet layer of paper, aluminum foil, cellophane, or the like have been used.
An example of the composite laminate film is shown in FIG. 6, which is used in roll-shaped color photographic paper products that are particularly required to have moisture resistance and physical strength. The LDPE resin light-shielding film layer 8a has an adhesive layer 5 Through the aluminum foil layer 9
, The flexible sheet layer 6 is further laminated via the adhesive layer 5, and the LDP is further laminated on the flexible sheet layer 6 via the adhesive layer 5.
The E resin light shielding film layer 8a is laminated.

The present inventor has conducted earnest research to improve a packaging material for a light-sensitive material and has improved physical strength by combining two uniaxially stretched film layers (Japanese Patent Laid-Open No. 57-6754).
Gazette) has already been disclosed. Further, in a laminated film obtained by laminating a uniaxial molecular orientation thermoplastic resin film on both sides of a sheet-shaped foam, the thickness of the sheet-shaped foam is 0.
It has already been disclosed a laminated film in which the foaming ratio is 3 to 2.0 mm, the expansion ratio is 5 to 50 times, and the bilayer uniaxial molecular orientation film is adhered to both sides of the foam so that the molecular orientation axes intersect at an angle of 30 degrees or more ( JP-A-59-201848).

[Problems to be solved by the invention]

The conventional composite laminate film is configured to improve the above-mentioned physical properties. However, because aluminum foil is used to prevent moisture and prevent static electricity, the physical properties are not sufficient for heavy products and roll film products with sharp edges. There was a defect such as the part peeling off. Furthermore, when a large amount of a light-shielding substance such as carbon black is added, the physical strength deteriorates and the heat-sealability deteriorates. The amount added is around 3% by weight and the total film thickness is 70%.
It was necessary to set the thickness to at least μm. For this reason, the bulkiness of the bulk laminate film is increased, the packaging workability is deteriorated, and the packaging is expensive.

For example, even with a 7-layer laminated film shown in Fig. 6, which was used for packaging roll-shaped color photographic paper, aluminum foil is used to prevent moisture and static electricity, so tear strength, impact hole strength, and gelbotest strength. Etc. are lacking. The packaging material described in JP-A-59-201848 has improved physical strength such as tensile strength, gelbotest strength and impact hole rake strength. However, this laminated film has a large thickness and is insufficient in anti-static properties for high-sensitivity photographic light-sensitive materials and has poor heat-sealing suitability for securing light-shielding properties and moisture-proof properties. The product was inserted into a bag made by a heat sealer using a special cooling device with a heat-resistant film sandwiched on the surface and sealed, resulting in very expensive packaging.

The present invention improves the above-mentioned problems and improves the product insertability, heat seal strength over time, physical strength, heat seal suitability, antistatic property, etc. of an inexpensive packaging material for photographic light sensitive materials and photographic light sensitive materials. The purpose is to provide a packaging method.

[Means for solving problems]

In order to achieve the above object, the present invention comprises 30 to 99.49% by weight of a linear low density polyethylene resin which is a copolymer of ethylene and α-olefin, 0.5 to 10% by weight of carbon black, and 0.01% of a lubricant. ~ 1.00 wt% heat seal layer with static friction coefficient of 0.12 ~ 0.37
An inner layer that is, an intermediate layer that is formed of a thermoplastic resin, and an outer layer that is formed of a thermoplastic resin and has a coefficient of static friction of 0.05 or more larger than the inner layer and an absolute value of 0.19 or more,
The adhesive strength between the inner layer and the intermediate layer and between the outer layer and the intermediate layer is 10 g / 1.
A packaging material for a photographic light-sensitive material, comprising a simultaneous multilayer coextrusion light-shielding film having a width of 5 mm or more.

Further, a packaging method for a photographic light-sensitive material is characterized in that a bag is formed using the packaging material for a photographic light-sensitive material such that an inner layer is an inner surface, and the photographic light-sensitive material is housed in the bag. .

Required ethylene and linear low density polyethylene resin is a copolymer of α- olefins inner layer of the present invention generally L-LDPE resin (L inear L ow D ensity P oly e tylane
That is, it is a linear low-density polyethylene resin called an acronym for linear low-density polyethylene). As the polymerization process, there are a gas phase method using a medium and low pressure apparatus, a liquid phase method (solution method) and a high pressure remodeling method using a high pressure improving apparatus. Particularly, the low-pressure method L-LDPE resin is preferable because it is low in cost.

If you show a concrete example with a product name, Unipol and TUFLIN
(UCC Co., Ltd.), Dow Rex (Dow Chemical Co.), Sclair (DuPont Canada Co.), Marlex (Phillips Co.), NeoZex and UltoZex (Mitsui Petrochemical), Nisseki Linilex (Nippon Petrochemical), Idemitsu Polyethylene-L (Idemitsu Petrochemical), Stamirex (DSM
Company), NUC polynitylene-LL (Nippon Unicar) and the like. As the α-olefin, butene-1, octene-1, hexene-1, 4-methylpentene-1,
Heptene-1, etc. are used, and the amount is 0.5 of the polymer.
It is about 15 mol%. The density is generally considered to be low or medium, but most commercial products have a density within the range of 0.87 to 0.94 g / cm ² . Among these L-LDPE resins, particularly preferable in terms of cost, physical strength and heat sealing strength are ethylene content of 90 to 99.5 mol% and α-
Olefin content 0.5 to 10 mol%, melt index (hereinafter referred to as MI) 0.4 to 30 g / 10 minutes (ASTM
D-1238-E condition), density 0.870-0.940g / cm ³ (A
STM D-1505), L- by low pressure liquid phase process and gas phase process in which the carbon number of α-olefin is 6 to 8
LDPE resin. The most preferable representative product name is Ultoxex of Mitsui Petrochemical Co., Ltd. as an L-LDPE resin using 4 methylpentene-1 having 6 carbon atoms as an α-olefin side chain in ethylene. Examples of L-LDPE resins using octene-1 having 8 carbon atoms as an olefin side chain include Stamilex of DSM and Dowlex of Dow Chemical Co., Ltd. (The above three products are liquid phase process of low pressure method) L-LDPE resin according to

Examples of the low-pressure vapor-phase process products include TUFLIN of UCC using hexene-1 as an α-olefin side chain.

The L-LDPE resin may be used alone or as a mixture with other various thermoplastic resins and various additives. In particular, to secure better characteristics than other resins such as physical strength (tear strength, impact hole strength, etc.) and heat sealability (ensure seal strength, hot tack, foreign matter sealability, etc.). It is essential that the resin composition contains at least 30% by weight of L-LDPE resin. It goes without saying that the L-LDPE resin may be a mixed composition of two or more L-LDPE resins having different α-olefins.

Polyolefin resin, especially LDPE resin, EV is used as a resin which is mixed with L-LDPE resin to improve blown film moldability and does not deteriorate physical properties so much.
A resin (ethylene / vinyl acetate copolymer resin), EEA
A resin (ethylene / ethyl acrylate copolymer resin) is preferable.

The essential carbon black for the inner layer is for maintaining the heat seal strength over time, light shielding property, antistatic property and the like, and the addition amount thereof is 0.5 to 10% by weight. This addition amount is limited in terms of physical strength of the film, film moldability, moisture resistance, antistatic property, and film quality. If the amount is less than 0.5% by weight, the light-shielding property does not maintain the heat seal strength over time, and the antistatic property is not satisfied. Is a problem. Further, it is worn by rubbing with the photographic light-sensitive material and a large amount of black powder is generated, which causes a spot-like failure in the light-sensitive material. In order to reduce the surface resistance value to 10 ¹⁰ Ω or less with carbon black alone, it is necessary to add conductive carbon black.

Representative examples of the conductive carbon black include acetylene carbon black and Ketjen carbon black which is a modified by-product carbon black. It is also preferable to blend various conductive materials with various carbon blacks to improve the antistatic effect.

For example, it is described in detail in various metal conductive particles and various antistatic agents {Hideo Marumoshi "Antistatic Agent" (Koushobo). }, A metal powder, a fibrous conductive filler, or a known conductive substance such as a substance obtained by hardening a conductive filler with a liquid polymer and / or a solvent-soluble polymer, and carbon black are also preferably blended. Among the carbon blacks of the present invention, those having a pH of 5 to 9 and an average particle size of 10 to 120 mμ are preferable, and particularly an oil furnace carbon black having a pH of 6 to 8 and an average particle size of 15 to 30 mμ is preferable in terms of ensuring dispersibility and light shielding properties. . In particular, by using such a pH and particle size packaging material for a photographic light-sensitive material, the occurrence of fog is small, the increase or decrease in the photosensitivity is small, the light-shielding ability is large, and the photographic light-sensitive material is adversely affected. However, it is possible to obtain a packaging material having various advantages such that pinholes such as lumps of carbon black and fish eyes hardly occur even when added to a thermoplastic resin film.

There are various types of use forms for blending carbon black with the L-LDPE resin, such as a powder addition method, a paste addition method, a moisturizing addition method, a granular addition method, a compound method, and a masterbatch method. It is preferable in terms of preventing contamination of working machines.

In Japanese Patent Publication No. 40-19616, there is disclosed a method for preparing a master batch of polymer carbon black by dispersing carbon black in a solution of a polymer dissolved in an organic solvent. Discloses a method of dispersing carbon black in polyethylene to form a masterbatch.

In the case of the masterbatch method, first, a polyolefin resin (preferably LDPE, L-LDPE, EVA, EE
A, EMA, etc.) is mixed with carbon black at a high density of 10% by weight or more, generally 30% by weight or more to prepare a masterbatch. Then, the masterbatch pellets are weighed so that finally the amount of carbon black in the inner layer becomes 0.5 to 10% by weight, and mixed with the L-LDPE resin or the thermoplastic resin added to the L-LDPE resin.

The lubricant essential for the inner layer does not adversely affect the photographic light-sensitive material,
It is for improving product insertion suitability, blocking prevention, film moldability, peeling antistatic property, and the like. The amount of this lubricant added is to prevent static electricity, product insertion suitability, film formability, blocking prevention, and to prevent stickiness or dust adhesion due to breeding out to photographic light-sensitive materials when the amount added is too large. Therefore, it is 0.01 to 1.0% by weight.

Typical commercially available lubricant names and manufacturer names that do not adversely affect the photographic light-sensitive material are listed below, but the present invention is not limited thereto.

(1) Silicon lubricants; various grades of dimethylpolysiloxane (Shin-Etsu Silicone, Toray Silicone, etc.) (2) Oleic acid amide lubricants: Armoslip CP (Lion, Akzo), Neutron (Nippon Seika), Neutron E -18 (Nippon Seika), Amide O (Nitto Kagaku),
Alfro E-10 (Nippon Yushi), Diamond O-200
(Nippon Kasei), Diamid G-200 (Nippon Kasei), etc. (3) Erucamide amide lubricant; Alfuro-P-10 (Nippon Yushi), etc. (4) Stearamide amide lubricant; Alfuro-S-10 (Japan Oil and fat), Neutron 2 (Nippon Seika), Diamond
200 (Nippon Kasei), etc. (5) Bisfatty acid amide lubricants; Pisamide (Nippon Kasei), Diamid 200 Pis (Nippon Kasei), Armowax EBS (Lion, Akzo), etc. (6) Alkylamine lubricants: Electrostripper T
There are S-2 etc.

The static friction coefficient of the inner layer is 0.12 to 0.37. For this static friction coefficient, a part of the sheet packaging material to be tested is cut out and attached to the bottom surface of a block having a length of 75 mm and a width of 35 mm and a load of 200 g. On the other hand, one of the sheet packaging materials to be tested
Similarly, the portion was cut and adhered to the inclined surface, the sheet packaging material surface of the block was placed on the inclined surface, the inclination angle of the inclined surface was changed, and the angle θ at which the block began to slide was read. This is the value obtained as the subsequent tan θ.

If the coefficient of static friction is less than 0.12, the photographic material will not move too much in the bag during transportation, causing scratches and frictional fog, and it will not be able to be wound because it is too slippery during winding after film formation or winding in the laminating process. It is difficult to put it into practical use because it has a bamboo shoot-like shape.

If the coefficient of static friction exceeds 0.37, it will be difficult to put the bag in the packaging process of the photographic light-sensitive material, and if it is peeled off, the bag will be broken or scratches or friction fog will be generated on the photographic light-sensitive material. In the case of a bag, the bag tends to be blocked, and not only the inner layer and the inner layer may be blocked but also the inner layer and the photographic light-sensitive material may adhere to each other to make them unusable. Further, during the transportation process, abrasion with the photographic light-sensitive material causes abrasion and black powder frequently occurs, and this black powder adheres to the photosensitive layer of the photographic light-sensitive material in spots to cause a failure.

The intermediate layer is formed of a single thermoplastic resin or a mixture of two or more thermoplastic resins. This thermoplastic resin is used in such a resin composition that the adhesive force between the inner layer and the outer layer is 10 g / 15 mm width or more. Securing adhesive strength with the inner layer of L-LDPE resin,
The following polyolefin resins are preferred because of their film formability, curl reduction, and low cost for general-purpose resins.

(1) Low density polyethylene resin (LDPE) (2) Medium density polyethylene resin (MDPE) (3) High density polyethylene resin (HDPE) (4) Linear low density polyethylene resin (L-LDPE) (5) Ethylene Propylene copolymer resin (random or block copolymer resin, etc.) (6) Ethylene / butene 1 copolymer resin (7) Propylene / butene 1 copolymer resin (8) Ethylene / propylene / butene 1 copolymer resin (9) Polybutene-1 resin (10) Polystyrene resin (11) Polymethyl methacrylate resin (12) Styrene-acrylonitrile copolymer resin (13) ABS resin (14) Polypropylene resin (15) Crystalline propylene-α-olefin copolymer Polymer resin (16) Modified polypropylene resin (17) Modified polyethylene resin (18) Polypropylene / maleic anhydride graft copolymer resin (19) Chlorinated polyolefin Resin (mainly chlorinated polyethylene resin) (HDPE, LDPE, PE copolymers,
(Atactic PP, etc.) (20) Ethylene / vinyl acetate copolymer resin (EVA) (21) Ethylene ionomer resin (resin obtained by crosslinking a copolymer of ethylene and unsaturated acid with a metal) (22) Poly-4-methyl Penten-1 resin (23) Ethylene / acrylic acid copolymer resin (EAA) (24) Ethylene / methyl alkyl copolymer resin (EM
A) (25) Ethylene / ethyl acrylate copolymer resin (EE
A) (26) Vinyl chloride / propylene copolymer resin (27) Ethylene / vinyl alcohol resin (28) Cross-linked polyethylene resin (electron beam irradiation cross-linking, chemical cross-linking, etc.) (29) Polyisobutylene resin (30) Ethylene-chloride Vinyl copolymer resin (31) 1,2-polybutazinine resin and the like.

The intermediate layer of the present invention is covered with the inner layer and the outer layer even if there is a problem in heat sealability, physical strength, abrasion resistance, moisture resistance and the like. Therefore, the above properties are changed or antistatic properties, Ketjen carbon black or metal powder, which is an antistatic agent or a conductive carbon black acetylene carbon black or a modified byproduct carbon black, which is a good substance of light shielding property,
Carbon fiber, metal fiber, graphite, metal-plated surface metallized filler, graphite fiber conductive zinc oxide or tin, graphite powder, carbonaceous or graphitic whisker short fiber, polyalkylene oxide compound, fibrous titanic acid Potassium or the like can be used. These antistatic agents, conductive powders, and conductive fibers can be used alone or as a mixture depending on the required conductivity and application.

The type, shape, size, and amount of these antistatic agents and conductive substances can be appropriately selected according to the purpose of use. The base resin may also be appropriately selected depending on the resin composition of the innermost layer and the outermost layer, but from the viewpoint of physical strength, economic efficiency (inexpensive), various polyolefin resins, particularly various polyethylene resins, copolymerized polypropylene resins with α-olefins, EEA resin, EM
A resin, EAA resin, EVA resin, ionomer resin,
Adhesive polymers and the like are preferred. In the middle layer, a commercially available conductive resin such as Tokyo Ink Co., Ltd. conductive plastic "Papiostat", Toyo Ink Co., Ltd. conductive plastic compound "Rioconduct", Dainippon Ink & Chemicals Co., Ltd. conductive Plastics "Dielek"
It is preferable to use the above as a commercially available pellet or as a blend with another resin. Further, the intermediate layer may be formed of a plurality of layers in addition to the single layer. The outer layer of the present invention has a coefficient of static friction (tan θ) of 0.05 or more and a value of 0.19 than that of the inner layer.
It is essential that it is above, and the adhesive strength with the intermediate layer is 10
It is essential that the width is g / 15 mm or more.

From these points, it is preferable to use the same kind of thermoplastic resin as that for the intermediate layer, and it is preferable to use various polyolefin resins used for the intermediate layer as the main components.

Various kinds of thermoplastic resins and additives can be mixed in the outer layer as well, but the static friction coefficient is limited, so that the addition amount and the like are limited. If the coefficient of static friction is equal to or less than that of the inner layer and it is easy to slip, film forming process, laminating process, bag making process,
Various problems occur in the distribution process after product packaging, making it difficult to put into practical use.

When using only the simultaneous multilayer co-extruded film of the present invention, it is preferable to use a thermoplastic resin having a melting point higher than that of the inner layer by 5 ° C. or more, preferably 10 ° C. or more. For example, it is preferable to use a mixed resin of HDPE resin, polyester resin, polypropylene resin, polyamide resin (various nylon) acrylic resin, and the polyolefin resin. It is also preferable to add a light-reflecting light-shielding substance to the outer layer because heat resistance, light-shielding property, moisture-proof printing suitability, appearance and the like can be improved.

The outer layer has a coefficient of static friction (tan θ) larger than that of the inner layer by 0.05 or more and a value of 0.19 or more. If the coefficient of static friction does not satisfy such conditions, various troubles may occur in the film forming process, laminating process, bag making process, product packaging process, and distribution process due to slippage between the films, which may cause practical problems. do not become.

The adhesive strength between the intermediate layer and the inner and outer layers is 10 g / 15 mm width or more. When the adhesive strength is less than 10 g / 15 mm width, delamination failure occurs in the laminating process, bag making process, heat sealing process and the like. The package having the delamination failure loses the functions required for the photographic photosensitive material package, such as light-shielding property, moisture-proof property and gas barrier property.

A light-shielding substance other than carbon black may be added to the inner layer, the intermediate layer and the outer layer. The light-shielding substance includes a light-reflecting light-shielding substance and a light-absorbing light-shielding substance.

As the light-reflecting light-shielding substance, metal powder, metal flakes,
Metal fibers, white pigments, etc. are used. The metal powder is a metal powder formed, and is preferably an aluminum powder or an aluminum paste from which low-volatile substances are removed.
Here, the aluminum powder is formed by forming molten aluminum into a powder by an atomizing method, a granulating method, a rotating disk dropping method, an evaporation method, or the like. Since the aluminum powder alone is unstable, various known treatments for inactivating the surface of the aluminum powder are performed. As a known method for producing a metal powder for filling synthetic resin, there is a method described in JP-A-59-75931.

Further, the aluminum paste is formed into a paste in the presence of mineral spirits and a small amount of higher fatty acids such as stearic acid or oleic acid when producing aluminum powder by a known method such as a ball mill method, a stamp mill method or an atomizing method. It was made.

The packaging material of the present invention may be composed of only a simultaneous multi-layer coextrusion film, but may also be used as a composite film by laminating other flexible sheet layers.

Other flexible sheet layers used in composite films include various types of thermoplastic resin films that are unstretched and uniaxially molecularly oriented, biaxially molecularly oriented, such as various polyethylene resins, ethylene copolymer resins, polypropylene resins, polychlorinated resins. There are known films of vinyl resin, polyvinylidene chloride resin, polyamide resin, polycarbonate resin, polyester resin and the like, and films of modified resins thereof. In addition, processed metal film (typically aluminum vacuum deposited film), aluminum vacuum deposited paper, cellulose acetate film, cellophane, polyvinyl alcohol film, various papers, various metal foils (aluminum foil as a typical example), non-woven fabrics. Also, well-known flexible sheet layers such as a warif, a perforated film and a foamed sheet of polyethylene, polystyrene, polypropylene, polyurethane and the like are suitable.

In the case of a composite film, it is essential to arrange it in the innermost layer which is in contact with the product of the inner layer of the simultaneous multi-layer coextrusion film in order to secure the moisture resistance and the heat sealability.

The composite film can be formed by any known adhesion method, but the dry lamination method and the extrusion lamination method are particularly preferable.

Particularly preferred adhesives used in the extrusion laminating method are various polyethylene resins, polypropylene resins, and polybutylene resins. , A polymer composed of a polyolefin resin and an ethylene copolymer {in addition to resins such as EVA, EMA, EEA, etc., ethylene is partially copolymerized with other monomers (for example, α-olefin etc.) such as L-LDPE resin. There are ionomer resins (ionic copolymers) such as Surlyn of Dupont and Hiramin of Mitsui Polychemicals, and Admers (adhesive polymers) of Mitsui Petrochemical Co., Ltd.}.

These adhesives preferably have a melting point of 5 ° or more lower than that of the flexible sheet layer to be laminated. If there is such a temperature difference, it is possible to completely perform the hot melt adhesion without adversely affecting the flexible sheet.

The thickness of the adhesive layer by the extrusion lamination method using a thermoplastic resin is usually 6 μm to 50 μm, preferably
Although it is 10 μm to 20 μm, it is determined based on the cost, the laminating speed, the total thickness of the laminate, etc., and is not particularly limited to this value.

The photographic light-sensitive material includes a silver halide photographic light-sensitive material, a diazo photographic light-sensitive material, a diazo type photosensitive recording material, a photosensitive resin, a self-developing photographic light-sensitive material, a diffusion transfer type photographic light-sensitive material and the like.

The packaging material of the present invention is used not only for the above-mentioned photographic light-sensitive materials but also for all light-sensitive materials that are discolored by light or hardened and deteriorated, and as a typical example of a material that causes a functional failure due to dust or static electricity. Optimal.

When the packaging material of the present invention is applied to the above photographic light-sensitive material, it can be used in a single flat bag, a double flat bag, a square bottom bag, a freestanding bag, a single gusset bag, a double gusset bag, a film sheet, and a moisture-proof box. Any known form such as sticking or leader paper is possible.

The bag-making method is a conventionally known plastic film sealing method such as heat sealing, impulse sealing, ultrasonic sealing, or high-frequency sealing depending on the properties of the laminated film used. In addition, it is also possible to make a bag by using an appropriate adhesive or pressure-sensitive adhesive.

[Action]

In the packaging material for a photographic light-sensitive material of the present invention, the inner layer has a light-shielding property,
Excellent in product insertability, anti-blocking property, anti-peeling property, moisture resistance, and gas barrier property. Further, it is excellent in heat sealability (hot tackiness, foreign matter sealability, heat seal strength, etc.), is excellent in maintaining time-dependent seal strength, and is also extremely excellent in physical strength. The intermediate layer not only prevents delamination but also improves physical strength by controlling the adhesive strength between the inner layer and the outer layer rather than the single layer. When a high concentration of carbon black is added, even if the resin has a problem in physical strength, abrasion resistance, film moldability, heat sealability, moisture resistance, printability, and appearance, these properties are 10% by weight of an antistatic light-shielding substance such as carbon black as it is covered with
In addition to the above intermediate layer, the antistatic property, antifouling property, antistatic property, light shielding property and the like can be improved. Further, since the intermediate layer does not come into contact with the photographic light-sensitive material, it may be a resin or an additive that improves characteristics such as physical strength, and may be harmful to the photographic light-sensitive material.

As the outermost layer, the coefficient of static friction is 0.05 or more larger than that of the innermost layer, and the value is 0.19 or more for slippage between packaging materials such as film forming process, laminating process, bag making process, and distribution process after product packaging. Prevents various troubles that occur.

By using a thermoplastic resin having a high melting point in the outer layer or adding various additives, heat resistance is improved and suitability for automatic bag making is improved. Further, when a reflective light-shielding substance is added, heat resistance, light-shielding property, appearance, printability, and front / back distinction in a photographic light-sensitive material packaging process under safelight can be improved.

Further, in the packaging method for photographic light-sensitive material of the present invention, the photographic light-sensitive material can be smoothly stored in the bag by sliding on the inner surface of the inner layer.

〔Example〕

A first embodiment of the packaging material for a photographic light-sensitive material according to the present invention
It will be described with reference to the drawings.

FIG. 1 is a partial sectional view of a packaging material for a photographic light-sensitive material.
This example has the most basic layer structure of the present invention, and is composed only of a simultaneous multilayer coextrusion film 4a composed of three layers of an inner layer 1a, an intermediate layer 2a and an outer layer 3a.

FIG. 2 is also a partial cross-sectional view of another example of the packaging material for a photographic light-sensitive material. In this example, the intermediate layer 2 is formed in multiple layers, and the central intermediate layer 21 and the inner intermediate layers 22 and the outer intermediate layers 23 on both sides thereof are formed.
And consists of. The inner layer 1a is formed on the inner intermediate layer 22,
The outer layer 3 is laminated on the outer intermediate layer 23 to form a simultaneous multilayer coextrusion film 4a composed of five layers.

FIG. 3 is also a partial cross-sectional view of another example of the packaging material for a photographic light-sensitive material. This example is formed by laminating a flexible sheet layer 6 with an adhesive layer 5 on the simultaneous multilayer coextrusion film 4a shown in FIG.

FIG. 4 is a partial cross-sectional view of the comparative product, which is composed only of the light-shielding L-LDPE resin layer 7a formed of the same resin composition as that of the inner layer 1a of the present invention except that no lubricant is added.

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

The product I of the present invention corresponds to the embodiment of FIG. The inner layer 1a has a thickness of 100 μm, and 96.3% by weight of Ultzex 2021L manufactured by Mitsui Petrochemical Co., Ltd., which is an L-LDPE resin in which α-olefin is 4-methylpentene-1 is 3% by weight of furnace carbon black, and olein. An acid amide lubricant, Armoslip CP manufactured by Lion Akzo Co., Ltd., is formed of 0.07% by weight of resin. The intermediate layer 2a has a thickness of 20μ
m, and is made of 80% by weight of conductive plastic Srioconduct PE COMP 245 manufactured by Toyo Ink Co., Ltd. and 20% by weight of ULTOZEX 2021L manufactured by Mitsui Petrochemical Co., Ltd. The outer layer 3a has a thickness of 60 μm, 2% by weight of aluminum paste manufactured by Toyo Aluminum Co., Ltd., and L-LDPE resin Ultzex 2021L60 manufactured by Mitsui Petrochemical Co., Ltd.
It is made of 38% by weight of HDPE resin HiZex 3300F 38% by weight of Mitsui Petrochemical Co., Ltd.

The product II of the present invention corresponds to the embodiment shown in FIG. The inner layer 1a is the same as the inner layer 1a of the product I of the present invention except that the thickness is 80 μm. The intermediate layer 2a has a thickness of 20 μm and is made of Dainippon Ink and Chemicals, Inc., a conductive plastic, Dielec PE.
・ 291 70% by weight, EEA resin N made by Nippon Unicar Co., Ltd.
UC-6170 (registered trademark) formed of 30% by weight of resin. The outer layer 3 has a thickness of 50 μm and is manufactured by Mitsui Petrochemical Co., Ltd.
HDPE resin Hi-Zex 3300F 30% by weight, LL
DPE resin Ultzex 2021L Made of 70 wt% resin. Comparative product I corresponds to the example in FIG. 4 and has a thickness of 15
At 0 μm, α-olefin which is L-LDPE resin is 4-
Methyl pentene-1 is 80% by weight of Ultzex 2021L manufactured by Mitsui Petrochemical Co., Ltd. and 17% by weight of NUC Polyethylene-LL 0171 manufactured by Nippon Unicar Co., Ltd. and 3% by weight of Furnace Carbon Black 44B manufactured by Mitsubishi Kasei. Has been formed.

The conventional product I corresponds to the example of FIG. 5, has a thickness of 150 μm, and LDPE resin DFD-011 97% by weight manufactured by Nippon Unicar Co., Ltd.
And Mitsubishi Kasei Co., Ltd. furnace carbon black 44B
(Registered trademark) formed of 3% by weight of resin.

The conventional product II corresponds to the example of FIG. 6, and the LDPE resin light-shielding film layer 8a having the same resin composition as the conventional product I and having the thickness of 52 μm has the LDPE extrusion adhesive layer 5 having the thickness of 15 μm and the aluminum foil layer having the thickness of 7 μm. 9 is laminated. Then, 35 g / cm ² of hinori base paper was laminated as the flexible sheet layer 6 and LDPE having the same resin composition as the conventional product I and a thickness of 50 μm.
It is a packaging material composed of a laminated film having a seven-layer structure in which the resin light-shielding film layer 8a is laminated.

Table 1 shows the results of comparing the characteristics of the products I and II of the present invention, the comparative product I, and the conventional products I and II.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to sufficiently secure physical strength, moisture resistance, gas barrier property, heat sealability and the like in the inner layer and the outer layer. Further, the intermediate layer does not need to have sufficient physical strength because the inner layer and the outer layer secure it, and a large amount of an antistatic substance can be added to improve the antistatic property. Further, the intermediate layer has these characteristics and is inexpensive, but a substance harmful to the photographic light-sensitive material can be added. Therefore, the packaging material as a whole has good physical strength, antistatic properties, and the like, and can be significantly thinned to be provided at a low cost. Further, the photographic light-sensitive material can be smoothly stored.

[Brief description of drawings]

1 to 3 are partial cross-sectional views of the packaging material which is an embodiment of the present invention. FIG. 4 is a partial sectional view of a comparative product. 5 and 6 are partial cross-sectional views of conventional packaging materials. 1 ... inner layer, 2 ... middle layer, 3 ... outer layer, 4 ... simultaneous multilayer coextrusion film a means to contain a light-shielding substance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-132555 (JP, A) JP-A-56-40550 (JP, A) JP-A-60-155210 (JP, A) JP-A-60- 35728 (JP, A) JP 61-42654 (JP, A) JP 57-60129 (JP, B2) JP 4-80372 (JP, B2) JP 5-53412 (JP, B2) Japanese Patent Publication 4-77893 (JP, B2)

Claims (5)

[Claims] 1. A linear low-density polyethylene resin, which is a copolymer of ethylene and α-olefin, is 30 to 99.49% by weight, carbon black is 0.5 to 10% by weight, and a lubricant is
0.01 ~ 1.00 wt% heat seal layer, the inner layer having a static friction coefficient of 0.12 ~ 0.37, an intermediate layer formed of a thermoplastic resin, the static friction coefficient formed of a thermoplastic resin is 0.05 or more greater than the inner layer A simultaneous multilayer coextrusion light-shielding film having an outer layer having an absolute value of 0.19 or more, and an adhesive strength between the inner layer and the intermediate layer and an outer layer and the intermediate layer of 10 g / 15 mm width or more. Packaging material for photographic materials 2. The packaging material for a photographic light-sensitive material according to claim 1, wherein the linear low-density polyethylene resin comprises a copolymer resin of ethylene and an α-olefin having 6 or more carbon atoms. 3. The outermost thermoplastic resin comprises at least one of various polyethylene resins or ethylene copolymer resins.
The packaging material for a photographic light-sensitive material according to claim 1 or 2, wherein the packaging material contains at least 5% by weight. 4. The packaging material for a photographic light-sensitive material according to claim 1, wherein the intermediate layer contains an antistatic agent and / or a conductive substance. 5. A linear low-density polyethylene resin which is a copolymer of ethylene and α-olefin is 30 to 99.49% by weight, carbon black is 0.5 to 10% by weight, and a lubricant is
0.01 ~ 1.00 wt% heat seal layer, the inner layer having a static friction coefficient of 0.12 ~ 0.37, an intermediate layer formed of a thermoplastic resin, the static friction coefficient formed of a thermoplastic resin is 0.05 or more greater than the inner layer A package for a photographic light-sensitive material, comprising an outer layer having an absolute value of 0.19 or more, and a simultaneous multilayer coextrusion light-shielding film having an inner layer and an intermediate layer and an outer layer and an intermediate layer having an adhesive strength of 10 g / 15 mm width or more. A method for packaging a photographic light-sensitive material, characterized in that a bag is formed by using a material so that an inner layer is an inner surface, and the photographic light-sensitive material is stored in the bag.