JP2598306B2 - Packaging materials for photographic photosensitive materials - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a packaging material suitable for packaging a photosensitive material, particularly a photographic photosensitive 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 the uses thereof.

As a packaging material for photographic light-sensitive materials, which loses its quality value when exposed to light, a packaging material that completely blocks light is used. In this case, the required properties are the suitability for packaging material slits, gas barrier properties, light shielding properties, moisture proofness, rigidity, physical strength (rupture strength, tear strength, impact puncture strength, gelbo test strength, friction strength, etc.) Seal strength, cut seal property, hot tack property, contaminant seal property, etc.), antistatic property, flatness, slip properties, and the like.

Conventionally, packaging materials for photographic light-sensitive materials have been made of high-pressure branched low-density polyethylene (hereinafter referred to as LD) incorporating carbon black.
As shown in FIG. 13, a high-density polyethylene (hereinafter, referred to as HDPE) resin film 9a,
There was a composite laminate film in which a plurality of films were laminated.

As a composite laminate film, for example, as shown in FIG. 14, a metal foil 11 and a flexible sheet 5 are provided between an LDPE resin film 7a containing a light-shielding substance and an adhesive layer 3.
There was a film laminated in 3.

Further, as shown in FIG. 15, on both sides of the metal foil 11, there was a film obtained by laminating uniaxially stretched films 8a, 8a having a predetermined stretching ratio so that the stretching axis was at a predetermined angle. (Japanese Utility Model Publication No. 61-20590).

Further, as shown in FIG. 16, on both sides of the metal foil 11, an L-LDPE resin film 10a obtained by adding a carbon black to a linear low-density polyethylene (hereinafter referred to as L-LDPE) resin.
There was a laminated film in which 10a was laminated (JP-A-60-189)
No. 438, etc.).

[Problems to be solved by the invention]

However, packaging materials such as LDPE resin film into which carbon black has been kneaded and HDPE resin film shown in Fig. 13 have poor heat sealability and physical strength (particularly tearing strength and impact piercing strength), and are not suitable for packaging and transportation. It is difficult to ensure light-shielding, moisture-proof, and gas-barrier properties due to holes, tears, and peeling of the heat-sealed part, especially roll-shaped photographic materials and sheet-shaped photographic materials weighing 1 kg or more It was difficult to put it into practical use as a sealed light-shielding bag.

In addition, the LDPE resin film containing carbon black and the aluminum foil, shown in FIG. 14, a film obtained by laminating a flexible sheet has a small physical strength such as a tear strength despite its thick thickness, and has poor heat seal suitability.
During packaging and transport, peeling of the bag and heat-sealed portions occurred, making it difficult to secure light-shielding properties, moisture-proof properties, and gas barrier properties, and were expensive.

The cross-laminated film shown in FIG.
Since it is composed only of the PE resin film, it has a low impact hole punching strength, has poor heat sealing suitability, and requires a laminating step of laminating another flexible sheet, which is expensive.

In addition, L-LDPE containing carbon black shown in FIG.
A laminated film made of a resin film has good heat sealing suitability, excellent tear strength and impact piercing strength, is inexpensive and is excellent as a packaging material for photographic materials, but L-LD
Laminated film of PE resin film and aluminum foil has low Young's modulus and insufficient tensile strength and rupture strength.Laminated film is stretched and thinned, and holes and tears do not occur, but light-shielding properties and moisture-proof properties cannot be secured. There has occurred.

For this reason, a nylon resin film obtained by vacuum-depositing aluminum having heat resistance, which is expensive but has a large Young's modulus, and a film obtained by laminating a polyester resin film have been put to practical use. However, this method requires a laminating step for laminating, and has a drawback that loss occurs in an aluminum vacuum evaporation step, a biaxially stretched film manufacturing step, and the like, resulting in an expensive packaging material.

The present invention solves the above problems, heat sealability,
Excellent physical strength (tensile strength, tear strength, impact puncture strength, burst strength, etc.), and all properties necessary for ensuring the quality of photographic materials, such as light-shielding properties, moisture-proof properties, and gas barrier properties, without using other flexible sheets. It is an object of the present invention to provide an inexpensive packaging material for photographic light-sensitive materials that can be secured.

[Means for solving the problem]

The present invention has been made to achieve the above object, and has at least one or more different uniaxially co-extruded uniaxial molecular orientation films having an HDPE resin-based film layer and an L-LDPE resin-based film layer. This has been solved by laminating the molecular orientation films so that the molecular orientation axes intersect.

The multi-layer co-extruded uniaxial molecular orientation film of the present invention is laminated so that the molecular orientation axes intersect. At least another different uniaxial molecular orientation film is a resin composition, a molecular orientation axis, a molecular orientation degree (including a stretching ratio). The number of film layers and the structure of the film layers may be different from those of the multi-layer co-extruded uniaxial molecular orientation film of the present invention. In particular, when laminating on the surface (anti-heat sealing surface), use a uniaxial molecular orientation film having a high melting point, and when using as a heat sealing layer, use a uniaxial molecular orientation film containing an ethylene copolymer resin and having excellent heat sealing suitability. Is preferred.

That is, the packaging material for a photographic light-sensitive material of the present invention has a density of 0.941 g / cm ³ or more and a melt index of 0.1 to 1.0 g / 10.
And a high-density polyethylene resin film layer containing 50% by weight or more of high-density polyethylene resin having a Vicat softening point of 120 ° C or more, and a density index of 0.940 g / cm ³ or less and a low index.
0.5-15.0g / 10min linear low density polyethylene resin for 30
At least one of the high-density polyethylene resin-based film layer and the linear low-density polyethylene resin-based film layer. Two or more multilayer co-extruded uniaxial molecular orientation films each containing 0.001 to 2.0% by weight of an antioxidant in one layer and at least another different uniaxial molecular orientation film are laminated so that the molecular orientation axes intersect. And at least one layer having a light-shielding property.

The HDPE resin-based film layer has a density of 0.941 g / cm ³ or more and a melt index (measured under the standard conditions of JIS K 6760-1981; hereinafter referred to as MI) of 0.1 to 1.0 g / 10 min. Contains more. If this HDPE resin is less than 50% by weight, the molecular orientation is insufficient and the tear strength as a laminated film cannot be sufficiently ensured. The density (JIS K 6760−
If measured in 1981) is less than 0.941 g / cm ³ , the molecular orientation is insufficient and the film surface strength, Young's modulus, cross laminating effect, etc. are small, and do not meet the purpose of improving physical strength.

Further, when MI is less than 0.1 g / cm ³ , the motor load increases, the amount of resin discharged decreases, and the film formability decreases. In particular, a practical problem arises when adding a light-shielding substance. When the MI exceeds 1.0 g / 10 minutes, the molecular orientation is insufficient and the tear strength as a laminated film cannot be sufficiently secured. In the present invention, the uniaxial molecular orientation film refers to a film in which the difference between the tear strength in the molecular orientation axis direction and the tear strength in the direction perpendicular to the molecular orientation axis direction is 1.5 times or more.

The HDPE resin useful in the present invention is a polyethylene resin obtained by a medium-low pressure method and has a density in the range of 0.941 to 0.975 g / cm ³ . Preferred for the HDPE resin-based film layer used in the present invention is a linear structure having a small number of branches obtained by a low pressure method, having heat resistance, high crystallinity, and crystallization and molecular orientation immediately after film formation. Are easy to occur and have a large Young's modulus in the above characteristic value range.

As the other resin used for the HDPE resin-based film layer, a polyolefin-based resin is preferable, and the physical strength is improved.
Ethylene copolymer resin is particularly preferred from the viewpoint of improving heat sealing suitability.

The HDPE resin-based film layer preferably has a softening point of 120 ° C. or higher.

The L-LDPE resin film layer has a density (JIS K 6760-19
81 is less than 0.940 g / cm ³ and MI is (JIS K 6760-19)
81 standard conditions) containing 30% by weight or more of L-LDPE resin of 0.5 to 15.0 g / 10 min. If this L-LDPE resin is less than 30% by weight, physical strength and heat sealing suitability will decrease. On the other hand, if the density exceeds 0.940 g / cm ³ , the strength of the impact hole is reduced, the molecules are easily oriented in the longitudinal direction, and the tear strength in the longitudinal direction is significantly reduced. Further, the heat sealability also deteriorates. Furthermore, if the MI is less than 0.5 g / 10 minutes, the fluidity of the resin is insufficient, so that the current load is increased, the film forming speed is reduced, and melt fracture occurs and the film surface is rough, which is not practical. . MI is 15.0g / 10
If the amount exceeds the above range, not only the physical strength is reduced, but also the bubbles become unstable, and uneven thickness and streaks occur.

L-LDPE resin is referred to as a third polyethylene resin,
It is a low-cost, high-strength resin that meets the needs of the era of energy and resource savings combining the advantages of medium / low density, high density polyethylene resins. This resin which is preferable for the present invention has ethylene and carbon number of 3 to 13 by a low pressure method or a high pressure improvement method.
And preferably 4 to 10 α-olefins, and is a low- to medium-density polyethylene resin having a linear linear structure with short branches.

As the α-olefin, butene-1, octene-1,
Hexene-1, 4-methylpentene-1, heptene-
1, etc. are used. Density is generally about low-medium density polyethylene resin, but used in the present invention is 0.87-
L-LDPE resin in the range of 0.940 g / cm ² .

If a specific example of L-LDPE resin is shown by a trade name, G resin,
TUFLIN, Nackflex (UCC), Dourex (Dow Chemical), Scrair (DuPont Canada), Marlex (Philips), Excellen (Sumitomo Chemical), NUC Polyethylene-LL, TUFTHENE (Nihon Unicar), Neozex and Ultzex (Mitsui Petrochemical), Nisseki Linirex (Nippon Petrochemical), Idemitsu Polyethylene-L, MORETEC (Idemitsu Petrochemical), Stamirex (DSM), and the like.

As another resin used for the L-LDPE resin film layer, a polyolefin-based resin is preferable, and an ethylene copolymer resin is particularly preferable. Further, it is preferable to add carbon black, a lubricant, or an antiblocking agent or an antioxidant to the L-LDPE resin-based film layer. For example, 0.01 to 5.0% by weight of silicon dioxide and 0.0
Addition of 5 to 20.0% by weight, 0.05 to 5.0% by weight of a plate-like substance having a layered crystal structure (talc, aluminum powder, aluminum paste, pyroferrite, kaolin, sericite, etc.) can prevent blocking and improve light shielding. It is preferred in terms of.

The L-LDPE resin film layer has a softening point of 105 ° C.
The following is preferred in terms of improving physical strength and heat sealing properties.

At least one is formed of a multilayer co-extruded uniaxial molecular orientation film having the above-described HDPE resin-based film layer and the L-LDPE resin-based film layer.

As a molding method and a molding machine for the multilayer co-extruded uniaxial molecular orientation film, for example, JP-A-47-34656,
JP-A-8-1000046, JP-B-40-5319, JP-B-47-38621
No. 47-39927, No. 53-18072, USP
There are facilities and methods of the type disclosed in Japanese Patent No. 3,322,613. A conventionally known method can be used as a forming method, a forming machine, and the like for a horizontal uniaxial or vertical uniaxial molecular orientation film.

In the present invention, the uniaxial molecular orientation film refers to a film in which the difference between the tear strength in the molecular orientation axis direction and the tear strength in the direction perpendicular to the molecular orientation axis direction is 1.5 times or more. The direction in which the tear strength is small at this time is defined as the uniaxial molecular orientation direction in the present invention.

Regarding the molecular orientation method, regardless of the most commonly used stretching method or the method of discharging from a narrow slot slot using a highly crystallized resin that is easily molecularly oriented, the blow ratio is reduced by using an inflation film to reduce the length. A film having a tear strength of 50 g in the vertical direction and a tear strength of 300 g in the horizontal direction of an inflation film is defined as a vertical uniaxial molecular orientation film.

Also, this multilayer co-extruded uniaxial molecular orientation film is HDPE
If a resin-based film layer and an L-LDPE resin-based film layer are provided, a film layer composed of various thermoplastic resins or the like may be laminated by co-extrusion in the middle or outside thereof. The molecular orientation axis of the multilayer co-extruded uniaxial molecular orientation film may be vertical, horizontal or oblique. The multi-layer co-extruded uniaxial molecular orientation film essential to the present invention and the at least one other mono-axial molecular orientation film laminated so that the molecular orientation axes intersect are the multi-layer co-extruded uniaxial film essential to the present invention. A monolayer uniaxial molecular orientation film may be different from the molecular orientation film in the layer configuration, the resin composition and the like. Further, it may be a metal thin film processed uniaxial molecular orientation film having a light blocking effect or a metal thin film processed uniaxial molecular orientation film having no light blocking effect. Even a uniaxial molecular orientation film having light shielding properties,
A uniaxial molecular orientation film having no light-shielding property may be used. The molecular orientation axis may be vertical, horizontal or oblique.

Such a multilayer co-extruded uniaxial molecular orientation film and at least one or more different uniaxial molecular orientation films,
The layers are directly laminated with or without an adhesive layer so that their molecular orientation axes intersect. As an adhesive for laminating the multilayer co-extruded uniaxial molecular orientation film and at least one or more different uniaxial molecular orientation films, various kinds of polyethylene resins, various polypropylene resins, polybutene resins, polyolefin thermoplastic resins such as polyisobutylene resins, etc. Hot melt adhesives, ethylene-propylene copolymer resins, ethylene-vinyl acetate copolymer resins, ethylene-copolymer resins such as ethylene-ethyl acrylate copolymer resins, ethylene-acrylic acid copolymer resins, ionomer resins, etc. There is a thermoplastic resin hot melt adhesive, other hot melt type rubber-based adhesives and the like, and the solution adhesive includes an adhesive for wet lamination, and an emulsion or latex adhesive. Representative examples of emulsion adhesives include polyvinyl acetate resin, vinyl acetate-ethylene copolymer resin, vinyl acetate resin and acrylate copolymer resin, vinyl acetate resin and maleate ester copolymer resin, acrylic acid There are emulsions such as copolymer resins and ethylene-acrylic acid copolymer resins.

Representative examples of latex type adhesives include rubber latex such as natural rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), and chloroprene rubber (CR). Further, examples of the adhesive for dry lamination include an isocyanate-based adhesive and a urethane-based adhesive. Other known adhesives such as hot melt laminate adhesives, pressure-sensitive adhesives, and heat-sensitive adhesives blended with paraffin wax, microcrystalline wax, ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer resin, etc. Can be used. Polyolefin resin adhesive for extrusion lamination
More specifically, in addition to various polyethylene resins, polypropylene resins, polyolefin resins such as polybutylene resins, and ethylene copolymer (EVA, EEA, etc.) resins, L
-Ionomer resin (ion copolymer resin) such as LDPE resin, which is obtained by copolymerizing ethylene monomer with some other monomer (α-olefin), Surlyn of Dupont, Himilan of Mitsui Polychemicals, etc. Mitsui Petrochemical Co., Ltd.
And ADMIC of Mitsubishi Yuka Co., Ltd. (adhesive polymer).

The thickness of the adhesive layer made of such an adhesive is preferably 50 μm or less, particularly 20 μm or less, and most preferably 13 μm or less from the viewpoint of improving physical strength (particularly, tear strength).

A flexible sheet layer can be laminated between or outside the multilayer co-extruded uniaxial molecular orientation film. As the flexible sheet layer, a thermoplastic resin film, for example, various polyethylene resins, ethylene copolymer resin, polypropylene resin, polyvinyl chloride resin,
Known films such as polyvinylidene chloride resin, polyamide resin, polycarbonate resin, polyester resin,
There are non-oriented films, multi-axial molecular oriented films, and films of modified resins, mixed resins, cross-linked resins and the like. In addition, a metal thin film processed film (a typical one is an aluminum vacuum deposited film), a cellulose acetate film, cellophane, polyvinyl alcohol, various papers (neutral paper, dust-free paper and synthetic paper are particularly preferred), various metal foils (Typical examples are aluminum foil) and nonwoven fabrics.

A particularly preferred flexible sheet layer has a basis weight of 20 to 400 g.
/ m ² of various types of paper (unbleached kraft paper, semi-bleached kraft paper, bleached kraft paper, bleached sulphite paper, hineri base paper, clupak paper, duostress paper, white board paper, photographic base paper, pure white roll paper, coated paper , Imitation paper, neutral paper, glassine paper, etc.),
Metal foil (aluminum foil, tin foil, zinc foil, lead foil, iron foil, etc.) with a thickness of 5 to 50 μm, biaxially stretched thermoplastic resin film, cellophane, and aluminum vapor-deposited paper, metal thin film processed film (typically Is an aluminum vacuum-deposited thermoplastic resin film).

Further, the packaging material for a photographic light-sensitive material of the present invention comprises at least one light-shielding layer that blocks visible light and ultraviolet light.
Layers. This light-shielding layer is formed of an HDPE resin-based film layer, an L-LDPE resin-based film layer, and at least one or more uniaxial molecular orientation films laminated so as to intersect with the multilayer co-extruded uniaxial molecular orientation film of the present invention. , An adhesive layer, and when laminated, an intermediate layer, a metal foil, a metal thin film processed film, or various other flexible sheet layers.

In order to have a light-shielding property, a light-shielding substance is formed by forming a metal foil, processing a metal thin film, or adding a light-shielding substance. This light-shielding substance means a substance which can be kneaded or dispersed in each layer and does not transmit visible light, ultraviolet light and the like. As the light-shielding substance that can be used in the present invention, various carbon blacks, graphite, graphite, iron oxide, zinc white,
Organic pigments such as titanium oxide, clay, aluminum powder, aluminum paste, calcium carbonate, mica, barium sulfate, talc, cadmium pigments, red iron oxide, cobalt blue, copper phthalocyanine pigments, monoazo or polyazo pigments, and aniline black Examples include inorganic pigments and coloring dyes.

Among these light-shielding substances, in terms of quality, cost, light-shielding ability, etc., color pigments which easily absorb or reflect light, in particular, various carbon blacks of black pigment, aluminum powder of light-reflective light-shielding substance, and aluminum It is preferable to remove the low volatility from the paste.

As a method of blending these light-shielding substances in each layer, there are a master batch coloring method, a die color granulation method, a compound coloring method, a dry color method, a liquid color method and the like, which have been conventionally performed. The light-shielding substance may be in the form of a powdery colorant, a granular colorant, a pastey colorant, a wettable colorant, a masterbatch pellet, a dye / pigment, a colored pellet, or the like depending on the resin used, the machine used, the cost, and the like.

Carbon black is classified into gas black, oil furnace black, channel black, anthracene black, acetylene black, oil smoke, pine smoke, animal black, vegetable black and the like depending on the raw material.

Among these carbon blacks, light shielding, price,
In terms of dispersibility, conductivity, and photographic properties, those having a pH of 5 to 9, particularly pH 6 to 8, and an average particle diameter of 10 to 200 mμ are preferable, and particularly those having a pH of 6 to 9,
Furnace black and acetylene carbon black having an average particle diameter of 15 to 80 μm are preferred. The use of such a pH and particle size reduces the occurrence of fogging of the photographic light-sensitive material, reduces the occurrence of increase / decrease in photosensitivity, has a large light-shielding ability, and produces a lump-shaped non-uniform substance, fisheye and It is possible to produce a packaging material having various advantages, such as a difficulty in generating pinholes. Further, when used as a packaging material for photographic light-sensitive materials, it is preferable to use carbon black having a free sulfur content of 1000 ppm or less for preventing fog and stabilizing the photosensitivity.

Furnace carbon black is preferred in the packaging material for photographic light-sensitive materials of the present invention for the purpose of improving light-shielding properties, cost and physical properties, and acetylene carbon black and Ketjen carbon black, which are expensive but have an antistatic effect, are also preferred. Channel black is expensive and often has a bad influence on a photographic material.

The content of carbon black is preferably 0.05 to 20.0% by weight. If the content is less than 0.05% by weight, it is necessary to further laminate another light-shielding layer in order to secure the light-shielding property. If the content exceeds 20.0% by weight, the physical strength and heat-sealing property of the film are reduced, and a lump-shaped nonuniform substance is generated. And the cost increases.

In the packaging material for a photographic light-sensitive material of the present invention, the thermal stability of a multilayer co-extruded uniaxial molecular orientation film, other performance improvements,
It is preferable to add an antioxidant, a lubricant and other additives in order to improve the ease of handling.

As the antioxidant, phenol-based antioxidants include n
Octadecyl-3 (3 ', 5'-di-tert-butyl 4'hydroxyphenyl) propinate, 2,6-di-tert-butyl 4-methylphenol, 2,6-di-tert-butyl-p-cresol, 2 , 2'-methylenebis (4-methyl-6-t-
Butylphenol), 4,4'-thiobis (3-methyl-6
-T-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), stearyl-β (3,5-di-4-butyl4-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.

As the sulfur-based compounds, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, laurylstearylthiodipropionate, distearyl-3'-thiodipropionate, ditridecyl- 3,3'-thiodipropionate and the like.

Examples of phosphorus-based compounds include trinonyl phenyl phosphite and triphenyl phosphite.

Among them, phenol-based antioxidants and phosphorus-based antioxidants are particularly preferred.

In particular, 2,6-di-t-butyl-p-cresol (BHT) and a low volatility high molecular weight cresol type antioxidant (trade name Ir)
eganox 1010, Ireganox 1076, Topano ICA, Ionox 330 etc.)
It is effective to use one or more, especially two or more, of dilauryl thiodipropionate, distearyl thiodipropionate and dialkyl phosphate.

The amount of addition is preferably 0.001 to 2.0% by weight when used alone or in combination of two or more.

If the amount is less than 0.001% by weight, the effect of the addition is almost nil. On the other hand, if the added amount exceeds 2.0% by weight, the photographic film utilizing the oxidizing and reducing actions may be adversely affected and the performance may be abnormal. For this reason, it is preferable to add the antioxidant in the minimum amount that does not cause coloring failure or blemishes.

Commercial products include various types of Irganox from Ciba-Geigy and Sumilizer BHR, Sumilizer BH-76, S from Sumitomo Chemical Co., Ltd.
umilizer WX-R, Sumilizer BP-101, etc.

Further, when an antioxidant is further used in combination with carbon black or the like, antioxidation exhibits a synergistic effect.

Preferred examples of the lubricant include silicone-based dimethylpolysiloxanes of various grades, fatty acid amides such as oleamide, stearamide, erucamide, and bisfatty acid amide, and alkylamines such as electrostripper. -TS-2 (Kao soap) and the like.

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

(Types of additives) (Typical examples) (1) plasticizer; phthalate ester, glycol ester, fatty acid ester, (2) stabilizer; lead, cadmium, zinc, alkaline earth metal, organic tin (3) Antistatic agents; cationic surfactants, anionic surfactants, nonionic surfactants, surfactants, various carbon blacks, metal powders, graphite, etc. (4) Flame retardants; phosphate esters , Halogenated phosphoric acid esters, halides, inorganic substances, combined phosphorus polyols, etc. (5) Fillers; alumina, kaolin, clay, calcium carbonate, mica, talc, titanium oxide, silica, etc. (6) Reinforcing agents; glass roving, metal fibers , Glass fiber, glass milled fiber, carbon fiber, etc. (7) Colorant; inorganic pigment (Al, Fe ₂ O ₃ , TiO ₂ , ZnO, CdS
Etc.), organic pigments (carbon black, dyes, etc.), etc. (8) foaming agents; inorganic foaming agents (ammonium carbonate, sodium bicarbonate), organic foaming agents (nitroso-based, azo-based), etc. (9) anti-deterioration agents; ultraviolet absorbers , Antioxidants, metal deactivators, peroxide decomposers, etc. (10) Coupling agents; silane-based, titanate-based, chromium-based, aluminum-based, etc. (11) Deodorants, water absorbers, oxygen absorbers, There are a fragrance, a dehumidifier, a water-absorbing resin and the like.

The packaging material for photographic light-sensitive materials of the present invention is suitable for photographic light-sensitive materials, but can also be used for foodstuffs, pharmaceuticals, chemical substances, and the like.

In particular, silver halide photographic materials whose quality is destroyed by a slight amount of gas, light or humidity, light-fixing type heat-sensitive materials,
Photosensitive materials such as diazo photographic photosensitive materials, photosensitive resins, ultraviolet-curable photosensitive materials, lithographic printing photosensitive materials, direct positive photographic photosensitive materials, self-developed photographic photosensitive materials, diffusion transfer photographic photosensitive materials, and photosensitive heat-sensitive materials Suitable for materials.

When the packaging material for a photosensitive material of the present invention is applied to, for example, the above photosensitive material, a single flat bag, a double flat bag, a freestanding bag, a single gusset bag, a double gusset bag, a laminated film,
The present invention can be used for all known forms such as inner and outer sticking of a moisture-proof box, inner and outer sticking of a light-shielding magazine loaded in a bright room, and leader paper.

The method of bag making depends on the properties of the laminated film used,
Conventionally known plastic film sealing methods such as heat sealing, fusing sealing, impulse sealing, ultrasonic sealing, and high frequency sealing. In addition, it is also possible to make a bag by using an appropriate adhesive, an adhesive or the like.

[Action]

In the packaging material for a photographic light-sensitive material of the present invention, a multilayer co-extruded uniaxial molecular orientation film is formed of an HDPE resin-based film layer and an L-LD.
Because of the structure of the PE resin film layer, it has excellent heat sealing properties, tear strength, and impact drilling strength, which are the advantages of L-LDPE resin, and has heat resistance due to insufficient tensile strength, abrasion resistance and a small Young's modulus. Heat sealability supplemented with HDPE resin,
All properties such as physical strength and heat resistance shall be excellent.

And since this film has a structure in which at least one or more uniaxial molecular orientation films and molecular orientation axes are crossed, the physical strength of the film, particularly the tear strength, the breaking strength, and the heat sealing strength, are reduced. Significantly improved.

〔Example〕

An embodiment of the packaging material for a photographic light-sensitive material of the present invention will be described with reference to FIGS.

1 to 12 are partial cross-sectional views showing a layer structure of a packaging material for a photosensitive material. Arrows in the figure indicate the molecular orientation directions.

1 is a multilayer co-extruded oblique uniaxial molecular orientation film I comprising an HDPE resin-based film layer 1a containing a light-shielding substance and an L-LDPE resin-based film layer 2a.
a and an oblique uniaxial light-shielding thermoplastic resin film 8 a are laminated with an adhesive layer 3.

The packaging material for photographic light-sensitive material shown in FIG. 2 is composed of the same multilayer co-extruded oblique uniaxial molecular orientation film Ia as in FIG. 1 and the oblique uniaxial molecular orientation thermoplastic resin film 7a obtained by processing the metal thin film processing layer 6 as an adhesive layer. 3 are laminated.

The packaging material for photographic light-sensitive material shown in FIG. 3 is composed of an HDPE resin-based film layer 1a containing a light-shielding substance and L-LDPE containing a light-shielding substance.
A multilayer coextruded longitudinal uniaxial molecular orientation film Ia composed of a resin-based film layer 2a and an oblique uniaxial molecular orientation light-shielding thermoplastic resin film 8a are laminated with an adhesive layer 3.

The packaging material for a photographic light-sensitive material shown in FIG. 4 has an HDPE resin-based film layer 1 containing no light-shielding substance and an L-
A multilayer co-extruded vertical uniaxial molecular orientation film Ia composed of an LDPE resin-based film layer 2a and a horizontal uniaxial molecular orientation thermoplastic resin film 7 obtained by processing a metal thin film processing layer 6 are laminated with an adhesive layer 3.

The packaging material for photographic light-sensitive material shown in FIG. 5 is a multilayer co-extruded longitudinally uniaxial molecular orientation film I comprising an HDPE resin-based film layer 1 and an L-LDPE resin film layer 2 containing no light-shielding substance.
And a cross-laminate film having a metal thin film processing layer 6 laminated with an adhesive layer 3a containing a light-shielding substance.

FIG. 6 shows a packaging material for a photographic light-sensitive material, in which the multilayer co-extruded longitudinal uniaxial molecular orientation film Ia of FIG. As described above) are laminated with the adhesive layer 3.

The packaging material for photographic light-sensitive material shown in FIG. 7 is obtained by laminating one multilayer co-extruded longitudinal uniaxial molecular orientation film Ia, metal foil 11 and horizontal uniaxial molecular orientation thermoplastic resin film 8 with an adhesive layer 3. .

The packaging material for photographic light-sensitive material shown in FIG. 8 comprises a multilayer co-extruded longitudinally uniaxial molecular orientation film Ia, a laterally uniaxial molecularly oriented thermoplastic resin film 8 and a longitudinally uniaxial molecularly oriented light-shielding thermoplastic resin film 8a with an adhesive layer 3. Each is laminated.

The packaging material for photographic light-sensitive material shown in FIG. 9 has a multilayer co-extruded longitudinal uniaxial molecular orientation film Ia and an oblique uniaxial molecular orientation thermoplastic resin film 8 and a metal thin film processed lateral uniaxial molecular orientation thermoplastic resin film 7 bonded to both sides. Each of the layers 3 is laminated.

The packaging material for photographic photosensitive material in FIG. 10 is obtained by laminating a metal thin film-processed flexible sheet 7 with an adhesive layer 3 on the oblique uniaxial molecular orientation light-shielding thermoplastic resin film 8a of the packaging material for photosensitive material in FIG. .

FIG. 11 shows a multi-layer co-extruded uniaxial molecular orientation film Ia having the same layer structure as that of FIG.

FIG. 12 shows a multi-layer co-extruded oblique uniaxial molecular orientation film Ia having the same layer structure as that of FIG. 1 on both sides of the flexible sheet 5 with an adhesive layer 3 interposed therebetween, and an oblique uniaxial molecular orientation thermoplastic resin on the outside with a metal thin film. The film 7 is laminated.

Next, experimental results comparing the characteristics of the products I to III of the present invention and the conventional products I to IV will be described.

Invention product I Invention product I corresponds to the layer configuration in FIG.

The HDPE resin-based film layer 1a has an MI of 0.4 g / 10 minutes and a density of
HDPE resin 98 with 0.964 g / cm ³ and Vicat softening point of 126 ° C
% By weight and 2% by weight of aluminum powder.
25 μm.

The L-LDPE resin-based film layer 2a is composed of 75% by weight of an L-LDPE resin which is a copolymer resin of ethylene and 4-methylpentene-1 having an MI of 2.1 g / 10 minutes and a density of 0.920 g / cm ³ , and silicon
0.25% by weight, oil furnace carbon black 4.5% by weight, oleic amide 0.05% by weight, phenolic antioxidant 0.2% by weight, MI 0.9g / 10min and density of 0.
It consists of 20% by weight of 954 g / cm ³ HDPE resin and has a thickness of 25 μm.

The multilayer co-extruded oblique uniaxial molecular orientation film composed of these layers is obliquely I-axis oriented at 45 degrees. The uniaxial molecular orientation thermoplastic resin film layer 8a is made of carbon black.
4.5 MI is 0.4 g / 10 min comprising by weight%, a density of 0.964 g / cm ³ HDPE
A light-shielding HDPE resin film having a thickness of 50 μm and uniaxially stretched at 45 ° using a resin.

Then, they are laminated via an LDPE resin extrusion laminate adhesive layer 3 having a thickness of 10 μm so that the molecular orientation axis becomes 90 degrees.

Inventive product II Inventive product II corresponds to the layer configuration in FIG.

HDPE resin film layer 1a, L-LDPE resin film layer
The resin composition and thickness of 2a and the adhesive layer 3 are the same as those of the product I of the present invention. However, a multi-layer co-extruded longitudinal uniaxial molecular orientation film Ia was formed by an inflation film molding method.

As another one or more different uniaxial molecular orientation films, MI containing 2% by weight of titanium oxide has a MI of 0.4 g / 10 minutes and a density of 0.964.
g / cm ³ HDPE resin 78% by weight, MI 2.1g / 10min, density 0.92
0 g / cm ³ ethylene and 4-methylpentene-1 copolymer resin
A 100 μm-thick cross-laminate film was used in which two 45% -thick 45 ° uniaxially stretched HDPE resin-based films 8 each containing 20% by weight were laminated so that the molecular orientation axes intersect with an adhesive layer having a thickness of 10 μm. .

The metal thin film processing layer 6 was a 400 ° aluminum vacuum deposited film, and the flexible sheet 5 was a 15 μm thick biaxially stretched nylon resin film.

As the adhesive layer 3, an LDPE resin extrusion laminate adhesive layer having a thickness of 15 μm was used.

Invention product III Invention product III corresponds to the layer configuration in FIG.

HDPE resin film layer 1a, L-LDPE resin film layer
2a, the diagonally uniaxially stretched light-shielding HDPE resin film 8a and the adhesive layer 3 are the same as the product I of the present invention. The metal thin film processing layer 6 is 40
A 0 ° aluminum vacuum deposited film was used.

Conventional product I Conventional product I corresponds to the layer configuration in FIG.

The HDPE resin film 9a has an MI of 0.4 g / 10 minutes containing 3% by weight of furnace carbon black and a density of 0.964 g / cm ³ of H.
This is a light-shielding HDPE resin film having a thickness of 100 μm manufactured by a blown film molding method using DPE resin.

Conventional product II Conventional product II corresponds to the layer configuration in FIG.

 The metal foil 11 is an aluminum foil having a thickness of 7 μm.

The uniaxially stretched film 8a is a light-shielding HD that is uniaxially stretched at 45 ° with a thickness of 45 μm using HDPE resin having an MI of 0.4 g / 10 minutes containing 4.5% by weight of carbon black and a density of 0.964 g / cm ^3.
It is a PE resin film.

The adhesive layer 3 is an LDPE resin extrusion laminate adhesive layer having a thickness of 13 μm.

The crossing angle of the stretching axis of the uniaxially stretched HDPE resin film 8a is 90 degrees.

Conventional product III Conventional product III corresponds to the layer configuration in FIG.

The metal foil 11 is an aluminum foil having a thickness of 7 μm. L
-LDPE resin film 10a is 3% by weight of carbon black
The light-shielding L-LDPE resin film having the same resin composition as the L-LDPE resin-based film layer 2a of the product I of the present invention and having a thickness of 50 μm.

The adhesive layer 3 is an LDPE resin extrusion laminate adhesive layer and has a thickness of 15 μm.

Conventional product IV Conventional product IV corresponds to the layer configuration in FIG.

LDPE resin film 7a contains 3% by weight of carbon black
A light-shielding LDPE resin film having a thickness of 50 μm.

 The metal foil 11 is an aluminum foil having a thickness of 7 μm.

The flexible sheet layer 5 is bleached kraft paper having a basis weight of 35 g / m ² .

The adhesive layer 3 is an LDPE resin extrusion laminate adhesive layer having a thickness of 15 μm.

 The experimental results are shown in Table 1.

Evaluation is based on the following.

◎… Excellent ○… Excellent ●… Possible (within practical limits) ▲… Problem (improved poor) ×… Not practical * A tear strength Same as JISP8134 * B Impact drilling strength Toyo Seiki Film Impact Tester And the cone is
The test was performed with a half hemisphere and a load of 30 kg · cm. (However, the measurement was performed with one laminated film.) * C hot tack property (hot sealing property) Two packaging materials (width 1) immediately after heat sealing at 160 ° C.
5mm) is measured by the hot peel distance (cm) when the open end is pulled with a load of 45g on one side at a peel angle of 22.5 degrees.

※ perform heat-sealing after the cigarette butts were 150 mg / m ² dispersed on the surface of the D contaminants sealable each packaging material, two samples of judgment ※ E over time heat sealing strength film 15mm wide by measuring the sheet strength Overlap and heat seal under the conditions of the desired sealing temperature, sealing pressure 1kg / cm ² , sealing time 1 second, and after leaving for 3 months naturally (room temperature 20 ° C, humidity 65% RH), peel the sealing surface at 180 ° angle Find the load required to perform

* F film formability Each sample is simultaneously extruded in two layers and the resin prescription is described using an inflation film forming machine, the current load is low when forming a film with the film thickness, bubble stability, and film wrinkling occurs. * Suitability for G-bag making Comprehensively judge the suitability for heat sealing and the presence or absence of curling and wrinkles when making flat bags with an automatic bag making machine using each packaging material.

* H burst strength According to JISP8112 [Effects of the Invention] As described above, the present invention has large physical strengths such as tear strength, impact drilling strength, burst strength, etc.
It is possible to provide an inexpensive packaging material for photographic light-sensitive materials that is excellent in heat sealing suitability such as impurity sealing property, has high heat seal strength over time, has good film moldability, is excellent in bag making suitability, and is inexpensive.

[Brief description of the drawings]

1 to 12 are partial cross-sectional views showing the layer structure of an embodiment of the packaging material for photographic light-sensitive material of the present invention. FIG. 13 to FIG. 16 are partial cross-sectional views showing a layer structure of a conventional packaging material. I, Ia: Multi-layer co-extruded oblique uniaxial molecular orientation film 1, 1a: HDPE resin film layer 2, 2a: L-LDPE resin film layer 3, 3a: Adhesive layer, 4, 4a: Intermediate layer 5, 5a: flexible sheet 6: metal thin film processing layer 7, 7a: metal thin film processing flexible sheet 11: metal foil a; indicating that it contains a light-shielding substance

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-1541 (JP, A) JP-A-63-1540 (JP, A) JP-A-59-201848 (JP, A) JP-A-57-2018 6754 (JP, A) JP-A-63-85540 (JP, A) JP-A-63-85539 (JP, A) JP-A-60-35728 (JP, A)

Claims (1)

(57) [Claims] 1. A high-density polyethylene resin film layer containing a high-density polyethylene resin having a density of 0.941 g / cm ³ or more, a melt index of 0.1 to 1.0 g / 10 min, and a Vicat softening point of 120 ° C. or more at 50% by weight or more. And a linear low-density polyethylene resin having a density of 0.940 g / cm ³ or less and a rut index of 0.5 to 15.0 g / 10 minutes or more, and silicon dioxide of 0.01 to 5.0%.
% Of a linear low-density polyethylene resin-based film layer containing at least 1% by weight, and wherein at least one of the high-density polyethylene resin-based film layer and the linear low-density polyethylene resin-based film layer contains 0.001 to 2.0 % Of a multilayer co-extruded uniaxial molecular orientation film and at least another different uniaxial molecular orientation film are laminated so that the molecular orientation axes intersect, and at least one layer having a light-shielding property is provided. Packaging material for photographic light-sensitive material, comprising: