JPH0480372B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a packaging material for photographic materials. [Prior Art] Various types of packaging materials for photographic materials have been widely put into practical use, and various performances are required depending on the intended use. Packaging materials that completely block light are used as packaging materials for photographic materials that lose their quality value when exposed to light. In this case, the required properties include packaging material slit suitability, gas barrier properties, light shielding properties, moisture proofing properties, rigidity, physical strength (breaking strength, tear strength, impact puncturing strength, gelbo test strength, abrasion strength, etc.), and heat seal suitability ( heat seal strength,
Cut sealing properties, hot tack properties, contaminant sealing properties, etc.), antistatic properties, flatness, sliding properties, etc. It is considered difficult to have all of these properties in a single film material, and conventionally, single-layer films made of high-pressure branched low-density polyethylene (hereinafter referred to as LDPE) resin in which carbon black, pigments, etc. are kneaded have been used. Composite laminate films of LDPE films and flexible sheet layers such as paper, aluminum foil, and cellophane have been used. Examples of composite laminate films are shown in No. 8.
As shown in Fig. 9 and Fig. 9, the one in Fig. 8 has a metal foil layer 3 laminated on an LDPE resin light-shielding film layer 6a with an adhesive layer 2 interposed therebetween, and a flexible sheet layer 4 further laminated with an adhesive layer 2 interposed therebetween. It is something. In addition, in the case of FIG. 9, an LDPE resin light-shielding film layer 6a is further placed on the flexible sheet layer 4 of the composite laminate film as shown in FIG. 8 via an adhesive layer 2.
This is an example of laminated layers, and has been used, for example, in the packaging of color photographic paper. The present inventor has conducted extensive research to improve packaging materials for photosensitive materials, and has already developed a material with improved physical strength by combining two layers of uniaxially stretched films (Japanese Patent Laid-Open No. 57-6754). Disclosed. In addition, linear low-density polyethylene (hereinafter L-
Regarding packaging materials using resin (labeled as LDPE), at least one layer of a light-shielding film consisting of a polyethylene polymer and a light-shielding substance of 1% or more by weight, with 50% or more by weight of the total ethylene-based polymer being L-LDPE resin is also used. We have already disclosed what we have (Japanese Unexamined Patent Publication No. 132555/1983). [Problems to be Solved by the Invention] Although conventional composite laminate films have been constructed to improve the physical properties mentioned above, the physical properties are still not sufficient, and they tend to tear or form holes during packaging operations. There were drawbacks such as cracking and peeling of the heat seal part. Furthermore, adding a large amount of light-blocking substances such as carbon black will significantly deteriorate the physical strength, so the amount added should be around 3%, and the thickness of the film laminated with other flexible sheet layers should be 70μ or more. It was hot.
As a result, the packaging becomes bulky and the rigidity of the laminate film increases, resulting in poor packaging workability and high costs. For example, in the laminated film shown in FIG. 8, aluminum foil 3 is used to provide gas barrier properties, improve moisture resistance, and prevent static electricity. On the contrary, the problem worsened to a large extent, and the problem of breakage sometimes occurred, especially when packaging heavy items. Therefore, carbon black
Although the thickness of the LDPE resin light-shielding film layer has been increased to 70 μm or more, it still does not have sufficient physical strength, and for example, a seven-layer laminated film as shown in Figure 9 has been used for packaging color photographic paper. . In addition, in the case of the packaging material described in JP-A-57-6754, the physical strength such as tear strength is improved to some extent, but as the adhesive layer becomes thicker and the adhesive strength increases, not only does the tear strength decrease. Because it uses a uniaxially stretched high-density polyethylene film layer, it has poor heat-sealing properties and sometimes causes problems during processing and packaging. In addition, when a cross-laminated film is made by directly laminating uniaxially stretched film layers crosswise without using aluminum foil, pinholes occur in the gusset part of the gusset bag when the product is packaged in a gusset bag, making it difficult to use as a packaging material for photographic materials. could not be put to practical use due to poor light-shielding, moisture-proofing, and gas barrier properties. By using L-LDPE resin as a packaging material, physical strengths such as tear strength and Gelbo test strength can be increased, and the amount of light-shielding substance kneaded can be increased, and the above-mentioned problems can be improved. However, when the film thickness is reduced, wrinkles and film folding occur, resulting in insufficient tensile strength, sliding properties, rigidity, moisture resistance, gas barrier properties, manufacturing suitability, etc., and when the film thickness is increased, slitting suitability, cut sealing properties, etc. are insufficient. Getting worse. Therefore, film formability,
It has been desired to develop a packaging material that is suitable for processing machines, has excellent film properties, and is inexpensive. In particular, packaging materials for dental X-ray films, packaging materials for radiographic films (batch films) used to detect the radiation exposure of radiation workers, and
As a packaging material for vacuum-sealing X-ray film as described in Publication No. 24089, even a single thermoplastic resin film layer can satisfy all the characteristics required as a packaging material for photographic materials. The development of inexpensive packaging materials has been desired. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a packaging material for photographic materials that has improved product insertability, slit suitability, physical strength, heat seal suitability, etc. [Means for Solving the Problems] The present invention can achieve the above object with a light-shielding film containing at least four types: L-LDPE resin, high-density polyethylene (hereinafter referred to as HDPE) resin, carbon black, and a lubricant. This was done after discovering that. That is, the present invention uses a linear low density polyethylene resin of 50 to 95% by weight and a melt index (ASTM D 1238-65T test method) of 0.3 to 95% by weight.
1.5g/10min high density polyethylene resin 5-49.5% by weight, carbon black 0.1-10% by weight and lubricant
The present invention relates to a packaging material for photographic materials comprising a film containing at least 0.01 to 1.0% by weight of four components. The L-LDPE resin, which is the first component essential to the film of the present invention, is an ethylene-α resin obtained by copolymerizing ethylene with an α-olefin having 3 to 13 carbon atoms, preferably 4 to 10 carbon atoms, using a low-pressure method. - An olefin copolymer resin having a linear linear chain structure with short branches having an ethylene content of 85 to 99.5 mol% and an α-olefin content of 0.5 to 15 mol%. Generally, this material is L-LDPE resin (Linear
It is called Low Density Polyethylene (an abbreviation for linear low-density polyethylene). The most common polymerization processes are gas phase and liquid phase methods that use medium/low pressure equipment, but in recent years French
CDF has developed an ionic polymerization method using high-pressure equipment. In particular, low-pressure L-LDPE resin is preferred because of its low cost. A specific example of a product name is Unipol (UCC).
), Dowlex (Dow Chemical), Sclar (DuPont Canada), Marex (Philips), Neozex and Ultuzex (Mitsui Petrochemical), Nippon Linirex (Nippon Petrochemical), Stamilex (DSM), NUC Polyethylene- Examples include LL and TUFLIN (Japan Unicar). α-olefins include butene-1,
Octene-1, hexene-1, 4-methylpentene-1, heptene-1, etc. are used in amounts ranging from 0.5 to 15 mole percent of the polymer. These α
-Among olefins, 4-methylpentene-
1, hexene-1 and octene-1 are preferred.
The density is generally considered to be about that of low-medium density polyethylene resin, but many commercially available products have a density within the range of 0.87 to 0.95 g/cm ³ . Among these L-LDPE resins, those with an ethylene content of 90 to 99.5 mol%, an α-olefin content of 0.5 to 10 mol%, and a melt index ( (hereinafter referred to as MI) is 0.8 to 30g/10 minutes (ASTMD-
1238). Density is 0.870~0.940g/ ^cm3 (ASTMD−
1505), L by low pressure liquid phase process and gas phase process when α-olefin has 6 to 8 carbon atoms.
-LPDE resin. The most preferred representative product name is Mitsui Petrochemical Co., Ltd.'s Urtozex, which is an L-LDPE resin that uses 4-methylpentene-1, which has 6 carbon atoms, as an α-olefin side chain in ethylene. L-LDPE resins using octene-1 having 8 carbon atoms as the α-olefin side chain include Stamilex manufactured by DSM and Dowlex manufactured by The Dow Chemical Company. (All of the above three companies' products are L-LDPE resins produced by the low-pressure liquid phase process.) As for the low-pressure vapor phase process products, Nippon Unicar Co., Ltd.'s products use hexene-1 as the α-olefin side chain. There is TUFLIN. The content of L-LDPE resin in the film of the present invention is about 50 to 95% by weight, preferably about 60 to 93% by weight. It is the second component essential to the film of the present invention.
HDPE resin is a medium-low pressure polyethylene resin with a density (ASTM D1505-67 test method) of 0.940 to 0.970 g/
cm ³ and the melt index (ASTM D
1238-65T test method) is 0.3 to 1.5 g/10 minutes. The production methods include (1) the Phillips method and (2) the standard method as medium pressure methods, and as low pressure methods there is a method in which ethylene is polymerized at low pressure using a Ziegler catalyst. Preferred for the film of the present invention are:
It has a linear structure with few branches obtained by a low-pressure method.
High crystallinity, density 0.945~0.970g/ ^cm3 , and MI (ASTM D1237-65T test method) 0.3~
It is a high-density polyethylene resin with a yield of 1.5g/10 minutes. The content of HDPE resin in the film of the present invention is about 5 to 49.5% by weight, preferably 5 to 40% by weight. Carbon black, which is the third component essential to the film of the present invention, can be categorized by raw material: gas black, oil furnace black, channel black, anthracene black, acetylene black, oil smoke, pine smoke, animal black, vegetable black, etc. . Among these, light blocking properties,
Furnace carbon black is preferred from the viewpoint of cost and improved physical properties, and acetylene carbon black and ketsien carbon black, which is a modified by-product carbon black, are preferred from the viewpoint of having an antistatic effect although they are expensive. If necessary, the former and the latter can be mixed according to the required characteristics. On the other hand, among these carbon blacks, PH5~
9. Oil furnace carbon black having an average particle diameter of 10 to 120 mμ, particularly PH 6 to 8, and an average particle diameter of 15 to 30 mμ is preferred. By using particles with such pH and particle size, there is less fogging on the photographic material, less increase or decrease in photosensitivity, large light shielding ability, and no adverse effects on the photographic material. Even when added to a thermoplastic resin film, it is possible to obtain a packaging material that has a number of advantages, such as being less likely to generate pinholes such as carbon black lumps and fish eyes. Forms for blending carbon black into a blend resin of L-LDPE resin and HDPE resin (hereinafter referred to as L-LDPE-HDPE resin) include powder addition method, paste addition method, moisturizing addition method, compounding method, and master batch method. etc. Among these, the master batch method is preferable in terms of cost, prevention of workplace contamination, and the like. Japanese Patent Publication No. 40-26196 discloses 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; A method for making a masterbatch by dispersing carbon black in polyethylene is shown. In the case of the masterbatch method, a masterbatch is first prepared by mixing carbon black with LDPE resin at a high concentration of 2% by weight or more, generally 10% by weight or more. Weigh this masterbatch so that the amount of carbon black in the final product becomes the specified value, and
Mix with LDPE-HDPE resin. Two advantages can be recognized in this method. First, carbon black is L-LDPE-
This method is easier to mix and disperse than directly mixing with HDPE resin, reduces costs, and improves the fixity. Secondly, LDPE is better than L-LDPE-HDPE resin.
A mixed system of resin and L-LDPE-HDPE resin has better processability when producing a film. L-LDPE resin may be used as the masterbatch resin to reduce the cost of carbon black mixing. As the base resin for the masterbatch, any thermoplastic resin can be used as long as it can be mixed with the L-LDPE-HDPE resin, but a polyolefin resin is preferred. In particular, it is desirable that the masterbatch resin be a thermoplastic resin with a higher MI than that of the L-LDPE-HDPE resin. Note that the same applies to cases where other light-shielding substances are used. The present inventors used a mixed resin of L-LDPE resin and HDPE resin, which had previously had problems in packaging films, instead of using only LDPE resin or HDPE resin, to test the effect of carbon black compounding. . As a result, an unexpected result was found in that when carbon black is blended with L-LDPE-HDPE resin, the physical strength increases significantly, contrary to the case of HDPE alone or LDPE alone. That is, although HDPE-based resin films and LDPE-based resin films have originally lower strength than L-LDPE-HDPE-based resin films, the strength decreases particularly when carbon black is added. On the other hand, the strength of the L-LDPE-HDPE resin film is improved by adding carbon black. The same thing can be said for L-LDPE single resin film, but L-LDPE single resin film is
In addition to having low tensile strength and rigidity, if a lubricant is not added, it will not slide easily, resulting in poor processing suitability, and its moisture and gas barrier properties will also be poor, as well as its high elongation, resulting in poor slitting suitability. However, it was difficult to put it into practical use as a packaging material for photographic materials. The effect of adding carbon black to L-LDPE-HDPE resin starts to appear from 0.1% by weight, becomes obvious at 1% by weight, and becomes noticeable when the amount exceeds 3% by weight, but as the amount added increases further. This increases the occurrence of bumps and increases costs. If it exceeds 20% by weight, the occurrence of lumps due to poor dispersion of carbon black will increase.
This poses a problem in terms of poor light-shielding properties due to pinholes. Moreover, the cost is also relatively high. Therefore, the amount of carbon black to be blended is preferably about 0.1 to 10% by weight, particularly preferably about 3 to 7% by weight, from the viewpoint of economy, occurrence of lumps, tear strength, etc. It is best to add carbon black in the same amount on the inside (the side that contacts the product when packaged, or the side that is heat-sealed in the case of a bag) in order to improve the barrier properties as much as possible. The lubricant, which is the fourth essential component of the film of the present invention, not only improves suitability for processing machines and makes it easier to insert the product, but also prevents static electricity from being generated during film molding and packaging of photographic materials. . Furthermore, it prevents blocking of the film and improves the formability of the film by T-die method, inflation method, etc. If the amount of lubricant added is large, the above characteristics can be greatly improved, but the heat sealability may deteriorate, adversely affect the photographic material (inhibit development), stickiness, and dust may form. This causes problems such as easy adhesion. Therefore, add a lubricant of 0.01 to 1.0
It is preferable to add about % by weight. Dimethylpolysiloxane and fatty acid amide-based lubricants (oleic acid amide, erucic acid amide, stearic acid amide, (acid amide, ethyl acid amide, etc.) and fatty acid-based lubricants are particularly preferred. Representative examples of commercially available lubricants preferred for the present invention are described below, but the present invention is not limited thereto. Silicone lubricant; Various dimethylpolysiloxanes (Shin-Etsu Silicone, Toray Silicone) Oleic acid amide lubricant; Armoslip CP
(Lion Akzo), Neutron (Nippon Fine Chemical),
Neutron E18 (Nippon Fine Chemical), Amide O (Nitto Chemical), Alflo E10 (NOF), Diamit O-200 (Nippon Kasei), Diamit G-200 (Nippon Kasei), etc. Eric acid amide lubricant; Alflo P-10 (NOF) etc. Stearic acid amide lubricant; Alflo S-10
(NOF), Neutron 2 (Nippon Fine Chemicals), Diamit 200 (Nippon Kasei), etc. Bis-fatty acid amide lubricants: Bisamide (Nippon Kasei), Diamit-200 Bis (Nippon Kasei), Armowacs-EBS (Lion Akzo), etc. Kao Soap's "Electro Stripper" which does not fall into the above classification but has great sliding properties and antistatic effect is also preferable. As a resin
Although LDPE resin is preferably used, other polyolefin resins may also be used, such as medium density polyethylene (hereinafter referred to as MDPE) resin, various polypropylene resins, ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) resin, etc. Ethylene-ethyl acrylate copolymer (hereinafter referred to as EEA) resin, ethylene-methacrylate copolymer (hereinafter referred to as EMA) resin, polyisobutylene resin, ethylene-
It is also possible to blend acrylic acid copolymer (hereinafter referred to as EAA) resin, etc., as long as the basic properties are not changed. Various additives other than those mentioned above can be added in required amounts to each layer of the present invention, if necessary. Representative examples of additives are described below, but the present invention is not limited thereto, and any additive can be selected from among all known additives. (Additive types) (Typical examples) (1) Plasticizers: phthalate esters, glycol esters, fatty acid esters, phosphate esters, etc. (2) Stabilizers: lead-based, cadmium-based, zinc-based, alkaline earth metal-based, Organotin-based etc. (3) Antistatic agents; cationic activators, anionic activators, nonionic activators, bifacial activators, etc. (4) Flame retardants; phosphoric acid esters, halogenated phosphoric esters, halides, inorganic substances, Phosphorus polyol, etc. (5) Fillers: alumina, kaolin, clay, calcium carbonate, mica, talc, titanium oxide, silica, etc. (6) Reinforcers: glass roving, metal fiber, glass fiber, glass milled fiber, carbon fiber, etc. 7) Colorants; inorganic pigments (Al, Fe ₂ O ₃ , TiO ₂ , ZnO,
CdS, etc.), organic pigments, dyes, etc. (8) Blowing agents; inorganic blowing agents (ammonia carbonate, soda bicarbonate), organic blowing agents (nitrone type, azo type)
etc. (9) Vulcanizing agents; vulcanization accelerators, accelerators, etc. (10) Deterioration inhibitors; UV absorbers, antioxidants, metal deactivators, peroxide decomposers, etc. (11) Cutting agents ; Silane type, titanate type,
Chromium-based, aluminum-based, etc. (12) Various thermoplastic resins, rubber, etc. As explained above, the packaging material for photographic materials of the present invention may be a single layer of L-LDPE-HDPE resin light-shielding film, or other It may be laminated with a flexible sheet layer. When used as a single layer of L-LDPE-HDPE resin light shielding film, it has light shielding properties, gas barrier properties, moisture proof properties, rigidity, physical strength (tensile strength, tear strength, impact puncture strength, gelbo test strength), heat sealing strength, cut sealing properties. , a thickness of 50 μm or more is required to ensure flatness, sliding properties, and prevention of pinholes in the heat-sealed part, especially for heavy products.
In the case of highly photosensitive products and products that are easily affected by humidity, oxygen gas, sulfur gas, etc., a film thickness of 70 μm or more, preferably 100 μm or more is required. On the other hand, the film thickness has low temperature heat sealability,
From the viewpoints of film slitting suitability, bag making suitability, cut-sealing properties, cost, etc., it is better to make the film thinner by 250 μm or less, preferably by 10% or more than conventional LDPE film. Practical film thickness when used as a single layer of L-LDPE-HDPE resin light shielding film
The thickness is 50 to 250 μm, preferably 70 to 180 μm, and more preferably 100 to 160 μm. When laminated with other flexible sheet layers, the L-LDPE-HDPE resin light-shielding film layer has higher rigidity, moisture resistance, gas barrier properties, etc. than when using L-LDPE resin or L-LDPE-LDPE resin film layer. It can be made thinner by 10% or more. Practically, the thickness of the L-LDPE-HDPE resin light-shielding film layer is 30 to 200 μm, preferably 40 to 200 μm.
It is 150 μm, more preferably 50 to 100 μm. Flexible sheet layers that can be laminated on the L-LDPE-HDPE resin light-shielding film layer include thermoplastic resin films (including unstretched, uniaxially oriented, and biaxially oriented), such as various polyethylene resins,
There are known films made of ethylene copolymer resins, polypropylene resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyamide resins, polycarbonate resins, fluorine resins, polyester resins, and films of modified resins thereof. In addition, metal thin film processed films (typically aluminum vacuum evaporated film), metal thin film processed paper, cellulose acetate film, cellophane, polyvinyl alcohol film, various papers, various metal foils (typical example aluminum foil), nonwoven fabrics. There are known flexible sheet layers such as , wall film, perforated film, and foamed sheets of polyethylene, polystyrene, polyurethane, and the like. If necessary, the L-LDPE-HDPE resin light-shielding film layer of the present invention may be used as two layers. The above flexible sheet layers can be used alone or in combination of two or more depending on the required characteristics. Even when laminated with other flexible sheet layers to form a composite film, the L-LDPE-HDPE resin light-shielding film layer must be placed on the surface in contact with the photographic material. This L-LDPE-HDPE resin light-shielding film layer may be part of a film obtained by coextruding two or more layers. Among the flexible sheet layers, a metal thin film processed flexible sheet layer which is particularly suitable for packaging photosensitive materials will be described in detail. Metal thin film processed flexible sheet layer Particularly desirable flexible sheet layers include biaxially stretched nylon film, biaxially stretched polypropylene film, biaxially stretched polyester film, cellophane, paper, unstretched polypropylene film, and reinforced high-density polyethylene film. , biaxially oriented high-density polyethylene film. If necessary, uniaxially oriented thermoplastic resin films (HDPE resin, polypropylene resin, L-
Using LDPE-HDPE resin, polyamide resin, polyester resin, L-LDPE resin, etc.,
A metal thin film processed flexible sheet layer may be formed using a film in which the molecules are uniaxially oriented either horizontally or diagonally. The thickness of the flexible sheet layer for metal thin film processing flexible sheet layer is preferably 8 to 50 μm, particularly preferably 10 to 30 μm, from the viewpoint of metal thin film processing cost. Metal thin film processing methods (also referred to as metal thin film forming methods) include vacuum evaporation, sputtering, ion plating, electron beam evaporation, and other conventionally known thin film production methods. It can be provided on one side). Metal thin films include Al, Sn, Zn, Co, Ni, Fe, Cu
All metals such as single metals, alloys, and other metals that can be used to form thin films can be used, but aluminum (Al) is particularly suitable in terms of cost and ease of processing. Metal thin films have physical strength as a laminate, light shielding properties,
A thickness of 55 to 1200 Å is preferable from the viewpoint of ensuring antistatic and moisture-proof properties, cost, and quality. That is, the thickness is 55 Å
If the thickness of the metal thin film processing flexible sheet layer alone is not sufficient to reduce the charge generated on the layers on both sides of the metal thin film, and the thickness of the flexible sheet layer and light shielding layer on both sides of the metal thin film is not increased, it will not be possible to use photosensitive materials. It is not possible to ensure the moisture-proofing and light-shielding properties required for packaging materials. In addition, if the thickness exceeds 1200 Å, antistatic, moisture-proof, and light-shielding properties can be maintained at low cost, and vacuum deposition methods cause problems such as deterioration of the flexible sheet layer due to heating and a decrease in the physical strength of the finished laminated film. Therefore, it is difficult to put it into practical use. In the case of an aluminum vapor-deposited film, the thickness is preferably 70 Å or more, 80 to 800 Å for normal use, and more preferably 100 to 600 Å. If necessary, the surface of the flexible sheet layer forming the metal thin film may be subjected to known activation treatment or anchor treatment, or a protective layer may be provided on the metal thin film. A conventional method may be used to laminate the L-LDPE-HDPE resin light-shielding film layer and other flexible sheet layers. For example, methods that do not use an adhesive include a hot plate sealing method, an impulse sealing method, an ultrasonic welding method, a vibration friction welding method, a rotational friction welding method, a hot air welding method, and the like. On the other hand, lamination methods using adhesives include wet lamination, dry lamination,
A hot melt lamination method, an extrusion lamination method (including a coextrusion lamination method), a coextrusion T-die method, an inflation film molding method, etc. are used. The thickness of the adhesive layer obtained by the extrusion lamination method using thermoplastic resin, which is the most effective lamination method, is usually
7 μm to 100 μm, preferably 13 μm to 50 μm,
This thickness is determined based on cost, coating speed, total thickness of the laminate, etc., and is not particularly limited to this value. Since the packaging material of the present invention is used for photographic materials, it is necessary to have light-shielding properties. Therefore, it is necessary that at least one of the layers constituting the laminate has a light-shielding property. That is, L-
It is essential to ensure the light-shielding property of the LDPE-HDPE resin light-shielding film layer alone, but if necessary, to further cover the light-shielding property, one or more of the flexible sheet layer, adhesive layer, or other layers may contain a light-shielding substance. Alternatively, a light-shielding layer may be used, such as colored paper, metal foil with a thickness of 5 μm or more and 50 μm or less, such as aluminum foil or galvanized thin-layer steel plate, or paper with a metal vapor deposition layer of 55 to 1200 Å (e.g. aluminum vapor deposited paper) or metal. The light-shielding property can be covered by laminating another layer having a light-shielding property such as a vapor-deposited film (eg, aluminum vapor-deposited film), or by adding a light-shielding property by printing. Hereinafter, typical embodiments of the present invention will be described with reference to cross-sectional views, but the present invention is not limited thereto. 1 to 6 are cross-sectional views of the product of the present invention. FIG. 1 shows a single layer 1a of an L-LDPE-HDPE resin moisture-proof and light-shielding film, which is the basis of the packaging material of the present invention. Figure 2 shows a light shielding flexible sheet layer 4a or L-LDPE-
This is a three-layer laminated film in which HDPE resin moisture-proof light-shielding film layers 1a are laminated. In Figure 3, a metal foil layer 3 is laminated on an L-LDPE-HDPE resin moisture-proof light-shielding film layer 1a via an adhesive layer 2, and a flexible sheet layer 4 or an L-LDPE-HDPE resin layer is further laminated via an adhesive layer 2. This is a five-layer laminated film in which a moisture-proof film layer 1 is laminated. 4 shows a structure in which a metal thin film processed light-shielding film layer 5a in which a metal thin film layer 5 is formed on a flexible sheet layer 4 or an L-LDPE-HDPE resin moisture-proof film layer 1 is laminated in place of the metal foil 3 in FIG. 3. It is a laminated film with a layered structure. Figure 5 shows a three-layer laminated film in which a flexible sheet layer 4 or an L-LDPE-HDPE resin moisture-proof film layer 1 is laminated on an L-LDPE-HDPE resin moisture-proof light-shielding film layer 1a via an adhesive layer 2. . Figure 6 shows an L-LDPE-HDPE resin moisture-proof light-shielding film layer 1a and a light-shielding flexible sheet layer 4a.
Alternatively, it is a two-layered film formed by co-extruding an L-LDPE-HDPE resin moisture-proof light-shielding film layer 1a. Figure 7 is the basics of conventional packaging materials.
It is a single layer of LDPE resin light-shielding film layer 6a. FIG. 8 shows an LDPE resin light-shielding film layer 6a, which has been conventionally used in products requiring moisture resistance, a metal foil layer 3 via an adhesive layer 2, and a flexible sheet layer 4 via an adhesive layer 2. Laminated 5
It is a laminated film with a layered structure. Figure 9 is an example of a packaging material that requires physical strength and is conventionally used for color photographic paper.
Further attach the adhesive layer 2 to the laminated film shown in the figure.
This is a seven-layer laminated film in which LDPE resin light-shielding film layers 6a are laminated. The packaging material for photographic light-sensitive materials of the present invention is also suitable for packaging light-sensitive materials. Photographic materials include silver halide photographic materials, diazo photographic materials, photosensitive resins, self-developing photographic materials, diffusion transfer photographic light-shielding materials, and the like. The packaging material for photographic materials of the present invention is a single-layer flat bag;
Double-layer flat bag, square bottom bag, free-standing bag, single-layer gusset bag, 2
All known forms such as heavy gusset bags, film sheets, moisture-proof box lining, and leader paper are possible. The bag manufacturing method is based on conventionally known plastic film sealing methods such as heat sealing, impulse sealing, ultrasonic sealing, and high frequency sealing, depending on the properties of the laminated film used. In addition, it is also possible to make bags using an appropriate adhesive, pressure-sensitive adhesive, or the like. [Function] The packaging material for photographic light-sensitive materials of the present invention has an L-LDPE-HDPE resin light-shielding film layer, which is a mixture of lubricant, carbon black, L-LDPE resin, and HDPE resin in a specific ratio, on the photographic light-sensitive material side. It is a film made with The lubricity, tear strength, impact puncture strength, gelbo test strength, film cutting property, and hot tack properties required for packaging materials for photographic materials that cannot be achieved with a single resin film layer using HDPE resin, LDPE resin, or L-LDPE resin. , low-temperature heat sealability, heat seal strength, drop strength, light shielding ability, impurity sealability, cut sealability, hermetic sealability (suitability for vacuum packaging), suitability for processing machines, suitability for bag making, rigidity, antistatic properties, etc. Improved characteristics. [Example] Preferred embodiments of the present invention and their effects will be described below. Products 1 to 4 of the present invention correspond to the embodiment shown in FIG. The composition is as shown in Table 1, and L-LDPE resin manufactured by Mitsui Petrochemicals (Urtozex 2021L) using 4-methylpentene-1 having 6 carbon atoms (C ₆ ) as α-olefin or α-olefin. A blend of L-LDPE resin (Stamilex #1026) manufactured by DSM (Netherlands) using octene-1 with 8 carbon atoms (C ₈ ) as a resin and HDPE resin (Highxx #3300F) with a density of 0.96 g/cm ³ and further oil L- containing 3% by weight of furnace carbon black and 0.05% by weight of oleic acid amide as a lubricant.
This is a single film layer of LDPE-HDPE resin light-shielding film layer 1a. Products 5 and 6 of the present invention correspond to the embodiment shown in FIG. 50 μm thick L-LDPE with the composition shown in Table 1
The HDPE resin light-shielding film layer 1a has a thickness of 13 μm.
Aluminum foil 3 with a thickness of 7 μm is laminated via an LDPE adhesive layer 2, and a flexible sheet layer 4 is layered with an LDPE adhesive layer 2 with a thickness of 13 μm.
It is a 5-layer laminated film made of 35g/ ^m2 bleached kraft paper. Comparative product 1 corresponds to the embodiment shown in FIG. The product of the present invention is a single layer L-LDPE resin light-shielding film having the same composition and the same thickness except that it does not contain HDPE resin (Mitsui Petrochemical's Ultzex 2021L is used as the L-LDPE resin). Comparative product 2 corresponds to the embodiment shown in FIG.
DSM L- which does not contain HDPE resin and lubricant
This is a single layer of L-LDPE resin light-shielding film made by adding 3% by weight of carbon black to LDPE resin (Stamilex #1026). Conventional product 1 corresponds to the embodiment shown in FIG. It is a single layer of LDPE resin light-shielding film with a thickness of 205 μm containing 3% by weight of carbon black and 0.05% by weight of lubricant. Conventional product 2 corresponds to the embodiment shown in FIG. 8, and includes a 70 μm thick LDPE resin light-shielding film layer 6a to which 3% by weight of carbon black and 0.05% by weight of a lubricant are added, and a 15 μm thick LDPE resin extrusion adhesive layer 2. This is a packaging material in which aluminum foil 3 with a thickness of 7 μm is laminated via an LDPE resin extrusion adhesive layer 2 with a thickness of 15 μm, and bleached kraft paper with a weight of 35 g/m ² is further laminated via an LDPE resin extrusion adhesive layer 2 with a thickness of 15 μm. Conventional product 3 corresponds to the embodiment shown in FIG. The thickness of the LDPE resin light-shielding film layer 6a of conventional product 2
This is a seven-layer packaging material in which a 50-μm-thick LDPE resin light-shielding film layer 6a is further laminated on a bleached kraft paper laminated film with a thickness of 70 μm to 50 μm via an LDPE resin extrusion adhesive layer 2 with a thickness of 15 μm. The above examples are representative examples of preferred embodiments of the packaging material for photographic light-sensitive materials of the present invention, but the present invention is not limited thereto, and other known materials and flexible sheet layers may be used. A combination is possible. Inventive products 1 to 6, comparative products 1 to 2, conventional product 1
Table 1 shows the layer structure, materials used, thickness of each layer, etc. of Examples 3 to 3, and Table 2 shows the results of comparing the properties. LDPE extrusion adhesive layer 2 in the example
As for Mirason 14 made by Mitsui Polychemical Co., Ltd.
(MI5.1g/10min, density 0.919g/cm ³ ), the carbon black was Mitsubishi Kasei Oil Furnace Black 44B (average particle size 21mμ, pH7.7), and the LDPE film layer was Nippon Unicar DFD- 0111
(MI2.4g/10min, density 0.923g/cm ³ ), and
As HDPE resin, Mitsui Petrochemical's Hi-Zex
3300F (MI 0.90 g/10 min, density 0.954 g/cm ³ ) was used.

【table】

【table】

【table】

〔Effect of the invention〕

The packaging material of the present invention has tear strength, impact puncture strength,
Gelbo test strength, tensile strength, light shielding properties, moisture proofing properties, slipperiness, heat sealability, etc. are good. If the physical strength is guaranteed to be the same, it can be made much thinner than conventional products, and as a result, costs can be reduced.

[Brief explanation of the drawing]

1 to 6 are partial sectional views of packaging materials according to embodiments of the present invention, and FIGS. 7 to 9 are partial sectional views of conventional packaging materials. FIG. 10 is a partial sectional view of an embodiment of a packaging bag using the packaging material of the present invention, and FIGS. 11 and 12 are partial sectional views of the same outer paper. 1... L-LDPE-HDPE resin moisture-proof film layer, 1a... L-LDPE-HDP resin moisture-proof light-shielding film layer, 2... Adhesive layer, 3... Metal foil layer, 4
...Flexible sheet layer, 4a...Light-shielding flexible sheet layer, 5...Metal thin film layer, 5a...
Metal thin film processed flexible sheet layer (= metal thin film formed flexible sheet layer), 6... LDPE resin film layer, 6a... LDPE resin light-shielding film layer, 11... Photographic light-sensitive material, 12... Packaging bag, 1
3... Outer paper, 14... Inner paper, 16... Tape, 1
7...Heat seal part, 18...Adhesive.

Claims (1)

[Claims] 1. 50 to 95% by weight of linear low density polyethylene resin
and melt index (ASTM D 1238-65T
Test method) is 0.3-1.5g/10 minutes of high-density polyethylene resin 5-49.5% by weight and carbon black 0.1
A packaging material for photographic materials comprising a film containing at least four components: ~10% by weight and a lubricant by 0.01~1.0% by weight. 2. The packaging material according to claim 1, wherein one or more flexible sheet layers are laminated on the outside of the film. 3 α-olefin of linear low density polyethylene resin is 4-methylpentene-1, hexene-1,
The packaging material according to claim 1 or 2, which is any octene-1. 4 Density of high-density polyethylene resin (ASTM D
1505-67 test method) is 0.945 to 0.97 g/cc. 5 More than 50% by weight of carbon black has a pH of 5~
9. The packaging material according to claim 1, 2, 3, or 4, which is oil furnace carbon black with an average particle diameter of 10 to 120 mμ.