JPS61179738A - Packaging material for photosensitive substance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a packaging material suitable for photosensitive materials, particularly 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 are gas barrier properties, light blocking properties, moisture proofing properties, physical strength (breaking strength, tear strength, impact puncture strength, rude test strength, abrasion strength, etc.), and heat sealability (heat seal strength, heat sealing strength, antistatic properties, flatness, surface properties, etc.). It is difficult to have all of these properties in a single film material, and conventionally, as shown in Figure 11, high-pressure low-density teriethylene (hereinafter referred to as LDPE), which is kneaded with Kagenbra, pigments, etc., has been commonly used. ) single layer film, LDPE and paper, aluminum foil, Shichirono 1
Composite laminate films with flexible sheets such as No. 7 have been used. An example of a composite laminate film is shown in FIG. 12, in which a metal foil light shielding layer 4a is laminated on an LDPE light shielding film layer 7a via an adhesive layer 2, and a flexible sheet layer 3 is further laminated via an adhesive layer 2. This is what I did.

The present inventor conducted extensive research to improve packaging materials for photosensitive materials, and discovered a material with improved physical strength by combining two layers of uniaxially stretched films (Japanese Patent Application Laid-Open No. 57-67
No. 54) has already been disclosed.

In addition, packaging materials using linear low-density polyethylene (hereinafter referred to as L-LDPK) resin must not contain polyethylene polymer and 1% by weight or more of a light-shielding substance, and must not contain more than 50% by weight of the total ethylene polymer. A device having at least one light-shielding film made of L-LDPE has already been disclosed (Japanese Patent Application Laid-open No. 132555/1983). In addition, 50% by weight was added on both sides of the metal vapor deposited film layer.
We have also developed a packaging material in which a single layer of polyethylene polymer containing the above L-LDPE and at least one containing a light-shielding substance is laminated, and the strength and thickness difference of the polyethylene polymer layer have a specific relationship (patent application Showa 59-1780
No. 47).

(Problems to be Solved by the Invention) Conventional composite laminate films have been constructed to improve the physical properties mentioned above, but the physical properties are still not sufficient, and they tend to tear or puncture during packaging operations. There were drawbacks such as openings and peeling of the heat seal part.

More cars? Adding a large amount of shielding materials such as Numbra and Yotsuk will result in a significant deterioration of physical strength, and the amount added will be around 3 inches, and the film thickness will be 70μ.
It was necessary to do more than that. As a result, the packaging is bulky, the rigidity of the laminate film is low, the packaging workability is deteriorated, and the cost is also high.

For example, in the laminated film shown in Figure 12, aluminum foil is used to provide gas barrier properties, improve moisture resistance, and prevent static electricity, but as a result, tear strength, impact puncture strength, glubutist strength, etc. On the contrary, the problem worsened to a large extent, resulting in breakage, especially when packaging heavy items. For this reason, Kadenbrack's polyethylene film has been made to have a thickness of 70 μm or more, but it still does not have sufficient physical strength, and for example, laminated films with an eight-layer structure have 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, but since a two-layer uniaxially stretched film is required, the thickness of the laminated film is It was a large piece of packaging material.

By using L-, LDPE resin as a packaging material, it is possible to increase the physical strength such as tear strength and R-test strength, as well as increase the amount of crosstalk of light-shielding substances, and it is possible to improve the above-mentioned problems. However, there has been a desire to develop packaging materials that are inexpensive and have excellent physical strength and other physical properties.

(Means for Solving the Problems) The present invention has been made to solve these problems, and contains a specific L-LDPE resin. This objective was achieved by molding the Lisprene polymer in a specific manner.

That is, the present invention has a density of 0.870, which is obtained by copolymerizing ethylene and heptene-1 or octene-1 by a liquid phase method.
~0.925777cm3 and containing 40% to 99% by weight of L-LDPE resin with a melt index of 1.2 to 10 p710 and a thickness of 20 μm or more (longitudinal tear strength)/(transverse direction) The present invention relates to a light-shielding packaging material for photosensitive materials having a polyethylene polymer film layer having a tear strength ratio of 0.6 or more.

The L-LDPK resin used in the packaging material of the present invention is made by copolymerizing ethylene with heptene-1 or octene-1 as an α-olefin by a liquid phase method, and has short branches in a linear chain. It is a polyethylene-based polymer with a long structure. The ethylene content is 90 to 99.5 molty, and the α-olefin heptene-1 or octene-1 content is 0.
A suitable amount is 5 to 10 mol. More favorable physical properties can be obtained with octene-1 than with heptene-1. The density is 0.870~0.92597cm3 (JI
SK 6760) and melt index (MI
) 1.2-10 g/l 0 min (JIS K 676
0) is used. Examples of such L-LDPE resins include Dowlex (Dow Chemical Co.) and Stamilex (DSM Co.) using octene-1.

The polyethylene polymer film contains this L-LDPE resin in an amount of 40% by weight or more, generally 50% by weight or more, and 60% by weight or more is particularly preferable. On the other hand, in terms of processing characteristics and balance of longitudinal and transverse tear strength, L-LDP
It is rather preferable that the amount of E resin be as small as possible. By blending polyethylene polymers and light-shielding substances, which will be described later, it is possible to not only improve processing properties but also improve physical properties, especially tear strength, heat seal strength, and glue strength. Test strength can be significantly improved. The upper limit of the content of L-LDPE resin is determined by taking these into consideration, but this upper limit value is also influenced by the addition of a light-blocking substance.

Other resins blended with L-LDPE resin include L
Although DPE resin is preferably used, other polyethylene polymers may also be used, such as ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) and ethylene-ethyl acrylate copolymer (hereinafter referred to as EEA). , ethylene-methacrylate copolymer (hereinafter referred to as EMA), polyisobutylene, ethylene-acrylic acid copolymer (hereinafter referred to as EA)
It is also possible to contain substances such as A) as long as the basic properties are not changed.

Since the packaging material of the present invention is used for photosensitive materials, it is necessary to have light-shielding properties. For this purpose, one or more of the flexible sheet layer, adhesive layer, or any other layer must be applied to the sail.
30% by weight of a light-shielding substance, or a light-shielding layer such as colored paper, or 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 100 μm or more of a light-shielding material.
By laminating other layers with light-shielding properties such as paper with a 1200X metal vapor-deposited layer (e.g. aluminum vapor-deposited paper) or metal vapor-deposited film (e.g. aluminum vapor-deposited film), or by adding light-shielding properties to printing. A method may also be used.

When only a light-shielding substance is contained to ensure light-shielding properties, the appropriate amount is 0.5 to 36.9 per unit area (m 2 ) of the entire laminate. It is generally undesirable to add 12% by weight or more of a light-shielding substance to a stretched film because it causes fish eyes and reduces physical strength.
A range of ~7% by weight is desirable, but when adding to flexible sheets such as non-stretched films and paper, this is not the limit; the blending amount is up to 30% by weight, 3% per unit area (m2).
It can be blended up to 6.9. Light-blocking substances refer to all substances that do not transmit visible and ultraviolet rays, but typical examples include various cargo/blacks with different raw materials, particle sizes, manufacturing methods, etc., aluminum powder, iron oxide, zinc white, and valves. pattern,
Examples include aluminum paste, various colored pigments, various colored dyes, cadmium pigments, yellow lead and titanium oxide, barium sulfate, calcium carbonate, white pigments such as mica, Merck, and clay, various metal powders, and various metal fibers. quality, cost,
From the viewpoint of light-shielding ability, it is desirable to use various carden blacks, aluminum powders, aluminum pastes, and other materials from which low volatile substances have been removed for packaging photographic materials.

The above-mentioned light-shielding substance may be used in the form of a powder coloring agent, a pasty coloring agent, a moisturizing coloring agent, a masterbatch, a dye/pigment, or a colored pellet, depending on the resin used, the machine used, the cost, etc.

Examples of the classification of carden black, which is a typical light-shielding substance used in the packaging material of the present invention, by raw material include gas black, oil furnace black, anthracene black, acetylene black, oil smoke, pine smoke, animal black, and vegetable black. There is. For the packaging material of the present invention, furnace carden black is preferable for the purpose of improving light-shielding properties, cost, and physical properties, and acetylene cardene plastic, which is expensive but has an antistatic effect, is preferable.
Ketchenkaden black is preferable.

It is also desirable to mix the former and the latter according to the required characteristics. On the other hand, among these carbon blacks, those having a pH of 9 to 9 and an average particle size of 10 to 50 m are preferable, and furnace carbon black having a pH of 6 to 9 and an average particle size of 15 to 30 m is particularly preferable. More than this
By using carbon black particles with a particle size of It is possible to obtain a packaging material that has a number of advantages such as being less likely to generate pinholes.

As mentioned above, there are various ways of blending light-shielding substances into polyethylene polymers, but the master patch method is cost effective and
This is desirable in terms of preventing contamination of the workplace, etc. A publicly known document, Japanese Patent Publication No. 40-26196, discloses a method of preparing a polymer by dispersing Cargin Black in a solution of a polymer dissolved in an organic solvent.

How to make a master patch for
No. 362 discloses a method for preparing a master patch by dispersing carton black in polyethylene.

In this method, a master patch is first prepared by mixing carbon black in a high concentration of 2% by weight or more, generally 10% by weight or more, with LDPE (high pressure low density polyethylene) resin. Weigh this master patch so that the amount of carbon black in the final product is a predetermined value, and
Mix with resin.

Two advantages can be recognized in this method.

First, it is easier to mix and disperse carbon black than directly mixing it with the L-LDPE resin, which reduces costs and improves fish eyes.

Secondly, compared to a single L-LDPE resin system, a mixed system of LDPE resin and L-LDPE resin has better processability when producing a film. L − is used as a master patch resin to reduce the cost of carbon black mixing.
LDPE resin may also be used. In particular, it is desirable that the melt intex of the resin for the master patch be a thermoplastic resin with a higher melt intex than L-LDPE resin. Note that the same applies to cases where other light-shielding substances are used.

The present inventors used L-LDPE resin, which had conventionally been problematic as a packaging film, as a substitute for LDPEIm resin, and tested the influence of carbon black blending. As a result, an unexpected result was found that when carbon black was blended with L-LDPE resin, the physical strength significantly increased, contrary to the case of high-pressure low density I lisprene (LDPE) resin.

That is, LDPE film originally has lower strength than L-LDPR film, but the strength decreases particularly when carbon black is added. On the other hand, L-L
The strength of the DPK film is greatly improved by adding carbon black.

The effect of carbon black blending is clearly visible at 1% by weight and becomes more pronounced when it exceeds 3% by weight, but as the blending amount is further increased, the occurrence of pimples increases and costs increase. When the amount exceeds 30% by weight, spots are often generated due to poor dispersion of carbon black, and problems arise in tables with poor light-shielding properties due to pinholes. Moreover, the cost is also relatively high.

Therefore, the blending amount of cargan black should be determined based on economic efficiency,
Tear strength, etc.) is preferably 1 to 30% by weight, and 3 to 1% by weight.
0iiJ1% is particularly desirable.

This tendency also holds true for other light-shielding substances.

To make the light shielding property as good as possible by adding the same amount,
It is desirable to add a light-blocking substance to the inside (the side that comes into contact with the product when packaged, or the side that is heat-sealed in the case of a bag).

/ Ri! The tyrenic polymer film is molded by an inflation molding method. The melt tension and flow characteristics are L
- It has been said that this is a major problem with LDPE resin, and that film production requires more energy than conventional polyethylene, and often requires modification or even installation of a new inflation molding machine.

Regarding this point, for example, Japanese Patent Application Laid-Open No. 55-117638 discloses a method of changing the screw structure in order to reduce the load on the screw and reduce heat generation due to rotation. According to the master 11 degree method of the present invention, 5% by weight or more of EEA resin, EVA resin, LDPEW
If it contains fat, etc., no such modification is required, and the existing T
Dies and inflation molding machines can be used as they are. This inflation molding uses a blow ratio of 1.
By setting it to 2 to 2.4, it is possible to obtain a product with a small difference in strength in the vertical direction (MD) and the horizontal direction (TD). The thickness of the inflation-molded polyethylene polymer film must be 20 μm or more, and approximately 35 μm to 120 μm is appropriate. When this polyethylene polymer film is used in a single layer as a packaging material, it has moisture-proof, light-shielding properties, In order to ensure heat-sealing strength, the thickness is preferably 30 μm or more, preferably 45 μm or more. (Tear strength in longitudinal direction)/(Tear strength in transverse direction) ratio must be 0.6 or more,
Approximately 0.75 to 1.25 is appropriate.

The packaging material of the present invention can be made into a composite film by laminating this polyethylene polymer film with another flexible sheet layer.

Other flexible sheet layers used in the composite film include thermoplastic resin films, such as various polyethylene resins, I-risprene copolymer resins, polypropylene resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyamide resins, and polycarnate resins. , fluororesin, polyester resin, and films of modified resins thereof. In addition, metal thin film processing film (
Representative examples include aluminum vacuum-deposited film), cellulose acetate film, cellophane, 4-rivinyl alcohol film, various papers, and various metal foils. Also suitable are known flexible sheet layers such as foamed sheets such as urethane and urethane.

In the case of forming a composite film, the polyethylene polymer film layer kneaded with L-LDBE resin is preferably disposed as the innermost layer in contact with the product. This polyethylene polymer film layer may be part of an inklage or ink film made by coextruding two or more layers.The seven lexipropylene film layers may be a single layer, or two or more layers may be combined. good.

Among flexible sheet layers, metal thin film processing flexible sheet layers are particularly suitable for packaging photosensitive materials. Metal thin film processing methods include vacuum evaporation, spavkling, ion preniting, and electron beam evaporation. It can be provided on both sides or one side (for example, one side of the light-shielding layer side) of the flexible sheet by a conventionally known thin film production method.

Metal thin films include ALlSn, Zn, Co1Cr, Ni, and F.
All metals such as E, Cu, etc., alloys, and other metals capable of forming a thin film can be used, but aluminum (HT) is particularly suitable in terms of cost, processing, and durability.

The metal thin film is 55 to 120 in terms of physical strength as a laminate, light shielding property, antistatic property and moisture proofing, cost, and quality.
A thickness of 0X is preferred. That is, if the thickness is less than 55X, the metal thin film processed flexible sheet layer alone cannot reduce the charge generated in 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 must be increased. Moisture-proofness, which is necessary as a packaging material for photosensitive materials, is not required.
It is not possible to ensure light-shielding properties.

If the thickness exceeds 1200X, antistatic, moisture-proof, and light-shielding properties can be ensured, but problems arise due to cost and vacuum deposition methods such as deterioration of the flexible sheet layer due to heating and reduction in physical strength of the finished laminated film. However, it is difficult to put it into practical use. In the case of an aluminum vapor deposited film, the thickness is preferably 70X or more, 80 to 800X for normal use, and more preferably 100 to 600X.

If necessary, you can add a protective layer on top of the metal thin film.Acrylic resin, acetic acid fiber*, etc. can be used as the metal thin film protective layer.
Appropriate resins such as cellulose resins, urethane resins, epoxy resins, polyester resins, ionomer resins, EEA resins, various polyethylene resins, and polypropylene resins can be used. Also wax, gelatin? Rivinyl alcohol and the like can also be used.

The protective layer of the metal thin film is preferably formed to have an extremely thin thickness. Even in the case of extrusion lamination, if the thickness is not 50 μm or less, static electricity will not be removed sufficiently.

If the thickness is 95 μm or less using a known solution coating method or spray coating method, the metal thin film can be protected and static electricity can be effectively removed. Flexible sheet layer, light shielding layer, adhesive layer,
It is also possible to mix antistatic agents, metal powders such as carbon black, aluminum powder, and aluminum yeast, and conductive substances such as carbon fibers into the metal thin film protective layer. In this way, static electricity can be removed even more completely. .

The flexible sheets may be laminated by any conventional method, such as thermal adhesive method (hot plate adhesive method, impulse adhesive method, ultrasonic adhesive method), adhesive method (wet lamination method,
Dry lamination method, hot melt lamination method, extrusion lamination method, coextrusion lamination method (including coextrusion lamination method), coextrusion method, etc. are used.

Typical adhesives include polyolefin thermoplastic resin hot-melt adhesives such as various polyethylene resins, polyzolopylene resins, and polybutene resins, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, and ethylene-ethyl acrylate copolymers. There are thermoplastic resin hot-melt adhesives such as olefin copolymers, ethylene-acrylic acid copolymers, and ionomer resins, and other hot-melt rubber adhesives. Typical examples of emulsion and latex type adhesives are polyvinyl acetate, vinyl acetate-ethylene copolymer, vinyl acetate and acrylic ester copolymer, and vinyl acetate and maleate ester. There are emulsions such as copolymers, acrylic copolymers, and ethylene-acrylic acid copolymers. Typical examples of latex adhesives include natural rubber, styrene pudadiene (S
There are rubber latexes such as BR), acrylonitrile pudadiene (NBR), and chloroprene (CR).

Adhesives for dry lamination include polyurethane adhesives, hot melt laminating adhesives blended with paraffin wax, microcrystalline wax, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, etc. Known adhesives such as pressure adhesives and heat-sensitive adhesives can be used. Preolefin adhesives for extrusion are better, specifically, various polyethylene resins, polypropylene resins, polybutylene resins, EPR, etc. In addition to polymers and copolymers made of lyolefin resins (EVA, EEA, etc.), copolymers of ethylene and some other monomers (α-olefins) such as linear low-density polyethylene (L-LDPE) resins It also includes ionomer resins (ionic copolymers) such as DuPont's Surlyn and Mikata Polychemical's Atomer, and graft polymerized products.

It is desirable that these adhesives have a melting point 5° or more lower than the flexible sheet layer to be laminated. If there is a temperature difference of this degree, it is possible to completely perform thermal melt bonding without adversely affecting the flexible sheet.

The thickness of the adhesive layer formed by the extrusion lamination method using a thermoplastic resin is usually 10 μm to 500 μm, preferably 15 μm to 200 μm, but this value is determined based on cost, coating speed, total thickness of the laminate, etc. is not particularly limited.

Various additives other than those mentioned above can be added in required amounts to each layer of the present invention, if necessary.

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

(Additive types) (Representative 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 , organic tin type, etc. (3) Antistatic agents; cationic activators, anionic activators.

Nonionic activator 9 Bifacial activator 9, etc. (4) Flame retardant: phosphate ester, halodanated phosphate ester, halide, inorganic substance, phosphorus-containing polyol, etc. (5) Filler: alumina, kaolin clay, calcium carbonate, mica, talc , titanium oxide.

Silica, etc. (6) Reinforcement agents Nigaras roving, metal fibers, glass fibers, glass milled fibers, carbon fibers, etc. (7) Colorants; Inorganic pigments (At r Fe2O3+ T
ie2y ZnO.

CdS, etc.), organic pigments (carbon).

Dyes 2nd class (8) Foaming agents; Inorganic foaming agents (ammonia carbonate, sodium bicarbonate) Organic foam fines (=troy type, azo type) 2nd class (9) Vulcanizing agents, vulcanization accelerators, accelerators, etc. α1 deterioration Inhibitors: UV absorbers, antioxidants, metal deactivators, peroxide decomposers, etc.01) Lubricants: Alpha nucleating agents such as paraffin wax, fatty acids, fatty acid amide types, esters, higher alcohols, etc. Coupling agents (silane-based, titanate-based, chromium-based, aluminum-based), various thermoplastic resins, rubber, etc. Representative embodiments of the present invention will be described below with reference to cross-sectional views, but the present invention is not limited to these.

1 to 10 are cross-sectional views of the product of the present invention.

FIG. 1 shows a single layer 1a of an L-LDPE film formed by inflation molding and containing a light-shielding substance, which is the most basic of the present invention.

FIG. 2 shows a packaging material in which a flexible sheet 3 is laminated on the L-LDPE light shielding film layer 1a of FIG. 1 with an adhesive layer 2 interposed therebetween.

Figure 3 shows a packaging material in which a light-shielding layer such as metal foil 48 is laminated between Ia and 3 in Figure 2 via adhesive layer 2. Figure 4 shows light-shielding L7 LDPE film layer 1a and adhesive layer. This is a packaging material in which a metal thin film-processed flexible sheet layer 1a (typically an aluminum vacuum-deposited film or paper) is laminated on a flexible sheet 3 via a metal thin film 5a to provide light-shielding properties.

FIG. 5 shows a co-extrusion of an L-LDPK light-shielding film layer 1a and a thermoplastic resin layer 6a containing a light-shielding substance.

FIG. 6 shows a packaged cup in which an L-LDPE film layer 1 is laminated with a flexible sheet layer 3a containing a light-shielding substance and an adhesive layer 2 interposed therebetween.

Figure 7 shows an L-LDPE film layer 1, an adhesive layer 2 interposed therebetween, a metal foil 4a, and a flexible sheet layer 3 laminated through the adhesive layer 2. Although each layer does not contain a light-shielding substance, the metal foil light-shielding layer is laminated. It is a packaging material that ensures light blocking properties.

Figure 8 shows a metal thin film processed flexible sheet ■a in which a metal thin film 5a is processed on a flexible sheet 3 via an L-Lppm film layer 1 and an adhesive layer 2a containing a light-shielding substance.
It is a packaging material made of laminated layers.

FIG. 9 shows a packaging material in which a flexible sheet layer 3 is laminated via an adhesive layer 2 to a co-extruded light-shielding film layer 1a, which is a co-extruded thermoplastic resin layer 6 co-extruded with an L-LDPE light-shielding film layer 1a.

FIG. 10 shows a packaging material in which a flexible sheet layer 3 is laminated in two stages on an L-LDPE optical film layer 1a with an adhesive layer 2 in between.

FIG. 11 shows a conventional packaging material of a single layer 7a of LDPK film containing a light-shielding substance.

FIG. 12 shows a conventional packaging material in which a metal foil 4a is laminated on an LDPE light-shielding film layer 7a with an adhesive layer 2 interposed therebetween, and a flexible sheet layer 3 is further laminated with the adhesive layer 2 interposed therebetween.

The packaging material for photosensitive substances of the present invention is suitable for packaging photosensitive substances. Photosensitive materials include photosensitive materials such as silver halide photographic materials, diazo photographic materials, photosensitive resins, self-developing photographic materials, and diffusion transfer photographic materials, as well as materials that discolor due to light or have deteriorated due to curing. Including all substances that cause

Specific examples include foods such as chocolate, margarine, miso, wine, and beer, and pharmaceuticals.

Examples include dyes and other chemical substances such as developing solutions and dyeing mordants. It is especially suitable as a packaging material for photographic and optical materials whose quality is destroyed by slight gases, light, and humidity.

When the packaging material for photosensitive materials of the present invention is applied to the above-mentioned photosensitive materials, it can be used in single-layer bags, double-layer bags, square bottom bags, free-standing bags, single-layer gusset bags, double-layer gusset bags, film sheets, and moisture-proof boxes. All known forms of stickers and leader papers 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) By using a polyethylene polymer film containing a specific L-LDPE resin as a packaging material, the tear strength, breaking strength, impact puncture strength, dull test strength, and hot peeling strength of the packaging material are determined. It has improved strength, drop strength, heat sealability, slipperiness, and antistatic properties.

(Example) Preferred examples of the present invention and their effects will be described below.

The product 1 of the present invention corresponds to the embodiment shown in FIG. DSM's LrLDPE (Stami Rexna 08-106 (Su2H-218)) resin containing 3% by weight of oil furnace Kagen black and having an α-olefin carbon number of s (C8) was inflation molded at a blow ratio of 1.95. It is a single layer of L-LDPE light-shielding film with a thickness of 50 μm.

Product 2 of the present invention has a thickness of 50 μm and has the same specifications as Product 1 of the present invention, except that DSM (Stami Rexna 1046) manufactured by Dutch DSM with C8 α-olefin was used as the L-LDPE resin.
Product 3 of the present invention is a single layer of L-LDPE light-shielding film of m.
89% by weight of resin, 8% by weight of LDPE resin, 712% by weight of resin
This is a single layer of L-LDPE light-shielding film having a thickness of 50 μm and having the same specifications as Invention Product 1 except that the content was 223% by weight.

Product 4 of the present invention is a single layer of L-LDPE light-shielding film having a thickness of 50 μm and having the same specifications as Product 3 of the present invention except that the LDPE resin was changed to Stamilexna 1046.

Product 5 of the present invention corresponds to the embodiment shown in FIG. 6 and does not contain a light-shielding substance.
) A single layer of L-LDPE film with a thickness of 50 μm formed by inflation molding at a blow ratio of 1.95 using a polyethylene-based dillimer consisting of 90% by weight and 10% by weight of LDPE resin, and a LDPE adhesive layer of 1311m containing 5% by weight of carbon black. This packaging material is made by laminating 3,517 m2 of bleached kraft paper.

Inventive product 6 is Stami L/, Ri X $08-106 (+
This packaging material has the same specifications as product 5 of the present invention, except that 2H-218) was changed to Stamilexna 1046.

The product 7 of the present invention corresponds to the embodiment shown in FIG.

LDPL: Adhesive layer 15 on 731 m2 Kurnoguktsu paper
Stamilexna 1046 in μm, resin 89% by weight, L
L-L with a thickness of 50 μm of product 4 of the present invention, which was inflation-molded at a blow ratio of 1.95 using 4-lyethylene polymer containing 8% by weight of DPE resin and 2712723% by weight of Kerr.
This is a packaging material laminated with DPK light-shielding film layers.

Inventive product 8 uses the same polyethylene polymer as inventive product 4, which corresponds to the embodiment shown in FIG. 3, and has a plow ratio of 1.95.
L-LD with a thickness of 50 μm made by inflation molding
This is a packaging material in which a PE light-shielding film layer is laminated with an LDPE adhesive layer of 13 μm and an aluminum foil of 7 μm, and on the outside of the aluminum foil, 301 m2 of twisted base paper and a 15 μm of LDPE adhesive layer are laminated.

The product 9 of the present invention corresponds to the embodiment shown in FIG. Invention product 4
．． 50μ thick using the same polyethylene polymer as
LDPE adhesive layer 2 on the L-LDPE light-shielding film layer of m
This is a packaging material consisting of 15 μm 811 layers of aluminum vacuum-deposited biaxially oriented nylon film with a thickness of 400×.

The product 10 of the present invention corresponds to the embodiment shown in FIG.

, the same polyethylene polymer composition as inventive product 4
- A 30 pm thick L-LDPE co-extruded light-shielding film layer 1a using DSM's Stamilexna 1046 as the LDPE resin and a 30 μm thick high-density layer containing 3 weight carton black. 4 polyethylene resin (HiZEX made by Mitsui Mameyu Kagaku) Film layer 6a Thickness 60 Jim's two-layer co-extruded light-shielding film layer■
It is an excellent packaging material.

The product 11 of the present invention corresponds to the embodiment shown in FIG.

L-LDPE with the same thickness of 50 tim as the invention product 6
Thickness 1 containing film layer 1 and 3% by weight of carbon black
400× thick aluminum vacuum-deposited biaxially stretched polypropylene film 2 via 5 μm LDPE adhesive layer 2a
This is a packaging material in which 5 μm of bleached kraft paper 3 is laminated with 5017 m of bleached kraft paper 3 via a 15 μm thick LDPE adhesive layer 2.

A 500 μm thick foam 4 styrene sheet (manufactured by Nippon Polystyrene D-A4- Co., Ltd.) is laminated with a 50 μm thick L-LDPE light-shielding film layer 1a, which is the same as the product 4 of the present invention, and a 15 μm thick LDPI adhesive layer. and further thickness 15
This is a packaging material laminated with a biaxially stretched polyester film 3 having a thickness of 12 μm via a μm LDPI adhesive layer.

Comparative product 1 corresponds to FIG. α-olefin has 4 carbon atoms
(butene-1) of L-LDPE resin (Stamilex φ1048) manufactured by DSM in the Netherlands 89% by weight and Kerr? L-LDPE with a thickness of 50 μm was made by inflation molding at a blow ratio of 1.95 using an I-lisprene polymer consisting of 3% by weight of black and 8% by weight of LDPE resin.
It is a single layer of light-shielding film 1a.

Comparative product 2 corresponds to FIG. Stamilexna 104
The number of carbon atoms in the alpha olefin is 8 (octyne-1) in place of 6.
Manufactured by DSM - LDPE resin (Stamilexna 1)
This is a single layer of L-LDPE light-shielding film layer 1a having a thickness of 50 μm and having the same specifications as Invention Product 4 except that 016 (φ2H235)) was used.

Comparative example 3 is Stamilexna 08-106 (÷2H-
218) A single layer 1 of I, -LDPE film with a thickness of 5011 m, which was inflation molded using only resin at a blow ratio of 1.4.

Comparative Example 4 is a 30 μm thick film made by inflation molding using only Stamilexna 1046 resin at a blow ratio of 1.4.
m of L-LDPR film single layer 1.

Comparative Example 5 is L-L with a thickness of 30 Jim, which is made by inflation molding at a blow ratio of 1.4 using only Mikata Petrochemical L-LDPE resin (Urtozechsna 2020L).
It is a single layer of DPE film.

Comparative Example 6 is an α-olefin made by Mikata Petrochemical Co., Ltd., which contains 3 carbon atoms equivalent to Figure 3, and has 6 carbon atoms (4-
Methylpentene-1) containing L-LDPK resin (Urtozechsna 2020L) and LDPK 7.5% by weight4
A 50 μm thick L-LDPE light shielding film layer 1a made by inflation molding using a polyethylene polymer at a blow ratio of 1.7 is laminated with a 7 μm thick aluminum foil with a 15 μm thick LDPE adhesive layer 2, and then a 15 μm thick L-LDPE light shielding film layer 1a is laminated with a 7 μm thick aluminum foil.
305'/m2 bleached kraft paper with m LDPE adhesive layer 3
It is a packaging material laminated with

Conventional product 1 corresponds to Figure 11 and contains 3% carbon black.
The LDPK light-shielding film layer is 7 m thick and has a thickness of 708 m, which is formed by inflation molding using an LDPE resin containing LDPE resin at a blow ratio of 1.7.

Conventional product 2 corresponds to FIG. 12. Conventional product 1 thickness 70μ
m LDPE light shielding film layer 7a with a thickness of 50 μm
-LDPE This packaging material is made of the same material and has the same layer structure as the product 8 of the present invention, except that it is used as a substitute for the light-shielding film layer 1a.

The above are inventive products 1 to 12, comparative products 1 to 6, and conventional products 1 to 12.
Table 1 shows the composition of No. 2, and Table 2 shows the results of comparing the characteristics.

Although the above examples are representative examples of preferred embodiments of the packaging material for packaging photosensitive materials of the present invention, the present invention is not limited thereto, and other known materials and flexible sheet layers may be used. A combination is possible.

The LDPE film layers 7 and 7a in the examples were DFD-0111 (MI 2.4.9/10 manufactured by Nippon Unicar).
minute, density 0.9231/cm'), LDPE adhesive layer 2
, 2a is Mirason 14 (MI
5.1g/10min1, density 0.91911/m')
The carbon black used is Mitsubishi Kasei Oil Furnace Blackna 44B.

The average particle size was 21 mμ and the pH was 7.7, respectively.

The evaluation in Table 2 is as follows.

Excellent Excellent, Good Excellent, Fair Within practical limits Needs improvement Some problems, not practical The test method is density according to the following: JTS K6760 (=ASTMD-1505)
).

Melt index (MI)...JTS K676
0 (=ASTM1238).

Thickness: According to JIS-8118.

Tear strength: JTS-P8116 //Impact puncture strength: Conforms to JTS-P8134.

Rude test strength: The number of times the packaging material is bent using a device based on the U.S. military standard MTL-B131 until a pinhole occurs and the light-shielding property cannot be ensured. A hole occurs.

Improvement required; 3 to 7 times; Fair; 7 to 50 times; Good; 51 to 100 times; Excellent; 1101 times or more. Expose the film to 10,000 lux light for 1 hour, and detect and evaluate the degree of fog on the photographic film.

Hot tack property: Immediately after heat sealing at 160℃ (
451 on one side! Measured by hot peel distance (Y) when pulled at a peel angle of 22.5 degrees with a load of .

Moisture resistance: Conforms to JIS-Z 0208-1976 K.

(Effects of the Invention) The packaging material of the present invention has a small difference in tear strength in the MD force direction and TD force direction, and has good physical strength, heat sealability, and light shielding property. Furthermore, if the physical strength is guaranteed to be the same, it is possible to significantly reduce the thickness compared to conventional products, and as a result, costs can be reduced.

[Brief explanation of the drawing]

1 to 10 are partial sectional views of packaging materials according to embodiments of the present invention, and FIGS. 11 and 12 are partial sectional views of conventional packaging materials. 1...L - A polyethylene polymer film layer containing LDPE, 1a...L, + A polyethylene polymer film layer containing LDPE and a light-shielding substance, 2...
・Adhesive layer, 2a... Adhesive layer containing a light-shielding substance, 3...
-Flexible sheet layer, 3a... Flexible sheet layer containing a light-shielding substance, 4a... Metal foil, 5a...
Metal thin film, ■a... Metal thin film processed flexible sheet layer, 6... Thermoplastic resin layer, 6a... Thermoplastic resin layer containing a light-shielding substance, 7... LDPE film layer, 7
a... LDPE film layer containing a light-shielding substance The circle mark indicates a combination layer of two or more layers. Patent applicant Fuji Photo Film Co., Ltd. Agent
Patent Attorney 1) Masahiro Naka Figure 1 Figure 2
3rd cause Figure 4 Figure 5 Figure 6 Figure 7 Figure 8I! ! Figure 9 Figure 10 Figure 11 Figure 12 Procedural amendment voluntarily) March 3, 1985

Claims (2)

[Claims] (1) Ethylene and heptene-1 or octene-1 are copolymerized by liquid phase method, with a density of 0.870 to 0.925 g
/cm^3 and melt index is 1.2~10g
40% by weight of /10 min linear low density polyethylene resin
A light-shielding packaging for photosensitive materials having a polyethylene polymer film layer containing ~99% by weight and having a thickness of 20 μm or more and having a (longitudinal tear strength)/(horizontal tear strength) ratio of 0.6 or more. material (2) The photosensitive material according to claim 1, wherein the polyethylene polymer film layer is formed by inflation molding a polyethylene polymer having a melt index of 1.2 g/10 minutes or more at a blow ratio of 1.2 to 2.4. Packaging materials for substances