JPS631540A - Packaging material for photosensitive material - 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 [Field of Industrial Application] The present invention relates to a packaging material suitable for photographic materials.

[Conventional technology]

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 perforation strength, R Lugo test strength, abrasion strength, etc.), Heat sealing properties (heat sealing strength, cut sealing properties, hot tack properties, impurities sealing properties, etc.), heat sealing strength over time, antistatic properties, flatness,
Examples include slip characteristics. It is extremely difficult to have all of these properties in a single film material.
Conventionally, a very thick high-pressure branched low-density polyethylene (hereinafter referred to as LDPE) resin light-shielding film layer 8a or a single layer film of a very thick high-pressure branched low-density polyethylene (hereinafter referred to as LDPE) resin light-shielding film layer 8a kneaded with carden black, pigments, etc. as shown in FIG. film and paper,
Composite laminate films with flexible sheet layers such as aluminum foil and cellophane have been used. An example of a composite laminate film is shown in Fig. 6, which is used in rolled color photographic paper products that particularly require moisture resistance and physical strength. An aluminum foil layer 9 is laminated through the adhesive layer 5, and a flexible sheet layer 6 is laminated through the adhesive layer 5.
LDPE resin light-shielding film layer 8& is further laminated thereon via an adhesive layer 5.

The present inventor has conducted extensive research to improve packaging materials for photosensitive materials, and has developed a material with improved physical strength by combining two layers of uniaxially stretched film (%
No. 54) has already been disclosed. In addition, in a laminated film formed by laminating uniaxial molecularly oriented thermoplastic resin films on both sides of a sheet-like foam, the thickness of the sheet-like foam is 0.3 to 2.0 ms, and the expansion ratio is 5 to 50. A laminated N film has already been disclosed in which two layers of -axis molecularly oriented films are adhered to both sides of a foam such that the molecular orientation axes intersect at an angle of 30 degrees or more. (Japanese Unexamined Patent Publication No. 59-201848) [Problems to be Solved by the Invention] Conventional composite laminate films are constructed to improve the above-mentioned physical properties. However, since aluminum foil is used to prevent moisture and static electricity, the physical properties of heavy products and roll film products with sharp edges cannot be said to be sufficient. There were drawbacks such as the seal part peeling off. Furthermore, if a large amount of light-shielding substances such as Carzan Black are added, the physical strength and heat sealability will deteriorate significantly.
It was necessary to make it more than μm. 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, even in the seven-layer laminated film shown in Figure 6, which was used to package rolls of color photographic paper, aluminum foil is used to prevent moisture and static electricity. Strength etc. is insufficient. The packaging material described in JP-A-59-201848 has improved physical strengths such as tensile strength, Gourdet test strength, and impact hole damage strength.

However, this laminated film is too thick and has insufficient antistatic properties for use in highly light-shielding photosensitive materials, and is not suitable for heat-sealing to ensure light-shielding and moisture-proof properties.Furthermore, it is not suitable for automatic bag making, and is not suitable for heat-sealing. The packaging was extremely expensive because the product was inserted into a bag made with a heat sealer using a special cooling device and a heat-resistant film sandwiched between the sides and then sealed.

The present invention solves the above-mentioned problems and provides an inexpensive packaging material for photographic materials that improves product insertability, heat-sealing strength over time, physical strength, heat-sealing suitability, antistatic property, etc. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention uses a copolymer of ethylene and α-olefin or a linear low density one. Liethylene resin weighs 30 to 99.49 kg, car? Black is 0.5-10% by weight and lubricant is 0.0
an inner layer that is a heat-sealing layer with a weight coefficient of 1 to 1.00 and a coefficient of static friction of 0.12 to 0.37, an intermediate layer made of a thermoplastic resin, and an inner layer made of a thermoplastic resin and a coefficient of static friction of 0.12 to 0.37. 0.05 or more and its absolute value is 0.05 or more.
19 or more, and a simultaneous multilayer coextruded light-shielding film having an adhesive strength of 109/i5m or more between the inner layer and the intermediate layer and between the outer layer and the intermediate layer. It is made up of packaging materials.

The linear low density polyethylene resin which is a copolymer of ethylene and α-olefin which is essential for the inner layer of the present invention is generally L-LDPE resin (L1near LovrDen
Linear low density polyethylene (abbreviation for linear low density polyethylene)
It is polyethylene resin. Polymerization processes include a gas phase method using medium and low pressure equipment, a liquid phase method (solution method), and a high pressure modification method using a high pressure modification equipment. Especially low pressure L-LDPE
Resins are preferred because of their low cost.

Specific examples are Unipol and rUFLIN (
UCC), Dowlex (Dow Chemical), Sclar (DuPont Canada), Marlex (Philips), Neozex and Ultose, Kusu (Mitsui Petrochemical), Nippon Linirex (Nippon Petrochemical), Idemitsu Polyethylene L (Idemitsu Petrochemical), Stamilex (DS
(Company M), N'UC Polyethylene-LL (Nippon 22 Car), etc. As the α-olefin, 1-butene, 1-octene, 1-hexene, 4-methylbentene-1, heptene-1, etc. are used, and the amount thereof is 0.1% of the polymer. It is about 5 to 15 molti. The density is generally considered to be low to medium density, but commercially available products have a density of 0.87 to 0.
．． Many of them are within the range of 94 fJ/CM.

Among these L-LDI'E resins, those having an ethylene content of 90 to 99.5 molt and an α ole 7 int of 0.05 are particularly preferred from the viewpoint of cost, physical strength, and heat seal strength. 5-10 molti, melt index (hereinafter referred to as Ml) is 0.4-30 g/10 min (ASTM
D-1238) Density is 0.8 7 0 to 0.9 4 0
FCrn3 (ASTM D-1505), L-LDPE bunsou produced by a low-pressure liquid phase process and a gas phase process in which the alpha olefin has 6 to 8 carbon atoms. The most preferred representative product name is L-LDPE, which uses 4-methylpentene-1 with 6 carbon atoms as the α-olefin side chain in ethylene.
There are Neozex and Urtozex, and L-LD uses octene-1 with 8 carbon atoms as the α-ole7yne side chain.
Examples of PE resins include Stamilex from DSM and Dowlex from Dow Chemical. (All of the above three companies' products are L-LDPE case resin produced by the low-pressure liquid phase process.)
As a low-pressure gas phase process product, UCC using hexene-1 as the α-olefin side chain! There are IN etc.

L-LDPK resin may be used alone or in combination with other various thermoplastic resins and various additives. Especially physical strength (
(tear strength, impact hole resistance, etc.) and heat sealability (ensuring sealing strength, hot tack performance, contaminant sealing performance, etc.)
In order to ensure better properties than when other resins are used, it is essential to have a resin composition containing at least 30 parts by weight of L-LDPE resin. L-LDPE 71 {fat is two or more types of L-LDPE having different α-olefins
It goes without saying that a mixed composition of @fat may also be used.

Among the resins that can be mixed with L-LDPE resin to improve the formability of blown film without significantly reducing physical properties are polyolefin resins, LDPK resin, and EvA.
Resin (ethylene/vinyl acetate copolymer resin) and EEA resin (ethylene/ethyl acrylate copolymer resin) are preferred.

Cargon black, which is essential in the inner layer K, is used to maintain heat seal strength over time, provide light shielding properties, antistatic properties, etc., and the amount added is 0.5 to 10% by weight. The amount added is limited in terms of the physical strength of the film, film formability, moisture resistance, antistatic property, and film quality. 0. If the weight is less than 5 weight, the light shielding properties, heat sealing strength over time, and antistatic properties will not be satisfied, and if the weight is 10 weight, the hygroscopicity will increase and the film formability will deteriorate. Characteristics are the problem. Also, due to rubbing with photographic materials. As a result of further abrasion, black powder is produced frequently, causing speckle-like failures in the photosensitive material. In order to reduce the surface resistance to 1010Ω or less using carbon plaque alone, it is necessary to add conductive carbon plaque.

Typical examples of conductive carpon black include acetylene carbon black and Ketjen Cargon Black, which is a modified by-product cargen black. It is also preferable to improve the antistatic effect by blending various conductive substances with various carbon blacks.

For example, various metal conductive particles, various antistatic agents (described in detail in "Antistatic Agents" by Hideo Marumo (Shin Shobo)), metal powders, fibrous conductive fillers, or conductive fillers. It is also preferable to blend Cargen Black with a known conductive substance such as one hardened with a liquid polymer and/or a solvent-soluble polymer. 10~120mμ
Those with Pl{6 to 8, average particle size 15 are preferable, and in particular
Oil furnace carbon black of ~30 mμ is preferable from the viewpoint of ensuring dispersibility and light-shielding properties. By using materials with such characteristics and particle sizes as packaging materials for special K photographic light-sensitive materials, there will be little fog, little increase or decrease in photosensitivity, high light-shielding ability, and no negative effects on the photographic light-sensitive materials. Even when it is added to a thermoplastic resin film without adding it, it is possible to obtain a packaging material that has a number of advantages, such as being less likely to generate clumps of carden black or bottle holes such as fish eyes.

car? Forms of use for blending black with L-LDPE resin include powder addition method, paste addition method, moisturizing addition method, granule addition method, and con-! Although there are various methods such as the wind method and the master patch method, the master patch method is preferable in terms of cost and prevention of contamination of working equipment.

Japanese Patent Publication No. 40-26196, which is a publicly known document, describes a method for preparing a masterbatch of polymer carbon plack by dispersing K cargon plac in a solution of a polymer dissolved in an organic solvent, and Japanese Patent Publication No. 10362/1982 describes a method for preparing a masterbatch of polymer carbon plac. describes a method for preparing a master patch by dispersing carden black in I-lyethylene.

In the case of the master patch method, K is first made of polyolefin resin (preferably <&'!. LDPE. L-L.) P
B, EVA, EEA. A master patch is made by mixing carbon black (e.g. EMA, etc.) at a high density of 10% by weight or more, generally 30% by weight or more. Finally, the amount of carbon black in the inner layer is 0. Weigh out 4 lets of this masterbatch so that it will weigh 5 to 10 times, and
- Mix with a thermoplastic resin to be added to the LDPE resin or L-LDPEm resin.

The lubricant, which is essential for the inner layer, does not have a negative effect on the photographic material.
This is to improve product insertion suitability, blocking prevention, film formability, anti-static properties when peeling off, etc. The amount of this lubricant added is determined to prevent static electricity, suitability for product insertion, film formability, prevention of blocking, and to prevent the occurrence of stickiness, dust adhesion, etc. due to bresdout on photographic materials if the amount added is too large. 0.01 to 1 to
．． It is 0 weight.

The names of typical commercially available lubricants and manufacturers that do not adversely affect photographic light-sensitive materials are listed below, but the present invention is not limited thereto.

(1) Silicone lubricant; various grades of dimethylpolysiloxane (Shin-Etsu Silicone, Toray Silicone, etc.) (2) Oleic acid amide lubricant: Armoslip CP (
Lion, Akzo). Neutron (Nippon Sheath Chemical), Neutron E-18 (Nippon Fine Chemical), Amide O (Nitto Chemical), Al7kuchi E-10 (Nippon Oil & Fats), Diamid 0-200 (Nippon Kasei), Diamid G -200 (Nippon Kasei) etc. (3) Erucic acid amide lubricant; Arunro P-10 (
(4) Stearic acid amide lubricant; Alflo S-10
(NOF), Neutron 2 (Nippon Fine Chemicals), Diamid 200 (Nippon Kasei), etc. (5) Bis fatty acid amide lubricants; Pisamide (Nippon Kasei), Diamid 200 Bis (Nippon Kasei), Armowax DBS ( (6) Alkylamine lubricants; Electro Stripper TS-2, etc.

Further, the inner layer has a static friction coefficient of 0.12 to 0.37.

This coefficient of static friction was determined by cutting out a part of the sheet to be tested and pasting it on the bottom of a block measuring 75 m long and 35 m wide and weighing 200 g. On the other hand, a part of the sheet to be tested is similarly cut out and pasted on an inclined surface, one side of the block is placed on the inclined surface, the inclination angle of this inclined surface is changed, and the This is the value obtained as tanθ after reading the angle θ at which the block started to slide.

If the friction coefficient is less than 0.12, the photographic material will not only move too much in the bag during transportation, causing scratches and frictional brittleness, but will also cause damage during winding after film forming or during the lamination process. It is difficult to put it into practical use because it is too slippery and cannot be rolled up, or it takes on a bamboo shoot shape.

Furthermore, if the static friction coefficient exceeds 0.37, the bag may be torn if the photosensitive material is squeezed into the bag during the packaging process, and the photosensitive material may be scratched or have friction brittleness. In the case of bags, it is easier to block,
Not only can the inner layer be damaged, but the inner layer and the photosensitive material may adhere to each other, making it unusable. In addition, during the transportation process, the photosensitive material is abraded due to rubbing against the photosensitive material, producing a large amount of black powder, and this black powder adheres to the photosensitive layer of the photosensitive material in the form of speckles, resulting in failure.

The intermediate layer is formed of a single thermoplastic resin or a mixture of two or more thermoplastic resins. This thermoplastic resin is used in such a resin composition that the adhesive force between the inner layer and the outer layer is 10'l/15cm or more. The following polyolefin resins are preferred because they ensure adhesive strength with the L-LDPE resin of the inner layer, have good film formability, reduce curling, are general-purpose resins and are inexpensive.

(1) Low density polyethylene resin (LDPE) (2)
Junior high school 1 (
! v! DPI) (3rd grade high school)
1 (HDPE) (4) Linear low density z
z (L-LDPE) (5) Ethylene・
Globylene copolymer resin (random or block copolymer resin, etc.) (6) Ethylene-butene-1 copolymer resin (7) Propylene (8) Ethylene-propylene-putene-1 copolymer fat (9) Polybutene-1 {Seal αQ Polystyrene resin Oυ Polymethyl methacrylate resin (6) Styrene-acrylonitrile copolymer resin (to) ABS resin α◆ Polypropylene resin α Crystalline propylene-α-olefin copolymer resin (4) Modified polypropylene resin αη I Polyethylene l α side Polypropylene/maleic anhydride graft copolymer resin α @ chlorinated polyolefin resin (mainly chlorinated polyolefin resin) (HDPE, LDPE, PE copolymer, atactic pp, etc.) Ethylene/vinyl acetate Copolymer resin (EVA) a!
υ Ethylene-based ionomer resin (resin in which a copolymer of ethylene and unsaturated acid is cross-linked with metal) (c) Poly 4-methylbentene-1 resin wire Ethylene-acrylic acid copolymer resin (FAA) (c) Ethylene・Methyl acrylate copolymer resin (EMA) (c) Ethylene/ethyl acrylate copolymer resin (
EEA ) (d) Vinyl chloride/propylene copolymer resin (a) Ethylene vinyl alcohol Jugetsuji (c) Crosslinked polyethylene resin (electron beam irradiation crosslinking, chemical crosslinking, etc.) Polyinoptylene resin (to) Ethylene-vinyl chloride copolymer resin Polymer resin ({1)
1.2-/ributazinine resin, etc.

Even if the intermediate layer of the present invention has problems in heat sealability, physical strength, abrasion resistance, moisture resistance, etc., it is covered by the inner layer and the outer layer. Therefore, the above characteristics can be changed by using antistatic agents, which are substances with good antistatic and light-shielding properties, acetylene carbon black, which is conductive carden black, Ketjenker black, which is a modified rat carbon black, metal powder, and carbon thickener. Fibers, metal fibers, graphite, metal plating with a metalized surface, graphite fiber fa conductive zinc oxide or tin, graphite powder, carbonaceous or graphite whisker-like short fibers, polyalkylene oxide compounds, fibrillar Potassium titanate and the like can be used. These antistatic agents, conductive powders, and tetraelectric fibers meet the required conductivity and usage. They can be used alone or in combination.

The type, shape, size, and amount of these antistatic agents and conductive substances can be appropriately selected depending on the purpose of use. The pace resin is also selected appropriately depending on the resin composition of the innermost layer and outermost layer5.
However, from the viewpoint of physical strength, economical efficiency (inexpensive), etc., various polyolefin resins, especially ethylene resins, copolypropylene resins with α-olefins, EEA resins, EMA resins, etc.
Resin, EAA resin, EvA resin, ionomer resin, adhesiveness? Rimmer etc. are preferred. In addition, commercially available conductive resins may be used in the intermediate layer, such as conductive glasstic 6 Papiostat 1 manufactured by Tokyo Ink, conductive plastic compound '゛Rioconduct 1 manufactured by Toyo Ink Co., Ltd., and Dainippon Ink Chemical Co., Ltd. 5. It is preferable to use conductive plastics such as "Guierec" by blending them with commercially available pellets or other resins. Also, the intermediate layer may be formed from a single layer or from multiple layers. good. It is essential that the outer layer of the present invention has a coefficient of static friction (tan θ) larger than the inner layer by 0.05 or more and a value of 0.19 or more, and has an adhesive strength of 10.9/i5m or more with the intermediate layer. It is essential that

From these points of view, it is preferable to use substantially the same type of thermoplastic resin as the intermediate layer.
Preferably, the main component is in-resin.

Although various thermoplastic resins and additives can be mixed in the outer layer, the amount added is limited because the coefficient of static friction is limited. This is because if the coefficient of static friction is equal to or lower than the inner layer and it is slippery, the film forming process, laminating process, bag making process, etc.
Various troubles occur during the logistics process after product packaging, making it difficult to put it into practical use.

When produced using only the simultaneous multilayer coextruded film of the present invention, the outer layer is 5°C or more higher than the inner layer, preferably 10°C.
It is preferable to use a thermoplastic resin having a higher melting point. For example, it is preferable to use HDPE resin, polyester resin, propylene resin, polyamide resin (various types of nylon), acrylic resin, and a mixed resin with the polyolefin resin. It is also preferable to add a light-reflecting light-shielding substance to the outer layer K since heat resistance, light-shielding properties, moisture-proofing properties, printability, appearance, etc. can be improved.

The coefficient of static friction (tanθ) of the outer layer is O. O
S or more and the value is 0.19 or more. If the static friction coefficient does not meet these conditions, various troubles will occur in the film forming process, laminating process, bag making process, torn product packaging process, and logistics process due to slippage between the films. It's not practical.

The adhesive strength between the intermediate layer, inner layer and outer layer is LoV15 width or more. If the adhesive strength is less than 10J7/15mm width, delamination failure will occur during the lamination process, bag making process, heat sealing process, etc. A package in which delamination occurs loses functions necessary for a photographic material package, such as light-shielding properties, moisture-proofing properties, and gas-repellent properties.

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

Examples of light-reflecting light-shielding materials include metal powder, metal flakes,
Metal fI & fiber, white pigment, etc. are used. The metal powder is a metal formed into powder, and is preferably one in which less volatile substances are removed than aluminum powder or aluminum paste. Here, the aluminum powder is obtained by forming molten aluminum into powder form by an atomizing method, a granulation method, a rotary disk drop method, an evaporation method, or the like. Since aluminum powder alone is unstable, various known treatments are performed to make the surface of the aluminum powder inert. As a known method for splitting metal powder for filling synthetic resins, there is a method described in JP-A-59-75931.

In addition, the aluminum paste is made into a paste in the presence of mineral spirit and a small amount of higher fatty acids such as stearic acid or oleic acid when making aluminum powder by a known method such as a ball mill method, a stamp mill method, or an atomization method. It was made in the shape of

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

The other seven lexical sheet layers used in the composite film include various non-stretched, uniaxially oriented and biaxially oriented thermoplastic resin films, such as various polyethylene resins, nethylene copolymer resins, polypropylene resins, There are known films of polyvinyl chloride resin, polyvinylidene chloride resin, polyamide resin, polycargenate resin, polyester resin, and films of modified resins thereof.

We also offer metal-coated film (typically aluminum vacuum-deposited film), aluminum vacuum-deposited paper, cellulose acetate film, cellophane, etc. Known flexible sheets such as ribinyl alcohol films, various papers, metal ffi of various types (aluminum foil as a typical example), nonwoven fabrics, warp sheets, perforated films, and foam sheets of polyethylene, polystyrene, polyglobylene, I-urethane, etc. Also suitable are layers.

When making a composite film, placing the inner layer of a simultaneous two-layer coextruded film as the innermost layer in contact with the product is the best way to achieve moisture resistance.
This is essential to ensure heat sealability.

The composite film can be formed by any known adhesive method, but particularly preferred are the dry lamination method and the extrusion/in-lamination method.

Particularly preferable adhesives used in the extrusion lamination method are, more specifically, polymers made of polyolefin resins such as various polyethylene resins, polyglobylene resins, polybutylene resins, etc.
(EVA + ER4A + EEA and other resins L-
LDPF. Like resin, some other monomers (
For example, copolymerized α-olefin etc.)), D
Examples include ionomer resins (ionic copolymers) such as Surlyn from Upont and Hylamin from Mitsui Polychemicals, and Admer (adhesive polymer) from Mitsui Petrochemicals.

It is preferable 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 extrusion lamination method K using thermoplastic resin is usually 6 μm to 50 μm, preferably 10 μm to 20 μm, but it is determined based on cost, lamination speed, total thickness of the laminate, etc. It is not particularly limited to numerical values.

The photographic materials include silver halide photographic materials, diazo photographic materials, noazo photosensitive recording materials, photosensitive resins, self-developing photographic materials, and diffusion transfer photographic materials.

The packaging material of the present invention can be used not only for the above-mentioned photographic light-sensitive materials, but also for all light-sensitive materials that discolor or degrade due to light K, as well as materials that cause functional problems due to dust and static electricity, such as IC packaging. It is ideal as a material.

When the packaging material of the present invention is applied to the above-mentioned photographic materials, single-layer flat bags, double-layer flat bags, square bottom bags, self-supporting bags, single-layer gusset bags, double-layer gusset bags, film sheets, All known forms such as lining inside a moisture-proof box, leader paper, etc. are possible.

The bag making method is based on conventionally known glass film sealing methods such as heat sealing, innolus sealing, ultrasonic sealing, and high frequency sealing, depending on the properties of the laminated film used. Furthermore, it is also possible to tear the bag using an appropriate adhesive or adhesive.

[action,]

゛In the packaging material for photographic light-sensitive materials of the present invention, the inner layer has light-shielding properties, breakage insertion properties, anti-blocking properties, peel-off antistatic properties,
Excellent moisture and gas barrier properties.

In addition, it has excellent heat sealing properties (hot tack properties, contaminant sealing properties, heat sealing strength, etc.), excellent ability to maintain sealing strength over time, and further excellent physical strength. The intermediate layer not only prevents delamination but also improves physical strength by controlling the adhesive strength between the inner layer and the outer layer compared to a single layer. If high-wavelength cargoon black is added, the resin will have problems with physical strength, abrasion resistance, film formability, heat sealability, moisture resistance, printability, and appearance. Therefore, antistatic properties, antistatic properties, light blocking properties, etc. can be improved by adding 10% or more of antistatic light blocking material such as carbon black to the intermediate layer. Furthermore, since the intermediate layer does not come into contact with the photographic material, it is possible to add individual fats and additives that improve properties such as physical strength, but which are harmful to the photographic material.

By increasing the static friction coefficient of the outermost layer by 0.05 or more than the innermost layer and setting the value to 0.19 or more, slippage between packaging materials during film forming process, laminating process, bagging process, logistics process after product packaging, etc. This prevents various troubles that may occur due to this.

By using a thermoplastic resin with a high melting point for the outer layer or adding various additives, heat resistance is improved and suitability for automatic bag making is improved. In addition, when a reflective light-shielding substance is added, it is possible to improve heat insulation, light-shielding properties, appearance, printability, front and back discrimination during the photographic material packaging process under safelight, etc.

〔Example〕

A first example of a packaging material for photographic light-sensitive materials produced by this punching process is shown in the first example.
This will be explained based on the diagram.

FIG. 1 is a partial sectional view of a packaging material for photographic light-sensitive materials.

This example has the most basic layer structure of the present invention, and is composed only of a simultaneous multilayer coextruded film 4a consisting of three layers: an inner layer 1&, an intermediate layer 2a, and an outer layer 3a.

FIG. 2 is also a partial sectional view of another example of the packaging material for photographic materials. In this example, the intermediate layer 2 is formed in multiple layers, and includes a central intermediate layer 21 and an inner intermediate layer 22 and an outer intermediate layer 23 on both sides thereof.

Then, the inner layer 1 is laminated on the inner intermediate layer 22, and the outer layer 3 is laminated on the outer intermediate layer 23, thereby forming a simultaneous multilayer coextruded film 4& consisting of five layers.

FIG. 3 is also a partial sectional view of another example of the packaging material for photographic materials. In this example, a flexible sheet layer 6 is laminated on a simultaneous multilayer coextruded film 4a shown in FIG. 1 with an adhesive layer 5 interposed therebetween.

In addition, FIG. 4 is a partial sectional view of a comparison product, which is the same as the inner layer 1a of the present invention except that no lubricant is added {light-shielding L-LDPE formed with a sealant composition *consisting only of a fat layer 7a It is.

Next, the results of comparing the characteristics of products 1 and 2 of the present invention, comparative product 11, and conventional products 1 and 2 will be described.

The product 1 of the present invention corresponds to the embodiment shown in FIG. The inner layer la has a thickness of lOOμm, and the α-olefin is L-LDPE @ fat with 4-methylbentene-l, Mitsui Petrochemical Co., Ltd. Ura Urto Zex 2021L has a thickness of 96.33ii, Furnace Kaden Black has a thickness of 32mm. Armorip CD, manufactured by Lion Akzo, which is an oleic acid amide-based lubricant, is made of 0.07 weight chloride.

The middle layer 12a has a thickness of 20 μm and is manufactured by Toyo Ink Co., Ltd.
Conductive plastic slioconduct PE COMP
It is made of a resin having a weight of 245 80 iL and a weight of 2021L made by Mitsui Petrochemical Co., Ltd. The outer layer 3a has a thickness of 60 μm, and is made of 2 parts of aluminum paste manufactured by Toyo Aluminum Co., Ltd. and Mitsui Petrochemical (Mitsui Petrochemical Co., Ltd.).
Co., Ltd. L-LDPE m fat Urto Zex 60 weight chain,
It is made of Mitsui Petrochemical Co., Ltd. IDPE i] 14-fat HiZEX 3300F 3 8% by weight resin.

The product 2 of the present invention corresponds to the embodiment shown in FIG. The inner layer 1a is the same as the inner layer 1a of the product 1 of the present invention, except that the thickness is 80 μm. The intermediate layer 2a has a thickness of 20 μm and is manufactured by Dainippon Ink Chemical Co., Ltd. (Kyusei Conductive Plastics PE 29170).
x quantity, EEA resin NUC-61 manufactured by Nippon Unicar Co., Ltd.
70 (registered trademark) Made of 30M resin. The outer layer 3 has a thickness of 50 μm and is manufactured by Mitsui Petrochemical Co., Ltd.
Made of HDPE resin HIZEX 33DDF'30 weight Chi L
,-LDPK resin Urto ZEX 2021L 7 0
It is made of n amount of resin. Comparative product 1 corresponds to the example shown in FIG. 4, and has a thickness of 150 μm and is made of L-LDPB resin.
- Ultzex 2021L manufactured by Mitsui Petrochemicals Co., Ltd., whose olefin is 1-methylpentene-1 80 weight section and Nippon Unicar Co., Ltd. % NUC polyethylene-1101
71 17% by weight and Furnace Caden Black 4483M (manufactured by Mitsubishi Chemical Corporation) resin.

Conventional product I corresponds to the example shown in Figure 5, has a thickness of 150 μm, and is made of LDPE resin DFD-01197 made by Nippon Unicar Co., Ltd. and Mitsubishi Kasei C Co., Ltd.). A Furnace Carbon Blacks 4B (registered trademark) is made of 3-weight resin.

Conventional product ■ corresponds to the example shown in Figure 6, and has the same resin composition as conventional product ■, with an 8 m thick LDPE resin light-shielding film layer of 52 μm thick, a 15 μm thick LDPE extrusion adhesive layer 5, and a 7 μm thick aluminum foil layer. Layer 9. And as flexible sheet layer 6, twisted base paper 355'/m2
50 μm thick with the same resin composition as the conventional product ■
This is a packaging material made of a seven-layer laminated film in which LDPK resin light-shielding film layers 8a are laminated.

Above are the products of the present invention 1. Table 1 shows the results of comparing the characteristics of Comparative Product 1, Conventional Product 1, and If.

The evaluation is as follows: Excellent: Very good Good: Fairly good
・Practical limit resistance Needs improvement ・Problems not possible ・
・・Not practical A Heat-sealing strength: Two samples with a film width of 15 mm are stacked and heat-sealed at the desired sealing temperature with a sealing pressure of 1Y/(7n” and a sealing time of 1 second), and after complete cooling, Seal surface 18
Find the load required to peel off at a 0 degree angle. Unit 8/
The heat sealing strength after 1 month of heat sealing with a width of 15W was defined as the heat sealing strength over time.

B Hot tack property (hot sealability): Hot peeling when the open end of two packaging materials (width 15 m) immediately after heat sealing at 160°C is pulled at a peeling angle of 22.5 degrees with a load of 45 g on each side. Judging by distance (CM).

C. Light-shielding property: A photographic film of ASA IOO is placed in a bag made of each packaging material, completely sealed, and then exposed to light of 80,000 lux for 1 hour, and the light-shielding property is detected and evaluated by the degree of fog on the photographic film.

D Peeling voltage: The width of the packaging material to be tested is 3. 5 cm, length 13
A 50-piece endless belt was made, and the endless belt-like packaging material was passed through opposing rollers (upper part made of SUS) with a load of 5oo9.
tllll-ra, lower SUS O-ra) Measure the amount of stored electricity with a deltmeter when sending it into darkness at a speed of 12 m/min.

E Static friction coefficient: Cut out a part of the sheet to be tested and cut it lengthwise 7 5
Attach it to the bottom of a block measuring 200 g (m x 3 5 cm) and weighing 200 g. On the other hand, a part of the sheet to be tested is similarly cut out and pasted on an inclined surface, the sheet surface of the block is placed on the inclined surface, and the inclination angle of this inclined surface is changed, and the block begins to slide. An example of the value obtained as tinθ after reading the angle θ.
0 degrees = 15 degrees # # Fin15 degrees"I IF Bag making suitability: Difficulty in generating bottle holes when photosensitive materials are packaged into 3-side seal bags using automatic top bags, suitability for heat sealing, and product Judging from insertability, etc.

G. Packaging material handling properties: Judgment based on total handling properties such as film forming process, laminating process, bag making process, logistics process, etc. [Effects of the invention] Since the present invention is configured as described above, physical strength and moisture resistance are achieved in the inner and outer layers. It is possible to ensure sufficient properties such as properties, properties, heat sealability, etc. Further, the intermediate layer does not need to be sufficient because physical strength and the like are ensured by the inner layer and the outer layer, and a large amount of antistatic substance can be added to improve antistatic properties. Further, although the intermediate layer has these characteristics and is inexpensive, it can also contain substances harmful to the photographic material. Therefore, the packaging material as a whole has good physical strength, antistatic properties, etc., can be made significantly thinner, and can be provided at low cost.

[Brief explanation of drawings]

1 to 3 are partial cross-sectional views of packaging materials that are embodiments of the present invention. FIG. 4 is a partial sectional view of a comparative product. 5 and 6 are partial cross-sectional views of conventional packaging materials. 1...Inner layer, 2...Middle layer, 3...Outer layer, 4...
- Simultaneous multilayer coextrusion film a means that it contains a light-shielding substance. Patent applicant Fuji Photo Film Co., Ltd. Representative Patent Attorney
Masahiro Tanaka and 1 other person Figure 1 Figure 3 Figure 5 [7P/ Figure 2 Figure 4 Figure 6

Claims (3)

[Claims] (1) Linear low density polyethylene resin, which is a copolymer of ethylene and α-olefin, is 30 to 99.49% by weight
, a heat-sealing layer containing 0.5 to 10% by weight of carbon black and 0.01 to 1.00% by weight of a lubricant, and an inner layer having a static friction coefficient of 0.12 to 0.37, and a thermoplastic resin. an outer layer made of a thermoplastic resin and having a coefficient of static friction 0.05 or more larger than the inner layer and an absolute value of 0.19 or more, and the adhesive between the inner layer and the intermediate layer and the outer layer and the intermediate layer. A packaging material for photographic materials characterized by comprising a simultaneous multilayer coextruded light-shielding film having a strength of 10 g/15 mm or more. (2) The packaging material for photographic materials as set forth in claim 1, wherein the linear low-density polyethylene resin is a copolymer resin of ethylene and an α-olefin having 6 or more carbon atoms. (3) The packaging material for photographic materials according to claim 1 or 2, wherein the thermoplastic resin in the outermost layer contains 30% by weight or more of any one or more of various polyethylene resins or ethylene copolymer resins.