JPH0480745A - Production of packing material for photosensitive substance - Google Patents

Abstract

PURPOSE:To ensure high adhesive strength to a heat resistant substrate, superior light shielding property and satisfactory suitability to heat sealing at low temp. and neck-in, to prevent the occurrence of foam and pinholes and to improve productivity by forming two light shielding coating layers each having a prescribed compsn. on the heat resistant substrate by extrusion. CONSTITUTION:A heat resistant substrate 21a is coated with polyolefin resin contg. <=5wt.% light shielding substance by extrusion to form a lower coating layer 22 of 7-50mum thickness and this layer 22 is coated with thermoplastic resin contg. 8-60wt.% carbon black by extrusion to form an upper coating layer 23a to 7-70mum thickness. Satisfactory adhesive strength to the substrate, light shielding and antistatic properties are maintained, suitability to heat sealing at low temp. and neck-in is improved, the occurrence of foam and pinholes in the upper coating layer is also prevented and line speed can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a packaging material for photosensitive materials, which involves extrusion coating a light-shielding resin layer on a heat-resistant support.

[Conventional technology]

For materials such as photographic materials that lose their quality value when exposed to light, packaging materials that completely block light are used. This packaging material is required to have various properties such as light-shielding properties, physical strength, heat-sealing properties, moisture-proofing properties, anti-blocking properties, and antistatic properties, and to be easy to manufacture.

Conventionally, light-shielding paper for photographic light-sensitive materials has been made of light-shielding black paper in which carbon black or black dye is added to paper, and solutions such as EVA resin containing 5% by weight or more of carbon blank dissolved in toluene or the like on a paper support. There were some that were gravure coated with a similar resin.

In addition, the present inventor has also developed a light-shielding paper for photographic film (Japanese Patent Application Laid-Open No. 1983-1990), in which at least an aluminum layer is provided on a support such as paper, in order to ensure light-shielding properties, moisture-proofing properties, and antistatic properties.
140835), less paper support (on both sides,
Light-shielding paper in which a polyethylene resin layer made of a blend of high-density polyethylene resin and low-density polyethylene resin is melt-extruded and lamirarded (Japanese Patent Laid-Open No. 60-35728)
etc. are proposed.

[Problem to be solved by the invention]

However, conventional light-shielding paper coated with a solution resin layer such as EVA resin has excellent flexibility and conductivity, and has sufficient adhesion between the paper support and the coated resin layer. must be evaporated, which not only causes air pollution but also requires the installation of expensive explosion-proof equipment.If the coating speed is not lower than 50 m/min, thermal expansion of the air in the paper support will destroy the coated layer. Pinholes and crater-shaped holes were generated in the film, resulting in incomplete moisture-proofing and light-shielding properties.

Further, when the material was wound into a roll, blocking and staining of the printed surface due to residual solvent, fogging and sensitivity abnormalities occurred in the photosensitive material. Furthermore, carbon black aggregates and causes failures.

The light-shielding paper proposed in Japanese Patent Application Laid-Open No. 55-140835 is
Aluminum powder is generated when cutting, and if a light-shielding film formed in a separate process is laminated to prevent pinholes from forming due to impacts such as bending, it is expensive and lacks flexibility. was there.

The light-shielding paper proposed in JP-A No. 60-35728 tends to lack adhesive strength with the paper support, causing delamination, and is not suitable for use in high-speed photographic films with ISO speeds of 100 or higher, as has recently been the case. The light shielding properties and antistatic properties seemed to be insufficient. An object of the present invention is to provide a method for manufacturing a packaging material for photosensitive materials that is inexpensive and has excellent properties, solving the various problems mentioned above.

(Means for Solving the Problems) In order to achieve the above object, the present inventor has made extensive research and has discovered a method comprising a heat-resistant support and a light-shielding multilayer coextrusion extrusion coating layer consisting of two layers with a predetermined composition. A packaging material for photosensitive materials was proposed (Japanese Patent Application No. 1-330138).

The above-mentioned packaging material for photosensitive materials solves the conventional problems and is extremely useful. However, since the coating layer is formed on the heat-resistant support by coextrusion, both layers must be extruded at approximately the same temperature.

Since the temperature must be high in order to adhere to the support, the coating layer on the surface side that does not adhere to the support will also be extruded at high temperature.

Therefore, low-temperature heat-sealing properties are not good, and it is difficult to suppress the neck-in sufficiently.Furthermore, at high temperatures, the carbon blank absorbs a large amount of moisture in the atmosphere, causing foaming and pinholes in the surface coating layer. was likely to occur.

Also, since two layers were extruded at a time, the cooling efficiency was poor and the line speed could not be increased.

The present invention maintains good adhesion strength, light shielding property, antistatic property, heat sealability, etc. with the heat-resistant support, has good low temperature heat sealability and neck-in, and has foaming and pins in the surface coating layer. It is an object of the present invention to provide a method for manufacturing a packaging material for photosensitive materials that does not generate holes and can increase line speed.

That is, the method for producing a packaging material for photosensitive materials of the present invention includes:
A first coating step of forming a support-side coating layer by extrusion coating a polyolefin resin containing 5% or less of a light-shielding substance on a heat-resistant support to a thickness of 7 to 50a+, and a carbon coating layer to the support-side coating layer. 7 to 70% of thermoplastic resin containing 8 to 60% by weight of blank. The invention is characterized by comprising a second coating step of forming a surface-side coating layer by extrusion coating to a thickness of .

The method for producing a packaging material for photosensitive materials of the present invention includes sequential coating consisting of a first coating step and a second coating step. The first and second coating steps may be performed individually using a single laminator, or may be performed simultaneously using a tandem laminator.

The heat-resistant supports used in the present invention include various papers, various plastic films, cellophane, various metal foils, various metal-deposited plastic films, various metal-deposited papers, various non-woven fabrics, various synthetic papers, various types of There are knitted fabrics, etc. Preferably, various papers containing carbon black and/or conductive substances, and - axially or biaxially molecularly oriented (including stretched) thermoplastic resin films, aluminum cladding - axially - axially molecularly oriented thermoplastic resin films or It is aluminum vaporized paper. Particularly preferably, the basis weight is 30 to 120 g/rri, preferably 50 g/rri, which does not adversely affect the photosensitive material.
~100g/rI? , particularly preferably 60 to 90 g/r
+ (Bleached, semi-bleached or unbleached papers, various synthetic valve papers, glassine papers, parchment papers, coated papers. Various papers include colored or uncolored wood-free paper, medium-quality paper, Waste paper, recycled paper, acid-free paper, bleached kraft paper, hand-patterned kraft paper, unbleached kraft paper, pure white roll paper, washi paper, white base paper, rayon paper, synthetic fiber paper, inorganic fiber paper, kuruvac paper, duostress paper etc.

Various types of plus-ink films include polypropylene resins with -axis or biaxial molecular orientation (including stretching), polyester resins, polyamide resins, vinylon resins, ethylene vinyl alcohol copolymer resins, polyacrylodrill resins, and polystyrene resins. There are molecularly oriented films using polycarbonate resins and vinyl chloride resins, and unstretched films using heat-resistant resins such as polypropylene resins, polyester resins, and polyamide resins. Furthermore, there are processed films in which these molecularly oriented films and heat-resistant unstretched films are coated with vinylidene chloride resin or coated with metal hollywood. Various metal foils include aluminum foil, stainless steel foil, iron foil, copper foil, and the like.

In the first coating step, the polyolefin resin is coated in a thickness of 7 to 50 parts (when solidified, the same applies hereinafter), preferably in a thickness of 9 to 30 μm, particularly preferably in a thickness of 10 to 2 O μm, to form a coating layer on the support side. form. If the thickness is less than 7n, film breakage will occur and adhesion to the heat-resistant support cannot be ensured, and if the thickness exceeds 50n, neck-in will be large and the lamination speed will be slow, making it expensive. .

In addition, the temperature when applying polyolefin resin is 150
-350°C1 Preferably 200-330°C5 Especially preferred is 250-320°C.

As the polyolefin resin, homopolyethylene resin, ethylene copolymer resin, modified polyolefin resin,
There are polypropylene resins, propylene copolymer resins, ionomers, vinyl chloride resins, etc., with heat sealability,
A resin composition containing an ethylene copolymer resin is preferred because it improves bag breakage strength and impact puncture strength. In particular, Ml is 1 g/10 min or more, density is 0.935 g/cm' or less, preferably Ml is 2.5 g/10 min or more, density is 0.
．． 5% by weight or more, preferably 20% by weight of high-pressure low-density homopolyethylene resin or improved high-pressure or low-pressure linear low-density polyethylene resin (ethylene/α-olefin copolymer resin) of 910 to 0.927 g/c+4 As mentioned above, resins containing 50% by weight or more are particularly preferred.

Representative examples of ethylene copolymer resins are shown below.

(1) Ethylene-vinyl acetate copolymer resin (hereinafter EVA
(2) Ethylene-propylene copolymer resin (3) Ethylene-1-butene copolymer resin (4) Ethylene-butadiene copolymer resin (5) Ethylene-vinyl chloride copolymer resin (6) Edylene-methyl methacrylate copolymer resin (
7) Ethylene-methyl acrylate copolymer resin (8) Ethylene-ethyl acrylate copolymer resin (hereinafter referred to as EEA resin) (9) Ethylene-acrylonitrile copolymer resin 00)
Ethylene-acrylic acid copolymer resin (hereinafter referred to as EEA resin) 00 Ionomer resin (resin in which a copolymer of ethylene and unsaturated acid is cross-linked with a metal such as zinc) 02) Ethylene-
α-olefin copolymer resin (L-LDPE resin) Side ethylene-propylene-butene-1 ternary copolymer resin (14) Ethylene-methacrylic acid copolymer resin 05) Ethylene-ethyl methacrylate copolymer resin, etc. be.

Linear low density polyethylene resin (L-LDPE resin) and ethylene ethyl acrylate copolymer resin (EEA resin), which are inexpensive and have excellent extrusion coating suitability, will be described in detail.

LL D P E (Liner Low Dens
Polyethylene) resin is called the third polyethylene resin, and is a low-cost, high-strength resin that meets the demands of the times for energy and resource conservation, combining the advantages of both medium-low pressure and high-pressure polyethylene resins. This resin is produced by a low-pressure method or a high-pressure improvement method, and the number of carbon atoms is 3 to 3.
It is a polyethylene resin that is a copolymer of 13, preferably 4 to 10 α-olefins, and has a linear straight chain structure with short branches. Especially ethylene butene
1 copolymer resin is preferable to conventional high-pressure branched low-density polyethylene resin in terms of physical strength and cost.

As the α-olefin, 1-butene, 1-octene, 1-hexene-1,4-methylpentene, 1-heptene, etc. are used. The amount thereof is preferably about 0.5·-15 mol% of the polymer from the viewpoint of cost.

The density is generally considered to be that of low-medium density polyethylene resin, but commercially available products have a density of 0.87 to 0.95 g/ci! Most of them are within the range of 0.90-0.94g/co! from the viewpoint of ease of extrusion application. It is. The melt index is often within the range of 0.1 to 50 g/10 minutes, but from the viewpoint of ease of extrusion coating, the preferred range is 1 to 35 g/10 minutes.

The polymerization process for L-LDPE resin includes a gas phase method using a medium/low pressure device, a liquid phase method, and an ionic polymerization method using a high pressure improving device.

Specific examples of L-LDPE resin are shown below.

Ethylene-butene-1 copolymer resin G resin and NtJC-FLX (UCC) Dowlex (Dow Chemical) Sflare (DuPont Canada) Marex (Filimbus) Stamilex (DSM) Fselen VL
(Sumitomo Chemical) Neozex (Mitsui Petrochemical) Mitsubishi Polyethylene LL (Mitsubishi Petrochemical) Mekasu Nilenx (Nippon Petrochemical) NUC Polyethylene-LL (Nippon Unicar) Idemitsu Polyethylene L (
Idemitsu Petrochemical) Ethylene-hexene-1 copolymer resin TUFL IN <IJCC) TUFT
HENE (Nippon Unicar) Ethylene/4-methylpentene-1 copolymer resin Ultzesox
(Mitsui Petrochemical) Ethylene-octene-1 copolymer resin Stamilex (DSM) Dowlex
(Dow Chemical Company) Souffle
(DuPont Canada) MORETEC (Idemitsu Petrochemical) Among these L-LDPE resins, those with an ethylene content of 90 to 99.5 mol% are particularly preferred from the viewpoint of physical strength, heat seal strength, and suitability for extrusion lamination. , α-olefin content is 0.5 to 10 mol%, melt index (hereinafter referred to as MFR) is 2 to 30 g/1
0 minutes (JISK-6760), density is 0.910-0.
930 g/cd (JISK-6760), and α-olefin having 4 to 10 carbon atoms was obtained by a liquid phase process and a gas phase process.

To give a particularly preferable representative example by trade name, polyethylene has a butene having 4 carbon atoms as an α-olefin side chain.
11 is the most widely used in countries around the world that have introduced 1.
Ethylene-butene-1 copolymer resin described on page 12 and Mitsui Petrochemical's Urtozex with 6-carbon 4-methylpentene-1 introduced and 8-carbon octene-1 as an α-olefin side chain. Idemitsu Petrochemical Company's MORETEC, DSM's Stamilex, and Dow Chemical Company's Dowlex, all of which have introduced 1. . A representative product name of a preferred example obtained by a low-pressure gas phase process is UCC's TUF, which has hexene-1 with 6 carbon atoms introduced as an α-olefin side chain.
Examples include LIN and Nippon Unicar's TUFTHENE.

In addition, recently released ultra-low-density linear low-density polyethylene resins with a density of less than 0.910 g/cm3, such as UCC
NUC-FLX manufactured by Sumitomo Chemical Co., Ltd. and F-selen VL manufactured by Sumitomo Chemical Co., Ltd. are also preferable (both of the above two companies use butene-1 whose α-olefin has 4 carbon atoms). Especially when the melt index is 2 g/
20 to 80% by weight of a homopolyethylene resin with a density of 0.90 to 0.94 g/cd for 10 minutes or more and the L-LDPE
A resin composition in which 80 to 20% by weight of resin is blended is preferred from the viewpoint of improving lamination suitability (neck-in, drawdown properties, pinhole resistance, adhesion to heat-resistant supports, etc.).

Furthermore, it is also preferable to add an adhesive resin in an amount of 5 to 50 parts per 100 parts by weight of the blended resin.

Typical manufacturers of the EEA resin include Union Carbide Co. (USA), Nippon Unicar Co., Ltd., Mitsubishi Yuka (2), Sumitomo Chemical (2), and Mitsui Polychemical (2).

A specific example is EEA, which is currently on the market with Nippon Unicar flavor.
Representative brand names of resins, their comonomer content, melt index, and density are shown (Comonomer content NUC
6% or more according to the test method).

List of commercially available EEA resins among Japan Unicar Among these resins, homopolyethylene resins, high-pressure modified or low-pressure L-LDPE resins, EVA resins, EE
A resin containing 10% by weight or more of A resin or EMA resin is preferable.

Modified polyolefin resins (=adhesive resins) are also preferred, although they are expensive but have a high adhesive strength to heat-resistant supports.

This modified polyolefin resin is a modified resin obtained by graft-modifying a polyolefin resin and an unsaturated carboxylic acid. For example, graft modified polyethylene resin, graft modified ethylene/ethyl acrylate copolymer resin, graft modified ethylene/vinyl acetate copolymer resin, graft modified polypropylene resin, and polybutene-1, poly-4
-α-olefins such as methylpentene-1, ethylene, etc.
There are resins obtained by graft-modifying α-olefin copolymer resins with unsaturated carboxylic acids and the like. Preferably acrylic acid,
This is a graft-modified polyolefin resin in which an unsaturated carboxylic acid such as maleic acid or maleic anhydride is grafted onto a polyolefin resin.

In addition, the grafting rate of unsaturated carboxylic acids is 0.01 to 1.
Preferably it is 0%.

Unsaturated carboxylic acids are a general term that includes their derivatives; representative examples include acrylic acid, methacrylic acid,
Maleic acid, fumaric acid, itaconic acid, tetrahydrophthalic acid, mesaconic acid, angelic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid, (endocys-bicyclo(2°2.1)hept-5-ene-2, 3-
dicarboxylic acid), maleic anhydride, citraconic anhydride,
Itaconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate Esters, dimethyl fumarate, diethyl itaconate, acrylamide, methacrylamide, maleic monoamide, maleic diamide, maleic acid-N monoethylamide, maleic acid-N, N-diethylamide, maleic acid-N-monoethylamide Butylamide, maleic acid-N, N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, fumaric acid-N, N-diethylamide, fumaric acid-N-monobutylamide, fumaric acid -NN-diethylamide, fumaric acid-N-monobutyramide, fumaric acid-N
, N-dibutylamide, maleimide, monomethyl maleate, dimethyl maleate, potassium matacrylate,
Sodium acrylate, zinc acrylate, magnesium acrylate, calcium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate,
Examples include N-butylmaleimide, N-phenylmaleimide, malenyl chloride, glycidyl maleate, dipropyl maleate, aconitic acid anhydride, sorbic acid, etc., and they can also be used in combination.

Among these, acrylic acid, maleic acid, maleic anhydride, and nadic acid are preferred, and maleic anhydride is particularly preferred.

The method of graft-modifying the polyolefin resin with unsaturated carboxylic acids is not particularly limited. For example, there is a method disclosed in Japanese Patent Publication No. 43-27421 where the reaction is carried out in a molten state, a method disclosed in Japanese Patent Publication No. 44-15422 where the reaction is carried out in a solution state, and a method disclosed in Japanese Patent Publication No. 43-18144 where the reaction is carried out in a slurry state. There are methods disclosed in Japanese Patent Publication No. 50-77493, etc., in which the reaction is carried out in a gas phase.

Among these methods, the melt-kneading method using an extruder is preferred because it is easy to operate and inexpensive.

The amount of unsaturated carboxylic acids used is determined by using polyolefin resin paste polymers (various polyethylene resins, various polypropylene resins, various polyolefin copolymer resins, polybutene-1 resin, poly-4-methylpentene-1 resin, etc.) to ensure adhesive strength. α-olefin resin, etc.) 0.01 to 20 parts by weight, preferably 0.2 to 5 parts by weight per 100 parts by weight
Parts by weight.

Peroxides and the like are used to promote the reaction between polyolefin resin and unsaturated carboxylic acids.

Examples of organic peroxides include benzoyl peroxide, lauroyl peroxide, abbisisobutyronitrile, dicumyl peroxide, α1α゛bis(t
-butylperoxydibrovir)benzene, 2,5-
Dimethyl-2,5-(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, di-t-butylperoxide, cumene hydroperoxide, t- Butyl hydroperoxide, dicumyl peroxide, t-butyl peroxylaurate, t-butyl peroxybenzoate, 1
, 3-bis(t-butylperoxyisopropyl)benzene, cumene hydroperoxide, monobutyl-butyloxyphthalate, t-butylperoxymaleic acid, isopropyl percarbonate, and the like. Examples of inorganic peroxides include azo compounds such as abbisisobutyronitrile, ammonium persulfate, and the like.

These may be used alone or in combination of two or more. Particularly preferred is a decomposition temperature of 170°C to 200°C.
Di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5 di(t-
butylperoxy)hexane, 2,5-dimethyl-2,
5 di(t-butylperoxy)hexyne, ■, 3 bis(
t-butylperoxyisopropyl)benzene.

The amount of these peroxides added is not particularly limited, but is 0.005 to 5 parts by weight, preferably 0.01 to 1 part by weight, per 100 parts by weight of the polyolefin resin.

Representative examples of commercially available adhesive polyolefin resins are shown below.

■Japan Petrochemicals KK ``N Polymer'' ■Mitsui Petrochemicals KK ``ADMER'' ■Showa Denko KK ER
RESIN”■Mitsubishi Chemical Industries KK “Tsubachik-
AP” “■ Mitsubishi Yuka KK “MODIC” ■ Ube Industries KK 'UBE BOND' ■ Jusumikagaku Kogyo KK “'Bondine” ■ Toso KK
“Mersen M” ■ Nippon Unicar KK “Nac Ace” The coating layer on the support side has a low adhesion strength to the heat-resistant support (in order to avoid this, the light-shielding substance is 5% by weight or less,
It is preferably contained in an amount of 3% by weight or less, particularly preferably 1% by weight or less. If 5 weight or more of the light-shielding substance is contained, the melt spreadability (drawdown property) will decrease, pinholes will easily occur (and it will be difficult to secure adhesive strength to the heat-resistant support).Light-shielding property Representative examples of substances are shown below.

(1) Inorganic compound A, oxides: silica, diatomaceous earth, alumina, titanium oxide, iron oxide, zinc oxide, magnesium oxide, antimony oxide, barium ferrite, strontium ferrite, helium oxide, pumice, pumice balloon, Alumina fiber B, hydroxide...aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate C0 carbonate...calcium carbonate, magnesium carbonate,
Dolomite, dawsonite D, (sulfite) sulfate...calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite E.

F.

G.

Silicates: talc, clay, mica, asbestos,
Glass fiber, glass balloon, glass peas, calcium silicate, montmorillonite, bentonite carbon...carbon black, graphite, carbon fiber, carbon hollow sphere, etc...iron powder, copper powder, lead powder, silver powder, brass powder, Stainless steel powder, Burl pigment, aluminum powder, aluminum flake, molybdenum sulfide, poron fiber, silicon carbide fiber, aluminum fiber, stainless steel fiber, nickel fiber, brass fiber, potassium titanate, lead zirconate titanate, zinc borate, metaboric acid Barium, calcium borate, sodium borate, aluminum paste, talc (2) Organic compounds Wood flour (pine, oak, sawdust, etc.), shell fibers (almond, peanut, rice husk), various colored fibers such as cotton , jute, paper strips, cellophane strips, nylon fibers, polypropylene fibers, starch, aromatic polyamide fibers Among these light-shielding substances, inorganic compounds that make them opaque are preferred, especially those with antistatic properties, heat resistance, and light resistance. is excellent,
The relatively inert materials light-absorbing carbon black, titanium nitride, and graphite are preferred.

Examples of particularly preferred classifications of carbon black by raw material include gas black, furnace black, channel black, anthracene black, acetylene black, ketchiene carbon black, thermal black, lamp black, oil smoke, powder smoke, animal black, and vegetable black. etc.

Further, it is preferable to contain 50% by weight or more of one or more of furnace carbon black, graphite, acetylene black, and ketchiene carbon black from the viewpoint of improving light-shielding properties and antistatic properties.

The forms in which the light-blocking substance is blended can be roughly classified as follows.

(1) Uniformly colored pellets (the most commonly used type is called color compound) (2) Dispersible powder (also called dry color, treated with various surface treatment agents and further treated with dispersion aids) (3) Paste (dispersed in plasticizer, etc.) (4) Liquid (liquid, also called liquid color, dispersed on the surface active side) (5) Master Hatch pellet form (light-shielding substance dispersed in high concentration in plastic to be colored) (6) Moisture granular powder form (light-shielding substance dispersed in plastic at high concentration, then granular powder) (7) Dry powder (ordinary unprocessed dry powder) There are various forms in which the light-shielding substance is blended, as mentioned above.
The masterbatch 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 polymer-carbon black masterbatch by dispersing carbon black in a solution of a polymer dissolved in an organic solvent; A method is disclosed for preparing a masterbatch by dispersing polyethylene into polyethylene.

Among carbon blacks, it causes less fogging on photographic light-sensitive materials and less increase/decrease in photosensitivity (and has a large light-shielding ability, preventing carbon black from hardening (fluorescence) and pinholes in the film such as fish eyes. pH 6°0-9.0, average particle size 10-120.
u, volatile component is 2.0% by weight or less, oil absorption is 50d/1
00 g or more of furnace carbon black is preferred.

Representative commercially available conductive carbon blacks are shown below.

For the acetylene method, use Denka Fluff manufactured by Denki Kagaku KK.

In the oil furnace method, Ketchen Black ECCabo manufactured by Japan Easy KK is used.
Palcan XC-72 manufactured by T company, Plan (Cabot)
Kubals''2000, Harkan SC, Palkan 9
Conductex 975 manufactured by Columbia, Conductex 950, Conductex SC manufactured by Asahi Carbon KK, Diablack A manufactured by Mitsubishi Kasei KK.

Further, the moisture content of the coating layer on the support side is preferably 0.5% by weight or less, particularly 0.2% by weight or less to prevent film breakage due to foaming.

In the second coating step, a thermoplastic resin of 7 to 701. The surface-side coating layer is formed by coating to a thickness of rm (at the time of solidification, the same applies hereinafter), preferably a thickness of 10 to 50 μm, particularly preferably a thickness of 13 to 30 μm. If the thickness is less than 7 mm, film breakage may occur or suitability for extrusion coating may deteriorate. Moreover, if the thickness exceeds 70 mm, the neck-in becomes large and the laminating speed becomes slow, resulting in an increase in cost.

In addition, the temperature when coating the thermoplastic resin should be lower than the coating layer on the support side, preferably <120 to 310°C1.
50-290°C1, particularly preferably 220-280°
It is C. In order to reduce neck-in, it is preferable to use a low temperature unless there is a problem.

Among the polyolefin resins mentioned above, thermoplastic resins include EVA resin, EAAl resin, ionomer, etc., which tend to thermally decompose at high temperatures but have excellent heat sealing properties, resins with large neck-in, -LDPE resin, PP resin, and HDPE. Even resins and resins with poor adhesiveness can be used because adhesive strength with the support-side coating layer formed in the first coating step can be obtained even at low temperatures. Especially MI is 10-40
g/10 min, H with a density of 0.945 g/10 min or more
DPE resin 30-95% by weight and Ml 1-35g/10
An LDPE resin having a density of 0.90 to 0.93 g/i and/or an L-LDPE resin having a resin composition of 5 to 70 g/i is preferable because it has excellent curl prevention, antistatic properties, lubricity, and the like.

polyolefin resin with MI of 1.0 g/10 minutes or more,
Preferably homopolyethylene resins of various densities with an MI of 2.5 g/10 min or more, modified high-pressure method or low-pressure method linear polyethylene resins (ethylene/α-olefin copolymer resins)
, EVA resin, EEA resin, modified polyolefin resin,
A resin containing 30 parts by weight or more of one or more HMA resins is preferred. Particularly preferred are the L-LDPE resin and EEA resin, which have excellent carbon black dispersibility and ensure heat sealability even when containing 8 to 60% by weight of carbon black.

Also, the water content of the resin composition used for the surface coating layer is 2000PP to prevent foaming and film breakage. ! Below, especially 600
It is preferable that it is PPM or less.

The surface coating layer contains 8 to 60% carbon black.
Preferably 15 to 40% by weight, particularly preferably 20 to 40% by weight
Contains 30% by weight. 8% carbon black by weight
If it is less than that, sufficient light-shielding properties cannot be ensured, and conductivity is also insufficient. Moreover, if it exceeds 60% by weight, melt spreadability (drawdown property) will be lost, film breakage will occur,
Not only do pinholes occur, which deteriorates light shielding and moisture resistance, and extrusion coating suitability, but also decreases physical strength, deteriorates heat sealability, and contaminates packaged items.
The carbon black often falls off, making it difficult to put it into practical use.

The type of carbon black contained in this surface-side coating layer can be the same as the carbon black used in the support-side coating layer.

Further, the carbon black added to the surface side coating layer and the carbon black added to the support side coating layer may be different.

Heat-resistant support, support side coating layer and surface side coating layer,
A conductive substance can be added to prevent static electricity.

Preferred various conductive substances that can prevent the occurrence of static are shown below.

■Nonionic surfactants (typical ingredients polyoxyethylene glycols) ■Anionic surfactants (typical ingredients sulfonates) ■Cationic surfactants (typical ingredients quaternary ammonium salts) ■Ampholytic surfactants ■Alkylamine derivatives ■Fatty acid derivatives ■Various lubricants ■Carbon black, graphite ■Metal surface-coated pigments [phase] Metal powder, metal flakes ■Carbon fiber @ metal fiber ■Whiskers (potassium titanate, alumina nitride, alumina, etc.) Non-ions listed above Representative examples of surfactants are shown below.

Polyethylene glycol fatty acid ester polyoxyethylene sorbitan fatty ester polyoxyethylene fatty acid alcohol ethyl polyoxyethylene glycerin fatty acid ester polyoxyethylene fatty acid amine sorbitan monofatty acid ester fatty acid pentaerythrite ethylene oxide adduct of fatty alcohol ethylene oxide adduct of fatty acid fatty acid amino or ethylene oxide adducts of fatty acid amides, ethylene oxide adducts of alkylphenols, ethylene oxide adducts of alkylnaphthols, ethylene oxide adducts of partial fatty acid esters of polyhydric alcohols, and other various non-containing compounds described in Japanese Patent Publication No. 63-26697, page 120. Ionic antistatic agents, etc.

Representative examples of anionic surfactants are shown below.

Wasylic acid sulfate ester soda salt Various fatty acid metal salts Lycyllate ester sulfate ester soda salt Sulfated oleate Ethyl aniline Olefin sulfate ester salt Oleyl alcohol sulfate ester sorter salt Alkyl sulfate ester salt Fatty acid ethyl sulfonate Alkyl sulfonate Alkylnaphthalene sulfone Acid salts, alkylbenzene sulfonates, succinate esters, sulfonates, phosphate ester salts, etc.

The cationic surfactants are shown below.

Primary amine salt Tertiary amine salt Quaternary ammonium salt Pyridine derivatives etc.

Representative examples of amphoteric surfactants are shown below.

carboxylic acid derivatives imidacillin derivatives Betaine derivatives, etc.

For example, in the case of the support-side coating layer, it is preferable that the above-mentioned conductive substance is not added in order to improve adhesive strength, and in the case of the surface-side coating layer, it is preferable to add it in order to improve the antistatic property.

The packaging material produced by the present invention has improved film formability,
It is preferable to add 0.01 to 1.0% by weight of a lubricant for the purpose of improving lubricity, improving the ability to insert photosensitive materials, preventing static electricity, etc.

Typical commercially available lubricant groups and manufacturer's salts that do not adversely affect photosensitive materials are listed below, but the present invention is not limited thereto.

(1) Silicone lubricant; various grades of dimethylpolysiloxane and modified dimethylpolysiloxane, etc. (Shin-Etsu Silicone, Toshi Silicone) (2) Oleic acid amide lubricant; Armoslip, cp
(Lion Akzo), Neutron (Nippon Rukka), Neutron E-18 (Nippon Seika), Amide O (Nitto Chemical), Alflo E-10 (Nippon Oil & Fats), Diamond 0-200 (Nippon Kasei), Diamond G-200 (Nippon Kasei), etc. (3) Erucic acid amide lubricant; Alflo P-10 (Nippon Oil & Fats), etc. (4) Stearic acid amide lubricant; Alflo 510 (
Nippon Oil & Fats), Neutron 2 (Japan Industrial Co., Ltd.), Diamond 200 (Nippon Kasei), etc. (5) Bis-fatty acid amide-based lubricants; Bisamide (Nippon Kasei), Diamit 200 Bis (Nippon Kasei), Armowax EBS (Lion Chemical), etc. (6) Nonionic surfactant; Electro Stripper T
S-2, Electrostripper-TS-3, Electrostripper-TS-5 (Kao Soap), etc. (7) Hydrocarbon lubricant; Liquid paraffin Natural paraffin micro wax Synthetic paraffin Polyethylene wax Polypropylene wax Chlorinated hydrocarbon Fluorocarbon etc. 8) Fatty acid lubricant; higher fatty acid (preferably C+□ or higher) oxyfatty acid, etc. (9) Ester lubricant; lower alcohol ester of fatty acid polyhydric alcohol ester of fatty acid polyglycol ester of fatty acid fatty alcohol ester of fatty acid etc. 00) Alcohol Lubricant: Polyhydric alcohol polyglycol polyglycerol, etc. 00 Metal soap: Higher fatty acids such as lauric acid, stearic acid, ricinoleic acid, naphthenic acid, and oleic acid, and Li, Mg, Ca, Sr,
Ba, Zn, Cd, AI, Sn.

In order to improve the adhesive strength between the heat-resistant support, such as a compound with a metal such as PB, and the coating layer on the support side, various surface treatment methods can be used for the heat-resistant support.

Representative examples are shown below.

Note that two or more of these may be used in combination.

Flame treatment: Running costs are high and there is a risk of fire.

Plasma treatment: Convert argon gas or the like into plasma to treat the surface of the heat-resistant support. The surface treatment effect is several times that of corona discharge treatment, but the equipment and cost are also several dozen times higher than corona discharge treatment machines.

Corona discharge treatment...Substrates that can be treated include paper, various polymer films, various sheets, iron foil, aluminum foil, aluminum vacuum-deposited film, etc. It is the most commonly used, inexpensive and highly effective treatment.

Sandblasting treatment: Roughen the surface by blasting silica, etc. at high pressure.

Chemical treatment: Surface treatment with dichromic acid solution, etc.

Ozone treatment: Surface treatment is performed in a box filled with ozone. Adhesive strength improves even when the temperature of the extrusion coating resin is lowered.

Preheat treatment: The heat-resistant support to which extrusion coating is to be applied is heat-treated using a heater drum, hot air, etc.

Other methods include ultraviolet irradiation treatment, high frequency heating treatment, electric induction heating treatment, and microwave treatment.

Furthermore, an AC agent may be used to improve the adhesive strength between the heat-resistant support and the support-side coating layer.

AC agent (Anchor CoatingA) is a general term for adhesion promoters or crosslinking agents used in the laminating industry
It is called ``gent''. This ACi is different from a simple adhesive, and is different from an adhesive in the sense of chemical adhesion.
Also called ter etc.

Representative examples of AC agents are described below.

(1) Organic titanate (titanium-based) anchor coating agent T
etra-propyl-titanate or T
The main component is tetra-iso-butyl titanate, and Tetra-stear is used as a hydrolysis regulator.
Use with addition of yl-titanate.

(2) Polyethyleneimine (imine-based) anchor coating agent polyethyleneimine (-CHz-CHz-NH-n)
A compound with a relatively high degree of polymerization is used. It is particularly preferred because it is easy to manage and has a long bond life.

(3) Isocyanate-based anchor coating agent There are two types: one that uses a polymer with isocyanate groups alone (one-pack type) and one that uses it in combination with polyester, etc. that has OH groups (two-pack type). A chemical reaction occurs, creating an adhesive effect. The disadvantage is that it has a short pot life and is expensive.

(4) Polyester-based and/or urethane-based anchor coating agent A saturated polyester resin or urethane resin is used by dissolving it in a solvent such as ethyl acetate or toluene.

(5) Polyolefin anchor coating agent (6) Polybutadiene anchor coating agent etc. The AC agent is preferably formed in an extremely thin thickness. As a coating method for the AC agent, a gravure roll coating method, a kiss roll coating method, a curtain coating method, a bar coating method, a reverse roll coating method, a direct roll coating method, an air knife coating method, etc. are used.

The packaging material for photosensitive materials produced according to the present invention can be used for packaging various products, but is particularly useful as a light-shielding paper that is rolled together with a roll of photosensitive material, for example, when a roll of light-sensitive material and light-shielding paper are rolled together. It can also be used as light-shielding paper for so-called cartridge-type roll-shaped photosensitive materials of 110 size and 126 size contained in cartridges, and light-shielding paper with photographic film fixed approximately in the center of the light-shielding paper with adhesive tape, adhesive, heat seal, etc. The so-called 12 paper and roll-shaped photosensitive material are rolled up on a flanged spool.
As a light-shielding paper for a roll-shaped photosensitive material of size 0, a so-called 220-size roll is prepared by joining a leader light-shielding paper to the tip of a roll-shaped photosensitive material and a leader light-shielding paper to the tip of a photographic film using adhesive tape, adhesive, heat seal, etc. It is used as a light-shielding paper for light-sensitive materials, as a light-shielding paper for peeler-type instant photographic films, and as a light-shielding paper for magazine-less packaging for loading in a bright room, as a packaging member, etc.

It is also suitable as packaging bags for ICs and high-sensitivity photographic materials, packaging bags for various photosensitive materials, light-shielding boxes, and light-shielding papers for inner and outer lining of light-shielding magazines.

Representative examples of applicable photosensitive materials are described below.

(1) Silver halide photographic materials (X-ray film, printing film, color photographic paper, color film,
(Printing master paper, DTR photosensitive material, computer typesetting film and paper, microfilm, movie film, self-developing photosensitive material, direct positive film and paper, etc.) (2) Diazonium photosensitive material (4-morpholinobenzene) diazonium crofilm, microfilm,
Copying film, printing plate material, etc.) (3) Azide- and diazide-based photographic materials (photosensitive materials containing roseazidobenshade, 4,4゛diazide stilbene, etc., such as copying film, printing plate material, etc.) (4) Quinonediazide-based photographic materials (ortho-quinonediazide, ortho-naphthoquinonediazide-based compounds, such as benzoquinone (1,2)-
Photosensitive materials containing diazide-4-sulfonic acid phenyl ether, etc., such as printing plates, copying films,
(5) Photopolymers (photosensitive materials containing vinyl monomers, printing plates, adhesion films, etc.) (6) Polyvinyl cinnamic acid esters (e.g., printing films, IC resists, etc.) Others , Photosensitive substances that change or deteriorate due to various types of light, oxygen, sulfur dioxide gas, etc., such as foods (Butterbee nuts, margarine, snack products, knobs, sweets, tea, seaweed, etc.)
It can be applied to pharmaceuticals (powdered and granular bagged medicines such as gastrointestinal medicines and cold medicines), dyes, pigments, photographic developing chemicals, photographic fixing chemicals, toners, etc.

When the packaging material of the present invention is applied to, for example, the above-mentioned photosensitive materials, it can be applied to - double flat bags, double flat bags, self-standing bags, - heavy gusset bags, double gusset bags, standing pouches, carrier bags, etc., as well as laminated films, It can be used for all known forms such as the inner lining of moisture-proof boxes, the inner lining of light-shielding magazines loaded in bright rooms, light-shielding paper (backing paper), leader paper, guide paper, etc.

Depending on the properties of the laminated film used, the bag can be made using conventionally known plastic film sealing methods such as heat sealing, fusing sealing, impulse sealing, ultrasonic sealing, and high frequency sealing.

[Function] The method for producing a packaging material for photosensitive materials of the present invention includes coating a polyolefin resin on a heat-resistant support at high temperature in the first coating step to completely fix the support-side coating layer to the heat-resistant support;
In addition, in the second coating process, a thermoplastic resin containing a predetermined amount of carbon black is applied to the coating layer on the support side at a low temperature to ensure light-shielding and antistatic properties, reduce neck-in, and improve low-temperature heat sealability. and suppresses the generation of bubbles, etc.

〔Example〕

An embodiment of the method for producing a packaging material for photosensitive materials according to the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 1 indicates a heat-resistant support delivery section, and reference numeral 2 indicates a packaging material winding-up section, in which a heat-resistant support web 3 is transferred from the heat-resistant support delivery section 1 to the packaging material winding-up section 2 at a predetermined speed. being sent.

Further, a first application section 4 and a second application section 5 are provided between the heat-resistant support delivery section 1 and the packaging material winding section 2. The first applicator 4 includes a nip roll 6 made of heat-resistant rubber that is in pressure contact, a cooling roll 7 that is a metal roll filled with cooling water, and a first applicator located above these.
A T-die 8 is provided. 2. Similarly to the first applicator 4, the second applicator 5 also has a nip roll 9, a cooling roll 1,
0 and a second T die 11 are provided.

Next, an example of a method for manufacturing a packaging material for photosensitive materials using the above-described apparatus will be described.

First, while feeding the heat-resistant support web 3 from the feeding section l to the winding-up section 2 at a predetermined speed, a polyolefin resin 12 containing no light-shielding substance is applied to the heat-resistant support web 3 on the nip roll 6 using the first T die 8. The polyolefin resin 12 is applied to a thickness of ~50 μm and solidified using a cooling roll 7. Then, in part A in FIG. 1, as shown in FIG. 2, a laminated film consisting of a heat-resistant support 21a and a support-side coating layer 22 is formed.

Next, in the second application section 5, a light-shielding thermoplastic resin 13 containing carbon black is applied to the laminated film on the nip roll 9 to a thickness of 7 to 70 mm using a second T-die 11, and the light-shielding thermoplastic resin 13 is coated with a thickness of 7 to 70 mm. The plastic resin 13 is solidified with a cooling roll 10. Then, in part B in FIG. 1, as shown in FIG. 3, a packaging material 14 for a photosensitive material is formed in which a heat-resistant support 21a is coated with a support-side coating layer 22 and a surface-side coating layer 23a. ing.

In addition, the reference numeral 15 is an anchor agent application part, and the reference numeral 16 is a corona discharge treatment part, each of which is used as appropriate to improve adhesiveness.

Next, other representative examples of packaging materials for photosensitive materials manufactured by the method for manufacturing packaging materials for photosensitive materials of the present invention will be explained based on FIGS. 4 to 8.

4 to 8 are partial cross-sectional views showing the layer structure of the packaging material for photosensitive materials.

The packaging material for photosensitive materials shown in FIG.
a, and a surface-side coating layer 23a containing a light-shielding substance is coated on this support-side coating layer 22a.

The packaging material for photosensitive materials shown in FIG.
2a, and a surface-side coating layer 23a containing a light-shielding substance is coated on the support-side coating layer 22a.

The packaging material for photosensitive materials shown in FIG.
A heat-resistant support 21a, which is a two-layer coextruded film 26a consisting of
2a, and a surface-side coating layer 23a containing a light-shielding substance is coated on the support-side coating layer 22a.

The packaging material for a photosensitive substance shown in FIG. 7 has a support-side coating layer 22a containing a light-blocking substance and a surface-side coating layer 2 containing a light-blocking substance on one side of a heat-resistant support 21a containing a light-blocking substance.
3a are sequentially applied, and a protective layer 27a containing a light-shielding substance is applied on the opposite side of the heat-resistant support 21a.

The packaging material for photosensitive materials shown in FIG. 8 includes a support-side coating layer 22a containing a light-blocking substance and a surface-side coating layer 2 containing a light-blocking substance on one side of a heat-resistant support 21a containing a light-blocking substance.
3a is sequentially applied, and a printing layer 28 is printed on the opposite side of the heat-resistant support 21a, and a transparent protective layer 2 is applied on top of the printing layer 28.
7 was printed using a multicolor printing machine.

Invention product I The layer structure corresponds to that shown in FIG.

The heat-resistant support 21a is a light-shielding paper containing 5% by weight of furnace carbon black and having a thickness of 80 nm and a basis weight of 70 g/rrT.

The support side coating layer 22a is made of modified ethylene copolymer resin (
Adhesive resin manufactured by Mitsui Petrochemical Industries KK, trade name "Atomer") 20% by weight, MFR 5.1g/10min, density 0
．． 13-thickness consisting of 78% by weight of LDPE resin of 919 g/cd and 2% by weight of furnace carbon black.
This is a polyolefin resin layer.

The surface-side coating layer 23a contains 80% by weight of a low-pressure ethylene-butene l copolymer resin and 20% by weight of a high-pressure low-density homopolyethylene resin. Polyolefin resin 79 with a density of 0.910 g/cd at 10 g/10 minutes
．． This is a 15 μm thick light-shielding/conductive polyolefin resin layer consisting of 9% by weight of furnace carbon black, 20% by weight of furnace carbon black, and 0.1% of calcium oxide.

Extrusion coating was performed using a tandem laminator at a resin temperature of 320° C. for the support side coating layer 22a, a resin temperature of 260° C. for the surface side coating layer 23a, and a line speed of 150 m/min.

This packaging material for photosensitive materials includes light-shielding bags, light-shielding paper for K-16 film, K-35 film, 220 film, 120 film, etc., light-shielding leader paper for peelervert type instant photographic film, and light-shielding paper for roll-shaped photosensitive materials. Even when used as a packaging member for a package for loading in a bright room, a light-shielding leader paper, etc., the adhesive strength between the heat-resistant support and the coating layer on the support side, and between the coating layer on the support side and the coating layer on the surface side is both high, ensuring light-shielding properties. It was possible to ensure a high degree of stability, no static marks were generated, and it was highly productive and could be manufactured at low cost.

Invention product■ The layer structure corresponds to that shown in FIG.

The heat-resistant support 21a is a two-layer coextruded film 26a consisting of a heat-resistant layer 24a and an ethylene copolymer resin layer 25a.
The heat-resistant layer 24a is made of 92.4% by weight homopolyethylene resin with an MFR of 0.4 g/10 minutes and a density of 0.965 g/cT1, and a density of 0.923 with an MFR of 2.3 g/10 minutes. g/CTII high pressure low density homopolyethylene resin 4.5% by weight, nonionic surfactant (manufactured by Kao KK, product name "Electro Stripper TS-3")
) 0.10% by weight and 3% by weight of furnace carbon black, the ethylene copolymer resin layer 25a is a 40 μm thick light-shielding homopolyethylene resin film layer.
has an MFR of 2.1 g/10 min and a density of 0.920 g/10 min.
cffl ethylene/4-methylpentene-1 copolymer resin 87% by weight, MFR 1.1g/10min, density 0.
954g/c+fl high density homopolyethylene resin 10
This is a light-shielding ethylene copolymer resin film layer having a thickness of 40p and consisting of 3% by weight and 3% by weight of furnace carbon blank.

The support side coating layer 22a and the surface side coating layer 23a are the same as those of the product I of the present invention.

The extrusion coating was also the same as that of product I of the present invention.

This packaging material for photosensitive materials was used for a light-shielding bag and a package for a band-shaped photosensitive material for loading in a bright room. Both were large, ensured light-shielding properties, did not generate static marks, had excellent heat-sealing properties, and were also excellent in ease of opening.

Invention product■ The layer structure corresponds to that shown in FIG.

The heat-resistant support 21a is the same as the product I of the present invention.

The support side coating layer 22a is the same as that of the product (2) of the present invention.

The surface side coating layer 23a is made of 50% by weight ethylene/ethyl acrylate copolymer resin having an MFR of 6 g/10 minutes and a density of 0.931 g/cm3, and a MFR of 5 g/10 minutes and a density of 0.919 g/cm3. Thickness 15JrrB consisting of 29.8% by weight of high-pressure low-density homopolyethylene resin of cm3, 20% by weight of furnace carbon black, 0.1% by weight of calcium oxide, and 0.1% by weight of nonionic antistatic agent.
This is a light-shielding and conductive polyolefin resin layer.

The extrusion coating was the same as for the product (2) of the present invention.

This packaging material for photosensitive materials includes light-shielding bags, light-shielding paper for K-16 film, K-35 film, 220 film, 120 film, etc., light-shielding leader paper for Peelabat type instant photographic film, and roll-shaped photosensitive material. Even when used as a light-shielding leader paper for a package for loading in a bright room, the adhesion strength between the heat-resistant support and the coating layer on the support side, and between the coating layer on the support side and the coating layer on the surface side is both high, ensuring light-shielding properties. , there was no generation of static marks, and the product had excellent productivity and could be manufactured at low cost.

Invention product■ The layer structure corresponds to that shown in FIG.

The heat-resistant support 1a is the same as the product ① of the present invention.

The support side coating layer 22a is an LDPE resin layer having a thickness of 13p and made only of LDPE resin with an MFR of 5.1 g/10 minutes and a density of 0.919 g/cut.

The surface side coating layer 23a is the same as that of the product (2) of the present invention.

The extrusion coating was also the same as that of product I of the present invention.

This packaging material for photosensitive materials includes light-shielding bags, light-shielding paper for K-16 film, K-35 film, 220 film, 120 film, etc., light-shielding leader paper for Peelabat type instant photographic film, and roll-shaped photosensitive material. Even when used as a packaging member for a package for loading in a bright room, a light-shielding leader paper, etc., the adhesive strength between the heat-resistant support and the coating layer on the support side, and between the coating layer on the support side and the coating layer on the surface side is both high, ensuring light-shielding properties. can be ensured, no static marks occur, and
It had excellent productivity and could be manufactured at low cost.

Invention product■ The layer structure corresponds to that shown in FIG.

The heat-resistant support 21a, the support side coating layer 22a, and the surface side coating layer 23a are the same as those of the product I of the present invention.

For extrusion application, use two single laminators.
First, use the first laminator at a resin temperature of 320″C.
, the support side coating layer 22a is applied at a line speed of 150 m/min, then it is cooled and wound up, and then the surface side coating layer 23a is applied with a second laminator at a resin temperature of 260°C and a line speed of 150 m/min. did.

This packaging material for photosensitive substances was excellent and suitable for various uses, similar to Invention Product 1-4'.

Further, since a single laminator is used, the line speed is as low as 85 m/min, and although it is inferior in terms of productivity, it is cheaper than a tandem laminator or a coextrusion laminator.

Furthermore, the time required to change the color of the laminator (black to transparent) is short, and less purge resin is needed for color change, so it can be produced at a lower cost than Comparative Products I, ■, and Conventional Product I, which will be described later. there were.

Comparative Product I This is a layered structure in which a two-layer coextrusion extrusion coating layer is coated on a heat-resistant support.

The heat-resistant support is the same as the product I of the present invention.

The resin composition of the two-layer coextrusion extrusion coating layer is:
This is the same as the support side coating layer and the surface side coating layer of the invention product (2).

For extrusion coating, a two-layer coextrusion laminator is used, and the resin temperature of the layer corresponding to the support side coating layer is set to 3.
The resin temperature of the layer corresponding to the 20°C1 surface side coating layer was lowered to 300"C for interlayer balance and foaming countermeasures, and coating was carried out at a line speed of 80 m/min.

This packaging material for photosensitive materials was superior in various properties such as pinhole resistance of the coating layer and adhesion to the support, and could be produced at a low cost, when compared with Comparative Product (2) and Conventional Product I, which will be described later.

However, since the resin temperature of the surface layer could not be lowered, foaming and resin deterioration occurred, resulting in poor low-temperature heat sealability. Furthermore, since the extrusion coating layer was about twice as thick, the cooling efficiency was poor and the peelability from the cooling roll was poor.

Therefore, the line speed is 80 m/min and the products of the present invention ■~I
It was significantly lower than V (150 m/min).

Comparative product■ This is a layered structure in which a single layer extrusion coating layer is coated on a heat-resistant support.

The heat-resistant support is the same as the product I of the present invention.

The single-layer extrusion extrusion coating layer has a thickness of 2Ebr and is made of the same resin composition as the surface side coating layer of the product I of the present invention.
This is a light-shielding and conductive polyolefin resin layer.

Extrusion coating was performed using a single laminator at a resin temperature of 310° C. and a line speed of 60 m/min.

This light-shielding laminated film has many pinholes, the adhesive strength between the heat-resistant support and the extrusion coating layer is very low, and it is impossible to even cut it to the size used.
Practical implementation was difficult.

Conventional product I It has a layer structure in which a solution coating layer is applied to a heat-resistant support.

The heat-resistant support is the same as the product I of the present invention.

The solution coating layer is a light-shielding layer having a dry film thickness of 20 mm and consisting of 75% by weight of ethylene vinyl acetate copolymer resin and 25% by weight of carbon black.

In the solution coating, a solution prepared by dissolving ethylene vinyl acetate copolymer resin and carbon black in toluene at 60° C. was applied by gravure coating at a line speed of 30 m/min.

This laminated film had excellent adhesion between the support and the coating layer and low-temperature heat sealability.

However, due to residual toluene, there is a bad odor, and
When left in the rolled state, blocking occurred in just one month. Furthermore, when toluene penetrates into the support during coating and drying, air contained in the support is expelled from the support, and craters and pinholes are likely to occur in the coated layer. For this reason, it is necessary to slow down the line speed, lower the drying temperature, or use two-layer circular paper or long-length paper as a heat-resistant support with different air permeability on the front and back sides. There wasn't.

Conventional product■ It has a layer structure in which a single extrusion coating layer is coated on a heat-resistant support.

The heat-resistant support is the same as the product I of the present invention.

The single layer extrusion coating layer contains 5% by weight of carbon black, M, 1. is 23g/10 minutes and the density is 0.9
20% by weight of high density polyethylene resin of 58 g/cd
and gate, ■, has a density of 0.918 g at 10 g/10 minutes
The polyolefin resin layer has a thickness of 20Q and is made of 80% by weight of low density polyethylene resin of /crl.

Extrusion coating was performed using a single laminator at a resin temperature of 310° C. and a line speed of 80 m/min.

This laminated film is made by increasing the resin temperature by 3 to improve the adhesion between the heat-resistant support and the single-layer extrusion coating layer.
Because the temperature was as high as 10°C, resin deterioration, increased neck-in, poor low-temperature heat sealing properties, and foaming due to moisture in the resin were likely to occur.

On the other hand, despite the problems mentioned above caused by raising the resin temperature, the adhesion between the support and the extrusion coating layer seems to be insufficient, and it cannot be put into practical use without surface treatment of the support. It was difficult to Furthermore, the addition of 20% by weight of high-density polyethylene resin to the extrusion coating layer was also a factor in deteriorating the low-temperature heat sealability and the adhesion between the heat-resistant support and the extrusion coating layer.

The results are shown in Table 1.

Invention product■ The layer structure corresponds to that shown in FIG.

The heat-resistant support 21a has a pile yarn of 50 denier,
Using a polyester yarn consisting of 36 filaments, and using a 75 denier polyester yarn consisting of 24 filaments as the chain yarn and insertion yarn of the base fabric, the pile density was 30,000/C112 and the total thickness was 1. 5
This is a light-shielding terempu cloth made by piece-dying terremp cloth with a SW knitting structure with black dye.

Support side (base fabric side) coating layer 22a and surface side coating layer 2
3a is the same as the invention product (2).

Extrusion coating was carried out by the same method and under the same conditions as in the case of the invention product (2).

This packaging material for photosensitive materials also had the same excellent properties as the above-mentioned product of the present invention.

〔Effect of the invention〕

The present invention has high adhesive strength with a heat-resistant support, excellent light-shielding properties, good low-temperature heat sealability and neck-in, no foaming or pinholes, and high productivity.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus for carrying out the method of manufacturing a packaging material for photosensitive materials of the present invention, FIGS. 2 and 3 are cross-sectional views of the packaging material for photosensitive materials in the manufacturing process of the present invention, and FIG. FIG. 8 is a sectional view showing the layer structure of the packaging material for photosensitive materials of the present invention. 1... Heat-resistant support 4... First application part 5...
Second application section 14...Packaging material for photosensitive material 21.
21a...Heat-resistant support 22.22a...Support side coating layer 23.23a...Surface side coating layer a: Indicates that it contains a light-shielding substance Patent applicant Fuji Photo Film Co., Ltd. Agent People Patent Attorney Japan-China Politics Haka1 person Figure Figure Figure Figure Figure Figure Procedure Amendment (Method) % Formula % Indication of Case Patent Application No. 194084/1999 Name of Invention Method for Manufacturing Packaging Materials for Photosensitive Substances Relationship with the case of the person making the amendment Patent applicant name (520) Fuji Photo Film Co., Ltd. Address: 3-21-3 Hatchobori, Chuo-ku, Tokyo 104
The date of the amendment order for No. 601 is October 30, 1990. The details of the amendment, page 59, are inscribed as shown in the attached sheet (there is no change in the content).

Claims (1)

[Claims] A first coating step in which a polyolefin resin containing 5% by weight or less of a light-shielding substance is applied to a heat-resistant support by extrusion coating to a thickness of 7 to 50 μm to form a support-side coating layer, and carbon black is applied to the support-side coating layer. and a second coating step of forming a surface side coating layer by extrusion coating a thermoplastic resin containing 8 to 60% by weight to a thickness of 7 to 70 μm. Method