JPH0643799Y2 - Container cap for photographic film cartridges - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a cap of a container for storing a photographic film cartridge.

[Conventional technology]

Conventionally, as a container cap for a photographic film cartridge, there has been, for example, one shown in FIGS. 12 to 15 (Japanese Patent Laid-Open No. 62-291639).

FIG. 12 shows a cap-fitting type container. In this figure, reference numeral 1 is a container body, and reference numeral 2 is a container cap. The container body 1 includes a bottom portion 3 and a week wall portion 4, and a fitting groove 5 is formed inside the upper portion of the peripheral wall portion 4.

The container cap 2 is formed with a bent portion 7 that is folded back in a substantially U shape from around the circular top surface portion 6, and a flange portion 8 is formed outward from the upper end of the bent portion 7. . Further, a fitting protrusion 9 that fits into the fitting groove 5 of the container body 1 is formed on the outer surface of the bent portion 7. Further, the resin injection portion (gate portion) G into which the resin is injected is on the inner surface of the top surface portion 6, and the resin injection trace 10 is projected and remains in this resin injection portion G.

FIG. 13 shows a cap-fitting type container. In this figure, a container body 1 is composed of a bottom portion 3 and a peripheral wall portion 4, and a fitting protrusion 11 is formed on the outer side of the upper end of the peripheral wall portion 4. .

The container cap 2 is formed with a bent portion 7 that is folded back in a substantially U-shape from around the circular top surface portion 6, extends outward from the upper end of the bent portion 7, and is then bent downward. Two mating pieces 12 are formed. Further, the resin injection portion G is on the inner surface of the top surface portion 6, and the resin injection trace 10 is projected and remains in the resin injection portion G.

FIG. 14 shows a cap-fitting type container cap. In this container cap 2, a recess 13 is formed at the center of the outer surface of the top surface part 6, and a resin injection part G is provided in this recess 13 and a resin injection trace 10 is formed. Is located in the recess 13.

FIG. 15 shows a cap-fitting type container cap. In this container cap 2, a concave portion 13 is formed in the center of the outer surface of the top surface portion 6, and a resin injection portion G is provided in this concave portion 13 and a resin injection trace 10 is formed. Is located in the recess 13.

The container cap as described above is formed by injection molding, that is, the resin which is heated and melted is injected from the resin injection part G, cooled and solidified, and then taken out from the cavity to be manufactured.

Conventionally, resins used for container caps include, for example, melt flow index (ASTM D-1238, hereafter MFI
Is displayed) for 10 to 50 g / 10 minutes, and the density is 0.920 to 0.935 g / cm ³ ,
There was an LDPE resin having a molecular weight distribution of 3.3 to 8.5 and a lubricant of 0.01 to 0.90% by weight (Japanese Utility Model Publication No. 63-113453).

Further, MFI is 16~80g / 10 min, density of 0.916~0.941g / cm ^3,
Tensile breaking strength of 150 kg / cm ² or less, tensile breaking elongation of 600% or less, 50% by weight or more of linear low density polyethylene (hereinafter
L-LDPE) resin and 0.01 to 0.90% by weight of lubricant
There was an L-LDPE resin (Japanese Patent Laid-Open No. 63-121047).

[Problems to be solved by the device]

By the way, in order to produce containers for photographic film cartridges, injection molding has often been performed in a high cycle using a hot-runner multi-cavity mold in order to enable rapid mass production.

However, when injection molding is performed using the resin or the like in a high cycle of about 10 seconds or less, due to the cooling balance of the resin injecting portion, the vicinity A of the resin injecting portion shown by the mesh in FIG. There was a problem that the water vapor permeability was increased due to the removal of pinholes and the formation of pinholes, or the thinning of the pinholes even if they did not occur.

An object of the present invention is to solve the above problems and provide a container cap for photographic film cartridges in which pinholes do not occur and moisture permeability does not increase even if the vicinity of the resin injection part is scraped off. And

[Means for Solving the Problems]

The present invention has been made in order to achieve the above-mentioned object. The thickness in the vicinity of the resin injection part is 2.5 mm or less, and
It is characterized by being thicker than 100%.

The reason why the vicinity of the resin injection part of the container cap according to the present invention is made thicker than the peripheral part is to maintain a thickness that can ensure a predetermined moisture resistance even when the vicinity of the resin injection part is scraped off. Is. Therefore, if this object can be achieved, the shape to be thickened can be arbitrarily selected, and preferably the flow mark and the weld mark can be reduced, so that the shape is a hemispherical shape, an elliptical shape in a vertical cross section, or the like.

In addition, the peripheral part of the resin injection part is formed with the thinnest thickness that can ensure moisture resistance in order to minimize the cooling time and molding cycle and to reduce the manufacturing cost, so the thickness to be thickened Is preferably formed to have a thickness corresponding to the length of the longest depth to be carved.

That is, the thickness in the vicinity of the resin injection part is
Although it varies depending on the required moisture permeability, etc., it is generally necessary that the thickness be 10% or more, more preferably 30% or more, and more preferably 50% or more thicker than the peripheral wall portion. Further, the thickness in the vicinity of the resin injection portion is preferably about 0.5 mm or more,
More preferably about 0.7 mm or greater, most preferably about 1.0 mm or greater. The thickness in the vicinity of the resin injection portion needs to be 2.5 mm or less from the viewpoint of cooling the container cap.

The resin injecting portion of the container cap may be located at any part of the container cap, but in the case of a container cap having a substantially circular shape, it is preferable to provide the resin injecting part near the center from the viewpoint of resin flow.

The container cap for the photographic film cartridge of the present invention,
Various resin compositions that have been conventionally used can be used, but MFI is 8 to 60 g / 10 minutes and density is 0.920 to 0.935 g / cm.
^{In 3} , a resin composition mainly composed of a homopolyethylene resin and / or an ethylene copolymer resin containing a lubricant and / or a surfactant and an antioxidant is preferable.

Polyethylene resin is obtained by polymerization of ethylene gas. Low density polyethylene (LDPE) resin made by high pressure method, medium pressure method and low pressure method, high density polyethylene (HDPE) resin made by medium and low pressure method. is there. A medium density polyethylene resin (MDPE) is one that has an intermediate density between LDPE resin and HDPE resin.

Examples of the ethylene copolymer resin include copolymer resins of ethylene and other monomers such as α-olefin, vinyl acetate, acrylic acid, and acrylic acid ester. Among them, a linear low-density polyethylene resin which is a copolymer with α-olefin is most preferable because it has good physical properties (JP-A-63).
The resin disclosed in JP-A-121047 is particularly preferable. ).

Ethylene / α-olefin copolymer resin includes linear low density polyethylene (L-LDPE) resin.
The resin is a low-cost resin that meets the demands of the times of energy saving and resource saving, which have the advantages of both medium / low density and high density polyethylene resin. This resin is a copolymer of ethylene and an α-olefin having 3 to 13 carbon atoms, preferably 4 to 8 carbon atoms, and is a low-to-medium density polyethylene resin having a linear straight chain with a short branch. It is a resin. Recently, L-LDPE resin, which is a high-pressure improved method, has also become commercially available.

As the α-olefin, butene-1, octene-1, hexene-1, 4-methylpentene-1, heptene-1 and the like are used. The density is generally considered to be low to medium density polyethylene resin, but most commercial products have a density in the range of 0.87 to 0.95 g / cm ³ . Most of MFIs are in the range of 0.1 to 50g / 10 minutes.

In the present invention, in particular, shortening the molding cycle, preventing static,
It is preferable to use various lubricants from the viewpoint of preventing blocking, improving lubricity, and the like.

Representative commercial products of fatty acid amide lubricants, which are particularly preferable lubricants, are shown below.

(1) Saturated fatty acid amide lubricant Behenic acid amide lubricant; Diamit KN (Nippon Kasei), etc. Stearamide amide lubricant; Armide HT (Lion oil and fat), Alflo S-10 (Nippon oil and fat), Fatty acid amide S (Kao) , Diamond 200
(Nippon Kasei), Diamid AP-1 (Nippon Kasei), Amide S, Amide T (Nitto Kagaku), Neutron-2 (Nippon Seika) Palmitamide amide lubricant; Neutron S-18 (Nippon Seika) ), Amide P (Nitto Kagaku), etc. Lauric acid amide lubricant; Armide C (Lion Akzo), Diamid (Nippon Kasei), etc. (2) Unsaturated fatty acid amide lubricant Erucamide amide lubricant; Alfuro-P-10 (Nippon Yushi), Neutron-S (Nippon Seika), LUBROL (I ・ C ・ I), Diamid L-200
(Nippon Kasei) etc. Oleic amide lubricants; Armoslip CP (Lion Akzo), Neutron (Nippon Seika), Neutron E-18 (Nippon Seika), Amide O (Nitto Kagaku), Diamid O- 200 (Nippon Kasei),
Alfro-E-10 (NOF CORPORATION), fatty acid amide O (Kao), etc. (3) Bisfatty acid amide lubricants Methylenebisbehenic acid amide lubricants; Diamid NK bis (Nippon Kasei) etc. Methylenebisstearic amide lubricants Lubricants; Diamid 200 bis (Nippon Kasei), etc., Armowax (Lion Akzo), Bisamide (Nitto Kagaku), etc. Methylenebisoleic amide lubricants; Lubron O (Nippon Kasei), etc. Slip EBS (Lion Akzo), etc. Hexamethylenebisstearic acid amide lubricant; Amide 65 (Kawaken Fine Chemicals), etc. Hexamethylenebisoleic acid; Amide 60 (Kawaken Fine Chemicals), etc. (4) Monoalkylolamide lubricants; N -(2-Hydroxyethyl) lauric acid amide lubricant; Toho N130 (Toho Kagaku), etc. N- (2-hydroxyethyl) stearic amide lubricant; Amizole (Kawaken Fine Chemicals), etc. N- (2-hydroxymethyl) stearic amide lubricant; Methylolamide (Nitto Kagaku) etc. It is preferable to add 0.01 to 5.0% by weight of these various lubricants. In particular, in the case of the fatty acid amide-based lubricant described above, which has a large lubricating effect and is easy to bleed out, 0.01 to 1.0
It is preferably added by weight%.

In the present invention, a surfactant may be used to prevent static electricity and improve lubricity.

The surfactants used in the present invention are described below.

(1) Nonionic surfactant Polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene aliphatic alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene aliphatic amine, sorbitan Mono-fatty acid ester, fatty acid pentaerythritol, ethylene oxide adduct of fatty alcohol, ethylene oxide adduct of fatty acid, ethylene oxide adduct of fatty acid amino or fatty acid amide, ethylene oxide adduct of alkylphenol, ethylene oxide adduct of alkylnaphthol, Ethylene oxide adducts of partial fatty acid esters of polyhydric alcohols, and other various nonionic bands described on page 120 of JP-B-63-26697. Prevention agents, and the like.

(2) Anionic surfactant Sodium salt of ricinoleic acid sulfuric acid ester, various fatty acid metal salts, sodium salt of silinoleic acid ester sulfuric acid ester, sulfuric acid ethylaniline oleate, sulfuric acid ester salt of olefin, oleyl alcohol sulfuric acid ester soda salt,
Alkyl sulfate ester salt, fatty acid ethyl sulfonate, alkyl sulfonate, alkyl naphthalene sulfonate, alkylbenzene sulfonate, succinate sulfonate, phosphate ester salt, etc. (3) Cationic surfactant No. 1 Primary amine salts, tertiary amine salts, quaternary ammonium salts, pyridine derivatives, etc. (4) Amphoteric surfactants Carboxylic acid derivatives, imidazoline derivatives, petaine derivatives, etc. These surfactants are added in an amount of 0.01 to 5.0% by weight. It is preferable. In particular, it is preferable to add 0.05 to 1.0% by weight from the viewpoint of preventing adverse effects on the photographic film, shortening the molding cycle, and economical efficiency.

Further, in the present invention, an antioxidant can be used in order to prevent coloration failure or spots of the resin when the resin temperature is raised. It is important to select an appropriate type because the degree of adverse effect varies depending on the sensitivity of the photographic film, the composition of the light-sensitive material and the like.

Representative examples of antioxidants are shown below.

(A) Phenolic antioxidant 6-t-butyl-3-methylphenyl derivative, 2.6
-Di-t-butyl-P-cresol t-butylphenol), 2.2'-methylenebis- (4-ethyl-6-t
-Butylphenol), 4,4'-butylidene bis (6
-T-Thier-m-cresol), 4.4'-thiobis (6-t-butyl-m-cresol), 4.4-dihydroxydiphenylcyclohexane, alkylated bisphenol, styrenated phenol, 2.6-di- t-butyl-4-methylphenol, n-octadecyl-3-
(3 ′ · 5′-di-t-butyl-4′-hydroxyphenyl) propinate, 2.2′-methienbis (4-methyl-6-t-butylphenol), 4.4′-thiobis (3-methyl-) 6-t-butylphenyl), 4 ・
4′-butylidene bis (3-methyl-6-t-butylphenol), stearyl-β (3.5-di-4-butyl-4-hydroxyphenyl) propionate, 1.1 ·
3-tris (2-methyl-4hydroxy-5-t-butylphenyl) butane, 1,3,5 trimethyl-2,4.
6-tris (3.5-di-t-butyl-4hydroxybenzyl) benzene, tetrakis [methylene-3 (3 '.
5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, etc. (b) Ketoneamine condensation-type antioxidant 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2.2 -Polymer of 4-trimethyl-1,2-dihydroquinoline, trimethyldihydroquinoline derivative, etc. (C) Allylamine antioxidants Phenyl-α-naphthylamine, N-phenyl-β-naphthylamine, N-phenyl-N'-iropyropyr -P
-Phenylenediamine, N.N'-diphenyl-P-phenylenediamine, N.N'-di-β-naphthyl-P-
Phenylenediamine, N- (3'-hydroxybutylidene) -1-naphthylamine, etc. (d) Imidazole-based antioxidant 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, etc. ) Phosphite antioxidants Alkylated allyl phosphite, diphenylisodecyl phosphite, tris (nonylphenyl) phosphite sodium phosphite, trinonylphenyl phosphite, triphenyl phosphite, etc. (f) Thiourea antioxidant Agents Thiourea derivatives, 1,3-bis (dimethylaminopropyl) -2-thiourea, etc. (G) Other antioxidants useful for air oxidation Dilauryl thiodipropionate, etc. These antioxidants are 0.01-1.50 wt. % Is preferably added. If the addition amount is less than 0.01% by weight, there is no effect to effectively prevent coloring failure and only a kneading cost is required. On the other hand, if the amount added exceeds 1.50% by weight, the photographic properties of the photographic film utilizing the oxidation / reduction effect are adversely affected.

In the present invention, various kinds of additives other than those described above can be added in necessary amounts as needed. Typical examples of the additives will be described below, but the present invention is not limited thereto and can be selected from all known substances.

(Type of additive) (Representative example) (1) Plasticizer; phthalate ester, glycol ester, fatty acid ester, phosphate ester, etc. (2) Stabilizer: lead-based, cadmium-based, zinc-based, alkaline earth metal-based, Organotin, etc. (3) Flame retardant; phosphoric acid ester, halogenated phosphoric acid ester, halide, inorganic material, phosphorus-containing polyol, etc. (4) Reinforcing agent: glass roving, metal fiber, glass fiber, glass milled fiber, carbon fiber, etc. ( 5) Deterioration inhibitor; UV absorber, metal deactivator, peroxide decomposer, etc. (6) Coupling agent: Silane-based, titanate-based, chromium-based, aluminum-based, etc. (7) Various thermoplastic resins, Rubber, etc. (8) Nucleating agent; organic nucleating agent (dibenzylidene sorbitol compound, etc.), inorganic nucleating agent (calcium carbonate, etc.) (9) Light-shielding substance; carbon black, a Luminium foil powder, other chromatic and achromatic inorganic pigments, organic dyes and pigments, etc. (10) Antiblocking agents; silica, calcium silicate, aluminum silicate, talc, higher fatty acid polyvinyl ester, etc. The container cap for the photographic film cartridge of the present invention is For example, it is formed by a normal injection molding method such as a hot runner method, a vacuum injection molding method in a mold, or a stack molding method. In particular, an injection molding method using a hot runner mold having 24 or more cavities is preferable, and among them, a stack mold having one or more cavities of 16 or more (1
The method of 32 shots or more) is particularly preferable.

The container cap for a photographic film cartridge of the present invention is suitably used for a container for hermetically storing food products, medical products, dolls, small items, small samples, etc., as well as for photographic film cartridges. Further, the container cap for the photographic film cartridge of the present invention and the container body can be combined to change the size and shape to some extent, or can be used as a container for seeds, dolls, small articles, and small samples with this size and shape unchanged.

[Operation] With the container cap for the photographic film cartridge of the present invention,
The thickness of the portion that is 10% or more thicker than the peripheral portion in the vicinity of the resin injection portion is sufficient to obtain sufficient moisture resistance even when the vicinity of the resin injection portion is scraped off.

〔Example〕

An embodiment of a container cap for a photographic film cartridge according to the present invention will be described with reference to FIGS.

1 and 2 are vertical cross-sectional views of the container cap, and FIG. 3 is an enlarged cross-sectional view of portion a in FIGS. 1 and 2.

The embodiment shown in FIG. 1 is a cap-fitting type container cap in which the resin injection portion G is on the outer surface of the top surface portion 6, and the embodiment shown in FIG. 2 is a cap in which the resin injection portion G is on the outer surface of the top surface portion 6. It is a fitting type container cap.

As shown in FIG. 3, these container caps 2 have a substantially hemispherical thick portion on the inner surface of the top surface portion 6 corresponding to the resin injection portion G.
14 are formed.

The thick portion 14 is formed with a radius r = 0.5 mm, the top surface portion 6 has a thickness t = 0.8 mm, the recess 13 has a diameter φ = 4 mm, and the recess depth d = 0.8 mm.

In the container cap having the above-described structure, even if the resin injection portion vicinity A indicated by the two-dot chain line in FIG. 3 is scraped off, the distance between the inner and outer surfaces of the top surface portion 6 is sufficient to prevent moisture due to the thick portion 14. It has become a length.

4 to 6 are partially enlarged cross-sectional views of an embodiment of a container cap of a cap fitting type or a cap fitting type in which the resin injection portion is on the outer surface of the top surface portion.

In the embodiment of FIG. 4, a thick portion 14 having a substantially semi-elliptical longitudinal section is formed on the inner surface of the top surface portion 6 corresponding to the resin injection portion G, and the thick portion 14 has a width b = 0.8 mm. The thickness c is 0.5 mm.

In the embodiment shown in FIG. 5, a substantially hemispherical thick portion 14 is formed substantially at the center of the outer surface of the top surface portion 6, and the tip portion of the thick portion 14 is formed as a resin injection portion G.

In the embodiment shown in FIG. 6, a thick wall portion 14 is formed on the inner surface of the top surface portion 6 corresponding to the recess 13 so as to be thickest at the center.

7 to 10 are partially enlarged cross-sectional views of an embodiment of a container cap of a cap fitting type or a cap fitting type in which the resin injection portion is on the inner surface of the top surface portion.

In the embodiment shown in FIG. 7, an approximately hemispherical thick portion 14 is formed on the outer surface of the top surface portion 6 corresponding to the resin injection portion G.

In the embodiment shown in FIG. 8, a substantially hemispherical thick portion 14 is formed at the center of the inner surface of the top surface portion 6, and the tip portion of this thick portion 14 is formed as a resin injection portion G.

In the embodiment shown in FIG. 9, a thick portion 14 that is thickest in the center is formed near the center of the outer surface of the top surface portion 6.

In the embodiment shown in FIG. 10, a thick portion 14 that is thickest in the center is formed near the center of the inner surface of the top surface portion 6.
The tip portion of 14 is formed to be the resin injection portion G.

Product I of the Invention The product I of the present invention has the same size and shape as the embodiment shown in FIGS.

The resin used has an MFI of 25 g / 1 according to the tubular high pressure polymerization method.
0 minutes, density 0.926 g / cm ³ , molecular weight distribution by DSC method Is 3.3, crystallization start temperature is 106 ℃, crystallization temperature (peak)
99.7% by weight of high-pressure branched homopolyethylene resin at 102 ° C, 0.1% by weight of phenolic antioxidant (Irganox 1010, manufactured by Ciba-Geigy), 0.1% by weight of oleic acid amide as a lubricant and alkylamine nonionic surfactant ( Electro stripper-TS-3, manufactured by Kao Corporation) 0.1
Made by Sumitomo Heavy Industries Co., Ltd. mold closing pressure 150t closed system injection molding machine Cycap (Sumitomo Nestal) using a LDPE resin composition consisting of wt. did.

The obtained container cap had a water vapor transmission rate of about 1.7 mg, which was significantly smaller than that of the conventional container cap (about 4.3 mg). Furthermore, the flow mark and weld mark are also better than in the past.

Inventive product II Inventive product II has the same size and shape as the embodiment shown in FIG.

The resin used is a low pressure ethylene / butene-1 copolymer resin MFI of 50 g / 10 min, a density of 0.920 g / cm ³ , a DSC molecular weight distribution of 3.0, a crystallization start temperature of 112 ° C., and a crystal. 99.65% by weight of L-LDPE resin having an oxidization temperature (peak) of 108 ° C, 0.1% by weight of phenolic antioxidant (Irganox 1010, manufactured by Ciba Geigy), 0.1% by weight of oleic acid amide as a lubricant and fatty acid ester type nonionic surfactant An L-LDPE resin composition containing 0.1% by weight of an agent (Electrostripper-TS-5, manufactured by Kao Co., Ltd.) was used and prepared in exactly the same manner as the product I of the present invention.

The obtained container cap had a water vapor transmission rate of about 1.0 mg, which was better than that of Invention I.

[Effect of device]

In the present invention, by making the vicinity of the resin injection part thicker than the peripheral part, even if the vicinity of the resin injection part is scraped off,
No pinholes are generated and sufficient moisture resistance can be secured. Therefore, the molding cycle can be accelerated, and the container caps for photographic film cartridges can be produced inexpensively and in large quantities.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a container cap for a photographic film cartridge according to the present invention, FIG. 2 is a vertical sectional view of another embodiment of the same as above, and FIG. 3 is a portion in FIGS. 1 and 2. FIG. 4 is an enlarged sectional view of another embodiment, FIG. 11 is an enlarged sectional view of a conventional example, and FIGS. 12 to 15 are also sectional views of a conventional example. . 2 ... Container cap for photographic film cartridge 6 ... Top part 10 ... Resin injection mark 14 ... Thick part A ... Near resin injection part G ... Resin injection part

Claims (1)

[Scope of utility model registration request] 1. A container cap for a photographic film cartridge, characterized in that the thickness in the vicinity of the resin injection portion is 2.5 mm or less and is 10% or more thicker than the peripheral portion.