JPH0643803Y2 - Light-shielding bag for photographic materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a light-shielding bag for various photographic light-sensitive materials.

[Conventional technology]

For photographic light-sensitive materials that lose their quality value when exposed to light, light-shielding bags that completely block light are used. For example, there are light-shielding bags shown in FIG. 11 or FIG. 12 ( Published by the Japan Patent Office in 1978, Collection of Well-Known and Conventional Technologies 367
page).

The light-shielding bag for the photographic light-sensitive material of FIG. 11 has a one-sided seal structure in which the bottom portion is heat-sealed using a tubular film, and has a structure of a single flat bag only for the heat-sealing portion 20.

FIG. 12 shows a light-shielding bag for a photographic light-sensitive material, which has a central joint-sealing type structure and is a single flat bag having only the heat-sealing portion 20.

When making a light-shielding bag for photographic light-sensitive materials like this,
In heat sealing, the sealing width is changed within the range of about 1 to 10 mm according to the product weight and application. As the heat sealing conditions, if strong sealing is performed, the film will melt too easily and break easily. In some cases, pinholes are generated in some cases, so that the melting was not excessive, and pinholes were not generated.

[Problems to be solved by the device]

However, causes such as fluctuations in the thickness of the film forming the light-shielding bag such as inflation film, laminated film, difference in film surface temperature between summer and winter, fluctuations in heat-sealing speed, fluctuations in heat-sealing power supply voltage, heater bar contamination, etc. This causes variations in heat seal conditions. Therefore, due to the fluctuation of the heat-sealing condition, the heat-sealing portion 20 may be a strong seal or a weak seal, and the light-shielding property and the hermeticity may not be maintained. In particular, in order to prevent incomplete sealing due to weak sealing, there is a tendency for strong sealing, and when the heat sealing layer melts and breaks due to overheating, it becomes impossible to secure light shielding and sealing performance, or when it becomes thin and strength decreases. There were many Therefore, a complete light-shielding property confirmation test of the light-shielding bag is required.

The present invention solves these problems, and even if the initial optimum heat-sealing conditions fluctuate, reliable heat-sealing can always be performed and complete light-shielding property and sealing property can be secured. An object is to provide a light-shielding bag for materials.

[Means for Solving the Problems]

The present invention has been made to achieve the above object, and is solved by applying a plurality of heat seals having different adhesive strengths.

That is, the light-shielding bag for a photographic light-sensitive material of the present invention is provided with a heat-sealing portion having a strong adhesive strength which is continuously provided on the periphery thereof and a heat-sealing portion having a strong adhesive strength which is substantially parallel to the inside of the heat-sealing portion. It is characterized in that a multi-strip heat seal is provided, which comprises a heat seal part having a weaker adhesive strength and a weaker adhesive strength than the strong heat seal part.

The multi-row heat seal is provided with two or more heat seals. The heat seals of this multi-thread heat seal are provided so that the adhesive strengths are different, and the heat seal portion provided on the periphery has a high adhesive strength, and the heat seal portion provided on the inner side has a low adhesive strength. ing. Further, it is preferable to provide a non-heat-sealed portion which is not heat-sealed between each heat-sealed multi-row heat-sealed from the viewpoint of securing light-shielding property and hermeticity.

Also, it is not necessary to provide the multi-row heat seal at all the places where the heat-shielding bag is heat-sealed, but the weak places where strength is particularly weak or the places where the sealing property is particularly desired to be strengthened are partially applied, for example, the product load is easily applied to the bottom. It may be provided only on the top or the corner.

In order to provide a multi-row heat seal, each heat seal is provided by a heat sealer having a different amount of emitted energy. That is, heat sealing is performed by changing the temperature, pressure, sealing time, etc. for each heat sealing.

The plastic film used in the light-shielding bag for a photographic light-sensitive material of the present invention includes a polyethylene resin containing a light-shielding substance or no light-shielding substance, an ethylene copolymer resin,
Ethylene vinyl acetate copolymer resin, ionomer resin,
Films of polypropylene resin, cellophane, vinylidene chloride copolymer resin, polyvinyl chloride resin, polystyrene resin, polyester resin, polyamide resin, polyvinyl alcohol resin, acrylic resin, polycarbonate resin, etc., and these, paper, and metal deposition flexible It is a laminated film with a sheet, an aluminum foil or other flexible sheets, and is a laminated film which has at least a perfect light-shielding property as an essential condition, and is any film which can be made into a bag by heat sealing. Among these, preferred are polyethylene resin containing a light-shielding substance, an ethylene copolymer resin, a film of a polyamide resin, and a laminated film of these and an aluminum vapor-deposited biaxially stretched thermoplastic resin film, an aluminum foil or the like. . The film used for the light-shielding bag of the present invention may be either a single layer film or a laminated film, but it is essential to ensure complete light-shielding property, and the light transmittance is 0%.

The light-shielding bag for the photographic light-sensitive material of the present invention is a single or double flat bag or a gusset bag, and the sealing structure is a side seal type, a two-way seal type, a three-way seal type, an envelope type, a central gas palm seal type. Any structure may be used as long as it is manufactured by a typical heat seal structure such as a pleated type, a flat bottom type, a square bottom type, and a self-standing type.

After filling the light-shielding bag for the photographic light-sensitive material of the present invention with the photographic light-sensitive material, the opening is completely sealed with the above-mentioned multi-stick seal, or after the opening end is folded, it is completely sealed with a tape, a label, an adhesive or the like. To do.

The light-shielding bag for a photographic light-sensitive material of the present invention can be used for packaging various photographic light-sensitive material products.

In particular, silver halide photographic light-sensitive materials, diazo photographic light-sensitive materials, photosensitive resins, self-developing photographic light-sensitive materials, diffusion transfer photographic light-sensitive materials, heat-sensitive light-sensitive materials, whose quality is destroyed by slight gas, light and humidity. It is suitable for photographic light-sensitive materials such as auto-positive type photographic light-sensitive materials and photosensitive heat-sensitive materials.

[Action]

Since the light-shielding bag for photographic light-sensitive material of the present invention is made by a multi-strip heat seal with different heat seal strength, at least one heat seal among a plurality of heat seals is always heat sealed under a condition close to the optimum condition and completely sealed. Always ensure reliable light shielding and sealing performance.

〔Example〕

A typical embodiment of the light-shielding bag for a photographic light-sensitive material of the present invention will be described with reference to FIGS.

1 to 8 are front views showing a typical structure of a light-shielding bag for a photographic light-sensitive material according to the present invention. In the figure, arrow A indicates the insertion position of the product, and arrow B indicates the sealing position after the product is inserted.

The light-shielding bag for photographic light-sensitive material of FIG. 1 has a structure of a three-side sealed flat bag that is heat-sealed with ears 12 left, and has an unheat-sealed portion inside the first heat-sealed portion 1 having high adhesive strength. 2nd heat seal part 3 with weak adhesive strength
It is a multi-row heat seal structure that has been subjected to.

The light-shielding bag for photographic light-sensitive material shown in FIG. 2 has a one-sided flat bag structure in which the bottom portion is heat-sealed by using a tubular film, and the inside of the first heat-sealed portion 1 having high adhesive strength is not heated. The second heat seal portion 3 having a weak adhesive strength is provided through the seal portion 2 to form a multiple heat seal.

The light-shielding bag for photographic light-sensitive material of FIG. 3 has a structure of a flat bag of a two-sided side seal type in which a plastic film is folded and the side faces are heat-sealed, and the side portions are of the first heat-sealing portion 1 having high adhesive strength. Through the unheated seal part 2 inside,
The second heat-sealing portion 3 having a weak adhesive strength is provided, and the bottom portion is a side surface strip having the second heat-sealing portion 3 having a weak adhesive strength provided inside the bent portion 9 via the unheat-sealed portion 2.
This is a configuration of a single-line heat seal at the bent portion.

The light-shielding bag for photographic light-sensitive material of FIG. 4 has a structure of a central bag-sealing type flat bag having a gas-sealing seal part in the center, and the bottom part is not heat-sealed inside the first heat-sealing part 1 having high adhesive strength. Heat seal part 3 with weak adhesive strength via part 2
It is a multi-row heat seal structure that has been subjected to.

The light-shielding bag for photographic light-sensitive material of FIG. 6 has a structure of a flat bag in which the opening of a three-way seal type is heat-sealed, and the notch 13 for opening is formed on the side, and the first heat-sealing portion has a high adhesive strength. 1 is a multi-row heat seal structure in which a second heat seal portion 3 having a weak adhesive strength is provided inside 1 through a non-heat seal portion 2.

The light-shielding bag for photographic light-sensitive material of FIG. 6 has a flat bag structure in which the opening portion of the side-sealed light-shielding bag shown in FIG. 3 is sealed by heat sealing, and is bonded with an opening notch 13 on the side. A multi-row heat seal in which the second heat-sealing portion 3 having a weak adhesive strength is provided inside the first heat-sealing portion 1 having high strength through the non-heat-sealing portion 2, and the top portion is the inner side of the multi-thread heat sealing. In addition, through the unheat-sealed portion 4, a multi-strip heat seal in which a third heat-sealed portion 5 having a weak adhesive strength is partially provided, and the bottom portion is inside the bent portion 9 through the unheat-sealed portion 2. The second heat-sealing portion 3 having weak adhesive strength is provided, and the non-heat-sealing portion 4 is further provided on the inner side.
Is a multi-row heat seal in which a third heat seal portion 5 having a weak adhesive strength is partially provided through the heat seal.

The light-shielding bag for the photographic light-sensitive material shown in FIG. 7 has a notch for opening in the ear 12.
A four-sided sealed flat bag structure having 13 and a second adhesive layer having a weak adhesive strength inside and outside the first heat-sealed portion 1 having a strong adhesive strength via unheat-sealed portions 2 and 7, respectively.
This is a multi-row heat seal structure in which the heat seal portions 3 and 3 are provided.

The light-shielding bag for a photographic light-sensitive material shown in FIG. 8 (a) has a structure of a flat bag having a four-sided seal having an opening notch 13 in the first heat-sealing portion 1 having high adhesive strength, and the first heat-sealing at four corners. A four-corner multi-row heat seal is provided in which an L-shaped second heat seal part 3 having a weak adhesive strength is partially provided inside the part 1 via an unheat seal part 2.

The light-shielding bag for the photographic photosensitive material of FIG. 8- (b) is shown in FIG.
Part (a) of the L-shaped second heat-sealed portion 3 having a weak adhesive strength is used as an unheat-sealed portion 2, and conversely, a second weak heat-sealed portion having a weak adhesive strength is used. A multi-row heat seal is provided except for the four corners provided with the heat seal part 3.

In order to provide the above-mentioned multi-row seals having different adhesive strengths, for example, the heat sealer shown in FIG. 9 or 10 is used. In FIG. 9, reference numeral 14 is a heat sealer, and the heat sealer 14 has long edges 15 and short edges 16. Then, the long edge 15 forms a heat-sealing portion having a strong adhesive strength, and the short edge 16 forms a heat-sealing portion having a weak adhesive strength.

In FIG. 10, the heat sealer 14 has a high temperature edge 17 and a low temperature edge 18 formed with an insulating member 19 interposed therebetween. Then, the high-temperature edge 17 forms a heat-sealed portion having high adhesive strength, and the low-temperature edge 18 forms a heat-sealed portion having low adhesive strength. It is also possible to form a heat-sealed portion having high adhesive strength by fusing and sealing at the high temperature edge 17.

As shown in FIG. 10, by using a heat sealer having a high temperature heat sealer 17 on one side and a low temperature heat sealer 18 on the other side with the heat insulating member 9 interposed therebetween, a strong heat seal part and a weak heat seal part are formed to form a bag. Is the easiest.
Similarly, it is easier to use a heat sealer having three edges to perform heat sealing for three threads than to individually heat seal.

Next, the experimental results comparing the characteristics of the invention products I to V and the conventional products I and II will be described.

The product I of the present invention corresponds to the flat bag configuration shown in FIG.

The resin composition of the film is 4 g of ethylene with a melt index (hereinafter referred to as MI) of 2.1 g / 10 minutes and a density of 0.920 g / cm ^3.
72.5% by weight of linear low-density polyethylene, which is a copolymer resin of methylpentene-1, MI of 1.1 g / 10 minutes, density of 0.954
High-density polyethylene (hereinafter referred to as HDPE) resin with g / cm ³ 20
% By weight, average particle size 21 mμ, oil absorption 76 ml / 100 g, pH
Furnace carbon black of 8.0% 3% by weight, conventional product I
Low density polyethylene (hereinafter referred to as LDPE) resin identical to 4.
Consists of 4% by weight and 0.1% by weight of phenolic antioxidant.

Thickness of resin composition is 100μm, Folding diameter is 22cm, Blow ratio is 1.76
Using a tubular film consisting of a single layer of inflation film, the non-body part is the bottom and the bottom is the
Heat sealing was performed using a heat sealer 14 shown in FIG. The width of the first heat seal part 1 with strong adhesive strength is 5 mm,
An unheat-sealed portion 2 having a width of 5 mm was provided inside the second heat-sealed portion 3 having a weak adhesive strength and a width of 2 mm.

Inventive product II Inventive product II corresponds to the flat bag configuration shown in FIG.

The resin composition of the film is MI 4g / 10min, density 0.925g / cm
97% by weight of linear low-density polyethylene (hereinafter referred to as L-LDPE) resin (stamilex # 1046, manufactured by DSM), which is a copolymer resin of ethylene and octene-1 of ³ , and furnace carbon black (described above). It consists of 3% by weight and has a blow ratio of 1.
80-μm thick L- molded by inflation film with 76
A 15 μm thick aluminum vacuum-deposited biaxially stretched nylon film with a thickness of 400 Å is laminated on the LDPE resin light-shielding film via an extrusion-laminated LDPE resin adhesive layer with a thickness of 13 μm. This is a laminate of unbleached neutral paper having a basis weight of 50 g / m ₂ through a 13 μm extrusion laminate LDPE resin adhesive layer.

From the laminated film, the width of the first heat-sealing portion 1 having a strong adhesive strength as a palm-sealing portion is 5 mm, and the unheat-sealed portion 2 having a width of 2 mm is provided inside the second heat-sealing portion 3 having a weak adhesive strength. The total heat seal width is 3 mm and the width is 1
A 0 mm tubular film was obtained, and the bottom seal portion was heat-sealed in the same manner as the product I of the present invention. The width of the first heat-sealing portion 1 having a strong adhesive strength is 5 mm, and the non-heat-sealing portion 2 having a width of 5 mm is provided inside the first heat sealing portion 1
The heat seal portion 3 has a width of 2 mm.

Inventive product III Inventive product III corresponds to the flat bag configuration shown in FIG.

As the film, the same laminated film as the product II of the present invention was used.
The width of the first heat-sealing part 1 with strong adhesive strength is 5 mm, the width of the non-heat-sealing part 2 is 3 mm, and the second heat-sealing part 3 with weak adhesive strength is L-shaped with a side length of 5 cm and a width of 3 mm. did.

Inventive product IV Inventive product II corresponds to the flat bag configuration of FIG.

As the film, the same laminated film as the product II of the present invention was used.
The width of the first heat seal 1 with strong adhesive strength on the side is 5 mm,
The non-heat-sealed portion 2 has a width of 3 mm, and the second heat-sealed portion having a weak adhesive strength has a width of 3 mm.

Product V of the Invention The product V of the present invention corresponds to the flat bag configuration of FIG.

The width of the first heat seal 1 with strong adhesive strength is 5 mm, the width of the non-heat sealed parts 2 and 4 is 3 mm, and the second with weak adhesive strength
The width of the heat-sealing portion 3 was 3 mm, and the width of the third heat-sealing portion 5 having a partially weak adhesive strength was 3 mm.

Conventional product I Conventional product I corresponds to the flat bag configuration shown in FIG. The resin composition of the film is: MI of 2.4 g / 10 minutes, density of 0.923 g / cm ³ of LDPE resin 97% by weight, furnace carbon black (above) 3% by weight, thickness 100 μm, folding diameter 22 cm, blow ratio. A tubular film made of a single layer of the inflation film of 1.76 was used, and the width of the heat seal portion 20 was set to 5 mm.

Conventional product II Conventional product II corresponds to the flat bag configuration shown in FIG. The resin composition of the film is the same as the conventional product I, and the LDPE resin light-shielding film with a thickness of 80 μm is laminated with the aluminum foil with a thickness of 7 μm through the extrusion laminate LDPE resin adhesive layer with a thickness of 40 μm. A laminated film in which bleached kraft paper having a basis weight of 35 g / m ² was laminated via an extrusion laminate LDPE resin adhesive layer having a thickness of 40 μm was used. The width of the heat seal part 20 of the palm part is 10 mm, the heat seal part 20 of the bottom part
The width was set to 5 mm.

The experimental results are shown in Table 1.

The evaluation is as follows.

◎… Extremely excellent ○… Excellent ▲… Problem (needs improvement) ×… Not practical [Effect of the Invention] The present invention provides at least one article by providing multiple heat seals with different heat seal strengths. Since the heat-sealing portion is properly heat-sealed, it is possible to always ensure the complete light-shielding property and moisture-proof property.

Further, the light-shielding property test of the light-shielding bag is not required, and it is not necessary to carry out the production under strict bag-making conditions, so that the production cost can be reduced.

[Brief description of drawings]

1 to 8 are front views of an embodiment of a light-shielding bag for a photographic light-sensitive material of the present invention. 9 and 10 are partial cross-sectional views of a typical heat sealer used in the manufacture of the light-shielding bag for a photographic light-sensitive material of the present invention. 11 and 12 are front views of a conventional light-shielding bag for a photographic light-sensitive material. 1 ... 1st heat-sealed part with strong adhesive strength 2, 4, 7 ... Unheat-sealed part 3 ... 2nd heat-sealed part with weak adhesive strength 5 ... 3rd heat-sealed part with weak adhesive strength 13 ... Notch 9 for opening Bent section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-79040 (JP, A) Actually opened 62-125737 (JP, U) Actually opened 63-342 (JP, U) Actually opened 60- 89142 (JP, U) Actual public 33-14156 (JP, Y1) Actual public 38-4503 (JP, Y1) Actual public 3-26511 (JP, Y2) Actual public 3-36993 (JP, Y2) Actual public Sho 60-4920 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. A heat-sealing portion having a strong adhesive strength, which is continuously provided on the periphery of the heat-sealing portion, and a heat-sealing portion having a strong adhesive strength, which is substantially parallel to the inside of the heat-sealing portion, has a higher adhesive strength. A light-shielding bag for a photographic light-sensitive material, characterized in that it is provided with a multi-strip heat seal consisting of a heat seal portion having a small adhesive strength.