JP2003075971A - Instant film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent offset sticking of a mask sheet when an instant film is produced. SOLUTION: A mask sheet 5 is produced by dry laminating using a PET sheet 13 and a VMPET sheet 14. The PET sheet 13 coated with an adhesive 36 and the VMPET sheet 14 are stuck together by hot pressing at a sticking section 27. A load of 5 kg is applied to the PET sheet 13, a load of 8 kg is applied to the VMPET sheet 14, and by this load difference the produced mask sheet 5 is curled in the width direction of the sheet 5 with the PET sheet 13 inward. When an instant film is produced, since the mask sheet 5 is conveyed with the PET side downward, edge parts of the mask sheet 5 are prevented from running upon guide chutes formed in a guide rail and from being crushed by the guide chutes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instant film of monosheet type, for example.

[0002]

2. Description of the Related Art A photographic film used for an instant camera is called an instant film, and a photographic image obtained after photographing can be viewed on the spot. For this reason, it is convenient for photographers, and due to its simplicity, the demand for instant films is increasing. Among them, the mono-sheet type instant film is convenient because it is not necessary to peel off the positive photographic photosensitive sheet after taking a picture.

The mono-sheet type instant film is
As is well known, a photosensitive sheet including an image receiving portion and an image forming portion and a cover sheet are formed, and a developing treatment liquid is injected between the photosensitive sheet and the cover sheet. At both ends of this photosensitive sheet, a developing solution pod containing a developing solution and a trap material for absorbing excess developing solution are arranged, and these are covered with an outer frame (mask sheet). .

The mask sheet is composed of a white printing layer, an aluminum metal layer, a resin film layer made of polyethylene terephthalate (PET), and an adhesive layer. The aluminum metal layer is vapor-deposited on the resin film layer to reduce the thickness of the frame, and at the same time keep the hiding and moisture-proof properties inside. The white surface layer protects the aluminum metal layer and allows the date and the like to be entered with a writing instrument or the like to facilitate the organization of the instant film. This white printing layer is disclosed in, for example, JP-A-11-35.
As described in Japanese Patent No. 2649, it is formed by applying a mixture of a white pigment such as titanium oxide and a polymer binder such as a vinyl chloride-vinyl acetate copolymer. As a result, peeling of the white printing layer that occurs when writing on the surface of the white printing layer with a writing instrument and scratches on the aluminum metal layer are reduced.

The printing process on the mask sheet is carried out in a state where the mask sheet is in the form of a series of strips. Especially, when the printing process by overcoating is carried out, the mask sheet is generally curled into a trough with the printing surface inside. . Therefore, in the next step of producing an instant film, a long and narrow strip of the mask sheet that has been subjected to the printing process is slit into a predetermined width.
As shown in FIG. 6A, a guide chute 61 having edges 61a on both sides is used to convey the mask sheet 60 while controlling both side edges of the mask sheet 60 with the edges 61a. It will be possible to send it stably without causing it.

[0006]

However, the degree of curl generated on the mask sheet after the printing process is not constant due to the change in the dry state and the temperature environment after printing, and depending on the conditions, the printing surface may be outside. It may curl. In such a case, as shown in FIG. 6B, one side of the mask sheet 65 rides on the edge 61a, and the mask sheet 65 is conveyed while being largely displaced in the width direction, and the positioning in the next step is extremely difficult. Becomes difficult. Since it is necessary to manufacture the instant film while accurately stacking the components such as the mask sheet, the cover sheet, and the photosensitive sheet, if the mask sheet meanders greatly during transportation, it will cause a significant decrease in manufacturing efficiency.

Further, as shown in FIG. 6 (C), even if the curl direction of the mask sheet 67 is proper, if the rigidity of the mask sheet 67 itself is too low, for example, the mask sheet 67 and the guide chute 61 will be. The mask sheet 67 may shift in the width direction due to fluctuations in contact frictional resistance with the bottom surface, and when one side of the mask sheet 67 is pressed against the edge 61a, the mask sheet 67 may be greatly bent and deformed. On the other hand, if the rigidity of the mask sheet is too high, the mask material becomes difficult to bend as shown in FIG. 1, and the dimension of the film fluctuates, resulting in a decrease in manufacturing efficiency. If the degree of curl is large, both edges are edge 6
The guide action by the edge 61a of the guide chute 61 cannot be expected from the position 1a, and the meandering amount increases. If the curl degree is small, even if both side edges are housed between the edges 61a, the friction between the both side edges and the edge 61a becomes large, and smooth conveyance cannot be performed.

Further, when a seal bar for heat sealing is provided on the mask sheet conveying line so as to face both side edges of the mask sheet, it faces the seal bar when the operation of the processing machine is temporarily stopped. Then, both sides of the stopped mask sheet are excessively heated. As a result, the rigidity of both side edges of the mask sheet is partially reduced to come into contact with the bottom of the guide chute, and the frictional resistance is increased to easily cause uneven conveyance and meandering.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an instant film devised so that a belt-shaped mask sheet after printing can be smoothly conveyed without causing a large meandering. And

[0010]

In order to achieve the above object, the instant film of the present invention is developed on a developing solution pod arranged at both ends of a photosensitive sheet and on the photosensitive sheet when the developing solution pod is crushed. While containing a trap material that absorbs the excess of the development processing liquid, a plurality of white printing layers on the outer peripheral surface, and a mask sheet is provided with a mask sheet laminated in order, the mask sheet, the developing solution A curl is applied in the direction in which the pod and the trap material are arranged and with the printed layer inside, and the loop stiffness of the curl is 15 to 40 g and the curl amount is 5 to 4
It is 0 mm.

The mask sheet after the printing process is shown in FIG.
In order to enable stable conveyance in the form shown in (A), the mask sheet is curled with the printing surface facing inward, and the curl amount is set within an appropriate range so that the mask sheet has a predetermined rigidity. Need to be given. For this reason, among the plurality of white printing layers, a binder that does not easily curl in the lower white printing layer, that is, a polyurethane layer that is a binder that does not easily shrink after drying, is used, and the uppermost layer and the decorative printing layer shrink after drying. The printing surface becomes concave and constant by forming a layer in which an acrylic polyol, which is an easy ink binder, and a vinyl chloride-vinyl acetate copolymer mixture are mixed and the ratio of the acrylic polyol is 60 to 70% by weight. It becomes possible to give a certain amount of curl. By adding resin powder having an average particle size of 5 to 20 μm to the above ink binder, it is possible to prevent friction resistance from increasing even when heat is applied to the mask material.

[0012]

1 is an exploded perspective view showing the structure of an instant film embodying the present invention. The instant film 2 has a layered structure in which a photosensitive sheet 6, a pair of spacer rail members 7, and a cover sheet 8 are sequentially joined to a mask sheet 5 having an image frame 4 formed in the center. Folds 5 provided before and after the mask sheet 5
The developer pod 9 and the trap material 10 are provided outside the b and 5c.
Are bonded together, the back surface of the photosensitive sheet 6 (the back surface of the photosensitive surface) is joined to the hot melt adhesive side of the mask sheet 5, and the pair of spacer rails 7 and the cover sheet 8 are provided on the photosensitive surface side of the photosensitive sheet 6. After being joined, the fold lines 5b, 5
The front and rear ends of the mask sheet 5 are bent from c and joined to the cover sheet 8. Further, on the side of the developing solution pod 9 of the photosensitive sheet 6, an under material 11 for receiving the developing solution pod 9 and adjusting the height between the developing solution pod 9 and the photosensitive sheet 6 is provided.
Are connected.

The photosensitive sheet 6 has a thickness of 100 to 1 containing, for example, a slight amount of titanium oxide to prevent light piping.
A 50 μm (125 μm in the following examples) PET support is coated on one side with an acetylcellulose-based back layer containing an ultraviolet absorber, and on the other side, an image receiving layer, a white reflective layer, a light shielding layer, A red-sensitive emulsion layer unit, a green-sensitive emulsion layer unit, a blue-sensitive emulsion layer unit, a UV absorber layer and a protective layer are sequentially coated, and a color mixing prevention layer is provided between each color-sensitive emulsion layer unit. ing.

The cover sheet 8 has a thickness of 50 to 100 μm.
A neutralization layer, a neutralization timing layer, and a temperature compensation layer are sequentially coated toward the surface of the photosensitive sheet 6 on a PET support colored for preventing light piping (in the following examples, 75 μm), The uppermost temperature compensation layer is joined to the spacer rail 7.

In the back layer (front side in FIG. 1) of the cover sheet 8, a filter dye for correcting a color that seems to be tolerant is added to an acetylcellulose-based binder according to the production lot of the photosensitive sheet. This cover sheet 8
The hot melt adhesive of the mask sheet 5 and the back layer of the cover sheet 8 are bonded together.

The spacer rail 7 is formed by coating a hot PET adhesive on both sides of a transparent PET base with a thickness of 5 to 10 μm, and the thickness is adjusted depending on the adhesive strength between the photosensitive sheet surface and the cover sheet surface. . Since the spacer has a great influence on the development thickness of the treatment liquid, the layer thickness can be divided into several ranks within a range in which the adhesive strength is acceptable, and the spacers can be selectively used to keep the development thickness constant.

The trap material 10 is made by compressing a polyester non-woven fabric to a certain thickness and contains an acrylic acid polymer for neutralizing the alkali content of the treatment liquid when the treatment station is trapped.

The instant film 2 is sent to the outside by the guide roller of the camera after the photographing is completed.
At this time, the developing solution pod 9 is crushed by the developing roller provided inside the camera, and the developing solution is sent out of the instant film 2 and the guide designed to be uniformly spread between the photosensitive sheet 6 and the cover sheet 8. Roller and ironing plate spread evenly. When the developing solution is developed by the developing roller, the developing solution permeates into each color-sensitive emulsion layer unit, and the dye generated in each emulsion layer unit is generated to progress the development. The generated dye diffuses into the image receiving layer and dyes the image receiving layer. Then, when a predetermined fixing time has elapsed, a color image is formed on the image receiving layer. Also,
Development is stopped by the neutralizing layer in the cover sheet 8 and the development stopping agent. The excess developing solution is absorbed by the trap material 10 and neutralized by the acid polymer in the trap material 10.

As shown in FIG. 2, the mask sheet 5 is a polyethylene terephthalate (PET) sheet 13 having a thickness of 12 μm, and aluminum vapor deposition (thickness 40) on one surface.
It is formed of a sheet obtained by laminating a polyethylene terephthalate (VMPET) sheet 14 having a thickness of 0 angstrom) and having a thickness of 12 μm by a dry lamination process. The VMPET sheet 14 has a surface on which aluminum is vapor-deposited as a bonding surface for dry lamination. In this embodiment, a PET sheet having a thickness of 12 μm was attached, but a PET film having a thickness of 25 μm having aluminum vapor-deposited on one surface thereof was used.
Sheets can be used as well. The base of the mask sheet 5 is a plastic film sheet such as polyethylene naphthalate (PEN), polycarbonate, polypropylene triacetate, and a basis weight of 30 to 100 g / m ^2.
High-strength paper materials, etc. can also be used.

On the surface of the VMPET sheet 14, a heat-sealing layer 15 having a thickness of 12 μm is formed by applying a hot melt adhesive made of, for example, an ethylene-vinyl acetate copolymer by a printing machine. In this embodiment, since the heat seal agent uses a printing machine, an organic solvent (for example, toluene) -soluble ethylene-vinyl acetate copolymer is used, but the coating machine and the coating method are changed. Various types of heat sealing agents such as hydrogen latex type and extrusion solvent-free type can be selected. In addition, the surface of the PET sheet 13 is printed with, for example, a white paint, and the thickness of each layer is 2 μm.
A maximum of four white printed layers 16 are formed. Decorative printing using, for example, gray paint is performed on the upper surfaces of these white printed layers 16 to form a decorative printed layer 20 of 1 μm, for example. The decorative print layer 20 is located on the cover sheet 8 side which is the back surface of the instant film.

Next, a method for producing the mask sheet 5 of the present invention will be described. A dry lamination process is performed using the PET sheet 13 and the VMPET sheet 14 to create the mask sheet web 21. As shown in FIG. 3, the laminating machine 22 includes delivery parts 23 and 24, a coating part 25, a drying part 26, and a laminating part 27. In the sending section 23, the PET roll 2 that has been set
The PET sheet 13 is sent from 9 toward the coating portion 25. At this time, the braking force applied to the PET roll 29 is 8 kg. In addition, the VMPET roll 30 is set on the delivery unit 24 with the aluminum vapor deposition surface facing outward, and the VMPET roll 30 is directed toward the bonding unit 27 via the nip roller pair 31.
Send out the ET sheet 14. In addition, VMPET sheet 1
The load applied to 4 is 8 kg.

The PET sheet 13 conveyed to the coating section 25 is sandwiched between the gravure roller 33 and the rubber roller 34. A part of the gravure roller 33 is dipped in an adhesive 36 made of, for example, a polyester adhesive in a tray 35 for adhesive, and an adhesive layer 37 (see FIG. 2) having a thickness of 3 μm is formed on the surface of the PET sheet 13 to be conveyed. ) Is formed. In addition, in the vicinity of the gravure roller 33, the doctor 3 (not shown)
8 is arranged so that the excess adhesive 36 is scraped off.

The drying section 26 is provided for drying the adhesive 36 coated on the PET sheet 13. The environmental temperature inside the drying section 26 is set to 75 ° C., and the tension applied to the PET sheet 13 in the drying section 26 is 5 kg. The PET sheet 13 whose adhesive 36 has been dried in the drying section 26 is conveyed toward the laminating section 27.

The laminating section 27 is composed of a pressure roller 41 made of, for example, a rubber roller and a heating roller 42. With these rollers, PET sheet 13 and VMPE
The T-sheet 14 and the T-sheet 14 are pressure-bonded to each other so that the aluminum vapor deposition surface becomes the inner laminating surface. The heating roll is heated to 35 to 60 ° C., and the adhesive layer 37 coated on the PET sheet 13 melts during pressure bonding, and at the same time, the PET sheet 13 and the VMPET sheet 14 are joined. At this time, the tension applied to the PET sheet 13 (5
kg) and the tension applied to the VMPET sheet 14 (8 k)
Due to the difference from (g), the laminated mask sheet web 21 curls in the width direction and with the PET sheet 13 side facing inward. Then, the mask sheet web 21 is wound up by the winding roll 44. In addition,
The tension of the mask sheet web 21 by the winding roll 44 is 10 kg.

The laminated mask sheet web 21 is left in a drying room at room temperature of 40 ° C. for 5 days. After that, gravure printing is performed on the surface of the mask sheet web 21 on the PET sheet 13 side. As shown in FIG. 4, the gravure printing machine includes a plate cylinder 50, an impression cylinder 51, a finisher roller 52, a doctor 53, and an ink tray 54. A part of the finisher roller 52 is soaked in the ink binder held in the ink tray 54, and when it is rotated, the ink is attached to the plate cylinder 50 having the gravure plate formed on the outer periphery thereof. Then, pressure is applied by the impression cylinder 51 to transfer it to the mask sheet web 21. The excess ink binder attached to the surface of the gravure plate is scraped off by the doctor 53. The mask sheet web 21 after the gravure printing is sent to the drying unit 55 at room temperature of 75 ° C. to be dried. In this gravure printing, a white ink binder that uses a white pigment made of titanium oxide is used.
The above-mentioned printing process is set as one cool and a maximum of four cools are performed.
As a result, a maximum of four white printing layers with a thickness of 2 μm are formed. The room temperature of the drying room may be in the range of 75 to 100 ° C. Further, a resin powder, a mixture of acrylic polyaol (AP) in which silica is dispersed and a vinyl chloride-vinyl acetate copolymer (weight ratio 66/34) is used for the white paint used in the final cool. This resin powder has an average particle size of 5 to 20 μm (7 in this embodiment).
(μm) benzoguanamine is used, and even if the mask sheet web 21 is stopped under a heat sealer heated to about 150 ° C. by adding resin powder, the surface slipperiness is maintained and the workability is hindered. Never.

After the white color printing, a decorative printing is performed as a fifth color, which is an external decoration. In decorative printing, a colored ink binder is used to perform the above-mentioned printing process for one cool. As a result, a decorative print layer having a thickness of 1 μm is formed on the white print layer (see FIG. 2). As the colored ink binder used for decorative printing, a mixture (weight ratio 66/34) of resin powder, silica-dispersed acrylic polyol and vinyl chloride-vinyl acetate copolymer is used.

The mask sheet web 21 on which the gravure printing has been carried out is wound around a winding roll 56, and the room temperature 4
It is left for 5 days in a drying room at 0 ° C. After that, VMPE
A hot-melt adhesive made of, for example, an ethylene-vinyl acetate copolymer is overcoated on the T sheet 14 side to form a 12 μm heat seal layer 15 (see FIG. 2). As a result, the loop rigidity of the mask sheet web 21 is 15 to 40.
g, the curl amount is 5 to 40 mm. The width of the mask sheet web 21 is 108.4 ± 0.2 mm.

As for the loop rigidity, a mask sheet printed in white is cut into a length of 24.2 mm and a width of 6.5 mm, and a double-sided tape of 5 mm having an arbitrary width is attached to one end on the VMPET sheet side. Precision compression measuring device KES-
It can be obtained by setting the FB3 measuring device (manufactured by Kato Tech) and measuring at room temperature and normal pressure. In addition, this KES-F
The B3 measuring device has a load sensor and a pressing member having a pressing surface parallel to the sensor surface of the load sensor, and a ring-shaped sample is sandwiched between the load sensor and the pressing member to attach the pressing member to the load sensor. The load is measured when the pressing member is moved to the load sensor side by 3 mm toward the load sensor. The curl amount was cut into a width of 108.4 mm and a length of 70 cm in the printing direction of the mask sheet, left for 2 hours or more under the conditions of temperature 23 ± 2 ° C. and humidity 60 ± 5% RH. The curl height curled in the direction is measured with a metal ruler. At this time, the measurement sample is placed on a flat table so that both ends are lifted, and the heights at which both ends are lifted are measured with a bending scale, and the average value is taken. A positive curl is obtained when both ends of the printing layer side are lifted, and a negative curl is obtained when both ends of the opposite side of the printing layer are lifted.

The instant film 2 is manufactured using the mask sheet web 21. The mask sheet web 21 sent from the winding roller is sent to a guide chute having a width of 108.5 mm with the VMPET sheet 14 side facing upward. At this time, since the mask sheet web 21 is curled with the VMPET sheet side being convex in the width direction (curl amount: 5 to 40 mm), FIG.
As shown in (3), the guide chute having a width is conveyed without meandering. If the width of the mask sheet web 21 is wide, the mask sheet web 21 is conveyed with both ends regulated, and if the width of the mask sheet web 21 is narrow, the mask sheet web 21 is conveyed with being regulated by the end regulation. If the width of the mask sheet web 21 becomes wider than 108.4 ± 0.2 mm, or if the curl exceeds 5 to 40 mm, both ends will be poorly regulated, resulting in improper conveyance and poor descent. The developer pod 9 and the trap material 10 are attached to predetermined positions on the delivered mask sheet web 21, and the image frame 4 is die-cut. After that, the photosensitive sheet 6, the spacer rails 7, and the cover sheet 8 are attached to predetermined positions, and the mask sheet web 21 is folded back and joined at the folds 5b and 5c in FIG. After that, the instant film 2 is completed by being cut into a predetermined length in the carrying direction. At this time, the riding on the guide chute 61 as shown in FIG. 6B and the crushing of the mask sheet by the edge 61a of the guide chute 61 as shown in FIG. 6C are prevented.

[0030]

EXAMPLES Examples of the present invention will be described below based on specific mask sheet samples. Note that FIG. 5 shows the main configurations of Samples 1 to 4 and Comparative Examples 1 and 2.
Are summarized in.

[Sample 1] In providing a four-layer white printed layer by gravure printing, polyurethane was used as the ink binder for the first and second colors, and acrylic polyol (hereinafter, AP) and vinyl chloride were used as the ink binder for the third and fourth colors. -Mixture with vinyl acetate copolymer (weight ratio 66/3
4) was used. As a colored ink binder for decorative printing, a mixture (weight ratio 66/34) of titanium oxide, a color pigment, resin powder, silica-dispersed AP and a vinyl chloride-vinyl acetate copolymer was used. The sample using these ink binders has a loop stiffness of 28 g and a curl amount of 20 mm. As shown in FIG. 6 (A), this mask sheet web 60 uses a guide chute 61 to suppress the meandering. It was possible to carry it, and the positioning in the post process could be done easily. The gravure plate may be a deep engraving plate after the second layer when it is difficult to secure the thickness due to remelting of the lower layer.

[Sample 2] White printed layer 1 of 4 layers
For the 3rd color, polyurethane is used for the ink binder and AP and vinyl chloride are used for the 4th color ink binder.
A mixture with a vinyl acetate copolymer (weight ratio 66/34) was used. The same color ink binder as that used in Sample 1 was used for decorative printing. The loop rigidity of this sample 2 is 20 g and the curl amount is 15 mm. Figure 6
As shown in (A), the mask sheet web 60 was able to be appropriately conveyed while suppressing the meandering by using the guide chute 61, and the positioning in the subsequent process could be easily performed.

[Sample 3] 1 of 4 layers of white printing layer
Regarding the color, polyurethane was used as the ink binder, and a mixture of AP and vinyl chloride-vinyl acetate copolymer was used as the ink binder for the second to fourth colors (weight ratio 66/34).
Was used. The same color ink binder as that used in Sample 1 was used for decorative printing. The sample 3 has a loop stiffness of 33 g and a curl amount of 30 mm. Figure 6
As shown in (A), the mask sheet web 60 was able to be appropriately conveyed while suppressing meandering by using the guide chute 61, and could be easily positioned in a post process.

[Sample 4] In this sample, the white printing layer formed by gravure printing was composed of three layers, and the AP / vinyl chloride-vinyl acetate copolymer mixture (weight ratio 66/34) was used as the ink binder for the second and third colors. Polyurethane was used as the first color ink binder. The same color ink binder as that used in Sample 1 was used for decorative printing. The loop rigidity of this sample 4 is 38 g and the curl amount is 40 mm. As shown in FIG. 6A, the mask sheet web 60 was able to be appropriately conveyed by suppressing the meandering by using the guide chute 61, and the positioning in the post process could be easily performed.

[Comparative Example 1] 1 to 4 of the white printing layer having a four-layer structure
Urethane is used for the fourth color ink binder and the colored ink binder used for decorative printing. The loop rigidity of Comparative Example 1 is 10 g. Further, the curl generated on the mask sheet web 60 is reverse curl and has a small curl amount (curl amount −5 to 2 mm). In this case, as shown in FIG. 6B, the mask sheet web 65
Rides on the edge 61a of the guide chute 61,
As shown in FIG. 6C, since the mask sheet 67 is crushed by the edge 61 a of the guide chute 61,
This is an example where an effect cannot be expected.

[Comparative Example 2] 1 to 4 of the white printing layer having a four-layer structure
AP is used for the fourth color ink binder and the colored ink binder used for decorative printing. The loop rigidity of this comparative example 2 is 14 g. In this case, the curl generated on the mask sheet web 60 is a reverse curl or an extremely large curl amount. In this case, as shown in FIG. 6 (B), the mask sheet web 65 rides on the edge 61a of the guide chute 61, or as shown in FIG. 6 (C), the mask sheet 67 is crushed by the edge 61a of the guide chute 61. Therefore, as in Comparative Example 1, the effect cannot be expected.

[0037]

As described above, according to the instant film of the present invention, the mask sheet is curled in the direction in which the developer pod and the trap material are arranged and the printing layer is on the inside. Curling loop stiffness of 15 ~
Since the curl amount is 40 g and the curl amount is 5 to 40 mm, it is possible to reduce riding on the guide chute of the guide rail for guiding the conveyance of the mask sheet and crushing of the edge of the mask sheet by the guide chute. In this example, a printing machine was used. Although a printing machine has a lower processing cost and is more efficient, white printing and a heat seal layer can be formed using various coaters.

Further, the ink binder of the paint used for at least the uppermost layer of the white printing layer and the decorative printing layer is composed of an acrylic polyol and a vinyl chloride-vinyl acetate copolymer mixture, and the ratio of the acrylic polyol is 60-.
Since it is 70%, the curl formed on the mask sheet can be formed in a predetermined direction and a mask sheet having high rigidity can be formed.

Further, since the resin powder is added to the ink used for at least the uppermost layer of the white printing layer and the decorative printing layer, for example, both end portions of the mask sheet during transportation when the manufacturing line is restarted after being stopped. Since it is possible to prevent the slipperiness from being reduced due to the softening of the mask sheet, it is possible to prevent the mask sheet from meandering and conveying.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an instant film embodying the present invention.

FIG. 2 is a cross-sectional view showing the structure of a mask sheet.

FIG. 3 is a front view showing an outline of a laminating machine.

FIG. 4 is a front view showing the outline of a gravure printing machine.

FIG. 5 is a table showing types of ink binders used on a printing surface, loop stiffness and curl amount at that time.

FIG. 6 is a cross-sectional view showing a conveyance state of a mask sheet.

[Explanation of symbols]

2 Instant film 5 mask sheet 13 PET sheet 14 VMPET sheet 16 White printing layer 20 decorative printing layer 21,60 Mask sheet web 61 Guide Shoot

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03C 8/42 502 G03C 8/42 502 8/44 8/44 8/52 8/52

Claims (4)

[Claims] 1. A developing solution pod disposed at both ends of a photosensitive sheet, and a trap material for absorbing an excessive amount of a developing solution developed on the photosensitive sheet when the developing solution pod is crushed, and the outer peripheral surface thereof. In an instant film provided with a mask sheet in which a plurality of white print layers and a decorative print layer are sequentially laminated, in the mask sheet, in the direction in which the developer pod and the trap material are arranged, and the print layer is An instant film characterized in that a curl is applied to the inside, the loop rigidity of this mask sheet is 15 to 40 g, and the curl amount is 5 to 40 mm. 2. At least one layer as a binder of the white printing layer is composed of polyurethane, and the ink binder used in the uppermost layer of the white printing layer and the decorative printing layer is acrylic polyol and vinyl chloride-vinyl acetate copolymer. It is composed of a mixture, and the ratio of the acrylic polyol is 60 to 70% by weight.
Instant film described. 3. The instant film according to claim 1, wherein a resin powder is added to the ink binder used in at least the uppermost layer of the white printed layer and the decorative printed layer. 4. The average particle size of the resin powder is 5 to 2
The instant film according to claim 3, wherein the instant film has a thickness of 0 μm.