JP2003015261A - Packaging material for heat developable recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material for a heat developable recording material having such an excellent barrier property as not to cause a density change even when the heat developable recording material in the form of processed goods is stored as a packaged body. SOLUTION: The heat developable recording material is packaged in the packaging material by bending the packaging material while keeping at least part of the heat developable recording material in direct contact with the packaging material. Paper is used in at least part of the packaging material and a protective film comprising a UV curable resin is formed on a face of the packaging material which comes in contact with the heat developable recording material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material for a light-sensitive material, and more particularly to a packaging material which prevents a change in heat development density with the passage of time and is easy to recycle.

[0002]

Various types of heat-developable recording materials have been developed. Thermal development recording materials having at least one image recording layer containing an organic silver salt on a support have begun to be used for X-ray diagnosis. When the heat-developable recording material is processed into a sheet film and stored as a package and then developed, the development density may change due to the influence of the packaging material. In order to suppress the change with time in this processed product form, a packaging material using a polypropylene or polyethylene sheet has been proposed, but these synthetic resin sheets have a high electrostatic property and thus adsorb dust in the air. However, there is an inconvenience that this adheres to the heat development recording material and causes a white spot failure. As another package, a packaging material in which aluminum foil is laminated has been proposed, but this packaging material cannot be recycled as waste paper, and even if incinerated, the aluminum foil does not completely burn and is deposited in the incinerator. Therefore, it is not preferable from the viewpoint of environmental protection. As another method for solving the problem, a method of sandwiching one sheet between the packaging material and the recording material can be considered.
This sheet may be a heat development recording material or another sheet. In the former case, the heat-developable recording material is packaged one more than the nominal number, and the last one is used as so-called "discarded sesame". However, in any case, it is necessary to process the sheet that becomes "discarded sesame" so that it can be automatically distinguished from other recording materials used for exposure and heat development, which complicates the production facility for recording materials. The problem arises. Furthermore, Japanese Patent Laid-Open No. 2000-235241 proposes a packaging material using laminated paper, and these laminated papers also have the same characteristics as synthetic resin sheets.
Since it is easily charged with electricity, dust in the air is adsorbed and adheres to the thermal development recording material to cause a white spot failure. It is possible to reduce the bending force (torque) by half-cutting laminated paper, but since the resin used for laminating has elasticity, the bent angular position is not retained and it gradually changes over time. There is also a problem that it is not suitable for automatic assembly because it is restored to. In addition, laminated paper is generally regarded as a contraindicated material for waste paper, and has poor recyclability. In order to recycle the laminated paper, it is necessary to separate and collect only the laminated paper first, and then to dissolve the laminated paper by using a dedicated processing facility in order to separate the pulp and the resin used for the lamination. Further, since the laminating process is performed on the roll-shaped base paper, the processing equipment becomes large and the cost becomes high.

[0003]

The problem to be solved by the present invention is to provide a heat-developable recording material having an excellent barrier property which does not cause a change in concentration even when the processed heat-developable recording material is stored as a package. It is to provide packaging material for. Another problem to be solved by the present invention is processing suitability, equipment suitability,
It is an object of the present invention to provide a packaging material for a heat-developable recording material (hereinafter, also referred to as “reliable ball”) that satisfies environmental suitability and low price.

[0004]

The above problems of the present invention are as follows.
It was achieved by the following means. (1) A packaging material for a thermal development recording material, which is packaged by folding a packaging material in a state where at least a part of the thermal development recording material is in direct contact, wherein the packaging material is paper at least partially A packaging material for a heat-development recording material, characterized in that a protective film made of an ultraviolet curable resin is formed on a surface of the packaging material that comes into contact with the heat-development recording material, (2) In a folding line of the packaging material The packaging material for the heat-developable recording material according to (1), wherein the protective film is not formed on at least one fold line portion.
(3) The packaging material for heat-developable recording material according to (1) or (2), wherein the protective film is formed on both sides of the packaging material, and (4) the protective film is formed by a printing method. The packaging material for a heat-developable recording material according to any one of (1) to (3).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-developable recording material according to the present invention,
Specifically, a heat-developable photographic film or the like used for medical X-ray or the like is a light-sensitive material having at least one image recording layer containing an organic silver salt on a support. This heat-developable recording material contains a catalytically active amount of a photocatalyst (silver halide, etc.), a reducing agent, a reducible silver salt (organic silver salt, etc.) and, if necessary, a toning agent for controlling the color tone of developed silver, in a binder matrix. It has a photosensitive layer dispersed therein. The photothermographic material is
After imagewise exposure, it is heated to a high temperature (for example, 80 ° C. or higher) to form a black silver image by redox reaction between silver halide or developable silver salt and a reducing agent. The redox reaction is promoted by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposed area.

The heat-developable recording material is cut into sheets of a predetermined size, for example, half-cut, B4, A4 size, a plurality of sheets are stacked and packaged with the packaging material of the present invention.

The packaging material of the present invention is in direct contact with at least a portion of the photosensitive material. This packaging material preferably uses at least a part of paper, and particularly preferably uses a paper board (base board) as a substrate, and its basis weight is preferably 250 to 400 g / m ² , and 270 to 270.
350 g / m ² is particularly preferred. As the pulp to be used for the paper board, BKP is preferable, and examples thereof include pine pulp, birch pulp and mixed pulp of birch and pine. Among them, wood pulp which is neutrally dissolved and bleached by the ECF method is preferable. Preferably used. It is preferable to suppress the generation of paper dust and fluff in the above paper board by using an ordinary sizing agent. Alkali ketene dimer (AKD) is preferably used as the sizing agent.

The ultraviolet curable resin of the present invention means a resin which is cured by active energy rays such as ultraviolet rays and electron beams. Such an ultraviolet curable resin has 2 in 1 molecule.
It contains the above-mentioned addition-polymerizable unsaturated compound having an acryloyl group or a methacryloyl group as a main component. Usually, the ultraviolet curable resin is used in combination with a small amount of a photopolymerization initiator. The polymerization initiator is preferably a radically polymerizable initiator and / or a cationically polymerizable initiator. To form a protective film on the packaging material of the present invention, an ultraviolet curable resin,
If necessary, a non-reactive resin, a UV-curable ink mixed with a surfactant, etc. is prepared, and the UV-curable ink is printed on the packaging material of the present invention by a suitable printing method,
Next, the ink is cured by irradiating with active energy rays such as ultraviolet rays to form a protective film. The UV curable ink used in the present invention is disclosed in JP-A-54-
8007, 56-93776, 56-1167.
63, JP-A-3-252472 and JP-A-8-17.
It can be prepared by appropriately mixing the polyfunctional monomer described in No. 3898, a photopolymerization initiator, and a non-reactive solid resin. In addition to the above-mentioned polyfunctional monomer, a prepolymer, an inorganic pigment, a polymerization inhibitor, and a wax may be used in combination with the above ultraviolet curable ink, if necessary.

The packaging material according to the present invention has O
It is preferable to form a protective film by printing a P (Over Print) varnish and curing it. In the present invention, OP varnish that is cured by active energy rays such as ultraviolet rays (UV) and electron rays is preferably used.
The UV-curable OP varnish refers to a varnish that is rapidly cured by irradiation with ultraviolet rays. The UV-curable OP varnish preferably contains a polyfunctional ethylenically unsaturated bond as a monomer that is cured by UV irradiation. Examples of the polyfunctional ethylenically unsaturated compound include esters of polyhydric alcohol and acrylic acid or methacrylic acid.
Examples of polyhydric alcohols are ethylene glycol, 1,2
-Dihydric alcohols such as propylene glycol and 1,3-butylene glycol, glycerin, trimethylolethane, trihydric alcohols such as trimethylolpropane, tetrahydric alcohols such as pentaerythritol, pentahydric alcohols such as pentit, and dipentaerythritol. And hexahydric alcohols such as sorbit. Trimethylolpropane triacrylate is preferably used as the monomer. The molecular weight of the monomer is preferably from 400 to 500, and the smaller the molecular weight, the better the folding suitability in the packaging material for a photosensitive material of the present invention. As commercially available products, Dicure Inline Offset OP Varnish (manufactured by Dainippon Ink Industry Co., Ltd.), Dicure RX OP Varnish T-6 (manufactured by Dainippon Ink Industry Co., Ltd.)
Etc.

In addition to the above monomers, usually UV curable O
The P varnish contains additives having various functions such as an inorganic pigment, a photopolymerization initiator, a polymerization inhibitor, a surfactant and a wax according to its purpose.

The UV curable varnish does not need to be sprinkled with powder such as cornstarch for preventing ink transfer.
It is particularly suitable as a packaging material for a photothermographic film which is averse to WS failure. In addition, since a typical OP varnish is transparent, it is possible to omit the deinking step when recycled as waste paper. When the OP varnish is lightly colored, it becomes easy to visually recognize the varnished portion during punching. Furthermore, black ink and OP
The varnish can be printed separately in one pass, and can be applied to a register mark for punching positioning, a code print for identifying a product type or a lot, and the like.

Examples of the method for forming the protective film include offset printing using a normal PS plate, a rubber plate, a resin plate or the like on a paper board which is a base material. The coating amount of OP varnish is preferably 1 to 5 g / m ² , and particularly preferably 1.5 to
It is 2.5 g / m ² . OP after applying and curing OP varnish
The friction coefficient of the varnished surface is μ =
0.25 or less is preferable, and μ = 0.19 or less is particularly preferable. In order to cure the OP varnish of the present invention, all the UV lamps of a general UV printer may be turned on and used.

The protective film of OP varnish may be formed only on the side (inner side) where the paper board comes into contact with the photosensitive material, but it is preferable to form it on both sides of the paper board. In the present invention, the OP varnish removal means that at least one side of the folding part of the packaging material for packaging the photosensitive material has a width of 0.
It means to provide a portion where the protective film of OP varnish is not formed over 5 to 2.0 mm. Whether OP varnish removal of the packaging material is sufficient on only one side of the packaging material, or whether both sides are required depends on the processing method of the bent line portion. When performing a half-cut bending process on the outside of the bending line,
It is sufficient to remove the varnish on the inside only. On the other hand, when the bending line portion is subjected to the scoring, it is preferable to provide OP varnished portions inside and outside the packaging material in the vicinity of the bending line portion in order to obtain good bending suitability of the packaging material. . Also, the varnished part is 1m from the edge of the film.
Since it is m or less, there is no concern that the barrier property of the entire protective film may be deteriorated. This OP varnish removal may be carried out at all the folding lines in the packaging material, but may be carried out only at locations where folding suitability is particularly poor. In addition, this OP varnish removal is also applied when the product type, lot identification code, expiration date, etc. of food products are printed individually after the packaging material is manufactured, or when a column for entering a name in a notebook is provided. it can. Specifically, the OP varnish may be removed in advance from the portion where the above information is to be printed by a known method such as an ink jet printer or a hot stamp, or the portion where characters are to be written using a water-based pen or pencil. In such a case, the varnished portion is generally the top surface 4 on the outside of the contact ball,
It can be provided on the bottom surface 2, the connecting portion 3, the flaps 6a, 6b, and the like.

The method of processing the packaging material of the present invention will be described in detail.
Alternatively, rotary punching is preferable. It is preferable to remove the paper dust by removing static electricity, vacuum cleaner, blowing clean air, brush removal, and the like. A known method can be used for the alignment of the print pattern and the punching pattern. After punching the packaging material of the present invention with a metal die, it is particularly preferable to prevent the generation of new paper dust by applying lacquer or the like on the punched cross section.

Further, in order to facilitate the packaging of a plurality of sheet-shaped light-sensitive materials laminated with the packaging material of the present invention, and to easily load and fit them in equipment, it is preferable to process the bent line portion. This can be carried out by appropriately combining outer half-cut processing, ruled line processing such as room temperature pressing and heating pressing, and perforation processing. In the present invention, the outer half cut is preferable. This processing may be performed simultaneously with the flat punching or separately.

A preferred embodiment of a package using the packaging material for heat-developable recording material of the present invention will be explained with a conceptual diagram.
As shown in FIG. 1 (a), a photothermographic recording material 10 is cut into a predetermined size and a predetermined number of layers are laminated to form a film laminated body 11
It is said that As shown in FIG. 1 (b), the film laminated body 11 is wrapped with a backing ball 1 according to the present invention. UV curable OP varnish 17 is applied to both surfaces of the contact ball 1. Further, as shown in FIG. 1 (c), the film laminated body 11 wrapped with the contact ball 1 has a light-shielding and moisture-proof inner bag 1
It is sealed at 2. As shown in FIG. 2, the backing ball 1 has a bottom surface 2, a connecting portion 3, and a top surface 4 which are integrally formed and can be freely bent from a half cut 5. The backing ball 1 has a shape that protects the bottom surface, top surface and two peripheral surfaces of the film laminated body 11 and is opened so that the thermal development recording materials 10 can be taken out one by one from the top surface. The bottom surface 2 of the contact ball 1 is approximately equal in size to protect the entire surface of the film laminated body 11, and the top surface 4 has a notch so as not to interfere with the film supply suction pad of the thermal processor. .

When the heat-developable recording material 10 is used, as shown in FIG. 3, first, the heat-development machine 1 together with the inner bag 12 in a bright room.
One end of the inner bag 12 is cut out while being loaded in the cassette 14 of No. 3. Next, the cassette 14 is housed in the thermal developing machine 13 to be in a light-shielding state, and then the inner bag 12 is pulled out of the machine, whereby the loading is completed. It is preferable to provide flaps 6a and 6b from the bottom surface 2 and the top surface 4 of the contact ball 1 to each other so that the film laminate 11 is integrally held and does not come apart when the inner bag 12 is pulled out. It is also preferable to provide a notch in the bottom flap 6a so that both flaps fit together.
In addition, since the bending points of the bottom surface 2 and the flap 6a and the top surface 4 and the flap 6b are particularly inferior in bending, it is preferable to provide the OP varnish removing portion 16 on the bending line.

Further, on the bottom surface 2 of the contact ball 1, means for leaking vacuum suction such as holes, cutouts and irregularities is provided at a position where the suction pad of the thermal developing machine 13 acts, and the heat remaining in the thermal developing machine 13 is provided. It is preferable that the presence or absence of the development recording material 10 can be detected. Long U-shaped notches 7 are particularly preferred.

When packaging the product in the moisture-proof inner bag 12, it is preferable to adjust the humidity in the bag before sealing.

[0020]

EXAMPLES The present invention will be specifically described below with reference to examples. The heat-developable recording material was cut into a B4 size, and as shown in FIG. 1, 150 sheets of the B4 size heat-developable recording material were piled up, and the image recording layer surface side was subjected to Table 1 at 25 ° C. and 60% RH (relative humidity). A cover ball 1 made of the following material as shown in Fig. 1 is wrapped so as to be in direct contact (the lower surface of the heat-developable recording material 10 in Fig. 1 is the image recording layer side), and the outer side thereof is covered with polypropylene to protect it from light and moisture. Packaged.

Contact ball: Paper pulp paper board bleached by ECF method using 425 μm thick BKP: Corona treatment was applied to the paper pulp paper board using 425 μm thick BKP, and PP (20 μm equivalent amount) was applied to both sides. Melt-laminated laminated paper: Using 425 μm thick BKP, corona treatment is applied to the paper pulp paper board bleached by the ECF method, and HDP is applied to the outer surface.
E (20 μm equivalent amount), LDPE (20 μm equivalent amount) melt-laminated on the inner surface: A 425 μm-thick BKP laminated UV-curable OP varnish on the outer surface of the paper pulp paper board bleached by the ECF method ( Dicure in-line offset OP varnish, 2 μm equivalent)
UV curable OP varnish (die cure in-line offset OP varnish, 2 μm equivalent amount) was applied to the inner surface by PS plate offset printing in a state where the bent line portion was varnished, and a protective film was formed by irradiating ultraviolet rays. Paper board.

<Amount of Change in Optical Density> Then, the film was stored in the above-mentioned form at 40 ° C. for 10 days. To the heat-developable heat-treated material after storage, two semiconductor lasers of 660 nm emission 35 mW were combined (1 / e ² diameter 100 μm), and gradation exposure was performed using a single mode laser beam. After that, in FIG. 21 of Japanese Patent Application Laid-Open No. 11-133,572, a plate heater type heat developing apparatus 10 whose outline is shown in FIG.
Thermal development was performed at 20 ° C. for 20 seconds, and the amount of change over time in the optical density of the portion exposed at 40 μJ / cm ² was measured. However,
A metal mesh and activated carbon filter was used to eliminate the odor. The results are shown in Table 1. This amount of change is preferably 10% or less. <Evaluation of bendability> Each packaging material was flat-punched with a Thomson blade type to prepare a contact ball. The bending line has a thickness of 0.7 mm and the blade height is 0.20 mm higher than the punching blade.
It was created by simultaneous punching using a low half-cut blade. Next, fold it in two along the folding line of the contact ball, press it with a force of 1 kN for 3 seconds, and force it to 90 °.
After returning to, it was opened naturally. The angle change after 1 hour was measured based on this 90 ° state, and 10 ° or less was marked with ◎, 1
5 ° or less was evaluated as ◯, 20 ° or less was evaluated as Δ, and deformation exceeding 20 ° was evaluated as x. <Number of WS occurrences> In the same manner as above, the heat-developable recording material is wrapped with a backing ball made of each packaging material, and then the inner bag 1
2. Packaged in individual packaging boxes (not shown) and transport boxes (not shown). This transport box was vibrated in the three directions of XYZ according to JIS Z0232, Method A-1, and then the heat-developable recording material was thermally developed. Three samples were prepared for each packaging material. Five outer sides of each of the recording materials were pulled out, and WS was counted. WS with a long side of 1 mm or less is small, 1
The WS exceeding 30 mm was set to be large, and the WS in 30 sheets was totaled. <Friction Coefficient with Cassette> The cassette 14 was removed from the heat developing machine 13 shown in FIG. 3, and a backing ball made of each packaging material and a predetermined number of heat developing recording materials were put therein. These were gradually tilted, and the friction coefficient μ was obtained from the tilt angle θ when the contact ball containing the recording material slipped out inside the cassette according to the following formula. When the friction coefficient μ = tan θ μ is 0.19 or less, ⊚, 0.22 or less is ◯, and 0.25 or less is Δ. <Recycled paper recycling> When recycling each packaging material,
Items that can be recycled without a deinking process are marked with ⊚, those that can be recycled with deinking are marked with ◯, and those that can be recycled with a dedicated facility for removing fine particles such as PE resin are marked with Δ.

[0023]

[Table 1]

The effects of the present invention are clear from Table 1.

[0025]

The packaging material for a photosensitive material of the present invention does not cause a change in development density even if the cut and laminated photosensitive material is stored as a package. The packaging material of the present invention can maintain a substantially right-angled shape regardless of whether it is folded manually or mechanically. In addition, it is possible to prevent the generation of WS, and since it has good slipperiness, it can be set at the correct position in the tray in a printer or the like, and can be easily recycled without using a dedicated processing facility. It is possible. Furthermore, the OP varnish cures and dries in a short time,
It also has the advantage of being highly scratch resistant.

[Brief description of drawings]

FIG. 1 is a schematic conceptual view of one embodiment of the present invention in which the packaging material for heat-developable recording material of the present invention is used as a contact ball. The heat-developable recording material is formed into a cut sheet laminate, which is wrapped with a contact ball and further wrapped with a moisture-proof inner bag.

FIG. 2 is a perspective view showing an embodiment of a backing ball formed from the packaging material of the present invention. The half cut 5 is inserted by processing from the back surface.

FIG. 3 is a schematic perspective view showing a state in which an inner bag for accommodating a heat-developable recording material laminate having the packaging material of the present invention as a contact ball is loaded into a cassette of a heat developing machine.

[Explanation of symbols]

1 hit ball 2 bottom 3 connection 4 Top 5 Half cut (folded line) 6a, 6b flap 7 notches 10 Thermal development recording material 11 Thermal development recording material (film) laminate 12 interior bags 13 Thermal processor 14 cassettes 15 heat seal 16 OP varnish removal part 17 UV curable OP varnish

[Procedure amendment]

[Submission date] July 6, 2001 (2001.7.6)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

The protective film of OP varnish may be formed only on the side (inner side) where the paper board comes into contact with the photosensitive material, but it is preferable to form it on both sides of the paper board. In the present invention, the OP varnish removal means that at least one side of the folding part of the packaging material for packaging the photosensitive material has a width of 0.
It means to provide a portion where the protective film of OP varnish is not formed over 5 to 2.0 mm. Whether OP varnish removal of the packaging material is sufficient on only one side of the packaging material, or whether both sides are required depends on the processing method of the bent line portion. When performing a half-cut bending process on the outside of the bending line,
It is sufficient to remove the varnish on the inside only. On the other hand, when the bending line portion is subjected to the scoring, it is preferable to provide OP varnished portions inside and outside the packaging material in the vicinity of the bending line portion in order to obtain good bending suitability of the packaging material. . Also, the varnished part is 1m from the edge of the film.
Since it is m or less, there is no concern that the barrier property of the entire protective film may be deteriorated. This OP varnish removal may be carried out at all the folding lines in the packaging material, but may be carried out only at locations where folding suitability is particularly poor. In addition, this OP varnish removal is also applied when the product type, lot identification code, expiration date, etc. of food products are printed individually after the packaging material is manufactured, or when a column for entering a name in a notebook is provided. it can. Specifically, an OP varnish may be removed in advance from a portion where the above information is desired to be printed by a known method such as an ink jet printer , a hot stamp , a laser marking machine , or a portion where a character is to be written using a water-based pen or pencil. .
In such a case, generally, the varnish removing portion can be provided on the top surface 4, the bottom surface 2, the connecting portion 3, the flaps 6a, 6b, etc. on the outside of the contact ball.

Claims (4)

[Claims] 1. A packaging material for a thermal development recording material, which is packaged by bending a packaging material in a state that at least a part of the thermal development recording material is in direct contact, wherein the packaging material is paper at least partially. A packaging material for a heat-development recording material, wherein a protective film made of an ultraviolet curable resin is formed on a surface of the packaging material that comes into contact with the heat-development recording material. 2. The packaging material for a heat-developable recording material according to claim 1, wherein the protective film is not formed on at least one folding line portion of the folding line of the packaging material. 3. The packaging material for a heat development recording material according to claim 1, wherein the protective film is formed on both sides of the packaging material. 4. The packaging material for a heat-developable recording material according to claim 1, wherein the protective film is formed by a printing method.