JP2000314942A - Light shielding knitted fabric and photographic film container using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a knitted fabric which lessens film drawing out resistance of films, does not give rise to a thermobleeding phenomenon and can be laminated with good workability by constituting a warp knitted fabric of cation dyeable polyester multifilaments and specifying the elongation rate in the specific weighting in the warp direction of the warp knitted fabric to a specific value or below. SOLUTION: The warp knitted fabric consists of the cation dyeable polyester multifilaments and the elongation rate at the weighting of 0.5 kg/2.5 cm in the warp direction of the warp knitted fabric is <=3%. The elongation rate at the weighting of 0.5 kg/2.5 cm is obtained by elongating the knitted fabric at a constant speed under conditions of a test width 2.5 cm, clamping distance 10 cm and tension rate 10 cm/ minute in a constant speed elongation testing machine of JIS L L1018, reading the elongation at the time of weighting of 2.5 cm and calculating the elongation rate. The ground part of the knitted fabric is formed of a weave small in the swing of a reed and is preferably formed by a combination of a chain stitch A and a Denbigh stitch B or a combination of warp insertion and the Denbigh stitch as a method for confining the elongation rate at the weighing of 0.5 kg/2.5 cm below 3%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding knitted fabric used for light-shielding of a photosensitive film or the like, and a photographic film container using the light-shielding knitted fabric.

[0002]

2. Description of the Related Art Conventionally, a photographic film container includes a cassette for a sheet film and a patrone for a roll film. In order to prevent the internal photographic film from being exposed to light, a light-shielding member called a telemping cloth is provided. This telemping cloth is generally colored black or the like in order to have the above-described light-shielding function, but in addition to this light-shielding function, it does not damage the photographic film when the photographic film is pulled out or rewound. It is necessary to have flexibility.

Japanese Utility Model Publication No. 46-20439 discloses a light-shielding terrain cloth made by weaving a coreless pile yarn obtained by crimping a flexible original yarn such as viscose or acetate on a base cloth, and a photographic film drawer. Has been proposed. However, in the case of a so-called velvet weave or velvet weave, which is a so-called woven structure made of pile yarn woven into a base fabric, it is easy to cause fraying and hair loss in the process of making the terram fabric, and the production is difficult. The process is complicated and the production cost is high.In addition, when incorporated into a film container, when the photographic film is pulled out or rewound, friction with the photographic film causes fraying and hair loss, and this debris causes In some cases, it adhered to the photosensitive film of the film and hindered photography. On the other hand, there is a problem that the knitted fabric is easily stretched, so that the tape width cannot be kept uniform when cut or wound into a tape shape, or it cannot be kept uniform light-shielding property when stretched when applied to a film container.

In Japanese Patent Application Laid-Open No. Hei 8-15825, a knitted fabric is used as a light-shielding cloth for a film. This method employs a so-called weft insertion method, and the elongation in the weft direction can be suppressed low. In this case, the weft direction must be used as the direction in which the force is applied, and when used as a product, there is a problem that it must be rotated by 90 °, so that the production efficiency is poor and the production cost is high.

As described above, polyester fibers have been used for the purpose of improving the material cost, the light-shielding property, the film drawing property, etc. for the fiber material used for the film light-shielding cloth. 7-50742
As described in the publication, in the coloring system of the polyester fiber disperse dye, the dyeing mechanism relies only on a physical bond mainly comprising a so-called Van der Waals bond. Therefore, there is a variety of problems such as a phenomenon in which the bond is easily released by heat energy or the like and the dye molecules float on the fiber surface, that is, a so-called thermobleeding phenomenon occurs.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such a situation, and has a low resistance to pulling out a film, does not cause a thermobleeding phenomenon, and has a knitted fabric when pasted on a photographic film container. An object of the present invention is to provide a light-shielding knitted fabric that can be stuck with good workability without stretching, and to provide a photographic film container that has low resistance to pulling out a film and does not contaminate the film due to a thermobleeding phenomenon. Things.

[0007]

According to the present invention, there is provided a warp knitted fabric having a pile attached to a film drawer of a photographic film container and used as a light shielding material. The fabric is made of a cationic dyeable polyester multifilament, and the elongation of the warp knitted fabric in the warp direction under a load of 0.5 kg / 2.5 cm is 3% or less, wherein the light-shielding knitted fabric and the pile are made of satin. The above-described light-shielding knitted fabric formed by raising the tissue, and the above-described light-shielding knitting wherein the ground portion of the warp knitted fabric is formed by a combination of a chain stitch and a denbi structure, or a combination of a warp insertion and a denbi structure. The present invention provides a photographic film container characterized in that a ground and the above-described light-shielding knitted fabric are provided at a portion where a film is drawn.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The light shielding knitted fabric of the present invention is a warp knitted fabric having a pile. A warp knitted fabric having a pile is cut into a cut pile by connecting two rows of needle beds of a knitted fabric knitted by a double tricot knitting machine or a double Russell knitting machine having two rows of needle beds. Cut pile by knitting with a long knitting structure such as a satin structure using a tricot knitting machine or a Russell knitting machine with a single-row needle bed, and raising the yarns of the long floating structure. A pile warp knitted fabric can be obtained. In the case of knitting with a satin structure using a tricot knitting machine or a Russell knitting machine having a single-row needle bed, as shown in the knitting structure diagram of FIG. It is preferable to form a pile warp knitted fabric by knitting with a satin structure and raising the traverse portion to form a cut pile.

The light-shielding knitted fabric of the present invention is composed of a cationic dyeable polyester multifilament. The cationic dyeable polyester multifilaments referred to herein are multifilaments made of a copolymer polyester that can be dyed with a cationic dye. Examples of the copolymer polyester that can be dyed with a cationic dye include 5-sulfoisophthalate in ethylene terephthalate units. A polyester obtained by copolymerizing 1.5 to 2.5 mol% of an acid is exemplified. The reason why the warp knitted fabric is composed of the cationic dyeable multifilament is, for example, a film container in which a knitted fabric composed of a polyester multifilament consisting of only polyethylene terephthalate is dyed with a disperse dye and used as a light shielding material. In the case of, when the camera is placed in a camera or stored in a film case, it is exposed to high temperatures such as in the interior of a car placed under the hot summer sun and left alone, it melts into the gelatin in the photosensitive emulsion layer of the film. The moisture that has been released evaporates and aggregates, causing the problem that the direct dye released on the fiber surface of the light-shielding member transfers to the photographic film and contaminates through the aggregated moisture, but with the cationic dyeable multifilament dyed with a cationic dye. In the case of knitted fabrics, the above-mentioned problems occur because the fibers and dyes are ionically bonded during dyeing. No et al.

The light-shielding knitted fabric of the present invention has a warp direction of 0.5 kg /
The elongation ratio under a load of 2.5 cm is 3% or less. 0.5kg /
The elongation rate under a 2.5 cm load is determined by elongating at a constant speed with a test width of 2.5 cm, a grip interval of 10 cm, and a pulling speed of 10 cm / min using a JIS L1018 constant speed elongation tester. Is read and calculated. 0.5kg / 2.5cm in the longitudinal direction
If the elongation ratio under load exceeds 3%, the tape width cannot be kept uniform when finishing into a tape shape, or the knitted fabric stretches when pasted on a film container, and the density of the knitted fabric varies. Problems, such as being unable to maintain uniform light shielding properties.

As a method of reducing the elongation rate of the knitted fabric under a load of 0.5 kg / 2.5 cm in the warp direction to 3% or less, the ground portion of the knitted fabric is formed of a reed to suppress the elongation in the warp direction. As a tissue having a small swing, a chain stitch A and a denbi tissue B are used as shown in FIG.
Or the combination of warp insertion D and Denbi structure B as shown in FIG. When knitting is performed by a denbi structure, a feeling of thickness is obtained, which contributes to suppression of light transmission and regulation of elongation.

The light-shielding knitted fabric of the present invention is dyed with a cationic dye, and is finished in a usual processing step of a cationic dyeable polyester. The light-shielding knitted fabric of the present invention is used for a light-shielding member provided at a draw-out opening of various film containers, a lining for light-shielding of equipment for photosensitive materials, and the like. The film container of the present invention stores various films light-tightly,
A film container having a structure in which a film is drawn out from a drawer port, wherein the light-shielding knitted fabric is provided in a drawer port of the film, and in particular, various photographic photosensitive materials in a sheet form and a roll form (color photographic paper, computer-printed film, etc.) And photographic paper, JIS135 type photographic film, thermal paper, photosensitive resin film microfilm, etc.).

As a method of providing the above-mentioned light-shielding knitted fabric on the film container, after blocking the light-shielding knitted fabric, applying a hot-melt type adhesive, cutting it into a predetermined size, and then applying the hot-melt type adhesive to a predetermined sticking portion of the film container. There is a method of sticking by placing, melting and reactivating by heat, ultrasonic waves or high frequency. In addition, there are a method using a sealing adhesive which also serves as a sealing agent and an adhesive, and a method using a double-sided adhesive tape.

[0014]

The light-shielding knitted fabric of the present invention is composed of polyester cationic dyeable multifilaments and is a pile knitted fabric with restricted extensibility, so that it can be easily attached to a film container and can be used in a high heat environment. In addition, the film can be drawn out and rewound without causing the thermo-bridging phenomenon, maintaining a light-shielding property, and having a small drawing-out resistance without damaging the film.

[0015]

Next, the present invention will be described in detail with reference to examples. The evaluation in the examples was performed by the following method. 1) Elongation rate under a load of 0.5 kg / 2.5 cm A test width of 2.5 was measured using a JIS L1018 constant speed elongation type tester.
Elongate at a constant speed under the conditions of cm, a grip interval of 10 cm, and a tensile speed of 10 cm / min, and read and calculate the elongation under a load of 2.5 cm. 2) Method for evaluating contamination of knitted fabric A sample was incorporated into a photographic patrone film outlet, a photographic film having an ASA sensitivity of 400 was loaded into the patrone, and the photographic film was accommodated in a film case.
After performing high-temperature exposure at 20 ° C. for 20 hours, the film was developed, and the state of contamination of the portion in contact with the sample was visually observed. ○: no contamination was observed, ×: contamination was observed. The evaluation was based on the following criteria. 3) Sticking property to container After applying a hot-melt type adhesive to the back surface of the sample, cut it into a tape, heat-bond it to the draw-out opening of the photographic film container, and visually inspect the sticking state. Good for sticking to container, ×: Evaluation was based on criteria of poor sticking to container.

Example 1 Using a 28 gauge tricot knitting machine, 75 denier / 36 filaments made of a copolymerized cationic dyeable polyester obtained by copolymerizing 1.5 mol% of 5-sulfoisophthalic acid were passed through each reed all-in. The knitted fabric knitted with the structure shown in FIG. 1 is treated with a cationic dye (Kayagryl manufactured by Nippon Kayaku Co., Ltd.).
Black R-ED) at 130 ° C. for 30 minutes, followed by brushing and shirring to raise the hair to obtain a light-shielding knitted fabric of the present invention having a high pile density. A urethane-based adhesive was applied to the back surface of the obtained knitted fabric and incorporated into a photographic cartridge film outlet to obtain a film container of the present invention.

Comparative Example 1 The cationic dyeable polyester used in Example 1 was changed to ordinary polyester 75 denier / 36 filament, and at the time of dyeing, a disperse dye (Sumitomo Chemical Co., Ltd., Sumikaron Black S = BL) was used at 130 ° C. A light-shielding knitted fabric of a comparative example was obtained in the same manner as in Example 1 except that dyeing was performed in 30 minutes.

Comparative Example 2 A knitting was carried out in the same manner as in Example 1 except that the structure employed in Example 1 was changed to a structure without chain knitting and warp insertion shown in FIG. Table 1 shows the evaluation results of Example 1 and Comparative Examples 1 and 2 together.

[0019]

[Table 1]

As is clear from Table 1, in Example 1, the evaluation of contamination, the elongation rate, and the sticking property to the container were all good. In Comparative Example 1, the elongation rate and the sticking property to the container were good, but the contamination evaluation was poor. In Comparative Example 2, the contamination evaluation was good, but the elongation of the knitted fabric was large, and the adhesion to the container was poor.

[0021]

The light-shielding warp knitted fabric of the present invention has good workability for sticking to a film drawer of a photographic patrone film container, and a photographic patrone film container using the light-shielding warp knitted fabric of the present invention in a film drawer. In this case, the film withdrawal resistance is low, and the film is not contaminated by the thermo-bleeding phenomenon, so that a beautiful photograph can be obtained.

[Brief description of the drawings]

FIG. 1 is a knitting structure diagram of an example of a knitted fabric of the present invention.

FIG. 2 is a knitting structure diagram of an example of the knitted fabric of the present invention.

FIG. 3 is a knitting structure diagram of a knitted fabric of a comparative example of the present invention.

Claims (4)

[Claims] 1. A warp knitted fabric having a pile attached to a film drawer portion of a photographic film container and used as a light-shielding material, wherein the warp knitted fabric is made of a cationic dyeable polyester multifilament. 0.5 in direction
A light-shielding knitted fabric having an elongation of 3% or less under a load of kg / 2.5 cm. 2. The light-shielding knitted fabric according to claim 1, wherein the pile is formed by raising a satin texture. 3. The light-shielding knitted fabric according to claim 1, wherein the ground portion of the warp knitted fabric is formed by a combination of a chain stitch and a denbi structure, or a combination of a warp insertion and a denvi structure. 4. A photographic film container, wherein the light-shielding knitted fabric according to claim 1, 2 or 3 is provided in a drawing portion of the film.