JPS6240696B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a magazine or cartridge for photographic film that has excellent light shielding properties and drawability, and that prevents troubles such as deterioration of image clarity due to static electricity during film filling and photography. Photographic films, which are currently commercially available and consumed in large quantities, have improved productivity due to the emergence of high-sensitivity films and improvements in mechanical strength and dimensional stability due to polyester film bases, as well as high-speed photography and It can be said that it has become possible to easily satisfy the various performances required for instantaneous photography. However, as productivity increases and photographing speeds increase, troubles caused by static electricity are attracting attention as a new major problem. For example, when taking high-speed photographs, the shooting speed is usually at least 60 frames per second, and in some cases, 600 frames or more, and the film movement speed is at least 30 cm/sec, and in some cases 2 frames per second.
It is said that the film can reach high speeds of ~3 m/sec or more, but when the film is pulled out from its magazine (cartridge) or cartridge at such high speed, the film is charged with a small amount of static electricity due to mechanical friction. As a result, the sharpness of the photographic image obtained may decrease due to this static electricity charging.
In some cases, the film may be partially exposed to light due to static electricity accumulation and discharge, making it practically unusable. The present inventors have conducted intensive research into the problems of the above-mentioned photographic film magazines or cartridges, and have discovered the present invention. That is, the present invention does not impair the functions of the photographic film magazine or cassette, such as its light-shielding properties or the ability to pull it out, and prevents static electricity damage caused by the movement of the film, especially when taking photographs. It provides a magazine (cartridge) or patrone that has been released. The present invention provides a light-shielding cloth with an electrical resistivity of 10 ⁸ Ω・cm at least at the film take-out part of a photographic film magazine or cartridge (which becomes the film entrance part when unwinding the film after shooting and when filling the film in the production process). Below, preferably 10 ² to ^{10 6} Ω
The above object is achieved by providing a fabric having naps containing organic conductive fibers in which linear polymers containing -cm of inorganic conductive substances are dispersed in a fiber-forming polymer in the form of streaks. Here, the organic conductive fibers used in the present invention include fibers whose constituent components are substantially organic polymers,
For example, a polymer composition in which a conductive substance such as carbon black is uniformly dispersed in a known fiber-forming polymer such as polyacrylonitrile, polyamide, or polyester polymer is mixed and spun. This fiber is made by dispersing a polymer composition containing a substance in a linear arrangement in the fiber axis direction. What is important here is that the conductive fiber exhibits conductivity with an electrical resistance value of 10 ⁸ Ω·cm or less. That is, the fabric provided as a light-shielding cloth in the film take-out part of the magazine or cartridge has a function (light-shielding property) of preventing light from entering the inside of the magazine (cartridge) or the cartridge, and has a function of preventing light from entering the inside of the magazine (cartridge) or the cartridge, and has a function of preventing light from entering the inside of the magazine (cartridge) or the cartridge, and has a function to protect the film during taking out and rewinding of the film. The conductive fiber must have a resistance of 10 ^{8 Ω} to satisfy these required properties, such as the ability to prevent damage (drawing resistance) and the ability to withstand abrasion or heat generation at the film drawing portion (wear resistance and heat resistance). It is desirable that the fiber has a conductivity of less than cm and has substantially the same fiber performance as conventionally known non-conductive fibers for textile textiles, and inorganic conductive fibers such as metal fibers are not preferred. . Examples of such organic conductive fibers include mixed spun fibers or composite spun fibers made of at least two types of polymers, in which one of the polymer components constituting the fiber contains a conductive substance such as carbon black or metal. Examples include fibers made by uniformly mixing and dispersing. However, as mentioned above, considering the fiber properties required for light-shielding cloth for magazines (cartridges) and cartridges, it is easy to spin, knit, and weave to form raised fabrics, and it is particularly suitable for blended, knitted, and knitted fibers with non-conductive fibers. The above-mentioned mixed spun fibers or composite fibers are particularly useful in the present invention because they are free from deterioration of conductive fibers and staining of the film due to contact with the film. Among these, JP-A-52-
The mixed spun fiber obtained from an acrylonitrile polymer and a polyether polymer containing carbon black, as proposed in Publication No. 103525, has not only durable electrical conductivity but also excellent light shielding properties and textile properties. This provides the best performance for the present invention, as will be discussed later. Such conductive fibers have an electrical resistivity of 10 ⁸ Ω·cm or less, preferably 10 ² to ^{10 6} Ω·cm.
cm, and if the electrical resistivity exceeds 10 ⁸ Ω·cm, it will no longer have sufficient antistatic and static neutralizing effects as a light shielding cloth for magazines (cartridges) and cartridges. The fabric used as the light-shielding fabric for the magazine (cartridge) or patrone may be any fabric as long as it has enough nap to prevent light from entering, and is not particularly limited, but specific examples include velvet, suede, and electric fabric. Examples include fabrics made of flocked products, nonwoven fabrics, knitted fabrics, or raised fabrics with a nap density of at least 5,000 fibers/cm ² on at least one surface, and naps of at least 0.05 mm. Of course, these raised fabrics can be applied directly to the film entrance/exit of a magazine (cartridge) or cartridge, or they can be laminated with another base fabric, which usually has an adhesive layer on the back side. good. Furthermore, it may be provided not only at the film entrance/exit portion but also throughout the inside of the magazine (cartridge) or cartridge. In addition, in order to improve the properties of the raised fabric as a light-shielding cloth, especially the drawability, abrasion resistance, and mechanical strength of the film, known non-conductive fibers, such as various synthetic fibers such as polyester, polyamide, and polyacrylic, may be used. It may be mixed with rayon, cotton, etc., but in order for the raised fabric obtained in this case to fully exhibit the antistatic and static neutralizing properties of the film, it must be at least 0.05, depending on the electrical specific resistance of the conductive fiber.
It is advisable to mix it in an amount of 0.2 to 40% by weight. Of course, by changing the weaving structure of the fabric and knitting or weaving conductive fibers into one end of the raised fabric in the form of a panel, and by composing the part that comes into direct contact with the film with non-conductive fibers, we can prevent static electricity. It can provide static elimination performance or light blocking performance. When mixed with non-conductive fibers, the conductive fibers may be present on the front and back sides of the fabric, but preferably the tips of the conductive fibers are woven so that they are exposed on the surface of the fabric in order to prevent or remove static electricity from the film. It is better. In addition, the single fiber denier of the conductive fiber used in the present invention is set so as not to cause scratches on the film surface.
In addition, in order not to affect the light-shielding properties, the denier needs to be 20 denier or less, and preferably the denier is about the same as or lower than the single fiber denier of the non-conductive fiber to be mixed. The present invention will be explained in more detail below with reference to the drawings. FIG. 1 is a partially cut away cross-sectional view of a cartridge tube showing one embodiment of the present invention. In the figure, 1 is a cartridge tube, 3 is a film drawer section, and 2 is a raised fabric provided in the drawer section. Also, Figure 2 is
It is a cross-sectional view of the raised fabric provided in the film drawer part of the figure, in which 4 is the base fabric, 2 is the raised fabric, 2-A is a non-conductive fiber, and 2-B is a conductive fiber. As can be seen from FIGS. 1 and 2, in the cartridge of the present invention, the surface of the light-shielding fabric in the film drawer section is covered with raised naps made of conductive fibers and non-conductive fibers, so that the film is not pulled out. Not only if it is charged before passing through the drawer section, but also if it is charged by passing through the drawer section, the charge is immediately removed by contacting the conductive fibers that make up the nap of the light-shielding fabric provided in the drawer section. Therefore, problems caused by charging the film can be almost completely prevented. FIG. 3 is an enlarged cross-sectional view of another embodiment of the light-shielding cloth provided in the film drawer section of the cartridge or magazine of the present invention. The raised part, 2
-B indicates a raised portion containing conductive fibers. A light-shielding cloth as shown in the figure is provided so that the raised part 2-A of the light-shielding cloth is placed in the narrow film drawer part that comes into most contact with the film of the cartridge. Non-conductive fibers with excellent mechanical properties and heat resistance are used in the parts that come into contact with the pulled film the most, and are not only electrically conductive but also usually darkly colored. By providing conductive fibers outside the drawer portion, the film can be prevented from being charged and exposed to light. As detailed above, the photographic film cartridge or magazine according to the present invention can be manufactured without impairing the characteristics required of the cartridge or magazine.
Not only does it have the outstanding effect of eliminating the problems caused by static electricity on film, which have become a problem with high-speed shooting in recent years, but it is also effective in eliminating static electricity when storing film, allowing for faster film storage. Possibility and productivity are also significantly helpful in terms of productivity. The present invention will be specifically explained below using Examples. Example 1 Furnace Black #40 (Mitsubishi polyethylene adipate/polyethylene glycol (manufactured by Kasei Co., Ltd.)
75) DMSO solution B of a polymer obtained by graft copolymerizing block polyether polyester (70 parts) with AN (30 parts) having a composition of The electrical resistivity is increased by wet spinning.
A conductive fiber having a diameter of 2.2×10 ³ Ω·cm, a strength of 2.5 g/d, an elongation of 2.1%, and a single yarn fineness of 7 d was prepared. This conductive fiber was cut to a fiber length of 51 mm, mixed with nylon staples with a single yarn fineness of 3D and a fiber length of 51 mm, and spun at 20/2 to create cut pile fabrics with different blend ratios of vertical pile double weave. After setting up, I did some relaxing exercises. Pile length is 1.4mm,
The pile density was approximately 27,000 pieces/cm ² . The cut pile fabric was left in the atmosphere at 20℃ and 30%RH for more than 24 hours, and then attached to the rotating body of a rotary static tester manufactured by Koa Shokai Co., Ltd. so that the pile surface was rubbed against it, and heated at 20℃ and 30%RH. The electrostatic voltage when the film was rubbed against the photosensitive surface in the atmosphere was measured. The results are shown in Table 1. At this time, the cut pile fabric was attached to a rotating body so that the friction surface was 2.5 cm x 4 cm, and the film to be rubbed (Fujicolor F-, not photographed) was cut into 2 cm x 15 cm, and both ends were gripped. A tension of 500 g was applied, and the contact height (contact pressure) with the cut pile was 2 mm. Furthermore, the rotation speed of the rotating body of the rotary static tester is
400 rpm.The distance between the cut pile and the current collector tube during friction was 1.2 cm. The reduction in triboelectrification voltage of cut pile fabrics by mixing conductive fibers is remarkable, and even a small amount of blending of about 0.2% has almost sufficient antistatic properties. These prototype cut piles were pasted on a support, and the unphotographed film (Fujicolor F
-) with scissors (scissor spacing 2mm), 20℃, 30%
The discharge phenomenon was observed when the film was moved at a speed of 30 cm/sec in a dark room under RH conditions, and then the film was developed and the degree of exposure was examined. No discharge phenomenon was observed in the cut pile fabric mixed with conductive fibers.
There were no abnormalities after development.

[Table] Example 2 By the same method as in Example 1, a 100D-30F multifilament yarn having the same electrical properties as in Example 1 was produced. The strength of the filament yarn is
The elongation at 2.4 g/d was 20%. By intermittently inserting the conductive filament yarn into the vertical pile yarn of a vertical double pile fabric of 110D-30F nylon yarn, the mixing ratio of the conductive yarn can be reduced to the total weight of the pile fabric.
A cut pile fabric was designed to have a concentration of 0.5%, and after setting the gray fabric, it was subjected to relaxing scouring. The pile density of the pile fabric was about 26,000 pieces/cm ² . As a result of measuring the cut pile fabric in the same manner as in Example 1, the frictional charging voltage was 1.3 kV, no discharge phenomenon was observed between the films, and there was no abnormality in the film after development.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged cross-sectional view of a cassette tube for photographic film according to an embodiment of the present invention, and FIGS. 2 and 3 are perspective views of a light-shielding cloth used in the cassette. 1: Patrone tube, 3: Film drawer, 2
-A: Non-conductive fiber, 2-B: Conductive fiber, 2:
Raised fabric, 4: Base fabric.

Claims (1)

[Claims] 1 A linear polymer containing an inorganic conductive substance is dispersed in a fiber-forming polymer as a light-shielding cloth in at least the film drawer part of a photographic film magazine or cartridge, and its electrical resistivity is 10 ⁸
A photographic film magazine or patrone provided with a fabric having naps containing 0.05% by weight or more of conductive fibers having a diameter of Ω·cm or less.