JPS60208751A - Shade fabric structure for photosensitive film boxes - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light-shielding cloth structure for a film box that has excellent anti-exposure properties for photosensitive films and less scratches and dust adhesion to the film surface. The term "photosensitive film" here refers to various forms of use such as black and white negatives, color negatives, bodies, polaroids, dry plates, rolls, sheets, etc.In short, it is a general term for film-like materials coated with photosensitive components. It's called photosensitive film.

Photosensitive film is stored in a film box to prevent exposure to light and pulled out when in use, but it is important that the film be pulled out with appropriate tension without damaging it, and that it be set with uniform stress without loosening during photography.

For this reason, velpet materials such as rayon, acetate, and nylon have traditionally been used. However, perhaps because these fibers are hydrophilic, the napped side of velvet absorbs moisture due to changes in weather conditions during long-term storage, causing the napped side to deform and become flattened. In terms of maintenance, it could not be said to be perfect.

The present inventors have arrived at the present invention as a result of intensive research on the stability of the raised surface.

In the case of a roll-like film, a stable tension is particularly required for the resistance force to pull out the gap between the film and the light-shielding cloth. The slip resistance force that pulls between the slits of a roll-like film needs to be maintained at a level that holds the film without curling.1 The inventors investigated this stress on various roll films and found that the slip resistance force of the film is 5f.
/cIn or less, the loosening of the film was observed, especially in the inner layer of the roll, and when this was more than 50 seconds, the problem was that the pulling stress was too strong and it was difficult to operate. It has been found that in order to operate stably, the film slipping resistance should be 10 j'/crn or more and 3097 cm or less. In addition.

The film slip resistance force referred to herein is the average stress when the film is pulled out through an Instron tensile tester at a speed of 10 c1n/mln.

In order to maintain such slip-off resistance and prevent exposure to light between the slits, an appropriate light-shielding space is required at the fiber gathering portion of the napped portion. When storing and rewinding the film, even if it is rewound, it must be ensured that no light enters through the slit while the film is completely rolled up and stored undeveloped for one year. For this reason, the compression characteristics and stability of the napped portion of the velvet are extremely important.

That is, the compression characteristics of the raised portion of velvet are determined as follows. Assuming that the optimum value of film slip resistance is 2.
097cm, then the slit width (the distance between the metal surfaces when the napped side faces the film surface and the base fabric surface mainly composed of ground yarn is adhered to the metal) is t.
o. Note that 5 earthquakes were used for the slit contact length. Next, the film is removed and the slit width is gradually widened in parallel, and the slit width just before light leakage begins is defined as ts. The ts-to is important for the fiber gathering portion that is effective for preventing exposure.

here.

If we define the amount of light-shielding Yuto9 as Y=ta-to, then Y
The larger the value, the better the light-blocking effect will be to create a space.

The smaller the value of Y is /JX, the less light-shielding the space becomes. It was also found that there is a close relationship between the amount of light-shielding clearance Y and the amount of compression work Wc of the applied raised blanket. That is, the compression characteristics of the raised fabric after pressure heat treatment or contact pressure aging under conditions for adhesion to slits are measured. The compression properties were measured using the KES system developed by the Textile Measuring and Standardization Research Committee of the Japan Textile Machinery Society.
A6 or KESF3 type measured, 50
Compression work W c (f - cm/
cni) is to blame. Compression work Wc and light shielding space p
A good correspondence with the quantity Y is obtained as shown in FIG.

9. When We becomes less than 0.3t-1-, Y becomes less than 0.2 mm.9. The phenomenon of partial exposure to light during film operation was observed, and it was found that the light shielding performance was poor. On the other hand, Wc is 1.
If it exceeds 52.cnv'crtE, the slit gap becomes too wide, the box slit part becomes bulky, and the convenience of devices such as turtles and horses is hindered, and the preferable range of Wc is 0.
．． 3? -cm/cJ or more and 1.52·l- or less.

The present inventors investigated fiber materials that can stably function as light-shielding cloth for photosensitive film boxes, and found that polyester fibers, which are hydrophobic and have excellent elastic recovery properties, are preferred, and polyethylene terephthalate fibers and their various types are preferred. It has been found that modified type fibers, polybutylene terephthalate fibers, modified types thereof, mixed fibers thereof, and conjugate fibers of polyethylene terephthalate and polybutylene terephthalate are suitable.

Generally, when adhering a raised blanket to a box made of metal or resin molded product, thermal adhesion is a preferred method in terms of production efficiency. However, the raised portions are suppressed by the temperature and adhesive pressure at this time, resulting in a low, floppy texture that cannot be used as a good light-shielding cloth. Therefore, it is preferable to make the napped surfaces face each other so that the napped surfaces do not fall down, and to efficiently press the fabric in a short period of time so that the base fabric side is only heated. According to the present inventors, polybutylene terephthalate (PB
T) It is a fiber. In order to make the napped fibers into a coiled spring shape and increase their elasticity, it has been found that it is best to use dorsoventral conjugate fibers of PBT and polyethylene terephthalate polymer (PES) to which coil curls have been added. Furthermore, false twisted yarn is suitable for providing a very fine ring and making the raised part dense. Polyethylene terephthalate (PET) fibers have elastic recovery properties similar to PBT.
Although it is slightly inferior to iron fiber, it has a high melting point and a high glass transition temperature, so it has excellent napping stability over time.

Since polyester fibers are thermoplastic fibers, the thermal bonding temperature is extremely important. If the hot-melt binder has a melting point or softening point close to the melting point of the napped fibers, the napped portion will be severely deformed or sag, making it unsuitable for use.
must be low. For adhesion between the fiber material and the box, in particular, to achieve good adhesion to metal, polyamide yarn hot melt binders such as nylon 12° and nylon 10 modified polyamides, polyester hot melt binders such as 1,4 butane as a glycol component, etc. Using diol, 1 in addition to terephthalic acid as the acid component.
0 to 30 mol of copolymerized polyester such as sepatenic acid, isophthalic acid, adipic acid, etc., and 1 to the glycol component.
, 4 Bucundiol as well as nitriethylene glycol, ethylene glycol, neopentine glycol, etc. are used as copolymerized components, and conversely, the glycol component is mainly ethylene glycol, and the acid component is modified with various acid components other than terephthalic acid. , these types of degeneration.

If a combination of the two or a modified version of three or more components is used, it is possible to achieve highly durable adhesion and thermal adhesion that does not easily damage the raised surface. Although olefin hot melt binder can also be used for adhesion.

When adhering metal material boxes, there are times when the adhesive force is insufficient, but this problem did not occur with polyamide-based or polyester-based true melt binders.

Compressive work of the raised surface obtained by heat processing in this way 1iI
Lt has a performance of Wc of 0.3 t-cm/aA or more and is pasted on both sides of the slit with the raised surfaces facing each other, and the slipping resistance of the film is 102/6n~309
The cloth processed by adjusting the slit width to 7 cm exhibits suitable performance as a light-shielding cloth for photosensitive film boxes with a light-shielding property Y of about 0.2 or more.

In addition to light-shielding performance, precautions that should be taken with photosensitive films include prevention of dust adhesion. First of all, the fibers used in the raised blanket do not become fluffy. For this purpose, an extra edge of the fabric is inserted into the box to adhere the napping cloth, and the area where the napping surfaces do not come into contact with the film is minimized, and the edges of the fabric are made with at least one edge.

By forming areas where there is no nap of 5 wm or less, an area is created to prevent the fluff from coming off from the edge of the fabric.

It is possible to prevent fluff from adhering during bonding, during storage, or during use. For a structure with no napped, the napped surface may not be created from the time of weaving or knitting, or the p-fuzz may be covered with heat sealing or No. good.

On the other hand, on the back of the napping blanket, if the roots of the napping are unstable, the tweezers tend to fall out, and if the tweezers are fixed with a preventive adhesive or resin finishing agent, the prevention of tweezers will be further strengthened. Hair loss in the piloerection area disappears.

Furthermore, good effects can be obtained in hot melt adhesion to the holder. In addition, in some cases, fibers made of a hot melt binder polymer may be used in the base fabric portion of the raised blanket, or fibers may be mixed or knitted.

It can also be used to both fix the fluff and adhere to the box surface.

It is also possible to make a contribution in the adhesion direction. 5. As a measure to prevent dust adhesion, if there is a risk of dust adsorption due to static electricity generated when the film slides apart from fluff generation and shedding, an antistatic agent may be kneaded into the napped fibers or an antistatic agent may be attached to the napped fibers, or conductive This can also be prevented by weaving the fibers into the fabric at intervals of 5 to 25 inches.

Next, the present invention will be explained with reference to examples.

Example 1 70 denier 7:) - rough 5 tenier rayon,
Velvet was made using nylon, acetate, PET, and PBTO long fibers with different nap lengths and dyed black.

In this case, the velvet was woven in such a way that the velvet was alternately 3cm wide with no napped portions and 10++ m wide with napped portions. As the binder polymer, a PBT-based polymer containing 70 mol of terephthalic acid, 10 mol% of isophthalic acid, and 20 mol of sepatenoic acid was used as the acid component and a glycol component of 1,4-butanediol. The melting point of this product was 160° C., and it was bonded to Seritonte 351+ll11 roll film Patrone Nonulit at a thermocompression temperature of 175° C. so that the raised surfaces faced each other.

Slit width: 1.8 van + 2.0 m + 2
．． 2 I created a patrone instead of rran. The contact area of the slit with the raised part has a width of 5 cm, the non-raised part is 2.5 m inside the cartridge, and the non-raised part is 0.5 m outside the slit.
A light-shielding cloth was attached so that the ratio was 5 vs. On the other hand, in order to measure the compression performance of the raised part, we carried out heat-setting treatment on a metal plate made of the same material as the cartridge, at the same temperature, with almost the same load and time, and then 1/l of that.
It was stored overnight in a room at 40° C. and 90% RH under a load of O, and then returned to the room under standard conditions.

f) We was measured using KES F3. On the other hand, for the Patrone, I reinstalled the film with the spool in a dark room and prepared multiple copies of each film at 40°C and 90°C.
It was left in a room with 0% RH for two days and nights under direct sunlight for 5 hours, and then returned to the room under standard conditions. On the one hand, we used an Instron to measure the film's slip resistance and check the operability of the roll film, and on the other hand, we developed the film and observed the state of leakage light. The results are shown in Table 1. In terms of ease of handling, the items marked with ○ indicate no abnormality.

An X indicates that the film is loose and moves easily and is difficult to handle. To check the leakage light situation, check the length of about 1'Ocm from the slit exit of the cartridge to the inner layer. ○ mark indicates no abnormality, X mark indicates discoloration due to leakage light, and Δ mark indicates slight discoloration. There are some things that have been determined to be true.

As is clear from the wood surface, polyester fibers were easy to handle, had little light leakage, and showed good results even with variations in slit width. On the other hand, hydrophilic nylon, rayon, and acetate are easily affected by changes in slit width.
In addition, polyester fibers have fewer drawbacks, such as poor practical effects unless the napped fiber length is increased.

Those with good results have a slip resistance of I Of/1ytr
With the above, the compression work We is 0.3 t cn
It is determined from Table 1 that the value is V/cd or higher.

Example 2 75 denier, 24 filament polyester filament yarn A: lOO% PBT circular cross section, B: t
oo% PBT flat cross section, C; 50 cm PBT, 50% PE
T flat cross section conjugate spun twisted fiber, D; 50%
8 mole isophthalic acid copolymerized PES, 5D%pE'I'
Velvet was made using flat cross-section conjugate spun twisted fibers. In this case, A and B have a napped fiber length of 1.7
For mlI C1D, the fiber length of the nape part was shortened by 2.0 sq. due to twist crimp. After dyeing, the thickness of the raised fabrics for A, B, C, and D could be made to be at the same level. These velvets are combined with a binder polymer and modified ether type block copolyester of triethylene glycol and ethylene glycol is used to soften the velvet at a softening temperature of 12.
Using binder polymer at 5℃, thermocompression temperature 160℃
C. and was bonded and evaluated in the same manner as in Example 1.

These compression works Wc are 0.58. B thread 0.40
．． The C yarn was 0.70° and the D yarn was 0.61rcm/cm, and good compression properties were obtained, and the S light weight loss Y was also large and it had excellent characteristics as a light-shielding sealing cloth. . In particular, types with D and C torsion crimps have good compression recovery properties, so they have the characteristic that no leakage light enters even if the slit width is varied to some extent.

[Brief explanation of drawings]

FIG. 1 is a graph showing the correspondence between the amount of compression work Wc and the amount of light shielding space Y. Patent applicant Kurashi Co., Ltd. Representative patent attorney Honda I

Claims (1)

[Claims] l) The napped side of the cloth facing the film surface is covered with polyester fibers, and the compression work Wc of the napped cloth used on one side is 0.3 to 1.51-cyv'cd. A light-shielding cloth structure for a photosensitive film box, which has a slipping resistance of 10 to 30 t/cm when the film passes through the opposing napped surface. 2) The side to be bonded to the film box is a non-napped side with reeds, and the adhesive binder is at least 30°C above the melting point of the napped fibers.
The light-shielding cloth structure for a photosensitive film box according to claim 1, which is bonded with a low polyamide or polyester thermal adhesive binder. 3) The fiber of the raised surface is any one of polyethylene tere-7 tallate fiber, polybutylene terephthalate fiber, and conjugate fiber of polyethylene tere-7 tallate and positive butylene terephthalate. Shade cloth structure for photosensitive film box 0