JPS62286043A - Spool for photographic film - Google Patents

Abstract

PURPOSE:To reduce load tension necessary for drawing out a photographic film, to improve extrusion moldability, and to lower the tendency to cause scratches and abrasion on the surface by forming the spool for the photographic film with a polystyrene type resin containing carbon black, linear polydimethylsiloxane, silica, and a rubber. CONSTITUTION:The spool is molded with the polystyrene resin containing the 0.05-3.00wt% carbon black, the 0.50-2.00wt% linear polydimethylsiloxane, the 0.05-2.00wt% silica, and the 0.5-6.0wt% rubber. If the content of the carbon black is <0.05wt%, light shading ability cannot be ensured without thickening the spool and light fog occurs, and the increase of the thickness extends a molding cycle, causes molding trouble, and raises an amount of resin to be used. If >3.0wt%, the physical strength of the spool lowers, a weld line occurs, and hygroscopicity rises, moreover, poor appearance of the spool, scratches and abrasion of the surface are made liable to occur, and injection extrudability is also deteriorated.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a spool for a cartridge for photographic film into which roll film such as 16 mm or 35 mm is loaded.

[Conventional technology]

As shown in FIG. 5, a conventional cartridge has a spool 2 housed in a cylindrical body plate 1, and caps 3,
3 is fitted. The body plate 1 is formed with a beak-shaped boat (film outlet) 5 to which a light-shielding ribbon 4 is attached. The spool 2 has bosses 7.7 formed at both ends of the photographic film winding shaft 6, and the bosses 7.7 are connected to the caps 3, 3.
It is rotatably fitted into shaft holes 8, 8 provided in the center of the shaft.

The spool 2 also has a flange 9.9 integrally molded near the inside of the cap 3.3.

The photographic film 10 has its tip 1] at the bow 1- of the body plate 1.
5, and most of the remaining photographic film 1. It is wound around the outer periphery of the winding shaft 6.

For the external dimensions and shape of the cartridge, see 1, IIS
Although standards such as M-7528 have been standardized, there are no specific regulations regarding the internal structure, so it differs depending on each photographic film manufacturer.

In particular, the shape of the cap 3 is designed to prevent light from leaking into the interior of the butt, to regulate the axial position of the spool 2, to support the boss 7 of the spool 2, etc. Manufacturers have made various efforts.

FIG. 6 shows the shape of a cap used in a conventional cartridge. The camp 30 shown in (a) is
A part of the inner wall contacts the outer edge of the flange 9 of the spool 2, and the end edge on the shaft hole 8 side is folded outward and contacts the outer periphery of the boss 7.

(The cap 31 shown in BL has its shaft hole 8 enlarged so that it does not come into contact with the boss 7. In order to prevent light from entering through this gap, a part of the cap 31 is in contact with the flange 9. .

The cap 32 shown in +C) is configured to have a large contact area with the flange 9 so that almost the entire surface of the flange 9 comes into contact with the camp 32.

However, it is difficult to form the inner wall of the fat cap 30 that comes into contact with the flange 9 or the edge that fits into the boss 7, making it difficult to regulate the position of the spool 2 in the length direction. However, since there are problems, caps shown in tb) and (C) are generally used.

However, a ballone comprising a FBL or C1 cap 3], 32 has a lower capacity than a fat cap.
The cap 31.32 A large frictional resistance is generated between the spool 2 and the spool 2. Therefore, it takes a cap 3],,3
In order to pull out the photographic film 10 from the cartridge boat 5 comprising the cartridge 2, a considerable amount of force is required, and in extreme cases, what is called a cut occurs when the photographic film 10 is fed into the camera.

This breakage phenomenon occurs when the photographic film 10 is moved by the sprocket in the camera and the load tension applied to the film vaporization by the active rotation of the sprocket exceeds the breaking strength of the vaporization. It is something to do.

Jitsuko 61. Publication No. 3000 considers that this load tension is mainly caused by the frictional resistance between the cap and the spool, and as a countermeasure to this problem, a lubricating surface is formed on the surface of the mutually contacting parts of at least either the spool or the camp. Patrone is disclosed.

For example, as shown in Fig. 7, the spool of this cartridge contains a lubricant solution in which lubricant is dissolved in a low-boiling organic solvent.
Using a brush, spool gun, or other means, remove the flange 9.
The lubricant layer 12 is applied to the outer surface of the lubricant and the outer peripheral surface of the boss 7.

[Problem that the invention seeks to solve]

However, such conventional methods use a volatile and flammable lubricant solution dissolved in a low-boiling solvent, which poses the problem of ignition, etc., and the handling of the lubricant solution is troublesome. In addition, these equipments are expensive, and in order to coat the lubricant layer with a dry thickness in the range of 0.1 to tz, productivity is low and extremely slow even if the evaporation rate of the solvent is high. There was a problem with increasing costs.

The present invention solves these problems and has low film draw-out load tension, good injection moldability (release from the mold), no surface scratches or abrasion, and excellent manufacturing suitability. The purpose is to sweep excellent photographic film spools.

[Means for solving problems]

The present invention has been made to achieve the above object, and it is possible to reduce the surface frictional resistance even if the spool itself is made of a resin containing a lubricant instead of forming a lubricant layer 12 on the spool. This was done with a focus on Then, the present inventor discovered that among a wide variety of lubricants, a resin to which a predetermined amount of linear polydimethylsiloxane was added was most suitable for spools, and the present invention was made for the first time. That is, if the amount of linear polydimethylsiloxane added is increased, problems will occur during the molding cycle, etc., and the range in which the frictional resistance can be lowered without causing other problems as described above is limited. In addition, among other lubricants, fluorosilicone oil and fluorine-modified silicone oil, which are described in the catalogs of silicone manufacturers as having a very small coefficient of friction and excellent lubricity, are made of polystyrene-based resins containing these. When a spool was formed using this method, the pull-out load tension of the photographic film was large (not much different from the additive-free product, and the object of the present invention could not be achieved).

As described above, the present invention is the result of intensive research by the inventors, and has made it possible for the first time to provide a spool that has advantages such as low frictional resistance on the surface and lower cost than conventional spools. .

That is, the photographic film spool of the present invention has a spool of 0.0
5-3.00 wt% carbon black and 0.50-2
．． 00% by weight cotton polydimethylsiloxane and 0.05% by weight
~2.00 wt% silicon oxide and 0.5-6.0 wt%
It is characterized by being made of polystyrene resin containing rubber.

As shown in FIG. 1, the winding shaft 6, boss 7, and flange 9.9 constituting the spool 2 are all made of polystyrene resin having the above composition. It is preferable to make one or both sides of the flange 9.9 matte to reduce frictional resistance, prevent generation of static electricity, and ensure light-shielding properties when incorporated into a film cartridge.

Carbon black is added to ensure physical strength, ensure light-shielding properties, and prevent static electricity. Various carbon blanks are used for this carbon black, but they are inexpensive and l! 1. It has excellent M power and does not cause adverse photographic effects on photographic films (occurrence of fog, sensitivity fluctuations such as decrease in sensitivity or increase in sensitivity,
p115-9. Furnace carbon black with an average particle size of 10 to 120 mμ is preferable, particularly one with an average particle size of 15 to 50 mμ and a pH of 6 to 8.
Oil furnace carbon black is preferred.

Furthermore, when the purpose is specifically to prevent static electricity, it is preferable to use acetylene carbon black and Ketjen carbon black, which is a modified by-product carbon black, although they are expensive.

However, even when the purpose is to prevent static electricity, it is preferable that 50% or more of the carbon blank be furnace carbon black from the viewpoints of price, ensuring the physical strength of the spool, ensuring light-shielding properties, preventing photographic sensitization, injection moldability, etc.

The amount of carbon blank added depends on price, physical strength of the spool, light shielding, prevention of photographic sensitization, injection moldability,
From the viewpoint of appearance etc., it is limited to 0.05 to 3.00% by weight.

If the amount of carbon blank added is less than 0.05% by weight, light shielding properties cannot be ensured unless the thickness of the spool is increased, and light scattering occurs. If the wall thickness is increased to 0.05% by weight to ensure light-shielding properties, the molding cycle will become longer and molding failures such as warping and whiskers will occur.2 The amount of resin used will increase, leading to increased costs.

If the amount of carbon added exceeds 3.00% by weight, not only will it be expensive, but the physical strength of the spool will decrease and weld lines will occur. It also absorbs moisture easily (which not only causes negative photographic effects, but also causes poor appearance of the spool (silver stripes, etc.).
This also increases the likelihood of uneven gloss (glossy unevenness, reduced gloss rings), and scratches and abrasion on the spool surface. Furthermore, the fluidity of the resin deteriorates, and the injection moldability also deteriorates.

Linear polydimethylsiloxane is added to improve the lubricity of the spool surface and reduce frictional resistance. This linear polydimethylsiloxane is manufactured by silicone oil manufacturers (Shin-Etsu Chemical ■, Toshiba Silicone, Toray Silicone ■).

11nion Carbide, Don Corn
In particular, a linear polydimethylsiloxane having the following chemical structural formula (product name KF 96) having a trimethylsilyl group at the terminal of Shin-Etsu Chemical is preferred.

Among kF-96, preferred for the present invention are those with a viscosity of 1,
(H)O~60000C3.

The linear polydimethylsiloxane having the structure -1- can be used in a wide variety of high viscosity products.

The amount of JJII added is limited to 0.05 to 2.00% by weight.

If the amount of linear polydimethylsiloxane added is less than 0.5% by weight, not only the desired lubricity effect cannot be obtained, but also the kneading cost and siliconization cost increase.

If the amount of linear polydimethylsiloxane added exceeds 2.00% by weight, the measured value of the resin will become unstable due to screw slippage, the resin charging time will become longer, the molding cycle will become longer, and the lubricity effect will be 2.00% by weight. %, there is almost no difference, and the cost will only increase. In addition, the appearance deteriorates, poor dispersion of the carpon blank occurs, and the amount of silicone on the surface increases, making it more likely to become sticky and attracting more dust. Furthermore, the amount of silicon on the surface increases, resulting in adverse photographic effects.

Silicon oxide (St(h) is added in combination with linear polydimethylsiloxane to not only reduce the frictional resistance when pulling out photographic film, but also to improve the deterioration in resin charging properties caused by the addition of linear polydimethylsiloxane. be.

The amount added is limited to 0.05 to 2.00% by weight.

If it is less than 0.05% by weight, there is not only no effect of addition, but also increases costs such as kneading costs. If it exceeds 2.00%, not only will the effect of increasing the addition amount not be obtained, but the surface will become rough and the cost will increase.

Rubber is added to increase the strength of polystyrene resin, which has low impact strength.

Various synthetic rubbers are generally used as the rubber, and among the synthetic rubbers, butadiene rubber is most commonly used.

The mode of adding rubber is an impact-resistant polystyrene resin (hereinafter referred to as +11P) obtained by graft polymerizing styrene monomer to rubber.
S) or medium impact polystyrene resin (hereinafter referred to as old P
(referred to as S) and general polystyrene resin (referred to as Jlz G
Even if a resin blended with P P S is used, I
Even if either IIPs or old PS is used alone,
A resin blended with GPPS and rubber may also be used. Preferably, a resin that is a blend of old PS and GPPS is used or old PS is used alone. This is because impact resistance and abrasion resistance are improved by graft polymerizing the rubber hestyrene monomer.

The amount of rubber added is 0.5 to 6.0% by weight based on cost, ensuring physical strength, injection moldability, ensuring surface strength (prevention of scratches and abrasion, etc.), and other considerations. If the amount of rubber is less than 0.5% by weight, there will be problems in securing physical strength and surface strength, and if the amount of rubber exceeds 6.0% by weight, there will be problems in terms of injection moldability, rigidity, appearance, price, etc. Yes, it cannot be put into practical use.

The most commonly used polymerization method at present is Gl)
PS uses bulk polymerization method, granular polymerization method, etc.
IPS and old PS use bulk polymerization method, bulk-granular polymerization method, etc.

As a method for adding carbon blank, linear polydimethylsiloxane, silicon oxide, and rubber, any known method such as a compounding method, powder method, masterbatch method, liquid method, etc. can be used.

Among these methods, the masterbatch method is particularly preferred from the viewpoint of preventing contamination of the workplace.

The masterbatch may be made of any one of carbon blank with a small amount added, linear polydimethylsiloxane, silicon oxide, rubber or rubber-containing polystyrene resin, or all three.

The master bunch resin does not need to be a polystyrene resin, but is preferably a thermoplastic resin that is easily kneaded with a polystyrene resin, such as a polyolefin resin.

Among polyolefin resins, ethylene ethyl acrylate copolymer resin (abbreviation E[!A), ethylene methyl acrylate!・Copolymer resin (abbreviation HMA), ethylene-vinyl acetate copolymer resin (abbreviation EVA), linear low density polyethylene resin (abbreviation L-LrlPH),
High-pressure branched low-density polyethylene resin (abbreviation: LDPIE)
), ethylene acrylic acid resin (abbreviation FAA), etc. are preferred. Further, the resin for the master hatch is preferably a thermoplastic resin having a higher melt index than the polystyrene resin which is the main resin.

This is because the carbon blank, cotton-like polydimethylsiloxane, and rubber or rubber-containing polystyrene resin to be made into a masterbatch can be uniformly dispersed in the base resin.

In addition, various additives can be suitably blended into the polystyrene resin composition of the present invention within a range that does not impair the effects of the invention. Specifically, antioxidants.

Light stabilizer, UV absorber 5 nucleating agent, antistatic agent, face ¥4.
Facial powder dispersant, lubricant, neutralizer, acid scavenger, dye.

Metal powder, etc. Further, a necessary amount of polyolefin resin, elastomer, etc. can also be added.

Blending with other lubricants (including various silicone oils), antiblocking agents, silicon oxide (SI02) I pigments, etc. is effective in improving injection moldability and last torque.

In the present invention, since carbon black and carboxyl-modified silicone oil are added, an antioxidant for rubber is not necessarily required, but it is suitable for long-term continuous injection molding production.
Various antioxidants can be added to improve suitability for high-temperature injection molding.

When adding antioxidants, the most preferred antioxidants that do not sensitize photographic film are phenol-based and phosphorus-based antioxidants; sulfur-based and amine-based antioxidants may sensitize photographic film, so it is best not to use them. is preferred. Addition amount is 0.0
It is 1 to 1.0% by weight.

The principle of photographic film is to use oxidation and reduction, so even when using phenolic or phosphorus antioxidants,
．． If it exceeds 0% by weight, sensitization occurs in photographic film.

[For production]

Since the photographic film spool of the present invention is made of a resin containing polydimethylsiloxane, the spool surface has good lubricity and the frictional resistance between the cap and the spool is reduced. This allows the photographic film drawer load tension to be reduced. That is, the largest factor in the photographic film drawer load tension is the frictional resistance between the cap and the spool, and by reducing this frictional resistance, the load tension can be reduced.

Furthermore, variations in the magnitude of the photographic film drawer load tension occur due to the types of photographic film and cartridges used, or differences in the structure of the camera, but in any case, the final load tension of the photographic film drawer (last torque) is often the largest.

Therefore, breaks in photographic film often occur when this last load tension acts, but this last load tension is reduced to prevent cuts.

〔Example〕

Table 1 shows examples of the photographic film spool of the present invention and experimental results comparing its characteristics with conventional products and comparison fabrics.

Here, as a molding machine, a mold squeezing force of 150 t of Nester I Full (trade name) manufactured by Jumite Heavy Industries was used, and a test piece for static friction coefficient measurement, a test piece for Izotsu impact strength, and a photograph of the shape shown in Fig. 4 were used. A spool for use in a film ballone was formed by injection molding.

Although the above examples are representative examples of preferred embodiments of the spool used in the photographic film cartridge of the present invention, the present invention is not limited thereto.

The evaluation in the table is based on the following.

◎; Very good O: Excellent; Practical limit; Problems, improvement required ×; Not practical (Note 1") l-lux (load tension when pulling out photographic film) Photographic film cartridge A used
is loaded into a 35 mm camera 20, the leading end 11 of the photographic film 10 is pulled out from the boat 5, and further it is pulled out through a notch 21 provided in the camera 20 while being held between nip rolls 22 and 23. This nip roll 2
Torque pink up 24 (manufactured by Denshi Kogyo Co., Ltd. 70M-3)
A motor 25 is connected continuously through a film (type 8), and this motor 25 is driven at a constant speed (linear speed 40 ml/5ee) to shoot 36 photographic films (Fujicolor H1L-1).
00) was pulled out to the end. The torque at that time is obtained by converting the torque value measured with the Pink Up 24 into tension, and is expressed in rgJ.

The smaller the value, the smaller the frictional resistance when pulling out, indicating that the spool is superior.

Note 23 Coefficient of Static Friction One test piece with a width of 35 mm and a length of 751 mm formed by injection molding was attached to an inclined surface, and the other was attached to the bottom of a metal block with a load of 200 g. The tanθ is calculated from the angle at which it starts to slide and is used as the coefficient of static friction.

The smaller the value, the lower the frictional resistance.

Note 31 Izot impact strength...JIS K7110.
(23℃).

Amine-modified silicone oil was excluded from the test because it had adverse photographic effects (fogging, etc.) on photographic film.

Next, FIG. 3 shows the relationship between the amount of silicon oxide added, the resin charging time, and the coefficient of static friction with the metal for the cap.

Here, the polystyrene resin is a blend of 70% GPPS and 30% old weight (butadiene rubber content 6%), and the amount of carbon blank added is 0.5%.
As the linear polydimethylsiloxane, KF-96 having a viscosity of 30000C5 manufactured by Shin-Etsu Chemical Co., Ltd. was added in an amount of 1.0% by weight. Then, change the amount of silicon oxide added, adjust the increase/decrease with polystyrene resin, and measure the resin charging time and static friction coefficient.The charging time when no silicon is added is set as 100%, and the charging time at each addition amount is It is expressed as a percentage. The coefficient of static friction with the metal for the cap is the same as in the method described in Note 2 above, except that a test piece of the same material as the spool and a test piece of the metal for the cap are brought into contact.

From FIG. 3, it can be seen that the resin charging time can be shortened by adding silicon oxide, and the static friction coefficient can also be lowered if the amount is within a predetermined range.

Furthermore, Figure 4 shows the relationship between the amount of linear polydimethylsiloxane added, last l-lux, Izod impact strength, resin chargeability of a resin containing 1% by weight of silicon oxide, and resin chargeability of a resin without silicon oxide. . Here, the last torque and Izot impact strength were measured by the methods described in Notes 1 and 3 above, and evaluated based on these values. Further, resin chargeability was evaluated based on resin charge time.

From FIG. 4, it can be seen that adding linear polydimethylsiloxane can improve the last torque, but on the other hand, the resin charging property deteriorates. However, it can be seen that resin chargeability can be improved by adding silicon oxide, and that the last torque and resin chargeability can be maintained favorably within a predetermined range.

Note that the characteristic evaluation is the same as in Table 1.

〔Effect of the invention〕

The photographic film spool of the present invention is made of polystyrene resin containing linear polydimethylsiloxane, silicon oxide, carbon blank, and rubber in a predetermined amount, so that it can reduce last torque and improve Izot impact strength. In addition, it is possible to improve the mold releasability when taking out the spool from the mold.

Therefore, it is possible to feed the photographic film from the cartridge extremely smoothly, which not only prevents the photographic film from breaking inside the camera, but also greatly reduces the consumption of the drive battery in modern cameras with automatic film winding mechanism. can be reduced to

Furthermore, since the equipment is inexpensive and the productivity is good, costs can be lowered compared to conventional methods.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of a spool according to the present invention, and FIG. 2 is a schematic diagram of a load tension measuring device. Figure 3 is a diagram showing the relationship between the amount of silicon oxide added and characteristics.
The figure shows the relationship between the amount of polydimethylsiloxane added and the properties. FIG. 5 is a cross-sectional view of a conventional cartridge, and FIG. 6 is a cross-sectional view showing the relationship between the spool and the cap of the conventional cartridge. FIG. 7 is a sectional view of a conventional spool. 1... body plate, 2... spool, 3... cap,
5...Boat, 7...Boss, 9...Flange, 1
0...Photographic film, 30-32...Gear Tsubu, 1
2...Lubricant layer. Patent distributor Fuji Photo Film Co., Ltd. Agent Patent attorney 1) Hiroshi Naka Masa and one other person Figure 7 Figure 1 Figure 31! A Salmon#-K1t22≦Int]l('!ishi4) Fig. 4 0 0, 5 10 1.5 20 A Salmon #-K1t 22≦Inner t]l ('!ishi4) Fig. 4 0 0, 5 10 1.5 20 i (Q) Figure 6(b)

Claims (4)

[Claims] (1) 0.05-3.00% by weight of carbon black, 0.50-2.00% by weight of linear polydimethylsiloxane, 0.05-2.00% by weight of silicon oxide, and 0.5-2.00% by weight of silicon oxide.
A spool for photographic film, characterized in that it is formed of a polystyrene resin containing 6.0% by weight of rubber. (2) The spool for photographic film according to claim 1, wherein 50% or more of the carbon black is furnace carbon black. (3) The photographic film according to claim 1 or 2, wherein the linear polydimethylsiloxane has a structural formula ▲A mathematical formula, a chemical formula, a table, etc.▼ (n is a degree of polymerization of 90 to 1500) spool for (4) Claims 1 and 2, wherein the polystyrene resin contains a phenolic or phosphorus antioxidant.
Spool for photographic film as described in paragraph or paragraph 3