JP3041376B2 - Photographic support - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic light-sensitive material suitable for use in a small camera which is convenient for taking and handling. More specifically, the present invention relates to a support capable of forming a thin film while maintaining strength. The present invention relates to a silver halide photographic support having excellent curling resolving properties.

[0002]

BACKGROUND OF THE INVENTION Small cameras that can be easily photographed and that are convenient to handle and carry have been put to practical use.

However, considering the convenience and convenience of carrying,
Although further miniaturization is desired, in order to pursue miniaturization, it is essential to make the storage space for the built-in photographic film compact. Usually, as a photographic film, a film in a state in which a roll-shaped film is wound on a spool is built in, so in order to make the space compact and secure a certain number of shots (for example, 36 shots), It is necessary to reduce the thickness of the photographic film itself. In particular, the thickness of the photographic film support is currently 120-125μ
m, which is considerably thicker than the thickness of the photosensitive layer above it (about 20 μm), so reducing the thickness of this support is the most effective way to reduce the overall thickness of the photographic film. Considered as a means.

The properties of the support required at this time are required to have high mechanical strength, particularly high breaking strength. In other words, a typical roll film is 35mm
It is connected to the spool with a width equal to or less than the width and stored in the patrone, loaded into the camera and wound up, if the bonding strength between the film and the spool is weak, the film will not come off the spool and cannot be rewound There is a problem. Conventionally, a method of bonding with tape has been widely used for this bonding. However, in order to reduce a tape attaching process, a method of perforating a film edge (so-called perforation) and replacing the film with a protrusion on a spool has been replaced. Have been. Generally, this bonding force is correlated with the breaking strength. That is, as the breaking strength increases, the bonding force also increases.

[0005] By the way, as a plastic film support conventionally used, a triacetate film such as triacetyl cellulose (TAC) and a polyester film such as polyethylene terephthalate (PET) are representative.

[0006] Since PET films have excellent productivity, mechanical strength and dimensional stability, they are mainly used for sheet-like films such as X-ray films and plate making films. However, rolls, which are widely used as photographic light-sensitive materials, have drawbacks in that they are difficult to take up even after development processing and that they are poor in handleability.

On the other hand, a TAC film mainly used for a roll film has a property that it has no optical anisotropy and a high transparency, and furthermore has an excellent property that a curl is eliminated after a development process. Having. However, T
AC films are inherently low in mechanical strength, and it is impossible to make the thickness of a photographic film support thinner than the current thickness.

[0008] As a method for improving the roll-up removability of a PET film, there has been proposed a copolymerized PET film having a hydrophilic property imparted by using an aromatic dicarboxylic acid component having a metal sulfonate as a copolymerization component. Kaihei 1-
244446).

In general, a polyester film is obtained by melt-extruding an unstretched sheet, stretching first in the longitudinal direction, then stretching in the transverse direction, and further heat-treating.
However, since the copolymerized PET is significantly inferior in stretchability as compared with ordinary PET, it is difficult to sufficiently molecularly align it, and only mechanical strength, particularly a film having poor mechanical strength in the longitudinal direction, can be obtained. There's a problem. Further, such a film having insufficient molecular orientation has a problem that the flatness is inferior. Therefore, these problems were solved, that is, the mechanical strength was maintained, and the film could be thinned.
There has been a demand for a photographic support that can be easily rolled up after development processing.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object the purpose of maintaining mechanical strength, making it possible to form a thin film, and easily removing the curl after development processing. Another object of the present invention is to provide a photographic support having good transparency.

[0011]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that, for the purpose of improving the stretchability, for example, polyethylene glycol (PE)
When G) is used as a copolymer component, the stretchability is improved, but the mechanical strength in the vertical direction imparted in the first-stage vertical stretching is reduced by the subsequent second-stage horizontal stretching. The resulting film has poor mechanical strength in the vertical direction.

If the vertical stretching ratio in the first step is increased in order to improve the mechanical strength in the vertical direction, the film after vertical stretching becomes cloudy and becomes poor in transparency, or the film breaks during horizontal stretching. As a result of further study, they have found that the intended photographic support can be easily obtained by adopting a specific stretching method in a copolymerized PET having a specific composition. The present invention has been accomplished.

That is, the gist of the present invention is to provide a copolymerized polyester having terephthalic acid as a main acid component and ethylene glycol as a main glycol component, wherein the aromatic dicarboxylic acid containing a metal sulfonate group is entirely contained as the acid component. 2 to 7 mol% is added to the acid component, and 3 to 10% by weight of a polyalkylene glycol is added as a glycol component to the total weight of the reaction product, and any of the following (A) to (C) By the method
It is axially stretched and has a breaking strength of at least 10 kg /
and mm ² or more, and wherein the haze is 3% or less. (A) The unstretched sheet is first stretched in the vertical direction, and then
A method of stretching in the vertical direction and stretching in the vertical direction again. (B) The unstretched sheet is first stretched in the horizontal direction, and then
A method of stretching in the te direction. (C) stretching the unstretched sheet in one or more stages in the vertical direction
After that, stretch in the vertical direction again, then stretch in the horizontal direction
Way.

Hereinafter, the present invention will be described in detail.

The polyester used in the present invention is a copolymerized polyester containing terephthalic acid as a main acid component and ethylene glycol as a main glycol component. As the acid component, an aromatic dicarboxylic acid containing a metal sulfonate group is entirely used. 2 to 7 mol% is blended with respect to the acid component, and 3 to 10 wt% is further blended with polyalkylene glycol based on the total weight of the reaction product.

The aromatic dicarboxylic acid containing a metal sulfonate group of the present invention includes 5-sodium sulfoisophthalic acid, 2-sodium sulfoterephthalic acid, 4-sodium sulfoterephthalic acid, and 4-sodium sulfo-2,6.
-Naphthalenedicarboxylic acid or an ester-forming derivative thereof, and compounds obtained by substituting sodium with another metal (potassium, lithium, etc.) are used.

As the polyalkylene glycol of the present invention, polyethylene glycol and polytetramethylene glycol are used. The molecular weight is not particularly limited, but may be 300
20,000 is preferable, and 600-1 is more preferable.
0000, particularly preferably 1000 to 5000.

Other components may be copolymerized or other polyesters may be blended as long as the effects of the present invention are not impaired.

Examples of the copolymerization component include diol components such as diethylene glycol, neopentyl glycol, propylene glycol, p-xylylene glycol, 1,4-cyclohexanedimethanol, adipic acid, sebacic acid, dodecanedicarboxylic acid, isophthalic acid, and the like. 2,
A dicarboxylic acid component such as 6-naphthalenedicarboxylic acid,
Examples include a polyfunctional dicarboxylic acid component such as trimellitic acid.

The polymer to be used may contain phosphoric acid, phosphorous acid and esters thereof and inorganic particles (silica, kaolin, calcium carbonate, calcium phosphate, titanium dioxide, etc.) in the polymerization step. After polymerization, inorganic particles may be blended with the polymer. Further transesterification stage polymerization stage, dye or pigment as appropriate at any stage after polymerization, ultraviolet absorber,
An antioxidant or the like may be added.

When the content of the aromatic sulfonate is less than 2 mol%, the film cannot be rolled up after the development process, and when it exceeds 7 mol%, the stretchability is remarkably deteriorated, the mechanical strength is deteriorated and the film has poor flatness. Become.

If the PEG content is less than 3% by weight, the curl after development processing cannot be removed and the stretchability is poor, so that the mechanical strength is also poor. If it exceeds 10% by weight, any method may be used. A film with sufficient mechanical strength cannot be obtained.

The photographic support of the present invention has a breaking strength in the vertical direction of at least 10.0 kg / mm ² or more, preferably 15.0 kg.
/ Mm ² or more. Further, the breaking strength in the transverse direction is preferably 10.0 kg / mm ² or more, and more preferably 12.5 kg / mm ²
That is all.

If the breaking strength is less than the above-mentioned value, the bonding strength between the film and the spool is weak, and the film cannot be unwound.

The vertical direction in the photographic support of the present invention means the direction in which the film is slit into a tape shape, and usually coincides with the extrusion direction during film formation.
The horizontal direction means a direction orthogonal to the vertical direction.

The haze value of the photographic support of the present invention is 3% or less, and is measured by the method described in Examples below. When the haze value exceeds 3%, the transparency is poor.

The thickness of the photographic support of the present invention is not particularly limited, but is preferably from 40 μm to 125 μm, particularly preferably from 60 μm to 100 μm.

When the thickness is less than 40 μm, the bonding strength between the film and the spool is inferior. When the thickness is more than 125 μm, thinning is meaningless as compared with a TAC film which is currently widely used.

The synthesis of the copolymerized polyester used in the present invention is not particularly limited, but can be carried out by an ordinary known method. That is, after transesterification of the dicarboxylic acid component and the glycol component, polycondensation is performed at a high temperature under reduced pressure to obtain a copolymerized polyester. At this time, a copolymer component, for example, an aromatic dicarboxylic acid containing a metal sulfonate group or polyethylene glycol may be added at the time of transesterification, or may be added at the time of polycondensation after the transesterification reaction.

The method for producing the film of the present invention will be described.

A method for obtaining an unstretched sheet may be a conventionally known method. For example, an extruder in which a copolymer polyester is sufficiently dried and then controlled to a temperature range of 270 to 320 ° C.
A method of melt extruding into a sheet through a filter and a die, casting on a rotating cooling drum, and quenching and solidifying.

Next, as a method of biaxially stretching the completed sheet , any one of the following methods (A) to (C) is adopted.
Used. (A) A method in which an unstretched sheet is first stretched in the vertical direction, then stretched in the horizontal direction, and then stretched again in the vertical direction. (B) A method in which an unstretched sheet is first stretched in the horizontal direction, and then stretched in the vertical direction. (C) A method in which the unstretched sheet is stretched in one or more stages in the vertical direction, then stretched again in the vertical direction, and then stretched in the horizontal direction.

The stretching conditions are slightly different depending on the composition of the copolymerized polyester to be used, but the total stretching ratio is 2.5 to 6.0 in the vertical direction in the temperature range from the glass transition temperature Tg to Tg + 100 ° C.
The stretching ratio is 2.5 to 4.0 times in the temperature range of Tg + 5 ° C. to Tg + 50 ° C. in the horizontal direction. The biaxially stretched film obtained from the above is usually heat-set at 150 ° C. to 240 ° C. and cooled. At this time, if necessary, it may be relaxed in the vertical direction and / or the horizontal direction.

The photographic support film of the present invention may be laminated with another substance by a coextrusion method or a laminating method as long as the effects of the present invention are not impaired, or before, during, or after stretching. May be laminated by a coating method.

The film thus obtained can be applied to various applications known at present, but is particularly useful for a photographic support, especially a photographic support used for a roll film.

The photographic support of the present invention comprises at least one silver halide emulsion layer on at least one side to constitute a silver halide photographic light-sensitive material. The silver halide emulsion layer here may be applied directly on the support, or may be applied via another layer, for example, a hydrophilic colloid layer containing no silver halide emulsion.

At this time, various surface treatments such as a corona discharge treatment and a chemical solution treatment can be performed as needed to improve the adhesiveness. Further, an undercoat layer may be applied to improve the adhesion.

The silver halide used in the present invention may have any composition. For example, there are silver chloride, silver chlorobromide, silver chloroiodobromide, pure silver bromide and silver iodobromide.

The silver halide emulsion used in the present invention may contain a sensitizing dye, a plasticizer, an antistatic agent, a surfactant, a hardener and the like.

For the development processing of the silver halide photographic light-sensitive material of the present invention, for example, T.I. H. The Theory of the Photographic Process, Fourth Ed by James
ition) pp. 291-334 and the Journal of the American Chemical Society (Journal of the Ame)
rican Chemical Society) Volume 73, 3,100 pages (1951)
The developer described in (1) can be used.

[0041]

The present invention will be described below in more detail with reference to examples.

Examples 1 to 6 and Comparative Examples 1 to 4 100 parts by weight of dimethyl terephthalate, ethylene glycol 6
0.1 part by weight of calcium acetate hydrate was added to 4 parts by weight, and a transesterification reaction was performed by a conventional method. An ethylene glycol solution of 5-sodium sulfodi (β-hydroxyethyl) isophthalic acid (concentration 35% by weight) was added to the obtained product.
0 to 52 parts by weight (changed as shown in Table 1), polyethylene glycol (number average molecular weight 3000) 0 to 15 parts by weight (changed as shown in Table 1), antimony trioxide 0.05 part by weight, trimethyl phosphate 0.13 Parts by weight were added. Then, the temperature was gradually increased and the pressure was reduced, and polymerization was performed at 280 ° C. and 0.5 mmHg to obtain a copolymerized polyester.

The copolyester was vacuum-dried at 150 ° C., melt-extruded at 280 ° C., and quenched and solidified on a cooling drum to prepare an unstretched sheet.

Then, the film is stretched 3.5 times in the horizontal direction at 70 to 100 ° C. (shown in Table 1), further stretched 3.5 times in the vertical direction at 80 to 110 ° C. (shown in Table 1), and heat-fixed at 200 ° C. Thus, a biaxially stretched film having a thickness of 80 μm was obtained. The characteristic values of the film are as shown in Table 1, and within the range of the present invention, a film having good characteristic values and a high strength in the vertical direction can be obtained. A photographic film in which a photographic photosensitive layer was formed on these film supports by a known method had no practical problem and had good performance.

Comparative Examples 5, 6 Ethylene glycol solution of 5-sodium sulfodi (β-hydroxyethyl) isophthalic acid (concentration 35% by weight) 28
Parts by weight, polyethylene glycol (number average molecular weight 3000)
An unstretched sheet was prepared in the same manner as described above except that the amount was 8.1 parts by weight.

Using this unstretched sheet, it is stretched four times in the vertical direction at 80 ° C., further stretched 3.0 times in the horizontal direction at 90 ° C., and then heat-set at 200 ° C. to form a biaxially stretched film having a thickness of 80 μm. (Comparative Example 5). Similarly, the film was stretched 3.5 times in the vertical direction at 80 ° C., further stretched 3.5 times in the horizontal direction at 90 ° C., and then heat-set at 200 ° C. to obtain a biaxially stretched film having a thickness of 80 μ (Comparative Example 6). . The characteristic values of the film are as shown in Table 2, and the method does not provide sufficient strength or results in a film having a very high haze.

Examples 7 and 8 Using the copolymerized polyester used in Example 2, unstretched sheets were obtained by the above method. Using this unstretched sheet, stretched 3.5 times in the vertical direction at 80 ° C, stretched 3.0 times in the horizontal direction at 90 ° C, and stretched again 1.1 times in the vertical direction at 130 ° C, and then heat-set at 200 ° C. A biaxially stretched film having a thickness of 80 μ was obtained (Example 7). In the same way, at 90 ° C in the vertical direction
The film was stretched 2.6 times, stretched 1.8 times in the vertical direction at 70 ° C., further stretched 3.1 times in the horizontal direction at 100 ° C., and heat-fixed at 200 ° C. to obtain an 80 μ biaxially stretched film (Example 8). ). The characteristic values of the film are as shown in Table 2. According to the present invention, a film having good characteristic values and high strength in the vertical direction can be obtained.

The method for measuring each physical property value of the present invention is described below.

<Breaking Strength> After leaving the film in a room controlled at a temperature of 23 ° C. and a relative humidity of 55% for 4 hours or more, the sample was cut into a 10 mm wide and 200 mm long sample, and a 100 mm gap between the chucks was set to a pulling speed of 100 mm. Per minute, a tensile test was performed to determine the breaking strength excluding the load at the time of breaking by the initial cross-sectional area.

<Flatness> The film was heated at 23 ° C. and relative humidity.
After leaving for more than 4 hours in a room adjusted to 55% temperature, cut into a sample size of 120 mm x 150 mm, heat-treated in a hot-air oven at 130 ° C for 30 minutes without tension, and heat-treated the sample at a temperature of 23 ° C. After standing for more than 4 hours in a room adjusted to a relative humidity of 55%, the degree of the waving was visually evaluated and ranked according to the following criteria. Rank Criteria 5 Very good 4 Good 3 Rippling is noticeable 2 Rippling 1 Rippling large The practicality in this ranking is determined based on the tolerance as a photographic support, and rank 3 or higher It is preferred that

<Transparency> The haze of the film was determined according to JIS K
Measured according to -6714. Practical as a photographic support 3
% Or less is preferable.

<Collective recovery> Sample size 12cm × 35
mm film on a 10mm diameter core, 55 ℃, 20% RH
Under the conditions of 3 days, and roll. Thereafter, the core is released from the core, immersed in pure water at 38 ° C. for 15 minutes, and then dried with a hot air dryer at 55 ° C. for 3 minutes under a load of 50 g. The load was removed, the sample was hung vertically, the distance between both ends of the sample was determined, and the degree of recovery from the original distance of 12 cm was evaluated. The photographic support is practically preferably at least 50%, particularly preferably at least 80%.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

As described above in detail, according to the photographic support of the present invention, it has excellent mechanical strength, can be formed into a thin film, can be easily rolled up after development processing, and has good flatness and transparency. It has an excellent effect with good properties.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-244446 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03C 1/795

Claims (3)

(57) [Claims] 1. A copolymerized polyester containing terephthalic acid as a main acid component and ethylene glycol as a main glycol component, wherein an aromatic dicarboxylic acid containing a metal sulfonate group is used as an acid component in an amount of 2 to the total acid component. to 7 is mol%. in addition as the glycol component relative to the total weight of the polyalkylene glycol reaction product, it is 3-10 wt% blend, and the following (a) ~
A photographic support, which is biaxially stretched by any one of the methods (C), has a breaking strength of at least 10 kg / mm ^{2 in the} vertical direction, and has a haze of 3% or less. (A) The unstretched sheet is first stretched in the vertical direction, and then
A method of stretching in the vertical direction and stretching in the vertical direction again. (B) The unstretched sheet is first stretched in the horizontal direction, and then
A method of stretching in the te direction. (C) stretching the unstretched sheet in one or more stages in the vertical direction
After that, stretch in the vertical direction again, then stretch in the horizontal direction
Way. 2. A breaking strength of at least 15 kg / in the vertical direction.
^2. The photographic support according to claim 1, wherein the thickness is at least ² mm. 3. The photographic support according to claim 1, wherein the breaking strength in the transverse direction is 10 kg / mm ² or more.