JPH06273887A - Film for photographic sensitive material - Google Patents

Abstract

PURPOSE:To prevent the rising of one edge of a film for a photographic sensitive material and the generation of cutting chips at the time of cutting as well as to easily straighten the film in a curled state. CONSTITUTION:This film for a photographic sensitive material is a biaxially oriented polyethylene-2,6-naphthalate film and has <=0.08 tandelta at 80 deg.C in the longitudinal direction on the basis of tensile viscoelasticity at 0.05Hz, 500-700kg/mm<2> Young's modulus in the longitudinal direction and >700kg/mm<2> Young's modulus in the transverse direction. The difference between the Young's modulus in the transverse direction and that in the longitudinal direction is >=100kg/mm<2>.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for a photographic light-sensitive material, and more specifically to a biaxially oriented polyethylene-2,6-na which has excellent decurling property and mechanical properties and cutting properties. The present invention relates to a film for a photographic light-sensitive material, which film comprises a phthalate film.

[0002]

2. Description of the Related Art Conventionally, a triacetate film has been widely used as a base film used in a photographic light-sensitive material such as an X-ray film, a plate-making film, a photographing roll film and the like.

Since this triacetate film uses an organic solvent in its manufacturing process, it must be carefully recovered so that it does not pollute the environment. In particular, recently, the problem of environmental destruction has been attracting attention, and there is a strong tendency to avoid the use of organic solvents that may cause environmental pollution as much as possible.

On the other hand, without using such an organic solvent,
There is a polyethylene terephthalate film as a film that can be formed into a film by the melt extrusion method, and it has come to be partially used as a base film of a photographic light-sensitive material.

However, the polyethylene terephthalate film has a problem that curling (rolling tendency) occurs and it is difficult to remove it. That is, a base film of a photographic light-sensitive material is once stored in a roll-up form, and the film is taken out from the film and cut into an appropriate size to obtain an X-ray film, a plate-making film, and a cut film. It is used as a flat sheet film such as. In the case of a roll film, the negative film stored in the patrone in roll form is
It will be cut into a certain length, put in a film album and saved as a sheet. However, in the case of a polyethylene terephthalate film, there is a problem that curl remains when it is wound into a roll and curls even after it is cut into a sheet.

As a method of solving such a curl problem, a method of heat-treating a film at a temperature 5 to 30 ° C. lower than the glass transition temperature for a long time has been proposed (Japanese Patent Laid-Open No. 51-16358). However, not only is the processing time consuming, but the curl cannot be removed sufficiently.

Further, the use of polyethylene-2,6-naphthalate film as a base film of a photographic light-sensitive material has been proposed in, for example, Japanese Patent Application Laid-Open No. 50-81325, but there are many problems to be solved. It remained, and it was not put into practical use.

[0008]

The inventors of the present invention, in the process of making practical use of a biaxially oriented polyethylene-2,6-naphthalate film as a base film for a photographic light-sensitive material, I learned that there is a problem that it is difficult to remove curl, and that it is also known that when cutting the film to a certain width, one end surface rises and a lot of chips are generated. It was

The object of the present invention is to solve the above problems,
It is an object of the present invention to provide a film for a photographic light-sensitive material, which comprises a biaxially oriented polyethylene-2,6-naphthalate film which is easy to remove curl and has excellent mechanical properties and cutting properties.

[0010]

The present inventors have completed the present invention as a result of further studies to achieve the above object.

That is, the present invention is a biaxially oriented polyethylene-2,6-naphthalate film, which has 0.05H
The longitudinal tan δ due to tensile viscoelasticity at z is 0.08 or less at 80 ° C. and the longitudinal Young's modulus (Y
_MD) is 500~700kg / mm ^2, lateral Young's modulus (Y _TD) is greater than 700 kg / mm ^2, and the difference between the lateral Young's modulus and longitudinal Young's modulus (Y _TD -Y _MD) is 1
A film for a photographic light-sensitive material, characterized in that it is at least 00 kg / mm ² .

The polyethylene-2,6-naphthalate in the present invention is not only a polyethylene-2,6-naphthalate homopolymer but also a small proportion (eg 10 mol% or less, further 5 mol% or less) of the third component. It also includes a modified polyethylene-2,6-naphthalate copolymer and a blend polymer in which a small proportion (for example, 20% by weight or less, further 10% by weight or less) of a third component is mixed.

Such polyethylene-2,6-naphthalate is basically known and can be produced by a known method. For example, polyethylene-2,6-naphthalate is generally produced by subjecting 2,6-naphthalenedicarboxylic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative to polycondensation reaction in the presence of a catalyst. It In the case of producing a copolymer, the third component may be added and reacted at a stage until the polycondensation reaction is completed, and in the case of producing a blended polymer, the polymer of the third component may be added before the film formation. Should be mixed.

Suitable third component is a compound having a divalent ester-forming functional group, for example, oxalic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, 2,7.
-Dicarboxylic acids such as naphthalene dicarboxylic acid and diphenyl ether dicarboxylic acid or lower alkyl esters thereof; oxycarboxylic acids such as p-oxybenzoic acid and p-oxyethoxybenzoic acid or lower alkyl esters thereof; or propylene glycol, trimethylene glycol And dihydric alcohols such as tetramethylene glycol, hexamethylene glycol, neopentyl glycol and the like.

Further, polyethylene-2,6-naphthalate may be obtained by blocking some or all of the terminal hydroxyl groups and / or carboxyl groups with a monofunctional compound such as benzoic acid or methoxypolyalkylene glycol. Alternatively, it may be modified with a trifunctional or higher functional ester-forming compound such as glycerin or pentaerythritol in a very small amount within a range where a substantially linear polymer is obtained.

The polyethylene-2,6-naphthalate may contain a lubricant such as finely divided silica, talc, clay or the like for imparting a slip property to the film, and other additives such as a stabilizer and an ultraviolet ray. Absorbents, colorants, flame retardants and the like can also be added.

Biaxially oriented polyethylene in the present invention
The 2,6-naphthalate film needs to have a longitudinal tan δ due to tensile viscoelasticity at 0.05 Hz of 0.08 or less at 80 ° C. If this tan δ exceeds 0.08, the curl cannot be sufficiently removed.

The biaxially oriented polyethylene-2,6-naphthalate film formed by a conventional method has a tan δ of about 0.10. To lower the tan δ to 0.08 or less, 70 ° C. ~ 150 ° C, preferably 80 ° C
It is effective to perform an annealing treatment at 130 ° C. If the annealing temperature is too low, the curl cannot be sufficiently removed.On the contrary, if it is too high, oligomer deposition on the film surface increases, which not only causes inconvenience in using the film, but also on the film surface. Transfer is likely to occur, which is not preferable.

As a heat treatment method for lowering this tan δ, there is biaxially stretched heat-fixed polyethylene-2.
6-Method of heating a naphthalate film (raw film) while it is in contact with a heating roll without temporarily winding it, heating it in a non-contact manner while running it in heated air, and winding the original film on a roll A method of annealing in a heating oven in such a state may be mentioned, but the method is arbitrary and is not limited to a specific method as long as tan δ can be 0.08 or less.

Among these methods, as a particularly preferable method, the original film is wound into a roll and gradually heated from room temperature in an oven (for example, over 24 hours).
After raising the temperature to a specified temperature and holding it at the specified temperature for a long time (for example, 24 hours or more), gradually (for example, over 24 hours)
A method of lowering the temperature to room temperature is used.

The biaxially oriented polyethylene-2,6-naphthalate film of the present invention has a longitudinal Young's modulus (Y _MD ) of 500 to 700 kg / mm ² , preferably 550 to 650 kg / mm ² . , The lateral Young's modulus (Y _TD ) is larger than 700 kg / mm ² , and the difference (Y) between the lateral Young's modulus (Y _TD ) and the vertical Young's modulus (Y _MD ).
_TD- Y _MD ) is 100 kg / mm ² or more, preferably 13
It should be 0 kg / mm ² or more. When the Young's modulus in the longitudinal direction is less than 500 kg / mm ² , when a roll film is manufactured as a photographic photosensitive material (photosensitive agent application, drying step, etc.), it is greatly deformed or wrinkled when various tensile tensions are applied. It is not preferable because it is likely to occur and causes problems such as uneven coating. On the other hand, if the Young's modulus in the longitudinal direction exceeds 700 kg / mm ² , the cuttability is significantly reduced, which is not preferable. The difference in the lateral direction Young's modulus and longitudinal Young's modulus (Y _TD -Y _MD) is 100 kg / mm
If it is less than ² , the cuttability is significantly reduced, which is not preferable.

As a method of obtaining such Young's modulus, a simultaneous biaxial stretching method of simultaneously stretching longitudinally and laterally using a roll or a stenter, a sequential stretching method of sequentially stretching longitudinally and laterally, and a method of stretching at least two stages in the longitudinal and lateral directions are used. Can be adopted. The stretching temperature, the stretching ratio, and the like may be selected from known conditions that satisfy the above Young's modulus. The above-mentioned annealing treatment has little effect on Young's modulus.

In the present invention, biaxially oriented polyethylene
The 2,6-naphthalate film has a haze of 2.0% or less, more preferably 1.5% or less, and particularly 1.0% or less in order to maintain the transparency required as a film for a photographic light-sensitive material. It is preferable.

The thickness of the biaxially oriented polyethylene-2,6-naphthalate film in the present invention can be appropriately set depending on the application of the photographic light-sensitive material used, but is usually 25 to 250 μm, and particularly 40 to 150 μm. Often.

Biaxially oriented polyethylene of the present invention-2,6-
On the surface of the naphthalate film, various thin layers including a light-sensitive emulsion layer can be formed to obtain a photographic light-sensitive material. Known means can be used to form these thin layers.

[0026]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

In the examples and comparative examples, tan δ,
Young's modulus, curl removal rate and cuttability were measured as follows.

(1) tan δ Seiko Denshi Kogyo Co., Ltd. thermal stress strain measurement system TMA / S
S120C was used and measured under the following conditions. Load mode: sin wave (load change frequency 0.05Hz) Median load per cross-sectional area: 120g / mm ² Load amplitude per cross-sectional area: 90g / mm ² Heating rate: 5 ° C / min Sample width: 4mm Sample length ( Between chucks: 10mm Measuring direction: Vertical direction

(2) Young's modulus The film was cut into a sample having a width of 10 mm and a length of 15 cm, the gap between the chucks was 100 mm, and the film was pulled with an Instron type universal tensile tester at a pulling speed of 10 mm / min and a chart speed of 500 mm / min. Young's modulus was calculated from the tangent line of the rising portion of the obtained load-elongation curve.

(3) Decurling rate A sample film having a size of 120 mm × 35 mm is
It is wound around a core having a diameter of 10 mm, heated at 70 ° C. and 30% RH for 72 hours, released from the core, and immersed in distilled water at 40 ° C. for 15 minutes. Then, a load of 50 g is applied, and the sample is dried in an air thermostatic bath at 55 ° C. for 3 minutes while vertically suspending the sample. After that, the load is removed, the sample is hung vertically, and the "sample length" (m in the state where the curl remains)
m) is measured, and the decurling rate is defined as the ratio (%) to the initial sample length of 120 mm.

In this case, the "sample length" is the diameter of the sample when the sample is greatly curled and has a circular to semi-circular shape, and is the diameter of the string when the curl of the sample is small and the shape is less than a semi-circle. Let it be the length.

The higher the curl removal rate, the easier the curl is removed.

(4) Cutting property The film is wound while cutting it to a width of 12.7 mm using a shear blade. (The slitter is TD-II type manufactured by Nishimura Seisakusho Co., Ltd., and winds a total length of 50 m at a speed of 50 m / min.) The appearance of the obtained roll is visually inspected and the cross section of the film is magnified and observed as follows. We ranked by criteria. ◯: The roll end has no protrusion and the cut end of the film cross section is flat. Δ: Some swelling is observed at the roll end, but the cut end of the film cross section is almost flat. Poor: The roll end portion was markedly raised and the cut end surface of the film section was also deformed and raised.

[0034]

Example 1 and Comparative Examples 1 to 4 Polyethylene-2,6-naphthalate having an intrinsic viscosity of 0.60 was melt extruded from a die slit by a conventional method and cooled and solidified on a casting drum to prepare an unstretched film.

The unstretched film was biaxially stretched under the conditions shown in Table 1, heat-fixed under tension, and annealed under the conditions shown in Table 1 to obtain a biaxially oriented film having a thickness of 75 μm.

In the annealing treatment, the film after biaxial stretching and heat setting is brought into contact with a quenching roll in a tensioned state to cool it, and the film is rolled up to a width of 500 m from a parent roll of the film.
The film of about 164 mm
It was carried out by winding in a roll shape on a mm core and heating in a heating oven.

The above annealing conditions are as shown below. Condition A: The temperature is raised to 100 ° C. over 24 hours, kept at this temperature for 24 hours, and then lowered to room temperature over 24 hours. Condition B: The temperature is raised to 60 ° C. over 12 hours, kept at this temperature for 24 hours, and then lowered to room temperature over 12 hours.

Main film forming conditions and longitudinal tan of the obtained biaxially oriented film due to tensile viscoelasticity at 0.05 Hz.
Table 1 shows the results of evaluation of δ (80 ° C.), Young's modulus in the vertical and horizontal directions, curl removal rate, and cuttability.

[0039]

[Table 1]

As is clear from the above results, the biaxially oriented polyethylene-2,6-naphthalate film of the present invention has a low tan δ, excellent curl removing property and excellent cutting property. On the other hand, if tan δ is higher than 0.08, the curl removing property is poor, and if the vertical and horizontal Young's modulus is out of the predetermined range, the cutting property is poor.

[0041]

EFFECT OF THE INVENTION The film for photographic light-sensitive material of the present invention can easily remove the curl generated when it is wound into a roll and is excellent in the cutting property of the film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI technical display location // C08G 63/189 NME 7107-4J B29K 67:00 B29L 7:00 4F (72) Inventor Kato Kotaro 3-37-19 Oyama, Sagamihara-shi, Kanagawa Teijin Limited Sagamihara Research Center

Claims (1)

[Claims] 1. A biaxially oriented polyethylene-2,6-naphthalate film, having a longitudinal tan δ due to tensile viscoelasticity at 0.05 Hz of 0.08 or less at 80 ° C. and a longitudinal Young's modulus. (Y _MD ) is 500-700
kg / mm ² and lateral Young's modulus (Y _TD ) of 700
A film for a photographic light-sensitive material, which is larger than kg / mm ² and has a difference (Y _TD -Y _MD ) between Young's modulus in the transverse direction and Young's modulus in the longitudinal direction of 100 kg / mm ² or more.