JPH09225953A - Production of support for photograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a production method for a cellulose triacetate film having a good planarity and avoiding a face failure damaging the transparency by a high speed film forming in a high temperature drying. SOLUTION: This device has a dry part 20 for drying a cellulose triacetate film stripped from a band or a drum formed by casting a dope for a cellulose triacetate film and a plane improvement part 50 to flatten the cellulose triacetate film. The planarity improvement part have a heating roller 54 and a cooling roller 56 for heating and cooling the cellulose triacetate film. Then, in forming a film consecutively on a coating part 60 on the upstream side of the plane improvement part, a cation polymer or an anion polymer is imparted to a top layer or a neighbourhood thereof of the film formed on the cellulose triacetate film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a cellulose triacetate film having good flatness and free of surface defects that impair transparency.

[0002]

2. Description of the Related Art One of the methods for producing a cellulose triacetate film is a solution casting method in which a dope is cast on a band or a drum, then peeled off as a film and dried.

Conventionally, as a drying method in this solution film-forming method, for example, as shown in FIG. 3, a cellulose triacetate film 73 stripped from a casting surface (drum surface) 71 is provided in a drying chamber 72. A large number of rollers 7
There is proposed a method of drying with hot air a, infrared rays, or the like while passing over between the rollers 4 and moving among a large number of rollers 74 (referred to as a roller transport method) (US Pat. Nos. 2,3).
19,053 specification).

There is also a method in which both side edges of the cellulose triacetate film stripped from the casting surface are dried while being conveyed without being stretched while being held by tenter clips or the like (JP-A-62-46625). JP-A-62-46626). This method is effective when the residual solvent of the cellulose triacetate film peeled off from the casting surface is very large and the surface of the cellulose triacetate film is damaged by contact with the roller surface when the method is carried out by the roller transport method.

By the way, the solution film forming method has a big drawback that the film forming speed is slow, and it has been an industrially important issue to increase the drying speed also in the drying step. Therefore,
Peel off the cellulose triacetate film from the casting surface as soon as possible, preferably dried at high temperature from both sides of the cellulose triacetate film, gelling agent therefor, for example, a high boiling solvent such as butanol is included in the dope ( U.S. Pat. No. 2,607,704
U.S. Pat. No. 2,739,069),
Also, a method of increasing the drying temperature has been proposed.

However, in the above-mentioned conventional method,
As the cellulose triacetate film, only a film having poor flatness was obtained. That is, when the cellulose triacetate film is transported in the drying step, continuous wrinkles (hereinafter referred to as streak burrs) are generated in the transport direction, and the streak burrs tend to occur frequently as the temperature rises. For example, the pitch is 30 to 50 mm, and the height of the unevenness during transportation is 5 to 6 mm (when the tension is stationary and there is no tension, 0.5 to
A streak of 1.0 mm) was generated.

[0007] When the cellulose triacetate film was used as a support for a photographic film or the like, this streak caused uneven thickness of the coated emulsion layer.

Therefore, the present inventors have proposed the following film forming method as a method for solving such a problem. That is, a casting step of casting the dope for cellulose triacetate film on a band or a drum, a drying step of drying the cellulose triacetate film stripped from the band or the drum of this casting step, and a drying step of this drying step. And having a flatness improving step of flattening the unevenness of the cellulose triacetate film, the flatness improving step, a roller heating step of conveying and flattening while heating the cellulose triacetate film that has undergone the drying step with a heating roller, Immediately after the roller heating step, the roller cooling step is performed in which the cellulose triacetate film is solidified by being conveyed while being cooled by a cooling roller.

According to this method, a cellulose triacetate film having good flatness can be formed without causing streaks even when the drying speed is increased by high temperature drying to form a high speed film. Therefore, it became possible to form an emulsion layer having a uniform thickness. However, after further research,
In this method, the plasticizer in the film may be deposited on the heating roller in the flatness improving step and adhere to the film in a thin film form, and a problem that a speckled pattern is generated on the film is still generated. It was not a satisfactory method.

[0010]

Accordingly, the present invention provides
It is an object of the present invention to provide a method for forming a cellulose triacetate film having good flatness without causing streaks even when it is dried at high temperature and formed at a high speed. Particularly, the present invention provides a cellulose triacetate film which has good flatness even at high-speed film formation by high-temperature drying, and has no surface defects (adhesion of plasticizer, generation of speckled patterns) that impair transparency. It is intended to provide a manufacturing method.

[0011]

The above-mentioned objects of the present invention have been achieved by the following film forming method. That is, the present invention includes (1) a casting step of casting a dope for a cellulose triacetate film on a band or a drum, and a drying step of drying the cellulose triacetate film peeled from the band or the drum of the casting step, It has a flatness improving step for flattening the surface of the cellulose triacetate film dried in the drying step, and the flatness improving step is performed by heating the cellulose triacetate film that has undergone the drying step while heating it with a heating roller to flatten it. In the method for producing a cellulose triacetate film, which comprises a roller heating step of, and a roller cooling step of solidifying the cellulose triacetate film by conveying while cooling with a cooling roller following this roller heating step, upstream of the flatness improving portion. The cellulose triacetate film When the coating film is continuously applied to the film, a cationic polymer or an anionic polymer is applied to both surfaces of the cellulose triacetate film, in the uppermost layer of the coating film to be applied or in the vicinity of the uppermost layer. And (2) in the method described in (1), the heating device in the roller heating step of the flatness improving portion is a far infrared heater,
A method for producing a cellulose triacetate film according to item (1), characterized in that a matting agent is applied to the back surface of the transport film as viewed from the far infrared heater, upstream of the flatness improving portion. It is provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when a material such as a gelatin-containing subbing layer or a conductive polymer is continuously applied upstream of the flatness improving portion, an anionic polymer or a cationic polymer as described above is used. Alternatively, the matting agent is applied at the same time. In the present invention, either the anionic polymer or the cationic polymer is on both sides of the cellulose triacetate film. Examples of the anionic polymer include homopolymers or copolymers containing a carboxyl group and containing acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, and maleic acid. Preferred are polymers containing maleic acid derivatives. Particularly preferred is a copolymer composed of a styrene-maleic acid derivative. As a specific embodiment, the styrene-maleic acid copolymer (hereinafter simply referred to as styrene-maleic acid copolymer) is formed on the side of the surface of the cellulose triacetate film coated with the gelatin-containing layer before the flatness improving step. A polymer) is applied. The coating amount is usually 0.1 to 50 mg, preferably 0.5 to 20 mg, and more preferably 1 to 15 per 1 m ^{2 of} the cellulose triacetate film.
mg. Although the coating method is not particularly limited, for example, a wire bar method, a slide coating method, a roller coating method, a dip coating method, a gravure coating method, or the like can be used. In this case, the thickness of the gelatin-containing layer is generally preferably 0.1 to 0.5 μ, but is not limited to this.
If necessary, a hardening agent, a surface-active agent, a synthetic polymer substance, and a matting agent are mixed in, but the effect does not change.

The styrene-maleic acid copolymer used in the present invention contains a large number of maleic acid units, and any one or more of these units which are esterified are included in the present invention. Therefore, each maleic acid unit has 1
Even if all or two of the carboxyl groups are not esterified, at least one esterified carboxyl group may be contained in the entire copolymer. Of course, a copolymer in which non-esterified maleic acid units, semi-esterified maleic acid units, and esterified maleic acid units are mixed is also included in the present invention. These copolymers preferably have a degree of esterification of 10 to 70%, and one or more of the unesterified carboxyl groups is preferably an alkali metal salt.
The styrene-maleic acid copolymer preferably used in the present invention is represented by the following general formula (I).

[0014]

Embedded image

(R ″, R ′ ″ are hydrogen atoms, Li, Na,
Represents an alkali metal atom containing K, an alkyl group having 1 to 12 carbon atoms, an alkenyl group, an alkynyl group or an aryl group (each of which may include a substituent), and w is 20 to 65.
Mol% and x represent 35 to 80 mol%. In the present invention, a particularly preferred styrene-maleic acid copolymer is represented by the following general formula (II).

[0016]

Embedded image

Here, n ₁ , n ₂ , n ₃ : 1 or 2 w: 20 to 60 mol% x: 0 to 40 mol% y + z: 10 to 70 mol%, y ≠ 0, z = 0 to 40 mol% M: Alkali metal atom such as lithium, sodium, potassium R ₁ , R ₂ , R ₃ : hydrogen atom, alkyl group having 1 to 4 carbon atoms, phenyl group The copolymer represented by the above general formula is an ordinary styrene-
Maleic anhydride copolymer

[0018]

Embedded image

It can be obtained by esterification with an alcohol represented by (R: hydrogen atom, lower alkyl group, phenyl group, n: 1 or 2) to form a part or all of the remaining carboxyl group into an alkali metal salt. The details of the synthesis method can be referred to the description in JP-A-51-23722. Specific examples of the styrene-maleic acid copolymer used in the present invention are shown below, but the present invention is not limited thereto.

[0020]

Embedded image

The styrene-maleic acid copolymer used in the present invention is preferably 2000 to 50000.
It is advantageous to have a molecular weight of 0, particularly preferably 5000 to 50000. Among the styrene-maleic acid copolymers used in the present invention, preferred ones are represented by the general formula (II), and among them, the preferred ones are:
In the general formula (II), n ₁ , n ₂ , n ₃ : 1;
w: 40-60 mol%; x: 20-40 mol%; y: 1
0 to 30 mol%; z: 0 to 10 mol%; M: sodium or potassium; R ₁ , R ₂ , R ₃ : hydrogen atom.

To apply the styrene-maleic acid copolymer according to the present invention onto a plastic film having a gelatin-containing undercoat layer, the solution is prepared by dissolving the copolymer in a non-solvent of the plastic film. To do. here,
The non-solvent of the plastic film means a solvent having no affinity for the cellulose triacetate film used as a support of the photographic light-sensitive material, and the solvent does not swell or dissolve the plastic film.

In another embodiment of the present invention, the surface of the cellulose triacetate film on which the gelatin-containing layer is not coated (generally the backside of the surface on which the silver halide emulsion layer is coated, This is called the back surface) and a cationic polymer is applied. The coating amount is usually 0.1 per 1 m ² of cellulose triacetate film.
The amount is 01 to 0.2 g, preferably 0.01 to 0.1 g. The coating method is not particularly limited, but for example, a slide coating method, a roller coating method, a dip coating method or the like can be used. Further, even if a matting agent having a binder such as a cellulose ester generally applied to a photographic light-sensitive material, a slip agent, a surfactant and a dye is added to the upper layer of the cationic polymer, the effect is not changed.

The cationic polymer contains a quaternary ammonium salt which is an antistatic agent. Preferably, the polymer is an ionene type, a styrene derivative or an acrylic ester derivative and contains a quaternary ammonium salt. More preferably, it is a cationic polymer represented by the following general formula (III).

[0025]

Embedded image

In the formula, R ₁ and R ₂ are each an alkyl group having preferably 1 to 10 carbon atoms, a substituted alkyl group (as the substituent, for example, a cycloalkyl group, a hydroxyl group, a cyano group, an amido group, a carboxyl group). Group, alkoxycarbonyl group, carbamoyl group, etc.), cycloalkyl group, aralkyl group, aryl group, alkenyl group (eg, allyl group). These R ₁ and R ₂ may combine with each other to form an alkylene chain (eg ethylene). R ₃ represents an alkylene group having 10 or less carbon atoms or an aralkylene group. X ₁ ⁻ and X ₂ ⁻ each represent an anion, and a halogen ion and R ₄ O—SO ₂ —O are preferable.
It represents —, R ₄ —SO ₂ —O—, (HO) ₂ PO—O—, particularly preferably a halogen ion such as chloride or bromide. n is about 10 to about 300,
It is preferably about 30 to about 200. Formula (II) or
The compound represented by (III) is, for example, JP-B-57-5.
It is synthesized by the method described in No. 6059. General formula (I
Specific examples of the cationic polymer represented by I) and (III) are shown below, but the present invention is not limited thereto.

[0027]

[Chemical 6]

In the present invention, when the heating device in the roller heating step in the step of improving flatness is a far-infrared heater, the carrier film is viewed from the far-infrared heater and a matting agent is applied to the back surface of the carrier film. Examples of the matting agent include fine particles having an average particle diameter of 0.01 to 1 μm, and the coating amount is usually 1 to ²⁰⁰ mg, preferably 1 to 50 mg, and more preferably 3 to 20 mg per 1 m ² of the cellulose triacetate film. .
Silicon dioxide is generally used as such a matting agent. When silicon dioxide is dispersed in the gelatin dispersion, silicon dioxide particles which are depolarized by silane coupling with an alkyl group are used for the stability of gelatin. In addition, an inorganic compound such as strontium barium sulfate or an organic polymer such as polymethylmethacrylate or polystyrene can be used as the matting agent material. The application method is
Liquid in which a matting agent is dispersed in a binder of a polymer such as cellulose ester (for example) cellulose diacetate in a non-solvent of cellulose triacetate, or a matting agent is dispersed in a gelatin dispersion liquid in which a polymer such as cellulose ester (for example) cellulose diacetate is a binder. The applied liquid is applied by a coating method such as a slide coating method, a roller coating method or a dip coating method.

The flatness improving step of the present invention will be further described. In order to heat and cool the cellulose triacetate film in the roller heating step and the cooling step of the flatness improving step, a plurality of heating roller groups and cooling roller groups are respectively provided, and after heating with the heating roller group, cooling with the cooling roller group. However, even if one heating roller and one cooling roller each having a large diameter are provided, and one heating roller is used for cooling and then one cooling roller is used for cooling, one half of the large diameter roller is used as a heating portion. One half may be used as a cooling unit, that is, one roller may be used as both a heating roller and a cooling roller, and heating may be performed by one heating unit and then cooled by another cooling unit. However, a method using a roller group is preferable because scratches due to shrinkage are less likely to occur.

The temperature of the heating roller may be a temperature at which the cellulose triacetate film is sufficiently softened, preferably 100 to 190 ° C, more preferably 120 to 17 ° C.
0 ° C. If the temperature of the heating roller is too high,
The plasticizer in the film is leached out, which is not preferable. To heat the heating roller, the heating roller itself may be provided with a built-in heat source such as a heater, heated by hot air, or heated by an external heat source such as a far infrared heater. Further, the built-in heat source and hot air may be combined, the built-in heat source and external heat source may be combined, the hot air and external heat source may be combined, or the built-in heat source, external heat source, and hot air may be combined.

The temperature of the cooling roller may be a temperature at which the rigidity of the cellulose triacetate film is sufficiently obtained, preferably 10 to 95 ° C., more preferably 20 to 8 ° C.
0 ° C. To maintain the cooling roller at a predetermined temperature, a cooling roller using warm air or a refrigerant having a predetermined temperature is used.

The interval between the end of heating by the heating roller and the cooling by the cooling roller is the interval at which the cellulose triacetate film having the unevenness flattened by the heating roller is cooled by the cooling roller while maintaining its flat state. It is set appropriately depending on the rigidity of the triacetate film. In the method for producing a cellulose triacetate film of the present invention, in the drying step, a cellulose triacetate film in which flatness is deteriorated due to occurrence of streaks due to buckling deformation in the width direction due to transport tension,
It is softened by being wound by a heating roller and conveyed, and at the same time flattened by eliminating streaks. Immediately, it is solidified by being wound by a cooling roller and conveyed to be straightened.

The method for producing the cellulose triacetate film of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of a manufacturing apparatus for carrying out the method for manufacturing a cellulose triacetate film.

In FIG. 1, reference numeral 10 is a casting portion for casting a dope for cellulose triacetate film, and reference numeral 2
Reference numerals 0 and 30 denote a first drying unit and a second drying unit for sequentially drying the cellulose triacetate film 40 peeled off from the casting unit 10, and a reference numeral 50 denotes a cellulose triacetate film sent from the second drying unit 30. This is a flatness improving portion that eliminates the 40 streaks. An undercoat coating section 60 is provided between the first drying section 20 and the second drying section 30.

The casting part 10 comprises a band 11 cooled to a predetermined temperature and a casting port 12 provided above the band 11. In addition, the first and second drying units 20 and 30 respectively include a hot air supply port 21 for supplying hot air a into the room.
And 31 are provided, and a plurality of rollers 22 and 32 for conveying the cellulose triacetate film 40 are provided.

The flatness improving portion 50 is provided with a heating chamber 51 and a cooling chamber 52 adjacent to each other, and a large number of heating rollers 53 are arranged in the heating chamber 51 so as to be adjacent to each other on a substantially same plane. A group 54 is provided, and cooling rollers 55 are arranged in the cooling chamber 52 so as to be adjacent to each other on a substantially same plane.
6 are continuously arranged in the heating roller group 54. Further, the heating chamber 51 is provided with a hot air supply port 57, the hot air b is supplied from the hot air supply port 57 into the room, and the cooling chamber 52 is provided with a cooling air supply port 58. The cooling air supply port 58 supplies the cooling air c into the room.

In order to manufacture a cellulose triacetate film with the above-described manufacturing apparatus, first, a dope having a predetermined composition is cast from the casting port 12 to the band 11 and dried under a temperature condition in which the cast dope does not foam. Carry while carrying.
Then, when the self-holding property is exhibited to some extent, it is peeled off from the band 11, then sent to the first drying unit 20, and the hot air a is sent from the hot air supply port 21 and conveyed by the roller 22,
Dry until primed. The thus-dried cellulose triacetate film 40 is sent to the undercoat application section 60, and the undercoat agent for the photographic light-sensitive material is applied. Then, the undercoated cellulose triacetate film 40 is sent to the second drying unit 30 and dried in the same manner as in the first drying chamber 20.

Next, the cellulose triacetate film 40 is sent to the flatness improving section 50, and first, in the heating chamber 51, while being blown with hot air, the heating roller group 54 is wound around and conveyed so as to be softened and streaks are generated. Then, the surface is made flat, and then, while cooling air is blown in the cooling chamber 52, it is solidified by the cooling roller group 56 in a flat state. Therefore, the cellulose triacetate film 40 discharged from the cooling chamber 52 is wound up in a good flat state with no surface irregularities. FIG.
FIG. 6 is a schematic view of another example in which the flatness improving portion of the manufacturing apparatus for carrying out the method for manufacturing a cellulose triacetate film is changed.

In this manufacturing apparatus, a far-infrared heater 59 is arranged in the heating chamber 51 so as to face the heating roller 53, and the other structure is the same as that of the manufacturing apparatus shown in FIG.
In this manufacturing apparatus, the heating roller 53 and the cellulose triacetate film are heated by the far infrared heater 59 in the heating chamber 51. The heating with hot air may or may not be performed at the same time.

Next, a light-sensitive material to which the present invention is applied will be described. In the present invention, a surface treatment is preferable in order to bond the support and the light-sensitive material constituting layer. Surface activation treatments such as chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment, ozone oxidation treatment, and the like. Among the surface treatments, ultraviolet irradiation treatment, flame treatment, corona treatment, and glow treatment are preferable.

The photosensitive layer preferably contains a matting agent. The matting agent may be on either the emulsion side or the back side, but is particularly preferably added to the outermost layer on the emulsion side. The matting agent may be soluble in the processing solution or insoluble in the processing solution, and preferably both are used in combination. For example, polymethyl methacrylate, poly (methyl methacrylate / methacrylic acid = 9/1 or 5/5 (molar ratio)), polystyrene particles and the like are preferable. The particle size is preferably 0.8 to 10 μm, and the particle size distribution is also preferably narrow. It is preferable that 90% or more of the total number of particles is contained between 0.9 and 1.1 times the average particle size. . Further, it is also preferable to add fine particles of 0.8 μm or less at the same time in order to enhance the matting property, for example, polymethyl methacrylate (0.2 μm), poly (methyl methacrylate / methacrylic acid = 9/1 (molar ratio), 0.3 μm )), Polystyrene particles (0.25
μm) and colloidal silica (0.03 μm).

In the present invention, the silver halide emulsion is usually used after physical ripening, chemical ripening and spectral sensitization. The additive used in such a process is RDNo. 1
7643, the same No. 18716 and the same No. 3071
No. 05, and the relevant parts are summarized in the table below. In the light-sensitive material of the present invention, two or more types of emulsions having at least one characteristic different from each other in the grain size, grain size distribution, halogen composition, grain shape and sensitivity of the photosensitive silver halide emulsion are mixed in the same layer. Can be used.
US Pat. No. 4,082,553, the surface fogged silver halide grains, US Pat. No. 4,626,498, and JP-A-59-214852, the inner fogged silver halide particles and colloidal silver. It is preferably applied to the photosensitive silver halide emulsion layer and / or the substantially light-insensitive hydrophilic colloid layer. The fogged silver halide grain inside or on the surface means a silver halide grain that enables uniform (non-imagewise) development regardless of the unexposed area of the light-sensitive material. Law is US 4,626,4
98, JP-A-59-214852. The silver halide forming the internal nucleus of the core / shell type silver halide grain having the inside of the grain fogged may have a different halogen composition. As the silver halide having the inside or surface of the grain fogged, any of silver chloride, silver chlorobromide, silver iodobromide and silver chloroiodobromide can be used. The average grain size of these fogged silver halide grains is preferably 0.01 to 0.75 μm, particularly preferably 0.05 to 0.6 μm. The grain shape may be regular grain or maybe acid emulsion, but monodispersity (at least 95% of the weight or the number of silver halide grains is ± 4 of the average grain size).
(Having a particle diameter of 0% or less).

In the present invention, it is preferable to use non-photosensitive fine grain silver halide for the color light-sensitive material. Non-photosensitive fine grain silver halide is silver halide fine grains that are not exposed during imagewise exposure to obtain a dye image and are not substantially developed in the developing process, and are preferably not fogged in advance. . The fine grain silver halide has a silver bromide content of 0 to 100 mol%, and may contain silver chloride and / or silver iodide as needed. Preferably, it contains 0.5 to 10 mol% of silver iodide. The fine grain silver halide preferably has an average grain size (average diameter of circles corresponding to the projected area) of 0.01 to 0.5 μm, more preferably 0.02 to 0.2 μm. Fine grain silver halide can be prepared by the same method as that for ordinary photosensitive silver halide. The surface of the silver halide grains does not need to be optically sensitized, and no spectral sensitization is required. However, prior to adding this to the coating solution, it is preferable to add a known stabilizer such as a triazole-based, azaindene-based, benzothiazolium-based, or mercapto-based compound or a zinc compound in advance. Colloidal silver can be contained in the layer containing fine silver halide grains. The amount of silver applied to the light-sensitive material of the present invention is 6.
0 g / m ² or less is preferable, and 4.5 g / m ² or less is most preferable.

In the color light-sensitive material, the photographic additives that can be used in the present invention are described in RD, and the relevant portions are shown in the table below. Type of additive RD17643 RD18716 RD307105 1. Chemical sensitizer page 23 page 648 right column page 866 2. Sensitivity increasing agent, page 648, right column 3. Spectral sensitizer, pages 23-24, page 648, right column 866-868, super sensitizer ~ page 649, right column Whitening agent Page 24 Page 647 Right column Page 868 5. 5. Light absorber, page 25-26, page 649, right column, page 873, filter-page 650, left column, dye, ultraviolet absorber. 6. Binder page 26 page 651 left column pages 873 to 874 7. Plasticizer, page 27, page 650, right column, page 876, lubricant Coating aid, pages 26 to 27, page 650, right column, pages 875 to 876, surfactant 9. Static, page 27, page 650, right column, pages 876-877, inhibitor 10. Matting agent 878-879

The support of the present invention can be used in a color negative or color reversal light-sensitive material, but it is particularly preferable to use it in a color negative light-sensitive material.

[0047]

Next, the present invention will be described in more detail with reference to examples.

Example 1 21% by weight of cellulose triacetate, 3% by weight of triphenyl phosphate, 65% by weight of methylene chloride,
A dope composed of 7% by weight of methanol and 4% by weight of butanol was prepared and cast by a band casting machine using the production apparatus shown in FIG. In the coating section 60 in the middle of the drying process, the following functionalization (undercoating, antistatic property) was performed as a support for coating a photographic emulsion. In FIG. 1, only one coating machine is shown in the coating section 60, but as the coating section 60, equipment capable of coating two layers each on the emulsion layer coating surface and the back surface was used.

Drying was carried out at a temperature of the first drying chamber 20 of 70 ° C. and a temperature of the second drying chamber 30 of 120 ° C. The radius of the heating roller 53 in the flatness improving portion is 5 cm, 20 pieces are arranged at a pitch of 12 cm, and the radius of the cooling roller 55 is 5 cm.
20 pieces are arranged at a pitch of 2 cm, and the heating chamber 51 is 120 ° C.,
The cooling chamber 52 was heated to 100 ° C., and the heating system was a far-infrared heater as shown in FIG.

The surface of the carrier film coated with the emulsion layer faces the far-infrared heater. Supply air volume (b, c) so that the plasticizer dew point of the heating chamber 51 and the cooling chamber 52 is below 60 ° C.
Was adjusted. A gelatin-containing layer was coated in a thickness of 0.1 to 0.5 μm on the first layer on the emulsion layer-coated surface and the back surface using the manufacturing apparatus set under the above conditions. At this time, an average particle size of 0.0
1 to 0.1 μm of silicon dioxide (Aerosil R972,
^{3 to 9} mg of fine particles (trade name) were applied per 1 m ² .
The silicon dioxide fine particles were dispersed in a gelatin-containing coating liquid together with a trace amount of cellulose diacetate and then coated. In order to stabilize the dispersed gelatin in the coating solution, the silicon dioxide fine particles used were silane-coupled with an alkyl group and made nonpolar. Styrene-maleic acid copolymer (PA-1) was added to the second layer of the emulsion layer coated surface and the back surface at 1 per 1 m ^2.
-8 mg was applied. Thus, a cellulose triacetate film having a thickness of 122 μm was transferred at a transport speed of 60 cm / sec.
It was continuously manufactured for 80 minutes. The flatness of the obtained film was good. No failure with the plasticizer occurred on the emulsion layer coated surface and the back surface of the film. No seizure failure such as a speckled pattern occurred on the back surface.

Comparative Example 1 A gelatin-containing undercoat layer (containing no matting agent) was applied to the first layer on the emulsion layer-coated side and the back side at a thickness of 0.1 to 0.5 μm, but the second layer was not coated. In the same manner as in Example 1, a cellulose triacetate film having a thickness of 122 μm was produced for 180 minutes at a conveying speed of 60 cm / sec.
Although the flatness of the obtained film was good, coating with an emulsion layer and a failure with a plasticizer on the back surface occurred, and a spotted adhesive pattern was generated on the back surface.

Comparative Example 2 Two layers each were coated on the emulsion layer-coated surface and the back surface in exactly the same manner as in Example 1 except that the matting agent was not added to the first-layer gelatin-containing undercoat layer on the back surface. Then, a cellulose triacetate film having a thickness of 122 μm was produced in exactly the same manner as in Example 1. The obtained cellulose triacetate film had a good flatness, and although the coating of the emulsion layer and the failure to attach the plasticizer to the back surface did not occur, a speckled pattern was generated on the back surface.

Example 2 A dope having the same composition as that of Example 1 was prepared, and the same band casting machine was used to form a film in the same manner as shown in FIG. 1. Then, the same drying conditions and flatness improving conditions were used. In the same manner, a cellulose triacetate film having a thickness of 120 μm was formed at a conveying speed of 60 cm / sec for 180 minutes. However,
The treatment on the emulsion layer coated surface and the back surface before the flatness improving step was performed as follows. A gelatin-containing undercoat layer having a thickness of 0.1 to 0.5 μm was coated on the first layer on the emulsion layer coating surface. Styrene-maleic acid copolymer (PA-3) was added to the second layer in an amount of 1 m ²
About 1 to 8 mg was applied. On the other hand, the antistatic agent (PC-1) is applied to the first layer on the back surface in an amount of 0.1 to 0.1 per 1 m ^2.
1.0 g was applied, and as a matting agent, fine particles of silicon dioxide having an average particle size of 0.01 to 0.1 μm were dispersed as a matting agent in an organic solvent using cellulose diacetate as a binder to obtain 10 to ²⁰ mg per 1 m ² . Granted. The flatness was good. Neither the plasticizer-related failure nor the seizure failure occurred on the back surface. No failure with a plasticizer occurred on the emulsion layer coated surface.

Comparative Example 3 A cellulose triacetate film having a thickness of 120 μm was conveyed in the same manner as in Example 2 except that the first layer was coated on the emulsion layer-coated surface and the back surface, but the second layer was not coated. Manufactured in 180 seconds. Although the flatness of the obtained film was good, a failure with a plasticizer occurred on the emulsion layer coated surface, and an adhesion failure occurred on the back surface.

Comparative Example 4 A thickness of 120 μm was obtained in the same manner as in Example 1 except that the styrene-maleic acid copolymer of the second layer on the emulsion layer coated surface was omitted.
m cellulose triacetate film with a conveying speed of 60
It was manufactured for 180 minutes at cm / sec. No failure with plasticizer and no adhesion failure occurred on the back surface, but failure with plasticizer occurred on the emulsion layer coated surface.

[0056]

EFFECTS OF THE INVENTION According to the present invention, even if high temperature drying or high temperature film formation is performed, it is possible to prevent deterioration of transparency, adhesion of plasticizer on the film surface, formation of spots, etc., and cellulose having good flatness. Triacetate films can be manufactured. Therefore, according to the present invention, the cellulose triacetate film can be dried at a high temperature and at a high speed while the flatness of the cellulose triacetate film is kept good, so that the production rate of the cellulose triacetate film can be remarkably increased. as a result,
It is possible to inexpensively produce a photographic film or the like having a good quality in which a uniform emulsion layer is formed.

[Brief description of drawings]

FIG. 1 is a schematic view of a manufacturing apparatus for carrying out the method for manufacturing a cellulose triacetate film of the present invention.

FIG. 2 is a schematic view of a flatness improving portion using a far infrared heater of a manufacturing apparatus for carrying out the method for manufacturing a cellulose triacetate film of the present invention.

FIG. 3 is a schematic view of a manufacturing apparatus for carrying out a conventional method for manufacturing a cellulose triacetate film.

[Explanation of symbols]

 10 Casting Part 20 First Drying Part 30 Second Drying Part 40 Cellulose Triacetate Film 50 Flatness Improvement Part 51 Heating Chamber 52 Cooling Chamber 53 Heating Roller 54 Heating Roller Group 55 Cooling Roller 56 Cooling Roller Group 59 Far Infrared Heater 60 Undercoat Layer coating section

Claims (2)

[Claims] 1. A casting step of casting a dope for a cellulose triacetate film on a band or a drum, a drying step of drying the cellulose triacetate film peeled from the band or the drum of the casting step, and a drying step. And a flatness improving step for flattening the surface of the dried cellulose triacetate film, wherein the flatness improving step is carried out by heating the cellulose triacetate film which has undergone the drying step with a heating roller and heating the roller to flatten it. In the method for producing a cellulose triacetate film, which comprises a step, and a roller cooling step which follows this roller heating step and conveys while cooling with a cooling roller to solidify the cellulose triacetate film, the cellulose triacetate upstream of the flatness improving portion. Continuously on the film A method for forming a film, which comprises applying a cationic polymer or an anionic polymer on both surfaces of a cellulose triacetate film on the uppermost layer of the applied coating or in the vicinity of the uppermost layer when the coating is applied. 2. The method according to claim 1, wherein the heating device in the roller heating step of the flatness improving section is a far-infrared heater, and the far-infrared heater sees the carrying film, and the above-mentioned surface is provided on the back surface of the carrying film. The method for producing a cellulose triacetate film according to claim 1, wherein a matting agent is applied upstream of the flatness improving portion.