AU603019B2 - Photographic film antistatic backing layer with auxiliary layer having improved properties - Google Patents

Description

AUSTRALIA

PATENTS ACT 1952 COMPLETE SPECIFICATION 6030 19 Form

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: This dorumcft contins the Iam~4efliens made under Section 49 and is corrCCt for rinting. d4 I~ V Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: E. I. DU PONT DE NEMOURS AND COMPANY 1007 MARKET STREET

WILMINGTON

DELAWARE, 19898

U.S.A.

GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Q Actual Inventors Address for Service: Complete Specification for the invention entitled: PHOTOGRAPHIC FILM ANTISTATIC BACKING LAYER WITH AUXILIARY LAYER HAVING IMPROVED PROPERTIES The following including the statement is a full description of this invention best method of performing it known to me:- I~ I 67 TITLE IM-0086 PHOTOGRAPHIC FILM ANTISTATIC BACKING LAYER WITH AUXILIARY LAYER HAVING IMPROVED PROPERTIES BACKGROUND OF THE INVENTION Cr0ss-reference to Related Applications This invention is related to Cho U.S. Patent No. 4,585,730, "Antistatic Backing Layer with Auxiliary Layer for a Silver Halide Element". granted April 29. 1986, This invention is also related to Miller U.S. Patent No. 4,701,403, "Two-Lau'er Process 4 9 Cfor Applying Antistatic Compositions to Polyester Supports," granted October 20, 1987, which is directed to a process tor applying a thin, clear lb antistatic layer to a photographic film. The present invention provides an auxiliary layer designed to be coated over (such layer.

Field of the Invention This invention relates to a photographic film. More particularly this invention relates to a too I C photographic film having an improved auxiliary backing layer for said film which can conduct antistatic properties from an antistatic underlayer C to the outside surface thereof.

BacKgiround Art Polymeric film supports for photoqraphic film are known for their propensity to accumulate static charges. This is a particular problem where the film is designed to be handled by machine and to be processed rapidly over unlike surfaces. Static charges which may be generated at this time cannot be readily tolerated because discharging these may expose the photographic layu, or layers, coated thereon.

359 i -2 2 The use of so-called antistatic layers to prevent the build-up of these static charges is well known in the art. Schadt U.S. Patent 4,225,665, describes one such composition comprising a mixture of a water-soluble copolymer of the sodium salt of styrene sulfonic acid and a carboxyl-containing monomer, a hydrophobic polymer containing carboxyl groups, and a water-soluble Sc, cpolyfunctional aziridine. When this mixture is 10 applied as a single layer to resin-subbed (:esin-subcoated)poly(ethylene terephthalate), for p 5€ example, it provides excellent protection from the a build-up of static charges surface resistivity).

Miller U.S. Patent 4,701,403 describes an improvement over the aforementioned Schadt patent wherein a polymer such as component for example, i is applied to the support in a first coating, optionally a composition containing component i a«o. 20 and, after drying, aziridine component is applied ,as a second coating contiguous thereto. This improved process permits the application of improved i thinner antistatic layers without premature reaction of the aziridine with the other ingredients.

C t C Products from such premature reaction can sometimes plug and foul coating equipment, which is not commercially tolerable.

Cho U.S. Patent 4,585,730 describes an auxiliary layer containing a conductive polymer as described therein. This layer is satisfactory in transporting antistatic properties from underlayers to the surface thereof. However, occasionally 'he layor described in this patent suffers from certain disadvantages such as problems with anchorage and 2

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3 poor processability in the fluids in which the photographic layer is processed.

It is desired to provide an improved auxiliary layer over an antistatic layer of a photographic film which is useful in conducting antistatic properties to the surface thereof. Such a layer also serves as a backing layer for a photographic film which contains an antistatic layer thereon. It is also desired to provide such an 10 auxiliary layer with good anchorage to previously applied layers and which is stable in photographic processing fluids, SUMMARY OF THE INVENTION In accordance with this invention there is 15 provided a photographic film comprising a support, at least one silver halide emulsion coated on one side of said support, and an antistatic layer coated on the opposite side of said support, characterized in that the antistatic layer is coated at a pH of 3 to 12 with an auxiliary layer consisting essentially of at least one crosslinkable conductive polymer having functionally attached carboxylic acid groups, and a crosslinking agent for the conductive polymer dispersed in a gelatin binder, whereby the antistatic properties of the antistatic layer are conducted through the auxiliary layer.

DETAILED DESCRIPTjON OFTHKINViNTION Consisting essentially of as used in the appended claims means that unspecified constituents or conditions are not excluded provided that they do not affect the advantage of the invention from being realized.

The crosslinkable conductive polymer may be present alone or in combination with at least one other crosslinkable conductive polymer. A

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ft e 4 particularly preferred crosslinkable conductive polymer is poly(sodlum styrene sulfonate-maleic anhydride). Other crosslinkable, conductive polymers include: hexadecyl betaine, alkyldimethyl betaines wherein alkyl is 1 to 12 carbon atoms, carboxylated imidazolines, coco amido betaines, etc. These conductive polymers which contain functionally attached carboxylic acid groups may be added to the auxiliary layer of this invention in a range of to 30% by weight of the gelatin binder, preferably at to 2.5% by weight. The term "gelatin binder" denotes a binder wherein the major componont is gelatin. Gelatin substitutes, polyvinyl alcohol, detran, cellulose derivatives, modified gelatins, a water-soluble acrylic latex, etc., may be present in minor amounts, loe than 17% by weight.

Crosslinking agents useful within the ambit of this invention include polyfunctional aziridines such as those described in Schadt U.S, Patent 4,225,665 and Miller U.S. Patent 4,701,403, The disclosures relating to the aziridinca are incorporated herein by reference. other useful crogalinking (hardening) agents include: chrome alum, carbodlimides, inoxazolinium salts. etc.

Particularly preferred is pentaerythritol-tri-beta- (2-methyl aziridine) propionate added to the gelatin binder. The crooslinking agent may be present in an amount of 0.5 to 5,0% by weight of the gelatin a0 binder. preferably in an amount of 2.0 to 3.01. by weight, A mixture of the gelatin binder in water, the croslinkablo- conductive polymer and the crooslinking agent of this invention in made up prior to coating. other additives ouch as, for example# 4 antihalation dyes, surfactants, wetting agents and hardeners, etc., may also be present in the mixture.

At this point, just prior to coating, the pH is adjusted to 3 to 1.2, preferably 6 to 8.

The aqueous coating composition made as described above may be applied with good results to any of the conventional photographic film supports but the preferred support is poly(ethylene V terephthalateN subcoated with a layer or layers of $for 10 conventional resins and bearing on one side a photosensitive layer, preferably a silver halide emulsion layer, and on the other side as a backing layer a layer of an antistatic composition. e.g., antistatic coatings of Schadt U.S. Patent 4,225,665.

Miller U.S. Patent 4,701,403, etc. The invention is not limited to any particular antistatic coating: cl however, the antistatic coatings of Miller. U.S.

Patent 4,701,403 are preferred (see particularly column 3, line 56 to column 4. line 56, the disclosure of which is incorporated herein by reference), The backing layer of this invention is then coated over the antistatic layer at a coating 2 weight of about 30 to 90 mg/din preferable about to 60 mg/din 2 Thus, In a particularly preferred mode, this invention is represented by a photographic film element which comprises a support, which is preferably dimensionally stable polyethylene Law"?terephthalate suitably subbed on both sides with a thin, anchoring substratum of a conventional resin sub over which may be applied a gelatin sublayer. on one side of this support a standard silver halide emulsion layer may be applied and this layer then overcoated with a protective overcoat layer, a conventional hardened gelatin, abrasion layer. on wwpxl_ i

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6 the side opposite to the side containing the emulsion layer, the antistatic layer of Miller U.S. Patent 4,701,403 is preferably applied followed by an auxiliary layer represented by this invention. The layer of this invention may be an antihalation layer or may be coated simply as a gelatin anti-curl layer, as is well-known to those of normal skill in the art.

In another embodiment, the auxiliary layer can be replaced by two separately coated layers, each layer containing gelatin, one layer of which contains at least one crosslinkable conductive polymer and the other layer of which contains a crosslinking agent, both as described and in the amounts set out above.

For example, the conductive polymer dispersed in some 1$ gelatin may be coated first followed by a coating of gelatin and crosslinking agent, When wet, the crosslinking agent will migrate into the conductive polymer-containing layer effectively serving to crosslink gelatin and polymer as described above.

When the layer of this invention is made as taught herein, many advantages are obtained, First, this layer will provide the desired transmission of antistatic properties from the antistatic layer to the surface of the film. Next, the layer of this 25 invention is stable and will survive the rigors of photographic processing without disintegration. This is very desirable since prior art layers tended to flake off during the processing steps. Loss of layer integrity is a defect that cannot be tolerated since particles of the layer tend to foul the processing fluids and, more importantly, cause loss of antistatic transmission proporties. Additionally, the adhesion between preViOUsly coated or subsequently coated layers is enhanced by the presence of a layer of this invention over those of P 7 the prior art. This is a surprising result since layers very similar to those described herein, which have the required hardness from gelatin hardeners, among others, and are satisfactory in transmitting the antistatic properties, do not have the characteristics described above.

while not being limited, it is theorized IJ that the crosslinking agents, such as those described above, interconnect the gelatin, the conductive poitymer and the carboxyl. groups available on the surface of the antistatic underlayer providing .qxcellent adhesion, it is suzprising, however, that transmission of the antistatic properties Is maintained since it was thought that the conductive polymer should have all of the groups on the polymer chains available to provide transmiss ion of the antistatic properties.

A host of conventional photosensitive A materials may be present as the emulsion layer described above, These include photopolymer. diazo, vesicular imaqe-torming materials,~ etc. The films described may be used in any of the well-known imaging fields such as graphic arts, printing, medical and Information systems, among othero. The photographic film of this invention Is particularly useful in processes whore rapid transport and handling by machines are practiced ouch as phototypesetting applications, for example.

Particularly useful elements include the so-called "bright-light" films which can be handled in relatively bright satelights, for example.

This invention will now be Illustrated but not limited by the following examples Wherein the 3~ prcenagesare by Weight.

re -08- EXAMPLES 1 TO A backing layer antihalation solution was prepared by mixing 1200 g of gelatin in 13,530 g of distilled water for 15 minutes at 49 0 C. The mixture was cooled to 38 0 C and the following ingredients added: ingredient Amount i bi

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'1 a C C e, c 4'I VI t e 0 C, 4.2% aqueous solution of sodium octyl phenoxy diether sulfonate wetting agent (Triton X200.

Rohm Haas Co.) ethyl alcohol distilled water SP Yellow Dyo(l) in 120) S-1240 Dye( 2 (16.0% in Acid Violet Dyo( 3 (12.0% in polyothyl aczylato latex (32.5% in H 6% aqueous solution of sodium my~ristyl3 t .iothor oulfatot~ wetting agent (Standapol ES4O.

Heonkel inc., U.S.A.) sodium hydroxide (3N) Wiqueous solution of parfluoroalkyl carboxylato (kC-127 3M Co.) silica matte (12 ml, Davidshon Cheiiic41 Co.) 720.0 cc 450.0 1050.0 108.0 50.0 54.0 540.0 250.0 18.0 270.0 5-3 "TRITON" referred to aboveno a X eifttoed trademarik v4, SF Yellow (D782) Io) 2 i CH 2 CH 3 CH 2 -p so Pa Cl 2 )S-I1240 Dye (D781) 0 11 NaO

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CH 3 3 Acid Violet Dye (D720) 0 C

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3 These ingredients were thoroughly mixed and split into portions of about 3040 q of each. Six portions were used for this example with further If additions and treatments as follows: if Crosslinking(l) Conductive( 2 Agent, Polymer Aq. Aq.

Example No. Soln) Soln) (q) 1 42 175 2 84 74 J3 84 175 4 126 100 125 Control 1 0 0 i 15 Control 2 Sample 3 from Ex. 1. U.S. Patent 4,585,730 is a solution of pentaerythritol-tri-beta- (2-methyl aziridine) propionate in distilled water is a crosslinKable conductive polymer polymer(sodium styrene sulfonate-maleic anhydride) diluted in distilled water (no.

average molecular wt. ca. 3,000 determined by known osmometry techniques) A sample of each of the above solutions was coated on a 0.004 inch (0.10 mm) polyethylene terephthalate, resin subbed (both sides) film which had been coated Previously with an antistatic layer siimilar to that described by m4iller tJ.S. Patent 4o701,403, Solution No. 4 of Example 1. Each of the afoeemeritioned solutions was coated over the described antistatic layer to give a coating weight 2 of ca. 55 mg/din After drying, the surface resistivity of each layer was measuroa following the procedure round in Cho U.S. Patent 4j685,730.

'Example 1. column 4. In each case, with the

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11 I exception of Control No. 1, the static protection was F excellent. Each sample was then run through a standard photographic processor (developer, fixer, wash an dry) and the surfaces were then examined for static resistivity and adhesion. In the case of Examples 1-5 resistivity and adhesion were found to be excellent. None of the material had come off during processing and all of the antistatic c transmission qualities were maintained. In the case S 10 of Controls 1 and 2, adhesion was poor, much of the PP layer had come off during the processing step.

S Control 2 static protection was poorer than that of I' Examples 1 to EXAMPLES 6 to 19 To text the efficacy of another crosslinking I c agent and another conductive polymer or combination Sof conductive polymers within the metes and bounds of j this invention, a large sample of the antihalation I 20 solution of Examples 1-5. above, was prepared and divided into 14 portions of 3040 gms as described therein. Additions were made to each portion as shown below: i i m

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Chrome Alum Crosslinking Agent Aq.

aSo 1ALq1g Conduc- (1) tive Polymer I (10% Aq, Soin) Wi Conduc- 2 tOve Polymer 11 (10% Aq.po2 kgJ) gxaMpke o.

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6 7 a 12 Control 13 14 16 lB 17 18 19 Control b .0 F5.9 (1) 2 0 COCO bMido betalno 0 CO 3 (C-NH--C14 2 H=CH 2 G H 2 *-C0 C11 3 manufactured by Alkaril Chemn~cals, Ltd.

ao A1)kateric CAll, came as~ he conductive polymer of, above.

aind sold Ex. 13 Samples of each solution were then applied to film supportJ containing an antistatic layer as described in Examples 1-5. Each sample was tested for static and adhesion as also described in Examples 1 to In the case of controls (Examples 12 and 19), there was a noticeable lack of static protection in both the pre-processed and processed samples and adhesion of the antihalation layer to the antistatic layer was poor. In the other Examples (6-11 and 13-18) static prQtOction was good to excellent, with those coated at pH 7 being better than those at pH 5. Adhesion was excellent in all of these samples indicating that other conductive polymers, alone or in combination will function within this Invention.

Claims (4)

1. A photographic film comprising a support, at least one silver halide emulsion layer coated on one side of said support, and coated on the opposite side of said support in order are a layer containing an antistatic agent at a pH of 3 to 12 and an auxiliary layer consisting essentially of at least one crosslinkable conductive polymer selected from the group consisting of poly(sodium styrene sulfonate-maleic anhydride), hexadecyl betaine, alkyldimethyl betaines, carboxylated l imidazolines, coco amido betaines, and mixtures thereof, lo and a crosslinking agent for the conductive polymer Sdispersed in a gelatin binder, whereby the antistatic properties of the antistatic layer are conducted through the auxiliary layer.

2. A photographic film according to claim 1 wherein the auxiliary layer is replaced by two separately coated golatin-containing layers, the first coated layer containing at least one crosslinkable conductive polymer i and the second coated layer containing a crosslinking i agent,

3. A photographic film according to claim 2 wherein the crosslinkablo conductive polymer is selected from the group consisting of poly(sodium styrene sulfonato-maloic anhydride), hoxadecyl botaino, alkyldimethyl botaines, carboxylated ai imidazolines, coco amido betaines, and mixtures thereof. i A photographic film according to claim 1 wherein the crosslinkable conductive polymer is present in an amount of 0.5 to 30% by weight based on the weight of the gelatin binder. A photographic film according to claim 2 wherein the crosslinkable conductive polymer is present in an amount of 0.5 to 30% by weight based on the weight of the gelatin binder. A photographic film according to claim 1 wherein 1 the crosslinking agent is selected from the group consisting of a polyfunctional aziridine. chrome alum, carbodiimides, and isoxazolinium salts. -82 A photographic film according to claim 2 wherein the crosslinking agent is selected from the group consisting of a polyfunctional aziridine, chrome alum, carbodilmidos, and isoxazolinium salts. A photographic film according to claim *)wherein the crosslinking agent is selected from the group consisting of a polyfunctional aziridino, chrome alum, carbodlimides, and isoxazolinium 1 30 sslta. -4 I4d9. A photographic film according to claim .wherein the crosslinking agent io present in an amount of 0.5 to 5% by weight based on the weight ot gelatin binder, 16 i1:Ij A photographic film according to claim -&wherein the crosslinking agent is present in an amount of 0,5 to 5% by weight based on the weight of gelatin binder. i A photographic film according to claim 3\wherein the crosslinable conductive polymer is poly(sodium polystyrene sulfonate-maloic anhydride). *Z .t3~A photographic film according to claim 4. wherein the crosslinkable conductive polymer is poly(sodium polystyrene sulfonato-maloic anhydrido). lb ;4~34 A photographic film according to claim -Awherein the crotslinking agent io a polyfunctionil aziridine. photographic film according to claim*-&)hereln the croslinking agent is a polyfunctional Oziridine -I.-l64W A photographic film according to claim -I3 2S wherein the polyfunctional aziridine is pentoerythritol-tri-bota-(2 methy aziridino). I-YtA/ A photographic film according to claim wherein the polytunctional aziridine is pentatythritol-tri-beta.(2-methyl aziridino). &8t.i/-A photographic film according to claim 1 wherein the support is a polyethylene torephthalate film. 17

18. A photographic film according to claim I. Wherein the silver halide emulsion is covered with a protective overcoat layer. A photographic film comprising a polyethylene terephthalate film support, a least one silver halide emulsion coated on one side of the support, the emulsion layer being overcoated with a protective overcoat layer, and on the opposite side of the support is coated in order layer containing an antistatic agent, and at a pH of 3 to 12 an auxiliary layer consisting essentially of a crosslinkable conductive polymer selected from the group consisting of poly~sodium styrene sulfonate- maleic anhydride), hexadocyl botalne, alkyldimethyl betainos, carboxylated imidazolines, coco amido botaines, and mixtures thereof, and a crosslinking agent selected from the group consisting of a polyfunctional aziridino, chrome alum, carbodlimidos, and isoxatolindum salts disapersed in a gelatin binder, wherein tho crosslinkable conductive polymer is present in, an amount of 0.5 to 30% by 26 weight and the crosolinking agent is present In an am~ount of 0.5 to 5% by Weight, both weights bated on the weight of gelatin binder, A photographic film according to claim e19 wherein the auxiliary layer Is teplaced by a crocalinkable, conductive polymer/gelatin layer followed by a crocalinking agent/golatin layer. A photographic film according to clAIM 241 wherein the crosalinkable conductive polymer to 1)? 18 present in an amount of 1.5 to 2.5% by weight based on the veight of gelatin binder. A photographic film according to claim 2.4'al wherein the crosslinking agent is present In an amount of 2 to 3% by weight based on the weight of gelatin binder. 'photographic film according to claim 1 wherein the crosslinkable conductive polymer is poly(sodiun styrene sulfonate-maleic anhydride) and the crosslinking agent is penta' ,rythritol- tri-beta- (2-methyl aziridine). -ei4: A photographic film according to claim 24D wherein the cross linkable conductive polymer Is poly(sodium styrene oulfonate-maleic anhy6zride) and the crosslinking agent is pentaerythrltol- tri-beta- (2-methyl aziridino). DATE~D THZS 29TIT DAY OF~ 1NQVMBEIR 15$8 E, 1, DU PONT DZ NEMOtJRS AND COMPANY D3y its Paitent Attorneys: GRIFFITHI HACK CO. eFo~2o Inatitute~ or2 Patent Attorneovs of Auntrnlia 33 18