US 3775126 A
A combination of improved coatability plus better control of static electricity can result from using a mixture of (a) a certain type of cationic perfluorinated alkyl surfactant such as perfluorooctylsulfonamido-(N-propyl-3-N,N,N-trimethyl) ammonium iodide plus (b) a certain type of alkylphenoxypoly-(propylene oxide) such as p-nonylphenoxy decaglycidol as a coating aid in the application of fluid coatings upon the surface(s) of radiation sensitive film elements. The presence of a polymeric binder such as gelatin in the coating composition is desirable. Synergistic coating results are obtained when a coating composition containing the mixture is applied to light sensitive layers that are troublesome to simultaneously overcoat because they contain materials that are extremely surface active.
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Description (OCR text may contain errors)
United States Patent [191' Babbitt et a1.
[451 Nov. 27, 1973 James F. Houle, Rochester, both of N.Y.
 Assignee: Eastman Kodak Company,
22 Filed: Feb. 29, 1972 21 App1..No.:230,450
 References Cited UNITED STATES PATENTS 2,976,250 3/1961 Walford 96/1 14.2
3,514,293 5/1970 Knox 96/114.5 3,549,369 12/1970 Koda 96/94 3,589,906 6/1971 McDowell... 96/114.5 3,630,740 12/1971 Joseph 96/1 14.2
5/1972 Groh 96/94 .OTHER PUBLlCATIONS Surface Active Materials From Perfluroocarboxylic and Perfluorosulfonic Acids," Guenther, 1nd. And Eng. Chem., Vol. 1, No. 3, 165-169, (1962).
Primary Examiner-Norman G. Torchin Assistant Examiner-Won H. Louie, Jr. AttorneyWi1liam T. French et a1.
[5 7] ABSTRACT A combination of improved coatability plus better control of staticelectricity can result from using a mixture of (a) a certain type of cationic perfluorinated alkyl surfactant such as perfluorooctylsulfonamido- (N-propyl-3-N,N,N-trimethyl) ammonium iodide plus (b) a certain type of alkylphenoxypoly-(propylene oxide) such as p-nonylphenoxy decaglycidol as a coating aid in the application of fluid coatings upon the surface(s) of radiation sensitive film elements. The presence of a polymeric binder such as gelatin in the coating composition is desirable. Synergistic coating results are obtained when a coating composition containing the mixture is applied to light sensitive layers that are troublesome to simultaneously overcoat because they contain materials that are extremely surface active.
19 Claims, No Drawings LIGHT-SENSITIVE ELEMENT COMPRISING A COATING LAYER CONTAINING A MIXTURE OF A CATIONIC PERFLUORINATED ALKYL AND AN ALKYLPIIENOXYPOLY(PROPYLENE OXIDE) This invention relates to coating processes used .in the manufacture of radiation sensitive films ,and to coating compositions. useful in such processes. More particularly, the present invention relates to the use of coating compositions which can be uniformly applied upon radiation sensitive films (and other types of films), the resulting coated surface(s)-of which have improved anti-static properties.
THE PROBLEM Many image-recording systems use image-forming materials comprising a support such as glass, metal, paper or plastic, overcoated with one or more layers comprising hydrophilic colloidal materials such as gelatin, at least some of which layers contain one or more materials that are sensitive to radiation. The. best known of the image-recording systems utilizes silver salt(s) as the sensitive material. However, a wide variety of other materials are sensitive to radiation (reacting in a desired manner upon exposure to radiation) including certain unsaturated polymers and non-silver photographic systems. In image-recording systems, the layer containing the radiation sensitive material is fre quently used in combination with several other layers which serve, for example, to provide reflective pigments, antihalation pigments or dyes, or filter dyes, or improved adhesion and/or abrasion resistance and the like. r
In the coating of such layers, particularly those containing gelatin, it hasbeen customary to employ surface active agents as coating aids to improve the quality and uniformity of the layers, and to improve the ease and reproducibility of their application. While the use of surfactants in this way can improve the properties of a particular coated layer, the presence of certain surfactants in one layer can result in deleteriously affecting the surface characteristics of the coated layer, thereby making it extremely difficultto apply an outer coating upon the surface of the first, even if a surfactant is present in the outer coating composition.
An example of a particularly troublesome case is that which results when a conventional coating composition comprising water, a photographic dye, silver halide, gelatin and an anionic surfactant such as a sodium alkylaryl sulfonate (in appropriate amounts) is applied to a conventional gelatin-subbed cellulose acetate photographic film support and one attempts to simultaneously overcoat a protective layer of gelatin, for example, from an aqueous coating composition upon such a highly surface active surface, a coated product having many surface defects results, even though one or more conventional surfactants are used in the aqueous overcoating composition in an attempt to solve the coating difficulties.
THE PRIOR ART One such conventional type of surfactant that is well I known for its surprisingly good ability as a coating aid is the nonionic type termed alkylphenoxy poly(propylene oxide) materials having the formula where R is alkyl and contains from 6 to 12 carbon atoms and Q is a polyether group comprising an average of from about 3 to about 15 units derived from glycidol (hydroxypropylene oxide), and the polyether group comprises n-propenoxy and isopropenoxy moieties. (Such nonionic materials are described in detail in U.S. Pat. No. 3,514,293 issued to Knox. The disclosure of this Knoxpatent is hereby incorporated by reference into the present patent application.) However, on certain highly surface active layers, such as that described above, even the use of the Knox invention has not provided to be entirely satisfactory. The same can be said, in terms of varying degrees of non-success, for many other surfactants that are ordinarily utilized as coating aids in the manufacture of radiation sensitive elements.
THE PRESENT INVENTION A solution to the foregoing problems has been found to reside in an unexpected combination of surfactants that somehow perform synergistically as coating aids when aqueous coatings are applied to highly surface active layers. An additional valuable benefit that can result from the practice of the present invention stems from the resulting overcoat(s)having improved resistance to the development of undesirably high levels of static electricity.
The present invention comprises aqueous coating compositions containing the special surfactant combinations of the present invention (which coating compositions also preferably contain a compatible polymeric binder). This invention also includes coated elements (including radiation sensitive elements) on at least one of the outersurfaces of which appears one of the surfactant blends of the present invention. The presence of such blend at the surface of the element or substrate effectively reduces the propensity of that surface to generate undesirable static electricity when the surface is contacted by another surface. Such blend should appear in the surface layer in an amount equal to at least about 0.002, to about 2, and preferably from about 0.005 to about 0.5, mg per dm of treated surface.
The synergistically acting combination of surfactants of the present invention comprises a mixture of (A) a first material having the formula wherein R. is alkyl and contains from 6 to 12 carbon atoms and O is a polyether group comprising from about 3 to about 15 units of hydroxypropylene oxide; said polycther group comprising n-propenoxy and isopropenoxy moieties.
Typical examples of cationic surfactants having the structure of formula 1, above, include perfluoroheptylsul-fonamido-(N-propyl-3-N,N dimethyl-N- ethyl)ammonium bromide, perfluorononylsulfonamido-(N-ethyl-Z-N,N,N-trimethyl)ammonium iodide, perfluoroheptylsulfonamido-(N-propyl-3-N,N,N-triethyl) ammonium iodide, perfluorooctylsulfonamido-(N- propyl-3-N,N,N-trimethyl)ammonium iodide, perfluorooctylsulfonamido-(N-propyl-3-N,N,N-trimethyl)ammonium chloride, perfluorohexyl-sulfonamido-(N- butyl-4-N,N-diethyl-N-propyl)ammonium iodide, and the like. Of these, perfluorooctylsulfonamido-(N- propyl-3-N,N,N-trimethyl)ammonium iodide and perfluorooctylsulfonamido-(N-ethyl-N,N,N-trimethyl)ammonium iodide are preferred. Typical examples of useful nonionic surfactants having the structure of formula 11, above, include the various products resulting from the conventional reaction of alkylphenols such as hexylphenol, octylphenols, nonylphenols, and dodecylphenols with an average of 3, 6, 8, 10, 12 and 15 moles of glycidol (per mole of the alkylphenol). Of these, octylphenoxy octaglycidol, octylphenoxy decaglycidol, octylphenoxy dodecaglycidol, nonylphenoxy octaglycidol, nonylphenoxy nonaglycidol, nonylphenoxy decaglycidol, and nonylphenoxy dodecaglycidol are preferred, particularly preferred products. having isoalkyl groups.
A particularly preferred combination of surfactants useful in the practice of this invention is a combination of (a) perfluorooctylsulfonamido -(N-propyl-3,N,N,N- trimethyl) ammonium iodide and (b) p-nonylphenoxy decaglycidol in a weight ratio of from about 2:1 to about 1:75, respectively. The use of such cationic materials as those designated 1, above, as charge control agents has been described and claimed in United States patent application Ser. No. 163,450, filed July 16, 1971, the disclosure of which is hereby incorporated by reference into the present patent application. Such materials can be readily prepared by conventional means. Similarly, the use of nonionic materials as those designated [1," above, as coating aids has been described and claimed in the aforementioned Knox patent (U.S. Pat. No. 3,514,293). Such nonionic materials can be prepared by reacting an appropriate alkylphenol with an appropriate amount of glycidol via a known method as described by Knox.
The valuable synergistic nature of the compositions of this invention can readily be illustrated by the following examples, wherein a simulated conventional photographic layer (which is extremely surface active) containing 0.86 mg. of sodium triisopropyl naphthalene sulfonate per dm 24.4 mg. gelatin per dm and 1.3 mg. per dm of a nonwandering magenta dye was coated on a conventional cellulose acetate film support and simultaneously overcoated with a water dispersion containing weight percent of gelatin plus an appropriate amount of one or more surfactants, as set out in Table 1, below. The coating was applied so that 10 mg. gelatin per dm were applied to the treated surface.
TABLE 1 Surfactant Example Coating Aid Observations g/dm) A. l 0 0 Extremely bad rcpellency 0 0.05 Very bad repellcncy and pulled in edges 3 0 0.1 l Repelleney and pulled-in edges 4 0 0.22 Crescents 5 0.05 O Repellency and pulled-in edges 6 0.1 l 0 Repellency and pulled-in edges 7 0.05 0.05 No rcpellency, some contraction at edges 8 0.05 0.1 1 Superior coating; no repelleney;
edges fine A=perfluorooctylsulfonamido -(N-propyl-3-N,N,N-trimcthyl ammonium iodide. B=p nonylphenoxy decaglycidol.
Whereas the valuable synergistic benefits described hereinbefore has been tested and detailed in the above examples with respect only to one particularly preferred embodiment of the present invention, it is believed that improved coatability can be observed through the use of any of the combinations of A" plus 8" materials, as set out hereinbefore, so long as the weight ratio of material A to material 13, respectively, is within the range of from about 2:1 to about 1:75, and preferably from about 1.5:1 to about 1:50.
The valuable benefits of the present invention can be obtained by application of the materials in admixture to the surface that is being treated, preferably by use of a coating composition containing at least water (preferably at least about 60 weight percent), at least about 0.005 and up to about 0.5 percent (and preferably from about 0.01 to about 0.2) weight percent (combined weight if more than one is used) of one or more 1" (cationic) materials, and enough of one or more ll (nonionic) materials to produce in the resulting aqueous coating composition the desired weight ratio of materials. Preferably, the aqueous coating compositions of this invention will contain a total of at least about 0.01 up to about 2 (and preferably from about 0.05 to about 0.5) weight percent of the nonionic surfactant material. It is also preferred that -the coating compositions of the present invention contain at least about 0.5 weight percent of one or more of the aforementioned polymeric binders and that the compositions be readily coatable by conventional means.
Materials other than the cationic and nonionic surfactants described above (as materials A" and B in Table I) can also be present in the coating compositions of the present invention. For example, the coating compositions can contain dyes, lubricants, pigments, dispersing agents, matting agents, polymers, and the like, generally in minor amounts less than about 5 weight percent. As a matter of fact, a preferred embodiment of such composition includes an amount of at least one compatible polymeric binder material suffrcient to cause the resulting mixture to adhere together (and to the underlying layer) when the solvent portion of the coating composition has been removed therefrom (usually via evaporation). Useful compatible polymeric binder materials include all of those that can be dispersed or dissolved in the aqueous portion of the coating composition, which are film-formers when the coating is dried under conventional conditions, and which are compatible with the cationic and nonionic surfactants thereon. Typical non-limiting examples of such compatible polymeric binder materials are polyvinyl alcohol, polyacrylamide, polyvinylpyrrollidone and gelatin. Of these, gelatin is preferred because of the contemporary large scale use of gelatin in radiation sensitive layers. The valuable coatings of the present invention can also be applied from non-aqueous coating compositionsif desired, the solvent portion of such compositions having to be readily volatile under conventional coating conditions.
The preferred type of cationic material for use in the practice of this invention includes the perfluorinated sulfonamido materials having the sturcture (III) wherein P is perfluorinated and contains from 6 to carbon atoms; n is an integer from'2 to 4, D is wherein R R and R are alkyl groups containing from 1 to 3 carbon atoms; and X is an anion selected from the group consisting of, chloride, bromide and iodide. Particularly preferred is perfluorooctyl-sulfonamido-N- propyl -3-N,N,N -trimethyl)ammonium iodide (presently commercially available from 3M Company under the trade designation PC-134. I
The preferred type of nonionic material for use in the practice of this invention includes those having the formula fit can be readily appreciated when it is realized that the triboelectric charge for a layer consisting essentially of gelatin is esu (electro-static units per square centimeter) that of Example 3, above (containing the nonionic surfactant plus gelatin) is about +28 esu, while that of Example 8 is only +2 esu. The significance of this improvement becomes clear in view of the fact that dangerous, troublesome static discharge oc curs when a net triboelectric charge of 8 to 10 esu accumulates at a given part of the gelatin coating. This is true particularly in the case of a polymeric film such as cellulose acetate or poly(ethylene terephthalate) coated with a conventional, mainly gelatin-based photographic emulsion, although the particular discharge level will vary somewhat, depending upon materials, humidity conditions, and the like.
It should also be noted that the particular type of substrate or radiation sensitive layer(s) over which the present compositions are applied are generally not determinative of the operability of the present invention. However, it is believed surprising that the present coating compositions can be successfully used (and can even exhibit the synergism demonstrated above) when applied over an extremely surface active layer such as that used in preparing the coatings of the above Examples, because of the anionic nature of the surface lates to the protection of the resulting coated elements from the excessive formation of static electricity during the subsequent handling of the elements. This protection is due to the peculiar ability of the perfluorinated cationic surfactant portion of the present compositions to function as a charge control agent, thereby reducing significantly the triboelectric charging characteristics of that surface of the product element treated therewith.
An extended discussion of charge control agents, triboelectric charging characteristics and methods for the measurement of the effect of such agents appears in US. Pat. application Ser. No. 163,450, filed July 16, 1971, (referred to hereinbefore). Also equipment for the measurement of triboelectric static charges is described in US. Pat. No. 3,501,653. This valuable beneactive layer (since one would ordinarily expect an undesirable reaction between the anionic surfactant in the underlayer and the cationic surfactant in the coating composition). Indeed, such a reaction could have helped explain therelatively poor performance of the cationic surfactant alone in the above Examples 5 and This invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of the invention.
What is claimed is:
l. A radiation sensitive element comprising a substrate, at least one radiation sensitive layer adhered to a'surface of said substrate, and contiguous to at least one surface of (a) said substrate or (b) one of said radiation sensitive layers, a coating layer comprising a mixture of (i) a first material having the formula wherein P is a member selected from the group consisting of perfluorinated carbon chains containing from 6 to 10 carbon atoms per chain;
n is an integer of from 1 to 6; I R R and R are either hydrogen or lower alkyl containing 1 to 4 carbon atoms; and X is a halide anion; with ii. a second material; said second material being an alkylphenoxypoly(hydroxypropylene oxide) compound having the structure wherein R, is alkyl and contains from 6 to 12 carbon atoms and Q is a polyether group containing an average of from about 3 to about units of hydroxypropylene oxide; said polyether group comprising n-propeneoxy and isopropenoxy moieties; the weight ratio of said first material to said second material in said mixture being from about 2:1 to about 1:75, respectively.
2. A radiation sensitive element as in claim 1, wherein said mixture is in at least one external surface layer of said element.
3. A radiation sensitive photographic element as in claim 2, wherein said external surface layer also con- I tains a polymeric binder.
4. An element as in claim 3, wherein said polymeric binder is gelatin.
5. An element as in claim 4, wherein said second material is a reaction product of nonylphenol and glycidol, respectively.
6. An element as in claim 5, wherein said first mate rial is perfluorooctylsulfonamido (N-propyl-3-N,N,N- trimethyl) ammonium iodide and said second material has the structure wherein Q is a polyether group comprising about 10 propenoxy units, and said weight ratio is from about 1.5:1 to about 1:50.
7. An element as in claim 6, wherein the nonyl group in said second material is para with respect to the position of the -OQ group on the benzene nucleus.
8 An element as in claim 7, wherein said surface of said polymeric substrate is a solid linear polyester, polyamide, polyolefin, or a lower alkyl ester of cellu lose.
9. A radiation sensitive photographic element comprising a solid transparent polymeric film substrate containing over at least one surface at least one radiation sensitive layer; said radiation sensitive layer being overcoated with a charge control layer comprising from about 0.01 to about 1 mg per dm of overcoated area of a blend of perfluorooctylsulfonamido (N-propyl-3-N,N,N-trimethyl) ammonium iodide, pisononylphenoxy decapropyleneoxide, and gelatin; the weight ratio of the cationic surfactant to nonionic surfactant in said blend being from about 1.5:1 to about 1:50, respectively.
10. A radiation sensitive element as in claim 1, wherein said mixture is contiguous to a radiation sensitive layer which contains an alkylaryl sulfonate surfactant.
11. A radiation sensitive element as in claim 9, wherein said blend is contiguous with said radiation sensitive layer; said radiation sensitive layer also containing an alkylaryl sulfonate surfactant.
12. An aqueous coating composition comprising a fluid mixture comprising water, a first material having the formula wherein R is alkyl and contains from 6 to 12 carbon atoms and Q is a polyether group comprising an average of from about 3 to about 15 combined units of hydroxypropylene oxide; said polyether group comprising n-propeneoxy and isopropenoxy moieties; said first material and said second material being present in said I composition in respective proportions, by weight, of
from about 2:1 to about 1:75 and in an amount equal to at least about 0.005 weight percent of said composition.
. 13. An aqueous coating composition as in claim 12, wherein said composition also contains at least about 0.5 weight percent of a polymeric binder, based on the combined weights of said first material, said second material and said polymeric binder.
14. A coating composition as in claim 13, wherein said second material is a reaction product of nonylpheno] and glycidol.
15. A coating composition as in claim 14, wherein said polymeric binder is gelatin.
16. A coating composition as in claim 15, wherein said first material is perfluorooctylsulfonamido -(N-propyl-3-N,N,N-trimethyl ammonium iodide and said second material glycidol.
17. A coating composition consisting essentially of a. at least about weight percent of water,
b. at least about 0.5 weight percent of gelatin,
0. at least about 0.005weight percent of perfluorooctylsulfonamido (-N-propyl-3-N,N,N-trimethyl) ammonium iodide, and
(d) at least about 0.01 weight percent of a material having the structure is p-isononylphenoxy decawherein P is a perfluorinated carbon chain containing from 6 to carbon atoms;
n is an integer of from 1 to 6;
R R and R are lower alkyl containing 1 to 4 carbon atoms; and X is an anion; and
ii. a second material; said second material being an alkylphenoxypoly(hydroxypropylene oxide) compound having the structure