US3121060A - Lubricant for photographic film - Google Patents

Description

United States ddzlfih Patented Feb. 11,- 1964 No Drawing. Filed June 6, 1960, Ser. No. 33,905 12 Claims. (Cl. 252--56) This invention relates to the lubrication of film. More particularly this invention concerns the lubrication of photographic film in its unexposed form.

It is well known in the industry that the Winding, withdrawing, passing of film through magazines and film gates and the like may be facilitated by the application of a lubricant to the film. A number of film lubricant compositions have already been suggested in the prior art. Many of such prior art lubricants are largely comprised of commercial Waxes. More recently certain lauric acid compounds have been suggested for film lubrication purposes and have obtained substantial usage. Such lauric acid materials appear to lubricate film better than the commercial Waxes. However, lauric acid is reactive with certain gelatins of high isoelectric point, making it difficult to coat uniformly and in some cases leaving a haze in the gelatin layer. Lauric acid materials also tend to reduce the quality of certain color films, making it undesirable to use from the photographic standpoint.

In the lubrication of photographic film products many of the prior art lubricating materials have not been entirely satisfactory. There is the problem that the lubricants adversely afiect the sensitive emulsion carried on the photographic film product. Some of the prior art fatty acid type lubricants may tend to streak the film surface which is detrimental to the quality of the photographic product. A large number of the prior art lubricants are not reasonably permanent in their lubricating effect on the film. That is, such lubricants become removed from the photographic film to a substantial extent during the passing of the film through photographic baths for the processing thereof. Other problems may be encountered such as undesirable interaction of the lubricant with other coatings or constituents contained in the photographic film.

Accordingly it is believed apparent that the develop ment of improved lubricants for film products represents a highly desirable result. After extended investigation I have found a lubricant and methods for use thereof which are thought to overcome or minimize many of the difiiculties encountered in the industry with prior art types of lubricants.

This invention has for one object to provide an improved film lubricating composition. Another object is to provide a lubricated unexposed photographic film which exhibitsa minimum of friction when passed through film magazine, film gates and the like. Still another object is to pro vide a film lubricating composition which will impart more permanent lubrication to film products than prior art lubricants. Other objects will appear hereinafter.

In the broader aspects of my invention I have found that certain waxy esters of higher fatty alcohols and higher fatty acids, typified by modified sperm oils, make execellent lubricants for this purpose and in addition, possess several advantages over prior art film lubricants as exemplified by lauric acid. In further detail a preferred material, having the greatest number of desirable characteristics, is Spermafol 52. This material is a waxy solid, characterized as a partially hydrogenated sperm oil, with a low level (7%) of unsaturation and a melting point in the range of 47-5 1 C. Spermafol 52 consists of a mixture of esters, varying between C and C chain length for the acid portion and between C and C chain length for the alcohol portion, largely C to Ci straight chain fatty acids and'-C -to'-C straight chain fatty alcohols, together with a portion of saturated triglycerides. A typical component ester present in large concentration might be cetyl palmitate, CH (CH COO(CH CH In practice, the modified sperm oil is dispersed in a photographic gelatin coating medium, then coated over a photographic emulsion, either black-and-White or color, to form a protective, lubricating top coat. Besides gelatin the dispersing agent may be some other colloidal material such as colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound. Some colloids which may be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe US. Patent 2,286,215, issued June 16, 1952; a far hydrolyzed cellulose ester such as cellulose acetate hydrolyzed to an acetyl content of 19-26% as described in US. Patent 2,327,808, of Lowe and Clark, issued August 24, 1943; a water-soluble ethanolamine cellulose acetate as described in Yutzy US. Patent 2,322,085, issued June 15, 1943; a polyacrylamide or an imidized polyacrylamide as described in Lowe, Minsk, and Kenyon U.S. Patent 2,541,474, issued February 13, 1951; zein as described in Lowe US. Patent 2,563,791, issued August 7, 1951; a vinyl alcohol polymer containing urethane carboxylic acid groups of the type described in Unruh and Smith US. Patent 2,768,154, issued October 23, 1956; or containing cyano-acetyl groups such as the vinyl alcohol-vinyl cyanoacetate copolymer as described in Unruh, Smith, and Priest U.S. Patent 2,808,331, issued October 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having a vinyl group as described in US. Patent 2,852,382, of Illingsworth, Dann, and Gates, issued September 16, 1958; or certain acrylate copolymers may be used such as the copolymers described in Houck et 211. Serial No. 786,227, now US. Patent 3,062,674.

If desired, compatible mixtures of two or more of these colloids may be employed for dispersing the lubricant in its preparation.

Although the aforementioned sperm oil product obtainable commercially as Spermafol 52 is preferred, there are several other sperm oil products which may be used such as follows:

Spermafol 45 Sperm oil 38 B/W Sperm oil 45 N/W Liquid Cosmol Cosmol 1000 Spermaceti wax These are all esters of higher fatty alcohols and higher fatty acids, essentially similar in structure but varying in average molecular weight, degree of unsaturation and triglyceride content. Each of these possesses some merit as film lubricants.

All of the sperm oil products referred to above are commercially available materials available from the Archer-Daniels-Midlands Company.

Synthetically prepared waxy esters of alcohols and acids, each component being a straight-chain aliphatic compound of 10 to 20 carbon atoms have been found to be as satisfactory a lubricant as the modified naturally occurring sperm oils.

Accordingly, it appears sufficient herein to generically identify these sperm oil products used in the present invention as being essentially comprised of esters of higher fatty alcohols and higher fatty acids of a molecular weight within the range of about 300 to about 600, and having a degree of unsaturation within the range of 2% to A modified sperm oil, as above described, may be compounded into a lubricating composition by a method as set forth below. This method illustrates the compounding of the preferred sperm oil product identified as Sperrnafol 52. However, the other waxy esters may be compounded into lubricating compounds of the present invention in a generally similar manner. A mixture of the following composition is prepared:

EXAMPLE I ADM Spermafol 52 g 30 photographic gelatin g 384 16% saponin solution "cc..- 40

The Spermafol was heated above its melting point, to about 60 C., then poured, with vigorous stinring, into the saponin-gelatin solution held at about 4050 C. This mixture was dispersed in a colloid mill, forming Spermafol particles of colloidal dimensions, up to about 3 microns diameter. The mill was rinsed with 25 cc. warm water and the dispersion diluted with 808 grams 10% gelatin. To make up a compositon containing the above dispersion for coating on a photographic product, the following two examples demonstrate the method and material.

EXAMPLE II To 0.2 lb. of the melted dispersion are added:

30 cc. of a saponin solution 4156 g. of a 10% photographic gelatin 1.2 g. of mucochloric acid in a 2.5% water solution Enough water to make up to a total weight of 14.0 lbs.

EXAMPLE III To 2.0 lbs. of the melted dispersion are added:

240 cc. of a 15% saponin solution 4156 g. of a 10% photographic solution 1.2 g. of mucochloric acid and in a 2.5% Water solution Enough water to make up a total of 66 lbs.

Additional examples showing the use of hydrophilic colloids other than gelatin are as follows:

EXAMPLE IV To: 50 cc. 5% aqueous polyvinyl alcohol (Elvanol 52-22) Add 1 cc. 10% sodium lauryl sulfate (Stepanol ME); 10

cc. sperm oil (ADM 38 N.W. Sperm) 2.5 grams of a medium viscosity grade of polyvinyl alcohol, about 88% hydrolyzed, was dissolved by stirring into 47.5 cc. of cold water containing the sodium lauryl sulfate. The sperm oil was added with vigorous stirring and the resulting coarse dispersion passed through a colloid mill to give a stable suspension of colloidally dispersed droplets of sperm oil in the polymer solution.

EXAMPLE V Four grams of a copolymer of ethyl acrylate (80 parts) and acrylic acid parts) were swollen in a mixture of 7.5 grams of isopropanol and 75 cc. of water. While stirring, sufiicient ammonium hydroxide was added to dissolve the polymer and being the pH to 6.3. The solution was then adjusted to 100 grams with additional water.

To 50 cc. of this solution there was added 1 cc. of 10% sodium lauryl sulfate solution, followed by 10 cc. of sperm oil, as in Example IV. A very good colloidal disperson resulted.

EXAMPLE VI Ten grams of zein were dissolved in 90 cc. of 50% aqueous isopropanol. One cc. of 10% aqueous Triton X-lOO was added, and 4 grams of sperm oil were stirred in with vigorous agitation to form a good dispersion.

EXAMPLE VII 70 cc. of a latex formed by the emulsion polymerization of 15' parts acrylonitrile, 85 parts of vinylidene chloride and 8 parts of acrylic acid and containing 15% l polymer solids by weight, were treated with ammonium hydroxide (7% N3 to form a viscous clouded solution at about pH 7.5. To this dope were added 4 grams of sperm oil and the mixture was stirred for about 10 minutes at room temperature to form a stable dispersion.

EXAMPLE VIII Ten grams of a high viscosity grade of polyacrylamide (American Cyanamid were dissolved by stirring into 400 cc. of cold water. To 50 cc. of this viscous solution were added 2 grams of sperm oil. After a few minutes stirring, a good dispersion resulted.

EXAMPLE IX 2.5% Union Carbide Cellosize WP 40, hydroxyethyl cellulose, was prepared as in Example VIII and 2 grams sperm oil stirred into 50 cc. of this solution to give a stable dispersion.

EXAMPLE X A 2% by weight solution of polyethylene oxide resin (Union Carbide Polyox Willi-205) was prepared by stirring 10 g. of this polymer into 500 cc. of water and 2 grams of sperm oil stirred into 50 cc. of polymer to give a good dispersion.

EXAMPLE XI To 50 cc. of 5% aqueous photographic gelatin, add:

5.0 cc. of a 15% saponin solution 3.0 g. of cetyl palmitate The oily melted ester was added with vigorous stirring and the resulting coarse dispersion is passed through a colloid mill as in Example IV.

EXAMPLE XII The dispersion was made exactly like Example XI except that 3.0 g. of the ester of dodecyl alcohol and stearic acid were used in place of cetyl palmitate.

While I have favored the formula which dispersed the lubricant in the gelatin with saponin, a somewhat coarser dispersion may be satisfactory such as would be obtained by omitting the saponin. If a finer dispersion is desired, to achieve a less hazy layer for example, this can be accomplished by using other surfactants.

The approximate range of particle sizes that would contain most of the particles obtained under these conditions is as follows:

Microns (1) No surfactant 1-5 (2) Surfactant 0.2-3

Note that Examples VII through X are prepared without added surfactant, the resin having suflicient dispersing activity to make a (relatively) stable colloidal dispersion. Other surfactants may be incorporated as desired in specific applications as is disclosed hereinafter.

The dispersion may contain a lauryl or oleyl monoether of polyethylene glycol as described in Knox and Davis U.S. Patent 2,831,766, issued April 22, 1958; a salt of a sulfated and alkylated polyethylene glycol ether as described in Knox and Davis U.S. Patent 2,719,087, issued September 27, 1955; an acylated alkyl taurine such as the sodium salt of N-oleyl-N-methyl taurine as described in Knox, Twardokus, and Davis U.S. Patent 2,739,891, issued March 27, 1956; the reaction product of a dianhydride of tetracarboxy-butane with an alcohol or an aliphatic amine containing from 8 to 18 carbon atoms which is treated with a base, for example, the sodium salt of the monoester of tetracarboxybutane as described in Knox, Stenberg, and Wilson U.S. Patent 2,843,487, issued July 15, 1958; a water-soluble maleopimarate as described in Knox and Fowler U.S. Patent 2,823,123, issued February 11, 1958; an alkali metal salt of a substituted amino acid as disodium N-(carbo-p-tert. octylphenoxypentaethoxy)-glutamate as described in Knox and Wilson U.S. patent application Serial No. 600,679, filed July 30, 1956, now U.S. Patent 3,038,804; or sulfosuccinamate such as tetrasodium N-(1,2-dicarboxyethyl)-N-octadecy1 sulfosuccinamate as described in Knox and Stenberg U.S. patent application 691,125, filed October 21, 1957, now U.S. Patent 2,992,108, or a sodium salt of an alkylarylpolyether sulfonate of Baldsiesen U.S. Patent 2,600,831, issued June 17, 1952.

The inclusion of mucochloric acid in Examples II and III is for the purpose of after-hardening the coated gelatin layers. Such gelatin hardener may be replaced in part or entirely by other chemicals such as formaldehyde; or salts of chromium (III) or aluminum (III); or a compound having a plurality of acid anhydride groups such as 7,8-diphenylbicyclo-(2,2,2)-7-octene-2,3,5,6-tetracarboxylic dianhydride, or a dicarboxylic or a disulfonic acid chloride such as terephthaloyl chloride as described in Allen and Carroll U.S. Patents 2,725,294 and 2,725,- 295, both issued November 29, 1955; a cyclic 1,2-diketone such as cyclopentane-1,2-dione as described in Allen and Byers U.S. Patent 2,725,305, issued November 29, 1955; a bisester of methanesulfonic acid such as 1,2-di-(methane-sulfonoxy)-ethane as described in Allen and Laakso U.S. Patent 2,726,162, issued December 6, 1955; 1,3-dihydroxymethylbenzimidazol-2-one as described in July, Knott, and Pollalk U.S. Patent 2,732,316, issued January 24, 1956; a dialdehyde or a sodium bisulfite derivative thereof such as ,B-methyl glutaraldehyde bis-sodium bisulfite as described in Allen and Burness U.S. patent application Serial No. 556,031, filed December 29, 1955, now abandoned; a bis-aziridine carboxamide such as trimethylene bis(1-aziridine carboxamide) as described in Allen and Webster U.S. patent application Serial No. 599,891, filed July 25, 1956, now U.S. Patent 2,950,197; 2,3-dihydroxy dioxane as described in Jeffreys U.S. Patent 2,870,013, issued January 20, 1959; or bis-isocyanate as described in Henn et al. U.S. patent application Serial No. 805,357, filed April 10, 1959.

After preparing the lubrication composition of the present invention by the aforesaid procedure, said composition may be applied by standard emulsion coating techniques to the photographic film product which it is desired to lubricate.

The gel-lubricant mixture is usually coated in a thin layer of about /2 to 1; in thickness. Or, in diiferent terms, the gel is coated at about 0.100 gm./ft. and the lubricant at about 0.0005 to 0.010 gm./ft. Although the lubricant would generally be applied over the emulsion surface of the film product, the lubricating composition of the present invention may be applied over a surface of the film opposite the emulsion surface, on both sides of the film or in layers within a multilayer structure.

The excellent lubricating effect of the lubricant of the present invention may be ascertained by any suitable test method. The recently issued U.S. Patent 2,882,157 to my associates described several cases where it may be desirable to reduce the friction on film by the lubricating of the film and such patent describes the tests which may be used, the conducting of such tests under certain relative humidity conditions and the like details.

One test not described in the aforementioned patent is the emulsion dig susceptibility test. This is conducted as follows: On the regular test on raw film two pieces of film are placed emulsion down beneath a weighted ball bearing. The top piece of film is then pulled from beneath the bearing, the bottom piece of film being held stationary. The rating is the minimum weight required to produce visible damage to the film when processed and examined under normal viewing conditions.

On processed film the test is made more severe by placing the film emulsion side up beneath the bearing and examining the surface. By this method only a range of digging susceptibility is determined. I

In the present invention for the purposes of comparison I have tested the lubricating effect of the new composition of the present invention in accordance with the foregoing test procedures and the results are as follows:

Testing to show the greater permanence of the lubricant of the present invention may be readily noted by comparison of photomicrographs of surface characteristics. 'Film lubricated by the present invention shows the same lubricant pattern on film which has passed through an entire color process (color developer, bleach, fix, washes), whereas film lubricated in accordance with the prior art (as a lauric acid lubricant after such a lubricated film has been through several comparable baths) shows the lubricant does not survive processing.

While in the above examples I have described the use of my preferred composition prepared from the sperm oil product Spermafol 52, satisfactory results may be obtained by using other of the modified sperm oil or synthetic materials referred to above. For example using a lubricating composition comprised of hydrophilic colloid, mucochloric acid and the wetting agents identified above but containing in place of Spermafol another sperm oil product such as spermaceti wax, results as follows were obtained:

Caefiicient 0f Fricti0n-Metal to Emulsion Spermaceti wax in protective coat 0.11 Spermafol 52 in protective coat 0.11 Lauric acid in protective coat 0.20 Control, no lubricant in protective coat 0.44

as described hereinabove and as defined in the appended claims.

I claim:

1. A lubricating composition for photographic film products, said composition consisting essentially of a hydrophilic photographic-type colloid and /2 to 15% by weight of the colloid of modified sperm oil essentially consisting of esters of higher fatty alcohols and higher fatty acids of a molecular weight within the range of about 300 to about 600, and having a degree of unsaturation within the range of 2% to 75%, wherein the alcohols and acids each have straight chain lengths from 10 to 20 carbon atoms.

2. A lubricating composition for photographic film products, said composition consisting essentially of a hydrophilic photographic-type colloid and /2 to 15% by weight of the colloid of modified sperm oil essentially about 360 to about 600, and having a degree of unsaturation within the range of 2% to 75%, wherein the alcohols and acids each have straight chm'n lengths from to 20 carbon atoms, and a surfactant compatible with photographic silver halide emulsions which aids in improving the spreading properties of the lubricant.

3. A lubricating composition for photographic film products, said composition consisting essentially of a hydrophilic colloid selected from the class consisting of gelatin, polyvinyl alcohol, a copolymer of ethyl acrylate and acrylic acid, zein, an interpolymer of acrylonitrile, vinylidene chloride and acrylic acid, polyacrylamide, hydroxyethyl cellulose, and polyethylene oxide resin, and A to by weight of the colloid, of modified sperm oil essentially consisting of esters of higher fatty alcohols and higher fatty acids of a molecular weight within the range of about 300 to about 600, and having a degree of unsaturation within the range of 2% to 75%, wherein the alcohols and acids each have straight chain lengths from 10 to carbon atoms.

4. A lubricating composition for photographic film products, said composition consisting essentially of a hydrophilic colloid selected from the class consisting of gelatin, polyvinyl alcohol, a copolymer of ethyl acrylate and acrylic acid, Zein, an interpolymer of acrylonitrile, vinylidene chloride and acrylic acid, polyacrylamide, hydroxyethyl cellulose, and polyethylene oxide resin, a surfactant compatible with silver halide photographic emulsions which aids in improving the spreading properties, and /2 to 15% by weight of the colloid of modified sperm oil essentially consisting of esters of higher fatty alcohols and higher fatty acids of a molecular weight within the range of about 300 to about 600, and having a degree of unsaturation within the range of 2% to 75%, wherein the alcohols and acids each have straight chain lengths from 10 to 20 carbon atoms.

5. The composition of claim 3 in which the hydrophilic colloid is gelatin.

6. The composition of claim 3 in which the hydrophilic colloid is polyvinyl alcohol.

7. A method of preparing a lubricating composition indicated in claim 1, which comprises heating the waxy ester above its melting point, adding the melted waxy ester to an agitated aqueous solution of a hydrophilic photographic-type colloid, the amount of waxy ester being about /2% to 15 by weight based on the colloid, and adding to the resulting composition a surfactant whereby the particle size of the melted waxy ester is reduced.

8. A method in accordance with claim 7 in which the hydrophilic colloid is polyvinyl alcohol.

9. A method in accordance with claim 7 in which the hydrophilic colloid is gelatin.

10. A method in accordance with claim 7 in which the hydrophilic colloid is a copolymer of ethyl acrylate and acrylic acid.

11. A method of lubricating photographic film which comprises applying to the emulsion layer a layer of a composition consisting essentially of a hydrophilic photographic-type colloid having dispersed therein /2 to 15% by weight of a modified sperm oil consisting essentially of esters of higher fatty alcohols and higher fatty acids of a molecular weight within the range of about 300 to about 600 and having a degree of unsaturation within the range of 2% to in which the alcohols and acids each have straight chain lengths from 10 to 20 carbon atoms.

12. A method of claim 11 wherein the hydrophilic colloid is gelatin.

References Cited in the file of this patent UNITED STATES PATENTS 1,883,913 Hickman Oct. 25, 1932 OTHER REFERENCES Hydrofol Products, copyright 1954 by Archer- Daniels-Midland Co. (Chemical Products Division), 2191 West th Street, Cleveland 2, Ohio; 40 pages.

Claims (1)

1. A LUBRICATING COMPOSITION FOR PHOTOGRAPHIC FILM PRODUCTS, SAID COMPOSITION CONSISTING ESSENTIALLY OF A HYDROPHILIC PHOTOGRAPHIC-TYPE COLLOID AND 1/2 TO 15% BY WEIGHT OF THE COLLOID OF MODIFIED SPERM OIL ESSENTIALLY CONSISTING OF ESTERS OF HIGHER FATTY ALCOHOLS AND HIGHER FATTY ACIDS OF A MOLECULAR WEIGHT WITHIN THE RANGE OF ABOUT 300 TO ABOUT 600, AND HAVING A DEGREE OF UNSATURATION WITHIN THE RANGE OF 2% TO 75%, WHEREIN THE ALCOHOLS AND ACIDS EACH HAVE STRAIGHT CHAIN LENGTHS FROM 10 TO 20 CARBON ATOMS.