US3733199A - Photographic composition of sodium and potassium ions for treating direct positive emulsions - Google Patents

Abstract

A DIFFUSION TRANSFER PROCESS COMPRISES DEVELOPING AN EXPOSED DIRECT POSITIVE EMULSION IN THE PRESENCE OF A SILVER HALIDE SOLVENT, A SILVER HALIDE DEVELOPING AGENT, A DEVELOPMENT RESTRAINER SUCH AS BENZOTRIAZOLE AND SODIUM AND POTASSIUM AS IONS OR IN COMBINED FORM E.G. AS COMPOUNDS, INCLUDING COMPLEXES. THE SODIUM AND POTASSIUM ARE PRESENT IN A CONCENTRATION OF ABOUT 8 TO ABOUT 27 MOLE PERCENT POTASSIUM AND ABOUT 92 TO ABOUT 73 MOLE PERCENT SODIUM, BASED ON THE TOTAL MOLES OF SODIUM AND POTASSIUM OF ABOUT 5 TO A ABOUT 30%, BY WEIGHT, DRY BASIS OF TOTAL DEVELOPING COMPOSITION.

Description

"United States Patent Ofice 3,733,199 Patented May 15, 1973 3 733 199 PHOTOGRAPHIC COMPOSITION F SODIUM AND POTASSIUM .IONS FOR TREATING DIRECT POSITIVE EMULSIONS Paul E. Crough and Henry J. Snyder, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N .Y. No Drawing. Filed June 14, 1971, Ser. No. 152,978 Int. Cl. G03c 5/24 US. CI. 96-64 13 Claims ABSTRACT OF THE DISCLOSURE A diffusion transfer process comprises developing ah exposed direct positive emulsion in the presence of a silver halide solvent, a silver halide developing agent, a development restrainer such as benzotriazole and sodium and potassium as ions or in combined form e.g. as compounds, including complexes. The sodium and potassium are present in a concentration of about 8 to about 27 mole percent potassium and about 92 to about 73 mole percent sodium, based on the total moles of sodium and potassium of about 5 to about 30%, by weight, dry basis of total developing composition.

BACKGROUND OF THE INVENTION This invention concerns diffusion transfer processes, more particularly diffusion transfer processes involving the use of a direct positive silver halide emulsion in the presence of a photographic developing solution containing a development restrainer. It also concerns the processing solution containing a development restrainer and containing both potassium and sodium ions.

Diffusion transfer processes are well known. For example, Rott US. Pat. 2,352,014 describes such a process wherein undeveloped silver halide of an exposed photographic emulsion layer is transferred in a silver complex imagewise by imbibition to a silver precipitating or nucleating layer generally to form a positive image therein. A silver precipitating or nucleating layer generally comprises a binder containing nuclei such as nickel sulfide, colloidal metal and the like.

Direct positive emulsions are also well known. For e ample, Berriman US. Pat. 3,367,778 describes a direct positive emulsion containing grains comprising a central core of a water insoluble silver salt containing centers which promote the deposition of photolytic silver and an outer shell or covering for such core of a fogged or spontaneously developable water insoluble silver salt. Another type of direct positive emulsion is known as a Herschel reversal emulsion in which the silver halide grains have been fogged by previous exposure and are printed by using light of a long wave length which gives a positive image or latent image by destroying parts of the latent image of the fogged areas.

It has been customary to use negative images for various graphic reproductions in which the negative is preposed to the light image after which a suitable transferred image is obtained on a nucleated transparent support. However, an attempt to use a direct positive emulsion resulted in no image being transferred from the direct positive emulsion to the receiving layer using conventional methods.

SUMMARY OF THE INVENTION It has now been found that the aforementioned problems are overcome when the diffusion transfer process employing a direct positive emulsion is carried out in the presence of a silver halide developing agent, a silver halide solvent such as sodium thiosulfate, and a development restrainer such as benzotriazole provided the solution comprises about 8-27 mole percent potassium and about 92- 73 mole percent sodium based on the total moles of potassium and sodium which is generally about 3 to about 30% by weight dry basis of developing composition. The processing solution preferably comprises about 0.1 to about 0.44 moles potassium per liter, a thiosulfate silver halide solvent, hydroquinone, 1-phenyl-4,4dimethyl-3- pyrazolidone and about 3 to about 30% by weight based on the total developing agent, dry basis, of a development restrainer. The processing solution can be a viscous composition containing a film forming material such as sodium carboxyl methyl cellulose or hydroxyl ethyl cellulose in sufficient quantity to impart to the composition a viscosity of 1,000 to 200,000 centipoises at a temperature of 20 C. It will be appreciated, of course, that the processing composition can be prepared ready to use, in a dry form or in a concentrated form for convenience in handling.

In a particularly useful embodiment of the invention, a transparent receiving sheet such as cellulose acetate, is used having thereon noble metal nuclei. It can also have a diffusion transfer toner such as a water soluble polyvinyl quaternary salt as described in Van Hoff et al. US. Pat. 3,174,858, 4-phenyl-5-imino thiourazole or phenylmercaptotetrazole. The processing is carried out by diffusion transfer in which a silver halide complex diffuses from the developing silver halide emulsion to the nucleated receiving sheet where an image is formed having good black tone.

The process described above is used advantageously to provide a photographic print which is negative with respect to the original light image used to expose the silver halide emulsion and which has excellent transmission density.

DESCRIPTION OF PREFERRED EMBODIMENTS In a preferred embodiment, a silver salt direct positive emulsion such as that described in Berriman US. Pat. 3,367,778 issued Feb. 6, 1968 is employed. These emulsions contain grains comprising a central core of a water insoluble silver salt containing centers which promote the deposition of photolytic silver and an outer shell or covering for such core of a fogged or spontaneously developable water insoluble silver salt. The fogged shell of such grain develops to silver without exposure.

Other suitable direct positive or reversal emulsions include Herschel emulsions in which the emulsion layers have been fogged by a previous exposure to radiation such as ultraviolet, visible or infrared light, or X-rays. The layers give a positive copy by destroying parts of the I latent image of the fogged layer.

In a preferred embodiment, the processing solution has the following components:

Water, 1.00 liter. pH, 10.5-12.5.

The components in the above formulation can be varied widely, but it will be appreciated that it is necessary to have a silver halide solvent such as, for example, sodium thiosulfate, sodium thiocyanate, ammonia or the like present in the quantity required to form a soluble silver complex which diffuses imagewise to the receiving support.

Silver halide developing agents used for initiating development of the exposed sensitive element can be conventional types used for developing films or papers. A developing agent and/or developing agent precursor can be employed in a viscous processing composition containing a thickener such as carboxy methyl cellulose or hydroxy ethyl cellulose imparting a viscosity from 1,000 to 200,000 centipoises at a temperature of 20 C. A typical developer composition is disclosed in U.S. Pat. 3,120,795 of Land et al. issued Feb. 11, 1964.

Developing agents and/or developing agent precursors can be employed alone or in combination with each other, as well as with auxiliary developing agents. Suitable silver halide developing agents and developing agent precursors which can be employed include, for example, polyhydroxybenzenes, alkyl substituted hydroquinones, as exemplified by t-butyl hydroquinone, methyl hydroquinone and 2,S-dimethylhydroquinone, catechol and pyrogallol; chloro substituted hydroquinones such as chlorohydroquinone or dichlorohydroquinone; alkoxy substituted hydroquinones such as methoxy hydroquinone or ethoxy hydroquinone; aminophenol developing agents such as 2,4- diaminophenols and methylaminophenols. These include, for example 2,4-diaminophenol developing agents which contain a group in the 6 position, and related amino developing agents. The aminophenol developing agents can be employed as an acid salt, such as a hydrochloride or sulfate salt.

Other silver halide developing agents include ascorbic acid, ascorbic acid derivatives, ascorbic acid ketals, such as those described in U.S. Pat. 3,337,342 of Green issued Aug. 22, 1967; hydroxylamines such as N,N-di(2-ethoxyethyl)-hydroxylarnine; 3-pyrazolidone developing agents such as l-phenyl-3-pyrazolidone, including those described in Kodak British Pat. 930,572 published July 3, 1963; and acyl derivatives of p-aminophenol such as described in Kodak British Patent 1,045,303 published Oct. 12, 1966; pyrimidine developing agents, such as 4-amino- 5,6-dihydroxy-2-methyl pyrimidine; and aminomethyl hydroquinone silver halide developing agents, such as 2- methyl-S-pyrrolidinomethyl hydroquinone, 2 methyl-S- morpholinomethyl hydroquinone, and 2-methyl-5-piperidinomethyl hydroquinone. The aminomethyl hydroquinone silver halide developing agents are especially suitable incorporated in the negative photographic element.

Another suitable silver halide developing agent which can be used in a reductone silver halide developing agent, especially an anhydro dihydroamino hexose reductone silver halide developing agent.

Lactone derivative silver halide developing agents which have the property of forming a lactone silver halide developing agent precursor under neutral and acid conditions are particularly useful.

Toning agents are generally present during the diffusion transfer step. For example, various toning agents can be contained in the processing solution or even, in some instances, contained in the silver halide emulsion. Toning agents which can be included for improving the tone of the image to make the image blacker or more blue-black include selenotetrazoles, including selenotetrazoles substituted by aliphatic residues, as for example, l-allyl-S-seleno- 1,2,3,4-tetrazole, selenotetrazoles substituted by aromatic or heterocyclic residues having l-12 carbon atoms, as for example, l-phenyl-S-seleno-l,2,3,4-tetrazole, etc., sulfur compounds such as 2-mercaptothiazoline, 2-amino-5-mercapto-1,3,4-thiadiazole, 2-thionoimidazolidene, 2-mercapto-5-methyloxazoline, 2 mercapto-S-phenyl-1,3,4-oxadiazole and 2-thionoimidazoline. It will be appreciated that these toners can be used either alone or in conjunction with other toning agents.

In a preferred embodiment, a polymeric toner is used. Polymers which are particularly useful are water soluble polyvinyl quaternary salts, as described in Van Hoff et al. U.S. Pat. 3,174,858 issued Mar. 23, 1965. These water soluble basic polymeric quaternary salts have a polyvinyl chain having 2 to 10,000 monomeric units each monomeric unit of which is linked directly to a five or six membered heterocyclic nucleus containing as heteroatoms only nitrogen atoms, one of which heteronitrogen atoms being a quaternary nitrogen atom.

In one embodiment, the polymer has the following structure:

in which n is an integer from 2 to 10,000 and X is any suitable anion such as CH SO para toluene sulfonate-', iodide, etc. R represents H, and alkyl group having 1 to 10 carbon atoms such as, for example, methyl, ethyl, propyl, butyl, etc., halogen, N0 NH aralkyl, aryl, etc. R is selected from the same group as R, but can be a different group than R. It will be appreciated, of course,

0 that the heterocyclic nucleus can contain additional nitrogen atoms and that the ring may be substituted with other groups. The substituents can be the same or different.

Typical polymeric materials include poly(l,2-dimethyl-5-vinylpyridinium methylsulfate), poly 1,4-vinylpyridinium methylsulfate) poly(1-methyl-Z-vinylpyridinium iodide), poly(1-methyl-2-vinylpyridinium methylsulfate), poly( l-methyl-4-vinylpyridinium iodide), poly(1-methyl-4-vinylpyridinium methylsulfate), poly(1-vinyl-3-methyl imidazolium iodide) and poly(l-vinyl-3-methyl imidazolium methylsulfate).

In a particularly useful coating composition the polymer is employed from 0.1 to mg./ft. preferably 0.2 to about 5 mg/ft. In a typical embodiment, 30 mg. of the polyvinyl polymer are used for 1 g. of gel in the receiving layer.

Typically, other toners can be used in the amount of about 1.005 to about 5.0 mg./ft. preferably 0.01 to about 1 mg./ft. either in the receiving layer. A particularly useful combination employs phenyl mercaptotetrazole and potassium iodide in a developer or activator solution. Other toning agents which may be used inlude 5,5'-dithia-bis(l-phenyltetrazole), the S-mercaptotetrazoles of Abbott et al., U.S. Pat. 3,295,971 and Weyde, U.S. Pat. 2,699,393. Still other toning agents are disclosed in Tregillus et al. U.S. Pat. 3,017,270 such as 2-thionothiazolidone, 4-phenyliminothiourazo1e, 4-phenyl-1,2,4-triazolidene-3,5-dithione, etc.

The processing composition contains a development restrainer in an amount of about 1 to about 8 grams per liter of solution or about 3 to about 30%, by weight, based on the total dry weight of silver halide developing agent. A development restrainer has a strong inhibiting action on development of latent image silver. In the preferred embodiments, development restrainers such as benzotriazole, 5-bromobenzotriazole, S-chlorobenzotriazole, S-methylbenzotriazole, 5-nitroindazoles, S-nitrobenzimidazole, etc. can be used. However, other development restrainers may be used including triazoles, tetrazoles, oxazoles, thiazoles, pyrimidines, indazoles, tetrazaindenes, pyl'azole, pyrazolone, imidazole, etc.

Both sodium and potassium are present, preferably in an amount of about 5 to about 30% by weight, dry basis of the total developing composition so that the composition contains about 8 to about 27 mole percent potassium and about 92 to about 73 mole percent sodium, based on total moles of sodium and potassium. It will be appreciated that the alkali metals are present as iOns or in combined form, e.g. as salts such as sodium thiosulfate, potassium sulfite and the like, which compounds may vary widely depending upon the particular purpose for which they are added.

The pH of the developing solution is preferably within the range of about 10.5 to about 12.5.

Various means may be used to provide the required pH such as organic bases including 2 methylaminoethanol, diethylaminoethanol and the like and inorganic bases such as sodium hydroxide, potassium hydroxide, and the like may also be used. Other addenda include sequestering agents such as ethylenediamine tetraacetic acid, sodium salt; 1,3-diamino 2 propanol tetraacetic acid, etc. Water softeners can be added or spreading agents including propylated naphthalene sulfonate, octyl phenoxy polyethyl oxide, sodium hexametaphosphate, etc.

The receiving sheets which may be used in carrying out the invention include any suitable support having thereon one or more layers at least one layer of which contains a silver precipitant such as silver precipitating nuclei. Suitable supports include cellulose esters, polyolefins, polyesters, polyacetals, metal, glass, paper, etc. Transparent cellulose ester film support is preferred, such as cellulose acetate.

Suitable paper supports include any of the conventional paper supports including those prepared from cotton, linen, and wood (sulfate and sulfite pulped). Such supports are typically about 5-60 pounds per 1000 square foot papers.

The support can have thereon a polymeric material, typically coated in a thickness of about .3 to 5 mils. Particularly useful polymeric materials include the polyolefins prepared from the alpha-olefins having 2-10 carbon atoms, blends of these polyolefins and copolymers of the alpha-olefins. The coatings may be applied by extrusion or hot melt coating techniques as latexes, as solvent coatings, etc.

In some instances it is desirable to incorporate in the polymeric material at least one pigment or dye, especially where a white background is required but this is not required. In a particularly useful embodiment, titanium dioxide is incorporated as a pigment in an amount of up to 25%, preferably 10-15% by weight of the resin. Other pigments or dyes which may be useful include those commonly known as pigments or dyes for polymeric materials.

Precipitating agents which are useful in receiving sheets include nuclei which are useful as precipitating agents with a silver halide complex, including all of those nuclei which are commonly useful in the diffusion transfer process. Suitable nuclei include silver precipitating agents known in the art such as sulfides, selenides, polysulfides, polyselenides, heavy metals, thiourea, Stannous halides, heavy metal salts, fogged silver halide, Carey Lea silver,

and complex salts of heavy metals with a compound such as thioacetamide, dithiooxamide and dithiobiuret. As examples of suitable silver precipitating agents and of imagereceiving elements containing such silver precipitating agents, reference may be made to US. Pats. 2,698,237, 2,698,238 and 2,698,245 issued to Edwin H. Land on Dec. 28, 1954, US. Pat. 2,774,667 issued to Edwin H. Land and Meroe M. Morse on Dec. 18, 1956, US. Pat. 2,823,122 issued to Edwin H. Land on Feb. 11, 1958, U8. Pat. 3,396,018 issued to Beavers et a1. Aug. 6, 1968 and also US. Pat. 3,369,901 issued to Fogg et al. Feb. 20, 196 8. The noble metals, silver, gold, platinum, palladium, etc., in the colloidal form are particularly useful.

Noble metal nuclei are particularly active and useful when formed by reducing a noble metal salt using a borohydride or hypophosphite in the presence of a colloid. The metal nuclei are prepared in the presence of a hydrophilic colloid such as gelatin and coated on the receiving sheet. The same or a different colloid may be added if desired. It will be appreciated that the coating composition generally contains not only nuclei, but also reaction products which are obtained from reducing the metal salt. Accordingly, the receiving layer can contain the re action by-products which are obtained during the reducing operation.

The photographic emulsions employed can contain spectral sensitizing dyes such as described in US. Pats. 2,526,632 of Brooker et al. issued Oct. 24, 1950 and 2,503,776 of Sprague issued Apr. 11, 1950. Spectral sensitizers which can be used include cyanines, merocyanines, styryls and hemicyanines.

The photographic emulsions can contain various photographic addenda, particularly those known to be beneficial in photographic compositions. Various addenda and concentrations to be employed can be determined by those skilled in the art. Suitable photographic addenda include hardeners, e.g., those set forth in British Pat. 974,317; buffers which maintain the desired developing activity and/ or pH level; coating aids; plasticizers, speed increasing addenda, such as amines, quaternary ammonium salts, sulfonium salts and alkylene oxide polymers; and various stabilizing agents, such as sodium sulfite. The photographic silver salt emulsions can be chemically sensitized with compounds of the sulfur group such as sulfur, selenium and tellurium sensitizers, noble metal salts such as gold, or reduction sensitized with reducing agents or combinations of such materials.

Various photographic silver salts can be used. These include photographic silver halides such as silver iodide, silver bromine, silver chloride, as well as mixed halides such as silver bromoiodide, silver chloroiodide, silver chlorobromide and silver bromochloroiodide.

The photographic silver salts are typically contained in an emulsion layer comprising any binding materials suitable for photographic purposes. These include natural and synthetic binding materials generally employed for this purpose, for example gelatin, colloidal albumin, watersoluble vinyl polymers, mono and polysaccharides, cellulose derivatives, proteins water-soluble polyacrylamides, polyvinyl pyrrolidone and the like, as well as mixtures of such binding agents.

Stripping agents can be used either on or in the surface of the silver halide emulsion layer, on or in the receiving layer containing the nuclei, or can be contained in the developing or processing solutions. When added to the processing solution in concentrations of about 3% to about 10% by weight, the stripping agents prevent the processing solution from sticking to the receiver. Suitable stripping agents normally are used which have a composition different from the binder used in the silver halide emulsion. Typical stripping agents include alkali permeable polysaccharides such as, for example, carboxymethyl cellulose or hydroxyethyl cellulose, 4,4'-dihydroxybiphenol, glucose, sucrose, sorbitol (hexahydric alcohol C H (OH) inositol (hexahydroxy-cyclohexane s d R Z resorcinol, phytic acid sodium salt, thixcin (a castor bean product), zinc oxide, and finely divided polyethylene. These coatings are relatively thin having a preferred coverage of about 6.0 mg./ft. However, a useful range may be from 1.0 mg. to 1.0 g./ft.

In one embodiment a resinous mixed ester lactone release agent is employed as a binder for the silver precipitant in an amount of 1 rug/ft. to about 1 g./ft. It will be appreciated that when smaller amounts are used, that the resinous material can be combined with a suitable colloid such as a proteinaceous material. For example, the resinous material might be coated at a range of 1 mg./ ft. and be combined with gelatin in an amount of 13 mg./ft.

Various colloids can be used as dispersing agents or as binders for the precipitating agents in the receiving layer. Any suitable colloid can be used. Particularly useful colloids are hydrophilic colloids which are used for binders in silver halide emulsions. Advantageously, they are coated in a range of about 5 to about 5,000 mg./ft. Included among suitable colloids are gelatin, preferably coated at a level in the range of about 7-100 mg./ft. polymeric latices such as copoly(2-chloroethylmethacrylate-acrylic acid) preferably coated in the range of "15- 350 mg./ft. a polymeric vehicle containing two components (1) polyvinyl alcohol, and (2) interpolymer of nbutylacrylate, 3-acryloyloxypropane-l-sulfonic acid, sodium salt and Z-acetoacetoxyethyl methacrylate, in a preferred range of about -300 mg./ft.

Coating solutions which contain addenda other than a silver precipitant are also useful in preparing receiving layers. In addition to various components contained in the coating composition according to this invention, toners, surfactants, coating aids, developing agents, silver halide solvents, etc., may be added to improve the image quality in the receiving sheet.

Particularly useful surfactants and spreading agents in receiver coatings include saponin, lauryl alcohol sulfate, p-tert octyl phenoxy ethoxy ethyl sodium sulfonate, etc.

The following examples are included for a further understanding of the invention:

EXAMPLE 1 A direct positive silver halide emulsion prepared and coated according to Example 1 of Berriman US. Pat. 3,367,778 issued February 6, 1968 is exposed to a light image and contacted with a developer having the following composition:

2-methylaminoethanol ml 27 Diethylaminoethanol ml 74 Potassium sulfite 45% solution ml 27 Sodium hydroxide gm 7 Sodium sulfite gm 46 Hydroquinone gm 18 1-phenyl-4-hydroxymethyl-4 methyl 3 pyrazolidone gm 3.0 1,3-diamino-2-propanol tetraacetic acid gm 0.5 Benzotriazole gm 3.0 Sodium thiosulfate gm 35.0 2-mercapto-5-phenyl-1,3,4-oxadiazole gm 0.10 Natrosol 250H (hydroxyethylcellulose) gm 1.5 Water, 1.00 liter. pH 1135305 While the emulsion is developing, it is contacted against a transparent receiving sheet having thereon palladium nuclei. The resulting image has a high transmission density and good contrast.

When benzotriazole is omitted from the above formulation, no image is obtained. When benzotriazole is included in an amount of about 2% by weight based on total developing agent, no image is obtained. When potassium ion is omitted from the formulation, no image is obtained.

EXAMPLE 2 Example 1 is repeated using the same formulation except instead of benzotriazole each of the following is used in the same amount:

5-brombenzotriazole 5-chlorobenzotriazole S-methylbenzotriazole S-nitroindazole S-nitrobenzimidazole Good images are obtained.

EXAMPLE 3 The process of Example 1 is repeated except that in place of 1-phenyl-4-hydroxymethyl-4-1nethyl-3-pyrazolidone, p-methylamino phenol sulfate is used. A good image is obtained.

EXAMPLE 4 Example 1 is repeated except that in place of l-phenyl- 4-hydroxymethyl-4-methyl-3-pyrazolidone, is used l-phenyl-4,4-dimethyl-3-pyrazolidone. A good image is obtained.

EXAMPLE 5 Example 1 is repeated except that the silver halide emulsion is a Herschel reversal emulsion having layers which have been fogged by previous exposure and which are printed using long wave length light. An image of high transmission density is obtained.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

We claim:

1. A photographic composition for treating a direct positive emulsion comprising a silver halide developing agent, a silver halide solvent, about 3 to about 30%, by weight, based on said developing agent, of a development restrainer and about 5 to about 30%, by weight, dry basis, of sodium and potassium as ions or in combined form, said composition containing about 8 to about 27 mole percent potassium and about 92 to about 73 mole percent sodium in combined or in ionic form, based on total moles of sodium and potassium in said composition.

2. A composition of claim 1 in which said restrainer is a member selected from the class consisting of triazoles, indazoles, tetrazaindenes, imidazoles, mercapto compounds, oxazoles, thiazoles, tetrazoles, pyrimidines, pyrazoles and pyrazolones.

3. A composition of claim 1 in which said restrainer is a benzotriazole.

4. A composition of claim 1 in which said restrainer is an indazole.

5. A composition of claim 1 in which said restrainer is an imidazole.

6. A liquid composition of claim 1 having a pH in the range of about 10.5 to about 12.5.

7. A composition of claim 1 in which said developing agent is a mixture of a polyhydroxybenzene developing agent and a 3-pyrazolidone developing agent.

8. A composition of claim 1 in which said silver halide developing agent is 1-phenyl-4-hydr0xymethyl-4-methyl- 3-pyrazolidone.

9. A composition of claim 1 in which said silver halide developing agent is hydroquinone.

10. A composition of claim 1 in which said silver halide developing agent is 1-phenyl-4,4-dimethyl-3-pyrazolidone.

11. A composition of claim 1 in which said silver halide solvent is sodium thiosulfate.

12. A composition of claim 1 in which the composition is a viscous solution having a viscosity of about 1,000 to about 200,000 centipoises at a temperature of 3,257,205 6/ 1966 Cassiers et a1. 9 695 20 C. 3,418,124 12/1968 Hunt -96-'64 13. A composition of claim 1 which further contains 3,458,317 7/1969 Ditzer 9695 an alkylaminoethanol.

5 NORMAN G. TORCHIN, Primary Examiner References Cted J. L. GOODROW, Assistant Examiner UNITED STATES PATENTS 3,260,598 7/1966 Yutzy et a1. 9 6-95 3,345,174 10/1967 Dotson e161. 9695 1