US2833650A - Photographic emulsions - Google Patents

Description

PHOTOGRAPHIC EMULSIONS Comer Drake Shacklett, Roselle, N. J., assignor to E. I. do Pout de Nemours and Company, Wilmington,Del., a corporation of Delaware No Drawing. Application February 7, 1955 Serial No. 486,696. 1

19 Claims. (Cl. 96-114) This invention relates to photography and more particularly to photographic emulsions in which the binding agent comprises an addition polymer containing extralinear amide groups and extralinear betaine and/ or glycol groups. Still more particularly, it relates to emulsions of. light-sensitive silver halide in ,a water-permeable colrelates to silver halide photographic emulsions in which synthetic polyamides containing betaine and/or glycol groups (as described in U. S. application Ser. Nos. 415,161, 415,162 and 415,163, filedMarch 9, 1954), are used instead of all or part of the gelatin which is ordinarily the carrier, binder and protective colloid for the light-sensitive agent. I

Heretofore, gelatin has been employed as the carrier, for the light-sensitive silver halide in commercial highspeed negative type photographic emulsions. However, this substance has numerous disadvantages and it has long been sought to obtain a substitute therefor which possesses the advantages of gelatin with a minimum of its disadvantages. Many materials have been proposed for this purpose including natural and synthetic colloids and polymers having hydrophilic properties. The previously proposed materials have the serious disadvantage that photographic emulsions with speeds equivalent to those of high-speed negative type gelatino-silver halide emulsions cannot be made in them. I

An object of this invention is to provide silver halide emulsions in synthetic colloids which are free fromthe disadvantages of gelatin and related natural protein colloid emulsions. Another object is to provide such emulsions which have speeds at least as high as those obtainable with gelatin. Yet another object is to' provide emulsions of silver halide in synthetic addition polymers that are uniform, stable, resistant to bacteria and from thin layers which are flexible over a wide range of temperatures. A further object is to prepare such emulsions which can be admixed with an additional amount of the same or another polymeric colloid and/or gelatin. A still further object is to prepare such emulsions in which polymeric and other non-diffusing color formers are readily dispersible and the developed photographic layers are free from haze and other disadvantages. Still other objects will be apparent from the above description of the invention.

The photographic emulsions of this invention, in their broader aspects, consist essentially of a dispersion of light-sensitive silver halide in a water-permeable colloid binding agent wherein at least 2% by weight of' such agent is an addition copolymer having hydrophilic properties composed of a substantial number of recurring intralinear units (a) of at least one of the types taken from the group consisting of those having Formula I and those having Formula I and (b) at least one type of a unit having Formula II (each of saidformulae being given below). The remaining proportion of the binding agent can be a dilferent copolymer of the same type and/or a dififerent compatible water-permeable colloid, preferably gelatin, polyvinyl alcohol, or a polyvinyl acetal having hydrophilic colloid properties, including p-hydroxbenzaldehyde polyvinyl acetal, sodium o-sulfobenzaldehyde polyvinyl acetal and polyvinyl acetals containing color former nuclei linked to the polyvinyl alcohol by an acetal linkage.

Copolymers containing one each of the types of units having Formula I and II and their preparation are described in Shacklett U. S. application Ser. No. 415,163,

filed March 9, 1954. These copolymers arecomposed of recurring intralinear units of the formulae:

. R2\ /Rl l I R-J:CoNHR1N+R'co0- H: I l wherein R is a member taken from the group consisting of hydrogen, alkyl radicals of 1 to 3 carbon atoms, phenyl andcyclohexyl, R is a saturated divalent, aliphatic hydrocarbon radical of 2 to 6 carbon atoms, R is an alkyl radical of l to 3 carbon atoms, R, is an alkyl radical of l to 3 carbon atoms, and R' is a saturated divalent, aliphatic hydrocarbon radical of lto 4 carbon atoms, and

/R n a-bn con wherein R, R" and-R are members taken from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, phenyl and cyclohexyl. These copolymers may contain one, two or more diiferent units of the type of Formula I and one, two or more different units of the type of Formula II. In the'se'copolymers, units of type I are present in an amount of 5 to 80 mol percent and the copolymers have a molecular weight of at least 5,000.

Copolymers containing one each of the types of units having Formula I and II and their preparation are described in Shacklett U. S. application Ser. No. 415,162, filed March 9, 1954, and the applications referredto units of the formula:

wherein R is a member taken from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, phenyl and cyclohexyl, R is a member taken from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, R" is a member taken from the group consisting of hydrogen and alkyl of l to 3 carbon atoms, In is a cardinal number from 0 to 4, and n is a cardinal number 0 to 1 and the sum of m and n equals at least 1. Units of type I constitute 10 to mol percent of the copolymers, which have molecular weights of at least 5,000.

Copolymers containing three intralinear units, namely thoseof Formulae I, I and H and their preparation are described in Shacklett U. S. application Ser. No. 415,161,

filed March 9, 1954, and in the applications referred to March 9, 1954, with the following changes: 600 parts of water and 157.2 parts of isopropyl alcohol were placed in the polymerization vessel instead of 800 parts of water, 48.4 parts of N,3-methacrylamidopropyl-N,N- dimethyl-B-aminopropionate betaine was used instead of 45.6 parts of N,2-methacrylamidoethyl-p-aminopropionate betaine, the hydrolysis of the dioxolane was carried out in a mixture of 150 parts of water and 39.3 parts of isopropyl alcohol, the yield of the resulting copolymer was 101 parts and the relative viscosity of a 1% aqueous solution thereof at 30 C. and pH 7 was 2.61, was used instead of the copolymer described in Example 1.

A similar emulsion containing gelatin as the sole binding agent was prepared and coated as described in Example l. Samples of the two films were exposed and processed as described in Example 1. The relative speed of the film containing the copolymer was 229 compared with the gelatin control film whose relative speed was 100 and was equal to that which is characteristic of currently available high-speed negative type photographic films.

Example 6 A photographic emulsion was prepared by precipitating by means of aqueous silver nitrate, ammonium bromide 2 and potassium iodide solutions, 141.6 parts of silver iodobromide (in which the ratio of silver iodide to silver bromide was 1123.7) in the presence of 11 parts in aqueous solution of the copolymer of methacrylamide and N,2-methylacrylamidoethyl-N,N-dimethyl-B-aminopropionate betaine prepared as described in Example 3 above. After precipitation, Ostwald ripening was carried out in the presence of excess bromide ion and ammonia. Thereafter, an additional portion of 40 parts of the same copolymer was added as a 10% aqueous solution and the polymer after thorough mixing, was precipitated by the addition of a large excess of acetone. The precipitated copolymer containing the silver halide was washed with aqueous methanol, then redissolved in a 10% aqueous solution of 169 additional parts of the same copolymer, and digested with the conventional additions, of water, sensitizing, and dispersing agents, etc. being made after which it was coated on a paper support and dried.

A similar emulsion was made in gelatin as the sole binding agent as described in Example 1 above and this emulsion was also coated on paper and dried. When samples of these two papers were exposed in a negative type 1B sensitometer, developed, fixed, washed and dried under identical conditions the relative photographic speed of the product made with gelatin was 200 compared with'that made with the copolymer which was 100, and was characteristic of currently available high-speed negative type photographic emulsions.

Example 7 Example 8 The procedure of Example 6 was repeated with a V :mixed polyvinyl acetal of orthosulfobenzaldehyde and 'N-m(3-methylsalicylamido)benzaldehyde similar to that described in U. S. Patent No. 2, 489,655, but containing 20 to 30% of each of the two aldehyde residues, used to -.replace those portions of the polymer described in Ex- .ample 6 that were employed after the ripening of the :silver halide was completed. Because this polyvinyl acetal is gellable by use of borate ion as a cross-linking agent, this emulsion was coated on a support having a layer containing a borate ion as described in U. S. Patent 2,534,326.

A similar emulsion was made in which the precipitating and ripening of the silver halide was done in the presence of 11 parts of gelatin rather than in the copolymer described in Example 6. The remainder of the procedure was as described in that example. When samples of these two films were exposed in a sensitometer, and processed according to the procedure described by Jennings et al., Journal of the Society of Motion Picture and Television Engineers, volume 55, pages 469 through 471, November 1950, they had the same photographic speed, and the saturation and hue of their photographic images were indistinguishable.

Example 9 The procedure of Example 6 was repeated with the 5 scribed in Example 6. Because the polymer of Example Example 0 The procedure of Example 7 was 'repeated with the exception that a copolymer of methacrylamide and N,2,3- dihydroxypropyl-methacrylamide, prepared as described in Table 1, Experiment 2 of Example 1 of U. S. application Ser. No. 415,162, filed March 9, 1954, except that the solvent for the polymerization'consisted of a mixture of 375 parts of water and 98.3 parts of isopropyl alcohol, and the relative viscosity of 1% aqueous solutions of the resulting polymer at 30 C. and pH 7 was1-.21, wasused instead of the copoymer, described in Example 6.-

The photographic speed of the product obtained in this experiment was essentially the same as thatobtained in Example 8.

Example 11 The procedure of Example 10 was repeated with the exception that the methacrylamide copolymer described in Example 5 was used instead of that mentioned in Example 10. The photographic speed of the product obtained here was similar to that reported in Example -7.

Example 12 A photographic emulsion was prepared by precipitating by means of aqueous silver nitrate, ammonium bromide, potassium bromide and potassium iodide solutions from aqueous solution, 140.8 parts of silver iodobromide (in which the ratio of'silver iodide to silver bromide was 1:50.1) in the presence of 24 parts in aqueous solution of a copolymer of methacrylamide and N,2-methacrylamido ethyl-N,N-dimethyl-l8-aminopropionate betaine, prepared as described in Example 1 of U. S. application Ser.'No; 415,163, filed March 9, 1954. After precipitation, Ostwald ripening was carried out in the presence of excess bromide ion and ammonia. Thereafter, 182.5 parts of gelatin was added and dissolved in the mixture: The emulsion was then cooled to form a firm gel, broken up and washed with water to remove soluble compounds. The washed gel was melted, and digested with the conventional-add? 7 tion's-of water, sensitizing and dispersing agents, hardeners, etc., being made after which it was coated on a celluloseacetate support and dried.

A similar emulsion was made .in the identical fashion with the exception that 24 parts of gelatin was substituted for the 24 partscof thecopolymer used during the precipitation. and ripening stage and this emulsion was also coated on a celluloseaceta'te support and dried. When samples of the two films were exposed in a positive type 1B sensitometer, developed, fixed, washed anddried under identical conditions, the'relative photographic speed of the film containing the copolymer was 213 compared with the gelatin control whose relative speed was 207 and was equal to that which is characteristic of currently available highest speed cine positive film s.

Still other soluble polyami'des'of the type disclosed in U. S. application Ser. Nos. 415,161, 415,162 and 415,163 can be employed as protective colloid, bulking and binding agent for the silver halide in place of or in addition to those described in the foregoing examples. Among such compounds may be mentioned Poly(methacrylamide co N,2,3-dihydroxypropylacrylamide co N,2-acrylamidoethyl-N,N-dimethyl-fl-aminopropionate-betaine) Poly(methacrylamide co N,2,3-dihydroxypropylacrylamidev co N,3-methacrylamidopropyl-N,N-dimethyl arninoacetate betaine) Poly(methacrylamide co N,2,3-dihydroxypropylmethacrylamide 'co N,2-acrylamidoethyl-N,N-dimethylaminoacetatebetaine) Poly(methacrylamide co N,2-methacrylamidoethyl-N,N-

dimethylaminoacetate betaine) Poly(methacry-lamide co N,3-methacrylamidopropyl-N,N- dimethylaminoacetate betaine),

Poly(methacrylamide co N,2-methacrylamidoethyl-N,N-

diethylaminoacetate betaine) Poly(methacrylamide co N,3-methacrylamidopropyl-N,N-

diethylaminoacetate betaine) Poly(rnethacrylarnide co N,3-acrylamidopropyl-N,N-dimethyl-fl-aminopropionate betaine) Poly(methacrylam'ide co N,2-acrylamidoethyl-N,N-dimethyl-,B-aminopropionate betaine) Poly(rnethacrylamide co N,2-acrylamidoethyl-N,N-dimethylaminoacetate betaine) Poly(methacrylamide co N,3-acrylamidopropyl-N,N-diethylaminoacetatebetaine), and

Poly(m'ethacr'ylamide co N,2,3'-dihydroxypropylacrylamide) 1 a In all of the above examples in which a hydroxylated polymer was used,great improvement in the toughness, permanence, resistance to-abrasion was obtained by crosslinking the copolymer by treatment with solutions of the titanium compounds described in U. S. application Ser. No. 433,286, filed May 28, 1954.

The invention is not limited to the specific lightsensitive materials described inthe above detailed examples. On the contrary, various other simple and mixed silver halidesmay be used as the light-sensitive materials,

in, like manner. Mixtures of silver bromide, chloride and/or iodidecan be made by adding mixtures of soluble salts of these halides in like manner. Other useful soluble halides include potassium bromide, potassium iodide, sodium, potassium and ammonium iodides, chlorides and bromides, etc. Other useful soluble silver salts include silver sulfamate, silver sulfate, silver citrate and silver acetate.

During" thedigestion stage or prior thereto, various typesof-sensitizing agents, e; g., sulfur sensitizers, such as flllylthioureas, thiocyanates, thiosulfates, allylthiocyanates, andiother organic or inorganic sulfur sensitizers can be added." In addition, various metal sensitizers may also be addedu suchas those normally used in gelatin emulsions and known to those skilled, in the art .of photographic emulsion manufacture. .In addition, various types of optical sensitizing dyes which modify the spectral characteristics of theresulting emulsions can be added. Suitable sensitizing dyes are described in U. S. Patents 2,010,388, 2,079,376, 2,202,990, 2,202,991, 2,202,992,. 2,278,461, 2,265,908, etc. Similarly desensitizingdyes canbe used when it is desired to make fogged emulsions for direct positives.

Various types of color forming aldehydes maybe used in forming the polyvinyl acetals used in certain specific embodiments of this invention Suitable such aldehydes and polyvinyl acetals are described in U. S. Patents 2,476,986, 2,476,987, 2,476,988, 2,472,910, 2,518,704, 2,538,259, 2,513,190, 2,513,189. Noncolor forming aldehydes may also be used in preparing these poly.- vinyl mixed acetalssuch as, for example, ortho-sulfobenzaldehyde, benzaldehyde, pehydroxbenzaldehyde, etc.

Thesynthetic polyamides described above are completely free from sulfur, metal, and other sensitizing materials, yet allow the preparation of silver halide grains of such type that these sensitizing materials can be added at or prior to the digestion stage in the emulsion manufacture and stillrexert their full sensitizing effects.

An important advantage of the invention is that it provides photographic emulsions having the high-speed characteristics desirable in negative films. is that silver halide emulsions of uniform characteristics can be made readily. A furtltier advantage is that the use of the synthetic polyamides described above admit of the precipitation and growth of silver halide grains which are potentially as sensitive to light as the high-speed negative emulsions made with gelatin. Still other advantages will be apparent from the above description of the invention.

The embodiments of the-invention in which an ex elusive property or privilege is claimed are defined as follows:

1. An emulsion of light-sensitive silver halide in a. water-permeable colloid binding agent wherein at least 2% by'weight is an addition copolymer having hydrophilic properties composed solely of a substantial number of recurring intralinear units of (a) at least one type of unit taken from the group consisting of those of formulae:

R: R: R-rl*'G 0 NH Ri- -N+ -R'0 0 oa.. I wherein R is amember taken from the group consisting of hydrogen, alkyl radicals" of 1 1 to 3 carbon atoms, phenyl and 'cyclohexyl, R is a saturated divalent, aliphatic hydrocarbon radical of 2 to 6 carbon atoms, R, is an of hydrogen, alkyl'of 1 to 3 carbon atoms, phenyl and cyclohexyl, R is a member taken from the group consisting of hydrogen and alkyl of 1 to 3' carbon atoms,

R is a member taken ,from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, m is a cardinal number from Oto 4, n is a cardinalnumber from 0 to 1 and the sum of m and n equals at least 1 and (b) at least one type ofunit of the formula:

Another advantage wherein R, R" and R are members taken from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, phenyl and cyclohexyl. said unit (a) being present in an amount of at least mol percent.

2. An emulsion as set forth in claim 1 wherein substantially 100% of the binding agent is selected from the group of copolymers recited in claim 1 p 3. An emulsion as set forth in claim 1 wherein the rest of the binding agent is gelatin.

4. An emulsion as set forth in claim 1 wherein the rest of the binding agent is a polyvinyl acetal.

5. An emulsion of lighbsensitive silver halide in a water-permeable colloid binding agent wherein at least 2% by weight is an'additio'n copolymer having hydrophilic properties composed solely of a substantial number of intralinear units of the formulae:

wherein R is a member taken from the group consisting of hydrogen, alkyl radicals of 1 to 3 carbon atoms, phenyl and cyclohexyl, R is a saturated divalent, aliphatic hydrocarbon radical'of 2 to 6 carbon atoms, R2 is an alkyl radical of 1 to 3 carbon atoms, R is an alkyl radical of 1 to 3 carbon atoms, and R is a saturated divalent,

aliphatic hydrocarbon radical of 1 to 4 carbon atoms,

and

wherein R, R" and R are members taken from the group consisting of hydrogen, alkyl of l to 3 carbon atoms, phenyl and cyclohexyl, wherein the first type of unit is present in the amount of 5 to 80 mol percent.

6. An emulsion as set forth in claim 5 wherein substantially 100% of the binding agent is selected from the group of copolymers recited in claim 5.

7. An emulsion as set forth in claim 5 wherein the rest of the binding agent is gelatin.

8. An emulsion as set forth in claim 5 wherein the rest of the binding agent is a polyvinyl acetal.

9. An emulsion of light-sensitive silver halide in a water-permeable colloid binding agent wherein at least 2% by weight is an addition copolymer having hydrophilic properties composed solely of a substantial number of intralinear units of the formulae:

wherein R is a member taken from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, phenyl and cyclohexyl, R' is a member taken from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, R is a member taken from the group consisting-of hydrogen and alkyl of 1 to 3 carbon atoms, m is a cardinal number from 0 to 4, n is a cardinal number from 0 to 1 and the sum of m and n equals at least 1, and

I H. RI" wherein R, R" and R" are members taken from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, phenyl and cyclohexyl, wherein the first type of unit is present in the amount of to 70 mol percent.

10. An emulsion as set forth in claim 9' wherein substantially 100% of the binding agent is selected from the group of copolymers recited in claim 9.

the group of copolymers recited in claim 13. v

15. An emulsion as set forth in claim 13 wherein'the 11.'An emulsion as set forth in claim 9 rest-of the binding agent is gelatin. 1

12. An emulsion as set forth in claim 9 wherein the rest of the'binding agent is a polyvinyl acetal.

13.An emulsion of light-sensitive silver halide in a water-permeable colloid binding agent wherein at least 2% by weight is an addition copolymer having hydrophilic properties'composed solely of a substantial intralinear units of the-formulae:

wherein R is a member taken from the group consisting of hydrogen, alkyl radicals of 1 to 3 carbon atoms, phenyl and cyclohexyl, R, is a saturated divalent, aliphatichydrocarbon radical of 2 to 6 carbon atoms, R is an alkyl radical of 1 to 3 carbon atoms, R is an alkyl radical of 1 to 3 carbon atoms, and R is a saturated divalent, aliphatic hydrocarbon radical of l to 4 carbon atoms, and

wherein the wherein R is a member taken from the group consisting of hydrogen, alkyl of l to 3 carbon atoms, phenyl and cyclohexyl, R' is a member taken from the group consisting of hydrogen and alkyl of l to 3 carbon atoms, R is a member taken from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, m is a cardinal number from 0 to 4, n is a cardinal number from 0 to 1 and'the sum of m and n equals at least 1, and

wherein R, R" and R' are members taken from the group consisting of hydrogen, alkyl of l to 3 carbon atoms, phenyl and cyclohexyl, wherein the types of units are in the proportions of 5 to 60, 5 to 60 and 30 to mol percent respectively.

14. An emulsion as set forth in claim 13 wherein substantially of the binding agent is selected from rest of the binding agent is gelatin.

16. An emulsion as set forth in claim 13 wherein the rest of the binding agent is a polyvinyl acetal.

17. The process which comprises precipitating lightsensitive silver halide in an aqueous solution containing an addition copolymer having hydrophilic properties composed solely of a substantial number of recurring intralinear units of (a) at least one type of unit taken from the group consisting of those of formulae:

1 R-L|3-C ONHR1N+R-C 0 0- (EH: wherein R is a member taken from the group consisting of hydrogen, alkyl radicals of 1 to 3 carbon atoms, phenyl and cyclohexyl, R is a saturated divalent, aliphatic hydrocarbon radical of 2 to 6 carbon atoms, R is an alkyl radical of 1 to 3 carbon atoms, R; is an alkyl radical of 1 to 3 carbon atoms, and R is a saturated divalent, aliphatic hydrocarbonradical of l to 4 carbon atoms, and

R! R-dlH-C ONE-(CH1) ,..i oHR" IHI H01:

number of new!!!" whereimk'lis a member taken; from the group consisting of hydrogen, alkyl of 1 to 3 carbongatoms phenylandh cyclohexyLRfis a member taken from the group consisting of hydrogen and alkyl of 1 to 3 carbonatoms R" is amember. taken from thegroup consisting of .hydrogerrancl; alkylof 1 to 3 carbon atoms, m is a cardinal number-fromOi to 4, n is-a cardinal number from Otto 1 and snm ofqm and n equals at least 11 and (b). at

least one type of unit of theformula:

wherein R, R" and R' are members taken from the gronp consi sting' of hydrogen, alkyl of 1 to 3 carbon atoms, phenyl and cyclohexyl, said unit" (a) being present inlan :amount of at least 5- mol percent; ripening thezemulsion, coagulating, the if emulsion, washing the-'coagulum';

and "admixing additional water-permeable colloid with the washed emulsion.

18. A- process as set forth in claim 17 wherein said colloid is gelatin.

19. A process .as setforth in claim 17 ivherein said colloidl isa;polyviny1 acetal;

References Cited in the file of this patent" UNITED STATESPATENTS

Claims (1)

1. AN EMULSION OF LIGHT-SENSITIVE SILVER HALIDE IN A WATER-PERMEABLE COLLOID BINDING AGENT WHEREIN AT LEAST 2% BY WEIGHT IS AN ADDITION COPOLYMER HAVING HYDROPHILIC PROPERTIES COMPOSED SOLELY OF A SUBSTANTIAL NUMBER OF RECURRING INTRALINEAR UNITS OF (A) AT LEAST ONE TYPE OF UNIT TAKEN FROM THE GROUP CONSISTING OF THOSE OF FORMULAE: