DE1572178A1 - Improved manufacture of photographic material, particularly photographic emulsions and the products obtained thereby - Google Patents

Description

Societa ¹ Per Azioni Ferrania, Milano / Italy

Improved production of photographic material, in particular of photographic emulsions and the products obtained thereby

The invention relates to a process for the preparation of photographic silver halide emulsions with improved Properties obtained by adding these emulsions to any stage of their manufacture one or more polymers are added which contain in their molecule v / repeating units of the following structure:

GH - ι

CONH,

/ R R ^! I. I. ~ f CH - C t \ CO

λ Ί

.R "
R ¹ "

where R = H or alkyl \

R '= H or alkyl |

R "and R ¹ " = identical or different alkyls, or

both together represent the atoms that

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a five- or sechsatomigen heterocyclic ring, Z ₀ B. can include a pyrrolidine or piperidine ring, etc. $

χ and y mean the ratio between the two units.

Another object of the invention are silver halide photographic emulsions and photographic materials, those made with the same, which improved hiding power of the developed silver, an increase in contrast and sensitivity, and in which part of the gelatin is replaced by one or more polymers which contain units of the following structure in their molecule:

R.
ι

- GH

R 'τ

SH-C-

CO -

R " RlIt

where R, R ', R ", R ¹ ", χ and y have the meanings and values given above »

_{It is known that compounds, Z 0} B ₀ salts of heavy metals or noble metals, are usually added to improve the sensitivity properties of photographic emulsions "but particularly with regard to increasing Y" and the MD (D max) of the developed image, favorable results are achieved by adding polyvinyl lactams, which contain 4 to 5 carbon atoms in the heterocyclic ring

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ORIGINAL INSPKTEO

e.g. polyvinylpiperidone or polyvinylpyrrolidone etc. to the emulsion (French patent Ί 234 882),

However, the photographic emulsions modified in this way show, over time, a strong tendency to Fogging · This disadvantage has so far been caused by the addition of a small amount of phenolic anti-fogging agents in connection with the polyvinyl lactam to the emulsion has been partially overcome (French patent 1 233 875)

Under such conditions, however, during storage under various conditions of temperature and relative humidity, an inconsistency in the sensitivity properties of the material so treated appear·

It has now been found that if the photographic emulsion is used during any stage of its manufacture one or more water-soluble polymers of the general formulas given above in a suitable amount adds, the emulsion shows improved sensitivity properties {in particular, the image shows a large increase in the maximum density, contrast and sensitivity.

These polymers can be used during any stage of the preparation of the photosensitive emulsion and ε.Β · are added in suitable amounts after the precipitation of the silver halide or silver halides, both during the physical and chemical ripening process, and also before application. Before-

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preferably they are in the gelatin-silver halide emulsion layer used.

The amounts can be in the range from 2 to 75 # "on the gelatin, are, depending on the type of polymer, the type of emulsion used or the extent of the desired V / MPACT _# Moreover, these polymers can the photographic emulsions during any stage of manufacture thereof incorporated are ·

The partial replacement of gelatin by the polymers described in the gelatin-silver halide emulsions has an increase in the opacity of the compared to the emulsions which only contain gelatin Silver entails, v / elches after exposure and development j i.e., it is possible to have noticeable increases with the amount and type of Polymerisates can vary, the maximum density and contrast of the developed image to achieve the same silver content, or to reduce the silver content of the sensitive material without the To impair sensitivity properties.

Opacity is usually defined as the numerical result of the ratio of optical Density to the number of grams of silver per square decimeter in the layer of the developed image « One advantage of the present invention is therein too

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see that they are a simple and effective means provides gelatin-silver halide emulsions with improved hiding power, while increasing opacity to an increase in contrast and maximum density, and usually to an Increasing the actual sensitivity, calculated at a significant density, leads to «

Another advantage is that the addition of these polymers to the emulsion is not particularly important Requires operation and can be carried out with the help of the usual devices} also exist no problems with solvent recovery, as these products can be used in the form of aqueous solutions, and the modified emulsions obtained by means of the usual application and drying procedures and devices can be applied and dried, which is clearer from an industrial point of view Advantage is.

The polymers suitable for carrying out the present invention can be obtained by free radical polymerization with the aid of peroxides and azo compounds, preferably in solution. The intrinsisohen viscosities in the range of 0.04 to 2 dl / g (measured at 30 ⁰ C in the Itano *) are the bevorzugtesten values in the range from 0.10 to 0.50 / g are dl,

909881 / 12S2

Suitable monomers are: acrylamide, dimethylacrylamide, Dimethylcrotonamide, diethylacrylamide, dibutyl acrylamide, N-acryloylpiperidine (acrylpiperidide), N-acryloylmorpholine (Acrylmorpholide), N-acryloylpyrrolidine (Acrylic pyrrolidide), etc.

The molar ratios of acrylamide to N-substituted acrylamide monomers can be used to achieve of the water-soluble polymers suitable for the purposes according to the invention within fairly further Limits vary depending on the type of monomers used, the molecular weight and the hydrophilic Character of the monomers to be used.

The polymers of the invention are particularly useful in the preparation of emulsions for X-ray films, particularly for medical X-ray diagnosis, as well as for the preparation of emulsions in the graphic arts. However, their use is not limited to a specific type of emulsion or a specific type of silver halide, since they can be used very well in silver bromide, bromide, chlorobromide and chloride emulsions, in emulsions for black and white * - and color photography. ^J

These emulsions can be sensitized with precious metal compounds, e.g. ammonium aurothiocyanate

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with chemical sensitizers, e.g. allyl thiourea, or polyoxyethylene sensitizers. They can also be one or more optical Sensitizers, couplers, antifoggants, stabilizers, plasticizers, hardeners and others Usual smocks included.

The following preparations and examples are intended to illustrate, but not restrict, the statements made above.

Preparation 1

In a three-necked flask equipped with a stirrer and reflux condenser, 28.4 g of acrylamide and 14.11 g N-acryloylmorpholine dissolved in 800 ml of acetone-methanol mixture in a volume ratio of 3: 1.

The solution is ^{heated to 68 °} C. for 5 minutes, 1.70 g of azo-bis-isobutyronitrile are added and the heating is continued for 5 hours with stirring.

The IJmsetzungsmischung is cooled and the polymer which has precipitated during the reaction, was filtered off, washed with acetone and dried under vacuum at 40-5O ⁰ C. Yield: 38.6 g.

[? j] = 0.48 dl / g in 1m NaNO ₃ at 30 ⁰ C. H? £ = 16.49.

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Preparation 2

According to the procedure described for preparation 1, 1.84 g of azo-bis-isobutyronitrile are added to a solution of 24.8 g of acrylamide and 21.17 g of N-acryloylmorpholine in 800 ml of acetone-methanol and the whole is refluxed for 5 hours . Yield of polymer: 40.7 g [71] = 0.26 dl / g in 1m NaNO ₃ at 30 ⁰ C W /> = 15,50

Preparation 3

1.69 g of azo-bis-isobutyronitrile are added to a solution of 28.43 g of acrylamide and 13.91 g of N-acryloylpiperidine in 800 ml of acetone-methanol and the whole is refluxed for 5 hours. Yield of polymer: 35.2 g ['Π ] = 0 _f 22 dl / g in 1m NaNO, at 3O ⁰ C = 16.07

Preparation, 4

To a solution of 24.87 g of acrylamide and 20.87 g of ir-acryloylpiperidine in 870 ml of acetone-methanol 1.83 g of azo-bis-isobutyronitrile are added and the whole is refluxed for 5 hours.

Yield of polymer} 34 g | [V J = 0.23 dl / g in domestic NaNO ₅ at 30 ⁰ C W = 15.64 °

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Preparation 5

0.15 g of azo-bis-isobutyronitrile are added to a solution of 30 g of acrylamide and 10 ml of N-aeryloylpyrrolidine in 500 ml of ethanol and the mixture is refluxed for 6 hours * Yield of polymer ι 24 g [4fc] * 0, 13 dl / g in Im NaHO ₃ at 3O ⁰ O S # * - 17.65

Preparation 6

To a solution of 5.27 g of acrylamide and 8.4 g in 268 ml Blmethylcrotonamid Aoeton methane oil 0.54 g Azö ~ isobutyronitrile given up and the mixture heated at EÜckfluB for 24 hours "" yield of polymer t 5 " 4 g [^] * 0.17 d3 / g in 1a HeHO ₃ at 30 ⁰ C H ^ «19.3

Preparation 7

For a solution of 28.4 g of acrylamide and 12.7 g of diethylactic amide in 780 ml of acetone-flethanol, 1.64 g is worth Azo-bia «-iaobutyrfnitril added and the whole * heated under reflux for a long time. Yield of polymer 33.1 g

3 * 0.35 dl / g in 1m HaHO ₃ at 30 ⁰ O 16.42

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Preparation 8

To a solution of 24 # 8 g of acrylamide and 19 g Diethylacrylamide in 835 ml of acetone - *! Ethanol is 1.75 g Azo ~ bis ~ i3obutyronitrile added and refluxed for 5 hours * Yield of polymer: 31.5 g

β 0.28 dl / g in 1m NaNO ₃ at 30 ° C 15.28

Preparation 9

0.3 g of azobieisobutyronitrile is added to a solution of 74 g of acrylamide and 6 ml of dibutyl acrylamide in 600 ml of ethanol, and the whole is heated in hot oil for 5 hours,
Yield of polymer ι 70 g

· 0 _P 13 dV « tn.fm. HaHO ₅ feel ⁰ 18.7

The nitrogen contents given above were determined according to the Kjeldahla method ^ after careful ! Drying of the products

Pie structure of the polymers was determined by infrared under he booking beetimjot.

Btiapiel 1

A highly sensitive AmnoniuBeBuleion, consisting of from a gelatin silver iodobromide BiepersiGn, which is about 2 MoIJi silver iodide and 98 Hol # silver bromide with one Contained silver / gelatin ratios of about 0.63, and

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ORIGINAL INSPECTED

to be used in an X-ray element with an intensifying screen and with the usual application means was completed, was divided into 5 parts

direct
The first portion was made on a standard cellulose

triacetate base applied, a layer thickness of about 108 / U was obtained after drying the film.

The polymers of preparations 1, 2, 3 and 4 were added to the remaining four portions in such an amount that that they had a ratio of gelatin to polymer of 100 to 25 according to the following scheme:

for the second part the polymer of the preparation 1 "third""""." 3 κ fourth " ⁿⁿ η η 2 ⁿ fifth" η «« _a 4 The various emulsions thus obtained were then applied to a useful gelatinous triacetate base, one of which the Htister's comparable splint thickness was obtained

a) After a Konat long Seeteil-Trocknejj the samples were covered under a wedge of constant 0 * 3 log E and danaoh 2 t and 30 Wiaiiit> n at 27 C iö an Eatwicklerböd of the following composition: K * tol 3g

anhydrous! Tatriuasxilfit 50 g

i ^ tröckinon 9 g

anhydrous batriate carbonate 50 g

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ORIGINAL INSPECTED

Potassium bromide 3 g

Glutaraldehyde bisulfite 13 g

5-methylbenzotriazole 0.15 g

Water 'up to 1000 ml

- After developing the 5 patterns as usual, when fixed and dried, they exhibited the properties shown in Table 1.

Table 1

template
No. Polymes
risat
of the pre
ready layer
strength
/ ^U Ag / m ²
* CP.
♦♦ veil Sensation
lich
speed ir D max 1 - 10.8 6.40 34.6 0.19 +0.25 1.20 2.07 2 1 10.6 5.30 36.2 0.18 +0.25 1.20 1.98 3 3 11.7 5.63 38.8 0.17 +0.30 1.30 2.20 4th 2 10.9 5.42 37.5 0.16 +0.30 1.20 1.98 5 4th 11.2 5.32 38.3 0.18 +0.25 1.20 2.00

* on unexposed. material
* ♦ at I) = 2

b) After rack drying for 40 days, the samples were placed under a; Wedge (wedge) exposed to a constant 0.3 log E and then ^{treated for 4 minutes at 20 °} C. in a developer bath of the following composition:
anhydrous sodium carbonate 50 g anhydrous sodium sulfite 50 g hydroquinone 9 g metol 3g

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Potassium bromide 3 g

Water up to 1000 g

After the 5 samples were developed, fixed and dried as usual, they showed the ones in the table specified properties:

of
Prep
council siärkf ' G Tabel evil Emi
no »Find ·
t 0, ^r D max Had to - 10.8 6.40 Tench: -0, 10 1, 95 1.84 1 1 10.6 5.30 30.6 0.15 +0, 10 1, 15th 1.86 2 3 11.7 5.63 35.6 0.15 +0, 10 1, 10 2.10 3 2 10.9 5.42 38.1 0.15 +0, 10 1, 15th 1.85 4th 4th 11.2 5.32 35.6 0.15 +0, 10 05 1.96 5 35.8 0.15

* on unexposed material
** if D = 2

The sensitivities were determined at density above the fog. For a more convenient comparison, the ones given are numerical values expressed as differences of log E with respect to an arbitrarily selected reference marking of the exposure wedge positive values indicate greater sensitivity.

Example 2

An ammonium solution similar to that used in Example 1

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'-14-

was divided into three parts. The first The portion was applied directly to a standard cellulose triacetate base, with a dry film a thickness of about 13.2 µ was obtained.

The polymer of preparation 7 was added to the second portion in an amount such that a gelatin-polymer ratio 100 to 25 was obtained, and then applied to a cellulose triacetate pad, a thickness of 13 / U was obtained after drying the film.

The polymer of preparation 8 was added to the third portion in an amount equivalent to a gelatin / Polymer ratio of 100 to 25 delivered, and then applied to a cellulose triacetate base, wherein after drying the film a layer thickness of 13.4 / rev was obtained.

a) After drying for 48 hours at 50 ^° C. and 65% relative humidity, the samples were exposed and then treated as already described in Example 1 / b! after completion of the treatment they showed the properties given in Table 3:

909881/1252 _G0PY

Polymes
risat
of
Prep
council layer
strength
/ ^U Table e 3 • veil 16 NS
speed i- .- t D ma> template - 13.2 Ag / 'm ² CP.
* » 17th -0, 40 0, 85 1.8 pounds 1 7th 13th 6.68 32.9 O, 17th 0 1. 10 2.23 2 8th 13.4 5.32 41.7 0, +0, 05 15th 2.1? 3 5.28 42

* on unexposed! material
** if D = 2

Eeiapiel 3

An ammonium solution similar to that described in Example 1 was divided into two parts.

The first portion was applied directly to a standard cellulose triacetate pad, with a dry film with a layer thickness of 14.8 / U was obtained.

The polymer of the prepa became the second part rates 6 added, in a kenge that gave a gelatin / polymer ratio of 100 to 25, and then applied to a cellulose triacetate base, wherein after drying the pilm a thickness of 14.5 / U was obtained became.

a) After one day of rack drying, the y.uster exposed and then, as already described in Example 1 / a, treated} after the end of the treatment

they showed the properties given in Table 4: 909881/1252

COPY

BAD ORiCiINAL

Table 4

template Polymeri Layer- kg / m ² veil , 19th Sensation 1 , 80 I) ma * Nrc sat des strength , 20 opportunity 1 , 95 , 00 Preparation / U G 3 , 95 1 - 14.8 7.48 0 + 0.50 2 2 6th 14.5 5.61 0 + 0.60

* on unexposed! material

b) After drying the rack for 30 days, the samples were exposed and then, as in Example 1 / b described, treated} after complete treatment they showed the properties given in Table 5:

Table 5

Pattern polymer- layer- Ag / r; i haze sensitivity- y.

sat of strength ■ * ability q

_T , preparation <u

^{1><r /} g

14.5

7.48 0.18 5.61 0.17

0.15 1.20 0.30 1.45

D max

2.33 2.30

* on unexposed! material

Example 4

An ammonium solution similar to that of Example 1 was divided into two parts «

The first portion was applied directly to a conventional cellulose triacetate base, with after Drying the film a layer thickness of 15 / U was obtained.

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BATH ORIGINAL

The polymer from preparation 9 was added to the second portion, in an amount such that a gelatin / polymer ratio of 100 to 25 was obtained, and then applied, a strength of 16.3 / U being obtained after the film had dried _o

After curing for 5 days at 50 ^° C. and 20% relative humidity, the two samples were exposed and then treated as already described in Example 1 / b; after completion of the treatment they showed the properties given in Table 6:

Table 6

Sample polymer of

No.

Preparation

Layer thickness

/ ^U
15th
16.3

Ag / V

7.77 6.87

Veil sensitivity

Ii

0.21
0.21

-0.40
-0.40

0.75 0.75

D max

1.85 1.97

* on unexposed! material

- patent claims -

BAD ORIGINAL 909881/1252

Claims (1)

P. 1185 157/178 -18- Claims 1 · / Process for the production of photographic gelatin-silver halide emulsions, characterized in that that one or at least partially as colloidal material for the photosensitive layer several water-soluble synthetic polymers are used which contain recurring units of the in their molecule contain the following structure: Γ ■ ■ N - HH. \ «Ι -CH ₂ - CH 1. CH - C '· ¹ B. " \ CONH ₂ : \ CO-N " where R = hydrogen or alkyl; R ^! = Hydrogen or alkyl; R "and R" ¹ = identical or different alkyls, or both together represent the atoms which can close a five- or six-atomic heterocyclic ring, for example a pyrrolidine or piperidine ring, etc.; χ and y mean the molar ratios between the two units. 2. The method according to claim 1, characterized in that 909 * 8 ^ / 1252 BAD ORiGiNAt that the synthetic polymers in an amount of 2 to 75 / »». based on the gelatin. 3. Photographic element, characterized in that that it has been manufactured according to the preceding claims. 4. Photographic images characterized in that they are made using the photographic element of the preceding claim have been obtained. 9098 81/1282 ORIGINAL INSPECTED