DD228370A1 - METHOD FOR CONTROLLING THE VISCOSITY OF WAESSER GELATINE-CONTAINING GAS SOLUTIONS - Google Patents

Abstract

The invention relates to a process for increasing the viscosity of gelatin-containing potting solutions for the production of photographic silver halide materials. The aim and task is to increase the viscosity of pouring solutions by means of copolymers. No photographic and physical-mechanical properties should be adversely affected. By variation in the quantity of the copolymers, desired viscosities can be set. At the same time, better gelatin compatibility is achieved. According to the invention, copolymers based on vinyl monomers with maleic anhydride and their reaction with urea are used.

Description

VEB Filmfabrik V / oIfen ^ "Wolfen, 17.09.1984

PN: 1 154

DC. B.Hesse Int. Cl. ³ : G 03 C 1/06

Dr. G.Roth

DC. D.Plaschnick

Dr. V.Steinert

Method for controlling the viscosity of aqueous gelatin-containing pouring solutions

Field of application of the invention

The invention relates to a process for increasing the viscosity of gelatinous pouring solutions for the preparation of photographic silver halide materials.

Characteristic of the known technical solutions

In the production of photographic materials, especially multi-layer materials, a different viscosity of the aqueous gelatin solution is required in order to obtain thin dry film thicknesses at high wet-cast. It should not be changed significantly the substance content of the solution to be applied. One way to increase the viscosity is by increasing the gelatin concentration, which method is unfavorable because excessive dry film thicknesses arise.

Another disadvantage of adjusting the viscosity by different gelatin concentrations is the insufficient viscoelasticity of such casting solutions. One does not reach a sufficient high casting speed and a bad funeral behavior.

A (ϊ "7 C

It is also possible to adjust by crosslinking the gelatin with curing agent, a higher viscosity of the casting solution, but this method is poorly reproducible and allows only a limited storage of the application solution. A number of compounds are known which, when added to aqueous gelatin solutions, increase their viscosity without complete crosslinking or binding of the main valences with gelatine. Many of them are not photographically inert, so that a deterioration of the photographic properties occurs, such as the use of polyethylene oxides (DE-OS 2 256 670).

An interaction with gelatin is shown by the polystyrene sulfonic acids (US Pat. No. 3,022,172 and US Pat. No. 3,861,924), but only a smaller increase in viscosity is achieved. This method also has the wax portion that by adding the polystyrenesulfonic an increase in the swelling occurs. Another possibility described is the use of polysaccharides and their reaction products. The viscosity increase of these polymers is based on their high intrinsic viscosity. Examples of these are carboxymethylcellulose GP-PS 629 593, cellulose sulfate DE-OS 2 703 776 or xanthan gum US Pat. No. 3,623,688. A disadvantage of these compounds is the partial inadequate gelatin compatibility which may occur, for example. in the turbidity of the gelatin layers or segregation of the layers expresses.

When using polysaccharides as viscosity enhancers (DE-OS 1 130 286, 2 541 754, GP-PS 1 287 971) is also a partially insufficient gelatin compatibility * Although it is possible to improve this by incorporation of acids, however, so that the swelling of Layers and. the fragility significantly worsens.

Polymers based on olefinically unsaturated monomers with maleic anhydride, as proposed in DE-PS 1,937,364, US Pat. No. 2,522,042, US Pat. No. 2,996,405, DE-PS 676 459, are likewise suitable as viscosity boosters. These polymers also show inadequate gelatin compatibility by being too. Turbidity of the solid gelatin layers lead.

Aim of the invention;

The aim of the invention is a method for controlling the viscosity of gelatin-containing Begießlösungen without causing turbidity or demixing phenomena of the gelatin layers and without deterioration of the photographic parameters occurs.

Explanation of the essence of the invention

It is an object of the invention to develop novel copolymers based on maleic anhydrides, which are photographically inactive, as well as improved gelatin compatibility with a good ViskositätserEöhung show, with no adverse effect on the mechanical and photographic parameters should take place.

According to the invention the object is achieved in that for controlling the viscosity of aqueous gelatinous Begießlösungen copolymers of "composition

- CH 3l 2T ₁ J

C = O C = O C = O C = O

I I I

OH 0 0 IiH

I II

R ₁ R ₀ C = O

1 2,

wherein ε = styrene, α-methylstyrene, ethylene, propylene, butylene, methyl, ethyl or propionyl acrylate

R-. = Hydrogen, monovalent cation such as Na ⁺ , K ⁺ , NH ₄ ⁺ , Ei ⁺ or alkyl group of 1-12 carbon atoms

Rp = hydrogen or monovalent cation such as Na ⁺

a ο 300 - 5 000

'b = 15-5,000

C = 1-5,000

mean, be added with a molecular weight of 60 000 to 1 000 000.

The copolymers are added to the casting solutions in an amount of from 0.5 to 30% by weight, based on the dry weight of the bead. The pH of the aqueous Begießlösung is between 5.0 to 9jO. The desired viscosity is set by appropriate addition of the amount of the copolymers.

The copolymers can be prepared by free-radical polymerization »by polymerizing vinyl monomers, preferably styrene, <= L- methylstyrene, ethylene, propylene with maleic anhydride. The introduction of the structural unit c of the invention is carried out by reacting the copolymerized maleic anhydride with urea.

This reaction may optionally be carried out in alcohols, at the same time forming the maleic acid half ester. It is also possible to synthesize the copolymers according to the invention by co- or terpolymerization of vinyl monomers, optionally maleic anhydride and the reaction product of maleic anhydride with urea. The reaction of maleic anhydride with urea is carried out as indicated by P.O. Tawney (A.A., J. Org. Chem.

Examples of the copolymers according to the invention are listed in the following table. The composition of the copolymers is in mol%.

O vo co -3 σ \ ui - £>

ro

ω Η · 4 03 H- O ΠΙ tr QD TJ C + ο

ι ι ι ι ι

U U U O O Oro ι

I Ul Ul J

O O

I I I II

ro ι

K ro

Ul Ul

O O

I II

I i

Ul I

ro ι

I I I

Ul Ul

O O

I I ro

Ω Ω

VJ

ro ^ ro-i-ro-rovjj ^ uiui UIUIUIUIUIUIUUUIVJIO O I Il

O-Ω - Ω K K

ro ι

Ο-Ω Ω

Il W

WOM

ro ro ro - »· ι UIUIUIUIUIUIUIUIUI

ro

O O I ι W Il -'Ω - Ω - ~ Ω JXJ ro - p ro prj Ω "~ -Ω Il Il O O

The copolymers according to the invention thus prepared show a significantly better gelatin compatibility than the. Hitherto Known Polymers The use of the copolymers according to the invention allows a good control of the viscosity without adversely affecting the photographic and mechanical parameters. In addition, the copolymers have no influence on the standing time behavior of the aqueous casting solution. The copolymers according to the invention are suitable both for the preparation of light-sensitive silver halide layers and for auxiliary layers, for example intermediate or coated layers.

embodiments

Example 1 (prior art)

Increasing amounts of the copolymer 1 are added to an 8% gelatin solution at a pH of 6.5. The viscosity is determined by means of a rotary viscometer at 40 ^° C.

Polymer solution (ml / 100 ml gelatin solution) 0 5 7.5 10 15 Viscosity (m Pa.s) 8.9 12.5 15.1 20.6 30.3

The layers poured thereon show cloudy layers as the amount of the polymer increases.

Example 2

Analogously to Example 1 increasing amounts of the copolymer 4 are added to an 8% gelatin solution, wherein the pH was also adjusted to 6.5.

Polymer solution (ml / 100 ml gelatin solution) O 5th 7.5 10 15 Viscosity (m Pa.s) 8.8 16.0 19.9 20.5 49.5

Lifting the viscosity increase, the layers show better gelatin compatibility.

Example 3

Analogously to Example 1, 10 ml of the copolymers 2, 5, 8 and 10 are added to 100 ml of an 85% gelatin solution.

The viscosity is determined fresh and after 6 hours standing time. The pH of the solution is adjusted to 6.5.

Polymer solution

2 3 5 , 4  8th »3 fresh 20 5 33 , 0 30 , 5 6 h 20 33 30

Viscosity (m Pa.s)

There is no change in viscosity.

35 * 6 34.8

Example 4

To a photographic silver halide gelatin emulsion (70 g of Ag Br and 80 g of gelatin / l) hardened with mucochloric acid, increasing amounts of the copolymer 6 are added at a pH of 6.5. The viscosity could be increased.

Amount of polymer / 1 emulsion (ml) 0 50 100 150 Viscosity (m Pa.s) 6.5 12.3 29.5 41.5

Example 5

On a polyester pad of. a thickness of 120 μm, which is provided with a gelatin adhesive layer and an NC layer, is applied with a black-and-white emulsion containing 6.5 g Ag / m. As a coating, a gelatin layer is applied. Per kg of emulsion, 100 ml and 200 ml of the copolymer 3 are added.

Type (without Polymer) 0 , 06 100 ml 0 , 05 200 ml O , 06

min

1/0

12.4 12.1 12.5

7.6 7.6 7.5

After lith development (2 '), the same photographic parameters are obtained ·

Claims (2)

CLAIM THE INVENTION 1) A method for controlling the viscosity of aqueous gelatinous Begießlösungen by the addition of polymers in the preparation of photographic silver halide materials characterized in that the gelatin-containing aqueous Begießlösung copolymers of the composition C = O C = O C = O C = O I I I OH 0 R ₁ 0 R ₀ NH 1 2, C = O where 2 / ~ styrene, «^ .- methylstyrene, ethylene, propylene» Butylene, methyl, ethyl or propionyl acrylate R ₁ = hydrogen, monovalent cation such as Na ⁺ , K ⁺ , NH / ¹ *, Li ⁺ or alkyl group of 1-12 carbon atoms Rp = hydrogen or monovalent cation, such as Na mean with a molecular weight of 60,000 to 1,000,000 v / erden. 2) A method for controlling the viscosity according to item 1, characterized in that the copolymers of Begießlösung in a concentration of 0.5 to 30 wt .-%, based on gelatin dry weight, are added.