DE2937027A1 - METHOD FOR MATTING PHOTOGRAPHIC MATERIALS - Google Patents

Description

Process for matting photographic materials

The invention relates to a method for matting photographic materials.

It is known. Surfaces of photographic layers matting by adding inorganic or organic pigments or synthetic polymers. To this This gives a surface roughness that ensures good retouchability and the creation of Newton's rings suppressed during the copying process. It is It is desirable to choose such a matting substance which is photographically inactive and has a refractive index that is similar to that of dry gelatine, thus causing cloudiness and loss of sharpness caused by scattered light be avoided. Furthermore, the matt surfaces should have a low level of abrasion and should be resistant towards fingerprints.

030013/0803

DT-AS 1 547 639 proposes adding amorphous silica as a matting agent.

However, this has the disadvantage that it tends to agglomerate at higher temperatures and is therefore difficult to filter is. Alkaline earth metal salts, as described in US Pat. No. 2,823,136, also have an unsatisfactory effect will. They have too high a density and too much opacity, which leads to an impairment of the photographic properties. Further matting options are the addition of wax (DD-PS 35 234), hardened gelatine (DT-OS 2 522 692), cellulose derivatives (DRP 725 698) or dispersions based on synthetic polymers. However, these known methods are with afflicted with a number of shortcomings. Layers matted with wax, for example, have an unsatisfactory roughness, since these is partially lost during the drying process. Starch, cellulose derivatives and hardened gelatin are only difficult to access in the desired grain size range and sometimes lose their matting effect at high humidity. Synthetic polymer dispersions have the advantage that you Matting effect not due to rapid settling during the Shedding is reduced. Polystyrene dispersions are known as such (GB-PS 645 954), dispersions on the Based on styrene copolymers (BE-PS 634 174, DT-OS 2,628,643) and polymethyl methacrylate.

However, it is very difficult to produce stable dispersions with a uniform particle distribution using polystyrene resins will.

030013/0803

-4- 2337 0

Di Pol ^ 'srv-rol as well'. "The Pol ^v methvlmethncrvlat differ considerably in the refractive index from gel-tine, photographic materials matted with these dispersions show increased cloudiness and loss of sharpness. Hire production is also very complex and can only be reproduced more sharply .. ·

Another disadvantage of many matting agents is that they do not iron the ·. · "" ■ nor the spherical shape qufi ".

The aim of the invention is an improved method of matting of photographic materials that have a more uniform Matting allows, ', - with cloudiness and scattered light by the matting agent as much as possible should be excluded and the matting agent can be produced reproducibly and without great effort.

The invention is based on the object ^W by using new pole merdispersionen for matting photographic M ~ t eri-lier, the disadvantages of known methods, such as increased haze and loss of sharpness due to an unfavorable refractive index of the Ma 11 ierungsmit means of, mangelrde stability during To eliminate the casting process and lack of matting or casting disturbances due to an unfavorable particle distribution.

According to the invention> Aufaabe the ird achieved in that as a matting agent, a Pol ^{v /} merdispersion * = uf based on polyvinyl chloride or Vin ^ 'lchloridmischpolymerisa th, erhnlten by Mikrosuspensionspolvmerisation or Saatpolvmerisation. is used in a concentration of 5 to 50% by weight, preferably 7.5 to 20% by weight, based on the dry binder weight of the layer to be matted.

03001 3/0303

OOPY

^mm O ^

These polymer dispersions have a narrow particle size distribution. They can be in a size from 0.1 to 5 / um according to DT-AS 1 301 529 or GB-PS 97R 875 (Mikrosuspensionspol ^ merisa tion) or..DT-OS 2 054 1OR (Sgn t polymerisation earthed.

In a watery phise they tend to sediment without agglomeration without additional protective colloids. By adding 20 to 500 % by weight of protective colloid, preferably 100 to 200 % by weight of gelatin, based on the polymer, very stable dispersions can be obtained. According to the invention, these can be used in liquid form as a matting dispersion without prior solidification. However, it is also possible, after adding the gelatin solution, to allow the dispersions to solidify and to store the gels. Even after storage for several months at 278 ^° K, there is no change in the particle size or particle size distribution. The gels can be melted easily and diluted with passer or gelatin solution. It is still possible to dry the gels. In order to achieve rapid redispersion, it is advantageous to granulate this after or during drying. According to the invention, silver halide layers, protective layers, filter layers and NC layers can be matted using the new matting process. The new matting process is distinguished by the fact that the matting dispersions used can be produced in a simple manner without the use of high-speed dispersing devices in the desired particle size and narrow particle size distribution. As a result, with particle sizes of 0.1 to 5 μm, effective roughening is achieved even with a low concentration of matting agent.

020013/0803

CX) PY

Since the refractive index of vinyl chloride polymers with 1.538 almost the same as that of gelatine, symptoms of cloudiness will appear and loss of sharpness avoided. The particles are very stable in the form of the dispersions against agglomeration and dimensional stability, too high humidity. Stabilized with gelatine and dried after solidification, they can be used without additional cooling capacity be stored over long periods of time and redispersed in water or aqueous protective colloid solution as required will. The method of the invention enables particularly fine-grained matt gelatin layers to manufacture.

example 1

Preparation of the matting dispersion

Animal dispersion A

1 kg of gelatin is swollen and melted in 14 liters of water. For this purpose, 2 kg of polymethyl methacrylate are added at 318 K, dissolved in 11.4 l of methylene chloride, added and dispersed by means of a high-speed stirrer. After the During the dispersion, the methylene chloride is removed and the dispersion solidifies at 283 K. The mean particle diameter the polymer particle is 0.478 µm. The index of refraction the polymer particle is 1.492.

Matting dispersion B

1 ta gelatine is poured into 9.5 1 V / water and melted. For this purpose, 6.45! Cq of a 31 wt.

030013/0803

CX) PY

vinyl chloride dispersion produced by microsuspension polymerisation. with an average particle diameter of 0.481 µm was added. After the addition is complete, the mixture is solidified at 283 K. The 3rachungo index of the polymer particles is 1,538 .. »

Matting dispersion C-E

The matting dispersions C to E are analogous to Matting dispersion B prepared using polyvinyl chloride dispersions of different particle sizes.

Matting dispersion mean particle diameter

C 0.789, um

D 0.948, um

E 1.312, um

M "animal sqelatine

10 1 matting dispersion B v. Ground into a solidification form poured and solidified at 283 K. The gel obtained is in Cut about 2 cm large cubes and air-dry at 308 K for 48 hours. Then it is made using a granulator crushed again. Slightly cloudy granules are obtained, referred to as matting gelatine in the following example will.

Example 2

In 100 liters of a 2% aqueous gelatin solution v / ground at 313 K 1.2 kq Msttierungsdispersion A dissolved. This dispersion is poured onto a Hulogensilver emulsion layer as a protective layer.

030013/0803

COPV

The dried protective layer is easy to retouch, has a surface roughness of 1.1 μm and shows few Newton's rings when copied.

Example 3

The procedure of Example 2 is repeated, 1.2 kp of Mnttierungsdispersion B are used. The dried protective layer has the following characteristics:

Retouchability: very good
Depth of rest: 1.2 µm

Newton's rings: keire

Example 4

The procedure of Example 2 is repeated, with 4.8 Mating dispersions A and B can be used. The dried protective layers have the following characteristics:

Retouchability: very good very good Rest depth: 1.6 1.7 Newton's rings: no no

D-.s material with the protective layer based on the Matting dispersion A was very cloudy and showed a lot strong loss of sharpness.

Example 5-7

The procedure of Example 2 is repeated, using 4.8 H matting dispersion C, D.E.

030013/0803

The dried protective layers have the following characteristics:

Mating dispersion CDE

Retouchability very good very good very good Rest depth 2.3 3.1 3.0 -

Nev'tonian rings none none none

Example B.

The procedure of Example 2 is repeated except for in 100 l of a 1.5% liquor solution, 0.45% q Mp11 ierungsoel «tine quenching at 313 K for 20 minutes and then redispersing with stirring. The dried protective layer has the following key data:

Retouchability: very out R Chest depth: 1.4 um

Nev / Tonian rings: none

Example 9

The magenta coupler Z 169 (Bios Fin-il Rep. 721, 21, 1946) so "ie the usual additives" contains a stabilizer, a hardening agent, a wetting agent on a multilayer color material, the finely sensitive f-nlogensilver color coupler emulsion layer a protective layer in example 3 was poured. the matting by means of M ^ ttierungsdispersion B fHhrt not affect the photographic Eigenschnften. during the storage at 90% relative humidity, no adhesion tendency of the backing layer is observed with the protective layer.

- 10 -

C300 13/0803

A comparison without a material dispersion B in the protective layer, on the other hand, shows a considerable tendency to stick, which can lead to damage under mechanical stress the backing layer and the protective layer.

02 0 013/0 303

Claims (1)

Claim Process for matting photographic materials, in particular of silver halide layers, protective layers or NC layers by means of polymer dispersions, characterized in that as Matting agent a polymer dispersion based on polyvinyl chloride or vinyl chloride copolymers, obtained by microsuspension or seed polymerization, in a concentration of 5-50% by weight, preferably 7.5-20% by weight, based on the dry binder weight the layer to be matted. £ 13001 3 / 08Ü3