DE2050288C3 - Photographic light-sensitive material - Google Patents

Description

FR-PS 15 26 402, GB-PS 8 05 549 and US-PS 34 49 142, polyalkylene oxides and their derivatives for the antistatic treatment of KunsibluiT surfaces, but not photographic record

55 materials to be used.

The object of the invention is to provide a light-sensitive photographic recording material with a Paper backing coated on both sides with a polyolefin indicate whose antistatic off-60 armament even further compared to the antistatic equipment known from FR-PS 15 56 240

The invention relates to a light-sensitive photo-improved, so that recording materials with graphic recording material, consisting of silver halide layers with a comparably very high sensitivity, coated on both sides with a polyolefin, can be protected ^{from electrostatic paper layer support, at least one on one side 6 5 charges,}
The invention is based on the knowledge that

borrowed emulsion layer and one on the opposite can solve the problem by that one lying side of the layer carrier applied anti-not only to produce the anti-static layer

a polyelectrolyte and silicon dioxide in certain Proportions but also a certain polyalkylene oxide in certain proportions used.

The invention relates to a photosensitive photographic recording material, consisting _of a paper base coated on both sides with a polyolefin, at least one photosensitive emulsion layer applied to one side of the paper base and an antistatic layer applied to the opposite side of the base, which has an aniomic, film-forming organic polyelectrolyte : containing colloidal silica and that dad · "- ¹ in that the antistetische IDR'ut the polyelectrolyte in an amount NIU ^Λ, - ■■ * 25 percent by weight and the colloidal .Si'mdioxyd in a..! sufficient amount enthä \ to aie antistatic layer not to make ^sticky:;!, · ■ · 1 that it further comprises a polyalkylene oxide having a molecular weight of 400 in an amount 16 to 35 percent by weight, up to 1000 on the total weight of the antistatic layer, contains.

The fact that the task at hand is achieved by antistatic layers of the specified composition could be solved, was not to be expected without further ado, especially since the task at hand can be exchanged of the polyalkylene oxide cannot be dissolved by other known antistatic compounds. According to the invention, it is possible to reduce the specific surface resistance of the substrate to less than 10 ″ ohms to diminish.

To achieve the best results, the proportions of the three components of the antistatic Layer lie within the specified limits. The examples that follow later also work shows that layers of the three specified components provide a much more effective protection Stat ^ chen charges offer as layers one of these three components or from a mixture of two of the components.

In the manufacture of light-sensitive photographic recording materials, as is known, electrostatic charges are generated in the devices for applying emulsion layers and in the cutting, transporting and unwinding devices operated at high speed, with essentially two different types of electrosu'ischen charges occurring, namely one by the Unwinding from rolls of the paper base material generated an electrostatic charge and a charge generated by the transport of the base material and recording material. At the unwinding devices at which the paper backing material to be unwound or the coated material ίο is pulled off the rollers, a charge takes place which can be referred to as an unwind charge. However, electrostatic charges are also generated within the manufacturing devices, which are caused by the contact and separation of the substrate and recording material from the transport rollers. This charge, which can be referred to as transport charge, depends on the speed of rotation and the nature of the transport rollers as well as on the nature of the surface of the material to be transported influenced. This means that the generation vr η of electrostatic charges is a dynamic phenomenon which is influenced by the degree of contact electrification by friction of the recording material and the electrical conductivity of the same, which determines the rate of dissipation of the 3: electrical charges. These two factors, the generation of the charge and the discharge of the charge, must be precisely coordinated with one another, since otherwise discharge surges and, as a result of a transport charge, spark discharges can occur during unwinding. To avoid the occurrence of static charges, the rate of discharge of the charges must be greater than the rate of charge formation. Whether this is the case can be determined by measuring the surface conductivity on the basis of the specific surface resistance under certain temperature and humidity conditions, namely at 23.9 C and 20 ° _o relative humidity between two electrode plates and from this the specific surface resistance calculated using the following formula:

Specific surface resistance (Ohm) = measured resistance (Ohm) Abs'-ind / wipe the electrodes (cm)

Length of electrodes (cm)

Regarding further details of the above Procedure for measuring the specific Surface resistance is referred to US Pat. No. 2,801,191.

An inventive sc ν '! Mmt-Mt'μ.> Τ 'thus produced, i.e. 1 mu ■ «lu-ni ■ · ■ layer carrier, example · · ■> ■■ : m:,; ■. 1 ,, 1,,> tung, by Lxtrudu- ■ '· ■ < >. H

by lamination e · "r · '

with a polyolefin ^. ^; 1 ■ · ■. . i.: ■;

len or polyathyne '·''■■<

both sides of the l \ ip im>

different polyolefins)! >>> '

Here, ic k-, μι · ν \ ι>! ;

be coated. The paper backing can also be used as an au. the US-PS 32 53 922 known with a solution 12 made of an electrically conductive salt,

I- ■■ -ispit-ΐ.Λ. _; .c emem /Mk.ilimetallsuifat. / B. N;! Num- ■ ·. Tit. InIItCiV-Ci-MiH, where ilts Sj ¹ / a --- nerc ¹ - -'4, IhKiIMi hi!.; unit, _u || in direct. ". mi ¹ Kt with l'.ipu-i .hu T" i ^ er hc! in. '·!

itl '/ Ii-'; ■! ! 1 llc! LU "lv.pfi; iil! I.Jv Jlhntcl-

Ui II .. · .-. !., · - \.: '. .. ilM.IIV .Μ., Ιι'Μ.Ι ¹ Π Il, 11 '! i Γ! I lld '.1 Il l!

l. Jl π. .v-k-'il

I> ι. - ■ ■ ■, Nui / tMi'hü'i'iLi, ni ι ei << ■ ' '■>'■ M -.- h. · - ■ -i. > ■■■ '·, ι Ii holds'-ii'er l: i and .lei.

, ·. ■■ ', ■ r „w-. ¹ ■ :: ·>'»iicl · ·' I! ■■■ i s-

■ ■ 14 / H nicr -I il · ■ - ■> ■ _-1

halide emulsion layer and the antistatic layer 13.

It appears that if the recording material has an internal antistatic agent and the surface of the polyolefin layer 11 to achieve a good adhesion of the emulsion layer 14 is activated by means of a corona discharge, the n "inner Any antistatic agent present leads to an uneven activation of the layer 11. This effect can However, this avoided Jaß ti.iN recording material is coated with the outer antistatic layer 13, whereby surprisingly a better activation of the Polyolehnoberflüchc achieved will.

If necessary, the paper backing itself can be used for improvement before the application of the polyolefin layer the adhesion of the same is irradiated with electrons, i.e. exposed to a corona discharge, will. Instead of, 'Jekiron irradiation can be used for Improvement of the adhesion of the polyolefin layer on the paper backing, including the primer or Interlayer can be used. The thickness of the paper backing can be varied within wide limits to be different. The thickness of the polymer layers, for example the polyethylene layers, can also be different within a wide range.

The polyolefins are extruded onto the paper substrate in such a way that from about 9.8 to about 39 g of polyolefin per m ^{2 of} face surface are applied to each side of the substrate

/ ur production of a light-sensitive ph <>tograr'ii ^ chcn Auf / tichiiungsmateridK after I rinse ki rinen as polyolefins PoKäthylen. Polypropylen and Äthvlei, Cropylen-Mischpolymensate used na suitable polyethylenes have a density of (). / (ι t is (M (HOg cm ³ , a viscosity measured by the .'M.hmclzindcx according to AST M D-1J38. Condition E, from IS'i l> is 20.0, preferably 3.0 to 12 , 0 decigrams per minute and a plasticity of 40 to 90 ". Suitable polypropylenes have a density of 0.90d to 0.910, a viscosity, determined according to ASTM D-17 38, condition L. of 10 to 90, preferably 40 to 90 Decigrams per minute and a crystallinity of 60 to 80 "". The polyolefins are prepared by known processes using, for example, / Legler catalysts. Mixtures of high-density polyolefins and low-density polyolefins can also be used, the latter either originate from the initial polymerization of olefins to polyolefins with low density or from thermal degradation of polymers with high density.Other suitable ^ aliphatic polyolefins are polyallomers, ie ethylene.propylene copolymers, such as those described in US Pat. No. 3,478,128, CA. -PS 7 98 911 and FR-PS 15 06 769 are known.

In the case of the production of an antistatic layer of a light-sensitive photographic recording material According to the invention usable polyelectrolytes are preferably water-soluble film-forming anionic compounds. Examples of such compounds are the alkali metal and ammonium salts of polymeric carboxylic acids. / B. Sodium salts of poly methacrylic acid, Salts of cellulose sulphates. Salts of polyvinylphnsphaien and salts from partially esterified lactones ones vinyl alcohol i./i- dicarboxylic acid mixed p.Wvmcris.iies The last mentioned blocks are made from lactones of resinous heteropolymers of vinyl alcohol and unsaturated ^ -dicarboxylic acids, which are optionally esterified by monohydroxy alcohols (see. US-PS 32 60 706) and converting the same into the alkali metal salts according to US Pat. No. 3,169,946. An example of such Ester lactone salt is the butyl lactone salt of Example 1 of US Pat. No. 3,260,706, which, as in Example 17 of U.S. Patent 3,169,946, in the sodium salt

ίο can be transferred

The PolyalkylenoiydkiTnponer'e the antistatic Layer of a light-sensitive photographic recording material of the invention is special critical in terms of molecular weight, such as is evident from the data in the examples described below. While the alkyl units of the Carbon chain can contain 2 to 4 carbon atoms, as in the case of polyethylene, polypropylene and Polybutylene oxide and mixtures thereof is the case, the molecular weight must be 400 to 1000.

The colloidal silica of the antistatic

A layer of a photographic light-sensitive material of the invention may be used as described in the LS-PS 27 01 218 described, produced -erden.

Suitable aluminum-modified colloidal silicon oxides are commercially available.

The quantitative proportions of the three components of the antistatic anti-viscous ¹ in the light-sensitive photographic recording material of the invention are critical, that is, they - nuts are within the specified limits

The antistatic layer of an inventive product Recording material · contains about 50 to 81: weight »Percent colloidal silicon dioxide. Before / Jt'swei ^ e the layer contains less than 80% Silicon dioxide and more than 4 percent by weight of the polyelectrolyte and more than 16 percent by weight of polyalkylene oxide. A very good one effective antistatic layer contains about 4 percent by weight of polyelectrolyte. z. ß. about 4 percent by weight a polymethacrylic acid salt, about 30 percent by weight of a polyalkylene oxide, e.g. B. one

Polyethylene oxide with a molecular weight of 400 and about 66 weight percent colloidal silica.

The antistatic layers are preferably after activation of the surfaces of the polyolefin

layers with chemical agents such as B. an acid dichromate solution or after a flame treatment. especially after activation of the polyolefin surfaces by a corona discharge applied to the polyolefin surfaces. To the

Conventional known power sources can be used to generate the corona discharges. The spark gap power source for the corona discharge supplies the electrodes with current in a known manner by means of an oscillator excited by a spark gap. One

This will change the fundamental frequency of the corona achieves that the primary frequency of the Oscillator changes within a range of up to 10 JOO or more Hertz. To achieve a sufficient Adhesion of the layers on the through

⁶ S corona discharge activated surface, a high-voltage corona discharge with peak voltages of, for example, 25,000 to 50,000 volts is expediently used. Tensions in this great

Order are for corona activation of polymers at transport speeds of the layer support of about 30 to about 300 nm per minute or more is suitable.

The corona discharge can be applied to the polymer surface, for example, with the help of various metal electrodes,; .- n, which are attached in the vicinity of the polymer surface and which are arranged at a point where the polymer surface is a grounded metal roller coated with a dielectric material, ζ is coated B a linear polyester happened Similarly, a metal roller as! 'rager for SchichtträiRThahn s along with a number of electric · ^1!. the planetary at the same distance from the (r-of the metal roll erfiäche are arranged and the minimum * ns with a dielectric on the dr Me'allwalze closest surface coated 'ind be used The tand From the F'ekt "the.. to the polymer surface and to the grounded roller should be so large that the corona discharge is generated by the applied spanning and a free passage of the layer path through the activation zone is guaranteed om odir generates a combination of a direct current with a superimposed alternating current.

According to a particularly advantageous embodiment of the invention, there is the light-sensitive emulsion layer The recording material consists of a black-and-white emulsion layer high sensitivity. The emulsion layer or layers of the recording material can, however, also consist of a wide variety of raised awareness in various ways color photographic emulsion layers exist

The following examples are intended to further illustrate the invention explain.

example 1

A photographic paper base weighing about 108 gm ^{2 was} used. Each side of the support was activated by corona discharge and coated with polyethylene by means of an extruder in such an amount that about 39 g of polyethylene were accounted for ^{on a support area of 1 m 2.} One of the polyethylene surfaces. was then ', and coated by a corona discharge Activate in one operation with a coating composition of the composition shown below such that ^{z is} from 0.5 g to a support surface of from 1 m to 2.5, preferably 1.5 g, solids accounted .

Colloidal silica
(30 weight percent dispersion). .. 22.0 g
Water soluble sodium cellulose

sulfate *) 0.4 g

Polyethylene oxide (molecular weight 400) 3.0 g

Water 74.6 g

*) Technical product with 2.5 sulfate units per anhydroglucose unit.

The coating compound used. which contained 66 percent by weight colloidal silicon dioxide, 4 percent by weight sodium sulphate and 30 percent by weight polyethylene oxide (based on dry weight), had a sufficient amount of silicon dioxide. io that a non-sticky surface was obtained. The specific surface resistance of the paper coated with this coating material, measured at 21 ° ^{C. and 20% relative humidity, was 5/10 ohms compared to 10 10} ohms for a polyethylene-coated paper which had no antistatic layer.

The other polyethylene surface of the paper backing was then also corona discharged activated and then with a coarse-grained gelatin silver bromide iodide emulsion of high sensitivity coated. It was found that when the emulsion was processed in the emulsion coater by static Charges was not affected, while

t5 rend the same, from an an'istatic backing layer free paper backing when coated with the emulsion static discharge builders in the generated Emulsion layer revealed.

Example 2

The procedure described in Example 1 was: repeated, but this time the following specified polyalkylene oxides were used, with which the results given below were achieved. The layers were dried at room temperature:

Molecular
Weight Specific Oher-
flat resistance at
21.1 C and 20 ° -, re'a-
tive moisture in
ohm Polyethylene <> xyd 200 6.3 ■ 10 ^s Polyethylene oxide 400 1.2-10 » ₄₀ polyethylene oxide 1000 2- 10 '° Polyethylene oxide 6000 3.1 ■ 10 '* Polypropylene oxide 400 4 ■ 10 ¹⁰

The data presented above show that polyalkylene oxides with a molecular weight of 200 to 1000 have considerable protective effects. lead to static charges, but if the emulsions are to have a specific layer surface ^{resistance of less than 10 10} ohms, polyalkylene oxides with a molecular weight within a range of 200 to 400 must be used.

Corresponding tests in which glycerine, triethylene glycol and diethylene glycol were used together with cellulose sulfate and colloidal silicon dioxide in place of the polyalkylene oxides in the antistatic layer, showed that the specific surface resistances obtained in the samples dried at room temperature were initially 6.3 ± 10 ⁸ to IO were ¹² ohms, but that dr prevailing in a Emulsionsbeschichtungsvonichtung during drying of the paper support at 93C to simulate tiedingungen the specific Oberrlächenwiderstände unsatisfactory were Under the same Tr cknungsbedingungen (03 O remained, however, the specific Obenlächenwiderslände the erftnvcr vcndeten samples in the anti-

609 61ΛΉ4

static layer a polyethylene oxide with a Molecular weight from 400 to 1000, practically unchanged.

Example 3

The procedure described in Example 1 was repeated, but this time by corona discharge activated surfaces with the same amounts of one or more of the three components the coating compound were coated. In doing so, those given in the table below were given Get results.

The test item (f) shows the surprising effectiveness of the combination of colloidal used Silicon dioxide, a polyelectrolyte and a polyalkylene oxide to make a non-sticky one anl / static layer.

Specific surface resistance at 21.1 T and 20 "" relative humidity in ohms

1.5 x 10 "*)

ID ¹⁰

(a) polyethylene oxide
(Molecular weight 400)

(b) a) plus colloidal
Silicon dioxide

(c) Sodium polymethacrylate 2 · I0 ¹⁰ *)

(d) c) plus 10 ¹² colloidal silica

(e) c) plus polyethylene oxide 10 ° 5 · 10 ° *) (Molecular weight 400)

(f) d) plus polyethylene oxide 10 ° - 5 · 10 " (Molecular weight 400)

*) The layers were too sticky to use.

1 sheet of drawings

Claims (6)

\ J static layer that contains an anionic film claims: forming organic polyelectrolytes and colloidal les silicon dioxide. 1. Photosensitive photographic recording It is generally known to make photographic paper drawing material, consisting of a two-sided 5 thereby largely water-impermeable, paper coated with a polyolefin that they are coated with hydrophobic polymers, ^beis P ^ie isschichtträger, at least one on one Side of the light-sensitive ethylene, coated with styrene polymers, polyacrylates or poly-paper backing. Such photographic pallets emulsion layer and one on the opposite side, however, have the disadvantage of keeping their overlying side of the substrate in the manufacture, processing and use of an electro-antistatic layer that charges one anionic and one statically. The generated electrostatic film-forming organic polyelectrolytes and charges lead to colloidal silicon dioxide applied to the paper, which is characterized by photographic emulsion layers that the antistatic formation of irregular fogging images. The coating of the polyelectrolyte in an amount of 15 to collect electrostatic charges on the Pa-4 to 25 percent by weight and the colloidal sizing is undesirable also because the dirt contains calcium in a sufficient amount, particles accumulated by the electrostatic charges around the antistatic layer not to be drawn sticky, to a desensitization, ochlesertnachen, anddul they can also lead to a polyalkylene oxide formation and to physical defects of the photo with a molecular weight of 400 to 1000 in 20 graphic recording material, an amount of 16 to 35 percent by weight, with a polymer, such as B. polyethylene, each based on the total weight of the anti-coated papers is the problem of the static static layer, contains. Due to the non-conductive nature of the poly- 2. Recording material according to claim 1, which is particularly large. However, since the polyolefins characterized in that the aniistatic layer 25 is exceptionally good for coating photographidas colloidal silicon dioxide in a quantity of shear papers for the manufacture of photographic products Contains 50 to 80 percent by weight. Recording materials are suitable, it has not been 3. Recording material according to claim 2, missing. To find ways that make it possible characterized in that the antistatic layer effectively amides papers coated with polyolefins To statically equip polyelectrolytes in an amount of 4 Ge 3 °. weight percent, the colloidal silicon dioxide in So is, for example from FR-PS 15 56 240, be an amount of 66 weight percent and 30 parts by weight of a photographic recording material weight percent polyalkylene oxide holds. a paper coated with a polyolefin 4. Recording material according to claims 1 known layer base, which has an antistatic layer up to 3, characterized in that the antistatic 35 consists of an anionic, film-forming organic layer as a polyelectrolyte em alkali metal or niche polyelectrolytes and colloidal silicon-ammonium salt of polymethacrylic acid, Contains cellulose. Such a non-static layer of loose sulphate, polyvinyl phosphate or one of them partially achieves the specific surface resistance of esterified lactones of a vinyl alcohol /, / -diethylene layers of about 10 ^ie ohms on about a carboxylic acid copolymer. 40 10 ¹² ohms, measured at 21.1 ° C and 20% dry 5. Recording material according to claims 1 tive moisture to reduce. It has, however to 4, characterized in that the aniistatic layer is shown to contain such silica particles Top layers produced as polyalkylene oxide, polyethylene oxide, are very effective holds. Protection of silver halide emulsion layers, with 6. Recording material according to claims 1 45 with an average photosensitivity to 5, characterized in that the layer offers over static charges, but that they are not supported on both sides with polyethylene, polypropylene, silver halide emulsion layers with a higher polyethylene / polypropylene mixture or sensitivity offer the desired protection against an ethylene / propylene copolymer via electrostatic charges,
is layered. 50 It is also already known, e.g. B. off