Antistatic plastic moldings

Antistatically treated plastic moldings which contain two layers on the surface to be antistatically treated, the layer situated nearer the plastic surface being an antistatic layer and the more remote layer being a protective layer of a radiation-curing coating composition which is cured by exposure to ionizing radiation, are distinguished by excellent antistatic properties and very good surface properties.

This invention relates to a firmly adhering antistatic coating for plastic 
moldings based on polythiophene or vanadium pentoxide preparations. 
It is known that preparations of polythiophenes containing polyanions can 
be used for the antistatic treatment of plastic moldings, particularly 
supports for photographic materials (EP 440 957). It is also known that 
vanadium pentoxide preparations can be used for the antistatic treatment 
of plastic moldings (DE 26 31 628). It has now been found that, despite 
its excellent antistatic effect, the antistatic coating has disadvantages 
in its strength of adhesion, in its adhesion behavior on gelatine surfaces 
and in its scratch resistance. 
The problem addressed by the present invention was to obviate this 
disadvantage without impairing the antistatic effect. 
More particularly, the problem addressed by the invention was to provide a 
hydrophobic plastic support, for example a polyethylene terephthalate film 
or a paper coated with polyethylene on both sides, which has at least one 
antistatic coating first layer with a protective second layer which does 
not impair the antistatic properties. 
More particularly, the problem addressed by the present invention was to 
provide a hydrophobic plastic support, which is coated with at least one 
gelatine silver halide emulsion layer and which has an antistatic layer on 
its reverse side, with a water-impermeable layer which would protect the 
antistatic layer without impairing its antistatic properties. 
According to the invention, the solution to this problem is characterized 
in that a radiation-curing coating composition is applied to the 
antistatic layer applied to the hydrophobic support and is cured by 
exposure to ionizing radiation, for example to UV radiation or an electron 
beam. 
In the context of the invention, an antistatic layer is understood to be a 
layer which provides the material with a mobility of the electrical 
charges, determined as the discharge time in-msec., of less than 10 msec. 
and, more particularly, less than 1 msec. at 21.degree. C./30% relative 
humidity. 
The antistatic layer preferably contains a preparation of a vanadium 
pentoxide sol or, in a particularly preferred embodiment, a preparation of 
a polythiophene which is made up of structural units corresponding to the 
following formula 
##STR1## 
in which R.sub.1 and R.sub.2 independently of one another represent 
hydrogen or a C.sub.1-4 alkyl group or, together, form an optionally 
substituted C.sub.1-4 alkylene radical, preferably an optionally 
alkyl-substituted methylene radical, an optionally C.sub.1-12 alkyl- or 
phenyl-substituted 1,2-ethylene radical, a 1,3-propylene radical or a 
1,2-cyclohexylene radical and 
An.sup..crclbar. is a polyanion. 
R.sub.1 and R.sub.2 are preferably methyl and ethyl groups. 
Representatives of the optionally substituted C.sub.1-4 alkylene radicals, 
which R.sub.1 and R.sub.2 may form together, are preferably the 
1,2-alkylene radicals derived from 1,2-dibromoalkanes of the type 
obtainable in the bromination of .alpha.-olefins, such as ethene, 
prop-1-ene, hex-1-ene, oct-1-ene, dec-1-ene, dodec-1-ene and styrene; the 
1,2-cyclohexylene, 2,3-butylene, 2,3-dimethyl-2,3-butylene and 
2,3-pentylene radicals are also mentioned. 
Preferred radicals for R.sub.1 and R.sub.2 together are the methylene, 
1,2-ethylene and 1,3-propylene radical, the 1,2-ethylene radical being 
particularly preferred. 
The polyanions are anions of polymeric carboxylic acids, such as 
polyacrylic acids, polymethacrylic acids, polymaleic acids, and polymeric 
sulfonic acids, such as polystyrene sulfonic acids and polyvinyl sulfonic 
acids. These polycarboxylic and sulfonic acids may also be copolymers of 
vinyl carboxylic and vinyl sulfonic acids with other polymerizable 
monomers, such as acrylates and styrene. 
The molecular weight Mn of the polyacids yielding the polyanions is 
preferably in the range from 1000 to 2,000,000 and, more preferably, in 
the range from 2000 to 500,000. The polyacids or their alkali metal salts 
are commercially available, for example polystyrene sulfonic acids and 
polyacrylic acids, or may be produced by known methods (see, for example, 
Houben-Weyl, Methoden der organischen Chemie, Vol. E 20, Makromolekulare 
Stoffe, Part 2, (1987), pages 1141 et seq.). 
Mixtures of alkali metal salts of the polyacids and corresponding 
quantities of monoacids may also be used instead of the free polyacids 
required for the formation of the preparations according to the invention 
of polythiophenes and polyanions. 
The preparations may also be true solutions, colloidal solutions or 
fine-particle dispersions. 
The production of these preparations is described in EP-A-0 440 957. 
Besides water, other protic solvents may be used as the solvent or 
dispersion medium of the polythiophene preparations, including for example 
lower alcohols, such as methanol, ethanol and isopropanol, and mixtures of 
water with lower alcohols and other water-miscible organic solvents, such 
as acetone. 
The polythiophene preparations may contain low molecular weight wetting 
agents or dispersants, for example anionic surfactants, such as sodium 
dodecyl sulfate, cationic surfactants, such as cetyl trimethyl ammonium 
bromide, and nonionic-surfactants, such as alkylphenol/polyethylene oxide 
adducts which are added before, during or after the polymerization. The 
incorporation of nonionic surfactants before polymerization is preferred. 
The term "dispersion" includes a macro-dispersion wherein the average 
particle size is larger than 100 nm as well as a "colloidal" dispersion 
wherein the particles have an average particle size ranging from polymer 
molecule size to the average particle size of polymer molecule 
conglomerates having an average particle size not larger than 100 nm. 
For the antistatic treatment of the plastic moldings, the polythiophene 
preparations may be applied to the moldings by known methods, for example 
by impregnation, casting, spraying, gravure printing, knife coating, 
spread coating, etc. After removal of the solvent, for example water, the 
antistatic layer unaffected by atmospheric moisture which is formed by the 
polythiophene on the treated molding is directly present on the molding. 
To obtain coatings of greater adhesion and scratch resistance, polymeric 
binders soluble or suspendable in water, for example polyvinyl alcohol or 
polyvinyl acetate dispersions, may also be added to the polythiophene salt 
preparations. 
In the case of acid-sensitive plastic moldings and to protect the equipment 
used for application, it can be of advantage to neutralize excess free 
acid groups in the polythiophene salt preparations before they are applied 
to the plastic moldings by addition of alkali metal or alkaline earth 
metal hydroxides, ammonia or amines. 
After drying, the thickness of the layers in which the polythiophene 
dispersions are applied to the plastic moldings to be antistatically 
treated is in the range from 0.001 to 100 .mu.m and preferably in the 
range from 0.002 to 10 .mu.m, depending on the desired conductivity of the 
molding and the desired transparency of the coating. 
Removal of the solvents after application of the solutions may be carried 
out simply by evaporation at room temperature. However, to obtain higher 
processing speeds, it is of greater advantage to remove the solvents at 
elevated temperatures, for example at temperatures of up to 150.degree. C. 
and preferably at temperatures in the range from 60.degree. to 130.degree. 
C. 
The production of the polythiophene dispersions or solutions in accordance 
with EP-OS 440 957 leads to products in which the content of polymerized 
thiophene makes up from 5 to 50% by weight, based on the total solids. In 
the production of the polythiophene dispersions, up to 90% by weight, 
based on the total solids, of other polymer latices or dispersions 
containing acidic groups (salts), such as --SO.sub.3.sup.-, --COO.sup.- 
phenolate or --PO.sub.3.sup.2-, may also be added. The content of acidic 
groups is preferably above 2% by weight to ensure adequate stability of 
the dispersion or solution. 
Polymers suitable for this purpose are described, for example, in DE-A 25 
41 230, DE-A 25 41 274, DE-A 28 35 856, EP-A-0 014 921, EP-A-0 069 671, 
EP-A-0 130 115, U.S. Pat. No. 4,291,113. 
The polymer dispersions or latices may contain linear, branched or 
crosslinked polymers. The crosslinked polymers with a high content of 
acidic groups are swellable in water and may be used in the form of 
so-called microgels. Microgels such as these are described, for example, 
in U.S. Pat. Nos. 4,301,240, 4,677,050 and 4,147,550. 
The applied quantity of polymerized thiophene in the dispersion or solution 
used is preferably from 0.001 to 0.3 g/m.sup.2 and, more preferably, from 
0.003 to 0.2 g/m.sup.2. 
The vanadium pentoxide sols used for the antistatic coating may be prepared 
by melting vanadium pentoxide and pouring the melt into water. The 
vanadium pentoxide sols obtained in this way may be directly used for 
coating plastics. 
The vanadium pentoxide sols are preferably prepared by reaction of alkali 
metal, alkaline earth metal or ammonium vanadates with strongly acidic ion 
exchangers, preferably with ion exchangers containing SO.sub.3 H groups. 
The vanadium pentoxide sols are prepared, for example, by stirring the ion 
exchanger with ammonium vanadate in aqueous solution. The vanadium 
pentoxide sol formed is filtered off from the ion exchanger and is 
directly ready for use. The ion exchanger is used in such a quantity that 
the number of acid groups present is sufficient to bind the total quantity 
of ammonium or alkali metal or alkaline earth metal ions. 
An excess of acid groups is preferably used. The vanadate is used in such a 
quantity that the vanadium pentoxide sol formed preferably contains less 
than 5% by weight and, more preferably, from 0.005 to 1% by weight 
vanadium pentoxide solid. To achieve a more uniform coating of the films, 
surfactants may be added to the vanadium pentoxide sols. Examples of 
suitable surfactants are alkali metal alkyl sulfonates or sulfates, 
fluorinated alkyl sulfonic acid salts, for example sodium perfluorooctyl 
sulfonate. 
After drying, the thickness of the layer, in which V.sub.2 O.sub.5 is 
applied to the plastic moldings to be antistatically treated, is between 
0.001 and 1 .mu.m and preferably between 0.003 and 0.1 .mu.m, depending on 
the desired conductivity of the molding. 
Substantially colorless coatings of high surface resistance are obtained if 
the vanadium pentoxide sol is aged before processing. The freshly prepared 
vanadium pentoxide sols are preferably used for coating only after ageing 
at room temperature for 1 week and, more preferably, for 2 to 20 weeks. In 
addition, it has been found to be useful to dilute the vanadium pentoxide 
sols with water before processing. The plastic moldings, particularly 
films, to be antistatically treated are coated by known methods, for 
example by dip coating, knife coating, spray coating, printing, for 
example intaglio printing, or casting. 
Substrates which may be antistatically or electrically conductively treated 
by the process according to the invention are, above all, moldings of 
organic polymers, more particularly films of polycarbonates, polyamides, 
polyethylenes, polypropylenes, polyvinyl chloride, polyesters, cellulose 
acetate and cellulose. However, inorganic materials, for example glass, or 
ceramic materials of aluminium oxide and/or silicon dioxide may also be 
antistatically treated by the process according to the invention. 
Suitable hydrophobic plastic supports for photographic silver halide 
materials are known from the literature and consist, for example, of 
polyester, cellulose triacetate, polyvinyl chloride or polycarbonate. 
Polyethylene terephthalate is preferred. A paper coated with 
poly-.alpha.-olefin, more particularly paper coated with polyethylene, is 
also suitable. 
Before coating with the antistatic layer, the hydrophobic plastic support 
is optionally provided with one or more substrate layers to improve the 
adhesion of hydrophilic colloid layers subsequently applied. Suitable 
substrate layers for polyethylene terephthalate supports are known, for 
example, from U.S. Pat. Nos. 3,397,988, 3,649,336, 4,123,278, 4,478,907, 
GB 1,234,755 and Research Disclosure, July 1967, page 6. Particularly 
suitable substrate layers consist of vinylidene polymers with 
copolymerized, ethylenically unsaturated hydrophilic monomers, preferably 
itaconic acid units (U.S. Pat. No. 3,649,336). 
In one embodiment of the invention, the antistatic layer is situated on the 
same side of the support as the photographic layers and is separated from 
them by the radiation-cured coating composition. 
In another embodiment of the invention, the antistatic layer is situated on 
that side of the support which is remote from the photographic layers. 
Accordingly, the radiation-cured coating composition becomes the outermost 
protective layer on the back of the photographic material and also serves 
as an anti-abrasion layer. 
In one preferred embodiment of the invention, a so-called NC layer 
(anti-curling layer), which counteracts the tendency of the wet-processed 
material to curl up, is present over the antistatic and protective layers 
applied to the back of the photographic material. The NC layer contains a 
hydrophilic colloid, for example gelatine, and may be at least partly 
hardened to reduce water absorption and abrasion. Suitable hardeners are 
described in The Theory of the Photographic Process, edited by T. H. 
James, 4th Edition, pages 77 to 87. 
In addition, the layer combination of the antistatic layer and protective 
layer applied to the back of the support in relation to the silver halide 
emulsion layers may be covered by an antihalo layer containing one or more 
dyes or pigments in a hydrophilic colloid, for example in gelatine. The 
dyes and pigments and may be capable of decoloration or may be stable in 
the processing solutions. 
The silver halide materials according to the invention may be used for 
half-tone photography, screen photography, microphotography and 
radiography. They are suitable for black-and-white materials and color 
materials and for silver complex diffusion transfer reversal (DTR) and dye 
diffusion transfer processes. 
The composition of the silver halide emulsion layers is described, for 
example, in Research Disclosure 17 643 (December 1978) and Research 
Disclosure 307 105 (November 1989). 
Problems caused by static charging can be avoided or considerably reduced 
by the combination of antistatic and surface layers according to the 
invention. This applies not only to photographic materials, but also to 
materials for diazotype processes, to vesicular materials, to magnetic, 
electrographic or electrophotographic recording materials. 
The following Examples relates to the use of the layer combination of 
antistatic and surface layers on polyethylene terephthalate supports 
comprising a substrate layer. However, the layer combination may also be 
used on supports of polystyrene, polyvinyl chloride or polyethylene, all 
the supports optionally being exposed beforehand to a corona discharge to 
improve the adhesion of the hydrophilic colloid layers. 
By virtue of their transparency, the coatings obtainable in accordance with 
the invention are particularly suitable for the antistatic treatment of 
photographic materials, more particularly films, for example 
black-and-white, color negative and reversal films, preferably in the form 
of a backing layer, i.e. in a layer which is applied to that side of the 
hydrophobic layer support which is remote from the silver halide emulsion 
layers. 
Suitable radiation-curing coating compositions are, for example, 
(meth)acryloyl-functional prepolymers containing at least two 
(meth)acryloyl groups and preferably two to four (meth)acryloyl groups per 
molecule which are derived from polyesters, polyethers, polyepoxide 
compounds, aliphatic polyols, polyurethanes and vinyl polymers. 
(Meth)acrylate prepolymers such as these are known and are described, for 
example, in U.S. Pat. Nos. 2,101,107; 2,413,973; 2,951,758; 3,066,112; 
3,301,743; 3,368,900; 3,380,831; 3,455,801; 3,469,982; 3,485,732; 
3,530,100; 3,551,246; 3,552,986; 3,628,963; 3,660,145; 3,664,861; 
3,689,610; 3,719,521; 3,732,107; 3,782,961; 3,840,369; 3,888,830; 
4,033,920; 4,081,492; 4,206,025; GB-PS 1,006,587; 1,241,823; 1,241,824; 
1,321,372; DE-OS 1 916 499; 2 429 527; 2 34 012; 2 737 406 and 2 853 921. 
Preferred (meth)acrylate prepolymers are polyester (meth)acrylates which 
may be obtained by azeotropic esterification of dicarboxylic acids with 
difunctional or higher polyols and (meth)acrylic acid. Typical 
dicarboxylic acids are, for example, phthalic acid and adipic acid. 
Polyols are, for example, glycol and polyethylene glycol, trimethylol 
propane, glycerol and pentaerythritol, reaction products of polyepoxides, 
for example bisphenol A bisglycidyl ether with (meth)acrylic acid and 
polyurethane (meth)acrylates which are obtained by addition of 
hydroxyalkyl (meth)acrylate onto aromatic or aliphatic polyisocyanates 
and, optionally, further addition onto polyols. 
In addition, amine-modified polyether acrylates obtainable from aliphatic 
primary amines and (meth)acrylates of ethoxylated or propoxylated polyols 
in accordance with DE-OS 3 706 355 may be used as the 
(meth)acryloyl-functional prepolymers as surface lacquer binders. 
Cationically curing lacquer systems activatable by UV radiation, for 
example based on epoxides or vinyl ethers, may also be used for the 
production of thin surface layers with a thickness below 4 .mu.m, because 
systems such as these do not have to be cured in an inert gas atmosphere, 
even in small layer thicknesses. 
Suitable systems are described, for example, in J. V. Crivello, J. L. Lee 
and D. A. Coulon, New Monomers for Cationic UV Curing, Radiation Curing 
VI, Conference Proceedings (Sep. 20 to 23, 1982), Chicago, Ill., and are 
marketed by Union Carbide, for example under the name Cyracure.RTM.. 
The surface lacquer binders according to the invention contain reactive 
radiation-curing diluents or mixtures of such diluents as typical 
auxiliaries. In addition to their function as a diluent for the 
prepolymers, these products may also be used to vary the mechanical 
properties, for example the hardness, of the resulting films. Reactive 
radiation-curing diluents of the type in question are, for example, 
acrylates and methacrylates, preferably of monohydric to trihydric 
alcohols or alkoxylation products thereof, particularly ethoxylation 
products thereof. In the case of the alkoxylation products, an average of 
0.8 to 12 mol alkylene oxide, such as ethylene oxide or propylene oxide, 
preferably ethylene oxide, has been added on for every hydroxyl group of 
the particular monohydric or polyhydric alcohol. 
The acrylates of dihydric and trihydric alcohols and ethoxylation products 
thereof are particularly preferred as the reactive radiation-curing 
diluents. 
The following diluents are mentioned by way of example: ethylene glycol 
di(meth)acrylate, di(meth)acrylates of diethylene glycol, triethylene 
glycol, tetraethylene glycol and pentaethylene glycol; propylene glycol 
di(meth)acrylate; di(meth)acrylates of di- to pentapropylene glycol; 
neopentyl di(meth)acrylate; butane-1,4-diol di(meth)acrylate; 
hexane-1,6-diol di(meth)acrylate; trimethylol propane tri(meth)acrylate, 
triacrylates of ethoxylated trimethylol propane having a degree of 
ethoxylation of 2.5 to 4 according to DE-PS 2 651 507. Reactive 
radiation-curing diluents are obtained in the range from 0 to 83% by 
weight, based on the total quantity of polymerizable constituents. The 
surface lacquer formulations according to the invention contain 
amine-modified polyether acrylate accelerators as key constituents. They 
are obtained by addition of secondary aliphatic amines onto reactive 
diluents containing at least two (meth)acryloyl groups per molecule. 
Suitable compounds are described in DE 23 46 424. 
0.001 to 0.2% by weight, based on radiation-curing components, of typical 
polymerization inhibitors or antioxidants may be present as auxiliaries in 
the surface lacquer binder. Compounds such as these are, for example, 
4,4'-bis-(2,6-ditert. butylphenol), 
1,3,5-trimethyl-2,4,6-tris-(3,5-ditert. butyl-4-hydroxybenzyl)-benzene, 
4,4'-butylidene-bis-(6-tert. butyl-n-cresol), 3,5-ditert. 
butyl-4-hydroxybenzyl phosphonic acid diethyl ester, 
N,N'-bis-(.beta.-naphthyl)-p-phenylenediamine, 
N,N'-bis-(1-methylheptyl)-p-phenylenediamine, phenyl-.beta.-naphthyl 
amine, 4,4'-bis-(.alpha.,.alpha.-dimethylbenzyl)-diphenyl amine, 
1,3,5-tris-(3,5-ditert. 
butyl-4-hydroxyhydrocinnamoyl)-hexahydro-s-triazine, hydroquinone, 
p-benzoquinone, hydroquinone monomethyl ether, 2,5-ditert. butyl quinone, 
toluhydroquinone, p-tert. butyl pyrocatechol, 3-methyl pyrocatechol, 
4-ethyl pyrocatechol, chloranil, naphthoquinone, copper naphthenate, 
copper octoate, Cu(I)Cl/triphenyl phosphite, Cu(I)Cl/trimethyl phosphite, 
Cu(I)Cl/trischloroethyl phosphite, Cu(I)Cl/tripropyl phosphite, 
p-nitrosodimethyl aniline. 
In addition, the surface lacquer binder may contain as further auxiliaries 
antisedimenting agents, such as dimethyl stearyl amine, distearyl amine, 
stearic acid, metal stearates, monovalent to trivalent metals, stearyl 
alcohol, the corresponding oleyl derivatives, or surface-active agents, 
such as highly disperse silicas, and lubricants, such as silicones, in 
quantities of 0.1 to 5% by weight, based on radiation-curing components. 
The antistatic layer is applied, for example, by the roller application 
systems typically used in the photographic industry. 
The surface layers according to the invention are applied by technical 
coating systems, for example by printing processes, such as flexographic 
and gravure printing, or by roller application systems or by knife coating 
or casting. Their dry layer thickness is, in particular, from 0.5 to 25 
g/m.sup.2. 
They are cured by ionizing radiation, optionally in an inert gas 
atmosphere, for example by electron beams. Although curing may be carried 
out with a radiation dose of about 0.1 to 200 kGy, it is preferred for 
economic reasons to use continuous coating machines of which the radiation 
sources have an acceleration voltage of 100 to 500 kilovolts (kV), 
corresponding to a radiation dose of 10 to 500 kGy. The distance of the 
electron beam source from the layer to be cured is typically 10 to 20 cm. 
If the surface layers are cured by UV radiation, the surface layer binders 
must be provided in known manner with photoinitiators and, optionally, 
photosensitizers. 
The photoinitiators or photosensitizers to be used are known per se and 
their choice is not the subject of the invention. Their use is largely 
confined to the appropriate application of UV radiation, although other 
forms of ionizing radiation may basically also be used. Useful 
photoinitiators and photosensitizers are, for example, benzophenone, 
acetophenone, benzoin and methyl, ethyl, isopropyl, butyl or isobutyl 
ethers of benzoin, .alpha.-hydroxy and .alpha.-aminoaryl ketones and 
benzil ketals. These substances are generally added in a concentration of 
0.1 to 7.5% by weight, based on polymerizable components. 
In one preferred embodiment, the radiation-curing surface lacquers 
according to the invention consist of 
(a) 25 to 95 parts by weight (meth) acryloyl-functional prepolymer, 
(b) 0 to 125 parts by weight reactive diluent, 
(c) 0 to 35 parts by weight amine-modified polyether acrylate, 
(d) 0 to 7.5% by weight UV initiator and 
(e) 0.1 to 5.0% by weight other additives, 
the percentages by weight being based on the sum of (a), (b) and (c).

EXAMPLES 
Example 1 
Preparation of Antistatic Coating Solution I 
A mixture of 20 g polystyrene sulfonic acid (M.sub.n approx. 44,000), 3.6 g 
potassium peroxodisulfate, 5.6 g 3,4-ethylenedioxythiophene and water is 
stirred for 24 hours at room temperature. The 
3,4-polyethylenedioxythiophene polystyrene sulfonate solution obtained is 
then ready for use. 
Example 2 
Preparation of Antistatic Coating Solution II 
A mixture of 20 g polystyrene sulfonic acid (M.sub.n approx. 44,000, 8.1 g 
potassium peroxodisulfate, 5.6 g 3,4-ethylenedioxythiophene, 0.1 g 
iron(III) sulfate (iron content 22% by weight) and 1 l water is stirred 
for 24 hours at room temperature. The 3,4-polyethylenedioxythiophene 
polystyrene sulfonate solution obtained is then ready for use. 
Example 3 
Preparation of Antistatic Coating Solution III 
A mixture of 6.7 g polystyrene sulfonic acid (M.sub.n approx. 38,000), 14.4 
g potassium peroxodisulfate, 33.6 g 3,4-ethylenedioxythiophene, 0.45 g 
sulfosuccinic acid diisooctyl ester Na salt and 1 l water is stirred for 
24 hours at room temperature. The 3,4-polyethylenedioxythiophene 
polystyrene sulfonate solution obtained is then ready for use. 
Example 4 
Preparation of Antistatic Coating Solution IV 
A mixture of 20 g polystyrene sulfonic acid (M.sub.n approx. 44,000), 3.6 g 
potassium peroxodisulfate, 5.6 g 3,4-ethylenedioxythiophene and 1,000 ml 
water is stirred for 24 hours at room temperature. The 
3,4-polyethylenedioxythiophene polystyrene sulfonate solution obtained is 
then ready for use. 
Before coating of the film supports, the solutions of Examples 1 to 4 are 
diluted with water to a solids content of 0.3% by weight. 
Examples 5 to 8 
Preparation of the Antistatic Film Supports 
The water-diluted antistatic coating solutions of Examples 1 to 4 are 
applied by a roller application system to 100 .mu.m thick polyethylene 
terephthalate film supports coated with an adhesion layer based on 
vinylidene chloride/methyl methacrylate/itaconic acid copolymer and the 
coating is subsequently dried. The coated films have the following 
properties: 
TABLE 1 
______________________________________ 
Film Coating Quantity Discharge time 
support solution of coating, 
msec. at 30% 
Ex. of Ex. dry mg/m.sup.2 
rel. humidity 
______________________________________ 
5 3 61 &lt;0.006 
6 4 52 &lt;0.006 
7 1 50 &lt;0.006 
8 2 200 &lt;0.006 
______________________________________ 
The coating compositions used for the production of the surface layers had 
the following compositions: 
Example 9 
100 parts by weight amine-modified polyether acrylate 
15 parts by weight hexane-1,6-diol diacrylate 
6.5 parts by weight trimethyl benzophenone, isomer mixture 
Example 10 
60 parts by weight epoxyacrylate resin according to DE-OS 24 29 527, 
Example 3 (compound 1) 
35 parts by weight propoxylated trimethylol propane triacrylate (compound 
2) 
24 parts by weight diethylamine-modified, propoxylated trimethylol propane 
triacrylate (compound 3) 
60 parts by-weight hexane-1,6-diol diacrylate 
10 parts by weight benzophenone 
Example 11 
60 parts by weight aliphatic urethane acrylate according to DE-OS 27 37 
406, Example 1 
32 parts by weight compound 2 
48 parts by weight compound 3 
84 parts by weight hexane-1,6-diol diacrylate 
12 parts by weight benzophenone 
Example 12 
75 parts by weight aliphatic urethane acrylate according to Example 11 
50 parts by weight polyether acrylate 
15 parts by weight compound 3 
100 parts by weight hexane-1,6-diol diacrylate 
10 parts by weight benzophenone 
5 parts by weight 1-hydroxycyclohexyl phenyl ketone 
3 parts by weight low-viscosity polydimethyl siloxane 
Example 13 
60 parts by weight compound 1 
35 parts by weight compound 2 
24 parts by weight compound 3 
60 parts by weight hexane-1,6-diol diacrylate 
12.5 parts by weight trimethyl benzophenone, isomer mixture 
0.3 part by weight low-viscosity polydimethyl siloxane 
Example 14 
81.5 parts by weight epoxyacrylate according to Example 10 
29 parts by weight compound 3 
58.5 parts by weight hexane-1,6-diol diacrylate 
12.5 parts by weight trimethyl benzophenone, isomer mixture 
5 parts by weight low-viscosity polydimethyl siloxane 
Example 15 
100 parts by weight amine-modified polyether acrylate 
15 parts by weight hexane-1,6-diol diacrylate 
6.5 parts by weight trimethyl benzophenone, isomer mixture 
5 parts by weight low-viscosity polydimethyl siloxane 
The surface layer coating compositions were applied by a hand coater to the 
antistatically treated film supports and subsequently cured by UV 
radiation or by electron beams (EBC). The properties of the film back 
layers are set out in Table 2 as Examples 19 to 29. 
The values shown were determined as follows: 
Scratch resistance: 
was evaluated after rubbing with a hard object. 
Adhesion strength dry: 
A crosshatch adhesion test was carried out in accordance with DIN 53 151 by 
making two groups of 6 cuts each at 1 mm intervals perpendicularly to one 
another so that they intersected. The results are evaluated on a graduated 
scale of 0 to 5 in which 0 stands for a lacquer otherwise undamaged after 
cutting while, at 5, more than 65% of the total of 25 squares formed 
actually flake off during cutting. 
Adhesion strength wet: 
The films were placed in water for 10 minutes at 38.degree. C. and then 
wiped dry under light pressure. The results are evaluated on a qualitative 
scale of 0 (undamaged) to 5 (completely detached). 
TABLE 2 
__________________________________________________________________________ 
Surface 
Antistatic 
layer 
layer (film 
(lacquer 
Thickness 
Scratch 
Adhesion 
Adhesion 
Curing 
Ex. 
support) 
formulation) 
[.mu.m] 
resistance 
dry wet conditions 
__________________________________________________________________________ 
19 5 9 4 Undamaged 
0 1 UV.sup.2 
20 5 10 4 " 0 0 UV 
21 6 10 4 " 0 0 UV 
22 7 10 4 " 0 0 UV 
23 5 11 4 " 0-1 0 UV 
24 6 12 4 " 0 0 UV 
25 7 12 4 " 0 0 UV 
26 7 13 4 " 0-1 0 UV 
27 7 14 4 " 0-1 0 UV 
28 7 15 4 " 0 0 UV 
29 7 10 4 " 0 3 EBC.sup.1 
__________________________________________________________________________ 
.sup.1 Radiation intensity: 50 KGy under N.sub.2 
.sup.2 IST lamp type U 300M-1-TR, tube type MC 200, UV = 180 to 450 nm 
Determination of Discharge Time 
For selected Examples, the capacitive resistance (RC) corresponding to the 
discharge time (in msec.), which is a measure of the mobility of the 
electrical charges, was determined at 30% relative air humidity/21.degree. 
C. before and after a wet development process. 
By wet development is meant a typical development and fixing treatment 
followed by washing baths and drying steps such as are typically applied 
in the processing of photographic silver halide emulsion materials. 
The results are set out in Table 3: 
TABLE 3 
______________________________________ 
RC value in msec. 
Before wet After wet 
Example development 
development 
______________________________________ 
7 &lt;0.006 0.023 
26 0.032 0.025 
28 &lt;0.006 &lt;0.006 
22 0.022 0.050 
27 0.016 0.015 
29 0.01 0.013 
19 &lt;0.006 0.10 
20 &lt;0.006 &lt;0.006 
23 0.057 0.12 
______________________________________ 
The results in Table 3 prove that the charge mobility in the 
antistatic/surface layer arrangements mentioned above is substantially 
unchanged before and after wet development corresponding to Comparison 
Example 7, in which there is no protective surface layer, the materials 
thus coated having a so-called permanently antistatic character. 
The adhesion behavior of the surface layers with respect to photographic 
silver halide emulsion layers was tested as follows: First each sample 
including Comparison Example 7 is conditioned for 24 hours at 21.degree. 
C. in an atmosphere of 60% relative air humidity, after which the samples 
are contacted with the silver halide emulsion layers for 3 days at 
57.degree. C. 
When the directly contacted materials were separated, the emulsion layer 
did not adhere to any of the samples (Examples 22, 26, 19, 20, 23, 27, 28, 
29) while the coating of sample 7, which was not provided with a surface 
layer, separated from the plastic support and was transferred to the 
emulsion layer. 
Example 30 
20 g NH.sub.4 VO.sub.3 and 300 g of a cationic ion exchanger are introduced 
into 1000 g water and stirred for 10 minutes at room temperature. 1500 g 
water are then added with intensive stirring. The ion exchanger is then 
separated off by filtration. A colloidal solution (sol) of V.sub.2 O.sub.5 
is obtained. 
The colloidal solution described above--after 142 ml have been diluted with 
858 ml water--is applied to a 100 .mu.m thick polyethylene terephthalate 
film support coated with an adhesion layer based on vinylidene 
chloride/methyl methacrylate/itaconic acid copolymer. The coating of 
colloidal solution is applied in a wet film thickness of 100 m.sup.2 /l. 
The coating is dried at 120.degree. C. A transparent and substantially 
colorless antistatic layer was obtained. 
Examples 31 to 33 
Pieces of the film produced in accordance with Example 30 were coated with 
various surface layer lacquer formulations (Examples 9 to 11) in a dry 
layer thickness of 4 .mu.m. 
Scratch resistance, charge mobility and adhesion (wet and dry) were 
determined. Table 4 below shows that the surface layer according to the 
invention is necessary for wet adhesion and for retention of the charge 
mobility of the antistatic layer after processing. 
TABLE 4 
__________________________________________________________________________ 
RC value in msec. 
Antistatic layer 
Surface 
Scratch 
before 
after 
Adhesion 
Curing 
Example 
(film support) 
layer 
resistance 
wet development 
dry 
wet 
conditions 
__________________________________________________________________________ 
34 30 -- Average 
&lt;0.006 
&gt;3200 
0 4 -- 
35 30 9 Undamaged 
0.053 
0.033 
0 0 UV 
36 30 10 " 0.067 
0.048 
0 0 UV 
37 30 11 " 0.020 
0.023 
0 0 UV 
__________________________________________________________________________