FR2493547A1 - Graphic or diazo:type reproduction polyester film - prepd. from aq. dispersions of film-forming binders and colloidal pigments - Google Patents

Abstract

Polyester fibres for graphic use or sensitised for diazotype reprodn. are characterised in that the liq. used in the compsn. of the various layers is mainly water contg., dispersed or dissolved, at least 2 (self-) crosslinkable film-forming binders, a colloidal pigment(s) keeping the pigments used in suspension and being itself crosslinkable, a crosslinking agent and a crosslinking accelerator. No organic solvent is used thus eliminating fire hazards and toxicity problems. The layers dry rapidly and machines operating at higher than usual speed can be used.

Description

Hello polyester polyester films have been known for many years. We know that such films are used to reproduce an original,
They can then be used in its place for future copies. Polyester drawing films have also been used for some time for drawing purposes.

 The technical advantages linked to such produnts are in large part due to the characteristics of solidity. of stability and permanence of the polyester film used as a suppJr '.

 The superiority of polyester products over the exclusive layers used in the past has proven such that the market for these products has grown rapidly.

 From the point of view of production, the manufacturer of products cast on polyester supports was faced with new problems, linked to the chemical inertness of these products: it is well known that all film producers use nour coating of these supports formulas based on the use of high concentrations of organic solvents. This fact implies the use of highly flammable and toxic products, with corollary the dangers and costs linked to their handling as well as the significant investments due to the use of casting machines exclusively using explosion-proof motors and devices.

 Of course, attempts have been made to eliminate organic solvents in the casting of the aforementioned products, but, so far, they have been unsuccessful.

 An object of the invention is to propose casting formulas applicable to the three layers normally used for the production of sensitive films (precoat backing, sensitive layer) or to the two layers used for drawing films, formulas characterized either by the total absence of solvent and then being only water-based, or then containing a small proportion of a solvent which is not very dangerous. This proportion is maintained at a level such that there is no risk of flammability.

 Another object of the invention is to propose formulas the cost price of which, owing to the elimination of the cost of solvents and of the related control and safety devices, is notably lower than that of conventional formulas.

 A third aim of the invention is to propose flow formulas which do not have the character of toxicity linked to the use of the usual organic solvents.

 Another object of the invention is to propose formulas which make it possible, due to the simplification of the coating and drying operations. a higher machine speed than that usually used, and by a noticeable reduction in production costs.

 The reason for the use of organic solvents for the casting of polyester films is linked in part to the difficulty of anchoring the layers. either on the film itself. either on a first layer. It is obvious that the large number of current industrial solvents makes it possible not only to more easily resolve these difficulties, but also to resolve much more easily the problems associated with the use of the resins necessary for the pursued purposes such as the homogeneity of the layer, its hardness, its resistance to outside adventures, etc. . .

 However, the Applicant has found that it was possible to obtain the same qualities of polyester films by using, as a casting vehicle, not organic solvents but water or a water-alcohol mixture in a proportion not exceeding 30%. alcohol, provided that a certain number of conditions are respected which will depend on the material to be produced.

 Polyester drawing films must meet a series of criteria, some of which are contradictory and which it is difficult to obtain simultaneously.

 The adhesion of the layer must be very good in order to resist the usual treatments.

 The pencil must take well, but. hard mines must not damage the surface of the film.

 The lines must resist the friction of the fingers.

 The exfoliation should be easy and not leave a ghost.

 The ink intake must be easy. The lines must not drool or have extra thickness at their ends.

 They must resist water.

 The exfoliation should be easy and not leave marks on the film.

The scraping must not significantly damage the surface,
All these ties can only be performed simultaneously by
the use of judiciously selected pigments and binders.

In the case of the invention, these products must also be able to be
used without the need for organic solvents.

For this, the invention uses various water-soluble polymers
or suspended in water combining to meet the necessary criteria
saires.

The first will have to provide in itself a hard film whose adhesion may not
not be perfect. For this, generally a polymer or a copoly
dispersed acrylic mother will be used.

The second will have to fix the whole on the poly base
ester. This polymer. most often acrylic, will be less hard than the pre
mier. It can also help guarantee a good suspension of pigments
used and ensure the homogeneity of the final mixture, acting in part
as colloidal protector. The colloidal protector itself will be a poly
water-soluble mother is different in nature from the first two binders. Outraged
the functions which have just been described, it must provide the film with anchoring points allowing the adhesion of a subsequent aqueous layer which
maybe the photosensitive layer an antistatic layer or a layer
improving the setting of the ink for example.

To obtain a very hard layer, all of these three types of
polymers must be removable. One or the first two may be self-crosslinkable.

 Cross-linking agents will also be incorporated into the pouring liquid.

The crosslinking accelerators will be added to this same liquid
in case the system is poured in a single layer.

On the other hand, if we superimpose several layers, we will have advantage
put the accelerator in the second to avoid the problems of # bn-
aging linked to the presence of a first layer that is too hydrophobic.

In this case, the first layer will only be really resistant
after application and drying of the second, or even after development
of the sensitized film as will be specified in one of the examples described.

The crosslinking accelerating agent present in the second layer, in this case the photosensitive layer, will be chosen from 1 ''. ' nrom products which happen to be both accelerator and stabilizer of the diazonium salts of said strain, namely
p-toluene sulfonic acid
m-benzene disulfonic acid
p-sulfosalicylic acid
oxalic acid
citric acid
ammonium monophosphate.

 It should be understood in this case that the crosslinking reaction will take place after application of the second layer as a result of the partial diffusion of the acid used, the latter diffusing from the upper layer into the adjacent lower layer.

 Besides the process of crosslinking by means of two separate layers, the invention makes use of other means of fixing DU for hardening of the layers such as the action of polyvalent metal ions.

 This effect can be reinforced by the combined use of polyvinyl alcohol in the photosensitive layer, this product, in addition to the curing reaction by crosslinking, also being cured by the azol dye formed during development.

 Example N 5 describes a use of these principles for the production of a sensitive polyester film intended for semi-humane development.

 Greater insolubilization, and therefore better fixation of the photosensitive layer. is also obtained if one adds to the first layer a certain amount of an alkali sulfocyanide such as sodium sulfocyanide. This compound gives, with the diazonium salts mentioned, at the time of the pouring of the photosensitive layer a particularly insoluble compound contributing to the fixing of this salt.

 The invention relates to the use of such sulfocyanides only in the pr # - layer, to the exclusion of all others. The example Ne 5 shows this proW prity.

 It is also possible to use incidentally, in the first layer, a certain amount of a polyether such as polyoxyetlylene, the hardening of this product then being caused by a bi or trivalent metallic salt such as ZnCl2 s MgC ,, Al2 (SO4) 3 , found in the adjacent layer and diffusing in the lower layer when applying the upper layer. Example Ne 6 describes such layers.

 The polymers, pigment binding agents or agents for fixing the layers can belong to various classes of aqueous dispersions such as polyvinyl acetates, polyacrylates, polymetacrylates, nolyacrylamides, butadiene acrylic latexes, vinyl acrylates, butadiene acrylates onitrile. , butadiene -acrylonitrile -carboocyl opolymers, butadiene-styrene, vinylidene-acrylic chlorides.

 In all cases, it has been found advantageous to use a mixture of products, the choice being essentially dictated by their adhesive power on the polyester film and by the abrasion resistance of the dried layers.

 Very often, the mixtures lead to results different from those obtained by the individual products without a general law having been able to be established.

 The following examples will in each case lead to good results.

 The use of wetting agents sometimes has an advantage for obtaining regular layers. The examples described mention two of them. Most often, however, their use results in poor regularity of the adjacent layer or reduced adhesion thereof.

The water-soluble protective collars capable of being used as binders and capable of being crosslinked are for example the following
polyvinyl alcohols.

oolyacrylates and their water-soluble cooolymers,
hydroxyethylcelluloses.

 the box.

polyoxyethylenes
methoxy cel..ulose having a degree of substitution of 1.6 to 2
bydroxypropylmethyl celluloses with the same characteristics,
gelatin,
sol lbles starches.

alginates
methyl celluloses
carboxypolymethylenes.

 According to what has been said, these agents, in addition to their function of stabilizing the disoersions used, also have the function of allowing good fixing of the layer which is possibly superimposed on the first.

The usable hardening agents are essentially represented by two classes
1) Those with an acid catalyst are derived from formulated derivatives such as
Diamonine AF (FMC)
Uralite F 305 (Plastogil)
Uropal FB 46 (Plastogil)
Lyofix CH (Ciba)
Parry (Cyanamid)
Aerotex (Cyanamid)
Maprenal VMF 80/15 (Hoechst)
Maprenal MF 517 (Hoechst)
Dicyanamide formalin (Protefix CR from proiex)
Dimethylol urea (Prote8ine DMU from Protex)
Dimethylethylene urea (Prox E from Protex)
Dimethyltriazine (Prox NTO2 from Protex)
Tetramethyloltriazine (Prox 15766 and Protex)
Melamine urea (Casamine Resamine 155 F)
Lesmélamine - formalin
Benzoguanamine - formalin.

 Benzeguanine melamine.

 Examples N 1 and N 3 to 7 describe layers based on their use.

2) Those 9 alkaline catalyst, represented by epoxy resins:
Example Ne 2 describes the use of such products. They are reserved for drawing films, the presence of alkaline products in the photosensitive layers being excluded of course.

 The examples which follow will illustrate the principles and the production of layers according to the invention.

Example No. 1: Drawing layer
A solution of Primal ASE 60 is prepared, starting from the commercial dispersion, with stirring for 30 minutes the mixture of acrylic polymer
Primal ASE 60: 1 L (Rohm and Haas)
Water: 3L
Ethanol: 1 L (1)
Ammonia: 220 cm
The ammonia is in excess to compensate for the acidity of the final dispersion.

A dispersion of
Water: 9L
Pigment Gasil 23: 500 g (Cros8field)
Syloid 244 pigment: 500 g (Grace Chem.)
Disperse at high speed for one hour, then pour this dispersion into (1).

The suspension is prepared:
Water 50: 5 L (2)
Superfine Superfioss pigment: 1200 g (Johns - Manville) (2)
Disperse for 10 minutes and then add to this dispersion, with slow stirring, a solution of colloitial protector at 2% in water:
Methocel HB: 200g (DowChem.)
Water: 10 L (3)
The set (2) + (3) is then added to the previous mixture
Then, with slow stirring, the self-crosslinking polyacrylic binder is added.
Primai HA 16: 14 L (Rohm and Haas)
Finally, the crosslinking solution is prepared:
Ptrotesine PHV: 500 g (Protex)
Ethanol: 0.5 L (4)
Water: 0.5 L
Catalyst 4040: 100 cm (Cyanamid)
Solution (4) is added to the previous mixture
Finally we prepare a solution of
Wetting 28: 50 g (Andrews Paper)
Ethanol: 0.5 L
This solution is poured into the mixture, stirring slowly
It is filtered, poured and dried at 140. We manage to deposit 8-10g / m2.

Example N 2: Drawing film
Mix with stirring until dissolution
Carboset 525: 4 Kg (Goodrich)
Ethanol: 20 L
Water: 20 L
ethylene diamine: 220 cm3
Add the pigment and disperse 30 minutes
Pigment Sylola 161: 4 Kg (Grace)
Then we add
Carboset XLII): 30 L (Goodrich)
This dispersion. Because of the presence of ethanol, partially dissolves, Carboset XL II thus also acting as colloidal protector.

The dispersion is then added:
Superfine-Superfloss pigment: 2 Kg
Water: 6L
Then, the solution of the second colloltlal protector, a polyacrylamide
Accostrength 70: 400 g (Cyanamid)
Water 2L
And finally, with moderate stirring, the crosslinking solution:
Sponge 812: 300 g (Shell)
Water: 1L
Ethanol: 2L
The final pH of the suspension is 7.5.

This mixture contains two crosslinkable acrylic binders (Carbon t 525 and XLII), two crosslinkable colloidal protectors (part of the Carboset
XLII and accostrength).

 The crosslinking principle, different from that of example Ne 1, comprises an epoxy resin (Epon 812), the hardener being the excess of ethylene diamine used to dissolve Carboset 525.

 The dispersion is poured as explained in Example No 1. The film obtained is a little more plastic and less hard than the first.

Example No. 3: Drawing layer
Cn dispersed with moderate stirring for 30 minutes
Superfine-Superfloss pigment: 6 Kg in:
Rhodopas PE 1104: 30 Kg (Styrene-acryli- dispersion, from Rhône-Poulenc)
10 liters of a 10% aqueous dispersion of Gasil 23 pigment in water are added.

Then 3 liters of a polyvinyl alcohol solution obtained as follows are prepared:
Disperse: 300 g of Rhodovlel BM (Rhône Poulenc) in 600 cm3 of ethanol, which causes the Rhodoviol to swell.

 Then added: 2.5 liters of water at 70, stirred until complete dissolution and poured this solution into the preceding dispersion.

 The pH is adjusted to 8 by adding approximately 9.2 liters of ammonia.

The acrylic binder solution is prepared with slow stirring:
Carboset 514 H: 20 L
Water: 20 L
Ammonia: 1 L
Once the solution is homogeneous, the pH of 7 is checked and poured into the previous dispersion.

Finally, the crosslinking mixture and the accelerator are poured:
Uformite 700: 2 Kg (Rohm and Haas)
Water: 5L
Citric acid: 100 g
The final dispersion is poured according to example N 1.

 We end up with a film of the same quality.

 This example uses a crosslinkable styrene-acrylic copolymer in the form of an aqueous dispersion, a crosslinkable acrylic polymer in the form of a solution also acting as a colloisdal protector, a second crosslinkable colloldal protector (polyvinyl alcohol), a crosslinking agent and an accelerator.

Example No 4: Drawing film
We disperse for 30 minutes
Pigment Superfine-Superfloss 5 5 Kg
Ethanol: 8L
Pigment Gasil 35: 5 Kg
Water: 20 L
A solution of Carboset 514 H is prepared
Water: 15 L
Ammonia: 1.3 L
Carboset 514 H: 12 L (Goodrich)
Once the Carboset has dissolved, the solution 9 is mixed with the previous dispersion.

The self-crosslinkable acrylic binder is then added:
Dynocrvl H-265-W: 10 L (Dyno Industrier-O @ lo)
The colloitlal protector solution is prepared:
Modocoîl E 600: 0.2 Kg (Berol Chtmic - Neuillfl
Water: 10 L
This solution is added to the previous mixture.

Finally, the crosslinking agent solution and the accelerator are prepared.
Dynomin MM 80: 1 Kg (Dyno Industrier)
Ethanol: 3L
Water: 2L
Benzene disulfonic acid: 0.1 Kg
After the final mixing; the dispersion is poured according to example N 1.

The film obtained has very similar characteristics.

Example No. 5: Pre-coat for sensitization
Pigments are dispersed using a high speed agitator
Pigment FK 320 DS: 3 Kg (Degussa)
Pigment Gasil 35: 7 Kg (Crossfield) in 100 liters of water.

 Then added with slow stirring: 100 liters of colloidal protector Polyox WSRN 80 (Union Carbide) 7.5% in water.

Once the dispersion has been made homogeneous, the acrylic polymer is added with slow stirring
Carboset XLII: 80 L (Goodrich)
Then we add
Acrylron B 35: 20 L (Pro @@ x)
We prepare the solution:
Manren @ l MF 900: 3 L
Ethanol: 20 L
Water: 20 L
We lock this solution in the previous mixture
The PH is 6.

Finally, add a caseinste solution of ammonium pre @@ rea as nit:
Casein: 4.5 Kg
Water: 30 L
Ammonia: 0.3 L
the pH of this solution is 8.5.

 Cetto @olution is cast in the previous dispersion.

 The final PH is 7.

 The final dispersion is filtered as above and poured as a precoat onto a polyester film intended for sensitization.

 we use a Moyer bar of Ne 14 2 20 and che at 110-130.

 In this example, the Carboset XLII and the Acrylron are respectively crosslinkable and aubo-retable acrylic polymers.

 The Polyox WSRN and the Caselne are collector protectors. Their hydrophilic nature ensures good absorption of the photosensitive layer.

 Carboset and casein are crosslinked with Maprénal MF 900 under the influence of p-toluene sulfonic acid contained in the superimposed photosensitive layer.

 The Polyox is hardened by the Zn ++ ions contained in this same layer.

A sensibllisation formula adapted to this type of precoat is for example the following:
We are all stirring:
Formic acid: 5 L
Isopropanol: 20 t
Water 50: 40 L
Citric acid: 2 Kg
D-toluene sulfonic acid: 1 Kg
Dichlorozincate 4 - morcholino-2,5-di @@ toxy benzènediazonium: 1.5 Kg
4-pyrrolidino-3-methyl trichlorozincate: 1.5 Kg
benzene diazonium
Resorcinol: 2 Kg
(Yellow Conulant)
Morpholinopropylamine of 3-hydroxy acid: 0.15 Kg
naphthalene -2-carboxylic (blue coupler)
Once the dissolution is complete, the solution is added
Zinc chloride: 2 Kg
Water: 10L
The dispersion is then prepared
Gasil 35: 0.4 Kg
Superfine-Sunerfloss: 0.6 Kg
Water: 15 L
After addition of the dispersion, the volume is adjusted to 100 liters and poured in a manner known per se, using an air knife, over the precoat which has just been described.

 The photosensitive product thus obtained is used in a manner known per se for the so-called "dry" development.

 A brown image of the original is obtained, having the usual criteria obtained from films produced using organic solvents.

Example No. 6: Pre-coat
We eat at high speed
Pigment 2710 - S: 1 Kg (Andrews NY)
Aerosil TS 100: 2 Kg (Degussa)
Water: 25 L
The polyvinyl resin is added to this dispersion:
Rhodonas A010: 10 L (Rhone Poulenc)
Water: 5L
Then add the collector protector solution:
Luviskol VA 55 - I: 5 L (BASF)
Water: 5L
Then the acrylic polymer:
Carboset 531: 3 L
Then add the solution
Sodium sulfocyanide: 150 g
Water: 1L
And finally, the crosslinking solution:
Resamine 155 F: 500 g (Hoechst)
Water: 1L
Ethanol 3L
The final dispersion has a pH of 6.5, and is used as before
In this example, the crosslinking process is obtained by Resamine under the influence of the acid contained in the superposed sensitization layer.

 Sodium sulfocyanide is used to precipitate the diazonium salt in a very insoluble form.

 The Luviskol VA ensures the setting of the next layer. It is also crosslinked by the acid of this same layer.

 An awareness layer adapted to this precoat is for example.

the next one:
The mixture is prepared with stirring:
Water 500: 15 L
Ethanol: 5L
Aluminum sulphate: 400 g
P-toluene sulfonic acid: 300 g
4'-methyl-2,5-diethoxy diphenyl-sulfide chlorozincate -: 200 g
4 -diazonium
Chlorozincate of 4 -diethylamino-2 -chloro-5 - (4'chlorphenoxy) -: 500 g
benzene diazonium
Rhodoviol BM solution described in Example N. 3 1 1 L,
This solution is poured over the previous precoat using an air knife for example and drying at 110,
P-Toluene sulfonic acid. diffusing into the underlying layer, it serves as a hardening accelerator,
We obtain a set resistant well to water and abrasion.

 In the example above, the sensitive film is intended to be developed by the so-called "semi-wet" process and acquires all of its qualities only after development and drying, these operations terminating the desired hardening-insolubilization processes.

Example No. 7 Pre-coat
We disperse
Pigment Gasil F137: 6 Kg
Pigment Gasil 200: 3 Kg in
Ethanol: 20 L
Water: 16 L
The solution is prepared with moderate stirring
CarbosetXL 17: 7 Kg
Water: 35 L
Ammonia: 1.3 L
Carboset goes into solution in about an hour.

 The PH is 9.

This solution is slowly added to the pigment dispersion.
We add the wetting agent:
Alcopol 0: 0.2 L (Allied Colloids)
Then adding with stirring:
Carboset XL 19: 15 L (Goodrich)
The PH is 7.5.

An aqueous solution of colloidal protector is prepared by stirring for two hours:
Natrosol 250 H: 0.15 Kg (Hercules)
Water: 10 L
This solution is poured into the previous dispersion.

Finally, the crosslinking solution is prepared:
Dynomin MM 75: 0.5 Kg (Dyno Industrier)
Ethanol: fi
Water: 2L
This solution, poured into the previous mixture gives the final dispersion which is used as already described, as a coating for photosensitive solution.

 In this example, two crosslinkable acrylic binders are used (Carboset XL 17 and XL 19). The former also acts as a collateral protector.

 Natrosol is a second collector protector which also ensures the setting of the next layer.

Claims (6)

RESELL I C A TI O NS  1) Polyesters films for drawing or sensitized for the reproduction in diazotypy. characterized in that the liquid used in the composition of the various layers is essentially water containing in dispersion or in solution at least two crosslinkable or self-crosslinkable film-forming binders, at least one colloidal protector keeping the pigments used in suspension and being itself crosslinkable, a crosslinking agent and a crosslinking accXlorator.  2) Nolyester film according to claim N. 1 in which all of the products are contained in a single layer  3) polyester film 'according to claim NO 1 in which the crosslinking accelerator is not contained in the first layer in order to keep the latter sufficient adhesion to a second layer superimposed on the first. The agent ensuring this adhesion is the crosslinkable colloidal protector. The second layer, which can be an antistatic layer, a layer facilitating the taking of ink or a photosensitive layer, contains the accelerating agent for crosslinking in solution, the diffusion of the latter in the first layer at the time of the pouring of the second layer ensuring the crosslinking reaction during the drying of the film.  4) Polyester film according to claim N. 3 in which the accelerator. of crosslinking simultaneously exerts the acid stabilizing function of the photosensitive layer.  5) Polyester film according to claim N. 3 in which an accessory insolubilization of the polymers is ensured by the absence of bi or trivalent metal salts contained in the layer superimposed on the first.  6) polyester film according to claim N. 3 wherein the lower layer contains a certain proportion of an alkali sulfocyanide contributing to insolubilize the diazonium salt of the upper layer.