CA1085155A - One-pass electroconductive coating color formulation - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
One-pass electroconductive coating color formulations are achieved by incorporating into electro-conductive coating color formulations an effective quantity of a perfluoroalkyl phosphate salt.

Description

8 S~ S 5 ~ his invention relates to a process for improv-ing the solvent holdout properties of coating color fo:rmu-lation~ employed in the manufacture of elect~oconductive paper~. Moro particularly, this invention relates to a yrocoss for improving the solvent holdout propertie~ of electroconductive polymer containing coating color for-mulations, 50 that such formulations may be applied to non-surface 6ized paper rsw stoc~ and the resultant coated paper will have solvent holdout and conductivity that are acceptable for conductive base stocks used in electrocon-ductive uaper grades, ~hich comprises incorporating into such coating color formulations an effective quantity of a fluo~ocarbon of the type hereinafter defined; to electro-conductive coating color formulations displaying improved ~olvent holdout prope~ties which contain said fluoroca~bon;
and to tho proce&s of preparing electroconductive paper~ :
employing ~uch im~roved coating color ~ormulations.

In general, electroconductive base ~heets for use ~n the manufacture o~ electrophotographic reprocluc-.~. j.~ C-1080 tion papers are prepared by applying to one or both sur-faces of a suitable ~aper substrate (a publication grade paper of basis weight in the range of 30 to ~5 pounds per 3,000 s(~uare feet) a resinous conductive layer to render the paper electroconductive. Commonly the conductive lay-er comprises an electroconductive polymer either alone or more usually, formulated with a binder (normally a water soluble, non~conductive film forming po]ymer such as a protein, starch, styrene-butadiene latices, a modi-fied or converted starch, casein, polyvinylacetate, poly-vinylalcohol, and the like) and with a pigment (such as calcium carbonate, kaolin clay, titanium dioxide, alumina or a combination of thesa materials~. In the electro-photoyraphic reproduction paper indu~try, such forrnula-tions including a conductive agent, a binder and a pig-ment are commonly referred to as coating color formulations ~.
or compositions.
The binders in conventional conductive coatingcolor formulations serve to make the paper less porous more uniform, to improve the adherence of the conductive layer to the base ~aper and, importantly, to impart to the conductive layer the properties of a holdout or barr-ier coatiny to prevent solvents employed in the later ; applied photosensitive layers from penetrating into the conductivized paper. A separate non-conductive solvent holdout layer comprising one or a mixture of convention-al binders is applied to the paper prior to the applica-tion of the conductive layer in order to assist in achiev-ing a solvent holdout effect. Solvent holdout ~o both toluene and parafinic solvents is essential because the ~5~L55 ~ ~

top side of a conductive base paper comes into contact with toluene during the subsequent application of the photosensitive coating which comprises dye-sensitized zinc oxide dispersed in a solution of toluene and a binder~ The back side of the zinc oxide coated base stock (now referred to as finished Electrofax~paper) comes into contact with kerosene during the copying pro-cess inside Electrox~Copy Machines that use "wet" toners which are comprised of carbon particles suspended in a solution of kerosene and binders. The usual type of electroconductive polymer in combination with the usual type of coating color additives, such as thc binders and pi~mcnts mentioned above, w:ill not CJiVC acceptable sol-vent ho~dout when applied at cor~merclally feas:Lble coat-weights of from 1 to 4 pounds of coating per 3,000 square feet per paper surface where attempts are made to prepare the conductive base sheet in an obviously desirable one-pass process without pretreatment of the paper raw stock with a separate solvent holdout layer.

The instant invention is based upon applicant's discovery that the solvent holdou-t properties of conven-tional coating color formulations, comprising the electro-conductive polymers, binders,and pigments commonly employ-ed in such formulations, can be markedly enhanced by in-corporating into such formulations an effective quantity of a fluorocarbon of the type hereinafter described. Appli-cant has found that the improved coating color formulations of this invention will give to the conductive base sheet surface resistivity, zinc oxide topcoatability, rebro}c-ability of broke and enhanced solvent holdout propert:ies ~_~ - 3 ~

,~ C~1080 ~(~8S~55 that are commercially acceptable for the manufacture of electrophotoyraphic reproduction papers according to current industry standards and practices, when applied to a non-surface si~ed raw stock (a raw stock that has no surface -treatment of starch, alginate or other surface sizing material). The improved coating color formula-tions of this invention, therefore, not only provide en-hanced solvent holdout properties, but make possible the application of the electroconductive layer to the base sheet in a one-pass operation thus eliminating any nec-essity ~or the application of separate solvent holdout layers. The surface resistivi-ty, zinc oxidc tOpCOclt-ab:Ll~ty, rebrokability and solvent holdout properties obtained through the use of the improved coating color formulations of this invention have been confirmed em~
ploying standard laboratory techniques. It is contem-plated, therefore, that suitable coatweights of the im-proved coating color formulations of this invention will be employed in the manufacture of electroconductive base sheets suitable ~or -the preparation of electrophotograE~hic and electrogra~hic reproduct:ion papers.

The nature of the electroconductive polymer component of the improved coating color formulations of this invention is not critical. Any of a variety of elect-roconductive polymers, both cationic and anionic, may beemployed provided that the conductive polymer selected is capable of imparting adequate surface resistivity to the base raw stock (industry xequirements for conductivity in base sheets are 10~ [ohms per square] decade at 15~
relative humidity). As cationic electroconductive poly-.

mers, there may be employed any water soluble cationic polymer containing quaternary ammonium f~mctional groups.
Included in such cationic polymers are those whereln the quaternary ammonium functional group is c:arried as a pendant group to the principal polymer chain, such as, for example, polyvinyl benzyl trimethyl ammonium chloride, poly-[alpha-(methylene trimethyl ammonium chloride) ethyl-ene oxide] and poly methacryloloxyethyl trimethyl ammonium chloride; those wherein the quaternary ammonium functional group is incorporated in a cyclic structure which com-prises a portion oE the polymer backbone, such as for ex-ample, poly-~dime-thyldiallyl ammonium chloride); ~nd those wherein the quaternary c~mmonium functional cJroup :~orms a part oE the polymer chain, such cationic polymers being commonly designated as, "ionenes".

Included in this ~roup, for example, are ionene polymers prepared from halo alkyl dialkyl amine monomer units, such as 3-ionene(poly-(dimethyl propyl)-ammonium chloride), prepared by the polymerization of,3-chloropropyl dimethyl amine, and ionene polymers prepared rom di--ter-tiaryamines an~ dihalides, such as 3,4-ionene which is pre-pared rom 1,3-bis-dimethylamino propane and 1,4-dichloro-butene. Other ionene polymers, of course, which are pre-pared similarly, may be employed as the electroconductive component of the coating color formulations of this in-vention.

In addition to the cationic electroconductive polymers mentioned above, water soluble cationic phosphon-. - ~

1G~85155 ium and sulfonium polymers also may be employed as the electroconductive component in the coating color formu-lations of this invention. Included among these are polymers, such as, for example, poly-(2-acryloxyethyl-dimethyl sulfonium chloride) and poly-(glycidyltributyl phosponium chloride) and the like.

~ ater soluble anionic polymers useful in the preparation of the coating color formulations of this in-vention typically are polymeric acids and alkali metal and alkaline earth metal salts. Included among such anion-ic polymers are, for exam~le, poly(sulfostyrene), poly(allyl ~ulEonic) acid, sulfonated urea-~ormalclehyde resin sulfon-ated pol~methylolacrylamide and the like.

It should be noted that the typical cationic and anionic polymers mentioned above may contain one or more other mer units. For example, copolymers such as the co- ;
polymer of dimethyl diallyl ammonium chloride and diace--tone acrylamide or the copolymer of styrene and maleic acid also can be used as the electroconductive component oE the coating color formulations of ~his invention. The ratio ~f mer units in such copolymers will be determined by the quantity of cationic or anionic necessary to im-part the desired surface resistivity to the base sheet.

Although any of the electroconductive polymers noted above, or other electroconductive polymers capable of imparting the necessary degree of surface resistivity to the base sheet, may be employed as the electrocon-ductive component in the improved coating color formula-tions of this invention, the preEerred electroconductive polymers are the cationic polymers and copolymers and especially cationic quaternary ammonium polymers and co- :
polymers. Of these the most preferred polymers are poly-(dimethyldiallylammonium chloride),copolymers of di-methyl diallyl ammonium chloride and diacetone acrylamide containing from 70 to 98% diallyl monomer, polyvinyl-benzyl trimethyl ammonium chloride, poly-methacrylol-oxyethyl trimethyl ammonium chloride, polymethacryl.ol-oxytrimethylammonium metho~ul~ate polyepichlorohydrin ~0 to 100% cluAt~rniz~d with tr~m~thylamine, aopolymer~ o~
acrylamide and me~hacryloloxyethyl trim~thyl ammonium chloride containing from 90 to 99.5% methacryloloxyethyl monomer and poly-(methacryloloxyethyl dimethyl hydroxy-ethyl ammonium chloride).

As noted a~ove, the binders employed in the im-proved coatiny color formulations of this invention can he o~ ~reat variety and do no-t constitute a critical as-pect of the instant invention. ~ny oE the water soluhle, non-conductive, film-forming polymers conventionally em-ployed for this purpose may be used in the coating color formulations of this invention. Su:i~a~le binders will include, for example, polyvinylalcohols, polyvinyl ace-tates, styrenebutadiene latices, polyethylene-polyvinyl acetate copolymers, unmodified starches, acetylated starches, hydroxyethyl starches, enzyme converted starches, oxidized starches, proteins, caseins, and the like or mixtures thereof. Similarly, any of the variety o~ pig-men-ts conventionally employed in coating color formulations ` C-1080 SS ~, may be employed in the improved color coating formula-tions of this inven-tion including commercially avail- ~ -able calcium carbonates, kaolin clays tit:anium dioxides aluminas or combinations of these materiaLls.

The fluorocarbon component of the improved elec-troconductive coating color formulations of this inven-tion is essential to achieving the enhanced solvent hold-out properties displayed by the improved coating color formulations. Applicant has found that certain mono--and bis-(lH,lH,2H,2~1-perfluoroalkyl)-phosphate esters, when incorpora-ted into electroconductive coating color formulations in the c~uantitie~ ~pecified below, ar~ effect-ive in imparting to such formulations improved solvent holdout properties. In general, useful perfluoroalkyl phosphate esters will have the formula, (CmF2m+lCnH2nO)y PO(OM)3_y~ wherein m is an integer between 4 and l0, n is an integer between l and ll, y is l or 2 and M is a water solubilizing cation, such as, for examplel an alkali-metal (Li, K, Na and tile like), ammonium or substituted ammonium including methylamir1e, dimethylamine, diethyl-amine, monoethanolamine, diethan~lamine, triethc~n~lamine or morpholine and the like. Preferred salts generally are the diet~anolamine sa~ts. Desirably Cm and Cn taken together, constitute a straight chaim of at least 8 car-bon atoms. Such perfluoroalkyl phosphate esters are well-known materials and are available commercially or reaclily prepared by methods fully described in the art. Particu-larly preferred is the perfluoroalkyl phosphate ester manu-factured by E. I. du Pont de Nemours Company, Inc. Wilming-ton, Delaware, under the Trademark, ZONYL RP, which con--~ C-1080 1~185~55 tains diethanolamine salts of mono- and bis-(lH,lH,2H,2H--perfluoroalkyl)phosphates where the alkyl group is even numbered in the range C8 - C18 and the salts have a fluor-ine content of 52.4 to 54.4% as determined on a solids basis.

The weight percent (dry coating) of the several components in the improved coating color formula~ions of this invention may vary widely. In general, the electroconductive polymer component will constitute from 15 to 50% by weight of the formulation; the binder will constitute rom 30 to 70% by weicJht of the Eormula~
tion and the ~îcJment will consti-tute from 10 to 60% by w~ight of the formulation. Such Eormulations are typiaal of the coating color formulations typical].y employed in the manufacture of electroconductive ~ase sheets. In the improved coating color formulations of this invention, there is added to the conventional coating color formula-tion from 0.5 to 10~ by weight of the formulation of a fluorocarbon, or mixture thereofl as defined above. ~ppli-cant ha~ found that incorporation of the fluorocarbon intothe coating color formulation markedly enhances the solvent holdout properties of the color coating ormulation.

Although any of the binders, or mixtures thereof, as noted above may be employed in the coating color formula-tions of this invention, mixtures of polyvinyl aceta-te and polyvinyl alcohol are preferred. The polyvinyl acetate may constitute from 20 to 50% by weight of the formulation and the polyvinyl alcohol may const.itute from 10 to 4n~ hy l353LS~

weight of the formulation. When polyvinyl alcohol is employed in the binder, it is preferred to include in the formulation from 1 to 15% by weight of melamine as a cross-linking agent for the polyvinyl alcohol. Thus, 5 preferred coating color formulations of this invention will contain:

Weight Percent of ComponentComponent in Dry Coa_ing Conductive Polymer 15 - 50 Polyvinyl Acetate20 - 50 Polyvinyl Alcohol10 - ~0 Fluorocarbon0.5 - 10 Mclam:ine 1 - 15 Pigment 10 - 60 In order to illustrate the advantages derived from the use of the improved coating color formulations of this invention, coating color ormulations containing fluorocarbon in accordance with the instant invention and coating color formulations containing no fluorocarbon were coated as aqueous emulsions on both sides oE non-surface sized raw StocK (31 lbs./3000 ft.2 basis weight). The raw stock sheets were coated via draw downs with the appropri-ate wire-wound rod according to standard lab practices.
The sheets were dried in a photographic print dryer for 15 seconds after coating.

A portion of the sheet, after conditioning at 50%
relative humidity for at least ~ hours, was evaluated for solvent holdout by contacting the sheet with the appropri-ate solvent/dye solution [Bruning~Dye (100 gm toluene, ~' - 1 0 ~3SlS5 35.8 gm polyvinyl acetate, 0.65 gm Sudan Irosol Dye, blue, General Anlline & Film Corporation) and Isopar~G
(Kerosene plus 2% flaming red dye)] for t~en seconds;
immediately wiping the dye solvent from t:he sheet;
visually inspecting the other side and estimating the penetration. Estimation of holdout was based on the reference chart used in the TAPPI (Technical Associa-tion of the Pulp and Paper Industry) New :Provisional Method T-528. Another portion of the sheet was also tested after conditioning at 15~ relative humidity, at least overnight, for surface resistivity using a 3.375 inch diametcr disc from the ~heet and a Keithley~610~
Electromcter. Results oE ty~ical experiments are set Eorth below.

Weight Percent of Component in Component Dry Coating Polymer 26lLV
[poly-(dimethyl diallyl ammonium chloride)] 20 CALGON CORPORATION
Pittsburgh, Pennsylvan:ia Fuller PD-069 (polyvinyl acekate) 35 H. B. FULLER COMPANY
St. Bernard, Ohio Elvanol~51-05 (polyvinyl alcohol) 26 E. I. du PONT de NEMOURS & COMPANY
Wilmington, Delaware Purecal~O
(Calcium carbonate) 15 BASF WYANDOTTE COMPANY
Wyandotte, Micnigan Virset~656-4 (melamine) 4 VIRGINIA CHEMICALS COMæANY
Portsmith, Virginia 100 ~3 - 11 -1~5~5 A coatweight equivalent to 4 lbs./3000 ft,2 was applied to each side of the raw stock. The coated sheet had unacceptable solvent holdout properties. Percent penetration by Bruning Dye was 60% and percent penetra-tion by Isopar G was 90%. Current conductive base stockgrades must have less than 10~ penetration by Bruning Dye to prevent significant penetration of the toluene-based zinc oxide coating into the conductive substrate, and less '~
than 50% penetration by Isopar G in order to obtain a 10 suitably dry print from wet toner copy machines.

~XAMPt.E 2 Weight Percent of Component in Comp,onent _Dry Coatin~__ Dow ECR-34 (polyvinylbenzyl trimethyl- 20 ammonium chloride) DOW CHEMICAL COMPANY
Midland, Michigan Dow~630 (styrene-butadiene latex) 31 DOW CHEMICAL COMPANY
Mldlan~, Michigan Vi~ol~523 ~polyvinyl alcohol) 30 AIR REDUCTION COMPANY, INC.
New York, N. Y.

NuClay~
(Kaolin clay) 15 FREEPORT ~AOLIN COMPANY
New York, N. Y.

Parez~613 (melamine) AMERICAN CYAMID COMPANY
Wayne, New Jersey 100%

A coatweight equivalent to 4 lbs./3000 ft,.2 was applied to each side of the raw stock. The coated sheet 1 i ~r....~

1~35155 had unacceptable solvent holdout properties. Percent penetration by Bruning Dye was 40% and percent penetra-tion by Isopar G was 80~.

Weight Percent of Component Comvonentin Drv Coating Dow ECR-34 22 Fuller PD-069 31 Elvanol 51-05 10 Purecal O 35 Virset 656-4 2 10~

A coatweight equivalent to 4 lbs./3000 t.2 was applied to each side of the raw stock. The coated sheet had unacceptable solvent holclout properties. Percent penetration by Bruning Dye was 60%, and percent penetra-tion by Isopar G wa~ 90%.

Weight Percent of ComponentComponent in Dry Coating _ Polymer 261LV 22 Fuller PD-069 32 Elvanol 51-05 12 Purecal O 30 Zonyl RP 2 Virset 656-4 2 100%

A coatweight equivalent to 2.5 lbs./300~ ft.2 was applied to each side oE the raw stoc:k. The coated sheet had acceptable solvent holdout properties. Per-cent penetration by Brunins Dye was less than 4% and percent penetration by Isopar G was 15%.

Surface resistivity at 15% R.H. was 7.4xlolQ
ohms per square on one side and 3.8x101 ohms per sq~lare on the other side. The usual industry requirements for surface resistivity in base s-tocks are 10 decade at 15% R.~l. or less.

~ z~nc oxidc formulakion ~200 g 2:inc oxide, 60.5 g polyvinylacetate, 205.5 g toluene, 0.25 mls bromo-phenol blue (2.5% by weight in metha~ol), 0.75 mls uranine (2.5% by weight in methanol), 0.40 mls acid green 16 (2.5%
by weight in methanol)], was coated on the wire side of the sheet and the resultant dry coating was uniform and free from cracks (i.e., "webbing").

Several conductive coa-ted ~ase sheets ~with no zinc oxide coating) were rebroked in a Valley Beater~
and then hand-sheets were prepared on a Noble & Wood~

Hand-sheet ~achine. The resultant hand-sheets had good formation and there was no evidence of fiber clumping or ropiness.

~5~55i EXAMæLE 5 Weight Percent of Component Component in Dry Coating Dow ECR-34 22 Fuller PD-069 28 Elvanol 51-05 10 Purocal O 35 Zonyl RP 3 Virset 656-4 2 10 0%

A coatweiyht equivalent to 2.7 lbs./3000 Et.2 was applied to each side o~ the raw stock. The coated sheet had acceptable solvent holdout properties. Per-cent penetration by Bruning Dye was less than 2% and percent penetration by Isopar G was 10%. Surface re-sistivities were 8.5x101 ohms per square on one side and 8.4x101 ohms per square on the other side at 15%
R.H. A zinc oxide topcoating, applied on the wire side, was ~ree of streaks and crac:~cs and the conductive coated 20 base sheet (no zinc oxide topcoatiny) rebroked well.

Weight Percent of ComponentComponent in Dry Coating Nalco~61J16 (polyepichlorohydrin quaternized with trimethylamine) 22 NALCO CHEMICAL coMæANy Chicago, Illinois Fuller PD-069 28 Vinol 523 10 Purocal o 35 ~ C-1080 Zo~y1 RP 3 Virset 656-4 _2 100%

A coatweight equivalent to 2.9 lbs./3000 ft.
was applied to each side of the raw stock. The coated sheet had acceptable solvent holdout and surface resis tivity properties. Percent penetration by Bruning Dye was less than 2%. Surface resistivities were 5.6x101 ohms per square on one side and 3.3x101 ohms per square on the other side at 15% R.H. ~ebrokability oE concluc-tive coated sheet~ (no zinc oxide coating) was acceptable and ~inc ox:ide coated well on th~ baso stock.

Although -the instant invention has been described above in terms of the use of certain mono- and bis-(lH,LH,2H,2H-perfluoroalkyl)phosphates as the essential component of the improved coating color formulations of this invention, many obvious modifications will sugcJest themselves to one skilled in the art from a consideration oE the Eoregoiny specification. :~t ~ill be obvious, for example, that Eluorocarbons other than the perfluoroalkyl phosphates disclosed above could be substituted in the practice of the instant invention. Included among such fluorocarbons, for ~xample, are long chain polyfluoro aliphatic fluorocarbons substituted with polar functions such as carboxyl, carbamate, carboxamide, sulfonamide, sulfonate, amino or quaternary amine groups. Applicant considers all such obvious modifications to be the full equivalent of the perfluoroalkyl phosphates speci~ically disclosed herein and to fall within the scope of the in-stant invention.

Claims (12)

The subject matter which applicant regards as his invention is particularly pointed out and distinctly claimed as follows:

1. A method for enhancing the solvent holdout properties of electroconductive coating color formula-tions containing from 15 to 50% by weight of a water soluble electroconductive polymer, from 30 to 70% by weight of a water soluble, non-conductive film-forming polymeric binder, and from 10 to 60% by weight of a pig-ment which comprises adding to such formulations form 0.5 to 10% by weight of mono- and bis-(1H,1H,2H,2H-perfluoroalkyl)-phosphate esters of the formula:

(CmF2mtlCnH2nO)yPO(OM)3-y wherein m is an integer between 4 and 10, n is an integer between 1 and 11, y is 1 or 2 and M is a water solubiliz-ing cation selected from the group consisting of an alkali metal, ammonium or substituted ammonium.

2. The method of Claim 1 in which the water solubilizing cation is diethanolamine and Cm and Cn, taken together, constitute a straight chain of at least eight carbon atoms.

3. The method of Claim 2 in which the fluoro-carbon is a member selected from the group consisting of diethanolamine salts of mono- and bis-(1H,1H,2H,2H-perfluoroalkyl)-phosphates wherein the alkyl group is even numbered in the range C8 - C18 and the salts have a fluorine content of 52.4 to 54.4% as determined on a solids basis.

4. The method of Claim 3 in which the water soluble electroconductive polymer is a cationic quater-nary ammonium polymer.

5. The method of Claim 4 in which the cationic quaternary ammonium polymer is a member selected from the group consisting of poly-(dimethyl diallyl ammonium chloride), a copolymer of dimethyl diallyl ammonium chlor-ide and diacetone acrylamide containing from 70% to 98%
of diallyl monomer units, polyvinylbenzyl trimethyl-ammonium chloride, polymethacryloloxyethyl trimethyl ammonium chloride, polymethacryloloxyethyl trimethyl ammonium methosulfate, plyepichlorohydrin 80 to 100%
fquaternized with trimethylamine, copolymers of acrylamide and methacryloloxyethyl trimethyl ammonium chloride con-taining from 90 to 99.5% methacryloloxyethyl monomer, and poly-(methacryloloxyethyl dimethyl hydroxyethyl ammonium chloride).

6. The method of Claim 5 in which the binder is a mixture of polyvinyl acetate and polyvinyl alcohol in which the polyvinyl acetate constitutes from 20 to 50% by weight of the formulation and the polyvinyl alcohol con-stitutes from 10 to 40% by weight of the formulation and wherein there is added to the formulation from 1 to 15% by weight of melamine.

7. In an electroconductive coating color formu-lation containing from 15 to 50% by weight of a water soluble electroconductive polymer, from 30 to 70% by weight of a water soluble, non-conductive film-forming polymer binder, and from 10 to 60% by weight of a pigment, the improvement which com-prises adding from 0.5 to 10% by weight of the coating color formulation of mono- and bis-(1H,1H,2H,2H-perfluoroalkyl)-phosphate esters of the formula:
(CmF2m+1cnH2nO)ypo(Om)3-y wherein m is an integer between 4 and 10, n is an integer between 1 and 11, y is 1 or 2 and M is a water solubilizing cation selected from the group consisting of an alkali metal, ammonium or substituted ammonium.

8. The coating color formulation of Claim 7 in which the water solubilizing cation is diethanolamine and Cm and Cn, taken together, constitute a straight chain of at least eight carbon atoms.

9. The coating color formulation of Claim 8 in which the fluorocarbon is a member selected from the group consisting of diethanolamine salts of mono- and bis-(1H,1H,2H,2H-perfluoroalkyl)phosphates wherein the alkyl group is even numbered in the ranye C8 - C18 and the salts have a fluorine content of 52.4 to 54.4% as determined on a solids basis.

10. The coating color formulation of Claim 9 in which the electroconductive polymer is a cationic-quaternary ammonium polymer.

11. The coating color formulation of Claim l0 in which the cationic quaternary ammonium polymer is a member selected from the group consisting of poly-(dimethyl diallyl ammonium chloride), a copolymer of dimethyl diallyl ammonium chloride and diacetone acryl-amide containing from 70 ko 98% of diallyl monomer units, polyvinylbenzyl trimethylammonium chloride, polymethacryl-oloxyethyl trimethyl ammonium chloride, polymethacryl-oloxyethyl trimethyl ammonium methosulfate, polyepichloro-hydrin 80 to 100% quaternized with trimethylamine, co-polymers of acrylamide and methacryloloxyethyl trimethyl ammonium chloride containing from 90 to 99.5% methacrylol-oxyethyl monomer, and poly-(methacryloloxyethyl dimethyl hydroxyethyl ammonium chloride).

12. The coating color formulation of Claim 11 in which the binder is a mixture of polyvinyl acetate and polyvinyl alcohol in which the polyvinyl acetate con-stitutes from 20 to 50% by weight of the formulation and the polyvinyl alcohol constitutes from l0 to 40% by weight of the formulation and wherein there is added to the formu-lation from 1 to 15% by weight of melamine.