US2335333A - Coating and process for applying same - Google Patents

Description

Patented Nov. 30, 1943 assess:

COATING is moss FOR APPLYING hil ' Marcellus E. Wysong, New York, N. Y., assignor,

by mesne assignments, to Wysong l'lastic @oating Corporation, Springfield, Mesa, a corporation of Massachusetts No Drawing. Application July M, 1939,

- sci-n1 No. 284,443

2 Claims. (cl. fit-15) This invention relates to the art of coating, sizing and waterproofing fiat sheets such as paper, cardboard, textiles, and the like, and is particularly concerned with the production of a paper or cardboard sheet on which a base coating is caused to adhere and upon which a secondary coating or finish can be applied in such a manner thatbase coating and finish coating form a single unitary structure, integral with one another without distinct lamination. A further product of the invention consists of an excellent decalcomania presenting marked advantages over the transfer sheets and decalcomania of the present art. The base coating is of such a nature that printing can be effected thereon and the-finish coating can then be applied over the printed material, in which case the printing forms part of the unitary structure.

The invention has important advantages in the art of mechandising where it has become of increasing importance to make up an article of merchandise in a package or wrapper of attractive appearance and to advertise the article by means of printed matter prepared with a considerable amount of artistic appeal. In order to improve the appearance of such material, attempts have been made to print the desired matter upon special types of glazed paper but, inasmuch as print ing upon a glossy surface is difiicult,'it has not been possible by this means to produce a finished article in whichv the printed matter satisfactorily combines with the glossy surface. Attempts to solve the. problem have also been proposed by printing the desired matter upon a paper capable of taking the print and then to cover the entire printed sheet with a lamination of cellulose reenerated from the viscose such as, for instance, that known by the trade name "Cellophane." However, the cements used to bind these laminations to the paper have been found to adhere ineflectively either to the paper or to the laminated coating, with the result that the glossy sheet or coating very easily separates from the base upon which it is superimposed.

Attempts have also been made to coat such The present invention has for its object the provision of a coating that may be 1y bonded to a sheet, such as paper, cardboard or textile,

and that will present a smooth. glossy surface.

without distortion. A further object is to provide a transfer sheetor decalcomania having the design sealed in and protected against scratching smooth, fiat, strong and durable with the printprinted material with a solution of cellulose acetate, which has the advantage of considerable tensile strength and is quite'waterproof and airtight. However, a, cellulose acetate solution, when applied direct to a sheet, causes he surface there of to contract. The result is that, although cellulose acetate has very many characteristics that render it highly desirable for this purpose, any paper, cardboard or textile to which it is applied will be distorted and will wrinkle and curl up to an extent that renders it useless as a fiat sheet. This circumstance renders cellulose acetate by itself impracticable for the purpose despite its many desirable qualities.

inc bright, sharp and brilliant; If it is desired, however, to produce a transfer sheet, -a coating 01 water soluble adhesive is applied first to a sheet of water absorbent paper and the base coat, printing and finish coating are then applied over the adhesive as hereinafter described. t

In a preferred form of the invention, I may use for a finishing coat cellulose acetate or the like and obtain as a product a sheet having the strength, smoothness and clarity of this material without any distortion, the color and printing of the base coat having 'theappearance of being lifted .into the finishing coat and of being at the surface thereof.

According to the preferred form of the invention it is of advantage to apply directly to the paper sheet, whether printed or blank, a special coating which is strongly adhesive to the paper,

cardboard or textile sheet to which it is applied;

which is transparent to anything printed on the paper or cardboard; or, which may be pigmented so as to be opaque, or may be printed upon, or

both, but in any case, whether transparent or pigmented, or printed upon, it is compatible with cellulose acetate or the lik so as to form an integral, unlaminated bond therewith and with the base material. Furthermore, this base coating is of such a nature as to afford an excellent printing surface, and particularly so with an ink having a carrier or vehicle of similar components with the base coating, so that the intermediate coating may be applied to any type of sheet, printing may be effected on said coating and a transparent finishing coating of cellulose acetate or the like they be then applied over the printing. Due to the thermoplastic nature of the materials employed in the two coatings and in the preferred ink, a firm, integral, single coating is formed into which the printing is actually incorporatedas an integral unitary part of the combined coating, in fact lifted up into the finish coating so that it seems to be on the surface of the combined coating. This combined coating applied in two steps is. in fact, including the v printed matter, a single coating adhering trongly to the paper or cardboard,1or sheet of whatever nature, and permeating the pores of the same,

and of such tensile strength and texture and of' such a waterproof nature that it cannot be removedfrom the sheet except by wetting and abrading the same, in which case the coating with its printed matter will still remain intact with all its brilliancy of color.

For a base coating I prefer to use a, polymerized vinyl compound, for example, a polymerized vinyl acetate if the application is to be made to'paper However, in the form of the invention now discussed, the base coating is such as to make a firm adhesion to the material to which it is applied and to unite and bond with the finish coating,

which may be of cellulose acetate. Moreover, the

base coating is capable of being printed upon, preferably with an ink oi! like composition to itself, and when the finish coating is applied upon the printed base coating, the finish coating forms a unitary structure with the base coating and the printed matter is apparently lifted into the finish coating so that it seems to be on the surface.

This structure has hereinabove been described as an unlaminated structure. It is, of course, true that the base coating and the finish coating are of different composition; but, nevertheless, the base coatingand the finish coating are so compatible in nature and each of them is so compatible with the print that they combine and merge into an integral unitary bond and no separation can be made by stripping one from the others. It is in this sense that the term unlaminated" is here used.

For example, I may employ for a transparent base coating directly applied to a paper or cardboard or textile sheet, the following:

Per cent Polymerized vinyl acetatenu d ll Acetone 50 Dibutyl phthalate ill be applied oi. which the iollowingis an example:

Percent Cellulose acetate 25 Anni-rune v 70 Dibutyl phthalate .5

The cellulose acetate is first added slowly to the acetone with vigorous agitation and when a clear solution is obtained the dibutyl phthalate is slowly added with continued agitation. This coating is then similarly applied in a thin film under a temperatureof about'llO F. The second coating immediately dries and shows a strong, transparent, glossy coating without any distortion of the material underlying the base coat to which it is applied and with which it has merged and united in an integral bond.

The coatings above illustrated are, as has been said, transparent and the color of the background is, therefore, the color of the sheet to which the coating is applied. However, (and this is particularly true where cheap grades of paper are employed), it may be desirable to furnish a good should not be deleteriously afiected.

color to the base coating to mask the poor color of the paper. In such case the desired color may be introduced into the base coating, the finish coating being still applied in transparent form over the colored base coating printed or otherwise at such temperatures as to form a single integral coating bonded to the paper. 4

It must be understood that when pigments are added to the base coating, an exemplary formula of which is given above, various other additions must also be made in order to hold the color in proper dispersion and the solvents and plasticizers must be accordingly of differentproportions and of such nature that the colors added I give the following practical formulae for base coatings of the invention with colors as indicated addedz' The whole should be ground from 24 to 30 hours in a ball mill.

Light blue (egg shell) Lithopone lb A9, Blue ultramarine 1b Dissolved cotton e0 seconds -.oz... 6 Dissolved cotton second oz 10 Polymerized vinyl acetate, viscosity about 15 pint l Acetone do 2 'Toluol do 1 Tricresyl phosphate oz 8 If dark blue is desired, two ounces of a suitable black, such as carbon black or lamp black, may be substituted for an equal amount of lithopone.

Egg shell white Zinc oxide lbs- 1% Titanium oxide lb- Dissolved cotton about 40 seconds oz 4 Dissolved cotton about /2 second oz 20 Polymerized vinyl acetate, viscosity about 15 L.. pints-- 2 Acetone do 2 Dammar solliflnn (in 2 Butanol .do 1 Trlcresyl phosphate oz 8 In the case of a flat blackcoating solution, a pigment stock may first be made of about the following composition:

Eight ounces medium viscosity dissolved cotton per gallon of a solvent consisting of ethyl acetate 5 1% pints, butyl acetate 1V2 pints, butanol Apint, alcohol V pint,- benzol 2 pints, and toluol 2 pints. To this may be added about 8 ounces of carbon it is compatible with the finish coat black and 2 ounces of lamp black to each gallon 36 hours in a ball mill.

r The formula for the flat black. coating follows:

Pints Foregoing pigment stock 1% Ester gum solution 16 oz. cotton dissolved in same solvents as the pigment stock to /2 second 4 Butyl acetate Acetone.

Polymerized vinyl acetate viscosity about 15 1 All mixtures above described should be centrifuged to obtain a homogeneous particle size.

It will be observed from the composition of the ink used for printing on the base coat as shown by the formulae above given, that the ink is substantially the same as the base coat-in fact, is the same as the pigmented base coat-and that of cellulose acetate or the like. It is also the case that when the finish coat is applied, the base coat and printing is taken up and merged integrally with the finish coating. Y This property of the base coat and the ink makes itpossible to use theinvention herein set forth for the production of an excellent decalcomania which is shielded and protected. For this.

purpose a suitable water absorbent paper is first coated with an adhesive that is soluble in water, the design or other matter is then printed in the ink above described directly upon the adhesive and the finish coat of cellulose acetate is then applied over the printed matter. The printed matter thus becomes an integral part of the finish coat-is, in fact, taken up by the finish coat, but owing to the presence of the water soluble adhesive the base coat or printed matter does not adhere to the paper. When, therefore, the paper support is wetted with water, the adhesive dissolves and releases the finish coat embodying the printed matter so that it will slide oil the paper support and may be aflixed to the desired object. This transfer sheet has a marked advantage over the ordinary decalcomania in that the printed matter is sealed and protected from injury or marring by the acetate coating.

The coating of the invention may be applied by any suitable apparatus having means for holding and casting the coating materials and means for printing. One such apparatus particularly devised for the practice of the invention is disclosed and claimed in my copending application Serial No. 271,923 filed May 5, 1939.

Having thus described my invention, what I claim is:

1. A fiat sheet of fibrous material, a base coating of polymerized vinyl acetate thereon, a printing upon said base coating, and a finish coating of cellulose acetate over said base coating and said printing, said sheet, base coating, printing and finish coating being so bonded one with another as to form a single, integral, unitary, unlaminated and inseparable structure.

2. The process of coating a fiat sheet of fibrous material which comprises casting a film of polymerized vinyl acetate solution on said sheet, drying said film, printing on said film and then casting a film of cellulose acetate solution as said film of polymerized vinyl acetate and said printing.

MARCELLUS' E. WYSOIJG.