US2273700A - Decorated foil and film - Google Patents

Description

Patented Feb. 17, 1942 DECORATED FOIL AND FILM Kurt Feuerstein, Frankfort-on-the-Main, Germany, assignor to Riihm Philadelphia, Pa.

No Drawing.

2 Claims.

This invention relates to a process of preparing decorated films, foil, and sheets of thermoplastic materials. It relates more partic ifarly to a process of applying designs in various colors to sheets of thermoplastic material by forming the sheet on a non-absorbent surface in which the design has been etched or engraved, the coloring material having been placed in the depressions of the engraving or etching prior to the formation of the plastic sheet.

' It has been proposed to make decorated, molded articles from hardenable, artificial resins by applying to the walls of a mold, which may or may not have a design engraved thereon, a color paste in which the vehicle is a solution of the artificial resin, evaporating the solvent, filling the mold with a molding powder, and forming and hardening thearticle under heat and pressure as is commonly done in the molding industry.

The present invention contemplates a process for decorating films or sheets of thermoplastic material, according to which the design is engraved, etched or carved on a plate of suitable material such as glass, metal or insoluble, heathardened resin, and the depressions of such design filled with a paste of color or pigment in a non-drying vehicle. A solution of a thermoplastic substance in a suitable solvent is then poured over the plate to a depth depending on the thickness desired in the final sheet and the concentration of the solution, after which the solvent is evaporated and the dried sheet removed from the plate. By this method the pigments and vehicle are transferred to the thermoplastic sheet and are removed with it from the plate without distorting even the finest lines in the design.

The plates on which the design is carried are not subjected to any very great mechanical strain and can. therefore, be made of glassylight, easily worked metal such as copper, brass, aluminum, etc.; or of an artificial resin which is insoluble in and unaffected by the solution of thermoplastic material. Porous materials such as wood may also be used when the surface is provided with an impervious, insoluble layer of material in which the design my be cut.

The design may be imparted to the surface of the plate in any desired manner as by etching, engraving, carving, or stamping. The design itself may be writing, drawing, picture, or an ornamental design.

The color pastes which are employed to fill the depressions of the design may be made of any pigment, white, black, luminous or colored which & Haas Company,

Application May 17, 1939, Serial In Germany June 4, 1938 is insoluble in any of the liquids employed. Color lakes may be used, provided the dyestufl is insoluble. On account of their greater fastness to light, inorganic pigments are preferred. Diiferent colors can, of course, be applied to diiferent parts of the design to secure any desired effects. The thermoplastic material may also be uniformly colored in addition to the colors in the design by means of soluble dyes or insoluble colors.

The vehicle used in preparing the pigment paste should be non-drying or slow drying. Oils, high boiling liquids commonly used as plasticizers in thermoplastics, and high boiling solvents which are soluble in the common organic solvents may be employed. Low boiling liquids usually evaporate too rapidly and are not suitable. Furthermore; the vehicle should have a fairly high viscosity. The paste may be applied by covering the plate and wiping off all except that in the depression. When different colored pastes are used on the same plate, it may be advantageous to apply them only in the proper depressions of the design.

The film-forming materials which are suitable are the plastic materials soluble in organic solvents, particularly the thermoplastics. Examples of such materials are polymers, co-polymers, or mixed polymers of vinyl, acrylic and methacrylic compounds such as the polyvinyl esters, the polyacrylic and methacrylic esters, polystyrene, polyvinyl carbazol. Cellulose ethers and esters may also be employed, for example cellulose nitrate. Particularly suitable are polyvinyl acetate, polymethyl methacrylate and polyethyl methacrylate. Plasticizers may also be employed with any of the thermoplastics as wellas inert fillers. It is thus possible to obtain hard, stiff sheets or soft, flexible foils depending on the composition of the thermoplastic material used. The films or sheets may be subsequently bent or shaped in any desired manner.

Since the vehicle employed-in making the pigment paste is more or less soluble in the solution of thermoplastic, the latter penetrates the paste and displaces the vehicle. It thus surrounds the pigment particles which are then embedded in the finished sheet a short distance below the surface so that the design cannot be rubbed off. A single plate can be used for the production of a large number of decorated sheets, each one of which will have the design reproduced on it in the finest detail.

In the manufacture of plain films by pouring a solution of plastic on a suitable base and the film is removed from the plate.

evaporating the solvent, it is common practice to put a thin film of oil on the base or to dust it with tale to reduce adhesion. The tale is used dry and the base on which it is spread has no depressions. According to the present invention, it i necessary to wet the pigment with the vehicle before application as, otherwise, the pigment cannot be properly retained in the depression when the solution of thermoplastic is poured on the plate. It is only by using a pigment thoroughly wet with the vehicle that an exact reproduction of the color design in the thermoplastic is possible.

The invention may be illustrated by the following examples but it is not limited to the exact thermoplastic, pigment, binder, etc. shown as it may be otherwise practised within the scope of the appended claims.

Example 1 A glass plate on which an ornamental design has been etched is rubbed over with a pigment Example 2 The depressions of a desi n engraved on a copper plate are filled with a pigment paste such as that used in Example 1. A solution of polystyrol in benzol is poured over the plate and the solvent evaporated. A hard sheet having the design embedded in it is obtained on removal from the copper plate.

Example 3 A paste of gold bronze in dibutyl phthalate is applied as described in Example 1 to a design etched on glass. A solution of Celluloid containing a black pigment is poured on the plate and the solvent evaporated. The dried film shows a gold design on a black background similar to the so-called Japanese lacquered articles.

Films obtained according to the process described may be used alone for decorative purposes or they may be mounted on a backing of leather, wood, fabric or paper for use in interior decorating, furniture, lamp shades, pocket books, mirrors, brushbacks, and other fancy articles. Very thin foil may be decorated by the process disclosed herein and used as a wrapping material.

Other vehicles for the pigment may be used, such as non-drying or semi-drying oils, other esters of phthalic and other dibasic organic acids, triaryl phosphates, etc. The main characteristic of the vehicle is that it should be soluble in the solvent used for the plastic and compatible with the latter.

I claim:

1. The process of applying designs to sheets of thermoplastic material which comprises filling the depressions of a design sunk in a non-porous plate with a paste consisting of a pigment and an organic vehicle, pouring a solution of a thermoplastic material on said plate, said vehicle being soluble in said solution, and evaporating the solvent.

2. The process of applying designs to sheets of thermoplastic material which comprises filling the depressions of a design sunk in a non-porous plate with a paste consisting of a pigment and an organic vehicle, pouring a solution of a thermoplastic material comprising a polymer selected from the group consisting of the lower aliphatic esters of acrylic and methacrylic acids on said plate, said vehicle being soluble in said solution, and evaporating the solvent.

KURT FEUERSTEIN.