US1684565A - Coated metallic articles such as stereotypic plates and method of producing same - Google Patents

Description

Patented Sept. 18, 1928.

UNITED, srArEs .i,684,565 PATENT OFFICE.

COLBY CHARLES WALLEB, OF NEW YQBK, N. Y.

I: COATED METALLIC ARTICLES SUCH AS ,STEREGTYPIC ELATES AND METHOD OF PRODUCING SAME.

N0 Drawing.

My invention relates to the art of metal coating and is adapted to a wide variety of applications. It is particularly useful, however, in themanufacture ofstereotypic plates wherein it is desirable to give type metal or other alloys a hard durable face, such as a copper face, to increase the wearing qualities thereof and the definition and clearness of prints therefrom.

By means of my invention it is possible to produce a stereotypic printing plate or cut equal, ifnot superior, to any heretofore in use, and, at the same time, to do so more cheaply, and with far greater rapidity, than has heretofore been possible.

Various features of the invention will hereinafter be more particularly described, but it will be readily understood that these are set forth merely for illustrative purposes, and are not to be understood as limitations to the scope of the invention which, it will he understood, is to be limited only by the appended claims. For convenient illustration,

the invention will now be described applied to the manufacture of a stercotypic copper faced plate.

'Heretofore, such plates have been produced by some such method as follows: A

matrix of paper, pulpor similar substance is first impressed with the desired characters and is then dried. Molten type metal is then poured into this matrix and a casting in re lief made therefrom. Thereafter a coating of copper is superimposed upon the face of the plate or casting by electro deposition after which the copper deposit is cleaned, burnished or otherwise treated to insure its clarity, definition and hardness. a Such processes. have proven satisfactory cept for their. cost and comparative slowness, thecost including the labor involved as well as the current consumes in producingthe deposit. .It will be vappreciated, however, that electro-depositio'n is a comparatively slow process, so that the propercoating or of the casting by this method requires 1 ,mal hours of time In addition, Various other factors and conditions are involved which may render the deposit uneven and not entirely satisfactory, inwhich case the entire plate is useless and must be discarded. It has been found that, by the invention herein described, stereotypic plates of extreme uniformity, great hardness, definition and cle'arness can be produced. with sub Application filed. February 7, 1924. Serial No. 691,284.

stantial saving in labor and cost, and, what is of great importance, especially in the newsoaper industry, is that several plates proper? ly coated can be produced from a single mat-- rix in a few moments time.

One method of practicing this invention which has been found satisfactory is, as follows: I

A matrix blank having a comparatively large fibrous cellulose content is first prepared. One satisfactory form comprises a base of comparatively heavyv blotting paper,

two or .more layers of absorbent material such as standard red rag absorbent paper,

gum arabic, and the mixture thoroughly stirred. To this is then added the proper proportion of hydrous aluminum silicate, and, if desired, a small port-ion of powdered slippery elm also introduced into the mixture at this time. The proportions used may vary within reasonable limits, but one satisfactory formula is as follows;

. Parts by weight.

Powdered crystalline copper sulphate--- 3 Powdered hydrous aluminum silicate 1 Boiling water 18 Powdered gum arabic 2 Powdered slippery elm It would seem that a portion of the gum arabic unites'with the copper sulphate to form a gum-copper precipitate which is held in suspension in the-emulsion, as is also the hydrous aluminum silicate and the slippery elm.

It is preferable to form toe mixture with thewater approximating boilin tempera' ture, and so formed, the emulsionis substantially stable and can be immediately used; or it may be allowed to cool and be reheated when desired for use. When used to satu rate the matrix blank the emulsion should be,

7 any satisfactory apparatus. It is preferable,

lmwevcr, that the pressing operation be performed ata substantially higher temperature, for instan e, at about 240 degrees Ftllllfillllfilt, and that the pressure employed be several thousand pounds. This may be effected by means of hydraulic presses operating in superheated steam chests, and when so performed, the heat and pressure are sufficient to cause an absorption of the emulsion byv the matrix blank, and upon this absorption here appears to take place a partial .chemi' cal reaction between the cellulose and copper contents of the solution and probably between the copper and the clay. The reaction is probably as follows, although this is not certain because of the indefinite formula for kaolin, V

H Al Si,O,+3CL1SO +18H O= Al (S0,) 1811 0 30110 ZH SiO three products resulting from the reaction are absorbed by the fibrous cellulose structure of the matrix blank, which acts as a medium or conveyor for these compounds for the further transposition, which occurs as will be hereafter described.

The matrix so prepared comes from the pressin a substantially dry condition. Itis now ready for use in producing the stereo typic plate. This is done in any well known manner and with any well known apparatus. That is, by pouring molten stereotypic metal upon it. This casting orvplate is allowed to cool and then removed, and will be found to possess upon the face which was in contact with the matrix, a complete surface layer or coating of copper. This coating will be found to be in part pure metallic copper, in part an alloy or mixture of copper andthe stereotypic metal and some copper oxide will be present, as will be seen from the pronounced malachite green appearance of the surface of the plate upon its removal from the matrix. After the plate cools, this oxide should be removed by brushing or rubbing the surface with diluted oxalic acid, the resulting surface being bright and clean with great definition and clearness.

It will be understood that the alunogen as well as the metasilicio acid lessens the heat radiation when the molten metal is cast against the matrix, and in addition, they provide a glutinous covering for the fibres of the paper and rerve as mordants or possibly as catalytic agents, in causing or aiding the leaf metal to adhere to or unite with the metal of the 'astiug. 'llheslippery elm adds smoothncss to the cellulose fibres, assists in preventing double printing, and increases the clear-' approximating between 600 and'TOO degrees Fahrenheit, as such metals seem to work best.

It would seem that when the molten type metal is cast against the matrix, the heat draws the three compounds to the surface of the matrix mold, the comic oxide is reduced to pure metallic copper leaf, the oxygen being driven off, and, aided by the presence of the mordants, (or catalytic agents), this copper leaf is transferred to andadheres to the surface of the stereotypic plate. While the fusing point of copper is considerably higher than that of the type metal, the copper does not completely 'blendwith the type-metal alloys, a portion ofit, at least, remaining on the surface. Nevertheless, some of the co per Seems to unite with the type-metal in the orm of an intimate mixture or alloy,'so that the plating or facing consists in part of pure copper, and in part of a copper type-metal mixture or alloy varying in composition from the surface inward, which alloy possessesa high degree of hardness and durabilit In fact, plates made in accordance with this invention appear to have much greater durability than those produced by the electro-deposition 'iet-als of manufacture.

In the foregoing, I have attempted to describe as accurately as possible the chemical and physical reactions occurring during the operation ofmy process. It will be understood, however, that from the very nature of the invention, it is at this time impossible to be certain that they occur inthe form, se-

quence and in the manner set forth. I wish 't to be understood, therefore, that these explanations are tentative merely, although based upon my best observations and experimentation, but a careful following-of the procedure above outlined cannot fail to result in theproduction of a plate of the superior character described.

' In describing the operation or function of certain of the ingredients above named, I have used the word mordant as to some extent approximating the affect of the substances named. It is quite pogsible that their action is more in the nature of a catalyst, so that wherever the word mordant is used herein, it is intended to mean a substance having sub stantially the same effect in producingsub stantially the results asthe substances above enumerated. As previously stated, the copper content of the emulsion can be varied from the proportion set forth in the specific for- Ion mula given. Generally speaking-the greater the copper content, the thicker will be the plate or coating imparted to the stereotypjic castin On the other hand, I have fount that an increase in the copper content, while increasing the thickness of the plating does so at some sacrifice to the hardness, durability and definition of the characters, so that an ex cessive copper content should be avoided.

in the foregoing I have referred only to copper sulphate as the copper salt employed, but itwillbe understood that other salts, such as copper acetate may be used,'if desired. Further, the process is by no means restricted to the production of copper plating as other metals may be used, for instance," nickel, in which case nickel salts may be employed, such for instance, as nickel sulphate or nickel ammoniunrsulphate.

It is obvious that many modifications and changes may be made in the process and ma terials used in practicing my invention, above set forth,without departing from the spirit and scope thereof. 1 do not mean to limit myself other than as is indicated in the appended claims.

\Vhat I'claim is: I i

1. The method of uniting a plurality of metals having different fusing points, comprising bringing a metal and ametallic salt into intimate association in the presence of a mordant.

2. The method of uniting a plurality of metals having different fusing points, comprising bringing a metal and a m'etallic'salt nto intimate assooiation in the presence of a mordant at a temperature approximating the fusing point of the metal having'the lower fusing point.

3. The method of producing a metallic coating on a metallic body, which comprises bringing the metal of said body and a metallic saltfor providing a coating metal into intimate association in the presence of a plurality of mordants.

l. The method of producing ametallic coating on a i netallic body, which comprises bringing together the metal of said body and a metallic salt for providing the coating metal into intimate association in the presence of a mordant at a temperature approximating the fusing point of the metal of said body.

5. The method of producing metallic coating on a metallic body, which comprises saturating a matrix with a inordant and bringing the metal of said body and a salt of the coating metal into intimate'association in the presence of tllGlUOlClilllt.

6. The method of producing a metallic coating on a metallic body, which comprises saturating a matrix with a mordant and bringing the metal of said body and a salt of the coating metal into intimate association on the matrix in the presence of a plurality of mordants.

7. The method of producing a metallic coating on. a metallic body, which comprises saturating a matrix with a mordant and bringing the metal of said body and a salt of the coating metal into intimate association in the presence of the mor'dant on the matrix a at a temperature approximating the fusing at atemperature approximating the'fusing point of the metal of the body.

. ,9. The method of. producing a metallic coating on a stereotypic plate, which includes casting molten type metal upon a fibrous matriximpregnated with a salt of the coating metal and a mordantl i 10. The method of producinga metallic coatingon a stereotypic plate, which includes casting molten type metal upon a fibrous matrix impregnated with a salt of the coating metal and a plurality .of mordants.

11. The method of producing a coated stereotypicplate' comprising casting molten type metal upon a fibrous matrix impregnated with an emulsion containing a salt of the coating metal and one or more mordants.

l2. The method of producing a coppersurfaced stereotypio plate which includes casting molten type metal upon a fibrous matrix previously impregnated'with an emulsion containing a copper salt, an emulsifying agent and a mordant.

13. The, method of producing a coppersurfaced stereotypic plate which includes casting molt-en type-metal uponfibrous matrix impregnated with an emulsion, including-powdered copper sulphate, hydrous aluminum silicateand gum arabic in water.

14. Themethod of producing a copper-stir faced stereotypic plate which includes casting moltentype metal upon a fibrousmatrix l'lel impregnated with "an" emulsion formed from powdered copper sulphate by weig it 3 parts, hydrous aluminum silicate-1 part, water-.18 parts, and gum arabic 2 parts.

15. The method of producing a coppercoated stereotypic plate comprising casting 'molten type metal upon a fibrous matrix impregnated with an emulsion containing a salt of the coating metal, an emulsifying agent and a mordant, and impressed at a temperature approximating 240 F.

16. The method of producing a copper coating upon a stereotypic plate which includes impregnating a fibrous blank with an emulsion containing copper sulphate, hydrous aluminum silicate, boiling water and powdered gum arable, impressing said matrix with the desired characters at a temperature 1 O'QAOO- F 0' 1;

appioxnna 111:, i .n cas 111, 1110i en ype metal against said matrix, removing said casting and cleaning the surface thereof.

17. Themethod of producing a metallic coating on a metallic body, which" process includes impregnating a fibrous matrix with a mordant and bringingthe metal/of said body and the coating metal into intimate association on the matrix in the presence of the mordant.

18. The method of producing a metallic coating on a metallic body, which includes impregnating a fibrous matrix with an aluminum-sulphate and bringing the metal of said body and the coating'metal into intimate association on the matrix under the application of heat inthe presence of said aluminumsulphate. a

19. The process of producing a metallic coating on a metallic body, which process includes impregnating a fibrous matrix with aluminum-sulphate, and bringing the metal of said body, and a salt of the coating metal into intimate association on the matrix under heat and in the presence of the aluminumsulphate;

20. The process of producing a metallic coating on a metallic body, which process includes bringing the metal of said body into intimate association with a fibrous matrix impregnated with a salt of the coating-metal and a'mordant.

21. The process of-producing acmetallic coating on a metallic body, which process includes bringing the metal of said body into intimate association under heat with a fibrous than the copper containing a salt of copper and a suitable mordant and a suitable emulsifier, secondly, impressing into said impregnated matrix the desired characters, and, thirdly, castingtypemetal against said matrix.

24. A matrix blank adapted for usein coatcontaining a salt of some metal and a cata} lyst agent and an emulsifier, secondly, converting said impregnated blank into a matrix by nnpressing the desired characters into it,

thirdly, melting some other metal or mixture of metals other than the first-named metal and casting the same against said matrix.

27. The process of producing a stereotype plate, which process comprises, firstly, 1mpregnating a fibrous blankwith an emulsion at a temperature of about212y F and containing the following ingredients in substantially the following proportions by weight, viz: 18 parts of water, 3 parts of coppersulphate, 1 part of hydrous aluminum-silicate, 2 partsirof gum-arabic, and one-eighth of 1 part of slippery-elm, secondly, convertingsaid impregnated blank into a matrix'b'y impressing the desired characters into it at a temperature of about 212 F., and thirdly, melting type-metal and. casting it against said matrix, whereby a surface of pure copper adheres to the casting and beneath said sur face other copper in ever-diminishing proportions is alloyed with the type-metal, the body of the cast type-metal and the intermediate alloy and the copper surface being united integrally, and the alloy being harder and the type-metal.

0. CHARLES WALLER.