US1265357A - Coated paper. - Google Patents

Description

JAMES Mimi, or 'ronon'ro, oi'rrnnro,

CANADA.

COATED PAPER.

Patented ma '7, acre.

film of glue that binds the very minute par- 1,265,351 Specification of Letters Patent. No Drawing. Application filed. October 1917. Serial it'd-194,69

To all whom it may cancer n:

Be it known that I, J AMES MILN, a s ub ect of the Kingrof Great Britain, res1dmg at the ,city of oronto, in the county of and Province of Ontario, Dominion 0 Canada, have invented certain new and use Improvements in Coated Paper; and I hereby declare that the following is a full, clear, and exact description of the same,

Ihe present invention relatesto a co ted paper which may be used in mechanical processes for the production of surfaces for rinting illustrations when such surfaces are adapted to be attached to printing cylinders or platens or to the lower surfaces of printing blocks in such a-manner to be exerted upon the difierent parts of the sheet to" be printed upon is regulated accordlhe preferred solutionof bleaching pow etch on the We g the hyp the color may ing to the light and and the invention paper surface. a coating of etchable material, which, after the impression of the picture is subjected whereby, the high lights left uncovered or lightly covered by be more or less deeply or etched by the action of the etchcompletely 7 washlng or brushing agent, and removed by Satisfactory results are obtainable by applying to the surface of the paper an etc able body capable of dissolution when subjectedto the action of an etching agent, such a body being preferably made by thoroughly v gr mixing together in a dry state, blanc fixe,

china clay, and an adhesive.

It is preferred to mix the blanc fixe and china clay in the proportion of two fixe to five died and ninety pounds of blanc hundred and eighty pounds of china clay, free from hard and gritty or substantially free particles and substances, to which is add approximately sixty-five gallons of water, and then combining with the mixture a solution consisting of approximately one hundred and twenty-five pounds of glue, twentyfive gallons of water, two pounds of glycerin and twelve ounces of aluminum acetate.-

which is employed the etching, is a der, commonly "called l' his solution causes an because ofthe fact that ochlorous acid-in the binding quality of the thin chlorid of lime.

ily destroys York would merely be softened, with the resu ing that the pressure shade of the picture,

consists of applying to a I chlorid, or other reagents reaction, the acidity j elly I tially 3 Baum' solution;-

' etching, the'paper,

washed to remove the origithe solution readinert materials used, such as blanc fixe and If water were used, the glule t entirely unsuited for that is required from china clay.

that the etch would be the high class of work the paper.

The alum'num acetate used in the composition because of its acid reaction with the etching. solution,

liberates an excess of the solution duractive reagent from the etching thereby aids the process of etching, and as well as hastens the etch.

It is possible, however, to use instead of aluminum acetate, such reagents as ferrous sulfate, copper sulfate, copper chlorid, ferric having an acid of which will tend to aid the etching qualities of the coating by liberatingthe excess of the active reagent solution.

to use, in the reparatiom of the solution, those grades 0 glue commercially known as gelatin, having a high strength, which are free or substanfree fromchondrin, and it is preferred over night and then heat from the etchin It is preferre to soak the gelatin it until in solution, aluminum acetate are added, the solution being well stirred to intimately mix the inedients. Any appropriate color may beused to impart to the-paper the required tint, and the coloring matter employed v should be free fromlumps. A preservative, such as a volatile oil, may be added to the glne solution. The mixture should be strained through very fine sieves before using. The aluminum acetate solution may be made by dissolving twelve ounces of lead acetate in two quarts of water and twelve ounces of aluminum s' fate in two quarts of water, the two solutions being subsequently mixed together and permitted to stand. When the lead sulfate has settled out on the bottom, as much as possible of the. solution may be poured To prevent shrinkage in the paper after before the coating is ap% plied, should be nal' size,- then resized with a solution of water and caseinimixture, in the-proportion when the glycerin and this etchable of three gallons of water to two quarts of casein mixture. The casein mixture should contain eight ounces of or solvent. After resizing, the paper should be put through a weak acid solut1on,,containing one and one-half ounces of concentrated hydrochloric acid to one gallon of Water. This'treatment applies to animal or glue sized papers. Casein and resin sized papers do not need this treatment.

The paper mass, is calendered between the calender rolls to prod printing surface, and is then ready for use in the printing press, thereafter being subjected to the etching process.

he etching process consists of the appli cation of an etch-proof color either on one side of the coated paper or on both sides, to increase the eflect; in which latter case, the printing block, with the picture to be reproduced, is supplied with prepared color ofl'ering a sulficient resistance to the etching or dissolving medium, and one or preferably several exactly reglstering impressions are or pressed uce a good prepared paper sheet having on both sides the etehable coating.

The printed sheet of prepared paper is then subjected for a short time to the action of an etchin agent to destroy the binding qualities of t e adhesive in the etchable coating, where exposed to the actionof such agent, and the coating, where the adhesive agent is so destroyed, is removed by washing or brushing, so that a relief is obtained corresponding to the picture.

It is thus possible .to obtain, by the use of a paper coated with an etchable material of this character, strong relief values accurately graduated in all details, and the height of the relief may be exactly regulated by the thickness of the coating and by the duration of the etching process.

Surfaces of the same tone are of the same height, and wh may be used as an overlayon the printing cylinder or platen, or as an underlay between the printing form andthe support.

Having thus y described the nature when it has been coated with thus always en so produced,

of my invention, what I claim as new and desire to secure by Letters Patent, is

1. In the herein described article of man ufacture, a sheet of paper having an etchable coating comprising blanc fixe, china clay, aluminum acetate, and an adhesive.

2. In the herein described article of manufacture, a sheet of paper having an etchable coating comprising blanc fixe, china clay, an agentto aid the etching qualities of the coatlng, and an adhesive.

3. In the h ufacture, a sheet of paper having an etchable coating comprising blanc fixe, china clay, glycerin, aluminum acetate, and an adeslve- 4.In,}the herein described article of man-.

ufactulte, a sheet of paper having an etchable coating consisting of blanc fixe, china clay, glue, glycerin and aluminum acetate, in the proportion of two hundred and ninety pounds of blanc fixe, five hundred and eighty pounds of china clay, one hundred and twenty-five pounds of glue, two pounds of glycerin, and twelve ounces of aluminum acetate. v

5. In the herein described 1 article of manufacture, a sheet of paper having an etchable coating comprising a mineral body and aluminum acetate.

6. the herein described aluminum acetate, and an adhesive.

, In the herein described article of manufacture, a sheet of paper having an etchable coating comprising a mineral body, an agent to aid the etch' mg qualities of the coatmg.

- 8. In the herein described article of man- JAMES MILN. Signed in the presence I oil- CHAs. -ICHES, EDWARD D. BERNSTEIN.

an etcherein described article of manbody, an

comprislng a mineral body,

and