US2000310A - Method of and means for mirror making - Google Patents

Description

May 7, 1935. H. G. WHITE Er AL METHO OF AND MEANS FOR MIRROR MAKING Filed Feb. 19, 1934 Patented May 7, r1935 l 'UNITED STATES RIETHOD F AND MEANS FOR IVIIRROB MAKING Henry G. White and Francis Logan Porter, High Point, N. C.

Application February 19, 1934, serial No. 712,017

9 Claims.

This invention relates tothe ornamentation of minors and the like, and more specifically relates to the placing of a resist on the rear surface of a glass to be madeinto a mirror so as to form an ornamental design, then applying a silver illm to the rear surface of the glass and the like, then subjecting the resist to a chemical agent to remove the resist from the glass, leaving an ornamental design which is unsilvered, and which design can be covered over or filled in with a "color material and then the entire rear surface usually has applied thereto a suitable protective backing, covering the silver nlm and the ornamented portions. By the term color material" used in the specification, it is not meant that the material must have color, but may be transparent or colorless.

It is an object of this invention to provide a method of ornamenting transparent sheets of material, such as glass, as employed in mirror making, by placing on the sheet a design by employing a water insoluble design forming material or resist which will protect that portion of the sheet from a coating of silvering and with the resist in position on the sheet, applying silver nitrate in solutionyto the side of the sheet having the resist thereon, which silvering will adhere to all portions of the surface except the portions covered by the resist, and even though the silver may cover the resist, the silver film is porous to the agent employed in removing the resist-then subjecting vatleast the` portions of the sheet having theresistlthereon to a suitable liquid agent -to penetrate the silver iilm and remove the resist from the sheet, leaving the portions of the sheet once covered by the resist in its original condition, to form an ornamental design which is unsilvered. 'Ihe mirror can then have -a suitable backing applied to the silver film, and if desired, such material such as color material, can be applied to the unsilvered portions before the backing is applied and the backing can be applied to the silver film and to the color material to protect the same.

It is a further object of this invention to pro- .vide methods and means for ornamentation of sheets of glass in mirror making wherein a suitable ornamental figure can be placed on the surface of the glass in the form of a. resist and f which can be applied by stencil or by hand, or

otherwise, and then subject the glass to a silvering operation to cover the rear surface thereof having the resist thereon with a silver film, then subjecting the glass to the action of a solvent l by immersion, spray or otherwise to cause the solvent to penetrate any portions of the silver fllmwhich might be disposed over the resist and to lift the resist together with any silver illm which may be deposited on the resist, from the glass and leave the surface of the glass formerly covered by the resist, in its Aoriginal condition. 'I'his unsilvered portion may be covered with a transparent backing along with the silver` film,

or if desired, any suitable color material may be applied to the unsilvered portions, then a suitable backing can be applied to the silver film and to the color material. I have found that solvent naptha or lacquer thinner or ethyl acetate, paint and varnish remover, makes a good solvent.

This application is a continuation in part of our copending application. Serial No. 621,640, filed July 9, 1932.

Some of the objects of the invention having been stated, the invention will appear more fully in the detailed description hereinafter following m when taken in connection with-the accompanying drawing, in whichz Figure 1 is an elevation of a mirror showing an ornamentation applied thereto;

Figure 2 is a vertical sectional view showing the 25 ornamental resist applied to the rear surface of the glass before 'the silvering operation;

Figure 3 is a view similar to Figure 2 but showing both the silvering and ornamental resist applied to the glass; 30

Figure 4 is a view similar to Figure 3 but showing the ornamental resist lifted from oif the glass after it has been subjected to the solvent bath;

Figure 5 is a view similar lto Figure 4 but 35 showing a color film disposed on the zportion formerly occupied by the ornamental resist;

Figure 6 is a view similar to Figure 5 and showing the completed mirror with the color material for ornamentation and backed-up by a suitable backing layer.

In carrying out the method, it has been found that a design forming material or resist having the following ingredients therein has produced excellent results:

Fourteen percent Chinawood oil, three and onehalf percent bodied linseed oil, twelve percent resin ester, four and one-quarter percent turpentine, twenty-one percent mineral spirits, onequarter percent metallic drier, three percent. blacii toner, twelve percent bone black, six percent carbon black, and twenty'-fourpercent calcium carbonate. The percentages in the above ingredients are exemplary, and it is evident thatvariations therein maybe made without affecting the efciency thereof. For example, the ingredients which give viscosity may be decreased or increased in percentages to determine the viscosity ofthe material to form a liquid-like material as desired.

l The design forming material orresist can be applied in any suitable manner. It has been found that a suitable silk lstencil may be em- This is conventional and4 does not affect the resist. "Then silver ,nitrate in solution is applied to the sensitizedy surface, which film I2. covers ythe entire `surface except that portion covered by the resist Il. In some instances, the silver film I2 may alsocover portions or vall of the resist, but on account ofa silver film being porous, this does no t prevent the removal of the resist by the solvent bath which is employed for this purpose.

',After the"silver film'has a sufficient time to ybecome a solid fllm I2, then a solvent is applied to the portions covered by 'the resist or the entire sheet Acan be submerged .inthe solvent. This solvent penetrates the silver film .if it covers the resist and removes Athe resist from the sheet,

usually lifting it as a whole and causes the lifted resist to float away from the sheet in a body, that is, when the sheet is immersed in the solvent. It

-h'asbee'nfound that a suitable solvent bath may be Y,provided by using xylol, which is a solvent naptha boiling at 165? C. lIf'de'sired, there may be added to the xylol approximately two percent acetone, three percent butyl acetone and eight percent butyl alcohol, thus decreasing the xylol to ap` `proxirmrtely eighty-seven percent. Also ethyl acetate, Apaint and varnish remover or lacquer thinner made fromon'e part'amyl'acetate and two parts toluol may be used as a solvent.

'It has been found that the above-named solv vents for the resist do not dissolve the resist but attack it and breaks its adhesion to the sheet fand cause it to expand and to float, as a whole,

away from the sheet. The removed resist resembles spawn. It is believed that the xylolat- .tacksthe resist and expands the same and the ispecific gravity Aoffthe resist being less than the napthalene or xylol bath, causes it to move away from vthe sheet and sink to the bottom of the napthalene bath or any other vsuitable solvent.

'If desired, a transparent'backing can be applied to the surface to cover the silvered and unsilveredportions, or if desired, a color material il can bev applied to the unsilvered portions and then a suitable backing'll'can be applied to the silver film and the color material.' This color material may 'be devoid of color if desired, 'or suit- 'able pigmentation may be present therein, as desired.

So far as weare advised, we believe that the provision of a suitable resist which can be removed by`a` suitable liquid penetrating the silver film andl removing the resist without attacking the silver film on the sheet is new, as it produces al sharp outline and lends itself 'to fine linework which permits use of a fine mesh silk screen, and

- spoilage.

which cannot be obtained by other methods employing paint, Whiting and the like, as a resist.

By the term bath herein employed as a means of subjecting the resist to the solvent agent, is meant immersion, spray or other forms.

If desired, a suitable paint remover may be used to remove the resist but the mirror must thenbe treated with a-suitable neutralizing solutin to remove all traces of the paint and varnish remover.

Also, any lacquer thinner may be employed to remove the resist but afterwards the mirror must 4be bathed'in a'neutralizing solution to remove.

all traces of the thinner to insure against silver A lacquer thinner may be made from one part amyl acetate and two parts toluol.

In ,the drawingand specification there has been set forth a preferred embodiment of .the invenltion, and although specific terms are employed,

they are lused in a generic and descriptive sense only, `and' not for purposes of limitation, the scope of the invention being set forth in the appended claims.v 1

We claim:

1. That method of ornamenting a sheet of glass which comprises applying a resist to one surface lof said sheet of glass to form an ornamental 'design visible through the glass, allowing the resist to dry, applying a film of silver to the surface of the glass on which the resist appears to cover the said surface, subjecting the glass 'to 'a' bath of solvent naptha, paint remover, lacquer thinner'and the like, to remove the resist bodily from the glass.

' 2. That method of mirror makingwhich com'- prises forming a design on the rear surface of a sheet of glass with a resist and which is visible through 'the glass, silvering the rear surface of the glass to cover alllportions thereof, subjecting the glass to abath to remove the resist from the surface Vof the glass to leave vthe portion vof the glass covered by the resist, unsilvered;

3;'I'hat method of ornamenting transparent objects which comprises applying resist to a portion of one surface of the object to form an orna` mental design visible'throughthe glass, allowing Vthe resist to dry, then applyingl silver nitrate in solution to said one side, allowing the silver nitrate to harden to form a silver film, then applying solvent naptha to said film, and said resist to openthe silver film and remove the resist.v

4. That method of mirror making which comprises 'forming a design by means of a soluble paste, on the rear surface of a sheet of transparent material, such as glass, silvering the .entire rear surface of said sheet, applying a liquid to the silvering and paste to remove the paste, then flowing color film into the places formerly occupied by the paste and then applying a suitable coating over the entire surface of the silvering and color nlm.

5. 'Ihat method of ornamenting the rear surface of a translucent object which comprises forming 'the desired design on said rear surface by means of a paste, then silvering the rear surface of said object, then applying a solvent to the paste and silver film near the paste to dissolve the paste, then applying a color film to the portions formerly occupied by the paste and then applying a suitable protective coating over the entire rear surface of the object.

6. That method of mirror making which comprises forming a design on the rear surface of a sheet of transparent material by means of a. paste, then silvering the rear surface 4of the sheet, then applying a solvent to remove the paste, then flowing a color film onto the spaces formerly occupied by the paste, then allowingthe color fllm to dry to form a lm and then placing a protective coating over the silver and the color.

7. That method of ornamenting hyaline substances which comprises forming a design on one side of the substance with a paste, sllvering the side having' the design thereon, applying a solvent' to remove the paste, then flowing a color film into the spaces formerly occupied by the paste.

8. That method of ornamenting hyaline substances which comprises forming a design on one surface of the substance from a suitable material,

-occupied by the material.

9. That method of ornamenting transparent sheets of material which comprises forming a design on one surface of the sheet with a soluble material then applying a silver lm to said one surface, then subjecting the soluble material to a solvent to remove the same from the sheet to leave an ornamental unsilvered portion on said surface of said sheet.

HENRY G. WHITE. FRANCIS LOGAN PORTER.

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