US1808372A - Process for the obtainment of sheets of plastic material which are combined or backed - Google Patents

Description

Patented June 2,1931

UNITED s'r 'rEs PATENT OFFICE man rarssnau, or um, rmcn I03 In OBTAIN'IENT- OF SEEMS OI PLLSTIO ILA-TRIAL WHICH ARE counmnn B BLCKED Io Drawing. Application fled Kay 85, 1928, Serial R0. and in France July 5, 1927.

In the. current manufacture of plastic substances based'u n nitro-cellulose or acetylcellulose, it is t e usual practice to place together and'unite-two sheets, one of which is transparent and the other opaque, for the obtainment of novel effects. r

For example, a thin sheet of artificial mother-of-pearl is backed by a. sheet of opaque materiahwhite or colored with black or various other pigments. The said opaque sheet is visible through the transparent material and-forms a background. The device co I of the two assembled sheets may be pl w. upon a strong and thick "plate of a less expensive substance which serves as a support, and the whole may be used for the manufacture of solid objects.

However, this method ,oifers certain disadvantages. The two thin sheets are caused to adhere together by the hot pressing process, j after coati ili fi one or both sheets with a suitable solvent. erefore to produce a successful operation,- it is necessary to keep within the strict limits of temperature and pressure,

since if the temperature becomes excessive, the substance will become softened and will sink down, th'us changing its appearance, and if the temperature is too low, the adhesion is imperfect i so In this latter case, the two sheets will he quentl separate during theirhandling in the manu acture of articles. This separation is almost inevitable when the thin sheets are I softened by immersion in hot water, or in a suitable liquid, in order to mount them upon backin which cannot be spread out, such as a w shoe heel.

The process according to the invention will obviate all such defects, and by the use of sim- 7 in an effective manner and may in certain the backing itself. Ehe said coating substance comprises different constituents whose proportions must ple and effective means,iI am'enabled to probe carefully calculated in order to obtain the desired efiect.

For instance, if the operation is to be performed upon a sheet of artificial mother-ofpearl or like substance having cellulose acetate as a base, the mixture should comprise:

" 1. A certain quantity of acetyl-cellulose which gives a certain stlfiness to the mixture andservesas binding material;

,2. A suitable amount of acolored powder, to or a'metalliccom ound, or'a lake colored by anilin dyes, or a w 'te pigment and a solution of. an anilin: color, and in general, any suitable pigments; e

3.YA diluting liquid, which is sufliciently volatile to allow the rapid drying of. the coating, and is so formed that in addition to the neutral substances serving exclusively as diluting bodies to afforl d the suitable consistency of the coating material for the purpose, it contains a solvent which is sufficiently active to'attack the surface of the coated sheet in order to obtain the adhesion, the said solvent being however used in such quantity that it will not dissolve or buckle the said sheet.

A formula corresponding to the above indications is given as follows,- solely by way of example a Parts Pi ent I Et llactate 25 Met l-alcohol 50 Ethy acetate 25 Cellulose acetate (plastic) 7 Obviously, each of the solvents or diluting liquids may be replaced by other products such as cyclohexanol, methyl acetate, acetone, methyl-ethyl-acetone, or the like, provided the mixture ofv such products forms acomplex substance of .a rather. volatile nature ,and slightly attacking the plastic substance, but not appreciably softening it. v For a coating upon aplastic substance having nitrocellulose as a base, instead of using cellulose acetate it is obviously preferable to use celluloid" as abindin'g substance, as well as the proper liquids or solvents.

In practice the coating or point thus formed may applied by any usual process,

- has a flat or dull .aspect which may be unfavorable when the backed sheet is to be used alone for the manufacture of fancy articles, such as lam shades, or in general, all articles made of thin material. In such cases it is an easy matter to ive to the whole a sufficient polish where y it will exactly resemble the product obtained by the adhesioli of. or a two sheets as inthe known methods. this urposeI polish the coated sheet in the poli ing press by the use of heat and pressure, according to the known polishing methods.

The aforesaid process has a further advantage from the fact that. it offers multiple combinationswhich would be difiicult to produce with the known methods.

In this manner I point by the stencil on the reverse side of the sheet to be backed, variegated patterns which may be as varied as desired, by the combination of suitable colors, and can also shade oif several tones to obtain shaded designs.

It will be easy to note the infinite diversity of the hues which can be obtained by my said method. On the contrary, in the known methods of backing by theuse of two pre-formed sheets, it is necessary to produce the colored sheets in large blocks which are then sliced, and this makes it very diflicult and expensive to obtain sheets of widely varying hues, due to the enormous number. of blocks which must be manufactured, and the-diificulty of producing plastic blocks whose colors are the .same throughoutthe several blocks.

I may further obtain novel as ects by applying successively two coats o paint having opposite tonality I obtain for instance a dead appearance by first'applying a bright color, optionall transparent, and then coverin it,'after rying, with a coat which is blac or neutral, or dark, which thus'forms a screen.

The aforesaid opaque black coat may contain lampblack, which is insoluble.

The sheet thus prepared is adapted for adhesion to apiece of thick plastic substance, as readily as the sheet obtained by the adhesion of two thin sheets by' the known method. I obtain such adhesion in the usual manner, by coating the two sheets, thin and thick, with a suitable solvent, and by placing them in the press, using heat and pressure for the proper time.

Due to my new method, the sheets are more closely united than by the current method in which the sheets must be perfectly dry. For this special use I may infact cause the thin sheet to adhere to the thick sheet before the widely varying effects. v

For the use of my said new product in thecoatingon the first sheet has entirely lost is solvent.

By the same method, I am further enabled to obtain novel effects by crackling or by sets of. lines. For this purpose I first coat a colored paint'in which the amount of plastic material used as a binding is less than the amount of color. When drying, the layer, which lacks binding, will shrink and will form sets of cracks,-these varying according to the relative amounts of color and of plastic material dissolved.

After this crackled coat has dried, I may readily use the same method to apply a layer of black or dark paint, or one which has a favorable color, so as to form an opaque layer which appears in' the interstices or cracks and thus affords a new artistic effect.

The said process is applicable not only to plastic substances of the artificial mother-ofpearl class, which aregiven by way of exampleas affording the most interesting results, but also to all other plastic material in thin sheets to which it is necessary, for any reason, to give a backing forming a screen, or which are to be placed'upon a thin sheet of a different color.

Also, according to the same principle, i. e. the use of a liquid consisting of a voltatile mixture of such composition that it will only slightly attack the plastic substance I may '(1)- either cause to adhere to one face of the latter a sheet of paper having a desired color, and herein the adhesion is obtained by placing the whole in the press with the use of heat and pressure, or (2) after the said paint or the like has been applied, I may cause to adhere to the coated face, by means of the same liquid, a sheet of spongy paper or a piece of thin cloth such as tarlatan, or wood in very thin sheets, or like strong and porous substances.

Such combinations afford a sheet of plastic material which due to the fact that it is rough on one side will be adaptedas well as any veneering wood-for suitable adhesion 'to wood, for instance by a suitable carpenters glue.

The tarlatan or like fabric is preferably substituted for paper, due to its greater strength, when it is desired to obtain a very 1 substantial adhesion, as for instance for the production of thin bands of marquetry.

Due tothis modification, the plastic substances can be used for cabinet making and for marquetry, and by a. suitable combination" produce most of colors, 8. given substance will pieces will adhere strongly together, and the backed by the fabric, adding if necessary a' thin sheet of plastic material of the same kind, for protecting purposes.

As an interesting improvement, I may substitute for the said fabric of natural textile fibres, a fabric consisting of artificial silk. This latter is based preferably upon the use of nitro-cellulose if the fabric is to be applied to celluloid, or the use of acetate of cellulose if applied to a plastic substance containing acetyl-cellulose. vFor this special purpose, susceptible of widely varying decorative uses, the fabric may consist of a non-loaded artificial silk, for a most efiective adhesion to the plastic substance.

I may further employ a colorless artificial fabric loaded with pearl essence. The fabric will sink into the plastic mass and thus becomes invisible, leaving in view only the pearl essence, which affords decorative effects (variable at will) due to its changing or opalescent hues.

Due to the said use of theartificial fabric which is caused to absorb the mixture accord ing to the invention and will sink into the plastic mass to form a single body, I may thus provide a sheet of valuable use which can be cut or punched, milled, or otherwise treated, with as great facility as ordinary plastic material.

Claims:

1. Process for the manufacture of sheets of plastic material which are combined or backed, consisting in applying, on a sheet of plastic material, a layer of a mixture adapted to attack but superficially the said sheet of plastic material and composed of a plastic materiallsimilar to that of the said sheet dissolved in a volatile compound comprising .a mixture of a so1v.ent of the said material and of a volatile liquid unable to dissolve the said material.

2. Process for the manufacture of sheets of plastic material which are combined or backed, consisting in applying, on a sheet of plastic material, a la er of a mixture adapted to attack but super ciallythe said sheet of of natural textile fibres,.

-to attack but material, and in subsequently subjecting said sheet thus prepared to the action of a polishing press.

3. Process for plastic material which are combined or backed,- consisting in applying, on a sheet of plastic material, a layer of a mixture adapted to attack but superficially the said sheet of plastic material and composed of plastic material similar to that of the said sheet dissolved in a volatile compound comprising a mixture of a solvent of the said material and of a volatile liquid unable to dissolve the said material, a colored filling substance being added to the first named mixture.-

4. Process for the manufacture of sheets of plastic material which are combined or backed, consisting in applying, on a sheet of plastic to attack but superficially the said sheet of plastic material and composed of a plastic material similar to that of'the said sheet dissolved in a-volatile compound comprising a mixture of a solvent of the said material and of a-volatile liquid unable 'to'dissolve the ,said material, and in applying on said layer material, a layer of a mixture adapted the manufacture of sheets of."

before'drying a sheet of spongy and resistant material. q

5. Process for the manufacture of sheets of plastic material which are combined'or backed, consisting in applying, on asheet of plastic material, a layer of a mixture adapted superficially the said sheet of plastic material and' composed of a plastic material similar to that of the said sheet 'dissolved in a volatile compound comprising a mixture of a solvent of the said material and of a volatile liquid unable to dissolve the said material, and in applying on said layer before drying, a layer of fabric.

(In testimony whereof I have hereunto aflixed my signature.

. JEAN PAIS SEAU,

plastic material and composed of a plastic 5 no v