US2124703A - Imitation leather finish - Google Patents

Description

atented July 26, 1938 UNITED STATES PATENT OFFICE IMITATION LEATHER FINISH No Drawing. Application May 7, 1936,

Serial No. 78,487

1 Claim.

This invention relates to a baked enamel finish on paper, rayon and other flexible supporting surfaces.

It is the object of my invention to provide a baked enamel finish that has the characteristics upon drying of forming an irregular surface, imitating the appearance of leather.

It is my particular object to provide such a finish that when it is dry, its surface will be hard and non-adherent, just as is the case with leather, and will be as flexible as leather.

It is my object for this purpose to provide a finish the flexibility of which is in proportion to and comparable with the supporting surface. I have found that by controlling the flexibility of the coating so as to be in harmony with the flexibility of the supporting surface that I am enabled to get a resulting unitary composite product in which there will be a permanent bond without cracking, flaking or the like between the enamel surface material and the supporting medium.

It is a further object to provide a finish of this desired plasticity which can be applied in any manner as by spray, roll coating, immersion and the like, and which can be dried preferably at room temperatures. By providing a finish which can be applied and brought to its finished hard state at temperatures below that which would be destructive to the supporting medium, it is possible to provide an enamel finish directly upon paper, rayon, sheet rubber, artificial leather and other similar materials and the resulting finish can not only be brought to its final hard, dry, smooth and flexible condition, but at a temperature that is satisfactory for the material in question which supports it.

It is my further object to provide an enamel finish which completely and of itself, when dry, assumes the irregular structure that is characteristic of an imitation leather. This irregularity extends throughout the body of the coating and not merely on the surface of it. By adjusting the plasticity of this coating this structural irregularity of the coating can take place upon drying without wrinkling the supporting paper, rayon or other materials which are in themselves flexible. It is further possible with my coating to coat delicate materials so as to present the imitation leather finish on one side, without the material so coating the medium coming through the medium and showing on the other side. It is therefore possible to print or otherwise use the back of this imitation leather finish, composite product.

The principle of my invention is also applicable to other imitation leather finishes of my invention, where the baking temperature is higher than that of room temperature. For instance, I have found that with the imitation leather finish of this invention, having this high plasticity, that I am able to coat paper and carry the temperature to 225 degrees F. for a period sufiicient to bring about the drying and irregular surface of the imitation leather finish without injuring the paper.

It will be understood that the proportions of the plasticizer that I have employed to bring about this novel result are very much greater than any heretofore ever contemplated in connection with lacquers, enamels and varnishes. I have found that by adding high boiling lacquer plasticizers in relatively large proportions and adjusting the proportions so as to bring about the same degree of flexibility in the imitation leather finish as in the paper or other medium being coated, I am enabled to get the novel result of this invention.

It is my further object to provide for the application of this same principle in imitation leather finishes that are baked, as on metal, such as metal foil or metal sheets at the higher temperatures of from 300 to 400 degrees F. approximately.

In order to accomplish the several objects of this invention, I prepare a varnish hereinafter described in Varnish I, a varnish described in Varnish II, and then combine the two varnishes as indicated in Varnish III, to which I add a sufiicient amount of plasticizer preferably a high boiling lacquer plasticizer in order to impart the proper degree of flexibility depending upon the material to which the imitation leather finish is to be applied. For instance, in the case of book paper I have found that by adding to ten gallons of Varnish III from one-fourth gallon to one gallon of high boiling lacquer plasticizer I am enabled to get the desired result. Amongst the plasticizers that can be successfully used in this connection are the following:

Diamyl phthalate, Tricresylphosphate, Triphenylphosphate,

Dibutyl phthalate,

Diethyl phthalate,

Phenyl stearate,

Monophenyl diphosphate, and Diphenyl phthalate.

Other plasticizers may be employed but I mention the foregoing as a sufficient number of typical illustrations to make it possible for anyone skilled in this art to practice this invention. When I refer in this specification and claim to a plasticizer, it will be understood that I comprehend within that term any one of these materials, or combinations thereof, or an unmentioned equivalent thereof.

Varnish I A typical formula is the following:

Pounds Amberol 13/5 1 Lt 6'7 Litharge 3%; Manganese linoleate, solid 8 Cobalt linoleate, solid 2 Gallons China-wood oil 20 Linseed oil 2% Heavy petroleum naphtha 14 Light petroleum naphtha 14-.

Amberol is a phenol, formaldehyde, synthetic resin. It is made as follows: To one hundred parts of phenol aldehyde resin difficultly fusible and only partly soluble in benzol and other solvents and produced, for instance, by heating 108 parts of cresol with 60 to '75 parts of formaldehyde (30% by weight) and distilling off the Water and the uncombined cresol, are added gradually to 800 parts of melted colophony. The whole mixture is then heated in an autoclave until a resin is produced which is clear in the cold, homogeneous and free from smell of phenol. The volatile substances are then removed while stirring and parts of glycerol of 28 degrees B. are added in small quantities whereupon the mixture is heated to 250 degrees C. and kept at this temperature for several hours while being stirred carefully. A typical formula for amberol is shown in United States Patent No. 1,623,901.

In order to prepare this varnish, we first take 20 gallons of China-wood oil or tung oil and 2 gallons refined linseed oil. These oils are mixed and heated at a normal rate to 480 degrees F. They are then pulled from the fire. These oils may undergo an automatic rise in temperature thereafter beyond 480 degrees F., but this is unnecessary and too great a rise should be avoided.

When the temperature of these oils has started to drop reaching approximately 475 degrees R; we add 3%.; pounds of litharge, stirring until the litharge is taken up by the oil. The temperature of this batch is then run back and forth between 460 degrees and 470 degrees, being held within this range for approximately 30 minutes and in some cases a little longer until suificient body has been imparted to the oil and litharge..

Thereafter we add 8 /2 pounds of manganese solid linoleate and 2 pounds of cobalt solid linoleate. These soluble driers melt into the batch.

We then add 67 pounds of synthetic resin solid, known to the trade as Amberol B/S 1 Light. This is melted at a low heat. Then the temperature is carried back to approximately 425 degrees F.

We then thin the batch at once with 14 gallons each of heavy and light petroleum naphtha.

The resulting compound may be used by itself or in combination with the product of the formula hereinafter recited.

Thereafter we prepare Varnish II.

Varnish II This formula is as follows:

' Pounds South Sea gum (Batu) 67 Litharge 3 Manganese linoleate 8 Cobalt linoleate 2 Gallons China-wood oil 20 Linseed oil 2%, Heavy petroleum naphtha 20 Light petroleum naphtha 20 The cooking is carried out in this manner. Sixty-seven pounds of South Sea gum, also known as Batu gum, are run in the ordinary approved fashion customary in varnish making. Then 20 gallons of China-wood oil and 2% gallons of refined linseed oil are mixed and heated'slowly until they reach 300 or 350 degrees F., then they are added slowly to the gum when the latter has been well run.

The mixture is then carried to a temperature of 460 to 470 degrees F. and held within this range, in order to impart body to the mixture, for about 30 minutes or a little longer.

We then stir into the batch 3 /2 pounds of litharge until it is taken up and fully incorporated in the batch. The 8 pounds of manganese solid linoleate and 2 pounds of cobalt solid linoleate In order to make the compound of this inven- 3 tion, either one of the above varnishes or both are combined with raw tung (China-wood) oil and a drier. A thinner can be added optionally. The proportion of Varnish I with respect to Varnish II may be two to one, or vary therebetween, or Varnish II with respect to Varnish I may be two to one, or vary therebetween. In either event, the China-wood oil will vary in number of parts from approximately 5 to 25 parts. The drier will vary from approximatey 5 to 25 parts, and the thinner will vary from 1 to 10 parts, depending upon the viscosity desired.

Varnish III A typical example of a satisfactory compound for the practice of this invention is the following:

Parts Varnish I 81 Varnish II 40 Raw tung (China-wood) oil 9 Drier 9 Petroleum naptha 5.10

Varnish IV To ten gallons of Varnish III I now add from gallon to 1 gallon of any one of the following Amongst such plasticizers or their equivalents.

high boiling lacquer plasticizers that I have employed are the following:

Diamyl phthalate, Tricresylphosphate, Triphenylphosphate,

Dibutyl phthalate,

Diethyl phthalate,

Phenyl stearate.

Monophenyl diphosphate, and Diphenyl phthalate.

It will be understood that under some circumstances, with extremely flexible supporting media, it may be necessary to increase the proportion of the plasticizer, but generally the amount of plasticizer to be added varies from 2 to 10% by volume of the imitation leather finish material such as that shown in Varnish III, but my invention rests in having a relatively high proportion of plasticizer in an imitation leather finish coating and adjusting the quantity so as to give a plastic finish of the same degree of flexibility as the supporting medium, susceptible of application to other formulas of imitation leather finishes.

I further have found that by adjusting the drying rate I am able to control the velocity of the surface drying and the drying through the film of imitation leather finish, so as not to wrinkle the paper or other material upon which the finish is being applied, and at the same time, preserve the flexibility of the coating.

For instance, when the compound of this invention is applied it must first flow out evenly on the surface treated and then the drying must begin almost at once on the surface of the wet compound by the formation of microscopic wrinkles. This initial wrinkling then proceeds through the whole thickness of the film as the complete drying proceeds.

The preferred drier that I have found to best serve this purpose comprises linoleate of lead, linoleate of cobalt, and linoleate of manganese. The cobalt and manganese, particularly the cobalt, accelerate the surface drying, as described above, while the lead and manganese are utilized for completing the drying completely through the film. This combination of cobalt and manganese supplies quick initial surface drying necessary, while the lead and the manganese supply the necessary catalytic action for the drying through the film.

Drier Example One of the preferred formulas which we have used is as follows:

385 pounds of linoleate of lead, 889 pounds of linoleate of cobalt,

14 pounds of linoleate of manganese.

These are melted at as low heat as possible, and when entirely fluid the mass is thinned with 1202 gallons of turpentine, either gum spirits or wood spirits, or some slowly evaporating coal tar fraction, such as xylene. It will be understood that the proportions of these elements of the drier can be varied according to the result desired. By adjusting these proportions the velocity of the surface drying and drying throughout the film can be regulated.

By utilizing the following formulas I find I am able to take my drying temperature of an imitation leather finish on paper up to 225 degrees F. without injuring the paper.

Varnish V A typical formula is the following:

Pounds Amberol B/S 1 Lt 67 Litharge 3 A; Manganese linoleate. solid 8 /2 Cobalt linoleate, solid 2 Gallons China-wood oil 20 Linseed oil 2% Heavy petroleum naphtha 14 Light petroleum naphtha 14 A suitable substance to be used as Amberol, in the above formula, is disclosed in U. S. Letters Patent No. 1,623,901, dated April 5, 1927.

In order to prepare this varnish, I first take 20 gallons of China-wood oil and 2%; gallons refined linseed oil. These oils are mixed and heated at a normal rate to 480 degrees F. They are then pulled from the fire. These oils may undergo an automatic rise in temperature thereafter beyond 480 degrees F. but this is unnecessary and too great a rise should be avoided.

When the temperature of these oils has started to drop reaching approximately 475 degrees F., I add 3 pounds of litharge, stirring until the litharge is taken up by the oil. The temperature of this batch is then run back and forth between 460 and 470 degrees F., being held within this range for approximately 30 minutes and in some cases a little longer until sufficient body has been imparted to the oil and litharge.

Thereafter I add 8 pounds of manganese solid linoleate and 2 pounds of cobalt solid linoleate. These soluble driers melt into the batch.

I then add 67 pounds of synthetic resin solid, known to the trade as Amberol 3/5 1 Light." This is melted at a low heat. Then the temperature is carried back to approximately 425 degrees F.

I then reduce the batch at once with 14 gallons each of heavy and light petroleum naphtha.

There may be added the plasticizers in proportions indicated heretofore.

Or, the addition of the plasticizer may be deferred until the following varnish, set forth in Varnish VI is added, whereupon the plasticizer can be added to the combined varnishes of V and VI.

In both cases of Varnish V or Varnishes V and VI, the imitation leather finish is applied to the paper or other media, and the temperature is carried up to 225 degrees F. for a period of approximately one-half hour to three hours. By regulating the proportion of the drier, as heretofore indicated, and the proportion of the plasticizer, it is possible to secure an irregular surfaced and an irregular body of an imitation leather finish, without wrinkling the paper and of the same flexibility or even greater flexibility than that of the paper and without the heat injuring the paper.

The cooking is carried out in this manner. Sixty-seven pounds of South Sea gum are run in the ordinary approved fashion customary in varnish making. Then 20 gallons of China-wood oil and 2% gallons of refined linseed oil are mixed and heated slowly until they reach 300 or 350 degrees F., then they are added slowly to the gum when the latter has been well run.

The mixture is then carried to a temperature of 460 to 4'70 degrees F. and held within this range in order to impart body to the mixture for about 30 minutes or a little longer.

I then stir into the batch 3% pounds of litharge until it is taken up and fully incorporated in the batch. The 8 pounds of manganese solid linoleate and 2 pounds of cobalt solid linoleate are allowed to melt in the batch.

I then reduce at once with 20 gallons each of heavy and light petroleum naphtha.

Turpentine may be substituted for the naphtha. Either the natural gum or a synthetic product as Amberol may be employed. When the natural product is used the result is a liquid of greater viscosity.

The fundamental basis is the combination of a guru and a low cooked China-wood oil. The litharge has the function of drying the compound through and through while the manganese and cobalt linoleates act primarily as surface or finish driers. The naphthas act as thinners. The linseed oil is an anti-polymerizing agent.

At this point I now preferably add to the co1nbination of varnishes V and VI in the approximate proportions of one part each of the proportion of the high boiling lacquer plasticizers heretofore enumerated of from gallon to one gallon of the plasticizer to each ten gallons of the combined Varnishes V and VI. This combination can be applied to paper and the like and heated to a temperature of 225 degrees F. for approximately one-half hour to three hours, depending on the ultimate use. The temperature of baking can be carried to approximately 225 degrees F. and held at that temperature for about 3 hours, but,

of course, the time of baking, the nature of the atmosphere in which baked, and the movement of that atmosphere will depend upon the supporting material and the coating.

For the application of a smooth enamel to paper, I take an enamel, preferably one made of a long oil spar varnish, and the necessary pigments to give the desired color.

To ten parts of this enamel I add from onefourth to one gallon of high boiling lacquer plasticizer and I am enabled to get the desired results.

Such an enamel can consist, for example, of 80 pounds of carbon black and 505 gallons of spar varnish. To ten gallons of the above varnish I add one-half gallon plasticizer.

Different colors may be imparted to the leather finish by adding ultra-marine blues, chrome yellows and greens, chrome oxide greens, and toluidine and lithol reds, etc.

It will be understood that I desire to comprehend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

An improved imitation leather enamel composition adapted for coating relatively thin flexible materials and drying to a high flexible wrinkle finish film at forced drm'ng temperatures approximating 225 degrees Fahrenheit, consisting by volume of approximately eighty-one parts of synthetic resin Varnish I; approximately forty and one-half parts of Varnish II; approximately nine parts of raw China-wood oil; approximately nine parts of a drier composed of a mixture of lead, cobalt, and manganese linoleate compounds dissolved in turpentine; five to ten parts petroleum naphtha thinner; color ground in spar varnish; and a high boiling point plasticizer in the amount approximating ten percent by volume of the enamel composition.

HARVEY G. KITTREDGE.