US2077112A - Imitation leather paper - Google Patents

Description

April 1937- H. e. KITTREDGE AL 2,077,112

IMITAT ION LEATHER PAPER Filed Dec. 28, 1954 INVENTORQ //41?V5 K/TTEEDGE 9:

flLBEET J. TUE/V512 By W pm 2 Patented A r. 13, 1937 UNITED STATES- PATENT OFFICE IMITATION LEATHER PAPER Delaware Application December 28, 1934, Serial No. 759,550

1 Claim.

This invention relates to a new article of manufacture for use as imitation leather having the appearance, feel and body of leather.

It is the object of the invention to provide imitation leather paper which has a wrinkled, leather-like surface but which is not embossed, pressed or formed.

It is an object to provide such a leather-like paper, paper board or any other cellulose material which has such an appearance.

It is a further object to provide such an imitation leather paper that the leather finish will be on one side but the other side will remain in its normal condition for ordinary uses of packag- 3 ing, printing, etc.

It is an object to provide a product to which the leather-like surface can be applied in any color, which can be applied and dried at ordinary temperatures of a room from sixty to seventy degrees Fahrenheit, or which may be baked as high as two hundred and twenty five degrees Fahrenheit; it is a further object to provide such a leather-like paper consisting of the wrinkled leather-like coating that can be sprayed, dipped,

i impregnated or applied in any manner to the surfaces of the paper without the necessity of any intermediate backing, sizing or other treatment of the paper.

It is anobject to provide such a leather-like finish that will penetrate the surface of the paper sufiiciently to .form an intimate bond with the paper or other cellulose material to which it is applied but which will not penetrate the paper itself completely.

It will be understood in this application that when we refer to paper, we refer to any compound of cellulose.

Referring to the drawing:

The figure is a section through a cellulose backing, such as of paper, with theimitation leather finish mounted thereon.

Referring to the drawing in detail, I is a cellulose backing of paper, pasteboard, straw-board, cellophane, or any other cellulose material. 2 indicates the zone of penetration forming the bond between the paper I and the imitation leather finish 3. This finish is corrugated in substantially regular corrugations indicated at 4.

Upon the application of this finish, depending upon its exact composition, the finish will begin to wrinkle and will be completely wrinkled substantially throughout the body of the finish.

Even though the paper or other supporting backing is of very thin material, its wrinkle will 55 not be imparted through the material. The

paper is opaque and the imitation leather finish will not penetrate through or be seen from the reverse side of the paper.

It is therefore possible to either have the plain paper on the opposite side from the flnish for printing and the like, or a finish of the same or diiferent color can be imparted to the supporting medium I.

In applying this imitation leather finish, as hereinafter described, it is essential that the temperature of drying be not carried to a point where the paper will be injured. It is possible with our invention to keep within the limits of safety for the paper as the finishes which we provide range from those that dry in the air at room temperatures from 60 to 70 degrees Fahrenheit to those that can be baked at from 200 to 225 degrees Fahrenheit.

Typical compounds for the production of this new article of manufacture are as follows:

. EXAMPLE 1 In this example we use one of two varnishes,

or a combination of two varnishes with a. drier. These varnishes are designated Varnish A" and Varnish B.

Varnish A Amberol is a phenol, formaldehyde, synthetic resin. It is made as follows: to one hundred parts of phenol aldehyde resin difiicultly 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 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 fromsmell of phenol. The volatile substances are then removed while stirring and IOU-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 /2 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 4'70 degrees, beingheld within this range for approximately 30 minutes and in some cases a little longer until sumcient body has been imparted tothe oil and litharge.

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

We then add 6'7 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 approximately425 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 B.

Varnish B This formula is as follows:

The cooking is carried out in this manner. Sixty-seven pounds of I 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., when' 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% pounds of litharge until it is taken up and fully incorporated in the batch. The 8 /2 pounds of manganese solid linoleate and 2 pounds of cobalt solid linoleate are allowed to melt in the batch. We then thin at once with 20 gallons each of heavy and light petroleum naphtha. Turpentine may be substituted for the naphtha.

In order to make the compound of this invention, 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.

Parts Varnish A 81 Varnish B 40 Raw tung (China-wood oil) 9 Drier 9 Petroleum naphtha 5-10 To one gallon of this compound we add 5 to 7 pounds of the desired color, previously ground in spar varnish.

Varnish A has the function of fast drying, and imparts a high luster. Varnish B has a medium drying rate, and provides a low luster. Chinawood oil facilitates a very wrinkled drying without gloss and adds opacity to the product. The thinner controls the viscosity and the drier has the following functions and characteristics.

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 f microscopic wrinkles. This initial wrinkling then proceeds through the whole thickness of the film as the complete drying proceeds.

The preferred drier that we 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:

- Pounds Linoleate of lead 385 Linoleate of cobalt 889 Linoleate of manganese 14 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.

- EXAMPLE 2 When it is desired particularly to utilize light colors and pastel shades in the imitation leather finish which may be baked at lower temperature with the minimum of discoloration, the finish of the present example is employed provided the temperature is not taken beyond approximately 225 degrees F. so as not to injure the paper.

In this example there are two varnishes known as Varnish C and Varnish D. Either one or both varnishes may be employed.

Varnish C In order to make the first varnish designated as above, we take 100 pounds of Amberol 3/8 1 Lt. and 14 gallons of raw China-wood oil, heating the China-wood oil and the above synthetic resin in a varnish kettle to 550 degrees F. Three pounds of linoleate of lead and one pound of linoleate of cobalt are then added and stirred thoroughly. The batch is then allowed to cool to 450 degrees F. and then reduced with 32 gallons of petroleum naphtha.

Varnish D 30 Varnish C gallons 11% Varnish D do Raw China-wood oil. do 1% Thinner composed of equal parts of toluol 35 and petroleum naphtha gallons.-- 1-2 Paste composed of pure titanium dioxide ground in a spar varnish pounds 120 This enamel may be applied in any manner, as by inking rolls or by spray.

40 When the supporting surface, such as the paper sheet, is so treated, it is passed through the varnish at a temperature not to exceed approximately 250 degrees F. and is held at-that temperature for about 2 to 3 hours. These tem- 45 peratures and the time oi baking, the nature of the atmosphere in which baked, and the movement of that atmosphere will depend upon the supporting material. We merely mention typical examples.

50 The resulting product will have a wrinkled surface imitating leather, but the paper structure itself will notbe disturbed except that on the surface to which the product is applied there will be suflicient penetration to bond the coating to 'the paper. The surface will appear wrinkled and substantially without discoloration irrespective of its delicate colors. There will v be provided a smooth, heavy and wrinkled or pebbled surface which is a close imitation of genuine leather.

Varnish C and Varnish D can be varied in proportions of two to one of Varnish C to Varnish D, ortwo to one of Varnish D with respect to Varnish C. Raw China-wood oil can be varied in the same combination from one to ten parts. That is, from one to ten gallons, when gallons are used as the measure of the parts. The more China-wood oil used, the less the luster, and the finer the finish or grain of the leather.

Difierent colors may: be employed; such as: ultramarine blues; chrome yellows and greens; chromium oxide greens; toluidine and lithol reds, etc.

In the foregoing varnishes the proportions may be varied, but we prefer the proportions indicated, which we have found to be practicalv'arnishes for this purpose;

By cellulose backing is comprehended a variety of products, such as paper, pasteboard, cellophane and any others made of cellulose or its derivatives. Enumeration of these specific articles is not to be construed as a limitation or an exclusion of others of similar character.

It will be understood that we desire to comprehend within our invention such modifications as come within the scope of our claims and our inventioni Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is: I

In a method of making imitation leather which comprises applying to one side only of flexible cellulose material a composition containing rosin modified phenol-formaldehyde resin, raw Chinawood oil, cobalt linoleate, lead linoleate, a thinner and a coloring agent, and drying the coating at a temperature sufiiciently high to form a wrinkled leather-like surface bonded to the flexible material by a partial penetration thereof.

the temperature of drying not being carried to a point where the flexible cellulose material will be injured.

HARVEY G. .KI'I'I'REDGE. AIBERTJ. TURNER.

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