US1981824A - Process for producing resins of petroleum origin - Google Patents

Description

Nov. 20, 1934; v I FULTON I 1,981,824

PROCESS OF PRODUCING RESINS OF PETROLEUM ORIGIN Filed Oct. 30 1.931

Patented Nov. 20, 1934 UNITED" STATES PROCESS FOR PRODUCING RESINS OF PETROLEUM ORIGIN 1 Stewart 0. Fulton, Elizabeth, N. J assignor to Standard Oil Development Company, a corporation of Delaware Application October 30, 1931, Serial No.

4 Claims.

This invention relates to the productionof synthetic resins from cracked taroils of petroleum origin and certain other petroleum distillates by condensation by means of chlorination 5 and will be understood from the following descriptionwhenreadin conjunction with the drawing, which is a semi-diagrammatic side elevation,

partly in section, of a suitable apparatus.

Cracked tar of petroleum origin obtained in liquid or vapor phase cracking, or any similar process involving cracking, is used as the preferred raw material for the production of resins. The tar which may have a gravity of, say, -11 A. P. I., is first subjected to distillation, preferably under vacuum, to remove the oily components overhead. If a high vacuum, for example, 1 mm. mercury, is used, the oily compo-, nents will distill over between the approximate temperatures of 300 F. to 660 F. corresponding I to about 600 F., and about 1100 F. respectively at atmospheric pressure. However, it is not necessary to use such an extreme vacuum, but less vacuum with or without steam or other distillation aid may also be used and the'distillation may even be carried out under atmospheric pressure using steam or other gaseous agent as carrier. Usually about 85% of the tar is obtained as distillate.

r The distillate is then chlorinated preferably 'by bubbling chlorine through it slowly. The temperature at which the chlorination is carried out may be ordinary'room temperature or it may be somewhat higher, say up to 150 F., depending on the viscosity of the distillate. The product to be chlorinated is preferably agitated while the chlorine is bubbled through it. The chlorination is continued until 10 to of chlorine is absorbed, although it may be interrupted earlier or may be carried out further, depending on the scrbed may be determined by any of the known analytical methods, or it may be roughly estimated by the increase of weight of the product. The chlorinated product is then heated in a still up to a temperature of about 660 F., first underatmosphericpressure, then under vacuum, the final step in the heating being preferably carried out under 1 mm. mercury pressure and at a temperature up to 660 F. The heating simultaneously removes as overhead products the chlorine in the form of hydrochloric acid and the oily products. Only traces of chlorine are found in the hydrocarbon material carried overhead and in the residue.

Thebottoms remaining in the still is cooled product desired. The amount of chlorine ab-- down to about 200 F. and then agitated with about three times its weight of a selective solvent for resin such as light petroleum hydrocarbon distillate (naphtha). to extract the resinous prod- Although the solvent described is preferred, it

will be understood that the present invention is I in no way limited thereto.

Instead of using agitation the still bottoms may be refluxed with the hydrocarbon solvent. In either case the solution is separated from the hydrocarbon insoluble material, the amount of which varies from 0% to 50% of the weight of the bottoms. The separation is effected by settling and decantation or by filtration, or by other methods of separation known in the art. The hydrocarbon solvent is then removed from the dissolved resin by distilling the solution under atmospheric pressure on under slight vacuum, leaving as distillation residue the final resin product. When a light-colored resin is required the solution in Varsol or naphtha is acid-treated before the final distillation step.

The concentration of the sulfuric acid used for this purpose is 95% more or less. The amount of the acid will be regulated according tot-he desired color of the final resin, and may vary within wide limits, say from 10% to 50% of the resinous material dissolved in the solvent. The acid sludge is separated and the solution is neutralized, either by contacting with fine clay or by washing with water or dilute alkali. The acid treated and neutralized solution is distilled to remove the naphtha from the resin, if a solid resin is required.

The yield of resin is on the average 15% of the tar distillate and will depend upon the degree.

of "chlorination. The more thorough the chlorination, the higher will be the softening point of the resin. The latter is' above about 80 F. and usually between and 225 F. ascletermined by the ball and ring method. .Increased chlorination, however, also increases the hydro carbon insoluble material and consequentlydecreases the yield. The final condensed resin is an unsaponifiable solid, odorless and tasteless, and

has a yellow to reddish-brown color. The color is lighter when acid treating is employed. In 5 the latter case the resin is transparent in thin plates of say centimeter thickness. It is soluble in petroleum naphtha, linseed oil, China wood oil, esters and benzol, and insoluble in water, lower alcohols and acetone.

The tar is often advantageously distilled in two steps. The first 60% is discarded and used as heating oil, and only the last 40% is used as starting material for the production of resins. Instead of the tar distillate other equally high boiling petroleum oils such as for example the sulfur dioxide extract of a petroleum distillate which is rich in aromatic and/or unsaturated hydrocarbons may be used for producing resins, if it has a distillation range within approximately 300 F. to 660 F. under an absolute pressure of 1 mm. mercury. Other hydrocarbons such as distillates from an asphalt base crude, etc., may also be used as raw materials if they fall within the same approximate distillation range.

My process may be varied in different ways without departing from the spirit of the invention. Thus, for example, light colored resin may be prepared without using an acid treat. For this purpose the bottoms remaining in the dechlorinating still are dissolved in a small quantity of solvent such as ethylene dichloride, benzol,

etc. A light parafiinic hydrocarbon such as petroleum ether, liquefied pentane or butane is then added to the solvent whereby the material dissolved, other than the resin, is precipitated and a fairly pure resin solution is obtained which does not need acid treatment. In another modification, still bottoms may be directly extracted by heating at atmospheric or higher pressure with a light parafiinic hydrocarbon such as petroleum ether, butane or pentane. In this'case aga'n the resin goes into solution without appreciable amounts of contaminants. The resin solutions may be used either as such or the solvent may be evaporated if a solid resin is required. The

products obtained by my process may be characterized according to their source as resinified cracked tar oil or more generally as a resinified hydrocarbon distillate of petroleum origin.

Referring now to the drawing, 1 is a chlorinating vessel, 2 and 3 are the lines for introducing the distillate and the chlorine respectively, 4 the line for removing the evolved gases of chlorine, and hydrochloric acid, 5 a scrubber to re- 55. .move the hydrochloric acid, and 6 a return line for the'chlorine, '7 is the still for dechlorinating the product with an overhead line 8 and a bottoms line and cooler 19 and the bottoms draw-off line 18 thru which the resin obtained as a residue is drawn off, cooled and sent to storage tank, (not shown).

The following example will serve to illustrate my process:

1,000 pounds of tar distillate from a cracking coil tar (10 A. P. 1.) representing the total overhead boiling up to 660 F. at 1 mm. pressure, was chlorinated until the percentage of combined chlorine reached 9.7%. The chlorinated distillate was then heated up to 660 F. in the still 7 provided with a condenser at atmospheric pressure, whereupon most of the chlorine was removed as hydrochloric acid. Then the distillate was subjected to a vacuum distillation under reduced pressure until a temperature corresponding to 660 F. at 1 mm. pressure was reached. 208 pounds of high softening point residue (S. P. 282 F. ball and ring method) was obtained in this way, which was extracted with light naphtha leaving an insoluble residue amounting to pounds. After removal of the naphtha by distillation 133 pounds of light colored resin was obtained having a softening point of 183 F. (ball and ring method). I

This invention is not to be limited by any theory or the particular details given for purpose of i1- lustration, but only by the following claims in which it is my intention to claim all novelty inherent in the process.

I claim:

1. A solid hydrocarbon resin produced by chlorination and dechlorination of a distillate boiling above about 300 F. at 1 mm. mercury absolute pressure, from a cracked petroleum tar, said resin being an unsaponifiable solid, clear, light yellow to reddish brown color, softening point above F., soluble in petroleum naphtha, linseed oil and benzol and insoluble in water, lower alcohols and acetone.

2. Process for producing a resin, which comprises chlorinating a distillate, boiling within the approximate limits of 300 to 660 F. under an absolute pressure of 1 mm. mercury, from a cracked petroleum tar, heating the chlorinated distillate under a pressure below atmospheric to remove the chlorine and oily constituents therefrom as distillate, treating the remaining residue, substantially free from oily materials, with a selective solvent for resin, and separating the insoluble products from the solution containing the resin. I

3. Process for producing a resin, which comprises chlorinating a distillate, boiling above about 300 F. at 1 mm. mercury absolute pressure, from-a cracked petroleumtar, dechlorinating the chlorinated distillate by heatingit to about 660 F. under vacuum, and extracting a resin from the dechlorinated residue product with 5 a solvent.

4. Process according to claim 3; in which the hydrocarbon distillate treated boils within the approximate limits of 300 to 660 F. under an absolute pressure of 1 mm. mercury.

STEWART C. FULTON.

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