US2468822A - Production of hydrocarbon resins - Google Patents

Description

Patented May 3, 1949 PRODUCTION OF HYDROCABBON RESINS William K. Griesinger, Drexel Hill, Pa., assignor to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application March 22, 1946. Serial No. 656,520

1 Claini. (Cl. 260-82) unsaturated petroleum distillates.

In accordance with this invention, an unsaturated petroleum distillate is intimately contacted with strong sulfuric acid, the mixture is then permitted to settle, and an acid layer containing unsaturated hydrocarbons is separated. The acid layer is thereafter diluted with sufflcient water to cause the separation of an insoluble, oily material, and the oil material, before or after neutralization with a suitable base, is heated to a temperature, sufilcient to cause solidification into a hard resin.

The unsaturated petroleum distillates which may be employed are exemplified by'unsaturated polymer distillates such as those derived by the fractionation of Gray tower polymers; unsaturated distillates derived by the treatment 'of cracked gasoline with Friedel-Crafts catalyst; and unsaturated distillates resulting from the fractionation of high boiling cracking still tars. A preferred charge material is an unsaturated hydrocarbon fraction of relatively high boiling point obtained from a by-product of the refining of cracked naphtha or gasoline with adsorbents.

It has long been conventional practice to treat cracked gasolines with a polymerizing adsorbent such as fullers earth or bauxite at a temperature between 350 F. and 450 F. to polymerize unsaturated constituents which normally tend to form gum and color bodies in the gasoline. This process is usually referred to as the Gray Process, and the unsaturated by-product polymers resulting from the process are separated from the treated gasoline by fractional distillation. By way of illustration, the present invention will be described in connection with the use of Gray tower polymers as the raw material for the production of thermoplastic resins. It is to be understood, however, that other unsaturated hydrocarbon fraction or distillates of similar nature may be used in lieu thereof.

In a preferred mode of operation, Gray tower polymers containing a minor amount of naphtha are fractionally distilled to remove the naphtha and light oils and to produce a bottoms or distillation residue having a Saybolt universal viscosity of about 300 seconds at 100 F. and an iodine number of about 180 (Wijs) This residue is then redistilled, preferably at reduced pressure, to obtain an unsaturated distillate fraction boiling between 300 F. and 600 F. at mm. pressure, the undistilled residue or bottoms having a softening 2 point between 170 F. and 200 F. It will be understood that the above properties, i. e., viscosity, iodine number, and boiling range are exemplary only, and may vary considerably depending upon the nature of the unsaturated charge stock and the conditions attending the fractionation.

The unsaturated distillate fraction boiling between 300 F. and 600 F. at 10mm. pressure is then preferably treated with dilute sulfuric acid to remove constituents readily polymerizable to tar. Sulfuric acid of from 40% to concentration is an amount ranging from 5% to 10% by volume of the distillate has been found very satisfactory for this purpose. The preliminary treatment with dilute sulfuric acid may be dispensed with, however, provided a somewhat darker color in the ultimate resin product is not objectionable. The unsaturated distillate, after separation from the dilute acid and tar-forming constituents, is then intimately contacted with strong sulfuric acid, preferably of from to concentration, in an amount about equal to the volume of the unsaturated distillate. The temperature during this treatment is preferably whereby there is formed an upper layer of unreacted distillate and a lower layer of acid containing unsaturated hydrocarbons, unsaturated polymers, and possibly olefine sulfates or sulfuric esters. The distillate layer is separated from the acid layer, and the latter is diluted with sufficient water to cause the separation of an insoluble, oily material. The quantity of water necessary to accomplish this result may vary between and 2 volumes per volume of acid layer, and in most cases a volume of water equal to that of the acid layer has been found satisfactory. In any case, water is added until no additional oily material separates from the acid layer. The oily material, probably composed of unsaturated hydrocarbons and polymers, is separated from the water-diluted acid layer, and is preferably neutralized by treatment with an alkaline agent, such as an aqueous solution of an alkali metal hyaaeaeaa which is thermoplastic and solublein hydrocarbon oils and solvents such as benzol, toluol, naphtha, and the like. The temperature employed in this conversion step is preferably between 200 F. and 400 F., although temperatures as low as 150 F. to 170 F. may be used if the heating period is prolonged. and temperatures slightly above 400 F. may be utilized provided the resin is not deleteriously affected. The conversion of the oily material to a solid resin by heating is usually slow and requires from 2 to 8 hours or more at the temperatures specified. Conversion appears to be favored by heating the oily material in relatively thin films rather than in bulk. The final product is a solid resin, usually orange to dark brown in color.

As an alternative procedure, the oily material after separation (mm the diluted acid layer. may be distilled under reduced pressure to take overhead alight colored distillate fraction which may then be converted to a solid resin by heating at an elevated temperature of, for example, 200 F. to 400 F. Or, the oily material, prior to redistillation may be neutralized as above described, then distilled, and the overheadconverted to a resin by heating.

The resins produced in accordance with this invention may be used in coating or impregnating compositions, rust-proofing composition, lubricants, insulating varnishes, compounded resins, paints, or when suitably plasticized with high boiling esters, may be used, per se, as a coating material.

I claim:

The method of producing a thermoplastic resin from an unsaturated hydrocarbon distillate boiling between 300 F. and 600 F. at 10 mm. pressure. such distillate being derived from hydrocarbon polymers resulting from the treatment of cracked gasoline with a polymerizing adsorbent, whichicomprises" intimately contacting said unsaturated hydrocarbon distillate with substantially an equal volume of sulfuric acid of from to concentration for a period of A hours to 3 hours at a temperature between 30 F. and 50 F... settling and separating from the mixture an acid layer containing unsaturated hy drocarbons, diluting the acid layer with an equal volume of water to cause the separation of an insoluble. oily material from the acid layer, neutralizing the oily material with an aqueous solution of sodium hydroxide. separating the neutralized oily material from the aqueous solution. and heating the oily material at a temperature of about 200 F. for a sumcient period oi time to cause solidification thereof to a hard, brittle resin.

WILIJAM K. GRIESINGER.

REFERENCES orran The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,374,277 Brownlee Apr. 12, 1921 1,778,329 Mason Oct. 14, 1930 1,869,231 Piotrowski July 26, 1932 2,025,738 Fulton Dec. 21, 1935 2,194,439 Chlttick Mar. 19, 1940 OTHER REFERENCES Ellis, "Chemistry of Synthetic Resins, vol. I, page 228, Reinhold (1935) Copy in Division 50.