US1669491A - Treatment of fatty still residues - Google Patents

Description

Patente dM W 1 152.8;

' UNITED STATES V 1,669,491 PATENT OFFICE.

WAELACE SAVAGE, OF ELIZABETH, NEW JERSEY, ASSIGNOR T0 SAVAGE-RUBBER I CORPORATION, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW F Ho Drawing.

ihis invention elates to the treatment of fatty still resi tree and compounds con taining such residues and embraces the processes of treatment and the various features thereof and the'products obtained'thereby.

When fatty acid still bottoms, tars and pitches are cured under proper conditions by means of vulcanizing reagents of the type applied in the curing'of rubber, a new, congealcd. highly resiiient pitchproduct is ob-= tained. These resilient pitches have much in common with vulcanized rubber, are not weak and crumbiy llike oii rubber substitutes,

and give strong compounds with speciai distinct characteristics.

The temperature range the resilient state varies. plastic flow being ordineriiy attained. at from ltitl to 180 Q. and vitreous fractures occurringet temperatures iovv as -1? G. according to the character and of the fatty material vuicaniaed.

ddesiiient pitch products of wide ran n properties can be obtained from any source of fatty still residues; by biending and cornire crude stiii bottoms, tars and pitches "i r one another or with other com ponriding ingredients; by dehydrogenation of the hydrocarbon with reagents such as air. steam sulphur dioxide, suiphur, or"del'iydrogecatalysts such as finely divided'nietais, iron grindingn-for example;

by desatnration by means of pyrolysis and chemical decomposition. of the fatty carbonyl group; by neutralization of all or a portion of the free acid component of the tatty 'tar to be cured -loy the use of vulcanization acceierators to obtain optimum vulcanization conditions and cures; and 'by means in conjunction with'thcse and various other features to be mercifully described hereinafter.

Among the objects? of this invention are to provide processes and process steps for-the treatment of fatty still residues having unstable and plastic properties to produce im+ proved products having satisfactory and desirable fixed. and resilient characteristics, and

.to provi'd'improved resilient pitch products.

The fatty still residues .which may be used "in the production of resilient pitch products according to the present invention, include the residue oils, fatty acids, tars and pitches obtained by the distillation of animal and vegetable oils and fats, and in particular of.

fatty acids rendered volatile for distillation by saponification of any fatty glycerides.

TREATMENT @E FATTY STEEL RESIDUES.-

Application filed June 12, 31923. @criai Ii'o. 6445939.

Residues. tars and pitches of this character are obtained in connection with the manufacture of distilled soap stocks, distilled stearine and hydroxy stearine, candle fats and the like, from such fatty sources as corn oil, cotton seed oil, fish oils; tanicage and garbage greases, and the like. it is not feasible to complete the decomposition. the fatty material constituting combined glycerine base with fatty organic acids, any practical saponification process, due the equiibrium set up by the reverse proves throupfh the recombining effect of the organic base and acids, the fatty acid charged into the still usu'aily contains from A 10% to 20% of combined giyceride inc matter. This oil or fat being'non-voiatiie as. mains as a constituent in the stiii bottom residnes and after completion of the distiilation process will be discharged as a tar or, Su'liiciently heated. as a pitch of con.

sistency. The glycerine basedrated to a considerable extent, yieiding the mono-organic base, acro'iein. was eoprsi '1 i "L no heating conditions. the still residues from oil sources are softer than those from the fat sources. with the talioav iii-re raw stocks fforminn; the hardest and linseed stocks abont the softest. due to the firming tendency the content of giyceride o: acroieide esters in the residue. in general, the more unsaturated the fatty acid, the more fluid the oil or fat and the softer the stiii boa tom residue obtained with it will he.

The still bottom residues obtained as an initial lay-product in the refining by distillation of fatty acids derived from vegetable and animal oils are'thick, sticky, brownishblaok, tar like oils or pitches having a. melting point in the neighborhood of from 15" to 50 C. They-usually retain from 15% to but good practice in the case of burning stocks such as for candles, when acid value is immaterial. An oil of fatty content of from to 30% has previously been alluded to.

The remaining portion is made up of poly merized fatty acids, fatt acid anhydridcs and asphalt like inert hyc rocarbon products resulting from a certain unavoidable amount -of thermaldecomposition. If pyrolytic disltt tillation is carried very far, the latter portion begins to predominate, giving a pitch verging into asphalt in all of its physical V characteristics. Pitch of this type has been known as candle tar or candle pitch. This material may be utilized in paint or roofing .or similar uses where the stearines are prefthe source of the oil or fat or fatty material is not of fundamental importance.

Briefly, "the process steps of the present invention include preheating, blending and compounding, curing with vulcanization agents or polymerization agents such as sulphur or its equivalent in conjunction with organic and inorganic bases, capable of changing the oily free fatty acid content from an undesirable solvent phase to a colloidal filler phase, and thereby accelerating and aiding the curing process, cooling the product, and casting, molding and mechanically treating the cooled product. The vari ous features of this invention may be used in conjunction with each other or applied separately.

Prior to vulcanization, the fatty residues tars or pitches to be vulcanized may be subjected to treatment to obtain material of standard and uniform consistency for the production of the desired product. Normally, the harder pitches yield a harder product thanthe softer pitches and tars. The softer tarsand pitches may be hardened to any required extent by destructive distillation with or without steam or air blowing, by saponi fication with bases such as magnesia or lime or by incorporating hard bitumens such as hard fatty pitch, asphalt, grahamite gilsonits, mineral rubber, or the like therein. All intermediate stages between extremely soft and very hard properties can be obtained in the vulcanized residue.

. may also be softened by blending therewith fluxes such as solvent aromatic, terpene, or paraflin oils, fatty" acids or their glycerides prior to vulcanization. Where flexibility at low temperature is required, the addition Harder pitches,

of oils or oily material is advantageous. The

amount of oil should be restricted below the plastic state, due to the severe heat necessary I to reduce or decompose the solvent oil phase of the free thio fatty acids. If the usual solvent definition of vulcanized cure, as accepted in the rubber art, is applied, th com- J pletely vulcanized state or cure is not attained by the use of sulphur alone, due to the fact that all such products-are soluble in solvents, such as carbon disulphide, benzol,

naphtha, and the like. Where reagents that react with the carboxyl group are used, the fatty acid is eliminated as a source of trouble and contributes desirable properties when combined into a colloidal dispersed mineral soap or into some similar organic compound of sufiiciently high melting point. Such products are not soluble in ordinary solvents and meet the above test for cure in the same manner as rubber does. This weakening effect, as exhibited by the solution in solvents, which is caused by thefree fatty acid phase, may advantageously be applied by partial neutralization to give a product of satisfactory cure and can be readily milled, mixed with. and thoroughly incorporated into such mediums as rubber or rubber compounds, in which it may be neutralized and cured upon vulcanization of the compound. In place of'sulphur and a base, curing agents having equivalent effects may be employed. Sulphur chloride and phosphorous chloride modify the fatty acids satisfactorily and bring about an individual type of cure which is characteristic of the curing reagent.

Bromine, iodine, chlorine, free or com-.

pounded with sulphur, selenium, antimony, arsenic, zinc or phosphorous, sulphur dioxide, the oxides of nitrogemmand their equivalents and chemically active compounds of themalso yield characteristic cures.

Theai'uount of sulphur required to bring about resiliency and cure amounts to at least 7% at temperatures between about 150 C. and 200 C. The rate of vulcanization is extremely slow belowabout 135 C. At 167 C. the reaction proceeds very favorably and at 185 C. excessive foaming begins so as to require violent agitation to confine the mass in a heating container of reasonable size. Five or six percent of sulphur does not de velop a completely resilient state no matter what time and heat are used, butby adding i so general use, though where excessive free crystalline sulphur is not, objectionable as much as several times this amount can be used. The sulphur should be finely divided or molten when added to the fatty tar or pitch to be treated. Molecular equivalents of other vulcanization reagents at temperatures giving equivalent vapor concentration and chemical reactivity will yield correspending curese The process of vulcanization may be efl'ccted by mixing curing agents with the compound comprising the fatty residues, tars or pitches, and subjecting the mass to suitable temperstores in any convenient apparatus. The vulcanization may be con'ipleted in a single step or carried out in stages. For example, 95 parts of fatty acid still residue may be heated to 175 C. in asuitable container provided with a mixing and agitating device, and

5 parts of linseed oil, 5 of basic magnesium carbonate, 2 0E aniline oil'and 8 of sulphurfiour then incorporated into the molten mass. it the temperature is maintained about one hour the product will gradually thicken, eventually congealing to a liver like consistcncy, when the hot cure is attained. @r 80 parts of fatty tar may be melted down and 20 parts of fatty oil such as linseed. Oil, it) parts ot sulphur, 5 of basic magnesium v carbonate, 2 of lead oxide, 2: of i3ll1QClllO-8Lllllide and 3 oi" nine oxide then incorporated into'the mass at a vulcanization temperature. Ur, as a further example, 8 parts of sulphur, 5 of basic magnesium carbonate or 2 of magnesium oxide and 3 of magnesium carbonate and 2 of aniline maybe incorporated into 100 parts of fatty pitch at a temperature between about 160 and 180 C. c

Usually it is best to allow the final cure to take place in the molds, into which the charge is cast in a semi-cured state, the heatin the mass-being sufiicient to maintain prolonged and gradually diminishing vulcanizing temperatures which do not give an over or dead cure as may happen where the product is kept under a'high heat head such,

as would be applied to thevulcanizing container. The al cure is best effected by cooling the reaction product very slowly.

-, Under-cured resilient pitches null better with rubber than do either the raw stillon the mill rolls. Very slight under'cures are often desirable as the product in agingcures to a small extent and improves in quality rather than taking on an over cure.

Too much under-cure is fatal, due to atmos nheric oxidation which induces a hard, brittle, non-resilient character in the material utes.

which will eventually become vitreous and brittle, similarly to the raw fatty acid residues upon weathering;

Spread films may be advantageously cured by exposure to sulphur dioxide. For example, the fumes from burning sulphur carrying some sublimed sulphur, in amounts of about 20 parts of sulphur dioxide and 3 of sulphur, may be passed through a chain her where fabrics coated with about 100 parts of fatty tar are exposed. A considerable amount of hydrogen sulphilc is dcveloped which reacts with the sulphur dioxide/ A cure is obtained in about 10 min- Similarly, gases of equivalent compositions may be blown through pitch. A. halogen proof packing material may be made, for example, by vulcanizing 100 parts of fatty pitch with about 20 parts of bromine iodide and 5 parts of zinc oxide.

The vulcanization reaction is exothermic and it is frequently advantageous to control the final cure by withholding a. portion of the sulphur and adding this portion after the major reaction has been efiected and utter the reaction mass has slightly-cooled. A. semi-finished product that can be stored and transported at any temperature can be obtained by combining the pitch with only a part, say from 1/ to of the sulphur required to fully vulcanize it. This material may then be finished by adding the remaintier of the sulphur and subjecting the semivulcanized material. with t to added sulphur a temperature of about 150 G. for a few minutes. Ur the pitch may be combined with a art ofthe sulphur at high temperature, t' e semi-vulcanized product then cooled below about 135 and the remainder of the sulphur required to efiect the vulcanization then incorporatedin the batch. Such products can be stored indefinitely and can be finished at any time ,by merely heating to the vulcanization temperature. A semi-finished product may likewise be prepared by incorporating the entire amount of sulphur necessary to effect vulcanization into the fatty still residue or compound thereof at a temperature below the point at which convenient as well as withholding the full amount of the accelerating bases or of the sulphur.

Where the fatty pitch contam's too large nolten Insufficient heat- Mill) Hill \ acid.

an amount of staurated fats such as stearic or palinitic acids of the acetic series to yield a product of the required elasticity and resil-' iency, it may either be compounded with sufficient of those acids of the oleic. linoleic, linolenic or risinoleic series to dilute the waxy phase or may be del aturated or del'iydrOgenated by heating With 4 to 5% of sulphur at a relatively high temperature, usually above 200 C. and preferably not over 300 C. The reaction proceeds violently and it is best to add the sulphur in small intermittent portions. For example, if 100 parts of stearine candle tar are heated with 4 parts of sulphur at a temperature of 250 C. the pitch will be dehydrogenated with evolution of quantities of hydrogen sulphide, forming a saturated thio fatty The amount of sulphur required to finish a cure may beadded after the product has cooled to about 175 (3., and the other vulcanizing a ents have been incorporated.

Hydro xystearmes can be desaturated by heat alone.

The fatty pitches due to their origin are always highly acid and any free-fatty acid, even when saturated with sulphur, left in the resilient pitch product limits.,the resilient cure and induces plasticity. The more acid products are meltable and selfhealing, whereas products in which the free thio i'aty acids have been substantially neutralized are more rigid, are "not self healing, and are not meltable by the application of dry heat alone. With more than 25% free thio fatty acids present, no resilient state can be obtained. Resiliency appears very slowly with 17% free acids present but fair cures begin when less than 10% are present. Most excellent products "are obtained'witli the lowest amounts of free fatty acids, that is, in the neighborhood of 3%. These free fatty acids may be neutralized partially or entirely with active bases such as lime, magnesia, zinc oxide, magnesium carbonate, aniline oil, and the like, forming a colloidal soap or amine phase dispersed through the product. Such dispersed soaps-are particu- J larly advantageous for certain purposes,

such as in rubber compounds. v

In order to obtain a substantially opti mum cure, it is always necessary to use some good vulcanization accelerator. These include all active bases heretofore mentioned as neutralizing agents as well as organic acceleratorssuch as diphenylguanidine and 'triphenylguanidine and aniline products such as ethylidene aniline, formaldehyde aniline, triocarbanilide, toluidene, and the like, also other types of bases such as hexamethylene tetramine, lead oleate, etc., such i as are used in curing rubber containing free resinous aC1dS. Amines are usually suitable.

' All alkaline substances in general ,will effect the necessary acceleration, although the caustic alkalies such as'sodium and potas sium hydroxide are not desirable because their fatty soaps are soluble. Magnesia is a good accelerator but the magnesium oxide gives an excessively rapid cure. Basic magnesium carbonate obtained by partial recarbonation of magnesium oxide is, in general, preferable. These alkaline bases and accelerators apparently serve a dual function, serving to fix the free, fatty acids in a desirable phase and toaccelerate, the curing reaction in general.

The hot vulcanized product, while fused or plastic, has a tendency to adhere to molding surfaces and the best method of sur moi'mting this obstacle is to mold the product on wet surfaces. The water film instantly cools the outer skin of the material and prevents it from fusing onto. the molding material. Vet fabrics, paper, or cloth on which soapstone has been powdered, give satisfaction. Amalgamated copper may be usedwhere the presence of water is undesirable.

Fillers such as aluminum flake, asbestine, aluminum silicate, barium carbonate, barytes, blanc fixe, chalk, china clay, cotton flockpcotton linters, fossil flour, graphite, infusorial earth, mica, pumice, rotten stone, silica, soapstone, talc, terra blanche, tripoli flour, whiting, Rvood pulp, mineral rubber, cumar resin, pine tar, Burgundy pitch, rosin, black substitutes, parafli-n wax, carbon 'black, iron oxide, lampblaek, lithoponeftitanox, zinc oxide, and the like. andtheir equivalents, may be compounded with the resilient pitch or resilient pitch rubber products. These fillers may be worked into the product on a rubber or kneading mill or may be stirred into the liquid fatty tar prior to its vulcanization. Free sulphur in excess of that required to effect vulcanization also actsas a filler.

Resilient pitch prodiicts-are particularly adapted for use in compounding with rub ber. Resilient pitches, particularly when they contain a colloidal soap phase resulting from neutralization of free fatty acids therein, act as lubricants in the rubber compound, decreasing the amount of internal heat, and also act to water-proof the rubber compound. The following examples are illustrations of suitable rubber compounds:-

Carbonblack I: Mineral rubber;

The components can be all compoundedin. one stage, but it is much more expedient to make such a resilient pitch product such as the first specifically described herein, substantially cure it, and then mill it into the rubber with the usual rubber compounding ingredients. The pitch may be vulcanized prior to introduction into the rubber, or the rubber and pitch may be vulcanized together. Likewise, the pitch may be partially vulcanized and the vulcanization completed in conjunction with the vulcanization of the rubber compound. Resilient pitch acts as a softening agent on the mill, c'ausing'the fillers to disperse better and with less friction, heat and depolymerization of the rubber stock. Colloidal fatty acid soap in the resilient pitch aids in obtaining a good strong cure and is an ameliorating agent of considerable value. Automobile tires containing rubber compounded with resilient pitch have proven satisfactory over extensive road tests.

Resilient pitch products are resilient compositions of very general application. They are water proof. They have given satisfactory service in jointing concrete over atest period of twenty months. They are suitable for use as a packing material, for liquid, vapor or gas-tight joint seals, such as are required for pipe gaskets, concrete roofing, tanks, dams, conduits, subways, roads and building foundations. They are resistant to the attack of strong acids such as muri-atic acid. They are moisture repellant and have good dielectric properties. They can be shaped by molding, hot pressing or cutting into very inexpensive resilient pitch articles of fair quality or into economically produced resilient pitch rubber articles of highest quality.

- In my co-pending application, filed Jan. 17, 1922, Serial No. 529,963, 1 have described and claimed processes and products related to the subject matter of this application.

The term fatty still residues, as used herein, is intended to include all the various generic terms which have been or may be used to designate these fatty acid still hottoms, tars and pitches, including candle tar, kerzenterr (German), gondron (French), candle pitch, fat pitch, stearine pitch, palm oil pitch, bone-fat pitch, cotton-seed oil pitch, cotton pitch, cotton-stearine pitch,

cotton seed foots pitch, corn oilpitch, corn oil foots pitch, packing house pitch, garbage pitch, sewage pitch, fullers grease pltch,

wool pitch, wool grease pitch, wool fat pitch,

cholesterol pitch, beta pitch, pitchene, vacuum pitch, fatty acid pitch, carboxylated petroleum pitch, synthetic fatty acid pitch, and the like, including tars and pitches from all "vegetable, animal and mineral sources of fatty acids, their compounds and allied products, without regard to their degree of distillation, physical or chemical characteristics, source or process of manufacture.

While the preceding description has been specific to many details, it will be understood that examples have been given as illustrations of the'broad principles of the invention set forth and are not to be considered as limiting the scope of the invention as many alterations and variations thereof will appear to those skilled in the art, all without departure from the spirit of my invention or the scopeot' the subjoined claims.

I claim:

1. The process which comprises trdating fatty still residues and compositions containing the same with vulcanizing agents including an active alkaline component.

2. The process which comprises treating fatty still residues and compositions conlaining the same with sulphur and an organic accelerating base.

3. The process which comprises treating fatty still residues and compositions conbase and an organic accelerating base.

' 4. The processwhich comprises treating fatty still residues and compositions containing the same at tem eratures between about 135 C. and 205 with sulfur and an organic accelerating base.

5. The process which comprises reducing the free fatty acid content of fatty still residues and compositions containing ,the same to less than 17% and treating the same with vulcanizing agents.

6. The process which comprises reducing the free fatty acid content of fatty still residues and compositions containing the same to less than 10% and treating the same with vulcanizing agents. i

7. The process which comprises subjecting fatty still residues and compositions containing the same to the action of vulcanizing agents including slilphur at gradually decreasing temperatures whereby to effect the final cure at a slow rate.

8. As a product, vulcanized resilient pitch comprising fatty still residues, a curing agent, an active base, and an organic vuleamzation accelerator.

WALLACE SAVAGE;

In testimony whereof I aflix my signature.