US2166103A

US2166103A - Art of treating fatty oils

Info

Publication number: US2166103A
Authority: US
Publication date: 1939-07-18
Anticipated expiration: 1956-07-18

Description

ram July 18, loss um rse s 'rA'rss- ART OF TREATING FATTY OILS ma. 1a. Bohr, atoms awn. CaiiL, alsignor to Vegetable Oil Products Company, Inc, Los Angeles, Calm, a corporation of Delaware No Drawing. Application May 10, 198'),

sel'lll No. 141,881

8Claims. (cuss-42s) This invention relates to the treatment of i'atty oils such as vegetable, marine and animal oilsand isparticularlydirectedtoaprocessoi treating oils containing mixtures of unsaturated 5 and saturated fatty acids or giycerides to the end that distinct liquid products be produced therefrom, these products being particularly adapted for use in the paint, lacquer, varnish and linoleum industries or for use as edible oils 10 or wherever a non-drying oil is required.

The invention also relates to drying oils characterised by their ability to polymerize and/or condense very readily, these oils being further characterized by their ability to form, upon bell ing heated, a true irreversible gel without exhibiting syneresis. and by their ability to form extremely hard, quick-drying films which are extremely stable to weather, alkalies, or the like.

Vegetable. marine and other similar oils are I) generally classified as drying or non-drying,

these being relative terms which to a certain extent indicate the proportionate amount of unsaturated constituents in the oil. For example, the iodine value normally assigned to such oils 25 is a measure of unsaturation and is closely associated with the ability of the oil to absorb oxygen and this in turn is indicative of the drying power of the oil. As a result, it may be generally stated that the more unsaturatedolis are so drying oils whereas those which contain saturated compounds are non-drying. Linseed oil is an example of what is known as a drying oil whereas cottonseed oil is'a substantially nondrying oil. Saturated and partly saturated oils :5 are usually employed and referred to as edible oils, the more unsaturated being generally considered as drying or non-edible.

In addition to the oils which fall into the above general classification, there are oils which con- 40 tain both saturated and unsaturated compounds and thereby partake of the characteristics of both the groups. Fish oil, such as sardine oil, for example, contains triglycerides of some very unsaturated acids such as clupanodonic,

as but the oil also contains relatively high proportions oi saturated compounds. Sardine oil per se is not a drying oil because 01' the presence of the saturated and partly saturated compounds and films of this oil will not dry to a hard, dense so film but instead remain tacky. The oil is thereiore not suited for use in good paints nor is it entirely edible.

The present invention is primarily directed toward a process whereby a semi-drying oil (or any gs oil containing saturated, partially saturated and unsaturated compounds) may be treated-to produce two separate and distinct liquid products, each of these products having properties which render it eminently suitedior use in a separate and distinct field. A fish oil such as sardine oil, 5

' for example, may be converted in accordance with the process 01 this invention into two iractions. one oi which is eminently suited for use in paints, varnishes and the like and has all of the valuable properties of a splendid drying oil such as China-wood oil, for example, whereas the other fractions or product is eminently suited for use either as an edible oil or for hydrogenation, saponification, or the like.

It has been discovered that certain organic solvents, although soluble in vegetable or marine oils, when not added thereto in excess (as for example in less than equal volume), have the property oLproducing remarkable and unexpected results when added to such oils in excess, i. e., in amounts 01 more than one volume to one volume 01 oil. When used in such amounts (preferably more than four volumes to one of oil) these solvents cause a selective precipitation or stratiilcation of certain. constituents of the as oil, thereby permitting these constituents to be readily withdrawn. In practice, the constituents contained in the settled or precipitated oily layer by action of the solvents are the polymerization and/or condensation products of the unsaturated triglycerides. These polymers and condensation products which are contained in the oily liquid separated from the oils in the manner described, have the property of gelling completely upon being heated so as to form a flexible, resinous gel, whereas most oils which are' ordinarily termed good drying oils will not gel completely upon prolonged heating but instead will still exhibit the characteristics of a thick fluid. The two liquid layers obtained by 4 stratification will contain the solvent and pertions 01' liquid oil.

The mixture of oily constituents and solvent which remains alter the settled or precipitated liquid portion has been withdrawn may then be separated by distillation into a portion of oil which consists almost essentially of non-drying and saturated components and the original solvent which can then be reused in cyclic operation of the process.

An object of the present invention, therefore, is to disclose and provide a method of treating vegetable, marine and animal oils for the production 01' separate and distinct liquid products 91' 0118 diil'ering greatly in physical and chemical unsaturated triglycerides.

properties and adapted for entirely difierent fields of. use.

Another object of this invention is to disclose and provide certain new and useful improved drying oils and methods of producing the same.

A further object of the invention is to disclose and provide a method of manufacturing drying oils which are more waterproof, much harder drying and faster drying, and much more readily and completely polymerized upon further treatment than normal drying oils.

An object of the invention is to disclose and provide a method of producing improved drying oils and improved saturated oils from mixtures thereof.

A still further object of the invention is to disclose and provide a method of precipitating polymerized unsaturated constituents from oils con taining the same by means of solvents.

These and other objects, uses, advantages and adaptations of the invention will become apparent to those skilled in the art from the following detailed description of the process, ingredients to be used therein, and products produced thereby. It is to be understood that the invention is not limited to the specific examples hereinabove referred to, specific materials and products being mentioned for purposes of illustration only.

In order to facilitate understanding of the invention, the process of this invention will be described as it may be used in the treatment of sardine oil, which is a semi-drying oil incapable of being used in quality paints and varnishes because it does not dry to a hard film but instead remains tacky and contains both saturated and Although this and other oils may be subjected to the process of this invention in their normal conditioner form, it is preferable in most instances to first subject the oil to a preliminary heating operation for the purpose of polymerizing or heat-bodying the oil. Sardine oil, for example, may be polymerized at temperatures of 525 F.-565 F. .Tem-

peratures of from about 480 F. to about 600 F.- 610 F. may be used, however. By heating this oil under vacuum, a lighter color is maintained. The heat-bodying is carried out to cause simple polymerization with no, or only a minimum, of gel formation and this control is attained by observing the drop in iodine value. The iodine value should not be reduced to a minimum but instead the heat-bodying treatment stopped at a suitable solvent such as acetone, the solvent being preferably added to the oil during agita= tion. It will be noted that up to about one volume of acetone may be added to anddissolved in the oil. The addition of acetone is continued, however, (with continuing agitation) until two or more volumes of acetone have been added. In practice, nine to twelve volumes oi acetone have been used but four to seven volumes are generally sumcient, particularly when the oil and solvent are heated to temperatures approacg the boiling point of the solvent. After such addition, agitation is discontinued and the resulting mixture permitted to stratify. It will be found that a certain quantity of oil will settle to the bottom of the container. After twoto eight hours the settled or precipitated liquid oil is drained off in any suitable manner and it will be found that this precipitated oil is composed essentially oi unsaturated polymers but contains from about 20% to 25% or acetone in solution therein. This withdrawn settled oil .is then heated to drive 011 the acetone dissolved therein or again treated with nine or more volumes of acetone. In the event retreatment is not desired, the small amount of acetone remag in solution in the settled or precipitated oil is re moved by distillation or heating and the residual liquid polymerized oil is now ready for use in paints, varnishes, linoleum or wherever a high quality drying oil is desired.

The mixture or upper layer, composed largely of acetone, remaining in the mixer is now distilled for the purpose of recovering. the acetone and it will be found that the residual oil obtained from this distillation is composed essentially of partially saturated compounds and is eminently suited for use either as an edible oil, in shortening, or in the manufacture of soaps and other products in which the non gzlrying oils are ordinarily used. As a specific example, an alkali refined bleached winterized sardine oil was heat-polymerized to Gardner Holdt X viscosity (12.9 pulses at 25 C.) and then treated with two 10% extractions with acetone, i. e., nine volumes of acetone to one volume of oil in each extraction. The characteristics of the original sardine oil, after being heat-bodied, and the characteristics and properties of the settled, liquid unsaturated polymer and of the nondrying saturated oil obtained in accordance with this invention are given in the following table:

Settled ly- Non-dry g Original oil Heat bodied oil an on Iodine value Wije 201 11 118.3. 100.9. Refractive index at 25 C 1.4795 1.4883 1.4 1.4872. Sponificatlon value 190 190 185 197. Free fatty acid as oelic percent. 0.2.- 1.56. 0.28-- 3.8. Color (Lovibond) 35Y/2 5R 35Y/4.0R 35YI4.0R Grcenisb. Upsaponifiahle percent 1 l l Xxscosity A if Z5 plus G.

aranoe- Clear--- Cloud Clear Cloud Ability to gel on heating No N y Yes No. y Drying Fast, but tacky.-. Slow, and tacky... Fest Non-drying. Surface Hard Do. Water r Poor- Poor Excellent Poor Taste Fish Burnt Cooked Tastless. Odor. n Cooked Odorless.... odorless.

such a point that the oil, at some subsequent time, is capable of exhibiting a further and appreciable drop in iodine value upon further heating. The resulting heat-bodied oil contains a mixture of polymerized unsaturated compounds and unpolymerized saturated constituents.

This heat-bodied sardine oil at atmospheric or superatmospheric temperatures is mixed ,with

The oil obtained by this process and containing the polymerization or condensation products, is distinguishable by its markedly improved drying and film characteristics, such as increased waterproofness and weather resistance, hardness 'I'hislastpropertyisofgreatvalueandpermits the use '01 the-product in varnishes as well as in other products requiring the presence of a desirable drying 1 that will form an irreversible gel on further heating. The condensation products of this invention will gel completely and can be used as substitutes for China-wood oil. with improved results in many cases.

The partially saturated edible oil (recovered from the solveht) can be neutralized, deodorized, and rendered tasteless by any normal treatment, such as agitation with steam under vacuum, and at temperatures as high as 4 50 it, without becoming heavy in body. This oil can be used in edible products, while ordinary sardine oils can not unless hydrogenated.

The original oil subjected to the treatment may or may not be heat-bodied prior to treatment, although best results are obtained when the original oil is heat-bodied to a point wherein maximum polymerization has occurred with a minimum of gel formation. This optimum point can be determined by plotting thecurve of the viscosity, specific gravity, refractivefindex or iodine value against time, temperature or both. This curve will be found to change rapidly when the proper polymerization temperature is reached and will then flatten out. I have found the optimum point is where the curve changes from the steep slope to the flatter portion.

Various solvents or liquid precipitants can be used. In general, it appears desirable that the solvent be capable of dissolving, to some extent, in the mixed oil. The solvent should not exert a solvent action upon triglycerides of high molecular weight, such as 900 or more. Ketones and the higher alcohols appear to be usable, and dimethyl ketone, methyl ethyl ketone, diethyl ketone, and higher ketones, such as diacetone, butyl and amylic alcohol, primary hewl, secondary amyl, hexyl, tetrahydrofurfuryl alcohol and other higher alcohols in primary, secondary and tertiary forms are examples. Alcohols of higher molecular weight (from those mentioned) give better results than those of lower molecular weight. Most of the aliphatic hydrocarbons, chlorinated aliphatics'and aromatics not ef-' fective. J 1

- The volume of solvent 1used.should b t least using heat during mixing and stratification or precipitation, a more effective precipitati tin is attained. The precipitated oils can be caused to' separate by gravity or by the aid of centrifugal separators. The entire process may be batch or of the continuors counterflowtype. By varying the ratio of solvent to oil, degree of initial polymerization, temperature of extraction and/or the number of extractions carried out on the heavier oil, great latitude in the character of the precipitated and residual oils may be obtained. In this specific exemplary form not described in detail.

I claim:

, 1. A method of treating partially polymerized vegetable and marine oils containing polymers of unsaturated constituents in liquid phase and not 5 g .4 as solid gels, theoils being capable of exhibiting a drop in iodine value upon heatodying, to produce-an oil fraction having enhanced drying properties, comprising: mixing a give volume of such partially polymerized oil with than three volumes of an organic solvent from the group consisting of ketones and higher alcohols, permitting the mixture to settle and stratify into two layers, each containing a solution of oily constituents and solvent, separating 10'' the bottom layer containing polymerized constituents having enhanced drying properties from the upper layer, and separating solvent from the upper layer to obtain a substantially non-drying oil.

2. A method of treating partially polymerized 15 vegetable and marine oils containing polymers of unsaturated constituents in liquid phase'and not as solid gels, the oils being capable of exhibiting a drop in' iodine value upon heat-bodying, to produce an oil fraction having enhanced dryingproperties, comprising: mixing a given volume of such partially polymerized oil with not less than three volumes of anorganic solvent from the group consisting of ketones and higher alcohols, permitting the mixture to settle and stratify into two layers, each containing a solution of oil and solvent, separating the settled bottom layer of solution containing polymerized constituents from the supernatant liquid, said bottom layer containing oil having enhanced drying properties, separating the solvent from the supernatant liquid to obtain an oil fraction having substantially non-drying properties, and removing solvent from the bottom layer.

3. A method of treating vegetable and marine oils to recover therefrom oil fractions having enhanced drying properties, comprising: subjecting the oil to an incomplete polymerizing treatment virtually insuflicient to form solid gels, the partially polymerized oil being capable of exhibiting a drop in iodine value upon further heatbodying; mixing said partially po y rized oil with not less than three volumes of an organic solvent from the group of ketones and higher alcohols; separating the mixture gravimetrically into two layers of solution of oil and solvent, recovering a liquid oil fraction having enhanced drying propertiesfrom one layer and recovering an'oil fraction having non-drying characteristics 'fromthe other layer. Y

4. A'method of treating vegetable and marine oils to recover therefrom oil fractions having enhanced drying properties, comprising: subjecting the oil to-an incomplete polymerizing treatment virtually insufllcient to form solid gels, the partially polymerized oil being capable of exhib- ,iting a drop in iodine value upon further heatbodying; mixing said partially polymerized oil with not less *than three volumes of an organic solvent from the group of ketones and higher alcohols; separating the mixture gravimetrically into two layers of solution of oil and solvent. separating organic solvents from each of said layers separately, recovering an oilfraction having enhanced drying properties from one layer, and recovering a liquid oil fraction having non-drying characteristics from the other layer.

5. A method of treating vegetable and marine oils to-recover therefrom oil fractions having enhanced drying properties, comprising: subjecting 7 the oilto a partial polymerizing treatment virtually insuflicient to form solid gels;.th partially polymerized oil being capable of exhibitinga drop in iodine value upon further heat-bodying; mixing said partially polymerized oil with not less .75

at less 8.

than three volumes of acetone; separa the mixture gravimetrically into two layers, each comprising a solution of oil and solvent; recovering an oil traction having enhanced drying properties from one layer, and recovering a liquid oil fraction having non-drying characteristics from the other layer.

6. A method of treating partially polymerized vegetable and marine oils to recover therefrom oil fractions having enhanced drying properties, comprising: mixing a partially polymerized oil with not less than three volumes of acetone; separating the mixture gravimetrically into two layers of solution of oil and acetone; separating acetone from each oi said solutions separately, recovering an oil fraction having enhanced drying properties from one layer and recovering a liquid oil fraction having non-drying characteristics'from the other layer.

7. In a method of treating partially polymerized vegetable and marine oils containing polymers of unsaturated constituents, the steps of: mixing a given volume of such partially polymerized oil with more than four volumes of an organic solvent from the group consisting oi ketones and higher memos alcohols, permitting the mixture. to stratify met "two layers, each comprising a solution oi oily constituents and solvent, separating solvent from each of said layers, recovering a liquid .oil con= taining polymerized constituents and having enhanced drying properties from one layer, and recovering a liquid oil having non-drying charac-= teristics from the other layer.

8. A method of treating fish oils comprising: subjecting fish oil to a partial polymerizing treatment virtually insuiiicient to form solid gels, the partially polymerized 011 being capable of errhibiting a drop in iodine value upon further heatbodying; mixing said partially polymerized fish oil with not less than three volumes of an organic solvent from the group of ketones and higher alcohols; separating the mixture gravimetrically into two layers of solution of oil and solvent, separating organic solvents from each of said layers separately, recovering a liquid oil having enhanced drying properties from one layer, and recovering a liquid oil having non-drying charac teristics from the other layer OTHO M. BEER.