US2192152A - Licanic acid resin and process of making - Google Patents

Description

s PATENT orrlcs I LICANIC ACID RESIN AND PROCESS OF MAKING Alfred E. Bheineck and mammnabm, Louisville, 1a., assiznors to Devoe & Baynolds 00.,

Inc., a corporation of New York No Drawing. I Application December 30, 1938,

Serial No. 248,514

8 Claims.

This invention relates to resinous licanic acid compositions and more particularly to the resin obtained by decomposition of 1 licanic acid, and modified products of such resin. This applica- 5 tion is a continuation in part of our application Serial No. 70,612 filed March '24, 1936, and contains subject matter derived from our application Serial No. 63,862 filed February 14, 1936.

The resin composition of this invention may 10 be prepared -from licanic acid itself or from a mixture of licanic acid with the other fatty acids that occur in oiticica oil and poyoak oil. The production of the resin is obtained by decomposing the licanic acid by proper heat treatment of 15 that acid or fatty acid mixtures containing licanic acid under-conditions that facilitate the splitting-01f the elements of water from the licanic acid molecule with progressive decomposition of the acid into a resin. This resin is useful. in

20 coating compositions and serves especially as a substitute for shellac. This resin may be modified by treatment with maleic anhydride and the resulting product may be esterified to produce valuable modified products of the licanic acid resin;

25 bond structure has been retained although the acid has been decomposed.

Prior workers in the fatty acids field have proposed thickening, bodying or gelling of the fatty acids of various drying and semi-drying oil's, the sole purpose being to produce an improved stand oil. The product is a viscous liquid oil having substantial body but definitely is not a resin and doesnot possess the solidity, hardness, and frac- 35 ture characteristics that distinguish the resins from the bodied oils.

In the prior processes the oils or fatty acids thereof are subjected to treating conditions con:- ducive to increasing the body or viscosity of the 40 oil but in all cases the treatingconditions are controlled to prevent decomposition of the oil. Therefore, the fatty acids do not decompose but simply polymerize and thereby efiect an increase in viscosity. In a typical process the oil or fatty 45 acids are distilled to remove the unpolymerlzable constituents and the distillation is carried out in the presence of a non-oxidizing gas such as for example under an atmosphere of carbon dioxide. The still residue is a thickened liquid 50 known as stand oil.- It has no fracture characteristic, it is not a solid at room temperatures and P ysical or does not possess any of the other chemical characteristics of the resins.

' Our present invention is based upon the dis-' 55 covery that licanic acid when treated under proper decomposing "conditions will decompose into a'resinous product that is a solid at normai,*atmospheric temperatures and has a fracture and hardness cha'racteristic that definitely o identifies itas a resin.. -Am0n g the numerous which is evidence that the conjugated double fatty acids of drying and semi-drying oils, we have found by our exhaustive tests that the fatty acids of only two of these oils are suitable as starting materials for the production of our new resin, and they are the fatty acids of oiticica oil and poyoak oil. It appears that both of these oils contain licanic acid or a like acid having a ketone group in'the fatty acid molecule; This licanic or ketone group acid may be isolated from the other fatty acids in the oiticica or poyoak oil before being decomposedint'o the desired resin product; or a mixture of thisacid with the other associated acids in oiticica or poyoak oil may be used in our process, but it is only the ketone type acid that decomposes and resinifies.

The resin obtained by decomposition of the licanic acid alone is harder and accordingly more desirable for a number of uses than the resin obtained by decomposition of the mixture of I icanic acid with the other fatty acids in oiticica and poyoak oils. The resinified product derived from the mixed acids is somewhat softer and more wax-like because of the presence of nonresinifying components.

Our numerous tests show that with the exception of the oiticica and poyoak oil acids, the fatty acids of the drying and semi-drying oils do not resinify upon heating and therefore do not form the resin products of our invention. The characterizing constituent of the oiticica and poyoak oils, namely the licanic acid with a ketone group, is an essential to our decomposition and resinifying process in which water is produced by combination of certain of the hydrogen and oxygen atomsin the acid molecule. When the water is split-off a rearrangement of the molecule takes place which is totally diiferent from the ordinary dehydration of a fatty acid. This decomposition reaction, which forms a resin, may be illustrated empirically as follows: a

lustrated by the above formulas is the result of an actual decomposition with evolution of water from the licanic acid molecule. We believe it likely that the ketone group undergoes a condensation with the carboxyl group of the acid as of water. Thus, if licanic acid is heated in an open vessel, it begins to lose water at about 200 C. and eventually decreases in acid'value and becomes very viscous, approaching a solid state or substantially resinifying. The speed with which this decomposition takes place is dependent upon the temperature. Thus while the effect begins at about 200 C. it is much more apparent at temperatures somewhat higher than this and, for direct heating, temperatures of between 240 C. and 300 C. and preferably between about 240 C. and 270 C. can be used. The top limit given is merely a practical one 'and is not critical to the reaction, the actual limit being a temperature at which the acid is materially darkened or otherwise injured.

The direct heating may take place either in vacuum (such as a vacuum of between about 1 mm. and 4 mm. of mercury) or in an open kettle and preferably is accompanied by entle agitation to facilitate removal of the water.

A preferred method of accomplishing the decomposition reaction is by dissolving the licanic acid in a solvent having a boiling point somewhat above 200 C. and then boiling the mixture under such conditions that the solvent is refluxed back to the boiling mass after separation of the evolved water. Under these solvent conditions, decomposition of the resin is facilitated. In such case a somewhat lower temperature is suflicient, as for example, temperatures in the order of about 225 C. to 275 0., though higher temperatures may also be used in this connection.

'usually soluble in mineral spirits or other petro- Various organic solvents of types now on the market are available about the only require= ment being that the solvent shall be substantially inert to the acid and so have a boiling range between about 200 C. and 300 C. A product which has been found excellent for this purpose is a product now on the market and widely known under the name of Hydrosolvent #4-a hydrocarbon which has a. boiling range of between about 215 C. and 238 C.

When licanic acid is thus heated under decomposing conditions'until the'evolution of water has ceased, it will be found that the acid has changed in many respects. Its acid number is greatly reduced (e. g. in one case from 175 to about 101) and on cooling it will set to a solid mass with a characteristic fracture and pleasant odor. This resinous mass is thermoplastic, being readily' softened with heat, is soluble at normal temperatures in the usual ketone, ester, aromatic hydrocarbon solvents and in blown oils, such as blown linseed oil, but is substantially insoluble in cold 7 aliphatic hydrocarbons and raw oils. Thus it is clearly distinguishable from the viscous products which result from heating the usual drying oil and semi-drying oil fatty acids. The latter are leum hydrocarbons.

The invention may be readily understood from the following example:

Oiticica oil fatty acids were separated from the oiticica oil by one of the methods commonly known in the art. The separated fatty acids were dissolved in a 50% solution in an aliphatic hydrocarbon solvent having a boiling range between 50 C. and C. (e. g.'hexane). The solution was then chilled down to a temperature of about 0 C. which caused the material which is here called licanic acid to separate out as a wax-like white solid. It was found that this acid was very susceptible to atmospheric oxidation so that either the separated acid or even the mixed raw acids were dlfllcult to store. The acids prepared by saponiflcation of the oil with alkali are usually light in color and when used promptly after preparation yield a light colored product, whereas the acids which are available commercially are longer was being condensed in the reflux apparatus. This usually requires about three hours.

It was found that about 100 parts of acid having an acid number of 176 evolved about 5.4 parts of water. Thisis simply an observation made and is not intended in any way as a limitation, as

experience may show that this figure is subject to substantial modification.

After the evolution of water was completed, the solution was allowed to cool downand the'resin was more completely precipitated by adding an excess of methanol. After removal of the solvent this resin product had an acid number of 93, was a hard solid at room temperatures and had a fracture characteristic of the resins.

Further modification of the licanic acid or licanic acid resin may be obtained by treating with maleic anhydride and the reaction product esterifled. These treatments may be carried out in open vessels or in a closed system with solvents or'combinations thereof. The maleic anhydride reaction may be effected by treatment of the licanic acid either before or after its decomposition into a resin. Whichever prop-l cedure is used the-resulting product may then be esterified with giycerine or glycerides. If the treatment is carried out before decomposition, that is, upon the normal licanic acid, the resulting product is then subjected to decomposition and resinification in a manner similar to that described 'hereinabove. Inaccordance with one illustrative embodiment the licanic acid may be dissolved in an aliphatic hydrocarbon, then the maleic anhydride added and the solution heated until considerable frothing takes place which indicates the reaction between the licanic acid and the maleic anhydride. The resulting product may then be heated, substantially as above described, under vacuum to effect resiniiication. The product so prepared is a solid atroom temperature and in one instance possessed an acid value of about 204 as compared with an acid value of 272 of the addition product of licanic acid and maleic anhydride prior to resiniflcation.

The product resulting from esterifying with glycerol the resinifled licanic acid-maleic anhydride reaction product (whether the reaction with the maleic anhydride is conducted before or after resiniflcation of the-licanic acid) is a resinous body which is definitely a solid at normal room temperature so that it has a characteristic fracture, and in this regard it definitely distinguishes from the usual product obtained by the reaction of maleic anhydrlde and a drying oil. which is 20 ing vigorously at about 225 C. until water no I characteristically soft or balsam-like. It should be noted that the resinificatio'n of the licanic acid is a distinct step from tl iesterification, and this resiniflcation can take place only prior to esterification, though/such resinification may take place either before or after the maleic anhydride addition. In other words, the resinified glyceride of this invention cannot be produced by any steps aimed to accomplish resiniflcation after esteriflcation.

. It is to be understood that the foregoing examples are given only byway of illustration and ill] may be modified and changed in many particulars without departing from the spirit of our invention.

What we claim is:

l. A resinous body consisting essentially of the product resulting from decomposing licanic acid by heating said acid to between about 200 C. and 300? C.-until the evolution of water substantial: ly ceases and the'acid is decomposed into a resin.

2. A resin product normally solid at atmospheric temperatures and having a definite resin fracture characteristic, comprising .a residue of heat treated fatty acids containing decomposed and resinified licanic acid, said fatty acids being those acids which occur in drying oils of the group consisting of oiticica and poyoak oils.

3. A process of preparing resinous licanic acid comprising decomposing licanic acid by heating said acid under decomposing conditions and with the evolution of a resinous product, which is solid at atmospheric temperatures and which has a definite fracture characteristic of resins, is produced.

4. A process for preparing a resin product as defined in claim 3 in whichthe licanic acid is mixed with the other fatty acids normally occurring in a drying oil selected from the group consisting of oiticica oil and poyoalr oil.

5. A process of preparing licanic acid resin comprising decomposing licanic acid by dissolving said acid in an organic solvent having a boiling point of at leastabout 200 C. and heating the licanic acid solution so as to continuously distill .oil the solvent and water until further evolufracture characteristic comprising -decomposed resinified ketone group fatty acid of oiticica oil.

ALFRED E. RHEDIECK. BENJAMIN RABBI.