US2480485A - Process for making bodied odls - Google Patents

Description

Patented Aug. 30, 1949 PROCESS FOR MAKING nonmn olLs Willy Langc, Cincinnati, and Robert G. Folzenlogen, Golf Manor, Ohio, assignors to The Procter & Gamble Company, Cincinnati, Ohio, a

corporation of Ohio No Drawing. Application January 27, 1945,

Serial No. 574,978 r 9 Claims. (Cl. 260407) This invention relates to improved bodied oils and to processes for producing th same.

The use of boron trifluoride as a catalyst in the bodyin of unsaturated fatty oils is known. In the course of our work in this field we have noted that when unsaturated fatty oils containing a proportion of combined saturated fatty acid are bodied in the presence of this catalyst, the bodied product may after storage separate a small quantity of crystallized glycerides of more or less saturated nature. These same bodied oils tend to develop polymer clouds in clear film products prepared therefrom.

Also we have noted that bodying processes involving the use of boron trifluoride as catalyst result in the production of bodied oils which have a dark red-brown color that cannot be reduced substantially by the usual methods of water or aqueous lye washing. Dark bodied oils have obvious disadvantages in some industries, such as for example some phases of the paint industry. Consequently there tends to be some limitation in use, which could be eliminated by the employment of an economical process which effects substantial color reduction.

We have discovered that by heating the unsaturated fatty oil for a short time at a substantially elevated temperature as more fully hereinafter described, before or after bodying in the presence of boron trifluoride, both of the above disadvantages, apparently characteristic of boron trifluoride bodied oils, are overcome.

This heating process apparently effects (1) a molecular rearrangement and distribution of saturated fatt acid radicals so that the content of substantially completely saturated constituents is reduced to an amount completely soluble in the bodied product whereby crystallization during storage is avoided, and (2) (when heattreatment precedes bodying) an inactivation of the substances which react with the boron trifluoride to form color imparting substances, or. (when heat treatment follows bodying) a thermal decomposition of the coloring substances themselves.

The rearrangement of fatty acid radicals in fatty materials efiected by high temperature treatment is known and explanatory comment appears unnecessary.

With regard to thedark colors encountered in bodying unsaturated oils in the presence of boron trifluoride, however, there is little known and we wish to offer the following explanation of our views, it being understood that any such theory or explanation is herein presented merely to assist in the complete understanding of the invention and that it is not to be considered as a limitation in any way. v

Certain groups of organic substances show halochromism, the property of forming colored salt-like products with strong inorganic acids or Friedel-Crafts halides including boron trifluoride, stannic tetrachloride, perchloric acid of a high concentration, etc. Such halochromic salts are readily decomposed by water with complete'elimination of the color, provided the water treat ment is conducted before the halochromic compounds can enter into secondary reactions, which are of an unknown nature as far as we are aware, but which result in the formation of colored compounds which do not lose their color completely upon treatment with water. This formation of more permanent color may become appreciable during a period such as that required for the bodying of unsaturated oil.

In the present instance we believe, that the boron trifluoride unites with sterols, and with the minute quantities of oxidized sterol present in all oils, to form such halochromic salts, and that the salts of the oxidized sterols in secondary reactions during the bodying process form colored compounds which are stable toward treatment with water. The halochromic salts of the unoxidized sterols apparently contribute but little to the more permanent color stable toward water.

Heating the unsaturated fatty oil at a temperature in excess of 250 C. for a short period of time with exclusion of air apparently renders the oxidized sterols non-reactive with the boron trifiuoride and other halochromic salt forming inorganic compounds, probably due to a thermal breakdown of the oxidized molecules, because such heating step avoids a substantial color formation during the bodying process in the presence of boron trifluoride. Furthermore, the application of a short-time heating treatment to dark bodied oils, after the boron trifluoride has been removed, apparently decomposes the colored compounds formed in secondary reactions of the halochromic salts from oxidized sterols with accompanying marked reduction in color of the oil.

We have noted in connection with this color formation that new sterol oxidation products are apparently formed when boron trifluoride bodied oils, which have been heat treated in accordance with the present process, are again exposed to air at lower temperatures, for example at C., for a short time, and that these newly formed sterol oxidation products can react with boron trifluoride and ultimately form dark colored com- 3 pounds just as do the oxidized sterols in the original oil.

The heating of either the unsaturated fatty oil or the bodied oil in accordance with the present invention should be carried out for such a short period of time that no significant drop in iodine less, it is then subjected to a water wash to invalue occurs. We have found that one of the outstanding advantages of .bodying at low temperature in the presence of boron trifluoride, insofar as the drying oil industry is concerned, lies in the relatively higher drying rate possessed by the bodied oil and that this advantage may be rendered non-existent by prolonged treatment at elevated temperature. Heating for a few minutes, such as for 3 to minutes. at a temperature of 300 C. is usually sufficient to obtain light colored products which do not precipitate crystalline material or form polymer clouds, but longer times, such as 30 minutes, are sometimes necessary, especially when working with oils which have been previously bodied in the pres-,

er. .e of boron trifluoride, and such conditions can be employed without seriously affecting the drying properties of the oil. When temperatures below 300 C. and above 250 C. are employed in the practice of the present invention, a longer heating time, even as much as 60 minutes, may temperature from about 90 C. to about 120 C., shorter times are preferable.

In that embodiment of the present invention wherein the unsaturated fatty oil is heat treated at high temperature with exclusion of air prior to bodying in the presence of boron trifluoride, the refined oil may be heated to 275 C. to 350 C. for a short period, cooled to temperatures below 50 C., and then bodied with the aid of the boron trifluoride catalyst.

The manner in which the actual step of bodying in the presence of the boron trifiuoride is conducted is not a limitation of our invention and any suitable process may be employed. However, we have found it advantageous to employ an improved process involving flrst the introduction into the oil, from which water has been substantially removed, of boron trifluoride gas diluted with a gas inert to the boron trifluoride and to the 011 being processed, such as nitrogen or carbon dioxide. The introduction of the mixture of boron trifluoride and inert gas is continued until the desired amount of the catalytic boron trifluoride has been absorbed by the oil. The solution of oil and catalyst is then heated at a relatively low temperature to effect bodying. When the process is applied in the production of oils for use in the drying oil industries, for example for use in paints and varnishes, it is preferable (1) to dilute the boron trifiuoride gas to a concentration from about 10 per cent to about 60 per cent before introduction into the oil, (2) to permit the absorption of from-about 0.1 per cent to about 2 per cent boron trifluoride by the oil, and (3) to heat the oil and catalyst to a temperature from about 90 C. to about 120 C. preferably 100 C., in a closed container in the absence of air and moisture until the desired degree of bodying (or increase in viscosity) is obtained.

After the oil has been bodied to the desired viscosity, the reaction may be terminated by inactivating the catalyst by the introduction of water, preferably in the form of steain, or by physically removing the catalyst by blowing the hot oil with an inert gas such as nitrogen. After the oil has been cooled to a temperature such as 60 C. or

sure complete inactivation of the catalyst. A lye wash may alsobe employed if desired in order to reduce the acid value of the bodied 011.

As above stated, the order in which the bodying and heat treatment steps herein described are practiced is not a limitation of the invention. If it is desired to body the oil first and then effect the improvements above referred to by the application of heat to the bodied oil, the operation may be conducted as follows.

After the desired viscosity of the oil has been attained in the boron trifluoride bodying process, the catalyst may be removed to a large extent by blowing the hot oil with an inert gas such as nitrogen. Any residual catalyst in the oil is then inactivated by the introduction of steam or by washing of the oil with water or dilute aqueous lye. The bodied oil thus freed from catalyst may then be heat treated to the high temperature necessary to eiiect reduction in color without significantly changing the viscosity or the iodine value of the bodied oil. It should be borne in mind at all times in this connection that heating the oil at high temperature such as 300 C. is eiiective in bringing about further bodying of the oil and in reducing the iodine value thereof, and that there are attendant disadvantages as pointed out above. If the high temperature treatment is prolonged, the resulting oil will have analytical and drying properties characteristic of an ordinary heat bodied oil and will not possess the advantages of an oil processed at low temperature in the presence of boron trifluoride.

The following examples will illustrate the manner in which our invention may be practiced and the advantages to be gained thereby but it is to be understood that the invention is not limited to the specific conditions recited therein.

Example 1.-Refined and bleachedlinseed oil having the following characteristics was employed in this example:

A sample of the above linseed oil was heated in the absence of air under nitrogen gas agitation for 6 minutes at 300 C. The resulting product was then cooled to 30 C. and into same was introduced a. gas mixture consisting of 50% boron trifluoride and 50% dry nitrogen by volume at about room temperature until 1.36% by weight of boron trifiuoride had been absorbed by the oil. This mixture of oil and catalyst was then heated for 2 hours at 0., after which the catalyst was inactivated and removed by washing the oil with water.

The resulting product did not precipitate glyceride crystals after standing at room temperature for several weeks. It had the following additional characteristics:

Acid value 2.7 Saponification value 189.0 Iodine value 158.5 Viscosity at 25 C. ..poises 13.4 Lovibond color ..red (1" column) 6.0

If the linseed oil above employed is not heat treated before bodying to substantially the same viscosity as described in the above example, a product is obtained which has a Lovibond color of about 70 yellow and 20 red (1" column) and which does precipitate glyceride crystals after storage at ordinary temperatures for several months.

The drying time of the product resulting from the above example was substantially the same as the drying time of a sample of th same linseed oil bodied in the presence of boron trifluoride without the preheating step.

Example 2.A portion of the refined and bleached linseed oil used in Example 1 was dried by blowing with steam under vacuum. Into a sample of the dried oil was introduced at room temperature a gas mixture consisting of 45% boron trifluoride and 55% dry nitrogen by volume. The introduction of the mixture of gases was continued until 0.82% by weight of boron trifluoride had been absorbed. This mixture of linseed oil and catalyst was then heated at 100 C. for 4 hours, after which the catalyst was inactivated and removed by washing the oil with water. The bodied oil had a Lovibond color of about 17.5 red (1" column) and had the following additional characteristics:

Acid value 1.59 Saponification value 190.0 Iodine value 163.0 Viscosity at 25 C. poises 9.48

The above bodied oil was then heated, under nitrogen, to 300 C. and held at that temperature for /2 hour. The resulting oil had the following characteristics This oil did not separate glyceride crystals during storage at ordinary temperature, whereas in the case of a sample which was bodied to about the same viscosity but which had not been subsequently rearranged at high temperature some crystallization was noted after several months.

The present invention is applicable to fatty oils of the drying oil class including tung, oiticica, linseed, perilla, sunflower seed, soybean, and others, as well as to oils of the semi-drying class such as cottonseed and rapeseed oils and a mixture of same. These oils are generally referred to here and in the claims as unsaturated fatty oils, and the term is understood as being so limited.

Having thus described our invention, what we claim anddesire to secure by Letters Patent is:

1. The process of producing a boron trifluoride bodied oil, characterized by rapid drying rate, improved color and freedom from crystallization at normal room temperature, which comprises heating an unsaturated fatty oil in the absence of a. polymerization catalyst at a temperature from about 250 C. to about 350 C. for a brief period to efiect rearrangement of fatty acid radicals in said oil and to inactivate substances in the oil reactive with boron trifluoride to form salts which in secondary reactions yield water-stable compounds with pigmentary value, without effecting substantial heat bodying and substantial reduction in the iodine value of the oil, and thereafter bodying the heat treated oil at lower temperature in the presence of a small amount of boron trifluoride until the desired degree of bodying is attained.

2. The process of producing a boron trifluoride bodied oil, characterized by rapid drying rate, im-

proved color and freedom from crystallization at normal room temperature, which comprises heating unsaturated fatty oil in the absence of a polymerization catalyst at a temperature from about 250 C. to about 350 C. for a brief period not substantially exceeding 60 minutes but sufficient to efiect rearrangement of fatty acid radicals and to inactivate substances in the oil reactive with boron trifluoride to form salts which in secondary reactions yield water-stable compounds with pigmentary value, and insuificient to efiect substantial heat bodying and substantial reduction in the iodine value of the oil, and thereafter bodying the heat treated oil at a temperature below 120' C. in the presence of about 0.1 per cent to about 2 per cent by weight of boron trifluoride until the desired degree of bodying is obtained.

3. The process of producing a boron trifluoride bodied oil, characterized by rapid drying rate,

improved color and freedom from crystallization at normal room temperature, which comprises heating unsaturated fatty oil in the absence of a polymerization catalyst at a temperature of about 300 C. for a brief period not substantially greater than 30 minutes but suflicient to efl'ect rearrangement of fatty acid radicals and to inactivate substances in the oil reactive with boron trifluoride to form salts which in secondary reactions yield water-stable compounds with pigmentary value, and insufficient to efiect substantial heat bodying and substantial reduction in the iodine value of the oil, and thereafter bodying the heat treated oil at a temperature below 20 C. in the presence of about 0.1 per cent to about 2 per cent by weight of boron trifluoride until the desired degree of bodying is obtained.

4. The process of producing a boron trifluoride bodied oil, characterized by rapid drying rate, improved color and freedom from crystallization at normal room temperature, which comprises treating unsaturated fatty oil in the presence of a small amount of boron trifluoride to effect substantial bodying of the oil without substantial heat bodying, thereafter inactivating the boron trifluoride and heating the bodied oil at a I temperature from about 250 C. to about 350 C.

for a brief period suflicient to effect rearrangement of fatty acid radicals and to decompose water-stable compounds with pigmentary value formed from salts of boron trifluoride and substances contained in the oil, but insuflicient to effect substantial heat bodying and substantial reduction of the iodine value of the boron trifluoride bodied oil.

5. The process of producing a boron trifluoridev bodied oil, characterized by rapid drying rate, improved color and freedom from crystallization at normal room temperature, from unsaturated fatty oils which comprises treating substantially dry unsaturated fatty oil at a temperature below C. in the presence of about 0.1 to about ;2 per cent by weight of boron trifluoride until the desired degree of bodying is obtained, inactivating the boron trifluoride catalyst and heating the bodied oil at a temperature from about 250 C. to about 350 C. for a brief period sufilcient to efiect rearrangement of fatty acid radicals and to decompose water-stable compounds with pigmentary value formed from salts of boron trifluoride and substances contained in the oil, but insufllcient to effect substantial heat bodying and substantial reduction of the iodine value of the boron trifluoride bodied oil.

6. The process of producing a boron trifluoride bodied ofl, characterized by rapid drying rate,

improved color and freedom from crystallization at normal room temperature, which comprises heating substantially dry unsaturated fatty oil at a temperature of about 90 C. to about 120 C. in the presence of about 0.1 to about 2 per cent by weight of boron trifiuoride until the desired degree of bodying is obtained, inactivating the boron trifiuoride catalyst and thereafter heating the bodied oil at a temperature from about 250 C. to about 350 C. for a period less than 60 minutes sufiicient to eflect rearrangement of fatty acid radicals and to decompose water-stable compounds with pigmentary value formed from salts of boron trifiuoride and substances contained in the oil, but insufficient to effect substantial heat bodying and substantial reduction of the iodine value of the boron trifiuoride bodied oil.

7. The process of producing a boron trifiuoride bodied oil characterized by rapid drying rate, improved color, and freedom from crystallization at normal room temperature, which comprises heating an unsaturated oil in the absence of a polymerization catalyst at a temperature from about 250 C. to about 350 C. for a short time to effect rearrangement of fatty acid radicals in said oil and to inactivate substances in the oil which react with boron trifiuoride to form salts which in secondary reactions yield water-stable compounds with'pigmentary value, without effecting substantial heat bodying and substantial reduction in iodine value of the oil, cooling the heat treated oil to a temperature not substantially higher than 50 C., introducing into the cooled oil a mixture of boron trifiuoride gas and a gas substantially inert to'the boron trifiuoride and to the oil until not substantially more than 2 per cent boron trifiuoride, based on the weight of the oil, has been absorbed, and thereafter, at a temperature insuficiently high to efiect substantial heat bodying, heating the oil in the presence of absorbed boron trifiuoride to "effect the desired degree of bodying.

8 quence, (1) heating unsaturated fatty oil in the 8. A process of producing from unsaturated fatty oil a bodied oil characterized by rapid drying rate, improved color, and freedom from crystallization at normal room temperature, comprising the following steps in indifierent se- Patent No. 2,480,485

presence of a small amount of boron trifiuoride, and (2) heating in the absence 0! a polymerization catalyst at a temperature from about 250 C. to about 350 C. for a short time insufllcient to eflect substantial heat bodying and substantial reduction in iodine value of the oil, but sufllcient to eflect rearrangement of fatty acid radicals, sufllcient to inactivate substances in the oil reactive with boron trifiuoride to form salts which in secondary reactions yield water-stable compounds with plgmentary value, and sufiicient to decompose such water-stable compounds.

9.A process of producing from unsaturated fatty oil a bodied oil characterized by rapid drying rate, improved color, and freedom from crystallization at normal room temperature, comprising the following stepsv in indifiereut sequence, (1) heating unsaturated fatty oil at a temperature from about 90 Cato about 120 C. in the presence of about 0.1 per cent to about 2 per cent by weight of boron trifiuoride, and (2) heating in the absence of a polymerization catalyst at a temperature from about 250 C. to about 350 C. for a short time not substantially exceeding minutes and insuflicient to effect substantial heat bodying and substantial reduction in iodine value of the oil, but sufficient to effect rearrangement of fatty acid radicals, suflicient to inactivate substances in the oil reactive with boron trifiuoride to form salts which in secondary reactions yield Water-stable compounds with pigmentary value, and sufficient to decompose such water-stable compounds.

WILLY LAN GE. ROBERT G. FOLZENLOGEN.

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

UNITED STATES PATENT Number Name Date 2,260,417 VVhitely Oct. 28, 1941 45 2,316,187 Pratt et al Apr. 13, 1943 2,325,040 Cook July 27, 1943 2,367,666 Carleton Jan. 23, 1945 August 30, 1949 WILLY LANGE ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent reqmrmg correction as follows:

Colun n 3, line 28, strike out "temperature from about C. to about C. and insert instead be tolerated, but at temperatures above 300C. I and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice. Signed and sealed this 17th day of January, A. D. 1950.

THOMAS F. MURPHY, 4

Assistant Omnmiasioner of Patents.