US2116125A - Method of producing oil-soluble phthalic acid, polybasic aliphatic acid resin - Google Patents

Description

Patented May 3, 1938 UNITED STATES METHOD OF PRODUCING OIL-SOLUBLE PHTHALIC ACID, POLYBASIO ALIPHATIC ACID RESIN Israel Bosenblum, New York, N. Y.

No Drawing. Application June 7, 1935, Serial No. 25,378

acid, one or more of the high molecular weight fatty acids obtainable by hydrolysis of a fatty triglyceride, particularly the fatty oils and fats, and a polybasic aliphatic acid or acids, particularly the more common and less expensive succinic, malic, and fumaric acids in such proportions and undersuch conditions that fusible, oilsoluble resinous mixed esters of the polyhydric alcohol are obtained. s

I have found that by incorporating the polybasic acid in a fatty triglyceride acid-modified glycerol phthalate resin, valuable and unexpected advantages are secured. Thus, by chemically combining succinic acid in a glycerol-phthalic acid-fatty acid resin a product is obtained which has an unusual degree of flexibility combined with satisfactory adhesion, color retention and water and weather-resistance.

As pointed out in my copending application, Ser. No. 702,366 (Patent No. 2,004,880) although reference is frequently made in the patent literature to the effect that maleic acid can be substituted for phthalic acid in the production of a fatty oil acid modified alkyd resin, I have found that this is not at all the case. Attempts by me and by others to my knowledge to replace the phthalic acid with maleic acid, that is, by reacting glycerol, maleic acid, and the acids of a fatty oil, have invariably resulted in the formation of two or more non-compatible materials, one of which appears to be the condensate of the glycerol and the maleic acid, and further heating, no matter how carefully, in the attempt to secure a homogeneous product resulted finally only in the charring of the lower layer.

As set forth in the above mentioned patent, maleic acid is not the equivalent of phthalic acid when the reaction involves the presence also of the acids of a fatty oil or fat; and that in a reaction involving the simultaneous heating of glycerol, maleic acid and fatty oil acids (the lastnamed' acids being present in an amount sufficient to make the product oil-soluble), such an amount of phthalic acid must likewise be present, that the molecular proportion of maleic to phthalic acid is no more than approximately 1: 1. Any con-.

siderably greater proportion of maleic acid will result in the formation of a non-homogeneous, useless mixture. Thus, while maleic and phthalic acids are full equivalents in the binary reaction system composed of glycerol and phthalic acid (which yields a resin insoluble in fatty oils), they are not fullequivalents in the ternary system glycerol-phthalic acid-fatty oil acid which yields an oil-soluble resin.

I have found that succinic, niche and fumaric acids likewise are not the equivalent of phthalic acid in a reaction system involving glycerol,

phthalic acid and fatty oil acids and that, as in the case of maleic acid, the maximmn molecular proportion of, for example, succinic to phthalic acid is approximately 1: 1. This limiting proportion applies not only when all of the reacting materials are heated simultaneously from the beginning, but also when the glycerol is first heated with one or both of the polybasic acids, and subsequently with the fatty oil acids, or is first partially reacted with the fatty oil acids and one of the polybasic acids and subsequently reacted with the other polybasic acid. Where, however, the glycerol is heated with a polybasic acid in the absence of the fatty oil acid, the reaction must not be permitted to go to completion; and the fatty oil acids must be added while the condensate of the glycerol and the polybasic acids is still plastic. In such case, of course, there are still free glycerol and polybasic acid present when the fatty oil acids are added, so that when the mixture is now heated, a reaction occurs between all of the materials simultaneously. This multi-step reaction applies not only to succinic, malic and fumaric acids, but also to maleic acid. In other words, where the glycerol is first heated with, for example, the phthalic and polybasic aliphatic acids, or with the phthalic acid alone, or with the polybasic aliphatic acid alone, followed by the addition of-the other constituents, the initial reaction must be of an incomplete character so that when the last step of the process is conducted, free glycerol, phthalic acid, polybasic aliphatic acid and fatty oil acids are present simultaneously. These seemingly multi-stage processes are thus in fact only single stage processes, or at most only partially multi-stage, and are accordingly to be regarded as equivalent to the true single-stage reaction.

As described in my patent referred to above the use of maleic acid in conjunction with phthalic acid yields a material of especially pale color, good color retention and body, the desired viscosity being obtained in a very much shorter period of time than in the absence of the maleic acid. I have found that by using maleic acid simultaneously with succinic acid, the advantages of the maleic acid are combined with those of succinic acid, namely, a high degree of flexibility.

The present application is a continuation in part of my copending application, Ser. No. 506,298,"-filed Jan. 2, 1931, which has issuedas Patent No. 2,081,154, dated .May 25, 1937.

The invention will be further described in greater detail with the aid of the following examples which show by way of illustration several methods of carrying out the invention.

Example 1 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride 1 148 Succinic anhydride 0.15 15 Glycerol 1.25 115 This mixture, in which the succinic anhydride is about 10% by weight of the phthalic anhydride and about 9% of excess glycerol over the equivalent proportion theoretically required for complete neutralization is employed, is heated gradually to about 230 C. and kept at that temperature until the desired low acid number and the desired viscosity are obtained. The material is a clear plastic, soluble in all common varnish solvents, and the solutions are miscible with varnish oils, varnishes and resin solutions. The solutions of the plastic can be used by themselves or mixture with others as coatings and as vehicles for enamels, paints, etc. The coatings are pale, durable and of remarkable flexibility, elasticity and adhesion. They can be used for air-drying as well as baking finishes. The operation is carried out preferably in a neutral atmosphere.

Example 2 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride '74 Succinic anhydride 50 Glycerol 1.1 101 Example 3 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride /2 74 Succinic anhydride 25 Maleic anhydride A; 24 Glycerol 1.1 101 The operation is conducted as in Example No. 1. The reaction proceeds rapidly and is completed in considerably shorter time than in Example 1. A resin of the same commercial viscosity and low acid number is obtained, giving in solution very hard and elastic coatings of outstanding paleness.

Example 4 Mols Grams Linoleic fatty acid 1 280 Phthalic anhydride 0.5 74 Succinic anhydride 0.15 15 Glycerine 1.3 120 are heated gradually to about 200 C. for a short time until a uniform system without layers is obtained. There are then added:

Mols Grams Phthalic anhydride 0.5 74 Maleic anhydride 0.082 8 and the reaction continued at about 280 C. until a uniform, resinous product is obtained. In

this example the succinic anhydride is about 10% by weight of the phthalic anhydride and the maleic anhydride is 5%. The operation is performed in two steps, leading in the end to a resin of the same general characteristics as in Example 3.

Example 5 When it is attempted to produce the oil acid modified oil-soluble alkyd resin, containing d1- basic aliphatic acid, in two steps, by first reacting the glycerol with the dibasic acids until a resinous intermediate product is obtained, followed by heating with the oil acid, a non-homogeneous useless product will be obtained unless, in accordance with the present invention, the amount of dibasic aliphatic acid is kept low. Where the molecular proportion of dibasic aliphatic acid to phthalic acid is approximately 1:1, the glycerol must not be heated with the dibasic acids to the point where a resinous condensate is obtained but may be heated to only a very limited extent; in fact, to only so small a degree that most of the glycerine and the acids are free when the fatty oil acids are added so that in effect the process really involves a single step. Thus when the following mixture Mols Grams Phthalic anhydride 0.5 74 Succinic anhydride 0.5 50 Glycerol 1.1 101 is heated prior to the addition of the fatty oil acid, great precautions must be taken to avoid any considerable degree of reaction.

The heating may be conducted to the point where the mixture is uniform and gives a clear mass when placed on glass. Thus the 'mixture may be quickly heated to about 140 C. and there are then immediately added 280 grams (1 mol.) of linoleic (linseed oil) fatty acids. The heating may now be continued with stirring to about 230 C. until a uniform, one phase system is obtained. The heating is continued until the desired viscosity is secured. A product similar tothat of Example 2' is obtained.

Ezcample 6 The use of relatively small amounts of succinic acid or of a mixture of succinic and maleic acids, say 3 to 10% of the weight of the phthalic, will usually be found to give markedly improved results, as will be found by the following experiment.

Mols Grams Linoleic fatty acids 1.1 308 Phthalic acid 1.8 300 Succinic acid 0.13 Glycerol 3.3 300 are heated to 190 C. and kept at this temperature for about one half hour. The temperature is then gradually raised to about 230 C. and maintained there until a sample removed from the reaction mass is found to be soluble in toluol in substantially all proportions, as well as in fatty acids obtainableupon hydrolysis of drying and non-drying oils. There is thus obtained a resinous material which is characterized particularly by baking pale when used with white coloring matter and by extraordinary adhesiveness upon smooth metallic surfaces, including tin surfaces.

The following two examples illustrate the effect of employing substantially more than 1 mol.

of the dibasic aliphatic acid to each mol. of

phthalic acid.

Example 7 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride $4; 49 succinic anhydride 67 Glycerol 1.1 101 On heating, two layers. form which persist even when the temperature of about 240 C. is reached and the material, is constantly stirred. Finally, without forming a clear, uniform sys-, tem, flocculent matter begins to form and a solid layer of gel forms on the bottom of the flask. This experiment shows that when the molecular proportion of succinic acid to phthalic acid is substantially greater than 1:1, a homogeneous system cannot be obtained if enough fatty oil acids are employed to make the product oil soluble when the dibasic acid is all phthalic acid,

Example 8 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride M; 37 succinic anhydride A 75 Glycero1 1.1 101 The ratio of succinic anhydride to phthalic anhydride is 3 mols to 1 mol. I The same behavior is observed as in Example 7, the two layers again persisting to the very end, except that the lower layergels even sooner and the gel is more pronounced.

The resinous products obtained as hereinabove described in Examples 1 to 6 are readily soluble in coal tar solvents and in mixtures of coal tar solvents and petroleum distillates, such as mineral spirits, at least up to the proportions of solvent which yield commercial solutions.

In any of the above examples, malic and fumaric acids may be substituted for the succinic acid; succinic acid, or a mixture of succinic and maleic acids, is however at present referred by me..

The high molecular weight fatty acids may be those obtained from drying, semi-drying and non-drying oils, such as linseed, China-wood,

soya bean,iperilla, sunflower, menhaden, cottonseed, castor, olive and other oils, and from fats.

I claim:

1. The method ofproducing in a single step a homogeneous, fusible resin soluble in fatty oils which comprises reacting simultaneously glycerol and a plurality of acids consisting essentially of phthalic acid, succinic acid in a substantial amount up to approximately 1 mol. for every mol. of phthalic acid, and an amount of acids obtainable on hydrolysis of a fatty triglyceride sufficient to make the product oil-soluble.

2. The method of producing in a single step a homogeneous, fusible resin soluble in fatty oils which comprises reacting simultaneously glycerol and a plurality of acids consisting essentially of phthalic acid, succinic acid in a substantial amount up, to approximately 1 mol. for every moi. of phthalic acid, and an amount of soya bean oil acids sufliclent to make the product oil-soluble.

3. The method of producing in a single step a homogeneous, fusible resin soluble in fatty oils having incorporated therein a polybasic aliphatic acid, which comprises reacting simultaneously glycerol with a plurality of non-resinous acids consisting essentially of phthalic acid, a mixture of maleic and succinic acids in a substantial amount up to approximately 1 mol. of both such acids for every mol. of phthalic'acid and an amount of acids obtained on hydrolysis of a fatty tri-glyceride suilicient to make the product oilsoluble.

4. The method of producing in a single step a homogeneous fusible resin soluble in fatty oils and having incorporated therein a polybasic allphatic acid which comprises reacting simultaneously glycerol with a'plurality of non-resinous acids consisting essentially of phthalic acid, a mixture of maleic and succinic acids comprising about 3 to 10% by weight of the phthalic acid, and an amount of acids obtained on hydrolysis of a fatty tri-glyceride suflicient to make the product oil-soluble.

5. The method of producing in a single step a homogeneous fusible resin soluble in fatty oils and having incorporated therein a polybasic aliphatic acid which comprises reacting simultaneously glycerol with a. plurality of non-resinous acids consisting essentially of phthalic acid, a mixture of maleic and succinic acids comprising about 3 to 10% by weight of the phthalic acid,

, and an amount of acids obtained on hydrolysis of a drying fatty oil suflicient to make the product oil-soluble.

6. The method of producing in a single step a homogeneous fusible resin soluble in fatty oils and having incorporated therein a polybasic aliphatic ,acid which comprises reacting simultaneously glycerol with a plurality of non-resinous acids consisting essentially of phthalic acid, and succinic acid in an amount comprising about 8 to 10% by weight of the phthallc acid, and an amount of acids obtained on hydrolysis of a fatty tri-glyceride sufficient to make the product oilsoluble.

7. The method as set forth in claim 1 wherein the glycerol and fatty triglyceride acids are present in approximately equimolecular proportions, the succinic acid being employed in an amount ranging from approximately 0.15 to 1 mol. for each moi. of phthalic acid, and the amount of glycerol being substantially equivalent to the total amount of acids.

ISRAEL ROSENBLUM.