US2586496A - Detergent composition and process of preparing same - Google Patents

Description

Patented Feb. 19, 1952 DETERGENT COMPOSITION AND PROCESS OF PREPARING Harland H. Young and Kurt H. Chicago, IlL, assig-uors to Swift Spitzmueller, &- Company,

Chicago, 111., a corporation of Illinois No Drawing, Application March 8, 1947, Serial No. 733,436

4 Claims. 1

The present invention relates to the preparation of an improved detergent product. More particularly, the invention has to do with the preparation of an improved detergent mixture containing the reaction products of an alkylolamine and an acylating substance, and having superior sudsing and detergent properties.

The usual soluble detergent soaps such as the sodium or potassium soaps of fatty acids are known to react with various polyvalent metal salts present in hard water, such as calcium and magnesium salts, to produce insoluble soaps or precipitates which form scum upon the surface of the Water and a ring on the walls of the container. These reactions not only decompose a substantial amount of the detergent soap, thus destroying its useful properties, but also suppress the foaming or production of suds by the remaining detergent soap. Relatively large amounts of soluble soaps still present after reaction with the polyvalent metal salts tend to maintain the'precipitated insoluble soap in suspension, but upon dilution of the soap solution, for example, in

rinsing fabrics, the insoluble soaps deposit upon- Furthermore, rinsing and adhere to the fabrics. of fabrics, impregnated with a soluble soap solution, in hard water causes insoluble soaps to be formed and deposited within the interstices of the fabric frequently along with the absorption or inclusion of dirt.

Since the alkali metal soaps react with hard Water with the attendant disadvantages described above, other detergents, particularly of a nonsoap type, have been developed to overcome the aforesaid disadvantages. tergents are the condensation products of alkylol amines and acylating substances, with which this invention is concerned. These products do not deposit an insoluble soap curd with the consequent precipitation of scum, and retain good sudsing properties, in hard water.

Various methods for the manufacture of condensation products from alkylolamines and acylating substances, and the utility of such prod? ucts as emulsifying, dispersing and Wetting agents, have been pointed out in the Kritchevsky patents, No. 2,089,212, issued August 10, 1937, and the Reissue Patent 21,530 of August 13, 1940.

In general the processes disclosed in the aforesaid patents involve reacting primary, secondary and tertiary alkylolamines with a fatty acid, or a suitable acylating derivative thereof, peratures ranging from about 100 C. to 250 C. for about 2 to 4 hours. The molar ratios of alkylolamine and fatty acid may be stoichio- Examples of such de-;

at temmetric or may range from an excess of one reactant to an excess of the other reactant. A wide range of acylating materials having 2 to 35 carbon atoms in the molecule are disclosed as suitable, for example, aromatic and aliphatic acids, cyclic and heterocyclic acids, and various derivatives thereof. naturally occurring animal and vegetable fats and oils are preferred.

The processes for condensing alkylolamines with carboxylic acids described in the above patents result in reaction products having relatively large amounts of multiacylated derivatives of the particular alkylolamine employed, that is, the alkylolamine diacid' ester, the alkylolamide monoacid ester, and the alkylolamide diac-id ester.

In copending application Serial No. 504,297, filed September 29, 1943, now Patent No. 2,429,445 which issued October 21, 1947, it is disclosed that the monoacylated derivatives of the alkylolamines having a single replaceable hydrogen of the alkylolamine replaced with an acyl group, that is, the a'lkylolamide and alkylolamine monoacid ester, have advantages for certain purposes over the multiacylated derivatives. The manufacture of the improved monoacylated products is effected by atwc-stage process involving first, theacylat-ionof the alkylo'lam-ine-at sufficiently high temperatures and for a sufficient time to cause substantial acylation of the alkylola-mine,

and second, aging the resulting mixture of compounds in the presence of excess alkylolamine at a lower temperature to shift the reaction mixture equilibrium and convert the multiacylated derivatives into the monoaeylated compounds.

It has also been discovered that an improved detergent is obtained when the reaction products include a mixture of the alkylolamide and the alkylolamine monoacid ester. For this reason, only primary and secondary alkylolami-nes are employed, since the tertiary alkylolamines do not contain an amino hydrogen and therefore cannot yield the amide compound but only the ester. Moreover, best results are obtained when the acylating substance contains 8 to '14 carbon atoms in the molecule, for example, coconut oil fatty acids.

In preparing the monoacylated alkylolamine I compounds by the two-stage process the initial acylation reaction is effected at a temperature I-Iowever, acids derived from ployed. Where a volatile material, such as water is split out as a result of the reaction, the initial heating stage may be carried out under vacuum, thereby providing for the removal of water at relatively low temperatures.

After completion of the acylating reaction, heating is discontinued and the reaction products allowed to cool, preferably under vacuum, to a temperature of about 40 C. to 90 C., at which temperature the mixture is held for a period of time ranging from about 4 to 100 hours, whereby the amide esters are converted into the monoacylated alkylolamide, and amine monoacid ester. At a temperature of about 50 C. to 80 0., aging is accomplished in about 24 hours.

In carrying out the aforesaid two-stage process, it is preferred to employ an excess of alkylolamine, for example, 1 /2 to mols of alkylolamine to 1 mol of acylating substance, a ratio of 1%, mols of amine to 1 mol of acylating agent being suitable. It has also been discovered that the aging step may be accelerated or catalyzed if the aging step is carried out in the presence of a small amount of alkylolamine soap, an amount of 3 to per cent thereof based on the reaction mixture being suitable. Where an acid is used as the acylating substance, the condensation produces initially alkylolamine fatty acid soap, which is later converted into the amide and the ester. By controlling the temperature and time of reaction, a complete conversion of the alkylolamine soap into the amide and ester compounds may be prevented, and the soap content reduced to the desired level. For example, when diethanolamine and coconut oil fatty acids are allowed to react at a temperature of about 150 C. for about 2 /2 hours, the reaction mixture will contain about 10 per cent of alkylolamine fatty acid soap. When employing an acylating substance incapable of forming soap with the alkylolamine, such as a triglyceride fat, the reaction is carried out until the fat has substantially reacted with the alkylolamine, and then before the aging step a sufficient amount of fatty acid is added to form with the excess alkylolamine the desired amount of alkylolamine fatty acid soap. As is the case with the initial acylating substances, it is desirable that fatty acids having 8 to 14 carbon atoms, such as coconut oil fatty acids, be used in forming the soap catalyst.

In accordance with the companion application hereinabove mentioned, the acylating agent is preferably a carboxylic acid or a derivative thereof having 8 to 14 carbon atoms in the molecule or less. The lower carboxylic acids, such as the coconut oil fatty acids, impart greater solubility and improved sudsing properties to the final product. By acylating agent is meant any substance which is capable of the formation or introduction of an acyl radical in or into the alkylolamine, and includes carboxylic acids, carboxylic acid chlorides, carboxylic esters, and organic acid anhydrides.

Examples of suitable primary and secondary alkylolamines are monoethanolamine, monopropanolamine, diethanolamine, diglycerolamine, diisopropanolamine, and dipropanolamine.

Although the alkylolamine detergents hereinabove described, are capable of inhibiting or preventing the precipitation of insoluble soaps in the presence of polyvalent metal ions, and possess good solubility and sudsing properties, they are often less efficient than the alkali metal soaps in detergent or purging ability. This is also true of various other detergents on the market, including the non-soap type. For this reason, these materials are suitable for the washing or cleansing of fine fabrics, such as wool, rayon, Celanese, silk, nylon, etc., but are ot recommended for the cleaning of cotton or linen goods, which are often more deeply soiled and form about per cent of all laundered materials. Moreover, if large amounts of the alkylolamine reaction products are attempted to be employed, particularly in certain types of mechanical washing machines, the materials produce suds so profusely that the detergent foams out of the machine.

An object of the present invention is to provide a detergent mixture including the reaction products of an alkylolamine and an acylating substance having improved detergent properties.

Another object of the invention is to provide a detergent mixture having an improved balance between detergent and sudsing properties.

A further object of the invention is to provide an improved detergent mixture capable of washing cotton and linen fabrics.

Yet another object of the invention is to provide a superior detergent mixture for use in automatic laundry machines.

Other objects and advantages of the invention will be apparent from the ensuing description of the invention.

In accordance with the invention it is proposed to incorporate a higher fatty acid soap into a mixture predominating in either the monoacylated derivatives prepared in accordance with the copending application mentioned above, or the multiacylated derivatives prepared in accordance with the processes of the patents hereinabove mentioned. In both cases, for purposes of the present invention, the acylating agent contains no more than about 14 carbon atoms in the molecule, and preferably about 8 to 14 carbon atoms. Preferably, the acylation reaction is carried out in the presence of excess alkylolamine.

A preferred embodiment of the invention will now be described in connection with the use of monoacylated derivatives of the aforesaid copending application.

An excess of a suitable primary or secondary alkylolamine, for example, diethanolamine, is allowed to react with an acylating agent having 8 to 14 carbon atoms in the molecule, for example, coconut oil fatty acids, until condensation has proceeded to the desired stage, as hereinbefore described. Following the initial condensation reaction, a higher fatty acid of a greater number of carbon atoms than the acylating agent, for example, oleic, is added to the reaction mixture, whereupon soap is formed by the neutralization of excess alkylolamine with the fatty acid. The resulting mixture is then allowed to age.

It is also preferred to effect the initial condensation reaction in such a manner as to produce in the reaction mixture the desired quantity of the alkylolamine soap of the initial low molecular weight acylating agents of 8 to 14 carbon atoms in the molecule as catalyst for the aging process. In case the initial soap is not formed because of a complete conversion of the acylating substance and alkylolamine into the amide and ester forms, or because of the nature of the acylating agent, for example, when using a triglyceride fat, 2. lower fatty acid, such as lauric, may

beadded to react with. the. excess alkylolamine to.

form the desired amount of soap catalyst.

We have found that the higher fatty acid alkylolamine soap incorporated into the condensation products before aging may serve to catalyze the aging step, thus making the presence of the lowerfatty acid soap catalyst unnecessary. The

soap catalyst of alower molecular weight fatty,

acid is, however, a more effective catalyst than the incorporated higher molecular weight fatty acid soap, and its presence is therefore desired.

l ou h We have obtained best results by inommut n he h r fatty i oap p or o. aging, alternatively the soap may be incorporated.

into the monoacylated allcylolamine products following the aging step; that is, the monoacylated product is prepared according to the two step process, preferably using a lower fatty acid soap catalyst, and there is then added thereto the desired amount of higher fatt acid, such as oleic, to form the alkylolaminesoap by the interaction of fatty acid and the free alkylolamine present thsmix ie.

In another embodiment of the invention, we may incorporate the higher fatty acid soap into the multiacylated alkylolamine condensation products prepared in accordance with the processes disclosed in Patent 2,089,2l2 and Reissue Patent 2l,530, hereinabove mentioned, and in which the acylating substance employed in the acylation of the amines contains about 8.to 14 carbon atoms in the molecule.

In carrying out this aspect of the invention. an acylating agent, having no more than about lloarbon atoms in the molecule, such as coconut oil fatty acids, is reacted with an. excess of a primary, secondary or tertiary alkylolamine at a temperature between about 100 C. and 250 C. for a period of two to four hours. After completion of the reaction, the mixture is allowed to cool, below 100 C., and preferabl between 60 to 80 C., whereupon a higher fatty acid of more than 14 carbon atoms in the molecule, such as oleic, is added to the cooled mixture to form soap with free alkylolamine. Cooling of the acylated alkylolamine derivatives before addition of the soap prevents discoloration of the final mixture. If color is not a consideration, the soap of :the higher fatty acid may be formed soon after the acylation reaction.

The combination of either the monoor multiacylated alkylolamine products with a soap hav ing a fatty acid radical, of more carbon atoms than the acyl radical in the alkylolamine reaction product, possesses new sudsing and detergent properties. The presence of the alkylolamine soap of a higher fatty acid serves to improve the detergent properties of the mixture, and at the same time inhibits or suppresses excessive foaming.

The use of an acylating agent having 8 to 14 carbon atoms in the molecule in the initial acylation of the alkylolamine is the effective agent in producing the good solubility and sudsingproperties of the mixture. On the 'o'ther'hand, the presence of the. alkylolamine soap of a higher fatty acid containing more carbon atoms in'the' molecule; than the acylating agent imparts the improved'detergent qualities thereto and inhibits the excessive sudsing due to the lower acylating substances. We have found that we may obtain the proper balance between sudsing or foaming anddetergency by employing such an amount of a higher fatty acid, for example, oleic, asto effect analkylolamine soap content thereof in thefinal produce desirable suds.

mixture of from aboutlo-to 50 percent, a soap contentof about 20/00. 40per cent being preferred.

In. determining the; amount of excess. alkylolamine to .be employed in the preparation of the monoandmultiacylated derivatives thereof, it is preferred, although, not. imperative, to have free alkylolamineremaining after the desired amount of, soap has been formed therewith. We have found that the free alkylolamine imparts a desired alkalinity to thefinal product, which makes the latter more effective. For example, a molar ratio of alkylolamine to lauric acid of about 1.2 to 1 provide just aboutv a sufficient excess of alkylolamine to provide a soap. content obtained from alkylolamine and .oleic acid of, about 20 per cent, leaving substantially no free amine.

Because it is desirable to have free alkylolamine in the final product, ratios of 1 /2 to 10 moles of alkylolamine to 1 mole of acylating agent have been found suitable.

The following table of data illustrates the improved detergentand sudsing properties of the mixtures prepared in accordance with the invention herein described when employed in the washing of cotton fabrics. The alkylolamine derivatives, called reaction product in the table, were prepared by reacting 9-moles of diethanolamine with 1 mole of coconut oil at to C. for

about 2 hours under a reduced pressure of 40- to 60 mm. of mercury. The reaction mixture was cooled to aboutSil C., after which there was added thereto about 7 per, cent of coconut oil fatty acids to produce about 10 per cent diethanolamine soap catalyst therewith. To samples of the resulting mixture. there were added the indicated parts of oleic. acid per 100 parts of mixture by weight, and the product was aged at 70 0-80" C. for about 24 hours. A bolt of cotton, uniformly soiled, was cut into pieces and equal amounts thereof were washed in separate operations for about 30 minutes in an automatic washing machine employing 5 to 6 gallons of water of 7 to 9 grain hardness and containing the indicated amounts of detergent mixture required to i The per cent whiteness of the cotton fabric for each washing operation was determined by means of aPulfrich photometer and is given below:

The data show that the photometer per cent whiteness of'the unwashed, soiled cotton fabric was 20. After Washing with talloW soap 2, value of 68 per cent whitenesswas obtained when using 28 g. of the soap. A considerable portion of the tallow soap reacted with .the polyvalent metal ions in the water, and explains the large amount of 28 g. of soap required to produce the given per, cent of whiteness. On the other hand, only 6 g. of. the vallq'lolamine. reaction product was .used. without.causingexcessive sudsing and gave 7 a value of 64. The addition of parts of oleic acid to the reaction product increased the purging properties of the reaction product, as indicated by a value of 68 per cent whiteness, and suppressed the sudsing properties thereof, as indicated by a larger amount of 8 g. of detergent mixture which it was possible to use. As the amount of added oleic acid was increased, the sudsing properties of the reaction product was further decreased, thus permitting larger additions of detergent mixture with consequent improvements in per cent whiteness reported. The table shows that best results were obtained by the addition of about to 40 parts of oleic acid giving per cent whiteness readings of between 78 and 84. The above amount of added higher fatty.

acid equals approximately the per cent of diethanolamine soap of the higher fatty acid formed in the mixture.

Suitable acids that may be employed in accordance with the invention are, for example, the tallow fatty acids, such as oleic, stearic palmitic, and linoleic; other sources of fatty acids of more than 14 carbon atoms in the molecule are soybean oil, corn oil and linseed oil. In general, any acid or mixture of acids, saturated or unsaturated, having preferably about 16 to 18 carbon atoms, is satisfactory for the purposes of the present invention.

The following examples are illustrative embodiments of the invention and are not intended to be limiting on the scope thereof.

Example 1 1 mole of coconut oil and 9 moles of diethanolamine were heated together at 155 C. under an inert atmosphere of nitrogen while stirring. Heating was continued until the titratable basicity of the mixture became constant, or for about 1 ,4 hours. The reaction mixture was then cooled to about 70 C., after which there was stirred therein about parts by weight of oleic acid for every 100 parts of reaction mixture. The resulting mixture was then aged at about 60 C. for about 36 hours. The finished product was superior to ordinary tallow soaps or untreated detergent in sudsing and detergent properties in washing cotton goods.

Example 2 1 mole of coconut oil fatty acids was heated with 3 moles of diethanolamine under a reduced pressure of about 40 minutes at 150 C. until the soap content was reduced to about 10 per cent, or for about 2 hours. Heating was then discontinued and the reaction mixture cooled to about 90 C. About 20 parts of a commercial stearic acid containing about per cent of palmitic acid was added to 100 parts of reaction mixture, while stirring. The whole was then allowed to age at 60 C. for about 48 hours. The resulting product was superior for the washing of cotton goods in an automatic washing machine.

Example 3 1 mole of coconut oil was reacted with 4.5 moles of dipropanolamine at 150 C. under a reduced pressure of about mm. of mercury until the mixture had a constant titratable basicity. There were added to the resulting mixture an additional 4.5 moles of the propanolamine and then 70 per cent of coconut oil fatty acids. The whole was aged for about 48 hours at 60 C., after which there were added 30 parts of oleic acid for every 100 parts of reaction. product. The resulting 8. detergent mixture was superior in sudsing and purging properties.

Example 4 1 mole of coconut oil fatty acids was mixed with 2 moles of monoethanolamine and heated for about 3 hours at a temperature of about 160 C. To the resulting material there was added about 35 parts of oleic acid, for every 100 parts of reaction product while stirring at a temperature of about 70 C. The resulting detergent mixture was superior in sudsing and detergent properties to a sample of untreated alkylolamine condensation product.

Example 5 1 mole of lauric acid was condensed with 2 moles of triethanolamine at a temperature of 175 C. for 2 hours. The mixture was allowed to cool to a temperature of about 60 C., whereupon there was stirred therein about 40 parts of palmitic acid per 100 parts of reaction product. The resulting detergent mixture was effective in washing cotton goods in an automatic washer.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. In the process of preparing an improved alkylolamine detergent from products comprising essentially the condensation product of an alkylolamine having at least 1 acylatable hydrogen atom in the amino group and a fatty carboxylic acid acylating material having from 8 to 14 carbon atoms in the carboxylic acid group in a ratio of at least 1.5 moles of alkylolamine to one mole of carboxylic acylating material, said materials being heated at a temperature of between 120 C. and 250 C. for a period of between 15 minutes and 16 hours in the presence of an excess of between and 10 mols of the alkylolamine to form alkylolamide and alkylolamine ester condensation products, and then cooling below 100 C. and maintaining the said products at a temperature of between 40 C. and C. for a period of between 4 and hours to form reaction products containing compounds having a single replaceable hydrogen atom of the alkylolamine replaced with an acyl group, the improvement which comprises: reacting higher carboxylic acid acylating material having more than 14 carbon atoms in the carboxylic acid group with the excess alkylolamine present in the condensation reaction mixture after cooling below 100 C. to form between approximately 10 and 50 percent of a higher alkylolamine soap in said mixture, thereby improving the detergent properties and suppressing the sudsing properties of the said reaction products.

2. In the process of preparing an improved detergent from products comprised essentially of the reaction products of diethanolamine and acylating substances wherein an excess of between A; and 10 mols of the diethanolamine with a higher fatty acid acylating substance having between 8 to 14 carbon atoms in the fatty acid group is heated at a temperature of between C. and 250 C. for a period of between 15 minutes and 16 hours to cause the production of reaction products containing a substantial amount of multiacylated alkylolamine derivatives, and after cooling below 100 C. the reaction products are thereafter aged at a lower temperature of between approximately, 40 C. and 90 C. for a period of between 4 and 100 hours to form compounds having a single replaceable hydrogen atom of the alkylolamine replaced with an acyl group, the improvement which comprises incorporating in the reaction products between approximately and 50 per cent of an alkylolamine soap by reacting a higher fatty acid having more than 14 carbon atoms per molecule with the excess diethanolamine in the said reaction products after cooling below 100 C. to improve the detergent properties and suppress the sudsing properties of the said aged reaction products.

3. An improved detergent composition having suppressed sudsing properties consisting essentially of at least 50 per cent by weight of the condensation product of an alkylolamine having at least one acylatable hydrogen atom in the amino group and a fatty acid acylating substance having between 8 and 14 carbon atoms in the fatty acid group, the mol ratio of alkylolamine to acylating substance, in said condensation product being at least 1.5:1; and from 10 to 50 per cent by weight of an alkylolamine soap of a higher fatty acid having more than 14 carbon atoms per molecule, said fatty acid soap having been formed in situ by reaction of the higher fatty acid with the excess alkylolamine remaining from the condensation of the alkylolamine and the acylating substance.

4 An improved detergent composition having suppressed sudsing properties consisting essentially of from to per cent by weight of the maining from the condensation of the diethanolamine and the carboxylic acid.

HARLAND H. YOUNG. KURT H. SPITZMUELLER.

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

UNITED STATES PATENTS Number Name Date Re. 21,530 Kritchevsky Aug. 13, 1940 1,833,899 Hoyt Dec. 1, 1931 2,055,581 Leben Sept. 29, 1936 2,089,212 Kritchevsky Aug. 10, 1937 2, 04,297 Kroll July 16, 1946 2,404,298 Kroll et a1. July 16, 1946 2,429,445 Young et a1 Oct. 21, 1947 2,483,253 Young et a1 Sept. 27, 1949

Claims (1)

1. IN THE PROCESS OF PREPARING AN IMPROVED ALKYLOLAMINE DETERGENT FROM PRODUCTS COMPRISING ESSENTIALLY THE CONDENSATION PRODUCT OF AN ALKYLOLAMINE HAVING AT LEAST 1 ACYLATABLE HYDROGEN ATOM IN THE AMINO GROUP AND A FATTY CARBOXYLIC ACID ACYLATING MATERIAL HAVING FROM 8 TO 14 CARBON ATOMS IN THE CARBOXYLIC ACID GROUP IN A RATIO OF AT LEAST 1.5 MOLES OF ALKYLOLAIME TO ONE MOLE OF CARBOXYLIC ACYLATING MATERIAL, SAID MATERIALS BEING HEATED AT A TEMPERATURE OF BETWEEN 120* C. AND 250* C. FOR A PERIOD OF BETWEEN 15 MINUTES AND 16 HOURS IN THE PRESENCE OF AN EXCESS OF BETWEEN 1/2 AND 10 MOLS OF THE ALKYLOLAMINE TO FORM ALKYLOLAMIDE AND ALKYLOLAMINE ESTER CONDENSATION PRODUCTS, AND THEN COOLING BELOW 100* C. AND MAINTAINING THE SAID PRODUCTS AT A TEMPERATURE OF BETWEEN 40* C. AND 90* C. FOR A PERIOD OF BETWEEN 4 AND 100 HOURS TO FORM REACTION PRODUCTS CONTAINING COMPOUNDS HAVING A SINGLE REPLACEABLE HYDROGEN ATOM OF THE ALKYLOLAMINE REPLACED WITH AN ACYL GROUP, THE IMPROVEMENT WHICH COMPRISES; REACTING A HIGHER CARBOXYLIC ACID ACYLATING MATERIAL HAVING MORE THAN 14 CARBON ATOMS IN THE CARBOXYLIC ACID GROUP WITH THE EXCESS ALKYLOLAMINE PRESENT IN THE CONDENSATION REACTION MIXTURE AFTER COOLING BELOW 100* C. TO FORM BETWEEN APPROXIMATELY 10 AND 50 PERCENT OF A HIGHER ALKYLOLAMINE SOAP IN SAID MIXTURE, THEREBY IMPROVING THE DETERGENT PROPERTIES AND SUPPRESSING THE SUDSING PROPERTIES OF THE SAID REACTION PRODUCTS.