US2454545A - Hydrocarbon-substituted phenolformaldehyde condensates modified in the phenolic hydroxyl - Google Patents

Description

Patented Nov. 23, 1948 HYDROCARBON-SUBSTITUTED PHENOL- FORMALDEHYDE CONDENSATES MODI- FIED IN THE PHENOLIC HYDROXYL Louis B. Bock, Huntlngdon Valley, and James L. Rainey, Abington, Pa., asslgnors to Rohm & Haas Company, Philadelphia, Pa., a corporation 01' Delaware No Drawing. Application September 9, 1944, Serial No. 553,480

9 Claims. (Cl. 260-53) This invention relates to surface-active or capillary-active agents. It relates to the preparation of materials which have high detergent action under a wide variety of conditions. More specifically, it relates to the preparation and use of polymeric, water-soluble detergents which have high molecular weights and contain within each molecule a multiplicity of hydrophobic and hydrophilic groups or portions so arranged and bal anced as to become oriented at an interface.

It is generally recognized that surface-active agents, as, for example, alkali-metal soaps or quaternary ammonium compounds, exist in water in the form of micelles. While the exact nature of such micelles is not established, there is evidence that they are electrically charged aggregates of molecules. For example, when a sodium soap of a fatty acid is dispersed in water, it dissociates into positively charged sodium ions and into negative ions. Some of the latter apparently form aggregates with soap molecules and, as a result, negatively charged micelles are produced. Because the micelles carry a negative charge, this type of soap is known as an anion-active detergent. In contrast, detergents of the type of quaternary ammonium compounds yield positively charged micelles in aqueous solution and, hence, are known as cation-active soaps or agents. This conception of the formation of micelles is based on measurements of freezing points, vapor pressures, and electrical conductivities of aqueous dispersions of surface-active agents. It is further recognized that surface activity is related to the formation of such micelles and to the orientation of the micelles at an interface.

The individual molecules in colloidal micelles are held together only by physical forces or by weak secondary valences; and, as a result, the extent of micelle formation depends upon the prevailing conditions, and it is affected by such factors as the concentration of the surface-active agent, the presence of electrolytes, solvents, and other surface-active agents, and also upon the temperature. Thus, dilution of the solution, elevation of the temperature, or a change in the amount of any salts which may also be present in solution favor the reversion of micelles into simple molecules and/or ions with the formation of true solutions. As an example, synthetic detergents known heretofore have no value at very low concentrations or in very hot water because under these conditions the micellar structure reverts, the molecules then exist in true solution, and, as a result, detergency is lost. The necessity of using relatively high concentrations plus the higher cost of synthetic detergents combines to make the use of such detergents uneconomical and often impractical. Furthermore, the materials are ineffective in many laundering operations wherein extremely hot water is used in order to accelerate the removal of soil.

The products of this invention difier fromand have advantages over-detergents known heretofore in that their effectiveness is not dependent upon the formation of loosely bound micelles. By the process of this invention, water-soluble macromolecules are synthesized in which all of the bonds between atoms are primary valence links and, hence, are strong and are not aifected by such factors as concentration and temperature. Furthermore, the synthesized macromolecules contain balanced hydrophilic and hydrophobic groups so positioned in the macromolecule that orientation can and does occur readily at an interface.

The products of this invention may be made by condensing hydrocarbon substituted phenols with formaldehyde to produce polymeric materials which are in fact macromolecules and then introducing into said macromolecules hydrophilic groups. The hydrophilic groups, which impart water solubility, may be ether-alcohol groups or.

esterified ether-alcohol groups and are introduced, for example, by the reaction of ethylene oxide or a propylene oxide or a butylene oxide with the macromolecule. If desired, the terminal hydroxyl of said ether-alcohol group may beconverted into a salt-forming ester group of a polybasic acid.

The resultant products may be considered to have three functional portions. Thus, they contain (a) as the hydrophobic portion, the hydrocarbon groups attached to the phenol nucleus; (b) as the hydrophilic portion, the modified or unmodified ether-alcohol groups, and (c) as the polymeric portion, the phenol nuclei joined by methylene bridges. The hydrocarbon groups attached to the phenol and the modified or unmodified ether-alcohol groups also attached to the phenol are so balanced as to assure water solubility three or four phenolic units per molecule, or it may be continued until each macromolecule contains many more units. The condensation products may range in physical properties from oils to brittle solids, depending upon the degree of condensation and the nature of the substituent hydrocarbon group on the phenol.

The polymeric detergents of this invention have the following general formula:

retical explanation only, and it must be understood that the so-called three portions of the macromolecule are not independent of each other but are all combined in one large molecule which functions as a concerted whole.

The type of hydrocarbon group which is attached to the phenol nucleus may vary as to kind but in every case must contain at least four carbon atoms. In reality, substituting groups of at least eight carbon atoms are much preferred. Generally, it is preferred that the substituent hydrocarbon group be a straight or branched chain acyclic group, such as n-butyl, iso-butyl, tertiary butyl, amyl, tertiary amyl, n-octyl, diisobutyl, decyl, dodecyl, hexadecyl, octadecyl, and the like. Alternatively, phenols substituted with alicyclic groups may be used. These are typified by cyclohexyl phenol, methyl-cyclohexyl phenol, butyl-cyclohexyl phenol, and dicyclohexyl phenol. While aryl-substituted phenols, such as p-phenyl phenol and p-naphthyl phenol, may be employed they are less satisfactory than those listed above unless they in turn contain an alkyl group. Thus, p-tolyl phenol is much preferred over p-phenyl phenol. Furthermore, a preference is given to the para-substituted phenols over those substituted in the ortho position. It is understood that although it is preferable to employ individual phenols, mixtures of phenols, for example, p-tert.-amyland p-diisobutyl-phenols, may be employed.

The ratio of formaldehyde should be between 0.5 and 1.0 mol per mol of phenol. The formaldehyde may be used in the form of a solution, such as the formalin of commerce, or in a polymeric form such as paraformaldehyde. Also, though not preferred, it may be in a form such as a formal or hexamethylene tetramine which will yield formaldehyde under the conditions of reaction.

Ordinarily, the substituted phenol and formaldehyde are reacted by condensing together in the presence of an acidic or alkaline condensation catalyst until the products have become relatively viscous. Solvents may be employed. Acidic condensation catalysts are preferred because of the ease with which the condensation may be controlled. Elevated temperatures naturally accelerate the rate of reaction. Condensation of formaldehyde and substituted phenols such as are here involved do not proceed to the infusible stage and, accordingly, no limit need be imposed upon the degree of condensation. In practice, it is convenient to follow the extent of condensation by means of viscosity measurements and the condensation may be halted at an early stage at which the molecular weight is low and the product on the average has no more than on. Q

Jr R

in which R is a hydrocarbon substituent of at least four, and preferably over seven, carbon 20 atoms; R is an alkylene group of two to four carbon atoms; inclusive; 1 has a value of zero to twenty, inclusive, and preferably a value of one to seven, inclusive; M is one equivalent of a metal, preferably of an alkali metal of group I 25 or group II metal, including beryllium, magnesium, calcium, barium, and strontium, and a: is an integer greater than one.

They may be made by first preparing an alcohol of the general formula:

CH, I

in which the symbols have the same significance as above. Such alcohols are described in detail in our application Serial No. 553,476, filed of even date, and are the products of condensing with 40 the substituted phenol-formaldehyde macromolecule an alkylene oxide such as ethylene oxide,

a propylene oxide such as trimethylene oxide or isopropylene oxide, or a butylene oxide such as isor butylene oxide. The condensation is preferably conducted in the presence of an alkaline catalyst such as a hydroxide of an alkali metal, although in some instances no catalyst is required. While the reaction may be carried on at lower temperatures and at atmospheric pressure in the presence of solvents, it is preferred to conduct it at temperatures above 100 C. under superatmospheric pressure with or without solvents. One or more mols, preferably two to eight mols, of alkylene oxide may be employed per mol of phenol condensed in the macromolecule. When one mol is used, the value of y in the above formula becomes zero. Although a maximum value of twenty for y is indicated as preferred, alcohols in which y had a value as high as sixty have been prepared.

60 Alternatively, the alcohols may be made by reacting a halohydrin with a sodium derivative of a hydrocarbon-substituted phenol-formaldehyde condensate, during which reaction the halogen of the halohydrin and the sodium of the macromolecule are split out as sodium chloride. The halohydrins are typified by the following:

ClCHzCHzOH BrCHzCHzCHzOI-I clcmcmcnncngon Br. (C2H40) 10C2H4OH and In the next step, acrylonitrile is reacted with the above alcohols and ,B-cyanoethyl ethers having the following general formula are the result:

of diisobutylphenol (,a,- -tetramethylbutylphen01), 162 grams of a 37% aqueous solution of formaldehyde, and 27.6 grams of water. The

In this formula, the symbols have the same signiflcance as above. The reaction proceeds readily at ordinary temperatures in the presence of an alkaline condensing agent and is preferably carried out in the presence of an inert solvent, such as benzene or toluene, although the use of solvent is not essential.

As alkaline condensing agent, there may be employed,..for example, oxides, hydroxides, alcoholates of the alkali metals, the alkaline earth hydroxides, quaternary ammonium hydroxides, and the'like. The amount of catalyst normally used is about 0.5% to 2% calculated on the weight of the polymeric alcohol.

Y The process is carried out by slowly adding the acrylonitrile to the alcohol containing the catalyst, the rate of addition being so regulated that the temperature of the reaction mixture does not rise sufficiently to cause'polymerization of the acrylonitr ile. Reaction temperatures between 0 C. and 70 C. are generally satisfactory. External cooling may be employed if desired. The reactants are usually employed in substantially'equimolecular proportions, although the use of a small excess of acrylonitrile is advantageous. Solvents such as dioxane, benzene, toluene, naphtha, etc., may be used. After the reaction has been carried to the desired point, it is generally desirable to neutralize the reaction mixture with an acid such as sulfuric, hydrochloric, or the like.

The nitrile is next hydrolyzed to the acid and finally converted. by neutralization, to a salt. The hydrolysis is preferably conducted in an acidic medium, and the product of hydroylsis is then neutralized with an alkaline material such as a hydroxide or carbonate of an alkali or alkaline earth metal.

The products are best described as water-soluble, surface-active, polymeric products containing in their chemical structure salt-forming 3- (hydrocarbon-substituted-phenoxy polyalkoxy)- propionic acid units, at least three of said units being joined in each molecule by means of methylene bridges, and in which units said hydrocarbon substituent contains at least four carbon atoms and each alkoxy group contains two to four carbon atoms, inclusive.

The following example will serve to illustrate a preferred method of preparing the detergent materials of this invention.

Step 1.Into a three-necked flask equipped with thermometer, mechanical agitator, and reflux condenser was charged the following: 412 grams mixture was agitated and heated to a temperature of C. At this point, 2.46 grams of oxalic acid and 0.92 gram of Twitchells reagent dissolved in ten grams of water were added. While being agitated, the reaction mixture was refluxed for six hours. Two hundred grams of water and 384 grams of toluene were added, and refluxing was continued for an hour. Agitation was stopped and the contents of the flask were removed to a separatory funnel. The aqueous and resinous layers were separated and the solvent was removed from the resinous layer by vacuum distillation. After the removal of the solvent, heating at a reduced pressure of 1.5 to 2.5 mm. and at a temperature of 245 to 250 C. was continued for four and one-half hours. The condensate then had a viscosity of 4.0 poises when measured as a 60% solution in toluene and, on cooling, solidified to a brittle mass.

Step 2. --Two parts of solid NaOH, 133 parts of ethylene oxide, and 218 parts of the product of step 1 were mixed with parts of toluene and heated at 120135 C. under pressure for two hours. This ratio corresponds to three mols of ethylene oxide per mol of phenol present in the product of step 1. The product, a viscous solution, was further diluted to 50% solids content with toluene. Its structure may be represented as follows:

Step 3.To 700 grams of a 50% solution as prepared in step 2 was added four grams of 40% aqueous trimethylbenzyl ammonium hydroxide. While the temperature ofthis mixture was maintained at 30-35 C., 79.5 grams of acrylonitrile was added dropwise. The mixture was then stirred and maintained at 30 to 35 C. for seven hours. The product was washed with water, filtered, and finally freed of solvents and excess acrylonitrile by stripping under vacuum.

Step 4.-One hundred eighty-six grams of the nitrile prepared in step 3 was mixed with 93 grams of a mixture of two parts of 85% phosphoric acid and one part of phosphorus pentoxide and heated for one hour at to C. The mixture was then cooled to 100 C., and 200 milliliters of water was added. Heating at 100 C. was continued for one hour, after which the mixture was cooled to room temperature and the aqueous layer was decanted off.

Step 5,-The product of step 4 was then dissolved in 200 milliliters of a 15% aqueous solution of sodium hydroxide.

The product having the formula:

aHu

aHn

in which a: is an integer greater than one, had capillary-active properties and functioned as a detergent both at high temperatures and in very low concentrations.

Although the above example is directed to the use of ethylene oxide, it is understood that a propylene oxide or a butylene oxide may be employed in a similar manner. In order to impart a given degree of water-solubility, it is advisable to use a greater amount of the higher oxides than the amount of ethylene oxide required. 'Furthermore, as the entire length of the hydrophilic group is increased, the product ordinarily becomes more water-soluble. It is, therefore, advisable to increase the hydrophobic group proportionately. This can be done by increasing the size of the hydrocarbon substituent of the phenol, as represented by R in the above general formula. In this way, a balance is maintained between the hydrophilic and hydrophobic portions of the macromolecule so that the product is water-soluble and at the same time capillaryactive, in that it becomes oriented at an interface.

All of the products of this invention function as capillary-active or surface-active agents. As such, they become oriented at an interface, lower the surface tension of water, and cause more rapid wetting of surfaces such as the surfaces of fibers as measured by the standard Draves Sinking Test. Their outstanding property is their effectiveness as detergents. In this capacity, as measured by wash tests and laundering tests, they are outstanding and are far superior to soaps and synthetic detergents known heretofore.

As detergents the products described herein may be used in hard water or in water of high salt content. Their advantage over synthetic detergents resides in the fact that they are not micellar but are in fact macromolecules which do not revert as do micelles. Thus, they are excellent detergents at very low concentrations or at very high temperatures where former synthetic detergents failed.

They are uncommonly advantageous in the laundering of cotton fabrics and in the scouring of wool, sized, dyed, and printed fabrics in general. They may be used for preparing dispersions of oil in water or dispersions of polymerizable' and synthetic detergents such as those shown in United States Patents 2,115,192 and 2,143,759.

Such combinations have extraordinarily high deformula Iva- 011 in which R is a saturated hydrocarbon substituent containing four to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group replacing the original phenolic hydrogen atoms and being attached to each phenol nucleus in said condensate through the phenolic oxygen atom thereof, wherein R in both occurrences is the same saturated alkylene group containing two to four'carbon atoms, 1! has a value of 0 to 20 inclusive, and M is a metal from the class consisting of alkali and alkaline earth' metals.

2. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mol of formaldehyde and one mol of a phenol from the class consisting of ortho-substituted and parasubstituted phenols, said phenol having the formula in which R is a saturated hydrocarbon substituent containing eight to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group replacing the original phenolic hydrogen atoms and being attached to each phenol nucleus in said condensate through the phenolic oxygen atom thereof, wherein R in both occurrences is the same saturated alkylene group containing two to four carbon atoms, 11 has a value of 0 to 20 inclusive, and M is a metal from the class consisting of alkali and alkaline earth metals.

3. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mol of formaldehyde and one mol of a phenol from the class consisting of ortho-substituted and parasubstituted phenols, said phenol having the forin which R is a saturated hydrocarbon substituent containing eight to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group replacing the original phenolic hydrogen atoms and being attached to each phenol nucleus in said condensate through the phenolic oxygen atom thereof, wherein R in both occurrences is the same saturated alkylene group containing two to four carbon atoms, y has a value of one to seven inclusive, and M is a metal from the class consisting of alkali and alkaline earth metals.

4. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mol of formaldehyde and one moi of a phenol from the class consisting of ortho-substituted and parasubstituted phenols, said phenol having the formula 9 in which R is a saturated hydrocarbon substituent containing eight to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group replacing the original phenolic hydrogen atoms and being attached to each phenol nucleus in said condensate through the phenolic oxygen atom thereof, wherein R in both occurrences is the same saturated alkylene group containing two to four carbon atoms, y has a value of one to seven inclusive, and M is an alkali metal.

5. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mole of formaldehyde and one mole of a phenol from the class consisting of ortho-substituted and para-substituted phenols, said phenol having the formula in which R is a saturated hydrocarbon substituent containing eight to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group (C2H4O) y C2H4 O CHzCHzCOOM formula in which R is a saturated hydrocarbon substituent containing eight to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group (CaHeO) v CaHe O CHzCHaCOOM replacing the original phenolic hydrogen atoms and being attached to each phenol nucleus in said condensate through the phenolic oxygen atom thereof, wherein y has a value of zero to twenty, inclusive, and M is a metal from the group consisting of alkaliand alkaline earth metals.

7. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mole of formaldehyde and one mole of a phenol from the class consisting of ortho-substituted and para-substituted phenols, said phenol having the formula in which R is a saturated hydrocarbon substituent containing eight to eighteen carbon atoms, and wherein the modification of said condensation product consists of the group (C4Ha0) y C4Ha O CHzCHzCOOM replacing the original phenolic hydrogen atoms and being attached to each phenol nulceus in said condensate through the phenolic oxygen atom thereof, wherein y has a value of zero to twenty, inclusive, and M is a metal from the group consisting of alkali and alkaline earth metals.

8. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mole of formaldehyde and one mole of a phenol having the formula and wherein the modification of said condensation product consists of the group replacing the original phenolic hydrogen atoms and being attached to each phenol nucleus in said condensatethrough the phenolic oxygen atom-thereof, in which group y has a value of zero to twenty, inclusive, and M is a metal from the group consisting of alkali and alkaline earth metals.

9. A modified phenol-formaldehyde condensation product having surface-active properties wherein the phenol-formaldehyde condensate is a condensation product of from 0.5 to 1.0 mole of formaldehyde and one mole of a phenol having the formula and wherein the modification of said condensation product consists of the group (721140) 1 C2H4 0 CHzCHzCOONa replacing the original phenolic hydrogen atoms 0 and being attached to each phenol nucleus in said condensate through the phenolic oxygen atom thereof, in which group :1; has a value of one to seven, inclusive.

LOUIS H. BOCK. JAMES L. RAINEY.'

No references cited.