Production of Alkoxylated N-Methylol Compounds

The invention relates to a process for the manufacture of alkoxylated N-methylol compounds, characterised in that

A. A N-methylolated organic nitrogen compound is reacted with

B. AN ALKYLENE OXIDE OF THE FORMULA ##EQU3## wherein R denotes phenyl, alkyl with 1 to 3 carbon atoms, a ##EQU4## radical or, preferably, hydrogen, in the presence of

C. AT LEAST ONE METAL ALCOHOLATE OF THE FORMULA

wherein Me denotes a n-valent transition metal of groups IV, V or VI of the periodic system, X denotes phenyl, benzyl, cycloalkyl with at most 12, especially 5 to 12, and above all 8 to 12, ring carbon atoms, halogenoalkyl with 2 to 4 carbon atoms, or preferably, alkyl with 1 to 4 carbon atoms, Q denotes halogen or alkoxy with 1 to 4 carbon atoms, r denotes 1 to n and n denotes 4, 5 or 6, and optionally

D. AT LEAST ONE ALKALI METAL HYDROXIDE OR ONE ALKALI METAL ALCOHOLATE OF AN ALKANOL WITH 1 TO 4 CARBON ATOMS, AT A TEMPERATURE OF 10.degree. TO 160.degree.C and a pressure of 1 to 20 atmospheres gauge.

The components (a) are as a rule addition products of formaldehyde to nitrogen compounds which can be methylolated such as, for example, urea or thiourea compounds, 1,3,5-aminotriazines or carboxylic acid amides.

Examples of suitable urea and thiourea compounds are urea, thiourea, substituted ureas such as alkylureas and arylureas, alkyleneureas and alkylenediureas, such as ethyleneurea propyleneurea, dihydroxyethyleneurea, hydroxypropyleneurea and acetylenediurea, and also dicyandiamide, dicyandiamidine, urones and hexahydropyrimidones.

As examples of 1,3,5-aminotriazines there may be mentioned: melamine and N-substituted melamines, such as N-butylmelamine, N-trihalogenomethylmelamines, triazones, ammeline, guanamines, for example benzoguanamines and acetoguanamines, or diguanamines.

In general, products which are as highly methylolated as possible yield particularly valuable products. Partial ethers of such methylol compounds with, for example, alkanols with 1 to 22 carbon atoms, such as methanol, ethanol, n-propanol, isopropanol, n-butanol or octadecyl alcohol can also be used.

The N-methylolated carboxylic acid amides are, for example, amides of aromatic or aliphatic carboxylic acids, such as benzoic acids optionally substituted by lower alkyl, lower alkoxy, hydroxyl or halogen, or, preferably, amides of saturated or unsaturated aliphatic carboxylic acids. Particularly suitable compounds of this nature are N-methylolated aliphatic carboxylic acid amides with at most 22 carbon atoms, above all N-methylolated alkylmonocarboxylic acid amides or alkenylmonocarboxylic acid amides with 3 to 22, preferably 10 to 18, carbon atoms. As examples, the mono- or di-N-methylolated amides of, for example, stearic acids, palmitic acid, lauric acid, hydroabietic acid, oleic acid, linoleic acid, linolenic acid, caprylic acid, butyric acid, acrylic acid and methacrylic acid may be mentioned here.

Preferably, N-methylolated 1,3,5-aminotriazines, ureas or aliphatic carboxylic acid amides with at most 22 carbon atoms are used as component (a) in the process according to the invention. Amongst these components, N-methylolmelamines and N-methylolureas are of great practical interest.

Compounds of the formula ##EQU5## wherein Y denotes alkyl with 1 to 4 carbon atoms or, preferably, hydrogen or methylol and Z denotes alkyl with 1 to 22 carbon atoms, alkenyl with 3 to 22 carbon atoms, a monoalkylene glycol or polyalkylene glycol radical with 2 or 3 carbon atoms per alkylene unit and with up to 100 alkoxy groups in the chain, cycloalkyl with 5 to 14, preferably 8 to 12, ring carbon atoms, phenyl or benzyl, or N-methylolmelamines with 2 to 6, optionally partially etherified methylol groups, for example 1 to 5 methylol groups etherified with an alkanol having 1 to 22 carbon atoms, especially with methanol, butanol or octadecylalcohol, have proved particularly suitable.

The radical Z is derived, for example, from n-butanol, lauryl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, ricinol, cetyl alcohol, cyclohexanol, cyclododecanol, p-nonylcyclohexanol, hydroabietyl alcohol, benzyl alcohol or phenol.

Amongst the compounds of the formula (3), those of the formula ##EQU6## wherein Y.sub.1 denotes hydrogen or methylol and Z.sub.1 represents alkyl or alkenyl each with 4 to 18, preferably 10 to 18, carbon atoms, benzyl, a monoethylene glycol or polyethylene glycol radical with 1 to 25 ethoxy radicals in the chain or a monopropylene glycol or polypropylene glycol radical with 1 to 25 propoxy radicals in the chain are above all particularly suitable.

Typical representatives of components (a) which are suitable for the process according to the invention are, for example ##EQU7##

The component (b) is, for example, ethylene oxide, propylene oxide, styrene oxide or diglycidyl ether. Propylene oxide and above all ethylene oxide are preferred.

The component (c) is as a rule an alcoholate of transition metals of groups IV, V or VI of the 4th, 5th or 6th period of the periodic system according to "Lange"s Handbook of Chemistry," 10th edition, 1967, pages 60 and 61. These transition metals, also called elements of the intermediate groups, of groups a or of groups b, include titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten. The process is appropriately carried out in the presence of metal alcoholates of the formula

wherein Me.sub.1 denotes niobium.sup.V, tantalum.sup.V, tungsten.sup.VI, molybdenum.sup.VI, zirconium.sup.IV or hafnium.sup.IV and n denotes 4, 5 or 6, depending on the valency of the metal, and X has the indicated meaning.

Preferred metal alcoholates correspond to the formula

wherein Me.sub.2 denotes zirconium.sup.IV, niobium.sup.V, tantalum.sup.V or tungsten.sup.VI and n.sub.1 denotes 4, 5 or 6 and X has the indicated meaning, especially alkyl with 1 to 4 carbon atoms. Amongst these metal alcoholates, niobium alcoholates and tantalum alcoholates with 1 to 4 carbon atoms, for example tantalum ethylate and tantalum tert. butylate and niobium ethylate and niobium tert. butylate are particularly effective. The radical --O--X in the formulae (2), (8) and (9) is preferably a radical of an optionally chlorinated alkanol with up to 4 carbon atoms, such as, for example, methanol, ethanol, .beta.-chloroethanol, isopropanol, n-propanol, n-butanol, sec.- or tert.-butanol, of a cycloalkanol with, appropriately, 5 to 12, or preferably 8 to 12, ring carbon atoms, such as cyclododecanol, or a radical of phenol or benzyl alcohol. As halogen, Q denotes, for example, bromine or preferably chlorine. As alkoxy, Q is as a rule different from OX and can, for example, be methoxy, ethoxy, propoxy, iso-propoxy, n-butoxy or, preferably, tert. butoxy. r preferably has the same meaning as n, so that metal alcoholates of the formula Me(OX).sub.n are preferred. The process according to the invention is preferably carried out in the presence of the optional additional component (d). Such components are, for example, alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide or caesium hydroxide or the corresponding alcoholates of alkanols with 1 to 4 carbon atoms, as indicated for the component (c).

Preferably, sodium hydroxide or potassium hydroxide or a sodium alcoholate or potassium alcoholate of an alkanol with 1 to 4 carbon atoms is used as the component (d).

Relative to the weight of the reaction mixture, 0.05 to 5%, preferably 0.1 to 2%, and especially 0.4 to 1%, of the catalysts (c) or (c) and (d) together are advantageously employed.

If the catalysts (c) and (d) are used together, the weight ratio of (c) to (d) is as a rule 9:1 to 1:9, preferably 4:1 to 1:4 or, above all, 7:3 to 3:7.

Typical representatives of the component (c) are, for example: (10.1) Ta(OCH.sub.3).sub.5 (10.2) Ta(OC.sub.2 H.sub.5).sub.5 (10.3) Ta(O--CH(CH.sub.3).sub.2).sub.5 (10.4) Ta(OC(CH.sub.3).sub.3).sub.5 (10.5) Ta(O--).sub.5 (10.6) Nb(OCH.sub.3).sub.5 (10.7) Nb(OC.sub.2 H.sub.5).sub.5 (10.8) Nb(O--CH(CH.sub.3).sub.2).sub.5 (10.9) Nb(OC(CH.sub.3).sub.3).sub.5 (10.10) Nb(O--).sub.5 (10.11) W(OCH.sub.3).sub.6 (10.12) W(OC(CH.sub.3).sub.3).sub.6 (10.13) Hf(O--CH(CH.sub.3).sub.2).sub.4 (10.14) Hf(O--C(CH.sub.3).sub.3).sub.4 (10.15) Mo(O--CH(CH.sub.3).sub.2).sub.6 (10.16) Mo(O--C(CH.sub.3).sub.3).sub.6 (10.17) Ti(OC.sub.2 H.sub.5).sub.4 (10.18) Ti(O--C(CH.sub.3).sub.3).sub.4 (10.19) Zr(OC.sub.2 H.sub.5).sub.4 (10.20) Zr(O--C(CH.sub.3).sub.3).sub.4 (10.21) Ta(OCH.sub.3)Cl.sub.4 (10.22) Nb(OCH.sub.3).sub.4 Cl (10.23) Ti(OC.sub.4 H.sub.9).sub.4 (10.24) ZrOCH.sub.3 (OC(CH.sub.3).sub.3).sub.4 (10.25) Zr(OCH.sub.3)Cl.sub.3

Typical representatives of the components (d) are, for example:

The reaction temperature is preferably 30.degree. to 120.degree.C or especially 40.degree. to 90.degree.C.

The reaction can be carried out at atmospheric pressure or at an excess pressure of up to 20 atmospheres gauge. Preferably, the pressure is 1 to 15 atmospheres gauge or especially 1 to 11 atmospheres gauge. As a rule, the reaction is carried out at the so-called autogenic pressure, that is to say the pressure generated by the reaction mixture itself, at the particular temperature.

Depending on the end use of the reaction products, 1 to 100, preferably 1 to 25, mols of the component (b) are as a rule added onto the component (a).

At times it can be appropriate to carry out the alkoxylation in the presence of a second alkoxide which does not participate in the actual reaction. For example it is possible to carry out the reaction with ethylene oxide and to use propylene oxide or dioxane as the reaction medium or as the suspension agent.

The process according to the invention has the advantage that alkylene oxides can be directly added onto an N-methylolated nitrogen compound under mild conditions, that is to say at relatively low temperatures and with a practically neutral catalyst system. It is known that N-methylol compounds are unstable in even a weakly acid medium and in a strongly alkaline medium form polycondensates or split off formaldehyde and water.

Addition reactions of, for example, ethylene oxide to an organic compound which possesses a mobile hydrogen atom are usually carried out at temperatures of 160.degree. to 200.degree.C. However, at such high temperatures most N-methylol compounds are no longer stable, that is to say a degradation of the methylol groups takes place. By means of the catalyst system used according to the invention (component (c) alone or (c) and (d) together) it has now become possible to carry out such addition reactions successfully even at relatively low temperatures, that is to say at temperatures below 160.degree.C, without a degradation of the methylol groups taking place.

Because of their methylol groups or etherified methylol groups the products manufactured according to the process of the invention are reactive and can be used for various purposes, depending on the substitution. In particular, they are suitable for use as so-called reactive surface-active agents, that is to say as reactive surface-active products which under certain conditions, for example in an acid medium or at an elevated temperature, can be converted into an irreversibly insoluble state. They can be used, for example, for the manufacture of micro-capsules. Furthermore, such products are suitable for use as detergents, detergent additives, emulsifiers, dispersing agents, additives to agents which confirm hydrophobic properties, or as such agents themselves, agents for imparting a soft handle and hydrophilic properties, or carriers.

Asymmetrical diether compounds which possess at least one hydrophobic and hydrophilic radical, are in particular valuable reactive surface-active agents.

The introduction of the hydrophilic and hydrophobic groups can be carried out in optional sequence.

In the case of the asymmetrical ethers of dimethylolurea the procedure followed is, for example, first to etherify the monomethylolurea hydrophobically or hydrophilically. A second molecule of formaldehyde is then added onto the resulting monoethers of monomethylolurea, to form the monoether of dimethylolurea. This monoether is again etherified hydrophilically or hydrophobically so that an end product which contains both a hydrophilic and a hydrophobic ether group results.

The introduction of the hydrophilic groups which confer solubility in water is effected, for example, by reacting the monomethylol compound in question, in the presence of a catalyst, with, for example, ethylene oxide, whereby a polyethylene glycol ether is formed. The hydrophobic group is most simply introduced by direct etherification of the methylol group in a weakly acid medium with a hydroxyl compound contain 4 or more carbon atoms. It is optionally also possible first to carry out an etherification with a lower alcohol and to introduce the higher alcohol of low volatility by trans-etherification. A further possibility of introducing hydrophobic groups consists of the reaction of the free methylol groups with, for example, propylene oxide. Since a reaction with ethylene oxide is carried out in the preceding or subsequent stage, one obtains, for example, dimethylolurea which is etherified on one side with propylene oxide and on the other with a polyethylene glycol.

A preferred procedure is, for example, the following: The monomethylol compound of the urea, which is manufactured in a known manner by addition of one molecule of formaldehyde, is appropriately first etherified with n-butanol, and the ethers of the higher alcohols are manufactured by trans-etherification of the n-butyl-ether. n-Butanol is preferred because with it the reaction can be carried out in a homogeneous phase and during the trans-etherification the n-butanol can again be distilled off in vacuo at a temperature which is not excessively high. The latter point is important because in the etherification which takes place in a weakly acid medium, for example a medium containing acetic acid, some insoluble carbamide resin is always produced. When etherifying monomethylolurea with n-butanol it is advisable to etherify methylolureas containing at least 5% of water, that is to say not to dry them too thoroughly before the etherification. The addition of the ethylene oxide onto the methylol groups of the ureas is carried out in accordance with the process of the invention. The length of the polyglycol-ether chain plays an important role because it influences the solubility of this surface-active agent, especially the solubility in water.

The examples which follow explain the invention without restricting it thereto. In the examples, percentages are percentages by weight throughout.

100 mg of Ta(OC(CH.sub.3).sub.3).sub.5, 6.6 g (corresponding to 8 mols) of ethylene oxide and 5.4 g of the compound of the formula (5.1) (1 mol) are sealed in a glass tube of 70 ml capacity. The mixture is allowed to react for 16 hours at a pressure of 10.5 atmospheres gauge, whilst shaking, in a heating bath thermostatically controlled to 90.degree.C, in the course of which 99% of the ethylene oxide undergo addition. This accordingly yields an end product which predominantly corresponds to the formula

the infra-red spectrum of this product shows the following bands:

100 mg of Ta(OC(CH.sub.3).sub.3).sub.5, 11 g (corresponding to 5 mols) of ethylene oxide and 14.4 g (1 mol) of the compound of the formula (5.2) (urea-monomethylol-dodecyl-ether post-methylolated with paraformaldehyde) are sealed in a glass tube, as described in Example 1. This reaction mixture is left to react for 16 hours at a pressure of 17.5 atmospheres gauge, whilst shaking, in a heating bath thermostatically controlled to 110.degree.C, in the course of which 98.7% of the ethylene oxide undergo addition. Hence, a reaction product which predominantly corresponds to the formula ##EQU8## is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of a catalyst mixture of NaOC.sub.2 H.sub.5 and Nb(OC(CH.sub.3).sub.3).sub.5 [mixed in the ratio of 1:1], 6.6 g of ethylene oxide [corresponding to 6 mols] and 6.7 g (1 mol) of the compound of the formula (5.3) are sealed in a glass tube, as described in Example 1. This reaction mixture is reacted for 16 hours at a pressure of 5.2 atmospheres gauge, whilst shaking, in a heating bath thermostatically controlled to 60.degree.C, in the course of which 98% of the ethylene oxide employed undergo addition.

A reaction product which in the main corresponds to the formula ##EQU9## is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of a catalyst mixture of KOC.sub.2 H.sub.5 and Nb(OC(CH.sub.3).sub.3).sub.5 [in the ratio of 1:1] together with 9.9 g (9 mols) of ethylene oxide and 10.15 g (1 mol) of the compound of the formula (5.4) are sealed in a glass tube, as described in Example 1. This mixture is reacted for 16 hours at a pressure of 5.2 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 60.degree.C, in the course of which 99.4% of the ethylene oxide undergo addition. A reaction product which predominantly corresponds to the formula

is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of a catalyst mixture of Ta(OC(CH.sub.3).sub.3).sub.5 and NaOC.sub.2 H.sub.5 [in the ratio of 1:1], 8.8 g of ethylene oxide [corresponding to 4 mols ] and 5.4 g of the compound of the formula (5.5) are sealed in a glass tube. This mixture is reacted for 16 hours at a pressure of 5.2 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 60.degree., in the course of which 97% of the ethylene oxide undergo addition.

A reaction product of the formula ##EQU10## is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of Ta(OC.sub.2 H.sub.5).sub.5, 13.2 g of ethylene oxide (corresponding to 15 mols) and 10 g (1 mol) of the compound of the formula (7.2) are sealed in a glass tube and reacted for 16 hours at a pressure of 10.5 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 90.degree.C, in the course of which 100% of the ethylene oxide undergo addition.

A reaction product which predominantly corresponds to the formula ##EQU11## is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of a catalyst mixture of NaOH and Nb(OC(CH.sub.3).sub.3).sub.5 [in the ratio of 1:1], 3.5 g of ethylene oxide (corresponding to 3 mols) of 7.6 g (1 mol) of the compound of the formula (6.1) are sealed in a glass tube. This mixture is reacted for 16 hours at a pressure of 5.2 atmospheres gauge, whilst shaking, in a heating bath thermostatically controlled to 60.degree.C, in the course of which 75% of the ethylene oxide undergo addition. The reaction product in the main corresponds to the formula

the infra-red spectrum of this product shows the following bands:

100 mg of Ta(OC(CH.sub.3).sub.3).sub.5, 13.2 g of ethylene oxide (corresponding to 6 mols) and 9.3 g (1 mol) of the compound of the formula (7.3) are sealed in a glass tube. This reaction mixture is reacted for 16 hours at a pressure of 5.2 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 60.degree.C, in the course of which 100% of the ethylene oxide undergo addition. A reaction product which predominantly corresponds to the formula ##EQU12## is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of Ta(OC.sub.2 H.sub.5).sub.5, 11 g of ethylene oxide (corresponding to 5 mols) and a mixture of 7.5 g (1 mol) of the compound of the formula (7.4) in 7.2 g of propylene oxide (as a suspending agent which can easily be removed again) are sealed in a glass tube. This mixture is reacted for 16 hours at a pressure of 10.5 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 90.degree.C. After removing the propylene oxide, which has not participated in the reaction, it is possible to ascertain that 100% of the ethylene oxide have undergone addition.

Hence, a reaction product which predominantly corresponds to the formula ##EQU13## is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of a catalyst mixture of KOC.sub.2 H.sub.5 and Nb(OC(CH.sub.3).sub.3).sub.5 or Ta(OC(CH.sub.3).sub.3).sub.5 [in the ratio of 1:1]and 3.5 g of ethylene oxide (corresponding to 4 mols) and 14 g (1 mol) of the compound of the formula (5.6), wherein n=18, are sealed in a glass tube. This mixture is reacted for 16 hours at a pressure of 5.2 atmospheres gauge, whilst shaking, in a heating bath thermostatically controlled to 60.degree.C, in the course of which 100% of the ethylene oxide undergo addition. A reaction product which predominantly corresponds to the formula

is obtained.

The starting product of the formula (5.6) can be obtained, for example, if 100 mg of catalyst mixture of KOC.sub.2 H.sub.5 and potassium metal (in the ratio of 1:1), a mixture of 26 g of propylene oxide (corresponding to 18 mols) and 1.0 g of ethylene oxide (as the starter) and 2.25 g/(1 mol) of monomethylolurea are sealed in a glass tube. This mixture is reacted for 16 hours at a pressure of 5.3 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 90.degree.C, in the course of which 100% of the propylene oxide undergo addition. Instead of the above catalyst mixture, a mixture of KOC.sub.2 H.sub.5 and Ta(OC.sub.2 H.sub.5).sub.5 (in the ratio of 1:1) can also be used. This reaction product is thereafter subjected to a post-methylolation with paraformaldehyde. The infra-red spectrum of the product (110) shows the following bands:

a. 100 mg of a catalyst mixture of KOC(CH.sub.3).sub.3 and Ta(OC.sub.2 H.sub.5).sub.5 [in the ratio of 1:1], 13.2 g (corresponding to 6 mols) of ethylene oxide and 4.5 g (1 mol) of monomethylolurea are sealed in a glass tube. This mixture is reacted for 2 hours at a pressure of 1 - 2 atmospheres gauge and whilst shaking, in a heating bath which is initially kept at room temperature (20.degree. to 25.degree.C). Thereafter the heating bath is thermostatically controlled to 60.degree.C and the reaction is continued for 16 hours at 5.2 atmospheres gauge, in the course of which 88% of the ethylene oxide undergo addition.

b. The reaction product described under (a) is subjected to a post-methylolation with paraformaldehyde and thereafter propylene oxide is added as follows onto this subsequently introduced methylol group. 100 mg of a catalyst mixture of (KOC.sub.2 H.sub.5) and Ta(OC(CH).sub.3).sub.3).sub.5 [in the ratio of 1:1], 8.7 g (corresponding to 6 mols) of propylene oxide and 9.6 g (1 mol) of the product of the formula (5.7) described under (a), wherein n = 6, are sealed in a glass tube. This mixture is reacted, whilst shaking, in a thermostatically controlled heating bath, in accordance with the following programme: 2 hours at 25.degree.C and 0.7 atmosphere gauge, 4 hours at 60.degree.C and 2.5 atmospheres gauge and 16 hours at 110.degree.C and 7.9 atmospheres gauge, in the course of which 100% of the propylene oxide undergo addition.

In the main, a reaction product of the formula

is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of W(OC(CH.sub.3).sub.3).sub.6, 6.6 g (0.15 mol) of ethylene oxide and 8.6 g (0.03 mol) of the compound of the formula (5.1) are sealed in a glass tube. The mixture is allowed to react for 16 hours at a pressure of 4.27 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 60.degree.C, in the course of which 99% of the ethylene oxide undergo addition. An end product which predominantly corresponds to the formula

is obtained.

The infra-red spectrum of this product shows the following bands:

100 mg of Ta(On--C.sub.3 H.sub.7).sub.5, 7.92 g (corresponding to 6 mols) of ethylene oxide and 8.64 g(1 mol) of the compound of the formula (5.1) are sealed in a glass tube of 70 ml capacity. The mixture is allowed to react for 16 hours at a pressure of 10.5 atmospheres gauge and whilst shaking, in a heating bath thermostatically controlled to 90.degree.C, in the course of which 95.2% of the ethylene oxide undergo addition. A highly viscous clear end product is obtained, which predominantly corresponds to the formula

if, in this example, instead of 100 mg of Ta(On-C.sub.3 H.sub.7).sub.5 the same amount of one of the following catalysts is employed, the same end product is obtained, with the corresponding yields shown below.