Abstract:
A process for producing a polyether carbonate surface active material having hydrocarbon residue at terminal thereof in an efficient manner, wherein an active hydrogen-containing compound which has a hydrocarbon residue containing 4 or more of carbon atoms and a five-membered ring carbonic acid ester are telomerized in the presence of an ate-complex of a metal of Group II,III or IV of the periodic table having at least two alkoxy groups.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a process for producing polyether carbonate surface active materials. 
     2. Description of the Prior Art 
     In general, polyether carbonates can be prepared by carbonatizing and esterifying a polyether such as diethylene glycol with phosgene to form a polyethercarbonate chain but this preparation process has little or no industrial value because of the use of noxious phosgene and it is very difficult to join hydrocarbon residues to terminals of the polymer chain by such a process, thus the process has no value as a process of producing surface active materials. 
     On the other hand, it is well known that when a five-membered ring carbonate and compounds having active hydrogen such as alcohols, phenols and the like are reacted with each other under heating, using a base or an acid as a catalyst, decarboxylation takes place, resulting in hydroxyetherization or formation of polyether. 
     The present inventors have made it clear that though in prior art processes of polymerizing ethylene carbonate the decarboxylation reaction takes place violently to give polyether alone, the polymerization of ethylene carbonate using a charged neutral complex [e.g. (C 4  H 9 ) 2  Sn(OCH 3 ) 2  ] or an ate-complex [e.g. NaSn(OCH 3 ) 5  ] proceeds while suppressing the decarboxylation reaction to a considerable extent, thereby forming a polyether carbonate [--COOC 2  H 4  OC 2  H 4  O-- n  ]. 
     However, such a polymerization proceeds only very slowly and the obtained product has no hydrocarbon residue at the terminals thereof and thus the product does not have surface active properties. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a process for producing a novel polyether carbonate surface active material in an efficient manner. 
     The process for producing a polyether carbonate surface active material according to the invention is characterized in that an active hydrogen-containing compound which has a hydrocarbon residue containing 4 or more carbon atoms and a five-membered ring carbonic acid ester are telomerized in the presence of an ate-complex of a metal of Group II, III or IV of the periodic table having at least two alkoxy groups. 
     PARTICULAR DESCRIPTION OF THE INVENTION 
     According to the process of the invention, the polymerization reaction proceeds readily in a very high yield and a novel polyether carbonate surface active material having hydrocarbon residues at the terminals thereof can be obtained. 
     The polymerization reaction of the invention proceeds as typically represented by the following formula: ##STR1## 
     In the above formula, RXH [1] represents an active hydrogen-containing compound having a hydrocarbon residue containing 4 or more carbon atoms and including, for example, linear or branched, long-chained or alicyclic monoalcohols such as 1-, 2- isobutanol, pentanol, hexanol, octanol, dodecanol and the like, polyhydric alcohols such as 1,2-octandiol, 1,5-dodecandiol and the like, alcohols having characteristic radicals such as butoxyethanol, dioctyl tartarate, 4-phenoxybutanol, carbamoylhydroxyethanol, and the like, saturated or unsaturated mono- and polycarboxylic acids such as caproic acid, lauric acid, 2-methyloctanoic acid, oleic acid, alkylbenzoic acid, methylcyclohexanecarboxylic acid, azelaic acid and the like, phenols such as phenol, butylphenol, methylnaphthol and the like, and primary or secondary, saturated or unsaturated amines such as butylamine, linear or cyclohexylamine, 1-methylheptylamine, dodecylamine, N-butylaniline, toluyl-N-methylamine and the like. Further, R 1 , R 2 , R 3  and R 4  represent, independently, a hydrogen atoms or a methyl group. Representatives of the five-membered ring carbonic acid ester [2] are ethylene carbonate, 1,2-propylene carbonate, and the like. 
     In the above formula, i and j are each an integer of above 1, inclusive, and generally from 1 to 10. A compound of the formula where i=1 and j=1 is a typical one. 
     The value of n can be arbitrarily selected depending on the property required for the product [3] and is generally an integer of above 2, inclusive. 
     For most ordinary applications, 5 to 30 times by mol of the compound [2] is preferably used and too large or too small values of n are not favorable due to a loss in balance of properties such as solubility in water, surface activity and the like. 
     A most important feature of the invention resides in the telomerization of a five-membered ring carbonate in combination with an active hydrogen-containing compound in the presence of a catalyst of an ate-complex of a metal of Group II, III or IV of the periodic table having at least two alkoxy groups. Examples of the ate-catalyst (M⊖) include NaB(OCH 3 ) 4 , KB(OC 2  H 5 ) 4 , NaB(OC 4  H 9 ) 4 , NaBPh(OCH 3 ) 3 , NaAl(OCH 3 ) 4 , NaGe(OCH 3 ) 5 , NaSnBu 2  (OCH 3 ) 3 , NaSn(OC 2  H 5 ) 5 , LiPb(OC 3  H 7 ) 4  and the like. Of these, MB(OR) 4 , MSn(OR) 5  and M 2  Sn(OR) 6  (in which M represents an alkali metal and R represents an aliphatic hydrocarbon residue) are preferable in view of the polymerization velocity and properties of a product. It will be noted that any combination of compounds which are able to produce in the reaction system such catalysts as indicated above is preferable. For example, LiAlH 4  or NaBH 4  and alcohols; SnCl 2  or SnCl.sub. 4 and NaOR; B(OCH 3 ) 3  and NaOCH 3 , Bu 3  SnOC 3  H 7  or Bu 2  Sn(OMe) 2  and NaOCH 3 , SnCl 4  or AlCl 3  and dimethylformamide, dimethylsulfoxide and an alkali base, and the like may be used under such conditions as to produce the ate-complexes in the reaction system. 
     The structural formula [3] of the product is shown merely as a typical structural formula and of course, the structure of an actual telomerization product varies depending on the structure of the active hydrogen-containing compound [1]. 
     In the process of the invention, coexistence of moisture at the time of the telomerization reaction is not favorable due to a tendency to cause decarboxylation and the telomerization is preferably conducted in a dry atmosphere. In general, the telomerization reaction is conducted in an atmosphere such as of N 2 , Ar, H 2 , CO 2  or ethylene oxide. 
     It is to be noted that the reaction carried out in the presence of CO 2  or ethylene oxide may involve incorporation of part of such a compound in the polymer, such incorporation having little or no influence on the polymer. 
     The polymerization is usually conducted at a normal pressure but is feasible under pressure. 
     The polymerization temperature is in the range of 60° to 200° C. Lower temperatures than 60° C. are unfavorable since the polymerization proceeds only too slowly and higher temperatures than 200° C. result in vigorous decarboxylation reaction, not giving the intended product. Preferably, a temperature ranging from 100° to 150° C. is most suitably used in the practice of the invention. 
     The telomerization polymerization is ordinarily conducted in the absence of solvent and may be carried out in the presence of an inactive solvent. The polymerization product may be used as a surface active material as it is and, if necessary, it may be subjected to a distillation under reduced pressure or a solvent extraction to remove unreacted materials therefrom. 
     The polyethercarbonate surfactant obtained according to the process of the invention is a novel one and can not be directly compared with prior-art products but is believed to have wide utility in various fields. 
     For instance, polyether nonionic active agents and their derivatives have a polyoxyethylene structure (C 2  H 4  O) n , which is hard to decompose biochemically, causing an environmental problem such as water pollution and which may be noxious. 
     In contrast, the surfactant obtained by the process of the invention has typically a polyether carbonate structure (OC 2  H 4  OCOOC 2  H 4 ) n , though including a random copolymer structure composed of C 2  H 4  O units and C 2  H 4  OCOOC 2  H 4  units. Because of the absence of a long-chained polyoxyethylene structure, it is, after application as a surfactant, readily hydrolyzed mainly into harmless diethylene glycol with a loss of surface activity, contributing to solve the environmental problem more or less. 
     Ethylene carbonate, which is a principal starting material used in the present invention can be easily synthesized from carbon dioxide and oxirane (ethylene oxide) by a known technique. Accordingly, if the surface active material obtained by the present invention can be utilized from viewpoints of engineering, carbon dioxide which is a final carbon source of mankind and is at present a harmful final waste, can be effectively utilized. 
     It is well known that ethylene carbonate polymers can be prepared by copolymerization of carbon dioxide and oxirane. However, this polymerization involves the following disadvantages; water-insoluble high molecular weight polymers are secondarily produced and zinc diethyl used as a catalyst reacts with active hydrogen-containing compounds such as alcohol used to prepare a surface active material thereby losing its activity. This is completely different from the conception of the invention. In addition, conventional industrial products from petroleum are chiefly comprised of carbon and hydrogen but the polyether carbonate obtained by the present invention has an oxygen content of nearly 50% and the heat of its partial combustion is small, giving a fresh guide to starting materials for synthetic purpose. 
     Further, conventional nonionic active agents are stable, poor in biodecomposability, without loss of surface activity when applied, and may frequently cause pollution of industrial effluent, whereas the surfactant of the invention is readily hydrolyzed at pH 9 (pH value of soap) with a loss of surface activity, so that it is expected to be widely applied industrially such as by adding the surfactant to a composition such as a machine oil, applying the mixture, hydrolyzing the surfactant in the composition to allow the surfactant to lose its activity, and de-emulsifying it to separate the oil therefrom, leading to prevention of industrial effluent from being polluted with such oil. 
     The product obtained by the present invention can be used widely as a nonionic active agent by itself, similarly to known polyoxyethylene or propylene nonionic surfactants and can also be utilized as a starting material or composition for preparing other active agents. The product itself obtained by the present invention can be used as, for example, an emulsifier, a solubilizing agent, a dispersant, a detergent and the like singly or as composition. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be particularly described by way of examples, which should not be construed as limitations of the invention. 
     EXAMPLE 1 
     A glass flask was equipped with an agitator, a nitrogen-charging tube and a condenser having an exhaustion tube and then the air in the inside of the flask was substituted with dry nitrogen. One part (by weight) of n-octanol and ethylene carbonate in an amount of 10 times by mol of the n-octanol were introduced into the flask, to which was further added 3 mol% of sodium pentamethoxystannate as a catalyst, followed by reaction at 150° C. for 5 hours. 
     During the reaction, CO 2  gas was generated in an amount corresponding to about 50% by mol of the employed ethylene carbonate. 
     As a result, a compound (3a) represented by C 8  H 17  O(COOC 2  H 4  OCH 2  CH 2  O) m  H (in which m is a value of 5 in average) was quantitatively obtained. 
     When analyzed by an infrared absorption spectrum technique, the compound (3a) showed absorptions by carbonyl at 1745 cm -1  and by ether at 1250 cm -1 , respectively. The H-NMR spectrum revealed that it showed two kinds of triple lines of methyl group at 0.90 ppm, methylene group of octyl group at 1.3 ppm or CH 2  O group (A) at 3.61 ppm, and CH 2  OCO group (B) at 4.23 ppm. 
     Further, when the compound (3a) was subjected to an adsorption liquid chromatographic separation using a silica gel-carrying column-dichloromethane developer, unreacted octanol was not isolated, from which it was confirmed that the octanol employed was joined to terminals of the polymer. 
     When a terminal hydroxy group value was measured by a pyridien-acetic anhydride method, a value corresponding to the molecular weight of the above compound (3a) was obtained. From the areas of the CH 2  O group (A) and the CH 2  OCO group (B) was calculated a ratio of a structure of the carbonic acid ester to a structure of the ether (decarboxylated ester structure), 100 i/(i+j) (hereinafter referred to as CO 3  fixing ratio, this value being 50 in an ideal condition where i=j=l), revealing that such value was 49%. 
     Then, the above compound (3a) was heated and hydrolyzed with a dilute alkali solution, neutralized with an acid, and extracted with ether. As a result, diethylene glycol was isolated and identified in an amount corresponding to 80% of diethylene glycol expected to be produced on hydrolysis of the compound (3a). 
     When tetraethoxystanate Sn(OC 2  H 5 ) 4  which was neutrally charged was used a catalyst to conduct the reaction at 150° C. for 20 hours, only 68% of the starting material took part in the reaction and the CO 3  ratio by % was lowered to 45%, from which it was found that NaSn(OC 2  H 5 ) 5  was more effective. From these facts, the product was proved to be the compound (3a). 
     Dilute aqueous solutions of these compounds were prepared, from which insoluble matters were removed. The aqueous solution of the compound (3a) (concentration: 0.2 wt%) had a surface tension (40° C.) of 45 dyne/cm. The concentration was varied to obtain a concentration-surface tension curve, from which a critical micelle concentration was determined to be about 0.1%. 
     When the reaction was conducted at 150° C. for 20 hours in the absence of an active hydrogen-containing compound in the same manner as in the above Example, the yield of the polymer was below 70% and the reaction velocity was low. In addition, the produced polymer showed no surface activity. 
     EXAMPLE 2 
     Example 1 was repeated using, instead of octanol, n-butanol or n-dodecanol, thereby obtaining a polyether carbonate telomer corresponding to the general formula [3] where R is C 4  H 9  or C 12  H 25 . The surface tensions of 0.3% aqueous solution of these telomers at 40° C. were found to be 40 and 46 dyne/cm, respectively. 
     EXAMPLE 3 
     Example 1 was repeated using ethylene carbonate amounts of 5 and 20 times by mol. The molecular weights of the resulting telomers corresponded to m=2.5 and 10, respectively. The surface tensions of solutions of these telomers were 45±2 dyne/cm in both cases. When the amounts of the catalyst NaSn(OCH 3 ) 5  were changed to levels of 3,4 or 10%, the yield of the telomer was not changed. The polymerization of 100° C. and 10 hours resulted in a yield of below 10% and with a polymerization of 200° C. and 2 hours, the CO 3  ratio by % was as low as 15%. 
     EXAMPLE 4 
     Example 1 was repeated except that an autoclave was used as a polymerization apparatus, the catalyst used was NaZn(OCH 3 ) 3  obtained by mixing ZnCl 2  and NaOCH 3 , and the reaction is conducted in an atmosphere of ethylene oxide under a pressure of 5 kg/cm 2 , with the results that the CO 3  ratio by % was 34%. This reveals that the obtained polymer has a structure of the general formula [3] where i=1 and j=2. The surface tension of a 0.2% aqueous solution of the product was 38 dyne/cm. 
     EXAMPLE 5 
     Example 1 was repeated using octylamine and octanoic acid as the active hydrogen-containing compound, thereby obtaining corresponding telomers almost quantitatively, respectively. The surface tension of these telomers in the form of a 0.3% aqueous solution were, respectively, 31 and 37 dyne/cm. 
     EXAMPLE 6 
     Several catalysts were provided including sodium boron hydride (converted into NaB(OR) 4  ate-catalyst by reaction with an alcohol during polymerization), a mixture of equimolar amounts of trimethyl borate and sodium methoxide (from which NaB(OCH 3 ) 4  is produced), aluminum chloride and 4 times by mole of sodium methoxide, a mixture of stannous chloride or stannic chloride and an excess of sodium isopropoxide (1:5), an equimolar mixture of tributyltinmonomethoxide and potassium methoxide (from which K(C 4  H 9 ) 2  Sn(OCH 3 ) 2  was produced), dibutyltin bis diethylamide and an equimolar amount of lithium methoxide, and dibutyltin oxide and two times by mol of sodium ethoxide being heated to give an ate-catalyst. Then, octanol and 10 times by mol of ethylene carbonate were heated at 150° C. for 10 hours by using 3% of each catalyst to obtain a corresponding polyether carbonate at a yield of 98% in case of sodium boron hydride, 85% for an equimolar mixture of trimethyl borate and sodium methoxide, 63% for aluminum chloride and 4 times by mol of sodium methoxide, 75 or 88% for a mixture of stannous chloride or stannic chloride and an excess of sodium isopropoxide, 92% for an equimolar mixture of tributyltin monomethoxide and potassium methoxide, 92% for dibutyltin bisdiethylamide and an equimolar amount of lithium methoxide, or 86% for dibutyltin oxide and sodium ethoxide. An aqueous solution of each product had a surface tension of below 40 dyne/cm. 
     EXAMPLE 7 
     To an alcohol represented by C 4  H 9  O(C 2  H 4  O) 2  H was added 4 times by mol of 1,2-propylene carbonate, to which was further added 3 mol% of a sodium tetramethoxy borate catalyst or a catalyst composed of a combination of dimethylgermyl dichloride and 3 times by mol of sodium methoxide, followed by heating at 150° C. for 10 hours to obtain polyether carbonate telomers at yields of 93% and 75%, respectively. The surface tensions of 0.5% aqueous solutions of the products were below 40 dyne/cm. 
     EXAMPLE 8 
     One part of a sugar ester of octanoic acid, 10 parts of dimethylformamide and 3 parts of ethylene carbonate were mixed, to which was added 4 mol% of sodium tetramethoxy borate, followed by heating at 140° C. for 5 hours to obtain a polyether telomer at a yield of 87%. The surface tension of a 0.1% aqueous solution of the telomer was 33 dyne/cm. 
     EXAMPLE 9 
     Five moles of ethylene oxide was addition reacted with butanol by a usual manner to obtain an alcohol with an average composition of C 4  H 9  (OC 2  H 4 ) 5  OH, to which was added 4 times by mol of isobutylene carbonate 1,1-dimethyl-ethylene carbonate), followed by polymerizing at 155° C. for 8 hours by the use of 2 mol % of sodium tetramethoxy borate as a catalyst thereby obtaining a corresponding polyether carbonate telomer at a yield of 90%. The surface tension of 0.1% aqueous solution of the telomer was 37 dyne/cm. 
     EXAMPLE 10 
     To dodecanol was added 5 times by mol of ethylene carbonate, followed by heating in an atmosphere of argon at 140° C. for 24 hours by the use of 3% sodium pentamethoxy stannate as a catalyst. Unreacted ethylene carbonate was recovered under a reduced pressure of 0.1 mmHg to obtain 86% of a corresponding polyether carbonate telomer. This telomer had a rather low CO 3  ratio of 39% and about 25% of water-insoluble matters were contained. The surface tension of a 0.2% aqueous solution of the telomer from which the insoluble matters had been removed was 45 dyne/cm. In the case when the pH was adjusted to 4.6, the surface tension was held unchanged even when the solution was allowed to stand at 40° C. for 200 hours while keeping the surface activity at a level. In contrast, the surface tension was lowered substantially to the same level as of water in an ammonium hydroxide-ammonium chloride aqueous solution with a loss of the surface activity.