MXPA97005438A - Process for the preparation of haluros of halohidroxipropiltrialquilamo - Google Patents

Abstract

The present invention relates to a process for producing halohydroxypropyltrialkylammonium salts by reacting, in a reaction mixture, a trialkylamine salt and the corresponding free amine with epihalohydrin, wherein the free trialkylamine is present in an amount corresponding to 1 to 10 per cent. one hundred mole of the combination of the free amine and amine hydrohalide and wherein the epihalohydrin is mixed and allowed to react for a first period with the free amine and the hydrohalide salt at a lower temperature than a second temperature at which it is of the epihalohydrin to further react with the amine and the hydrohalide salt during a second period wherein the second temperature is sufficiently greater than the first in which there is less unreacted amine after the reaction that is present if the same reactants are mixed and they are reacted at the first temperature for a time equal to the sum of the first and second period

Description

PROCESS FOR THE PREPARATION OF HALOHIDROXIPROPILTRIALQUILAMONIO HALURES This invention relates to the preparation of halohydroxypropyltrialkylammonium halides. The halohydroxypropyltrialkylammonium halides are known to be useful as intermediates used in the modification of natural and synthetic polymers, particularly in the production of cationic polysaccharides, for example starch. The halohydroxypropyltrialkylammonium halides are generally prepared by the reaction of certain trialkylamines or their salts with epihalohydrins for example by the methods taught in European Patent Application No. 55,796 and Patents of E. U.A. Numbers 2, 876, 217; 3, 135,788; 4,450,295 and 4, 594,452. The U.A. Patent 2, 876,217 describes reactions of epihalohydrins and certain tertiary amines or salts in aqueous systems at a pH of at least 5. The use of said method results in a series of by-products, including unreacted epihalohydrins and 1,3-dihalo-2 -propanol, which are preferably removed by careful purification by solvent extraction or vacuum distillation. European Patent Application No. 55,796 and Patent of E. U.A. 3, 135, 788 also describes aqueous systems for similar reactions that require careful purification. In the prior art, the trialkylamines salts are normally used in place of the free amines to avoid the production of epoxypropyl- (glycidyl) compounds in place of the desired halohydroxypropyl compounds. However, Japanese Application 04-145054 (1992) describes a synthesis using trialkylamine and a hydrogen halide in less than a stoichiometric amount, the acid is used in an amount corresponding to 10-95 molar of the amine to achieve neutralization partial. A temperature of -10 ° C to 50 ° C is used. This reference explains the problems with production of by-products in the prior art using completely neutralized amine. It also reveals the production of diquaternary by-product and diol and epoxide product together with a high concentration of residual amine after synthesis. It may be desirable to have a process for producing halohydroxypropyltrialkylammonium halides that produces a high yield of the desired product and fewer byproducts, especially dicuaternary compounds, or less residual trialkylamine (which is commonly in the hydrochloride form after the reaction) than that observed with prior art process. In one aspect, the invention is a method for producing a halohydroxypropyltrialkylammonium salt by reacting, in an aqueous reaction mixture, a trialkylamine salt and the corresponding free amine with an epihaiohydrin, wherein the free trialkylamine is from 1 to 10 percent. molar of the combined trialkylamine hydrochloride and free amine and wherein the epihaiohydrin is mixed and allowed to react for a first period with the free amine and the hydrohalide salt at a lower temperature than a second temperature at which the epihaiohydrin is allowed to react in addition to the amine and the hydrohalide salt during a second period wherein the second temperature is sufficiently greater than the first in which less unreacted amine is present after the reaction than it is present if the same reactants are mixed and they react at the first temperature for a time equal to the sum of the first and second periods. The epichlorohydrin is preferably mixed and allowed to react with the free amine and the hydrohalide amine at a first temperature of 0 ° C to 15 ° C and the resulting mixture is further allowed to react at a second temperature of less than 50 ° C at least at 15 ° C. This process advantageously produces high yields of desired product with low yields of by-products, especially dicuaternary compound and low levels of starting trialkylamine remain in the final solution. Advantageously, the purification of the product is facilitated and the environmental concern is reduced by having a lower amount of organic by-product produced. The process of the invention is highly applicable and is particularly useful for the preparation of 3-chloro-2-hydroxypropyltrimethylammonium chloride of trimethylamine and trimethylamine hydrochloride which was reacted with epichlorohydrin. While the description is given partially in terms of the specific example for clarity, the invention is thus not limited. The process of the invention is suitable for any trialkylamine and the corresponding hydrohalide but is particularly useful for trialkylamines and their hydrohalides such as trimethylamine, tri-n-propylamine, dimethylstearylamine, dimethyldodecylamine, triethylamine, tri-n-butylamine, tri-n-hexylamine. , dimethylmonoe ti sheet, dimethylmono-n-butylamine, dimethylcyclohexylamine, dimethyl-monoisopropylamine, methylethyl-n-propylamine, methylethyl-n-butylamine, methyldialkylamines and other tertiary amines having linear, branched or cyclic hydrocarbon groups each containing 1 to 20 carbon atoms and its hydrohalide preferably dimethylstearylamine, dimethyldodecylamine or trimethylamine, and their hydrohalides, more preferably trimethylamine and its hydrohalides, particularly its hydrochloride. Trialkylamines and their salts are commercially available, or are formed in reactions within the practice such as the reaction of the corresponding trialkylamine with an acid, preferably a hydrohalic acid, to form the amine hydrohalide, more preferably with hydrochloric acid. While the hydrohalide is preferred, any acid could sufficiently neutze the base useful in the practice of the invention; therefore, any acid salt is suitable in the present invention, preferably salts that do not form a pH buffer, more preferably inorganic acid salts, even more preferably monovalent inorganic salts such as nitrates or bivalent inorganic salts such as sulfates, but also organic salts such as acetate or formate.

Any epihaiohydrin is suitably used, but epichlorohydrin is the preferred epihaiohydrin since it is readily available and the chloride ion is considered more environmentally acceptable than other halides. In a preferred embodiment, it is mixed with the corresponding trialkylammonium salt, preferably hydrohalide, preferably in aqueous solution, more preferably both the amine and the hydrohalide are in aqueous solution. While any concentration of the amine combined with trialkylamine salt is suitable for use in the practice of the invention, for convenience and to achieve a desirable rate of reaction with epihaiohydrin while avoiding the handling of excessive waste water, the initial concentrations preferably they are high enough to achieve a rapid reaction rate, conveniently at least 10 weight percent, but insufficient to precipitate the salt or product, hence less than 60 weight percent, more preferably 40 to 60, still more preferably from 55 to 60 weight percent based on the combined amine and the hydrohalide weight based on aqueous mixture prior to the addition of epihaiohydrin. Alternatively, an amine is partially neutralized with the acid, preferably hydrohalic acid or an amine salt is partially neutralized with a base. The partial neutralization optionally takes place in situ, for example, by simultaneous or sequential addition of amine and acid. Any means within the art to form mixtures of the free amine and its salt in the preferred ratios is suitable for use in the practice of the invention. The amine and hydrohalide are conveniently mixed just before the reaction with epihaiohydrin. Alternatively, a mixture is prepared in advance or obtained commercially. If the mixture is stored, it is advantageous to store the mixture in a closed container to prevent the free amine from escaping when the amine is volatile. Sufficient amine is mixed with, or otherwise, present with the amine salt, preferably hydrohalide, to reach an initial pH (before the addition of epihaiohydrin) from 8.1 to 9.2, preferably from 8.1 to 9.0, more preferably from 8.1 to 8.9 to 10 ° C. These pH correspond to an amine hydrohalide for the total free amine plus the percentage of amine hydrohalide from 99.0 to 90.0, preferably from 99.0 to 93.0, more preferably from 99.0 to 95.0 as calculated based on a pKa graph of trimethylamine and temperatures of Dissociation Consti- cants of Organic Bases in Aaueous Solution by DD Perrin (Butterworths, London, 1965, page 15) reproduced below. This percentage corresponds to the molar percentage of hydrohalic acid used to neutralize amine.

Trimethyl amine pKa Temperature (° C) 10,355 0 10,128 10 9,907 20 9.692 30 9,477 40 9.270 50 As the table shows, the pH measured varies with temperature. For example, a pH of 8.5 measured at 30 ° C corresponds to 94 mole percent of trimethylamine hydrochloride, but the same pH measured at 20 ° C corresponds to 96.4 mole percent of trimethylamine hydrochloride. The present invention, therefore, is defined in terms of hydrohalide salt in molar percentage based on combined free amine and hydrohalide salt and the pH is set for convenience as measured at 0 ° C. For convenience, the following graph gives the corresponding molar percentage of trimethylamine (TMA) and pH calculated at 15 ° C and molar concentration.

The mixture of trialkylamine hydrohalide / trialkylammonium is reacted with epihaiohydrin. At least a stoichiometric amount of epihaiohydrin is advantageously reacted with the mixture so that the amine is reacted completely with the epihaiohydrin to form the desired product. Preferably, the ratio of epihaiohydrin to amine plus hydrohalide is from 1 to 12, more preferably from 1,005 to 1,20 and even more preferably from 1:10 to 1,20. Excessive amounts of which are reacted with other reagents, usually form dihalopropanol under reaction conditions.

Advantageously, the epihaiohydrin is added to the mixture of aqueous amine, amine hydrohalide (hereinafter, reaction mixture). Alternatively, the epihaiohydrin is added simultaneously with the aqueous mixture to form the desired product. When the epihaiohydrin is added, the temperature is advantageously sufficient to result in a desired reaction rate, conveniently to cause the reaction to proceed with minimal reagent buildup and a slow exotherm, but slow enough to avoid appreciable compound formation dicuaternario and dihaloalcohol byproduct. "Substantial" is understood to be less than 1 weight percent of the diquaternary compound based on the weight of the desired product, in the case of trimethylamine reacted with epichlorohydrin, 3-chloro-2-hydroxypropyltrimethylammonium chloride, plus diquaternary compound and less than 10 per cent. weight percent dihaloalcohol byproduct based on the weight of the desired product plus dihaloalcohol. The addition temperature is preferably 0 ° C to 15 ° C, more preferably 5 ° C to 15 ° C, still more preferably 10 ° C to 15 ° C. The pH of the reaction mixture will be increased by the addition of epihaiohydrin and its reaction with the amine / hydrohalide mixture. The observed pH is preferably 7.5 to 1 1 after all is added to epihaiohydrin. The epihaiohydrin preferably that adds to the mixture for a time instead of all at once to avoid an exotherm which is difficult to control and leads to high levels of aqueous and organic byproducts. Conveniently, it is added over a period of 1 to 4 hours. Alternatively, the process is continuous and comprises adding the hepihalohydrin and amine / amine salt mixture in stoichiometric amounts or the preferred ratios in a continuous form. The continuous process advantageously has a short residence time in a mixer with a long residence time in a reactor. A batch process has advantageously slowly added the epihaiohydrin to the amine salt mixture with continuous mixing during and after the addition. It has now been found that the use of a mixture of amine reagents / amine hydrohalide, while a relatively low temperature for the addition or mixing of epihaiohydrin with the amine mixture is advantageous, a relatively higher temperature is advantageous for at least part of the reaction time. Therefore, it is advantageous to have a first period that preferably includes the addition of at least a majority of the epihaiohydrin at a temperature of at least 10 degrees centigrade below a second period during which it is allowed to proceed more the reaction. The second period at a higher temperature results in a lower residual unreacted amine in the reaction mixture after the reaction is finished. The variations within these two periods are within the practice of the invention. For example, while it is preferable to add the epihaiohydrin during the first period while the temperature is lower, optionally at least a portion, preferably less than half, more preferably little or none of the epihaiohydrin is added during the second period to the higher temperature. In a preferred embodiment, the first period extends beyond the time required for the addition of epihaiohydrin to allow the reaction to include that which is achieved during the addition as well as continuous reaction. The time after the addition of epihaiohydrin is completed during which the additional reaction takes place, it is referred to herein as the digestion time. The first period preferably includes in addition to an addition time, a digestion time, said digestion time preferably being sufficient to allow a predetermined amount, preferably at least 85 percent of the amine and amine salt to react with the epihaiohydrin, more preferably it is at least 0.5 hours, even more preferably it is at least 1 hour. Preferably, the digestion period ends when enough product is formed since the dihaloalcohol formation rate becomes at least equal to the rate of product formation. While this first period, whether or not it includes digestion time, is preferably at the set temperatures for addition of epihaiohydrin, the second period is at a second higher temperature, sufficiently higher to result in less residual amine after the reaction of what could be observed if the same reaction (same reactants, total time, addition time and reaction conditions) except for the temperature of the second period completely took place at the temperature used during the first period. This second temperature is preferably at least 10 degrees centigrade above that used for the first period and preferably is less than 50 ° C but at least 15 ° C, more preferably less than 50 ° C but at least 30 ° C C, even more preferably less than 50 ° C but at least 40 ° C. The second period preferably is a digestion time, said digestion time is preferably sufficient to result in less residual amine, more preferably it is at least 0.5 hours, even more preferably at least 2 hours. Preferably, this digestion time ends when, at least, 90 weight percent of the amine, more preferably at least 99 weight percent of the amine has reacted, more preferably, at least 50 ppm of amine it remains. Preferably, the second period varies from 0.5 to 4 hours, even more preferably digestion is from 1 to 3 hours. Those skilled in the art will recognize that the present invention includes variations such as gradual increase in temperature from one period to another, for example, in response to the reaction exotherm. Even when there is a gradual increase, there is a period within a first temperature scale and a second period within a second temperature range. In such cases, the preferred period at any individual temperature will be shorter than that which is preferred when there are two relatively constant temperatures. The term "relatively constant" is used to recognize that in practice, there is often variation within a "constant" maintained temperature.; for example, a thermostat can allow a few degrees above and below a fixed temperature, said temperature maintained within a scale is more constant than a continuous rise or decrease in temperature. In reactions where the temperature changes, during a period the temperature is taken as an average temperature during the period. The invention also includes the use of more than two or three temperatures, for example, several short digestions at different temperatures. After the reaction of epihaiohydrin and trialkylamine and its salt a predetermined step to be completed is reacted, preferably it is essentially complete, i.e., at least 90 weight percent, more preferably 99 weight percent, is reacted limiting reagent (preferably the amine plus trialkylamine salt), the reaction is terminated by the removal of epihaiohydrin by any means within the skill in the art such as by extraction of organic solvents or azeotropic distillation by vacuum. Some by-products are inevitably produced and optionally reacted appropriately before, after, or when possible during the process of the invention. The epoxy by-product, in the case of reacting epichlorohydrin with trimethylamine, 2,3-epoxypropyltrimethylammonium chloride, is optionally converted to the product of 3-chloro-2-hydroxypropyltrimethylammonium chloride by hydrochlorination. Hydrochlorination is within the practice in the art, for example, where an equimolar amount of hydrochloric acid is added and reacted at 20-100 ° C. After the epichlorohydrin, the reaction of amine / amine salt is terminated, the dihaloalcohol is terminated, in the case of reacting epichlorohydrin with trimethylamine, 1,3-dichloro-2-propanol and residual epichlorohydrin, the product is advantageously separated. The removal is suitable by any method within the skill in the art, but preferably by distillation, preferably azeotropic distillation, more preferably azeotropic vacuum distillation. This means that distillation is preferred since they provide economic separation and do not introduce foreign solvent material. Additionally, the vacuum conditions minimize the temperatures and terminal degradation resulting from the product. Preferably, the azeotropic distillation takes place in the presence of sufficient water to provide the azeotropic composition of water with dihalopropanol, which is 75 weight percent water. The water phase can be allowed to separate and heat to reflux. Initially, there is advantageously enough water to allow losses due to the solubility of the water removed with the dihalopropanol (including dissolved water) and sufficient to provide water for the azeotrope. Given the heterogeneous nature of the azeotrope that allows the water to warm again at reflux, very little additional water will be required. Vacuum distillation can be achieved at any pressure below atmospheric, conveniently 50 to 100 mm Hg corresponding to temperatures within the column varying from 30 to 90 ° C. Preferably, the product is produced "substantially without" diquaternary or diol byproducts. By substantially no, it is understood that said by-products are each present in amounts less than 1 weight percent relative to the halohydroxypropylammonium salt of the product. Preferably, there is less than 500 ppm of diol by-product in an aqueous product solution of 65 weight percent. More preferably, less than 1 percent of a by-product is converted to halohydroxypropyltrialkylammonium halide, thereby improving the efficiency of use of raw materials. Measuring said concentrations of diquaternary byproducts and diol is within the skill of the art, for example, by liquid chromatography of an aqueous solution of the halohydroxypropyltrialkylammonium halide product., said product is more preferably in a concentration of 65 weight percent water. Said chromatography, preferably ion equalization, is suitably carried out in a system such as the "Waters Liquid Chromatograph System" commercially available from "Millipore, Waters, Cromatography Division". Said system has a pump, sample injection system, radial column compression system and a refractive index detector. Suitable columns include, for example, reversed phase columns of C-18. An ion equalization chromatography reagent such as the preparation of 3.98 g (grams) of 1-octane sulfonic acid, 16 g of sodium perchlorate, 132 g of methanol and 1750 g of water with high purity, filtered through, for example, 0.45 micron paper and degassed 15 minutes under vacuum, is suitably used as a chromatographic solvent and a solution such as 5 percent methanol in water (filtered and similarly degassed) is suitably used to wash the column before the periods of inactivity These concentrations of the solution are optionally optimized for some columns of liquid chromatography. The determination of chromatography parameters is within the skill in the art, but for the suggested system, suitable combinations include a pump flow rate of 1.5 ml / min and using a detector having an internal temperature of 40 °. C. The chromatography system is preferably used with an integrator, such as that commercially available from Hewlett-Packard and designated as Model 3393. The high purity standards were prepared by the methods within the material experience and were used to calibrate the system. Preferably the system is purged with the ion equalization chromatography reagent, at least, until a flat base line is obtained. Then a heavy sample is introduced into the system, for example, using a syringe and sample injection valve. Peak areas are obtained using the system and the integrator and compared to the calibration standard to ensure concentration. This procedure is within the skill in the art and is published, for example, in 'Dow Analytical Method DOWN 100484' "1, 2-Dihydroxypropyl Trimethylammonium Chloride and Bis- (Trimethylammonium Chloride) -2-Hydroxypropane in Quat 188 Cationic Monomer" . The level of dihaloalcohol, in the case of epichlorohydrin reacted with trimethylamine hydrochloride, 1,3-dichloro-2-propanol, is advantageously low, preferably 1.0 weight by weight in an aqueous solution of 65 weight percent of the product at 10.0 weight percent in an aqueous solution of 65 weight percent of the product, more preferably 1.0 weight percent in an aqueous solution of 65 weight percent of the product at 5.0 weight percent of an aqueous solution of 65 percent by weight of the product. The measurement of said diahaloalcohol by-product concentrations is within the skill in the art, for example, by gas chromatography of an extraction using an organic solvent such as ethyl ether, methylene chloride, perchlorethylene, or carbon tetrachloride. an aqueous solution of halohydroxypropyltrialkylammonium halide product, said product is more preferably in a 65 weight percent concentration of water. The organic layer was then analyzed in a gas chromatograph equipped with a column such as a (5 percent phenyl) -methylpolysiloxane column coating commercially available from J & amp;; W Scientific under the trade designation DB-5 using a flame ionization detector. The level of starting trialkylamine hydrochloride left in the reaction solution is advantageously lower than with other processes, preferably less than 250 ppm in a 65 weight percent solution of the product, more preferably less than 50 ppm in a 65 weight percent solution of the product. percent in weight of the product. Analysis for residual amine (exemplified herein in the form of the hydrochloride salt) is within the skill in the art. For example, a sample containing trimethylamine hydrochloride and 3-chloro-2-hydroxypropyltrimethylammonium chloride was conveniently prepared for analysis by preparing a 0.1 weight percent sample in a mobile phase solution of ion chromatography. The sample was analyzed in an ion chromatography system using a poly (butadiene) maleic acid absorbed on an amorphous silica column commercially available from Waters Corporation under the trade designation IC-Pak ™ Cation M / D column. The analysis is done using a conductivity detector. The mobile phase is a 98 weight percent solution of 3 millimolar (mM) HNO3 / 0.1 mM EDTA (ethylenediaminetetraacetic acid) and 2 molar percent isopropanol.

The following examples were presented to illustrate the invention and should not be construed as limiting thereof. All percentages, parts and relationships are by weight unless otherwise stated. The examples (Ej) of the invention are designated numerically, while the Comparative Samples (MC) are not examples of the invention and are designated alphabetically. Unless otherwise designated, the compounds are analyzed as described in the preceding paragraphs. EXAMPLES Example 1: Preparation of 3-Chloro-2-hydroxypropyl-trimethylammonium Chloride To a 250 ml necked round bottom flask equipped with a condensing stir bar, thermometer, and pH probe, it was they added 99.61 g of a solution of 57.019 weight percent trimethylamine hydrochloride. The solution was brought to 10 ° C by a glycol cooling bath at a temperature of 8 ° C. A 3.25 g sample of an aqueous solution of 21.4 weight percent trimethylamine was added and the pH rises from 3.88 to 8.51. A sample of 61.7099 g of epichlorohydrin was then added over a period of three hours while a temperature of 10 ° C was maintained by a glycol cooling bath at a temperature of 5 ° C. The solution was digested for three additional hours, in the first hour, the temperature was maintained at 10 ° C and the next two hours was increased by a glycol heating bath at a temperature of 42 ° C and maintained at 40 ° C . The analyzes for additional reagents and products formed were carried out by gas chromatography as described above using a column for 1,3-dichloro-2-propanol and analysis of epichlorohydrin commercially available from J &W Scientific under the trade designation DB- 5; ion chromatography using a cationic column for analysis of trimethylamine hydrochloride commercially available from Waters Corporation under the trade designation IC-PAK ™ Cation M / D column; high performance liquid chromatography for analysis of 1,3-bis (trimethylammonium chloride) -2-hydroxypropane and 2,3-dihydroxypropyltrimethylammonium chloride using a C-18 reversed phase column commercially available from Waters Corporation, under the commercial designation μBondapak C 10 10 μm Cartridge and a titration to measure the content of 3-chloro-2-hydroxypropyltrimethylammonium. The alkali consumed in the reaction of 3-chloro-2-hydroxypropyltrimethylammonium chloride to form the 2,3-epoxypropyltrimethylammonium chloride was determined in the titration. Ten ml of 0.5 N sodium hydroxide was added to a one gram sample containing the product to be measured. The solution was allowed to stir for ten minutes before titrating with 0.1N hydrochloric acid to determine how much sodium hydroxide was used in the reaction with the 3-chloro-2-hydroxypropyltrimethylammonium chloride. The endpoint was optionally determined by changing chlorine using phenophthalein.

The sample that was analyzed was free of any 1, 3-dichloro-2-propanol since it also consumed sodium hydroxide thus giving artificially low values for the activity of 3-chloro-2-h idroxy propyltrimethanolamine chloride. The analysis shows: 3-Chloro-2-hydroxypropyltrimethylammonium chloride: 63.49 weight percent based on the weight of the total reaction mixture 2, 3-epoxypropyltrimethylammonium chloride: 5.93 weight percent 1,3-bis (sodium chloride) trimethylammonium) -2-hydroxypropane: 0.34 weight percent epichlorohydrin: 0.53 weight percent 1,3-dichloro-2-propanol: 3.61 weight percent Trimethylamine hydrochloride: less than 30 ppm by weight Chloride 2, 3 -dihydroxypropyltrimethylammonium: less than 100 ppm by weight of water (by difference); 26.10 weight percent Examples 2-8 and Comparative Samples AH: Preparation of 3-chloro-2-hydroxypropyltrimethylammonium chloride The procedure of Example 1 was repeated for the Examples and Comparative samples (without examples of the invention) in the Table 1 except for the conditions and results observed in the Table.

TABLE 1 ro Chptmac is 3-chloro-2-hydroxypropyltrimethylammonium chloride Epi is epichlorohydrin Dicuat. is 1, 3-bis (trimethylammonium chloride) -2-hydroxypropane DCP equivalent is% by weight of DCP plus% by weight equivalent of unreacted epichlorohydrin NA is not analyzed. Epoxide is 2,3-epoxypropyltrimethylammonium chloride Quantity Equiv. of Chptmac relative is% by weight of Chptmac / (% by weight equivalent of Chptmac +% by weight of dicuat. +% by weight equivalent of DCP) Number of Dicuat. Relative is% by weight of Dicuat / (% by weight equivalent of Chptmac% by weight of Dicuat +% by weight equivalent of DCP) Equivalent amount of relative DCP is% by weight equivalent of DCP / (% by weight equivalent of Chtpmac + % by weight equivalent of dicuat +% by weight equivalent of DCP) The yield of Chptmac in moles of Chptmac formed / (moles of amine + amine hydrochloride added to the reactor) TMA is trimethylamine DCP is 1,3-dichloro-2-propanol TMA «HCL is trimethylamine hydrochloride Equivalent of Chptmac is% by weight of Chptmac plus% equivalent weight of Epoxide The amounts of 2,3-dihydroxypropyltrimethylammonium chloride are < 500 ppm% is percentage NAOH is sodium hydroxide The data in Table 1, show that the use of free amine amounts within the practice of the invention results in less TMA «HCI than in Comparative Sample A where it was used a free amine hydrochloride. In each example of this invention, less than 500 ppm of 2,3-dihydroxypropyltrimethylammonium chloride (diol by-product) was observed. It was also observed when Comparative Sample A was compared with examples of the invention that the Epi conversion was less than 55 percent indicating that the reaction did not proceed beyond 55 percent in the M .C. TO . Comparative Sample B illustrates the use of sodium hydroxide as an initial pH adjuster, but does not involve at least two temperatures. Comparative Sample C shows the inability to obtain less than 50 ppm of trimethylamine hydrochloride when the initial pH was adjusted and the first time had a temperature of 10 ° C, but the second period had a temperature that was also at 10 ° C. Comparative Sample D shows increasing amounts of Dicuaternary and DCP when the initial pH was adjusted, for the temperature for the first period was 20 ° C. The Comparative sample E shows the decreased purity of the product when the PH was adjusted initially, but the reaction temperature was not cold enough to inhibit the higher levels of Dicuaternary and DCP that were compared with the examples in the invention. The Comparative sample F shows a higher level of impurities formed when the molar percentage of amine HCl was higher than in the practice of the invention. The levels of Dicuaternario, DCP and TMA * HCI were significantly higher than in the examples of the invention. Comparative Sample G shows an increase in Dicuaternary and DCP formation when the second digestion temperature was above the limits in the invention. A strong exotherm was observed when the second digestion temperature of 50 ° C was reached. It is thought that this exotherm was the cause of higher levels of Dicuaternario and DCP found in this comparative sample. Comparative Sample H shows increased levels of Dicuaternarians and DCP when the initial molar percentage of amine HCl was lower than that of the examples of the invention. The data in Table 1 also show that within the practice of the invention, adding an excess of 1.10 molar of epichlorohydrin to a pH-adjusted mixture of trimethylamine and trimethylamine hydrochloride at 10 ° C and allowing a one hour digestion 10 ° C and a subsequent digestion of two hours at 40 ° C gives a product with high purity, low residual amine, low formation of Dicuaternario and low Diol formation. Reactions at 20 ° C and 30 ° C give equivalent values of higher DCP and higher Dicuaternary levels resulting in a product of lower purity. Reactions with a molar excess of 1.05 of epichlorohydrin to trimethylamine and trimethylamine hydrochloride give a product with lower values of DCP than with an excess of 1.0 moles of epichlorohydrin, under Dicuaternary, but a high level of residual trimethylamine hydrochloride (greater than 500 ppm). Examples that have digestion temperatures of 20 or 30 ° C give residual amounts of trimethylamine hydrochloride higher than runs that give digestion temperatures of 40 ° C.

Claims (10)

1. CLAIMS 1. A process for producing halohydroxypropyltrialkylammonium salts by reacting, in a reaction mixture, a trialkylamine salt and the corresponding free amine with epihaiohydrin, wherein the free trialkylamine is present in an amount corresponding to 1 to 10 molar percent. of the combination of the free amine and amine hydrohalide and wherein the epihaiohydrin is mixed and allowed to react for a first period with the free amine and the hydrohalide salt at a first temperature lower than a second temperature at which the epihaiohydrin to further react with the amine and the hydrohalide salt during a second period wherein the second temperature is sufficiently greater than the first in which less unreacted amine is present after the reaction that is present if the same reactants are mixed and they are reacted at the first temperature for a time equal to the sum of the first and second pe Rodos. The process of claim 1, wherein the epichlorohydrin is mixed and allowed to react with the free amine and the amine hydrohalide at a first temperature of 0 ° C to 15 ° C during the first period and the mixture is allowed to react in addition to a second temperature lower than 50 ° C but at least 15 ° C during the second period. 3. The process of claim 2, wherein the first period comprises a first addition time for addition of epihaiohydrin and a second time which is a time of digestion. The process of claim 3, wherein the first period comprises a first time of 1 to 4 hours and a time of digestion of 0.5 to 2. The process of claim 4, wherein the second period is 0.5 to 4 hours. 6. The process of claim 2, wherein there is from 90 to 99 mole percent of amine hydrohalide. The process of claim 6, wherein the first temperature is from 0 ° C to 15 ° C and the second temperature is less than 50 ° C but at least 15 ° C. The process of claim 7, wherein the reaction mixture comprises water, epichlorohydrin and trialkylamine and trialkylamine hydrochloride wherein the alkyl group has from 1 to 20 carbon atoms. 9. The process of claim 7, wherein the trialkylamine is trimethylamine, dimethylstearylamine, or dimethyldodecylamine. The process of claim 7, wherein the reaction mixture comprises water, epichlorohydrin and trimethylamine, and trimethylamine hydrochloride.