BR112020019329B1 - ALKYL TAURATE AMIDE PREPARATION PROCESS AND USE OF PHOSPHORIC ACID CATALYST - Google Patents

Abstract

The present invention relates to a method of increasing the yield of alkyl taurate amides using the increase of specific phosphoric acid catalysts. It also refers to the use of phosphoric acid to increase yield, while avoiding and/or reducing undesirable browning.

Description

FIELD OF INVENTION

[001] The present invention relates to a method or process of increasing the yield of alkyl taurate amides (“ATA”), which are typically prepared through the amidation reaction of taurine or taurine salts with fatty acid ( for example, fatty acid with chain lengths C8 to C24), using phosphoric acid catalysts.

BACKGROUND OF THE INVENTION

[002] References describing the production of alkyl taurate amides through the reaction of taurine and fatty acids are known.

[003] Burnette's North American Patent No. 2,880,219, for example, teaches the production of N-acyl taurates from fatty acids and taurines. From the table in column 7, it can generally be seen that the conversion rates are very good, although all temperatures are relatively high. Apparently, no catalyst is used, which leaves open the discussion of how any specific catalyst could be unexpectedly superior to another.

[004] Reaction of Fatty Acids with N-Methyl Taurine by Burnette and Chiddix describes a similar reaction. Apparently, there is no description of the use of any catalyst.

[005] Schenk's North American Patent No. 3,232,968 describes a process for preparing N-acyl taurates specifically using hypophosphoric acid. The superiority of phosphoric acid over other catalysts is not recognized.

[006] Unexpectedly, depositors discovered that, under conditions and process steps that are otherwise identical, the specific use of phosphoric acid (for example, with respect to another catalyst) is much superior.

BRIEF DESCRIPTION OF THE INVENTION

[007] The present invention relates to a process for increasing the conversion of taurine into alkyl taurate amide. The use of a specific catalyst, phosphoric acid catalyst, has been found to provide unexpectedly improved efficacy where all other parameters are identical.

[008] More specifically, the present invention provides a process for preparing alkyl taurate amide, wherein the process comprises the reaction of C8 to C20 fatty acid with taurine or taurine salt; wherein the molar ratio between fatty acid and taurine (or salt) is 1.5:1 to 10:1, preferably 1.6:1 to 7:1 or 1.9:1 to 5:1; wherein the reaction temperature varies from 180 °C to 250 °C, preferably from 190 to 245 °C; wherein the catalyst is phosphoric acid, used in an amount of 0.1 to 0.7; preferably 0.1 to 0.5% by weight; and wherein the reaction time varies from 1 to 10 hours, preferably 1 to 6 hours.

[009] The use of a specific phosphoric acid catalyst allows more efficiency, that is, greater yield is obtained, while avoiding undesirable darkening.

DETAILED DESCRIPTION OF THE INVENTION

[0010] Except in the examples or when explicitly indicated otherwise, all numbers in this specification that indicate quantities of material or reaction conditions, physical properties of materials and/or use should be understood as modified by the expression “about”.

[0011] As used herein, ranges are used as constraints to describe any and all values that lie within the range. Any value within the range can be selected as the range end. The use of and/or indicates that any of the list can be selected individually or any combination of the list can be selected.

[0012] For the avoidance of doubt, the expression “which comprises” is intended to indicate “which includes”, but not necessarily “which consists of” or “composed of”. In other words, the related steps or options do not need to be exhaustive.

[0013] Unless otherwise indicated, all percentages of quantity(s) of ingredients used must be understood as percentages by weight based on the active weight of the material in the total weight of the composition, the total of which is 100%.

[0014] The present invention relates to a process for increasing the conversion of taurine into alkyl taurate amide specifically using phosphoric acid as a catalyst.

[0015] Specifically, it refers to a process in which taurine or taurine salt reacts with C8 to C22, preferably C8 to C20 fatty acid in defined ratios between fatty acid and taurine or taurine salts. It was concluded that the use of phosphoric acid provides increased yield and/or efficiency and additionally there is no observable darkening.

[0016] As indicated, the present invention relates to a reaction in which a fatty acid reacts (for example, C8 to C22 or C8 to C20 fatty acid, preferably straight and saturated chain; preferably, C10 to C18 fatty acid, again preferably linear and saturated chain; more preferably, C10 to C14 fatty acid). More specifically, fatty acid reacts with taurine and/or taurine salt in defined molar ratios between fatty acid and taurine and/or taurine salt. If more than one fatty acid is used, the ratio is defined as the molar ratio between all the fatty acid in the mixture and taurine or taurine salt. The reaction takes place in the presence of specific phosphoric acid catalyst and is carried out at the reaction temperature and defined reaction time ranges indicated.

[0017] Within the indicated use of C10 to C14, C12 fatty acid is particularly highly preferred when using the C8 to C22 or C8 to C20 fatty acid range. 50 to 100%, for example, are preferably C10 to C14 and, preferably, C12 fatty acids. In a preferred embodiment, 100% of the fatty acid can be C12, that is, C12 is the only reacting fatty acid.

[0018] The fatty acid reacts with taurine or taurine salt, such as NH2CH2CH2SO3-M+, where M+ can be sodium or potassium counterion.

[0019] The present invention comprises a process for reacting fatty acid or a mixture of fatty acids (preferred fatty acid is C12 straight chain fatty acid) with taurine and/or taurine salt, wherein: a. the molar ratio between fatty acid and taurine (or salt) is 1.5:1 to 10:1, preferably 1.6:1 to 7:1 or 1.7:1 to 5:1; B. the reaction temperature is 180 °C to 250 °C, preferably 190 to 245 °C and, even more preferably, 200 to 245 °C; and c. the reaction time is 1 to 10, preferably 1 to 6 hours.

[0020] As indicated above, the fatty acid reacts with taurine or taurine salt, such as NH2CH2CH2SO3- M+, where M+ can be sodium or potassium counterion.

[0021] As indicated, the molar ratio between fatty acid or total fatty acids and taurine or taurine salt is 1.5:1 to 10:1, preferably 1.6:1 to 7:1.

[0022] The reaction temperature is 180 °C to 250 °C, preferably 190 to 245 °C and, more preferably, 200 to 245 °C. In some aspects, the reaction temperature is 220 ° C to 245 ° C and the catalyst is used at 0.1 to 0.7, preferably 0.3 to 0.6%.

[0023] The reaction time is 1 to 100, preferably 1 to 6 hours and, more preferably, 2 to 5 hours.

[0024] Although several catalysts were used in the indicated reaction of producing alkyl taurate amide, depositors are unaware of the disclosure of specific use of phosphoric acid, much less the improved yields found in relation to the use of other catalysts.

[0025] The catalyst is present at a level of 0.1% to 0.7% by weight, preferably 0.1% to 0.5% by weight.

[0026] The present invention relates to alkyl taurate amides produced using the process according to claim 1.

[0027] Process:

[0028] The typical process is described below. 1. In a 250 ml flask with a domed bottom and four necks, equipped with a mechanical stirrer, condenser, solvent receiver/siphon and thermocouple/nitrogen flow inlet (N2), sodium N-methyl taurine (92) was added. .78 g, 61.53% solution, 1 eq). The N2 flow was set at 0.2 liters per minute (LPM). 2. The reaction temperature was increased to about 240°C and lauric acid (141.91 g, 2 eq) and phosphoric acid (1.18 g, 85% solution) were added. Phosphoric acid was added in an amount of 0.5% by weight. The reaction mixture was stirred at 240 °C for one to four hours. EXAMPLES TABLE 1 EXAMPLES 1-5 AND COMPARATIVES AF TABLE 2 EXAMPLES 6-8 AND COMPARATIVES GL

[0029] From Tables 1 and 2, several points can be observed regarding the unexpected beneficial effects of phosphoric acid (H3PO4) in relation to other catalysts, such as hypophosphorus (H3PO2) and sodium hypophosphite (NaPO2H2) used exactly in same conditions.

[0030] In Examples 1 and 2 in comparison with Comparative Examples A and B, it can be seen that, at identical amounts of catalysts, temperatures and reaction times, phosphoric acid clearly provides superior yield. Examples 3 and 4 versus Benchmarks C and D exhibit the same improved benefit (e.g., 98.8% or 97.9% yield compared to 91.7% or 91.5% yield for Benchmarks) in time reaction time of two hours. Again, Example 5 against Comparatives E and F exhibits the same superior result for phosphoric acid compared to another catalyst at a reaction time of three hours.

[0031] Table 2 displays exactly the same results as the example in Table 1, using 0.3% catalyst instead of 0.5% catalyst. In Example 6 against Comparatives G and H, for example (0.3% catalyst, reaction temperature of 240 °C and reaction time of one hour), phosphoric acid is superior. Same reaction at 2 hours and 3 hours (Example 7 against Comparatives I and J; Example 8 against Comparatives K and L) exhibits the same superiority of phosphoric acid in yield.

[0032] Products manufactured using phosphoric acid were white.

[0033] These results, based entirely on the use of a specific catalyst against other related catalysts, are totally unexpected. TABLE 3 EXAMPLES 9-10 AND COMPARATIVES M, N, OEP

[0034] Examples 9 and 10 and Comparisons M to P (Table 3 above) demonstrate once again that, with all other variables equal, phosphoric acid surprisingly provides yield. In Table 3, driving at lower temperatures than the examples in Tables 1 and 2 (driving at 195 °C versus 240 °C), yields are generally lower; Phosphoric acid, however, relative to other catalysts (hypophosphorus, zinc oxide), provides superior yield even at these lower temperatures. One set of three examples was conducted for one hour and another set of three for two hours. All examples in Table 3 used 0.5% catalyst. As indicated, this table demonstrates superiority not only over just other catalysts in the phosphorus family, but also over zinc oxide, a well-known and commonly used catalyst. Products manufactured using phosphoric acid were white. TABLE 4 EXAMPLES 11 AND COMPARATIVES Q, R, SET

[0035] Table 4 displays the same pattern of relative superiority of phosphoric acid compared to other catalysts (e.g., hypophosphorus). Again, now using 0.3% catalyst and a reaction temperature of 195 °C, pairs of reactions (phosphoric acid VS. hypophosphorus in this table) were compared after 1, 2, 3 and 4 hours of reaction and the yields using phosphoric acid as catalysts were superior in all cases. Products manufactured using phosphoric acid were white.

Claims (4)

1. PROCESS FOR PREPARING ALKYL TAURATE AMIDE, characterized by comprising the reaction of C8 to C20 fatty acid with taurine salt, in which: a) the molar ratio between fatty acid and taurate or taurine salt is 1.5 :1 to 10:1, preferably 1.6:1 to 7:1; b) reaction temperature is 180 °C to 250 °C, preferably 190 to 245 °C; c) catalyst is used in an amount of 0.1 to 0.7% by weight, preferably 0.1 to 0.5% by weight; d) the reaction time is 1 to 10 hours, preferably 1 to 6 hours; and e) the catalyst is phosphoric acid. 2. USE OF PHOSPHORIC ACID CATALYST, in an amount of 0.1 to 0.7% by weight, preferably 0.1 to 0.5% by weight, characterized by being in an alkyl taurate amide preparation process which comprises the reaction of C8 to C20 fatty acid with taurine salt, which increases the yield of taurate amide and reduces browning. 3. USE, according to claim 2, characterized in that: - the molar ratio of fatty acid and taurate or taurine salt is 1.5:1 to 10:1, preferably 1.6:1 to 7:1; - reaction temperature varies from 180 °C to 250 °C, preferably from 190 to 245 °C; - reaction time is 1 to 10 hours, preferably 1 to 6 hours. 4. USE, according to any one of claims 2 to 3, characterized in that the reduction in darkening is relative to other catalysts used in the same process.