JPS6136249A - Production of n-methylol fatty acid amide - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a sensitizer for thermosensitive paper, etc. in high quality and yield without requiring post-treatment after the reaction, by reacting a fatty acid amide with a formaldehyde in the presence of a basic catalyst under specific conditions. CONSTITUTION:A fatty acid amide expressed by the formula RCONH2 (R is 9- 23C alkyl or alkenyl), e.g. capric amide, is reacted with a formaldehyde in the presence of a basic catalyst, e.g. triethylamine or potassium tertiary phosphate, to give an N-methylol fatty acid amide. In the process, the above-mentioned reaction is carried out usually under 0.2-10kg/cm<2>.G, preferably 0.2-5kg/cm<2>.G pressure at the melting point of the aimed substance formed by the reaction or above in the molten state in a closed vessel, preferably a metallic autoclave. The above-mentioned temperature is preferably not higher than the above-mentioned melting point by >=20 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing N-methylol fatty acid amide by the reaction of fatty acid amide with formaldehyde, and more specifically, a method for producing high quality N-methylol fatty acid amide, which does not require complicated post-processing steps. This invention relates to a method for easily manufacturing the invention without any problems.

(Industrial Application Field) The N-methylol fatty acid amide obtained by the production method of the present invention is of high quality and can be used as a sensitizer in information paper, especially thermal paper, and as an additive for modifying polymeric materials.

It can be widely used as a fiber treatment agent, etc.

(Prior art) Conventionally, as a method for producing N-methylol fatty acid amide,
A method has been known in which a fatty acid amide dispersed in an aqueous medium is heated to react with formalin in the presence of an alkali catalyst (Japanese Patent Publication No. 32-7420). However, in this method, a large amount of formalin is consumed by the Canitzaro reaction, which is a side reaction, and a large amount of water is used as the reaction medium. Complicated post-treatment steps such as drying were required, which was disadvantageous in terms of industrial implementation.

In addition, it has been known to produce N-methylol fatty acid amide by reacting fatty acid amide and formaldehyde in a heated molten state in the case of the reaction of lower fatty acid amide with acrylamide and paraformaldehyde. Namely, acrylamide and NoJ? It has already been proposed to react with formaldehyde in an open system at normal pressure in the presence of trialkylamines such as triethylamine, tributylamine, and morpholine, or basic catalysts such as caustic soda and soda carbonate (Japanese Patent Publication No. -4208 and Japanese Patent Publication No. 36-9865). However, in order to methylolate a higher fatty acid amide as in the present invention by such a method, since the melting point of the N-methylol fatty acid amide produced is extremely high, the N-methylol fatty acid amide produced in the reaction must be If the reaction is carried out at a temperature lower than the melting point, the entire reaction system will solidify during the reaction, making it impossible to obtain the desired conversion rate. In addition, if the reaction is carried out at a high temperature higher than the melting point of the N-methylol fatty acid amide that is produced, the N-methylol fatty acid amide is rapidly produced, but the N-methylol fatty acid amide that is simultaneously produced also rapidly undergoes a decomposition reaction. However, it is not possible to consistently obtain high quality N-methylol fatty acid amide.

(Problems to be Solved by the Invention) The present invention allows the methylolation reaction of higher fatty acid amides with formaldehyde to be carried out by an advantageous heat-melting reaction,
Moreover, it is an object of the present invention to provide a method capable of producing high-quality N-methylol fatty acid amide at a high conversion rate.

(Means for Solving Problems) The method for producing N-methylol fatty acid amide of the present invention is based on a fatty acid represented by the general formula RCON)I2 (wherein R represents an alkyl group or an alkenyl group having 9 to 23 carbon atoms). When amide and formaldehyde are reacted in the presence of a basic catalyst, the reaction is carried out in a sealed container under pressure.
This method is characterized in that it is carried out in a molten state at a temperature equal to or higher than the melting point of the methylol fatty acid amide.

The production reaction in the present invention is represented by the following formula.

RCONH2+2HCHO→RCONHCH20H Examples of the fatty acid amide used as a raw material in the present invention include capric acid amide, undecanoic acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, arachinic acid amide, behenic acid amide 1, and oleic acid amide. and fatty acid amides produced from animal and vegetable oil fatty acids, such as erucic acid amide.

Examples of formaldehydes in the present invention include formaldehyde aqueous solutions (eg, formalin) having a concentration of 30 to 50% by weight, paraformaldehyde, formaldehyde low polymers such as trioxane, and hemiacetal. The amount of formaldehyde used is 1 to 1 molar ratio of formaldehyde to raw fatty acid amide.
3, preferably 1-2. If the molar ratio is too small, the yield of the target N-methylol fatty acid amide will decrease, and if it is too large, a large amount of unreacted formaldehyde will be produced.

The basic catalyst in the present invention includes trialkylamines such as triethylamine, tripropylamine, morpholine, and diethylethanol; basic inorganic salts such as tripotassium phosphate, trisodium phosphate, potassium carbonate, and sodium carbonate; Examples include basic hydroxides such as caustic potash and caustic soda. Among these basic catalysts, tripotassium phosphate is particularly preferred because it narrows the melting point range of the produced N-methylol fatty acid amide. Generally, one type of basic catalyst is used alone, but in some cases, two or more types can be used in combination. The amount of the catalyst used is usually 0.05 to 5% by weight, preferably 0.05 to 5% by weight, based on the raw fatty acid amide.
．． I am in charge of 2-1 layers of IT.

Since the production reaction of the present invention is carried out in a closed container under pressure, the closed container is preferably a metal autoclave.

The reaction pressure in the present invention is usually 0.2 to 10 kg/c
m2G, preferably 0.2 to 5 kg/cm G. If the pressure is too low, the produced N-methylol fatty acid amide will be decomposed, which will not only reduce the product yield (conversion rate) but also cause a decline in the quality of the product.

Furthermore, if the pressure is too high, it is not possible to expect a corresponding improvement in product yield, which is economically disadvantageous.

Pressurization of the reaction system in the present invention may be a pressure naturally generated by heating, but usually, an inert gas such as nitrogen, helium, argon, carbon dioxide, etc. is introduced into a closed container at a desired pressure. It is desirable to apply more pressure. Further, the presence of air in the reaction system causes thermal deterioration of the raw fatty acid amide and the produced N-methylol fatty acid amide, so it is desirable to purify the inside of the closed container with the above-mentioned inert gas.

The reaction temperature in the present invention needs to be higher than the melting point of the N-methylol fatty acid amide produced by the reaction,
It is desirable that the temperature is not higher than the melting point by 20°C or more. If the reaction temperature is lower than the melting point of the N-methylol fatty acid amide produced, the reaction system will solidify during the reaction, making it impossible to carry out the reaction smoothly. Furthermore, if the reaction temperature is 20° C. or more higher than the above melting point, the decomposition reaction of the generated N-methylol fatty acid amide rapidly proceeds. Since the melting point of N-methylol fatty acid amide varies depending on the type of fatty acid, the preferred reaction temperature varies depending on the type of raw fatty acid amide.

The reaction time in the present invention depends on the type of raw fatty acid amide,
Although it varies depending on the type of basic catalyst, reaction temperature, etc., it is usually within the range of 10 to 180 minutes.

If the reaction temperature is too short, the methylolation reaction will not proceed sufficiently, and if it is too high, the resulting N-methylol fatty acid amide will be decomposed.

(Effects of the Invention) According to the production method of the present invention, high quality N-methylol fatty acid amide can be obtained in high yield (high conversion rate), and a complicated post-treatment step is not required after the reaction.

(Examples, etc.) Next, the present invention will be further described in detail with reference to Examples and Comparative Examples.

Example 1 Stearic acid amide 200# (0,707 mol) was placed in a metal autoclave equipped with a stirrer, a thermometer, and a pressure gauge, and after the air in the autoclave was sufficiently replaced with nitrogen gas, it was placed in an oil bath at 120°C. It was heated inside to completely melt it.

Then, A'la formaldehyde 27 with a purity of 80% by weight
．． After adding 8 g (0,742 mol) and 1 g of tripotassium phosphate and completely sealing the autoclave, the reaction was carried out by heating at 120°C. At that time, the pressure inside the autoclave was 1
．． The nitrogen gas pressure was adjusted to 5 kglon G.

After 15 minutes, the reaction product was taken out from the autoclave to obtain 218 g of the desired N-methylolstearamide.

The melting point of the obtained N-methylol stearic acid amide was measured using a differential thermal balance device (M-8075, manufactured by Rigaku Denki Co., Ltd.). In addition, after acetylating the methylol group of N-methylol stearic acid amide with trifluoroacetic acid anhydride, the methylol group of
The purity of N-methylol stearic acid amide was analyzed by HP. The results were as shown in Table 1.

Further, the reaction was carried out in the same manner as above except that potassium carbonate and triethylamine were used as catalysts in place of tripotassium phosphate. Similar analysis results for each of the obtained N-methylol stearic acid amides are shown in Table 1.

Table 1 Example 2 Stearamide 20 was added to the same apparatus as in Example 1.
After 0 g (0,707 mol) of autoclave was added, the air in the autoclave was sufficiently replaced with nitrogen gas, and the autoclave was heated in an oil bath at 120° C. to completely melt it.

Next, 27.8 g of 80-chiparaformaldehyde (0
After adding 1 g of tripotassium phosphate and completely sealing the autoclave, heat the reaction at 120°C while adjusting nitrogen gas so that the pressure inside the autoclave was 1.0 kg 7 cm 2 G. I let it happen.

The reaction products were taken out after 60 minutes, 120 minutes, and 180 minutes, respectively, and analyzed for the purity of N-methylolstearamide in the same manner as in Example 1. The analysis results were as shown in Table 2.

Comparative Example 1 The reaction was carried out in the same manner as in Example 2, except that the autoclave was not sealed and the reaction was carried out in an open system (that is, at normal pressure), and the reactions were carried out after 60 minutes, 120 minutes, and 180 minutes. The product was taken out, and the purity of the produced N-methylol fatty acid amine P was analyzed in the same manner as in Example 1. The analysis results were as shown in Table 2.

Table 2 Example 3 Using the same apparatus as in Example 1, lauric acid amide, palmitic acid amide, and erucic acid amide were reacted in the same manner as in Example 1, respectively.

The analysis results of each N-methylol fatty acid amide obtained were as shown in Table 3.

Table 3 Notes to Table 3: Since analysis by gas chromatography was not possible, it was confirmed that it was N-methylolerucic acid based on absorption at 1000 to 1100 m'.

Claims (1)

[Claims] 1) General formula RCONH_2 (wherein R has 9 to 23 carbon atoms)
represents an alkyl group or an alkenyl group. ) and formaldehyde in the presence of a basic catalyst, the reaction is carried out in a molten state at a temperature equal to or higher than the melting point of the N-methylol fatty acid amide in a sealed container under pressure. A method for producing an N-methylol fatty acid amide, characterized by the following. 2) The production method according to claim 1, wherein the reaction temperature is higher than the melting point of the N-methylol fatty acid amide and is not higher than the melting point by 20°C or more.