JPS6153372B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyamide. More specifically, the present invention relates to a method for producing polyamide by subjecting a diamino compound and a bis (cyclic imino ester) compound to a thermal reaction. It has been known that polyamides are synthesized by polycondensation of dicarboxylic acids and diamines. It is also known that cyclic imino ester compounds easily react with amino groups to give amide compounds, and furthermore, this reaction can be used to combine hexamethylene diamine and 2,2'-p-xylidene-bis[4,
When reacting with 4-diphenyl-5(4H)-oxazolone], 2,2'-tetramethylenebis[5(4H)-oxazolone], or 2,2'-p-phenylenebis[5(4H)-oxazolone], It is known that polyamides can be obtained. The method of obtaining polyamide from bis (cyclic imino ester) and diamine is useful as a method for producing polyamide because it is easy to purify and handle the monomer, and it does not cause gelation during the production of linear polyadducts. This is a great method. However, polyamides synthesized from such bisoxazolone and diamine generally have a low melting point or are easily soluble in highly polar solvents such as phenol, m-cresol, dimethylformamide, and dimethyl sulfoxide.
The disadvantage is that fibers, films, or resin molded products obtained from these polyamides have poor solvent resistance. The inventors of the present invention have arrived at the present invention as a result of intensive studies to obtain a polyamide free from such drawbacks from a bis (cyclic imino ester) compound and a diamino compound. That is, the present invention relates to a diamino compound and the following general formula () (However, in the formula, Y is an orthophenylene group.) This is a method for producing a polyamide, which is characterized by subjecting a bis (cyclic imino ester) represented by the following formula to a thermal reaction. The bis (cyclic imino ester) used in the present invention is a bisoxazinone compound, and is a compound represented by the above general formula (). In the above general formula, Y is an orthophenylene group, more specifically an O-phenylene group, an O-phenylene group having a nuclear substituent,
A phenylene group is mentioned. Examples of the nuclear substituent include a lower alkyl group having 1 to 6 carbon atoms, a nitro group, a halogen atom, a methoxy group, an ethoxy group, and the like. Specific examples of the bis (cyclic imino ester) represented by the general formula () include 2.2'-
bis[3,1-benzoxazin-4-one],
Examples include compounds in which 1 to 4 aromatic nuclear hydrogen atoms are substituted with a lower alkyl group having 1 to 6 carbon atoms, a nitro group, a halogen atom, a methoxy group, an ethoxy group, and the like. The bis (cyclic imino ester) compound represented by the general formula () is the compound represented by the general formula () (However, Q in the formula is an alkyloxy, aryloxy, or halogen atom.) Ester-forming derivatives such as ester (e.g. alkyl ester, aryl ester) derivatives of dicarboxylic acids represented by the formula or acid halides and the general formula () H ₂ N-Y-COOH ...... () [However, Y is the same as in the case of formula ()] General formula () synthesized using the compound expressed as a raw material [However, Y in the formula is the same as in the general formula ()] It is synthesized by further dehydrating and ring-closing the bisimidocarboxylic acid represented by the following by a conventionally known method.
To describe the synthesis method in more detail, the general formula ()
Dihalide of dicarboxylic acid represented by [formula ()
When Q is a halogen atom] and the above general formula ()
A bisimide carboxylic acid represented by the general formula () is obtained by reacting the aminocarboxylic acid represented by the formula (2) under the conditions of a deoxidizing agent. Next, the bisimidecarboxylic acid is heated under reflux in an excess amount of an aliphatic acid anhydride such as acetic anhydride to cause dehydration and ring closure, thereby obtaining a bis(cyclic iminoester) represented by the general formula (). The diamino compound used in the present invention is a compound represented by the general formula () H ₂ NR-NH ₂ () [where R is a divalent organic group]. As such a diamino compound, any conventionally known diamino compound that gives a linear polyamide can be used, such as ethylenediamine, hexamethylene diamine, decamethylene diamine, dodecamethylene diamine, p-phenylene diamine, m-phenylene diamine, etc. Nylene diamine, 4,4'-
Examples include diaminodiphenyl, 4,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl sulfone. In the present invention, the above-mentioned bis (cyclic imino ester) and diamino compound are heated and reacted. This heating reaction can be carried out using a suitable solvent if necessary. When using a reaction solvent, a solvent inert to bis (cyclic imino ester) and diamino compounds, such as n-hexane,
Aliphatic hydrocarbons such as heptane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene and pyridine; ethers such as dioxane, tetrahydrofuran, anisole; N/N-dimethylformamide,
N・N-dimethylacetamide, N-methyl-2
-Pyrrolidone etc. can be used. The heating reaction between bis (cyclic imino ester) and diamine compound usually takes several minutes to several tens of minutes at 50℃ to 280℃.
Do time. Generally, the higher the reaction temperature, the shorter the reaction time, and the lower the reaction temperature, the longer the reaction time. Furthermore, if necessary during the heating reaction, the inside of the system may be placed under a nitrogen gas atmosphere, especially when the reaction is carried out at a high temperature, by carrying out the reaction under a nitrogen gas atmosphere, a clean polyamide without coloring can be obtained. Further, in the present invention, not only one type of bis (cyclic imino ester) and diamino compound is reacted by heating, but also two or more types of both components or one of the components can be used and copolymerized. There is no particular restriction on the reaction molar ratio of bis (cyclic imino ester) and diamine as long as the respective components have a substantially 1:1 molar ratio in the resulting polymer, but in general, 0.8＜Diamine/
Bis(cyclic imino ester) (molar ratio)<1.2, particularly preferably 0.9 to 1.1. The polyamide obtained in the present invention includes phenol,
It has high solvent resistance to polar solvents such as m-cresol, dimethylformamide, and dimethyl sulfoxide, and can be used as synthetic fibers, films, and other resin molded products. Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to the Examples.
The reduced viscosity (ηsp/c) in the examples is a value measured at 35°C in an O-chlorophenol solvent. Example 1 2,2'-bis(3,1-benzoxazine-4
-on) 10.00gr, dodecamethylenediamine
6.89gr and anhydrous N-methyl-2-pyrrolidone 150
ml was placed in a three-necked flask, and heated and reacted at 200°C for 2 hours with stirring under a nitrogen atmosphere. The resulting reaction solution was poured into 500 ml of ice water, and the precipitated solid was separated and washed with water, followed by drying at 110° C. and 1 mmHg for 5 hours to obtain 15.8 gr of polymer (yield: 94%).
The reduced viscosity of this polymer is 0.33 and the melting point is
The temperature was 283-286℃. Also, elemental analysis is C: 68.30
%, H: 7.34%, N: 11.40% (calculated value C: 68.27
%, H: 7.37%, N: 11.37%), and the infrared absorption spectrum is as shown in Figure 1, ν _NH 3310cm
^-1 , 3080cm ^-1 , -(CH ₂ ) - ₁₂ ν _CH 2850cm ^-1 , 2980
cm ^-1 ,

[Formula] νco 1690cm ^-1 ,

[Formula] was νco 1632cm ^-1 . From the above analysis results, the structure of the polymer is considered to be as follows. This polyamide does not dissolve in 20 minutes at the boiling points of acetone, chloroform, alcohol, and water, and does not dissolve in dimethylformamide, m-cresol, formic acid, dimethyl sulfoxide, or nitrobenzene even at 140°C for 5 minutes. This shows that the polyamide has high solvent resistance to various solvents. 2,2'-bis(3,1-benzoxazin-4-one) used in this example was synthesized as follows. Dissolve 280g of anthranilic acid in 500ml of pyridine, add oxalate dichloride under stirring under ice cooling.
127gr was added dropwise over about 15 minutes, stirred for another 15 minutes at room temperature, and the product was washed with water and dried to give 235gr (yield ~
72%) of product was obtained. Next, the product was reacted in 3 acetic anhydride under heating under reflux for 6 hours. After cooling, the reaction product was separated and recrystallized from nitrobenzene to obtain 184g of bis(3,1-benzoxazin-4-one) (melting point: 300°C or higher). Example 2 A polymer of 10.7 gr (yield: 78%) was obtained in the same manner as in Example 1, except that 3.699 gr of p-phenylene diamine was used instead of dodecamethylene diamine.
The infrared absorption spectrum of this polymer is shown in Figure 2, with ν _NH 3300cm ^-1 , 3070cm ^-1 ,

[Formula] ν _Cp 1685cm ^-1 ,

[Formula] ν _Cp was 1637cm ^-1 . Furthermore, the reduced viscosity of this polymer is 0.31, and the melting point is
The temperature was over 300℃. Also, elemental analysis is C: 68.28
%, H: 7.40%, N: 15.19% (calculated value C: 68.27
%, H: 7.37%, N: 15.21%). From the above, the structure of this polymer is it is conceivable that. Similar to the polymer obtained in Example 1, this polyamide did not dissolve in acetone, chloroform, alcohol, or water even after stirring for 20 minutes at their respective boiling points, and it also did not dissolve in dimethylformamide, m-cresol, formic acid, or dimethylsulfonate. It does not dissolve in oxide and nitrobenzene even at 140℃ for 5 minutes. This shows that this polyamide has high resistance to solvents. Comparative Example 1 10.00 gr of 2,2'-octamethylene-bis(3,1-benzoxazin-4-one) and 2.68 gr of p-phenylenediamine were mixed in 100 ml of anhydrous N-methyl-2-pyrrolidone under a nitrogen atmosphere for 200 g. The reaction was allowed to take place at 110°C for 2 hours, and after cooling, the crystals were poured into 700ml of acetone and the precipitated crystals were thoroughly washed with acetone.
It was dried for 5 hours. The amount of polymer produced was 12.5 g (yield 98.6%). The reduced viscosity of this polymer is
0.30, and the melting point was 124-6°C. Infrared absorption is ν _NH 3260cm ^-1 , 3050cm ^-1 , (−
CH ₂ ) ₋₈ ν _CH 2860cm ^-1 , 2930cm ^-1 ,

[Formula] ν _Cp 1675cm ^-1 ,

[Formula] is ν _Cp 1655cm ^-1 , and the elemental analysis is C: 70.26%, H: 6.32%, N: 10.91%
(Calculated values C: 70.29%, H: 6.29%, N: 10.93%)
It was hot. From the above, the structure of this polymer is it is conceivable that. This polyamide is insoluble in acetone, chloroform, alcohol, and water, but dimethyl sulfoxide, nitrobenzene, formic acid,
It is soluble in m-cresol and dimethylformamide, and its solvent resistance is inferior to that of the polyamide of the present invention. The 2,2'-octamethylene-bis(3,1-benzoxazin-4-one) used in this example was synthesized as follows. 27.9g of anthranilic acid was dissolved in 300ml of pyridine, and 24.3g of sebacyl chloride was added dropwise to the solution while stirring under ice cooling. The mixture was further stirred at room temperature for 30 minutes, and then the pyridine was removed under reduced pressure and the solid was washed with water. Dry. The product obtained is
The amount was 40g (yield 89%). The product was then heated under reflux in 600 ml of acetic anhydride for 6 hours, and the reaction product was separated after cooling and recrystallized from nitrobenzene.
34.5 g of benzoxazin-4-one) were obtained. Comparative Example 2 2・2′-p-phenylene-bis(4-methyl-
5 (4H) oxazolone 6.00g and hexamethylene diamine 2.56gr in anhydrous anisole 200ml at 150℃
After reacting under nitrogen atmosphere for 10 hours and cooling,
After pouring into 900 ml of acetone and washing the precipitated polymer, it was dried at 110° C. and 1 mmHg for 5 hours.
The obtained polymer was 6.0 gr (yield 46%). This polymer had a reduced viscosity of 0.28 and a melting point of 217-219°C. In addition, infrared absorption is ν _NH and ν _Cp , each of which is 3270 cm
^-1 , 3050cm ^-1 , 1670cm ^-1 , and 1655cm ^-1 , and this polymer seems to have the following structure. This polyamide is soluble in dimethylsulfoxide, nitrobenzene, formic acid, m-cresol, and dimethylformamide, and has inferior solvent resistance compared to the polyamide of the present invention.

[Brief explanation of the drawing]

1 and 2 are infrared absorption spectra.

Claims (1)

[Claims] 1. Diamino compound and the following general formula (However, in the formula, Y is an orthophenylene group.) A method for producing polyamide, which comprises subjecting a bis (cyclic imino ester) represented by the following formula to a heating reaction.