JPH0995611A - Polyamide organo gel and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject gel useful as a chemomechanical system material, etc., in a simple easy manner by dissolving a specific polyamide in a solvent and adding a metal salt or a metallic tin to the obtained solution to gel it. SOLUTION: (A) A polyamide synthesized from an aromatic dicarboxylic acid (preferably, nitroterephthalic acid or 5-nitroisophthalic acid) having a nitro substitutional group is dissolved in (B) a solvent (preferably, an amide compound, especially, N-methyl-2-pyrrolidinone). Subsequently, (C) a compound containing at least one metallic element selected from iron, tin and nickel [preferably, at least one selected from salts of iron(II), tin(II) and nickel(II) and metallic tin, especially metallic tin] is added to the obtained solution to gel it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organogel applicable to chemo-mechanical system materials, shock / vibration absorbing materials and the like, and a simple and rapid production method thereof.

[0002]

2. Description of the Related Art A gel is a crosslinked polymer having a three-dimensional network structure and a finite degree of swelling in a solvent. Recently, expectations for polymer gels as chemo-mechanical system materials, shock / vibration absorbing materials, materials with sustained drug release properties, liquid recovery agents, etc. have increased. The polymer gel is
Hydrogels and organogels are classified according to whether the constituent solvent is water or an organic solvent.

On the other hand, when the gels are classified according to their preparation method, they are roughly classified into those by network formation by covalent bonds and those by network formation by non-covalent intermolecular bonds. The latter is generally characterized by a simple production method, and in particular, it is known to prepare various hydrogels utilizing crosslinking of water-soluble polymers by addition of metal ions.

The former has been synthesized so far in various polymer systems and is widely used industrially. However, the latter is an unexplored field that has hardly been studied so far, and is a field that is expected to develop greatly in the future (Kazuyoshi Ogino, et al., Industrial Books "Basics and Applications of Gel-Soft Materials", 1993 Industrial. Books).

The latter organogel can be prepared, for example, by using an organic solvent having a higher boiling point than water as its constituent component,
It is expected to be applied as a chemo-mechanical system material that can be used at high temperatures and as a shock / vibration absorbing material. Further, it is possible to realize applications that are difficult to use when hydrogels are used, such as materials for sustained-release chemicals in organic solvents and recovering agents for organic liquids.

However, the number of preparation examples of the organogel is extremely smaller than that of the hydrogel. For example, an organogel composed of poly (benzyl glutamate) and dioxane as an organic solvent and a method for preparing the same have been reported (Macromolecule, Volume 23, page 3779, 1990). The formation of the network by the covalent bond requires a long time of 10 to 20 days or more under the temperature condition of 70 ° C.

The method of preparing a polymer gel is roughly classified into a method of forming a network by a covalent bond and a method of forming a network by a non-covalent intermolecular bond. In particular, the latter is characterized in that the production method is simple, and in particular, the preparation of polymer gels utilizing crosslinking of polymers by non-covalent bond addition of metal ions is prominent.

However, as described above, the reported preparation examples of polymer gels by addition of metal ions are, for example, as shown in an example using polyoxazoline having a bipyridyl group (Macromolecule, Vol. 26, p. 6315). It was limited to those targeting hydrogels.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyamide organogel which uses a non-covalent bond and can be prepared simply and quickly, and a method for producing the same.

[0010]

The present inventors have used a non-covalent cross-linking from a solution of a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent by adding a compound having a metal element. The present inventors have found that a polyamide-based organogel can be obtained easily and quickly, and completed the present invention.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a polyamide-based organogel containing a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent, a divalent metal salt and an amide solvent as components, and a method for producing the same. is there.

That is, the present invention relates to a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent, iron,
A polyamide organogel comprising a compound having one or more metal elements selected from the group consisting of tin and nickel and a solvent, and more specifically, the compound having metal elements is iron (II), tin ( II), one or more metal salts selected from the group consisting of nickel (II), or the compound having a metal element is metal tin, which is a polyamide organogel.

The present invention is a polyamide-based organogel characterized in that the aromatic dicarboxylic acid having a nitro substituent is in particular nitroterephthalic acid or 5-nitroisophthalic acid, and the diamine is in particular an aromatic diamine. A polyamide-based organogel characterized by the above.

Further, the solvent used in the present invention is characterized in that it is an amide compound.
It is a polyamide-based organogel characterized by being -methyl-2-pyrrolidinone. Furthermore, the present invention involves dissolving a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent in an amide compound, and then divalent iron,
A method for producing a polyamide-based organogel, which comprises gelling by adding at least one metal salt of a metal selected from the group consisting of divalent tin and divalent nickel or metal tin.

More specifically, the aromatic dicarboxylic acid having a nitro substituent, which is used in the method for producing a polyamide-based organogel of the present invention, is particularly nitroterephthalic acid or 5-
It is characterized in that it is nitroisophthalic acid, and that the diamine used is an aromatic diamine. Furthermore, the present invention also includes a method of reversibly changing the viscosity of the polyamide-based organogel according to the present invention by changing the temperature.

In the present invention, a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent and a diamine is used. The aromatic dicarboxylic acid having a nitro substituent as used herein refers to one obtained by substituting one or more hydrogens of any benzene ring of the dicarboxylic acid with a nitro group, and nitroterephthalic acid or 5-nitroisophthalic acid is Preferably
Of these, nitroterephthalic acid is particularly preferable.

As the diamine used in the present invention,
Aromatic diamines are preferable, and p-phenylenediamine is particularly preferable. These aromatic dicarboxylic acids and diamines having a nitro substituent may be combined with other types of dicarboxylic acids, other types of diamines, and carboxylic acids having an amino group for use in the synthesis of polyamide.

The method for synthesizing the polyamide is not particularly limited, but is a so-called low temperature polymerization method in which the carboxylic acid group is acylated and then subjected to the reaction, or a so-called direct reaction in which the carboxylic acid group is left unmodified as it is in the reaction. A polymerization method can be mentioned.

Next, the obtained polyamide is dissolved in a solvent to obtain a solution state. As the solvent used at this time, any solvent having a sufficient dissolving power for the polyamide may be used, but an amide solvent is particularly preferable. Also, from the viewpoint of the stability of the obtained gel at high temperature, the solvent having a boiling point of 150 ° C. or higher is preferable.

A typical example of the amide solvent is N-
Methyl-2-pyrrolidinone (boiling point 202 ° C.), tetramethylurea (boiling point 177 ° C.), and dimethylacetamide (boiling point 165 ° C.) can be mentioned, but among them, N-methyl is excellent in solubility in polyamide. -2-Pyrrolidinone is preferred. The polyamide concentration in the solution is preferably 0.1% by weight or more.

Next, a compound having a metal element is added to the obtained polyamide solution to gelate the solution and form a polyamide-based organogel. Examples of the compound having a metal element include a metal salt or a metal. Among them, iron (II) ions and tin (I
A metal salt having an I) ion or a nickel (II) ion is preferable, and specific examples thereof include iron (II) chloride (chemical formula Fe
Cl ₂ ), iron (II) oxalate (chemical formula FeC ₂ O ₄ ), tin (II) acetate (chemical formula Sn (OCOCH ₃ ) ₂ ), tin chloride (II) (chemical formula SnCl ₂ ), nickel chloride (II) ( Chemical formula NiCl ₂ ) and the like can be mentioned.

These metal salts may be used in the hydrated or non-hydrated form. On the other hand, as a specific example of the metal, metal tin (chemical formula Sn) can be cited. Among the compounds having these metal elements, the use of iron (II) chloride is extremely effective when rapid gelation is desired. The compounds containing these metal elements may be used in combination. The compounds having these metal elements can be used as solids or in the form of being dissolved or dispersed in an amide solvent or the like, but in order to obtain more rapid gelation, a powder or a sandy form is required. It is preferable to use.

The amount of the compound having such a metal element added is 0.06 mol or more of metal atom per 1 mol of the nitro group in the polyamide, and particularly, in order to obtain a more stable parallel swelling degree in the solvent used. It is preferably 1 mol or more. The upper limit of the amount of metal atoms added is not particularly limited, but is usually 0.1 to 10 mol, preferably 0.5 to 5
Add about a mole.

The temperature condition for gelation is not particularly limited as long as it is in a temperature range that causes gelation, but it is 0 ° C.
It is possible to obtain a gel in the range of ~ 120 ° C. Especially when iron (II) chloride is used, rapid gelation can be realized even at room temperature.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. Example 1 Poly (p-phenylene nitroterephthalamide) obtained by a direct synthesis method from paraphenylenediamine and nitroterephthalic acid (inherent viscosity = 4 determined at 30 ° C. using a sulfuric acid solution of 0.1 g / dL). .1 dL
/ G) 1 g was dissolved in 99 g of N-methyl-2-pyrrolidinone by stirring at room temperature for 24 hours to obtain a yellow transparent solution.

The amount of iron (II) chloride in the form of powder (0.
A polyamide organogel was prepared by adding 447 g to 0.058 g) at once. Table 1 shows the time required for gelation and the equilibrium swelling degree of the obtained gel at 25 ° C. Here, the gelation time means the time at which the solution does not show fluidity even when the container containing the solution is turned over, and the gelation time of 0 means that the system instantly gels.

The degree of swelling referred to herein is a value obtained by dividing the weight of the gel by the weight of the polymer contained therein. The equilibrium swelling degree means that the obtained polyamide-based organogel has a sufficient amount of N
It is a swelling degree in an equilibrium state in which it is immersed in methyl-2-pyrrolidinone and the swelling degree becomes constant. At this time, the equilibrium swelling degree when the gel is dissolved is infinite.

It can be seen from Table 1 that a polyamide-based organogel is produced under these conditions. The polyamide-based organogel obtained was red. The viscosity of the obtained polyamide-based organogel can be reversibly changed depending on the temperature. For example, when the iron atom / nitro group ratio shown in Table 1 is 100 mol / mol and 100 ° C of the gel. 25 ° C
The reversible change in viscosity between the two is shown in FIG.

Here, the vertical axis of FIG. 1 represents the viscosity (Pa · s) examined by a Vismetron viscometer VDH-K (using a rotor No. 4) manufactured by Shibaura System Co., Ltd., and the horizontal axis. Represents hours (minutes). Also, 100 ℃, 25 ℃ in the figure
Indicates the temperature of the gel.

Example 2 Poly (p-type) used in Example 1
2 g of phenylene nitroterephthalamide)
It was dissolved in 98 g of 2-pyrrolidinone by stirring at room temperature for 24 hours to obtain a uniform solution. While stirring the obtained solution, iron (II) chloride 0.44 was added at a temperature of 25 ° C.
7 g (metal atom / nitro group = 1.0 mol / mol) of N-
A red polyamide-based organogel was obtained by adding a solution prepared by dissolving 100 g of methyl-2-pyrrolidinone at once. The gel time was 20 to 30 hours. The equilibrium swelling degree at 25 ° C. of the gel was 103.

(Example 3) 0.635 g of tin (II) acetate in powder form (metal atom / nitro group = 1.0 mol / mol) in place of the iron (II) chloride powder in Example 1 The same procedure as in Example 1 was carried out except for using, to obtain a red polyamide-based organogel. The gel time was 3 minutes.

Example 4 Paraphenylenediamine and 5
-Poly (p-phenylene nitroisophthalamide) obtained by direct synthesis from nitroisoterephthalic acid
(Inherent viscosity determined at 30 ° C. using a 0.1 g / dL sulfuric acid solution = 0.7 dL / g) 3 g of N-methyl-2
-Pyrrolidinone was dissolved in 97 g by stirring at room temperature for 24 hours to obtain a uniform solution. While stirring the resulting solution, powdery iron chloride 0.4
A red polyamide-based organogel was obtained by adding 47 g (metal atom / nitro group = 0.33 mol / mol) at once. The gel time was 10 to 20 hours.

(Example 5) Poly (4,4'-oxydiphenylene nitroterephthalamide) obtained by a direct synthesis method from 4,4'-diaminodiphenyl ether and nitroterephthalic acid (0.1 g / dL sulfuric acid solution) Using 30
2 g of an inherent viscosity determined at ℃ = 1.9 dL / g) was dissolved in 98 g of N-methyl-2-pyrrolidinone by stirring at room temperature for 24 hours to obtain a uniform solution. While stirring the obtained solution, 0.447 g of powdered iron chloride (metal atom / nitro group = 0.40) under a temperature condition of 25 ° C.
(Mol / mol) was added at once to obtain a red polyamide-based organogel. The gel time was 30-40 hours.

(Example 6) Iron (II) oxalate dihydrate in powder form was added to the iron (II) chloride powder in Example 1 (0.635).
g (metal atom / nitro group = 1.0 mol / mol),
Further, except that the temperature condition was set to 80 ° C., the same procedure as in Example 1 was carried out to obtain a red polyamide organogel.
The gel time was 2-3 hours.

Example 7 Powdered iron (II) chloride in Example 1 was added to powdered tin (II) chloride in an amount of 0.669 g (metal atom / nitro group = 1.0 mol / mol). Instead, the same operation as in Example 1 was carried out except that the temperature condition was set to 80 ° C. to obtain a yellow polyamide organogel. The gel time was within 30 minutes.

Example 8 The powdery iron (II) chloride in Example 1 was added to 0.458 g of powdery nickel (II) chloride (metal atom / nitro group = 1.0 mol / mol). Instead, the same procedure as in Example 1 was carried out except that the temperature was set to 80 ° C. to obtain a red polyamide organogel. The gel time was 30-40 hours.

(Example 9) The powdery iron (II) chloride of Example 1 was replaced with 0.419 g of sandy metallic tin (metal atom / nitro group = 1.0 mol / mol), and the temperature condition was changed. 80 ℃
Except for the above, the same procedure as in Example 1 was carried out to obtain a red polyamide organogel. The gel time was within 30 minutes.

Comparative Example 1 The same operation and evaluation as in Example 1 were carried out except that the amounts of powdered iron (II) chloride in Example 1 were changed to 0.030 g and 0.015 g. . The results are shown in Table 1. It can be seen from Table 1 that a stable gel cannot be produced if the amount of the compound having a metal element added is insufficient.

(Comparative Example 2) 0.636 g of powdered iron (III) chloride was used in place of the powdered iron (II) chloride of Example 1.
The same operation as in Example 1 was carried out except that (metal atom / nitro group = 1.0 mol / mol) was used, but gelation did not occur within 100 hours.

(Comparative Example 3) Liquid tin (IV) chloride 0.9 was used in place of the powdery tin (II) chloride 0.669 g of Example 7.
The same operation as in Example 7 was carried out except that 20 g (metal atom / nitro group = 1.0 mol / mol) was used.
No gelation occurred within 00 hours.

(Comparative Example 4) Sandy metallic tin of Example 9
The same operation as in Example 9 was carried out except that 0.197 g of sandy metallic iron (metal atom / nitro group = 1.0 mol / mol) was used instead of 419 g, but the gel was used within 100 hours. It did not happen.

[0042]

[Table 1]

[0043]

According to the present invention, by adding a compound having a metal element to a solution of a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent, a polyamide organogel and a method for producing the same can be easily and quickly obtained. Can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a reversible viscosity change between 100 ° C. and 25 ° C. of a polyamide-based organogel obtained in Example 1 of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C08G 69/32 NST C08G 69/32 NST

Claims (11)

[Claims] 1. A composition comprising a polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent, a compound having at least one metal element selected from the group consisting of iron, tin and nickel, and a solvent. Polyamide-based organogel. 2. The compound containing a metal element is iron (II),
The polyamide-based organogel according to claim 1, which is one or more metal salts selected from the group consisting of tin (II) and nickel (II). 3. The polyamide organogel according to claim 1, wherein the compound having a metal element is tin metal. 4. The polyamide-based organogel according to claim 1, wherein the aromatic dicarboxylic acid having a nitro substituent is nitroterephthalic acid or 5-nitroisophthalic acid. 5. The polyamide organogel according to claim 1, wherein the diamine is an aromatic diamine. 6. The polyamide organogel according to any one of claims 1 to 5, wherein the solvent is an amide compound. 7. The polyamide-based organogel according to claim 6, wherein the amide compound is N-methyl-2-pyrrolidinone. 8. A polyamide synthesized from an aromatic dicarboxylic acid having a nitro substituent is dissolved in an amide compound,
Next, a polyamide-based organogel characterized by being gelled by adding at least one metal salt of a metal selected from the group consisting of divalent iron, divalent tin and divalent nickel or metal tin. Production method. 9. The method for producing a polyamide organogel according to claim 8, wherein the aromatic dicarboxylic acid having a nitro substituent is nitroterephthalic acid or 5-nitroisophthalic acid. 10. The method for producing a polyamide-based organogel according to claim 8 or 9, wherein the diamine is an aromatic diamine. 11. A method of reversibly changing the viscosity of the polyamide-based organogel according to claim 1 by changing the temperature.