JPS62161828A - Production of polyamide - Google Patents

Abstract

PURPOSE:To obtain a polyamide having low melting point and excellent transparency, glossiness, water-resistance, chemical resistance, processability and hygroscopicity and suitable as an adhesive, etc., by polymerizing a salt of a specific aliphatic dicarboxylic acid and a specific diamine singly or in combination with other components. CONSTITUTION:A salt of an aliphatic dicarboxylic acid of formula HOOC-R- COOH (R is <=5C alkylene) and a diamine of formula (m and n are 1-5) or its mixture is polymerized singly or together with other polyamide-forming component. The aliphatic dicarboxylic acid is preferably sebacic acid or dodecanedicarboxylic acid and the diamine is the one having tetraoxaspiroundecane ring such as 3,9-bis(3-aminopropyl)-2,4,8,10- tetraoxaspiro[5,5]undecane, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application in the FM industry) The present invention relates to a novel method for producing polyamides, and particularly to a method for producing novel polyamides in which a tetraoxaspirolafdeca/ring is incorporated into the molecule.

(Prior art) Polyamides represented by nylon 6, nylon 66, and nylon 12 are used as industrial materials because of their excellent mechanical strength, abrasion resistance, and hardness, but they have a high melting point. Therefore, it is necessary to increase the molding degree, which tends to cause thermal deterioration. Furthermore, these nylons are highly crystalline and suffer from the disadvantage of lacking transparency. For this reason, some efforts have been made to prevent whitening by adding additives to the polymer to improve its transparency, or by increasing the speed of the metal part after extrusion to avoid clouding during the molding process, but this is not an essential solution. Furthermore, when used as a hot-melt adhesive, the high crystallinity causes rapid melting when the melting point is reached, making it difficult to weld in minutes. In order to improve these drawbacks, for example, sulfamide-based plasticizers have been used. However, there is no fundamental solution.

(Means for Solving the Problems) The present inventors have made extensive studies and efforts to solve the problems in the conventional techniques, and as a result, have finally completed the present invention. That is, the present invention is a method for producing a polyamide using a salt consisting of an aliphatic dicarboxylic acid represented by the following general formula (I) and a diamine represented by the following general formula (II), or a mixture thereof alone or, if necessary, other polyamides.

1100C-R-COOH (I) In the present invention, examples of the aliphatic dicarboxylic acid represented by the general formula (I) include pimelic acid, superric acid, azelaic acid, sebacic acid, undecanedio/acid, dodecanedioic acid, and hexadecanedione. Examples include acids, but sebacic acid and dodeca/dicarboxylic acid are particularly preferred in view of the stability and industrial property of the nylon salt. When R is 4 or less, the nylon salt thereof is thermally unstable, and higher dicarboxylic acids of 24 or more are difficult to obtain industrially in pure form, and their use is not advantageous.

In addition, the hydrogen in the methylene chain of these dicarboxylic acids is
Even if it is substituted with a relatively short-chain alkyl group having 1 to 4 carbon atoms, it can be used without significantly affecting the polymerizability.

Next, as a diamine represented by the general formula (II), that is, a tetraoxaspiroundeca/ring, if t O diamine, 3,9-bis(3-aminopropyl)-2,4
,8,10-tetraoxaspiroC5,5)undecane,3,9-bis(aminomethyl)-2,4,8,10
-Tetraoxaspiro(5,5)undecane, 3.9-
Bis(aminomethyl)-2,4,8,10-tetraoxaspiroundecane, 3,9-bis(4-aminohexyl)-2,4,8,10-tetraoxaspiroundecane, 3,9-bis( 5-aminopentyl”)-2,4,
Examples include 8,10-tetraoxaspiroundecane.

In the method of the present invention, a salt of an aliphatic dicarboxylic acid represented by the general formula (1) and a diamine represented by the general formula (II) or an equimolar mixture thereof may be used as long as it does not impair the effects of the present invention. , other polyamide-forming components can be used.

Other polyamide-forming components include α-pyrrolidone,
Lactams such as e-caprolactam, ω-7naractam, ω-decyllactam, ω-undecyllactam, ω-dodecyllactam and their corresponding ω-ami7carboxylic acids or aliphatic, alicyclic and aromatic diamines and dicarboxylic acids or equimolar mixtures thereof, such as Nylon No. 6, Nylon 6.6, Nylon:/G,
10, nylon 6T1 nylon: /10,10, nylon:
/G, 12, nylon 12.12, etc.

The other polyamide-forming component accounts for 3% of the total copolyamide.
It can be used in a range of 0 mol% or less. If this component exceeds 30 mol%, the melting point becomes too high, which not only reduces processability but also tends to cause a loss of flexibility and transparency, which is not preferable.

In the present invention, the polyamide can be obtained by any conventional polyamide manufacturing method, and is not limited to such a method. A polyamide is obtained by heating to 250° C. and removing almost all of the water which is separated by formation of nylon salts and condensation. It should be noted that adding a small amount of water at the beginning of the polycondensation reaction, for example, about 1 to 15 mol% of water to the total amount of the raw material mixture, will improve the thermal conductivity in the system at the initial stage of the reaction. It is very effective in obtaining high-quality and homogeneous copolyamides.

In addition, during the polycondensation reaction, an alkali catalyst may be added to the system to promote ring opening of the lactam (and, if necessary, a polymerization degree regulator such as acetic acid, a small amount of a viscosity stabilizer,
Antistatic agents, antioxidants, light stabilizers, pigments, etc. may be added.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the scope of the present invention is not limited thereby.

Example 1゜3.9-bis(3-aminopropyl)-2,4,8,
80 mol% salt of IO-tetraoxaspiro(5,5)undecane and sebacic acid, 20 mol% ε-caprolactam, e-aminocaproic acid (5 mol% based on e-caprolactam), oxidation of hindered phenol. Inhibitor 1
,3.5-)limethyl2.4. (i-tris(3,5
-ditertiary-butyl-4-hydroxybenzyl)benzene (Ciba Gaiki Co., Ltd., trade name 1onox 133)
0) 1 mW 1% was charged into an autoclave, the inside of the system was completely purged with nitrogen, and then heated to 230° C. for 1 hour. Next, the temperature was raised to 250°C in 2 hours, and after the pressure was released, heating was continued at normal pressure for 2 hours while flowing a nitrogen cable.The pressure inside the system was gradually reduced, and this state was maintained for 30 minutes. (After holding the temperature at 1, the resulting polymer was extruded into water. The resulting polymer was colorless and transparent with excellent gloss, and the relative viscosity at 25"C of a metacresol solution with a concentration of 0.jff/100m was 1.40. The melting peak by scanning calorimetry (DSC) was 130"C. The polymer was then heated to 150"Cs 5 kg/
Press molding was performed for 3 minutes at cJ to obtain a film with a thickness of 50 μm. The haze of this film according to ASTM-D-1003 was 1.0%, and the transparency was good.

Comparative Example 1.2 3.9-His (3-aminoprohyl) -2,4,8,
Polycondensation was carried out in the same manner as in Example 1, except that the charging composition of 10-tetraoxaspiro(5,5)undecane-sebacate and ε-caprolactam was changed as shown in Table 1. The obtained polymer was formed into a film in the same manner as in Example 1 to obtain a film with a thickness of 50 μm. The results are shown in Table 1.

Table 1 Example 2, Comparative Example 3 In Example 1, 3,9-bis(3-aminopropyl)
-2,4,8,10-Tetraoxaspiro[5,5]/deca/ Acid component forming a salt The same method as in Example 1 except that dodecazio/acid or succinic acid was used first. m ktr was combined and made into a film. The results are shown in Table 2.

Table 2 As is clear from Table 2, Comparative Example 3 using succinic acid
It can be seen that the heat resistance of the nylon salt was poor and the polycondensation did not proceed much.

(Effects of the Invention) The polyamide obtained by employing the method of the present invention has the following two excellent properties.

1) The melting point is relatively low, generally in the range of 150°C or lower.

2) Excellent transparency and gloss.

3) Excellent water resistance and chemical resistance.

4) Good flow and excellent workability.

5) It has excellent hygroscopicity.

In addition, polyamides with the above characteristics can be used for various purposes, such as aluminum foil, mild steel, metal scraps such as copper, adhesives for obtaining composite materials of the same or different types such as wood, paper, fibers, etc. , or hot melt for the clothing field such as interlining and patches! ! :! Can be used as an adhesive. In addition, it can be used as a single fiber or film.
7. Laminate +j lyamide onto a film that is difficult to heat seal, such as nylon 6, nylon 66, polyethylene terephthalate, or oriented polypropylene, by a method such as extrusion coating, or preliminarily coat the nylon 6, nylon 66, polyethylene terephthalate, polypropylene, etc. By blending the polyamide, it is possible to provide materials with good performance, such as various woven textile industrial materials for clothing and packaging materials for foods and the like.

Claims (1)

[Claims] A salt consisting of an aliphatic dicarboxylic acid represented by the following general formula (I) and a diamine represented by the following general formula (II), or a mixture thereof, is polymerized alone or optionally with other polyamide-forming components. A method for producing polyamide characterized by the following. HOOC-R-COOH (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(II) (However, in the formula, R is an alkylene group with 5 or more carbon atoms, m
, n represents an integer of 1 to 5. )