JPH08208833A - Production of polyether nylon - Google Patents

Abstract

PURPOSE: To obtain a polyether nylon having low compatibility with a raw material polymer, having a high melt viscosity, excellent in safety and suitable for the food industry or medical uses by feeding a specific polyether and a polyamide prepolymer to a polymerization apparatus and providing a high degree of polymerization. CONSTITUTION: An aqueous solution of a nylon salt is concentrated in a batch type reactional vessel to prepare (A1 ) a polyamide prepolymer in a melt state (e.g. having a cyclic structure having a recurring unit comprising bisaminomethylcyclohexane and isophthalic acid). The resultant polyamide prepolymer and (A2 ) a polyether which is a polyalkylene oxide having active hydrogens at both terminals (e.g. polyethylene oxide, propylene oxide or polytetramethylene oxide) are then fed into a polymerization apparatus (e.g. a twin-axle type reactor) to provide a high degree of polymerization under a reduced pressure. Thereby, the objective polymer (having >=2000P, especially >=50000P melt viscosity) is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a continuous process for producing polyether nylon.

[0002]

2. Description of the Related Art As a method for producing polyether nylon, a method of polycondensing a polyamide and a polyether in a molten state is known (Japanese Patent Publication No. 45-7559). Further, Japanese Patent Publication No. 63-38052 discloses a method of producing a polyamide and a polyether by pressure polycondensation in a molten state. However, in these methods, the compatibility of both polyether and polyamide is relatively good, and the melt viscosity of the polymer finally obtained is as low as 10,000 poise or less. Therefore, with these methods, polyether nylon can be produced only with a limited combination of polyamide and polyether, and its application is limited to industrial applications. That is, since the obtained polymer has a molecular weight that is not sufficiently high, its use in the food industry and medical applications poses a problem due to the relationship with the eluate, and for this purpose it is necessary to incorporate a thorough washing step. It was

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a novel method for producing a polyether nylon, in particular, the production of a polyether nylon in which the compatibility of polyether and polyamide is not so good and the final product has an extremely high melt viscosity. To provide a method.

[0004]

The above object can be achieved by the following method.

1) In the production of polyether nylon, an aqueous solution of a nylon salt is concentrated in a batch type reaction kettle to prepare a polyamide prepolymer in a molten state, and then a polyalkylene oxide having active hydrogen groups at both ends is prepared. A method for producing a polyether nylon, characterized in that a polyether and the polyamide prepolymer are continuously fed into a polymerization apparatus to increase the degree of polymerization.

2) In the production of polyether nylon, a step of concentrating an aqueous solution of a nylon salt in a polymerization apparatus, a step of prepolymerizing a polyamide prepolymer, and a polyether which is a polyalkylene oxide having active hydrogen groups at both ends are added. Finally, a high degree of polymerization step for increasing the degree of polymerization,
A method for producing a polyether nylon, characterized in that each of the steps is continuously performed.

3) The method for producing a polyether nylon according to any one of claims 1 and 2, wherein a high-efficiency mixing stirrer is used in the polymerization apparatus.

4) The method for producing polyether nylon according to claim 3, wherein a high-viscosity reactor is used as the mixing stirrer.

5) The method for producing polyether nylon according to claim 4, wherein a biaxial reactor is used as the high viscosity reactor.

6) The method for producing a polyether nylon according to any one of claims 1 to 5, wherein the step of increasing the degree of polymerization for carrying out the condensation reaction between the polyamide prepolymer and the polyether is performed under reduced pressure.

7) The method for producing a polyether nylon according to any one of claims 1 to 6, wherein the melt viscosity of the polyether nylon is 20000 poise or more.

8) The method for producing a polyether nylon according to claim 7, wherein the melt viscosity of the polyether nylon is 50,000 poise or more.

9) The method for producing a polyether nylon according to any one of claims 1 to 8, wherein the polyamide portion of the polyether nylon is amorphous.

10) The method for producing a polyether nylon according to any one of claims 1 to 8, wherein at least a part of the polyamide portion of the polyether nylon has a repeating unit having a cyclic structure.

11) The method for producing a polyether nylon according to claim 10, wherein the repeating unit having the cyclic structure is a polyamide composed of bisaminomethylcyclohexane and isophthalic acid.

12) Polyalkylene oxide having active hydrogen groups at both terminals is polyethylene oxide, polypropylene oxide, polytetramethylene oxide,
The method for producing a polyether nylon according to claim 1, which is a propylene oxide-ethylene oxide copolymer.

The polyamide prepolymer of the present invention can be obtained by melt polycondensation of diamine and dicarboxylic acid nylon salt and / or ω-aminocarboxylic acid, ring-opening polymerization of lactam, etc. It is desirable to control to 10,000 or less. Furthermore, it is desirable to suppress the amount to 7,000 or less from the viewpoint of reactivity with polyether. In the production method of the present invention, the chemical structure of the polyamide is basically not limited, but the polyamide has a high glass transition point such that it has an amorphous structure or a cyclic structure as a repeating unit. , The effectiveness of the present invention becomes remarkable. As the diamine component constituting the polyamide, metaxylylenediamine, paraxylylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, 4,4′-diamino3,3′-dimethyldicyclohexyl Alicyclic diamines or aromatic diamines such as methane, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylpropane, isophoronediamine, 4,4'-diaminodiphenylmethane, tolylenediamine, phenylenediamine, diaminodiphenylether. And aliphatic diamines such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, decamethylenediamine, and trimethylhexamethylenediamine. Examples of the dicarboxylic acid constituting the polyamide include isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, biphenylcarboxylic acid, 4,
Examples thereof include alicyclic or aromatic dicarboxylic acids such as 4′-dicarboxydiphenyl ether, naphthalenedicarboxylic acid, and phenylenedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and dimer acid. Among these, isophthalic acid, terephthalic acid,
Adipic acid, azelaic acid, sebacic acid, etc. are preferable in terms of raw material price and stable availability. As the lactam (including the ring-opened ω-aminocarboxylic acid) constituting the polyamide, caprolactam, laurolactam and the like can be freely used.

In the present invention, the polyalkylene oxide having active hydrogen groups at both ends is polyethylene oxide,
Examples thereof include polypropylene oxide, polytetramethylene oxide, and ethylene oxide-propylene oxide copolymer. This molecular weight is preferably in the range of 200 to 50,000, more preferably 800 to 200.
The range of 00 is desirable from the viewpoint of the effect of adding the polyether. The active hydrogen groups at both ends are amino, hydroxyl and carboxylic acid groups.

The effectiveness of the method of the present invention is remarkably exhibited when the polyamide prepolymer is amorphous. That is, in the case of a crystalline polymer, the melt viscosity required to obtain mechanical strength is sufficient even at 10,000 poises or less, whereas the amorphous polyamide for this purpose has a melt viscosity of 20,000 poises or more, more preferably 30,000 poises or more. It is desirable to have more than poise. When the melt viscosity is 20,000 or more, the efficiency of stirring and mixing becomes insufficient in a conventional batch type reactor using a helical blade or a ribbon blade, which is not preferable. On the other hand, a biaxial reactor often used in the final polymerization step in continuous polymerization has a melt viscosity of 100,000.
Mixing is possible even at poise or higher.

The continuous polymerization in the present invention is a complete continuous polymerization method in which all the steps from the step of concentrating an aqueous solution of nylon salt to the prepolymerization to a prepolymer and finally the final polymerization step of increasing the degree of polymerization are carried out continuously. And a semi-continuous polymerization method in which only the step of preparing a polyamide prepolymer in a batch reaction kettle and increasing the degree of polymerization using the prepolymer is continuous. The polyether is supplied in the final step of increasing the degree of polymerization. If the prepolymer of polyether nylon is synthesized in advance, the degree of polymerization increases with time, and it becomes impossible to stably supply the raw material to the biaxial reactor, which is not desirable.
Further, as the polymerization apparatus in this final step, a twin-screw type reactor capable of handling 100,000 poise or more is desirable from the melt viscosity of the produced polyether nylon. In order to enhance the mixing and stirring ability of high-viscosity fluid,
It is a twin-screw extruder in which two parallel screws rotate in the same direction or in opposite directions, or a space volume larger than that. The screw shape is not particularly limited.

In the continuous polymerization method of the present invention, the pressure of the reaction system is preferably normal pressure or reduced pressure. That is, the reaction between the polyamide and the polyether is a dehydration condensation and is therefore an equilibrium reaction. Therefore, when this equilibrium is sufficiently biased toward the product side, it is not necessary to make the reaction system a reduced pressure system, and it is possible to obtain a polyether nylon by simply flowing nitrogen and removing the produced water. On the other hand, when the equilibrium is not sufficiently large on the product side, it is necessary to reduce the pressure of the reaction system and forcibly remove the produced water. The degree of reduced pressure at this time cannot be uniquely determined because it depends on the type of polyether nylon to be synthesized, and is appropriately determined within the range of 760 mmHg to 1 mmHg.

As described above, the present invention is characterized in that a polyalkylene oxide having active hydrogen groups at both ends, for example, aminated polyether at both ends is supplied to the final step. If it is supplied in a step before this, the molar ratio of carboxylic acid and amine in the reactor becomes 1, so that the degree of polymerization of the prepolymer increases, which exceeds the stirring ability of the reactor and is not desirable. Further, in the case of semi-continuous polymerization, when the polyether is fed into the batch reactor, the degree of polymerization rises and the prepolymer feed to the final step becomes unstable, and of course, it is held in the molten state for several hours, so that it is not thermally stable. This is a big problem when using stable polyethers.

Further, according to the present invention, since strong mixing power and liquid surface renewal property are obtained, the conversion of the polymerization is sufficiently increased and the low molecular weight oligomers are reduced, so that medical materials and food packaging materials are used. A highly safe polyether nylon suitable for use in, for example, is obtained.

[0024]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(Examples 1 to 4) 1,3-bisaminomethylcyclohexane (abbreviated as B) (manufactured by Mitsubishi Gas Chemical) 9.
31 kg (65.43 mol) and isophthalic acid (abbreviated as I) (manufactured by AGIC) 11.02 kg (66.34 mo)
l) was dissolved in 20 kg of water and heated to 240 ° C. under a pressure of 10 kg / cm ² according to a usual polyamide polymerization method to prepare a polyamide (NyBI) prepolymer. While maintaining the molten prepolymer in a molten state, a gear pump was used to supply the molten prepolymer to a biaxial reactor at a rate of 3.8 kg / h. Further, in parallel, both ends aminated polytetramethylene oxide (abbreviated as PTMO) # 1100 (B
ASF) was supplied at a rate of 0.2 kg / h. 4k
Polyether nylon produced at a rate of g / h (PTM
O-NyBI) was extracted. The reaction temperature in the reactor was 280 ° C., and the reaction pressure was the conditions shown in Table 1.

Example 5 Metaxylenediamine (abbreviated as M) (Mitsubishi Gas Chemical Co., Ltd.) 7.94 kg (58.38 m)
ol) and sebacic acid (abbreviated as 10) (Toyoku Oil & Refinery Co., Ltd.)
Made) 12.54 kg (62.08 mol) in 30 kg of water
And a polyamide prepolymer was prepared at 220 ° C. in the same manner as in Example 1. The molten prepolymer and aminated PTMO # 2100 at both ends (manufactured by BASF) were supplied to a biaxial reactor at a rate of 2.8 kg / h and 1.2 kg / h, respectively, and a polyether produced at a rate of 4 kg / h. Nylon (PTMO-NyM10) was extracted.
The residence time in the reactor was 60 minutes and the reaction temperature was 2
It was 40 ° C.

Comparative Example 1 A polyamide (NyBI) oligomer composed of isophthalic acid and bisaminomethylcyclohexane was prepared in the same manner as in Example 1 using a batch type reactor having a double helical blade, and 1 kg of PTMO having both ends aminated therein was prepared. Was added and pressure polymerization was continued for 2 hours, and then pressure reduction polymerization was carried out at 600 mmHg for 30 minutes to synthesize polyether nylon (PTMO-NyBI).

(Comparative Example 2) Referring to Example 5 and Comparative Example 1, a polyether nylon (PT
MO-NyM10) was synthesized. The reaction conditions at this time were the same as those in Comparative Example 1 except that the pressure reaction was the same as that of Comparative Example 1, but the pressure reduction reaction was carried out at 20 mmHg for 1 hour.

(Comparative Example 3) In the same manner as in Example 1, a NyBI prepolymer was first synthesized using a batch type reactor, then aminated PTMO at both ends was added and mixed therein, and the mixture was kept under pressure to a biaxial reactor. It was used as a prepolymer for supply. Although the melt viscosity was 6300 poise immediately after mixing, it increased to 16200 poise after 6 hours, and the stable supply to the biaxial reactor by the gear pump was not possible. Therefore, the obtained polyether nylon was also constant. It wasn't something.

The results of the polymers obtained in Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 1.

Comparing the amounts of the ethanol extract of Examples and Comparative Examples, the method using the biaxial reactor of the present invention can increase the polymerization conversion, and the amount of low molecular weight polyether nylon which may be eluted is small and safe. A polyether nylon having excellent properties was obtained. In addition, the polyether was mixed in the final step of the twin-screw reactor to produce a polyether nylon of stable quality.

[0032]

[Table 1]

[0033]

EFFECTS OF THE INVENTION The method for producing a polyether nylon of the present invention provides a polyether nylon in which the compatibility of polyether and polyamide is not very good, and the final product has an extremely high melt viscosity and is excellent in safety. it can.

Claims (12)

[Claims] 1. In the production of polyether nylon, an aqueous solution of a nylon salt is concentrated in a batch type reaction kettle to prepare a polyamide prepolymer in a molten state, and then a polyalkylene oxide polyalkylene oxide having active hydrogen groups at both ends is prepared. A method for producing a polyether nylon, characterized in that ether and the polyamide prepolymer are continuously fed into a polymerization apparatus to increase the degree of polymerization. 2. In the production of polyether nylon, a step of concentrating an aqueous solution of a nylon salt in a polymerization apparatus, a prepolymerization step of forming a polyamide prepolymer, and a polyether which is a polyalkylene oxide having active hydrogen groups at both ends are added. A method for producing a polyether nylon, characterized in that each step of a high degree of polymerization step of finally increasing the degree of polymerization is continuously performed. 3. The method for producing a polyether nylon according to claim 1, wherein a high-efficiency mixing stirrer is used in the polymerization apparatus. 4. The method for producing a polyether nylon according to claim 3, wherein a high-viscosity reactor is used as the mixing stirrer. 5. The method for producing a polyether nylon according to claim 4, wherein a biaxial reactor is used as the high viscosity reactor. 6. The method for producing a polyether nylon according to claim 1, wherein the step of increasing the degree of polymerization for carrying out the condensation reaction between the polyamide prepolymer and the polyether is performed under reduced pressure. 7. The melt viscosity of the polyether nylon is 2
7. The method for producing a polyether nylon according to claim 1, which has a poise of 0000 or more. 8. The melt viscosity of the polyether nylon is 5
The method for producing a polyether nylon according to claim 7, which has a poise of 0000 poise or more. 9. The method for producing a polyether nylon according to claim 1, wherein the polyamide portion of the polyether nylon is amorphous. 10. The method for producing polyether nylon according to claim 1, wherein at least a part of the polyamide portion of the polyether nylon has a repeating unit having a cyclic structure. 11. The method for producing a polyether nylon according to claim 10, wherein the repeating unit having the cyclic structure is a polyamide composed of bisaminomethylcyclohexane and isophthalic acid. 12. The polyalkylene oxide having active hydrogen groups at both ends is polyethylene oxide, polypropylene oxide, polytetramethylene oxide,
The method for producing a polyether nylon according to claim 1, which is a propylene oxide-ethylene oxide copolymer.