阅读说明：本技术 一种半芳香族聚酰胺缩聚催化剂及其制备方法 (Semi-aromatic polyamide polycondensation catalyst and preparation method thereof ) 是由 杨杰 张美林 杨家操 王孝军 龙盛如 于 2021-09-28 设计创作，主要内容包括：本发明涉及一种半芳香族聚酰胺缩聚催化剂及其制备方法,属于高分子合成技术领域。本发明提供一种半芳香族聚酰胺缩聚催化剂的制备方法,所述制备方法为：将高分子配体、金属化合物和有机膦化合物通过络合反应制得半芳香族聚酰胺缩聚催化剂；其中,所述高分子配体为能和金属化合物发生络合反应的物质；各原料的质量比为：高分子配体70～130重量份,金属化合物0.1～10重量份,有机膦化合物1～50重量份。本发明提供了一种新型的半芳香族聚酰胺缩聚催化剂及其制备方法,所得催化剂具有催化效率高和成本低的优点；并且本发明采用一釜法工艺,具有操作简单和收率高的优点。(The invention relates to a semi-aromatic polyamide polycondensation catalyst and a preparation method thereof, belonging to the technical field of polymer synthesis. The invention provides a preparation method of a semi-aromatic polyamide polycondensation catalyst, which comprises the following steps: preparing a semi-aromatic polyamide polycondensation catalyst by a complexing reaction of a macromolecular ligand, a metal compound and an organic phosphine compound; wherein the macromolecular ligand is a substance capable of carrying out a complex reaction with a metal compound; the mass ratio of the raw materials is as follows: 70-130 parts of polymer ligand, 0.1-10 parts of metal compound and 1-50 parts of organic phosphine compound. The invention provides a novel semi-aromatic polyamide polycondensation catalyst and a preparation method thereof, and the obtained catalyst has the advantages of high catalytic efficiency and low cost; the invention adopts a one-pot process, and has the advantages of simple operation and high yield.)

1. A preparation method of a semi-aromatic polyamide polycondensation catalyst is characterized by comprising the following steps: preparing a semi-aromatic polyamide polycondensation catalyst by a complexing reaction of a macromolecular ligand, a metal compound and an organic phosphine compound; wherein the macromolecular ligand is a substance capable of carrying out a complex reaction with a metal compound; the mass ratio of the raw materials is as follows: 70-130 parts of polymer ligand, 0.1-10 parts of metal compound and 1-50 parts of organic phosphine compound.

2. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to claim 1, wherein the polymeric ligand is prepared by the method comprising: adding unsaturated carboxylic acid, comonomer, deionized water and ammonia water into itaconic acid, and preparing the macromolecular ligand through free radical polymerization under the action of oxidant and reducer; wherein, the itaconic acid amide acid accounts for 1.57-19.7 weight parts, the unsaturated carboxylic acid accounts for 58-86 weight parts, the comonomer accounts for 0.99-13 weight parts, the ammonia water accounts for 31-47 weight parts, the oxidant accounts for 0.05-2 weight parts, and the reducing agent accounts for 0.07-1.7 weight parts.

3. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to claim 2, wherein the itaconamic acid is at least one of those represented by the following structural formula;

whereinAt least one of (1).

4. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to claim 3, wherein the itaconamide acid is a product obtained by reacting itaconic anhydride and an aliphatic secondary amine;

further, the aliphatic secondary amine is at least one of dimethylamine, diethylamine, tetrahydropyrrole or piperidine.

5. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to any one of claims 2 to 4, wherein the unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid, maleic acid, fumaric acid, or itaconic acid;

further, the comonomer is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, N-dimethylacrylamide or N, N-dimethylmethacrylamide;

further, the oxidizing agent is any one of hydrogen peroxide, tert-butyl hydroperoxide or cumene hydroperoxide;

further, the reducing agent is any one of oxalic acid, furfural, 5-hydroxymethylfurfural or glucose.

6. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to any one of claims 2 to 5, wherein the metal compound is at least one of zinc sulfate, zinc chloride, zinc nitrate, zinc acetate, zinc carbonate, zinc hydroxycarbonate, zinc hydroxide, zinc oxide, copper sulfate, copper chloride, copper nitrate, copper acetate, copper hydroxycarbonate, copper hydroxide, copper oxide, cuprous chloride, cuprous oxide, nickel sulfate, nickel dichloride, nickel nitrate, nickel carbonate, nickel hydroxide, or nickel oxide;

further, the organic phosphine compound is at least one of triphenylphosphine, triphenylphosphine oxide, tris (2-thienyl) phosphine, tris (2-furyl) phosphine, P-diphenyl-2-phosphinopyridine, P '-tetraphenyl-1, 2-diphosphinobenzene, P' -tetraphenyl-1, 8-diphosphinonaphthalene, P '-tetraphenyl-2, 2' -diphosphinobiphenyl, P '-tetraphenyl-2, 2' -diphosphinodiphenyl ether, or P, P '-tetraphenyl-1, 1' -diphosphinoferrocene.

7. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to any one of claims 2 to 6, wherein the complexation reaction process is: the polymer ligand, the metal compound, the organic phosphine compound and ammonia water are uniformly mixed, and stirred and reacted for 1-3 hours at 50-90 ℃ under the protection of inert gas.

8. The method for preparing a semi-aromatic polyamide polycondensation catalyst according to any one of claims 2 to 7, wherein the method for preparing a semi-aromatic polyamide polycondensation catalyst comprises the steps of:

(1) adding 1.12-11.2 parts of itaconic anhydride and 5-30 parts of solvent into a reaction kettle, introducing inert gas, and stirring; cooling with water, adding 0.45-8.5 parts of aliphatic secondary amine, and reacting for 0.5-2 h while maintaining the temperature not to exceed 50 ℃ to obtain an itaconic acid reaction solution;

(2) adding 58-86 parts of unsaturated carboxylic acid and 200-500 parts of deionized water into the obtained itaconic acid reaction liquid, adding 31-47 parts of ammonia water with the mass concentration of 20-28%, and reacting for 0.5-1 h at the temperature not higher than 50 ℃;

(3) opening the reaction kettle, and sequentially adding 0.99-13 parts of comonomer, 0.05-2 parts of oxidant and 0.07-1.7 parts of reducing agent; stirring, stopping introducing inert gas, sealing the reaction kettle, and carrying out heat preservation reaction at 60-90 ℃ for 0.5-3 hours to obtain a polymer ligand reaction solution;

(4) cooling the obtained polymer ligand reaction liquid to 40-60 ℃, and adding 0.1-10 parts of metal compound, 1-50 parts of organic phosphine compound and 34-52 parts of ammonia water with mass concentration of 20-28%; introducing inert gas, stirring, and reacting for 1-3 hours at the temperature of 50-90 ℃;

(5) cooling to room temperature, stopping introducing the inert gas, discharging, and drying the product until the water content is less than or equal to 1% to obtain the semi-aromatic polyamide polycondensation catalyst.

9. The method of preparing a semi-aromatic polyamide polycondensation catalyst according to claim 8, wherein in step (1), the solvent is any one of N, N-dimethylacetamide, N-methyl-2-pyrrolidone, or 1, 3-dimethyl-2-imidazolidinone;

further, in the step (3), the oxidizing agent is any one of hydrogen peroxide, tert-butyl hydroperoxide or cumene hydroperoxide;

further, in the step (3), the reducing agent is any one of oxalic acid, furfural, 5-hydroxymethylfurfural or glucose.

10. A semi-aromatic polyamide polycondensation catalyst, characterized in that the semi-aromatic polyamide polycondensation catalyst is obtained by the method according to any one of claims 1 to 9.

Technical Field

The invention relates to a semi-aromatic polyamide polycondensation catalyst and a preparation method thereof, which are mainly used for synthesizing semi-aromatic polyamide and belong to the technical field of polymer synthesis.

Background

The semi-aromatic polyamide is a high polymer material with excellent performance, has the advantages of high temperature resistance, corrosion resistance, low water absorption and the like, and is widely applied to the fields of electronic and electric appliances, mechanical manufacturing, automobile industry and the like. In recent years, bio-based polymers have been increasingly popular as carbon-neutralizing products among consumers in various countries around the world. The poly (phenylene terephthalamide) (PA5T) can be prepared by fermenting agricultural products to prepare the pentamethylene terephthalamide and then carrying out polycondensation with terephthalic acid. PA5T is a semi-aromatic polyamide with partial bio-base, has excellent comprehensive performance and is expected to be widely applied in future production and life.

The semi-aromatic polyamide is prepared by high-temperature solution polycondensation of aromatic dibasic acid, aliphatic dibasic acid and diamine in an aqueous solution under the action of a phosphorus-containing catalyst, and further performing solid phase polycondensation or melt polycondensation to prepare the high-molecular-weight semi-aromatic polyamide resin. For example, chinese patents CN102532528A and CN110423344A both report the preparation of semi-aromatic polyamide using phosphoric acid, polyphosphoric acid, sodium phosphite, sodium hypophosphite, etc. as catalysts. However, in the synthesis of PA5T, when a conventional phosphorus-based catalyst is used, the pentanediamine is easily subjected to deamination cyclization reaction at high temperature to generate piperidine (piperidine), which causes imbalance of monomer ratio and reduction of molecular weight, and finally, PA5T is deteriorated in performance and reduced in yield.

Therefore, it is necessary to develop a catalyst that can be used for producing semi-aromatic polyamides such as PA 5T.

Disclosure of Invention

The invention aims to provide a semi-aromatic polyamide polycondensation catalyst (namely a catalyst for preparing semi-aromatic polyamide) and a preparation method thereof aiming at the defects of the prior art, wherein the obtained catalyst has the advantages of high catalytic efficiency and low cost; the invention adopts a one-pot process, and has the advantages of simple operation and high yield.

Technical scheme of the invention

The first technical problem to be solved by the present invention is to provide a preparation method of a semi-aromatic polyamide polycondensation catalyst, the preparation method comprising: preparing a semi-aromatic polyamide polycondensation catalyst by a complexing reaction of a macromolecular ligand, a metal compound and an organic phosphine compound; wherein the macromolecular ligand is a substance capable of carrying out a complex reaction with a metal compound; the mass ratio of the raw materials is as follows: 70-130 parts of polymer ligand, 0.1-10 parts of metal compound and 1-50 parts of organic phosphine compound.

Further, the macromolecular ligand is prepared by the following method: adding unsaturated carboxylic acid, comonomer, deionized water and ammonia water into itaconic acid, and preparing the macromolecular ligand through free radical polymerization under the action of oxidant and reducer; wherein, the itaconic acid amide acid accounts for 1.57-19.7 weight parts, the unsaturated carboxylic acid accounts for 58-86 weight parts, the comonomer accounts for 0.99-13 weight parts, the ammonia water accounts for 31-47 weight parts, the oxidant accounts for 0.05-2 weight parts, and the reducing agent accounts for 0.07-1.7 weight parts.

Further, the itaconic amide acid is at least one of the substances shown in the following structural formula;

wherein R ═At least one of (1).

Further, the itaconic amide acid is a product obtained by reacting itaconic anhydride and aliphatic secondary amine according to a molar ratio of 1: 1.

Further, the aliphatic secondary amine is at least one of dimethylamine, diethylamine, tetrahydropyrrole or piperidine.

Further, the unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid, maleic acid, fumaric acid, or itaconic acid.

Further, the comonomer is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, N-dimethylacrylamide or N, N-dimethylmethacrylamide.

Further, the oxidizing agent is any one of hydrogen peroxide, tert-butyl hydroperoxide or cumene hydroperoxide.

Further, the reducing agent is any one of oxalic acid, furfural, 5-hydroxymethylfurfural or glucose.

Further, the metal compound is at least one of zinc sulfate, zinc chloride, zinc nitrate, zinc acetate, zinc carbonate, basic zinc carbonate, zinc hydroxide, zinc oxide, copper sulfate, copper chloride, copper nitrate, copper acetate, basic copper carbonate, copper hydroxide, copper oxide, cuprous chloride, cuprous oxide, nickel sulfate, nickel dichloride, nickel nitrate, nickel carbonate, nickel hydroxide, or nickel oxide.

Further, the organic phosphine compound is at least one of triphenylphosphine, triphenylphosphine oxide, tris (2-thienyl) phosphine, tris (2-furyl) phosphine, P-diphenyl-2-phosphinopyridine, P '-tetraphenyl-1, 2-diphosphinobenzene, P' -tetraphenyl-1, 8-diphosphinonaphthalene, P '-tetraphenyl-2, 2' -diphosphinobiphenyl, P '-tetraphenyl-2, 2' -diphosphinodiphenyl ether, or P, P '-tetraphenyl-1, 1' -diphosphinoferrocene.

Further, the complexing reaction process comprises the following steps: the polymer ligand, the metal compound, the organic phosphine compound and ammonia water are uniformly mixed, and stirred and reacted for 1-3 hours at 50-90 ℃ under the protection of inert gas.

Further, the preparation method of the semi-aromatic polyamide polycondensation catalyst comprises the following steps:

(1) adding 1.12-11.2 parts of itaconic anhydride and 5-30 parts of solvent into a reaction kettle, introducing inert gas (such as nitrogen), and stirring; cooling with water, adding 0.45-8.5 parts of aliphatic secondary amine, and reacting for 0.5-2 h while maintaining the temperature not to exceed 50 ℃ to obtain an itaconic acid reaction solution;

(2) adding 58-86 parts of unsaturated carboxylic acid and 200-500 parts of deionized water into the obtained itaconic acid reaction liquid, adding 31-47 parts of ammonia water with the mass concentration of 20-28%, and reacting for 0.5-1 h at the temperature not higher than 50 ℃;

(3) opening the reaction kettle, and sequentially adding 0.99-13 parts of comonomer, 0.05-2 parts of oxidant and 0.07-1.7 parts of reducing agent; stirring, stopping introducing inert gas, sealing the reaction kettle, and carrying out heat preservation reaction at 60-90 ℃ for 0.5-3 hours to obtain a polymer ligand reaction solution;

(4) cooling the polymer ligand reaction liquid to 40-60 ℃, and adding 0.1-10 parts of metal compound, 1-50 parts of organic phosphine compound and 34-52 parts of ammonia water with mass concentration of 20-28%; introducing inert gas, stirring, and reacting for 1-3 hours at the temperature of 50-90 ℃;

(5) cooling to room temperature, stopping introducing the inert gas, discharging, and drying the product until the water content is less than or equal to 1% to obtain the semi-aromatic polyamide polycondensation catalyst.

Further, in the step (1), the solvent is any one of N, N-dimethylacetamide, N-methyl-2-pyrrolidone, or 1, 3-dimethyl-2-imidazolidinone.

Further, in the step (3), the oxidizing agent is any one of hydrogen peroxide, tert-butyl hydroperoxide, or cumene hydroperoxide.

Further, in the step (3), the reducing agent is any one of oxalic acid, furfural, 5-hydroxymethylfurfural or glucose.

The second technical problem to be solved by the invention is to provide a semi-aromatic polyamide polycondensation catalyst, which is prepared by the method.

In the invention, the raw materials are in parts by weight except for special specifications.

The invention has the beneficial effects that:

1. the catalyst can effectively reduce the deamination cyclization side reaction of diamine such as pentamethylene diamine and the like in the high-temperature polycondensation process, and has the advantages of strong selectivity and less by-products.

2. The catalyst has high catalytic efficiency and small addition amount, the content of the aliphatic polycarboxylate introduced into a polymerization system is low, the crosslinking effect on the semi-aromatic polyamide is very limited, and the performance of the semi-aromatic polyamide is not influenced.

3. The macromolecular ligand is synthesized by taking common monomers as raw materials, and the used metal compound is a common compound, so that the macromolecular ligand has the advantages of wide raw material source and low cost.

4. The invention has simple operation, mature process and stable quality of the obtained product.

Detailed Description

The invention prepares a novel catalyst for preparing semi-aromatic polyamide: firstly, preparing itaconic acid amide in a polar aprotic solvent by using itaconic anhydride and aliphatic secondary amine as raw materials; adding unsaturated carboxylic acid, comonomer, deionized water and ammonia water into itaconic acid, and carrying out free radical polymerization under the action of an oxidation-reduction initiator to obtain a high molecular ligand; then adding a metal compound, triphenylphosphine and ammonia water for complex reaction, and drying to obtain the semi-aromatic polyamide polycondensation catalyst. The invention adopts a one-pot process, has the advantages of simple operation and high yield, and the obtained catalyst has the advantages of high catalytic efficiency and low cost.

The present invention is described in detail below by way of examples, it should be noted that the examples are only for the purpose of further illustrating the present invention and are not to be construed as limiting the scope of the present invention, and that those skilled in the art can make insubstantial modifications and adaptations to the invention described above based on the disclosure of the present invention.

Example 1

Adding 5.6g of itaconic anhydride and 15g N-methyl-2-pyrrolidone into a reaction kettle, introducing nitrogen, and stirring; cooling with water, adding 3.65g of diethylamine, and reacting for 1 hour at the temperature not higher than 50 ℃; adding 86g of methacrylic acid, 350g of deionized water and 39g of ammonia water with the mass concentration of 24%, and reacting for 0.5 hour at the temperature not higher than 50 ℃; opening the reaction kettle, sequentially adding 6.5g of hydroxyethyl methacrylate, 0.5g of hydrogen peroxide with the mass fraction of 30% and 1g of glucose, stopping introducing nitrogen, sealing the reaction kettle, and carrying out heat preservation reaction at 70 ℃ for 2 hours; then, cooling to 50 ℃, continuously adding 3g of copper sulfate, 20g of triphenylphosphine and 43g of ammonia water with the mass concentration of 24%, introducing nitrogen, stirring, and carrying out heat preservation reaction at 90 ℃ for 3 hours; then cooling to room temperature, discharging, drying the product until the water content is less than or equal to 1 percent, and obtaining the semi-aromatic polyamide polycondensation catalyst.

15g of the catalyst prepared in example 1, 1129g of terephthalic acid, 467g of adipic acid, 1030g of pentamethylenediamine and 800g of deionized water were added to a reaction kettle, stirring was started, and the air in the kettle was replaced with nitrogen gas for 3 times; sealing the reaction kettle, heating to 230 ℃ within 1.5 hours, and carrying out heat preservation reaction for 2 hours; opening an exhaust valve, discharging water vapor in the kettle to normal pressure within 1 hour, and maintaining the temperature not to exceed 330 ℃; continuously vacuumizing to-0.08 MPa, and reacting for 3 hours at 320 ℃; and (3) introducing high-pressure nitrogen, opening a bottom valve of the reaction kettle, discharging a casting belt, and cooling and drying to obtain the semi-aromatic polyamide resin. Intrinsic viscosity [ eta ] of the obtained resin]＝0.88dL·g^-1The resin yield was 97%.

The performance parameters of the semi-aromatic polyamides obtained in each example and comparative example are shown in table 1. In the embodiment of the invention, concentrated sulfuric acid is used as a solvent for intrinsic viscosity test, the concentration of a sample is 0.50g/dL, the sample is measured in an Ubbelohde viscometer at 30 +/-0.1 ℃, and the intrinsic viscosity is calculated by adopting a one-point method.

Example 2

Adding 2.24g of itaconic anhydride and 10g N, N-dimethylacetamide into a reaction kettle, introducing nitrogen, and stirring; cooling with water, adding 1.36g of a 33% dimethylamine aqueous solution and 0.85g of piperidine, and reacting for 1.5 hours at a temperature not higher than 50 ℃; adding 72g of acrylic acid, 250g of deionized water and 35g of 25% ammonia water, and reacting for 1 hour at the temperature of not more than 50 ℃; opening the reaction kettle, sequentially adding 0.58g of hydroxyethyl acrylate, 0.50g N, N-dimethylacrylamide, 1.2g of cumene hydroperoxide and 0.8g of furfural, stopping introducing nitrogen, closing the reaction kettle, and carrying out heat preservation reaction at 80 ℃ for 1 hour; cooling to 40 ℃, continuously adding 1g of zinc chloride, 8g of triphenylphosphine, 2g P, P, P ', P' -tetraphenyl-1, 2-diphosphobenzene and 39g of ammonia water with the mass concentration of 25%, introducing nitrogen, stirring, and carrying out heat preservation reaction at 60 ℃ for 2 hours; then cooling to room temperature, discharging, drying the product until the water content is less than or equal to 1 percent, and obtaining the semi-aromatic polyamide polycondensation catalyst.

20g of the catalyst prepared in example 2, 1162g of terephthalic acid, 498g of isophthalic acid, 1032g of pentamethylene diamine and 1000g of deionized water are added into a reaction kettle, stirring is started, and the air in the kettle is replaced by nitrogen for 2 times; sealing the reaction kettle, heating to 220 ℃ within 1 hour, and carrying out heat preservation reaction for 3 hours; opening an exhaust valve, discharging water vapor in the kettle to normal pressure within 1.5 hours, and maintaining the temperature not to exceed 330 ℃; continuously vacuumizing to-0.09 MPa, and reacting for 4 hours at 315 ℃; and (3) introducing high-pressure nitrogen, opening a bottom valve of the reaction kettle, discharging a casting belt, and cooling and drying to obtain the semi-aromatic polyamide resin. Intrinsic viscosity [ eta ]]＝0.86dL·g^-1The resin yield was 98%.

Example 3

Adding 1.12g of itaconic anhydride and 7g of 1, 3-dimethyl-2-imidazolidinone into a reaction kettle, introducing nitrogen, and stirring; cooling with water, adding 2.25g of 20% dimethylamine aqueous solution, and reacting for 0.5 hour at the temperature of not more than 50 ℃; adding 68.8g of methacrylic acid, 5.8g of cis-butenedioic acid, 6.5g of itaconic acid, 220g of deionized water and 32g of ammonia water with the mass concentration of 27% to react for 1 hour, and maintaining the temperature to be not more than 50 ℃; opening the reaction kettle, sequentially adding 4.64g of hydroxyethyl acrylate, 0.9g of tert-butyl hydroperoxide and 0.7g of oxalic acid, stopping introducing nitrogen, sealing the reaction kettle, and carrying out heat preservation reaction for 2 hours at 90 ℃; cooling to 50 ℃, continuously adding 0.2g of nickel dichloride, 4g of triphenylphosphine oxide, 0.5g of tris (2-furyl) phosphine, 0.5g P, P, P ', P ' -tetraphenyl-1, 1 ' -diphosphinoferrocene and 35g of ammonia water with the mass concentration of 27%, introducing nitrogen, stirring, and keeping the temperature at 80 ℃ for reacting for 1 hour; then cooling to room temperature, discharging, drying the product until the water content is less than or equal to 1 percent, and obtaining the semi-aromatic polyamide polycondensation catalyst.

10g of the catalyst prepared in example 3, 1129g of terephthalic acid, 531g of isophthalic acid, 892g of butanediamine and 1200g of deionized water are added into a reaction kettle, stirring is started, and the air in the kettle is replaced by nitrogen for 3 times; sealing the reaction kettle, and heating to the temperature within 2 hoursKeeping the temperature at 240 ℃ and reacting for 2 hours; opening an exhaust valve, discharging water vapor in the kettle to normal pressure within 2 hours, and maintaining the temperature not to exceed 330 ℃; continuously vacuumizing to-0.08 MPa, and reacting for 4 hours at 320 ℃; and (3) introducing high-pressure nitrogen, opening a bottom valve of the reaction kettle, discharging a casting belt, and cooling and drying to obtain the semi-aromatic polyamide resin. Intrinsic viscosity [ eta ]]＝0.94dL·g^-1The resin yield was 95%.

Comparative example 1

Adding 15g of sodium hypophosphite, 1129g of terephthalic acid, 467g of adipic acid, 1030g of pentanediamine and 800g of deionized water into a reaction kettle, starting stirring, and replacing the air in the kettle with nitrogen for 3 times; sealing the reaction kettle, heating to 230 ℃ within 1.5 hours, and carrying out heat preservation reaction for 2 hours; opening an exhaust valve, discharging water vapor in the kettle to normal pressure within 1 hour, and maintaining the temperature not to exceed 330 ℃; continuously vacuumizing to-0.08 MPa, and reacting for 3 hours at 320 ℃; and (3) introducing high-pressure nitrogen, opening a bottom valve of the reaction kettle, discharging a casting belt, and cooling and drying to obtain the semi-aromatic polyamide resin. Intrinsic viscosity [ eta ]]＝0.54dL·g^-1The resin yield was 82%.

TABLE 1 Properties of the semi-aromatic polyamides obtained in the examples and comparative examples

	Intrinsic viscosity (dL g)-1)	Resin yield (%)
			Example 1	0.88	97
Example 2	0.86	98
			Example 3	0.94	95
Comparative example 1	0.54	82