High-fluidity nylon resin and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses high-fluidity nylon resin and a preparation method thereof. The high-fluidity nylon resin comprises aliphatic amide salt and an accelerant, wherein the accelerant is one or a mixture of more of chemicals such as unit acid, binary acid, polybasic acid, unit amine, diamine and polyamine. According to the high-flowability nylon resin disclosed by the invention, the accelerant is added, and a polyamide macromolecular chain is changed from a linear shape into a wound spherical shape through molecular structure design, so that the flowability of the resin is greatly improved under the condition of keeping the high molecular weight of the resin, namely the same level of the relative viscosity of the resin.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a high-fluidity nylon resin and a preparation method thereof. Background Art

[0002] Polyamides synthesized from fatty chain diacids and fatty chain diamines, as well as polyamides synthesized from lactams are generally called fatty chain polyamides, including polyhexamethylene adipamide, i.e. polyamide 66 (commonly known as nylon-66), polycaprolactam, i.e. polyamide 6 (commonly known as nylon 6), and long carbon chain polyamides (commonly known as long carbon chain nylons).

[0003] The linear molecular chain of fatty chain polyamide can bring very good physical and mechanical properties to the material itself, but the flow properties of the material in the molten state will be subject to certain restrictions. If higher flow properties are required, it can usually be achieved by reducing the molecular weight of the polymer. This method is very effective in improving the flow properties of polyamide melt, but the important physical and mechanical properties of the material are greatly affected, especially the toughness of the material is greatly reduced. Another common practice is to add a second or even a third or fourth monomer for copolymerization to obtain a low-melting-point polymer. Although this method can improve the fluidity of the melt, it sacrifices the heat deformation temperature of the material, and the application field of the product is limited. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a high-fluidity nylon resin and a preparation method thereof.

[0005] To achieve the above objectives, the present disclosure adopts the following technical solutions: A high-fluidity nylon resin comprises aliphatic amide salt and an accelerator, wherein the accelerator is a mixture of one or more of monobasic acid, dibasic acid, polybasic acid, monoamine, diamine and polyamine.

[0006] In some embodiments of the present disclosure, the unit acid includes any one of acetic acid, benzoic acid, 2-naphthoic acid or 2-naphthoacetic acid, or a combination of two or more thereof; the dibasic acid includes any one of adipic acid, terephthalic acid, isophthalic acid, or phthalic acid, or a combination of two or more thereof; the polybasic acid includes any one of trimellitic acid, pyromellitic acid, pyromellitic anhydride, 1,4,7-naphthalenetricarboxylic acid, or a combination of two or more thereof.

[0007] In some embodiments of the present disclosure, the monoamine includes any one of methylamine, ethylamine, propylamine, aniline, and benzylamine, or a combination of two or more thereof; the diamine includes any one of pentamethylenediamine, hexamethylenediamine, nonanediamine, decanediamine, dodecanediamine, p-phenylenediamine, p-phenylenediamine, m-phenylenediamine, and o-phenylenediamine, or a combination of two or more thereof; the polyamine includes any one of trimethylamine, 1,3,5-benzenetrimethylamine, 1,2,4,5-benzenetetramine, naphthalene-1,4,5,8-tetramine, and melamine, or a combination of two or more thereof.

[0008] In some embodiments of the present disclosure, the high-flow nylon resin further includes a catalyst, an antioxidant, a stabilizer and / or an additive.

[0009] In some embodiments of the present disclosure, in parts by weight, the aliphatic amide salt is 70-100 parts, the promoter is 0.01-30 parts, the catalyst is 0-0.5 parts, the antioxidant is 0-5 parts, and the stabilizer is 0-5 parts.

[0010] In some embodiments of the present disclosure, the aliphatic amide salt is 85-100 parts, the promoter is 0.1-15 parts, the catalyst is 0.1-0.3 parts, the antioxidant is 0.3-2.0 parts, and the stabilizer is 0.3-2.0 parts.

[0011] In some embodiments of the present disclosure, the antioxidant is a hindered phenol antioxidant, and the stabilizer is a hindered amine light stabilizer.

[0012] In some embodiments of the present disclosure, the hindered phenol antioxidant includes any one or a combination of two or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, ethylene glycol (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), triethylene glycol bis-3-(3-di-tert-butyl-4-hydroxyphenyl)propionate) and N,N'-di-(2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy); the hindered amine light stabilizer includes any one or a combination of two or more of 4-amino-2,2,6,6-tetramethylpiperidine, di(2,2,6,6-tetramethyl-3-piperidinylamino)-isophthalamide, N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-oxalamide and N-(5-(1,1)dimethylethyl)-2-ethoxyphenyl)-N'-(2-ethylphenyl)oxalamide.

[0013] In some embodiments of the present disclosure, the aliphatic amide salt includes any one of a 5X salt, a 6X salt, a 1012 salt, a 1212 salt and a lactam monomer.

[0014] In some embodiments of the present disclosure, the preparation method of high-fluidity nylon resin includes: adding the aliphatic amide salt, the accelerator, and optional catalysts, antioxidants, stabilizers or additives to a polymerization reactor, controlling the temperature in the polymerization reactor to 220°C-260°C and the pressure to 0-4.0MPa, maintaining the pressure for 0.5-4 hours, and then gradually reducing the pressure in the reactor to below 1.0MPa; increasing the temperature in the polymerization reactor to 250-300°C, and after the temperature and pressure reach the set values, maintaining for 5-60 minutes to obtain the desired target polymer.

[0015] According to some embodiments of the present disclosure, the high-fluidity nylon resin and its preparation method can bring beneficial technical effects. For example, according to some embodiments of the present disclosure, the high-fluidity nylon resin is added with a promoter, and through the molecular structure design, the polyamide polymer chain is changed from a linear shape to a "tangled" "spherical shape", thereby greatly improving the fluidity of the resin and expanding the scope of application while maintaining the high molecular weight of the resin, that is, the relative viscosity of the resin at the same level. For another example, according to some embodiments of the present disclosure, the high-fluidity nylon resin can be quickly injection molded, improve injection molding production efficiency, and thus reduce production costs. For another example, the high-fluidity nylon resin according to some embodiments of the present disclosure has a higher heat deformation temperature than, for example, nylon 6 series high-fluidity resins. DETAILED DESCRIPTION

[0016] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0017] The present disclosure provides a high-flow nylon resin. In some embodiments of the present disclosure, the high-flow nylon resin may include aliphatic amide salts and a promoter, and the promoter is a mixture of one or more of chemicals such as monobasic acids, dibasic acids, polybasic acids, monoamines, diamines, and polyamines.

[0018] During the research process, the inventors found that the use of polyacids and / or polyamines as promoters can change the polyamide polymer chain from a linear shape to a "tangled" "spherical" shape, thereby greatly improving the fluidity of the resin while maintaining the high molecular weight of the resin, that is, the relative viscosity of the resin at the same level. The fluidity of the nylon resin can be greatly improved while maintaining the mechanical properties of the resin without major changes.

[0019] In some embodiments of the present disclosure, the unit acid may include any one or a combination of two or more of acetic acid, benzoic acid, 2-naphthoic acid or 2-naphthylacetic acid.

[0020] In some embodiments of the present disclosure, the dibasic acid may include any one of adipic acid, terephthalic acid, isophthalic acid, and phthalic acid, or a combination of two or more thereof.

[0021] In some embodiments of the present disclosure, the polyacid may include trimellitic acid (e.g., 1,3,5-benzenetricarboxylic acid and 1,2,4-benzenetricarboxylic acid), pyromellitic acid (or pyromellitic anhydride), 1,4,7-naphthalenetricarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid (or 1,4,5,8-naphthalenetetracarboxylic anhydride), and the like.

[0022] In some embodiments of the present disclosure, the monoamine may include any one of methylamine, ethylamine, propylamine, aniline, and benzylamine, or a combination of two or more thereof.

[0023] In some embodiments of the present disclosure, the diamine may include any one of pentamethylenediamine, hexamethylenediamine, nonanediamine, decanediamine, dodecanediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, p-phenylenediamine, m-phenylenediamine, and o-phenylenediamine, or a combination of two or more thereof.

[0024] In some embodiments of the present disclosure, the polyamine may include any one of trimethylamine, 1,3,5-benzenetrimethylamine, 1,2,4,5-benzenetetramine, naphthalene-1,4,5,8-tetramine, and melamine, or a combination of two or more thereof.

[0025] In some embodiments of the present disclosure, the high-flow nylon resin may further include a catalyst, an antioxidant, a stabilizer and / or an auxiliary agent.

[0026] In some embodiments of the present disclosure, the high-flow nylon resin may include, by weight: 70-100 parts of aliphatic amide salt, 0.01-30 parts of accelerator, 0-0.5 parts of catalyst, 0-5 parts of antioxidant, and 0-5 parts of stabilizer.

[0027] In some preferred embodiments of the present disclosure, the high-flow nylon resin may include, by weight: 85-100 parts of aliphatic amide salt, 0.1-15 parts of accelerator, 0.1-0.3 parts of catalyst, 0.3-2.0 parts of antioxidant, and 0.3-2.0 parts of stabilizer.

[0028] In some embodiments of the present disclosure, the antioxidant is a hindered phenol antioxidant, and the stabilizer is a hindered amine light stabilizer.

[0029] In some embodiments of the present disclosure, the hindered phenol antioxidant may include any one or a combination of two or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, ethylene glycol (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), triethylene glycol bis-3-(3-di-tert-butyl-4-hydroxyphenyl)propionate) and N,N'-di-(2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy).

[0030] In some preferred embodiments of the present disclosure, the hindered phenol antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0031] In some embodiments of the present disclosure, the hindered amine light stabilizer may include any one of 4-amino-2,2,6,6-tetramethylpiperidine, di(2,2,6,6-tetramethyl-3-piperidinylamino)-isophthalamide, N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-ethanediamide and N-(5-(1,1)dimethylethyl)-2-ethoxyphenyl)-N'-(2-ethylphenyl)ethanediamide or a combination of two or more thereof.

[0032] In some preferred embodiments of the present disclosure, the hindered amine light stabilizer is 4-amino-2,2,6,6-tetramethylpiperidine and / or di(2,2,6,6-tetramethyl-3-piperidinylamino)-isophthalamide. In some particularly preferred embodiments of the present disclosure, the hindered amine light stabilizer is 4-amino-2,2,6,6-tetramethylpiperidine.

[0033] In some preferred embodiments of the present disclosure, the additives include but are not limited to: plasticizers, antistatic agents, flame retardants, catalysts, molecular weight regulators, anti-hydrolysis agents, fluorescent agents, dyes, inorganic powders such as inorganic pigments, matting agents, nucleating agents, and anti-ultraviolet agents, etc. Any of the above can be added alone or in any combination.

[0034] Those skilled in the art will understand the conventional selection of the above-mentioned additives, and can obtain the above-mentioned additives through commercial purchase. For example, nucleating agents include, but are not limited to, inorganic powders such as silicon dioxide, talc, barium sulfate, montmorillonite, and metal oxides such as zinc oxide, titanium dioxide, etc. Inorganic powders include, but are not limited to, inorganic functional powders such as carbon black, titanium dioxide, barium sulfate, magnesium sulfate, calcium carbonate, zinc oxide, montmorillonite, kaolin, glass fiber, glass microbeads, carbon fiber, graphene, carbon nanotubes, mica, etc.

[0035] In some embodiments of the present disclosure, the aliphatic amide salt may include a 5X salt, a 6X salt, a 1012 salt, a 1212 salt, and a lactam monomer.

[0036] In some embodiments, 5X salt may include one or more of 54 salt, 56 salt, 59 salt, 510 salt, 511 salt, 512 salt, 513 salt, 514 salt, 516 salt, etc. In some preferred embodiments, 5X salt may include one or more of 56 salt, 510 salt, 512 salt, 514 salt.

[0037] In some embodiments, 6X salts may include one or more of 66 salts, 69 salts, 610 salts, 611 salts, 612 salts, 613 salts, 614 salts, 616 salts, etc. In some preferred embodiments, 6X salts may include one or more of 66 salts, 610 salts, 611 salts, 612 salts, and 614 salts.

[0038] In some embodiments, the lactam monomer may include one or more of caprolactam, undecanoic acid, laurolactam, and the like.

[0039] In some embodiments of the present disclosure, the aliphatic amide salt can be obtained by reacting an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid with an aliphatic diamine. The aliphatic dicarboxylic acid or the alicyclic dicarboxylic acid can include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, one or more of dimethylmalonic acid, 3,3-diethylsuccinic acid, 2-methylhexanodioic acid, 2,2-dimethylglutaric acid, 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, particularly preferably adipic acid or sebacic acid. The aliphatic diamine may include one or more of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 2-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, preferably one or more of 1,6-hexanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, particularly preferably 1,6-hexanediamine and 1,10-decanediamine.

[0040] In some embodiments, the catalyst may include any one of trioctyl phosphite, octyl phosphite, potassium hypophosphite (dipotassium hypophosphite, potassium dihydrogen hypophosphite), sodium hypophosphite (disodium hypophosphite, sodium dihydrogen hypophosphite), magnesium hypophosphite, calcium hypophosphite, or zinc hypophosphite.

[0041] In some embodiments of the present disclosure, aliphatic polyamide also includes the following polyamides and copolymer resins thereof, such as: one or more of nylon 6, nylon 66, nylon 69, nylon 610, nylon 612, nylon 1010, nylon 11, nylon 12, nylon 1012, nylon 1212, nylon 1214 and nylon 46.

[0042] In some embodiments of the present disclosure, a method for preparing a high-fluidity nylon resin comprises: adding aliphatic amide salt, a promoter, and optional catalysts, antioxidants, stabilizers or functional additives into a polymerization reactor, controlling the temperature in the polymerization reactor to 220°C-260°C and the pressure to 0-4.0 MPa, maintaining the pressure for 0.5-4 hours, and then gradually reducing the pressure in the reactor to below 1.0 MPa; increasing the temperature in the polymerization reactor to 250-300°C, and after the temperature and pressure reach the set values, maintaining for 5-60 minutes to obtain the desired target polymer.

[0043] In some embodiments, the temperature in the polymerization reactor is controlled at 220°C-250°C.

[0044] In some embodiments, the polymerization reactor is controlled at 0.1-3.0 MPa.

[0045] In some embodiments, the holding time is 1.0-3.0 hours.

[0046] In some embodiments, the pressure in the autoclave is gradually reduced to below 0-0.8 MPa.

[0047] In some embodiments, the temperature in the polymerization reactor is increased to 250-290°C.

[0048] In some embodiments, after the temperature and pressure reach the set value, they are maintained for 5-30 minutes.

[0049] According to some embodiments of the present disclosure, the high-fluidity nylon resin has a relative viscosity of 2.0 to 3.2, preferably 2.2 to 3.0.

[0050] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw materials in the examples can all be purchased through commercial sources. Example

[0051] The high-flow nylon resin includes 5.0 kg of amide 66 salt, an accelerator including 1.0 kg of benzenetetracarboxylic acid and 1.0 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0052] The above raw materials were added to the polymerization reactor, and the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 300°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1MPa within 60 minutes, and the melt temperature in the reactor was 280°C, which was maintained for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.2 and the melting point of the polymer was 260°C; the melt index of the resin was measured to be 150 under the conditions of 275°C and 0.325 kg pressure by a melt index instrument. Other mechanical properties of the product are shown in Table 1. Example

[0053] The high-fluidity nylon resin includes: 5.0 kg of amide 66 salt, an accelerator: including 0.5 kg of benzenetetracarboxylic acid and 0.5 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0054] The above raw materials were added to the polymerization reactor, and the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 300°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1MPa within 60 minutes, and the melt temperature in the reactor was 280°C, which was maintained for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.3 and the melting point of the polymer was 260°C; the melt index of the resin was measured to be 110 using a melt index instrument at 275°C and 0.325 kg pressure. Other mechanical properties of the product are shown in Table 1 below. Example

[0055] The high-fluidity nylon resin includes: 5.0 kg of amide 66 salt, an accelerator: including 0.3 kg of benzenetetracarboxylic acid and 0.3 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0056] The above raw materials were added to the polymerization reactor, the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 300°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1MPa within 60 minutes, the melt temperature in the reactor was 280°C, and it was kept for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.4 and the melting point of the polymer was 260°C; the melt index of the resin was measured to be 90 at 275°C and 0.325 kg pressure using a melt index instrument. Other mechanical properties of the product are shown in Table 1. Example

[0057] The high-fluidity nylon resin includes: 5.0 kg of amide 56 salt, an accelerator: including 0.3 kg of benzenetetracarboxylic acid and 0.3 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0058] The above raw materials were added to the polymerization reactor, and the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 300°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1MPa within 60 minutes, and the melt temperature in the reactor was 280°C, which was maintained for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.4 and the melting point of the polymer was 250°C; the melt index of the resin was measured to be 100 by using a melt index instrument at 275°C and 0.325 kg pressure. Other mechanical properties of the product are shown in Table 1. Example

[0059] The high-flow nylon resin includes: 5.0 kg of amide 610 salt, accelerator: including 0.3 kg of benzenetetracarboxylic acid and 0.3 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0060] The above raw materials were added to the polymerization reactor, and the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 280°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1MPa within 60 minutes, and the melt temperature in the reactor was 260°C, which was maintained for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.4 and the melting point of the polymer was 215°C; the melt index of the resin was measured to be 80 by using a melt index instrument at 250°C and 0.325 kg pressure. Other mechanical properties of the product are shown in Table 1 below. Example

[0061] The high-flow nylon resin includes: 5.0 kg of amide 612 salt, accelerator: including 0.3 kg of benzenetetracarboxylic acid and 0.3 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0062] The above raw materials were added to the polymerization reactor, and the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 280°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1MPa within 60 minutes, and the melt temperature in the reactor was 260°C, which was maintained for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.4 and the melting point of the polymer was 210°C; the melt index of the resin was measured to be 90 by using a melt index instrument at 250°C and 0.325 kg pressure. Other mechanical properties of the product are shown in Table 1 below. Example

[0063] The high-flow nylon resin includes: 5.0 kg of amide 1012 salt, accelerator: including 0.3 kg of benzenetetracarboxylic acid and 0.3 kg of 1,2,4,5-benzenetetramine, 12 grams of catalyst sodium hypophosphite, 30 grams of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 30 grams of 4-amino-2,2,6,6-tetramethylpiperidine (4-amino-2,2,6,6-tetramethylpiperidine), and 6 kg of pure water.

[0064] The above raw materials were added to a polymerization reactor, and the air in the polymerization reactor was replaced with nitrogen three times, and then nitrogen was filled until the pressure in the polymerization reactor was 0.10 MPa higher than the atmospheric pressure; the temperature in the reactor reached 220°C and the pressure in the reactor reached 2.0 MPa by heating, and the temperature and pressure were kept stable for 2.0 hours; then the temperature of the heat medium in the insulation jacket was continued to be increased to 260°C, and the water vapor in the polymerization reactor was started to be released, and the pressure in the reactor was reduced to 0.1 MPa within 60 minutes, and the melt temperature in the reactor was 240°C, which was maintained for 30 minutes, and then the polymer obtained by the reaction was discharged from the reactor, and its relative viscosity was 2.2 and the melting point of the polymer was 185°C; the melt index of the resin was measured to be 100 by using a melt index instrument at 230°C and 0.325 kg pressure. Other mechanical properties of the product are shown in Table 1 below.

[0065] Comparative Example 1 The raw material formula and polymerization process of Example 3 were repeated, except that no accelerator was added, to obtain polyamide 66 of this comparative example 1, a resin with a relative viscosity of 2.4 (the same as in Example 3) and a melt index of 50. Other mechanical properties of the product are shown in Table 2.

[0066] Comparative Example 2 The raw material formula and polymerization process of Example 4 were repeated, except that no accelerator was added, to obtain polyamide 56 corresponding to Example 4, with a relative viscosity of 2.4 and a melt index of 60. Other mechanical properties are shown in Table 2.

[0067] Comparative Example 3 The raw material formula and polymerization process of Example 5 were repeated, except that no accelerator was added, to obtain polyamide 610 with a relative viscosity of 2.4 (the same as Example 5) and a melt index of 40. Other mechanical properties are shown in Table 2.

[0068] Comparative Example 4 The raw material formula and polymerization process of Example 6 were repeated, except that no accelerator was added, to obtain polyamide 612 with a relative viscosity of 2.4 (the same as Example 6) and a melt index of 38. Other mechanical properties are shown in Table 2.

[0069] Comparative Example 5 The raw material formula and polymerization process of Example 7 were repeated, except that no accelerator was added, to obtain polyamide 1012 with a relative viscosity of 2.4 (the same as Example 6) and a melt index of 30. Other mechanical properties are shown in Table 2.

[0070] The high-fluidity nylon resin of some embodiments of the present disclosure can significantly improve the fluidity of the nylon resin after adding a promoter while basically maintaining the mechanical properties of the resin, thereby expanding the application range of the nylon resin. The high-fluidity nylon resin of some embodiments of the present disclosure can provide the following added value to downstream industries: 1) Rapid injection molding, improve injection molding production efficiency and reduce production costs; 2) Improve the surface "floating fiber" condition of glass fiber reinforced nylon products, such as nylon 66 products, to obtain a beautiful and delicate product appearance; 3) It can be used to make glass fiber reinforced modified products with high glass fiber content such as 60%, and it also has a beautiful appearance; 4) High fluidity makes the melt have good wetting properties, which can be used for long glass fiber modification and carbon fiber composites; 5) Compared with nylon series such as nylon 6 series high fluidity resin, it has a higher heat deformation temperature.

[0071] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A high-fluidity nylon resin, characterized in that: The invention comprises aliphatic amide salt and an accelerator, wherein the accelerator is a mixture of one or more of monobasic acid, dibasic acid, polybasic acid, monoamine, diamine and polyamine.

2. The high-fluidity nylon resin according to claim 1, characterized in that: The monobasic acid includes any one of acetic acid, benzoic acid, 2-naphthoic acid or 2-naphthoacetic acid or a combination of two or more thereof; the dibasic acid includes any one of adipic acid, terephthalic acid, isophthalic acid, phthalic acid or a combination of two or more thereof; the polybasic acid includes any one of trimesic acid, pyromellitic acid, pyromellitic anhydride, 1,4,7-naphthalenetricarboxylic acid, and 1,4,5,8-naphthalenetetracarboxylic acid or a combination of two or more thereof.

3. The high-fluidity nylon resin according to claim 1, characterized in that: The monoamine includes any one or a combination of two or more of methylamine, ethylamine, propylamine, aniline, and benzylamine; the diamine includes any one or a combination of two or more of pentamethylenediamine, hexamethylenediamine, nonanediamine, decanediamine, dodecanediamine, p-phenylenediamine, p-phenylenediamine, m-phenylenediamine, and o-phenylenediamine; the polyamine includes any one or a combination of two or more of trimethylamine, 1,3,5-benzenetrimethylamine, 1,2,4,5-benzenetetramine, naphthalene-1,4,5,8-tetramine, and melamine.

4. The high-fluidity nylon resin according to claim 1, characterized in that: It also includes catalysts, antioxidants, stabilizers and / or additives.

5. The high-fluidity nylon resin according to claim 4, characterized in that: In parts by weight, the aliphatic amide salt is 70-100 parts, the accelerator is 0.01-30 parts, the catalyst is 0-0.5 parts, the antioxidant is 0-5 parts, and the stabilizer is 0-5 parts.

6. The high-fluidity nylon resin according to claim 5, characterized in that: The aliphatic amide salt is 85-100 parts, the accelerator is 0.1-15 parts, the catalyst is 0.1-0.3 parts, the antioxidant is 0.3-2.0 parts, and the stabilizer is 0.3-2.0 parts.

7. The high-fluidity nylon resin according to claim 4, characterized in that: The antioxidant is a hindered phenol antioxidant, and the stabilizer is a hindered amine light stabilizer.

8. The high-fluidity nylon resin according to claim 7, characterized in that: The hindered phenol antioxidant includes any one or a combination of two or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol, ethylene glycol (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), triethylene glycol bis-3-(3-di-tert-butyl-4-hydroxyphenyl)propionate) and N,N'-di-(2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy); the hindered amine light stabilizer includes any one or a combination of two or more of 4-amino-2,2,6,6-tetramethylpiperidine, di(2,2,6,6-tetramethyl-3-piperidinylamino)-isophthalamide, N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-oxalamide and N-(5-(1,1)dimethylethyl)-2-ethoxyphenyl)-N'-(2-ethylphenyl)oxalamide.

9. The high-fluidity nylon resin according to claim 1, characterized in that: The aliphatic amide salt includes any one of 5X salt, 6X salt, 1012 salt, 1212 salt and lactam monomer.

10. The method for preparing a high-fluidity nylon resin according to any one of claims 1 to 9, characterized in that: The aliphatic amide salt, the accelerator, and optional catalysts, antioxidants, stabilizers or auxiliary agents are added into a polymerization reactor, and the temperature in the polymerization reactor is controlled at 220° C.-260° C. and the pressure is controlled at 0-4.0 MPa. After maintaining the pressure for 0.5-4 hours, the pressure in the reactor is gradually reduced to below 1.0 MPa; the temperature in the polymerization reactor is increased to 250-300° C., and after the temperature and pressure reach the set values, they are maintained for 5-60 minutes to obtain the desired target polymer.

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