High-temperature-resistant high-strength transparent nylon as well as preparation method and application thereof

Abstract

The invention relates to the technical field of nylon materials, in particular to a high-temperature-resistant high-strength transparent nylon material and a preparation method and application thereof. According to the invention, 3, 3 '-dimethyl-4, 4-diaminodicyclohexylmethane (MACM), aromatic diacid and aliphatic diamine are used as reaction monomers, and the transparent nylon is obtained by adjusting the dosage ratio of the monomers, further adjusting the preparation process and regulating the reaction process. The high-temperature-resistant transparent nylon provided by the invention has the advantages of high temperature resistance, high strength and high light transmittance; the method has great application prospect and value.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon materials, and in particular to a high-temperature resistant, high-strength transparent nylon material and a preparation method and application thereof. Background Art

[0002] Polyamide (PA), commonly known as nylon, refers to a polymer containing an amide group (-CONH-) in the main chain repeating unit of the molecule. It belongs to the category of the five general engineering plastics. According to the source of monomers, it can be divided into: (1) AB type polyamide (such as PA6, PA11, PA12), which is made by ring-opening polymerization of amino acids or caprolactam; (2) AABB type polyamide (such as PA66, PA46, PA610), which is made by condensation of diamine and dibasic acid. According to the difference in molecular chain structure, it can be further divided into aliphatic polyamide and aromatic polyamide. Aromatic polyamides are those in which one of the monomers is an aromatic compound. Among them, semi-aromatic polyamides (such as PA6T, PA9T) are synthesized from terephthalic acid and aliphatic diamine.

[0003] Semi-aromatic nylons, such as PA46, PA6T, and PA9T, due to their aromatic ring structure incorporated into their molecular chains, exhibit excellent thermal stability (melting point >300°C), high strength (tensile strength >80 MPa), and low deionized water absorption (<2.5%), making them a key material bridging general-purpose engineering plastics and specialty high-temperature-resistant resins. Currently, semi-aromatic nylons are primarily used in precision electronic components such as automotive sensor housings and LED brackets. Existing semi-aromatic nylons synthesized from terephthalic acid and aliphatic diamines suffer from low mechanical strength, low light transmittance, and insufficient high-temperature resistance.

[0004] Traditional nylon materials, due to their high molecular chain regularity and significant crystallinity, have a light transmittance of less than 85%, severely limiting their use in optical devices. While transparent nylon has been successfully applied in medical devices and cosmetic packaging, existing products generally suffer from technical bottlenecks such as reduced mechanical strength and insufficient heat distortion temperature. Summary of the Invention

[0005] In order to solve the technical problem of low light transmittance of the existing semi-aromatic nylon synthesized from terephthalic acid and aliphatic diamine, the present invention provides a high-temperature resistant high-strength transparent nylon material and its preparation method and application.

[0006] This invention utilizes 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM), aromatic diacids, and aliphatic diamines as reactive monomers. By adjusting the ratio of the monomers and further adjusting the preparation process (controlling the reaction process), a new transparent nylon is obtained. The transparent nylon provided by this invention has the advantages of high temperature resistance, high strength, and high light transmittance.

[0007] One of the purposes of the present invention is to provide a high temperature resistant transparent nylon.

[0008] The structural formula of the high temperature resistant transparent nylon is shown in Formula I;

[0009]

[0010] In Formula I,

[0011] m is any integer between 500 and 5000;

[0012] n is any integer between 500 and 5000;

[0013] p is any integer between 1 and 12;

[0014] Structural unit The C=O on the benzene ring is located at the meta or para position of the benzene ring;

[0015] Structural unit The C=O on the benzene ring is located at the meta or para position of the benzene ring.

[0016] Formula I can specifically be:

[0017] One of, but not limited to.

[0018] The compound of formula I in the high temperature resistant transparent nylon comprises a structural unit A derived from 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM) Structural unit B derived from a fatty diamine and the structural unit C derived from an aromatic diacid

[0019] The structural unit B of the high-temperature resistant transparent nylon contains a methylene chain; the methylene chain is flexible, and the introduction of the methylene chain can improve the toughness of nylon.

[0020] The structural unit A of the high-temperature-resistant transparent nylon contains two methyl groups (located at the 3 and 3' positions) on the dicyclohexylmethane. The introduction of these two methyl groups significantly increases steric hindrance. The steric bulk of the methyl groups hinders the close stacking of molecular chains, forcing adjacent segments to form a regular lattice structure, reducing crystallinity and improving light transmittance. The steric hindrance effect of the methyl groups increases the activation energy required for nucleation, hindering grain growth and forming small, dispersed crystals, thereby reducing haze and improving light transmittance.

[0021] The introduction of a methyl group into the structural unit A of the heat-resistant transparent nylon disrupts the geometric symmetry of the molecular chain, reducing the uniformity of the repeating unit (uniformity refers to the presence of only one repeating unit structure, while the heat-resistant transparent nylon of the present invention has three repeating units), ultimately increasing light transmittance. The hydrophobicity and steric repulsion of the methyl group weaken the density of hydrogen bonds between amide bonds, reducing the penetration rate of solvent molecules and improving weather resistance.

[0022] The steric hindrance of the methyl group in structural unit A and the rigidity of the aromatic ring in structural unit B in the high-temperature resistant transparent nylon form a "rigid yet flexible" structure. The introduction of structural unit A allows the prepared polyamide to be processed at higher temperatures without causing excessive crystallization. The resulting nylon exhibits excellent heat resistance and high mechanical properties while maintaining a certain degree of light transmittance.

[0023] The high-temperature resistant transparent nylon is prepared from raw materials including 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, aromatic diacids, and fatty diamines.

[0024] A second object of the present invention is to provide a method for preparing the high-temperature resistant transparent nylon described in the first object of the invention.

[0025] The preparation method comprises the following steps:

[0026] (1) mixing 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM), aromatic diacid, fatty diamine, catalyst, antioxidant, light stabilizer and deionized water to obtain a mixed material;

[0027] (2) Under an inert atmosphere, the mixed material is subjected to a condensation reaction.

[0028] The product of the condensation reaction in step (2) is the high-temperature resistant transparent nylon. After step (2) is completed, in addition to the product high-temperature resistant transparent nylon, there are impurities (such as unreacted monomers) in the system; impurities are usually removed by water washing to obtain the high-temperature resistant transparent nylon. The water washing adopts a conventional water washing method.

[0029] The aromatic diacid is selected from at least one of terephthalic acid and isophthalic acid.

[0030] The fatty diamine is selected from C1-C12 linear fatty diamines. Preferably, the fatty diamine is selected from at least one of methylenediamine, ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octanediamine, nonamethylenediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine. Compared to other C1-C12 linear fatty diamines, transparent nylon prepared using methylenediamine, ethylenediamine, propylenediamine, butylenediamine, and pentamethylenediamine exhibits significantly improved thermodynamic properties, enhanced processing performance (such as lower processing temperature and easier volatility), and significantly increased modulus and strength. Preferably, the fatty diamine is selected from at least one of methylenediamine, ethylenediamine, propylenediamine, butylenediamine, and pentamethylenediamine.

[0031] The catalyst can be selected from any one or more existing catalysts for synthesizing polyamides. As a specific embodiment, the catalyst is selected from at least one of N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethylalkylenediamine, triethylamine, N,N-dimethylbenzylamine, solid amine, N-ethylmorpholine, N-methylmorpholine, N,N-diethylpiperazine, potassium phosphate, sodium phosphate, potassium hypophosphite, sodium hypophosphite, potassium phosphite, sodium phosphite, potassium hypophosphite, sodium hypophosphite, n-butyl titanate, propyl titanate, and isopropyl titanate. As a preferred embodiment, the catalyst is selected from at least one of N,N-dimethylcyclohexylamine, triethylamine, N-ethylmorpholine, N-methylmorpholine, potassium phosphate, sodium phosphate, potassium hypophosphite, sodium hypophosphite, potassium phosphite, sodium phosphite, potassium hypophosphite, sodium hypophosphite, n-butyl titanate, propyl titanate, and isopropyl titanate.

[0032] The antioxidant can be selected from any one or more existing antioxidants used in the synthesis of polyamide. Specifically, the antioxidant is selected from at least one of pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (Antioxidant 1010), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Antioxidant 1076), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (Antioxidant 1098), tris(2,4-di-tert-butyl)phenyl phosphite (Antioxidant 168), potassium iodide, and a copper salt. The copper salt can be selected from at least one of copper iodide, cuprous iodide, copper acetate, copper carbonate, copper oxide, and cuprous oxide.

[0033] The light stabilizer can be selected from any one or more existing light stabilizers used for synthesizing polyamide. As a specific solution, the light stabilizer is selected from at least one of UV-3346, UV-123, UV-292, UV-622, UV-770DF, UV-944, UV-2020, and UV-660.

[0034] The molar ratio of the total amount of the fatty diamine and 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM) to the aromatic diacid determines the molar ratio of the total amount of structural units derived from the fatty diamine and structural units derived from MACM to structural units derived from the aromatic diacid in the transparent nylon. In the transparent nylon, the molar ratio of the total amount of structural units derived from the fatty diamine and structural units derived from MACM to structural units derived from the aromatic diacid is 1:1. Therefore, the ratio of the total molar amount of the fatty diamine and 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM) to the molar amount of the aromatic diacid is approximately 1:1, for example (0.8-1.3):1.

[0035] The molar ratio of the fatty diamine to 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM) determines the molar ratio of the structural units derived from the fatty diamine to the structural units derived from MACM in the transparent nylon. The molar ratio of the structural units derived from the fatty diamine to the structural units derived from MACM in the transparent nylon is m:n, i.e., (500-5000):(500-5000), preferably 1:(0.6-1.4). Therefore, the molar ratio of the fatty diamine to 3,3'-dimethyl-4,4-diaminodicyclohexylmethane (MACM) is m:n, preferably 1:(0.6-1.4), and more preferably 1:(0.8-1.2).

[0036] As a preferred solution, the molar ratio of the aromatic diacid to the fatty diamine is 2:(0.6-1.4); more preferably 2:(0.8-1.2).

[0037] The catalyst can be used in a conventional amount. As a preferred embodiment, the catalyst is added in an amount of 0.05% to 0.30% of the total mass of the aromatic diacid, aliphatic diamine and 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, more preferably 0.10% to 0.25%.

[0038] The amount of the antioxidant can be a conventional amount. As a preferred embodiment, the amount of the antioxidant added is 0.1% to 1.0% of the total mass of the aromatic diacid, aliphatic diamine and MACM, more preferably 0.10% to 0.8%.

[0039] The amount of the light stabilizer can be a conventional amount. As a preferred embodiment, the amount of the light stabilizer added is 0.08% to 0.20% of the total mass of the aromatic diacid, aliphatic diamine and MACM, more preferably 0.11% to 0.15%.

[0040] The amount of deionized water used can be a conventional amount. As a preferred solution, the amount of deionized water added is 35% to 65% of the total mass of the aromatic diacid, aliphatic diamine and MACM, more preferably 40% to 60%.

[0041] The control of the reaction process and reaction conditions of the condensation reaction in step (2) of the preparation method is the key to synthesizing the transparent nylon, which is one of the purposes of the invention. The present invention adjusts the reaction temperature and pressure so that the condensation reaction is carried out in four stages.

[0042] The condensation reaction in step (2) of the preparation method includes a first stage reaction, a second stage reaction, a third stage reaction and a fourth stage reaction carried out in sequence:

[0043] The first stage reaction conditions are: 150-250°C, normal pressure, reaction time 2.2-2.5h;

[0044] The reaction conditions for the second stage are: 255-300°C, 2.5-3 MPa, reaction time 3.0-3.5 hours;

[0045] The reaction conditions for the third stage are: 310-320°C, 0.3-0.4 MPa, reaction time 2.2-2.5 hours;

[0046] The fourth stage reaction conditions are: room temperature, normal pressure, reaction for 1 to 1.5 hours.

[0047] As a preferred option,

[0048] The first stage reaction conditions are: 180-220℃, normal pressure, reaction time 2.2-2.4h,

[0049] The second stage reaction conditions are: 260-290℃, 2.6-3MPa, reaction time 3-3.2h,

[0050] The third stage reaction conditions are: 310-315℃, 0.3-0.35MPa, reaction time 2.2-2.4h,

[0051] The fourth stage reaction conditions are: room temperature, normal pressure, reaction for 1 to 1.3 hours.

[0052] The condensation reaction is carried out under stirring conditions, and the stirring speed is 300-500 r / min.

[0053] The inert atmosphere is a nitrogen atmosphere.

[0054] As a specific solution, the preparation method includes:

[0055] (1) adding aromatic diacid, aliphatic diamine, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, catalyst, antioxidant, light stabilizer, hydrophobic agent and deionized water to a magnetically driven high-pressure reactor according to parts by weight, and replacing the air in the reactor with nitrogen;

[0056] (2) stirring the reactor and heating it to 150-250°C, and reacting at normal pressure for 2.2-2.5 hours;

[0057] (3) Raise the reactor temperature to 255-300°C, introduce nitrogen until the system pressure reaches 2.5-3 MPa, and react for 3.0-3.5 hours;

[0058] (4) reducing the pressure to 0.3-0.4 MPa and raising the temperature of the reactor to 310-320° C. for 2.2-2.5 hours;

[0059] (5) Cool to room temperature, reduce pressure to normal pressure and continue reaction for 1 to 1.5 hours;

[0060] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon;

[0061] Steps (2), (3), (4) and (5) are carried out at a stirring speed of 300 to 500 r / min.

[0062] The third object of the present invention is to provide the application of the high-temperature resistant transparent nylon described in the first object of the invention or the high-temperature resistant transparent nylon prepared by the preparation method described in the second object of the invention in the fields of food and beverage packaging, medical equipment, precision instruments, optical instruments, electronic appliances, automobile manufacturing, machinery, aviation, sporting goods, etc.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] The molecular main chain of the high-temperature resistant transparent nylon provided by the invention contains both rigid benzene rings and flexible methylene chains, so that it has both the thermoplasticity of aliphatic nylon and the high rigidity and high heat resistance of wholly aromatic nylon.

[0065] The high-temperature resistant transparent nylon provided by the present invention contains benzene rings and aliphatic rings and is a semi-aromatic nylon. Compared with fully aromatic nylon and fully aliphatic nylon, the transparent nylon provided by the present invention has a good balance between processing performance and heat resistance.

[0066] The high-temperature resistant transparent nylon provided by the present invention introduces flexible methylene chains and dicyclohexylmethane chains, thereby improving the toughness and light transmittance of the transparent nylon and broadening the downstream application range of the transparent nylon.

[0067] The high-temperature resistant transparent nylon provided by the present invention not only ensures more excellent heat resistance and higher mechanical properties but also maintains a certain light transmittance; the optical properties are improved and the application field is expanded.

[0068] Unless otherwise specified, the room temperature in the present invention is 10-30°C. DETAILED DESCRIPTION

[0069] The present invention will be described in detail below with reference to specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0070] Unless otherwise specified, the raw materials used in the Examples and Comparative Examples are publicly available in the prior art and can be purchased directly or prepared according to methods disclosed in the prior art. The solvents used in the Examples and Comparative Examples were purchased from Shanghai MacLean Biochemical Technology Co., Ltd., and all reaction raw materials were purchased from Alfa Aesar.

[0071] Example 1

[0072] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0073] (1) After adding 25 parts of terephthalic acid, 3.5 parts of ethylenediamine, 15 parts of MACM, 0.04 parts of sodium hypophosphite, 0.04 parts of potassium iodide, 0.4 parts of UV-3346 and 17.4 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0074] (2) Set the stirring speed to 350 r / min, heat the reactor to 150°C, and react for 2.2 h;

[0075] (3) The reactor temperature was raised to 270°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0076] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0077] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0078] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0079] Example 2

[0080] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0081] (1) After adding 25 parts of terephthalic acid, 5.6 parts of propylene diamine, 17 parts of MACM, 0.05 parts of sodium hypophosphite, 0.06 parts of potassium iodide, 0.35 parts of UV-123 and 20.5 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0082] (2) Set the stirring speed to 350 r / min, heat the reactor to 180°C, and react for 2.3 h;

[0083] (3) The reactor temperature was raised to 255°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0084] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0085] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0086] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0087] Example 3

[0088] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0089] (1) After adding 25 parts of terephthalic acid, 6.7 parts of dibutyl amine, 21 parts of MACM, 0.06 parts of sodium hypophosphite, 0.07 parts of potassium iodide, 0.4 parts of UV-292 and 25 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0090] (2) Set the stirring speed to 350 r / min, heat the reactor to 180°C, and react for 2.3 h;

[0091] (3) The reactor temperature was raised to 255°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0092] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0093] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0094] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0095] Example 4

[0096] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0097] (1) After adding 25 parts of terephthalic acid, 8.5 parts of pentamethylenediamine, 24 parts of MACM, 0.08 parts of sodium hypophosphite, 0.08 parts of potassium iodide, 2.5 parts of UV-622 and 29 parts of deionized water into a magnetically driven high-pressure reactor according to parts by weight, nitrogen was introduced to replace the air in the reactor;

[0098] (2) Set the stirring speed to 350 r / min, heat the reactor to 180°C, and react for 2.3 h;

[0099] (3) The reactor temperature was raised to 255°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0100] (4) reducing the pressure to 0.4 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0101] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0102] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0103] Example 5

[0104] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0105] (1) After adding 25 parts of isophthalic acid, 3.5 parts of ethylenediamine, 15 parts of MACM, 0.04 parts of sodium hypophosphite, 0.04 parts of potassium iodide, 0.4 parts of UV-770DF and 17.4 parts of deionized water into a magnetically driven high-pressure reactor according to parts by weight, nitrogen was introduced to replace the air in the reactor;

[0106] (2) Set the stirring speed to 350 r / min, heat the reactor to 150°C, and react for 2.2 h;

[0107] (3) The reactor temperature was raised to 270°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0108] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0109] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0110] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0111] Example 6

[0112] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0113] (1) After adding 25 parts of isophthalic acid, 5.6 parts of propylene diamine, 17 parts of MACM, 0.05 parts of sodium hypophosphite, 0.06 parts of potassium iodide, 2.2 parts of UV-944 and 20.5 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0114] (2) Set the stirring speed to 350 r / min, heat the reactor to 180°C, and react for 2.3 h;

[0115] (3) The reactor temperature was raised to 255°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0116] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0117] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0118] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0119] Example 7

[0120] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0121] (1) After adding 25 parts of isophthalic acid, 6.7 parts of dibutyl amine, 21 parts of MACM, 0.06 parts of sodium hypophosphite, 0.07 parts of potassium iodide, 2.4 parts of UV-2020 and 25 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0122] (2) Set the stirring speed to 350 r / min, heat the reactor to 180°C, and react for 2.3 h;

[0123] (3) The reactor temperature was raised to 255°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0124] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0125] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0126] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0127] Example 8

[0128] A method for preparing high-temperature resistant high-strength transparent nylon, the method comprising the following steps:

[0129] (1) After adding 25 parts of isophthalic acid, 8.5 parts of pentamethylenediamine, 24 parts of MACM, 0.08 parts of sodium hypophosphite, 0.08 parts of potassium iodide, 0.5 parts of UV-660 and 29 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0130] (2) Set the stirring speed to 350 r / min, heat the reactor to 180°C, and react for 2.3 h;

[0131] (3) The reactor temperature was raised to 255°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0132] (4) reducing the pressure to 0.4 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0133] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0134] (6) washing with water and discharging the material to obtain the high-temperature resistant high-strength transparent nylon.

[0135] Comparative Example 1

[0136] A method for preparing nylon, comprising the following steps:

[0137] (1) After adding 25 parts of terephthalic acid, 3.5 parts of ethylenediamine, 15 parts of MACM, 0.04 parts of sodium hypophosphite, 0.04 parts of potassium iodide, 0.4 parts of UV-3346 and 17.4 parts of deionized water into a magnetically driven high-pressure reactor according to weight parts, nitrogen was introduced to replace the air in the reactor;

[0138] (2) Set the stirring speed to 350 r / min, heat the reactor to 100°C, and react for 1 h;

[0139] (3) The reactor temperature was raised to 200°C, and nitrogen was introduced until the system pressure reached 2 MPa and the reaction was continued for 2 h.

[0140] (4) reducing the pressure to 0.25 MPa and raising the reactor temperature to 250°C for 2 h;

[0141] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0142] (6) washing with water and discharging to obtain the nylon.

[0143] Comparative Example 2

[0144] A method for preparing nylon, comprising the following steps:

[0145] (1) After adding 25 parts of terephthalic acid, 18 parts of ethylenediamine, 10 parts of MACM, 0.04 parts of sodium hypophosphite, 0.04 parts of potassium iodide, 0.4 parts of UV-3346 and 17.4 parts of deionized water into a magnetically driven high-pressure reactor according to parts by weight, nitrogen was introduced to replace the air in the reactor;

[0146] (2) Set the stirring speed to 350 r / min, heat the reactor to 150°C, and react for 2.2 h;

[0147] (3) The reactor temperature was raised to 270°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0148] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0149] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0150] (6) washing with water and discharging to obtain the nylon.

[0151] Comparative Example 3

[0152] A method for preparing nylon, comprising the following steps:

[0153] (1) After adding 25 parts of terephthalic acid, 3.5 parts of ethylenediamine, 0.04 parts of sodium hypophosphite, 0.04 parts of potassium iodide, 0.4 parts of UV-3346 and 17.4 parts of deionized water to a magnetically driven high-pressure reactor in parts by weight, nitrogen was introduced to replace the air in the reactor;

[0154] (2) Set the stirring speed to 350 r / min, heat the reactor to 150°C, and react for 2.2 h;

[0155] (3) The reactor temperature was raised to 270°C, and nitrogen was introduced until the system pressure reached 2.5 MPa, and the reaction was continued for 3.0 h.

[0156] (4) reducing the pressure to 0.3 MPa and raising the reactor temperature to 310°C for 2.2 h;

[0157] (5) Cool to room temperature, reduce pressure to normal pressure and continue the reaction for 1 h.

[0158] (6) washing with water and discharging to obtain the nylon.

[0159] Experimental example

[0160] The high-temperature-resistant, high-strength transparent nylon prepared in Examples 1 to 8 and the nylon prepared in Comparative Examples 1 to 3 were injection molded into standard nylon material specimens. The tensile modulus of the nylon material specimens was tested according to ISO 527-1 / -2; the yield stress of the nylon material specimens was tested according to ISO 527-1 / -2; and the deflection temperature under load of the nylon material specimens was tested according to ISO 75-1 / -2.

[0161] The high-temperature-resistant, high-strength transparent nylon prepared in Examples 1 to 8 and the nylon prepared in Comparative Examples 1 to 2 were respectively made into film strips, and the transmittance of the strips was tested using an ultraviolet-visible spectrophotometer according to GB / T 2410-2008.

[0162] The test results are shown in Table 1.

[0163] Table 1

[0164]

[0165] The data in Table 1 show that the high-temperature-resistant, high-strength, transparent nylon prepared in Examples 1-8 exhibits improved tensile modulus, yield stress, load-deflection temperature, and light transmittance compared to the nylon prepared in Comparative Examples 1-3. The load-deflection temperature and light transmittance are significantly improved. As shown in Table 1, the high-temperature-resistant, high-strength, transparent nylon prepared in accordance with the present invention exhibits excellent mechanical properties, high-temperature resistance, and light transmittance.

[0166] Example 1 differs from Comparative Example 1 in the polymerization reaction conditions (temperature, pressure, time, etc.). Compared to the nylon prepared in Comparative Example 1, the nylon prepared in Example 1 exhibits improvements in tensile modulus, yield stress, heat distortion temperature, and light transmittance; the tensile modulus increases by 0.43%, the yield stress by 8.43%, the heat distortion temperature by 17.14%, and the light transmittance by 7.23%. This demonstrates that the present invention improves the mechanical properties, high-temperature resistance, and light transmittance of nylon by regulating the polymerization reaction process.

[0167] The difference between Example 1 and Comparative Example 2 lies in the different monomer ratios. Compared to the nylon prepared in Comparative Example 2, the nylon prepared in Example 1 exhibits significant improvements in tensile modulus, yield stress, heat distortion temperature, and light transmittance; the tensile modulus increased by 10.24%, the yield stress increased by 20%, the heat distortion temperature increased by 19.42%, and the light transmittance increased by 12.66%. This demonstrates that adjusting the ratio of the reactive units significantly improves the mechanical properties, high-temperature resistance, and light transmittance of the nylon.

[0168] The difference between Example 1 and Comparative Example 3 lies in the different types of monomers used. Example 1 adds MACM, while Comparative Example 3 does not. The structure of the nylon in Example 1 is different from that of the nylon in Comparative Example 3. Compared with the nylon in Comparative Example 3, the tensile modulus, yield stress, heat deformation temperature, and light transmittance of the nylon prepared in Example 1 are greatly improved; among them, the tensile modulus is increased by 21.69%, the yield stress is increased by 55.17%, the heat deformation temperature is increased by 44.71%, and the light transmittance is increased by 20.27%. This shows that the present invention changes the specific structure of nylon by adding MACM, greatly improving the mechanical properties, high temperature resistance, and light transmittance of nylon.

[0169] In summary, the high-temperature resistant transparent nylon provided by the present invention has a good balance between processing performance and heat resistance. Its main molecular chain contains both rigid benzene rings and flexible methylene chains, which makes it have both the thermoplasticity of aliphatic nylon and the high rigidity and high heat resistance of fully aromatic nylon. The methyl group in MACM destroys the lattice stacking, weakens the hydrogen bond network, reduces the crystallization driving force, increases the segment flexibility, and inhibits the three core mechanisms of nucleation through steric hindrance, systematically reduces the crystallinity of nylon, and thus improves the transmittance. The flexible methylene chain improves the toughness of the material and broadens the scope of application. Therefore, the high-temperature resistant transparent nylon provided by the present invention has great application prospects and value.

Claims

1. A high-temperature resistant transparent nylon, the structural formula of which is shown in Formula I; In formula I, m and n are independently selected from any integer between 500 and 5000, p is selected from any integer between 1 and 12, and C=O on the benzene ring is independently located at the meta position or para position of the benzene ring.

2. The high temperature resistant transparent nylon according to claim 1, characterized in that: Formula I is selected from one of the following structural formulas; 3. The high temperature resistant transparent nylon according to claim 1, characterized in that: The invention is prepared from raw materials including 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, aromatic diacid and fatty diamine.

4. A method for preparing the high temperature resistant transparent nylon according to any one of claims 1 to 3, comprising the following steps: (1) mixing 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, aromatic diacid, fatty diamine, catalyst, antioxidant, light stabilizer and deionized water to obtain a mixed material; (2) Under an inert atmosphere, the mixed material is subjected to a condensation reaction.

5. The preparation method according to claim 4, wherein The aromatic diacid is selected from at least one of terephthalic acid and isophthalic acid; or / and, The fatty diamine is selected from C1-C12 linear fatty diamines, preferably at least one selected from methylenediamine, ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octanediamine, nonanediamine, 1,10-decanediamine, 1,11-undecylamine and 1,12-dodecylamine; or / and, The catalyst is selected from at least one of N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethylalkylenediamine, triethylamine, N,N-dimethylbenzylamine, solid amine, N-ethylmorpholine, N-methylmorpholine, N,N-diethylpiperazine, potassium phosphate, sodium phosphate, potassium hypophosphite, sodium hypophosphite, potassium phosphite, sodium phosphite, potassium hypophosphite, sodium hypophosphite, n-butyl titanate, propyl titanate and isopropyl titanate; or / and, The antioxidant is at least one selected from pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, tris (2,4-di-tert-butyl) phenyl phosphite, potassium iodide, copper salt; or / and, The light stabilizer is selected from at least one of UV-3346, UV-123, UV-292, UV-622, UV-770DF, UV-944, UV-2020, and UV-660.

6. The preparation method according to claim 4, wherein The molar ratio of the aromatic diacid to the aliphatic diamine is 2:(0.6-1.4), preferably 2:(0.8-1.2); or / and, The molar ratio of the fatty diamine to 3,3'-dimethyl-4,4-diaminodicyclohexylmethane is 1:(0.6-1.4), preferably 1:(0.8-1.2); or / and, The added amount of the catalyst is 0.05% to 0.30% of the total mass of the aromatic diacid, the fatty diamine and 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, preferably 0.10% to 0.25%; or / and, The added amount of the antioxidant is 0.1% to 1.0% of the total mass of the aromatic diacid, the fatty diamine and 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, preferably 0.10% to 0.8%; or / and, The amount of the light stabilizer added is 0.08% to 0.20% of the total mass of the aromatic diacid, the aliphatic diamine and 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, preferably 0.11% to 0.15%; or / and, The added amount of the deionized water is 35% to 65% of the total mass of the aromatic diacid, the fatty diamine and the 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, preferably 40% to 60%.

7. The preparation method according to claim 4, wherein The condensation reaction includes a first stage reaction, a second stage reaction, a third stage reaction and a fourth stage reaction which are carried out in sequence: The first stage reaction conditions are: 150-250°C, normal pressure, reaction time 2.2-2.5h; The reaction conditions for the second stage are: 255-300°C, 2.5-3 MPa, reaction time 3.0-3.5 hours; The reaction conditions for the third stage are: 310-320°C, 0.3-0.4 MPa, reaction time 2.2-2.5 hours; The fourth stage reaction conditions are: room temperature, normal pressure, reaction for 1 to 1.5 hours.

8. The preparation method according to claim 4, wherein: The first stage reaction conditions are: 180-220℃, normal pressure, reaction time 2.2-2.4h, The second stage reaction conditions are: 260-290℃, 2.6-3MPa, reaction time 3-3.2h, The third stage reaction conditions are: 310-315℃, 0.3-0.35MPa, reaction time 2.2-2.4h, The fourth stage reaction conditions are: room temperature, normal pressure, reaction for 1 to 1.3 hours.

9. The preparation method according to claim 4, wherein: The condensation reaction is carried out under stirring conditions with a stirring speed of 300 to 500 r / min; or / and, The inert atmosphere is a nitrogen atmosphere.

10. Use of the high-temperature resistant transparent nylon according to any one of claims 1 to 3 or the high-temperature resistant transparent nylon prepared by the preparation method according to any one of claims 4 to 9 in the fields of food and beverage packaging, medical equipment, precision instruments, optical instruments, electronic appliances, automobile manufacturing, machinery, aviation, and sporting goods.

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