Photoluminescent polyamide, and preparation method therefor and use thereof

Abstract

Provided in the present invention is an optical material made of polyamide. The material is characterized in that the specific conditions in the present invention are met; and the polyamide is a copolymer of a lactam and an optically functional ring-opening agent, which copolymer comprises a first structural unit derived from the lactam, and a second structural unit and a third structural unit which are derived from the optically functional ring-opening agent, and further optionally has a fourth structural unit derived from the optically functional ring-opening agent. The resulting polyamide optical material has intrinsic photoluminescence, and has a fluorescence emission wavelength greater than 450 nm and a Stokes shift greater than 60 nm. Moreover, the material has low transmittance regarding both UV having a wavelength of 250-400 nm and blue-violet light, and exhibits good transmittance in the visible-light region at a wavelength of 600 nm. The polyamide optical material of the present invention exhibits good film-forming properties and processability, and can be widely used in fields such as optical protection, fluorescence imaging, smart lenses, optical data storage and anti-counterfeiting.

Description

Photoluminescent polyamides, their preparation methods and applications Technical Field

[0001] This invention relates to the field of functional materials technology, specifically to a polyamide optical material, its preparation method, and its application. Background Technology

[0002] Photoluminescence refers to the process by which a substance absorbs photons and then re-emits them. Based on the delay time, it is classified into fluorescence and phosphorescence. Compared to inorganic or organic small molecule luminescent materials, polymeric luminescent materials can achieve precise control over the emission wavelength, efficiency, and stability through molecular design. They also possess good film-forming properties and processability, making them applicable to fields such as optical protection, fluorescence imaging, smart lenses, optical data storage, and anti-counterfeiting.

[0003] Besides photoluminescence caused by valence bond conjugation, various non-conjugated natural and synthetic polymers have been reported to exhibit photoluminescence in recent years. Proteins and polyamides are examples of non-conjugated photoluminescent materials. CN112457486A discloses a method for preparing polyamides containing light absorbers in the main chain and the resulting material to improve the coloring effect of 3D printed products; the amino acid light absorber is selected from 4-amino-1,8-naphthalenedimide or 7-amino-4-methyl-3-coumarinacetic acid. This technology requires the introduction of light absorbers to prepare photoluminescent polyamides. The amino acid light absorbers used have relatively complex structures and contain benzene ring conjugated structures, resulting in high preparation costs. Furthermore, this technology cannot achieve the modulation of the fluorescence wavelength of the polyamide material.

[0004] Existing polyamide products containing amino acid derivatives are mainly prepared by anionic polymerization and are used as antibacterial materials in the pharmaceutical field. For example, CN111116472 A discloses a quaternized poly(ε-lysine) derivative material prepared by polymerization of a seven-membered cyclic lysine-derived monomer, and CN115707727A discloses a quaternized polyamide material obtained by copolymerization of cyclic lysine and caprolactam. However, anionic polymerization conditions are relatively harsh, requiring high levels of water and oxygen, resulting in high material preparation costs. Summary of the Invention

[0005] The inventors of this invention discovered that aminocaprolactam possesses photoluminescent properties, with a fluorescence excitation wavelength of 350 nm, a corresponding peak fluorescence emission wavelength of 410 nm, and a Stokes shift of 60 nm. In contrast, polylysine, directly thermally polymerized from aminocaprolactam, is a dark reddish-brown amorphous solid with a transmittance of less than 50% at 600 nm. Those skilled in the art know that polycaprolactam (nylon 6) is a polymer with a crystallinity between 20% and 40%, low visible light transparency, a narrow processing window, and rapid crystallization; it does not exhibit significant photoluminescence. Based on the above, developing polyamide optical materials with fluorescence wavelengths >500 nm, Stokes shifts >90 nm, and high visible light transparency remains a technical challenge.

[0006] The inventors of this invention have surprisingly discovered that when ring-opening polymerization is carried out using the lactam compound shown in formula (1), the aminocaprolactam shown in formula (2), and the polyacid shown in formula (3), without adding an anionic initiator, without using water, and without introducing additional small molecule luminescent material, and optionally further adding the polyamine shown in formula (4), the lactam compound shown in formula (1) and the aminocaprolactam shown in formula (2) can be smoothly ring-opened under mild conditions, thereby obtaining the polyamide of this invention, which includes a first structural unit, a second structural unit, and a third structural unit, and optionally includes a fourth unit.

[0007] In contrast, when a large amount of aminocaprolactam and diacid are present simultaneously in the polymerization system, high-temperature polymerization is prone to explosive polymerization due to excessively rapid crosslinking, making it impossible to obtain a processable copolyamide. Furthermore, high-temperature polymerization can also cause aminocaprolactam to self-polymerize or isomerize, and polymer discharge oxidation, thereby adversely affecting the regularity of the product structure, visible light transparency, and fluorescence properties. Therefore, specific monomer and ring-opening agent ratios must be used, along with lower polymerization temperatures and other specific polymerization conditions, to obtain the polyamide optical material described in this invention.

[0008] Based on the above, the inventors of this invention conducted in-depth research and found that by using the optical functional ring-opening agent of this invention and through the preparation method of the polyamide optical material of this invention, lactam compounds, aminocaprolactam, polybasic acids, and optionally polyamines can be polymerized in anhydrous conditions without the use of anionic polymerization initiators. The resulting polyamide optical material has low transmittance for short-wavelength incident light such as ultraviolet light, excellent transmittance in the visible light wavelength region, and excellent branching degree, exhibiting good film-forming properties and processability. It can be widely used in optical protection, fluorescence imaging, smart lenses, optical data storage, and anti-counterfeiting fields.

[0009] In particular, the polyamide of the present invention has structural units derived from lactam compounds, structural units derived from aminocaprolactam, and structural units derived from polybasic acids, and optionally structural units derived from polyamines. Furthermore, on the main chain of the polyamide of the present invention, the amino groups derived from the aminocaprolactam units can participate in the amidation reaction as branching sites of the main chain, thereby introducing branches into the main chain and introducing branching degree into the polymer as a whole.

[0010] More specifically, a first aspect of the present invention provides a polyamide optical material, characterized by satisfying at least one of the following conditions:

[0011] 1) The fluorescence emission wavelength of the polyamide is greater than 450 nm, preferably greater than 500 nm;

[0012] 2) The polyamide has a Stokes shift greater than 60 nm at an excitation wavelength of 400 nm, preferably greater than 90 nm;

[0013] 3) The UVB transmittance of the polyamide is less than 30%, preferably less than 20%; the transmittance of the polyamide at a wavelength of 600 nm is greater than 75%, preferably greater than 90%;

[0014] and,

[0015] The polyamide is a copolymer of lactam and an optically functional ring-opening agent, comprising a first structural unit derived from the lactam, and second and third structural units derived from the optically functional ring-opening agent.

[0016] The first structural unit has the structure shown in formula (I), the second structural unit has at least one structure shown in formulas (II) to (IV), and the third structural unit has the structure shown in formula (V).

[0017] The content of the first structural unit is 20-98 wt% relative to the total mass of each structural unit, preferably 30-95 wt%, and more preferably 50-90 wt%.

[0018] The content of the third structural unit is 3-70 wt%, preferably 5-65 wt%, and more preferably 10-60 wt%, relative to the total amount of structural units derived from the optically functional ring-opening agent.

[0019] Where * indicates the bonding location between structural units.

[0020] R1 represents C with or without substitution. 1～20 Alkylene (preferably substituted or unsubstituted C) 2～18 Alkylene, more preferably substituted or unsubstituted C 3～10 Alkylene),

[0021] R2 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkyl), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 (hybrid aryl);

[0022] The substituents of R1 and R2 are each independently selected from C1. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0023] A second aspect of the present invention provides a method for preparing a polyamide optical material, characterized in that the method comprises the following steps:

[0024] A reaction system comprising a lactam compound of formula (1), an optically functional ring-opening agent comprising aminocaprolactam of formula (2), and a polybasic acid of formula (3) was subjected to polymerization under an inert atmosphere.

[0025] The content of the lactam compound is 20-98 wt% relative to the total amount of reactants in the reaction system, preferably 30-95 wt%, and more preferably 50-90 wt%.

[0026] The content of polybasic acid is 3-70 wt% relative to the total amount of optical functional ring-opening agent, preferably 5-65 wt%, and more preferably 10-60 wt%.

[0027] Where R1 is substituted or unsubstituted C 1～20 Alkylene (preferably substituted or unsubstituted C) 2～18 Alkylene, more preferably substituted or unsubstituted C 3～10 Alkylene),

[0028] R2 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkyl), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 (hybrid aryl);

[0029] The substituents of R1 and R2 are each independently selected from C1. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0030] A third aspect of the present invention also provides an optically functional ring-opening agent, characterized in that it comprises aminocaprolactam and a polyacid, and optionally a polyamine, wherein the aminocaprolactam is a compound represented by formula (2).

[0031] The polyacid is the polyacid shown in formula (3) below.

[0032] The polyamine is the polyamine shown in formula (4).

[0033] R2 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkyl), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 (hybrid aryl);

[0034] The substituents of R2 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group,

[0035] R3 is selected from substituted or unsubstituted C3. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkylene), substituted or unsubstituted (C 3～15 Cycloalkyl-C 1～10 Alkylene-C 3～15 Cycloalkylene (preferably substituted or unsubstituted (C) 5～10 Cycloalkyl-C 1～6 Alkylene-C 5～10 Cycloalkylene), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 One or more of the following: heteroaryl groups and polyether chains with a degree of polymerization of 3 to 500;

[0036] The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C)1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group;

[0037] Preferably, the polyacid is selected from C 4～40 aliphatic polyacids, C 4～40 Alicyclic polyacids, C 6～40 Aromatic polyacids and C 5～40 The polyacid is selected from one or more of the following furan acids: succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, heptadecanoic acid, octadecanoic acid, docosanoic acid, terephthalic acid, isophthalic acid, trimesic acid, biphenyl dicarboxylic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, cyclohexanedicarboxylic acid, and furan dicarboxylic acid; preferably, the polyacid is selected from one or more of the following: glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, benzoic acid, terephthalic acid, trimesic acid, and cyclohexanedicarboxylic acid; more preferably, the polyacid is selected from one or more of the following: succinic acid, azelaic acid, dodecanoic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and trimesic acid.

[0038] Preferably, the polyamine is selected from C 2～40 aliphatic amines, C 2～40 Alicyclic amines, C 2～40 Aromatic amines, C 5～40 The polyamine is selected from one or more of furan amines and polyetheramines with a degree of polymerization of 5 to 500; preferably, the polyamine is selected from one or more of butanediamine, pentanediamine, hexanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, trimethylhexanediamine, methylpentanediamine, aniline, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, furan diamine, polyetheramine D200, polyetheramine D400, polyetheramine D1000 or polyetheramine D2000; preferably The polyamine is selected from one or more of pentanediamine, hexanediamine, decanediamine, undecanediamine, dodecanediamine, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, polyetheramine D400, polyetheramine D1000, or polyetheramine D2000; more preferably, the polyamine is selected from one or more of acediamine, polyetheramine D400, polyetheramine D1000, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), or 4,4'-methylenebis(cyclohexylamine);

[0039] The condition is that when the optical functional ring-opening agent contains only aminocaprolactam and polybasic acid, the content of aminocaprolactam is 30-97 wt%, preferably 40-95 wt%, more preferably 45-90 wt%, and the content of polybasic acid is 3-70 wt%, preferably 5-65 wt%, more preferably 10-60 wt%, relative to the total mass of the ring-opening agent.

[0040] When the optically functional ring-opening agent contains only aminocaprolactam, polyacid, and polyamine, the content of aminocaprolactam relative to the total mass of the ring-opening agent is 0.2-80 wt%, preferably 0.4-20 wt%, more preferably 1-15 wt%, the content of polyacid is 3-70 wt%, preferably 5-65 wt%, more preferably 10-60 wt%, and the content of polyamine is 10-90 wt%, preferably 15-80 wt%, more preferably 20-70 wt%.

[0041] A fourth aspect of the present invention provides the application of the polyamide of the present invention and the polyamide obtained by the preparation method of the present invention in gas barrier, optical protection, agricultural light conversion, optical display, fluorescence imaging, smart lens, optical anti-counterfeiting, optical data storage and anti-counterfeiting materials.

[0042] Technical effect

[0043] The polyamide of the present invention has structural units derived from lactam compounds, structural units derived from aminocaprolactam, and structural units derived from polybasic acids. It may also optionally have structural units derived from polyamines. In this case, the amino group of the aminocaprolactam unit can participate in the amidation reaction as a branching site of the main chain on the polyamide backbone, thereby introducing branches into the main chain through the aminocaprolactam unit, thus introducing branching degree into the polyamide as a whole.

[0044] By employing the types and proportions of structural units of the present invention, especially by simultaneously introducing the second and third structural units derived from the optical functional ring-opening agent of the present invention, as well as the optional fourth structural unit, the resulting product has a wider processing window and crystallization temperature range, a lower melting enthalpy (crystallinity), and is more likely to achieve crystallinity control of the copolyamide, thereby obtaining an optically transparent material.

[0045] The copolyamide of this invention has a Stokes shift > 90 nm and a fluorescence emission wavelength > 500 nm, which can convert blue-violet light into green or red light, and has the properties of protecting against blue light and photoluminescence in visible light. The introduction of the third structural unit of this invention can effectively control the fluorescence excitation wavelength and fluorescence emission wavelength of the copolyamide, and has application advantages in the fields of light conversion films, LEDs and the like.

[0046] Therefore, the resulting polyamide optical material has low transmittance for short-wavelength incident light such as UVA and blue-violet light, but excellent transmittance in the 600nm visible light wavelength region. It also exhibits good film-forming properties and processability, and can be widely used in optical protection, fluorescence imaging, smart lenses, optical data storage and anti-counterfeiting fields.

[0047] Furthermore, in the preparation method of the photoluminescent polyamide of the present invention, without the use of anionic polymerization initiators, and under anhydrous conditions, lactam compounds, aminocaprolactam, polybasic acids, and optionally polyamines are polymerized to obtain the photoluminescent polyamide of the present invention, and the monomer conversion rate is >90%. The preparation method of the present invention is simple and easy to implement, and the structural unit composition of the polyamide is easily adjustable. Attached Figure Description

[0048] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0049] Figure 1 is the infrared spectrum of the polyamide products obtained in Examples I-1 to I-6 of the present invention.

[0050] Figure 2 is the infrared spectrum of the polyamide products obtained in Examples I-17, I-19 and I-20 of this invention.

[0051] Figure 3 is a two-dimensional fluorescence spectrum of the polyamide obtained in Example I-1 of the present invention.

[0052] Figure 4 is a two-dimensional fluorescence spectrum of the polyamide obtained in Example I-3 of the present invention.

[0053] Figure 5 is a two-dimensional fluorescence spectrum of the polyamide obtained in Examples I-4 of the present invention.

[0054] Figure 6 is a two-dimensional fluorescence spectrum of the polyamide obtained in Examples I-6 of the present invention.

[0055] Figure 7 shows the ultraviolet-visible light spectra of the polyamide products obtained in Examples I-5 and I-11 of this invention after hot pressing into films.

[0056] Figure 8 is a photograph of the copolyamide obtained in Example II-12 of this invention.

[0057] Figure 9 shows the thermogravimetric analysis curves of Comparative Examples II-3, II-4, and II-6 of the present invention. Detailed Implementation

[0058] The structure, principle, and preparation process of the catalyst of the present invention will be further elaborated below.

[0059] In this invention, except where expressly stated, any matters or issues not mentioned herein are directly applicable to what is known in the art without any changes. Furthermore, any implementation described herein can be freely combined with one or more other implementations described herein, and the resulting technical solutions or concepts are considered part of the original disclosure or record of this invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider the combination clearly unreasonable.

[0060] All features disclosed in this invention can be combined arbitrarily, and such combinations should be understood as the content disclosed or recorded in this invention. Unless those skilled in the art consider such combinations to be obviously unreasonable, they should all be regarded as specifically disclosed and recorded in this invention. The numerical points disclosed in this specification, unless otherwise specified, include not only the numerical points specifically disclosed in the embodiments, but also the endpoints of each numerical range in the specification. Any combination of these numerical points should be regarded as the range disclosed or recorded in this invention.

[0061] In this specification, the term "single bond" is sometimes used in the definition of a group. A "single bond" means that the group does not exist. For example, suppose the structural formula is -CH2-A-CH3, where group A is defined as selected from single bonds and methyl groups. In this case, if A is a single bond, it means that group A does not exist, and the structural formula is correspondingly simplified to -CH2-CH3.

[0062] In this specification, the optional presence of a spacer group between two groups indicates that the two groups are directly connected. For example, assume the structural formula -CH2-(A). p -CH3, where A is a spacer group. If p is 0, it means that group A does not exist. In this case, -CH2- and -CH3 are directly bonded to form the structure -CH2-CH3.

[0063] In the context of this specification, the expression "number + valence + group" or similar terms refers to a group obtained by removing the number of hydrogen atoms represented by that number from the basic chemical structure (such as a chain, ring, or combination thereof) corresponding to that group. Preferably, it refers to a group obtained by removing the number of hydrogen atoms represented by that number from the carbon atoms contained in that structure (preferably saturated carbon atoms and / or not the same carbon atom). For example, "trivalent straight-chain or branched alkyl" refers to a group obtained by removing three hydrogen atoms from a straight-chain or branched alkane (i.e., the basic chemical structure corresponding to the trivalent straight-chain or branched alkyl).

[0064] In this invention, the technical and scientific terms that are given a definition shall be used as defined thereon, and those that are not given a definition shall be understood according to their common meaning in the art.

[0065] In the context of this invention, unless otherwise specified, the physical properties of a substance (such as light transmittance) are measured at room temperature (25°C) and normal pressure (101325 Pa).

[0066] [definition]

[0067] In the context of this specification, alkyl means a group obtained by removing a hydrogen atom from an alkane without violating its valence, preferably a group obtained by removing a hydrogen atom from a terminal carbon atom of an alkane. In this invention, alkyl can be a straight-chain alkyl or a branched-chain alkyl. In this invention, alkyl can be listed as C... 1～10 Alkyl, C 1～5 Alkyl, C 1～4 Alkyl groups. Specific examples of these alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl and their isomers.

[0068] In the context of this specification, alkoxy refers to the group obtained by bonding an oxygen (-O-) to the alkyl terminus described above in this invention. In this invention, the alkoxy group can be a straight-chain alkoxy or a branched-chain alkoxy. In this invention, the alkoxy group can be, for example, C... 1～20 Alkoxy, C 1～5 Alkoxy, C 1～4 Alkoxy groups. Specific examples of these alkyl groups include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, nonoxy, decoxy, and their isomers.

[0069] In the context of this specification, alkylene refers to a group obtained by removing two hydrogen atoms from an alkane without violating its valence; preferably, it is a group obtained by removing one hydrogen atom from each of two different carbon atoms; more preferably, it is a group obtained by removing one hydrogen atom from each of the two terminal carbon atoms of an alkane. In this invention, alkylene can be a straight-chain alkylene or a branched alkylene. In this invention, alkylene can be exemplified by C... 1～40 Alkylene, C 2～24 Alkylene, C 2～18 Alkylene, C 3～15 Alkylene, C 3～10 Alkylenes. Specific examples of these alkylenes include, but are not limited to, methylene, ethylene, propylene, isopropylene, butylene, sec-butylene, isobutylene, tert-butylene, pentylene, isopentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, and their isomers.

[0070] In the context of this specification, cycloalkylene refers to a group obtained by removing two hydrogen atoms from a cycloalkanes without violating the valence, preferably a group obtained by removing one hydrogen atom from each of two different carbon atoms. In this invention, cycloalkylene can be exemplified by C... 3～40 Cycloalkylene, C 3～15 Cycloalkylene, C 5～10 Cycloalkylene compounds. Specific examples of these cycloalkylene compounds include, but are not limited to, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, cyclononylene, cyclodecylene, cycloundecylene, cyclododecylene, cyclotridecylene, cyclotetradecylene, cyclopentadecanylene, cyclohexadecylene, and their isomers.

[0071] In the context of this specification, arylene refers to a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon without violating its valence. In this invention, arylene can be exemplified by C... 6～40 Aromatic group, C 6～24 Aromatic group, C 6～10 Aromatic groups. Specific examples of these aromatic groups include, but are not limited to, phenylene, biphenylene, naphthylene, fluorene, phenanthrene, anthraceneylene, etc.

[0072] In the context of this specification, a heteroaryl group refers to a group obtained by removing two hydrogen atoms from a heteroaromatic hydrocarbon without violating its valence. In this invention, aryl groups can be categorized as C... 5～20 Hybrid aryl, C 5～18 Hybrid aryl, C 5～10 Hypoaryl groups. Specific examples of these hypoaryl groups include, but are not limited to, imidazole, pyrazolyl, imidazolyl, imidazolyl, imidazolyl, imidazolyl, imidazolyl, imidazodiazolyl, imidadinyl, pyrimidinyl, triazinyl, imidazinyl, imidazolyl, imidazolyl, imidazolyl, imidazolyl, imidazolyl, imidazolyl, imidazolyl, imidazothiazolyl, imidazothiaphenyl, imidazofuranyl, etc.

[0073] In the context of this specification, ester group refers to the structure of an ester group (-OC(O)-R, or -C(O)-OR, where R represents an alkyl group in this invention (e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl)). Examples of ester groups in this invention include C... 2～20 Ester group, C 2～6 Ester groups, as specific examples of these ester groups, include -C(O)-O-methyl, -C(O)-O-ethyl, -C(O)-O-propyl, -C(O)-O-butyl, and -C(O)-O-isobutyl.

[0074] In the context of this specification, the urea group refers to the structure obtained by removing a hydrogen atom from urea, namely -NH-C(O)-NH2.

[0075] In the context of this specification, amide group refers to the structure of an amide group, i.e., -NH-C(O)-. Examples of amide groups in this invention include C... 1～24 Amide group, C 1～6 Amide group, C 1～4 Amide groups, as specific examples of these amide groups, wherein C 1～24 Alkyl, C 1～6 Alkyl, C 1～4 Alkyl groups can be bonded to the N-terminus or the carbonyl terminus; the other terminus is bonded to the substituted group.

[0076] In the context of this specification, carbonyl group refers to the structure of the present invention with an alkyl terminus bonded to -C(O)-. Examples of carbonyl groups in the present invention include C... 1～20 carbonyl group, C 1～8 carbonyl group, C 1～4 Carbonyl groups, that is, as specific examples of these carbonyl groups, where C 1～20 Alkyl, C 1～8 Alkyl, C 1～4 The alkyl group is bonded to one end of the carbonyl group, and the other end of the carbonyl group is bonded to the substituted group.

[0077] In the context of this specification, ether group refers to a group formed by inserting an oxygen atom into a chain of an alkyl group having two or more carbon atoms, as described in this invention. Examples of ether groups in this invention include C... 2～20 ether group, C 2～6 ether group, C 2～4 Ether groups, that is, as a specific example of these ether groups, C 2～20 Alkyl, C 2～6 Alkyl, C 2～4 An alkyl group is formed by inserting an oxygen atom between two adjacent carbon atoms.

[0078] In the context of this specification, a polyether chain refers to a chain having -RO- structural units. The polyether chains of the present invention may include polyoxyethylene chains, and more specifically, chains formed of polyethylene oxide chains and chains formed of propylene oxide chains. The degree of polymerization of the polyether chain may be selected as needed.

[0079] In the context of this specification, an aldehyde group refers to a group obtained by bonding a -C(O)H group to the end of an alkyl group of the present invention. Examples of aldehyde groups in the present invention include C... 1～20 Aldehyde group, C 1～8 Aldehyde group, C 1～4 Aldehyde groups, that is, as specific examples of these aldehyde groups, in C 1～20 Alkyl, C1～8 Alkyl, C 1～4 A group obtained by bonding -C(O)H to the end of an alkyl group.

[0080] In the context of this specification, in the case of a substituted or unsubstituted group, the maximum number of substituents that the group can be substituted is the upper limit. For example, it can be 1 substituent, 2 substituents, 3 substituents, 4 substituents, 5 substituents, 6 substituents, 7 substituents, 8 substituents, 9 substituents, 10 substituents, etc. When there are 2 or more substituents, the substituents can be the same or different.

[0081] In the context of this specification, aromatic polyacids or aromatic polyamines refer to polycarboxylic acids or polyamines that contain aromatic rings such as benzene rings or naphthalene rings in their molecular structure; examples of aromatic polyacids include phthalic acid, terephthalic acid, isophthalic acid, trimesic acid, 1,3,5-phenyltricarboxylic acid, biphenyl dicarboxylic acid, and naphthalenedicarboxylic acid; examples of aromatic polyamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diaminodiphenylmethane, benzidine, 2,4-toluenediamine, 2,6-toluenediamine, 4,4'-diaminobiphenyl, 3,3'-diaminodiphenylmethane, and 4,4'-diaminodiphenylmethane.

[0082] In this invention, the asterisk (*) in the structural unit indicates the bonding position between the structural unit and other structural units.

[0083] A first aspect of the present invention provides a polyamide optical material, characterized in that it satisfies at least one of the following conditions.

[0084] 1) The fluorescence emission wavelength of the polyamide is greater than 450 nm, preferably greater than 500 nm;

[0085] 2) The polyamide has a Stokes shift greater than 60 nm at an excitation wavelength of 400 nm, preferably greater than 90 nm;

[0086] 3) The UVB transmittance of the polyamide is less than 30%, preferably less than 20%; the transmittance of the polyamide at a wavelength of 600 nm is greater than 75%, preferably greater than 90%;

[0087] and,

[0088] The polyamide is a copolymer of lactam and an optically functional ring-opening agent, comprising a first structural unit derived from the lactam, and second and third structural units derived from the optically functional ring-opening agent.

[0089] The first structural unit has the structure shown in formula (I), the second structural unit has at least one structure shown in formulas (II) to (IV), and the third structural unit has the structure shown in formula (V).

[0090] The content of the first structural unit is 20-98 wt% relative to the total mass of each structural unit, preferably 30-95 wt%, and more preferably 50-90 wt%.

[0091] The content of the third structural unit is 3-70 wt%, preferably 5-65 wt%, and more preferably 10-60 wt%, relative to the total amount of structural units derived from the optically functional ring-opening agent.

[0092] Where * indicates the bonding location between structural units.

[0093] R1 represents C with or without substitution. 1～20 Alkylene (preferably substituted or unsubstituted C) 2～18 Alkylene, more preferably substituted or unsubstituted C 3～10 Alkylene),

[0094] R2 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkyl), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 (hybrid aryl);

[0095] The substituents of R1 and R2 are each independently selected from C1. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0096] It should be noted that in this invention, the second structural unit is derived from the structural unit of aminocaprolactam shown in formula (2). In the preparation of polyamide, the aminocaprolactam shown in formula (2) undergoes ring-opening. Simultaneously, the amino group at the α-position of the aminocaprolactam also participates in the amidation reaction, thereby providing a site for the amidation reaction through the side-chain amino group in the second structural unit (sometimes referred to as α-amino group in this invention), introducing a side chain into the polyamide of this invention. Furthermore, different polyamide backbones can be cross-linked through side chains with amide groups; that is, different polyamide backbones are connected via the amino groups of each polyamide through chains with amide groups, thereby forming a cross-linked structure. Therefore, the polyamide of this invention includes linear, branched, and cross-linked structures.

[0097] At this point, the α-amino group can undergo amidation to produce the structural unit shown in formula (III), or it can undergo imidation to produce the structural unit shown in formula (II). In addition, during the ring-opening polymerization of aminocaprolactam, some α-amino groups do not undergo amidation, thus producing the structural unit shown in formula (IV).

[0098] In one embodiment of the present invention, the polyamide has a number-average molecular weight of 0.5-6.0 million, preferably 2.0-5.0 million, and more preferably 2.5-4.5 million. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the number-average molecular weight is 1.0 million, 1.5 million, 2.0 million, 2.5 million, 3.0 million, 3.5 million, 4.0 million, 4.5 million, 5.0 million, or 5.5 million.

[0099] In one embodiment of the present invention, the polydispersity index of the polyamide is between 1.2 and 2.5, preferably between 1.4 and 2.0, and more preferably between 1.5 and 2.0. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the polydispersity index of the polyamide is 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, or 2.4.

[0100] In one embodiment of the present invention, the relative viscosity of the polyamide at 25°C is 1.2-4.5, preferably 1.8-4.0, and more preferably 2.0-3.8. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the relative viscosity at 25°C is 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, or 4.4.

[0101] In one embodiment of the present invention, the degree of branching of the polyamide is 0.001-0.4, preferably 0.002-0.3, and more preferably 0.005-0.12. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the degree of branching is 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15.

[0102] In one embodiment of the present invention, the secondary melting enthalpy of the polyamide is <50 J·g. -1 Preferably <40 J·g -1 More preferably <35 J·g -1 In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the secondary melting enthalpy is <48 J·g. -1 <45J·g -1 <43J·g -1 <42J·g -1 <41J·g -1 <38J·g -1 or <37 J·g -1 .

[0103] In one embodiment of the present invention, the processing window of the polyamide is >30°C, preferably >33°C, and more preferably >35°C. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the processing window is >31°C, >32°C, >34°C, >36°C, or >37°C.

[0104] In one embodiment of the present invention, the crystallization temperature range of the polyamide is >25°C, preferably >28°C, and more preferably >30°C. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the crystallization temperature range is >26°C, >27°C, >29°C, >31°C, >32°C, or >33°C.

[0105] In one embodiment of the present invention, the polyamide is an amorphous polymer or its secondary melting enthalpy is <20 J·g. -1 When the glass transition temperature is >40°C, preferably >50°C, and more preferably >60°C. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, and a third structural unit, the glass transition temperature is >40°C, >42°C, >45°C, >48°C, >51°C, >54°C, >57°C, or >60°C.

[0106] In one embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second and third structural units, the content of the second structural unit relative to the total mass of each structural unit is 3-50 wt%, preferably 5-40 wt%, and more preferably 7-30 wt%. In another embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second and third structural units, the content of the second structural unit relative to the total mass of each structural unit is 4 wt%, 6 wt%, 8 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%.

[0107] In one embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second and third structural units, the content of the third structural unit relative to the total mass of all structural units is 0.5-20 wt%, preferably 1-18 wt%, and more preferably 1.5-15 wt%. In another embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second and third structural units, the content of the third structural unit relative to the total mass of all structural units is 0.6 wt%, 0.8 wt%, 1.2 wt%, 1.6 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, or 18.0 wt%.

[0108] In the photoluminescent polyamide of the present invention, the content of the first structural unit is 20-98 wt%, preferably 30-95 wt%, and more preferably 50-90 wt%, relative to the total mass of each structural unit, and the first structural unit has the structure shown in formula (I).

[0109] In one embodiment of the present invention, the content of the first structural unit in the photoluminescent polyamide of the present invention is 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, or 85wt%, relative to the total mass of each structural unit.

[0110] It should be noted that the first structural unit is derived from the structural unit of the lactam compound shown in formula (1). In the preparation of polyamide, the lactam compound shown in formula (1) undergoes ring opening to produce the structural unit shown in formula (I).

[0111] In the photoluminescent polyamide of the present invention, the content of the third structural unit is 3-70 wt%, preferably 5-65 wt%, and more preferably 10-60 wt%, relative to the total amount of structural units derived from the optically functional ring-opening agent, and the third structural unit has the structure shown in formula (V).

[0112] In one embodiment of the present invention, the content of the third structural unit in the photoluminescent polyamide of the present invention is 7 wt%, 9 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 65 wt%, relative to the total amount of structural units derived from the optically functional ring-opening agent.

[0113] It should be noted that the third structural unit is derived from the structural unit of the polybasic acid shown in formula (3). In the preparation of polyamide, the polybasic acid shown in formula (3) undergoes an amidation reaction with an amino group to produce the structural unit shown in formula (V).

[0114] In one embodiment of the present invention, R1 is substituted or unsubstituted C. 1～20 Alkylene, preferably substituted or unsubstituted C 2～18 Alkylene, more preferably substituted or unsubstituted C 3～10 Alkylene.

[0115] In one embodiment of the present invention, R1 is selected from one or more of substituted or unsubstituted ethylene, substituted or unsubstituted propylene, substituted or unsubstituted butylene, substituted or unsubstituted pentylene, substituted or unsubstituted hexylene, substituted or unsubstituted nonylene, substituted or unsubstituted decylene, and substituted or unsubstituted undecylene.

[0116] In one embodiment of the present invention, R2 is selected from substituted or unsubstituted C. 1～40 Alkylene, preferably substituted or unsubstituted C 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene.

[0117] In one embodiment of the present invention, R2 is selected from substituted or unsubstituted C. 3～40 Cycloalkylene, preferably substituted or unsubstituted C 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkylene.

[0118] In one embodiment of the present invention, R2 is selected from substituted or unsubstituted C. 6～40 Aromatic groups, preferably substituted or unsubstituted C 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromatic groups.

[0119] In one embodiment of the present invention, R2 is selected from substituted or unsubstituted C. 5～20 Heteroaryl, preferably substituted or unsubstituted C 5～18 Heteroaryl, more preferably substituted or substituted C5～10 Hybrid aryl.

[0120] In one embodiment of the present invention, R2 is selected from substituted or unsubstituted C. 2～24 Alkylene, substituted or unsubstituted C 3～15 Cycloalkylene, substituted or unsubstituted C 6～24 Aromatic groups, substituted or unsubstituted C 5～18 One or more of the heteroaryl groups, preferably, R2 is selected from one or more of the following: substituted or unsubstituted ethylene, substituted or unsubstituted propylene, substituted or unsubstituted butylene, substituted or unsubstituted pentylene, substituted or unsubstituted hexylene, substituted or unsubstituted nonylene, substituted or unsubstituted decylene, substituted or unsubstituted undecylene, substituted or unsubstituted dodecylene, substituted or unsubstituted cyclopentylene, substituted or unsubstituted cyclohexylene, substituted or unsubstituted phenylene, and substituted or unsubstituted furanylene.

[0121] In one embodiment of the present invention, the substituent of R2 is selected from C. 1～5 Alkyl, C 2～5 Alkoxy, C 2～6 Ester group, urea group, C 1～12 amide group, C 2～8 carbonyl group, C 2～6 ether group, hydroxyl group, carboxyl group and C 1～8 One or more of the aldehyde groups; preferably, the substituents of R2 are selected from one or more of methyl, ethyl, propyl, butyl, carboxyl, hydroxyl and aldehyde groups.

[0122] In one embodiment of the present invention, the substituents of R1 and R2 are each independently selected from C 1～10 Alkyl, C 1～20 Alkoxy, C 2～20 Ester group, urea group, C 1～24 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group, C 2～20 ether group and C 1～20 One or more of the aldehyde groups.

[0123] In one embodiment of the present invention, the substituents of R1 and R2 are each independently selected from C 1～4 Alkyl, C 1～4 Alkoxy, C 2～6 Ester group, urea group, C 1～4 amide group, hydroxyl group, carboxyl group, C 1～4 carbonyl group, C 2～4 ether group and C 1～4 One or more of the aldehyde groups.

[0124] In one embodiment of the present invention, the substituents of R1 and R2 are each independently selected from C1～4 Alkyl, C 1～4 Alkoxy, C 2～6 Ester group, hydroxyl group, carboxyl group, C 1～4 carbonyl and C 1～4 One or more of the aldehyde groups.

[0125] In one embodiment of the present invention, the substituent of R1 is selected from C. 1～5 Alkyl, C 2～5 Alkoxy, C 2～6 Ester group, hydroxyl group, carboxyl group, C 2～8 carbonyl group, C 2～6 ether group, C 5～13 One or more of amide and aldehyde groups, preferably one or more of methyl, ethyl, propyl and butyl groups.

[0126] In one embodiment of the present invention, the substituent of R2 is selected from C. 1～5 Alkyl, C 2～5 Alkoxy, C 2～6 Ester group, urea group, C 1～12 amide group, C 2～8 carbonyl group, C 2～6 ether group, hydroxyl group, carboxyl group and C 1～8 One or more of the aldehyde groups; preferably, the substituents of R2 are selected from one or more of methyl, ethyl, propyl, butyl, carboxyl, hydroxyl and aldehyde groups.

[0127] In one embodiment of the invention, the polyamide further comprises a fourth structural unit derived from an optically functional ring-opening agent, the fourth structural unit having the structure shown in formula (VI).

[0128] The mass ratio of the fourth structural unit to the third structural unit is 0.1 to 20:1, preferably 0.5 to 15:1, and more preferably 0.8 to 12:1.

[0129] Where * indicates the bonding location between structural units.

[0130] R3 is selected from substituted or unsubstituted C3. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkylene), substituted or unsubstituted (C 3～15 Cycloalkyl-C 1～10 Alkylene-C 3～15Cycloalkylene (preferably substituted or unsubstituted (C) 5～10 Cycloalkyl-C 1～6 Alkylene-C 5～10 Cycloalkylene), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 One or more of the following: heteroaryl groups and polyether chains with a degree of polymerization of 3 to 500;

[0131] The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0132] It should be noted that the fourth structural unit is derived from the structural unit of the polyamine shown in formula (4). In the preparation of polyamide, the polyamine shown in formula (4) undergoes an amidation reaction with the carboxyl group to produce the structural unit shown in formula (V).

[0133] In one embodiment of the present invention, R3 is selected from substituted or unsubstituted C. 1～40 Alkylene, preferably substituted or unsubstituted C 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene.

[0134] In one embodiment of the present invention, R3 is selected from substituted or unsubstituted C. 3～40Cycloalkylene, preferably substituted or unsubstituted C 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkylene.

[0135] In one embodiment of the present invention, R3 is selected from substituted or unsubstituted C. 6～40 Aromatic groups, preferably substituted or unsubstituted C 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromatic groups.

[0136] In one embodiment of the present invention, R3 is selected from substituted or unsubstituted C. 5～20 Heteroaryl, preferably substituted or unsubstituted C 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 Hybrid aryl.

[0137] In one embodiment of the present invention, R3 is selected from polyether chains of 3 to 500.

[0138] In one embodiment of the present invention, R3 is selected from substituted or unsubstituted C. 2～24 Alkylene, substituted or unsubstituted C 3～15 Cycloalkylene, substituted or unsubstituted C 6～24 Aromatic groups, substituted or unsubstituted C 5～18 R3 is selected from one or more of the following: heteroaryl groups and polyether chains with a degree of polymerization of 3 to 500. Preferably, R3 is selected from one or more of the following: substituted or unsubstituted ethylene, substituted or unsubstituted propylene, substituted or unsubstituted butylene, substituted or unsubstituted pentylene, substituted or unsubstituted hexylene, substituted or unsubstituted nonylene, substituted or unsubstituted decylene, substituted or unsubstituted undecylene, substituted or unsubstituted dodecylene, substituted or unsubstituted cyclopentylene, substituted or unsubstituted cyclohexylene, substituted or unsubstituted phenylene, substituted or unsubstituted furanylene, and polyether chains with a degree of polymerization of 5 to 50.

[0139] In one embodiment of the present invention, the substituents of R3 are each independently selected from C. 1～10 Alkyl, C 1～20 Alkoxy, C 2～20 Ester group, urea group, C 1～24 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group, C 2～20 ether group and C 1～20 One or more of the aldehyde groups.

[0140] In one embodiment of the present invention, the substituents of R3 are each independently selected from C. 1～4 Alkyl, C 1～4 Alkoxy, C 2～6Ester group, urea group, C 1～4 amide group, hydroxyl group, carboxyl group, C 1～4 carbonyl group, C 2～4 ether group and C 1～4 One or more of the aldehyde groups.

[0141] In one embodiment of the present invention, the substituents of R3 are each independently selected from C. 1～4 Alkyl, C 1～4 Alkoxy, C 2～6 Ester group, hydroxyl group, carboxyl group, C 1～4 carbonyl and C 1～4 One or more of the aldehyde groups.

[0142] In one embodiment of the present invention, the substituent of R3 is selected from C. 1～5 Alkyl, C 2～5 Alkoxy, C 2～6 Ester group, urea group, C 1～12 amide group, C 1～8 carbonyl group, C 2～6 Ether group, hydroxyl group, carboxyl group and C 1～8 One or more of the aldehyde groups; preferably, the substituents of R3 are selected from one or more of methyl, ethyl, propyl, butyl, carboxyl, hydroxyl and aldehyde groups.

[0143] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the content of the first structural unit is 20-95 wt%, preferably 30-90 wt%, and more preferably 50-85 wt%, relative to the total mass of all structural units. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the content of the first structural unit is 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, or 85 wt%, relative to the total mass of all structural units.

[0144] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the content of the fourth structural unit in the polyamide is 10-90 wt%, preferably 15-80 wt%, and more preferably 20-70 wt%, relative to the total amount of structural units derived from the optically functional ring-opening agent. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the content of the fourth structural unit in the polyamide, relative to the total amount of structural units derived from the optically functional ring-opening agent, is 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, or 80 wt%.

[0145] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the number-average molecular weight of the polyamide is 15,000-60,000, preferably 20,000-50,000, and more preferably 25,000-45,000. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the number-average molecular weight is 10,000, 15,000, 20,000, 25,000, 30,000, 35,000, 40,000, 45,000, 50,000, or 55,000.

[0146] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the polydispersity index of the polyamide's molecular weight distribution is between 1.2 and 2.5, preferably between 1.4 and 2.0, and more preferably between 1.5 and 1.9. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the polydispersity index of its molecular weight distribution is 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, or 2.4.

[0147] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the relative viscosity of the polyamide at 25°C is 1.8-4.5, preferably 1.9-4.0, and more preferably 2.0-3.8. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the relative viscosity at 25°C is 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, or 4.4.

[0148] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the degree of branching of the polyamide is 0.001-0.4, preferably 0.002-0.3, and more preferably 0.005-0.12. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the degree of branching is 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15.

[0149] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the secondary enthalpy of melting of the polyamide is <45 J·g. -1 Preferably <42 J·g -1 More preferably <40 J·g -1 In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the secondary melting enthalpy is <48 J·g. -1 <45J·g -1 <43J·g -1 <42J·g -1 <41J·g -1 <38J·g -1 or <37 J·g -1 .

[0150] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the processing window of the polyamide is >30°C, preferably >35°C, and more preferably >40°C. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the processing window is >31°C, >32°C, >34°C, >36°C, or >37°C.

[0151] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, the crystallization temperature range of the polyamide is >25°C, preferably >26°C, and more preferably >28°C. In another embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the crystallization temperature range is >26°C, >27°C, >29°C, >31°C, >32°C, or >33°C.

[0152] In one embodiment of the present invention, when the polyamide includes a fourth structural unit, and the polyamide is an amorphous polymer or its secondary enthalpy of melting is <20 J·g -1When the polyamide has a glass transition temperature >40°C, preferably >45°C, more preferably >50°C, and even more preferably >60°C, the glass transition temperature is greater than 40°C, greater than 42°C, greater than 45°C, greater than 48°C, greater than 51°C, greater than 54°C, greater than 57°C, or greater than 60°C. In one embodiment of the present invention, when the polyamide is a polyamide formed from a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit, the glass transition temperature is greater than 40°C, greater than 42°C, greater than 45°C, greater than 48°C, greater than 51°C, greater than 54°C, greater than 57°C, or greater than 60°C.

[0153] In one embodiment of the present invention, when the structural units derived from the optical functional ring-opening agent comprise only the second, third, and fourth structural units, the content of the second structural unit relative to the total mass of each structural unit is 0.05-30 wt%, preferably 0.1-10 wt%, more preferably 0.2-2 wt%, the content of the third structural unit is 0.5-40 wt%, preferably 1-30 wt%, more preferably 2-15 wt%, and the content of the fourth structural unit is 1.0-40 wt%, preferably 2.0-30 wt%, more preferably 3.0-25 wt%.

[0154] In one embodiment of the present invention, when the structural units derived from the optical functional ring-opening agent include only the second structural unit, the third structural unit, and the fourth structural unit, the content of the second structural unit is 0.05-30 wt%, preferably 0.1-10 wt%, and more preferably 0.2-2 wt%, relative to the total mass of each structural unit. In one embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second, third, and fourth structural units, the content of the second structural unit relative to the total mass of each structural unit is 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, 1.2 wt%, 1.6 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 20.0 wt%, or 25.0 wt%.

[0155] In one embodiment of the present invention, when the structural units derived from the optical functional ring-opening agent include only the second, third, and fourth structural units, the content of the third structural unit is 0.5-40 wt%, preferably 1-30 wt%, and more preferably 2-15 wt%, relative to the total mass of each structural unit. In one embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second, third, and fourth structural units, the content of the third structural unit relative to the total mass of each structural unit is 0.5 wt%, 0.6 wt%, 0.8 wt%, 1.2 wt%, 1.6 wt%, 1.8 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 20.0 wt%, 25.0 wt%, 30.0 wt%, or 35.0 wt%.

[0156] In one embodiment of the present invention, when the structural units derived from the optical functional ring-opening agent include only the second structural unit, the third structural unit, and the fourth structural unit, the content of the fourth structural unit is 1.0-40 wt%, preferably 2.0-30 wt%, and more preferably 3.0-25 wt%, relative to the total mass of each structural unit. In one embodiment of the present invention, when the structural units derived from the optically functional ring-opening agent comprise only the second, third, and fourth structural units, the content of the fourth structural unit relative to the total mass of each structural unit is 1.2 wt%, 1.6 wt%, 1.8 wt%, 2.0 wt%, 2.2 wt%, 2.5 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 20.0 wt%, 25.0 wt%, 30.0 wt%, or 35.0 wt%.

[0157] A second aspect of the present invention provides a method for preparing a photoluminescent polyamide, characterized in that the method comprises the following steps:

[0158] A reaction system comprising a lactam compound of formula (1), an optically functional ring-opening agent comprising aminocaprolactam of formula (2), and a polybasic acid of formula (3) was subjected to polymerization under an inert atmosphere.

[0159] The content of the lactam compound is 20-98 wt% relative to the total amount of reactants in the reaction system, preferably 30-95 wt%, and more preferably 50-90 wt%.

[0160] The content of polybasic acid is 3-70 wt% relative to the total amount of optical functional ring-opening agent, preferably 5-65 wt%, and more preferably 10-60 wt%.

[0161] Where R1 is substituted or unsubstituted C 1～20 Alkylene (preferably substituted or unsubstituted C) 2～18 Alkylene, more preferably substituted or unsubstituted C 3～10 Alkylene),

[0162] R2 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkyl), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 (hybrid aryl);

[0163] The substituents of R1 and R2 are each independently selected from C1. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0164] In one embodiment of the present invention, no anionic initiator is added to the reaction system in the polyamide preparation method of the present invention.

[0165] In one embodiment of the present invention, water is not added to the reaction system in the polyamide preparation method of the present invention.

[0166] In one embodiment of the present invention, the polyamide preparation method of the present invention includes the following steps:

[0167] The optically functional ring-opening agent further comprises the polyamine shown in formula (4).

[0168] The content of the lactam compound is 20-95 wt% relative to the total amount of reactants in the reaction system, preferably 30-90 wt%, and more preferably 50-85 wt%.

[0169] The content of polyamine relative to the total amount of optical functional ring-opening agent is 10-90 wt%, preferably 15-80 wt%, and more preferably 20-70 wt%.

[0170] R3 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkylene), substituted or unsubstituted (C 3～15 Cycloalkyl-C 1～10 Alkylene-C 3～15 Cycloalkylene (preferably substituted or unsubstituted (C) 5～10 Cycloalkyl-C 1～6 Alkylene-C 5～10 Cycloalkylene), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10One or more of the following: heteroaryl groups and polyether chains with a degree of polymerization of 3 to 500;

[0171] The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0172] In one embodiment of the present invention, the mass ratio of the polyamine to the polyacid in the reaction system is 0.1 to 20:1, preferably 0.5 to 15:1, and more preferably 0.8 to 12:1.

[0173] In the method for preparing the polyamide of the present invention, the mass percentage of the lactam compound represented by formula (1) in the reaction system relative to the total amount of reactants in the reaction system is 20-98 wt%, preferably 30-95 wt%, and more preferably 50-90 wt%. In one embodiment of the present invention, the mass percentage of the lactam compound represented by formula (1) in the reaction system relative to the total amount of reactants in the reaction system is 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, or 85 wt%.

[0174] In the preparation method of polyamide of the present invention, when the optical functional ring-opening agent contains only aminocaprolactam and polybasic acid, the content of aminocaprolactam is 30-97 wt%, preferably 40-95 wt%, more preferably 45-90 wt%, and the content of polybasic acid is 3-70 wt%, preferably 5-65 wt%, more preferably 10-60 wt%, relative to the total mass of the ring-opening agent.

[0175] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, when the optically functional ring-opening agent contains only aminocaprolactam and polybasic acid, the content of aminocaprolactam relative to the total mass of the ring-opening agent is 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, or 85wt%.

[0176] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, when the optically functional ring-opening agent contains only aminocaprolactam and a polybasic acid, the content of the polybasic acid relative to the total mass of the ring-opening agent is 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 65 wt%.

[0177] In the preparation method of the polyamide of the present invention, when the optical functional ring-opening agent contains only aminocaprolactam, polyacid, and polyamine, the content of aminocaprolactam relative to the total mass of the ring-opening agent is 0.2-80 wt%, preferably 0.4-20 wt%, more preferably 1-15 wt%, the content of polyacid is 3-70 wt%, preferably 5-65 wt%, more preferably 10-60 wt%, and the content of polyamine is 10-90 wt%, preferably 15-80 wt%, more preferably 20-70 wt%.

[0178] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, when the optically functional ring-opening agent contains only aminocaprolactam, polyacid, and polyamine, the content of aminocaprolactam relative to the total mass of the ring-opening agent is 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1.2wt%, 1.6wt%, 2.0wt%, 3.0wt%, 4.0wt%, 5.0wt%, 6.0wt%, 7.0wt%, 8.0wt%, 9.0wt%, 10.0wt%, 11.0wt%, 12.0wt%, 14.0wt%, 15.0wt%, 18.0wt%, 20.0wt%, 25.0wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, or 75wt%.

[0179] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, when the optically functional ring-opening agent contains only aminocaprolactam, a polyacid, and a polyamine, the content of the polyacid relative to the total mass of the ring-opening agent is 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 65 wt%.

[0180] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, when the optically functional ring-opening agent contains only aminocaprolactam, polyacid, and polyamine, the content of polyamine relative to the total mass of the ring-opening agent is 11.0 wt%, 12.0 wt%, 14.0 wt%, 15.0 wt%, 18.0 wt%, 20.0 wt%, 25.0 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, or 75 wt%.

[0181] In the preparation method of the polyamide of the present invention, the groups of R1, R2, and R3 in the lactam compound represented by formula (1), the polyacid represented by formula (3), and the polyamine represented by formula (4) are the same as those described in the polyamide of the present invention for R1, R2, R3 and their respective substituents.

[0182] In the preparation method of the polyamide of the present invention, the lactam compound represented by formula (1) is a 5- to 15-membered cyclic lactam. Preferably, the lactam compound is selected from one or more of butyrolactam, caprolactam, undecylactam, dodecalactam and tridecalactam, and is preferably caprolactam.

[0183] In the method for preparing the polyamide of the present invention, the polyacid represented by formula (3) is selected from C 4～40 aliphatic polyacids, C 4～40 Alicyclic polyacids, C 6～40 Aromatic polyacids and C 5～40The polyacid is selected from one or more of the following furan acids: succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, heptadecanoic acid, octadecanoic acid, docosanoic acid, terephthalic acid, isophthalic acid, trimesic acid, biphenyl dicarboxylic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, cyclohexanedicarboxylic acid, and furan dicarboxylic acid; preferably, the polyacid is selected from one or more of the following: glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, benzoic acid, terephthalic acid, trimesic acid, and cyclohexanedicarboxylic acid; more preferably, the polyacid is selected from one or more of the following: succinic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and trimesic acid.

[0184] In the preparation method of the polyamide of the present invention, the polyamine represented by formula (4) is selected from C 2～40 aliphatic amines, C 2～40 Alicyclic amines, C 2～40 Aromatic amines, C 5～40 The polyamine is selected from one or more of furan amines and polyetheramines with a degree of polymerization of 3 to 500; preferably, the polyamine is selected from one or more of butanediamine, pentanediamine, hexanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, trimethylhexanediamine, methylpentanediamine, aniline, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, furan diamine, polyetheramine D200, polyetheramine D400, polyetheramine D1000 or polyetheramine D2000; preferably The polyamine is selected from one or more of pentanediamine, hexanediamine, decanediamine, undecanediamine, dodecanediamine, p-phenylenediamine, m-phenylenediamine, cyclohexanedimethylamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, polyetheramine D400, polyetheramine D1000, or polyetheramine D2000; more preferably, the polyamine is selected from one or more of acediamine, polyetheramine D400, polyetheramine D1000, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), or 4,4'-methylenebis(cyclohexylamine).

[0185] In one embodiment of the present invention, the preparation method of the polyamide of the present invention can be carried out according to conventional methods.

[0186] In one embodiment of the present invention, the polymerization reaction conditions in the polyamide preparation method of the present invention include: the polymerization is carried out under stirring conditions, the polymerization temperature is 100-360°C, preferably 170-350°C; the time is 3-16 h, preferably 4-12 h; the pressure is 0-2.0 MPa, preferably 0.2-1.2 MPa; and the stirring rate is 20-400 r / min, preferably 50-150 r / min. In another embodiment of the present invention, in the polyamide preparation method of the present invention, the polymerization is carried out in multiple stages within the polymerization temperature range, and the reaction is carried out at each temperature for a specific time, for example, 1 hour to 3 hours. For example, heat to 180°C and react at this temperature for 3 hours; then heat to 230°C and continue reacting at this temperature for 3 hours; or heat to 180°C and react for 1 hour; then heat to 210°C and continue reacting for 1 hour; then heat to 230°C and react for 3 hours; or heat to 180°C and react for 1 hour; then heat to 230°C and continue reacting for 1 hour; then heat to 300°C within 3 hours; or heat to 180°C and react for 1 hour; then heat to 230°C and continue reacting for 1 hour; then heat to 330°C within 3 hours; or heat to 220°C and react for 2 hours; then heat to 270°C and continue reacting for 2 hours.

[0187] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, the lactam compound, the polyacid, the aminocaprolactam and optional polyamine are mixed under an inert atmosphere and then subjected to a pre-reaction, followed by heating and then carrying out the polymerization reaction.

[0188] In one embodiment of the present invention, the pre-reaction conditions in the polyamide preparation method of the present invention include: the reaction is carried out under stirring conditions, the pre-reaction temperature is 80-160°C, preferably 80-120°C; the pre-reaction time is 0.1-4h, preferably 0.5-2h; and the stirring rate is 20-400r / min, preferably 50-200r / min.

[0189] In one embodiment of the present invention, in the method for preparing the polyamide of the present invention, after the polymerization reaction, the reaction system is depressurized to a second pressure, and then the reaction continues; the second pressure is 0.3 to -0.1 MPa, preferably 0 to -0.09 MPa, and the reaction time is 0.1 to 16 h, preferably 2 to 12 h.

[0190] More specifically, in one embodiment of the present invention, the method for preparing the polyamide of the present invention includes the following steps: mixing the lactam compound, the polyacid, the optionally added polyamine and the aminocaprolactam under an inert atmosphere and then performing a pre-reaction; heating and then performing the polymerization reaction; after the polymerization reaction, depressurizing the reaction system to a second pressure and then continuing the reaction.

[0191] A third aspect of the present invention provides an optically functional ring-opening agent, characterized in that it comprises aminocaprolactam and a polyacid, and optionally a polyamine, wherein the aminocaprolactam is a compound represented by formula (2).

[0192] The polyacid is the polyacid shown in formula (3) below.

[0193] The polyamine is the polyamine shown in formula (4).

[0194] R2 is selected from substituted or unsubstituted C. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkyl), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 (hybrid aryl);

[0195] The substituents of R2 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4One or more of the following groups: aldehyde group,

[0196] R3 is selected from substituted or unsubstituted C3. 1～40 Alkylene (preferably substituted or unsubstituted C) 2～24 Alkylene, more preferably substituted or unsubstituted C 3～15 Alkylene, substituted or unsubstituted C 3～40 Cycloalkylene (preferably substituted or unsubstituted C4) 3～15 Cycloalkylene, more preferably substituted or unsubstituted C 5～10 Cycloalkylene), substituted or unsubstituted (C 3～15 Cycloalkyl-C 1～10 Alkylene-C 3～15 Cycloalkylene (preferably substituted or unsubstituted (C) 5～10 Cycloalkyl-C 1～6 Alkylene-C 5～10 Cycloalkylene), substituted or unsubstituted C 6～40 Aromatic groups (preferably substituted or unsubstituted C) 6～24 Aromatic groups, more preferably substituted or unsubstituted C 6～10 Aromaticyl group, substituted or unsubstituted C 5～20 Heteroaryl (preferably substituted or unsubstituted C) 5～18 Heteroaryl, more preferably substituted or substituted C 5～10 One or more of the following: heteroaryl groups and polyether chains with a degree of polymerization of 3 to 500;

[0197] The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

[0198] In the optical functional ring-opening agent of the present invention, the groups of R2 and R3 in the polyacid represented by formula (3) and the polyamine represented by formula (4) are the same as those described in the polyamide of the present invention for R2, R3 and their respective substituents.

[0199] In one embodiment of the present invention, the polybasic acid in the optically functional ring-opening agent of the present invention is selected from C 4～40 aliphatic polyacids, C 4～40 Alicyclic polyacids, C 6～40 Aromatic polyacids and C 5～40 The polyacid is selected from one or more of the following furan acids: succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, heptadecanoic acid, octadecanoic acid, docosanoic acid, terephthalic acid, isophthalic acid, trimesic acid, biphenyl dicarboxylic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, cyclohexanedicarboxylic acid, and furan dicarboxylic acid; preferably, the polyacid is selected from one or more of the following: glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, benzoic acid, terephthalic acid, trimesic acid, and cyclohexanedicarboxylic acid; more preferably, the polyacid is selected from one or more of the following: succinic acid, azelaic acid, dodecanoic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and trimesic acid.

[0200] In one embodiment of the present invention, the polyamine in the optically functional ring-opening agent of the present invention is selected from C 2～40 aliphatic amines, C 2～40 Alicyclic amines, C 2～40 Aromatic amines, C 5～40The polyamine is selected from one or more of furan amines and polyetheramines with a degree of polymerization of 5 to 500; preferably, the polyamine is selected from one or more of butanediamine, pentanediamine, hexanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, trimethylhexanediamine, methylpentanediamine, aniline, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, furan diamine, polyetheramine D200, polyetheramine D400, polyetheramine D1000 or polyetheramine D2000; preferably The polyamine is selected from one or more of pentanediamine, hexanediamine, decanediamine, undecanediamine, dodecanediamine, p-phenylenediamine, m-phenylenediamine, cyclohexanedimethylamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, polyetheramine D400, polyetheramine D1000, or polyetheramine D2000; more preferably, the polyamine is selected from one or more of acediamine, polyetheramine D400, polyetheramine D1000, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), or 4,4'-methylenebis(cyclohexylamine).

[0201] In one embodiment of the present invention, when the optical functional ring-opening agent of the present invention contains only aminocaprolactam and polybasic acid, the content of aminocaprolactam is 30-97 wt%, preferably 40-95 wt%, more preferably 45-90 wt%, and the content of polybasic acid is 3-70 wt%, preferably 5-65 wt%, more preferably 10-60 wt%, relative to the total mass of the ring-opening agent.

[0202] In one embodiment of the present invention, when the optically functional ring-opening agent of the present invention contains only aminocaprolactam and a polyacid, the content of aminocaprolactam is 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, or 85wt% relative to the total mass of the ring-opening agent.

[0203] In one embodiment of the present invention, when the optically functional ring-opening agent of the present invention comprises only aminocaprolactam and a polybasic acid, the content of the polybasic acid relative to the total mass of the ring-opening agent is 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 65 wt%.

[0204] In one embodiment of the present invention, when the optically functional ring-opening agent of the present invention contains only aminocaprolactam, a polyacid, and a polyamine, the content of aminocaprolactam relative to the total mass of the ring-opening agent is 0.2-80 wt%, preferably 0.4-20 wt%, more preferably 1-15 wt%, the content of the polyacid is 3-70 wt%, preferably 5-65 wt%, more preferably 10-60 wt%, and the content of the polyamine is 10-90 wt%, preferably 15-80 wt%, more preferably 20-70 wt%.

[0205] In one embodiment of the present invention, when the optically functional ring-opening agent of the present invention comprises only aminocaprolactam, polyacid, and polyamine, the content of aminocaprolactam relative to the total mass of the ring-opening agent is 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1.2wt%, 1.6wt%, 2.0wt%, 3.0wt%, 4.0wt%, 5.0wt%, 6.0wt%, 7.0wt%, 8.0wt%, 9.0wt%, 10.0wt%, 11.0wt%, 12.0wt%, 14.0wt%, 15.0wt%, 18.0wt%, 20.0wt%, 25.0wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, or 75wt%.

[0206] In one embodiment of the present invention, when the optically functional ring-opening agent of the present invention contains only aminocaprolactam, a polyacid, and a polyamine, the content of the polyacid relative to the total mass of the ring-opening agent is 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, 14.0 wt%, 14.0 wt%, 18.0 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 65 wt%.

[0207] In one embodiment of the present invention, when the optically functional ring-opening agent of the present invention contains only aminocaprolactam, a polyacid, and a polyamine, the content of the polyamine relative to the total mass of the ring-opening agent is 11.0 wt%, 12.0 wt%, 14.0 wt%, 15.0 wt%, 18.0 wt%, 20.0 wt%, 25.0 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, or 75 wt%.

[0208] A fourth aspect of the present invention provides a composition comprising the polyamide of the present invention or the polyamide obtained by the preparation method of the present invention; preferably, the composition is in the form of powder, wire, fiber, film, coating, sheet, plate, irregular material, porous material, or gel material.

[0209] The fifth aspect of the present invention provides the application of the polyamide of the present invention, and the polyamide obtained by the polyamide preparation method of the present invention, in gas barrier, optical protection, agricultural light conversion, optical display, fluorescence imaging, smart lens, optical anti-counterfeiting, optical data storage and anti-counterfeiting materials.

[0210] Example

[0211] The present invention will be described in detail below with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0212] The α-amino-ε-caprolactam (ACL, CAS No.: 671-42-1), caprolactam (CPL, CAS No.: 105-60-2), and aminocaproic acid (AS, CAS No.: 60-32-2) used in this invention are all commercially available products with a purity > 95%.

[0213] Branching degree analysis: The copolyamide was dissolved in deuterated-trifluoroacetic acid and tested using a Bruker AVANCE NEO 500MNMR analyzer. 1 1H NMR spectra, based on peak positions and integrated areas, yield the proportions of branched, linear, and terminal structural units, and calculate the degree of branching. "Degree of branching (DB)" has the meaning commonly understood in this art, referring to the proportion of branched structural units to the total structural units, and is determined by the following formula:

[0214] Branching degree (DB) = (D+T) / (D+T+L)

[0215] Where D represents the number of branched structural units, T represents the number of end structural units, and L represents the number of linear structural units.

[0216] The characteristic peaks and their integral areas are assigned as follows:

[0217] Table 1

[0218] Further analysis of the structural characteristics of the copolyamide,

[0219] Ratio A refers to the proportion of lysine-based branched structural units based on the total amount of lysine-based structural units, where ratio A = M4 / (M1 / 6 - M2 / 2) / E×%, and E is the molar proportion of lysine-based structural units in the copolyamide (calculated from the feed ratio).

[0220] The proportion B refers to the proportion of lysine-branched structural units based on the total number of structural units, where proportion B = M4 / (M1 / 6 - M2 / 2) × %.

[0221] The ratio C refers to the proportion of lysine-based branched structural units based on the total amount of lysine-based branched structural units, and the proportion of lysine-based branched structural units in "ε-polymerization", where the ratio C = M5 / M4 × .

[0222] The degree of branching of the copolyamide is calculated as (M4 + M3 / 2 - M6 / M4 × E(M1 / 6 - M2 / 2) × (1 - A)) / (M1 / 6 - M2 / 2), where the proportion of "α-polymerization" in the linear lysine structural unit is considered to be the same as the proportion of "α-polymerization" in the branched lysine structural unit.

[0223] If the influence of the linear lysine structural unit of "α-polymerization" on the content of terminal structural units is not considered, then the reference value of the degree of branching of the copolyamide is (M4+M3 / 2) / (M1 / 6-M2 / 2).

[0224] Infrared spectral characterization: Fourier transform infrared (FTIR) spectra were measured using a Bruker INVENIO FT-IR spectrophotometer in ATR mode with a resolution of 4 cm⁻¹. -1 Test range 400-4000cm -1 The sample was scanned 32 times.

[0225] Impurity Analysis: According to GB / T 38138-2019 - Test Method for Slicing Fiber-Grade Polycaprolactam (PA6), residual impurities in the copolyamide sample were removed by hot water extraction. The dry weights m1 and m2 of the copolyamide before and after extraction were weighed. The extractability of the copolyamide was calculated as (m1 - m2) / m1 × %. The extract was collected, and its composition was analyzed by liquid chromatography-mass spectrometry (LC-MS).

[0226] Melting point, crystallization temperature, and enthalpy of fusion: Measurements were performed using a Mettler DSC3 differential scanning calorimeter under a nitrogen atmosphere at a temperature control rate of 10℃ / min. The test temperature range was -20℃ to 260℃. The melting point, crystallization temperature, and enthalpy of fusion were analyzed based on the second heating and cooling cycle curves.

[0227] Thermal stability performance: Characterized using a Mettler RT-800 thermogravimetric analyzer, with a heating rate of 10℃ / min, a test temperature range of 40~600℃, and measurements were taken under a nitrogen atmosphere.

[0228] Relative viscosity: The relative viscosity of the polymerization system at 25°C was measured using an Ubbelohde viscometer method with 96% concentrated sulfuric acid as the solvent.

[0229] Molecular weight and its distribution: The sample was dissolved in hexafluoroisopropanol at a concentration of 0.1 mg / mL, filtered through a 0.45 μm filter membrane, and the molecular weight and molecular weight distribution were tested using an Agilent PL-GPC220 micrometer.

[0230] Photoluminescence properties: The sample was hot-pressed into a polymer film with a thickness of 200 μm at a temperature 30°C above the melting point, and the fluorescence intensity was analyzed on a fluorescence lifetime and steady-state spectrometer (FLS 980, Edinburgh Instruments).

[0231] Transmittance: The sample was hot-pressed into a polymer film with a thickness of 200 μm at a temperature 30°C above the melting point. The transmittance of the polymer film was tested using a PerkinElmer Lambda 950 UV-Vis spectrophotometer equipped with an integrating sphere.

[0232] Example I series

[0233] Examples I-1 to I-20 and Comparative Examples I-1 to I-9

[0234] Specific reactants containing lactams were added to a pressure-resistant reaction vessel, heated to 80°C, and the stirring speed was set to 100 r / min. The air inside the vessel was then replaced with nitrogen, and the pressure was maintained at 0.3 MPa. Copolyamides were prepared under the following polymerization conditions (polymerization temperature and reaction time).

[0235] i) Heat to 180°C and react at this temperature for 10 hours;

[0236] ii) Raise the temperature to 180°C and react at this temperature for 3 hours; then raise the temperature to 230°C and continue the reaction at this temperature for 3 hours;

[0237] iii) Increase the temperature to 230°C and react at this temperature for 6 hours;

[0238] Stop stirring, slowly release the pressure, and open the container to remove the reaction product once the pressure drops to 0 MPa.

[0239] The reactants and polymerization conditions used in Examples I-1 to I-20 and Comparative Examples I-1 to I-8 are specifically shown in Tables 2 and 3. The products obtained in Comparative Examples I-1 and I-2 are meltable at 80°C and completely soluble in water at room temperature, indicating that the products are mainly monomer mixtures, rather than the copolyamides described in this invention. When the CPL and ACL feed amounts were similar, Comparative Example I-9 exhibited explosive polymerization during the reaction, resulting in fine, granular products that could not form a continuous fluid and lacked melt processability; while the products obtained in Examples I-12 and I-8 could form films under hot-pressing conditions.

[0240] Table 2

[0241] Table 3

[0242] Examples I-21 to I-24

[0243] The difference between Examples I-21 to I-24 and Example I-16 lies in the different pressure and time during the decompression stage in Examples I-21 to I-24, as shown in Table 5. The specific method is as follows: 10g ACL, 90g CPL, and 0.92g azelaic acid are added to a pressure-resistant reaction vessel, heated to 80°C, and then the air inside the vessel is replaced with nitrogen, maintaining the pressure at 0.3MPa; the temperature is then raised to 230°C, the stirring speed is set to 100r / min, and the reaction is carried out under these conditions for 6 hours; the pressure is slowly released using a vent valve and a vacuum pump, and after the pressure of the reaction system drops to a specific value, the pressure is maintained and the reaction continues for a specific duration (polymerization during decompression stage); stirring is stopped, the pressure is slowly released, and after the pressure drops to a specific value, the pressure is maintained and the reaction continues for a specific time. After the pressure reaches 0MPa, the container is opened and the reaction product is removed.

[0244] Table 5

[0245] Test Case I-1

[0246] Infrared spectroscopy was performed on the products obtained in Examples I-1 to I-6 and Comparative Example I-4, and the results are shown in Figure 1. The infrared spectrum of the products obtained at 3300 cm⁻¹ was [not specified]. -1 The absorption peak for the stretching vibration of -NH- is at 2860 cm⁻¹. -1 The absorption peak at 2930 cm⁻¹ is the symmetric stretching vibration of -CH₂-. -1 The absorption peak at 1640 cm⁻¹ is the antisymmetric stretching vibration of -CH₂-. -1 The absorption peak at 1550 cm⁻¹ is the -C=O stretching vibration peak. -1The absorption peak at 1690–1710 cm⁻¹ corresponds to the -NH₄⁻ bending vibration, indicating that polyamide was formed in all reactions. The products obtained in Examples I-1–I-6 show absorption peaks at 1690–1710 cm⁻¹. -1 No characteristic stretching vibration peak of the carboxylic acid group -CO- was observed at 1660 cm⁻¹, indicating that the polybasic acid reaction was complete; the product showed an absorption peak at 1660 cm⁻¹. -1 The weak or absent absorption peak of the -C=O stretching vibration indicates that the lactam reaction is essentially complete; the product absorption peak is located at 3400–3500 cm⁻¹. -1 The weak or absent absorption peak of the -NH2 stretching vibration indicates that the aminocaprolactam reaction is essentially complete. Similarly, the infrared spectra of the polyamide products obtained in Examples I-17, I-19, and I-20 were tested, and the results are shown in Figure 2.

[0247] Test Case I-2

[0248] The products obtained in Examples I-1 to I-24 and Comparative Examples I-3 to I-8 were tested by DSC, and their melting point (Tm) and crystallization temperature (Tc) were analyzed. c ), cold crystallization temperature Glass transition temperature (T) g ), processing window (ΔT1=T) m -T c ), crystallization temperature range (ΔT2, i.e., the difference between the onset and termination temperatures of the crystallization peak), and enthalpy of fusion (ΔH). m The mass ratios of the first structural unit (derived from autolactam), the second structural unit (derived from aminocaprolactam), and the third structural unit (derived from dicarboxylic acid) in the polymer were calculated based on the reactant composition, and the results corresponding to x1, x2, and x3 are shown in Table 6.

[0249] Table 6

[0250] As can be seen from Examples I-1 to I-9 and Comparative Example I-3, the introduction of the third structural unit of the present invention can significantly reduce the crystallization temperature of the copolyamide by 25 to 38°C, while the melting point can be reduced by up to 12°C or even increased by 2°C. This can broaden the processing window ΔT1 of the copolyamide from 45.1°C to 71.9°C.

[0251] On the other hand, by using preferred types of dicarboxylic acids, the crystallization temperature range ΔT2 of the copolyamides in some examples can be widened from 35.1℃ to 56.1℃; the copolyamides obtained in Examples I-3 to I-6 exhibited cold crystallization or non-crystallization under the test conditions.

[0252] As can be seen from the examples and comparative examples I-4 to I-7, when using the preferred structural unit types and proportions of the present invention, especially when simultaneously introducing the second and third structural units, the resulting product has a wider processing window and crystallization temperature range, and a lower melting enthalpy (crystallinity). In summary, the embodiments of the present invention more easily achieve the control of the aggregated state structure of copolyamides, thereby obtaining optically transparent materials.

[0253] As can be seen from Examples I-12 and Comparative Examples I-8, the addition of the preferred third structural unit of the present invention significantly increases the glass transition temperature of the resulting copolyamide by 70.5°C, which is beneficial to improving the thermal stability of the amorphous copolyamide material.

[0254] Test Case I-3

[0255] The products obtained in Examples I-1 to I-24 and Comparative Examples I-3 to I-8 were hot-pressed into films with a thickness of 200 μm. Their average transmittance in the UVB (280–320 nm) and UVA (320–400 nm) bands and their transmittance at 600 nm were tested, and the results are shown in Table 7. The UV-Vis spectra of the copolyamide films obtained in Examples I-5 and I-11 are shown in Figure 7. The film obtained in Example I-5 had a transmittance of 11.6% at 300 nm and 91.3% at 600 nm. The film obtained in Example I-11 had a transmittance of 0.7% at 300 nm and 81.3% at 600 nm. A comparison between Examples I-5 and I-11 shows that, within the preferred structural unit mass ratio range of this invention, the obtained copolyamide has lower UV transmittance and higher visible light transmittance.

[0256] Table 7

[0257] Test Case I-4

[0258] The branching degree, solubility, and two-dimensional fluorescence properties of the products obtained in Examples I-1 to I-9 and Comparative Examples I-3 and I-4 were tested, and the results are shown in Table 8 and Figures 3 to 6. The solubility test method involved dispersing 0.2 g of the product in 10 ml of trifluoroethanol, stirring for 1 h, and then observing the experimental phenomena. The Stokes shift was determined by the fluorescence peak emission wavelength of the material at an excitation wavelength of 400 nm.

[0259] Table 8

[0260] Compared to Comparative Example I-4, when aminocaprolactam was not added during the preparation of polyamide, the resulting product had a linear structure and a branching degree of 0. In this invention, adding aminocaprolactam during the preparation of polyamide can impart a branched structure to the polyamide, with a branching degree of up to 0.1158. Increasing the amount of polybasic acid during preparation can impart a crosslinked structure to the polyamide, causing the polyamide to swell.

[0261] According to fluorescence data, the copolyamide of this invention has a Stokes shift > 90 nm and a fluorescence emission wavelength > 500 nm, which can convert blue-violet light into green or red light, exhibiting both blue light protection and visible light photoluminescence properties; while Comparative Example I-4 does not exhibit significant photoluminescence. As shown in Examples I-1 to I-9 and Comparative Example I-3, the introduction of the third structural unit of this invention can effectively control the fluorescence excitation and emission wavelengths of the copolyamide; compared to Comparative Example I-3, the polyamide obtained by this invention has a higher fluorescence peak emission wavelength or a larger difference between the excitation and emission wavelengths, giving it application advantages in fields such as light-conversion films and LEDs.

[0262] Test Case I-5

[0263] The relative viscosities of the copolyamides obtained in Examples I-16 and I-21 to I-24 were tested. Their relative viscosities at 25°C were 2.1, 2.4, 2.6, 3.0, and 3.2, respectively. This indicates that when further reduced pressure polymerization is carried out after polymerization, the resulting polyamide has a higher relative viscosity, which is beneficial for its application in the field of optical thin films.

[0264] Test Case I-6

[0265] The relative molecular weights and distributions of the copolyamides obtained in Examples I-7 to I-9, I-15, and I-16 were tested. Their number-average molecular weights were 42,000, 39,000, 35,000, 40,000, and 38,000, respectively, and their polydispersity indices were 1.6, 1.6, 1.9, 1.5, and 1.7, respectively. The relative molecular weights and distributions of the copolyamides obtained in Comparative Examples I-3 to I-7 were tested. Their number-average molecular weights were 35,000, 20,000, 24,000, 25,000, and 25,000, respectively, and their polydispersity indices were 1.5, 1.6, 1.8, 1.7, and 1.5, respectively.

[0266] Example II series

[0267] Examples II-1 to II-17 and Comparative Examples II-1 to II-9

[0268] Specific reactants containing lactams were added to a pressure-resistant reaction vessel, heated to 80°C, and the stirring speed was set to 50 r / min. The air inside the vessel was then replaced with nitrogen, and the pressure was maintained at 0.3 MPa. After stirring at 80°C for 0.5 h, a copolyamide was prepared using one of the following polymerization conditions (polymerization temperature and reaction time).

[0269] iv) Heat to 180℃ and react for 1 hour; then heat to 210℃ and continue reacting for 1 hour; then heat to 230℃ and react for 3 hours, slowly depressurize to 0 MPa, and continue reacting for 1 hour.

[0270] v) Heat to 180℃ and react for 1 hour; then heat to 230℃ and continue reacting for 1 hour; within 3 hours, heat to 300℃, slowly depressurize to 0 MPa, and continue reacting for 1 hour.

[0271] vi) Heat to 180℃ and react for 1 hour; then heat to 230℃ and continue reacting for 1 hour; within 3 hours, heat to 330℃, slowly depressurize to 0 MPa, and continue reacting for 1 hour.

[0272] vii) Heat to 220℃ and react for 2 hours; then heat to 270℃ and continue reacting for 2 hours, slowly depressurize to 0 MPa, and continue reacting for 2 hours;

[0273] Stop stirring, slowly release the pressure, and open the container to remove the reaction product once the pressure drops to 0 MPa.

[0274] The reactants and polymerization conditions used in Examples II-1 to II-17 and Comparative Examples II-1 to II-9 are specifically shown in Tables 9 and 10. The products obtained in Comparative Examples II-1 and II-2 can melt at 80°C and are completely soluble in water at room temperature, indicating that the obtained products are mainly a mixture of monomers, rather than the copolyamide described in this invention.

[0275] Table 9

[0276] Table 10

[0277] Test Example II-2

[0278] The products obtained in Examples II-1 to II-17 and Comparative Examples II-3 to II-9 were tested by DSC, and their melting points (T) were analyzed. m ), crystallization temperature (T) c ), cold crystallization temperature Glass transition temperature (T) g ), processing window (ΔT1=T) m -T c), crystallization temperature range (ΔT2, i.e., the difference between the onset and termination temperatures of the crystallization peak), and enthalpy of fusion (ΔH). m The mass ratios of the second structural unit (derived from aminocaprolactam), the first structural unit (derived from autolactam), the third structural unit (derived from dicarboxylic acid), and the fourth structural unit (derived from diamine) in the polymer were calculated based on the reactant composition, corresponding to x1, x2, x3, and x4 respectively. The results are shown in Table 11.

[0279] Table 11

[0280] As can be seen from Examples II-1 to II-17 and Comparative Examples II-1 to II-9, by using the types and proportions of structural units of the present invention, the resulting products have a wider processing window and crystallization temperature range, a lower melting enthalpy (crystallinity), and are easier to control in the aggregated state structure of the copolyamide. As can be seen from Examples II-1 to II-16 and Examples II-10, II-16, and II-17, by introducing the third and fourth structural units, the melting point of the copolyamide can be increased to 300°C, or the glass transition temperature can be increased to 100°C, which is beneficial for improving the thermal stability of amorphous copolyamide materials.

[0281] Test Case II-3

[0282] The products obtained in Examples II-1 to II-17 and Comparative Examples II-3 to II-9 were hot-pressed into thin films with a thickness of 200 μm. The average transmittance in the UVB (280–320 nm) and UVA (320–400 nm) bands and the transmittance at 600 nm were tested. The results are shown in Table 12.

[0283] Table 12

[0284] As can be seen from the comparison of the above examples and comparative examples, the copolyamide obtained by the present invention has low ultraviolet transmittance and higher visible light transmittance.

[0285] Test Case II-4

[0286] The solubility of the products obtained in Examples II-1 to II-17 and Comparative Examples II-3 to II-9 was tested. The results showed that, except for Examples II-9 and II-10 which showed swelling, the other products were fully soluble. The solubility test method was to disperse 0.2 g of the product in 10 ml of trifluoroethanol, stir for 1 h, and then observe the experimental phenomena.

[0287] Test Case II-5

[0288] The two-dimensional fluorescence spectra of the products obtained in Examples II-1 to II-17 were tested. The fluorescence peak excitation wavelength was between 420 and 480 nm, the fluorescence peak emission wavelength was between 480 and 610 nm, and the Stokes shift at 400 nm was between 80 and 120 nm.

[0289] Test Case II-6

[0290] The degree of branching of the products obtained in Examples II-1 to II-17 and Comparative Examples II-3 to II-9 was tested. The results showed that, except for Comparative Example II-4 which lacked a branched structure, the degree of branching of the other products ranged from 0.001 to 0.3. As can be seen from Comparative Examples II-4 and II-6, the embodiments of the present invention, by adding aminocaprolactam to participate in the copolymerization, endow the copolyamide with a branched structure, which can reduce the crystallization temperature and crystallinity of the polyamide, broaden its processing temperature window, and improve the transparency of the product. A photograph of the polyamide obtained in Example II-12 is shown in Figure 8, demonstrating its good visible light transparency.

[0291] Compared to Comparative Example II-3, this invention lowers the crystallization temperature of the copolyamide by adding polybasic acids and polyamines to participate in copolymerization, which is beneficial for broadening the processing temperature window of the copolyamide.

[0292] Test Case II-7

[0293] The molecular weights and distributions of the products obtained in Test Examples II-1 to II-3 were 24,000, 27,000, and 29,000 respectively, with polydispersity indices of 1.6, 1.9, and 2.0 respectively. The molecular weights and distributions of the products obtained in Test Examples II-11 to II-13 were 25,000, 33,000, and 30,000 respectively, with polydispersity indices of 1.7, 1.6, and 2.0 respectively. The molecular weights and distributions of the products obtained in Comparative Examples II-3 to II-6 were 21,000, 16,000, 24,000, and 23,000 respectively, with polydispersity indices of 1.8, 1.8, 1.5, and 1.5 respectively. The comparison shows that, under similar reaction conditions, using the preferred structural units and proportions of the present invention is beneficial for obtaining polyamides with higher molecular weights and narrower molecular weight distributions.

[0294] Test Case II-8

[0295] The products obtained from Comparative Examples II-3 to II-6 were subjected to hot water extraction and drying. The mass percentage of hot water extractables (extractability) was tested, and the mass percentage of the extractable composition was analyzed. The results are shown in Table 13. The extractables mainly included caprolactam and caprolactam cyclic oligomers with a degree of polymerization of 2 to 5.

[0296] Table 13

[0297] As shown in Table 13, the method of the present invention can yield polyamides with a hot water extractability as low as 6.64%. No residual ACL, polyamines, or polyacids were detected in the extracts of Comparative Examples II-5 and II-6, indicating that all four types of reactants of the present invention can participate well in copolymerization.

[0298] Compared to Comparative Example II-3, this invention, by adding polyamines and polyacids to participate in copolymerization, significantly reduces the hot water extractability of the resulting copolyamide, thereby improving the monomer utilization rate of the polymerization. Further thermogravimetric analysis of the above products, as shown in Figure 9, reveals that Comparative Example II-6, obtained using the optically functional ring-opening agent system of this invention, has a lower content of residual monomers or oligomers.

[0299] Test Case II-9

[0300] The relative viscosities of the copolyamides obtained in Examples II-1 to II-6 and Examples II-14 to II-17 were tested, and their relative viscosities at 25°C were 2.0, 2.1, 2.0, 2.2, 2.4, 2.1, 3.4, 3.6, 2.1, and 2.5, respectively.

[0301] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0302] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0303] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A polyamide optical material, characterized by meets at least one of the following conditions, 1) the polyamide has a fluorescence emission wavelength of greater than 450 nm, preferably greater than 500 nm; 2) the polyamide has a Stokes shift of greater than 60 nm, preferably greater than 90 nm, at an excitation wavelength of 400 nm; 3) the polyamide has a UVB transmittance of less than 30%, preferably less than 20%; and the polyamide has a transmittance of greater than 75%, preferably greater than 90%, at a wavelength of 600 nm; and the first structural unit has a structure represented by formula (I), the second structural unit has at least one structure represented by formula (II) to formula (IV), and the third structural unit has a structure represented by formula (V); The polyamide is a copolymer of a lactam and an optically functional ring-opening agent, which includes a first constitutional unit derived from the lactam, and a second constitutional unit and a third constitutional unit derived from the optically functional ring-opening agent, the content of the first structural unit is 20 to 98 wt%, preferably 30 to 95 wt%, and further preferably 50 to 90 wt%, relative to the total amount of the mass of each structural unit; the content of the third structural unit is 3 to 70 wt%, preferably 5 to 65 wt%, and further preferably 10 to 60 wt%, relative to the total amount of the structural units derived from the optically functional ring-opening agent; wherein * represents a bonding position between structural units, meets at least one of the following conditions: R1is substituted or unsubstituted C 1～20 alkylene (preferably substituted or unsubstituted C 2～18 alkylene (preferably substituted or unsubstituted C 3～10 alkylene (preferably substituted or unsubstituted C R2is selected from substituted or unsubstituted C 1～40 alkylene (preferably substituted or unsubstituted C 2～24 alkylene, more preferably substituted or unsubstituted C 3～15 alkylene), substituted or unsubstituted C 3～40 cycloalkylene (preferably substituted or unsubstituted C 3～15 cycloalkylene, more preferably substituted or unsubstituted C 5～10 cycloalkylene), substituted or unsubstituted C 6～40 arylene (preferably substituted or unsubstituted C 6～24 arylene, more preferably substituted or unsubstituted C 6～10 arylene), substituted or unsubstituted C 5～20 heteroarylene (preferably substituted or unsubstituted C 5～18 heteroarylene, more preferably substituted or substituted C 5～10 heteroarylene); R1, R2are each independently selected from one or more of H, C 1～10 alkyl (preferably C 1～5 alkyl, preferably C 1～4 alkyl), C 1～20 alkoxy (preferably C 1～5 alkoxy, C 1～4 alkoxy), C 2～20 ester (preferably C 2～6 ester), urea, C 1～24 amide (preferably C 1～6 amide, preferably C 1～4 amide), hydroxyl, carboxyl, C 1～20 carbonyl (preferably C 1～8 carbonyl, preferably C 1～4 carbonyl), C 2～20 ether (preferably C 2～6 ether, preferably C 2～4 ether), and C 1～20 aldehyde (preferably C 1～8 aldehyde, preferably C 1～4 aldehyde).

2. The polyamide optical material according to claim 1, characterized by, the number average molecular weight of the polyamide is 0.5 to 60,000, preferably 2.0 to 50,000, and more preferably 2.5 to 45,000; the polydispersity index of the molecular weight of the polyamide is 1.2 to 2.5, preferably 1.4 to 2.0, and more preferably 1.5 to 2.0; the relative viscosity of the polyamide at 25°C is 1.2 to 4.5, preferably 1.8 to 4.0, and more preferably 2.0 to 3.8; the branching degree of the polyamide is 0.001 to 0.4, preferably 0.002 to 0.3, and more preferably 0.005 to 0.12; the processing window of the polyamide is > 30°C, preferably > 33°C, and more preferably > 35°C; the secondary melting enthalpy of the polyamide is < 50 J-g -1 , preferably < 40 J-g -1 , more preferably < 35 J-g -1 ; the crystallization temperature range of the polyamide is > 25°C, preferably > 28°C, and more preferably > 30°C; when the structural units derived from the optically functional ring-opening agent only include the second structural unit and the third structural unit, the content of the second structural unit is 3 to 50 wt%, preferably 5 to 40 wt%, and further preferably 7 to 30 wt%, and the content of the third structural unit is 0.5 to 20 wt%, preferably 1 to 18 wt%, and further preferably 1.5 to 15 wt%, relative to the total amount of the mass of each structural unit. The polyamide is an amorphous polymer or has a secondary melting enthalpy < 20 J.g -1 a glass transition temperature > 40 °C, preferably > 50 °C, more preferably > 60 °C; R1 is selected from one or more of substituted or unsubstituted ethylene, substituted or unsubstituted propylene, substituted or unsubstituted butylene, substituted or unsubstituted pentylene, substituted or unsubstituted hexylene, substituted or unsubstituted nonylene, substituted or unsubstituted decylene, and substituted or unsubstituted undecylene; 3. The polyamide according to claim 1 or 2, characterized in that, the mass ratio of the fourth structural unit to the third structural unit is 0.1 to 20:1, preferably 0.5 to 15:1, and further preferably 0.8 to 12:1, R1is selected from one or more of a C 1～5 alkyl group, C 2～5 alkoxy group, C 2～6 ester group, hydroxyl group, carboxyl group, C 2～8 carbonyl group, C 2～6 ether group, C 5～13 amide group, and aldehyde group, preferably one or more of a methyl group, ethyl group, propyl group, and butyl group.

4. The polyamide according to any one of claims 1 to 3, characterized in that, R2is selected from one or more of substituted or unsubstituted C 2～24 alkylene, substituted or unsubstituted C 3～15 cycloalkylene, substituted or unsubstituted C 6～24 arylene, substituted or unsubstituted C 5～18 heteroarylene, preferably R2is selected from one or more of substituted or unsubstituted ethylene, substituted or unsubstituted propylene, substituted or unsubstituted butylene, substituted or unsubstituted pentylene, substituted or unsubstituted hexylene, substituted or unsubstituted nonylene, substituted or unsubstituted decylene, substituted or unsubstituted undecylene, substituted or unsubstituted dodecylene, substituted or unsubstituted cyclopentylene, substituted or unsubstituted cyclohexylene, substituted or unsubstituted phenylene, substituted or unsubstituted furanylene; substituents of R2are selected from one or more of C 1～5 alkyl, C 2～5 alkoxy, C 2～6 ester, urea, C 1～12 amide, C 2～8 carbonyl, C 2～6 ether, hydroxyl, carboxyl and C 1～8 aldehyde; preferably, the substituents of R2are selected from one or more of methyl, ethyl, propyl, butyl, carboxyl, hydroxyl and aldehyde.

5. The polyamide of claim 1, wherein, The polyamide further comprises a fourth structural unit derived from an optically functional ring-opening agent, the fourth structural unit having a structure represented by Formula (VI), wherein * represents a bonding position between structural units, 6. The polyamide according to claim 5, characterized in that R3is selected from one or more of substituted or unsubstituted C 1～40 alkylene (preferably substituted or unsubstituted C 2～24 alkylene, more preferably substituted or unsubstituted C 3～15 alkylene), substituted or unsubstituted C 3～40 cycloalkylene (preferably substituted or unsubstituted C 3～15 cycloalkylene, more preferably substituted or unsubstituted C 5～10 cycloalkylene), substituted or unsubstituted (C 3～15 cycloalkylene-C 1～10 alkylene-C 3～15 cycloalkylene) (preferably substituted or unsubstituted (C 5～10 cycloalkylene-C 1～6 alkylene-C 5～10 cycloalkylene)), substituted or unsubstituted C 6～40 arylene (preferably substituted or unsubstituted C 6～24 arylene, more preferably substituted or unsubstituted C 6～10 arylene), substituted or unsubstituted C 5～20 heteroarylene (preferably substituted or unsubstituted C 5～18 heteroarylene, more preferably substituted or substituted C 5～10 heteroarylene), polyether chain having a degree of polymerization of 3 to 500; The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group. meets at least one of the following conditions: R3 is selected from substituted or unsubstituted C 2～24 alkylene, substituted or unsubstituted C 3～15 cycloalkylene, substituted or unsubstituted (C 5～10 cycloalkylene-C 1～4 alkylene-C 5～10 cycloalkylene), substituted or unsubstituted C 6～24 arylene, substituted or unsubstituted C 5～18 heteroarylene, one or more of a polyether chain having a degree of polymerization of 5 to 500, preferably R3 is selected from substituted or unsubstituted ethylene, substituted or unsubstituted propylene, substituted or unsubstituted butylene, substituted or unsubstituted pentylene, substituted or unsubstituted hexylene, substituted or unsubstituted nonylene, substituted or unsubstituted decylene, substituted or unsubstituted undecylene, substituted or unsubstituted dodecylene, substituted or unsubstituted cyclopentylene, substituted or unsubstituted cyclohexylene, substituted or unsubstituted phenylene, substituted or unsubstituted furanylene, one or more of a polyether chain having a degree of polymerization of 5 to 50; substituents of R3are selected from one or more of alkyl, C 1～5 alkyl, C 2～5 alkoxy, C 2～6 ester, urea, C 1～12 amide, C 1～8 carbonyl, C 2～6 ether, hydroxyl, carboxyl, and C 1～8 aldehyde; preferably, the substituents of R3are selected from one or more of methyl, ethyl, propyl, butyl, carboxyl, hydroxyl, and aldehyde.

7. The polyamide according to claim 5 or 6, characterized in that, ​ The content of the first structural unit in the polyamide is 20-95 wt%, preferably 30-90 wt%, and further preferably 50-85 wt%, relative to the total amount of mass of each structural unit; The content of the fourth structural unit in the polyamide is 10-90 wt%, preferably 15-80 wt%, and further preferably 20-70 wt%, relative to the total amount of structural units derived from the optically functional ring-opening agent; The number average molecular weight of the polyamide is 15-60 thousand, preferably 20-50 thousand, and more preferably 25-45 thousand; The polyamide has a molecular weight distribution polydispersity coefficient of 1.2-2.5, preferably 1.4-2.0, and more preferably 1.5-2.0; The relative viscosity of the polyamide at 25°C is 1.8-4.5, preferably 1.9-4.0, and more preferably 2.0-3.8; The branching degree of the polyamide is 0.001-0.4, preferably 0.002-0.3, and more preferably 0.005-0.12; the secondary melting enthalpy of the polyamide is < 45 J.g -1 , preferably < 42 J.g -1 , more preferably < 40 J.g -1 ; The processing window of the polyamide is >30°C, preferably >35°C, and more preferably >40°C; The crystallization temperature interval of the polyamide is >25°C, preferably >26°C, and more preferably >28°C; the polyamide is an amorphous polymer or has a secondary melting enthalpy < 20 J g -1 when the polyamide has a glass transition temperature > 40 °C, preferably > 45 °C, more preferably > 50 °C, more preferably > 60 °C; When the structural units derived from the optically functional ring-opening agent only include the second structural unit, the third structural unit, and the fourth structural unit, the content of the second structural unit is 0.05-30 wt%, preferably 0.1-10 wt%, and further preferably 0.2-2 wt%, relative to the total amount of mass of each structural unit; the content of the third structural unit is 0.5-40 wt%, preferably 1-30 wt%, and further preferably 2-15 wt%; and the content of the fourth structural unit is 1.0-40 wt%, preferably 2.0-30 wt%, and further preferably 3.0-25 wt%.

8. An optically functional ring-opening agent characterized by, A compound comprising an aminocaproamide and a polyacid, and optionally a polyamine, the aminocaproamide being a compound of the following formula (2), The polybasic acid is a polybasic acid represented by the following formula (3), The polyamine is a polyamine represented by the following formula (4), R2is selected from substituted or unsubstituted C 1～40 alkylene (preferably substituted or unsubstituted C 2～24 alkylene, more preferably substituted or unsubstituted C 3～15 alkylene), substituted or unsubstituted C 3～40 cycloalkylene (preferably substituted or unsubstituted C 3～15 cycloalkylene, more preferably substituted or unsubstituted C 5～10 cycloalkylene), substituted or unsubstituted C 6～40 arylene (preferably substituted or unsubstituted C 6～24 arylene, more preferably substituted or unsubstituted C 6～10 arylene), substituted or unsubstituted C 5～20 heteroarylene (preferably substituted or unsubstituted C 5～18 heteroarylene, more preferably substituted or substituted C 5～10 heteroarylene); The substituents of R2 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group, R3is selected from one or more of substituted or unsubstituted C 1～40 alkylene (preferably substituted or unsubstituted C 2～24 alkylene, more preferably substituted or unsubstituted C 3～15 alkylene), substituted or unsubstituted C 3～40 cycloalkylene (preferably substituted or unsubstituted C 3～15 cycloalkylene, more preferably substituted or unsubstituted C 5～10 cycloalkylene), substituted or unsubstituted (C 3～15 cycloalkylene-C 1～10 alkylene-C 3～15 cycloalkylene) (preferably substituted or unsubstituted (C 5～10 cycloalkylene-C 1～6 alkylene-C 5～10 cycloalkylene)), substituted or unsubstituted C 6～40 arylene (preferably substituted or unsubstituted C 6～24 arylene, more preferably substituted or unsubstituted C 6～10 arylene), substituted or unsubstituted C 5～20 heteroarylene (preferably substituted or unsubstituted C 5～18 heteroarylene, more preferably substituted or substituted C 5～10 heteroarylene), polyether chain having a degree of polymerization of 3 to 500; The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group; Preferably, the polyacid is selected from C 4～40 aliphatic polyacids, C 4～40 Alicyclic polyacids, C 6～40 Aromatic polyacids and C 5～40 The polyacid is selected from one or more of the following furan acids: succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, heptadecanoic acid, octadecanoic acid, docosanoic acid, terephthalic acid, isophthalic acid, trimesic acid, biphenyl dicarboxylic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, cyclohexanedicarboxylic acid, and furan dicarboxylic acid; preferably, the polyacid is selected from one or more of the following: glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, benzoic acid, terephthalic acid, trimesic acid, and cyclohexanedicarboxylic acid; more preferably, the polyacid is selected from one or more of the following: succinic acid, azelaic acid, dodecanoic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and trimesic acid. Preferably, the polyamine is selected from C 2～40 aliphatic amines, C 2～40 Alicyclic amines, C 2～40 Aromatic amines, C 5～40 The polyamine is selected from one or more of furan amines and polyetheramines with a degree of polymerization of 5 to 500; preferably, the polyamine is selected from one or more of butanediamine, pentanediamine, hexanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, trimethylhexanediamine, methylpentanediamine, aniline, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, furan diamine, polyetheramine D200, polyetheramine D400, polyetheramine D1000 or polyetheramine D2000; preferably The polyamine is selected from one or more of pentanediamine, hexanediamine, decanediamine, undecanediamine, dodecanediamine, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, polyetheramine D400, polyetheramine D1000, or polyetheramine D2000; more preferably, the polyamine is selected from one or more of acediamine, polyetheramine D400, polyetheramine D1000, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), or 4,4'-methylenebis(cyclohexylamine); provided that, when the optically functional ring-opening agent only includes the amino caprolactam and the polybasic acid, the content of the amino caprolactam is 30-97 wt%, preferably 40-95 wt%, and further preferably 45-90 wt%, and the content of the polybasic acid is 3-70 wt%, preferably 5-65 wt%, and further preferably 10-60 wt%, relative to the total amount of mass of the ring-opening agent; when the optically functional ring-opening agent only includes the amino caprolactam, the polybasic acid, and the polyamine, the content of the amino caprolactam is 0.2-80 wt%, preferably 0.4-20 wt%, and further preferably 1-15 wt%, the content of the polybasic acid is 3-70 wt%, preferably 5-65 wt%, and further preferably 10-60 wt%, and the content of the polyamine is 10-90 wt%, preferably 15-80 wt%, and further preferably 20-70 wt%, relative to the total amount of mass of the ring-opening agent.

9. A method for producing a polyamide optical material, characterized by, The method comprises the following steps: polymerizing a reaction system comprising a lactam compound represented by the following formula (1) and an optically functional ring-opening agent comprising an amino caprolactam represented by formula (2) and a polybasic acid represented by formula (3) under an inert atmosphere, The content of the lactam compound is 20-98wt%, preferably 30-95wt%, and further preferably 50-90wt%, relative to the total amount of reaction raw materials in the reaction system; The content of the polybasic acid is 3-70 wt%, preferably 5-65 wt%, further preferably 10-60 wt%, relative to the total amount of the optically functional ring-opening agent; wherein R1is a substituted or unsubstituted C 1～20 alkylene (preferably substituted or unsubstituted C 2～18 alkylene (preferably substituted or unsubstituted C 3～10 alkylene (preferably substituted or unsubstituted C R2is selected from substituted or unsubstituted C 1～40 alkylene (preferably substituted or unsubstituted C 2～24 alkylene, more preferably substituted or unsubstituted C 3～15 alkylene), substituted or unsubstituted C 3～40 cycloalkylene (preferably substituted or unsubstituted C 3～15 cycloalkylene, more preferably substituted or unsubstituted C 5～10 cycloalkylene), substituted or unsubstituted C 6～40 arylene (preferably substituted or unsubstituted C 6～24 arylene, more preferably substituted or unsubstituted C 6～10 arylene), substituted or unsubstituted C 5～20 heteroarylene (preferably substituted or unsubstituted C 5～18 heteroarylene, more preferably substituted or substituted C 5～10 heteroarylene); The substituents of R1 and R2 are each independently selected from C1. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

10. The method of producing a polyamide according to claim 9, characterized in that, The method comprises the following steps: The optically functional ring-opening agent further comprises a polyamine of formula (4), The content of the lactam compound is 20-95wt%, preferably 30-90wt%, and further preferably 50-85wt%, relative to the total amount of reaction raw materials in the reaction system; The content of the polyamine is 10-90 wt%, preferably 15-80 wt%, further preferably 20-70 wt%, relative to the total amount of the optically functional ring-opening agent; wherein R3is selected from one or more of substituted or unsubstituted C 1～40 alkylene (preferably substituted or unsubstituted C 2～24 alkylene, more preferably substituted or unsubstituted C 3～15 alkylene), substituted or unsubstituted C 3～40 cycloalkylene (preferably substituted or unsubstituted C 3～15 cycloalkylene, more preferably substituted or unsubstituted C 5～10 cycloalkylene), substituted or unsubstituted (C 3～15 cycloalkylene-C 1～10 alkylene-C 3～15 cycloalkylene) (preferably substituted or unsubstituted (C 5～10 cycloalkylene-C 1～6 alkylene-C 5～10 cycloalkylene)), substituted or unsubstituted C 6～40 arylene (preferably substituted or unsubstituted C 6～24 arylene, more preferably substituted or unsubstituted C 6～10 arylene), substituted or unsubstituted C 5～20 heteroarylene (preferably substituted or unsubstituted C 5～18 heteroarylene, more preferably substituted or substituted C 5～10 heteroarylene), polyether chain having a degree of polymerization of 3 to 500; The substituents of R3 are each independently selected from C. 1～10 Alkyl (preferably C) 1～5 Alkyl, preferably C 1～4 Alkyl), C 1～20 Alkoxy (preferably C) 1～5 Alkoxy, C 1～4 alkoxy), C 2～20 Ester group (preferably C) 2～6 ester group), urea group, C 1～24 Amide group (preferably C) 1～6 Amide group, preferably C 1～4 amide group, hydroxyl group, carboxyl group, C 1～20 carbonyl group (preferably C) 1～8 carbonyl group, preferably C 1～4 carbonyl), C 2～20 Ether group (preferably C) 2～6 Ether group, preferably C 2～4 ether group) and C 1～20 Aldehyde group (preferably C) 1～8 Aldehyde group, preferably C 1～4 One or more of the following groups: aldehyde group.

11. The production method according to claim 9 or 10, characterized by, At least one of the following conditions is met: No anion initiator is added in the reaction system; No water is added in the reaction system; When the optically functional ring-opening agent only comprises aminocaproic lactam and a polybasic acid, the content of aminocaproic lactam is 30-97wt%, preferably 40-95wt%, and further preferably 45-90wt%, and the content of the polybasic acid is 3-70wt%, preferably 5-65wt%, and further preferably 10-60wt%, relative to the total mass of the ring-opening agent; When the optically functional ring-opening agent only comprises aminocaproic lactam, a polybasic acid and a polyamine, the content of aminocaproic lactam is 0.2-80wt%, preferably 0.4-20wt%, and further preferably 1-15wt%, the content of the polybasic acid is 3-70wt%, preferably 5-65wt%, and further preferably 10-60wt%, and the content of the polyamine is 10-90wt%, preferably 15-80wt%, and further preferably 20-70wt%, relative to the total mass of the ring-opening agent.

12. The method of manufacturing according to claims 9-11, characterized in that, The mass ratio of the polyamine to the polybasic acid is 0.1-20:1, preferably 0.5-15:1, and further preferably 0.8-12:

1.

13. The production method according to any one of claims 9 to 12, characterized by, The conditions of the polymerization reaction comprise: being carried out under stirring, the polymerization temperature is 100-360℃, preferably 170-350℃; the time is 3-16h, preferably 4-12h; the pressure is 0-2.0MPa, preferably 0.2-1.2MPa; and the stirring rate is 20-400r / min, preferably 50-150r / min.

14. The production method according to any one of claims 9 to 13, characterized by, The method comprises the following steps: The lactam compound, the polybasic acid, the aminocaproic lactam and the optional polyamine are mixed under an inert atmosphere, and then pre-reacted, and then the polymerization reaction is carried out after being heated; The conditions of the pre-reaction comprise: being carried out under stirring, the pre-reaction temperature is 80-160℃, preferably 80-120℃; the pre-reaction time is 0.1-4h, preferably 0.5-2h; and the stirring rate is 20-400r / min, preferably 50-200r / min.

15. The preparation method according to claim 14, characterized in that, The method comprises the following steps: After the polymerization reaction, the reaction system is depressurized to a second pressure, and then the reaction is continued; the second pressure is 0.3 to -0.1MPa, preferably 0 to -0.09MPa, and the reaction time is 0.1-16h, preferably 2-12h.

16. The method of any one of claims 9-15, wherein, At least one of the following conditions is met: The lactam compound is a 5-15 membered cyclic lactam, preferably, the lactam compound is selected from one or more of butyrolactam, caprolactam, undecanolactam, dodecanolactam and tridecanolactam, preferably caprolactam; said polyacid is selected from one or more of aliphatic polyacids of formula C 4～40 cycloaliphatic polyacids of formula C 4～40 aromatic polyacids of formula C 6～40 and furanic acids of formula C 5～40 ; preferably, said polyacid is selected from one or more of succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, heptadecanedioic acid, octadecanedioic acid, docosanedioic acid, terephthalic acid, isophthalic acid, trimesic acid, diphenyldicarboxylic acid, naphthalene dicarboxylic acid, diphenyl ether diacid, cyclohexanedicarboxylic acid and furandicarboxylic acid; preferably, said polyacid is selected from one or more of glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, benzoic acid, terephthalic acid, trimesic acid and cyclohexanedicarboxylic acid; more preferably, said polyacid is selected from one or more of adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, trimesic acid; The polyamine is selected from C 2～40 aliphatic amines, C 2～40 Alicyclic amines, C 2～40 Aromatic amines, C 5～40 The polyamine is selected from one or more of furan amines and polyetheramines with a degree of polymerization of 5 to 500; preferably, the polyamine is selected from one or more of butanediamine, pentanediamine, hexanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, trimethylhexanediamine, methylpentanediamine, aniline, p-phenylenediamine, m-phenylenediamine, cyclohexanediamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, furan diamine, polyetheramine D200, polyetheramine D400, polyetheramine D1000 or polyetheramine D2000; preferably The polyamine is selected from one or more of pentanediamine, hexanediamine, decanediamine, undecanediamine, dodecanediamine, p-phenylenediamine, m-phenylenediamine, cyclohexanedimethylamine, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodicyclohexylpropane, polyetheramine D400, polyetheramine D1000, or polyetheramine D2000; more preferably, the polyamine is selected from one or more of acediamine, polyetheramine D400, polyetheramine D1000, polyetheramine D2000, 4,4'-methylenebis(2-methylcyclohexylamine), or 4,4'-methylenebis(cyclohexylamine).

17. A composition comprising the polyamide of any one of claims 1-8; preferably, the composition is in the form of a powder, a wire, a fiber, a film, a coating, a sheet, a plate, a profile, a porous material, a gel material.

18. Use of the polyamide of any one of claims 1-8 and the polyamide obtained by the process of any one of claims 9-17 in gas barrier, optical protection, agricultural light conversion, optical display, fluorescence imaging, smart lenses, optical anti-counterfeiting, optical data storage and anti-counterfeiting materials.

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