Diamine compound and polyimide film

Abstract

The present invention provides a diamine compound and a polyimide film made from the diamine compound. The present invention uses a diamine compound represented by formula (1) to polymerize with an aromatic dianhydride compound to prepare a polyimide and a film. The obtained polyimide film has good high-temperature resistance and good transparency, and is a high-performance polyimide film material.

Description

Technical Field

[0001] The present invention relates to the field of polymers, in particular to a diamine compound and a polyimide film made from the diamine compound. Background Art

[0002] Polyimide (PI) is a class of polymer materials containing imide rings in its molecular chain. Flexible organic light-emitting display (OLED) technology has developed rapidly in recent years. Due to its advantages such as fast response, low power consumption, wearable and foldable features, it is one of the most competitive new display technologies of the future.

[0003] The development of flexible substrates is a key link in realizing flexible OLED displays. Polyimide has become the most promising application material in the field of flexible substrates due to its excellent comprehensive performance.

[0004] Currently, common fully aromatic polyimides exhibit a darker color in the visible light region due to the generation of charge transfer complexes (CTCs) between and within their molecules, affecting their optical properties. The heat resistance and optical properties of polyimides are closely related to their molecular structure, and these two properties are mutually exclusive. Therefore, a balanced balance between high-temperature resistance and transparency is required through rational molecular design. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present application provides a diamine compound for synthesizing a polyimide film. The obtained polyimide film has good high temperature resistance and good transparency.

[0006] In one aspect, the present invention provides a diamine compound represented by formula (1):

[0007]

[0008] Wherein n is selected from 0 or 1.

[0009] In a preferred embodiment, the diamine compound is selected from:

[0010]

[0011] The present application also provides an intermediate for synthesizing the compound represented by formula (1), which has the structure represented by formula (1-1):

[0012]

[0013] In a preferred embodiment, the intermediate is selected from:

[0014]

[0015] The second aspect of the present invention provides a polyimide film prepared from an aromatic dianhydride compound and an aromatic diamine compound; the aromatic diamine compound includes the compound represented by the above formula (1).

[0016] Preferably, the aromatic dianhydride compound is selected from the compounds represented by formula (2) or formula (3):

[0017]

[0018] Wherein ring A and ring B are independently selected from substituted or unsubstituted: benzene ring, naphthalene ring, anthracene ring, phenanthrene ring; in formula (3), ring A and ring B are connected by a single bond.

[0019] In one embodiment, the substituted or unsubstituted group refers to being unsubstituted, or being mono- or poly-substituted by a group selected from a C1-C12 alkyl group, a C1-C12 alkoxy group, a C6-C20 aromatic hydrocarbon group, a halogen, or CN.

[0020] Preferably, the C1-C12 alkyl group is selected from C1-C6 alkyl groups, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, and hexyl.

[0021] Preferably, the C1-C12 alkoxy group is selected from C1-C6 alkoxy groups, preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentyloxy, and hexyloxy.

[0022] Preferably, the C6-C20 aromatic hydrocarbon group is selected from phenyl, naphthyl, and biphenyl.

[0023] Preferably, the halogen is selected from fluorine, chlorine, bromine, and iodine, preferably fluorine or chlorine.

[0024] Furthermore, the compound represented by formula (2) or formula (3) is selected from the following structures:

[0025]

[0026]

[0027] Preferably, the dianhydride compound is selected from

[0028] The present invention also provides a method for preparing the polyimide film, comprising the following steps:

[0029] (1) reacting a diamine compound represented by formula (1) and an aromatic dianhydride compound in an organic solvent to obtain a polyamic acid solution;

[0030] (2) Casting the obtained polyamic acid solution into a film, and then drying, imidizing and curing in sequence to obtain a polyimide film.

[0031] Preferably, the aromatic dianhydride compound is selected from the compound represented by formula (2) or formula (3).

[0032] Preferably, the organic solvent is selected from: ethyl acetate, DMF, DME, DMSO, HMPA or a mixture of two thereof.

[0033] Preferably, the molar ratio of the diamine compound represented by formula (1) to the diamine compound represented by formula (2) or formula (3) is 0.8:1 to 1:0.8, preferably 1:1.

[0034] Preferably, the diamine compound represented by formula (1) and the compound represented by formula (2) or formula (3) are reacted in an organic solvent at a temperature of -20 to 80°C for 3 to 48 hours. More preferably, the reaction temperature is 20 to 50°C for 6 to 18 hours.

[0035] Preferably, the drying comprises drying at 150-200° C. for 1-12 hours.

[0036] Preferably, the imidization is carried out at 260-320° C. for 0.5-5 h.

[0037] Preferably, the curing refers to curing at 340-400° C. for 0.5-3 h.

[0038] Beneficial effects:

[0039] The present invention provides a diamine compound and a polyimide film made from the same. The present invention uses a novel diamine compound to polymerize with an aromatic dianhydride compound to produce a polyimide and prepare the film. The resulting polyimide film has good high-temperature resistance and transparency, and is a high-performance polyimide film material. DETAILED DESCRIPTION

[0040] The following describes a preferred embodiment of the invention in detail. The examples are provided to better illustrate the invention and are not intended to limit the invention to the examples. Non-essential improvements and adjustments to the embodiments based on the invention remain within the scope of the invention.

[0041] The experimental methods in the following examples are all conventional methods unless otherwise specified. If no specific techniques or conditions are specified in the examples, they were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0042] Synthesis Example 1

[0043] When n=0, the synthesis method of the compound represented by formula (1) is:

[0044]

[0045] (1) Synthesis of 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene

[0046] In a 1000 ml three-necked flask, 23 g of 9,9,10,10-tetramethyl-9,10-dihydrophenanthrene, 200 ml of dichloromethane, and 100 ml of glacial acetic acid were added. Under stirring, 26 g of 60% nitric acid aqueous solution was slowly added dropwise at 20 ° C. After the addition, the reaction was carried out at 25 ° C-30 ° C for 4 hours. Water was added to separate the organic layer, and the organic layer was washed with water, concentrated to dryness under reduced pressure in a 50 ° C water bath, and crystallized 3 times with ethanol to obtain 11.3 g of 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene.

[0047] The mass spectrum of the obtained 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene was measured, and the m / z was 326.13.

[0048] The NMR of 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene was measured and the data are as follows:

[0049] (Bruker, Switzerland, AvanceⅡ400MHz NMR spectrometer, CDCl3), δ: 8.39 (d, 2H), 8.13 (m, 2H), 7.90 (d, 2H), 1.31 (s, 12H).

[0050] (2) Synthesis of 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene

[0051] To a 500 ml autoclave were added 5 g of 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene, prepared according to the previous method, 100 ml of anhydrous ethanol, and 0.5 g of 5% Pd / C. The atmosphere was purged with nitrogen and then replaced with hydrogen. The reaction was then hydrogenated at 0.2 MPa and 60°C for 6 hours. The temperature was lowered, the Pd / C was filtered off, and the mother liquor was concentrated to dryness, followed by recrystallization from methanol to yield 2.9 g of 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene.

[0052] The mass spectrum of the obtained 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene was measured, and the m / z was 266.18.

[0053] Synthesis Example 2

[0054] When n=1, the synthesis method of the compound represented by formula (1) is:

[0055]

[0056] (1) Synthesis of 4,4,8,8,9,9-hexamethyl-2,6-dinitro-8,9-dihydro-4H-cyclopenta[def]phenanthrene:

[0057] Refer to the synthesis of 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene, except that the raw material of the nitration reaction is replaced by 4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene.

[0058] The mass spectrum of the obtained 4,4,8,8,9,9-hexamethyl-2,6-dinitro-8,9-dihydro-4H-cyclopenta[def]phenanthrene was measured, and the m / z was 366.16.

[0059] (2) Synthesis of 4,4,8,8,9,9-hexamethyl-2,6-diamino-8,9-dihydro-4H-cyclopenta[def]phenanthrene:

[0060] Refer to the synthesis of 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene, except that the raw material of the hydrogenation reaction is replaced by 4,4,8,8,9,9-hexamethyl-2,6-dinitro-8,9-dihydro-4H-cyclopenta[def]phenanthrene.

[0061] The mass spectrum of the obtained 4,4,8,8,9,9-hexamethyl-2,6-diamino-8,9-dihydro-4H-cyclopenta[def]phenanthrene was measured, and the m / z was 306.21.

[0062] The NMR of 4,4,8,8,9,9-hexamethyl-2,6-diamino-8,9-dihydro-4H-cyclopenta[def]phenanthrene was measured and the data are as follows:

[0063] (Bruker, Switzerland, AvanceⅡ400MHz NMR spectrometer, CDCl3), δ: 6.75 (d, 2H), 6.59 (d, 2H), 6.01 (s, 4H), 1.71 (s, 6H), 1.32 (s, 12H).

[0064] The diamine monomer of the present invention has a parent ring structure of 9,9,10,10-tetramethyl-9,10-dihydrophenanthrene and 4,4,8,8,9,9-hexamethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene, so that the polyimide film prepared using the diamine monomer has improved high temperature resistance and transparency.

[0065] Polyimide film preparation example 1:

[0066] 500 ml three-necked flask, nitrogen protection, mechanical stirring, add 0.01 mol of 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene, 0.01 mol of 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene, 80 ml of DMF (N,N-dimethylformamide), react at 35°C for 12 hours to obtain a light yellow polyamic acid solution; the obtained polyamic acid solution is coated on a glass plate, dried at 180°C for 8 hours, then imidized at 300°C for 2 hours, and cured at 360°C for 1 hour to obtain a polyimide film.

[0067] The absorption spectrum of the obtained polyimide film was measured using a Shimadzu UV-1800 spectrophotometer from Japan, and the transmittance of light at 380 nm, 420 nm, and 550 nm was tested. Details are shown in the table below.

[0068] The glass transition temperature (Tg) of the polyimide film obtained was analyzed using a Q800DMA instrument from TA Company, USA, in a tensile mode. Details are shown in the table below.

[0069] Polyimide film preparation examples 2-8:

[0070] Referring to the method of Example 1 for preparing an imide film, the following polyimide film was prepared, except that the diamine compound and the dianhydride compound were different, as shown in the following table:

[0071] Polyimide Film Comparative Examples 1-4

[0072] Referring to the method of Example 1 for preparing imide film, the following polyimide film was prepared, except that the diamine compound was different, as shown in the following table:

[0073]

[0074]

[0075] As can be seen from the table above, compared with Comparative Examples 1-4, the polyimide film according to the present invention has significantly higher light transmittance and glass transition temperature, and thus has better heat resistance, which is obviously derived from the specific diamine compound of the present invention.

[0076] According to Example 3 and Example 7, when the dianhydride compound is selected from When the prepared polyimide film has a higher transmittance.

[0077] According to Example 7, when the diamine compound is selected from 4,4,8,8,9,9-hexamethyl-2,6-diamino-8,9-dihydro-4H-cyclopenta[def]phenanthrene, the dianhydride compound is selected from When the polyimide film is prepared, the transmittance is high and the glass transition temperature is also high.

[0078] According to Example 4, when the dianhydride compound is selected from When the diamine compound is selected from 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene and the dianhydride compound is selected from 1,4-diamino-2,7-diamino-9,10-dihydrophenanthrene, the prepared polyimide film has a higher glass transition temperature.

[0079] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A diamine compound represented by formula (1): ； Wherein n is selected from 0 or 1.

2. A compound represented by formula (1-1): 。 3. A polyimide film prepared from an aromatic dianhydride compound and an aromatic diamine compound; the aromatic diamine compound is selected from the compound represented by formula (1) according to claim 1, and the aromatic dianhydride compound is selected from the following structures: 。 4. The method for preparing a polyimide film according to claim 3, comprising the steps of: (1) reacting a diamine compound represented by formula (1) and an aromatic dianhydride compound in an organic solvent to obtain a polyamic acid solution; (2) The obtained polyamic acid solution is cast into a film, and then dried, imidized and cured in sequence to obtain a polyimide film.

5. The preparation method according to claim 4, wherein The molar ratio of the diamine compound represented by formula (1) to the aromatic dianhydride compound is 0.8:1 to 1:0.8; the diamine compound represented by formula (1) and the aromatic dianhydride compound are reacted in an organic solvent at a reaction temperature of -20 to 80° C. for 3 to 48 hours.

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