Diamine compound and polyimide film

Abstract

The invention provides a diamine compound and a polyimide film prepared from the same. The diamine compound shown in the formula (1) and the aromatic dianhydride compound are polymerized to prepare polyimide, the film is prepared, and the obtained polyimide film is good in high-temperature resistance and transparency and is a polyimide film material with good performance. # imgabs0 #

Description

Technical Field

[0001] The 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 type of polymer material containing an imide ring in its molecular chain. In recent years, flexible organic light-emitting display (OLED) technology has developed rapidly. It is one of the most competitive new display technologies in the future due to its advantages such as fast response, low power consumption, wearability and foldability.

[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 properties.

[0004] At present, common fully aromatic polyimide exhibits a darker color in the visible light region due to the charge transfer complex (CTC) generated between and within the molecules, which affects its optical properties. The heat resistance and optical properties of polyimide are closely related to its molecular structure, and the two are contradictory. Therefore, it is necessary to achieve a balanced unification of high temperature resistance and transparency through reasonable 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 shown in formula (1), which has a structure shown in 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 refers to being unsubstituted, or being mono- or poly-substituted by a group selected from C1-C12 alkyl, C1-C12 alkoxy, C6-C20 aromatic hydrocarbon group, halogen, and 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, 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, 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 are performed 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 of the diamine compound. The present invention uses a novel diamine compound to polymerize with an aromatic dianhydride compound to obtain polyimide and prepare a film. The obtained polyimide film has good high temperature resistance and good transparency, and is a polyimide film material with good performance. DETAILED DESCRIPTION

[0040] The preferred embodiments of the invention are described in detail below. The examples are provided to better illustrate the content of the invention, but the content of the invention is not limited to the examples. Non-essential improvements and adjustments to the implementation scheme according to the content of the invention still fall 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 are carried out according to the techniques or conditions described in the literature in the art 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, add 23 g of 9,9,10,10-tetramethyl-9,10-dihydrophenanthrene, 200 ml of dichloromethane, and 100 ml of glacial acetic acid. Under stirring, slowly add 26 g of 60% nitric acid aqueous solution at 20°C. After the addition, react at 25°C-30°C for 4 hours, add water to separate, wash the organic layer with water, concentrate to dryness under reduced pressure in a 50°C water bath, and crystallize it with ethanol 3 times 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] In a 500 ml autoclave, 5 g of 9,9,10,10-tetramethyl-2,7-dinitro-9,10-dihydrophenanthrene prepared according to the above method, 100 ml of anhydrous ethanol, and 0.5 g of 5% Pd / C were added, and the atmosphere was replaced with nitrogen and then replaced with hydrogen, and then the hydrogenation reaction was carried out at a hydrogen pressure of 0.2 MPa and a temperature of 60°C for 6 hours. After cooling and filtering off Pd / C, the mother liquor was concentrated to dryness, and then recrystallized from methanol to obtain 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 Company, 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 high temperature resistance and transparency of the polyimide film prepared by using the diamine monomer are improved.

[0065] Polyimide film preparation example 1:

[0066] 500 ml three-necked flask, nitrogen protection, mechanical stirring, add 0.01 mol, 9,9,10,10-tetramethyl-2,7-diamino-9,10-dihydrophenanthrene 0.01 mol, DMF (N, N-dimethylformamide) 80 ml, 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, and the transmittance of light at 380nm, 420nm, and 550nm was tested. Details are shown in the table below.

[0068] The glass transition temperature Tg of the polyimide film obtained by testing was analyzed using the Q800DMA instrument of TA Company of the United States in the tensile mode. Details are shown in the table below.

[0069] Polyimide film preparation example 2-8:

[0070] Referring to the method of preparing imide film in Example 1, the following polyimide film was prepared, the difference being 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 preparing imide film in Example 1, the following polyimide film was prepared, the difference being 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 to 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 transmittance of the prepared polyimide film is higher.

[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 prepared polyimide film has high transmittance and high glass transition temperature.

[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, 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 rather than to limit it. 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 comprises the compound represented by formula (1) according to claim 1.

4. The polyimide film according to claim 3, characterized in that: The aromatic dianhydride compound is selected from the compounds represented by formula (2) or formula (3): 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.

5. The polyimide film according to claim 4, characterized in that: The substituted or unsubstituted refers to being unsubstituted, or being monosubstituted or polysubstituted by a group selected from a C1-C12 alkyl group, a C1-C12 alkoxy group, a C6-C20 aromatic hydrocarbon group, a halogen, and CN.

6. The polyimide film according to claim 5, characterized in that: The C1-C12 alkyl group is selected from C1-C6 alkyl groups; the C1-C12 alkoxy group is selected from C1-C6 alkoxy groups; the C6-C20 aromatic hydrocarbon group is selected from phenyl, naphthyl, and biphenyl; and the halogen is selected from fluorine, chlorine, bromine, and iodine.

7. The polyimide film according to claim 4, characterized in that: The compound represented by formula (2) or formula (3) is selected from the following structures: 。 8. The method for preparing a polyimide film according to claim 3, comprising the following steps: (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) Casting the obtained polyamic acid solution into a film, and then drying, imidizing and curing are performed in sequence to obtain a polyimide film.

9. The preparation method according to claim 8, characterized in that: The aromatic dianhydride compound is selected from the compound represented by formula (2) or formula (3) as described in any one of claims 4 to 7.

10. The preparation method according to claim 9, characterized in that: The molar ratio of the diamine compound represented by formula (1) to the compound represented by formula (2) or formula (3) is 0.8:1 to 1:0.8; the diamine compound represented by formula (1) and the compound represented by formula (2) or formula (3) react in an organic solvent at a reaction temperature of -20 to 80°C for 3 to 48 hours.

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