Diamine compound and polyimide film

Abstract

The present invention belongs to the field of polymers, and specifically relates to a diamine compound and a polyimide film made of the same. The diamine compound has a structure shown in formula (A). The present invention uses a diamine compound shown in formula (A) with a novel structure 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. #imgabs0#

Description

Technical Field

[0001] The invention belongs to the field of polymers, and in particular relates 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. It is widely used in the fields of electric power, atomic energy industry, aerospace, national defense and military industry in the form of films, fibers, composite materials, photosensitivity, foams, adhesives, etc. In recent years, flexible organic light-emitting display (OLED) technology has developed rapidly. With its advantages of fast response, low power consumption, wearable and foldable, it is one of the most competitive new display technologies in 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 properties.

[0004] At present, the common fully aromatic polyimide presents 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 invention provides a diamine compound for synthesizing a polyimide film. The obtained polyimide film has good high temperature resistance and good transparency.

[0006] Specifically, the present invention is realized through the following technical solutions:

[0007] In a first aspect, the present invention provides a diamine compound represented by formula (A):

[0008]

[0009] Wherein, n is selected from an integer between 1 and 5;

[0010] One of o and p is selected from 0, and the other is selected from 1;

[0011] The diamine compound represented by formula (A) does not include compounds with the following structures:

[0012] , .

[0013] In a preferred embodiment, n is selected from an integer between 2 and 4.

[0014] In a preferred embodiment, the diamine compound represented by formula (A) is selected from the compounds represented by the following structural formula:

[0015]

[0016] In a second aspect, the present invention provides a polyimide film, which is prepared from an aromatic dianhydride compound and an aromatic diamine compound; the aromatic diamine compound is a diamine compound represented by formula (A):

[0017]

[0018] Wherein, n is selected from an integer between 1 and 5;

[0019] One of o and p is selected from 0, and the other is selected from 1.

[0020] In a preferred embodiment, n is selected from an integer between 2 and 4.

[0021] In a preferred embodiment, the diamine compound represented by formula (A) used in preparing the polyimide film is selected from the compounds represented by the following structural formula:

[0022] .

[0023] In a preferred embodiment, the aromatic dianhydride compound is selected from the compounds represented by formula (2) or formula (3):

[0024]

[0025] In formula (3), ring A and ring B are connected by a single bond; ring A and ring B are independently selected from substituted or unsubstituted benzene ring, naphthalene ring, anthracene ring, phenanthrene ring; wherein the substituent in the substitution is selected from C 1 -C 12 Alkyl, C 1 -C 12 Alkoxy, C 6 -C 20 Aryl, halogen, -CN, preferably C 1 -C 6 Alkyl, C 1 -C 6 Alkoxy, C 6 -C 12Aryl, -F, -Cl, -Br, -I, -CN, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyl, phenyl, naphthyl, biphenyl, -F, -Cl, -CN.

[0026] In a preferred embodiment, the compounds represented by formula (2) and formula (3) are selected from the compounds represented by the following structural formulas:

[0027]

[0028]

[0029]

[0030]

[0031] .

[0032] In a third aspect, the present invention provides a method for preparing the polyimide film according to the second aspect, the method comprising the following steps:

[0033] (1) reacting a diamine compound represented by formula (A) and an aromatic dianhydride compound in an organic solvent to obtain a polyamic acid solution;

[0034]

[0035] Wherein, n is selected from an integer between 1 and 5;

[0036] One of o and p is selected from 0, and the other is selected from 1;

[0037] (2) Casting the polyamic acid solution obtained in step (1) into a film, and then drying, imidizing and curing in sequence to obtain a polyimide film.

[0038] In a preferred embodiment, in the above step (1), the aromatic dianhydride compound is selected from the compound represented by formula (2) or formula (3):

[0039]

[0040] In formula (3), ring A and ring B are connected by a single bond; ring A and ring B are independently selected from substituted or unsubstituted benzene ring, naphthalene ring, anthracene ring, phenanthrene ring; wherein the substituent in the substitution is selected from C 1 -C 12 Alkyl, C 1 -C 12 Alkoxy, C 6-C 20 Aryl, halogen, -CN, preferably C 1 -C 6 Alkyl, C 1 -C 6 Alkoxy, C 6 -C 12 Aryl, -F, -Cl, -Br, -I, -CN, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyl, phenyl, naphthyl, biphenyl, -F, -Cl, -CN.

[0041] In a preferred embodiment, in the above step (1), the organic solvent is selected from one of ethyl acetate, DMF, DME, DMSO, HMPA, or a mixture of two of them.

[0042] In a preferred embodiment, in the above step (1), the molar ratio of the diamine compound represented by formula (A) to the aromatic dianhydride compound is 0.8:1 to 1:0.8, preferably 1:1.

[0043] In a preferred embodiment, in the above step (1), the reaction temperature is -20 to 80°C, preferably 20 to 50°C; the reaction time is 3 to 48 hours, preferably 6 to 18 hours.

[0044] In a preferred embodiment, in the above step (2), the drying refers to drying at 150-200° C. for 1-12 hours.

[0045] In a preferred embodiment, in the above step (2), the imidization is carried out at 260-320° C. for 0.5-5 h.

[0046] In a preferred embodiment, in the above step (2), the curing refers to curing at 340-400° C. for 0.5-3 h.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention provides a diamine compound and a polyimide film made of the same. The present invention adopts a novel diamine compound to polymerize with an aromatic dianhydride compound to obtain polyimide and prepare the film. The obtained polyimide film has good high temperature resistance and good transparency, and is a polyimide film material with good performance. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are described in detail below. The embodiments are given to better illustrate the contents of the present invention and are only used to explain the present invention, but should not be understood as limiting the present invention.

[0050] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0051] Example 1

[0052] The synthesis method of the diamine compound represented by formula A1 is as follows:

[0053]

[0054] In a 500 ml autoclave, add 1.8 g of intermediate M-A1 and 60 ml of anhydrous ethanol, cool to 0 degrees Celsius, slowly introduce ammonia gas through a liquid ammonia cylinder until saturation, then heat to 120°C and perform amination reaction for 24 hours. Cool down, concentrate the reaction solution to dryness, add ethyl acetate and water, separate the liquids, dry the organic layer, and concentrate to dryness. Then crystallize with a mixed solvent of methanol and petroleum ether to obtain 1.1 g of the diamine compound represented by formula A1.

[0055] The mass spectrum of the obtained diamine compound represented by Formula A1 was measured, and the result was m / z: 250.15.

[0056] The obtained diamine compound represented by formula A1 was measured by nuclear magnetic resonance (H) spectrum (Bruker, Switzerland, Avance II 400 MHz nuclear magnetic resonance spectrometer), and the data are as follows: 1 H-NMR (400 MHz, CDCl 3 ), δ7.72 (d, 2H), δ6.88 (d, 2H), 6.71 (m, 2H), δ3.97 (s, 4H), δ2.25 (m, 4H), δ1.53 (m, 4H).

[0057] Example 2

[0058] The synthesis method of the diamine compound shown in formula A2 is as follows:

[0059]

[0060] Referring to the synthesis method of the diamine compound represented by Formula A1, the diamine compound represented by Formula A2 is synthesized.

[0061] The mass spectrum of the obtained diamine compound represented by Formula A2 was measured, and the result was m / z: 250.15.

[0062] Example 3

[0063] The synthesis method of the diamine compound shown in formula A3 is as follows:

[0064]

[0065] Referring to the synthesis method of the diamine compound represented by Formula A1, the diamine compound represented by Formula A3 is synthesized.

[0066] The mass spectrum of the obtained diamine compound represented by Formula A3 was measured, and the result was m / z: 250.15.

[0067] Example 4

[0068] The synthesis method of the diamine compound shown in formula A4 is as follows:

[0069]

[0070] Referring to the synthesis method of the diamine compound represented by Formula A1, the diamine compound represented by Formula A4 is synthesized.

[0071] The mass spectrum of the obtained diamine compound represented by Formula A4 was measured, and the result was m / z: 264.16.

[0072] Example 5

[0073] The polyimide film is prepared using the diamine compound shown in Formula A1:

[0074] 500 ml three-necked flask, nitrogen protection, mechanical stirring, add 0.01 mol of the diamine compound represented by formula A1, 0.01 mol 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.

[0075] The absorption spectrum of the prepared polyimide film was detected by using a Shimadzu UV-1800 spectrophotometer to detect the transmittance of light at 380nm, 420nm, and 550nm. The results are shown in Table 1.

[0076] The glass transition temperature Tg of the prepared polyimide film was detected by using a Q800DMA instrument produced by TA Company of the United States in a tensile mode. The results are shown in Table 1.

[0077] Embodiment 6-11

[0078] Referring to the preparation method of the polyimide film in Example 5, a polyimide film was prepared using the diamine compounds and dianhydride compounds corresponding to Examples 6-11 in Table 1, and the transmittance of the prepared polyimide film was detected by a UV-1800 spectrophotometer produced by Shimadzu of Japan, and the glass transition temperature Tg was detected by a Q800DMA instrument produced by TA Company of the United States. The results are shown in Table 1.

[0079] Comparative Examples 1-3

[0080] Referring to the preparation method of the polyimide film in Example 5, a polyimide film was prepared using the diamine compounds and dianhydride compounds corresponding to Comparative Examples 1-3 in Table 1, and the transmittance of the prepared polyimide film was detected by a UV-1800 spectrophotometer produced by Shimadzu of Japan, and the glass transition temperature Tg was detected by a Q800DMA instrument produced by TA Company of the United States. The results are shown in Table 1.

[0081] Table 1 Transmittance and glass transition temperature test results of the prepared polyimide film

[0082]

[0083]

[0084] As can be seen from Table 1, compared with Comparative Examples 1-3, the polyimide film prepared using the diamine compound represented by formula (A) provided by the present invention has significantly higher light transmittance and glass transition temperature, that is, the prepared polyimide film has better transparency and high temperature resistance. This may be because the diamine compound represented by formula (A) provided by the present invention has a cycloalkyl spirofluorene structure, so it has strong rigidity and weak absorption of visible light, so that the high temperature resistance and transparency of the polyimide film prepared therefrom are improved.

[0085] Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A diamine compound represented by formula (A): ； in, n is selected from an integer between 1 and 5; One of o and p is selected from 0, and the other is selected from 1; The diamine compound represented by formula (A) does not include compounds with the following structures: 、 。 2. The diamine compound represented by formula (A) according to claim 1, characterized in that: The diamine compound is any one of the following compounds: 。 3. A polyimide film, characterized in that: The polyimide film is prepared from an aromatic dianhydride compound and an aromatic diamine compound; the aromatic diamine compound is a diamine compound represented by formula (A): ； Wherein, n is selected from an integer between 1 and 5; One of o and p is selected from 0, and the other is selected from 1.

4. The polyimide film according to claim 3, characterized in that: The diamine compound represented by formula (A) used in preparing the polyimide film is any one of the following compounds: 。 5. The polyimide film according to claim 3, characterized in that: The aromatic dianhydride compound used in preparing the polyimide film is selected from the compound represented by formula (2) or formula (3): ； In formula (3), ring A and ring B are connected by a single bond; ring A and ring B are independently selected from substituted or unsubstituted benzene ring, naphthalene ring, anthracene ring, and phenanthrene ring; wherein the substituent in the substitution is selected from C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 20 Aryl, halogen, -CN.

6. The polyimide film according to claim 5, characterized in that: The compound represented by formula (2) or formula (3) is any one of the following compounds: 。 7. The method for preparing a polyimide film according to any one of claims 3 to 6, characterized in that: The method comprises the following steps: (1) reacting a diamine compound represented by formula (A) and an aromatic dianhydride compound in an organic solvent to obtain a polyamic acid solution; ； Wherein, n is selected from an integer between 1 and 5; One of o and p is selected from 0, and the other is selected from 1; (2) Casting the polyamic acid solution obtained in step (1) into a film, and then drying, imidizing and curing in sequence to obtain a polyimide film.

8. The preparation method according to claim 7, characterized in that: In step (1), the aromatic dianhydride compound is selected from the compound represented by formula (2) or formula (3): ； In formula (3), ring A and ring B are connected by a single bond; ring A and ring B are independently selected from substituted or unsubstituted benzene ring, naphthalene ring, anthracene ring, and phenanthrene ring; wherein the substituent in the substitution is selected from C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 20 Aryl, halogen, -CN.

9. The preparation method according to claim 7, characterized in that: In step (1): The organic solvent is selected from one of ethyl acetate, DMF, DME, DMSO, HMPA or a mixture of two thereof; The molar ratio of the diamine compound represented by formula (A) to the aromatic dianhydride compound is 0.8:1 to 1:0.8; The reaction temperature is -20 to 80°C, and the reaction time is 3 to 48 hours.

10. The preparation method according to claim 7, characterized in that: In step (2): The drying refers to drying at 150-200° C. for 1-12 hours; The imidization refers to imidization at 260-320° C. for 0.5-5 h; The curing refers to curing at 340-400° C. for 0.5-3 hours.

Images