Polyimide resin and preparation method thereof, polyimide resin slurry and film

Abstract

The present application relates to a polyimide resin and a preparation method thereof, a polyimide resin slurry and a film, the polyimide resin preparation raw materials comprise a diamine monomer and a dianhydride monomer, the diamine monomer comprises at least one of naphthyl-containing diamine, anthryl-containing diamine and pyrenyl-containing diamine, and the dianhydride monomer comprises at least one of naphthyl-containing diamine, anthryl-containing diamine and pyrenyl-containing diamine. The dianhydride monomer comprises at least one of ester group-containing dianhydride and fluorine-containing dianhydride. According to the polyimide resin disclosed by the invention, the water absorption rate is greatly reduced and can be less than 1%, and the polyimide resin has excellent chemical stability, mechanical property, insulating property and heat resistance.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and in particular to a polyimide resin and a preparation method thereof, a polyimide resin slurry and a film. Background Art

[0002] Polyimide (PI) is a high-performance engineering plastic that is widely used in aerospace, electronics, automobiles, and chemical industries due to its excellent thermal stability, good mechanical and chemical properties, and outstanding insulation. However, traditional polyimide has high water absorption, which will lead to a decrease in performance in a humid environment, thus limiting its application. Summary of the invention

[0003] Based on this, it is necessary to provide a polyimide resin with low water absorption and a preparation method thereof, a polyimide resin slurry and a film.

[0004] In a first aspect of the present application, a polyimide resin is provided, wherein raw materials for preparing the polyimide resin include a diamine monomer and a dianhydride monomer, wherein the diamine monomer includes at least one of a naphthyl-containing diamine, an anthracene-containing diamine and a pyrene-containing diamine, and the dianhydride monomer includes at least one of an ester-containing dianhydride and a fluorine-containing dianhydride.

[0005] The polyimide resin of the present application adopts naphthyl-containing diamine, anthracene-containing diamine and / or pyrene-containing diamine as diamine monomers, introduces naphthyl structure, anthracene structure and / or pyrene structure into the polyimide resin, so that the structure is stacked more tightly, thereby reducing the water absorption of the polyimide resin; at the same time, by adopting ester-containing dianhydride and / or fluorine-containing dianhydride as dianhydride monomers, the hydrophobicity of the polyimide resin is enhanced, thereby further reducing the water absorption of the polyimide resin. The polyimide resin of the present application not only greatly reduces the water absorption rate, which can make the water absorption rate less than 1%, but also has excellent chemical stability, mechanical properties, insulation properties and heat resistance.

[0006] In some embodiments, the polyimide resin includes partially oxidized perhydropolysilazane, and the partially oxidized perhydropolysilazane dopes the diamine monomer and the dianhydride monomer to form a polyimide.

[0007] In some embodiments, the added amount of the partially oxidized perhydropolysilazane accounts for 1% to 12% of the mass of the polyimide resin.

[0008] In some embodiments, the polyimide resin satisfies at least one of the following conditions:

[0009] (1) The naphthyl-containing diamine comprises a naphthalene ring and two amino groups, with the naphthalene ring as the mother ring and the two amino groups connected to the naphthalene ring;

[0010] (2) The anthracene-containing diamine comprises an anthracene ring and two amino groups, with the anthracene ring as the parent ring and the two amino groups connected to the anthracene ring;

[0011] (3) The pyrene-containing diamine comprises a pyrene ring and two amino groups, with the pyrene ring serving as a parent ring and the two amino groups being connected to the pyrene ring.

[0012] In some embodiments, the polyimide resin satisfies at least one of the following conditions:

[0013] (1) The naphthyl-containing diamine includes at least one of 2,6-naphthalene diamine, 1,5-naphthalene diamine, 2,7-naphthalene diamine, 2,2'-diaminobinaphthyl, 4,4'-diamino-2,2'-dimethylbinaphthyl and 4,4'-diamino-3,3'-dimethylbinaphthyl;

[0014] (2) the anthracene-containing diamine includes at least one of 1,4-diaminoanthracene and 2,6-diaminoanthracene;

[0015] (3) The pyrene-containing diamine includes at least one of 1,6-diaminopyrene and 1,8-diaminopyrene.

[0016] In some embodiments, the polyimide resin satisfies at least one of the following conditions:

[0017] (1) The molar ratio of the dianhydride monomer to the diamine monomer is 1:0.9-1.2;

[0018] (2) The dianhydride monomers include ester-containing dianhydrides and fluorine-containing dianhydrides.

[0019] In some embodiments, the structural formula of the ester-containing dianhydride is as follows:

[0020]

[0021] Wherein, L represents a structure containing an ester group; and n represents the degree of polymerization.

[0022] In some embodiments, the ester-containing dianhydride includes at least one of phenyl benzoate-3,4,3'4'-tetracarboxylic dianhydride, trimellitic anhydride hydroquinone ester, trimellitic anhydride resorcinol ester, trimellitic anhydride methyl hydroquinone ester, trimellitic anhydride tert-butyl hydroquinone ester, trimellitic anhydride-4,4'-biphenyl diphenol ester, trimellitic anhydride-2,2'-biphenyl diphenol ester, trimellitic anhydride bisphenol A ester, trimellitic anhydride-4.4'-diphenyl sulfone diphenol ester, trimellitic anhydride-2,2'-binaphthol ester, diether diphenyl anhydride containing a chalcone structure, and diether diphenyl anhydride containing a divinyl ketone structure.

[0023] In some embodiments, the fluorine-containing dianhydride includes at least one of 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and 9,9-bis(trifluoromethyl)-2,3,6,7-oxanthenetetracarboxylic dianhydride.

[0024] The second aspect of the present application provides a method for preparing the polyimide resin as described in the first aspect, comprising the following steps:

[0025] The diamine monomer and the dianhydride monomer are subjected to imidization reaction in a solvent to obtain the polyimide resin;

[0026] The diamine monomer includes at least one of a naphthyl-containing diamine, anthracene-containing diamine and a pyrene-containing diamine, and the dianhydride monomer includes at least one of an ester-containing dianhydride and a fluorine-containing dianhydride.

[0027] In some embodiments, after the imidization reaction and before obtaining the polyimide resin, the following step is further included: adding perhydropolysilazane to the reaction solution obtained from the imidization reaction and blending them to obtain the polyimide resin doped with perhydropolysilazane.

[0028] In some embodiments, the imidization reaction satisfies one or more of the following conditions:

[0029] (1) The starting temperature of the imidization reaction is 120°C to 180°C, the isothermal reaction temperature is 200°C to 280°C, and the heating rate is 4°C / min to 6°C / min;

[0030] (2) The isothermal reaction time of the imidization reaction is 1 h to 10 h;

[0031] (3) the imidization reaction is carried out in the presence of a catalyst, wherein the catalyst is selected from one or more of isoquinoline, N-ethylpiperidine and triethylamine;

[0032] (4) The imidization reaction is carried out in the presence of a catalyst, wherein the amount of the catalyst used accounts for 2% to 6% of the total weight of the monomer;

[0033] (5) the imidization reaction is carried out in the presence of a dehydrating agent, wherein the dehydrating agent is selected from one or both of acetic anhydride and toluene;

[0034] (6) The imidization reaction is carried out in the presence of a dehydrating agent, wherein the amount of the dehydrating agent is 1 to 4 times the mass of the catalyst;

[0035] (7) The solvent is selected from one or more of: N-methylpyrrolidone, m-methylphenol, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, cyclohexanone, N,N-dimethylformamide, tetramethylene sulfone and hexamethylphosphoramide.

[0036] The third aspect of the present application provides a polyimide resin, which is prepared by the preparation method described in the second aspect.

[0037] The fourth aspect of the present application provides a polyimide resin slurry, comprising the polyimide resin described in the third aspect and a solvent.

[0038] The fifth aspect of the present application provides a polyimide film, which comprises the polyimide resin described in the third aspect; or the raw materials for preparing the polyimide film include diamine monomers and dianhydride monomers, the diamine monomers include at least one of naphthyl-containing diamines, anthracene-containing diamines and pyrene-containing diamines, and the dianhydride monomers include at least one of ester-containing dianhydrides and fluorine-containing dianhydrides. DETAILED DESCRIPTION

[0039] The polyamic acid slurry of the present invention and its preparation method and application are further described in detail below in conjunction with specific examples. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0041] The optional scope of the terms "and / or", "or / and", and "and / or" used in this article includes any one of two or more related listed items, and also includes any and all combinations of the related listed items, said any and all combinations include any combination of any two related listed items, any more related listed items, or all related listed items.

[0042] As used herein, "at least one" means one, two or more than two.

[0043] In the present invention, "the first aspect", "the second aspect", "the third aspect", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "the first", "the second", "the third", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0044] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0045] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0046] Traditional polyimide exhibits high water absorption in high humidity environments, which can lead to a series of adverse effects: dimensional changes, the water absorption of polyimide can cause the material to expand or shrink, thus affecting its dimensional stability. This change may lead to poor fit or structural failure in precision engineering applications; mechanical properties are reduced, water absorption can cause changes in the physical structure inside the material, thereby reducing its mechanical strength and stiffness, affecting the overall performance of the product; electrical insulation performance is reduced, the water absorption of polyimide can reduce its electrical insulation performance, increasing the risk of electrical failure, in high-demand electronic packaging and insulation applications, this effect is particularly significant; long-term durability issues, during long-term use, the absorption of water may cause aging and degradation of the material, thereby shortening the service life of the product. In order to overcome these problems, the synthesis of low water absorption polyimide has become an important research and development direction, but the current results are not satisfactory. The water absorption rate of polyimide has always hovered around 2%~4%, which is difficult to reduce.

[0047] Based on this, in the first aspect of the present application, one embodiment provides a polyimide resin, wherein the raw materials for preparing the polyimide resin include a diamine monomer and a dianhydride monomer, the diamine monomer includes at least one of a naphthyl-containing diamine, an anthracene-containing diamine and a pyrene-containing diamine, and the dianhydride monomer includes at least one of an ester-containing dianhydride and a fluorine-containing dianhydride.

[0048] The polyimide resin of the present application adopts naphthyl-containing diamine, anthracene-containing diamine and / or pyrene-containing diamine as diamine monomers, introduces naphthyl and / or anthracene-containing structures into the polyimide resin, so that the structure is stacked more tightly, thereby reducing the water absorption of the polyimide resin; at the same time, by adopting ester-containing dianhydride and / or fluorine-containing dianhydride as dianhydride monomers, the hydrophobicity of the polyimide resin is enhanced, thereby further reducing the water absorption of the polyimide resin. The polyimide resin of the present application not only greatly reduces the water absorption rate, making the water absorption rate less than 1%, but also has excellent chemical stability, mechanical properties, insulation properties and heat resistance.

[0049] In some embodiments, the polyimide resin includes partially oxidized perhydropolysilazane, and the partially oxidized perhydropolysilazane dopes the diamine monomer and the dianhydride monomer to form a polyimide.

[0050] The structure of perhydropolysilazane PHPS is as follows:

[0051]

[0052] The curing mechanism of perhydropolysilazane at about 200°C is as follows:

[0053]

[0054] As a highly active polymer, perhydropolysilazane contains Si-N bonds in its molecular structure. These bonds can be combined with polyimide molecular chains. The Si-N bonds on the surface of the Si-N network structure can interact with certain polar groups in the polyimide molecules, such as nitrogen atoms on the imide ring, to produce hydrogen bond interactions or non-covalent bond interactions such as van der Waals forces, forming a tight PI / PHPS complex. Moreover, at high temperatures, the Si-N network partially forms a silicon oxide network structure, making the structure further dense. This tight combination in the structure helps to reduce the penetration and adsorption of water molecules, thereby reducing the water absorption of polyimide resins. Moreover, the mechanical properties and heat resistance of polyimide resins are greatly improved after doping with perhydropolysilazane.

[0055] Furthermore, the polyimide resin also includes a coupling agent, and the amount of the coupling agent added accounts for 0.5% to 5% of the mass ratio of the perhydropolysilazane. The amount of the coupling agent added accounts for preferably 1% to 3% of the mass ratio of the perhydropolysilazane. By adding a coupling agent to act as a bridge, the interfacial bonding force between perhydropolysilazane and polyimide can be further enhanced, the interfacial tension can be reduced, the two can be better mixed and interpenetrated, and the interfacial compatibility can be improved; the Si-N bond in the perhydropolysilazane structure can be combined with the polyimide molecular chain through the coupling agent to form a tighter PI / PHPS complex.

[0056] In some embodiments, the addition amount of the partially oxidized perhydropolysilazane accounts for 1% to 12% of the mass ratio of the polyimide resin. The partially oxidized perhydropolysilazane greatly reduces the water absorption rate of the polyimide at a doping amount of 1% to 12%, and obtains an unexpected effect in reducing the water absorption rate.

[0057] As an example, the added amount of the partially oxidized perhydropolysilazane may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11% and 12% by mass of the polyimide resin, or may be within the range consisting of any two of the above point values ​​as end values, preferably 3% to 8%.

[0058] In some embodiments, the diamine monomer includes a naphthyl-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride.

[0059] In some embodiments, the diamine monomer includes a naphthyl-containing diamine, and the dianhydride monomer includes a fluorine-containing dianhydride.

[0060] In some embodiments, the diamine monomer includes a naphthyl-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride and a fluorine-containing dianhydride. Introducing the naphthyl-containing diamine, the ester-containing dianhydride and the fluorine-containing dianhydride simultaneously in the preparation of the monomer is conducive to further reducing the water absorption of the polyimide resin.

[0061] In some embodiments, the diamine monomer includes an anthracene-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride.

[0062] In some embodiments, the diamine monomer includes an anthracene-containing diamine, and the dianhydride monomer includes a fluorine-containing dianhydride.

[0063] In some embodiments, the diamine monomer includes an anthracene-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride and a fluorine-containing dianhydride. The simultaneous introduction of an anthracene-containing diamine, an ester-containing dianhydride and a fluorine-containing dianhydride in the preparation of monomers is conducive to further reducing the water absorption of the polyimide resin, and after film formation, not only the water absorption is low, but also excellent chemical stability, mechanical properties, insulation properties and heat resistance.

[0064] In some embodiments, the diamine monomer includes a naphthyl-containing diamine and an anthracene-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride.

[0065] In some embodiments, the diamine monomer includes a naphthyl-containing diamine and an anthracene-containing diamine, and the dianhydride monomer includes a fluorine-containing dianhydride.

[0066] In some embodiments, the diamine monomer includes a naphthyl-containing diamine and an anthracene-containing diamine,

[0067] The dianhydride monomers include dianhydrides containing an ester group and fluorine-containing dianhydrides.

[0068] In some embodiments, the diamine monomer includes a pyrene-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride.

[0069] In some embodiments, the diamine monomer includes a pyrene-containing diamine, and the dianhydride monomer includes a fluorine-containing dianhydride.

[0070] In some embodiments, the diamine monomer includes a pyrene-containing diamine, and the dianhydride monomer includes an ester-containing dianhydride and a fluorine-containing dianhydride. The simultaneous introduction of the pyrene-containing diamine, the ester-containing dianhydride and the fluorine-containing dianhydride in the preparation of the monomer is conducive to further reducing the water absorption of the polyimide resin.

[0071] In some embodiments, the naphthyl-containing diamine includes a naphthalene ring and two amino groups, the naphthalene ring is used as a mother ring, and the two amino groups are connected to the naphthalene ring. The introduction of the naphthalene ring of diphenyl makes the structure stack more tightly, reduces the water absorption of the polyimide, and improves the mechanical properties and heat resistance.

[0072] In some embodiments, the naphthyl-containing diamine includes at least one of 2,6-naphthalene diamine, 1,5-naphthalene diamine, 2,7-naphthalene diamine, 2,2'-diaminobinaphthyl, 4,4'-diamino-2,2'-dimethylbinaphthyl and 4,4'-diamino-3,3'-dimethylbinaphthyl. By introducing the naphthyl structure of diphenyl into the polyimide through these naphthyl-containing diamines, the structure is stacked more tightly, the water absorption of the polyimide is reduced, and the mechanical properties and heat resistance are improved.

[0073] The structural formula of 2,6-naphthalenediamine is as follows:

[0074]

[0075] The structural formula of 1,5-naphthalenediamine is as follows:

[0076]

[0077] The structural formula of 2,7-naphthalenediamine is as follows:

[0078]

[0079] The structural formula of 2,2'-diaminobinaphthyl is as follows:

[0080]

[0081] The structural formula of 4,4'-diamino-2,2'-dimethylbinaphthyl is as follows:

[0082]

[0083] The structural formula of 4,4'-diamino-3,3'-dimethylbinaphthyl is as follows:

[0084]

[0085] In some embodiments, the anthracene-containing diamine includes an anthracene ring and two amino groups, the anthracene ring is used as a parent ring, and the two amino groups are connected to the anthracene ring. The introduction of the anthracene ring of terphenyl makes the structure stacked more tightly, reduces the water absorption of the polyimide, and improves the mechanical properties and heat resistance.

[0086] In some embodiments, the anthracene-containing diamine includes at least one of 1,4-diaminoanthracene and 2,6-diaminoanthracene. By introducing the anthracene-containing diamine into the polyimide, the structure is stacked more tightly, the water absorption of the polyimide is reduced, and the mechanical properties and heat resistance are improved.

[0087] The structural formula of 1,4-diaminoanthracene is as follows:

[0088]

[0089] The structural formula of 2,6-diaminoanthracene is as follows:

[0090]

[0091] In some embodiments, the pyrene-containing diamine includes a pyrene ring and two amino groups, the pyrene ring is used as a parent ring, and the two amino groups are connected to the pyrene ring.

[0092] In some embodiments, the pyrene-containing diamine includes at least one of 1,6-diaminopyrene and 1,8-diaminopyrene.

[0093] The structural formula of 1,6-diaminopyrene is as follows:

[0094]

[0095] In some embodiments, the ester-containing dianhydride includes at least one of phenyl benzoate-3,4,3'4'-tetracarboxylic dianhydride, trimellitic anhydride hydroquinone ester, trimellitic anhydride resorcinol ester, trimellitic anhydride methyl hydroquinone ester, trimellitic anhydride tert-butyl hydroquinone ester, trimellitic anhydride-4,4'-biphenyl diphenol ester, trimellitic anhydride-2,2'-biphenyl diphenol ester, trimellitic anhydride bisphenol A ester, trimellitic anhydride-4.4'-diphenyl sulfone diphenol ester, trimellitic anhydride-2,2'-binaphthol ester, diether diphenyl anhydride containing a chalcone structure, and diether diphenyl anhydride containing a divinyl ketone structure.

[0096] The structural formula of phenyl benzoate-3,4,3'4'-tetracarboxylic dianhydride is as follows:

[0097]

[0098] The structural formula of trimellitic anhydride hydroquinone ester is as follows:

[0099]

[0100] The structural formula of trimellitic anhydride resorcinol ester is as follows:

[0101]

[0102] The structural formula of trimellitic anhydride methyl hydroquinone ester is as follows:

[0103]

[0104] The structural formula of trimellitic anhydride tert-butyl hydroquinone ester is as follows:

[0105]

[0106] The structural formula of trimellitic anhydride-4,4'-biphenyl diphenol ester is as follows:

[0107]

[0108] The structural formula of trimellitic anhydride-2,2'-biphenyl diphenol ester is as follows:

[0109]

[0110] The structural formula of bisphenol A trimellitic anhydride ester is as follows:

[0111]

[0112] The structural formula of trimellitic anhydride-4.4'-diphenyl sulfone diphenol ester is as follows:

[0113]

[0114] The structural formula of trimellitic anhydride-2,2'-binaphthol ester is as follows:

[0115]

[0116] The structural formula of the diether diphthalic anhydride containing chalcone structure is as follows:

[0117]

[0118] The structural formula of diether diphenyl anhydride containing diethylene ketone structure is as follows:

[0119]

[0120] Furthermore, the dianhydride monomer includes ester-containing dianhydride and fluorine-containing dianhydride.

[0121] Further, the ester-containing dianhydride includes at least one of trimellitic anhydride hydroquinone ester, trimellitic anhydride resorcinol ester, trimellitic anhydride methyl hydroquinone ester, trimellitic anhydride tert-butyl hydroquinone ester, trimellitic anhydride-4,4'-biphenyl diphenol ester, trimellitic anhydride-2,2'-biphenyl diphenol ester, trimellitic anhydride bisphenol A ester, trimellitic anhydride-4.4'-diphenyl sulfone diphenol ester and trimellitic anhydride-2,2'-binaphthol ester.

[0122] Furthermore, the ester-containing dianhydride includes at least one of trimellitic anhydride hydroquinone ester, trimellitic anhydride resorcinol ester, trimellitic anhydride methyl hydroquinone ester, trimellitic anhydride tert-butyl hydroquinone ester, and trimellitic anhydride-4,4'-biphenyl diphenol ester.

[0123] Furthermore, the ester group-containing dianhydride includes at least one of trimellitic anhydride hydroquinone ester, trimellitic anhydride resorcinol ester and trimellitic anhydride-4,4'-biphenyl diphenol ester.

[0124] In some embodiments, the fluorine-containing dianhydride includes at least one of 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and 9,9-bis(trifluoromethyl)-2,3,6,7-oxanthenetetracarboxylic dianhydride.

[0125] In some embodiments, the dianhydride monomer includes 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and trimellitic anhydride hydroquinone ester.

[0126] In some embodiments, the dianhydride monomer includes 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and trimellitic anhydride-4,4'-biphenyl diphenol ester.

[0127] In some embodiments, the dianhydride monomer includes 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and phenyl benzoate-3,4,3'4'-tetracarboxylic acid dianhydride. Using 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and phenyl benzoate-3,4,3'4'-tetracarboxylic acid dianhydride as dianhydride monomers plays a particularly prominent role in reducing the water absorption of the polyimide film.

[0128] In some embodiments, the molar ratio of the dianhydride monomer to the diamine monomer is 1:0.9-1.2.

[0129] As an example, the molar ratio of the dianhydride monomer to the diamine monomer may be 1:0.9, 1:0.95, 1:1, 1:1.1, and 1:1.2, or may be within a range consisting of any two of the above point values ​​as end values.

[0130] In some embodiments, the structural formula of the polyimide resin is as follows:

[0131]

[0132] Wherein, L represents a structure containing an ester group; X represents a structure in which one amino group that has reacted is removed from a diamine group and the other amino group loses 2 H groups; and n represents the degree of polymerization.

[0133] In some embodiments, the structural formula of the polyimide in the polyimide resin includes the following formula (1) and formula (2):

[0134] (1),

[0135] (2),

[0136] Wherein, X represents the structure of a diamine group after removing one amino group that has reacted and the other amino group has lost 2 H groups, R is a dianhydride containing an ester group, n is the degree of polymerization, 20≤n≤80, and m is the degree of polymerization, 20≤m≤80. The degree of polymerization is preferably 30≤n≤50, 50≤m≤70.

[0137] The second aspect of the present application provides a method for preparing the polyimide resin as described in the first aspect, comprising the following steps:

[0138] The diamine monomer and the dianhydride monomer are subjected to imidization reaction in a solvent to obtain the polyimide resin;

[0139] The diamine monomer includes at least one of a naphthyl-containing diamine, anthracene-containing diamine and a pyrene-containing diamine, and the dianhydride monomer includes at least one of an ester-containing dianhydride and a fluorine-containing dianhydride.

[0140] In some embodiments, after the imidization reaction and before obtaining the polyimide resin, the following step is further included: adding perhydropolysilazane to the reaction solution obtained from the imidization reaction and blending them to obtain the polyimide resin doped with perhydropolysilazane.

[0141] Perhydropolysilazane is added to the synthesized polyimide resin slurry, and the perhydropolysilazane and the polyimide resin slurry are blended in a physical mixing manner. As a highly active polymer, perhydropolysilazane contains Si-N bonds in its molecular structure, which can interact with the polyimide molecular chain to form a tighter PI / PHPS complex. Moreover, at high temperatures, the Si-N network part forms a silicon oxide network structure, making the structure further dense. This tight structural combination helps to reduce the penetration and adsorption of water molecules, thereby reducing the water absorption of the polyimide resin.

[0142] In some embodiments, the polyimide resin is as defined in the first aspect.

[0143] In some embodiments, the solvent is selected from one or more of: N-methylpyrrolidone, m-cresol, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, cyclohexanone, N,N-dimethylformamide, tetramethylene sulfone and hexamethylphosphoramide.

[0144] In some embodiments, the diamine monomer and the dianhydride monomer are first dissolved in a solvent and then subjected to an imidization reaction. During the dissolution of the diamine monomer in the solvent, the temperature is raised to 40°C~120°C for dissolution, and the preferred dissolution temperature is 60°C~100°C; after the diamine monomer is completely dissolved, the dianhydride monomer is added, and the dissolution temperature is raised to 120°C~180°C, preferably 130°C~160°C.

[0145] In some embodiments, the starting temperature of the imidization reaction is 120°C to 180°C, the isothermal reaction temperature is 200°C to 280°C, the heating rate is 4°C / min to 6°C / min, and the isothermal reaction temperature is preferably 220°C to 250°C.

[0146] In some embodiments, the isothermal reaction time of the imidization reaction is 1 h to 10 h. The isothermal reaction time of the imidization reaction is preferably 3 h to 7 h.

[0147] In some embodiments, the imidization reaction is carried out in the presence of a catalyst, and the catalyst is selected from one or more of isoquinoline, N-ethylpiperidine and triethylamine.

[0148] In some embodiments, the imidization reaction is carried out in the presence of a catalyst, and the amount of the catalyst used is 2% to 6% of the total weight of the monomer. The amount of the catalyst used in the imidization reaction is preferably 2.5% to 5% of the total weight of the monomer.

[0149] In some embodiments, the imidization reaction is carried out in the presence of a dehydrating agent, and the dehydrating agent is selected from one or both of acetic anhydride and toluene.

[0150] In some embodiments, the imidization reaction is carried out in the presence of a dehydrating agent, the amount of which is 1 to 4 times the mass of the catalyst. The amount of the dehydrating agent used in the imidization reaction is preferably 2 to 3 times the mass of the catalyst.

[0151] The third aspect of the present application provides a polyimide resin, which is prepared by the preparation method described in the second aspect.

[0152] The fourth aspect of the present application provides a polyimide resin slurry, comprising the polyimide resin described in the third aspect and a solvent.

[0153] The fifth aspect of the present application provides a polyimide film, which comprises the polyimide resin described in the third aspect; or the raw materials for preparing the polyimide film include diamine monomers and dianhydride monomers, the diamine monomers include at least one of naphthyl-containing diamines, anthracene-containing diamines and pyrene-containing diamines, and the dianhydride monomers include at least one of ester-containing dianhydrides and fluorine-containing dianhydrides.

[0154] Furthermore, the curing conditions of the polyimide film are as follows: the curing temperature is 180° C. to 260° C., preferably 200° C. to 240° C., and the curing time is 1 to 2 hours.

[0155] In some embodiments, the process of preparing a polyimide film includes dissolving the raw materials: adding a solvent to a three-necked flask kept flowing with nitrogen, wherein the solvent is selected from one or more of N-methylpyrrolidone, m-methylphenol, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, cyclohexanone, N,N-dimethylformamide, tetramethylene sulfone, and hexamethylphosphoramide; adding a naphthyl-containing diamine and / or anthracene-containing diamine to the above-mentioned organic solvent, and heating to 40~120°C for dissolution, preferably 60~100°C; after the diamine is completely dissolved, adding a fluorine-containing dianhydride and an ester-containing dianhydride respectively, and then raising the dissolution temperature to 120~180°C, preferably 130~160°C.

[0156] In some embodiments, the process of preparing a polyimide film includes adding a catalyst and a dehydrating agent for chemical imidization: the catalyst is selected from one or more of isoquinoline, N-ethylpiperidine, and triethylamine, and its amount is 2-6% of the total mass of the monomer, preferably 2.5-5%; the dehydrating agent is selected from one or more of acetic anhydride and toluene, and its amount is 1-4 times the mass of the catalyst, preferably 2-3 times; and the temperature is gradually raised to the target reaction temperature of 200°C~280°C, preferably 220°C~250°C, and continuous stirring and constant temperature reaction are performed for 1-10 hours, preferably 3-7 hours; after the reaction is completed, a high-viscosity polyimide resin is obtained, which is cooled to room temperature, and a solvent is added for dilution to obtain a polyimide resin slurry with moderate viscosity.

[0157] In some of the embodiments, the process of preparing the polyimide film includes blending perhydropolysilazane: weighing a certain amount of polyimide resin slurry, and then weighing a corresponding proportion of perhydropolysilazane according to the weight of the polyimide resin, dissolving or dispersing it in a small amount of organic solvent, the addition ratio of perhydropolysilazane is 1% to 12% of the mass of the polyimide resin, preferably 3% to 8%, to obtain a perhydropolysilazane solution; slowly adding the perhydropolysilazane solution to the polyimide resin slurry under stirring conditions, stirring for a certain time, and obtaining a mixed solution after complete dispersion.

[0158] In some embodiments, the process of preparing the polyimide film includes film formation: vacuum degassing the mixed solution, then using a desktop coater to scrape on a glass substrate to form a wet film, and placing the wet film in an oven to bake it into a dry film.

[0159] Furthermore, the baking temperature is 180° C. to 260° C., preferably 200° C. to 240° C., to obtain a polyimide film, which is a PI / PHPS composite film.

[0160] The following are specific embodiments.

[0161] Example 1

[0162] Build a four-necked flask, a stirring paddle, a reflux device and a ventilation device, test the air tightness, adjust to good air tightness, and introduce N2 into it to fully replace the air; at 70°C, dissolve 3.1359 grams of dry 2,6-diaminoanthracene in 30 grams of N, N-dimethylpyrrolidone. After the diamine monomer is completely dissolved, add 3.3785 grams of 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and 3.4856 grams of trimellitic anhydride hydroquinone ester, and raise the temperature to 140°C;

[0163] After dissolving for a certain period of time, 0.5 g of N-ethylpiperidine and 1.5 g of acetic anhydride were added, the temperature was raised to 250° C. at a heating rate of 5° C. / min, and the mixture was stirred at a constant temperature for 5 h for chemical imidization to obtain a polyimide colloidal solution with high viscosity. The polyimide colloidal solution was cooled to room temperature, and 15.5556 g of NMP was added for dilution, and the solid content thereof was controlled at 18%, thereby obtaining a polyimide resin slurry;

[0164] Weigh 15 g of polyimide resin slurry, use the weighed polyimide resin slurry as a standard, calculate the coating film based on 10% solid content, weigh 1.35 g of perhydropolysilazane, and disperse it in 12 g of NMP (N-methylpyrrolidone) to obtain a perhydropolysilazane solution; slowly add the perhydropolysilazane solution to the polyimide resin slurry under stirring, stir for a certain period of time, and obtain a mixed solution after complete dispersion;

[0165] The mixed liquid was vacuum degassed, and then coated on a glass substrate using a desktop coater to form a wet film. The wet film was placed in an oven for segmented baking, with a maximum baking temperature of 210° C. and a baking time of 1 h to obtain a polyimide film with a thickness of 25 μm, which was a PI / PHPS composite film.

[0166] Example 2

[0167] The reaction device was built, and the air tightness was tested and adjusted to good air tightness, and N2 was introduced into it to fully replace the air; at 70°C, 2.9644 g of dry 2,6-naphthalenediamine was dissolved in 30 g of N, N-dimethylpyrrolidone. After the diamine monomer was completely dissolved, 3.1937 g of 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and 3.8419 g of trimellitic anhydride-4,4'-biphenyl diphenol ester were added, and the temperature was raised to 140°C;

[0168] After dissolving for a certain period of time, 0.5 g of N-ethylpiperidine and 1.5 g of acetic anhydride were added, and the temperature was raised to 250° C. and stirred at a constant temperature for 5 hours for chemical imidization to obtain a polyimide colloidal solution with high viscosity. The polyimide colloidal solution was cooled to room temperature and 15.5556 g of NMP was added for dilution, and the solid content was controlled at 18% to obtain a polyimide resin slurry;

[0169] Weigh 15 g of polyimide resin slurry, use the weighed polyimide resin slurry as a standard, calculate the coating film based on 10% solid content, weigh 1.35 g of perhydropolysilazane, and disperse it in 12 g of NMP (N-methylpyrrolidone) to obtain a perhydropolysilazane solution; slowly add the perhydropolysilazane solution to the polyimide resin slurry under stirring, stir for a certain period of time, and obtain a mixed solution after complete dispersion;

[0170] The mixed liquid was vacuum degassed, and then coated on a glass substrate using a desktop coater to form a wet film. The wet film was placed in an oven for segmented baking, with a maximum baking temperature of 210° C. and a baking time of 1 h to obtain a polyimide film with a thickness of 25 μm, which was a PI / PHPS composite film.

[0171] Example 3

[0172] The preparation method of Example 3 is substantially the same as that of Example 1, except that no perhydropolysilazane is added.

[0173] Example 4

[0174] The preparation method of Example 4 is substantially the same as that of Example 1, except that 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride is not added.

[0175] Example 5

[0176] The preparation method of Example 5 is basically the same as that of Example 1, except that: trimellitic anhydride hydroquinone ester is not added.

[0177] Example 6

[0178] The preparation method of Example 6 is substantially the same as that of Example 1, except that 2,6-diaminoanthracene is replaced by a mixed diamine of equimolar amounts of 2,6-diaminoanthracene and 1,5-naphthalenediamine.

[0179] Example 7

[0180] The preparation method of Example 7 is basically the same as that of Example 1, except that an equal molar amount of phenyl benzoate-3,4,3'4'-tetracarboxylic dianhydride is used to replace trimellitic anhydride hydroquinone ester.

[0181] Example 8

[0182] The preparation method of Example 8 is basically the same as that of Example 1, except that an equimolar amount of trimellitic anhydride bisphenol A ester is used to replace trimellitic anhydride hydroquinone ester.

[0183] Comparative Example 1

[0184] The preparation method of Comparative Example 1 is substantially the same as that of Example 1, except that an equimolar amount of p-phenylenediamine is used to replace 2,6-diaminoanthracene.

[0185] Comparative Example 2

[0186] The preparation method of Comparative Example 2 is substantially the same as that of Example 1, except that an equal molar amount of pyromellitic dianhydride is used to replace 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and trimellitic anhydride hydroquinone ester.

[0187] The polyimide films with a thickness of 25 μm prepared in Examples 1 to 8 and Comparative Examples 1 to 2 were tested for tensile strength, glass transition temperature and water absorption. The test results are shown in Table 1 below.

[0188] Among them, the test standards for each performance test item are as follows:

[0189] Tensile strength: GB / T 13542.6-2006 "Electrical insulating films Part 6: Polyimide films for electrical insulation".

[0190] Glass transition temperature: GB / T 22567-2008 "Test method for determining glass transition temperature of electrical insulating materials".

[0191] Water absorption: GB / T 1034-1970 "Test method for water absorption of plastics".

[0192] Table 1

[0193]

[0194] As can be seen from Table 1 above, the water absorption rate of the polyimide film prepared by using diamine monomers containing biphenyl structures such as naphthyl structures and anthracene structures and using ester-containing dianhydrides and / or fluorine-containing dianhydrides as dianhydride monomers is significantly lower than the water absorption rate of the polyimide precursor solution prepared by using p-phenylenediamine as the diamine monomer in Comparative Example 1. The polyimide prepared by using pyromellitic dianhydride as the dianhydride monomer in Comparative Example 2 is too rigid to form a film.

[0195] It can be seen from Example 3 that the addition of perhydropolysilazane can significantly reduce the water absorption rate of polyimide.

[0196] It can be seen from Example 7 that when an anthracene-containing diamine is used as the diamine monomer and a fluorine-containing dianhydride and an ester-containing dianhydride are used at the same time, the water absorption rate of the prepared polyimide film is lower.

[0197] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0198] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polyimide resin, characterized in that: The raw materials for preparing the polyimide resin include diamine monomers and dianhydride monomers. The diamine monomers include at least one of naphthyl-containing diamines, anthracene-containing diamines and pyrene-containing diamines. The dianhydride monomers include at least one of ester-containing dianhydrides and fluorine-containing dianhydrides.

2. The polyimide resin according to claim 1, wherein The polyimide resin includes partially oxidized perhydropolysilazane, and the partially oxidized perhydropolysilazane dopes the diamine monomer and the dianhydride monomer to form a polyimide.

3. The polyimide resin according to claim 1, wherein The added amount of the partially oxidized perhydropolysilazane accounts for 1% to 12% of the mass of the polyimide resin.

4. The polyimide resin according to claim 1, wherein At least one of the following conditions is met: (1) The naphthyl-containing diamine comprises a naphthalene ring and two amino groups, with the naphthalene ring as the mother ring and the two amino groups connected to the naphthalene ring; (2) The anthracene-containing diamine comprises an anthracene ring and two amino groups, with the anthracene ring as the parent ring and the two amino groups connected to the anthracene ring; (3) The pyrene-containing diamine comprises a pyrene ring and two amino groups, with the pyrene ring serving as a parent ring and the two amino groups being connected to the pyrene ring.

5. The polyimide resin according to claim 1, wherein At least one of the following conditions is met: (1) The naphthyl-containing diamine includes at least one of 2,6-naphthalene diamine, 1,5-naphthalene diamine, 2,7-naphthalene diamine, 2,2'-diaminobinaphthyl, 4,4'-diamino-2,2'-dimethylbinaphthyl and 4,4'-diamino-3,3'-dimethylbinaphthyl; (2) the anthracene-containing diamine includes at least one of 1,4-diaminoanthracene and 2,6-diaminoanthracene; (3) The pyrene-containing diamine includes at least one of 1,6-diaminopyrene and 1,8-diaminopyrene.

6. The polyimide resin according to claim 1, wherein At least one of the following conditions is met: (1) The molar ratio of the dianhydride monomer to the diamine monomer is 1:0.9-1.2; (2) The dianhydride monomers include ester-containing dianhydrides and fluorine-containing dianhydrides.

7. The polyimide resin according to claim 1, wherein The structural formula of the dianhydride containing the ester group is as follows: Wherein, L represents a structure containing an ester group; and n represents the degree of polymerization.

8. The polyimide resin according to any one of claims 1 to 7, characterized in that The ester-containing dianhydride includes at least one of phenyl benzoate-3,4,3'4'-tetracarboxylic dianhydride, trimellitic anhydride hydroquinone ester, trimellitic anhydride resorcinol ester, trimellitic anhydride methyl hydroquinone ester, trimellitic anhydride tert-butyl hydroquinone ester, trimellitic anhydride-4,4'-biphenyl diphenol ester, trimellitic anhydride-2,2'-biphenyl diphenol ester, trimellitic anhydride bisphenol A ester, trimellitic anhydride-4.4'-diphenyl sulfone diphenol ester, trimellitic anhydride-2,2'-binaphthol ester, diether diphenyl anhydride containing a chalcone structure, and diether diphenyl anhydride containing a divinyl ketone structure.

9. The polyimide resin according to any one of claims 1 to 7, characterized in that The fluorine-containing dianhydride includes at least one of 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride and 9,9-bis(trifluoromethyl)-2,3,6,7-oxanthene tetracarboxylic dianhydride.

10. A method for preparing a polyimide resin according to any one of claims 1 to 9, characterized in that: The following steps are involved: The diamine monomer and the dianhydride monomer are subjected to imidization reaction in a solvent to obtain the polyimide resin; The diamine monomer includes at least one of a naphthyl-containing diamine, anthracene-containing diamine and a pyrene-containing diamine, and the dianhydride monomer includes at least one of an ester-containing dianhydride and a fluorine-containing dianhydride.

11. The method for preparing a polyimide resin according to claim 10, wherein: After the imidization reaction is carried out and before the polyimide resin is obtained, the following step is further included: adding perhydropolysilazane to the reaction solution obtained from the imidization reaction and blending them to obtain the polyimide resin doped with perhydropolysilazane.

12. The method for preparing a polyimide resin according to claim 10 or 11, characterized in that: The imidization reaction satisfies one or more of the following conditions: (1) The starting temperature of the imidization reaction is 120°C to 180°C, the isothermal reaction temperature is 200°C to 280°C, and the heating rate is 4°C / min to 6°C / min; (2) The isothermal reaction time of the imidization reaction is 1 h to 10 h; (3) the imidization reaction is carried out in the presence of a catalyst, wherein the catalyst is selected from one or more of isoquinoline, N-ethylpiperidine and triethylamine; (4) The imidization reaction is carried out in the presence of a catalyst, wherein the amount of the catalyst used accounts for 2% to 6% of the total weight of the monomer; (5) the imidization reaction is carried out in the presence of a dehydrating agent, wherein the dehydrating agent is selected from one or both of acetic anhydride and toluene; (6) The imidization reaction is carried out in the presence of a dehydrating agent, wherein the amount of the dehydrating agent is 1 to 4 times the mass of the catalyst; (7) The solvent is selected from one or more of: N-methylpyrrolidone, m-methylphenol, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, cyclohexanone, N,N-dimethylformamide, tetramethylene sulfone and hexamethylphosphoramide.

13. A polyimide resin, characterized in that: The polyimide resin is prepared by the preparation method according to any one of claims 10 to 12.

14. A polyimide resin slurry, characterized in that: The invention comprises the polyimide resin according to claim 13 and a solvent.

15. A polyimide film, characterized in that: The polyimide film comprises the polyimide resin described in claim 13; or the raw materials for preparing the polyimide film include diamine monomers and dianhydride monomers, the diamine monomers include at least one of naphthyl-containing diamines, anthracene-containing diamines and pyrene-containing diamines, and the dianhydride monomers include at least one of ester-containing dianhydrides and fluorine-containing dianhydrides.

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