A hyperbranched polyimide adhesive composition, its preparation method and application

Abstract

This invention discloses a hyperbranched polyimide adhesive composition, its preparation method, and its applications. The hyperbranched polyimide adhesive composition includes a reactive hyperbranched polyimide resin, an epoxy resin having three or more epoxy groups, and a latent curing agent. The preparation method of the reactive hyperbranched polyimide resin involves reacting an aromatic dianhydride compound with a polyamine, then adding an end-capping agent to introduce crosslinkable end groups, and finally adding a dehydrating agent and a catalyst to carry out a chemical imidization reaction. This invention combines the low dielectric properties of the hyperbranched structure with the high heat resistance of the terminal crosslinking groups, and forms a synergistic interpenetrating network with a multifunctional epoxy resin. The adhesive layer formed after curing of this composition has extremely low dielectric constant and dielectric loss, high glass transition temperature, excellent solder heat resistance, and high peel strength, making it particularly suitable for the manufacture of high-frequency copper-clad laminates and printed circuit boards in fields such as 5G communication and high-speed computing.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a hyperbranched polyimide adhesive composition, its preparation method, and its application. Background Technology

[0002] With the rapid development of technologies such as 5G communication, artificial intelligence, high-performance computing, and millimeter-wave radar, the requirements for signal transmission rate and integrity of electronic circuit boards are becoming increasingly stringent. Signal transmission loss is related to the dielectric constant (D) of the substrate material. k ) and dielectric loss factor (D f It is proportional to the square root of ), therefore, the development of ultra-low D k / D f Adhesive materials with high heat resistance, high reliability, and good processability have become current research hotspots and challenges.

[0003] Polyimide (PI) is widely used as a cover layer and adhesive for flexible printed circuit boards due to its excellent heat resistance, mechanical properties, and electrical insulation. To reduce its dielectric constant, a traditional method is to introduce fluorinated groups or aliphatic segments into the polyimide molecular chain. However, fluorinated monomers are expensive and sometimes lack sufficient thermal stability; while introducing flexible aliphatic segments typically lowers the material's glass transition temperature (Tg). g This leads to a decrease in its heat resistance, making it difficult to meet the requirements of high-end packaging. Therefore, there is an urgent need to develop a new polyimide and use it in adhesives to solve the above problems. Summary of the Invention

[0004] To address the problems mentioned in the background section, the present invention aims to provide a hyperbranched polyimide adhesive composition, its preparation method, and its applications. This invention, through innovative molecular design, combines the low dielectric properties of the hyperbranched structure with the high heat resistance of the terminal crosslinking groups, forming a synergistic interpenetrating network with a multifunctional epoxy resin. The adhesive layer formed after curing of the hyperbranched polyimide adhesive composition possesses extremely low dielectric constant and dielectric loss, high glass transition temperature, excellent solder heat resistance, and high peel strength, making it particularly suitable for the manufacture of high-frequency copper-clad laminates and printed circuit boards in fields such as 5G communication and high-speed computing.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On one hand, the present invention provides a method for preparing reactive hyperbranched polyimide resin, comprising the following steps:

[0006] An aromatic dianhydride compound and a polyamine are reacted, then a capping agent is added to introduce crosslinkable end groups, and finally a dehydrating agent and a catalyst are added to carry out a chemical imidization reaction to obtain the reactive hyperbranched polyimide resin.

[0007] Furthermore, the specific steps include:

[0008] An aromatic dianhydride compound is dissolved in an organic solvent to obtain an aromatic dianhydride compound solution. A polyamine is dissolved in an organic solvent to obtain a polyamine solution. The polyamine solution is slowly added dropwise to the aromatic dianhydride compound solution at 30℃~100℃. After the addition is completed, the reaction continues for 2h~8h to obtain a hyperbranched polyamic acid solution. Then, an end-capping agent is added, and the reaction continues for 1h~6h at 30℃~100℃ to introduce crosslinkable end groups. Finally, a dehydrating agent and a catalyst are added, and a chemical imidization reaction is carried out at 120℃~180℃ for 3h~10h to obtain the reactive hyperbranched polyimide resin.

[0009] The molecular chain ends of the hyperbranched polyamic acid of this invention can be either an anhydride group or an amine group. The terminal functional group can be controlled by adjusting the ratio of aromatic dianhydride compound to polyamine. If the molecular chain end is an anhydride group, a crosslinkable end group can be introduced by an amino-containing end-capping agent; if the molecular chain end is an amine group, a crosslinkable end group can be introduced by an anhydride-containing end-capping agent.

[0010] Further, the aromatic dianhydride compound includes at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-biphenyl ether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride), 4,4'-(hexafluoroisopropene)phthalic anhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, and bis(triphenyl phthalate).

[0011] Furthermore, the polyamine is a ternary primary amine, a primary amine with more than three components, a combination of ternary primary amines and more than three components, a combination of diamine and ternary primary amines, a combination of diamine and more than three components, or a combination of diamine, ternary primary amines, and more than three components. Ternary primary amines and more than three components can provide three-dimensional growth points, ensuring the formation of a highly branched molecular structure.

[0012] Furthermore, the ternary primary amine includes at least one of tris(2-aminoethyl)amine, tris(3-aminopropyl)amine, polyether triamine, etc.

[0013] Furthermore, the polyether triamine includes at least one of commercially available products such as Baxxodur EC 310, JEFFAMINE T-403, JEFFAMINE T-3000, and JEFFAMINE T-5000.

[0014] Furthermore, the ternary or higher primary amines include dendritic polyamide-amines (PAMAM), etc.

[0015] Furthermore, the dendritic polyamide-amine includes at least one of 1.0 generation PAMAM and 2.0 generation PAMAM.

[0016] Furthermore, the primary diamine includes at least one of aliphatic diamines, alicyclic diamines, and aromatic diamines.

[0017] Further, the aliphatic diamine includes at least one of ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, PRIAMINE 1074, PRIAMINE 1075, etc.

[0018] Furthermore, the alicyclic diamine includes at least one of 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,2-cyclohexanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-isopropyldicyclohexylamine, isophoronediamine, etc.

[0019] Further, the aromatic diamine includes at least one of 4,4'-diaminodiphenyl ether, p-phenylenediamine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, and 4,4'-diaminodiphenylmethane.

[0020] Furthermore, the crosslinkable end group is selected from allyl, vinyl, styrene, phenylethynyl, ethynyl, maleimide, or nadicimide.

[0021] Furthermore, the end-capping agent is selected from 4-allyloxyaniline, 4-vinylaniline, 3-vinylaniline, 3-ethynylaniline, 4-ethynylaniline, 4-(phenylethynyl)phthalic anhydride, maleic anhydride, or nadic anhydride, etc. The end-capping agent introduces active groups that can undergo highly efficient reactions at high temperatures while completing the molecular chain end-capping.

[0022] Furthermore, the dehydrating agent includes at least one of aliphatic carboxylic anhydrides and aromatic carboxylic anhydrides.

[0023] Furthermore, the aliphatic carboxylic anhydride includes at least one of acetic anhydride, trifluoroacetic anhydride, propionic anhydride, etc.

[0024] Furthermore, the aromatic carboxylic anhydride includes benzoic anhydride, etc.

[0025] Furthermore, the catalyst is at least one of aliphatic tertiary amines, aromatic tertiary amines, and heterocyclic tertiary amines.

[0026] Furthermore, the aliphatic tertiary amine includes triethylamine, etc.

[0027] Furthermore, the aromatic tertiary amine includes dimethylaniline, etc.

[0028] Furthermore, the heterocyclic tertiary amine includes at least one of pyridine, methylpyridine, isoquinoline, etc.

[0029] Furthermore, the organic solvent includes at least one of amide solvents, ketone solvents, ester solvents, ether solvents, alcohol solvents, and hydrocarbon solvents.

[0030] Furthermore, the amide solvent includes at least one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-diethylacetamide.

[0031] Furthermore, the ketone solvent includes at least one of methyl ethyl ketone, methyl n-propyl ketone, methyl isopropyl ketone, diethyl ketone, cyclopentanone, cyclohexanone, and methyl cyclohexanone.

[0032] Further, the ester solvent includes at least one of n-propyl formate, isopropyl formate, n-butyl formate, isobutyl formate, ethyl acetate, n-propyl acetate, and isopropyl acetate.

[0033] Furthermore, the ether solvent includes at least one of tetrahydrofuran, 1,4-dioxane, ethyl n-propyl ether, di n-propyl ether, diisopropyl ether, 1,2-dimethoxyethane, 1,1-diethoxyethane, and 1,2-diethoxyethane.

[0034] Furthermore, the alcohol solvent includes at least one of methanol, ethanol, n-propanol, isopropanol, and tert-butanol.

[0035] Furthermore, the hydrocarbon solvent includes at least one selected from n-hexane, n-octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, and xylene.

[0036] Furthermore, the molar ratio of the anhydride group to the amino group of the polyamine in the aromatic dianhydride compound is 100:(50~150), preferably 100:(80~120).

[0037] Furthermore, when the polyamine includes a diamine, the molar number of the diamine is 10% to 95% of the molar number of the polyamine.

[0038] Furthermore, the molar number of the capping agent is 1 to 2 times the difference between the molar number of the anhydride group of the aromatic dianhydride compound and the molar number of the amino group of the polyamine.

[0039] Furthermore, the molar number of the dehydrating agent is 2 to 10 times the molar number of the aromatic dianhydride compound.

[0040] Furthermore, the number of moles of the catalyst is 1 to 5 times the number of moles of the aromatic dianhydride compound.

[0041] Furthermore, the weight-average molecular weight of the reactive hyperbranched polyimide resin is 5000-50000. This molecular weight range ensures that the resin has good solubility, low melt viscosity, and a moderate functional group density.

[0042] On the other hand, the present invention provides a reactive hyperbranched polyimide resin, which is prepared by any of the preparation methods described above.

[0043] On the other hand, the present invention provides a hyperbranched polyimide adhesive composition comprising the following components in parts by weight:

[0044] Component A: 100 parts of the reactive hyperbranched polyimide resin described above; Component B: 1 to 50 parts (preferably 5 to 30 parts) of epoxy resin having three or more epoxy groups; Component C: 1 to 20 parts (preferably 1 to 10 parts) of latent curing agent.

[0045] Further, the epoxy resin having three or more epoxy groups is selected from at least one of tris(ethylene oxide-2-ylmethyl)amine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetra(ethylene oxide methyl)-1,3-phenylenediamine, triglycidyl-p-aminophenol, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane, and triglycidyl isocyanate. Epoxy resins having three or more epoxy groups contribute to improving the peel strength and solder heat resistance of polyimide adhesive compositions. These multifunctional epoxy resins can form a network with high cross-linking density, which interpenetrates with the hyperbranched polyimide network.

[0046] Further, the latent curing agent includes at least one of dicyandiamide, adipate dihydrazide, sebacic dihydrazide, dodecanoic dihydrazide, isophthaloyl hydrazide, diaminomaleonitrile, 4,4'-diaminodiphenyl sulfone, and microencapsulated aromatic amines. Preferably, the microencapsulated aromatic amine includes diaminodiphenylmethane-polymethyl methacrylate (PMMA) microcapsules, etc. These latent curing agents ensure the composition is stable at room temperature and reacts rapidly only when heated to a predetermined temperature, providing excellent processability.

[0047] Furthermore, component B in the hyperbranched polyimide adhesive composition may also include an epoxy resin having two epoxy groups. The epoxy resin having two epoxy groups includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, and N,N-bis(glycidyl)aniline.

[0048] Furthermore, the hyperbranched polyimide adhesive composition may also include component D: 1 to 30 parts of inorganic filler (preferably 5 to 20 parts).

[0049] Furthermore, the inorganic filler is silicon dioxide or boron nitride with a surface treated with a silane coupling agent, and its average particle size is 0.05~2μm. The introduction of the inorganic filler can further adjust the dielectric constant, reduce the coefficient of thermal expansion, and improve thermal conductivity.

[0050] In another aspect, the present invention provides a resin film prepared by the following method: dissolving the components of any of the above-described hyperbranched polyimide adhesive compositions in a solvent to obtain an adhesive solution, coating the adhesive solution onto a substrate, and drying and / or semi-curing to obtain a resin film.

[0051] Furthermore, the solvent is an organic solvent. The amount of solvent used is selected by those skilled in the art based on experience and process requirements to achieve a suitable viscosity for the composition, facilitating the coating of the adhesive composition. Subsequently, during the drying and curing stages, the solvent in the adhesive composition will partially or completely evaporate.

[0052] The organic solvent used to dissolve and disperse the hyperbranched polyimide adhesive composition is not particularly limited and can be: amide solvents such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-diethylacetamide; ketone solvents such as methyl ethyl ketone, methyl n-propyl ketone, methyl isopropyl ketone, diethyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone; ester solvents such as n-propyl formate, isopropyl formate, n-butyl formate, isobutyl formate, ethyl acetate, n-propyl acetate, and isopropyl acetate; ether solvents such as tetrahydrofuran, 1,4-dioxane, ethyl n-propyl ether, di-n-propyl ether, diisopropyl ether, 1,2-dimethoxyethane, 1,1-diethoxyethane, and 1,2-diethoxyethane; and hydrocarbon solvents such as n-hexane, n-octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, and xylene. The solvents mentioned above can be used alone, or two or more can be mixed together.

[0053] In another aspect, the present invention provides the application of any of the above-described hyperbranched polyimide adhesive compositions or the above-described resin films in adhesive sheets, resin-coated copper foils, copper-clad laminates, and printed circuit boards.

[0054] In another aspect, the present invention provides an adhesive sheet comprising a support film and the resin film described above.

[0055] Furthermore, the support film includes films such as polyimide, polyester, polyethylene, polypropylene, and polytetrafluoroethylene.

[0056] Furthermore, the adhesive sheet is prepared by dissolving the components of any of the above-described hyperbranched polyimide adhesive compositions in a solvent and coating them onto a support film, followed by drying and / or semi-curing.

[0057] Alternatively, a resin film can be bonded to the other side of the adhesive sheet support film to form a double-sided adhesive sheet.

[0058] In another aspect, the present invention provides a resin-coated copper foil, comprising a copper foil and the resin film described above.

[0059] Furthermore, the resin-coated copper foil is prepared by dissolving the components of any of the above-described hyperbranched polyimide adhesive compositions in a solvent and coating them onto a copper foil, followed by drying and / or semi-curing.

[0060] Alternatively, a resin film can be further laminated onto the copper foil with resin to form a double-sided resin-coated copper foil.

[0061] In another aspect, the present invention provides a copper-clad laminate, the copper-clad laminate comprising the resin-coated copper foil described above, and a copper foil or insulating substrate.

[0062] Furthermore, the copper-clad laminate is formed by pressing the resin-coated copper foil onto one or both sides of various known copper foils or insulating substrates under heating. When only one side is bonded, a material different from the resin-coated copper foil can be pressed onto the other side. Additionally, there is no particular limitation on the number of sheets of resin-coated copper foil, copper foil, and insulating substrate in the copper-clad laminate.

[0063] Furthermore, the insulating substrate is preferably a prepreg or a support film. The prepreg refers to a sheet material formed by impregnating a resin in a reinforcing material such as glass cloth and then curing it to stage B. The resin can be an insulating resin such as the hyperbranched polyimide adhesive composition of the present invention, phenolic resin, epoxy resin, or bismaleimide resin.

[0064] In another aspect, the present invention provides a copper-clad laminate, the copper-clad laminate comprising the adhesive sheet described above, and copper foil or the resin-coated copper foil described above.

[0065] Furthermore, the copper-clad laminate is formed by pressing the copper foil or resin-coated copper foil onto one or both sides of the adhesive sheet under heating.

[0066] Furthermore, the heating temperature is 150℃~280℃, preferably 180℃~250℃.

[0067] Furthermore, the pressing pressure is 0.5MPa to 20MPa, preferably 1MPa to 8MPa; the pressing time is 5min to 240min.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] (1) This invention is the first to combine hyperbranched structure with end-crosslinking technology in polyimide adhesives. The unique three-dimensional structure and large internal free volume of hyperbranched molecules fundamentally endow the material with extremely low dielectric constant and loss. The end crosslinkable groups (such as acetylene groups) undergo efficient crosslinking reactions at high temperatures (such as the trimerization of acetylene groups into benzene rings), forming a highly crosslinked, dense, and rigid network structure, which greatly improves the heat resistance (T) of the material. g >300℃). This crosslinking reaction does not produce small molecule byproducts, thus avoiding porosity issues. Furthermore, hyperbranched polyimide (component A) and multifunctional epoxy resin (component B) can form interpenetrating network (IPN) or semi-interpenetrating network (Semi-IPN) structures during the curing process. The hyperbranched molecules, acting as a "molecular scaffold," enhance the uniformity and toughness of the entire network, resulting in a synergistic effect of "1+1>2".

[0070] (2) The hyperbranched polyimide adhesive composition of the present invention exhibits excellent comprehensive performance: its cured product has extremely low dielectric properties, and at a high frequency of 10 GHz, Dk It can be lower than 2.7, D f It can be controlled at an extremely low level of 0.0020~0.0025, which is superior to existing technologies and can greatly reduce signal transmission loss; in terms of heat resistance, the cured material T g Exceeding 350°C, it easily passes solder heat resistance tests at 288°C for over 60 seconds without delamination or blistering; simultaneously, its adhesion strength to copper foil reaches over 1.3 N / mm. The hyperbranched polyimide adhesive composition exhibits good solubility and low melt viscosity during processing, and the B-stage adhesive film possesses excellent spreadability and gap-filling ability. These properties make it particularly suitable for manufacturing interlayer bonding materials for high-frequency copper-clad laminates and printed circuit boards. Detailed Implementation

[0071] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0072] Example 1

[0073] Preparation of reactive hyperbranched polyimide resins:

[0074] In a reaction vessel equipped with a mechanical stirrer, thermometer, water separator, and nitrogen protection, 150 g of N-methylpyrrolidone (NMP) and 0.10 mol of 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride) (BPADA) were added and stirred to dissolve. The mixture was heated to 50 °C, and 50 g of NMP solution containing 0.05 mol of tris(2-aminoethyl)amine and 0.02 mol of 4,4'-diaminodiphenyl ether (ODA) was slowly added dropwise. The reaction was continued for 6 hours to obtain a hyperbranched polyamic acid solution. Subsequently, 0.01 mol of 3-ethynylaniline was added as a capping agent, and the reaction was continued for 4 hours. Finally, 0.4 mol of acetic anhydride and 0.2 mol of pyridine were added as a dehydrating agent and catalyst, and the temperature was gradually increased to 150 °C for a chemical imidization reaction for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, poured into a large amount of deionized water to precipitate, filtered, and washed three times with methanol. The obtained solid was dried in a vacuum oven at 120°C for 24 hours to obtain a brownish-red powder of terminal acetylene hyperbranched polyimide resin (A-1) with a yield of 92%.

[0075] Example 2

[0076] Preparation of reactive hyperbranched polyimide resins:

[0077] The preparation steps are basically the same as in Example 1, except that the 0.01 mol 3-ethynylaniline end-capping agent is replaced with 0.01 mol 4-allyloxyaniline to obtain terminal allyl hyperbranched polyimide resin (A-2).

[0078] Example 3

[0079] Hyperbranched polyimide adhesive composition: comprising the following components in parts by weight: 100 parts of A-1 resin prepared in Example 1, 10 parts of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604) and 2.5 parts of dicyandiamide.

[0080] Preparation of the adhesive sheet: 100 parts by weight of A-1 resin, 10 parts by weight of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604), and 2.5 parts by weight of dicyandiamide were added to a container containing 262.5 parts by weight of a mixed solvent of N,N-dimethylacetamide / xylene (mass ratio 7:3). The mixture was stirred at high speed and dispersed evenly to obtain a glue solution with a solid content of 30%. The glue solution was coated onto a 25 μm thick polyimide film (DuPont, Kapton 100EN) using a slit coater and dried in an oven at 150°C for 5 minutes to obtain a stage B glue film with a thickness of 15 μm.

[0081] Preparation of copper-clad laminate: The adhesive side of the above adhesive sheet is stacked with an 18μm thick electrolytic copper foil (mirror finish), placed in a vacuum press, and pressed for 120 minutes at 220℃ and 3MPa pressure. After natural cooling, it is taken out to obtain the copper-clad laminate.

[0082] Example 4

[0083] Hyperbranched polyimide adhesive composition: comprising the following components in parts by weight: 100 parts of A-2 resin prepared in Example 2, 10 parts of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604) and 2.5 parts of dicyandiamide.

[0084] Preparation of the adhesive sheet: 100 parts by weight of A-2 resin, 10 parts by weight of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604), and 2.5 parts by weight of dicyandiamide were added to a container containing 262.5 parts by weight of a mixed solvent of N,N-dimethylacetamide / xylene (mass ratio 7:3). The mixture was stirred at high speed and dispersed evenly to obtain a glue solution with a solid content of 30%. The glue solution was coated onto a 25 μm thick polyimide film (DuPont, Kapton 100EN) using a slit coater and dried in an oven at 150°C for 5 minutes to obtain a stage B glue film with a thickness of 15 μm.

[0085] Preparation of copper-clad laminate: The adhesive side of the above adhesive sheet is stacked with an 18μm thick electrolytic copper foil (mirror finish), placed in a vacuum press, and pressed for 120 minutes at 220℃ and 3MPa pressure. After natural cooling, it is taken out to obtain the copper-clad laminate.

[0086] Comparative Example 1

[0087] Preparation of hyperbranched polyimide resin:

[0088] The preparation steps are basically the same as in Example 1, except that the end-capping agent 3-ethynylaniline is not added during synthesis, that is, the step "Subsequently, 0.01 mol of 3-ethynylaniline is added as an end-capping agent and the reaction continues for 4 hours" is omitted, resulting in uncapped hyperbranched polyimide resin (A-3).

[0089] Comparative Example 2

[0090] Preparation of linear polyimide resin:

[0091] The preparation steps were basically the same as in Example 1, except that 0.05 mol of tris(2-aminoethyl)amine was replaced with 0.075 mol of 1,6-hexanediamine to obtain linear polyimide resin (A-4).

[0092] Comparative Example 3

[0093] Hyperbranched polyimide adhesive composition: comprising the following components in parts by weight: 100 parts of A-3 resin prepared in Comparative Example 1, 10 parts of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604) and 2.5 parts of dicyandiamide.

[0094] Preparation of the adhesive sheet: 100 parts by weight of A-3 resin, 10 parts by weight of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604), and 2.5 parts by weight of dicyandiamide were added to a container containing 262.5 parts by weight of a mixed solvent of N,N-dimethylacetamide / xylene (mass ratio 7:3). The mixture was stirred at high speed and dispersed evenly to obtain a glue solution with a solid content of 30%. The glue solution was coated onto a 25 μm thick polyimide film (DuPont, Kapton 100EN) using a slit coater and dried in an oven at 150°C for 5 minutes to obtain a stage B glue film with a thickness of 15 μm.

[0095] Preparation of copper-clad laminate: The adhesive side of the above adhesive sheet is stacked with an 18μm thick electrolytic copper foil (mirror finish), placed in a vacuum press, and pressed for 120 minutes at 220℃ and 3MPa pressure. After natural cooling, it is taken out to obtain the copper-clad laminate.

[0096] Comparative Example 4

[0097] Linear polyimide adhesive composition: comprising the following components in parts by weight: 100 parts of A-4 resin prepared in Comparative Example 2, 10 parts of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604) and 2.5 parts of dicyandiamide.

[0098] Preparation of the adhesive sheet: 100 parts by weight of A-4 resin, 10 parts by weight of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane (Mitsubishi Chemical, JER604), and 2.5 parts by weight of dicyandiamide were added to a container containing 262.5 parts by weight of a mixed solvent of N,N-dimethylacetamide / xylene (mass ratio 7:3). The mixture was stirred at high speed and dispersed evenly to obtain a glue solution with a solid content of 30%. The glue solution was coated onto a 25 μm thick polyimide film (DuPont, Kapton 100EN) using a slit coater and dried in an oven at 150°C for 5 minutes to obtain a stage B glue film with a thickness of 15 μm.

[0099] Preparation of copper-clad laminate: The adhesive side of the above adhesive sheet is stacked with an 18μm thick electrolytic copper foil (mirror finish), placed in a vacuum press, and pressed for 120 minutes at 220℃ and 3MPa pressure. After natural cooling, it is taken out to obtain the copper-clad laminate.

[0100] The copper-clad laminate prepared above was subjected to the following performance tests:

[0101] (1) Dielectric properties (D) k D f The SPDR (Split Post Dielectric Resonator) method was used to test the D at 10 GHz according to IPCTM-650 2.5.5.13. k and D f value.

[0102] (2) Peel strength: Tested according to the method of IPC TM-650 2.4.9.

[0103] (3) Glass transition temperature T g Dynamic thermomechanical analysis (DMA) was used, and the determination was performed according to the DMA method specified in IPC TM-650 2.4.24.4.

[0104] (4) Solder heat resistance: Immerse the sample in a molten solder bath at 288°C and observe the time until bubbling and delamination occur (unit: seconds).

[0105] The test results are shown in the table below.

[0106]

[0107] As can be seen from the data in the table, the hyperbranched polyimide adhesive compositions in Examples 3 and 4 of this invention exhibit significantly better overall performance than Comparative Examples 3 and 4, particularly with a substantial improvement in the heat resistance of the cured products. This fully demonstrates that the synergistic effect of the hyperbranched structure and end crosslinking plays a positive role in improving the overall performance in terms of dielectric properties, solder heat resistance, glass transition temperature, peel strength, and other aspects.

[0108] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A hyperbranched polyimide adhesive composition, characterized in that, Includes the following components in parts by weight: 100 parts of reactive hyperbranched polyimide resin, 1-50 parts of epoxy resin with three or more epoxy groups, and 1-20 parts of latent curing agent. The preparation method of the reactive hyperbranched polyimide resin includes the following steps: An aromatic dianhydride compound is dissolved in an organic solvent to obtain an aromatic dianhydride compound solution. A polyamine is dissolved in an organic solvent to obtain a polyamine solution. The polyamine solution is slowly added dropwise to the aromatic dianhydride compound solution at 30℃~100℃. After the addition is completed, the reaction continues for 2h~8h to obtain a hyperbranched polyamic acid solution. Then, a capping agent is added, and the reaction continues at 30℃~100℃ for 1h~6h to introduce crosslinkable end groups. Finally, a dehydrating agent and a catalyst are added, and a chemical imidization reaction is carried out at 120℃~180℃ for 3h~10h to obtain the reactive hyperbranched polyimide resin. The polyamine is a combination of diamines and triamines; The ternary primary amine includes at least one of tris(2-aminoethyl)amine and tris(3-aminopropyl)amine; The end-capping agent is selected from 4-allyloxyaniline, 4-vinylaniline, 3-vinylaniline, 3-ethynylaniline, 4-ethynylaniline, 4-(phenylethynyl)phthalic anhydride, maleic anhydride, or nadic anhydride. The molar number of the diamine is 10% to 95% of the molar number of the polyamine.

2. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The aromatic dianhydride compound includes at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-biphenyl ether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride), 4,4'-(hexafluoroisopropene)phthalic anhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, and bis(triphenylamine) phenyl ester.

3. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The primary diamine includes at least one of aliphatic diamines, alicyclic diamines, and aromatic diamines.

4. The hyperbranched polyimide adhesive composition according to claim 3, characterized in that, The aliphatic diamines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, PRIAMINE 1074, and PRIAMINE. At least one of 1075; the alicyclic diamine includes at least one of 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,2-cyclohexanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-isopropyldicyclohexylamine, and isophoronediamine; the aromatic diamine includes at least one of 4,4'-diaminodiphenyl ether, p-phenylenediamine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, and 4,4'-diaminodiphenylmethane.

5. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The dehydrating agent includes at least one of aliphatic carboxylic anhydrides and aromatic carboxylic anhydrides.

6. The hyperbranched polyimide adhesive composition according to claim 5, characterized in that, The aliphatic carboxylic anhydride includes at least one of acetic anhydride, trifluoroacetic anhydride, and propionic anhydride; the aromatic carboxylic anhydride includes benzoic anhydride.

7. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The catalyst is at least one of aliphatic tertiary amines, aromatic tertiary amines, and heterocyclic tertiary amines.

8. The hyperbranched polyimide adhesive composition according to claim 7, characterized in that, The aliphatic tertiary amine includes triethylamine; the aromatic tertiary amine includes dimethylaniline; the heterocyclic tertiary amine includes at least one of pyridine, methylpyridine, and isoquinoline.

9. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The molar ratio of the anhydride group to the amino group of the polyamine in the aromatic dianhydride compound is 100:(50~150).

10. The hyperbranched polyimide adhesive composition according to claim 9, characterized in that, The molar ratio of the anhydride group to the amino group of the polyamine in the aromatic dianhydride compound is 100:(80~120).

11. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The molar number of the capping agent is 1 to 2 times the difference between the molar number of the anhydride group of the aromatic dianhydride compound and the molar number of the amino group of the polyamine.

12. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The molar number of the dehydrating agent is 2 to 10 times the molar number of the aromatic dianhydride compound.

13. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The number of moles of the catalyst is 1 to 5 times the number of moles of the aromatic dianhydride compound.

14. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The weight-average molecular weight of the reactive hyperbranched polyimide resin is 5000~50000.

15. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The epoxy resin having three or more epoxy groups is selected from at least one of tris(ethylene oxide-2-ylmethyl)amine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetra(ethylene oxide methyl)-1,3-phenylenediamine, triglycidyl-p-aminophenol, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane, and triglycidyl isocyanurate.

16. The hyperbranched polyimide adhesive composition according to claim 1, characterized in that, The latent curing agent includes at least one of dicyandiamide, adipate dihydrazide, sebacic dihydrazide, dodecanoic dihydrazide, isophthalic dihydrazide, diaminomaleonitrile, 4,4'-diaminodiphenyl sulfone, and microencapsulated aromatic amines.

17. The hyperbranched polyimide adhesive composition according to claim 16, characterized in that, The microencapsulated aromatic amines include diaminodiphenylmethane-polymethyl methacrylate microcapsules.

18. A resin film, characterized in that, It is prepared by the following method: dissolving the components of the hyperbranched polyimide adhesive composition according to any one of claims 1-17 in a solvent to obtain an adhesive solution, coating the adhesive solution onto a substrate and drying and / or semi-curing to obtain a resin film.

19. The use of the hyperbranched polyimide adhesive composition according to any one of claims 1-17 or the resin film according to claim 18 in adhesive sheets, resin-coated copper foils, copper-clad laminates, and printed circuit boards.

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