Solvent-free high-filling resin composition as well as preparation method and application thereof

Abstract

The invention provides a solvent-free high-filling resin composition as well as a preparation method and application thereof. The solvent-free high-filling resin composition comprises the following components: liquid epoxy resin, an epoxy diluent, a photoinitiator, a latent heat curing agent, a dispersing agent, a functional filler and a thixotropic agent, the viscosity of the epoxy diluent is less than 500 mPa.s; the dispersing agent comprises a polyether modified polysiloxane dispersing agent; the content of the functional filler is 60%-90%. The photoinitiator is compounded with the latent heat curing agent, so that the problems that the heating viscosity of a high-specific-gravity system is reduced, the resin is vertically baked and sags during hole plugging, the filler sinks during horizontal baking, the filler is concentrated at the lower end, the resin is concentrated at the upper layer, and the performance of the whole hole plugging resin is unstable are solved, and the problems that the heating viscosity is reduced, sags and lacks the resin are solved; and the problem of sedimentation of the high-specific-gravity functional filler is solved, so that the cured product has stable performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of circuit boards, and relates to a solvent-free high-filling resin composition and a preparation method and application thereof. BACKGROUND

[0002] With the development of high-frequency, high-speed and high-integration electronic circuits, higher requirements are put forward for the miniaturization and thinning of electronic devices, and the circuit boards used in electronic devices also need to be further miniaturized and have high-density lines. Integrating traditional external circuits, inductors and heat dissipation into circuit boards is an inevitable trend in future development. By punching holes in the board material, the functions of heat dissipation, conduction and inductance can be realized to achieve the functions of lightness, thinness and smallness.

[0003] Therefore, the demand for hole resin with different functions is urgent. Traditional hole resin has small functional requirements and is realized through a single thermal curing process. During the hole curing process, sinking and sagging occur, and finally the upper and lower surfaces are polished. With the development of high-tech, the integrated embedded hole in the PCB or between the double-layer multi-layer board needs to be conductive, or the hole needs to maintain certain heat conduction and heat dissipation performance in the field of high-heat conduction and heat dissipation. Higher requirements are put forward for the uniformity and stability of the performance between the layers. Therefore, the traditional material technology process cannot meet the demand. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a solvent-free high-filling resin composition and a preparation method and application thereof. The technical problem to be solved by the present application is to provide a solvent-free high-filling resin composition which can be used as a hole resin. The resin composition is solvent-free, uses liquid epoxy resin, and can realize high filling of functional fillers with a filling content of 60%-90%. The main product feature is that after the hole resin is prepared, it will not cause insufficient curing degree due to single photocuring, nor will it cause temperature rise, viscosity smaller than normal temperature viscosity, sagging, delamination and unstable performance due to single thermal curing. By using this cationic and latent thermal curing agent composite curing, the hole is irradiated after curing to make the upper and lower ends of the hole dry to realize hole sealing, and further thermal post-curing improves the crosslinking density. In addition, a low-viscosity epoxy diluent is used to realize high filling. The high filling amount improves the functionality, whether it is used for heat dissipation, conduction or magnetism, and can realize higher performance without causing sagging, delamination and unstable performance due to high filling and high density.

[0005] To achieve the purpose of the present application, the following technical solutions are adopted:

[0006] In a first aspect, the present application provides a solvent-free high filling resin composition, which comprises the following components: liquid epoxy resin, epoxy diluent, photoinitiator, latent thermal curing agent, dispersant, functional filler, thixotropic agent;

[0007] The viscosity of the epoxy diluent at 25 DEG C is less than 500 mPa s, for example, it can be 490 mPa s, 480 mPa s, 450 mPa s, 400 mPa s, 380 mPa s or 300 mPa s, and specific point values between the above point values, for the sake of brevity and simplicity, the present application does not list the specific point values included in the range.

[0008] The dispersant comprises a polyether-modified polysiloxane dispersant.

[0009] The content of the functional filler is 60%-90%, for example, it can be 60%, 62%, 64%, 65%, 66%, 68%, 70%, 72%, 74%, 75%, 76%, 78%, 80%, 82%, 84%, 85%, 86%, 88% or 90%, and specific point values between the above point values, for the sake of brevity and simplicity, the present application does not list the specific point values included in the range, based on the total mass of the solvent-free high filling resin composition being 100%.

[0010] The resin composition of the prior art can achieve 100% filling in the presence of solvent, but the filling amount is not high in the absence of solvent. The solvent-free high filling resin composition provided by the present application can achieve high filling of the functional filler in the absence of solvent by selecting an epoxy diluent with a specific viscosity and a specific type of dispersant.

[0011] The solvent-free high filling resin composition provided by the present application can achieve a light and heat dual curing process by using a composite curing agent (i.e. a combination of photoinitiator and latent thermal curing agent), and can be used in the field of high filling plug resin. In the light curing process, the pre-curing achieves surface dryness, and the upper and lower surfaces of the hole on the circuit board are sealed. Further heat curing improves the crosslinking density and achieves complete curing in the deep layer. The problems of low curing degree in the deep layer where light cannot reach and deformation caused by shrinkage of the cured product can be solved. The problems of resin composition stratification, plug resin sagging during vertical baking, filler sinking during horizontal baking, and filler concentrating at the lower end and resin concentrating at the upper layer, which lead to unstable performance of the entire plug resin, can be solved. The present application provides the above technical solutions to solve the series of problems of unstable performance of high filling.

[0012] Preferably, the polyether-modified polysiloxane dispersant includes any one or a combination of at least two of polyether-modified polydimethylsiloxane, polyether-modified polymethylphenylsiloxane, polyether-modified polymethylhydrogenated diene siloxane.

[0013] Preferably, the solventless high loading resin composition includes, by weight percent, the following components: liquid epoxy resin 3-15%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness, epoxy diluent 3-15%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness, photoinitiator 0.5-5%, for example, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness, latent thermal curing agent 0.5-3%, for example, 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness, dispersant 0.1-1%, for example, 0.1%, 0.2%, 0.3%, 0.5%, 0.6%, 0.8%, or 1%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness, functional filler 60-90%, for example, 60%, 62%, 64%, 65%, 66%, 68%, 70%, 72%, 74%, 75%, 76%, 78%, 80%, 82%, 84%, 85%, 86%, 88%, or 90%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness, and thixotropic agent 1-10%, for example, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%, and specific point values between the aforementioned point values, the present disclosure does not exhaustively recite the specific point values included in the range for the sake of brevity and conciseness.

[0014] Preferably, the liquid epoxy resin includes any one or a combination of at least two of a glycerol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol AF type epoxy resin, a naphthalene type epoxy resin, a phenol resin type epoxy resin, an alicyclic type epoxy resin having an ester skeleton, a cyclohexane dimethanol type epoxy resin, an epoxy resin having a butadiene structure, a dicyclopentadiene type epoxy resin, a triphenol type epoxy resin, a phenol novolac epoxy resin, a tert-butyl catechol type epoxy resin, a naphthol novolac type epoxy resin, a naphthalene type epoxy resin, a naphthol type epoxy resin, and an anthracene type epoxy resin.

[0015] Preferably, the epoxy diluent includes any one or a combination of at least two of a glycerol ester type epoxy resin, a glycerol amine type epoxy resin, a glycidyl amine type epoxy resin, a glycidyl ester type epoxy resin, a cresol novolac type epoxy resin, a biphenyl type epoxy resin, a linear aliphatic epoxy resin, an alicyclic epoxy resin, a heterocyclic epoxy resin, an epoxy resin containing a spiro ring, a cyclohexane dimethanol type epoxy resin, a trimethylol type epoxy resin, and a tetraphenyl ethane type epoxy resin.

[0016] Preferably, the photoinitiator is a cationic photoinitiator including an onium salt type photoinitiator and / or a non-onium salt type photoinitiator.

[0017] Preferably, the onium salt type photoinitiator includes any one or a combination of at least two of a diaryl iodonium salt, a triaryl sulfonium salt, and a ferrocenium salt.

[0018] Preferably, the non-onium salt type photoinitiator includes a sulfonyl imine type photoinitiator and / or an oxime ester sulfonate type photoinitiator.

[0019] Preferably, the latent thermal curing agent includes any one or a combination of at least two of an acid anhydride type curing agent, an imidazole type curing agent, an amine type curing agent, and a phenol resin type curing agent.

[0020] Preferably, the acid anhydride-based curing agent can use a curing agent having one or more acid anhydride groups in one molecule, preferably a curing agent having two or more acid anhydride groups in one molecule as the acid anhydride-based curing agent, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl naphthalene anhydride, hydrogenated methyl naphthalene anhydride, trialkyl tetrahydrophthalic anhydride, polydicyclopentadiene succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride; trimellitic anhydride, pyromellitic anhydride, benzophenone tetra carboxylic dianhydride, biphenyl tetra carboxylic dianhydride, naphthalene tetra carboxylic dianhydride, oxalic diphthalic dianhydride, 3,3'-4,4'-diphenyl sulfonic acid tetra carboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(trimellitate), styrene-maleic acid copolymerized styrene-maleic acid resin, and the like polymer type acid anhydride, and the like commercially available products of acid anhydride-based hardening agents.

[0021] Preferably, the imidazole-based curing agent such as 2-methylimidazole, 2-undecylimidazole, 2-heptylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole; 1-cyanoethyl-2-undecylimidazole; 1-cyanoethyl-2-ethyl-4-methylimidazole; 1-cyanoethyl-2-phenylimidazole; 1-cyanoethyl-2-undecylimidazole triazine, 1-cyanoethyl-2-phenylimidazole triazine, 2,4-diamino-6-[2'-methylimidazolidin-(1')]-ethyl-s-triazine; 2,4-diamino-6-[2'-undecylimidazolidin-(1')]-ethyl-s-triazine; 2,4-diamino-6-[2'-ethyl-4'-methylimidazolidin-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolidin-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazole chloride, and the like.

[0022] Preferably, the amine curing agent, having at least one amino group per molecule, is preferably used as an amine curing agent having two or more amino groups, such as aliphatic amines, polyether amines, alicyclic amines, aromatic amines, and the like, among which, amine curing agents of aromatic amines are preferred, preferably primary amines or secondary amines, as a specific example of amine curing agents of more preferred primary amines, 4,4'-methylenebis'(2,6-dimethyl aniline), 4,4'-diaminodiphenyl methane; 4,4'-diaminodiphenyl sulfone; 3,3'-diaminodiphenyl sulfone; m-phenylenediamine, m-phenylenediamine, diethyltoluene diamine, 4,4'-diaminodiphenyl ether; 3,3'-dimethyl-4,4'-diaminobiphenyl; 2,2'-dimethyl-4,4'-diaminobiphenyl; 3,3'-dihydroxybenzidine; 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenyl methane diamine, 2,2-bis(4-aminophenyl)propane; 2,2-bis(4-(4-aminophenoxy)phenyl propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy) sulfonic acid, bis(4-(3-aminophenoxy)phenyl sulfonic acid, and the like. Commercially available products can be used as the amine curing agent.

[0023] Preferably, the amine curing agent can be used as commercially available products, such as boron trifluoride monoethylamine, triethylamine, tributylamine, and the like, trialkylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6,-trimethyl(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, and the like.

[0024] Preferably, the functional filler has a density of greater than 4 g / cm 3 , for example, 4.2 g / cm 3 , 4.5 g / cm 3 , 4.8 g / cm 3 , or 5 g / cm 3 , and specific point values between the above point values. The present application does not exhaustively list the specific point values included in the range for the sake of brevity and simplicity.

[0025] Preferably, the functional filler includes any one or a combination of at least two of inorganic fillers, metal fillers, or magnetic fillers. When the functional filler is selected from among inorganic fillers, metal fillers, or magnetic fillers, the resin composition can have thermal conductivity, electrical conductivity, or magnetic conductivity.

[0026] Preferably, the thixotropic agent includes any one or a combination of at least two of inorganic materials, metal materials, or magnetic materials at a sub-micron or nanometer level.

[0027] Preferably, the inorganic material can be selected from fumed silica, bentonite, montmorillonite, carbon powder, etc.

[0028] Preferably, the metal material can be selected from silver powder, copper powder, conductive powder, etc.

[0029] Preferably, the magnetic material can be selected from ferrite, alloy, carbonyl iron, etc.

[0030] It should be noted that when the thixotropic agent is an inorganic material, it can be matched with the functional filler system of inorganic fillers, metal fillers and magnetic fillers, and when the thixotropic agent is a metal material or a magnetic material, it can only be matched with the corresponding system according to the function of the specific product.

[0031] Preferably, the solvent-free high-filling resin composition can further include other auxiliary agents, such as triethyl borate can be added to extend the storage period. In order to achieve other properties, flame retardants, organic fillers, organic copper compounds, organic zinc compounds and organic cobalt compounds, etc. Organic metal compounds, and thickening agents, defoaming agents, leveling agents, adhesion imparting agents, and resin additives such as colorants, etc.

[0032] In the second aspect, the present application provides a preparation method of the solvent-free high-filling resin composition according to the first aspect, the preparation method comprising the following steps:

[0033] (1) mixing and dispersing the liquid epoxy resin and the epoxy diluent;

[0034] (2) adding a latent thermal curing agent to the system of step (1) and dispersing;

[0035] (3) adding a dispersant and a photoinitiator to the system of step (2) and dispersing;

[0036] (4) adding a functional filler and a thixotropic agent to the system of step (3) and dispersing to obtain the solvent-free high-filling resin composition.

[0037] Preferably, the dispersing speed of step (1) is 1000-1500 r / min, for example, it can be 1000 r / min, 1100 r / min, 1200 r / min, 1300 r / min, 1400 r / min or 1500 r / min, and specific point values between the above point values. Due to the limitation of the length and the consideration of simplicity, the present application does not exhaustively list the specific point values included in the range, and the dispersing time is 3-5 min, for example, it can be 3 min, 3.5 min, 4 min, 4.5 min or 5 min, and specific point values between the above point values. Due to the limitation of the length and the consideration of simplicity, the present application does not exhaustively list the specific point values included in the range.

[0038] It should be noted that if the latent thermal curing agent added in step (2) is liquid, the dispersion parameters in step (1) can be continued to be used, if the latent thermal curing agent added in step (2) is solid, the rotation speed needs to be increased and the time needs to be reduced, so that the latent thermal curing agent is quickly collided and uniformly dispersed in the resin, and the feeling temperature is taken out every 30 s-1 min according to the actual addition amount, until the solid curing agent is uniformly dispersed in the resin.

[0039] Preferably, the rotation speed for the dispersion in step (3) is 1000-1500 r / min, for example, it can be 1000 r / min, 1100 r / min, 1200 r / min, 1300 r / min, 1400 r / min or 1500 r / min, and specific point values between the above point values, limited to the length and for the sake of simplicity, the present application will not list the specific point values included in the range. The dispersion time is 1-3 min, for example, it can be 1 min, 1.5 min, 2 min, 2.5 min or 3 min, and specific point values between the above point values, limited to the length and for the sake of simplicity, the present application will not list the specific point values included in the range. The feeling temperature is taken out every 1 min during the dispersion process in step (3).

[0040] Preferably, the rotation speed for the dispersion in step (4) is 1000-1500 r / min, for example, it can be 1000 r / min, 1100 r / min, 1200 r / min, 1300 r / min, 1400 r / min or 1500 r / min, and specific point values between the above point values, limited to the length and for the sake of simplicity, the present application will not list the specific point values included in the range. During the dispersion process in step (4), the observation and feeling temperature are taken out every 30 s-1 min, and finally the dispersion of the functional filler is identified by using a doctor blade fineness instrument until there is no scratch.

[0041] Preferably, the dispersion in steps (1)-(4) is carried out in a homogenizer.

[0042] Preferably, the dispersion in step (4) is carried out under vacuum. The purpose of vacuum is to remove the micro-bubbles in the resin composition.

[0043] In a third aspect, the present application provides a use of the solvent-free high-filling resin composition according to the first aspect in via hole resin, copper paste, silver paste, carbon paste, heat dissipation material bonding, and magnetic via hole paste.

[0044] Preferably, the solvent-free high-filling resin composition can be used as via hole resin in a circuit board, or can be coated to form a thin film layer, and finally cured to realize the functions of heat conduction, electrical conduction or magnetic conduction.

[0045] In a fourth aspect, the present application provides a cured product, which is obtained by first curing the solvent-free high-filling resin composition according to the first aspect by light curing and then by heat curing.

[0046] Preferably, the light curing ultraviolet light energy is 1000-3000 Joules (J), for example, it can be 1000 Joules, 1500 Joules, 2000 Joules, 2500 Joules or 3000 Joules, and specific point values between the above-mentioned point values, limited by the length and for the sake of simplicity, the present application does not list the specific point values included in the range. The solvent-free high-filling resin composition provided by the present application can achieve surface drying and initial curing after light curing.

[0047] Preferably, the heat curing temperature is 180-200℃, for example, it can be 180℃, 185℃, 190℃, 195℃ or 200℃, and specific point values between the above-mentioned point values, limited by the length and for the sake of simplicity, the present application does not list the specific point values included in the range, and the heat curing time is 80-120min, for example, it can be 80min, 85min, 90min, 95min, 100min, 105min, 110min, 115min or 120min, and specific point values between the above-mentioned point values, limited by the length and for the sake of simplicity, the present application does not list the specific point values included in the range.

[0048] In order to obtain a high-filling solvent-free hole filling resin with stable performance, the present application provides a dual-curing composite curing agent design scheme, which realizes initial curing and surface drying by cationic light curing, and improves the curing degree after heating, so that the composite curing agent has stable performance, no sagging and no delamination.

[0049] In a fifth aspect, the present application provides a circuit board comprising the cured product according to the fourth aspect.

[0050] Compared with the prior art, the present application has the following beneficial effects:

[0051] The solvent-free high-filling resin composition provided by the present application can realize high filling of functional fillers in a solvent-free state by selecting an epoxy diluent with a specific viscosity and a specific type of dispersing agent; the composite curing system using a photoinitiator and a latent thermal curing agent avoids the problems of viscosity drop of high specific gravity systems, sagging of resin during vertical baking and sinking of fillers during horizontal baking, and concentration of fillers at the lower end and resin at the upper layer, resulting in unstable performance of the entire hole filling resin, solves the problems of resin sagging and high specific gravity functional filler settling, and makes the cured product have stable performance. DETAILED DESCRIPTION

[0052] The technical solutions of the present application are further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0053] The raw materials used in the following examples and comparative examples of the present application are as follows unless otherwise specified:

[0054] (1) Liquid epoxy resin

[0055] Bisphenol AF type epoxy resin, trade name ZLX165H;

[0056] (2) Epoxy diluent

[0057] Cyclohexane dimethanol type epoxy resin, viscosity at 25°C 240 mPa·s, trade name CYD-016UV;

[0058] Aliphatic epoxy resin, viscosity at 25°C about 300 mPa·s, trade name CELLOXIDE 2021P;

[0059] (3) Photoinitiator

[0060] UVI-6974;

[0061] (4) Latent thermal curing agent

[0062] Boron trifluoride monoethylamine;

[0063] (5) Dispersant

[0064] Polyether modified polysiloxane dispersant: BYK-9076, BYK-345, BYK-347;

[0065] Aminosilane: A1100;

[0066] (6) Functional filler, specifically magnetic filler:

[0067] Iron-based nanocrystal, D50 5 μm, density 7.3 g / cm 3 ;

[0068] Amorphous nanocrystal, D50 30 μm, density 6.0 g / cm 3 ;

[0069] FeSiCr alloy, D50 10 μm, density 5.0 g / cm 3 ;

[0070] (7) Thixotropic agent

[0071] Ferrite: D50 0.5 μm;

[0072] Fumed silica: D50 of 0.3 μm.

[0073] Example 1

[0074] In this example, a solvent-free high-filled resin composition is provided, the specific components and amounts (parts by weight) of the solvent-free high-filled resin composition are shown in Table 1.

[0075] The preparation method of the solvent-free high-filled resin composition comprises the following steps:

[0076] (1) The formula amount of liquid epoxy resin and epoxy diluent is added to the special mixing tank of homogenizer, and dispersed at a speed of 1200 r / min for 4 min;

[0077] (2) The latent thermal curing agent is added to the system of step (1), if the latent thermal curing agent is liquid, continue to disperse at a speed of 1200 r / min for 4 min, if the latent thermal curing agent is solid, the speed needs to be increased and the time needs to be reduced, so that the curing agent is uniformly dispersed in the resin by rapid collision, according to the actual amount added, the feeling temperature is taken out every 30 s, until the solid curing agent is uniformly dispersed in the resin;

[0078] (3) The dispersant and photoinitiator are added to the system of step (2), and dispersed at a speed of 1200 r / min for 2 min, and the feeling temperature is taken out every 1 min intermittently;

[0079] (4) The functional filler and thixotropic agent are added to the system of step (3), and dispersed at a speed of 1200 r / min under vacuum using a homogenizer, the observation and feeling temperature are taken out every 30 s, finally the fineness instrument is used to identify the dispersibility of the filler, until there is no scratch, the solvent-free high-filled resin composition is obtained.

[0080] In this example, a cured product is also provided, the preparation method comprises the following steps:

[0081] The above solvent-free high-filled resin composition is first photocured under 3000 joule ultraviolet light, and then cured at 180℃ for 90 min, to obtain the cured product.

[0082] The solvent-free high-filled resin composition and the cured product are tested, and the testing method is as follows:

[0083] (1) Thixotropic index: the ratio of the viscosity of the solvent-free high-filled resin composition at a small speed of 0.5 r / min to the viscosity at a large speed of 5 r / min;

[0084] (2) Appearance of the cured product: whether the resin is eluted, voided, and whether the cured product is uniform is observed by naked eye;

[0085] (3) Heat resistance: Tg of the cured product was tested by DSC;

[0086] (4) Magnetic property: The magnetic property was tested by using the impedance analyzer E4991B of Keysight Company with 16454A test fixture.

[0087] Examples 2-9, Comparative Examples 1-4

[0088] A solvent-free high-filling resin composition and a cured product comprising the same, which are different from Example 1 in that the formulation of the solvent-free high-filling resin composition, the curing conditions of the cured product, etc. are different, and are specifically shown in Tables 1-3; wherein the amount of each component is in "parts by weight"; the preparation method of the cured product, the performance test method of the solvent-free high-filling resin composition and the cured product are the same as those of Example 1.

[0089] Table 1

[0090]

[0091] Table 2

[0092]

[0093] Table 3

[0094]

[0095] As can be seen from Tables 1-3, the thixotropic index of the resin composition provided by the examples of the present application is greater than 1, the cured product has no resin precipitation, no void, the cured product is uniform, and the cured product has a high Tg and excellent magnetic properties.

[0096] Compared with Example 3, the apparent uniformity of the cured product provided by Comparative Examples 1-4 is poor, and the Tg is reduced.

[0097] The applicant declares that the solvent-free high-filling resin composition of the present application and its preparation method and application are illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement on the present application, equivalent replacement of the materials selected by the present application, addition of auxiliary ingredients, selection of specific methods, etc. all fall within the protection scope and disclosure scope of the present application.

Claims

1. A solvent-free, highly filled resin composition, characterized in that, The solvent-free, highly filled resin composition comprises the following components: liquid epoxy resin, epoxy diluent, photoinitiator, latent thermosetting agent, dispersant, functional filler, and thixotropic agent; The epoxy diluent has a viscosity of less than 500 mPa·s at 25°C; The dispersant includes polyether-modified polysiloxane dispersants; The content of the functional filler is 60%-90% based on the total mass of the solvent-free, highly filled resin composition of 100%.

2. The solvent-free, highly filled resin composition according to claim 1, characterized in that, The polyether-modified polysiloxane dispersant includes any one or a combination of at least two of polyether-modified polydimethylsiloxane, polyether-modified polymethylphenylsiloxane, and polyether-modified polymethylhydrodienesiloxane. Preferably, the solvent-free, highly filled resin composition comprises, by weight percentage, the following components: 3%-15% liquid epoxy resin, 3%-15% epoxy diluent, 0.5%-5% photoinitiator, 0.5%-3% latent thermosetting agent, 0.1%-1% dispersant, 60%-90% functional filler, and 1%-10% thixotropic agent.

3. The solvent-free, highly filled resin composition according to claim 1 or 2, characterized in that, The liquid epoxy resin includes any one or a combination of at least two of the following: glycerol-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol AF-type epoxy resin, naphthalene-type epoxy resin, phenolic resin-type epoxy resin, alicyclic epoxy resin with an ester skeleton, cyclohexanediol-type epoxy resin, epoxy resin with a butadiene structure, dicyclopentadiene-type epoxy resin, triphenol-type epoxy resin, phenolic epoxy resin, tert-butylcatechol-type epoxy resin, naphtholic epoxy resin, naphthalene-type epoxy resin, naphthol-type epoxy resin, and anthracene-type epoxy resin. Preferably, the epoxy diluent comprises any one or a combination of at least two of the following: glyceryl ester type epoxy resin, glycerylamine type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol phenolic type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spirocyclic rings, cyclohexanediol type epoxy resin, tris(hydroxymethyl) type epoxy resin, and tetraphenylethane type epoxy resin.

4. The solvent-free, highly filled resin composition according to any one of claims 1-3, characterized in that, The photoinitiator is a cationic photoinitiator, including onium salt photoinitiators and / or non-onium salt photoinitiators; Preferably, the onium salt photoinitiator includes any one or a combination of at least two of diaryliodoonium salt, triarylsulfonium salt, and ferroceneonium salt; Preferably, the non-onium salt photoinitiator includes sulfonylimide photoinitiators and / or oxime sulfonate photoinitiators; Preferably, the latent thermosetting agent includes any one or a combination of at least two of the following: acid anhydride curing agents, imidazole curing agents, amine curing agents, and phenolic resin curing agents.

5. The solvent-free, highly filled resin composition according to any one of claims 1-4, characterized in that, The density of the functional filler is greater than 4 g / cm³. 3 ; Preferably, the functional filler includes any one or a combination of at least two of inorganic fillers, metallic fillers, or magnetic fillers; Preferably, the thixotropic agent comprises any one or a combination of at least two of submicron or nanoscale inorganic materials, metallic materials, or magnetic materials.

6. A method for preparing a solvent-free, highly filled resin composition as described in any one of claims 1-5, characterized in that, The preparation method includes the following steps: (1) Mix and disperse the liquid epoxy resin and epoxy diluent; (2) Add a latent thermosetting agent to the system of step (1) and disperse it; (3) Add dispersant and photoinitiator to the system of step (2) and disperse; (4) Add functional filler and thixotropic agent to the system of step (3), disperse, and obtain the solvent-free high-filled resin composition.

7. The preparation method according to claim 6, characterized in that, The dispersion speed in step (1) is 1000-1500 r / min, and the dispersion time is 3-5 min; Preferably, the dispersion speed in step (3) is 1000-1500 r / min, and the dispersion time is 1-3 min; Preferably, the dispersion rotation speed in step (4) is 1000-1500 r / min.

8. The use of a solvent-free, highly filled resin composition as described in any one of claims 1-5 in hole-filling resins, copper pastes, silver pastes, carbon pastes, heat dissipation material adhesives, and magnetic hole-filling pastes.

9. A cured product, characterized in that, The cured product is obtained by first photocuring and then thermocuring the solvent-free, highly filled resin composition according to any one of claims 1-5. Preferably, the ultraviolet light energy for photocuring is 1000-3000 joules; Preferably, the thermosetting temperature is 180-200℃ and the thermosetting time is 80-120 min.

10. A circuit board, characterized in that, The circuit board includes the cured material as described in claim 9.

Images