Halogen-free epoxy resin composition and application thereof

Abstract

The invention provides a halogen-free epoxy resin composition and application thereof, and the halogen-free epoxy resin composition comprises the following components by weight: 100 parts of epoxy resin; 30-80 parts of hydroxyl aluminum oxide coated barium sulfate; and 60-100 parts of a filler. The hydroxyl aluminum oxide coated barium sulfate is introduced into the halogen-free epoxy resin composition, the affinity between the surface of the barium sulfate and a resin system is increased, the resin composition is used for a metal foil-coated laminated board, and the barium sulfate and the resin are combined more tightly in the laminated board, so that tiny gaps in the resin material of the laminated board are reduced, and the bonding strength of the resin material is improved. The water absorption rate of the board can be reduced, and the heat resistance of the board can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of laminated boards, and relates to a halogen-free epoxy resin composition and application thereof, and specifically relates to a halogen-free epoxy resin composition and a prepreg, a metal foil-clad laminate and a printed circuit board comprising the same. Background Art

[0002] As electronic components on printed circuit boards continue to develop towards high precision, high performance and multi-layering, higher requirements are placed on the reliability of copper clad laminates. Traditional FR-4 copper clad laminates have good insulation, flame retardancy, dimensional stability, water absorption and processing performance, but as the performance requirements for copper clad laminates continue to increase, these properties have gradually failed to meet the demand. Therefore, it is necessary to further improve the water absorption and heat resistance of the board.

[0003] Barium sulfate (BaSO4) is a widely used chemical raw material with good heat resistance and flame retardancy. It has a high density and can inhibit the warping and stress deformation of the board to a certain extent, and can improve the electrical safety performance. However, barium sulfate has a small particle size, a large specific surface area, and a surface inertness. It has poor affinity with epoxy resin, resulting in weak bonding with the resin system, and more gaps in the board under high filling. As the requirements for electrical safety of printed circuit boards become higher and higher, it is necessary to find a suitable surface treatment method for barium sulfate and a suitable resin glue composition, in the hope that it can effectively improve the heat resistance of the board and reduce the water absorption rate of the board after being applied to the copper clad laminate. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a halogen-free epoxy resin composition and its application, specifically to provide a halogen-free epoxy resin composition and a prepreg, a metal foil-clad laminate, and a printed circuit board comprising the same.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a halogen-free epoxy resin composition, wherein the halogen-free epoxy resin composition comprises the following components in parts by weight:

[0007] Epoxy resin 100 parts;

[0008] 30-80 parts of barium sulfate coated with aluminum oxyhydroxide;

[0009] 60 to 100 parts of filler.

[0010] The halogen-free epoxy resin composition provided by the present invention comprises an epoxy resin, barium sulfate coated with aluminum hydroxide, and a filler. By introducing barium sulfate coated with aluminum hydroxide and limiting its dosage, the bonding force between barium sulfate and the matrix resin can be improved. When this halogen-free epoxy resin composition is used in a metal-clad laminate, the thermal stability of the board can be enhanced, and the water absorption rate of the board can be reduced.

[0011] In the present invention, for the halogen-free epoxy resin composition by weight, based on the dosage of the epoxy resin (100 parts), the dosage of barium sulfate coated with aluminum hydroxide can be, for example, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0012] In the present invention, for the halogen-free epoxy resin composition by weight, based on the dosage of the epoxy resin (100 parts), the dosage of the filler can be, for example, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts or 100 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0013] Preferably, the barium sulfate coated with aluminum hydroxide is prepared by the following method:

[0014] Mix barium sulfate powder with water to obtain a barium sulfate slurry. Add an alkali solution to the barium sulfate slurry, then add an aluminum salt aqueous solution, and then adjust the pH value of the system, stir and age, and perform post-treatment to obtain the barium sulfate coated with aluminum hydroxide.

[0015] In the present invention, by coating a layer of aluminum hydroxide on the surface of barium sulfate, it can be ensured that for the laminate prepared using the modified barium sulfate, the micro-gaps inside the board are fewer than those of the laminate prepared using unmodified barium sulfate, the heat resistance of the board is better, and the water absorption rate is lower.

[0016] Preferably, the D50 particle size of the barium sulfate powder is 1 - 3 μm, and can be, for example, 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2 μm, 2.2 μm, 2.4 μm, 2.6 μm, 2.8 μm or 3 μm, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0017] In the present invention, the particle size is measured using a MS3000 Malvern laser particle size analyzer.

[0018] Preferably, the alkali solution includes an aqueous sodium hydroxide solution.

[0019] Preferably, the concentration of the alkali solution is 0.01 wt.% to 10 wt.%, for example, it can be 0.01 wt.%, 0.03 wt.%, 0.05 wt.%, 0.08 wt.%, 0.1 wt.%, 0.3 wt.%, 0.5 wt.%, 0.8 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.% or 10 wt.%, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0020] Exemplarily, sodium hydroxide can be stirred and dissolved in pure water to prepare a sodium hydroxide alkali solution with a mass fraction of 0.01 wt.% to 10 wt.%.

[0021] Preferably, the aluminum salt includes aluminum sulfate and / or aluminum nitrate.

[0022] Preferably, the concentration of the aluminum salt aqueous solution is 0.1 wt.% to 30 wt.%, for example, it can be 0.1 wt.%, 0.3 wt.%, 0.5 wt.%, 0.8 wt.%, 1 wt.%, 3 wt.%, 5 wt.%, 8 wt.%, 10 wt.%, 13 wt.%, 15 wt.%, 18 wt.%, 20 wt.%, 23 wt.%, 25 wt.%, 28 wt.% or 30 wt.%, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0023] Exemplarily, aluminum sulfate and / or aluminum nitrate can be stirred and dissolved in pure water to prepare an aluminum salt aqueous solution with a mass fraction of 0.1 wt.% to 30 wt.%.

[0024] Preferably, the mass ratio of aluminum ions in the aluminum salt aqueous solution to the barium sulfate powder is 1:(100 - 1000), for example, it can be 1:100, 1:105, 1:125, 1:150, 1:160, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:650, 1:700, 1:750, 1:800, 1:850, 1:900, 1:950 or 1:1000, and specific ratios between the above ratios. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific ratios included in the range.

[0025] Preferably, the pH value of the adjustment system is adjusted to 7.5 - 10.5. For example, it can be 7.5, 8, 8.5, 9, 9.5, 10 or 10.5, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0026] Preferably, the time for stirring and aging is 1 - 8 h. For example, it can be 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h or 8 h, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0027] Preferably, the post-treatment includes suction filtration, washing, drying, and grinding.

[0028] Preferably, the drying temperature is 120 - 160 °C. For example, it can be 120 °C, 130 °C, 140 °C, 150 °C or 160 °C, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. The drying time is 2 - 6 h. For example, it can be 2 h, 3 h, 4 h, 5 h or 6 h, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0029] In the preparation method of barium sulfate coated with hydroxyaluminum oxide provided by the present invention, by controlling the pH value and the drying temperature, the coating layer is hydroxyaluminum oxide, rather than aluminum hydroxide or aluminum oxide.

[0030] Preferably, the D50 particle size of the barium sulfate coated with hydroxyaluminum oxide is 1 - 3 μm. For example, it can be 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2 μm, 2.2 μm, 2.4 μm, 2.6 μm, 2.8 μm or 3 μm, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0031] As a preferred technical solution of the present invention, the barium sulfate coated with hydroxyaluminum oxide is prepared by the following method:

[0032] Mix barium sulfate powder with water to obtain a barium sulfate slurry. Add an alkali solution with a concentration of 0.01 wt.% to 10 wt.% to the barium sulfate slurry, and then add an aluminum salt aqueous solution with a concentration of 0.1 wt.% to 30 wt.%. Wherein, the mass ratio of aluminum ions in the aluminum salt aqueous solution to the barium sulfate powder is 1: (100 - 1000). Then adjust the pH value of the system to 7.5 - 10.5, stir and age for 1 - 8 h, and then after suction filtration and washing, dry the filter cake at 120 - 160 °C for 2 - 6 h, and grind to obtain the barium sulfate coated with hydroxyaluminum oxide.

[0033] Preferably, the epoxy resin includes any one or a combination of at least two of bifunctional epoxy resin and / or polyfunctional epoxy resin.

[0034] Preferably, the epoxy resin includes any one or a combination of at least two of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, phosphorus-containing epoxy resin, dicyclopentadiene-type epoxy resin, dimethylphenol-type phenolic epoxy resin, tetramethylbiphenyl epoxy resin, biphenyl epoxy resin, MDI-modified epoxy resin, naphthalene ring-containing epoxy resin or alicyclic epoxy resin.

[0035] Preferably, the epoxy equivalent of the epoxy resin is 100 - 600 g / eq, for example, it can be 100 g / eq, 150 g / eq, 200 g / eq, 250 g / eq, 300 g / eq, 350 g / eq, 400 g / eq, 450 g / eq, 500 g / eq, 550 g / eq or 600 g / eq, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0036] Preferably, the filler includes any one or a combination of at least two of silica powder, composite silica, fused silica, talc powder, wollastonite, magnesium oxide, calcium silicate, calcium carbonate, clay or mica.

[0037] Preferably, the median particle size (D50) of the filler is 1.1 to 2.8 μm, for example, it can be 1.1 μm, 1.3 μm, 1.5 μm, 1.6 μm, 1.8 μm, 1.9 μm, 2 μm, 2.2 μm, 2.4 μm, 2.5 μm, 2.6 μm or 2.8 μm, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range. The maximum particle size (D100) is 4 to 12 μm, for example, it can be 4 μm, 4.8 μm, 5 μm, 5.9 μm, 6.3 μm, 7.6 μm, 8.8 μm, 9.5 μm, 10.1 μm, 11.2 μm or 12 μm, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0038] Preferably, the physical form of the filler can be flaky, rod-shaped, spherical, hollow spherical, granular, fibrous or plate-shaped.

[0039] Preferably, the halogen-free epoxy resin composition further includes a curing agent.

[0040] Preferably, the curing agent includes any one or a combination of at least two of phenolic resin curing agents, active ester curing agents, amine curing agents, acid anhydride curing agents, carboxylic acid curing agents, cyanate ester curing agents, benzoxazine curing agents or maleimide curing agents.

[0041] Preferably, the amount of the curing agent is 15 to 50 parts, for example, it can be 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or 50 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0042] Preferably, the halogen-free epoxy resin composition further includes a flame retardant.

[0043] Preferably, the flame retardant includes a phosphorus-containing flame retardant.

[0044] Preferably, the phosphorus-containing flame retardant includes a phosphorus-containing curing agent and / or an additive phosphorus-containing flame retardant.

[0045] Preferably, the phosphorus-containing curing agent is a compound containing a phosphorus element and a reactive group.

[0046] Preferably, the reactive group includes an amino group and / or a phenolic hydroxyl group.

[0047] Preferably, the phosphorus-containing curing agent includes a phosphorus-containing phenolic resin.

[0048] Preferably, the additive phosphorus-containing flame retardant includes any one or a combination of at least two of tris(2,6-dimethylphenyl)phosphine, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6-bis(2,6-dimethylphenyl)phosphinobenzene, 10-phenyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phosphazene compounds or phosphate esters.

[0049] Preferably, the amount of the flame retardant is 30 to 60 parts, for example, it can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts or 60 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0050] Preferably, the halogen-free epoxy resin composition further includes a curing accelerator.

[0051] Preferably, the curing accelerator includes any one or a combination of at least two of imidazole-based accelerators, pyridine-based curing agents, Lewis acid-based curing agents, amine-based accelerators, phenolic curing agents, cyanate ester compounds or active ester compounds.

[0052] The "parts" and "parts by weight" involved in the present invention are calculated based on the solid content and do not include solvents, dispersants, etc. therein.

[0053] Preferably, the halogen-free epoxy resin composition further includes a solvent.

[0054] Preferably, the solvent includes any one or a combination of at least two of methyl ethyl ketone, acetone, dimethylformamide (DMF), ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, toluene, xylene, cyclohexanone, isopropanol.

[0055] Preferably, the amount of the solvent is 50 to 300 parts, for example, it can be 50 parts, 80 parts, 100 parts, 120 parts, 140 parts, 160 parts, 180 parts, 200 parts, 220 parts, 240 parts, 260 parts, 280 parts or 300 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0056] The halogen-free epoxy resin composition provided by the present invention is prepared by the following method, and the preparation method includes: mixing and uniformly dispersing the components in the halogen-free epoxy resin composition to obtain the halogen-free epoxy resin composition.

[0057] In a second aspect, the present invention provides a prepreg, and the prepreg includes the halogen-free epoxy resin composition as described in the first aspect.

[0058] Preferably, the prepreg includes a base material and a halogen-free epoxy resin composition adhered to the base material.

[0059] Preferably, the prepreg includes a base material and a halogen-free epoxy resin composition adhered to the base material after impregnation and drying treatments.

[0060] In a third aspect, the present invention provides a metal-clad laminate, which includes at least one prepreg as described in the second aspect and metal foils coated on one or both sides of the stacked prepregs.

[0061] In a fourth aspect, the present invention provides a printed circuit board, which includes at least one of the prepreg as described in the second aspect or the metal-clad laminate as described in the third aspect.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] By introducing barium sulfate coated with aluminum hydroxide into the halogen-free epoxy resin composition, the present invention increases the affinity between the surface of barium sulfate and the resin system. When this resin composition is used in a metal-clad laminate, the combination of barium sulfate and the resin in the laminate is more compact, thereby reducing the micro-gaps in the resin material of the laminate, being able to reduce the water absorption rate of the board, and being able to effectively improve the heat resistance of the board. Description of the Drawings

[0064] Figure 1 It is the Fourier transform infrared spectrum of barium sulfate coated with aluminum hydroxide prepared in Preparation Example 1. Detailed Embodiments

[0065] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0066] Preparation Example 1

[0067] In this preparation example, a barium sulfate coated with aluminum hydroxide (denoted as modified barium sulfate 1) is provided, and the preparation method includes the following steps:

[0068] Take 50 g of barium sulfate powder (D50 particle size is 2 μm, Yunfu Hongzhi H-700), disperse it, add it to 500 mL of pure water, stir and beat to make a slurry, take 1 g of sodium hydroxide, dissolve it in 100 mL of water, pour it into the barium sulfate slurry, then dissolve 2 g of aluminum sulfate in 100 mL of water and slowly drip it into the above solution. After adding the aluminum sulfate aqueous solution, adjust the pH value of the system to 9 with a 1 wt.% aluminum sulfate aqueous solution, continue to stir and age for 6 h, then after suction filtration and washing, dry the filter cake at 140 °C for 4 h, and grind it to obtain the barium sulfate coated with hydroxyaluminum oxide (D50 particle size is 2 μm).

[0069] Perform Fourier transform infrared spectroscopy test on the barium sulfate coated with hydroxyaluminum oxide prepared in this preparation example. The test result diagram is as Figure 1 shown. It can be seen that in the spectrum of the barium sulfate coated with hydroxyaluminum oxide, a characteristic peak at 1070 cm -1 (i.e., the characteristic peak of the hydroxyl group) can be observed, which indicates that the barium sulfate coated with hydroxyaluminum oxide has been successfully synthesized.

[0070] Preparation Example 2

[0071] In this preparation example, a barium sulfate coated with hydroxyaluminum oxide (denoted as modified barium sulfate 2) is provided, and the preparation method includes the following steps:

[0072] Take 200 g of barium sulfate powder (D50 particle size is 2 μm, Yunfu Hongzhi H-700), disperse it, add it to 1000 mL of pure water, stir and beat to make a slurry, take 5 g of sodium hydroxide, dissolve it in 100 mL of water, pour it into the barium sulfate slurry, then dissolve 10 g of aluminum sulfate in 100 mL of water and slowly drip it into the above solution. After adding the aluminum sulfate aqueous solution, adjust the pH value of the system to 9 with a 1 wt.% aluminum sulfate aqueous solution, continue to stir and age for 6 h, then after suction filtration and washing, dry the filter cake at 140 °C for 4 h, and grind it to obtain the barium sulfate coated with hydroxyaluminum oxide (D50 particle size is 2 μm).

[0073] Preparation Example 3

[0074] In this preparation example, a barium sulfate coated with hydroxyaluminum oxide (denoted as modified barium sulfate 3) is provided, and the preparation method includes the following steps:

[0075] Take 50 g of barium sulfate powder (D50 particle size is 2 μm, Yunfu Hongzhi H-700), disperse it and add it to 500 mL of pure water, stir and beat to make a slurry, obtaining a barium sulfate slurry. Take 2 g of sodium hydroxide, dissolve it in 100 mL of water, and pour it into the barium sulfate slurry. Then dissolve 3 g of aluminum sulfate in 100 mL of water and slowly drip it into the above solution. After the aluminum sulfate aqueous solution is added completely, adjust the pH value of the system to 9 with a 1 wt.% aluminum sulfate aqueous solution, continue to stir and age for 6 h, then after suction filtration and washing, dry the filter cake at 140 °C for 4 h, and grind it to obtain the barium sulfate coated with hydroxyaluminum oxide (D50 particle size is 2 μm).

[0076] Comparative Preparation Example 1

[0077] In this comparative preparation example, a barium sulfate coated with aluminum hydroxide (denoted as modified barium sulfate 4) is provided, and the preparation method includes the following steps:

[0078] Take 200 g of barium sulfate powder (D50 particle size is 2 μm, Yunfu Hongzhi H-700), disperse it and add it to 1000 mL of pure water, stir and beat to make a slurry, obtaining a barium sulfate slurry. Take 5 g of sodium hydroxide, dissolve it in 100 mL of water, and pour it into the barium sulfate slurry. Then dissolve 10 g of aluminum sulfate in 100 mL of water and slowly drip it into the above solution. After the aluminum sulfate aqueous solution is added completely, adjust the pH value of the system to 9 with a 1 wt.% aluminum sulfate aqueous solution, continue to stir and age for 6 h, then after suction filtration and washing, dry the filter cake at 90 °C for 4 h, and grind it to obtain the barium sulfate coated with aluminum hydroxide (D50 particle size is 2 μm).

[0079] Comparative Preparation Example 2

[0080] In this comparative preparation example, a barium sulfate coated with alumina (denoted as modified barium sulfate 5) is provided, and the preparation method includes the following steps:

[0081] Take 200 g of barium sulfate powder (D50 particle size is 2 μm, Yunfu Hongzhi H-700), disperse it and add it to 1000 mL of pure water, stir and beat to make a slurry, obtaining a barium sulfate slurry. Take 5 g of sodium hydroxide, dissolve it in 100 mL of water, and pour it into the barium sulfate slurry. Then dissolve 10 g of aluminum sulfate in 100 mL of water and slowly drip it into the above solution. After the aluminum sulfate aqueous solution is added completely, adjust the pH value of the system to 9 with a 1 wt.% aluminum sulfate aqueous solution, continue to stir and age for 6 h, then after suction filtration and washing, dry the filter cake at 300 °C for 4 h, and grind it to obtain the barium sulfate coated with alumina (D50 particle size is 2 μm).

[0082] The experimental materials involved in the following examples and comparative examples of the present invention are as follows:

[0083] (1) Epoxy resin

[0084] NPEL-128, bisphenol A epoxy resin, Nan Ya Plastics Corporation, Taiwan, China;

[0085] NPEF-170, bisphenol F epoxy resin, Nan Ya Plastics Corporation, Taiwan, China;

[0086] (2) Unmodified barium sulfate: Yunfu Hongzhi H-700

[0087] Barium sulfate coated with hydroxyaluminum oxide: Modified barium sulfates 1-3 provided in Preparation Examples 1-3;

[0088] Barium sulfate coated with aluminum hydroxide: Modified barium sulfate 4 provided in Comparative Preparation Example 1;

[0089] Barium sulfate coated with aluminum oxide: Modified barium sulfate 5 provided in Comparative Preparation Example 2;

[0090] (3) Curing agent

[0091] Phenolic resin curing agent: BN120, Changchun, China;

[0092] (4) Phosphorus-containing flame retardant

[0093] Phosphorus-containing phenolic resin: XZ92741, Dow, USA;

[0094] Phosphate ester flame retardant: PX200, Daihachi, Japan;

[0095] (5) Filler

[0096] Silica powder: DS2032A, D100 is 11μm, Jiangsu Lianrui.

[0097] Example 1

[0098] This example provides a halogen-free epoxy resin composition, and the specific components and dosages (parts by weight) are shown in Table 1 below.

[0099] This example also provides a prepreg and a metal-clad laminate, and the specific preparation method includes the following steps:

[0100] According to the formula in Table 1, each component and the solvent (methyl ethyl ketone) are placed in a container and mixed, and after stirring evenly, a resin solution with a solid content of 65% is prepared. The 2116 electronic-grade glass fiber cloth is impregnated with the resin solution, and the prepreg is obtained after baking in an oven;

[0101] Six prepregs are bonded together by heating and pressing, and metal foils (copper foils) with a thickness of 18μm are pasted on the upper and lower surfaces. Smooth steel plates and plastic pads are placed outside the upper and lower metal foils, and the metal-clad laminate is pressed in a laminator.

[0102] The properties of the above prepreg or metal-clad laminate are tested, and the specific method is as follows:

[0103] (1) Copper foil peel strength: Prepare samples of the metal-clad laminate and measure according to the method specified in IPC-TM-650 2.4.8;

[0104] (2) Glass transition temperature: Differential scanning calorimetry (DSC), measure the metal-clad laminate according to the DSC method specified in IPC-TM-650 2.4.25;

[0105] (3) T288: Use a thermomechanical analyzer to measure the metal-clad laminate according to the method specified in IPC-TM-650 2.4.24.1;

[0106] (4) High-temperature pressure cooker cooking experiment (PCT-6h): Conduct a high-temperature cooking experiment on the metal-clad laminate at 120 °C and measure according to the test method specified in IPC-TM 650 2.6.16;

[0107] (5) PCT water absorption rate - 6h: Measure the metal-clad laminate according to the laminate water absorption test method specified in IPC-TM 650 2.6.2.1.

[0108] The test results are shown in Table 1.

[0109] Examples 2-5, Comparative Examples 1-6

[0110] A halogen-free epoxy resin composition, prepreg, and metal-clad laminate containing the same, which are different from those in Example 1 in that the formulation of the halogen-free epoxy resin composition is different, as specifically shown in Table 1 and Table 2; among them, the dosage unit of each component is "parts"; the preparation methods and performance test methods of the prepreg and metal-clad laminate are the same as those in Example 1.

[0111] Table 1

[0112]

[0113] Table 2

[0114]

[0115] It can be seen from Table 1 and Table 2 that the metal-clad laminates provided in Examples 1-5 all have good heat resistance (T288 test is greater than 60 min), and the water absorption rates are all low (0.11% - 0.24%).

[0116] Compared with Example 1, in Comparative Example 1, due to the absence of barium sulfate, its heat resistance is poor and the water absorption rate is high; in Comparative Example 2, since the added barium sulfate is unmodified, its heat resistance is also poor and the water absorption rate is on the high side; in Comparative Example 3, due to the low dosage of the modified barium sulfate added, its heat resistance is poor and the water absorption rate is high; in Comparative Example 4, due to the high dosage of the modified barium sulfate added, the copper foil peel strength is reduced and the Tg of the board is reduced; in Comparative Example 5, aluminum hydroxide-coated barium sulfate is added, resulting in poor heat resistance; in Comparative Example 6, aluminum oxide-coated barium sulfate is added, and due to its poor affinity with the resin system, the copper foil peel strength is reduced and the water absorption rate is on the high side.

[0117] The applicant declares that the present invention uses the above examples to illustrate the halogen-free epoxy resin composition and its application of the present invention, but the present invention is not limited to the above examples, that is, it does not mean that the present invention must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of the raw materials selected for the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A halogen-free epoxy resin composition, characterized in that The halogen-free epoxy resin composition comprises the following components in parts by weight: Epoxy resin 100 parts; 30-80 parts of barium sulfate coated with aluminum oxyhydroxide; 60 to 100 parts of filler.

2. The halogen-free epoxy resin composition according to claim 1, characterized in that The aluminum oxyhydroxide-coated barium sulfate is prepared by the following method: The barium sulfate powder is mixed with water to obtain a barium sulfate slurry, an alkali solution is added to the barium sulfate slurry, and then an aluminum salt aqueous solution is added, and then the pH value of the system is adjusted, stirred for aging, and post-treated to obtain the aluminum hydroxide-coated barium sulfate.

3. The halogen-free epoxy resin composition according to claim 2, characterized in that: The barium sulfate powder has a D50 particle size of 1 to 3 μm; Preferably, the alkali solution comprises an aqueous solution of sodium hydroxide; Preferably, the concentration of the alkali solution is 0.01wt.% to 10wt.%; Preferably, the aluminum salt comprises aluminum sulfate and / or aluminum nitrate; Preferably, the concentration of the aluminum salt aqueous solution is 0.1wt.% to 30wt.%; Preferably, the mass ratio of the aluminum ions in the aluminum salt aqueous solution to the barium sulfate powder is 1:(100-1000); Preferably, the pH value of the adjustment system is adjusted to 7.5 to 10.5; Preferably, the stirring aging time is 1 to 8 hours; Preferably, the post-treatment includes filtration, washing, drying and grinding; Preferably, the drying temperature is 120-160°C and the drying time is 2-6 hours; Preferably, the D50 particle size of the aluminum oxyhydroxide-coated barium sulfate is 1 to 3 μm.

4. The halogen-free epoxy resin composition according to any one of claims 1 to 3, characterized in that: The aluminum oxyhydroxide-coated barium sulfate is prepared by the following method: The barium sulfate powder is mixed with water to obtain a barium sulfate slurry, and an alkali solution with a concentration of 0.01wt.% to 10wt.% is added to the barium sulfate slurry, and then an aluminum salt aqueous solution with a concentration of 0.1wt.% to 30wt.% is added, wherein the mass ratio of aluminum ions in the aluminum salt aqueous solution to the barium sulfate powder is 1:(100-1000), and then the pH value of the system is adjusted to 7.5-10.5, and the mixture is stirred and aged for 1-8 hours, and then after suction filtration and washing, the filter cake is dried at 120-160°C for 2-6 hours and ground to obtain the aluminum hydroxide-coated barium sulfate.

5. The halogen-free epoxy resin composition according to any one of claims 1 to 4, characterized in that: The epoxy resin includes any one of a bifunctional epoxy resin and / or a multifunctional epoxy resin or a combination of at least two thereof; Preferably, the epoxy resin includes any one or a combination of at least two of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, phosphorus-containing epoxy resin, dicyclopentadiene epoxy resin, dimethylphenol novolac epoxy resin, tetramethyl biphenyl epoxy resin, biphenyl epoxy resin, MDI-modified epoxy resin, naphthalene ring-containing epoxy resin or alicyclic epoxy resin; Preferably, the epoxy equivalent of the epoxy resin is 100 to 600 g / eq.

6. The halogen-free epoxy resin composition according to any one of claims 1 to 5, characterized in that: The filler includes any one or a combination of at least two of silicon micropowder, composite silicon dioxide, fused silicon dioxide, talc, wollastonite, magnesium oxide, calcium silicate, calcium carbonate, clay or mica; Preferably, the median particle size of the filler is 1.1 to 2.8 μm, and the maximum particle size is 4 to 12 μm.

7. The halogen-free epoxy resin composition according to any one of claims 1 to 6, characterized in that: The halogen-free epoxy resin composition also includes a curing agent; Preferably, the curing agent includes any one or a combination of at least two of a phenolic resin curing agent, an active ester curing agent, an amine curing agent, an acid anhydride curing agent, a carboxylic acid curing agent, a cyanate curing agent, a benzoxazine curing agent or a maleimide curing agent; Preferably, the amount of the curing agent is 15 to 50 parts; Preferably, the halogen-free epoxy resin composition further comprises a flame retardant; Preferably, the flame retardant comprises a phosphorus-containing flame retardant; Preferably, the flame retardant is used in an amount of 30 to 60 parts; Preferably, the halogen-free epoxy resin composition further comprises a curing accelerator; Preferably, the curing accelerator includes any one or a combination of at least two of an imidazole accelerator, a pyridine curing agent, a Lewis acid curing agent, an amine accelerator, a phenolic curing agent, a cyanate ester compound or an active ester compound; Preferably, the halogen-free epoxy resin composition further comprises a solvent; Preferably, the amount of the solvent used is 50 to 300 parts.

8. A prepreg, characterized in that: The prepreg comprises the halogen-free epoxy resin composition according to any one of claims 1 to 7.

9. A metal foil-clad laminate, characterized in that: The metal foil-clad laminate comprises at least one prepreg as claimed in claim 8 and a metal foil coated on one side or both sides of the stacked prepreg.

10. A printed circuit board, characterized in that: The printed circuit board includes at least one of the prepreg according to claim 8 or the metal foil clad laminate according to claim 9.

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