High-temperature-resistant glass fiber reinforced epoxy molding sealing material for manufacturing automobile motor accessories

Abstract

The invention discloses a high-temperature-resistant glass fiber reinforced epoxy molding sealing material for manufacturing automobile motor accessories, the high-temperature-resistant glass fiber reinforced epoxy molding sealing material comprises main materials and auxiliary materials, the main materials comprise a matrix resin component and a reinforced fiber component, and the auxiliary materials comprise a high-temperature-resistant filler, a flame retardant and a coupling agent. The matrix resin component comprises 40-60 wt% of bisphenol A epoxy resin and 10-20 wt% of novolac epoxy resin, the reinforced fiber component comprises 15-30 wt% of modified glass fibers, and the modified glass fibers are subjected to surface treatment by a silane coupling agent. The composite material comprises matrix resin, modified glass fibers, a high-temperature-resistant filler and a flame retardant, and is characterized in that a three-layer gradient structure (a surface compact layer / a middle transition layer / a bottom reinforcing layer) is adopted, the content of each layer of fibers and the filler is in gradient change, mechanical property distribution of'rigid outside and tough inside 'is realized, and the material is good in strength and high-temperature resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive parts manufacturing materials, and specifically to a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor parts. Background Art

[0002] Epoxy molding compound, also known as epoxy plastic packaging material, is mainly composed of epoxy resin as the matrix resin, high-performance phenolic resin as the curing agent, added with silica powder, etc. as fillers, and added with various additives such as plasticizers, pigments, etc. to be mixed into a powdery molding compound. Epoxy molding compound has a wide range of applications in the field of electronic packaging, mainly used for the packaging of electronic components, such as integrated circuits, semiconductor devices, automotive electronic components, etc., to provide protection and support.

[0003] Epoxy molding compound has the following advantages

[0004] 1. Good electrical performance - It has excellent insulation performance and dielectric properties, and can effectively protect electronic components from external electromagnetic interference.

[0005] 2. Good mechanical strength - It has relatively high mechanical strength and hardness, and can effectively support and protect electronic components.

[0006] 3. Good corrosion resistance - It has good resistance to corrosive substances such as acids and alkalis, and can extend the service life of electronic components.

[0007] However, traditional epoxy molding compounds are prone to problems such as thermal decomposition and decline in mechanical properties in high-temperature environments, and it is difficult for a single filler system to balance the requirements of heat conduction and flame retardancy. There is room for improvement. Summary of the Invention

[0008] The purpose of the present invention is to provide a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor parts, so as to solve the problems raised in the above background art.

[0009] To achieve the above object, the present invention provides the following technical solutions: A high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, comprising a main material and auxiliary materials. The main material includes a matrix resin component and a reinforcing fiber component. The auxiliary materials include a high-temperature resistant filler, a flame retardant, and a coupling agent. The matrix resin component is composed of 40-60 wt% of bisphenol A epoxy resin and 10-20 wt% of phenolic epoxy resin. The reinforcing fiber component is composed of 15-30 wt% of modified glass fiber, and the modified glass fiber is surface-treated with a silane coupling agent. The high-temperature resistant filler is composed of 5-10 wt% of nano-aluminum oxide and 3-8 wt% of hexagonal boron nitride. The flame retardant is composed of 3-8 wt% of a phosphorus-based flame retardant. The coupling agent is composed of 0.5-2 wt% of a titanate coupling agent. And the glass fiber reinforced epoxy molding compound is made of a three-layer gradient structure of a surface dense layer, an intermediate transition layer, and a bottom reinforcing layer.

[0010] A preparation method of a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, comprising

[0011] Step S1: Pre-impregnate the modified glass fiber with a part of the epoxy resin to form a fiber preform;

[0012] Step S2: Mix and grind the high-temperature resistant filler, the flame retardant, and the remaining epoxy resin to prepare a masterbatch;

[0013] Step S3: Lay the bottom reinforcing layer, the intermediate transition layer, and the surface dense layer in sequence by a gradient layering process;

[0014] Step S4: Perform microwave step curing under vacuum conditions. The curing uses a 2.45 GHz microwave source and a power density of 5-15 W / cm 3 . First, pre-cure at 80-100 °C for 30-60 min, and then post-cure at 150-180 °C for 2-4 h.

[0015] As a further aspect of the present invention: A high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, wherein the silane coupling agent of the modified glass fiber is γ-aminopropyltriethoxysilane, with a treatment concentration of 1-3 wt%, a fiber diameter of 8-15 μm, a length-to-diameter ratio ≥ 50:1, and the surface hydroxyl content reduced to 0.8-1.5 mmol / g.

[0016] As a further aspect of the present invention: A high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, wherein the nano-aluminum oxide is α-phase spherical particles, with an average particle size of 50-100 nm and a specific surface area of 20-50 m 2 / g; the hexagonal boron nitride has a sheet diameter of 1-5 μm, a thickness ≤ 100 nm, and a mass ratio of the two of 2:1-1:1.

[0017] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, wherein the phosphorus-based flame retardant is a composite material of ammonium polyphosphate and DOPO derivatives, the particle size of ammonium polyphosphate is ≤5 μm, and the DOPO derivative is DOPO-HQ, and the mass ratio of the two is 3:1 - 5:1.

[0018] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, in the three-layer gradient structure, the volume fraction of glass fiber in the surface dense layer is 25 - 35%, and the filler content is 12 - 18%; the volume fraction of glass fiber in the middle transition layer is 15 - 25%, and the filler content is 8 - 12%; the volume fraction of glass fiber in the bottom reinforcement layer is 35 - 45%, and the filler content is 5 - 8%.

[0019] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, a polyimide coating with a thickness of 0.5 - 2 μm is provided on the outer surface of the surface dense layer, and silicon carbide nanowires with a mass fraction of 5 - 10% are dispersed in the coating. The diameter of the silicon carbide nanowires is 50 - 100 nm, and the length is 1 - 5 μm.

[0020] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, the thermal conductivity of the glass fiber reinforced epoxy molding compound ≥

[0021] 1.5 W / (m·K), the flame retardant grade reaches UL94 V-0 level, and the glass transition temperature ≥ 180 °C.

[0022] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, the bending strength retention rate of the glass fiber reinforced epoxy molding compound after aging at 200 °C for 1000 h ≥ 85%.

[0023] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, further comprising 0.5 - 3 wt% of a core-shell structure toughening agent, the core is acrylonitrile-butadiene rubber particles with a particle size of 100 - 300 nm; the shell is an epoxy resin grafted layer with a shell layer thickness of 20 - 50 nm.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] This material contains matrix resin, modified glass fiber, high-temperature resistant filler and flame retardant, and adopts a three-layer gradient structure (surface dense layer / intermediate transition layer / bottom reinforcement layer). The fiber and filler contents in each layer show a gradient change, realizing a "rigid outside and tough inside" mechanical property distribution, with good material strength and high-temperature resistance. Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the method flow in a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories according to the present invention. Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be noted that for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. Next, the embodiments of the present invention will be described according to its overall structure.

[0029] Referring to the accompanying drawings, in an embodiment of the present invention, a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories includes a main material and an auxiliary material. The main material includes a matrix resin component and a reinforcing fiber component. The matrix resin component is composed of 40-60 wt% of bisphenol A epoxy resin and 10-20 wt% of phenolic epoxy resin. The reinforcing fiber component is composed of 15-30 wt% of modified glass fiber, and the modified glass fiber is surface-treated with a silane coupling agent. The silane coupling agent of the modified glass fiber is γ-aminopropyltriethoxysilane, with a treatment concentration of 1-3 wt%, a fiber diameter of 8-15 μm, a length-to-diameter ratio ≥ 50:1, and the surface hydroxyl content reduced to 0.8-1.5 mmol / g;

[0030] The auxiliary material includes a high-temperature resistant filler, a flame retardant and a coupling agent. The high-temperature resistant filler is composed of 5-10 wt% of nano-aluminum oxide and 3-8 wt% of hexagonal boron nitride. The nano-aluminum oxide is α-phase spherical particles, with an average particle size of 50-100 nm and a specific surface area of 20-50 m 2 / g; The phosphorus-based flame retardant is a composite material of ammonium polyphosphate and DOPO derivative, where the particle size of ammonium polyphosphate is ≤5 μm and the DOPO derivative is DOPO-HQ, and the mass ratio of the two is 3:1 - 5:1. The diameter of the hexagonal boron nitride flakes is 1 - 5 μm, where the thickness is ≤100 nm and the mass ratio of the two is 2:1 - 1:1. The flame retardant comprises 3 - 8 wt% of the phosphorus-based flame retardant composition, and the coupling agent comprises 0.5 - 2 wt% of the titanate coupling agent composition;

[0031] The glass fiber reinforced epoxy molding compound is made of a three-layer gradient structure of a surface dense layer, an intermediate transition layer, and a bottom reinforcement layer. In the three-layer gradient structure, the glass fiber volume fraction of the surface dense layer is 25 - 35%, and the filler content is 12 - 18%; the glass fiber volume fraction of the intermediate transition layer is 15 - 25%, and the filler content is 8 - 12%; the glass fiber volume fraction of the bottom reinforcement layer is 35 - 45%, and the filler content is 5 - 8%. A polyimide coating with a thickness of 0.5 - 2 μm is provided on the outer surface of the surface dense layer, and silicon carbide nanowires with a mass fraction of 5 - 10% are dispersed in the coating. The diameter of the silicon carbide nanowires is 50 - 100 nm, and the length is 1 - 5 μm. The thermal conductivity of the glass fiber reinforced epoxy molding compound is ≥

[0032] 1.5 W / (m·K), the flame retardant grade reaches UL94 V-0, and the glass transition temperature is ≥180 °C.

[0033] Please refer to the following parameters for the production of the main and auxiliary materials

[0034] Example 1

[0035] Matrix resin: Bisphenol A epoxy resin (EPON 828) 50 wt% + phenolic epoxy resin (DEN 431) 15 wt%;

[0036] Reinforcing fiber: γ-aminopropyltriethoxysilane modified glass fiber 25 wt% (diameter 10 μm, aspect ratio 60:1);

[0037] High-temperature resistant filler: α-Al 2 O 3 nanoparticles 8 wt% (particle size 80 nm, specific surface area 35 m 2 / g) + h-BN flakes 5 wt% (flake diameter 3 μm, thickness 50 nm);

[0038] Flame retardant: Ammonium polyphosphate (APP, particle size 3 μm) 4.5 wt% + DOPO-HQ 1.5 wt%;

[0039] Coupling agent: Titanate coupling agent (KR-TTS) 1.2 wt%;

[0040] Surface dense layer: The volume fraction of glass fiber is 30%, and the filler content is 15% (Al 2 O 3 : h-BN = 2:1), and short-cut fibers (length 200μm) are arranged directionally;

[0041] Intermediate transition layer: The volume fraction of glass fiber is 20%, and the filler content is 10% (Al 2 O 3 : h-BN = 1:1), and the fiber length of 500μm is randomly distributed;

[0042] Bottom reinforcement layer: The volume fraction of glass fiber is 40%, and the filler content is 6%, and continuous fiber woven cloth is used for reinforcement.

[0043] Please refer to the following parameters for surface functionalization treatment

[0044] Example 2

[0045] Preparation of polyimide coating

[0046] Dissolve the polyimide precursor (PMDA-ODA type) in NMP solvent, add 8wt% silicon carbide nanowires (diameter 80nm, length 3μm), and form a 1.2μm thick coating on the surface dense layer through spraying process;

[0047] Preparation of toughening agent: Core layer: Nitrile rubber emulsion (acrylonitrile content 28%) is polymerized by emulsion polymerization to obtain rubber particles with a particle size of 200nm;

[0048] Shell layer: Epoxy resin (EPON 1001) is coated by in-situ polymerization, the shell layer thickness is 30nm, and the addition amount is 2wt%;

[0049] A preparation method of a high-temperature resistant glass fiber reinforced epoxy molding compound for manufacturing automotive motor accessories, including

[0050] Step S1: Pre-impregnate the modified glass fiber with part of the epoxy resin to form a fiber preform;

[0051] Step S2: Mix and grind the high-temperature resistant filler, flame retardant and the remaining epoxy resin to prepare a masterbatch;

[0052] Step S3: Use the gradient layering process to lay the bottom reinforcement layer, intermediate transition layer and surface dense layer in sequence;

[0053] Step S4: Carry out microwave step curing under vacuum conditions. The curing uses a 2.45GHz microwave source, the power density is 5 - 15W / cm 3 Under the condition of, pre-cure at 80 - 100°C for 30 - 60min first, and then post-cure at 150 - 180°C for 2 - 4h.

[0054] As a further solution of the present invention: a high-temperature resistant glass fiber reinforced epoxy molding encapsulation material for manufacturing automotive motor accessories, further comprising 0.5-3 wt% of a core-shell structure toughening agent, wherein the core is acrylonitrile-butadiene rubber particles with a particle size of 100-300 nm; the shell is an epoxy resin grafted layer with a shell layer thickness of 20-50 nm. Therefore, this material comprises a matrix resin, modified glass fibers, high-temperature resistant fillers and flame retardants, and adopts a three-layer gradient structure (surface dense layer / intermediate transition layer / bottom reinforcement layer), and the fiber and filler contents in each layer change in a gradient manner, realizing a "rigid outside and tough inside" mechanical property distribution, and the material has good strength.

[0055] The working principle of the present invention is: this material comprises a matrix resin, modified glass fibers, high-temperature resistant fillers and flame retardants, and adopts a three-layer gradient structure (surface dense layer / intermediate transition layer / bottom reinforcement layer), and the fiber and filler contents in each layer change in a gradient manner, realizing a "rigid outside and tough inside" mechanical property distribution, and the material has good strength and good high-temperature resistance.

[0056] The above-mentioned are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts, comprising a main material and auxiliary materials, characterized in that: The main material comprises a matrix resin component and a reinforcing fiber component, and the auxiliary materials comprise a high temperature resistant filler, a flame retardant and a coupling agent. The matrix resin component comprises 40-60wt% of bisphenol A epoxy resin and 10-20wt% of phenolic epoxy resin, the reinforcing fiber component comprises 15-30wt% of modified glass fiber, and the modified glass fiber is surface-treated with a silane coupling agent, the high temperature resistant filler comprises 5-10wt% of nano alumina and 3-8wt% of hexagonal boron nitride, the flame retardant comprises 3-8wt% of a phosphorus-based flame retardant, the coupling agent comprises 0.5-2wt% of a titanate coupling agent, and the glass fiber reinforced epoxy molding material is made of a three-layer gradient structure of a surface dense layer, an intermediate transition layer and a bottom reinforcement layer.

2. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 1, characterized in that: The silane coupling agent of the modified glass fiber is γ-aminopropyltriethoxysilane, wherein the treatment concentration is 1-3wt%, the fiber diameter is 8-15μm, the aspect ratio is ≥50:1, and the surface hydroxyl content is reduced to 0.8-1.5mmol / g.

3. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 2, characterized in that: The nano-alumina is an α-phase spherical particle with an average particle size of 50-100nm and a specific surface area of ​​20-50m 2 / g; the diameter of the hexagonal boron nitride sheet is 1-5μm, the thickness is ≤100nm and the mass ratio of the two is 2:1-1:

1.

4. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 3, characterized in that: The phosphorus-based flame retardant is a composite material of ammonium polyphosphate and a DOPO derivative, wherein the particle size of the ammonium polyphosphate is ≤5 μm and the DOPO derivative is DOPO-HQ, and the mass ratio of the two is 3:1-5:

1.

5. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 4, characterized in that: In the three-layer gradient structure, the glass fiber volume fraction of the surface dense layer is 25-35%, and the filler content is 12-18%; the glass fiber volume fraction of the middle transition layer is 15-25%, and the filler content is 8-12%; the glass fiber volume fraction of the bottom reinforcement layer is 35-45%, and the filler content is 5-8%.

6. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 5, characterized in that: The outer surface of the surface dense layer is provided with a polyimide coating with a thickness of 0.5-2 μm, in which 5-10% by mass fraction of silicon carbide nanowires are dispersed, and the silicon carbide nanowires have a diameter of 50-100 nm and a length of 1-5 μm.

7. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 6, characterized in that: The thermal conductivity of glass fiber reinforced epoxy molding materials is ≥1.5W / (m·K), the flame retardancy grade reaches UL94 V-0, and the glass transition temperature is ≥180℃.

8. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 7, characterized in that: The bending strength retention rate of the glass fiber reinforced epoxy molding material after aging for 1000 hours at 200° C. is ≥85%.

9. The high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 8, characterized in that: It also includes 0.5-3wt% of a core-shell structure toughening agent, wherein the core is a nitrile rubber particle with a particle size of 100-300nm; the shell is an epoxy resin graft layer with a shell layer thickness of 20-50nm.

10. The method for preparing a high temperature resistant glass fiber reinforced epoxy molding material for manufacturing automobile motor parts according to claim 9, characterized in that: include Step S1: pre-impregnating the modified glass fiber with a portion of epoxy resin to form a fiber preform; Step S2: mixing and grinding the high temperature resistant filler, the flame retardant and the remaining epoxy resin to prepare a masterbatch; Step S3: using a gradient plying process to sequentially lay a bottom reinforcement layer, an intermediate transition layer and a surface dense layer; Step S4: Microwave step curing is performed under vacuum conditions, using a 2.45 GHz microwave source with a power density of 5-15 W / cm 3 Conditions: pre-cure at 80-100℃ for 30-60min, then post-cure at 150-180℃ for 2-4h.

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