Epoxy resin system bulk molding compound and preparation method thereof

Abstract

The invention discloses an epoxy resin system bulk molding compound and a preparation method thereof. The epoxy resin system bulk molding compound is prepared from the following raw materials in parts by weight: 20 to 60 parts of epoxy resin, 5 to 15 parts of curing agent, 2 to 10 parts of magnesium oxide, 2 to 10 parts of silicon filler, 20 to 40 parts of chopped glass fiber, 0.5 to 1.5 parts of thixotropic agent, 0.1 to 1 part of defoaming agent and 0.1 to 0.5 part of wetting dispersant, wherein the silicon filler is talcum powder and / or hollow glass beads. According to the epoxy resin system bulk molding compound disclosed by the invention, the epoxy resin is taken as a matrix, the prepared epoxy resin system bulk molding compound can be quickly cured and molded by optimizing the component type and proportion of a curing system, and a cured product of the bulk molding compound has good strength and toughness and is resistant to high temperature.

Description

Technical Field

[0001] The invention belongs to the technical field of materials, and in particular relates to an epoxy resin system bulk molding compound and a preparation method thereof. Background Art

[0002] Bulk molding compound (BMC) is a thermosetting composite material made of resin, organic additives, initiators, powdered fillers, thickeners and chopped glass fibers. It has a wide range of applications. Bulk molding compound has good electrical insulation, antistatic, anti-leakage, chemical corrosion resistance and other properties, so it is widely used in electrical components, automotive components and electronic plastic packaging. However, with the development of high technology, people have higher and higher requirements on the performance of BMC materials, especially its mechanical properties, electrical properties and heat resistance. Traditional BMC materials use unsaturated polyester as the base resin, and need to use initiators, promoters, cross-linking agents and low shrinkage agents. The formula system is relatively complex, and there are many low-molecular volatiles and strong odors during the processing process, which does not conform to the concept of green environmental protection. In addition, the comprehensive performance of traditional BMC materials is not ideal, and its application in the fields of electrical, construction and aerospace military is limited.

[0003] As a high-performance resin, epoxy resin has many advantages such as good temperature resistance, corrosion resistance, high mechanical strength, good insulation effect, low shrinkage, low water absorption, etc. Using epoxy resin instead of unsaturated resin as the resin matrix of BMC material can effectively reduce the volume shrinkage during the molding process and the generation of small molecular gases during cross-linking, while improving the appearance and dimensional stability of the product, which can effectively expand the application field of bulk molding compounds.

[0004] At present, although the existing bulk molding compound of epoxy resin system meets the conventional performance requirements, its products still need to be improved in terms of comprehensive performance, especially they cannot meet the requirements of short curing time, high tensile strength, high bending strength, high heat resistance and the like at the same time. Chinese patent CN113817293A discloses a lightweight glass microbead reinforced bulk molding compound, the curing molding temperature of the bulk molding compound is 80°C, the molding time is 60min, the curing time is relatively long, and the tensile strength of the cured product is 39-48MPa, the bending strength is 65.8-83.0MPa, both lower than the pure resin, and the mechanical properties of the cured product are poor. Chinese patent CN117050469A discloses a high temperature wear-resistant epoxy bulk molding compound, the curing molding temperature of the high temperature wear-resistant epoxy bulk molding compound is 100-160°C, the curing molding time is 2-3h, the curing time is long, which is not conducive to the industrial large-scale production of bulk molding compound products. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an epoxy resin system bulk molding compound and a preparation method thereof. The present invention optimizes the type and ratio of the curing system components in the epoxy resin system bulk molding compound so that the prepared epoxy resin system bulk molding compound can be quickly cured and formed, and at the same time, the cured product of the epoxy resin system bulk molding compound has excellent mechanical properties and is resistant to high temperatures.

[0006] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0007] The present invention provides an epoxy resin system bulk molding compound, the raw materials of which include the following components by weight:

[0008]

[0009] The silicon-based filler is talcum powder and / or hollow glass microspheres.

[0010] Furthermore, an epoxy resin system bulk molding compound, the raw materials include the following components by weight:

[0011]

[0012] Furthermore, the epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, and multifunctional resin.

[0013] Furthermore, the bisphenol A epoxy resin includes one or more of 127 epoxy resin, 128 epoxy resin, 127E epoxy resin and 128E epoxy resin.

[0014] Preferably, the 127 epoxy resin is NPEL-127 produced by Nan Ya Company, the epoxy equivalent of NPEL-127 is 176-184 g / mol, and the viscosity is 8000-11000 cps (25° C.); the 128 epoxy resin is NPEL-128 produced by Nan Ya Company, the epoxy equivalent of NPEL-128 is 184-190 g / mol, and the viscosity is 12000-15000 cps (25° C.); The 127E epoxy resin is NPEL-127E produced by Nan Ya Company, the epoxy equivalent of NPEL-127E is 176-184 g / mol, and the viscosity is 8000-11000 cps (25° C.); the 128E epoxy resin is NPEL-128E produced by Nan Ya Company, the epoxy equivalent of NPEL-128E is 184-190 g / mol, and the viscosity is 12000-15000 cps (25° C.).

[0015] Furthermore, the bisphenol F epoxy resin includes one or more of 170 epoxy resin, 180 epoxy resin and 185 epoxy resin.

[0016] Preferably, the 170 epoxy resin is NPEF-170 produced by Nan Ya Company, the epoxy equivalent of NPEF-170 is 160-180 g / mol, and the viscosity is 2000-5000 cps (25°C); the 180 epoxy resin is NPEF-180 produced by Nan Ya Company, the epoxy equivalent of NPEF-180 is 170-190 g / mol, and the viscosity is 5000-7000 cps (25°C); the 185 epoxy resin is NPEF-185 produced by Nan Ya Company, the epoxy equivalent of NPEF-185 is 160-180 g / mol, and the viscosity is 6000-8000 cps (25°C).

[0017] Furthermore, the novolac epoxy resin includes 631 epoxy resin and / or 638S epoxy resin.

[0018] Preferably, the 631 epoxy resin is NPPN-631 produced by Nan Ya Company, the epoxy equivalent of NPPN-631 is 168-170 g / mol, and it is semi-solid; the 638S epoxy resin is NPPN-638S produced by Nan Ya Company, the epoxy equivalent of NPPN-638S is 170-190 g / mol, and it is semi-solid.

[0019] Furthermore, the multifunctional epoxy resin includes AG-80 epoxy resin and / or AFG90 epoxy resin. The epoxy equivalent of the AG-80 epoxy resin is less than 125 g / mol and the viscosity is 3000-7000 cps (50° C.); the epoxy equivalent of the AFG-90 epoxy resin is less than 110 g / mol and the viscosity is 1500-2500 cps (25° C.).

[0020] Furthermore, the curing agent includes one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent, aromatic amine curing agent and dicyandiamide curing agent.

[0021] Furthermore, the fatty amine curing agent includes triethylenetetramine and / or tetraethylenepentamine; the alicyclic amine curing agent includes one or more of menthane diamine (MDA), isophorone diamine (IPDA), [bis(4-amino-3-methylcyclohexyl) methane] (DMDC) and 4,4'-diaminodicyclohexyl methane (HMDA); the aromatic amine curing agent includes meta-phenylenediamine and / or diaminodiphenylmethane; the dicyandiamide curing agent includes one or more of dicyandiamide, phenylbiguanide and o-methylphenylbiguanide (1-o-toluene biguanide); the polyamide curing agent includes one or more of polyamide resin 200#, polyamide resin 300, polyamide resin 400#, polyamide resin 500# and polyamide resin 600#.

[0022] Furthermore, the length of the chopped glass fibers is 3-12 mm.

[0023] Furthermore, the length of the chopped glass fibers is 3-6 mm.

[0024] Furthermore, the thixotropic agent includes fumed silica and / or organic bentonite.

[0025] Furthermore, the defoaming agent includes 1-butyl alcohol, 1,2-propylene glycol, tributyl phosphate, emulsified methyl silicone oil, emulsified phenyl silicone oil, BYK-A530 defoaming agent produced by German BYK Company and BYK-A560 defoaming agent produced by German BYK Company.

[0026] Among them, the ingredients of BYK-A530 defoamer produced by BYK in Germany are petroleum hydrogenated light distillates and 2,6-di-tert-butyl-p-methylphenol. The chemical composition of BYK-A530 defoamer produced by BYK in Germany is foam-breaking polymer and polysiloxane solution. The CAS registration number of petroleum hydrogenated light distillates is CAS: 64742-47-8, and the CAS registration number of 2,6-di-tert-butyl-p-methylphenol is CAS: 128-37-0; the chemical composition of BYK-A560 defoamer produced by BYK in Germany is silicone-free foam-breaking polyacrylate and polymer solution.

[0027] Furthermore, the wetting and dispersing agent includes BYK-P9920 wetting and dispersing agent produced by BYK of Germany and / or BYK-P104 wetting and dispersing agent produced by BYK of Germany.

[0028] The BYK-P9920 wetting and dispersing agent produced by German BYK Company is composed of a mixture of oligomers containing wetting agents; the chemical composition of the BYK-P104 wetting and dispersing agent produced by German BYK Company is a solution of a low molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer.

[0029] The present invention also provides a method for preparing the epoxy resin system bulk molding compound as described in any one of the above items, comprising the following steps:

[0030] (1) mixing an epoxy resin and a curing agent to obtain a first mixture;

[0031] (2) adding a thixotropic agent, a defoaming agent and a wetting and dispersing agent to the second mixed material and mixing them evenly, and then adding magnesium oxide and a silicon-based filler, and mixing until there is no dry powder to obtain a second mixed material;

[0032] (3) Add chopped glass fibers to the second mixed material and knead to obtain a bulk molding compound.

[0033] Furthermore, the step (1) is specifically as follows: mixing the epoxy resin and the dicyandiamide curing agent at 25-50° C. until there is no dry powder, and then grinding, and then adding one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent and aromatic amine curing agent at 25-40° C., and mixing evenly to obtain a first mixture;

[0034] Alternatively, the epoxy resin is uniformly mixed with one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent and aromatic amine curing agent at 25-40° C. to obtain a first mixture.

[0035] Furthermore, the grinding is specifically grinding on a three-roll grinder for 3-5 times.

[0036] Furthermore, in step (3), the kneading temperature is 25-70° C., and the kneading time is 30-60 min.

[0037] Furthermore, in step (3), the kneading is performed using a kneader.

[0038] Furthermore, in steps (1)-(3), the mixing method is stirring.

[0039] The present invention also provides a cured bulk molding compound, which is obtained by curing the epoxy resin system bulk molding compound described in any one of the above or the epoxy resin system bulk molding compound prepared by the preparation method of the epoxy resin system bulk molding compound described in any one of the above.

[0040] Furthermore, the curing time is 5-10 minutes, and the curing temperature is 120-180°C.

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] (1) The present invention redesigns the formula of the epoxy resin system bulk molding compound, takes the epoxy resin as the matrix, and works together with the curing agent, filler, chopped glass fiber, thixotropic agent, defoaming agent, wetting dispersant, etc., to optimize the type and ratio of the curing system components, so that the epoxy resin system bulk molding compound can be quickly cured and formed at 120-180°C, with low requirements for operators, and improves the industrial production efficiency of bulk molding compound products. In addition, the cured bulk molding compound has high temperature resistance and excellent mechanical properties. The glass transition temperature of the cured bulk molding compound is above 100°C, the tensile strength is above 40MPa, the tensile modulus is above 3000MPa, the flexural strength is above 110MPa, the tensile modulus is above 4000MPa, and the strength and toughness are good.

[0043] (2) Compared with unsaturated polyester, the epoxy resin used in the present invention has better heat resistance, wear resistance, mechanical strength and dimensional stability, and has higher interface strength with glass fiber. The curing system is simple, there is no violent reaction, and no small molecules are volatilized during the processing. It has better processability, is more environmentally friendly and safe, and is suitable for preparing high-end molding compounds.

[0044] (3) The present invention uses magnesium oxide mixed with talcum powder and / or hollow glass microspheres as fillers, and at the same time supplemented with a relatively high proportion of short-cut glass fibers with a length of less than 6 mm. Therefore, the product is dense, has high mechanical strength, and has low production cost. In addition, the filler and the short-cut glass fibers have a good degree of compatibility with the epoxy resin matrix, ensuring that the bulk molding compound will not have surface defects such as ripples and pinholes during curing in the mold. DETAILED DESCRIPTION

[0045] The specific implementation of the present invention is further described below in conjunction with examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. If the manufacturer of the reagents or instruments used is not indicated, they are deemed to be conventional products that can be purchased commercially.

[0046] It should be noted that, in the present invention, the terms "first", "second", etc. are only used to facilitate the description of the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, the term "dicyandiamide curing agent" refers to dicyandiamide and its derivatives that can be used as epoxy resin curing agents. In the embodiments, the dicyandiamide curing agent is purchased from German Azken (product model: Dyhard 100S), German Azken (product model: Ecure 14) or German Evonik (product model: DICYANEX 1400F).

[0048] The first aspect of the present invention provides an epoxy resin system bulk molding compound, the raw materials comprising components by weight:

[0049] Epoxy resin 20-60 parts

[0050] Curing agent 5-15 parts

[0051]

[0052] The silicon-based filler is talcum powder and / or hollow glass microspheres.

[0053] In some embodiments of the present invention, the epoxy resin system bulk molding compound comprises raw materials by weight:

[0054]

[0055] The resin matrix is ​​the main component of the bulk molding compound. It plays the role of linking reinforcements, fillers, and transferring and dispersing loads. The present invention adopts epoxy resin as the resin matrix, which has the beneficial effects of good mechanical properties, low water absorption, low shrinkage, good chemical stability and excellent electrical insulation. In the present invention, the epoxy resin is not particularly limited and can be a monomer, oligomer or polymer containing two or more epoxy groups in one molecule. In some embodiments of the present invention, the epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and multifunctional resin.

[0056] Preferably, the bisphenol A epoxy resin includes one or more of 127 epoxy resin, 128 epoxy resin, 127E epoxy resin and 128E epoxy resin. In a specific embodiment of the present invention, the 127 epoxy resin is NPEL-127 produced by Nan Ya Company, and the epoxy equivalent of NPEL-127 is 176-184 g / mol, and the viscosity is 8000-11000 cps (25°C). In a specific embodiment of the present invention, the 128 epoxy resin is NP EL-128 produced by Nan Ya Company, and the epoxy equivalent of NPEL-128 is 184-190 g / mol, and the viscosity is 12000-15000 cps (25°C). In a specific embodiment of the present invention, the 127E epoxy resin is NPEL-127E produced by Nan Ya Company, the epoxy equivalent of NPEL-127E is 176-184 g / mol, and the viscosity is 8000-11000 cps (25°C). In a specific embodiment of the present invention, the 128E epoxy resin is NPEL-128E produced by Nan Ya Company, the epoxy equivalent of NPEL-128E is 184-190 g / mol, and the viscosity is 12000-15000 cps (25°C).

[0057] Preferably, the bisphenol F type epoxy resin includes one or more of 170 epoxy resin, 180 epoxy resin and 185 epoxy resin. In a specific embodiment of the present invention, the 170 epoxy resin is NPEF-170 produced by Nan Ya Company, and the epoxy equivalent of NPEF-170 is 160-180 g / mol, and the viscosity is 2000-5000 cps (25°C). In a specific embodiment of the present invention, the 180 epoxy resin is NPEF-180 produced by Nan Ya Company, and the epoxy equivalent of NPEF-180 is 170-190 g / mol, and the viscosity is 5000-7000 cps (25°C). In a specific embodiment of the present invention, the 185 epoxy resin is NPEF-185 produced by Nan Ya Company, and the epoxy equivalent of NPEF-185 is 160-180 g / mol, and the viscosity is 6000-8000 cps (25°C).

[0058] Preferably, the phenolic epoxy resin includes 631 epoxy resin and / or 638S epoxy resin. In a specific embodiment of the present invention, the 631 epoxy resin is NPPN-631 produced by Nan Ya Company, the epoxy equivalent of NPPN-631 is 168-170 g / mol, and it is semi-solid. In a specific embodiment of the present invention, the 638S epoxy resin is NPPN-638S produced by Nan Ya Company, the epoxy equivalent of NPPN-638S is 170-190 g / mol, and it is semi-solid.

[0059] Preferably, the multifunctional epoxy resin comprises AG80 epoxy resin and / or AFG90 epoxy resin. The epoxy equivalent of the AG-80 epoxy resin is <125 g / mol and the viscosity is 3000-7000 cps (50° C.); the epoxy equivalent of the AFG-90 epoxy resin is <110 g / mol and the viscosity is 1500-2500 cps (25° C.).

[0060] In some embodiments of the present invention, the curing agent includes one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent, aromatic amine curing agent and dicyandiamide curing agent. Preferably, the aliphatic amine curing agent includes triethylenetetramine and / or tetraethylenepentamine; the alicyclic amine curing agent includes one or more of menthane diamine (MDA), isophorone diamine (IPDA), [bis(4-amino-3-methylcyclohexyl) methane] (DMDC) and 4,4'-diaminodicyclohexyl methane (HMDA); the polyamide curing agent includes one or more of polyamide resin 200#, polyamide resin 300, polyamide resin 400#, polyamide resin 500# and polyamide resin 600#.

[0061] The aromatic amine curing agent includes meta-xylylenediamine and / or diaminodiphenylmethane; the dicyandiamide curing agent includes one or more of dicyandiamide, phenylbiguanide and o-methylphenylbiguanide (1-o-tolylbiguanide).

[0062] In some embodiments of the present invention, the length of the chopped glass fibers is 3-12 mm. Glass fibers serve as reinforcements for bulk molding plastics. The resin matrix fixes the glass fibers in place, provides interlaminar shear strength, protects them from wear and load transfer, and has a blocking effect on crack propagation, so as to improve the strength and toughness of bulk molding plastic products. When the glass fibers have a certain length, the resin matrix can transfer the force to the glass fibers. If the glass fibers are too long, the glass fibers are easily broken and damaged under the action of large shear or friction forces, and the mechanical strength of the products decreases. Therefore, the present invention selects chopped glass fibers with a length of 3-12 mm. Preferably, the length of the chopped glass fibers is 3-6 mm. In bulk molding compound products, if the glass fiber content is too little, areas lacking glass fiber will appear inside the material. These areas will become stress concentration points, making the mechanical properties of the product worse. If the glass fiber content is too much, the resin will be difficult to penetrate, the bonding strength of the components will be poor, and the mechanical properties of the product will also decrease. Therefore, 20-40 parts of chopped glass fiber can make the bulk molding compound products have better mechanical properties.

[0063] In some embodiments of the present invention, the thixotropic agent includes fumed silica and / or organic bentonite.

[0064] In some embodiments of the present invention, the defoaming agent includes 1-butyl alcohol, 1,2-propylene glycol, tributyl phosphate, emulsified methyl silicone oil, emulsified phenyl silicone oil, BYK-A530 defoaming agent produced by BYK in Germany, and BYK-A560 defoaming agent produced by BYK in Germany.

[0065] In some embodiments of the present invention, the wetting and dispersing agent includes BYK-P9920 wetting and dispersing agent produced by BYK of Germany and / or BYK-P104 wetting and dispersing agent produced by BYK of Germany.

[0066] Magnesium oxide is compounded with talcum powder and / or hollow glass microspheres as a filler additive. Magnesium oxide has excellent heat conductivity and is conducive to the curing of molding plastics. Talc has excellent temperature resistance, electrical insulation and dielectric properties, and does not decompose under high temperature, high voltage and strong electric field conditions, and has good arc resistance. Hollow glass microspheres are a micron-level lightweight material, whose main component is borosilicate, and have high compression strength. Using hollow glass microspheres as fillers can reduce the density of products and improve wear resistance and chemical corrosion resistance. However, too much filler will make the fluidity of bulk molding plastics worse. Therefore, magnesium oxide is compounded with talcum powder and / or hollow glass microspheres, 2-10 parts of magnesium oxide, 0-10 parts of talcum powder, and 0-8 parts of hollow glass microspheres, which can make the bulk molding plastic have better fluidity and ensure the compact structure of the product after curing and molding.

[0067] The second aspect of the present invention provides a method for preparing the epoxy resin system bulk molding compound as described in any one of the above, comprising the following steps:

[0068] (1) mixing an epoxy resin and a curing agent to obtain a first mixture;

[0069] (2) adding a thixotropic agent, a defoaming agent and a wetting and dispersing agent to the second mixed material and mixing them evenly, and then adding magnesium oxide and a silicon-based filler, and mixing until there is no dry powder to obtain a second mixed material;

[0070] (3) Add chopped glass fibers to the second mixed material and knead to obtain a bulk molding compound.

[0071] In some embodiments of the present invention, the step (1) is specifically: mixing the epoxy resin and the dicyandiamide curing agent at 25-50°C until there is no dry powder and then grinding, then adding one or more of the aliphatic amine curing agent, the polyamide curing agent, the alicyclic amine curing agent and the aromatic amine curing agent at 25-40°C, and mixing uniformly to obtain the first mixed material; or, mixing the epoxy resin and one or more of the aliphatic amine curing agent, the polyamide curing agent, the alicyclic amine curing agent and the aromatic amine curing agent at 25-40°C to obtain the first mixed material. Preferably, the grinding is specifically grinding on a three-roll grinder for 3-5 times.

[0072] In some embodiments of the present invention, in step (3), the kneading temperature is 25-70° C., and the kneading time is 30-60 min.

[0073] In some embodiments of the present invention, in step (3), the kneading uses a kneader.

[0074] In some embodiments of the present invention, in steps (1)-(3), the mixing method is stirring.

[0075] A third aspect of the present invention provides a cured bulk molding compound, which is obtained by curing the epoxy resin system bulk molding compound described in any one of the above or the epoxy resin system bulk molding compound prepared by the preparation method of the epoxy resin system bulk molding compound described in any one of the above.

[0076] In some embodiments of the present invention, the curing time is 5-15 minutes, and the curing temperature is 120-180°C.

[0077] Traditional bulk molding compound products have a long production cycle and low production efficiency. The epoxy resin system bulk molding compound of the present invention requires a short curing time and has low requirements on operators, which is conducive to improving the industrial production efficiency of bulk molding compound products. In addition, the cured bulk molding compound of the present invention has high strength, good toughness, and almost no warping; the glass transition temperature is above 100°C, and has excellent high temperature resistance.

[0078] Example 1

[0079] (1) 30 parts of 128 resin and 1 part of dicyandiamide (DICY) were mixed at room temperature. Stirred until no dry powder appeared, ground on a three-roll mill for 3 times, and set aside. 6 parts of isophorone diamine (IPDA) were added at room temperature to obtain a first mixed material.

[0080] (2) Add 0.5 parts of thixotropic agent fumed silica, 0.2 parts of defoaming agent BYK-A530, and 0.2 parts of wetting and dispersing agent BYK-P9920 to the first mixture, stir and mix, then add 5 parts of talcum powder and 5 parts of magnesium oxide, and continue stirring until no dry powder appears, to obtain a second mixture.

[0081] (3) After adding 30 parts of chopped glass fibers to the second mixed material, place it in a kneader for 30-60 minutes, and control the material temperature at 25-35°C. If the material temperature is too high, it needs to be cooled. The blank of the bulk molding compound is obtained and is ready for use.

[0082] The blank is cured at 170° C. for 10 minutes. The obtained cured product has a glass transition temperature of 100-120° C., a tensile strength of 40-50 MPa, a tensile modulus of 4000-5000 MPa, a flexural strength of 120-150 MPa, and a flexural modulus of 4000-5000 MPa.

[0083] Example 2

[0084] (1) 40 parts of 170 resin, 5 parts of AG80 resin and 1 part of dicyandiamide (DICY) were mixed at 40-50° C. and stirred until no dry powder appeared. The mixture was ground on a three-roll mill for 3-5 times for standby use. 10 parts of isophorone diamine (IPDA) were added at room temperature to obtain a first mixed material.

[0085] (2) Add 0.4 parts of thixotropic agent fumed silica, 0.3 parts of defoaming agent BYK-A530, and 0.3 parts of wetting and dispersing agent BYK-P9920 to the first mixture, stir and mix, then add 2 parts of talcum powder, 2 parts of magnesium oxide, and 2 parts of hollow glass microspheres, and continue stirring until no dry powder appears to obtain a second mixture.

[0086] (3) After adding 40 parts of chopped glass fibers to the second mixed material, place it in a kneader for 30-60 minutes, and control the material temperature at 30-40°C. If the material temperature is too high, it needs to be cooled. The blank of the bulk molding compound is obtained and is ready for use.

[0087] The blank is cured at 180° C. for 10 minutes. The obtained cured product has a glass transition temperature of 110-130° C., a tensile strength of 40-60 MPa, a tensile modulus of 3500-3500 MPa, a flexural strength of 110-130 MPa, and a flexural modulus of 4000-5000 MPa.

[0088] Example 3

[0089] (1) 25 parts of 127 resin, 5 parts of AG80 resin, 2 parts of 4,4'-diaminodicyclohexylmethane (HMDA), and 6 parts of isophoronediamine (IPDA) were mixed at 30-40° C. to obtain a first mixed material for standby use.

[0090] (2) Add 0.5 parts of thixotropic agent organic bentonite, 0.2 parts of defoaming agent BYK-A560, and 0.3 parts of wetting and dispersing agent BYK-P104 to the first mixture, stir and mix, then add 2 parts of talcum powder and 2 parts of magnesium oxide, and continue stirring until no dry powder appears to obtain a second mixture.

[0091] (3) After adding 40 parts of chopped glass fibers to the second mixed material, place it in a kneader for 30-60 minutes, and control the material temperature at 50-60°C. If the material temperature is too high, it needs to be cooled. The blank of the bulk molding compound is obtained and is ready for use.

[0092] The blank is cured at 180° C. for 10 minutes. The obtained cured product has a glass transition temperature of 110-130° C., a tensile strength of 40-60 MPa, a tensile modulus of 4000-6000 MPa, a flexural strength of 120-140 MPa, and a flexural modulus of 4000-6000 MPa.

[0093] Example 4

[0094] (1) Mix 30 parts of 127 resin, 10 parts of 638 resin and 11 parts of tetraethylene pentamine at room temperature to obtain a first mixed material for standby use.

[0095] (2) Add 0.4 parts of thixotropic agent fumed silica, 0.3 parts of defoaming agent BYK-A560, and 0.3 parts of wetting and dispersing agent BYK-P9920 to the first mixture, stir and mix, then add 5 parts of magnesium oxide and 2 parts of hollow glass microspheres, and continue stirring until no dry powder appears to obtain a second mixture.

[0096] (3) After adding 40 parts of chopped glass fibers to the second mixed material, place it in a kneader for 30-60 minutes, and control the material temperature at 60-70°C. If the material temperature is too high, it needs to be cooled. The blank of the bulk molding compound is obtained and is ready for use.

[0097] The blank is cured at 180° C. for 10 minutes. The obtained cured product has a glass transition temperature of 100-120° C., a tensile strength of 50-70 MPa, a tensile modulus of 4500-6500 MPa, a flexural strength of 130-160 MPa, and a flexural modulus of 4500-6500 MPa.

[0098] Example 5

[0099] (1) Mix 40 parts of 128 resin, 10 parts of 638 resin and 2 parts of dicyandiamide (DICY) at 40-50° C., stir until no dry powder appears, grind on a three-roll grinder for 3-5 times, and set aside. Add 12 parts of 4,4'-diaminodicyclohexylmethane (HMDA) and mix at room temperature to obtain a first mixed material, which is set aside.

[0100] (2) Add 0.6 parts of thixotropic agent organic bentonite, 0.2 parts of defoaming agent emulsified phenyl silicone oil, and 0.2 parts of wetting and dispersing agent BYK-P104 to the first mixture, stir and mix, then add 5 parts of talcum powder and 2 parts of magnesium oxide, and continue stirring until no dry powder appears to obtain a second mixture.

[0101] (3) After adding 35 parts of chopped glass fibers to the second mixed material, place it in a kneader for 30-60 minutes, and control the material temperature at 60-70°C. If the material temperature is too high, it needs to be cooled. The blank of the bulk molding compound is obtained and is ready for use.

[0102] The blank is cured at 180° C. for 10 minutes. The obtained cured product has a glass transition temperature of 100-120° C., a tensile strength of 60-80 MPa, a tensile modulus of 5000-7000 MPa, a flexural strength of 130-160 MPa, and a flexural modulus of 5000-7000 MPa.

[0103] Example 6

[0104] (1) 40 parts of 170 resin, 20 parts of 638 resin and 4 parts of dicyandiamide (DICY) are mixed at 40-50° C. and stirred until no dry powder is present. The mixture is ground on a three-roll mill for 3-5 times and set aside. 7 parts of [bis(4-amino-3-methylcyclohexyl)methane] (DMDC) and 3 parts of tetraethylenepentamine are added and mixed at room temperature to obtain a first mixed material, which is set aside.

[0105] (2) Add 0.5 parts of thixotropic agent fumed silica, 0.2 parts of defoaming agent BYK-A530, and 0.3 parts of wetting and dispersing agent BYK-P9920 to the first mixture, stir and mix, then add 2 parts of talcum powder and 2 parts of magnesium oxide, and continue stirring until no dry powder appears to obtain the second mixture.

[0106] (3) After adding 35 parts of chopped glass fibers to the second mixed material, place it in a kneader for 30-60 minutes, and control the material temperature at 60-70°C. If the material temperature is too high, it needs to be cooled. The blank of the bulk molding compound is obtained and is ready for use.

[0107] The blank is cured at 180° C. for 10 minutes. The obtained cured product has a glass transition temperature of 100-120° C., a tensile strength of 40-70 MPa, a tensile modulus of 3000-5000 MPa, a flexural strength of 130-160 MPa, and a flexural modulus of 4000-6000 MPa.

[0108] The bulk molding compounds prepared in Examples 1-6 can all be rapidly cured at 120-180°C, and the glass transition temperature of the cured products is above 100°C, the tensile strength is above 40MPa, the tensile modulus is above 3000MPa, the flexural strength is above 110MPa, the tensile modulus is above 4000MPa, and the bulk molding compounds have good strength and toughness and are resistant to high temperatures. The bulk molding compounds are simple to store and operate, have good process adaptability, and are suitable for molding processes.

[0109] The above embodiments are only preferred implementation modes of the present invention and are only used to explain the present invention rather than to limit the present invention. Any changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. An epoxy resin system bulk molding compound, characterized in that: The raw materials include components by weight: The silicon-based filler is talcum powder and / or hollow glass microspheres.

2. The epoxy resin system bulk molding compound according to claim 1, characterized in that: The epoxy resin system bulk molding compound comprises the following components by weight:

3. An epoxy resin system bulk molding compound according to claim 1 or 2, characterized in that: The epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, and multifunctional resin; And / or, the curing agent includes one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent, aromatic amine curing agent and dicyandiamide curing agent; And / or, the length of the chopped glass fibers is 3-12 mm.

4. The epoxy resin system bulk molding compound according to claim 3, characterized in that: The bisphenol A type epoxy resin includes one or more of 127 epoxy resin, 128 epoxy resin, 127E epoxy resin and 128E epoxy resin; the bisphenol F type epoxy resin includes one or more of 170 epoxy resin, 180 epoxy resin and 185 epoxy resin; the novolac type epoxy resin includes 631 epoxy resin and / or 638S epoxy resin; the multifunctional epoxy resin includes AG-80 epoxy resin and / or AFG90 epoxy resin; The fatty amine curing agent includes triethylenetetramine and / or tetraethylenepentamine; the alicyclic amine curing agent includes one or more of menthane diamine, isophorone diamine, [bis(4-amino-3-methylcyclohexyl)methane] and 4,4'-diaminodicyclohexylmethane; the aromatic amine curing agent includes meta-xylylenediamine and / or diaminodiphenylmethane; the dicyandiamide curing agent includes one or more of dicyandiamide, phenylbiguanide and o-methylphenylbiguanide.

5. The epoxy resin system bulk molding compound according to claim 1 or 2, characterized in that: The thixotropic agent includes fumed silica and / or organic bentonite; And / or, the defoamer includes one or more of 1-butyl alcohol, 1,2-propylene glycol, tributyl phosphate, emulsified methyl silicone oil, emulsified phenyl silicone oil, BYK-A530 defoamer produced by BYK in Germany, and BYK-A560 produced by BYK in Germany; And / or, the wetting and dispersing agent includes BYK-9920 wetting and dispersing agent produced by BYK of Germany and / or BYK-P104 wetting and dispersing agent produced by BYK of Germany.

6. The method for preparing the epoxy resin system bulk molding compound according to any one of claims 1 to 5, comprising the following steps: (1) mixing an epoxy resin and a curing agent to obtain a first mixture; (2) adding a thixotropic agent, a defoaming agent and a wetting and dispersing agent to the second mixed material and mixing them evenly, and then adding magnesium oxide and a silicon-based filler, and mixing until there is no dry powder to obtain a second mixed material; (3) Add chopped glass fibers to the second mixed material and knead to obtain a bulk molding compound.

7. The preparation method according to claim 6, characterized in that: The step (1) specifically comprises: mixing the epoxy resin and the dicyandiamide curing agent at 25-50° C. until there is no dry powder, then grinding, and then adding one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent and aromatic amine curing agent at 25-40° C., mixing evenly to obtain a first mixture; Alternatively, the epoxy resin is uniformly mixed with one or more of aliphatic amine curing agent, polyamide curing agent, alicyclic amine curing agent and aromatic amine curing agent at 25-40° C. to obtain a first mixture.

8. The preparation method according to claim 6, characterized in that: In step (3), the kneading temperature is 25-70° C., and the kneading time is 30-60 min.

9. A bulk molding compound solidified product, characterized in that: The BMC cured product is obtained by curing the epoxy resin system BMC prepared by the epoxy resin system BMC described in any one of claims 1 to 5 or the epoxy resin system BMC prepared by the preparation method of the epoxy resin system BMC described in any one of claims 6 to 8.

10. The solidified bulk molding compound according to claim 9, characterized in that: The curing time is 5-15 minutes, and the curing temperature is 120-180°C.

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