Grinding apparatus and method for using said apparatus to prepare epoxy resin encapsulant

Abstract

Disclosed are a grinding apparatus, and a method for using said apparatus to prepare an epoxy resin encapsulant. The grinding apparatus comprises a grinding machine body (1), baffles (3) being symmetrically disposed between two grinding rollers (2) on the grinding machine body (1), and an adjusting assembly (4) used to adjust a distance between two baffles (3) being disposed on a rear side of the grinding machine body (1). The grinding apparatus utilizes a screw rod on the adjusting assembly of the grinding machine body to drive an adjusting plate to move, and to simultaneously adjust the baffles on the grinding roller. In addition, during a preparation process, epoxy encapsulant using a modified resin composition and a curing agent composition as raw materials has the advantages of not flowing when heated, strong molding capability, and excellent heat resistance; modified phenol F epoxy resin exhibits improved heat resistance, tensile strength, and affinity with lipid-based materials, and low-temperature pretreatment is carried out before curing, causing a tighter bond between mixture and substrate, thereby enhancing the tensile performance of the encapsulant.

Description

Grinding device and method for preparing epoxy resin encapsulating material using the same Technical Field

[0001] The present invention relates to the technical field of encapsulation material preparation, in particular to a grinding device and a method for preparing epoxy resin encapsulation material by using the device. Background Art

[0002] Epoxy resin encapsulant is a powder coating. It is a hot-melt thermosetting powder material made by mixing, kneading, crushing, and grading epoxy resin, adding curing agent, inorganic filler, colorant and other additives. Epoxy resin encapsulant is widely used in the production of electronic components due to its excellent properties such as toughness, electrical insulation and mechanical properties after coating.

[0003] The preparation process of epoxy resin encapsulant generally requires the following steps: preparation of modified resin composition, preparation of curing agent composition and heating and curing molding. In the preparation process of modified resin composition, the evenly mixed resin components need to be ground on a grinding device. The grinding device usually has a material baffle on its grinding roller to limit the raw material by the material baffle to prevent the raw material from flowing out from both ends of the grinding roller. However, the existing grinding device is not convenient for adjusting the two material baffles at the same time, which makes the preparation of modified resin composition more time-consuming. Therefore, the above problem needs to be solved. Summary of the Invention

[0004] The object of the present invention is to provide a grinding device and a method for preparing epoxy resin encapsulant using the device, so as to overcome the above-mentioned defects in the prior art.

[0005] The grinding device comprises a grinding machine body, wherein baffles are symmetrically arranged between two grinding rollers on the grinding machine body, and an adjusting component for adjusting the distance between the two baffles is arranged on the rear side of the grinding machine body.

[0006] Preferably, the adjustment assembly includes a screw and an adjustment plate, the two sides of the adjustment plate are slidably connected to the slide rails on the inner wall of the grinder body through slide bars, and the two sides of the adjustment plate are symmetrically provided with inclined drive grooves, and the rear sides of the two baffles are provided with support plates, and the support plates are provided with insertion rods inserted into the drive grooves on the adjustment plates. The screw is threadedly connected to the mounting bracket on the rear side of the grinder body, the front end of the screw is rotatably connected to the adjustment plate, and the rear end of the screw is provided with a rotating rod.

[0007] Preferably, the mounting frame is an "L"-shaped structure.

[0008] A method for preparing an epoxy resin encapsulant is provided, using the above-mentioned grinding device, and the preparation method comprises the following steps:

[0009] Step 1, preparation of modified resin composition: add 5-15 parts of alicyclic epoxy resin to a high-speed dispersion tank, preheat to 70°C, add 17-42 parts of phenolic F epoxy resin, raise the temperature to 70-80°C, add 8-10 parts of high-white inorganic filler and 5-8 parts of ultrafine organic bentonite in sequence, stir, maintain the dispersion tank temperature at 70-80°C, continue to add 40-50 parts of nano-silica, and grind the mixed resin components on a grinding device;

[0010] Step 2, preparation of curing agent composition: add 50-75 parts of liquid composite acid anhydride to a reaction kettle, stir and heat to 110-130°C, then add 20-40 parts of trimellitic anhydride, stir, cool to 70-75°C, add 5-10 parts of composite accelerator, and stir while keeping warm for 20-30 minutes;

[0011] Step 3, heating and curing molding: the modified resin composition and the curing agent composition are mixed and stirred evenly in a mass ratio of 100:25-50, the mixture is pretreated at a low temperature of 5-10°C for 1-2 hours, then coated on the surface of the substrate, and then placed in an oven for curing, according to the curing temperature of 60-80°C for 2-4 hours, 90-110°C for 2-4 hours, and 120-130°C for 6-8 hours.

[0012] Preferably, in step 1, the stirring speed is 400-600 r / min, and the stirring and mixing time is 30 min.

[0013] Preferably, in step 2, the stirring speed is 40 to 60 r / min, and the stirring and mixing time is 20 to 30 min.

[0014] Preferably, the alicyclic epoxy resin is selected from one or more of 3,4-epoxycyclohexylmethyl-3′,4′epoxycyclohexyl carboxylate, bisphenol A epoxy resin, and hydrogenated bisphenol A.

[0015] Preferably, the high-white inorganic composite filler is selected from one or more of aluminum hydroxide, aluminum oxide, and boron nitride.

[0016] Preferably, the liquid composite acid anhydride is selected from one or more of methylhexahydroanhydride, methylnadic anhydride, and methyltetrahydrophthalic anhydride.

[0017] Preferably, the composite accelerator is selected from one or more of benzyldimethylamine, DMP-30, and imidazole.

[0018] The present invention has the following advantages:

[0019] The present invention drives the adjustment plate to move by the screw on the adjustment component of the grinder body, and simultaneously adjusts the baffle on the grinding roller, so that the evenly mixed resin components can be ground on the grinding device. At the same time, the new epoxy encapsulant using the modified resin composition and the curing agent composition as raw materials in the preparation process has the advantages of no flow when heated, strong shaping and forming ability, and strong heat resistance compared with traditional encapsulants. The heat resistance, tensile properties and affinity for lipid materials of the modified phenolic F type epoxy resin are significantly improved compared with those before modification. Low-temperature pretreatment is performed before curing to make the mixture more tightly connected to the substrate, and the tensile properties of the encapsulant are also enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 and FIG2 are schematic diagrams showing the structure of the grinding device of the present invention at different angles.

[0021] FIG3 is a schematic structural diagram of the adjustment assembly of the grinding device of the present invention.

[0022] FIG4 is a schematic structural diagram of a baffle of the grinding device of the present invention.

[0023] FIG5 is a schematic structural diagram of the adjustment plate of the grinding device of the present invention.

[0024] Among them: 1. Grinding machine body; 2. Grinding roller; 3. Baffle; 31. Support plate; 4. Adjustment assembly; 41. Adjustment plate; 411. Drive slot; 42. Slide bar; 43. Slide rail; 44. Insert rod; 45. Screw; 46. Mounting frame; 47. Rotating rod.

[0025] Implementation Method

[0026] The specific implementation methods of the present invention will be further explained in detail below through the description of embodiments with reference to the accompanying drawings to help those skilled in the art have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention.

[0027] Example 1

[0028] As shown in Figures 1-5, the present invention provides a grinding device, including a grinder body 1, characterized in that a baffle 3 is symmetrically provided between two grinding rollers 2 on the grinder body 1, and an adjustment component 4 for adjusting the distance between the two baffles 3 is provided on the rear side of the grinder body 1.

[0029] It should be noted that the adjustment assembly 4 includes a screw 45 and an adjustment plate 41. The two sides of the adjustment plate 41 are slidably connected to the slide rails 43 on the inner wall of the grinder body 1 through slide bars 42. The two sides of the adjustment plate 41 are symmetrically provided with inclined drive grooves 411. The rear sides of the two baffles 3 are provided with support plates 31. The support plates 31 are provided with insertion rods 44 that are inserted into the drive grooves 411 on the adjustment plates 41. The screw 45 is threadedly connected to the mounting bracket 46 on the rear side of the grinder body 1. The mounting bracket 46 is an "L"-shaped structure. The front end of the screw 45 is rotatably connected to the adjustment plate 41, and the rear end of the screw 45 is provided with a rotating rod 47.

[0030] Step 1, preparation of modified resin composition: add 10g bisphenol A epoxy resin E44 to a high-speed dispersion storage tank and preheat it to 70°C; add 25g phenolic F epoxy resin and heat it to 75°C; add 8g aluminum hydroxide and 5g ultrafine organic bentonite in sequence, disperse while adding, stir and mix at a speed of 400r / min for 30min, maintain the temperature of the dispersion tank at 75°C, continue to add 40g nano-silicon dioxide, at this time the viscosity of the mixture increases, reduce the dispersion speed to 200r / min and continue stirring for 30min, grind the mixed resin component on the grinding device, and during grinding, by rotating the screw 45, the screw 45 drives the adjustment plate 41 to move along the slide rail 43 on the inner wall of the grinder body 1, and drives the baffle 3 to move through the drive groove 411 on the adjustment plate 41 and the rod 44 on the baffle 3, thereby adjusting the distance between the two baffles 3, and then pour the mixed resin component between the two grinding rollers 2 for corresponding grinding operation;

[0031] Step 2, preparation of curing agent composition: add 50g of methyl hexahydroanhydride to the reaction kettle, stir and heat to 110°C, then add 20g of trimellitic anhydride, stir at 40r / min for 20min, cool to 70°C, add 5g of benzyldimethylamine, stir at 40r / min for 20min;

[0032] Step 3: Heating and curing molding: 40g of the modified resin composition and 10g of the curing agent composition are mixed and stirred evenly, the mixture is pretreated at a low temperature of 5°C for 1h, then coated on the surface of the substrate, and then placed in an oven and cured according to the curing process of curing at 60°C for 2h, 90°C for 2h, and 120°C for 6h. Example 2

[0033] The same grinding apparatus as in Example 1 was used to prepare the epoxy resin encapsulant.

[0034] A grinding device according to any of the above embodiments and a method for preparing an epoxy resin encapsulant using the same mainly comprises the following steps:

[0035] Step 1: Modification of Novolac F-type epoxy resin: Dissolve 20g of sodium hydroxymethylsulfonate in an appropriate amount of 60% aqueous ethanol. Add 15g of Novolac F-type epoxy resin and heat to reflux. Stir at this temperature for 1 hour. Filter while hot. Cool the precipitate to room temperature, wash twice with deionized water, then twice with anhydrous ethanol, and dry in a dryer. Dissolve the resulting precipitate and 20g of p-hydroxyanisole in DMSO. Add 2g of potassium carbonate and heat to 100°C. Stir at this temperature for 2 hours. Concentrate under reduced pressure until the solvent residue is 30-35%. Add an extractant and extract three times. Collect the organic phase and evaporate and concentrate to obtain modified Novolac F-type epoxy resin. The extractant is a mixture of ethyl acetate and deionized water in a volume ratio of 3:2.

[0036] Step 2, preparation of modified resin composition: add 10g bisphenol A epoxy resin E44 to a high-speed dispersion tank, preheat to 70°C; add 25g phenolic F epoxy resin, heat to 75°C; add 8g aluminum hydroxide and 5g ultrafine organic bentonite in sequence, disperse while adding, stir and mix at 400r / min speed for 30min, maintain the temperature of the dispersion tank at 75°C, continue to add 40g nano-silica, at this time the viscosity of the mixture increases, reduce the dispersion speed to 200r / min and continue stirring for 30min, grind the mixed resin components on a grinding device

[0037] Step 3, preparation of curing agent composition: add 50g of methyl hexahydroanhydride to the reaction kettle, stir and heat to 110°C, then add 20g of trimellitic anhydride, stir at 40r / min for 20min, cool to 70°C, add 5g of benzyldimethylamine, stir at 40r / min for 20min;

[0038] Step 4: Heating and curing molding: 40g of the modified resin composition and 10g of the curing agent composition are mixed and stirred evenly, the mixture is pretreated at a low temperature of 5°C for 1h, then coated on the surface of the substrate, and then placed in an oven and cured according to the curing process of curing at 60°C for 2h, 90°C for 2h, and 120°C for 6h.

[0039] Comparative Example 1

[0040] The same grinding apparatus as in Example 1 was used to prepare the epoxy resin encapsulant.

[0041] A grinding device according to any of the above embodiments and a method for preparing an epoxy resin encapsulant using the same mainly comprises the following steps:

[0042] Step 1, preparation of modified resin composition: add 10g bisphenol A epoxy resin E44 to a high-speed dispersion tank, preheat to 70°C; add 25g phenolic F epoxy resin, heat to 75°C; add 8g aluminum hydroxide, disperse while adding, stir and mix at 400r / min speed for 30min, keep the temperature of the dispersion tank at 75°C, continue to add 40g nano-silica, at this time the viscosity of the mixture increases, reduce the dispersion speed to 200r / min and continue stirring for 30min, grind the mixed resin components on a grinding device

[0043] Step 2, preparation of curing agent composition: add 50g of methyl hexahydroanhydride to the reaction kettle, stir and heat to 110°C, then add 20g of trimellitic anhydride, stir at 40r / min for 20min, cool to 70°C, add 5g of benzyldimethylamine, stir at 40r / min for 20min;

[0044] Step 3: Heating and curing molding: 40g of the modified resin composition and 10g of the curing agent composition are mixed and stirred evenly, the mixture is pretreated at a low temperature of 5°C for 1h, then coated on the surface of the substrate, and then placed in an oven and cured according to the curing process of curing at 60°C for 2h, 90°C for 2h, and 120°C for 6h.

[0045] Comparative Example 2

[0046] The same grinding apparatus as in Example 1 was used to prepare the epoxy resin encapsulant.

[0047] A grinding device according to any of the above embodiments and a method for preparing an epoxy resin encapsulant using the same mainly comprises the following steps:

[0048] Step 1, preparation of modified resin composition: add 10g bisphenol A epoxy resin E44 to a high-speed dispersion tank, preheat to 70°C; add 25g phenolic F epoxy resin, heat to 75°C; add 5g ultrafine organic bentonite, disperse while adding, stir and mix at 400r / min speed for 30min, keep the temperature of the dispersion tank at 75°C, continue to add 40g nano-silica, at this time the viscosity of the mixture increases, reduce the dispersion speed to 200r / min and continue stirring for 30min, grind the mixed resin components on a grinding device

[0049] Step 2, preparation of curing agent composition: add 50g of methyl hexahydroanhydride to the reaction kettle, stir and heat to 110°C, then add 20g of trimellitic anhydride, stir at 40r / min for 20min, cool to 70°C, add 5g of benzyldimethylamine, stir at 40r / min for 20min;

[0050] Step 3: Heating and curing molding: 40g of the modified resin composition and 10g of the curing agent composition are mixed and stirred evenly, the mixture is pretreated at a low temperature of 5°C for 1h, then coated on the surface of the substrate, and then placed in an oven and cured according to the curing process of curing at 60°C for 2h, 90°C for 2h, and 120°C for 6h.

[0051] Comparative Example 3

[0052] The same grinding apparatus as in Example 1 was used to prepare the epoxy resin encapsulant.

[0053] A grinding device according to any of the above embodiments and a method for preparing an epoxy resin encapsulant using the same mainly comprises the following steps:

[0054] Step 1, preparation of modified resin composition: add 10g bisphenol A epoxy resin E44 to a high-speed dispersion tank, preheat to 70°C; add 25g phenolic F epoxy resin, heat to 75°C; add 8g aluminum hydroxide and 5g ultrafine organic bentonite in sequence, disperse while adding, stir and mix at 400r / min speed for 30min, maintain the temperature of the dispersion tank at 75°C, continue to add 40g nano-silica, at this time the viscosity of the mixture increases, reduce the dispersion speed to 200r / min and continue stirring for 30min, grind the mixed resin components on a grinding device

[0055] Step 2, preparation of curing agent composition: add 50g of methyl hexahydroanhydride to the reaction kettle, stir and heat to 110°C, then add 20g of trimellitic anhydride, stir at 40r / min for 20min, cool to 70°C, add 5g of benzyldimethylamine, stir at 40r / min for 20min;

[0056] Step 3: Heating and curing: 40g of the modified resin composition and 10g of the curing agent composition are mixed and stirred evenly, the mixture is coated on the surface of the substrate, and then placed in an oven for curing according to the curing process of curing at 60°C for 2h, 90°C for 2h, and 120°C for 6h. Example 3

[0057] Epoxy encapsulants were prepared using Examples 1 and 2. A control example 1, in which no ultrafine organic bentonite was added, a control example 2, in which no aluminum hydroxide was added, and a control example 3, in which the mixture was not subjected to low-temperature pretreatment, were also prepared. Performance measurements were performed on Examples 1 and 2 and Control Examples 1 and 3, and the results are shown in Table 1.

[0058] Table 1 Performance test of epoxy encapsulant

[0059] Test Items Tensile Strength (MPa) Heat Resistance Example 152 132°C No sliding, flowing, or dripping Example 26 1 151°C No sliding, flowing, or dripping Control Example 139 120°C No sliding, flowing, or dripping Control Example 238 118°C No sliding, flowing, or dripping Control Example 332 121°C No sliding, flowing, or dripping

[0060] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the concept and technical solution of the present invention, or the present utility invention and technical solution are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A grinding device, comprising a grinding machine body (1), characterized in that: A baffle (3) is symmetrically arranged between the two grinding rollers (2) on the grinding machine body (1), and an adjustment component (4) for adjusting the distance between the two baffles (3) is arranged on the rear side of the grinding machine body (1).

2. The grinding device according to claim 1, characterized in that: The adjustment assembly (4) comprises a screw rod (45) and an adjustment plate (41). The two sides of the adjustment plate (41) are respectively slidably connected to the slide rails (43) on the inner wall of the grinding machine body (1) through the slide bars (42). The two sides of the adjustment plate (41) are symmetrically provided with inclined driving grooves (411). The rear sides of the two baffles (3) are each provided with a support plate (31). The support plate (31) is provided with an insertion rod (44) inserted into the driving groove (411) on the adjustment plate (41). The screw rod (45) is threadedly connected to the mounting frame (46) on the rear side of the grinding machine body (1). The front end of the screw rod (45) is rotatably connected to the adjustment plate (41). The rear end of the screw rod (45) is provided with a rotating rod (47).

3. The grinding device according to claim 2, characterized in that: The mounting frame (46) is an "L"-shaped structure.

4. A method for preparing an epoxy resin encapsulant, characterized in that: The preparation is carried out using the grinding device according to any one of claims 1 to 3, and the preparation method comprises the following steps: Step 1, preparation of modified resin composition: add 5-15 parts of alicyclic epoxy resin into a high-speed dispersion tank, preheat to 70°C, add 17-42 parts of phenolic F epoxy resin, heat to 70-80°C, add 8-10 parts of high white inorganic filler and 5-8 parts of ultrafine organic bentonite in sequence, stir, keep the temperature of the dispersion tank at 70-80°C, continue to add 40-50 parts of nano-silicon dioxide, and grind the mixed resin components on a grinding device; Step 2, preparation of curing agent composition: add 50-75 parts of liquid composite acid anhydride into a reaction kettle, stir and heat to 110-130°C, then add 20-40 parts of trimellitic anhydride, stir, cool to 70-75°C, add 5-10 parts of composite accelerator, keep warm and stir for 20-30 minutes; Step 3, heating and curing molding: the modified resin composition and the curing agent composition are mixed and stirred evenly according to the mass ratio of 100:25-50, the mixture is pretreated at a low temperature of 5-10°C for 1-2 hours, then coated on the surface of the substrate, and then placed in an oven for curing, according to the curing temperature of 60-80°C for 2-4 hours, 90-110°C for 2-4 hours, and 120-130°C for 6-8 hours.

5. The method for preparing an epoxy resin encapsulant according to claim 4, wherein: In step 1, the stirring speed is 400-600 r / min, and the stirring and mixing time is 30 min.

6. The method for preparing an epoxy resin encapsulant according to claim 4, characterized in that: In step 2, the stirring speed is 40 to 60 r / min, and the stirring and mixing time is 20 to 30 min.

7. The high heat-resistant non-flowing epoxy resin encapsulant according to claim 4, characterized in that: The alicyclic epoxy resin is selected from one or more of 3,4-epoxycyclohexylmethyl-3′,4′epoxycyclohexylcarboxylate, bisphenol A epoxy resin, and hydrogenated bisphenol A.

8. The high heat-resistant non-flowing epoxy resin encapsulant according to claim 4, characterized in that: The high-white inorganic composite filler is selected from one or more of aluminum hydroxide, aluminum oxide, and boron nitride.

9. The high heat-resistant non-flowing epoxy resin encapsulant according to claim 4, characterized in that: The liquid composite acid anhydride is selected from one or more of methyl hexahydroanhydride, methyl nadic anhydride, and methyl tetrahydrophthalic anhydride.

10. The high heat-resistant non-flowing epoxy resin encapsulant according to claim 4, characterized in that: The composite accelerator is selected from one or more of benzyl dimethylamine, DMP-30 and imidazole.

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