WO2022155815A1 - Bulk molding compound and led display screen using same - Google Patents

Bulk molding compound and led display screen using same Download PDF

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Publication number
WO2022155815A1
WO2022155815A1 PCT/CN2021/072893 CN2021072893W WO2022155815A1 WO 2022155815 A1 WO2022155815 A1 WO 2022155815A1 CN 2021072893 W CN2021072893 W CN 2021072893W WO 2022155815 A1 WO2022155815 A1 WO 2022155815A1
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WO
WIPO (PCT)
Prior art keywords
molding compound
bulk molding
led display
thermal conductivity
display screen
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PCT/CN2021/072893
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French (fr)
Chinese (zh)
Inventor
李小明
甘志勇
徐勋明
夏建平
徐建飞
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惠州市艾比森光电有限公司
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Priority to PCT/CN2021/072893 priority Critical patent/WO2022155815A1/en
Publication of WO2022155815A1 publication Critical patent/WO2022155815A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/02—Fibres or whiskers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/06—Unsaturated polyesters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/33—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes

Definitions

  • the present application relates to the technical field of LED display screens, in particular to a slug molding compound for a bottom shell of an LED display screen and an LED display screen using the slug molding compound.
  • LED Light Emitting Diode, light-emitting diode
  • LED Light Emitting Diode, light-emitting diode
  • the LED display will generate a lot of heat during use. If the heat cannot be dissipated in time, it will seriously affect the optoelectronic function of the LED display. If the heat is too high, the lamp bead packaging glue of the LED display will be yellowed or even aged, and then Affect the luminous efficiency of the LED display, resulting in obvious light decay.
  • the heat dissipation path of the LED display is generally as follows: the heat dissipated by the lamp chip or electronic components arranged on the PCB (Printed Circuit Board) board is transferred to the bottom case carrying the PCB substrate through the PCB board. Therefore, the thermal conductivity of the bottom case material has a great influence on the service life of the LED display.
  • PCB Print Circuit Board
  • the thermal conductivity of the bottom case material has a great influence on the service life of the LED display.
  • people have higher and higher requirements for the fire resistance of LED display. Many countries or regions require LED display to meet BS476-7 Class 1 & BS 476-6 Class 0 flame retardant certification , and the bottom case, as an important part of the LED display, also needs to meet the BS476-7 Class 1 & BS 476-6 Class 0 flame retardant and fireproof certification.
  • bottom shell materials for LED displays there are two types of bottom shell materials for LED displays, one is a composite material of polycarbonate (PC) and glass fiber (GF), and the other is a metal material, such as ADC12 die-casting aluminum alloy.
  • PC polycarbonate
  • GF glass fiber
  • ADC12 die-casting aluminum alloy a metal material
  • the thermal conductivity of PC and GF composite materials is low, about 0.2W/(mK), which cannot effectively dissipate the heat on the LED display, and the flame retardant grade of such materials does not meet BS476-7 Class 1 and BS 476-6 Class 0 fire retardant certified.
  • the thermal conductivity and fire retardant grade of ADC12 material are both higher, but the density of ADC12 material is higher, generally above 2.7g/cm 3 , and the bottom shell of the LED display screen made of it is heavy and does not meet the LED display screen. Lightweight development trend.
  • the present application provides a slug molding compound, which has low density, high thermal conductivity and high flame retardancy, and can be used to prepare a bottom case of an LED display screen, so as to realize the lightweight of the LED display screen while taking into account the reliability.
  • the present application provides a bulk molding compound (Bulk Molding Compound, BMC), the bulk molding compound comprising the following components by mass percentage:
  • Inhibitor 0 ⁇ 0.05%
  • Fiber reinforcement 6% to 10%
  • High thermal conductivity filler 20% to 30%;
  • the bulk molding compound in the first aspect of the present application, through the synergistic effect of the above-mentioned components in the mass percentage, the bulk molding compound can have both low density, high thermal conductivity and high flame retardancy.
  • the density of the molding compound does not exceed 2g/cm 3 , the thermal conductivity is above 1.6W/(m ⁇ K), and it can pass BS476-6 Class 0 and BS476-7 Class 1 fire-retardant certification.
  • the bulk molding compound has a high thermal conductivity, it can dissipate the heat generated by the LED display screen in a timely and effective manner, and can effectively reduce the temperature of the LED display screen; due to the density of the bulk molding compound The use of it to make the bottom shell of the display screen is helpful to realize the lightweight of the LED display screen and reduce the cost; in addition, the slug molding compound has a high fire resistance and flame retardant grade, which helps to improve the fire resistance of the LED display screen. combustion performance.
  • the unsaturated resin is a polymer compound containing unsaturated groups such as carbon-carbon double bonds and carbon-carbon triple bonds.
  • the unsaturated resin can undergo cross-linking polymerization with the diluent monomer.
  • the unsaturated resin is an unsaturated polyester resin, which contains unsaturated carbon-carbon double bonds and ester bonds.
  • the unsaturated polyester resin may include o-phthalic unsaturated polyester resin, iso-phthalic unsaturated polyester resin, bisphenol A unsaturated polyester resin, vinyl ester type and halogenated unsaturated polyester at least one of resins.
  • the unsaturated polyester resin is an ortho-phthalic unsaturated polyester resin and/or an iso-phthalic unsaturated polyester resin. The resin is cheap and has good mechanical properties such as stretchability and flexibility.
  • the diluent monomer may undergo a crosslinking reaction with the unsaturated resin.
  • the diluting monomer may be selected from at least one of styrene, methyl methacrylate, dipropylene phthalate, and the like.
  • the diluting monomer is styrene, which is cheap and has strong diluting ability. After the resin is diluted, it can be wetted and impregnated more quickly by fiber reinforcements, fillers, etc., while the copolymerization of styrene and unsaturated resin The activity is also strong.
  • the function of the low shrinkage agent is to reduce the shrinkage rate of the bulk molding compound during the molding process so as to improve the apparent effect of the obtained product.
  • the low shrinkage agent can be selected from polystyrene, polyvinyl acetate, polyethylene, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate, modified polyurethane, nylon , synthetic rubber, etc., but not limited thereto.
  • the initiator is an organic peroxy compound type initiator.
  • the initiator may include tert-butyl peroxybenzoate (TBPB for short), tert-butyl peroxy-2-ethylhexanoate (TBPO for short), benzoyl peroxide (BPO), 2 -One or more of tert-amyl ethylhexyl acid (TAPO), tert-amyl peroxyacetate (TAPA), tert-amyl peroxybenzoate (TAPB), but not limited thereto.
  • the initiator is TBPB and/or TBPO, which are relatively inexpensive.
  • the introduced thickener can physically react with the unsaturated resin, so that the bulk molding compound has suitable injection fluidity.
  • the thickener is selected from at least one of magnesium oxide, calcium oxide, and calcium hydroxide, but is not limited thereto.
  • the thickener is magnesium oxide.
  • the mass percentage content of the thickener in the dough molding compound is 0.01% to 0.05%. It is preferably 0.02% to 0.04%.
  • the introduction of an internal mold release agent can facilitate the smooth peeling of the bulk molding compound from the mold and avoid mold sticking.
  • the internal mold release agent may be selected from at least one of zinc stearate, calcium stearate, magnesium stearate, and sodium stearate.
  • the release agent is zinc stearate.
  • the mass percentage content of the internal mold release agent in the bulk molding compound may be 0.5% to 1.5%. For example, it may be 0.6%, 0.8%, 1%, 1.1%, 1.2%, 1.3% or 1.4%.
  • the mass percentage content of the internal mold release agent in the bulk molding compound is 0.6%-1.2% or 0.75%-1.0%.
  • the polymerization inhibitor can capture a part of the free radicals and prolong the gelation time of the unsaturated resin.
  • the polymerization inhibitor may include hydroquinone, tert-butyl catechol, 2-tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone, p-benzoquinone, methylbenzene
  • hydroquinone tert-butyl catechol
  • 2-tert-butyl hydroquinone 2,5-di-tert-butyl hydroquinone
  • p-benzoquinone methylbenzene
  • the polymerization inhibitor is one or more of hydroquinone, 2-tert-butyl hydroquinone and p-benzoquinone.
  • the mass percentage content of the polymerization inhibitor in the bulk molding compound is 0.01% to 0.05%; for example, it may be 0.01%, 0.02%, 0.03%, 0.04% or 0.05%. In some embodiments, the mass percentage content of the polymerization inhibitor in the bulk molding compound may be 0.015% to 0.03%.
  • the flame retardant is used to improve the flame retardant properties of the products made of the bulk molding compound.
  • the flame retardant includes one or more of aluminum hydroxide, magnesium hydroxide, zinc borate, antimony trioxide, antimony pentoxide, red phosphorus, ammonium polyphosphate, diammonium hydrogen phosphate, etc., but not limited to this.
  • the flame retardant may include aluminum hydroxide and/or magnesium hydroxide, both of which have higher flame retardant grades and are highly environmentally friendly.
  • the mass percentage content of the flame retardant in the bulk molding compound is 26%-29%, preferably 27%-28%.
  • the loss on ignition of the aluminum hydroxide and/or magnesium hydroxide flame retardant is 25% to 40%, and the particle size D50 is 1 ⁇ m to 20 ⁇ m.
  • Loss on ignition refers to the percentage of mass lost after burning for a long enough time under certain high temperature conditions to the mass of the original sample. Lower loss on ignition can reflect better flame retardant performance.
  • the loss on ignition of the aluminum hydroxide is 30% to 40%, and the particle size D50 is 5 ⁇ m to 15 ⁇ m.
  • the loss on ignition of the magnesium hydroxide is 25% to 35%, and the particle size D50 is 1 ⁇ m to 5 ⁇ m.
  • the fiber reinforcement is mainly used to enhance the strength of the bulk molding compound.
  • the mass percentage content of the fiber reinforcement in the bulk molding compound is 7% to 9%.
  • the fiber reinforcement may include one or more of glass fiber and carbon fiber, but is not limited thereto.
  • the fiber reinforcement is glass fiber.
  • the bonding force between the reinforcement of glass fiber and the unsaturated resin is stronger, which can better enhance the strength of the bulk molding compound, and the cost is lower.
  • the fiber reinforcement is a glass fiber with a length of 3 mm to 9 mm. This can enhance the strength of the bulk molding compound while ensuring good injection properties.
  • the glass fiber is an alkali-free glass fiber with a diameter of 13 ⁇ m ⁇ 15 ⁇ m and a length of 3 mm ⁇ 9 mm, for example, the length may be 3 mm ⁇ 6 mm or 6 mm ⁇ 9 mm.
  • the high thermal conductivity filler has a relatively high thermal conductivity, which can impart good thermal conductivity to the slug molding compound, so that it can better reduce the temperature of the LED display screen when it is used on the LED display screen.
  • the high thermal conductivity filler may include one or more of aluminum oxide, zinc oxide, magnesium oxide, silicon carbide, aluminum nitride, boron nitride, fibrous carbon powder, and scaly carbon powder.
  • the high thermal conductivity filler is one or more of aluminum oxide, silicon carbide, and aluminum nitride, and their thermal conductivity is relatively high, and a small amount of addition can ensure that the thermal conductivity of the bulk molding compound is 1.6 W/(m.K) or more.
  • the mass percentage content of the high thermal conductivity filler in the bulk molding compound may be 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28% or 29%.
  • the bulk molding compound may further include a low-cost reinforcing filler in a mass percentage of 0.1% to 10%.
  • the low-cost reinforcing filler may include one or more of calcium carbonate, barium sulfate, silicon dioxide, titanium dioxide, etc., but is not limited thereto.
  • the cost of these fillers is low, and they have a reinforcing effect on the bulk molding compound, and play a thermal conductivity role, which can partially replace the high thermal conductivity filler, so that the overall amount of the high thermal conductivity filler is reduced, and the cost of the bulk molding compound is reduced.
  • the low-cost reinforcing filler is calcium carbonate and/or silica.
  • the mass percentage content of the low-cost reinforcing filler in the bulk molding compound is 1% to 9%.
  • the introduction of pigments into the mass molding compound can impart a certain color to the mass molding compound.
  • the pigment may include one or more of titanium oxide, titanium dioxide, carbon black, red iron oxide, etc., but is not limited thereto.
  • the mass percentage content of the pigment in the bulk molding compound is 0.5% to 1%; for example, it can be 0.6%, 07%, 0.8% or 0.9%, and further can be 0.6% to 0.9% %.
  • the bulk molding compound comprises the following components by mass percentage:
  • Inhibitor 0.01% ⁇ 0.05%
  • Fiber reinforcement 6% to 10%
  • High thermal conductivity filler 20% to 30%;
  • Low-cost reinforcing filler 0.1% to 10%
  • Pigment 0.5% to 1%.
  • the thermal conductivity of the bulk molding compound is above 1.6 W/(m ⁇ K).
  • the thermal conductivity may be 1.6 W/(m ⁇ K), 1.7 W/(m ⁇ K), 1.8 W/(m ⁇ K), or 2.0 W/(m ⁇ K).
  • the thermal conductivity of the bulk molding compound may be above 1.8 W/(m ⁇ K), and may even be above 2.2 W/(m ⁇ K).
  • the bulk molding compound has a thermal conductivity in the range of 1.6 W/(m ⁇ K) to 2.0 W/(m ⁇ K).
  • the density of the bulk molding compound does not exceed 2.0 g/cm 3 , for example 1.7 g/cm 3 , 1.8 g/cm 3 or 1.9 g/cm 3 .
  • the bulk molding compound has a density of 1.8 g/cm 3 to 2.0 g/cm 3 .
  • the flexural strength of the bulk molding compound is above 120 MPa, sometimes above 130 MPa.
  • Bending strength refers to the maximum stress that a material can withstand under a bending load, which reflects the ability of a material to resist bending.
  • a bottom shell made of a higher flexural strength bulk molding compound can better support the load.
  • the flexural strength of the bulk molding compound is between 120 MPa and 135 MPa.
  • the impact strength of the bulk molding compound is above 20 kJ/cm 2 .
  • Impact strength is the ratio of the energy absorbed during the impact failure of the sample to the original cross-sectional area, which can be used to evaluate the toughness of the material. The higher impact strength reflects the higher toughness and less brittleness of the bulk molding compound.
  • the impact strength of the bulk molding compound is above 22 kJ/cm 2 , for example, may be 23 kJ/cm 2 , 24 kJ/cm 2 or 25 kJ/cm 2 .
  • the bulk molding compound has an impact strength of 20 kJ/cm 2 to 25 kJ/cm 2 .
  • a second aspect of the present application provides a method for preparing a bulk molding compound, comprising the following steps:
  • the manner of mixing the above materials can be stirring or kneading, etc., and the equipment used can be a mixer, a kneader, and the like.
  • the word "kneading” refers to the operation of uniformly mixing pasty, viscous and plastic materials by mechanical stirring, including the two functions of dispersion and mixing of materials, which can be carried out in a kneader.
  • the resin slurry can be obtained by stirring the unsaturated resin, low shrinkage agent, diluting monomer, initiator, thickener, internal mold release agent, and polymerization inhibitor.
  • the stirring speed is 800r/min ⁇ 1200r/min
  • the stirring time can be 30min ⁇ 40min.
  • the subsequent addition of other raw materials to the resin slurry can be carried out in a kneader to improve the mixing effect.
  • the above-mentioned low-cost reinforcing fillers when adding flame retardants, high thermal conductivity fillers and pigments to the resin slurry, the above-mentioned low-cost reinforcing fillers may be further added.
  • the mass percentage content of the low-cost reinforcing filler in the bulk molding compound may be 0.1% to 10%.
  • the temperature is controlled not to exceed 45°C, which can prevent the initiator from triggering the cross-linking polymerization of the unsaturated resin and the diluent monomer in advance at high temperature, so as not to affect the properties of the bulk molding compound. Injection flow and processability.
  • the preparation method of the mass molding compound provided by the second aspect of the present application is simple and easy to implement and has strong operability.
  • a third aspect of the present application further provides an LED display screen.
  • the LED display screen includes an LED display screen bottom case, which is processed and formed by the slug molding compound provided in the first aspect of the present application.
  • the bulk molding compound is processed by injection molding or compression molding.
  • the LED display screen contains a bottom case made of the above-mentioned slug molding compound, which can make the LED display screen light in weight, and at the same time, has high flame retardancy, and maintains a low temperature of the screen body during use.
  • FIG. 1 is a schematic structural diagram of a display screen provided by an embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of a display module of an LED display screen provided by an embodiment of the present application.
  • FIG. 3 is a schematic structural diagram of a bottom case in the module shown in FIG. 2 according to an embodiment of the present application.
  • the structure of the display screen 1000 is first introduced.
  • the display screen 1000 is formed by splicing a plurality of display boxes 100 , and each display box 100 includes a box frame (not shown in FIG. 1 ) and a plurality of display modules 120 .
  • the plurality of display modules 120 Regularly fixed on the box frame to form a complete display box 100 .
  • the box frame of each display box 100 is fixed on the back of the display module 120 .
  • each display module 120 includes components such as a light panel 121 and a bottom case 122 supporting the light panel 121 , wherein the bottom case 122 and the box frame are respectively fixedly connected to the back of the light panel 121 .
  • the lamp board 121 includes a printed circuit board 1210 (printed circuit board, PCB), and the LED lamp beads 1211 and the driving circuit and the like disposed on the printed circuit board 1210 .
  • the bottom case 122 is obtained by processing and molding the following group molding compound, and the specific processing and molding method may be injection molding method, compression molding method, or the like.
  • the above-mentioned bulk molding compound may be placed in a mold, and then cured and formed under a certain temperature and pressure.
  • the mass molding compound comprises the following components by mass percentage:
  • Inhibitor 0 ⁇ 0.05%
  • Fiber reinforcement 6% to 10%
  • High thermal conductivity filler 20% to 30%;
  • the bulk molding compound can have both low density, high thermal conductivity and high flame retardant properties, for example, the bulk molding compound has a density of not more than 2g/cm 3 , the thermal conductivity is above 1.6W/(m ⁇ K), and it can pass BS 476-6Class 0 and BS476-7Class 1 fire and flame retardant certification.
  • the above-mentioned bulk molding compound can be prepared by the following method: at a temperature of less than or equal to 45 ° C, unsaturated resin, low shrinkage agent, diluting monomer, initiator, thickener, internal mold release agent, polymerization inhibitor Add the flame retardant, high thermal conductivity filler and pigment to the resin slurry at a temperature of less than or equal to 45°C, and after mixing evenly, add fiber reinforcement to it, disperse evenly, A mass molding compound is obtained.
  • the raw material for the preparation of the bulk molding compound can also be the above-mentioned low-cost reinforcing filler, which can be added together with the high thermal conductivity filler.
  • the bulk molding compound has the above-mentioned excellent properties and also has a lower cost.
  • a slug molding compound the slug molding compound comprises the following components by mass percentage:
  • Unsaturated resin (specifically, isophthalic unsaturated polyester resin): 17%;
  • Low shrinkage agent (specifically polyvinyl acetate): 7%;
  • Diluted monomer (specifically styrene): 12%;
  • Initiator 0.5% (specifically, 0.25% of tert-butyl peroxybenzoate, 0.25% of tert-butyl peroxide of 2-ethylhexyl peroxide);
  • Thickener (specifically magnesium oxide): 0.03%;
  • Internal release agent (specifically sodium stearate): 0.75%;
  • Polymerization inhibitor (specifically, p-benzoquinone): 0.02%;
  • Flame retardant (specifically aluminum hydroxide): 28%;
  • Fiber reinforcement (specifically glass fibers): 7%;
  • High thermal conductivity filler (specifically alumina): 27%;
  • Pigment (specifically carbon black): 0.7%.
  • the preparation method of the above-mentioned mass molding compound includes: 1) firstly adding unsaturated resin, low shrinkage agent, diluting monomer, initiator, thickening agent, internal mold release agent, and polymerization inhibitor to the mixer, at a rate of 1000r/min Stir at a speed of 35 min to obtain a resin slurry, and control the temperature during the stirring process to be less than or equal to 45 ° C; 2) Put the resin slurry stirred in step 1) into a kneader, add flame retardants, high thermal conductivity fillers, low-cost reinforcing fillers, pigments , knead for 10min at a temperature ⁇ 45°C to obtain a mixture of resin slurry and powder; 3) finally add fiber reinforcement to the kneader, knead at a temperature ⁇ 45°C for 9min to obtain a bulk molding compound (BMC).
  • BMC bulk molding compound
  • a slug molding compound the slug molding compound comprises the following components by mass percentage:
  • Unsaturated resin (specifically, o-phthalic unsaturated polyester resin): 17%;
  • Low shrinkage agent specifically polystyrene: 7%;
  • Diluted monomer (specifically styrene): 12%;
  • Initiator 0.5% (specifically, 0.25% of tert-butyl peroxybenzoate, 0.25% of tert-butyl peroxide of 2-ethylhexyl peroxide);
  • Thickener (specifically magnesium oxide): 0.03%;
  • Internal release agent (specifically zinc stearate): 0.75%;
  • Polymerization inhibitor (specifically, p-benzoquinone): 0.02%;
  • Flame retardant (specifically aluminum hydroxide): 28%;
  • Fiber reinforcement (specifically glass fibers): 8%;
  • High thermal conductivity filler (specifically alumina): 21%;
  • Low cost reinforcing filler (specifically calcium carbonate): 5%;
  • Pigment (specifically carbon black): 0.7%.
  • a slug molding compound the slug molding compound comprises the following components by mass percentage:
  • Unsaturated resin (specifically o-phthalic unsaturated polyester resin): 18%;
  • Low shrinkage agent (specifically polymethyl methacrylate): 7%;
  • Diluted monomer (specifically styrene): 12%;
  • Initiator specifically 0.25% tert-butyl peroxybenzoate, 0.25% tert-butyl peroxy 2-ethylhexyl acid
  • Thickener (specifically magnesium oxide): 0.03%;
  • Internal release agent (specifically zinc stearate): 0.75%;
  • Polymerization inhibitor (specifically, p-benzoquinone): 0.02%;
  • Flame retardant (specifically magnesium hydroxide): 27%;
  • Fiber reinforcement (specifically glass fibers): 8%;
  • High thermal conductivity filler (specifically aluminum nitride): 21%;
  • Low cost reinforcing filler (specifically silica): 5%;
  • Pigment (specifically carbon black): 0.7%.
  • BMCs bulk molding compounds
  • Example 1 Example 2
  • Example 3 Density (g/cm 3 ) 1.8 1.82 1.81 Thermal conductivity (W/(m ⁇ K)) 1.8 1.7 1.6 Bending Strength(Mpa) 120 130 130 Impact Strength (kJ/m 2 ) 20 25 twenty four Linear expansion coefficient (10 -6 /K) 12 12 13 Mold shrinkage 0.05% 0.02% 0.03%
  • the density of the BMC provided in the examples of this application does not exceed 2g/cm 3 , generally around 1.8g/cm 3 , the thermal conductivity is above 1.6W/(m ⁇ K), and the impact strength is 20kJ/ cm 2 above, the bending strength is above 120MPa, the linear expansion coefficient is ⁇ 16 ⁇ 10 -6 /K, the molding shrinkage rate is low, at 0.01%-0.1%, the thermal deformation temperature is low, and the performance is stable; and it is not easy to ignite.
  • each bottom case is assembled into the display module shown in FIG. 2 above, and then assembled into the display screen shown in FIG. 1, and the temperature of the display screen is tested; wherein, the lamp beads 1211, the printed circuit board 1210, the bottom case 122 are respectively connected with thermocouples.
  • the bottom case made of BMC of the present application can pass BS 476-6 Class 0 and BS476-7 Class 1 fire and flame retardant certification, and the LED display
  • the temperature of the screen can be lowered by 3°C to 5°C; compared with the bottom case made of ADC12, the bottom case made of BMC of this application can pass the BS 476-6 Class 0 and BS476-7 Class 1 fire and flame retardant certifications. It also has lighter weight and lower cost.

Abstract

A bulk molding compound, comprising the following components, in percentage by mass: 15%-20% of an unsaturated resin, 7%-10% of a low-shrinkage agent, 10%-15% of a diluted monomer, 0.2%-0.5% of an initiator, 0-0.05% of a thickening agent, 0-1.5% of an internal mold release agent, 0-0.05% of a polymerization inhibitor, 25%-30% of a flame retardant, 6%-10% of a fiber reinforcement, 25%-30% of a high-thermal-conductivity filler, and 0-1% of a pigment. Also provided is an LED display screen (1000) using the bulk molding compound as a bottom case (122). The bulk molding compound has low density, high thermal conductivity and high flame retardancy properties; and the bottom case (122) of the LED display screen made therefrom has a relatively light mass, so that the LED display screen (1000) can have higher flame retardancy while also being lightweight, and maintains a lower screen body temperature during use.

Description

一种团状模塑料及使用该团状模塑料的LED显示屏A slug molding compound and LED display screen using the slug molding compound 技术领域technical field
本申请涉及LED显示屏技术领域，具体涉及一种LED显示屏底壳用团状模塑料及使用该团状模塑料的LED显示屏。The present application relates to the technical field of LED display screens, in particular to a slug molding compound for a bottom shell of an LED display screen and an LED display screen using the slug molding compound.
背景技术Background technique
LED(Light Emitting Diode，发光二极管)显示屏具有发光亮度高、发光效率高、色彩鲜艳、对比度高、能耗低、工作温度范围广、响应时间短等特点，广泛应用于商场、机场、火车站、舞台、体育馆、医院等公共场所的显示设备中。LED显示屏在使用过程中会产生大量的热量，热量如果不能及时散发出去，将严重影响LED显示屏的光电功能，如热量过高将造成LED显示屏的灯珠封装胶黄化甚至老化，进而影响LED显示屏的发光效率，产生明显的光衰。LED (Light Emitting Diode, light-emitting diode) display has the characteristics of high luminous brightness, high luminous efficiency, bright colors, high contrast, low energy consumption, wide operating temperature range, short response time, etc. It is widely used in shopping malls, airports, railway stations , display equipment in public places such as stages, gymnasiums, hospitals, etc. The LED display will generate a lot of heat during use. If the heat cannot be dissipated in time, it will seriously affect the optoelectronic function of the LED display. If the heat is too high, the lamp bead packaging glue of the LED display will be yellowed or even aged, and then Affect the luminous efficiency of the LED display, resulting in obvious light decay.
LED显示屏的散热途径一般是：设置在PCB(Printed Circuit Board，印刷电路板)板上的灯珠芯片或电子元器件散出的热量，经过PCB板传递到承载PCB基板的底壳。因此，底壳材料的导热性能对LED显示屏的使用寿命影响很大。此外，随着LED显示屏的发展，人们对LED显示屏的防火阻燃的要求越来越高，很多国家或地区均要求LED显示屏满足BS476-7 Class 1&BS 476-6 Class 0阻燃防火认证，而底壳作为LED显示屏的重要部件，也需要满足BS476-7 Class 1&BS 476-6 Class 0阻燃防火认证。The heat dissipation path of the LED display is generally as follows: the heat dissipated by the lamp chip or electronic components arranged on the PCB (Printed Circuit Board) board is transferred to the bottom case carrying the PCB substrate through the PCB board. Therefore, the thermal conductivity of the bottom case material has a great influence on the service life of the LED display. In addition, with the development of LED display, people have higher and higher requirements for the fire resistance of LED display. Many countries or regions require LED display to meet BS476-7 Class 1 & BS 476-6 Class 0 flame retardant certification , and the bottom case, as an important part of the LED display, also needs to meet the BS476-7 Class 1 & BS 476-6 Class 0 flame retardant and fireproof certification.
目前，LED显示屏的底壳材料有两类，一类是聚碳酸酯(polycarbonate，PC)与加玻璃纤维(glass fibre，GF)的复合材料，另一类是金属材料，如ADC12 压铸铝合金材料。但PC和GF的复合材料的导热系数较低，约为0.2W/(m.K)，不能将LED显示屏上热量的有效散发出去，且该类材料的阻燃等级不符合BS476-7 Class 1及BS 476-6 Class 0防火阻燃认证。而ADC12材料的导热系数及防火阻燃等级均较高，但ADC12材料的密度较高，一般在2.7g/cm 3以上，由其制成的LED显示屏底壳较重，不符合LED显示屏轻量化的发展趋势。 At present, there are two types of bottom shell materials for LED displays, one is a composite material of polycarbonate (PC) and glass fiber (GF), and the other is a metal material, such as ADC12 die-casting aluminum alloy. Material. However, the thermal conductivity of PC and GF composite materials is low, about 0.2W/(mK), which cannot effectively dissipate the heat on the LED display, and the flame retardant grade of such materials does not meet BS476-7 Class 1 and BS 476-6 Class 0 fire retardant certified. The thermal conductivity and fire retardant grade of ADC12 material are both higher, but the density of ADC12 material is higher, generally above 2.7g/cm 3 , and the bottom shell of the LED display screen made of it is heavy and does not meet the LED display screen. Lightweight development trend.
因此，有必要提供一种适合用作LED显示屏底壳的新材料，在满足轻量化要求的同时，兼顾高导热和高阻燃性。Therefore, it is necessary to provide a new material suitable for use as the bottom shell of the LED display screen, which can meet the requirements of light weight and take into account high thermal conductivity and high flame retardancy.
发明内容SUMMARY OF THE INVENTION
鉴于此，本申请提供了一种团状模塑料，其兼具低密度、高导热和高阻燃性能，可用于制备LED显示屏底壳，实现LED显示屏轻量化的同时兼顾可靠性。In view of this, the present application provides a slug molding compound, which has low density, high thermal conductivity and high flame retardancy, and can be used to prepare a bottom case of an LED display screen, so as to realize the lightweight of the LED display screen while taking into account the reliability.
第一方面，本申请提供了一种团状模塑料(Bulk Molding Compound，BMC)，所述团状模塑料包括如下质量百分含量的各组分：In a first aspect, the present application provides a bulk molding compound (Bulk Molding Compound, BMC), the bulk molding compound comprising the following components by mass percentage:
不饱和树脂：15％～20％；Unsaturated resin: 15%～20%;
低收缩剂：7％～10％；Low shrinkage agent: 7%～10%;
稀释单体：10％～15％；Diluted monomer: 10% to 15%;
引发剂：0.2％～0.5％；Initiator: 0.2%～0.5%;
增稠剂：0～0.05％；Thickener: 0～0.05%;
内脱模剂：0～1.5％；Internal release agent: 0～1.5%;
阻聚剂：0～0.05％；Inhibitor: 0～0.05%;
阻燃剂：25％～30％；Flame retardant: 25%～30%;
纤维增强体：6％～10％；Fiber reinforcement: 6% to 10%;
高导热填料：20％～30％；High thermal conductivity filler: 20% to 30%;
颜料：0～1％。Pigment: 0～1%.
本申请第一方面提供的团状模塑料中，通过上述质量百分含量的各组分的协同作用，可以使得该团状模塑料兼具低密度、高导热和高阻燃性能，例如该团状模塑料的密度不超过2g/cm 3，导热系数在1.6W/(m·K)以上，且能通过BS476-6 Class 0和BS476-7 Class 1防火阻燃认证。由于该团状模塑料具有较高的导热系数，其可将LED显示屏在使用过程中产生的热量及时而有效地散发出去，可有效降低LED显示屏的温度；由于该团状模塑料的密度低，采用其制作显示屏底壳，有助于实现LED显示屏的轻量化，并可降低成本；此外，该团状模塑料的防火阻燃等级高，有助于提高LED显示屏的防火阻燃性能。 In the bulk molding compound provided in the first aspect of the present application, through the synergistic effect of the above-mentioned components in the mass percentage, the bulk molding compound can have both low density, high thermal conductivity and high flame retardancy. The density of the molding compound does not exceed 2g/cm 3 , the thermal conductivity is above 1.6W/(m·K), and it can pass BS476-6 Class 0 and BS476-7 Class 1 fire-retardant certification. Because the bulk molding compound has a high thermal conductivity, it can dissipate the heat generated by the LED display screen in a timely and effective manner, and can effectively reduce the temperature of the LED display screen; due to the density of the bulk molding compound The use of it to make the bottom shell of the display screen is helpful to realize the lightweight of the LED display screen and reduce the cost; in addition, the slug molding compound has a high fire resistance and flame retardant grade, which helps to improve the fire resistance of the LED display screen. combustion performance.
本申请中，所述不饱和树脂为含有碳碳双键、碳碳叁键等不饱和基团的高分子化合物。后续在团状模塑料的成型过程中，在引发剂的引发下，不饱和树脂可以与稀释单体发生交联聚合。本申请一些实施方式中，所述不饱和树脂为不饱和聚酯树脂，其含有不饱和碳碳双键和酯键。其中，所述不饱和聚酯树脂可以包括邻苯型不饱和聚酯树脂、间苯型不饱和聚酯树脂、双酚A型不饱和聚酯树脂、乙烯基酯型和卤代不饱和聚酯树脂中的至少一种。优选地，所述不饱和聚酯树脂为邻苯型不饱和聚酯树脂和/或间苯型不饱和聚酯树脂。该树脂的价格低廉，且拉伸性、弯曲性等力学性能较好。In this application, the unsaturated resin is a polymer compound containing unsaturated groups such as carbon-carbon double bonds and carbon-carbon triple bonds. In the subsequent molding process of the bulk molding compound, under the initiation of the initiator, the unsaturated resin can undergo cross-linking polymerization with the diluent monomer. In some embodiments of the present application, the unsaturated resin is an unsaturated polyester resin, which contains unsaturated carbon-carbon double bonds and ester bonds. Wherein, the unsaturated polyester resin may include o-phthalic unsaturated polyester resin, iso-phthalic unsaturated polyester resin, bisphenol A unsaturated polyester resin, vinyl ester type and halogenated unsaturated polyester at least one of resins. Preferably, the unsaturated polyester resin is an ortho-phthalic unsaturated polyester resin and/or an iso-phthalic unsaturated polyester resin. The resin is cheap and has good mechanical properties such as stretchability and flexibility.
所述稀释单体可以与不饱和树脂发生交联反应。可选地，所述稀释单体可以选自苯乙烯、甲基丙烯酸甲酯、邻苯二甲酸二丙烯酯等中的至少一种。优选地，所述稀释单体为苯乙烯，其价格低廉，稀释能力强，树脂被稀释后可被纤 维增强体、填料等更快地被润湿和浸渍，同时苯乙烯与不饱和树脂的共聚活性也较强。The diluent monomer may undergo a crosslinking reaction with the unsaturated resin. Optionally, the diluting monomer may be selected from at least one of styrene, methyl methacrylate, dipropylene phthalate, and the like. Preferably, the diluting monomer is styrene, which is cheap and has strong diluting ability. After the resin is diluted, it can be wetted and impregnated more quickly by fiber reinforcements, fillers, etc., while the copolymerization of styrene and unsaturated resin The activity is also strong.
本申请中，所述低收缩剂的作用是降低团状模塑料在成型过程中的收缩率从而提高所得制品的表观效果。可选地，所述低收缩剂可以选自聚苯乙烯、聚醋酸乙烯酯、聚乙烯、聚氯乙烯、聚甲基丙烯酸甲酯、聚对苯二甲酸乙二醇酯、改性聚氨酯、尼龙、合成橡胶等中的一种或多种，但不限于此。In the present application, the function of the low shrinkage agent is to reduce the shrinkage rate of the bulk molding compound during the molding process so as to improve the apparent effect of the obtained product. Optionally, the low shrinkage agent can be selected from polystyrene, polyvinyl acetate, polyethylene, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate, modified polyurethane, nylon , synthetic rubber, etc., but not limited thereto.
本申请中，所述引发剂为有机过氧化合物类引发剂。具体地，所述引发剂可以包括过氧化苯甲酸叔丁酯(简称TBPB)、过氧化-2-乙基己酸叔丁酯(简称TBPO)、过氧化苯甲酰(BPO)、过氧化2-乙基己基酸叔戊酯(TAPO)、过氧化醋酸叔戊酯(TAPA)、过氧化苯甲酸叔戊酯(TAPB)中的一种或多种，但不限于此。优选地，所述引发剂为TBPB和/或TBPO，其价格较低廉。In this application, the initiator is an organic peroxy compound type initiator. Specifically, the initiator may include tert-butyl peroxybenzoate (TBPB for short), tert-butyl peroxy-2-ethylhexanoate (TBPO for short), benzoyl peroxide (BPO), 2 -One or more of tert-amyl ethylhexyl acid (TAPO), tert-amyl peroxyacetate (TAPA), tert-amyl peroxybenzoate (TAPB), but not limited thereto. Preferably, the initiator is TBPB and/or TBPO, which are relatively inexpensive.
本申请一些实施方式中，引入的增稠剂能够与不饱和树脂发生物理反应，使团状模塑料具有合适的注塑流动性。可选地，所述增稠剂选自氧化镁、氧化钙、氢氧化钙中的至少一种，但不限于此。优选地，所述增稠剂为氧化镁。可选地，所述增稠剂在所述团状模塑料中的质量百分含量为0.01％～0.05％。优选为0.02％～0.04％。In some embodiments of the present application, the introduced thickener can physically react with the unsaturated resin, so that the bulk molding compound has suitable injection fluidity. Optionally, the thickener is selected from at least one of magnesium oxide, calcium oxide, and calcium hydroxide, but is not limited thereto. Preferably, the thickener is magnesium oxide. Optionally, the mass percentage content of the thickener in the dough molding compound is 0.01% to 0.05%. It is preferably 0.02% to 0.04%.
本申请一些实施方式中，引入内脱模剂能够有利于团状模塑料从模具上顺利剥离，避免发生黏模现象。可选地，所述内脱模剂可以选自硬脂酸锌、硬脂酸钙和硬脂酸镁、硬脂酸钠中的至少一种。优选地，所述脱模剂为硬脂酸锌。可选地，内脱模剂在所述团状模塑料中的质量百分含量可以为0.5％～1.5％。例如可以为0.6％、0.8％、1％、1.1％、1.2％、1.3％或1.4％。可选地，所述内脱模剂在所述团状模塑料中的质量百分含量为0.6％～1.2％或0.75％～1.0％。In some embodiments of the present application, the introduction of an internal mold release agent can facilitate the smooth peeling of the bulk molding compound from the mold and avoid mold sticking. Optionally, the internal mold release agent may be selected from at least one of zinc stearate, calcium stearate, magnesium stearate, and sodium stearate. Preferably, the release agent is zinc stearate. Optionally, the mass percentage content of the internal mold release agent in the bulk molding compound may be 0.5% to 1.5%. For example, it may be 0.6%, 0.8%, 1%, 1.1%, 1.2%, 1.3% or 1.4%. Optionally, the mass percentage content of the internal mold release agent in the bulk molding compound is 0.6%-1.2% or 0.75%-1.0%.
阻聚剂的加入能够捕捉一部分自由基，延长不饱和树脂的凝胶化时间。可选地，所述阻聚剂可以包括对苯二酚、叔丁基邻苯二酚、2-叔丁基对苯二酚、2,5-二叔丁基对苯二酚、对苯醌、甲基氢醌、四氯苯醌、对羟基苯甲醚中的一种或多种。优选地，所述阻聚剂为对苯二酚、2-叔丁基对苯二酚和对苯醌中的一种或多种。可选地，所述阻聚剂在所述团状模塑料中的质量百分含量为0.01％～0.05％；例如可以为0.01％、0.02％、0.03％、0.04％或0.05％。在一些实施方式中，阻聚剂在所述团状模塑料中的质量百分含量可以为0.015％～0.03％。The addition of the polymerization inhibitor can capture a part of the free radicals and prolong the gelation time of the unsaturated resin. Optionally, the polymerization inhibitor may include hydroquinone, tert-butyl catechol, 2-tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone, p-benzoquinone, methylbenzene One or more of hydroquinone, tetrachlorobenzoquinone and p-hydroxyanisole. Preferably, the polymerization inhibitor is one or more of hydroquinone, 2-tert-butyl hydroquinone and p-benzoquinone. Optionally, the mass percentage content of the polymerization inhibitor in the bulk molding compound is 0.01% to 0.05%; for example, it may be 0.01%, 0.02%, 0.03%, 0.04% or 0.05%. In some embodiments, the mass percentage content of the polymerization inhibitor in the bulk molding compound may be 0.015% to 0.03%.
本申请中，所述阻燃剂用于提高所述团状模塑料制成的制品的阻燃性能。可选地，所述阻燃剂包括氢氧化铝、氢氧化镁、硼酸锌、三氧化二锑、五氧化锑、红磷、聚磷酸铵、磷酸氢二铵等中的一种或多种，但不限于此。优选地，所述阻燃剂可以包括氢氧化铝和/或氢氧化镁，这二者的阻燃等级较高，且环保性高。可选地，所述阻燃剂在所述团状模塑料中的质量百分含量为26％～29％，优选为27％～28％。In the present application, the flame retardant is used to improve the flame retardant properties of the products made of the bulk molding compound. Optionally, the flame retardant includes one or more of aluminum hydroxide, magnesium hydroxide, zinc borate, antimony trioxide, antimony pentoxide, red phosphorus, ammonium polyphosphate, diammonium hydrogen phosphate, etc., But not limited to this. Preferably, the flame retardant may include aluminum hydroxide and/or magnesium hydroxide, both of which have higher flame retardant grades and are highly environmentally friendly. Optionally, the mass percentage content of the flame retardant in the bulk molding compound is 26%-29%, preferably 27%-28%.
可选地，所述氢氧化铝和/或氢氧化镁阻燃剂的烧失量为25％～40％，粒径D50为1μm～20μm。烧失量是指在一定的高温条件下灼烧足够长的时间后失去的质量占原始样品质量的百分比，较低的烧失量可反映出较优的阻燃性能。在本申请一些实施方式中，所述氢氧化铝的烧失量为30％～40％，粒径D50为5μm～15μm。所述氢氧化镁的烧失量为25％～35％，粒径D50为1μm～5μm。Optionally, the loss on ignition of the aluminum hydroxide and/or magnesium hydroxide flame retardant is 25% to 40%, and the particle size D50 is 1 μm to 20 μm. Loss on ignition refers to the percentage of mass lost after burning for a long enough time under certain high temperature conditions to the mass of the original sample. Lower loss on ignition can reflect better flame retardant performance. In some embodiments of the present application, the loss on ignition of the aluminum hydroxide is 30% to 40%, and the particle size D50 is 5 μm to 15 μm. The loss on ignition of the magnesium hydroxide is 25% to 35%, and the particle size D50 is 1 μm to 5 μm.
本申请中，所述纤维增强体主要用于增强所述团状模塑料的强度。可选地，所述纤维增强体在所述团状模塑料中的质量百分含量为7％～9％。其中，所述纤维增强体可以包括玻璃纤维和碳纤维中的一种或多种，但不限于此。优选地， 所述纤维增强体为玻璃纤维。玻璃纤维这一增强体与不饱和树脂之间的结合力较强，能更好地增强团状模塑料的强度，且成本较低。在本申请一些实施方式中，所述纤维增强体为长度为3mm～9mm的玻璃纤维。这样可以在增强团状模塑料的强度的同时，保证良好的注塑性。在一些实施例中，所述玻璃纤维为无碱玻璃纤维，其直径为13μm～15μm，长度为3mm～9mm，例如长度可以为3mm～6mm或6mm～9mm。In the present application, the fiber reinforcement is mainly used to enhance the strength of the bulk molding compound. Optionally, the mass percentage content of the fiber reinforcement in the bulk molding compound is 7% to 9%. Wherein, the fiber reinforcement may include one or more of glass fiber and carbon fiber, but is not limited thereto. Preferably, the fiber reinforcement is glass fiber. The bonding force between the reinforcement of glass fiber and the unsaturated resin is stronger, which can better enhance the strength of the bulk molding compound, and the cost is lower. In some embodiments of the present application, the fiber reinforcement is a glass fiber with a length of 3 mm to 9 mm. This can enhance the strength of the bulk molding compound while ensuring good injection properties. In some embodiments, the glass fiber is an alkali-free glass fiber with a diameter of 13 μm˜15 μm and a length of 3 mm˜9 mm, for example, the length may be 3 mm˜6 mm or 6 mm˜9 mm.
本申请中，所述高导热填料的导热系数较高，其可以赋予所述团状模塑料良好的导热性能，便于其用在LED显示屏上时更好地降低LED显示屏的温度。可选地，所述高导热填料可以包括氧化铝、氧化锌、氧化镁、碳化硅、氮化铝、氮化硼、纤维状碳粉、鳞片状碳粉中的一种或多种。优选地，所述高导热填料为氧化铝、碳化硅、氮化铝中的一种或多种，它们的导热系数较高，较少的添加量就可保证团状模塑料的导热系数在1.6W/(m.K)以上。具体地，所述高导热填料在所述团状模塑料中的质量百分含量可以为21％、22％、23％、24％、25％、26％、27％、28％或29％。In the present application, the high thermal conductivity filler has a relatively high thermal conductivity, which can impart good thermal conductivity to the slug molding compound, so that it can better reduce the temperature of the LED display screen when it is used on the LED display screen. Optionally, the high thermal conductivity filler may include one or more of aluminum oxide, zinc oxide, magnesium oxide, silicon carbide, aluminum nitride, boron nitride, fibrous carbon powder, and scaly carbon powder. Preferably, the high thermal conductivity filler is one or more of aluminum oxide, silicon carbide, and aluminum nitride, and their thermal conductivity is relatively high, and a small amount of addition can ensure that the thermal conductivity of the bulk molding compound is 1.6 W/(m.K) or more. Specifically, the mass percentage content of the high thermal conductivity filler in the bulk molding compound may be 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28% or 29%.
本申请一些实施方式中，所述团状模塑料中还可以包括质量百分含量为0.1％～10％的低成本增强填料。其中，所述低成本增强填料可以包括碳酸钙、硫酸钡、二氧化硅、二氧化钛等中的一种或多种，但不限于此。这些填料的成本较低，且对团状模塑料有增强作用，并起到导热作用，可部分取代高导热填料，使得高导热填料的整体用量减少，降低团状模塑料的成本。优选地，所述低成本增强填料为碳酸钙和/或二氧化硅。可选地，所述低成本增强填料在所述团状模塑料中的质量百分含量为1％～9％。In some embodiments of the present application, the bulk molding compound may further include a low-cost reinforcing filler in a mass percentage of 0.1% to 10%. Wherein, the low-cost reinforcing filler may include one or more of calcium carbonate, barium sulfate, silicon dioxide, titanium dioxide, etc., but is not limited thereto. The cost of these fillers is low, and they have a reinforcing effect on the bulk molding compound, and play a thermal conductivity role, which can partially replace the high thermal conductivity filler, so that the overall amount of the high thermal conductivity filler is reduced, and the cost of the bulk molding compound is reduced. Preferably, the low-cost reinforcing filler is calcium carbonate and/or silica. Optionally, the mass percentage content of the low-cost reinforcing filler in the bulk molding compound is 1% to 9%.
在团状模塑料中引入颜料，可以赋予团状模塑料一定的颜色。可选地，所 述颜料可以包括氧化钛、钛白粉、碳黑和氧化铁红等中的一种或多种，但不限于此。可选地，所述颜料在所述团状模塑料中的质量百分含量为0.5％～1％；例如可以是0.6％、07％、0.8％或0.9％，进一步地可以为0.6％～0.9％。The introduction of pigments into the mass molding compound can impart a certain color to the mass molding compound. Optionally, the pigment may include one or more of titanium oxide, titanium dioxide, carbon black, red iron oxide, etc., but is not limited thereto. Optionally, the mass percentage content of the pigment in the bulk molding compound is 0.5% to 1%; for example, it can be 0.6%, 07%, 0.8% or 0.9%, and further can be 0.6% to 0.9% %.
本申请一些实施方式中，所述团状模塑料包括如下质量百分含量的各组分：In some embodiments of the present application, the bulk molding compound comprises the following components by mass percentage:
不饱和树脂：15％～20％；Unsaturated resin: 15%～20%;
低收缩剂：7％～10％；Low shrinkage agent: 7%～10%;
稀释单体：10％～15％；Diluted monomer: 10% to 15%;
引发剂：0.2％～0.5％；Initiator: 0.2%～0.5%;
增稠剂：0.01％～0.05％；Thickener: 0.01%～0.05%;
内脱模剂：0.5％～1.5％；Internal release agent: 0.5% to 1.5%;
阻聚剂：0.01％～0.05％；Inhibitor: 0.01%～0.05%;
阻燃剂：25％～30％；Flame retardant: 25%～30%;
纤维增强体：6％～10％；Fiber reinforcement: 6% to 10%;
高导热填料：20％～30％；High thermal conductivity filler: 20% to 30%;
低成本增强填料：0.1％～10％；Low-cost reinforcing filler: 0.1% to 10%;
颜料：0.5％～1％。Pigment: 0.5% to 1%.
本申请提供的上述团状模塑料具有较低的密度、较高的导热性能和较高的阻燃性能。可选地，所述团状模塑料的导热系数在1.6W/(m·K)以上。具体地，该导热系数可以为1.6W/(m·K)、1.7W/(m·K)、1.8W/(m·K)或2.0W/(m·K)。在一些实施方式中，团状模塑料的导热系数可在1.8W/(m·K)以上，甚至可在2.2W/(m·K)以上。在一些实施方式中，所述团状模塑料的导热系数在1.6 W/(m·K)-2.0W/(m·K)。The above-mentioned bulk molding compound provided by the present application has lower density, higher thermal conductivity and higher flame retardancy. Optionally, the thermal conductivity of the bulk molding compound is above 1.6 W/(m·K). Specifically, the thermal conductivity may be 1.6 W/(m·K), 1.7 W/(m·K), 1.8 W/(m·K), or 2.0 W/(m·K). In some embodiments, the thermal conductivity of the bulk molding compound may be above 1.8 W/(m·K), and may even be above 2.2 W/(m·K). In some embodiments, the bulk molding compound has a thermal conductivity in the range of 1.6 W/(m·K) to 2.0 W/(m·K).
可选地，所述团状模塑料的密度不超过2.0g/cm 3，例如为1.7g/cm 3、1.8g/cm 3或1.9g/cm 3。在一些实施方式中，所述团状模塑料的密度为1.8g/cm 3-2.0g/cm 3。 Optionally, the density of the bulk molding compound does not exceed 2.0 g/cm 3 , for example 1.7 g/cm 3 , 1.8 g/cm 3 or 1.9 g/cm 3 . In some embodiments, the bulk molding compound has a density of 1.8 g/cm 3 to 2.0 g/cm 3 .
可选地，所述团状模塑料的弯曲强度在120MPa以上，有时可在130MPa以上。弯曲强度是指材料在弯曲负荷作用下所能承受的最大应力，它可反映材料抗弯曲的能力。由较高的弯曲强度的团状模塑料制成的底壳可以更好地起承载作用。在一些实施方式中，团状模塑料的弯曲强度在120MPa-135MPa。Optionally, the flexural strength of the bulk molding compound is above 120 MPa, sometimes above 130 MPa. Bending strength refers to the maximum stress that a material can withstand under a bending load, which reflects the ability of a material to resist bending. A bottom shell made of a higher flexural strength bulk molding compound can better support the load. In some embodiments, the flexural strength of the bulk molding compound is between 120 MPa and 135 MPa.
可选地，所述团状模塑料的冲击强度在20kJ/cm 2以上。冲击强度是试样冲击破坏过程中所吸收的能量与原始横截面积之比，可用于评价材料的韧性强度。较高的冲击强度反映出该团状模塑料的韧性较高、脆性小。在一些实施方式中，团状模塑料的冲击强度在22kJ/cm 2以上，例如可以为23kJ/cm 2、24kJ/cm 2或25kJ/cm 2。在一些实施方式中，所述团状模塑料的冲击强度为20kJ/cm 2-25kJ/cm 2。 Optionally, the impact strength of the bulk molding compound is above 20 kJ/cm 2 . Impact strength is the ratio of the energy absorbed during the impact failure of the sample to the original cross-sectional area, which can be used to evaluate the toughness of the material. The higher impact strength reflects the higher toughness and less brittleness of the bulk molding compound. In some embodiments, the impact strength of the bulk molding compound is above 22 kJ/cm 2 , for example, may be 23 kJ/cm 2 , 24 kJ/cm 2 or 25 kJ/cm 2 . In some embodiments, the bulk molding compound has an impact strength of 20 kJ/cm 2 to 25 kJ/cm 2 .
相应地，本申请第二方面提供了一种团状模塑料的制备方法，包括以下步骤：Correspondingly, a second aspect of the present application provides a method for preparing a bulk molding compound, comprising the following steps:
在小于或等于45℃的温度下，将不饱和树脂、低收缩剂、稀释单体、引发剂、增稠剂、内脱模剂、阻聚剂混合均匀，得到树脂浆液，向所述树脂浆液中加入阻燃剂、高导热填料、颜料，混合均匀后，再加入纤维增强体，分散均匀，得到团状模塑料；其中，上述各原料按如下质量百分含量混合：不饱和树脂：15％～20％；低收缩剂：7％～10％；稀释单体：10％～15％；引发剂：0.2％～0.5％；增稠剂：0～0.05％；内脱模剂：0～1.5％；阻聚剂：0～0.05％；阻燃剂：25％～30％； 纤维增强体：6％～10％；高导热填料：20％～30％；颜料：0～1％。At a temperature of less than or equal to 45°C, uniformly mix unsaturated resin, low shrinkage agent, diluent monomer, initiator, thickener, internal mold release agent, and polymerization inhibitor to obtain a resin slurry. Add flame retardants, high thermal conductivity fillers, and pigments to the mixture, and after mixing uniformly, add fiber reinforcements to disperse uniformly to obtain a mass molding compound; wherein, the above-mentioned raw materials are mixed according to the following mass percentages: Unsaturated resin: 15% ～20%; low shrinkage agent: 7%～10%; diluent monomer: 10%～15%; initiator: 0.2%～0.5%; thickener: 0～0.05%; internal mold release agent: 0～1.5 %; polymerization inhibitor: 0-0.05%; flame retardant: 25%-30%; fiber reinforcement: 6%-10%; high thermal conductivity filler: 20%-30%; pigment: 0-1%.
上述物料进行混合的方式可以是搅拌或捏合等，所采用的设备可以是搅拌机、捏合机等。词语“捏合”是指利用机械搅拌使糊状、黏性及塑性物料均匀混合的操作，包括物料的分散和混合两种作用，可在捏合机中进行。The manner of mixing the above materials can be stirring or kneading, etc., and the equipment used can be a mixer, a kneader, and the like. The word "kneading" refers to the operation of uniformly mixing pasty, viscous and plastic materials by mechanical stirring, including the two functions of dispersion and mixing of materials, which can be carried out in a kneader.
其中，所述树脂浆液可以是通过将不饱和树脂、低收缩剂、稀释单体、引发剂、增稠剂、内脱模剂、阻聚剂进行搅拌得到。可选地，所述搅拌的速度为800r/min～1200r/min，搅拌的时间可以为30min～40min。而后续在树脂浆液中加入其它原料时可以在捏合机中进行，以提高混合效果。Wherein, the resin slurry can be obtained by stirring the unsaturated resin, low shrinkage agent, diluting monomer, initiator, thickener, internal mold release agent, and polymerization inhibitor. Optionally, the stirring speed is 800r/min～1200r/min, and the stirring time can be 30min～40min. The subsequent addition of other raw materials to the resin slurry can be carried out in a kneader to improve the mixing effect.
本申请一些实施方式中，在向所述树脂浆液中加入阻燃剂、高导热填料和颜料时，还可以再加入上述低成本增强填料。低成本增强填料在所述团状模塑料中的质量百分含量可以为0.1％～10％。In some embodiments of the present application, when adding flame retardants, high thermal conductivity fillers and pigments to the resin slurry, the above-mentioned low-cost reinforcing fillers may be further added. The mass percentage content of the low-cost reinforcing filler in the bulk molding compound may be 0.1% to 10%.
本申请中，在团状模塑料的整个制备过程中，控制温度不超过45℃，可以防止引发剂在高温下提前引发不饱和树脂和稀释单体发生交联聚合，以免影响团状模塑料的注塑流动性和加工性。In the present application, during the whole preparation process of the bulk molding compound, the temperature is controlled not to exceed 45°C, which can prevent the initiator from triggering the cross-linking polymerization of the unsaturated resin and the diluent monomer in advance at high temperature, so as not to affect the properties of the bulk molding compound. Injection flow and processability.
本申请第二方面提供的团状模塑料的制备方法，简单易行，可操作性强。The preparation method of the mass molding compound provided by the second aspect of the present application is simple and easy to implement and has strong operability.
本申请第三方面还提供了一种LED显示屏，所述LED显示屏包括LED显示屏底壳，其通过本申请第一方面提供的团状模塑料加工成型。例如，该团状模塑料通过注塑成型法或模压成型法来加工成型的。A third aspect of the present application further provides an LED display screen. The LED display screen includes an LED display screen bottom case, which is processed and formed by the slug molding compound provided in the first aspect of the present application. For example, the bulk molding compound is processed by injection molding or compression molding.
LED显示屏中含有由上述团状模塑料制成的底壳，可以使LED显示屏实现轻量化的同时，还具有较高的阻燃性，并在使用过程中保持较低的屏体温度。The LED display screen contains a bottom case made of the above-mentioned slug molding compound, which can make the LED display screen light in weight, and at the same time, has high flame retardancy, and maintains a low temperature of the screen body during use.
附图说明Description of drawings
图1是本申请实施例提供的显示屏的结构示意图；1 is a schematic structural diagram of a display screen provided by an embodiment of the present application;
图2为本申请实施例提供的LED显示屏的显示模组的一种结构示意图；2 is a schematic structural diagram of a display module of an LED display screen provided by an embodiment of the present application;
图3为本申请实施例提供的图2显示模组中底壳的结构示意图。FIG. 3 is a schematic structural diagram of a bottom case in the module shown in FIG. 2 according to an embodiment of the present application.
具体实施方式Detailed ways
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述。The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.
如图1所示，首先介绍显示屏1000的结构。一般地，显示屏1000由多个显示箱体100拼接而成，每个显示箱体100包括一个箱体框架(图1中未示出)和多个显示模组120，多个显示模组120规律地固定在箱体框架上组成一个完整的显示箱体100。图1中所示，每个显示箱体100的箱体框架固定在显示模组120的背面。As shown in FIG. 1 , the structure of the display screen 1000 is first introduced. Generally, the display screen 1000 is formed by splicing a plurality of display boxes 100 , and each display box 100 includes a box frame (not shown in FIG. 1 ) and a plurality of display modules 120 . The plurality of display modules 120 Regularly fixed on the box frame to form a complete display box 100 . As shown in FIG. 1 , the box frame of each display box 100 is fixed on the back of the display module 120 .
参见图2，每个显示模组120包括灯板121和承载灯板121的底壳122等组件，其中底壳122和上述箱体框架分别与灯板121的背面固定连接。灯板121包括印刷电路板1210(printed circuit board，PCB)以及设置在印刷电路板1210上的LED灯珠1211和驱动电路等。Referring to FIG. 2 , each display module 120 includes components such as a light panel 121 and a bottom case 122 supporting the light panel 121 , wherein the bottom case 122 and the box frame are respectively fixedly connected to the back of the light panel 121 . The lamp board 121 includes a printed circuit board 1210 (printed circuit board, PCB), and the LED lamp beads 1211 and the driving circuit and the like disposed on the printed circuit board 1210 .
本申请中主要针对底壳122的成型材料进行改进。其中，底壳122由下述团状模塑料加工成型得到，具体的加工成型方式可以是注塑成型法、模压成型法等。在由上述团状模塑料制备底壳122时，可以先将上述团状模塑料置于模具中，在一定的温度和压力下而固化成型。其中，该团状模塑料包括如下质量百分含量的各组分：In this application, improvement is mainly made on the molding material of the bottom case 122 . Wherein, the bottom case 122 is obtained by processing and molding the following group molding compound, and the specific processing and molding method may be injection molding method, compression molding method, or the like. When the bottom case 122 is prepared from the above-mentioned bulk molding compound, the above-mentioned bulk molding compound may be placed in a mold, and then cured and formed under a certain temperature and pressure. Wherein, the mass molding compound comprises the following components by mass percentage:
不饱和树脂：15％～20％；Unsaturated resin: 15%～20%;
低收缩剂：7％～10％；Low shrinkage agent: 7%～10%;
稀释单体：10％～15％；Diluted monomer: 10% to 15%;
引发剂：0.2％～0.5％；Initiator: 0.2%～0.5%;
增稠剂：0～0.05％；Thickener: 0～0.05%;
内脱模剂：0～1.5％；Internal release agent: 0～1.5%;
阻聚剂：0～0.05％；Inhibitor: 0～0.05%;
阻燃剂：25％～30％；Flame retardant: 25%～30%;
纤维增强体：6％～10％；Fiber reinforcement: 6% to 10%;
高导热填料：20％～30％；High thermal conductivity filler: 20% to 30%;
颜料：0～1％。Pigment: 0～1%.
在上述特定质量百分含量的各组分的协同作用下，可使得该团状模塑料兼具低密度、高导热和高阻燃性能，例如该团状模塑料的密度不超过2g/cm 3，导热系数在1.6W/(m·K)以上，且能通过BS 476-6Class 0和BS476-7Class 1防火阻燃认证。 Under the synergistic effect of the above-mentioned specific mass percentages of the components, the bulk molding compound can have both low density, high thermal conductivity and high flame retardant properties, for example, the bulk molding compound has a density of not more than 2g/cm 3 , the thermal conductivity is above 1.6W/(m·K), and it can pass BS 476-6Class 0 and BS476-7Class 1 fire and flame retardant certification.
其中，上述团状模塑料可以通过以下方法制备：在小于或等于45℃的温度下，将不饱和树脂、低收缩剂、稀释单体、引发剂、增稠剂、内脱模剂、阻聚剂混合均匀，得到树脂浆液；在小于或等于45℃的温度下，向所述树脂浆液中加入阻燃剂、高导热填料和颜料，混合均匀后，再向其中加入纤维增强体，分散均匀，得到团状模塑料。Wherein, the above-mentioned bulk molding compound can be prepared by the following method: at a temperature of less than or equal to 45 ° C, unsaturated resin, low shrinkage agent, diluting monomer, initiator, thickener, internal mold release agent, polymerization inhibitor Add the flame retardant, high thermal conductivity filler and pigment to the resin slurry at a temperature of less than or equal to 45°C, and after mixing evenly, add fiber reinforcement to it, disperse evenly, A mass molding compound is obtained.
本申请一些实施方式中，所述团状模塑料的制备原料还可以上述低成本增强填料，其可随高导热填料一起添加。此时，所述团状模塑料在具有上述优异性能的同时，还具有较低的成本。In some embodiments of the present application, the raw material for the preparation of the bulk molding compound can also be the above-mentioned low-cost reinforcing filler, which can be added together with the high thermal conductivity filler. At this time, the bulk molding compound has the above-mentioned excellent properties and also has a lower cost.
下面通过具体的实施例对本发明进行进一步的说明。The present invention will be further described below through specific embodiments.
实施例1Example 1
一种团状模塑料，该团状模塑料包括以下质量百分含量的各组分：A slug molding compound, the slug molding compound comprises the following components by mass percentage:
不饱和树脂(具体为间苯型不饱和聚酯树脂)：17％；Unsaturated resin (specifically, isophthalic unsaturated polyester resin): 17%;
低收缩剂(具体为聚醋酸乙烯酯)：7％；Low shrinkage agent (specifically polyvinyl acetate): 7%;
稀释单体(具体为苯乙烯)：12％；Diluted monomer (specifically styrene): 12%;
引发剂：0.5％(具体为0.25％的过氧化苯甲酸叔丁酯，0.25％的过氧化2-乙基己基酸叔丁酯)；Initiator: 0.5% (specifically, 0.25% of tert-butyl peroxybenzoate, 0.25% of tert-butyl peroxide of 2-ethylhexyl peroxide);
增稠剂(具体为氧化镁)：0.03％；Thickener (specifically magnesium oxide): 0.03%;
内脱模剂(具体为硬脂酸钠)：0.75％；Internal release agent (specifically sodium stearate): 0.75%;
阻聚剂(具体为对苯醌)：0.02％；Polymerization inhibitor (specifically, p-benzoquinone): 0.02%;
阻燃剂(具体为氢氧化铝)：28％；Flame retardant (specifically aluminum hydroxide): 28%;
纤维增强体(具体为玻璃纤维)：7％；Fiber reinforcement (specifically glass fibers): 7%;
高导热填料(具体为氧化铝)：27％；High thermal conductivity filler (specifically alumina): 27%;
颜料(具体为炭黑)：0.7％。Pigment (specifically carbon black): 0.7%.
上述团状模塑料的制备方法包括：1)先将不饱和树脂、低收缩剂、稀释单体、引发剂、增稠剂、内脱模剂、阻聚剂添加到搅拌机中，以1000r/min的速度搅拌35min，得到树脂浆液，搅拌过程中控制温度≤45℃；2)将步骤1)搅拌好的树脂浆液置于捏合机中，加入阻燃剂、高导热填料、低成本增强填料、颜料，在温度≤45℃下捏合10min，得到树脂浆液和粉料的混合物；3)最后向捏合机中加入纤维增强体，在温度≤45℃下捏合9min，得到团状模塑料(BMC)。The preparation method of the above-mentioned mass molding compound includes: 1) firstly adding unsaturated resin, low shrinkage agent, diluting monomer, initiator, thickening agent, internal mold release agent, and polymerization inhibitor to the mixer, at a rate of 1000r/min Stir at a speed of 35 min to obtain a resin slurry, and control the temperature during the stirring process to be less than or equal to 45 ° C; 2) Put the resin slurry stirred in step 1) into a kneader, add flame retardants, high thermal conductivity fillers, low-cost reinforcing fillers, pigments , knead for 10min at a temperature≤45℃ to obtain a mixture of resin slurry and powder; 3) finally add fiber reinforcement to the kneader, knead at a temperature≤45℃ for 9min to obtain a bulk molding compound (BMC).
实施例2Example 2
一种团状模塑料，该团状模塑料包括以下质量百分含量的各组分：A slug molding compound, the slug molding compound comprises the following components by mass percentage:
不饱和树脂(具体为邻苯型不饱和聚酯树脂)：17％；Unsaturated resin (specifically, o-phthalic unsaturated polyester resin): 17%;
低收缩剂(具体为聚苯乙烯)：7％；Low shrinkage agent (specifically polystyrene): 7%;
稀释单体(具体为苯乙烯)：12％；Diluted monomer (specifically styrene): 12%;
引发剂：0.5％(具体为0.25％的过氧化苯甲酸叔丁酯，0.25％的过氧化2-乙基己基酸叔丁酯)；Initiator: 0.5% (specifically, 0.25% of tert-butyl peroxybenzoate, 0.25% of tert-butyl peroxide of 2-ethylhexyl peroxide);
增稠剂(具体为氧化镁)：0.03％；Thickener (specifically magnesium oxide): 0.03%;
内脱模剂(具体为硬脂酸锌)：0.75％；Internal release agent (specifically zinc stearate): 0.75%;
阻聚剂(具体为对苯醌)：0.02％；Polymerization inhibitor (specifically, p-benzoquinone): 0.02%;
阻燃剂(具体为氢氧化铝)：28％；Flame retardant (specifically aluminum hydroxide): 28%;
纤维增强体(具体为玻璃纤维)：8％；Fiber reinforcement (specifically glass fibers): 8%;
高导热填料(具体为氧化铝)：21％；High thermal conductivity filler (specifically alumina): 21%;
低成本增强填料(具体为碳酸钙)：5％；Low cost reinforcing filler (specifically calcium carbonate): 5%;
颜料(具体为炭黑)：0.7％。Pigment (specifically carbon black): 0.7%.
实施例3Example 3
一种团状模塑料，该团状模塑料包括以下质量百分含量的各组分：A slug molding compound, the slug molding compound comprises the following components by mass percentage:
不饱和树脂(具体为邻苯型不饱和聚酯树脂)：18％；Unsaturated resin (specifically o-phthalic unsaturated polyester resin): 18%;
低收缩剂(具体为聚甲基丙烯酸甲酯)：7％；Low shrinkage agent (specifically polymethyl methacrylate): 7%;
稀释单体(具体为苯乙烯)：12％；Diluted monomer (specifically styrene): 12%;
引发剂(具体为0.25％的过氧化苯甲酸叔丁酯，0.25％的过氧化2-乙基己基酸叔丁酯)；Initiator (specifically 0.25% tert-butyl peroxybenzoate, 0.25% tert-butyl peroxy 2-ethylhexyl acid);
增稠剂(具体为氧化镁)：0.03％；Thickener (specifically magnesium oxide): 0.03%;
内脱模剂(具体为硬脂酸锌)：0.75％；Internal release agent (specifically zinc stearate): 0.75%;
阻聚剂(具体为对苯醌)：0.02％；Polymerization inhibitor (specifically, p-benzoquinone): 0.02%;
阻燃剂(具体为氢氧化镁)：27％；Flame retardant (specifically magnesium hydroxide): 27%;
纤维增强体(具体为玻璃纤维)：8％；Fiber reinforcement (specifically glass fibers): 8%;
高导热填料(具体为氮化铝)：21％；High thermal conductivity filler (specifically aluminum nitride): 21%;
低成本增强填料(具体为二氧化硅)：5％；Low cost reinforcing filler (specifically silica): 5%;
颜料(具体为炭黑)：0.7％。Pigment (specifically carbon black): 0.7%.
为对本申请实施例的技术方案带来的有益效果进行有力支持，特提供各实施例的团状模塑料(BMC)的性能测试结果(参见表1)。In order to strongly support the beneficial effects brought by the technical solutions of the embodiments of the present application, the performance test results of the bulk molding compounds (BMCs) of the respective embodiments are provided (see Table 1).
表1 各实施例中BMC的性能测试结果The performance test result of BMC in each embodiment of table 1
测试项目Test items 实施例1Example 1 实施例2Example 2 实施例3Example 3
密度(g/cm 3) Density (g/cm 3 ) 1.81.8 1.821.82 1.811.81
导热系数(W/(m·K))Thermal conductivity (W/(m·K)) 1.81.8 1.71.7 1.61.6
弯曲强度(Mpa)Bending Strength(Mpa) 120120 130130 130130
冲击强度(kJ/m 2) Impact Strength (kJ/m 2 ) 2020 2525 24twenty four
线膨胀系数(10 -6/K) Linear expansion coefficient (10 -6 /K) 1212 1212 1313
成型收缩率Mold shrinkage 0.05％0.05% 0.02％0.02% 0.03％0.03%
燃烧性UL-94Flammability UL-94 5VA5VA 5VA5VA 5VA5VA
1.82MPa热变形温度(℃)1.82MPa heat distortion temperature (℃) 200200 200200 200200
灼热丝起燃性温度(℃)Glow wire ignition temperature (℃) 850850 850850 850850
吸水率water absorption 0.04％0.04% 0.03％0.03% 0.04％0.04%
漏电起痕性(V)Tracking (V) 600600 600600 600600
耐电弧性(s)Arc resistance (s) 180180 180180 180180
从表1中可以获知，本申请实施例提供的BMC的密度不超过2g/cm 3，一般在1.8g/cm 3左右，导热系数在1.6W/(m·K)以上，冲击强度在20kJ/cm 2以上，弯曲强度在120MPa以上，线膨胀系数≤16×10 -6/K，成型收缩率较低，在0.01％-0.1％，热变形温度低，性能稳定；且其不易起燃。 It can be known from Table 1 that the density of the BMC provided in the examples of this application does not exceed 2g/cm 3 , generally around 1.8g/cm 3 , the thermal conductivity is above 1.6W/(m·K), and the impact strength is 20kJ/ cm 2 above, the bending strength is above 120MPa, the linear expansion coefficient is ≤16×10 -6 /K, the molding shrinkage rate is low, at 0.01%-0.1%, the thermal deformation temperature is low, and the performance is stable; and it is not easy to ignite.
为了进一步支持本申请实施例的技术方案带来的有益效果，将各实施例的BMC材料分别注塑成LED显示屏的底壳(如图3所示)，测试各底壳的重量，按BS476-7 Class 1和BS 476-6 Class 0对各底壳进行防火阻燃认证。此外，还将各底壳装配成如上述图2所示的显示模组、再装配成图1所示的显示屏，测试显示屏的温度；其中，灯珠1211、印刷电路板1210、底壳122分别与热电偶连接。另外，还通过压铸法将ADC12压铸铝合金制成相同体积的底壳、将PC+10％GF的复合材料也注塑成相同体积的底壳，并装配成LED显示屏。将它们的性能测试结果汇总在下表2。In order to further support the beneficial effects brought about by the technical solutions of the embodiments of the present application, the BMC materials of each embodiment were injection-molded into the bottom case of the LED display screen (as shown in Figure 3), and the weight of each bottom case was tested according to BS476- 7 Class 1 and BS 476-6 Class 0 are fire retardant certified for each bottom shell. In addition, each bottom case is assembled into the display module shown in FIG. 2 above, and then assembled into the display screen shown in FIG. 1, and the temperature of the display screen is tested; wherein, the lamp beads 1211, the printed circuit board 1210, the bottom case 122 are respectively connected with thermocouples. In addition, the ADC12 die-casting aluminum alloy was also made into the bottom case of the same volume by the die-casting method, and the PC+10% GF composite material was also injected into the bottom case of the same volume, and assembled into an LED display. Their performance test results are summarized in Table 2 below.
表2 由本申请的BMC制成的底壳与其他材料制成的底壳的性能对比Table 2 Performance comparison between the bottom case made of BMC of the present application and the bottom case made of other materials
Figure PCTCN2021072893-appb-000001
Figure PCTCN2021072893-appb-000001
Figure PCTCN2021072893-appb-000002
Figure PCTCN2021072893-appb-000002
从表2可以获知，相较于PC+10％GF制成的底壳，由本申请BMC制成的底壳可以通过BS 476-6 Class 0及BS476-7 Class 1防火阻燃认证，同时LED显示屏的温度可下降3℃～5℃；相较于ADC12制成的底壳，由本申请BMC制成的底壳能在通过BS 476-6 Class 0及BS476-7 Class 1防火阻燃认证的前提下，还具有更轻的质量，成本也更低。It can be known from Table 2 that, compared with the bottom case made of PC+10% GF, the bottom case made of BMC of the present application can pass BS 476-6 Class 0 and BS476-7 Class 1 fire and flame retardant certification, and the LED display The temperature of the screen can be lowered by 3°C to 5°C; compared with the bottom case made of ADC12, the bottom case made of BMC of this application can pass the BS 476-6 Class 0 and BS476-7 Class 1 fire and flame retardant certifications. It also has lighter weight and lower cost.
以上实施例仅表达了本申请的示例性实施方式，其描述较为具体和详细，但并不能因此而理解为对本申请专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不脱离本申请构思的前提下，还可以做出若干变形和改进，这些都属于本申请的保护范围。因此，本申请专利的保护范围应以所附权利要求为准。The above embodiments only represent exemplary embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the scope of the present application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (15)

  1. 一种团状模塑料，其特征在于，所述团状模塑料包括如下质量百分含量的各组分：A bulk molding compound, characterized in that the bulk molding compound comprises the following components by mass percentage:
    不饱和树脂：15％～20％；Unsaturated resin: 15%～20%;
    低收缩剂：7％～10％；Low shrinkage agent: 7%～10%;
    稀释单体：10％～15％；Diluted monomer: 10% to 15%;
    引发剂：0.2％～0.5％；Initiator: 0.2%～0.5%;
    增稠剂：0～0.05％；Thickener: 0～0.05%;
    内脱模剂：0～1.5％；Internal release agent: 0～1.5%;
    阻聚剂：0～0.05％；Inhibitor: 0～0.05%;
    阻燃剂：25％～30％；Flame retardant: 25%～30%;
    纤维增强体：6％～10％；Fiber reinforcement: 6% to 10%;
    高导热填料：20％～30％；High thermal conductivity filler: 20% to 30%;
    颜料：0～1％。Pigment: 0～1%.
  2. 如权利要求1所述的团状模塑料，其特征在于，所述高导热填料包括氧化铝、氧化锌、氧化镁、碳化硅、氮化铝、氮化硼、纤维状碳粉、鳞片状碳粉中的一种或多种。The bulk molding compound of claim 1, wherein the high thermal conductivity filler comprises aluminum oxide, zinc oxide, magnesium oxide, silicon carbide, aluminum nitride, boron nitride, fibrous carbon powder, and flake carbon one or more of the powders.
  3. 如权利要求2所述的团状模塑料，其特征在于，所述高导热填料为氧化铝、碳化硅和氮化铝中的一种或多种。The bulk molding compound according to claim 2, wherein the high thermal conductivity filler is one or more of aluminum oxide, silicon carbide and aluminum nitride.
  4. 如权利要求1所述的团状模塑料，其特征在于，所述阻燃剂包括氢氧化铝、氢氧化镁、硼酸锌、三氧化二锑、五氧化锑、红磷、聚磷酸铵、磷酸氢二中的一种或多种。The bulk molding compound of claim 1, wherein the flame retardant comprises aluminum hydroxide, magnesium hydroxide, zinc borate, antimony trioxide, antimony pentoxide, red phosphorus, ammonium polyphosphate, phosphoric acid One or more of hydrogen bis.
  5. 如权利要求4所述的团状模塑料，其特征在于，所述阻燃剂包括氢氧化铝和氢氧化镁中的至少一种。The bulk molding compound of claim 4, wherein the flame retardant comprises at least one of aluminum hydroxide and magnesium hydroxide.
  6. 如权利要求1所述的团状模塑料，其特征在于，所述纤维增强体包括玻璃纤维和碳纤维中的一种或多种。The bulk molding compound of claim 1, wherein the fiber reinforcement comprises one or more of glass fibers and carbon fibers.
  7. 如权利要求1所述的团状模塑料，其特征在于，所述增稠剂在所述团状模塑料中的质量百分含量为0.01％～0.05％；所述增稠剂选自氧化镁、氧化钙、氢氧化钙中的至少一种。The bulk molding compound according to claim 1, wherein the mass percentage content of the thickener in the bulk molding compound is 0.01% to 0.05%; the thickener is selected from magnesium oxide , at least one of calcium oxide and calcium hydroxide.
  8. 如权利要求1-7任一项所述的团状模塑料，其特征在于，所述内脱模剂在所述团状模塑料中的质量百分含量为0.5％～1.5％。The bulk molding compound according to any one of claims 1-7, wherein the mass percentage content of the internal mold release agent in the bulk molding compound is 0.5% to 1.5%.
  9. 如权利要求1-8任一项所述的团状模塑料，其特征在于，所述阻聚剂在所述团状模塑料中的质量百分含量为0.01％～0.05％。The bulk molding compound according to any one of claims 1-8, wherein the mass percentage content of the polymerization inhibitor in the bulk molding compound is 0.01% to 0.05%.
  10. 如权利要求1-9任一项所述的团状模塑料，其特征在于，所述团状模塑料中还包括质量百分含量为0.1％～10％的低成本增强填料；所述低成本增强填料包括碳酸钙、硫酸钡、二氧化硅、二氧化钛中的一种或多种。The bulk molding compound according to any one of claims 1-9, characterized in that, the bulk molding compound further comprises a low-cost reinforcing filler with a mass percentage content of 0.1% to 10%; The reinforcing filler includes one or more of calcium carbonate, barium sulfate, silicon dioxide, and titanium dioxide.
  11. 如权利要求1-10任一项所述的团状模塑料，其特征在于，所述颜料在所述团状模塑料中的质量百分含量为0.5％～1％。The bulk molding compound according to any one of claims 1-10, wherein the mass percentage content of the pigment in the bulk molding compound is 0.5% to 1%.
  12. 如权利要求1-11任一项所述的团状模塑料，其特征在于，所述团状模塑料的导热系数在1.6W/(m·K)以上。The bulk molding compound according to any one of claims 1 to 11, wherein the bulk molding compound has a thermal conductivity of 1.6 W/(m·K) or more.
  13. 如权利要求1-12任一项所述的团状模塑料，其特征在于，所述团状模塑料的密度小于或等于2g/cm 3。 The bulk molding compound according to any one of claims 1 to 12, wherein the bulk molding compound has a density of less than or equal to 2 g/cm 3 .
  14. 如权利要求1-13任一项所述的团状模塑料，其特征在于，所述团状模塑料的弯曲强度在120MPa以上。The bulk molding compound according to any one of claims 1 to 13, wherein the flexural strength of the bulk molding compound is above 120 MPa.
  15. 一种LED显示屏，所述LED显示屏包括底壳，所述底壳通过权利要求1-14任一项所述的团状模塑料加工成型。An LED display screen, the LED display screen comprises a bottom case, and the bottom case is processed and formed by the mass molding compound according to any one of claims 1-14.
PCT/CN2021/072893 2021-01-20 2021-01-20 Bulk molding compound and led display screen using same WO2022155815A1 (en)

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CN1344429A (en) * 1999-03-19 2002-04-10 量子组合物公司 Highly conductive molding compounds and fuel cell bipolar plates comprising these compounds
WO2006041553A1 (en) * 2004-10-08 2006-04-20 Reichhold, Inc. Crosslinkable polymer systems
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