Transparent addable curable LED filament packaging silicone

Abstract

The invention discloses transparent addable curable LED filament packaging silicone which is characterized by comprising the following components in parts by weight: 50-100 parts of methyl phenyl vinyl silicone resin, 4-30 parts of phenyl hydrogen-containing silicon resin, 5-15 parts of HDK.H2O fumed silica, 0.5-2 parts of gamma-glycidyloxypropyltrimethoxysilane or gamma-methacryloxypropyltrimethoxysilane, 0.02 part of addition reaction catalyst (1,3-platinum divinyltetramethyldisiloxane complex) and 0.02 part of inhibitor (1-ethynylcyclohexanol). The phenyl silicone rubber has the light transmittance of more than 95%, has a remarkable reinforcing effect, is good in rebound resilience and high in tear resistance, tensile strength and break elongation rate and has a remarkable, stable and consistent thixotropic effect.

Description

technical field [0001] The invention relates to LED packaging silica gel, in particular to a transparent addition-curable LED filament packaging silica gel. Background technique [0002] LED filament encapsulation silicone, used in the filament encapsulation process of emerging 360-degree full-circle luminous LED bulb lamps. LED filament packaging is different from the traditional PLCC single LED packaging form. It uses glass filament as the substrate, connects dozens of LED chips in series, and encapsulates it with organic silica gel mixed with phosphor powder. A bulb lamp is usually connected in series with 2~4 such filaments, which are fixed in the center of the bulb lamp like the luminous tungsten filament of a traditional incandescent lamp, which can achieve 360-degree full-circle lighting. [0003] Filament glue requires instant setting after dispensing, no deformation when pre-baked at 60~80°C, and maintains the initial dispensing size and shape until it is completel...

AI Technical Summary

Problems solved by technology

[0004] Fumed silica can be used to adjust the thixotropy of LED packaging adhesives. Many filament LED manufacturers use ordinary packaging silica gel and fumed silica to make filament adhesives during the packaging and trial production process, but they encounter many problems: such as mixing uniformity The problem is that highly thixotropic materials can only flow under high-speed shear conditions, so when the thixotropic powder is added to a certain amount, the stirring and mixing efficiency decreases, and the thixotropic powder is difficult to be "eaten" into the colloid and form a uniform mixture; Consistency problem, fumed silica itself is easy to agglomerate, and different degrees of agglomeration occur locally under the action of different shear forces and standing time after mixing, so that the mixture cannot guarantee a high consistency; such as the problem of light transmittance reduction, due to ordinary stirring The dispersion efficiency of the process is low. After adding more than 15% mass fraction of silica, the colloidal light transmittance is often reduced to less than 70%, which affects the luminous effect of the bulb

The study found that due to the thermoplasticity of phenyl materials, temperature has a great influence on their properties. When the phenyl content is less than 20%, the introduction of phenyl groups will significantly reduce the properties of phenyl materials, such as tensile strength, resistance The tear strength is very low. When the phenyl content reaches 35-50%, the performance of the phenyl material will be greatly improved, showing a certain tensile and tear strength. When the phenyl content exceeds 50%, the phenyl material will The thermoplastic change is obvious, it is difficult to use normally

Therefore, the phenyl content of phenyl silica gel currently on the market is between 35% and 50%, and the refractive index is between 1.50 and 1.54. To synthesize low phenyl content, the refractive index is between 1.45 and 1.48, and the mechanical properties are excellent. Phenyl silica gel is more difficult to achieve