CN102134383A - Light scattering polycarbonate composition for light emitting diode (LED) lighting and use thereof - Google Patents

Abstract

The invention discloses a light-scattering polycarbonate composition for LED lighting and an application thereof. It includes polycarbonate and a light-scattering agent, the light-scattering agent is a core-shell type light-scattering agent powder, the core-shell type light-scattering agent powder is made of glass microspheres, silicon dioxide, polysiloxane microspheres or poly Styrene as the core, acrylate polymer or methacrylate polymer as the shell. Compared with other light-scattering compositions, the light-scattering polycarbonate composition for LED lighting of the present invention has better transparency and more excellent uniform light effect. The composition of the invention can be used to prepare shell materials in the fields of lighting or display such as LED lamps, fluorescent lamps, and incandescent lamps.

Description

Light-scattering polycarbonate composition for LED lighting and its application

technical field

The invention relates to an LED lamp housing material, in particular to a light-scattering polycarbonate composition for LED lighting and an application thereof.

Background technique

With the rapid development of my country's social economy and the increasing depletion of non-renewable energy resources, people's requirements for environmental protection and energy conservation are getting higher and higher, which will inevitably lead people to pay more attention to the popularization and use of light-emitting diode (LED) lighting. Due to the advantages of energy saving, environmental protection, and long life, LED lighting has a very broad application prospect, such as permanent lights in tunnels, decoration and lighting facilities used by enterprises, lighting devices in municipal facilities, high-end auto parts, high-end home lighting, etc. In 2009, China launched the "Ten Cities, Ten Thousand Lamps" semiconductor lighting application project, which covers 21 domestic developed cities such as Beijing, Shanghai, Shenzhen, and Wuhan. There are similar LED lighting popularization or research and development plans abroad, such as the "Solid State Lighting Plan" in the United States, the "Rainbow Plan" in Europe and the "21st Century Lighting Plan" in Japan. Taiwan Topology predicts that the global demand for LED street lamps will double to 2.5 million this year, with an annual growth rate of 178%.

With the rapid development of the LED lighting industry, the use of LED lamp housing materials, that is, light-scattering materials, is also increasing rapidly. There are two main requirements for the use of light-scattering materials. One is that the light transmittance should be above 80%, and the other is that it has a light-scattering rate (also called haze) of more than 90% to achieve a soft uniform light effect. Excellent light scattering materials should have high light transmittance and high haze index at the same time. It can convert point and line light sources into line and surface light sources. It has the advantages of large scattering angle, good light guiding and uniform light transmission. At present, the domestic light scattering materials mainly use polymethyl methacrylate as the matrix resin, and the research on light scattering materials basically remains in the empirical science. Housing materials for LED lighting in the Chinese market mainly rely on imports, and the price is relatively high, which seriously hinders the development of the LED lighting industry. Domestic patents on light-diffusing polycarbonate are basically applied by foreign companies such as Mitsubishi, Sumitomo, and Idemitsu, such as Idemitsu Kosan's patent "light-diffusing resin composition" (patent number 200580011385.0) and "light Diffusion polycarbonate resin composition and light diffusion plate using the resin composition” (Patent No. 200680024308.3), the patent of Mitsubishi Engineering Plastics Co., Ltd. and Mitsubishi Gas Chemical Co., Ltd. “Polycarbonate resin combination for light diffusion plate Materials and Light Diffusion Plate" (Patent No. 200680044508.5), these patents are mainly aimed at the application field of liquid crystal displays, the polycarbonate composition used is mainly some polycarbonate copolymers, the molecular weight and viscosity of polycarbonate are strictly required, and The preparation of the light diffusing agent is also relatively complicated.

At present, most new light scattering materials are prepared by blending transparent polymer matrix and scattering agent particles. The particles used as light scattering agents mainly include inorganic particles, such as glass microspheres, silicon dioxide and other substances, and organic polymer particles, including polyglycidyl methacrylate, polystyrene, silicone resin and the like. Compared with inorganic and organic light scattering materials, the latter has a wider range of applications. Inorganic light scattering agent only enlarges its scattering effect, and because of the large diameter of inorganic particles, it also reflects part of the light source. In addition, because the refractive index of transparent polymer materials generally does not match that of inorganic nanofillers, the prepared inorganic nanoparticles/polymer composites inevitably have light scattering, and it is difficult to prepare inorganic nanoparticles with high transparency. Nanoparticle/polymer composites.

Contents of the invention

The object of the present invention is to provide a light-scattering polycarbonate composition for LED lighting with good transparency and light uniformity for the defects of the existing light-scattering materials such as low light transmittance and haze.

The object of the present invention is also to provide the application of the light-scattering polycarbonate composition for LED lighting.

The light-scattering polycarbonate composition for LED lighting of the present invention comprises the following components in parts by mass:

Polycarbonate resin 91～99.89 parts

Light scattering agent powder 0.01～8 parts

Antioxidant 0.1～1 parts

The polycarbonate resin is an optical grade polycarbonate, with a weight-average molecular weight of 15000-25000, a light transmittance>89%, and a melt index of 50-75g/10min.

The light-scattering agent powder is a core-shell type light-scattering agent powder, which is prepared by seed emulsion polymerization. Add an acrylate polymer or a methacrylate polymer or a mixture of the two, then add a crosslinking agent and an initiator, and then initiate the reaction, so that the second polymer is crosslinked and polymerized on the surface of the seed latex particle to form Particles with a core-shell structure.

The above-mentioned light-scattering powder is preferably a light-scattering powder with polysiloxane microspheres as the core and polyglycidyl methacrylate as the shell.

The acrylic polymer is polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyglycidyl acrylate, polyhydroxyethyl acrylate, polyhydroxypropyl acrylate or polyacrylate 2-ethylhexyl A kind of; methacrylate polymers are polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polyglycidyl methacrylate, polyhydroxyethyl methacrylate, poly One of hydroxypropyl methacrylate or 2-ethylhexyl methacrylate.

The antioxidant is a phosphite antioxidant or a hindered phenolic antioxidant. Among them, the phosphite antioxidants are triethyl phosphite, triisopropyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenylisodecyl phosphite and triphenylisodecyl phosphite. More than one of phenyl phosphite; hindered phenolic antioxidant is more than one of 2,6-di-tert-butyl-4-methylphenol, antioxidant 1010 or antioxidant 1076.

The light scattering agent powder is a polymer layer with a shell thickness of 0.3-1.5 μm, and the thickness is preferably 0.7-1.2 μm, because when the thickness of the polymer layer is greater than 0.3 μm, it can ensure that it is blended with polycarbonate before blending. After blending, the distance between the light scattering agents is greater than 0.8 μm, and the wavelength of visible light is between 390 nm and 780 nm, which means that more visible light can be transmitted and the transparency of polycarbonate is increased.

In the light-scattering polycarbonate composition for LED lighting of the present invention, the refractive index of the core-shell type light-scattering agent powder is preferably 1.5 to 1.7, because the refractive index of the polycarbonate resin is also in this range, which can increase Transparency of thin polycarbonate products. The particle size of the light-scattering polycarbonate composition is limited to 1-20 μm, preferably 5-15 μm. Because when the particle size is less than 1 μm, it is easy to cause agglomeration due to the increase of the surface area. When the particle size is greater than 20 μm, the reflection and refraction of the light scattering agent powder in the polycarbonate are enhanced, thereby reducing the transparency of the polycarbonate sheet. Likewise, the mass fraction of the core-shell type light scattering agent powder is 0.01-8 parts, preferably 0.05-6 parts. Because when the mass part is less than 0.01 part, the uniform light effect is reduced due to the small amount of light scattering. When the mass part is greater than 8 parts, the reflection and refraction of the light scattering agent in polycarbonate are very strong, and the polycarbonate will also be reduced. The transparency of the ester sheet.

The application of the light-scattering polycarbonate composition for LED lighting of the present invention comprises the following steps: mix 91-99.89 parts of polycarbonate resin, 0.01-8 parts of light-scattering agent powder, and 0.1-1 part of antioxidant Finally, dry at 120°C for 4 hours, extrude and granulate through a twin-screw extruder, the temperature of each area of the twin-screw extruder should be kept at 200-300°C, then cool, dry, pelletize and pack to obtain the LED lamp shell Material.

In the light-scattering polycarbonate composition for LED lighting of the present invention, the core-shell type light-scattering agent powder is coated with a polymer layer with a thickness of 0.3-1.5 μm before being compounded with polycarbonate, that is, it is prepared first. A light-scattering agent with a core-shell structure can be uniformly dispersed with the polycarbonate matrix, and the light-scattering agent and polycarbonate can be effectively adjusted by adjusting the type, particle size and layer thickness of the light-scattering agent core layer and shell layer. The degree of matching of the refractive index achieves high transparency.

Compared with the prior art, the present invention has the following advantages:

(1) Compared with other light-scattering agent compositions, the light-scattering polycarbonate composition of the present invention has better transparency and more excellent uniform light effect.

(2) The light-scattering polycarbonate composition of the present invention can be used to prepare housing materials for lighting or display fields such as LED lamps, fluorescent lamps, and incandescent lamps.

Detailed ways

Example 1

The light scattering agent (particle size: 10 μm, polyglycidyl methacrylate shell thickness 0.7 μm) with polysiloxane microspheres as the core and polyglycidyl methacrylate as the shell in 4 parts by mass , 95.99 parts by mass of polycarbonate with a melt index of 50 g/10min and 0.01 part by mass of triethylphosphite antioxidant are mixed and dried at 120°C for 4 hours, and passed through a twin-screw extruder For extrusion granulation, the temperature of each zone of the twin-screw extruder should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 81.3%, and the haze is 90.5%.

Example 2

The light scattering agent (particle diameter is 12 μ m, polymethyl methacrylate shell thickness 0.8 μ m) with silicon dioxide as the core and polymethyl methacrylate as the shell in parts by mass, the number of parts by mass is 96.95 parts of polycarbonate with a melt index of 55g/10min and 0.05 parts by mass of triisopropyl phosphite antioxidant were mixed and dried at 120°C for 4 hours, extruded and granulated by a twin-screw extruder , The temperature of each zone of the twin-screw extruder should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 80.4%, and the haze is 91.2%.

Example 3

2 parts by mass of a light-scattering agent with glass microspheres as the core and polybutylacrylate as the shell (the particle diameter is 12 μm, the thickness of the polybutylacrylate shell layer is 0.9 μm), and 97.90 parts by mass of the molten Polycarbonate with an index of 60g/10min and a triisodecyl phosphite antioxidant with a mass fraction of 0.1 part were mixed and dried at 120°C for 4 hours, extruded and granulated by a twin-screw extruder, and twin-screw extruded The temperature of each area of the extruder screw should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 80.1%, and the haze is 93.4%.

Example 4

6 parts by mass of polysiloxane microspheres as the core and polybutyl acrylate as the shell light scattering agent (particle size is 12 μm, polybutylacrylate shell thickness 1.0 μm), the mass part is 93.85 Parts of polycarbonate with a melt index of 65g/10min and 0.15 parts by mass of trilauryl phosphite antioxidant were mixed and dried at 120°C for 4 hours, extruded and granulated by a twin-screw extruder. The temperature of each zone of the screw of the screw extruder should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 83.2%, and the haze is 92.6%.

Example 5

The light scattering agent (particle diameter is 11 μ m, polyglycidyl methacrylate shell thickness 1.2 μ m) with glass microspheres as the core and polyglycidyl methacrylate as the shell in parts by mass, parts by mass 97.80 parts of polycarbonate with a melt index of 70g/10min and 0.20 parts by mass of triphenylphosphite antioxidant were mixed and dried at 120°C for 4 hours, and extruded by a twin-screw extruder to produce The temperature of each zone of the twin-screw extruder should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 81.2%, and the haze is 91.4%.

Example 6

8 parts by mass of polysiloxane microspheres as the core, polybutylacrylate as the shell of light scattering agent (particle size is 12 μm, polybutylacrylate shell thickness of 1.1 μm), the number of parts by mass is 91 1 part of polycarbonate with a melt index of 75g/10min and 1 part by mass of 2,6-di-tert-butyl-4-methylphenol antioxidant were mixed and dried at 120°C for 4 hours, and extruded by twin-screw Extrusion and granulation, the temperature of each zone of the twin-screw extruder should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 82.3%, and the haze is 91.7%.

Example 7

The light scattering agent (particle size is 12 μ m, polymethyl methacrylate shell thickness 0.8 μ m) with polystyrene as the core and polymethyl methacrylate as the shell of 0.01 parts by mass, the number of parts by mass is 99.89 parts of polycarbonate with a melt index of 75g/10min and 0.1 part by mass of antioxidant 1010 were mixed, dried at 120°C for 4 hours, extruded and granulated by a twin-screw extruder, and the twin-screw extruder The temperature of each zone of the screw should be kept at 200-300°C, then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. After measurement, the light transmittance of the 2mm thick LED lamp shell material is 80.6%, and the haze is 92.8%.

Claims (8)

1. A light-scattering polycarbonate composition for LED lighting, characterized in that it comprises polycarbonate and a light-scattering agent, and the light-scattering agent is a core-shell type light-scattering agent powder, and the core-shell type light-scattering agent powder The body uses glass microspheres, silicon dioxide, polysiloxane microspheres or polystyrene as the core, and acrylate polymer or methacrylate polymer as the shell; it consists of the following components in parts by mass : Polycarbonate resin 91～99.89 parts Light scattering agent powder 0.01～8 parts Antioxidant 0.1～1 parts The polycarbonate resin is an optical grade polycarbonate, with a weight-average molecular weight of 15000-25000, a light transmittance>89%, and a melt index of 50-75g/10min. 2. The composition according to claim 1, wherein the light-scattering agent powder is prepared by seed emulsion polymerization, comprising: first containing glass microspheres, silicon dioxide, polysiloxane microspheres or Add acrylic polymer or methacrylic polymer or a mixture of the two to the seed emulsion of polystyrene, add crosslinking agent and initiator, and then initiate the reaction, so that the second polymer is on the surface of the seed latex particle Carry out cross-linking polymerization to generate particles with a core-shell structure. 3. The composition according to claim 1 or 2, characterized in that the thickness of the shell of the light scattering agent powder is 0.3-1.5 μm. 4. The composition according to claim 3, characterized in that the refractive index of the light scattering agent powder is 1.5 to 1.7, polysiloxane microspheres with a diameter of 2 to 4 μm are used as the core, and polymethacrylic acid shrinks The glyceride is the shell, and the thickness of the shell is 0.7-1.2 μm; it is obtained by coating the microsphere with a polyglycidyl methacrylate layer by free radical emulsion polymerization technology. 5. composition according to claim 2, it is characterized in that described acrylate polymer is polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyglycidyl acrylate, polyhydroxyethyl acrylate, One of polyhydroxypropyl acrylate or poly 2-ethylhexyl acrylate; methacrylate polymers are polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polymethacrylate One of glycidyl acrylate, polyhydroxyethyl methacrylate, polyhydroxypropyl methacrylate or 2-ethylhexyl methacrylate. 6. The composition according to claim 1, wherein the antioxidant is a phosphite antioxidant or a hindered phenolic antioxidant; wherein the phosphite antioxidant is triethylphosphorous acid One or more of ester, triisopropyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenylisodecyl phosphite and triphenyl phosphite; hindered phenols The antioxidant is more than one of 2,6-di-tert-butyl-4-methylphenol, antioxidant 1010 or antioxidant 1076. 7. The application of the composition according to any one of claims 1 to 6 in the preparation of LED lamp housing materials, characterized in that polycarbonate resin, light scattering agent powder, and antioxidant are mixed and dried, and then extruded by twin-screw The temperature of each area of the screw of the twin-screw extruder is kept at 200-300°C, and then cooled, dried, pelletized and packaged to obtain the LED lamp housing material. 8. The application according to claim 7, characterized in that the polycarbonate resin, light scattering agent powder, and antioxidant are mixed and dried at 120°C for 4 hours; the particle size of the LED lamp shell material is 1- 20 μm.