CN104503013A - Light emitting diode (LED) fluorescent transparent polycarbonate grating and production method thereof - Google Patents

Abstract

The invention discloses a light emitting diode (LED) fluorescent transparent polycarbonate grating and a production method thereof. The method comprises the following steps of: material screening, preparing, mixing, drying, preparing additives, mixing, smelting, forming, annealing, etching and packaging, wherein the forming step, uniformly-mixed fluorescent polycarbonate obtained by melting is directly subject to injection molding in a mold in a bead shape by using a twin-screw extrusion method. According to the method, the direct injection molding method is used to save the step of polishing, so that the transmittance rate cannot be reduced by polishing; laser cutting in the prior art is omitted, so that a fluorescent material cannot lose the activity at high temperature; because the thickness is large, so that the fluorescent material can be prevented from losing the activity to the maximum extent; and the fluorescent transparent polycarbonate sheet surface etching grating can solve the problems of glare and uneven light distribution of an LED. The LED fluorescent transparent polycarbonate grating and the production method thereof can be widely applied in the field of the LEDs.

Description

A kind of LED fluorescent transparent polycarbonate grating and preparation method thereof

technical field

The invention relates to the field of LEDs, in particular to an LED fluorescent transparent polycarbonate grating and a preparation method thereof.

Background technique

White LED is considered as a "green lighting source" because of its significant advantages such as high efficiency, low power consumption, long life, solid-state energy saving, and environmental protection. It is expected to become the third generation of lighting source after incandescent lamps and fluorescent lamps. development potential. At present, domestic enterprises generally adopt high-power white LEDs, mainly by adding phosphor powder on blue LED chips to achieve white light. However, it is difficult to control the coating thickness and shape of phosphor powder in this packaging process, resulting in the uniformity of color temperature of LED devices. Still not ideal, even the angular color temperature difference of a single LED can be as large as 800K, while the color temperature difference that human eyes can distinguish is 50-100K. On the other hand, the existing LED lamp beads/luminaires generally use the LED light source to emit directly into the lighting space (usually the ground). Because the light emitted by the LED is not uniform, it is more irritating to the human eye and seriously affects the LED lamp. The lighting effect is easy to cause visual fatigue and even vision loss. This is the light pollution-glare problem that often exists in LED lamp beads/lamps.

Chinese invention patent CN102337017A discloses a polycarbonate composition with LED light conversion function and its application, which is characterized in that polycarbonate resin, additives (additives include: phosphor, flame retardant, antioxidant, mold release agent, weather resistance agent) mixed in a certain proportion and melted and extruded by a screw extruder. There are no coupling agents and dispersants in these additives, which will lead to uneven dispersion of phosphor powder during the extrusion molding process, resulting in polycarbonate The light transmittance of the ester composition decreases, it is difficult to obtain a light conversion material with excellent performance, and the optical performance of the material will be adversely affected after long-term use.

Contents of the invention

In order to solve the above-mentioned technical problems, the object of the present invention is to provide a fluorescent sheet with uniform thickness, smooth surface and uniform phosphor distribution, and with a specific grating design on the surface of the fluorescent sheet. The color temperature of LED lamp beads/lamps can be effectively controlled in lamp beads/lamps, and the glare problem of LED lamp beads/lamps can be effectively solved at the same time

The technical solution adopted in the present invention is: a preparation method of LED fluorescent transparent polycarbonate grating, comprising the following steps:

A, sieve material, screen out the polycarbonate powder that particle diameter is 30-90um with 150 purpose experiments;

B, prepare materials, take phosphor powder by component mass ratio, particle diameter is 30-90um polycarbonate;

C. Mixing, put the polycarbonate powder and fluorescent powder into a variable frequency planetary ball mill for mixing, the speed of the variable frequency planetary ball mill is 160-250r/min, and the mixing time is 1-5h to obtain a compound;

D, drying, put the mixed material into a vacuum constant temperature drying oven to dry, the drying temperature is 50-120 ℃, and the drying time is 3-20h, to obtain a dried mixed material, the maximum moisture content of the polycarbonate powder is less than 0.020%;

E, compounding auxiliary agent, weigh antioxidant and light diffusing agent according to the mass ratio of components;

F, mixing, mixing the dry mixture and additives to obtain evenly mixed raw materials;

G, banburying, put the uniformly mixed raw materials in the step F into the banbury mixer, banbury 8-20 minutes, banbury temperature is 200-300 ℃, banbury mixer speed is 20-60r/min;

H, forming, adopting the twin-screw extrusion method to directly inject the homogeneously mixed fluorescent polycarbonate obtained by banburying in the required lamp bead-shaped abrasive tool;

1, annealing, the formed fluorescent transparent polycarbonate is placed in a certain temperature and slowly cooled to obtain a hard fluorescent transparent polycarbonate;

J. Etching, using a laser to etch the upper or lower surface of the fluorescent transparent polycarbonate into a grating with a special structure to obtain a LED fluorescent transparent polycarbonate sheet with a special optical structure;

K. Encapsulation, encapsulating the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure into LEDs to obtain LED lamp beads/lamps with adjustable color temperature.

Further, in the step E, wherein the mass ratio of the antioxidant is changed within the range of 0.1%-1% according to the actual demand, and the mass ratio of the light diffusing agent is changed within the range of 0.5%-1% according to the actual demand.

Further, the special structure described in step J is columnar, triangular or trapezoidal.

Another technical solution adopted in the present invention is: a kind of LED fluorescent transparent polycarbonate grating prepared according to the above method, and the fluorescent transparent polycarbonate grating includes the following components by mass ratio:

Further, the composition of the fluorescent powder is 5%-49.5% by mass ratio.

Further, the phosphor is yellow phosphor or red phosphor or a mixture of yellow phosphor and red phosphor.

Further, the mass ratio of the yellow fluorescent powder is 10%-25%.

Further, the mass ratio of the yellow phosphor is 20%, and the mass ratio of the red phosphor is 2%.

Further, the light diffusing agent is a silicone light diffusing agent.

Further, the light transmittance of the polycarbonate is not less than 91.0%, and the particle size of the polycarbonate powder is 30-90um.

The beneficial effects of the present invention are: in the method of the present invention, twin-screw extrusion method is used for direct injection molding, so that polishing on both sides or at least the light-emitting surface is not polished, so the transmittance will not be reduced by polishing; The laser cutting part in the technology avoids the deactivation of the fluorescent material at high temperature, and due to its large thickness, it can slow down and avoid the problem of the deactivation of the fluorescent material to a greater extent, by etching the grating on the surface of the fluorescent transparent polycarbonate sheet To improve the glare and uneven light distribution of LEDs.

Another beneficial effect of the present invention is: the grating of the present invention is directly injection-molded by twin-screw extrusion method, which can save polishing on both sides or at least the light-emitting surface is not polished, so the transmittance will not be reduced by polishing; Remove the laser cutting part in the prior art, avoid the loss of activity of the fluorescent material at high temperature, and due to its large thickness can slow down and avoid the problem of loss of activity of the fluorescent material to a greater extent, by engraving on the surface of the fluorescent transparent polycarbonate sheet The grating is etched to improve the glare and uneven light distribution of the LED; at the same time, the grating of the present invention can be combined with the epoxy resin lens during the packaging process, saving the processing technology.

Description of drawings

Fig. 1 is a flow chart of the main steps of the inventive method;

Fig. 2 is a schematic diagram a of the grating surface structure of the present invention;

Fig. 3 is a schematic diagram b of the grating surface structure of the present invention;

Fig. 4 is a schematic diagram c of the grating surface structure of the present invention;

Fig. 5 is a schematic structural diagram of a white light LED packaged in a fluorescent transparent polycarbonate grating in an example of the present invention.

Detailed ways

The specific embodiment of the present invention will be further described below in conjunction with accompanying drawing:

Referring to Fig. 1, a method for preparing a LED fluorescent transparent polycarbonate grating includes the following steps:

A, sieve material, screen out the polycarbonate powder that particle diameter is 30-90um with 150 purpose experiments;

B, prepare materials, take phosphor powder by component mass ratio, particle diameter is 30-90um polycarbonate;

C. Mixing, put the polycarbonate powder and fluorescent powder into a variable frequency planetary ball mill for mixing, the speed of the variable frequency planetary ball mill is 160-250r/min, and the mixing time is 1-5h to obtain a compound;

D, drying, put the mixed material into a vacuum constant temperature drying oven to dry, the drying temperature is 50-120 ℃, and the drying time is 3-20h, to obtain a dried mixed material, the maximum moisture content of the polycarbonate powder is less than 0.020%;

E, compounding auxiliary agent, weigh antioxidant and light diffusing agent according to the mass ratio of components;

F, mixing, mixing the dry mixture and additives to obtain evenly mixed raw materials;

G, banburying, put the uniformly mixed raw materials in the step F into the banbury mixer, banbury 8-20 minutes, banbury temperature is 200-300 ℃, banbury mixer speed is 20-60r/min;

H, forming, adopting the twin-screw extrusion method to directly inject the homogeneously mixed fluorescent polycarbonate obtained by banburying in the required lamp bead-shaped abrasive tool;

1, annealing, the formed fluorescent transparent polycarbonate is placed in a certain temperature and slowly cooled to obtain a hard fluorescent transparent polycarbonate;

J. Etching, using a laser to etch the upper or lower surface of the fluorescent transparent polycarbonate into a grating with a special structure to obtain a LED fluorescent transparent polycarbonate sheet with a special optical structure; The grating is etched on the surface of the sheet to improve the glare and uneven light distribution of the LED;

K. Encapsulation, encapsulating the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure into LEDs to obtain LED lamp beads/lamps with adjustable color temperature. As shown in Figure 5, it includes: fluorescent transparent polycarbonate grating 1 (upper surface 1a, lower surface 1b), LED chip 2, electrode 3, epoxy resin lens 4, heat dissipation substrate 5, reflective cup 6 and filling connector 7.

As a further preferred embodiment, in the step E, wherein the mass ratio of the antioxidant is changed in the range of 0.1%-1% according to the actual demand, and the mass ratio of the light diffusing agent is changed in the range of 0.5%-1% according to the actual demand.

As a further preferred embodiment, the special structure in step J is a column as shown in FIG. 2 , a triangle as shown in FIG. 3 or a trapezoid as shown in FIG. 4 .

A kind of LED fluorescent transparent polycarbonate grating prepared according to the above method, the fluorescent transparent polycarbonate grating includes the following components by mass ratio:

As a further preferred embodiment, the composition of the phosphor is 5%-49.5% by mass ratio.

Further as a preferred embodiment, the phosphor is yellow phosphor or red phosphor or a mixture of yellow phosphor and red phosphor; the glare and light distribution of the LED can be improved by etching the grating on the surface of the fluorescent transparent polycarbonate sheet uneven.

As a further preferred embodiment, the mass ratio of the yellow fluorescent powder is 10%-25%.

Further as a preferred embodiment, the mass ratio of the yellow phosphor is 20%, and the red phosphor is 2% by mass. Refer to the 18th group of data in Table 1 below. This group of data achieve the best results.

As a further preferred embodiment, the light diffusing agent is a silicone light diffusing agent.

Silicone light diffusing agent is a pure white regular spherical micropowder, which can form three-dimensional molecular chains in the resin, effectively disperse and absorb phosphor powder, make it evenly distributed, eliminate light spots and yellow circles, increase luminous flux, and improve resin flow at the same time. Denaturation, improve yield and consistency, different from the traditional process of using light refraction to achieve the purpose of removing light spots.

As a further preferred embodiment, the light transmittance of the polycarbonate is not less than 91.0%, and the particle size of the polycarbonate powder is 30-90um.

The specific embodiment of the present invention is illustrated below in conjunction with component mass ratio data form:

Embodiment 1: comprise the following steps:

A, sieve material, screen out the polycarbonate powder that particle diameter is 30-90um with 150 purpose experiments;

B, prepare materials, weigh the phosphor powder according to the mass ratio of the first group of components in Table 1, and the particle size is 30-90um polycarbonate; wherein the phosphor powder only weighs the yellow phosphor powder;

C. Mixing, put the polycarbonate powder and fluorescent powder into a variable frequency planetary ball mill for mixing, the speed of the variable frequency planetary ball mill is 160-250r/min, and the mixing time is 1-5h to obtain a compound;

D, drying, put the mixed material into a vacuum constant temperature drying oven to dry, the drying temperature is 50-120 ℃, and the drying time is 3-20h, to obtain a dried mixed material, the maximum moisture content of the polycarbonate powder is less than 0.020%;

E, adjuvant, weigh antioxidant, light diffusing agent according to the mass ratio of the first group of components in Table 1;

Among them, antioxidant 1010 and antioxidant 168 are selected as the antioxidant, and the mass ratio of antioxidant 1010 can be changed within the range of 0.1%-0.5% according to actual needs, and the mass ratio of antioxidant 168 can be changed within the range of 0.05%-1% according to actual needs. The mass ratio can be changed within the range of 0.5%-1% according to actual needs;

F, mixing, mixing the dry mixture and additives to obtain evenly mixed raw materials;

G, banburying, put the uniformly mixed raw materials in the step F into the banbury mixer, banbury 8-20 minutes, banbury temperature is 200-300 ℃, banbury mixer speed is 20-60r/min;

H, forming, adopting the twin-screw extrusion method to directly inject the homogeneously mixed fluorescent polycarbonate obtained by banburying in the required lamp bead-shaped abrasive tool;

1, annealing, the formed fluorescent transparent polycarbonate is placed in a certain temperature and slowly cooled to obtain a hard fluorescent transparent polycarbonate;

J. Etching, using a laser to etch the upper or lower surface of the fluorescent transparent polycarbonate into a grating with a special structure to obtain a LED fluorescent transparent polycarbonate sheet with a special optical structure; The grating is etched on the surface of the sheet to improve the glare and uneven light distribution of the LED;

K. Encapsulation, encapsulating the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure into LEDs to obtain LED lamp beads/lamps with adjustable color temperature.

Embodiment 2-7, the step flow is the same as that of embodiment 1, and the data used in the steps B and E are according to the data of the 2-7 groups in Table 1 respectively.

Embodiment 8: comprise the following steps:

A, sieve material, screen out the polycarbonate powder that particle diameter is 30-90um with 150 purpose experiments;

B, prepare materials, according to the 8th group component mass ratio of table 1, take phosphor powder, particle diameter is 30-90um polycarbonate; Wherein phosphor powder only weighs yellow phosphor powder;

C. Mixing, put the polycarbonate powder and fluorescent powder into a variable frequency planetary ball mill for mixing, the speed of the variable frequency planetary ball mill is 160-250r/min, and the mixing time is 1-5h to obtain a compound;

D, drying, put the mixed material into a vacuum constant temperature drying oven to dry, the drying temperature is 50-120 ℃, and the drying time is 3-20h, to obtain a dried mixed material, the maximum moisture content of the polycarbonate powder is less than 0.020%;

E, adjuvant, weigh antioxidant, light diffusing agent according to the mass ratio of the 8th group of the following table 1;

Among them, antioxidant 264 is selected as the antioxidant, and the mass ratio of antioxidant 264 can be changed within the range of 0.1%-1% according to the actual demand, and the mass ratio of the light diffusing agent can be changed within the range of 0.5%-1% according to the actual demand.

F, mixing, mixing the dry mixture and additives to obtain evenly mixed raw materials;

G, banburying, put the uniformly mixed raw materials in the step F into the banbury mixer, banbury 8-20 minutes, banbury temperature is 200-300 ℃, banbury mixer speed is 20-60r/min;

H, forming, adopting the twin-screw extrusion method to directly inject the homogeneously mixed fluorescent polycarbonate obtained by banburying in the required lamp bead-shaped abrasive tool;

1, annealing, the formed fluorescent transparent polycarbonate is placed in a certain temperature and slowly cooled to obtain a hard fluorescent transparent polycarbonate;

J. Etching, using a laser to etch the upper or lower surface of the fluorescent transparent polycarbonate into a grating with a special structure to obtain a LED fluorescent transparent polycarbonate sheet with a special optical structure; The grating is etched on the surface of the sheet to improve the glare and uneven light distribution of the LED;

K. Encapsulation, encapsulating the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure into LEDs to obtain LED lamp beads/lamps with adjustable color temperature.

Embodiment 9-14, the step flow is the same as that of embodiment 8, and the data used in Step B and Step E are according to the 9th-14th group data in Table 1 respectively.

Embodiment 15: comprise the following steps:

A, sieve material, screen out the polycarbonate powder that particle diameter is 30-90um with 150 purpose experiments;

B, prepare materials, according to the 8th group component mass ratio of table 1, take phosphor powder, particle diameter is 30-90um polycarbonate; Wherein phosphor powder is the mixture that yellow phosphor, red phosphor form;

C. Mixing, put the polycarbonate powder and fluorescent powder into a variable frequency planetary ball mill for mixing, the speed of the variable frequency planetary ball mill is 160-250r/min, and the mixing time is 1-5h to obtain a compound;

D, drying, put the mixed material into a vacuum constant temperature drying oven to dry, the drying temperature is 50-120 ℃, and the drying time is 3-20h, to obtain a dried mixed material, the maximum moisture content of the polycarbonate powder is less than 0.020%;

E, adjuvant, according to the weight ratio of the 15th group of components in Table 1, take antioxidant and light diffusing agent;

Among them, antioxidant 1010 and antioxidant 168 are selected as the antioxidant, and the mass ratio of antioxidant 1010 can be changed within the range of 0.1%-0.5% according to actual needs, and the mass ratio of antioxidant 168 can be changed within the range of 0.05%-1% according to actual needs. The mass ratio of the light diffusing agent can be changed within the range of 0.5%-1% according to actual needs.

F, mixing, mixing the dry mixture and additives to obtain evenly mixed raw materials;

G, banburying, put the uniformly mixed raw materials in the step F into the banbury mixer, banbury 8-20 minutes, banbury temperature is 200-300 ℃, banbury mixer speed is 20-60r/min;

H, forming, adopting the twin-screw extrusion method to directly inject the homogeneously mixed fluorescent polycarbonate obtained by banburying in the required lamp bead-shaped abrasive tool;

1, annealing, the formed fluorescent transparent polycarbonate is placed in a certain temperature and slowly cooled to obtain a hard fluorescent transparent polycarbonate;

J. Etching, using a laser to etch the upper or lower surface of the fluorescent transparent polycarbonate into a grating with a special structure to obtain a LED fluorescent transparent polycarbonate sheet with a special optical structure; The grating is etched on the surface of the sheet to improve the glare and uneven light distribution of the LED;

K. Encapsulation, encapsulating the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure into LEDs to obtain LED lamp beads/lamps with adjustable color temperature.

Embodiment 16-21, the step flow is the same as embodiment 15, and the data used in step B and step E are according to the 16th-21st group data in Table 1 respectively.

Embodiment 22: comprise the following steps:

A, sieve material, screen out the polycarbonate powder that particle diameter is 30-90um with 150 purpose experiments;

B, prepare materials, according to the 8th group component mass ratio of table 1, take phosphor powder, particle diameter is 30-90um polycarbonate; Wherein phosphor powder is the mixture that yellow phosphor, red phosphor form;

C. Mixing, put the polycarbonate powder and fluorescent powder into a variable frequency planetary ball mill for mixing, the speed of the variable frequency planetary ball mill is 160-250r/min, and the mixing time is 1-5h to obtain a compound;

D, drying, put the mixed material into a vacuum constant temperature drying oven to dry, the drying temperature is 50-120 ℃, and the drying time is 3-20h, to obtain a dried mixed material, the maximum moisture content of the polycarbonate powder is less than 0.020%;

E, adjuvant, according to the weight ratio of the 15th group of components in Table 1, take antioxidant and light diffusing agent;

Among them, antioxidant 264 is selected as the antioxidant, and the mass ratio of antioxidant 264 can be changed within the range of 0.1%-1% according to the actual demand, and the mass ratio of the light diffusing agent can be changed within the range of 0.5%-1% according to the actual demand.

F, mixing, mixing the dry mixture and additives to obtain evenly mixed raw materials;

G, banburying, put the uniformly mixed raw materials in the step F into the banbury mixer, banbury 8-20 minutes, banbury temperature is 200-300 ℃, banbury mixer speed is 20-60r/min;

H, forming, adopting the twin-screw extrusion method to directly inject the homogeneously mixed fluorescent polycarbonate obtained by banburying in the required lamp bead-shaped abrasive tool;

1, annealing, the formed fluorescent transparent polycarbonate is placed in a certain temperature and slowly cooled to obtain a hard fluorescent transparent polycarbonate;

J. Etching, using a laser to etch the upper or lower surface of the fluorescent transparent polycarbonate into a grating with a special structure to obtain a LED fluorescent transparent polycarbonate sheet with a special optical structure; The grating is etched on the surface of the sheet to improve the glare and uneven light distribution of the LED;

K. Encapsulation, encapsulating the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure into LEDs to obtain LED lamp beads/lamps with adjustable color temperature.

Embodiment 23-28, the step flow is the same as embodiment 22, and the data used in step B and step E are according to the 23-28th group data in Table 1 respectively.

Table 1: The mass ratio of each embodiment component

The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent transformations or replacements without violating the spirit of the present invention. These equivalent modifications or replacements are all within the scope defined by the claims of the present application.

Claims (10)

1. a LED fluorescent transparent polycarbonate grating preparation method, is characterized in that: include following steps:

A, sieve material, select with 150 object testing sieves the polycarbonate powder that particle diameter is 30-90um;

B, getting the raw materials ready, is 30-90um polycarbonate by constituent mass than weigh phosphor powder, particle diameter;

C, batch mixing, will take polycarbonate powder and fluorescent powder and insert in frequency conversion planetary ball mill and mix, frequency conversion planetary ball mill rotating speed is 160-250r/min, and incorporation time is 1-5h, obtains compound;

D, drying, compound is put into vacuum constant temperature drying box dry, baking temperature is 50-120 DEG C, and drying time is 3-20h, and obtain dry compound, the maximum moisture of polycarbonate powder is less than 0.020%;

E, join auxiliary agent, take antioxidant, light diffusing agent by constituent mass ratio;

F, mixing, by the compound of drying and auxiliary agent mixing, obtain the raw material mixed;

G, banburying, join in Banbury mixer by the raw material mixed in step F, banburying 8-20 minute, and banburying temperature is 200-300 DEG C, and Banbury mixer rotating speed is 20-60r/min;

H, shaping, take twin-screw extrusion method by the direct injection mo(u)lding in the grinding tool of required lamp pearl shape of the fluorescent polycarbonate mixed of banburying gained;

I, annealing, be positioned over Slow cooling under uniform temperature, obtain hard fluorescent transparent polycarbonate by type fluorescent transparent polycarbonate;

J, etching, fluorescent transparent polycarbonate upper surface or lower surface are etched into the grating with special construction by utilization laser, obtain the LED fluorescent transparent polycarbonate sheet with special optical structure;

K, encapsulation, be encapsulated into the above-mentioned LED fluorescent transparent polycarbonate sheet with special optical structure in LED the LED lamp bead/light fixture obtaining adjustable color.

2. a kind of LED fluorescent transparent polycarbonate grating preparation method according to claim 1, it is characterized in that: in described step e, wherein antioxidant changes mass ratio according to actual demand within the scope of 0.1%-1%, and light diffusing agent changes mass ratio according to actual demand within the scope of 0.5%-1%.

3. a kind of LED fluorescent transparent polycarbonate grating preparation method according to claim 1, is characterized in that: special construction described in step J is cylindricality, triangle or trapezoidal.

4. a kind of LED fluorescent transparent polycarbonate grating of preparing of method according to claim 1, is characterized in that: described fluorescent transparent polycarbonate grating comprises following component in mass ratio: polycarbonate 48%-94.4%;

Fluorescent powder 5%-49.5%;

Antioxidant 0.1%-1.5%;

Light diffusing agent 0.5%-1%.

5. a kind of LED fluorescent transparent polycarbonate grating according to claim 4, is characterized in that: described fluorescent powder component is in mass ratio 5%-49.5%.

6. a kind of LED fluorescent transparent polycarbonate grating according to claim 5, is characterized in that: described fluorescent powder is the potpourri of yellow fluorescent powder or red fluorescence powder or yellow fluorescent powder and red fluorescence powder.

7. a kind of LED fluorescent transparent polycarbonate grating according to claim 6, is characterized in that: described yellow fluorescent powder component is in mass ratio 10%-25%.

8. a kind of LED fluorescent transparent polycarbonate grating according to claim 6, it is characterized in that: described yellow fluorescent powder component is in mass ratio 20%, described red fluorescence powder component is in mass ratio 2%.

9. a kind of LED fluorescent transparent polycarbonate grating according to claim 4, is characterized in that: described light diffusing agent is organosilicon light diffusing agent.

10. a kind of LED fluorescent transparent polycarbonate grating according to claim 4, it is characterized in that: the transmittance of described polycarbonate is not less than 91.0%, the powder diameter of described polycarbonate is 30-90um.