CN114675356A

CN114675356A - Foaming diffusion plate and preparation method thereof

Info

Publication number: CN114675356A
Application number: CN202210164864.1A
Authority: CN
Inventors: 郑日新; 王兴礼; 梁满意; 何小磊
Original assignee: Guangdong Regency Photoelectric Co ltd
Current assignee: Guangdong Regency Photoelectric Co ltd
Priority date: 2022-02-23
Filing date: 2022-02-23
Publication date: 2022-06-28

Abstract

The invention discloses a foaming diffusion plate which comprises a foaming core layer, wherein the upper surface and the lower surface of the foaming core layer are covered with protective layers, and the thickness ratio of the foaming core layer to the protective layers on the upper surface and the lower surface is 1: 7-9: 1; the protective layer comprises the following raw materials in percentage by mass: 90-99% of PS raw material, 0.01-1% of stabilizing agent, 0.1-3% of organic silicon, 0.1-3% of inorganic dispersing agent, 0.1-3% of dispersing oil, 0.1-2% of styrene-butadiene copolymer and 0.1-6% of magnesium silicate mineral; the foaming core layer comprises the following raw materials in percentage by mass: 95-99% of GPPS raw material, 0.3-0.6% of antioxidant, 0.6-1% of organosilicon diffusant, 0.5-2% of foaming agent, 0.3-0.6% of UV resistance, 0.5-2% of flexibilizer, 0.3-0.6% of stabilizer and 1-5% of nucleating agent, wherein a plurality of foam cells are formed inside the foaming core layer. The invention provides a foaming diffusion plate which has good total reflection performance, better uniformity and better taste. The invention also provides a preparation method of the foaming diffusion plate.

Description

Foaming diffusion plate and preparation method thereof

Technical Field

The invention relates to the technical field of light diffusion plates, in particular to a foaming diffusion plate and a preparation method thereof.

Background

The light diffusion plate is characterized in that through chemical or physical means, when light meets two media with different refractive indexes in the traveling path, the physical phenomena of refraction, reflection and scattering are generated, inorganic or organic light diffusants are added into base materials such as PMMA, PC, PS, PP and the like, or the light is artificially adjusted through array arrangement of micro-feature structures on the surface of the base materials, so that the light is refracted, reflected and scattered in different directions, the traveling path of the light is changed, the effect of optical diffusion is generated by filling and dispersing colors of incident light, and the light diffusion plate is widely applied to liquid crystal display, LED illumination and imaging display systems.

In the existing display screen backlight source, concave-convex points or concave-convex point stripes are processed on one surface or two surfaces of the existing light diffusion plate and are used for improving the light dispersion performance of the diffusion plate, so that light rays emitted by LED light strip point-shaped light sources can be homogenized after being emitted through the diffusion plate. However, with the continuous upgrade and update of display screens, the structure of the existing light diffusion plate cannot meet the requirements of manufacturers, and the existing diffusion plate generally has the defects of larger weight and poor diffusion effect caused by poor refractive index.

Disclosure of Invention

The invention aims to provide a foaming diffusion plate and a preparation method thereof, which have better total reflection performance, better uniformity and better taste.

The invention discloses a foaming diffusion plate and a preparation method thereof, and the technical scheme is as follows:

a foaming diffusion plate comprises a foaming core layer, wherein the upper surface and the lower surface of the foaming core layer are covered with protective layers, and the thickness ratio of the foaming core layer to the protective layers on the upper surface and the lower surface is 1: 7-9: 1;

the protective layer comprises the following raw materials in percentage by mass: 90-99% of PS raw material, 0.01-1% of stabilizing agent, 0.1-3% of organic silicon, 0.1-3% of inorganic dispersing agent, 0.1-3% of dispersing oil, 0.1-2% of styrene-butadiene copolymer and 0.1-6% of magnesium silicate mineral;

the foaming core layer comprises the following raw materials in percentage by mass: 95-99% of GPPS raw material, 0.3-0.6% of antioxidant, 0.6-1% of organosilicon diffusant, 0.5-2% of foaming agent, 0.3-0.6% of UV resistance, 0.5-2% of flexibilizer, 0.3-0.6% of stabilizer and 1-5% of nucleating agent, wherein a plurality of foam cells are formed inside the foaming core layer.

Preferably, the side of the protective layer, which is far away from the foam core layer, is provided with lines for improving the refraction and reflection performance of light.

Preferably, a quantum dot layer is further arranged between the two protective layers and covers the surface of the foaming core layer.

Preferably, the quantum dot layer comprises the following raw materials in percentage by mass: 90-99% of plastic raw material, 0.01-1% of stabilizing agent, 0.1-3% of organic silicon, 0.1-3% of inorganic dispersing agent, 0.1-3% of dispersing oil, 0.1-2% of styrene-butadiene copolymer, 0.1-6% of magnesium silicate mineral and 0.01-1% of quantum dot, wherein the particle size of the quantum dot is 2-12 nm. .

Preferably, the foamed core layer further comprises quantum dots, the mass percentage of the raw materials of the quantum dots is 0.01-1%, and the particle size of the quantum dots is 2-12 nm.

As a preferable scheme, PS heat-resistant agents are added to the components of the foamed core layer and the protective layer, and the PS heat-resistant agents comprise, by mass: 0.1 to 3 percent.

The preparation method of the foaming diffusion plate comprises the following steps:

preparing two parts of raw materials of the protective layer with the same components and one part of raw material of the foaming core layer;

respectively and uniformly mixing the raw materials of the protective layer and the foamed core layer;

respectively adding the mixed protective layer raw material and the foamed core layer raw material into screw extrusion equipment for heating to form a molten state;

and finally, extruding the mixture through a die head of a screw extrusion device, and extruding the raw materials of the protective layer and the foamed core layer in a sheet manner, wherein the protective layer covers the surface of the foamed core layer.

Preferably, the screw extrusion device comprises three sections of heating zones, wherein the first section temperature of the heating zone is 140-.

Preferably, the temperature control range of the die extrusion is 170-260 ℃.

As the preferred scheme, the screw extrusion equipment is provided with a plurality of feed inlets, and the screw extrusion equipment is suitable for putting various different raw materials into the screw extrusion equipment.

The foaming diffusion plate disclosed by the invention has the beneficial effects that: PS raw materials are adopted for the protective layers on the upper surface and the lower surface of the foaming core layer, and inorganic diffusant is added to make the protective layers into hard protective layers, the foaming core layer between the two protective layers is protected, and can also refract and reflect light, and the foaming core layer is added with foaming agent to form a plurality of foam cells in the foaming core layer, an air medium is arranged in the foam holes, so that when light rays are emitted into the foam core layer, the light rays firstly pass through the base material of the foam core layer, then the light is emitted into the foam holes to further refract and reflect the light, so that the total reflection of the foam core layer is higher, the uniformity is better, the taste is better, and because the foam holes are arranged in the foam core layer, thereby the density is reduced, the whole weight is also lightened, and the organic silicon diffusant plays a role in diffusion, plays a role in stabilizing the bubble size of the foaming agent through the nucleating agent, and prevents the yellowing of the foaming core layer through the antioxidant.

Drawings

FIG. 1 is a schematic view of a foam diffuser plate according to the present invention.

FIG. 2 is a sectional view of a foamed core layer of a foamed diffuser plate according to the present invention.

FIG. 3 is an enlarged view of a magnifier used in a planar lighting state of a foaming diffuser plate according to the present invention.

FIG. 4 is a schematic view of a test backlight module.

FIG. 5 shows the light-equalizing effect of a conventional diffuser plate before the backlight source.

FIG. 6 shows the light-equalizing effect of a foam diffuser plate before the backlight source.

FIG. 7 is a schematic view of a quantum dot layer structure of a foam diffuser plate according to the present invention.

FIG. 8 is a schematic structural diagram of a foam core layer of a foam diffuser plate according to the present invention, which contains quantum dots.

FIG. 9 is a process flow chart of a method for manufacturing a foam diffuser plate according to the present invention.

Detailed Description

The invention will be further elucidated and described with reference to the embodiments and drawings of the specification:

referring to fig. 1, a foam diffuser plate includes a foam core layer 10, wherein the upper surface and the lower surface of the foam core layer 10 are covered with a protection layer 20, and the thickness ratio of the foam core layer 10 to the protection layer 20 on the upper surface and the lower surface is 1: 7-9: 1.

The protective layer 20 comprises the following raw materials in percentage by mass: 90-99% of PS raw material, 0.01-1% of stabilizing agent, 0.1-3% of organic silicon, 0.1-3% of inorganic dispersing agent, 0.1-3% of dispersing oil, 0.1-2% of styrene-butadiene copolymer and 0.1-6% of magnesium silicate mineral.

The foaming core layer 10 comprises the following raw materials in percentage by mass: 95-99% of GPPS raw material, 0.3-0.6% of antioxidant, 0.6-1% of organosilicon diffusant, 0.5-2% of foaming agent, 0.3-0.6% of UV resistance, 0.5-2% of flexibilizer, 0.3-0.6% of stabilizer, 1-5% of nucleating agent, and a plurality of foam cells are formed inside the foam core layer 10.

The protective layers 20 on the upper and lower surfaces of the foam core layer 10 are made of PS raw materials, and inorganic diffusant is added, so that the protective layers 20 are hard protective layers 20, the foam core layer 10 between the two protective layers 20 is protected, and light can be refracted and reflected.

Referring to fig. 2 and 3, the foaming core layer 10 is formed with a plurality of cells inside the foaming core layer 10 by adding a foaming agent, and an air medium is provided in the cells, so that when light is injected into the foaming core layer 10, the light passes through the base material of the foaming core layer 10 and then is injected into the cells, and the light is further refracted and reflected, so that the total reflection of the foaming core layer 10 is relatively high, the uniformity is better, the taste is better, and since the cells are provided inside the foaming core layer 10, the density is reduced, and the overall weight is also reduced. The organosilicon diffusant plays a role in diffusion, plays a role in stabilizing the bubble size of the foaming agent through the nucleating agent, and prevents the foaming core layer 10 from yellowing through the antioxidant.

In this embodiment, the ratio of the thickness of the foam core layer of the foam diffusion plate to the thickness of the protection layers on the upper and lower surfaces is 1: 8: 1; the protective layer comprises the following raw materials in percentage by mass: 93% of PS raw material, 0.5% of stabilizer, 1.5% of organic silicon, 1% of inorganic diffusant, 1% of diffusion oil, 1% of styrene-butadiene copolymer and 2% of magnesium silicate mineral; the foaming core layer comprises the following raw materials in percentage by mass: 95% of GPPS raw material, 0.5% of antioxidant, 0.8% of organosilicon dispersing agent, 1% of foaming agent, 0.5% of UV resistance, 1% of toughening agent, 0.2% of stabilizer and 1% of nucleating agent.

The thickness ratio of the protective layer to the diffusion layer of the common plate is 1: 8: 1, and the protective layer comprises the following raw materials in percentage by mass: 93% of PS raw material, 0.5% of stabilizer, 1.5% of organic silicon, 1% of inorganic diffusant, 1% of diffusion oil, 1% of styrene-butadiene copolymer and 2% of magnesium silicate mineral; the diffusion layer comprises the following raw materials in percentage by mass: 97.8% of GPPS raw material, 0.5% of antioxidant, 0.5% of UV resistance, 1% of flexibilizer and 0.2% of stabilizer.

And (3) correctly assembling the manufactured foaming diffusion plate and the manufactured common diffusion plate, placing a backlight source, turning on a power switch, checking if the foaming diffusion plate and the common diffusion plate are correct, preheating for 30min, placing the plate in a fixed test area which is arranged in the middle above the backlight source and below the BEF, and measuring by using a corrected brightness meter, wherein the structure of the backlight source can refer to the figure 4.

Data pairs of the foamed panels and the plain panels are shown in table 1 below.

As is apparent from the above table, the luminance and leveling effect of the foam board are improved as compared with those of the ordinary board, and the density of the foam board is lower than that of the ordinary board, and the weight of the foam board diffuser plate is further reduced.

Referring to fig. 5 and 6, fig. 5 shows the light-equalizing diffusion effect when the ordinary diffusion plate is disposed in front of the backlight source, and it can be seen that the brightness at the middle position of the ordinary diffusion plate is higher than that at the upper and lower sides, while fig. 6 shows the light-equalizing diffusion effect when the foaming diffusion plate is disposed in front of the backlight source, comparing with fig. 5, it can be seen that the light-equalizing effect of fig. 6 is better and more uniform, and the brightness is also improved significantly.

In the above scheme, the protective layer 20 is provided with the lines for improving the refraction and reflection performance of light on the side away from the foaming core layer 10, so that the reflection and refraction of light can be more uniform.

Referring to fig. 7, a quantum dot layer is further disposed between the two protective layers 20, and the quantum dot layer covers the surface of the foam core layer 10. The quantum dot layer comprises the following raw materials in percentage by mass: 90-99% of plastic raw material, 0.01-1% of stabilizing agent, 0.1-3% of organic silicon, 0.1-3% of inorganic dispersing agent, 0.1-3% of dispersing oil, 0.1-2% of styrene-butadiene copolymer, 0.1-6% of magnesium silicate mineral, 0.01-1% of quantum dot, and the grain size of the quantum dot is 2-12 nm.

The quantum dot material has the characteristics of wide excitation spectrum, narrow emission spectrum, high color purity and good light stability, can improve the optical performance of the diffusion plate, can improve the visual effect of the quantum dot plate by combining the quantum dot and the foaming structure, can reduce the width of the luminous peak of three primary colors and improve the display color gamut by performing light conversion on the spectrum band of light in the original backlight, and can improve the utilization rate of light of the backlight module which penetrates through the color filter after light conversion, thereby improving the brightness.

Referring to fig. 8, the foamed core layer 10 further includes quantum dots, the quantum dots are made of 0.01-1% by mass of the raw material, and the particle size of the quantum dots is 2-12 nm. Compared with the quantum dot layer, the quantum dot layer of the embodiment directly mixes the quantum dots into the raw material of the foam core layer 10, so that the quantum dots are directly embedded into the foam core layer 10, thereby reducing the overall thickness of the foam diffusion plate, and the quantum dot layer can ensure that the foam core layer 10 is correspondingly covered with the quantum dot layer, both have respective advantages, and can be processed by different processes according to actual conditions.

PS heat-resistant agents are added to the components of the foaming core layer 10 and the protective layer 20, and the PS heat-resistant agents comprise the following components in percentage by mass: 0.1-3%, improve and add the heat resistance that PS heat-resistant agent improves the foaming diffuser plate main part, avoid in the use, because the LED lamp is when shining, the high temperature causes the condition that the foaming diffuser plate takes place the deformation, and the effect after increasing the PS heat-resistant agent can refer to the following table:

Type number

Light transmission

X

Y

Center brightness

Average brightness

Temperature resistant

RS-50M

40.40%

0.2741

0.2451

240nit

180nit

71.3℃

RS-50M adding PS heat-resistant agent

40.10%

0.2746

0.2453

241nit

181nit

76.3℃

From the above table, it can be seen that the temperature resistance of the foamed diffuser plate after the addition of the PS heat-resistant agent is significantly improved compared to the foamed diffuser plate without the addition of the PS heat-resistant agent.

Referring to fig. 9, a method for manufacturing the foam diffuser plate includes the following steps:

and finally, extruding the mixture through a die head of screw extrusion equipment, and extruding the raw materials of the protective layer and the foamed core layer in a sheet manner, wherein the protective layer covers the surface of the foamed core layer.

Through the processing steps, the protective layer and the foaming core layer are extruded together, so that the bonding and fixing are realized, the protective layer can be covered on the surface of the foaming core layer, and the processing technology is more convenient.

The screw extrusion equipment comprises three sections of heating areas, wherein the first section temperature of the heating area is 140-. The raw materials of the protective layer and the foaming core layer can be fully heated and mixed by adopting a sectional heating mode to form a molten state, the temperature control range of the die head extrusion is 170-260 ℃, the protective layer and the foaming core layer are still in the molten state in the extrusion process, and the smoothness of the die head is kept.

And screw extrusion equipment is equipped with a plurality of feed inlet, and applicable multiple different raw materials are put into screw extrusion equipment, can part multiple different raw materials simultaneously and add and extrude to realize the preparation of extruding of multiply wood, like the quantum dot layer that increases, can play the purpose of extruding in step through the raw materials on a set of quantum dot layer of synchronous increase, form the foaming diffuser plate of quadruple layer structure.

Through the mode of above-mentioned crowded altogether, the difference adopts the fixed mode of viscose with the tradition, convenient and fast more, and make the foaming agent produce gas in heating process, thereby vacuole formation in the foaming layer, make foaming layer and protective layer carry out the integration production, reduce the follow-up process that needs the manual work to make up, also avoided the viscose to appear ageing in long-term use simultaneously, can't play the fixed problem of bonding between each layer, and adopt the mode of crowded altogether to extrude and to also can accurately control the thickness between every layer, realize intelligent manufacturing.

The invention provides a foaming diffuser plate and a preparation method thereof, wherein protective layers on the upper surface and the lower surface of a foaming core layer are made of PS raw materials and are added with inorganic diffusant to form hard protective layers, the foaming core layer between the two protective layers is protected and can refract and reflect light, the foaming core layer is added with a foaming agent to form a plurality of foam holes in the foaming core layer, and air media are arranged in the foam holes, so that the light firstly passes through a base material of the foaming core layer and then is emitted into the foam holes to further refract and reflect the light out, the total reflection of the foaming core layer is higher, the uniformity is better, the taste is better, and the density is reduced due to the foam holes in the foaming core layer, the whole weight is lightened, the organosilicon diffusant plays a role in diffusing, and plays a role in stabilizing the size of the foaming agent through the nucleating agent, and the yellowing of the foam core layer is prevented by the antioxidant.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A foaming diffusion plate is characterized by comprising a foaming core layer, wherein the upper surface and the lower surface of the foaming core layer are covered with a protective layer, and the thickness ratio of the foaming core layer to the protective layers on the upper surface and the lower surface is 1: 7-9: 1;

2. The foam diffuser plate as claimed in claim 1, wherein the side of said protective layer away from the foam core layer is provided with texture for improving the refraction and reflection properties of light.

3. The foam diffuser plate as claimed in claim 1, wherein a quantum dot layer is further disposed between two of said protective layers, and said quantum dot layer covers the surface of the foam core layer.

4. A foam diffuser plate according to claim 3, wherein said quantum dot layer comprises the following raw materials by mass: 90-99% of plastic raw material, 0.01-1% of stabilizing agent, 0.1-3% of organic silicon, 0.1-3% of inorganic dispersing agent, 0.1-3% of dispersing oil, 0.1-2% of styrene-butadiene copolymer, 0.1-6% of magnesium silicate mineral and 0.01-1% of quantum dot, wherein the particle size of the quantum dot is 2-12 nm.

5. The foam diffuser plate as claimed in claim 1, wherein the foam core layer further comprises quantum dots, the quantum dots are made of raw materials with a mass percentage of 0.01-1%, and the particle size of the quantum dots is 2-12 nm.

6. The foam diffuser plate as claimed in any one of claims 1 to 5, wherein the PS heat-resistant agent is added to the foam core layer and the protective layer, and the PS heat-resistant agent comprises the following components in percentage by mass: 0.1 to 3 percent.

7. A method for preparing a foamed diffuser plate according to claim 1, comprising the steps of:

respectively and uniformly mixing the raw materials of the protective layer and the foaming core layer;

respectively adding the mixed protective layer raw material and the mixed foam core layer raw material into screw extrusion equipment for heating to form a molten state;

and finally, extruding the raw materials through a die head of screw extrusion equipment, and extruding the raw materials of the protective layer and the foamed core layer in a flaky manner, wherein the protective layer covers the surface of the foamed core layer.

8. The method as claimed in claim 7, wherein the screw extrusion device comprises three heating zones, the first temperature of the heating zone is 140-220 ℃, the second temperature of the heating zone is 160-240 ℃, and the third temperature of the heating zone is 180-260 ℃.

9. The method as claimed in claim 7, wherein the temperature control range of the die head extrusion is 170-260 ℃.

10. The method as claimed in claim 7, wherein the screw extruder has a plurality of inlets for a plurality of different materials.