A high-intensity light-diffusing backplane and its preparation method

Abstract

The present invention relates to the technical field of light diffuser panels, and more specifically to a high-strength light diffuser backsheet and a method for preparing the same. MS is highly brittle, and its flexibility, heat resistance, and dimensional stability when used as a light diffuser backsheet are poor. In response to the above-mentioned technical problems, the present invention provides a high-strength light diffuser backsheet, which uses MS as a resin matrix and chopped glass fibers as a reinforcing agent. The chopped glass fibers are added to the resin matrix by side feeding, resulting in a high-strength light diffuser backsheet having excellent toughness, heat resistance, and dimensional stability, and having good market application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of light diffusion plates, and in particular to a high-intensity light diffusion back plate and a preparation method thereof. Background Art

[0002] In the existing technology, polystyrene resin (PS), styrene-methyl methacrylate copolymer resin (MS), polymethyl methacrylate (PMMA), and polycarbonate resin (PC) can all be used as light-diffusing backplanes. PS is prone to yellowing after continuous heating; PMMA has good weather resistance, but is easily deformed by moisture; PC has excellent performance properties, but is expensive and difficult to process. MS, as a copolymer of methyl methacrylate (MMA) and styrene (S), has good heat resistance and dimensional retention. However, MS is brittle, and its flexibility, heat resistance, and dimensional stability are poor when used as a light-diffusing backplane.

[0003] With the development of the LED industry, the demand for LED lights in displays has increased, placing higher demands on the toughness, heat resistance, and dimensional stability of diffuser plates. Currently, there are no reports on the use of glass fiber modified MS for light diffusion backplanes. Summary of the Invention

[0004] The problem in the prior art is that MS is brittle and has poor flexibility when used as a light-diffusing backsheet. To address the above technical issues, the present invention provides a high-strength light-diffusing backsheet comprising the following components by weight:

[0005] MS 50-90%;

[0006] MBS 0-20%;

[0007] Glass fiber 10-30%;

[0008] Antioxidant 0.1-0.5%;

[0009] Lubricant 0.1-0.3%.

[0010] Preferably, the weight ratio of MS is 65-85%.

[0011] Preferably, the weight ratio of the MBS is 0-15%.

[0012] Preferably, the weight ratio of the glass fiber is 10-20%.

[0013] Preferably, the glass fibers are chopped glass fibers, and the average chopped length is 1-3 mm.

[0014] Preferably, the antioxidant comprises one or a combination of two or more of aromatic amine antioxidants, hindered phenol antioxidants, and phosphite antioxidants.

[0015] Preferably, the aromatic amine antioxidant includes BHA, BHT, TBHA, DPHP or DPPD.

[0016] Preferably, the hindered phenol antioxidant includes antioxidant 1010, antioxidant 1076 or antioxidant 3114.

[0017] Preferably, the phosphite antioxidant includes antioxidant 168 or antioxidant 626.

[0018] Preferably, the lubricant includes at least one of fatty acid amides, fatty acids, hydrocarbons, alcohols, metal soaps, and composite lubricants.

[0019] Preferably, the high-intensity light-diffusing backsheet is prepared by extruding the raw materials by side-feeding, and specifically comprises the following steps:

[0020] Under light-proof conditions, all raw materials except glass fiber are first mixed uniformly and added to a screw extruder. The mixed material is heated and melted by the screw and continuously extruded from the main feeding port toward the extruder discharge port to obtain a composite material. The obtained composite material is cooled and solidified, melt-extruded, and roll-formed to obtain a high-strength light diffusion backboard. During the screw extrusion process, glass fiber is added through a side feeding port provided on the screw extruder barrel, the horizontal distance between the side feeding port and the main feeding port is 101-105 cm, the horizontal distance between the main feeding port and the extruder discharge port is 228-230 cm, and the screw diameter is 35-65 mm.

[0021] Preferably, the extrusion temperature is 200°C-240°C.

[0022] Preferably, the feeding speed of the main feeding port is 25-28 rpm, and the feeding speed of the side feeding port is 7-10 rpm.

[0023] The present invention has the following beneficial effects:

[0024] (1) The present invention adds chopped glass fibers to the MS resin matrix by side feeding, and the resulting high-strength light-diffusing backsheet has better toughness, heat resistance, and dimensional stability;

[0025] (2) The present invention further improves the toughness, heat resistance and dimensional stability of the obtained high-strength light diffusion backsheet by preferably using ECS303W-1.7-K or ECS304A-1.7-K as the chopped glass fiber;

[0026] (3) The present invention further improves the comprehensive performance of the obtained high-strength light-diffusing backplane by optimizing the length of the chopped glass fibers to be about 1.7 mm. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to the following examples. However, it should be understood that the following examples are merely illustrative of the embodiments of the present invention and are not intended to limit the scope of the present invention.

[0028] The high-intensity light-diffusing backsheets obtained in the following Examples 1-3 of the present invention are all prepared by extruding the raw materials by side-feeding, and the specific steps are as follows:

[0029] Under light-proof conditions, the raw materials except the glass fiber are first mixed evenly and added to the screw extruder. The mixed material is heated and melted by the screw and then screw extruded from the main feeding port toward the extruder discharge port to obtain a composite material. The obtained composite material is cooled and solidified, melt-extruded, and roll-formed to obtain a high-strength light diffusion backplane with a thickness of 2 mm. During the screw extrusion process, the glass fiber is added through the side feeding port provided on the screw extruder barrel. The horizontal distance between the side feeding port and the main feeding port is 101 cm, and the horizontal distance between the main feeding port and the extruder discharge port is 228 cm. The screw diameter is 65 mm; the extrusion temperature is 200°C; the feeding speed of the main feeding port is 25 rpm, and the feeding speed of the side feeding is 7 rpm; the melting temperature is 200°C, and the three-roller roll forming temperatures are 100°C for the front roller, 120°C for the middle roller, and 100°C for the rear roller.

[0030] The chopped glass fibers ECS303W-1.7-K, ECS307AT-3-M4, and ECS304A-1.7-K in the following examples of the present invention were purchased from Chongqing International Composite Materials Co., Ltd.

[0031] Example 1

[0032] A high-intensity light-diffusing backsheet, comprising the following components by weight:

[0033]

[0034] The glass fiber is chopped glass fiber ECS304A-1.7-K, and the average length is 1.7 mm.

[0035] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0036] The lubricant is lubricant PETS.

[0037] Example 2

[0038] A high-intensity light-diffusing backsheet, comprising the following components by weight:

[0039]

[0040] The glass fiber is chopped glass fiber ECS304A-1.7-K, and the average length is 1.7 mm.

[0041] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0042] The lubricant is lubricant PETS.

[0043] Example 3

[0044] A high-intensity light-diffusing backsheet, comprising the following components by weight:

[0045]

[0046] The glass fiber is chopped glass fiber ECS304A-1.7-K, and the average length is 1.7 mm.

[0047] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0048] The lubricant is lubricant PETS.

[0049] Example 4 is the same as Example 3, except that the glass fiber length of the chopped glass fiber ECS304A-1.7-K in Example 4 is 3 mm.

[0050] Example 5 is the same as Example 3, except that the glass fiber length of the chopped glass fiber ECS304A-1.7-K in Example 5 is 6 mm.

[0051] Example 6 is the same as Example 3, except that the glass fiber in Example 6 is chopped glass fiber ECS307AT-3-M4.

[0052] Example 7 is the same as Example 3, except that the glass fiber in Example 7 is chopped glass fiber ECS303W-1.7-K.

[0053] Example 8 is the same as Example 3, except that the glass fiber in Example 8 is milled glass fiber EMG11-100, the average particle size of the glass fiber is 9 μm, and it is purchased from Chongqing International Composite Materials Co., Ltd.

[0054] Comparative Example 1 is the same as Example 3, except that the resin in Comparative Example 1 is commercially available styrene-methyl methacrylate copolymer resin MS800 purchased from Nippon Electric Chemical Co., Ltd.

[0055] Comparative Example 2 is the same as Example 3, except that Comparative Example 2 is commercially available polystyrene resin PS535N, purchased from Guo'en Yisu (Zhejiang) New Material Technology Co., Ltd.

[0056] Performance Testing

[0057] The high-intensity light-diffusing backsheets obtained in the embodiment of the present invention and the comparative example were subjected to relevant performance tests. Specific test results are shown in Table 1 and Table 1.

[0058] Light transmittance: The test standard is ASTM D1003. Light transmittance ≥ 56% meets the requirements for diffuser panels.

[0059] Flexural modulus, flexural strength: The test standard is ASTM D790.

[0060] Breaking strength: The test standard is ASTM D638.

[0061] Impact strength: The test standard is ASTM D256.

[0062] Heat Deflection Temperature: The test standard is ASTM D1525.

[0063] Table 1

[0064]

[0065] Table 1

[0066]

[0067] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A high-intensity light-diffusing backplane, characterized in that: The ingredients are as follows by weight: MS 85%; Glass fiber 15%; Antioxidant 0.5%; Lubricant 0.3%; The glass fiber is chopped glass fiber ECS304A-1.7-K or ECS303W-1.7-K, with an average length of 1.7 mm; The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; The lubricant is lubricant PETS; The obtained high-intensity light-diffusing backsheet is obtained by mixing and extruding the raw materials through side feeding. The specific steps are as follows: Under light-proof conditions, the raw materials except the glass fiber are first mixed evenly and added to the screw extruder. The mixed material is heated and melted by the screw and then screw extruded from the main feeding port toward the extruder discharge port to obtain a composite material. The obtained composite material is cooled and solidified, melt-extruded, and roll-formed to obtain a high-strength light diffusion backplane with a thickness of 2 mm. During the screw extrusion process, the glass fiber is added through the side feeding port provided on the screw extruder barrel. The horizontal distance between the side feeding port and the main feeding port is 101 cm, and the horizontal distance between the main feeding port and the extruder discharge port is 228 cm. The screw diameter is 65 mm; the extrusion temperature is 200°C; the feeding speed of the main feeding port is 25 rpm, and the feeding speed of the side feeding is 7 rpm; the melting temperature is 200°C, and the three-roller roll forming temperatures are 100°C for the front roller, 120°C for the middle roller, and 100°C for the rear roller.

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