Optical function board and preparation method thereof

Abstract

The invention relates to an optical function plate which comprises a polymer layer playing a role in bearing and supporting. The elastomer layer is attached to the polymer layer, and the elastomer layer and the polymer layer are attached in a double-layer co-extrusion mode; the outer surface of the elastomer layer is provided with a microstructure used for brightening, the microstructure is formed through transfer printing, and the polymer layer serves as a supporting structure of the elastomer layer in the transfer printing process. According to the invention, by utilizing the resilience and wear resistance of the elastomer, the problem of wear easily caused in the preparation and transportation processes of the optical function plate is effectively improved. The elastomer and the polymer matrix have good optical performance, the manufacturing cost is low, and a high-performance optical functional layer can be prepared. And the wear resistance of the elastomer after crosslinking can be further improved.

Description

Technical Field

[0001] The invention relates to an optical functional plate and a preparation method thereof. Background Art

[0002] As one of the core components of LED TV, the optical performance of the backlight module directly affects the brightness, contrast, color reproduction and visual experience of the screen. Traditional LED TV backlight modules mainly rely on brightness enhancement film (BEF) and micro lens film (MLF) to improve the uniformity and brightness of light. That is, UV soft glue is coated on the polyethylene terephthalate (PET) substrate and cured to form the required brightening and M structure. Or optical transparent polymers such as polystyrene (PS), polymethyl methacrylate (PMMA) or polycarbonate (PC) are used as substrates to directly transfer the microstructure to the polymer surface. The corresponding defects are: UV glue has a high cost and cannot be recycled after curing, which reduces the economic efficiency of the solution. Ordinary optical grade polymers have high hardness and strong rigidity, are easily worn during preparation, transportation and use, and have many restrictions on product yield and transportation. Summary of the invention

[0003] In view of the shortcomings of the above technologies, the present invention uses an elastomer as a structural bearing layer on the polymer surface to prepare a plate with an optical microstructure, providing an excellent application solution for a new type of microstructure optical functional plate. The specific solution is as follows: An optical functional plate comprises a polymer layer that serves as a load-bearing support; an elastomer layer bonded to the polymer layer, wherein the elastomer layer and the polymer layer are bonded by double-layer co-extrusion; the outer surface of the elastomer layer has a microstructure for brightness enhancement, wherein the microstructure is formed by transfer printing, and during the transfer printing process, the polymer layer serves as a support structure for the elastomer layer.

[0004] The optical functional plate is further designed in that: the thickness of the elastomer layer is 50-700 μm, and the thickness of the polymer layer is 300-1000 μm.

[0005] The optical functional plate is further designed in that the elastomer layer is prepared by using any one of ethylene-vinyl acetate copolymer, polyolefin elastomer, thermoplastic elastomer, thermoplastic polyurethane, polyether ester elastomer, polyamide elastomer and ethylene propylene diene monomer rubber.

[0006] The optical functional plate is further designed in that: the polymer layer is prepared by using any one of polystyrene, polymethyl methacrylate, polyethylene terephthalate, and styrene-methyl methacrylate copolymer.

[0007] A method for preparing an optical functional plate comprises the following steps: adding an elastomeric material to a first extruder at an extrusion temperature of 80-120°C, adding a polymer material to a second extruder at an extrusion temperature of 180-200°C, and mixing them at a die mouth to form a double-layer structure using a double-layer extrusion technology; transferring a microstructure on the mold to an elastomer layer using a microstructure transfer technology, and the transfer mold temperature is 80-120°C; placing the double-layer structure plate in an oven at 80-120°C or an irradiation device to promote crosslinking, thereby obtaining a double-layer structure optical functional plate.

[0008] The optical functional plate preparation method is further designed in that the elastomeric material is any one of ethylene-vinyl acetate copolymer, polyolefin elastomer, thermoplastic elastomer, thermoplastic polyurethane, polyether ester elastomer, polyamide elastomer, and EPDM rubber.

[0009] The optical functional plate preparation method is further designed in that: the elastomer material is further added with 0-5% by weight of a cross-linking agent and 0-5% by weight of an initiator.

[0010] The method for preparing the optical functional plate is further designed in that: the crosslinking agent is any one or more of triallyl isocyanurate, methyl allyl isocyanate, trimethylolpropane trimethacrylate, triallyl cyanurate, and trimethylolpropane diallyl ether; and the initiator is tert-butyl peroxide 2-ethylhexyl carbonate.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The resilience and wear resistance of the elastomer can be utilized to effectively improve the wear problem of the optical functional plate that is easily caused during the preparation and transportation process.

[0012] (2) The elastomer and polymer matrix have good optical properties and low manufacturing cost, and can be used to prepare high-performance optical functional layers.

[0013] (3) The wear resistance of the elastomer can be further improved after cross-linking.

[0014] It is worth noting that the elastomer is very soft and can easily deform as an optical layer, resulting in poor uniformity of the image. Therefore, it is usually not used as an optical functional plate. The present invention uses double-layer co-extrusion and combines the rigidity of PS as a support layer to make it less likely to deform. In addition, the extrusion temperature of elastomer materials is generally relatively low, which can easily cause a large difference in the melt index between the elastomer and the polymer material, resulting in difficulty in double-layer co-extrusion. Therefore, elastomer materials are generally not used as materials for double-layer co-extrusion molding technology. The present invention selects elastomer materials and polymer materials with similar melt indexes; the prior art uses UV glue / PET mother film, which can cause the elastomer to stick and destroy the overall structure. Using a metal template for transfer has better results and is easy to separate; conventional UV glue / PET film is used as a transfer mother film. The film is relatively soft and can easily cause incomplete embossing structure or embossing deformation during the transfer process. Using a metal template can better complete the structure transfer and is not prone to deformation during the transfer process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention.

[0016] Figure 2 This is a data table of optical functional panels according to embodiments of the present invention and a comparative example.

[0017] Figure 3 This is a test data table of the optical functional board of the embodiment of the present invention and the comparative example.

[0018] Figure 4 This is the surface microstructure diagram of the sample in Example 12.

[0019] Figure 5 This is a surface microstructure diagram of the sample in Example 12 after being rubbed 20 times by the friction meter. DETAILED DESCRIPTION

[0020] The present invention is further described below with reference to the accompanying drawings and embodiments: like Figure 1 An optical functional plate shown includes a polymer layer 1 that supports the load-bearing structure; an elastomer layer 2 bonded to the polymer layer, wherein the elastomer layer and the polymer layer are bonded by double-layer co-extrusion; the outer surface of the elastomer layer has a microstructure 3 for brightness enhancement, wherein the microstructure is formed by transfer printing, and the polymer layer serves as a support structure for the elastomer layer during the transfer printing process. The thickness of the elastomer layer is 50-700 μm, and the thickness of the polymer layer is 300-1000 μm.

[0021] The elastomer layer is prepared from any one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), polyether ester elastomer (TPEE), polyamide elastomer (TPAE), and ethylene propylene diene monomer (EPDM).

[0022] The polymer layer is prepared by using any one of polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and styrene-methyl methacrylate copolymer (MS).

[0023] A method for preparing an optical functional plate, comprising the following steps: adding an elastomeric material to a first extruder at an extrusion temperature of 80-220°C, adding a polymer material to a second extruder at an extrusion temperature of 180-260°C, and mixing at a die mouth to form a double-layer structure using a double-layer extrusion technique; transferring the microstructure on the mold to the elastomeric layer using a microstructure transfer technique, and the transfer mold temperature is 80-160°C; placing the double-layer structure plate in an oven at 80-160°C to heat and promote crosslinking, thereby obtaining a double-layer structure optical functional plate. The elastomeric material is also added with a crosslinker accounting for 0-5% by mass and an initiator accounting for 0-5% by mass. The crosslinking agent is any one or more of triallyl isocyanurate (TAIC), methyl allyl isocyanate (TMAIC), trimethylolpropane trimethacrylate (TMPTMA), triallyl cyanurate (TAC), and trimethylolpropane diallyl ether (TMPDE); the initiator is tert-butyl peroxide 2-ethylhexyl carbonate (TBEC).

[0024] like Figure 3 , Figure 4 The illustrated embodiment is as follows: Example

[0025] 100g TAIC and 100g TBEC were added to 10kg EVA and mixed evenly using a high-speed mixer, and then added to the first extruder at an extrusion temperature of 80-120°C. 40kg PS was added to the second extruder at an extrusion temperature of 180-200°C, and mixed at the die mouth using double-layer extrusion technology to form a double-layer structure. The microstructure on the mold was transferred to the elastomer layer using microstructure transfer technology, and the transfer mold temperature was 80-120°C. The double-layer structure board was placed in an oven at 80-120°C and heated to promote crosslinking to obtain a double-layer structure board.

[0026] Example 2: 100g TAIC and 100g TBEC were added to 10kg POE and mixed evenly using a high-speed stirrer. The mixture was added to the first extruder at an extrusion temperature of 100-140°C. 40kg PS was added to the second extruder at an extrusion temperature of 180-200°C. The mixture was mixed into a double-layer structure at the die using double-layer extrusion technology.

[0027] The microstructure transfer technology transfers the microstructure on the mold to the elastomer layer, and the transfer mold temperature is 100-140°C.

[0028] The double-layer structure board is placed in an oven at 100-140° C. to heat and promote cross-linking, thereby obtaining a double-layer structure board.

[0029] In Examples 3, 4, 5, and 6, 100 g of TAIC was added to 10 kg of TPE, 10 kg of TPEE, 10 kg of TPAE, and 10 kg of EPDM, and the mixture was uniformly mixed using a high-speed mixer, and then added to the first extruder at an extrusion temperature of 180-200 ° C. 40 kg of PS was added to the second extruder at an extrusion temperature of 180-200 ° C. The double-layer extrusion technology was applied to mix the mixture at the die mouth into a double-layer structure. The microstructure transfer technology was used to transfer the microstructure on the mold to the elastomer layer, and the transfer mold temperature was 140-160 ° C. The double-layer board was cross-linked using an irradiation device, and the electron accelerator energy was 1-5 MeV. Example

[0030] 10 kg of TPU was added into the first extruder at an extrusion temperature of 160-180°C, and 40 kg of PS was added into the second extruder at an extrusion temperature of 180-200°C. The two-layer extrusion technology was used to mix them at the die to form a two-layer structure.

[0031] The microstructure transfer technology transfers the microstructure on the mold to the elastomer layer, and the transfer mold temperature is 140-160°C.

[0032] Control group The UV soft glue is evenly coated on the PET surface, the microstructure on the mold is transferred to the UV glue using transfer technology, and the UV / PET film is obtained by curing through ultraviolet light.

[0033] Depend on Figure 3 Test results combined Figure 4 , Figure 5 It can be seen that the transmittance and brightness decreased after the addition of the elastomer, but compared with the control group 1, the optical properties did not change significantly, and the wear resistance was effectively improved.

Claims

1. An optical functional plate, characterized in that: It includes a polymer layer that plays a bearing and supporting role; an elastomer layer bonded to the polymer layer, wherein the elastomer layer and the polymer layer are bonded by double-layer co-extrusion; the outer surface of the elastomer layer has a microstructure for brightening, and the microstructure is formed by transfer, and the polymer layer serves as a supporting structure of the elastomer layer during the transfer process.

2. The optical functional plate according to claim 1, characterized in that: The thickness of the elastomer layer is 50-700 μm, and the thickness of the polymer layer is 300-1000 μm.

3. The optical functional plate according to claim 1, characterized in that: The elastic body layer is prepared by any one of ethylene-vinyl acetate copolymer, polyolefin elastomer, thermoplastic elastomer, thermoplastic polyurethane, polyether ester elastomer, polyamide elastomer and ethylene propylene diene monomer rubber.

4. The optical functional plate according to claim 1, characterized in that: The polymer layer is prepared from any one of polystyrene, polymethyl methacrylate, polyethylene terephthalate, and styrene-methyl methacrylate copolymer.

5. A method for preparing an optical functional plate, characterized in that: The elastomer material is added to the first extruder at an extrusion temperature of 80-120°C, and the polymer material is added to the second extruder at an extrusion temperature of 180-200°C, and mixed into a double-layer structure at the die mouth using a double-layer extrusion technology; the microstructure on the mold is transferred to the elastomer layer using a microstructure transfer technology, and the transfer mold temperature is 80-120°C; the double-layer structure plate is placed in an 80-120°C oven or irradiation equipment to promote crosslinking, and a double-layer structure optical functional plate is obtained.

6. The method for preparing an optical functional plate according to claim 5, characterized in that: The elastomer material is any one of ethylene-vinyl acetate copolymer, polyolefin elastomer, thermoplastic elastomer, thermoplastic polyurethane, polyether ester elastomer, polyamide elastomer and EPDM rubber.

7. The method for preparing an optical functional plate according to claim 6, characterized in that: The elastomer material is further added with 0-5% by weight of a crosslinking agent and 0-5% by weight of an initiator.

8. The method for preparing an optical functional plate according to claim 7, characterized in that: The crosslinking agent is any one or more of triallyl isocyanurate, methyl allyl isocyanate, trimethylolpropane trimethacrylate, triallyl cyanurate, and trimethylolpropane diallyl ether; and the initiator is tert-butyl peroxide 2-ethylhexyl carbonate.

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