CN106154400A - A kind of method improving inkjet printing quantum dot dot light guide plate - Google Patents

Abstract

The present invention relates to a kind of method improving inkjet printing quantum dot dot light guide plate, it is intended to solve the uniform and stable sex chromosome mosaicism of quantum dot site.The present invention passes through the composition of quantum point ink and the pretreatment to substrate, by inkjet printing, quantum dot slurry is graphically printed to substrate surface according to certain, a kind of quantum dot site array being formed at substrate surface after solidification, a diameter of 250～450 um in single quantum dot site, and no more than dot matrix film diameter, it is thus achieved that uniform and stable quantum dot site.

Description

A method for improving inkjet printing quantum dot dot light guide plate

technical field

The invention relates to a method for improving ink-jet printing quantum dot dot light guide plate.

Background technique

With the development of display technology, liquid crystal display (LCD) has become the most mature and widely used display device among many flat-panel display devices, and is still developing rapidly. LCD has the advantages of light and thin, low power consumption, and good heat dissipation performance. However, LCD itself does not emit light and needs to rely on an external backlight source. At present, the backlight sources on the market mainly use blue LEDs to excite the phosphor layer or the quantum dot layer to achieve white light. Because the white light obtained by the blue LED excitation phosphor layer is not natural enough, the color gamut is narrow, and the color rendering index is low. The narrow luminescence peak ensures the high purity of light; the luminescence color of quantum dots can be adjusted to achieve a higher color gamut, and the luminous efficiency is higher and the service life is longer. Therefore, quantum dot backlight has become a research hotspot.

At present, there are three main methods of mixing white light by exciting quantum dots: one is quantum dot tube (QD Tube): the quantum dot colloid is encapsulated in a glass tube, and then the quantum dot tube is placed in front of the LED.

This method uses the capillary principle to inject quantum dots into the glass tube. The method is simple and feasible, and saves quantum dot materials. However, the LED chip heats up seriously during the working process, and thermal radiation will cause luminescence quenching to quantum dots. , which reduces the luminous efficiency of quantum dots, and at the same time, it will cause color drift due to the influence of temperature; the second is quantum dot film (QDEF): coating quantum dot colloid on the upper surface of the light guide plate, although this method can avoid The influence of thermal radiation, but the large-area preparation causes waste of materials. The third is the quantum dot network: the quantum dot slurry is transferred to the lower surface of the light guide plate by screen printing or inkjet printing to form the quantum dot network. Although the screen printing process is simple, the printing accuracy is low, and the quantum dot glue also brings a certain surplus, resulting in waste. Although inkjet printing can print on demand and save quantum dot materials, the current quantum dot inks suitable for printing will have obvious coffee ring effect, which will affect the deposition morphology, and in order to achieve white balance, secondary printing is often performed Or multiple printings, the diffusion of the ink on the light guide leads to an increase in the area of the quantum dot dots, resulting in poor uniformity of the outgoing light.

Contents of the invention

The purpose of the present invention is to provide a method for improving the inkjet printing quantum dot network dot light guide plate, aiming to solve the problem of uniform stability of quantum dot network dots.

In order to achieve the above object, the technical solution of the present invention is: a method for improving the inkjet printing quantum dot dot light guide plate, by adjusting the composition of the quantum dot ink and the pretreatment of the light guide plate, using inkjet printing to print the quantum dot ink according to The predetermined pattern is printed on the surface of the light guide plate, and uniform and stable quantum dot dots are formed after curing to obtain a quantum dot dot light guide plate.

In an embodiment of the present invention, the light guide plate is made of organic glass with a refractive index of 1.49 and a thickness of 1.4-2mm.

In an embodiment of the present invention, the pretreatment of the light guide plate is to cover the light guide plate with the oleophobic film in the form of a surface or in the form of a dot matrix.

In an embodiment of the present invention, the oleophobic film includes polyvinylidene fluoride resin and acrylic polymer, and the refractive index of the oleophobic film is less than or equal to 1.49.

In an embodiment of the present invention, the oleophobic film covering the light guide plate in the form of a surface is realized by a scraping or spin coating process; the oleophobic film covering the light guide plate in the form of a dot matrix is realized by a printing process The single point diameter is 250~450um.

In an embodiment of the present invention, the uniform and stable quantum dot dot formation process specifically includes: printing the quantum dot ink on the surface of the light guide plate according to a predetermined pattern by inkjet printing, and forming quantum dot dots on the surface of the light guide plate after curing Arranging, the diameter of a single quantum dot network is 250-450 um, and not larger than the diameter of the dot matrix film.

In one embodiment of the present invention, the components of the quantum dot ink include quantum dots, solvents and polymers. According to the mass ratio, the quantum dots account for 2.3% to 6.8% of the total mass, and the solvent accounts for 51.4% of the total mass. % to 76.1%, the polymer accounts for 17.1% to 46.3% of the total mass.

In one embodiment of the present invention, the polymer is UV glue, and its components include acrylate prepolymer, active monomer and ultraviolet photoinitiator.

In one embodiment of the present invention, the quantum dots are a mixture of red quantum dots and green quantum dots, including CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS, the size distribution 1nm-10nm; the emission wavelength of the green quantum dots is 510-540 nm; the emission wavelength of the red quantum dots is 610-640 nm.

Compared with the prior art, the present invention has the following beneficial effects: the present invention adjusts the composition of the quantum dot ink and the pretreatment of the substrate, and prints the quantum dot slurry on the surface of the substrate according to a certain pattern by inkjet printing , a quantum dot network array formed on the surface of the substrate after curing, the diameter of a single quantum dot network is 250 ~ 450 um, and not larger than the diameter of the dot matrix film, to obtain uniform and stable quantum dot network; solve the problem of uniform quantum dot network Stability issues.

Description of drawings

Figure 1 is a schematic diagram of the distribution of quantum dots on an oleophobic film.

Figure 2 is the printing effect of the ink/substrate untreated (left picture) and treated (right picture).

Figure 3 is a schematic diagram of the distribution of quantum dots on the oleophobic lattice film.

Fig. 4 is a schematic diagram of the structure of a single quantum dot network.

detailed description

The technical solution of the present invention will be specifically described below in conjunction with the accompanying drawings.

A method for improving inkjet printing of quantum dot dot light guide plate of the present invention, by adjusting the composition of quantum dot ink and pretreatment of the light guide plate, inkjet printing is used to print the quantum dot ink on the surface of the light guide plate according to a predetermined pattern After curing, uniform and stable quantum dot dots are formed to obtain a quantum dot dot light guide plate.

The light guide plate is plexiglass with a refractive index of 1.49 and a thickness of 1.4-2 mm. The pretreatment of the light guide plate is to cover the light guide plate with the oleophobic film in the form of a surface or in the form of a lattice. The oleophobic film includes polyvinylidene fluoride resin and acrylic polymer, and the refractive index of the oleophobic film is less than or equal to 1.49. The oleophobic film covering the light guide plate in the form of a surface is realized by scraping or spin coating; the oleophobic film covering the light guide plate in the form of a dot matrix is realized by printing, and its single point diameter is 250 ~450um.

The uniform and stable quantum dot dot formation process specifically includes: printing the quantum dot ink on the surface of the light guide plate according to a predetermined pattern by inkjet printing, and forming quantum dot dots on the surface of the light guide plate after curing. The diameter of a single quantum dot dot is 250 ~ 450 um, and not larger than the diameter of the dot matrix film. The components of the quantum dot ink include quantum dots, solvents and polymers. According to the mass ratio, the quantum dots account for 2.3% to 6.8% of the total mass, the solvent accounts for 51.4% to 76.1% of the total mass, and the polymer Matter accounted for 17.1% to 46.3% of the total mass. The polymer is UV glue, and its components include acrylate prepolymer, active monomer and ultraviolet photoinitiator. The quantum dots are a mixture of red quantum dots and green quantum dots, including CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS, with a size distribution of 1 nm to 10 nm; the green The emission wavelength of the quantum dot is 510-540 nm; the emission wavelength of the red quantum dot is 610-640 nm.

The following is the specific embodiment process of the present invention.

In order to achieve the above purpose, the substrate spin-coating solution is photocurable glue (UV) diluted with absolute ethanol, wherein the UV glue accounts for 23.8% to 58.8% of the total mass; and the absolute ethanol accounts for 41.2% to 76.2% of the total mass. The ink of the quantum dot network dots printed by inkjet includes quantum dots, UV glue and chlorobenzene, the quantum dots account for 2.3% to 6.8% of the total mass, and the UV glue accounts for 17.1% to 46.3% of the total mass. Chlorobenzene accounts for 51.4% to 76.1% of the total mass.

Example 1

Referring to FIG. 1 , it is a schematic diagram of a first embodiment of a quantum dot grid light guide plate provided by the present invention. The quantum dot network point light guide plate includes organic glass 101 , oleophobic film 102 and quantum dot network point 103 .

The oleophobic film 102 is a photocurable glue (UV glue) with a refractive index of 1.48. The main function of UV glue is to change the surface free energy of the substrate, increase the contact angle of ink droplets on the substrate, and inhibit the diffusion of ink droplets.

The quantum dot network point 103 is a mixture of red quantum dots, green quantum dots and UV glue. Referring to FIG. 4, quantum dots 105 are dispersed in UV glue 106. Adding UV glue to quantum dot ink can increase the viscosity of the ink, and it can be quickly cured under the action of ultraviolet lamps, which inhibits the diffusion of ink droplets on the substrate.

In order to prepare the above-mentioned quantum dot network, the specific steps are as follows:

1) Prepare quantum dot ink:

First dissolve the quantum dots in the chlorobenzene solution, ultrasonically oscillate for 5-10 minutes in a low-power ultrasonic instrument to disperse the quantum dots evenly; then add the UV glue into the solution, and oscillate ultrasonically for 5-10 minutes to disperse the UV glue evenly. The mass relationship of each component is: 5.8 wt% quantum dots; 29.2 wt% UV glue; 65 wt% chlorobenzene;

2) Processing of the substrate

Prepare the UV solution, wherein the UV glue accounts for 55% of the total mass of the solution, and the solvent is selected from dehydrated alcohol, accounting for 45% of the total mass of the solution; Curing under action for 1min.

3) Preparation of quantum dot network

Print the dot array shown in Figure 1 with the prepared quantum dot ink through an inkjet printer. In order to avoid the coffee ring effect, after the printing work is completed, the printed quantum dot dots are immediately cured under the action of a UV lamp for 1 min. , to obtain a quantum dot dot light guide plate.

Figure 2 is the printing effect of ink/substrate untreated (left picture) and treated (right picture). It can be seen from the figure that the untreated quantum dot dots have obvious coffee rings, while the printed quantum dots after treatment The quantum dots are uniform and stable, which obviously greatly improves the printing effect of quantum dots.

Example 2

Referring to FIG. 3 , it is a schematic diagram of a second embodiment of the quantum dot grid light guide plate provided by the present invention. The quantum dot network point light guide plate includes organic glass 101 , oleophobic film 104 and quantum dot network point 103 .

The oleophobic film 104 is printed with a dot matrix film on the substrate by means of inkjet printing, and cured by an ultraviolet lamp. Wherein the UV glue accounts for 55% of the total mass of the solution, and absolute ethanol accounts for 45% of the total mass of the solution;

5.8 wt% of quantum dots, 29.2 wt% of UV glue and 65 wt% of chlorobenzene were formulated into quantum dot inks to print quantum dot dots in the original dot matrix film by printing, and cured by ultraviolet light for 1 min to obtain quantum dots Dot light guide plate.

The above are the preferred embodiments of the present invention, and all changes made according to the technical solution of the present invention, when the functional effect produced does not exceed the scope of the technical solution of the present invention, all belong to the protection scope of the present invention.

Claims (9)

1. A method for improving inkjet printing quantum dot dot light guide plate, characterized in that: by adjusting the composition of quantum dot ink and the pretreatment of light guide plate, inkjet printing is used to print the quantum dot ink to the On the surface of the light guide plate, uniform and stable quantum dot dots are formed after curing to obtain a quantum dot dot light guide plate. 2. A method for improving inkjet printing quantum dot dot light guide plate according to claim 1, characterized in that: said light guide plate is plexiglass with a refractive index of 1.49 and a thickness of 1.4-2 mm. 3. A method for improving inkjet printing quantum dot dot light guide plate according to claim 1 or 2, characterized in that: the pretreatment of the light guide plate is to form the oleophobic film in the form of a surface or in a dot matrix The form covers the light guide plate. 4. A method for improving inkjet printing quantum dot dot light guide plate according to claim 3, characterized in that: said oleophobic film includes polyvinylidene fluoride resin, acrylic polymer, and the refractive index of this oleophobic film is Less than or equal to 1.49. 5. A method for improving inkjet printing quantum dot dot light guide plate according to claim 3, characterized in that: said oleophobic film covering the light guide plate in the form of a surface is realized by scraping or spin coating; The oleophobic film covering the light guide plate in the form of a dot matrix is realized through a printing process, and the diameter of a single dot is 250-450um. 6. A method for improving inkjet printing of quantum dot network dot light guide plate according to claim 1, characterized in that: said uniform and stable quantum dot network dot formation process is specifically: inkjet printing quantum dot ink according to predetermined Graphically printed on the surface of the light guide plate, after curing, quantum dot dots are formed on the surface of the light guide plate. The diameter of a single quantum dot dot is 250-450 um, and it is not larger than the diameter of the dot matrix film. 7. A method of improving inkjet printing quantum dot dot light guide plate according to claim 6, characterized in that: the composition of said quantum dot ink comprises quantum dots, solvent and polymer, and by mass ratio, said quantum dot Points account for 2.3%-6.8% of the total mass, the solvent accounts for 51.4%-76.1% of the total mass, and the polymer accounts for 17.1%-46.3% of the total mass. 8. A method for improving inkjet printing quantum dot dot light guide plate according to claim 7, characterized in that: said polymer is UV glue, and its composition includes acrylate prepolymer, active monomer and UV photoinitiator. 9. A method for improving inkjet printing quantum dot dot light guide plate according to claim 7, characterized in that: said quantum dots are a mixture of red quantum dots and green quantum dots, including CdSe/ZnS, InP/ZnS , PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS, with a size distribution of 1 nm to 10 nm; the emission wavelength of the green quantum dots is 510 to 540 nm; the emission wavelength of the red quantum dots is 610 to 640 nm nm.