WO2021204034A1

WO2021204034A1 - Projection reflective screen coating and preparation method therefor

Info

Publication number: WO2021204034A1
Application number: PCT/CN2021/084195
Authority: WO
Inventors: 陆志毅; 张红秀; 王霖; 李屹
Original assignee: 深圳光峰科技股份有限公司
Priority date: 2020-04-07
Filing date: 2021-03-30
Publication date: 2021-10-14
Also published as: CN113493636B; CN113493636A

Abstract

The present application relates to the technical field of imaging display, and specifically disclosed thereby are a projection reflective screen coating and a preparation method therefor. A coating layer formed by the projection reflective screen coating has an average reflectivity of 10-30% for visible light in the wavelength range of 400-700 nm. The projection reflective screen coating comprises, in percentage by mass: 10-70% of film-forming resin, 0-5% of a crosslinker, 3-10% of aluminum silver paste, 3-10% of black paste, 5-15% of a discharge-promoting agent, 0.5-1% of a leveling agent, 0.5-3% of a dispersant, 0-0.5% of a defoamer and 10-75% of a first solvent. By using the means described above, the present application may significantly improve the brightness and contrast of a projection curtain, and reduce the impact of cluttered reflected light on the contrast of a screen while maintaining the considerable gain of the screen.

Description

Projection reflection screen paint and preparation method thereof

Technical field

This application relates to the field of imaging and display technology, in particular to a projection reflective screen coating and a preparation method thereof.

Background technique

The exquisite picture perceived by the human eye is directly displayed on the projection screen. According to different optical characteristics, the projection screens on sale in the market are mainly classified as follows: 1. Scattering screens-common varieties are relatively cheap white plastic screens, gray plastic screens, The metal screen is an improved product with improved image quality; 2. The gain screen at the incident angle—its product types are divided into glass bead screens and glass fiber screens; 3. The gain screen at the reflection angle—its product types are divided into Fresnel type and grating Type, micro lens\micro prism type.

In the long-term research and development process, the inventor of the present application found that the existing gain screens at the reflection angle have problems such as unclear projected content, uneven brightness of the projected content, and low brightness gain, which cannot satisfy the audience’s intuitive quality effects. desire.

Summary of the invention

The purpose of this application is to provide a projection reflective screen coating and a preparation method thereof to overcome the deficiencies of the prior art.

In order to solve the above technical problems, a technical solution adopted in this application is to provide a projection reflective screen coating, the coating formed by the projection reflective screen coating has an average reflectivity of 10-30% for visible light with a wavelength range of 400-700nm , Calculated by mass percentage, projection reflective screen coatings include: film-forming resin 10-70%, cross-linking agent 0-5%, aluminum silver paste 3-10%, black paste 3-10%, discharging accelerator 5-15 %, 10-75% of the first solvent.

In order to solve the above technical problems, another technical solution adopted in this application is to provide a method for preparing a projection reflective screen coating. Add 0.6-2 parts of the first solvent and 0.5-2 parts of the first solvent to the dispersing machine, stir until completely dispersed to obtain the aluminum-silver paste dispersion; according to the mass fraction, add 0.5-1 parts of the black paste and 4-10 parts of the film-forming resin 1 part and 1 to 6 parts of the first solvent are added to the dispersing machine and stirred to complete dispersion to obtain a basic dispersion; at least add the aluminum-silver paste dispersion and the first solvent to the basic dispersion, stir until the dispersion is completely dispersed, and then filter to obtain a preliminary Set the viscosity of the projection reflective screen paint.

The beneficial effects of this application are: different from the prior art, this application utilizes the light reflectivity of aluminum silver paste and the light absorption of black paste to control the paint’s full-spectrum reflectance of visible light within 10-30%. At the same time, this application adds a discharge promoter to improve the regularity of the filler arrangement in the paint, and the reflected light is also more regular. Therefore, the brightness and contrast of the projection screen can be significantly improved, while maintaining considerable screen gain, while reducing clutter The effect of reflected light on the contrast of the screen.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. in:

Figure 1 is a schematic structural diagram of a ring-shaped Fresnel reflective structure;

Figure 2 (a) is a schematic diagram of the structure of the flaky aluminum silver powder arranged in disorder;

Figure 2(b) is a schematic view of the structure of the regular arrangement of flaky aluminum silver powder;

Fig. 3 is a schematic diagram of the principle of the arrangement of silver powder promoted by the discharge accelerator of the present application;

Fig. 4 is a graph showing the reflectance curve of the coating formed by the coating for the projection reflective screen of the present application to visible light with wavelengths of 400-700nm;

5 is a schematic flow chart of an embodiment of a method for preparing a coating for projection reflective screens according to the present application;

Fig. 6 is a plane effect diagram of the projection reflective screen coating of the present application coated on the structural substrate;

Figure 7 is a cross-sectional effect view of the projection reflective screen coating applied to the structural substrate of the present application

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

First of all, this application provides a projection reflective screen paint, which is used to coat the Fresnel structure layer of a Fresnel screen to form a low-reflectivity coating. Figure 1 shows a ring-shaped Fresnel coating.尔Reflective structure. In Figure 1, the horizontal direction is the left and right direction of the screen, and the vertical direction is the up and down direction of the screen. As shown in Figure 1, the Fresnel structure layer is composed of a plurality of concentric rings.

The coating formed by the projection reflective screen paint has an average reflectivity of 10-30% for visible light with a wavelength range of 400-700 nm. Preferably, the coating formed by the projection reflective screen paint has a wavelength range of 400-700 nm. The average reflectivity of visible light is 20-25% (for example, 20%, 22%, or 25%). For example, in this embodiment, the thickness of the coating formed by the projection reflective screen paint is not uniform, and the coating is divided into There are 3 visible light reflection areas, each visible light reflection area has a reflectivity of 27%, 25%, and 23% for the visible light in the wavelength range of 400-700nm, respectively, (27+25+23)/3=25% becomes the coating The average reflectivity of the layer to visible light in the wavelength range of 400-700nm.

Among them, in terms of mass percentage, the projection reflective screen coating includes: 10-70% (for example, 10%, 40%, or 70%) of film-forming resin, and 0-5% (for example, 0%, 3%, or 5%) of cross-linking agent. , Aluminum and silver paste 3-10% (for example, 3%, 7% or 10%), black paste 3-10% (for example, 3%, 7% or 10%), 5% to 15% (for example, 5% , 7% or 15%), 10-75% of the first solvent (for example, 10%, 35%, or 75%).

Specifically, those skilled in the art know that the formulation of the paint has a greater impact on the projection effect of the screen. In order to realize the reflection of the projection light, aluminum silver paste is added to the projection reflective screen coating of the present application. The aluminum silver paste contains flake aluminum silver powder. The flake aluminum silver powder has good reflection ability to the projection light at a certain angle. .

Because the projection reflective screen coating contains aluminum silver paste, it is necessary to use a resin with good compatibility with aluminum silver paste. The film-forming resin has the following characteristics: low solid content, high viscosity, large molecular weight, narrow distribution, low acid value, High hydroxyl value and moderate glass transition temperature.

Preferably, the film-forming resin is a modified hydroxy acrylic resin that can achieve good alignment of aluminum and silver powder, and the hydroxyl value of the film-forming resin is 60-120 mgKOH/g (for example, 60, 80 or 120 mgKOH/g). The acid value is less than or equal to 0.5 mgKOH/g, and the solid content of the film-forming resin is 10-20% (for example, 10%, 15%, or 20%).

In order to achieve the purpose of high contrast and high gain at the same time, the projection reflective screen coating of the present application is added with a row-promoting agent. Figure 3 shows the principle of the row-promoting agent promoting the arrangement of silver powder. The discharging accelerator is used for coating rheological modification, reducing shrinkage and drying time to the touch, and can promote the parallel arrangement of the flake aluminum silver powder in the aluminum silver paste along the side of the structure substrate, and the flake aluminum silver powder forms a unified whole The reflection direction, thereby improving the utilization rate of the projection light of the projection reflective screen coating.

During the coating film formation process, with the volatilization of the solvent, the displacement promoter molecules with lower molecular weight and poor compatibility with the film-forming resin itself will tend to be distributed on the outer surface of the entire coating due to the edge effect. Solvent volatilization will cause the volume of the coating to shrink. For the molecules of the excretion accelerator, this volume shrinkage is more pronounced. This creates a strong contraction pressure at both ends of the coating. The aluminum and silver powders are flattened and arranged neatly. In addition, the molecules of the discharging promoter have a faster surface drying speed, and the arrangement of the aluminum-silver powder is set faster, so that the aluminum-silver powder has a better arrangement. Among them, as shown in Figure 2 (a) is the disorderly arrangement of the flake aluminum silver powder, each aluminum silver powder is like a small mirror reflecting the incident light in different directions, and finally causes the incident light from a fixed direction to pass through the coating After reflection, it becomes the reflected light with scattered directions, which is not good for projection light. As shown in Figure 2(b), the flaky aluminum and silver powders are arranged in a regular manner. The flaky aluminum and silver powders are all arranged in parallel along the side of the structural substrate, forming a unified reflection direction as a whole, so that the incident from a fixed direction The light has a more regular reflected light, which improves the utilization of the projection light and reduces the influence of the cluttered reflected light on the screen contrast.

In the long-term research and development process, the applicant found that if the color light reflectivity of a certain wavelength is high, and the color light reflectivity of another wavelength is low, even if the average reflectivity meets the design, it will cause chromatic aberration and affect the projection effect. In order to ensure that the projection screen has a certain contrast, the application adds black light-absorbing pigments that absorb light, such as light-absorbing particles such as carbon black, graphite, or metal oxide. The black paste can reduce the reflectivity of the coating and achieve a good balance between the absorption of ambient light and the reflection of projection light.

Figure 4 shows that the reflectance curve of the coating formed by the projection reflective screen coating on the visible light of 400-700nm wavelength is affected by different color fillers. (a) The reflectance curve of the coating with only aluminum silver paste and no black paste. The reflectivity gradually decreases from 400nm to 700nm. The coating reflects more blue light and less red light, and the reflectivity is very high. (The average reflectivity is about 82%), which is not up to the requirement. (b), (c), and (d) are all coating reflectance curves with black paste added and an average reflectance of 25%. (b) The black paste with coarse particle size is used, and the reflectivity of the coating increases gradually from 400nm to 700nm, the blue light is less reflected, and the red light is more reflected, resulting in a reddish screen hue. (c) is the reflectance curve of the coating with carbon black and blue pigment added with coarse particle size. The blue pigment has a certain effect on balancing the reddish phase, but the overall curve is wavy, and the effect is also unsatisfactory. (d) It is the coating reflectance curve of the black slurry with fine particle size. The visible curve is relatively flat in the full spectrum of visible light, and the screen does not have a large color shift, and the projection effect is better.

In terms of mass percentage, projection reflective screen coatings also include: leveling agent 0.5-1% (such as 0.5%, 0.8% or 1%), dispersing agent 0.5-3% (such as 0.5%, 1.5% or 3%), dispersant Foaming agent 0-0.5% (e.g. 0%, 0.3% or 0.5%).

Among them, the leveling agent can be polymethacrylate, polysiloxane or BYK-333, preferably, the leveling agent is BYK-333.

The dispersant is used to integrate the fusion and distribution uniformity of the above components. Among them, the dispersant can be amines, lipids, fatty acid polymers, such as epoxy/amine adducts, comb polyether alkanolamines, Dispersant such as isocyanate, preferably, the dispersant is BYK-163.

The defoaming agent may be a polysiloxane defoaming agent, a polyether modified silicone oil defoaming agent, and the like. Polysiloxane defoamers are easy to emulsify in water, also known as "self-emulsifying defoamers", and have a long-lasting defoaming effect. It has the characteristics of low surface tension, rapid defoaming, long anti-foaming time, low cost, low dosage, and wide application range. The polyether modified silicone oil defoamer has good heat resistance, shear resistance, acid, alkali, and salt resistance, plus the advantages of non-toxic, odorless, stable storage and convenient use. It has become a kind of excellent performance and has a wide range of applications. Prospective defoamer.

Different from the state of the art, this application uses the light reflectivity of aluminum silver paste and the light absorption of black paste to control the full-spectrum reflectivity of the paint to be between 10-30%. At the same time, this application adds The discharging promoter is used to improve the regularity of the fillers in the paint, and the reflected light is also more regular. Therefore, the brightness and contrast of the projection screen can be significantly improved. While maintaining the considerable gain of the screen, it reduces the influence of the cluttered reflected light on the screen contrast. .

In one embodiment, the aluminum-silver paste is a non-floating aluminum-silver paste, and the non-floating aluminum-silver paste has an excellent degree of coloring. The silver powder in the non-floating aluminum-silver paste is evenly arranged in parallel in the paint film and can be A variety of pigments are mixed with high stability. Among them, the non-floating aluminum silver paste contains flake aluminum silver powder, the average particle size of the non-floating aluminum silver paste is 10-12μm (for example, 10μm, 11μm or 12μm), and the solid content of the non-floating aluminum silver paste is 60- 70% (e.g. 60%, 65% or 70%).

In an embodiment, the discharging accelerator may be a cellulose resin solution. Preferably, in terms of mass percentage, the discharging accelerator includes: 25-35% of cellulose acetate butyrate resin and 65-75% of the second solvent.

The cross-linking agent can be a polyisocyanate cross-linking agent, which is used for cross-linking reaction with the hydroxyl group of the film-forming resin, and the cross-linking agent can be a hexamethylene-diisocyanate cross-linking agent, such as BASF Basonat HI 190 or One or a combination of Bayer N3390.

When visible light passes through the carbon black layer, short-wave blue light has a stronger scattering effect than long-wave red light. The finer the carbon black, the more obvious this effect. Therefore, when observing the reflection process, a blue hue appears after the coloring of fine carbon black. In addition, since the degree of light scattering of carbon black decreases as the particle size decreases, the finer the carbon black, the higher the blackness. If the carbon black is coarse, the carbon black with a coarse particle size (such as >30μm) shows a reddish hue. However, the particle size of the black paste is not as small as possible. When it reaches the nanometer level, it is not easy to disperse. Therefore, preferably, the application selects black paste with a light-absorbing particle diameter of 3-6μm and a solid content of 40% as the black light-absorbing pigment, which can control the average reflectivity of the coating at 10-30% while ensuring the The full spectrum of visible light has a flat reflectance curve, which reduces the chromatic aberration of the screen.

The first solvent and the second solvent are selected from at least one of methyl isobutyl ketone, butyl acetate, cyclohexanone, isophorone, or propylene glycol methyl ether acetate.

Referring to Fig. 5, Fig. 5 is a schematic flow diagram of an embodiment of a method for preparing a projection reflective screen coating according to the present application, and the method includes:

Step S101: In terms of parts by mass, add 0.5-1 part of the aluminum-silver paste, 0.6-2 parts of the discharging accelerator, and 0.5-2 parts of the first solvent into the dispersing machine, and stir until completely dispersed to obtain an aluminum-silver paste dispersion.

Step S102: adding 0.5-1 part of the black slurry, 4-10 parts of the film-forming resin and 1-6 parts of the first solvent to the dispersing machine based on the mass fraction, and stirring to complete dispersion to obtain a basic dispersion.

Wherein, the black slurry at least includes at least one light-absorbing particles of carbon black, graphite or metal oxide and a third solvent. Preferably, the composition of the third solvent may be the same as the composition of the first solvent. Further, the black paste may contain other auxiliary agents, such as a dispersant, which can enhance the stable dispersibility of the light-absorbing particles in the third solvent. It should be noted that the black paste is commercially available.

In step S102, 0.01-0.1 parts of dispersant can be added to the dispersing machine in terms of mass fraction to integrate the fusion and uniformity of distribution of the above-mentioned components (black paste, film-forming resin, and first solvent).

Furthermore, in step S102, 0.01-0.03 parts of leveling agent can be added to the disperser based on the mass fraction to promote the projection reflective screen paint to form a flat, smooth and uniform coating during the drying and film forming process.

Step S103: Add at least the aluminum-silver paste dispersion and the first solvent to the basic dispersion, stir until the dispersion is completely dispersed, and filter to obtain a projection reflective screen paint with a preset viscosity.

It is understandable that a defoamer with strong anti-foaming properties and not affecting various technical parameters of the system can be added to the slurry in step S103.

The above-mentioned aluminum-silver paste may be a non-floating aluminum-silver paste. The silver powder in the non-floating aluminum-silver paste is uniformly and parallelly arranged in the paint film, and can be mixed with a variety of pigments with high stability. Among them, the non-floating aluminum-silver paste contains flake aluminum-silver powder, the average particle size of the non-floating aluminum-silver paste is 10-12 μm, and the solid content of the non-floating aluminum-silver paste is 60-70%.

The discharging accelerator is used for coating rheological modification, reducing shrinkage and drying time to the touch, and can promote the parallel arrangement of the flake aluminum silver powder in the aluminum silver paste along the side of the structure substrate, and the flake aluminum silver powder forms a unified whole The reflection direction, thereby improving the utilization rate of the projection light of the projection reflective screen coating. In terms of mass percentage, the excretion promoting agent includes: 25-35% of cellulose acetate butyrate resin and 65-75% of the second solvent.

The black paste can reduce the reflectivity of the coating and achieve a good balance between the absorption of ambient light and the reflection of projection light. Preferably, this application selects black paste with a light-absorbing particle diameter of 3-6μm and a solid content of 40% as the black light-absorbing pigment, which can control the average reflectivity of the coating to 10-30% while ensuring full exposure to visible light. The spectrum has a flat reflectance curve, reducing the chromatic aberration of the screen.

The film-forming resin may be a modified hydroxy acrylic resin with good aluminum-silver powder alignment. The hydroxy value of the film-forming resin is 60-120 mgKOH/g, and the acid value of the film-forming resin is less than or equal to 0.5 mgKOH/g. The solid content of the resin is 10-20%.

Step S103 further includes: adding the aluminum-silver paste dispersion, a crosslinking agent, and a first solvent to the basic dispersion. Wherein, the amount of the crosslinking agent is 3-10% of the total mass of the film-forming resin.

The method includes step S104: adding 2.5-3.5 parts of cellulose acetate butyrate resin and 6.5-7.5 parts of the second solvent into a stirring tank in parts by mass, at a temperature of 60-70°C and a stirring speed of 300-400 rpm Under the conditions, stirring for 1-2 hours until the cellulose acetate butyrate resin is completely dissolved, and cooling to room temperature to obtain the excretion promoting agent.

Referring to Figures 6-7, the effect of the projection reflective screen coating on the structural substrate is shown. The coating obtained by the composition and preparation method of the application can be uniformly attached to the structural substrate, and the aluminum-silver powder The arrangement tends to be parallel to the plane of the structural substrate.

In order to make the objectives, technical solutions, and advantages of the present application clearer, the application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain this application, and are not limited to this application.

Example 1

Preparation of CAB Promoting Agent Solution

The cellulose acetate butyrate resin (CAB) and the second solvent are put into a stirring tank at a mass ratio of 3:7, and the temperature is raised to 70° C. while stirring, and the stirring speed is 300-400 rpm. Mix and dissolve for 1-2 hours, until the cellulose acetate butyrate resin is completely dissolved to obtain a transparent and colorless solution, and the material is cooled and discharged to obtain a CAB drainage accelerator solution with a mass percentage of 30%. Among them, the second solvent is cyclohexanone, and may also be other solvents that are compatible with CAB.

Example 2

Preparation of low-reflection paint for single-component spraying

Add the aluminum silver paste (particle size 3μm, solid content 70%), the CAB discharge accelerator solution prepared in Example 1, and ethyl acetate into the high-speed disperser, where the aluminum silver paste, CAB discharge accelerator solution, ethyl acetate The ratio of esters in parts by mass is (0.5-1):(0.6-2):(0.8-2). Set the stirring speed to 300-400 rpm, stir and disperse for 2-3 hours, to prepare the aluminum-silver paste dispersion.

Add the black slurry (particle size 3μm, solid content 50%-70%), 10% solid content modified hydroxy acrylic resin, leveling agent BYK-333, dispersant, and ethyl acetate into the high-speed disperser and stir to disperse , Wherein the ratio of mass parts of black paste, modified hydroxy acrylic resin, dispersant, and ethyl acetate is: (0.5-1):(4-10):(0.01-0.1):(2-6). Set the stirring speed to 300-400rpm. After the black slurry is completely dispersed, add the prepared aluminum-silver slurry dispersion to the system while stirring, add ethyl acetate to adjust the viscosity to 3000-5000 cps, and stir for 20 minutes.

The paint prepared in Example 2 can be applied to the back of the Fresnel structure layer of the Fresnel screen by spraying, silk screen printing, coating and other construction methods.

Example 3

Preparation of low-reflection coating for single-component roll coating

Add the aluminum silver paste (particle size 3μm, solid content 70%), the CAB discharge accelerator solution, dispersant, and ethyl acetate prepared in Example 1 into the high-speed disperser, among which the aluminum silver paste, the CAB discharge accelerator solution The ratio of parts by mass of ethyl acetate is (0.5-1):(0.6-2):(0.5-2). Set the stirring speed to 300-400 rpm, stir and disperse for 2-3 hours, to prepare the aluminum-silver paste dispersion.

Add the black slurry (particle size 3μm, solid content 50%-70%), 10% solid content modified hydroxy acrylic resin, leveling agent BYK-333, dispersant, and ethyl acetate into the high-speed dispersant, stir and disperse , Wherein the ratio of mass parts of black paste, modified hydroxy acrylic resin, dispersant, and ethyl acetate is: (0.5-1):(4-10):(0.01-0.1):(1-6). Set the stirring speed to 300-400rpm. After the black slurry is completely dispersed, add the prepared aluminum-silver slurry dispersion to the system while stirring, and add ethyl acetate to adjust the viscosity to a suitable viscosity of 5000-8000cps.

After the pigments and fillers are completely dispersed, use a 400-mesh filter to filter the paint to obtain a one-component low-reflection paint for roller coating.

Example 4

Preparation of low-reflection paint for two-component spraying

Add aluminum silver paste (particle size 3μm, solid content 70%), the CAB discharge accelerator solution, dispersant, and ethyl acetate prepared in Example 1 into the high-speed dispersing machine, where aluminum silver paste, CAB, ethyl acetate The ratio of mass parts is (0.5-1):(0.6-2):(0.8-2). Set the stirring speed to 300-400 rpm, stir and disperse for 2-3 hours, to prepare the aluminum-silver paste dispersion.

Add the black slurry (particle size 3μm, solid content 50%-70%), 10% solid content modified hydroxy acrylic resin, leveling agent BYK-333, dispersant, and ethyl acetate into the high-speed dispersant dispersing machine Stir and disperse. The ratio of the mass parts of the black slurry, modified hydroxy acrylic resin, dispersant, and ethyl acetate is: (0.5-1):(4-10):(0.01-0.1):(2-6) . Set the stirring speed to 300-400rpm. After the black paste is completely dispersed, add the prepared aluminum-silver paste dispersion to the system while stirring, add 3%-10% of the crosslinking agent by mass of the acrylic resin, and add ethyl acetate to adjust the viscosity to Suitable viscosity 3000-5000cps,

The prepared paint can be applied to the back of the Fresnel structure layer of the Fresnel screen by spraying, silk screen and other construction methods.

Example 5

Preparation of low-reflection coating for two-component roll coating

Add aluminum silver paste (particle size 3μm, solid content 70%), the CAB discharge accelerator solution, dispersant, and ethyl acetate prepared in Example 1 into the high-speed disperser, among which aluminum silver paste, CAB, ethyl acetate The ratio of mass parts is (0.5-1):(0.6-2):(0.5-2). Set the stirring speed to 300-400 rpm, stir and disperse for 2-3 hours, to prepare the aluminum-silver paste dispersion.

Add the black slurry (particle size 3μm, solid content 50%-70%), 10% solid content modified hydroxy acrylic resin, leveling agent BYK-333, dispersant, and ethyl acetate into the high-speed dispersant disperser Stir and disperse, in which the ratio of mass parts of black slurry, modified hydroxy acrylic resin, dispersant, and ethyl acetate is: (0.5-1):(4-10):(0.01-0.1):(1-6) . Set the stirring speed to 300-400rpm. After the black paste is completely dispersed, add the prepared aluminum-silver paste dispersion to the system while stirring, add 3%-10% of the crosslinking agent by mass of the acrylic resin, and add ethyl acetate to adjust the viscosity to Suitable viscosity 5000-8000cps,

After the pigments and fillers are completely dispersed, use a 400-mesh filter to filter the paint to obtain a low-reflection paint for two-component roll coating.

Example 6

The applicant conducted a research on the influence of the black paste and aluminum-silver paste ratio on the average reflectivity of the coating. The experimental results show that see Table 1. By adjusting the ratio of the black paste and aluminum-silver paste, the wavelength of the coating can be adjusted regularly. The average reflectance of visible light in the range of 400-700nm. With the increase of the black paste, the reflectivity of the coating gradually decreases. Therefore, the appropriate ratio between the two can be adjusted to prepare a low reflectivity coating with an average reflectivity of 10-30%.

Table 1 The influence of the proportion of black paste and aluminum-silver paste on the average reflectivity of the coating

The above are only implementations of this application, and do not limit the scope of this application. Any equivalent structure or equivalent process transformation made using the content of the description and drawings of this application, or directly or indirectly applied to other related technologies In the same way, all fields are included in the scope of patent protection of this application.

Claims

A projection reflective screen coating, wherein the coating formed by the projection reflective screen coating has an average reflectivity of 10-30% for visible light with a wavelength range of 400-700nm, and the projection reflective Screen coatings include: film-forming resin 10-70%, cross-linking agent 0-5%, aluminum silver paste 3-10%, black paste 3-10%, discharge accelerator 5-15%, first solvent 10-75 %.
The projection reflective screen coating according to claim 1, characterized in that, in terms of mass percentage, the projection reflective screen coating further comprises: 0.5-1% of leveling agent, 0.5-3% of dispersant, and 0-% of defoaming agent. 0.5%.
The projection reflective screen coating of claim 1, wherein:

The hydroxyl value of the film-forming resin is 60-120 mgKOH/g, the acid value of the film-forming resin is less than or equal to 0.5 mgKOH/g, and the solid content of the film-forming resin is 10-20%.
The projection reflective screen paint according to claim 1, wherein the aluminum silver paste is a non-floating aluminum silver paste, and the non-floating aluminum silver paste contains flake aluminum and silver powder, and the non-floating aluminum silver paste The average particle size of the silver paste is 10-12 μm, and the solid content of the non-floating aluminum silver paste is 60-70%.
The projection reflective screen coating of claim 1, wherein:

In terms of mass percentage, the discharge promoting agent includes: 25-35% of cellulose acetate butyrate resin and 65-75% of the second solvent;

The crosslinking agent is a polyisocyanate crosslinking agent;.

The black paste contains light-absorbing particles, the particle size of the light-absorbing particles is 3-6 μm, and the solid content of the black paste is 40%;

The first solvent and the second solvent are selected from at least one of methyl isobutyl ketone, butyl acetate, cyclohexanone, isophorone, or propylene glycol methyl ether acetate.
A preparation method of projection reflective screen coating, characterized in that the preparation method comprises the following steps:

In terms of parts by mass, add 0.5-1 part of aluminum-silver paste, 0.6-2 parts of the discharging accelerator and 0.5-2 parts of the first solvent into the dispersing machine, and stir until it is completely dispersed to obtain an aluminum-silver paste dispersion;

According to the mass fraction, add 0.5-1 part of the black slurry, 4-10 parts of the film-forming resin and 1-6 parts of the first solvent into the dispersing machine, and stir until completely dispersed to obtain a basic dispersion;

At least add the aluminum-silver paste dispersion and the first solvent to the basic dispersion, stir until the dispersion is completely dispersed, and then filter to obtain the projection reflective screen paint with a preset viscosity.
The preparation method according to claim 6, wherein the step of adding at least the aluminum-silver paste dispersion and the first solvent to the basic dispersion further comprises:

Adding the aluminum-silver paste dispersion, the crosslinking agent and the first solvent to the basic dispersion;

Wherein, the amount of the crosslinking agent is 3-10% of the total mass of the film-forming resin;

The first solvent is selected from at least one of methyl isobutyl ketone, butyl acetate, cyclohexanone, isophorone, or propylene glycol methyl ether acetate.
The preparation method according to claim 6, wherein the method further comprises the following steps:

In parts by mass, add 2.5-3.5 parts of cellulose acetate butyrate resin and 6.5-7.5 parts of the second solvent into the stirring tank, and stir under the conditions of a temperature of 60-70°C and a stirring speed of 300-400 rpm 1-2 hours, until the cellulose acetate butyrate resin is completely dissolved, and the excretion promoting agent is obtained after cooling to room temperature;

The second solvent is selected from at least one of methyl isobutyl ketone, butyl acetate, cyclohexanone, isophorone, or propylene glycol methyl ether acetate.
The preparation method according to claim 6, wherein:

The hydroxyl value of the film-forming resin is 60-120 mgKOH/g, the acid value of the film-forming resin is less than or equal to 0.5 mgKOH/g, and the solid content of the film-forming resin is 10-20%;

The aluminum-silver paste is a non-floating aluminum-silver paste, the non-floating aluminum-silver paste contains flake aluminum-silver powder, the average particle size of the non-floating aluminum-silver paste is 10-12 μm, and the non-floating aluminum-silver paste The solid content of aluminum silver paste is 60-70%;

The crosslinking agent is a polyisocyanate crosslinking agent;.

The black paste contains light-absorbing particles, the particle size of the light-absorbing particles is 3-6 μm, and the solid content of the black paste is 40%.
The preparation method according to claim 7, wherein:

When the projection reflective screen paint is a spray paint, the preset viscosity is 3000-5000cps;

When the projection reflective screen paint is a paint for roller coating, the preset viscosity is 5000-8000 cps.