Optical plate capable of removing formaldehyde and preparation method thereof

Abstract

The application relates to the field of formaldehyde-removing optical diffusion plates, and particularly discloses a formaldehyde-removing optical plate and a preparation method thereof. The formaldehyde-removing optical diffusion plate comprises a formaldehyde-removing layer and a diffusion layer, the formaldehyde-removing layer comprises 2-10% of formaldehyde-removing master granules and the balance of base material resin; the formaldehyde-removing master granules comprise 10-30% of nano-titanium dioxide solution, 1-4% of a compatilizer, 0.1-2% of a dispersing agent and the balance of base material resin; the nano-titanium dioxide solution comprises 5-30% of nano-titanium dioxide, 64-90% of silica sol, 0.1-2% of a dispersing agent and 1-4% of a compatilizer; the preparation method of the formaldehyde-removing master granules comprises nano-titanium dioxide solution preparation and extrusion granulation; the diffusion layer comprises 1.5-2% of anti-aging master granules, 1-4% of diffusion master granules and the balance of base material resin; and the method is as follows: mixing components of the formaldehyde-removing layer, mixing components of the diffusion layer and extruding and calendering through a double-layer composite device. The application obtains the formaldehyde-removing optical diffusion plate which can slow down the yellowing phenomenon.

Description

TECHNICAL FIELD

[0001] The application relates to the field of formaldehyde-removing optical diffusion plates, in particular to a formaldehyde-removing optical diffusion plate and a preparation method thereof. BACKGROUND

[0002] The optical diffusion plate refers to a plate used for transmitting light, and an organic material is usually used as the base material. With the improvement of people's living standards, people have higher and higher requirements for optical diffusion plates, such as producing optical diffusion plates with formaldehyde-removing function. At present, the optical diffusion plate mainly removes formaldehyde by coating a photocatalyst coating on the surface of the plate. The photocatalyst coating usually takes nano-titanium dioxide as the main component. After the photocatalyst coating is coated on the surface of the optical diffusion plate, the photocatalyst coating can catalyze water or oxygen in the air to form hydroxyl radicals and other groups with oxidation ability under light irradiation. The hydroxyl radicals and formaldehyde in the air undergo oxidation-reduction reaction to generate carbon dioxide and water, and the photocatalyst coating realizes the effect of absorbing and decomposing formaldehyde in the air.

[0003] However, under the action of photocatalysis, the photocatalyst coating not only can decompose formaldehyde in the air, but also can easily oxidize the organic material base material in the optical diffusion plate, causing corrosion of the optical diffusion plate, yellowing of the optical diffusion plate and affecting the service life of the optical diffusion plate. SUMMARY

[0004] In order to reduce the phenomenon that the photocatalyst coating is easy to oxidize the organic material base material in the optical diffusion plate when the photocatalyst coating is directly coated on the surface of the optical diffusion plate, causing yellowing of the optical diffusion plate, the application provides a formaldehyde-removing optical diffusion plate and a preparation method thereof.

[0005] The formaldehyde-removing optical diffusion plate and the preparation method thereof provided by the application adopt the following technical scheme:

[0006] In a first aspect, the application provides a formaldehyde-removing optical diffusion plate, which adopts the following technical scheme:

[0007] The formaldehyde-removing optical diffusion plate comprises a formaldehyde-removing layer and a diffusion layer, and the formaldehyde-removing layer comprises the following components by weight percentage: formaldehyde-removing master batch 2-10%, and the balance is base material resin; the formaldehyde-removing master batch comprises the following components by weight percentage: nano-titanium dioxide solution 10-30%, compatibilizer 1-4%, dispersant 0.1-2%, and the balance is base material resin; the nano-titanium dioxide solution comprises the following components by weight percentage: nano-titanium dioxide 5-30%, silica sol 64-90%, dispersant 0.1-2%, and compatibilizer 1-4%.

[0008] The preparation method of the formaldehyde-removing master batch comprises the following steps:

[0009] The nano-titanium dioxide solution is prepared by ball-milling and blending the weighed nano-titanium dioxide, silica sol, dispersant and compatibilizer, the ball-milling speed is 400-600 rpm, and the ball-milling time is 5-6 h.

[0010] The nano-titanium dioxide solution is stirred and mixed with the base resin, and then extruded and granulated by a double screw extruder.

[0011] The diffusion layer comprises the following components by weight percentage: 1.5-2% of anti-aging masterbatch, 1-4% of light diffusion masterbatch, and the balance of base resin.

[0012] By adopting the technical scheme, the optical diffusion plate with a composite layer structure is obtained by arranging the formaldehyde removal layer and the diffusion layer, i.e., a multi-layer composite structure of formaldehyde removal layer-diffusion layer-formaldehyde removal layer. The optical diffusion plate absorbs and decomposes formaldehyde in the formaldehyde removal layer under the photocatalysis. In the composite layer structure of the optical diffusion plate, the yellowing of the optical diffusion plate caused by oxidation of the formaldehyde removal layer and the diffusion layer is alleviated, thereby prolonging the service life of the optical diffusion plate. The reason may be that the nano-titanium dioxide, silica sol, dispersant and compatibilizer are uniformly dispersed by ball-milling. The silica sol forms a crystal capsule for coating the nano-titanium dioxide particles in the ball-milling process. The addition of the dispersant and compatibilizer is beneficial to the silica sol fully coating the nano-titanium dioxide particles, and the nano-titanium dioxide solution is prepared. The nano-titanium dioxide solution is mixed with the base resin, and then extruded and granulated by a double screw extruder to obtain the formaldehyde removal masterbatch. The nano-titanium dioxide solution formed by the silica sol coating the nano-titanium dioxide penetrates into the inside of the base resin. The coating crystal capsule of the silica sol can reduce the direct contact between the nano-titanium dioxide and the base resin, thereby reducing the yellowing of the base resin caused by the oxidation of the nano-titanium dioxide to the base resin. The optical diffusion plate has excellent formaldehyde removal effect and prolongs the service life.

[0013] The addition of the light diffusion masterbatch and the anti-aging masterbatch in the diffusion layer can obtain the inner layer material of the optical diffusion plate with good optical performance and anti-aging performance.

[0014] Optionally, the formaldehyde removal masterbatch further comprises auxiliary additives 0.8-1.5% by weight percentage, and the auxiliary additives comprise sodium stearate and isoamyl acetate in a weight ratio of 1:(0.6-1.0).

[0015] During the experiment, it is found that the mechanical properties of the optical diffusion plate are improved by adding sodium stearate and isoamyl acetate into the formaldehyde-removing master batch and then preparing the formaldehyde-removing layer through the formaldehyde-removing master batch. The reason is that sodium stearate and isoamyl acetate can improve the tensile strength and bending strength of the formaldehyde-removing layer, and then improve the tensile strength and bending strength of the optical diffusion plate. Further analysis shows that the volume of the silica sol shrinks or aggregates due to temperature change during the preparation of the formaldehyde-removing layer through the formaldehyde-removing master batch. There is a gap between the silica sol particles and the base resin. Sodium stearate is uniformly distributed between the silica sol and the base resin through isoamyl acetate, which has good compatibility. Sodium stearate can improve the cross-linking degree between the silica sol particles and the base resin, so that the tensile strength and bending strength of the optical diffusion plate are improved, and the optical diffusion plate has good wear resistance.

[0016] Optionally, the base resin is one of polymethyl methacrylate, polycarbonate, styrene-methyl methacrylate resin, polystyrene or polypropylene.

[0017] By adopting the above technical solution, the polymethyl methacrylate, polycarbonate, styrene-methyl methacrylate resin, polystyrene and polypropylene have high transparency and good heat resistance, and the optical diffusion plate with good optical performance can be prepared.

[0018] Optionally, the particle size of the nano-titanium dioxide is 50-100 nm.

[0019] By adopting the above technical solution, the particle size of the nano-titanium dioxide is 50-100 nm, which is beneficial to the dispersion of the nano-titanium dioxide and the full mixing of the nano-titanium dioxide and the silica sol. The silica sol fully covers the nano-titanium dioxide particles to ensure the anti-yellowing performance of the formaldehyde-removing master batch on the base resin.

[0020] Optionally, the dispersing agent is one or more of sodium pyrophosphate, sodium hexametaphosphate and sodium tripolyphosphate.

[0021] By adopting the above technical solution, sodium pyrophosphate, sodium hexametaphosphate and sodium tripolyphosphate are beneficial to the dispersion of the nano-titanium dioxide coated with the silica sol in the base resin, and improve the filling property and dispersibility of the silica sol and the nano-titanium dioxide.

[0022] Optionally, the temperature of the first zone in the extrusion granulation is 180-195℃, the temperature of the second zone is 190-200℃, the temperature of the third zone is 200-220℃, the temperature of the fourth zone is 205-220℃, the temperature of the fifth zone is 210-220℃, and the temperature of the sixth zone is 210-220℃.

[0023] By adopting the technical scheme, the formaldehyde-removing master batch can be prepared, the silica sol fully coats the nano titanium dioxide and is uniformly dispersed in the base resin in the formaldehyde-removing master batch. The formaldehyde-removing master batch is added to the formaldehyde-removing layer, the formaldehyde-removing layer has good formaldehyde absorption and decomposition effect, and the silica sol coated nano titanium dioxide can reduce the contact possibility between the nano titanium dioxide and the base resin.

[0024] Optionally, in the preparation method of the formaldehyde-removing master batch, the extrusion speed of the extrusion granulation is 280-480 r / min.

[0025] By adopting the technical scheme, the silica sol is fully mixed with the base resin under the action of the dispersant and the compatibility agent I to form a uniform master batch mixture, thereby improving the finished product quality of the formaldehyde-removing master batch.

[0026] Optionally, the particle size of the silica sol is 8-25 nm.

[0027] By adopting the technical scheme, when the particle size of the silica sol is 8-25 nm, the silica sol particles are beneficial to be dispersed in the base resin, the phenomenon of automatic coalescence of the silica sol particles is reduced, and the stability of the silica sol is improved.

[0028] Optionally, the thickness ratio of the formaldehyde-removing layer to the diffusion layer is 1:(4-9).

[0029] By adopting the technical scheme, the thickness distribution of the formaldehyde-removing layer and the diffusion layer is reasonable, the optical diffusion plate material has good formaldehyde-removing effect and improves the durability of the formaldehyde-removing effect while ensuring the mechanical properties of the optical diffusion plate material.

[0030] In a second aspect, the application provides a preparation method of an optical diffusion plate material capable of removing formaldehyde, which adopts the following technical scheme:

[0031] A preparation method of an optical diffusion plate material capable of removing formaldehyde, comprising the following steps:

[0032] Preparation of the mixture A: the weighed components of the formaldehyde-removing layer are stirred to be uniformly mixed to obtain the mixture A;

[0033] Preparation of the mixture B: the weighed components of the diffusion layer are stirred to be uniformly mixed to obtain the mixture B;

[0034] Extrusion and calendering: the mixture A and the mixture B are respectively melted and plasticized and then extruded and calendered to form the optical diffusion plate material, the extrusion temperature is 160-220℃, and the calendering temperature is 110-140℃.

[0035] By adopting the technical scheme, the optical diffusion plate material comprises a formaldehyde removal layer and a diffusion layer, the formaldehyde removal layer absorbs and decomposes formaldehyde, and the addition of nano titanium dioxide coated with silica sol in the formaldehyde removal layer can reduce the phenomenon of oxidation and yellowing of the optical diffusion plate material. The optical diffusion plate material is prepared by extrusion and calendering to obtain an optical diffusion plate material with a composite layer structure, which can save processing procedures and reduce the cost of photocatalyst coating caused by coating process.

[0036] In summary, the present application has the following beneficial effects:

[0037] 1. The present application obtains an optical diffusion plate material with a composite layer structure by setting a formaldehyde removal layer and a diffusion layer. Nano titanium dioxide is ball milled and mixed with silica sol. The silica sol forms a crystal capsule coated with nano titanium dioxide during the ball milling process. The coated crystal capsule formed by the silica sol can reduce the possibility of direct contact between nano titanium dioxide and the base resin, making it difficult for nano titanium dioxide to directly oxidize the base resin under photocatalysis, thereby reducing the yellowing problem of the optical diffusion plate material. The optical diffusion plate material has excellent formaldehyde removal effect and prolongs its service life;

[0038] 2. The addition of sodium stearate and isoamyl acetate can improve the mechanical properties of the optical diffusion plate material. The tensile strength and bending strength of the optical diffusion plate material are improved, and the optical diffusion plate material has good wear resistance;

[0039] 3. The preparation method of the present application can obtain an optical diffusion plate material with a composite layer structure. The optical diffusion plate material has good formaldehyde removal effect, reduces the yellowing problem of the optical diffusion plate material caused by oxidation of the base resin by nano titanium dioxide, prolongs the service life of the optical diffusion plate material, and saves the coating process and cost of the formaldehyde removal layer and the diffusion layer by extrusion and calendering. DETAILED DESCRIPTION

[0040] The present application is further described below.

[0041] Raw material introduction

[0042] Table 1 Preparation of optical diffusion plate material

[0043] Embodiment

[0044] Embodiment 1

[0045] The application discloses a formaldehyde-removing optical diffusion plate, which comprises a formaldehyde-removing layer and a diffusion layer, and the thickness ratio of the formaldehyde-removing layer to the diffusion layer is 1:4; the formaldehyde-removing layer comprises the following components in percentage by weight: 2% of formaldehyde-removing master batch and the balance of polystyrene; the formaldehyde-removing master batch comprises the following components in percentage by weight: 30% of nano-titanium dioxide solution, 1% of MAH-g-EPDM, 2% of sodium pyrophosphate and the balance of polystyrene; the nano-titanium dioxide solution comprises the following components in percentage by weight: 5% of nano-titanium dioxide, 90% of silica sol, 0.1% of sodium pyrophosphate and 4% of MAH-g-EPDM; the particle size of the nano-titanium dioxide is 50 nm, and the particle size of the silica sol is 25 nm.

[0046] The preparation method of the formaldehyde-removing master batch comprises the following steps:

[0047] The nano-titanium dioxide solution is prepared by ball milling and blending the weighed nano-titanium dioxide, silica sol, sodium pyrophosphate and MAH-g-EPDM, the ball milling speed is 600 rpm, and the ball milling time is 5 hours;

[0048] The nano-titanium dioxide solution is injected into the cylinder of a double-screw extruder through a hot-body metering injector, and the weighed polystyrene is added into the cylinder of the double-screw extruder for mixing and plasticizing, the extrusion speed is 280 r / min, and the extrusion granulation is carried out through the double-screw extruder, wherein the temperature of the first zone is 185 DEG C, the temperature of the second zone is 195 DEG C, the temperature of the third zone is 205 DEG C, the temperature of the fourth zone is 215 DEG C, the temperature of the fifth zone is 210 DEG C, and the temperature of the sixth zone is 215 DEG C.

[0049] The diffusion layer comprises the following components in percentage by weight: 1.5% of anti-aging master batch, 1% of light diffusion master batch and the balance of polystyrene.

[0050] The preparation method of the formaldehyde-removing optical diffusion plate comprises the following steps:

[0051] The preparation of mixture A: the components of the formaldehyde-removing layer are stirred to be uniformly mixed to obtain mixture A;

[0052] The preparation of mixture B: the components of the diffusion layer are stirred to be uniformly mixed to obtain mixture B;

[0053] The mixture A and the mixture B are respectively melt-plasticized, extruded into plates through a distributor and a die, and formed into optical diffusion plates through three-roller calendering, the extrusion temperature is 220 DEG C, and the calendering temperature is 120 DEG C.

[0054] Example 2

[0055] The application discloses a formaldehyde-removing optical diffusion plate, which comprises a formaldehyde-removing layer and a diffusion layer, and the thickness ratio of the formaldehyde-removing layer to the diffusion layer is 1:9; the formaldehyde-removing layer comprises, in percentage by weight, 10% of formaldehyde-removing master batch and the balance of polystyrene; the formaldehyde-removing master batch comprises, in percentage by weight, 10% of nano-titanium dioxide solution, 4% of MAH-g-EPDM, 0.1% of sodium pyrophosphate and the balance of polystyrene; the nano-titanium dioxide solution comprises, in percentage by weight, 30% of nano-titanium dioxide, 64% of silica sol, 2% of sodium pyrophosphate and 1% of MAH-g-EPDM; the nano-titanium dioxide has a particle size of 100 nm, and the silica sol has a particle size of 8 nm.

[0056] The preparation method of the formaldehyde-removing master batch comprises the following steps:

[0057] The nano-titanium dioxide solution is prepared by ball milling and blending the weighed nano-titanium dioxide, silica sol, sodium pyrophosphate and MAH-g-EPDM, wherein the ball milling speed is 400 rpm, and the ball milling time is 6 hours.

[0058] The nano-titanium dioxide solution is injected into the cylinder of a double-screw extruder through a hot-body metering injector, and the weighed polystyrene is added into the cylinder of the double-screw extruder for mixing and plasticizing, wherein the extrusion speed is 480 r / min, the temperature of the first zone is 185 DEG C, the temperature of the second zone is 195 DEG C, the temperature of the third zone is 205 DEG C, the temperature of the fourth zone is 215 DEG C, the temperature of the fifth zone is 210 DEG C, and the temperature of the sixth zone is 215 DEG C.

[0059] The diffusion layer comprises, in percentage by weight, 0.8% of anti-aging master batch, 4% of light diffusion master batch and the balance of polystyrene.

[0060] The preparation method of the formaldehyde-removing optical diffusion plate comprises the following steps:

[0061] The preparation of the mixture A: the weighed components of the formaldehyde-removing layer are stirred to be uniformly mixed to obtain the mixture A.

[0062] The preparation of the mixture B: the weighed components of the diffusion layer are stirred to be uniformly mixed to obtain the mixture B.

[0063] The mixture A and the mixture B are respectively melt plasticized, extruded into plates through a distributor and a die, and formed into the optical diffusion plate through three-roller calendering, wherein the extrusion temperature is 220 DEG C, and the calendering temperature is 120 DEG C.

[0064] Example 3

[0065] The application discloses a formaldehyde-removing optical diffusion plate, which comprises a formaldehyde-removing layer and a diffusion layer, and the thickness ratio of the formaldehyde-removing layer to the diffusion layer is 1:6; the formaldehyde-removing layer comprises the following components in percentage by weight: formaldehyde-removing master batch 7%, and the rest is polystyrene; the formaldehyde-removing master batch comprises the following components in percentage by weight: nano-titanium dioxide solution 20%, MAH-g-EPDM 3%, sodium pyrophosphate 1.5%, and the rest is polystyrene; the nano-titanium dioxide solution comprises the following components in percentage by weight: nano-titanium dioxide 20%, silica sol 75%, sodium pyrophosphate 1%, and MAH-g-EPDM 3%; the particle size of the nano-titanium dioxide is 60 nm, and the particle size of the silica sol is 15 nm.

[0066] The preparation method of the formaldehyde-removing master batch comprises the following steps:

[0067] Preparation of the nano-titanium dioxide solution: the weighed nano-titanium dioxide, silica sol, sodium pyrophosphate and MAH-g-EPDM are ball milled and blended to obtain the nano-titanium dioxide solution, the ball milling speed is 500 rpm, and the ball milling time is 5.5 h;

[0068] Extrusion granulation: the weighed nano-titanium dioxide solution is injected into the cylinder of a double-screw extruder through a hot body metering injector, and the weighed polystyrene is added into the cylinder of the double-screw extruder for mixing and plasticizing, the extrusion speed is 350 r / min, and the extrusion granulation is carried out through the double-screw extruder, wherein the temperature of the first zone is 185 DEG C, the temperature of the second zone is 195 DEG C, the temperature of the third zone is 205 DEG C, the temperature of the fourth zone is 215 DEG C, the temperature of the fifth zone is 210 DEG C, and the temperature of the sixth zone is 215 DEG C;

[0069] The diffusion layer comprises the following components in percentage by weight: anti-aging master batch 1.2%, light diffusion master batch 2%, and the rest is polystyrene;

[0070] The preparation method of the formaldehyde-removing optical diffusion plate comprises the following steps:

[0071] Preparation of mixture A: the components of the formaldehyde-removing layer are stirred to be uniformly mixed to obtain mixture A;

[0072] Preparation of mixture B: the components of the diffusion layer are stirred to be uniformly mixed to obtain mixture B;

[0073] Extrusion calendering: mixture A and mixture B are respectively melt plasticized, extruded into plates through a distributor and a die, and formed into optical diffusion plates through three-roll calendering, the extrusion temperature is 220 DEG C, and the calendering temperature is 120 DEG C.

[0074] Example 4

[0075] Example 4 differs from Example 3 in that the formaldehyde masterbatch further comprises auxiliary additives 0.8% by weight, the auxiliary additives comprising sodium stearate and isoamyl acetate in a weight ratio of 1: 1.0.

[0076] Example 5

[0077] Example 5 differs from Example 3 in that the formaldehyde masterbatch further comprises auxiliary additives 1.5% by weight, the auxiliary additives comprising sodium stearate and isoamyl acetate in a weight ratio of 1: 0.6.

[0078] Example 6

[0079] Example 6 differs from Example 4 in that an equal amount of sodium stearate is used instead of isoamyl acetate.

[0080] Example 7

[0081] Example 7 differs from Example 4 in that an equal amount of isoamyl acetate is used instead of sodium stearate.

[0082] Example 8

[0083] Example 8 differs from Example 4 in that the formaldehyde masterbatch further comprises auxiliary additives 2.0% by weight.

[0084] Example 9

[0085] Example 9 differs from Example 4 in that the auxiliary additives comprise sodium stearate and isoamyl acetate in a weight ratio of 1: 1.8.

[0086] Example 10

[0087] Example 10 differs from Example 3 in that the nano-titanium dioxide has a particle size of 30 nm.

[0088] Example 11

[0089] Example 11 differs from Example 3 in that the silica sol has a particle size of 30 nm.

[0090] Example 12

[0091] Example 12 differs from Example 3 in that the formaldehyde layer further comprises anti-aging masterbatch 1.5% by weight.

[0092] Comparative Example

[0093] Comparative Example 1

[0094] Comparative Example 1 differs from Example 3 in that an equal amount of polystyrene is used instead of silica sol in the formaldehyde masterbatch.

[0095] Comparative Example 2

[0096] The difference between Comparative Example 2 and Example 3 is that ball milling was not used for dispersion treatment in the preparation method of the formaldehyde removal masterbatch.

[0097] Comparative Example 3

[0098] The difference between Comparative Example 3 and Example 3 is that the formaldehyde-removing optical diffusion plate was purchased from the market and the surface of the optical diffusion plate was coated with a photocatalytic coating.

[0099] Performance testing

[0100] Yellowing resistance test: Optical diffusion plate samples with a thickness of 1.5 mm were prepared by Examples 1-11 and Comparative Examples 1-3. The optical diffusion plate samples were placed in an ultraviolet accelerated weathering test chamber at a temperature of 50°C and an irradiation intensity of 2 W / m². 2 The wavelength of the ultraviolet light was 340 nm. The optical diffusion plate sample was irradiated with ultraviolet light, and the yellow index Y and Δb of the optical diffusion plate sample were measured at 0 h and 96 h, respectively. * (Hue) value.

[0101] Transmittance test: The transmittance of the optical diffusion plate samples that have completed the aging resistance test is tested according to the national standard GB / T2410.

[0102] Tensile strength test: The optical diffusion plate samples prepared in Examples 1-11 and Comparative Examples 1-3 were subjected to tensile strength test according to the national standard GB / T 1043.2.

[0103] Bending strength test: The bending strength of the optical diffusion plate samples prepared in Examples 1-11 and Comparative Examples 1-3 was tested according to the national standard GB / T 9341.

[0104] Formaldehyde removal test: Optical diffusion plate samples were prepared through Examples 1-11 and Comparative Examples 1-3. The optical diffusion plate samples were placed in a test chamber with a volume of 1 m³, a test temperature of 25 °C, a relative humidity of 59%, and a test time of 24 h under indoor sunlight and other conditions. The formaldehyde purification efficiency was calculated based on the initial concentration and the final concentration (mg / m³) of formaldehyde gas measured in the test chamber.

[0105] Table 2. Aging resistance test results of the optical diffusion plates prepared in Examples 1-11 and Comparative Examples 1-3

[0106]

[0107] Table 3 shows the test results of light transmittance, tensile strength, flexural strength, and formaldehyde removal of the optical diffusion plates prepared in Examples 1-11 and Comparative Examples 1-3.

[0108]

[0109] Based on the experimental data recorded in Table 2, it can be seen from Examples 1-3 and Comparative Examples 1-3 that the yellow index Y and ∆b of the optical diffusion plate are... * The values ​​are all relatively small, therefore the composite layer structure of the optical diffusion plate can alleviate the yellowing phenomenon caused by oxidation of the formaldehyde removal layer and the diffusion layer, thus extending the service life of the optical diffusion plate. The reason for this may be that the nano-titanium dioxide, silica sol, dispersant, and compatibilizer are uniformly dispersed through ball milling. During ball milling, the silica sol forms crystal capsules to coat the nano-titanium dioxide particles. The addition of dispersant and compatibilizer helps the silica sol to fully coat the nano-titanium dioxide particles, resulting in a nano-titanium dioxide solution. The nano-titanium dioxide solution is mixed with the substrate resin and extruded and granulated to obtain formaldehyde removal masterbatch. The nano-titanium dioxide solution formed by the silica sol coating penetrates into the interior of the substrate resin. The silica sol coating capsules reduce the direct contact between the nano-titanium dioxide and the substrate resin, thereby reducing the oxidation of the formaldehyde removal layer and the surface of the diffusion layer near the formaldehyde removal layer by the nano-titanium dioxide, thus preventing yellowing of the substrate resin. This allows the optical diffusion plate to have excellent formaldehyde removal performance while extending its service life.

[0110] By adding optical diffusion masterbatch and anti-aging masterbatch to the diffusion layer, an inner layer material with good optical performance and anti-aging properties can be obtained for an optical diffusion plate.

[0111] According to the experimental data recorded in Table 3, it can be seen from Examples 3-9 that adding sodium stearate and isoamyl acetate to the formaldehyde removal masterbatch can improve the mechanical properties of the optical diffusion plate. The reason for this is that sodium stearate and isoamyl acetate can improve the tensile strength and flexural strength of the formaldehyde removal layer, thereby improving the tensile strength and flexural strength of the optical diffusion plate. Further analysis shows that during the preparation of the formaldehyde removal layer from the formaldehyde removal masterbatch, the silica sol undergoes volume shrinkage or aggregation due to temperature changes, resulting in gaps between the silica sol particles and the substrate resin. Sodium stearate, through isoamyl acetate, exhibits good compatibility and is evenly distributed between the silica sol and the substrate resin. Sodium stearate can improve the degree of cross-linking between the silica sol particles and the substrate resin, thereby improving the tensile strength and flexural strength of the optical diffusion plate, and giving the optical diffusion plate good wear resistance.

[0112] Based on the experimental data in Tables 2 and 3, it can be seen from Examples 3 and 10 that using nano-titanium dioxide with a particle size of 50-100 nm is beneficial for the dispersion of nano-titanium dioxide and the thorough mixing of nano-titanium dioxide with silica sol. The silica sol fully coats the nano-titanium dioxide particles to ensure the anti-yellowing performance of the formaldehyde removal masterbatch on the substrate resin.

[0113] As can be seen from Example 3 and Example 11, when the particle size of the silica sol is 8-25 nm, the silica sol particles are beneficial to be dispersed in the base resin, the phenomenon of the silica sol particles from self-agglomeration is reduced, the stability of the silica sol is improved, and then the oxidation resistance of the optical diffusion plate is improved.

[0114] According to the formaldehyde removal test results in Table 3, as can be seen from Example 1-3 and Comparative Example 3, the optical diffusion plate absorbs and decomposes formaldehyde in the formaldehyde removal layer under the photocatalysis.

[0115] The above specific examples are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the present application without creative contribution after reading the present specification, but all should be covered in the protection scope of the present application.

Claims

1. An optical board material capable of removing formaldehyde, characterized in that, The product includes a formaldehyde removal layer and a diffusion layer. The formaldehyde removal layer comprises, by weight percentage, the following components: 2-10% formaldehyde removal masterbatch, with the balance being base resin; the formaldehyde removal masterbatch comprises, by weight percentage, the following components: 10-30% nano titanium dioxide solution, 1-4% compatibilizer, 0.1-2% dispersant, with the balance being base resin; the nano titanium dioxide solution comprises, by weight percentage, the following components: 5-30% nano titanium dioxide, 64-90% silica sol, 0.1-2% dispersant, and 1-4% compatibilizer. The method for preparing the formaldehyde removal masterbatch includes the following steps: Preparation of nano-titanium dioxide solution: Weighed nano-titanium dioxide, silica sol, dispersant and compatibilizer are ball-milled and mixed to obtain nano-titanium dioxide solution. The ball milling speed is 400-600 rpm and the ball milling time is 5-6 h. Extrusion granulation: The weighed nano titanium dioxide solution is mixed and plasticized with the base resin, and then granulated by twin-screw extrusion. The diffusion layer comprises the following components by weight percentage: 1.5-2% anti-aging masterbatch, 1-4% light diffusion masterbatch, and the balance being the base resin; The formaldehyde removal masterbatch also includes 0.8-1.5% auxiliary additives by weight, which include sodium stearate and isoamyl acetate in a weight ratio of 1:(0.6-1.0). The substrate resin is one of polymethyl methacrylate, polycarbonate, styrene-methyl methacrylate resin, polystyrene, or polypropylene. The dispersant is one or more of sodium pyrophosphate, sodium hexametaphosphate, and sodium tripolyphosphate; In the extrusion granulation process, the temperature of the first zone is 180–195°C, the temperature of the second zone is 190–200°C, the temperature of the third zone is 200–220°C, the temperature of the fourth zone is 205–220°C, the temperature of the fifth zone is 210–220°C, and the temperature of the sixth zone is 210–220°C.

2. The formaldehyde-removing optical board according to claim 1, characterized in that: The particle size of the nano-titanium dioxide is 50–100 nm.

3. The formaldehyde-removing optical board according to claim 1, characterized in that: In the preparation method of the formaldehyde removal masterbatch, the extrusion speed of the extrusion granulation is 280-480 r / min.

4. The formaldehyde-removing optical board according to claim 1, characterized in that: The particle size of the silica sol is 8–25 nm.

5. The formaldehyde-removing optical sheet according to claim 1, characterized in that: The thickness ratio of the formaldehyde removal layer to the diffusion layer is 1:(4-9).

6. A method for preparing a formaldehyde-removing optical board according to any one of claims 1 to 5, characterized in that: It includes the following steps: Preparation of mixture A: Weigh each component of the formaldehyde removal layer and stir to mix them evenly to obtain mixture A; Preparation of mixture B: The weighed components of the diffusion layer are stirred to mix them evenly to obtain mixture B; Extrusion calendering: Mixture A and mixture B are melted and plasticized and then extruded and calendered to form an optical diffusion plate. The extrusion temperature is 160-220℃ and the calendering temperature is 110-140℃.

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