A process for preparing a light guide plate

Abstract

This application relates to the technical field of light guide plate film pasting. More specifically, it relates to a light guide plate preparation process, which includes the following preparation steps: S1. Coat an adhesive on the surface of a diffusion film to form a first adhesive area. The first adhesive area is provided with a first air permeation channel to obtain an adhesive diffusion film; S2. Through vacuum heating adsorption, adsorb the adhesive diffusion film on the surface of the cut light guide plate substrate, and connect the diffusion film with the light guide plate substrate to obtain a semi-finished product; S3. Coat an adhesive on the surface of a reflective film to form a second adhesive area. The second adhesive area is provided with a second air permeation channel to obtain an adhesive reflective film; S4. Through vacuum heating adsorption, adsorb the adhesive reflective film on the side of the light guide plate substrate away from the diffusion film and on the side of the light guide plate substrate, and connect the reflective film with the light guide plate substrate to obtain a primary product. Through the process of this application, during the vacuum heating film pasting process of the diffusion film and the reflective film, gas is discharged from the first air permeation channel and the second air permeation channel, reducing the residual bubbles.

Description

Technical Field

[0001] This application relates to the technical field of light guide plate film pasting, and more specifically, to a light guide plate preparation process. Background Art

[0002] A light guide plate is required in a backlight assembly or a reflective assembly. The light guide plate is mainly prepared from a reflective layer, a light guiding layer, and a diffusion layer. Its preparation process is usually as follows: A diffusion film is prepared by forming a diffusion film, an upper brightness enhancement film, and a lower brightness enhancement film, and then the diffusion film is pasted on the surface of the light guiding layer, and then the reflective film is pasted on the other surface of the light guiding layer to obtain the light guide plate. However, after the existing diffusion film and reflective film are pasted on the surface of the light guide plate, the four peripheral edges of the diffusion film and the reflective film are prone to curling. If glue is used to seal the four peripheral edges of the diffusion film and the reflective film, bubbles are easily generated during the pasting process, and the bubbles cannot be discharged, resulting in loose connection between the edges of the diffusion film and the reflective film and the light guide plate, easy warping or curling, and increased product defect rate. Summary of the Invention

[0003] In order to solve the problem that bubbles are easily generated during the pasting process of the diffusion film and the reflective film, this application provides a light guide plate preparation process.

[0004] In a first aspect, this application provides a light guide plate preparation process, adopting the following technical solution:

[0005] A light guide plate preparation process includes the following preparation steps:

[0006] S1. Coat an adhesive on the surface of the diffusion film to form a first adhesive area, and form a first air permeable channel between adjacent coating sites to obtain an adhesive diffusion film;

[0007] S2. Through vacuum heating adsorption, adsorb the adhesive diffusion film on the surface of the cut light guide plate substrate, so that the diffusion film is connected to the light guide plate substrate to obtain a semi-finished product;

[0008] S3. Coat an adhesive on the surface of the reflective film to form a second adhesive area, and form a second air permeable channel between adjacent coating sites to obtain an adhesive reflective film;

[0009] S4. Through vacuum heating adsorption, adsorb the adhesive reflective film on the side of the light guide plate substrate away from the diffusion film and the side of the light guide plate substrate, so that the reflective film is connected to the light guide plate substrate to obtain a semi-finished product;

[0010] S5. Then cut the semi-finished product with a laser to obtain the light guide plate.

[0011] By adopting the above technical solution, no bubbles will be generated during the bonding process of the diffusion film to the light guide plate substrate and the reflective film to the light guide plate substrate, reducing the phenomenon of the edges of the diffusion film warping or curling up and the edges of the reflective film warping or curling up.

[0012] First air-permeable channels are formed between adjacent coating sites in the first adhesive region. When the diffusion film is attached to the light guide plate substrate, air bubbles are discharged along the first air-permeable channels, increasing the air bubble discharge space and reducing the air bubbles remaining between the diffusion film and the light guide plate substrate. Similarly, second air-permeable channels are formed between adjacent coating sites in the second adhesive region. When the reflective film is attached to the light guide plate substrate, air bubbles are discharged along the second air-permeable channels, increasing the air bubble discharge space and reducing the air bubbles remaining between the reflective film and the light guide plate substrate.

[0013] In step S4, by adopting vacuum adsorption of the reflective film, on the one hand, it is to improve the bonding stability of the reflective film to the light guide plate substrate and prevent the reflective film from falling off the surface of the light guide plate; on the other hand, it is to edge-wrap the light guide plate to prevent light leakage of the light guide plate.

[0014] By adopting the methods of automatic cutting and laser cutting, the accuracy of cutting the diffusion film is improved, preventing the shape of the cut diffusion film from being different from the shape of the light guide plate substrate, and at the same time not damaging the surface of the diffusion film.

[0015] Preferably, in step S1, the light guide plate substrate is first cut or the light guide plate is formed by injection molding, and subsequent cutting of the light guide plate is not required. After attaching the diffusion film, cutting is likely to scratch or dirty the diffusion film. Therefore, the light guide plate needs to be cut first.

[0016] Preferably, the first adhesive region is coated along the edge of the diffusion film and on the surface of the diffusion film, and the width of the first adhesive region does not exceed 10% of the narrowest width of the diffusion film.

[0017] By adopting the above technical solution, it is prevented that the glue in the first adhesive region flows excessively to the surface of the light guide plate substrate, affecting the use of the light guide plate. When the width of the first adhesive region exceeds 10% of the narrowest width of the diffusion film, it will cause an increase in the area of the first adhesive region, which will affect the light transmission efficiency and further affect the function of diffused light.

[0018] Preferably, the second adhesive region is coated along the edge close to the reflective film and on the surface of the reflective film, and the width of the second adhesive region does not exceed 10% of the thickness of the light guide plate.

[0019] By adopting the above technical solution, it is possible to prevent the glue in the second adhesive area from flowing to the surface where the light guide plate substrate contacts the reflective film, which affects the reflection efficiency and the use of the light guide plate. If the width of the second adhesive area exceeds 10% of the narrowest width of the diffusion film, the area of the second adhesive area will increase, which will affect the reflection efficiency and further affect the function of the reflected light. Preferably, the glue application shapes of the first adhesive area and the second adhesive area are strip-shaped, arc-shaped, dot-shaped or wavy-shaped.

[0020] By adopting the above technical solution, the bonding stability between the edge of the diffusion film and the light guide plate substrate is improved, and the use of the light guide plate is prevented from being affected by large-area glue application. Strip-shaped, arc-shaped, dot-shaped or wavy-shaped are suitable for light guide plate substrates of different shapes.

[0021] The strip-shaped adhesive area is suitable for light guide plates with regular shapes, such as square and rectangular light guide plates, and the adhesive can be coated along one long side and / or one short side thereof.

[0022] The arc-shaped adhesive area is suitable for circular light guide plates, and the arc-shaped adhesive area can be coated at intervals along the edge of the circular light guide plate.

[0023] The strip-shaped adhesive area and the arc-shaped adhesive area are not suitable for light guide plates with irregular shapes, while the dot-shaped adhesive area and the wavy-shaped adhesive area are suitable for various irregular light guide plates.

[0024] Preferably, the vacuum degree of the vacuum adsorption in step S2 is -0.01 to -5 KPa.

[0025] By adopting the above technical solution, the vacuum degree of the vacuum adsorption is optimized, which is beneficial to improving the flatness of the diffusion film and the bonding performance between the diffusion film and the light guide plate substrate. If the vacuum degree is less than -5 KPa, the adsorption force between the diffusion film and the light guide plate substrate will be poor, the film layers of the diffusion film and the light guide plate substrate will be loose, and the firmness will be poor; if the vacuum degree is greater than -0.01 KPa, wrinkles are likely to appear on the surface of the diffusion film or the reflective film during the vacuum adsorption process.

[0026] Preferably, heating is carried out simultaneously during the vacuum adsorption in step S2, and the heating temperature is 100 - 150 °C.

[0027] By adopting the above technical solution, the temperature during the vacuum heating is optimized, the performance of the diffusion film adhering to the light guide plate substrate is improved, and the situation of unstable bonding of the diffusion film is further prevented. If the temperature is lower than 100 °C, it is easy to cause unstable bonding between the diffusion film and the light guide plate substrate; if the temperature is higher than 150 °C, it is easy to cause the diffusion film to curl or wrinkle, and the quality of the finished product is poor.

[0028] Preferably, the method of coating the adhesive in the first adhesive area is spraying or dot coating, and the spraying amount is 10 - 12 g / m 2 。

[0029] By adopting the above technical solution, the adhesive can be evenly coated on the surface of the diffusion film, which is beneficial to the lamination of the diffusion film. The spraying amount is less than 10 g / m 2 , the adhesive cannot be evenly sprayed on the surface of the diffusion film, and at the same time, the adhesive layer is thin and the adhesive force is insufficient, so it is still easy to edge or warp; when the spraying amount is greater than 12 g / m 2 , the situation of glue overflow is likely to occur, resulting in the glue in the glued area entering the unglued area, affecting the light guiding effect and air permeability of the light guide plate.

[0030] Preferably, the method of applying the adhesive in the second glued area is spraying or dotting, and the spraying amount is 8 - 12 g / m 2 .

[0031] By adopting the above technical solution, the adhesive can be evenly coated on the surface of the reflective film, which is beneficial to the lamination of the reflective film. The spraying amount is less than 8 g / m 2 , the adhesive cannot be evenly sprayed on the surface of the reflective film, and at the same time, the adhesive layer is thin and the adhesive force is insufficient, so it is still easy to edge or warp; when the spraying amount is greater than 12 g / m 2 , the situation of glue overflow is likely to occur, resulting in the glue in the glued area entering the unglued area, affecting the reflection effect and air permeability of the light guide plate.

[0032] Preferably, the adhesive is composed of the following raw materials in weight percentages:

[0033] Polyether polyol 10 - 15%

[0034] Organosilicon modified polyester resin 2 - 5%

[0035] Aqueous acrylic resin solution 5 - 10%

[0036] Crosslinking agent 1 - 2%

[0037] The balance is diluent.

[0038] Preferably, the molecular weight of the polyether polyol is 500 - 15000, and the functionality is 2 - 5.

[0039] Preferably, the diluent is at least one of hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate or pentaerythritol triacrylate.

[0040] Preferably, the molecular weight of the aqueous acrylic resin solution is 2000 - 10000, and at 25 °C, the viscosity is 4000 - 15000 mPa·s.

[0041] By adopting the above technical solution, the prepared adhesive has good light transmittance, adhesiveness and processability, as well as moderate viscosity. At 25°C, the viscosity is 3000-5000 mPa·s, and it has good light transmittance, which will not affect the light emission or reflected light of the light guide plate. Good adhesiveness is conducive to improving the bonding stability between the diffusion layer and the light guide plate substrate, and the bonding stability between the reflective layer and the light guide plate substrate, preventing the diffusion layer and the reflective film layer from separating from the light guide plate substrate. Moderate viscosity is conducive to controlling the formation of air-permeable channels between adjacent coating sites and facilitating the discharge of air bubbles. If the viscosity is less than 3000 mPa·s, it is difficult to coat evenly; if the viscosity is greater than 5000 mPa·s, the fluidity is good, and the air-permeable channels are easily blocked, affecting the air-permeable effect.

[0042] The co-use of organosilicon-modified polyester resin, aqueous acrylic resin solution and cross-linking agent can improve the adhesiveness of the adhesive, control the fluidity of the adhesive, and at the same time improve the light transmittance after the adhesive is cured, reducing the influence of the adhesive on the diffusion film. Even if part of the adhesive flows to the light-emitting area of the light guide plate, it will not affect the brightness of the light guide plate. Further, in this application, a diluent and polyether polyol are added to adjust the viscosity of the adhesive, so that the adhesive is not likely to flow to the unbonded area during the coating process, affecting the use of the diffusion film.

[0043] Preferably, the organosilicon-modified polyester resin is prepared by the following method:

[0044] 1) By weight, mix 10-20 parts of polybasic acid, 20-25 parts of polyol and 10-20 parts of diluent, heat up to 200-230°C, react for 1-2 h, and detect that the acid value is less than 5 to obtain a polyester prepolymer;

[0045] 2) By weight, stir 5-10 parts of vinyltriisopropenyloxysilane and 3-9 parts of dimethyldiethoxysilane, heat up to 80-90°C, add 1-2 parts of catalyst and the polyester prepolymer, react for 0.5-1 h, add triethylamine, and adjust the pH to 6.5-7.5 to obtain the organosilicon-modified polyester resin.

[0046] Preferably, the polybasic acid is at least one of isophthalic acid, phthalic anhydride, terephthalic acid, succinic acid, glutaric acid, maleic anhydride, azelaic acid, maleic acid or tetrahydrophthalic acid.

[0047] Preferably, the polyol is one of diethylene glycol, 1,4-butanediol, hexanediol, trimethylolethane, trimethylolpropane, neopentyl glycol or polycarbonate diol. Preferably, the catalyst is one of dibutyltin dilaurate, dibutyltin oxide chloride, monobutyltin oxide, dibutyltin oxide, dibutyltin diacetate or monobutyltin trichloride.

[0048] By adopting the above technical solution, the prepared silicone-modified polyester resin can crosslink with the waterborne acrylic resin to form an adhesive with a stable structure, which is beneficial to improving the adhesive performance and light transmittance of the adhesive, and improving the brightness uniformity of the light guide plate. By using the silicone-modified polyester resin in this application to prepare the adhesive, the coating amount of the adhesive can reach 2-6 g / m 2 , and the bonding effect is good, and the influence on the diffusion film is basically zero.

[0049] Preferably, the adhesive is prepared by the following method:

[0050] Mix the polyether polyol and the solvent, heat up to 80-100 °C, add the silicone-modified polyester resin and the waterborne acrylic resin solution, stir, and then add the crosslinking agent until the viscosity reaches 5000-7000 mPa·s, and cool to obtain the adhesive.

[0051] By adopting the above technical solution, the prepared adhesive has good light transmittance and adhesiveness, can improve the bonding stability of the diffusion film, the reflection film and the light guide plate substrate, and effectively prevent the edges of the diffusion film from curling or warping.

[0052] In summary, this application has the following beneficial effects:

[0053] 1. In this application, an adhesive is coated on the diffusion film to form a first adhesive zone, and a first air permeation channel is formed between adjacent coating sites to obtain an adhesive diffusion film. Then, the adhesive diffusion film is adsorbed on the surface of the light guide plate substrate by vacuum heating to obtain a semi-finished product; then, an adhesive is coated on the reflection film to form a second adhesive zone, and a second air permeation channel is formed between adjacent coating sites to obtain an adhesive reflection film. Then, the adhesive reflection film is adsorbed on the surface of the light guide plate substrate by vacuum heating and cut to obtain a light guide plate. By adopting the above process, during the vacuum heating and laminating process of the diffusion film and the reflection film, the gas is discharged from the first air permeation channel and the second air permeation channel, reducing the bubble residue. Description of the Drawings

[0054] Figure 1 It is a schematic structural diagram of the diffusion film coated with the adhesive in Example 1.

[0055] Figure 2 It is a schematic structural diagram of the reflection film coated with the adhesive in Example 1.

[0056] Figure 3 It is a schematic structural diagram of the diffusion film coated with the adhesive in Example 2.

[0057] Figure 4 It is a schematic structural diagram of the reflection film coated with the adhesive in Example 2

[0058] Description of reference numerals: 1, diffusion film; 2, first adhesive area; 3, reflective film; 4, first air-permeable channel; 5, second adhesive area; 6, second air-permeable channel. Detailed implementation mode

[0059] Embodiment

[0060] The light guide plate substrate used in this embodiment is an acrylic light guide plate, with a thickness of 4 mm, a light transmittance of 1%, a tensile strength of 95 Kg / cm 2 , a flexural strength of 100 Kg / cm2, and an impact strength of 800 kg.cm / cm; the uniformity of the diffusion film is 99%, the light transmittance is 74%, the haze is 90%, the thickness is 0.01 mm, and the flexural strength is 100 MPa; the reflectance of the reflective film is 99%, the haze is 90%, the thickness is 0.01 mm, the flexural strength is 120 MPa, the adhesive is an organosilicon-modified polyester adhesive, at 25 °C, the viscosity is 5000 mPa.s, the refractive index is 1.56, and the curing temperature is 90 °C.

[0061] Embodiment 1

[0062] A light guide plate preparation process includes the following preparation steps:

[0063] S1. As Figure 1 shown, spray the adhesive along the edge of the diffusion film 1 and on the surface of the diffusion film 1, with a coating amount of 12 g / m 2 , the spraying width is 10% of the narrowest width of the diffusion film 1, forming the first adhesive area 2. The glue application shape of the first adhesive area 2 is arc-shaped, and a first air-permeable channel 4 is formed between adjacent coating sites to obtain an adhesive diffusion film;

[0064] S2. Through vacuum heating adsorption, with a vacuum degree of -0.01 KPa and a temperature of 90 °C, adsorb the adhesive diffusion film on the surface of the cut light guide plate substrate so that the diffusion film 1 is connected to the light guide plate substrate to obtain a semi-finished product;

[0065] S3. As Figure 2 shown, spray the adhesive along the edge of the reflective film and on the surface of the reflective film 3, with a coating amount of 12 g / m 2 , forming the second adhesive area 5. The glue application shape of the second adhesive area 5 is arc-shaped, the width of the second adhesive area 5 is 10% of the thickness of the light guide plate substrate, and a second air-permeable channel 6 is formed between adjacent coating sites to obtain an adhesive reflective film;

[0066] S4. Through vacuum heating adsorption, with a vacuum degree of -6 KPa and a temperature of 90 °C, adsorb the adhesive reflective film on the side of the light guide plate substrate away from the diffusion film and the side of the light guide plate substrate so that the reflective film 3 is connected to the light guide plate substrate to obtain a semi-finished product;

[0067] S5. Then, the semi-finished product is cut using a laser to obtain a light guide plate.

[0068] Example 2

[0069] A light guide plate preparation process includes the following preparation steps:

[0070] S1. As shown in Figure 3 , an adhesive is sprayed along the edge of the diffusion film 1 and on the surface of the diffusion film 1, with a coating amount of 12 g / m 2 to form a first adhesive zone 2. The width of the first adhesive zone 2 is 2% of the narrowest width of the diffusion film. The glue application shape of the first adhesive zone 2 is dot-shaped, and a first air permeation channel 4 is formed between adjacent coating sites to obtain an adhesive diffusion film;

[0071] S2. Through vacuum heating adsorption, with a vacuum degree of -5 KPa and a temperature of 160 °C, the adhesive diffusion film is adsorbed on the surface of the cut light guide plate substrate, so that the diffusion film is connected to the light guide plate substrate to obtain a semi-finished product;

[0072] S3. As shown in Figure 4 , an adhesive is sprayed along the edge of the reflective film 3 and on the surface of the reflective film, with a coating amount of 10 g / m 2 to form a second adhesive zone 5. The width of the second adhesive zone 5 is 2% of the thickness of the light guide plate. The glue application shape of the second adhesive zone 5 is dot-shaped, and a second air permeation channel 6 is formed between adjacent coating sites to obtain an adhesive reflective film;

[0073] S4. Through vacuum heating adsorption, with a vacuum degree of -6 KPa and a temperature of 90 °C, the adhesive reflective film is adsorbed on the side of the light guide plate substrate away from the diffusion film and the side of the light guide plate substrate, so that the reflective film 3 is connected to the light guide plate substrate to obtain a semi-finished product;

[0074] S5. Then, the semi-finished product is cut using a laser to obtain a light guide plate.

[0075] Example 3

[0076] A light guide plate preparation process. The difference between this example and Example 1 is that in this example, the vacuum degree is -0.01 KPa and the temperature is 90 °C, and the rest of the preparation steps are the same as those in Example 1.

[0077] Example 4

[0078] A light guide plate preparation process. The difference between this example and Example 1 is that in this example, the vacuum degree is -6 KPa and the temperature is 160 °C, and the rest of the preparation steps are the same as those in Example 1.

[0079] Example 5

[0080] A process for preparing a light guide plate. The difference between this embodiment and Embodiment 1 is that the adhesive used in this embodiment is prepared by the following method:

[0081] Mix 0.15 Kg of polyester polyol and 0.77 Kg of diluent (diacrylate of hexanediol), heat up to 80 °C, add 0.02 Kg of organosilicon-modified polyester resin (commercially available) and 0.05 Kg of aqueous acrylic resin solution, stir, and then add 0.01 Kg of crosslinking agent (adipic dihydrazide) until the viscosity reaches 5000 mPa·s, and then cool to obtain the adhesive.

[0082] The molecular weight of the aqueous acrylic resin is 2000, and at 25 °C, the viscosity is 4000 mPa·s.

[0083] The molecular weight of the polyester polyol is 500, and the functionality is 2.

[0084] The silicone content of the organosilicon-modified polyester resin is 50%, the acid value is 4.5 mg KOH / g, and at 25 °C, the viscosity is 4500 mPa·s.

[0085] The difference between Embodiments 6 - 7 and Embodiment 5 is that the types and amounts of some raw materials for preparing the adhesive are different. The specific differences are shown in Table 1:

[0086] Table 1 Types and amounts of raw materials of the adhesive in Embodiments 5 - 7

[0087]

[0088] Embodiment 8

[0089] A process for preparing a light guide plate. The difference between this embodiment and Embodiment 7 is that this embodiment uses polyether polyol to replace an equal amount of polyester polyol, and the other raw material amounts, types, and preparation steps are the same as those in Embodiment 7.

[0090] The molecular weight of the polyether polyol is 15000, and the functionality is 4.

[0091] Embodiment 9

[0092] A process for preparing a light guide plate. The difference between this embodiment and Embodiment 7 is that polyurethane resin is used to replace an equal amount of organosilicon-modified polyester resin, and the other raw material amounts, types, and preparation steps are the same as those in Embodiment 7.

[0093] At 25 °C, the viscosity of the polyurethane resin is 2000 mPa·s, and the molecular weight is 8500.

[0094] Embodiment 10

[0095] A process for preparing a light guide plate. The difference between this example and Example 7 is that polyurethane resin is used to replace an equal amount of aqueous acrylic resin solution, and the dosage, type of the remaining raw materials and the preparation steps are the same as those in Example 7.

[0096] Under the condition of 25 °C, the viscosity of the polyurethane resin is 2000 mpa.s and the molecular weight is 8500.

[0097] Example 11

[0098] A process for preparing a light guide plate. The difference between this example and Example 8 is that the dosage is 2m 2 / g, and the organosilicon-modified polyester resin in the preparation of the adhesive is prepared by the following method:

[0099] 1) Mix 0.10 Kg of polybasic acid (isophthalic acid), 0.25 Kg of polyol (1,4-butanediol) and 0.20 Kg of (hexanediol diacrylate), heat up to 200 °C, react for 1 h, detect the acid value of 4.5, and obtain a polyester prepolymer;

[0100] 2) Stir 0.05 Kg of vinyltriisopropenyloxysilane and 0.03 Kg of dimethyldiethoxysilane, heat up to 80 °C, add 0.02 Kg of catalyst (dibutyltin dilaurate) and the polyester prepolymer, react for 0.5 h, add triethylamine, and adjust the pH to 7 to obtain the organosilicon-modified polyester resin.

[0101] The differences between Examples 12-13 and Example 11 are that the types, dosages of some raw materials and test parameters for preparing the organosilicon-modified polyester resin are different, and the specific differences are shown in Table 2:

[0102] Table 2 Types, dosages of raw materials and test parameters of the organosilicon-modified polyester resin

[0103]

[0104]

[0105] Comparative example

[0106] Comparative example 1

[0107] A process for preparing a light guide plate. The difference between this example and Example 1 is that in step 2 of this comparative example, the adhesive is sprayed along the edge of the diffusion film and on the surface of the diffusion film, the coating amount is 12 g / m 2 , the width of the first adhesive zone is 10% of the narrowest width of the diffusion film, forming the first adhesive zone, and the first air permeation channel is not provided, and the remaining preparation steps are the same as those in Example 1.

[0108] Comparative example 2

[0109] A light guide plate preparation process. The difference between this comparative example and Example 1 is that in step S3 of this comparative example, the adhesive is sprayed along the edge of the diffusion film and on the surface of the reflective film, and the coating amount is 12 g / m 2 , and the spraying width is 10% of the narrowest width of the reflective film, forming a second adhesive area. The second air permeable channel is not provided, and the remaining preparation steps are the same as those in Example 1.

[0110] Performance detection test

[0111] The light guide plates prepared in Examples 1-13 and Comparative Examples 1-2 were subjected to bubble curling or warping tests, brightness uniformity tests, and adhesion tests

[0112] Detection method / Test method

[0113] Bubble curling or warping test: The light guide plates prepared in Examples 1-13 and Comparative Examples 1-2 were placed in an environment of 200 °C and heated for 15 min, then taken out. A magnifying glass (magnification factor of 40 times) was used to observe whether the edges of the light guide plates prepared in Examples 1-13 and Comparative Examples 1-2 were curled, warped, or had bubbles and other phenomena.

[0114] Light emission test of the light guide plate: The light guide plates prepared in Examples 1-13 and Comparative Examples 1-2 were placed in a dark room environment, and the light sources were successively placed under the light guide plates to observe whether the brightness of the light guide plates was uniform. If the brightness of the light guide plate was uneven, it was possible that the adhesive in the first adhesive area flowed into the bright area, reducing the brightness of the bright area.

[0115] The test data is shown in Table 3:

[0116] Table 3 Performance detection experimental data

[0117] Example or comparative example Bubble curling or warping test Brightness uniformity Example 1 No bubbles Non-uniform Example 2 No bubbles Uniform Example 3 With curling Non-uniform Example 4 Surface wrinkling Non-uniform Example 5 No bubbles Uniform Example 6 No bubbles Uniform Example 7 No bubbles Uniform Example 8 No bubbles Uniform Example 9 With curling Non-uniform Example 10 With bubbles Non-uniform Example 11 No bubbles Uniform Example 12 No bubbles Uniform Example 13 No bubbles Uniform Comparative example 1 With bubbles Uniform Comparative example 2 With bubbles Uniform

[0118] Bonding strength detection: The organosilicon-modified polyester adhesive and the adhesives prepared in Examples 5-13 were respectively coated on the surface of the diffusion film, and the coating amount was 12 g / m2. After the adhesive was cured, the above-mentioned light guide plates were respectively cut into samples with a width of 15 mm and a length of 200 mm. The pre-bonded diffusion film was peeled off by 50 mm in advance, and a 6.35 mm aluminum round rod was inserted at the peeling position. Then the diffusion film and the light guide plate substrate were installed between the upper and lower clamps of a strain-type tensile testing machine, and the lower chuck was lowered at a speed of 125 mm / min until the specimen was completely peeled off, and the tensile load at this time was read to calculate the average load during the peeling test. The average load was divided by the specimen width to obtain the bonding force, and the unit was N / mm.

[0119] The test data is shown in Table 4:

[0120] Table 4 Performance detection experimental data

[0121]

[0122]

[0123] From Examples 1-12, Comparative Examples 1-2 and in combination with Table 3, it can be seen that the light guide plate preparation process of the present application can reduce the possibility of bubbles generated by using glue for sealing the edges of the diffusion film, and reduce the phenomena of warping or curling at the edges of the diffusion film and warping or curling at the edges of the reflection film. Moreover, the adhesive prepared in the present application is used to bond the diffusion film and the reflection film, and will not affect the light brightness performance of the light guide plate.

[0124] Comparing Example 1 with Comparative Examples 1-2, in the case of not setting a ventilation channel, the phenomenon of bubbles appeared in Comparative Examples 1-2, indicating that by adopting the method of setting a ventilation channel, the generation of bubbles can be effectively reduced.

[0125] Comparing Example 1 with Examples 3-4, it shows that by optimizing the vacuum degree and temperature of vacuum heating, the phenomena of curling and surface wrinkling can be reduced.

[0126] Comparing Example 1 with Example 5, the phenomenon of uneven light brightness appeared in Example 1, while by using the adhesive prepared in the present application, the phenomenon of uneven light brightness did not appear, indicating that the adhesive prepared in the present application has a moderate viscosity, effectively preventing the adhesive from flowing into the light-emitting area of the light guide plate during the adhesion process and affecting the light emission uniformity of the light guide plate.

[0127] From Examples 5-13, epoxy resin glue and in combination with Table 4, it can be seen that the adhesive prepared from the organosilicon-modified polyester resin prepared in the present application has good light transmittance and adhesiveness, and can improve the bonding stability between the diffusion film and the light guide plate substrate, and between the reflection film and the light guide plate substrate.

[0128] This specific embodiment is only an explanation of the present application, and it does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A process for preparing a light guide plate, characterized in that, It includes the following preparation steps: S1. Coating an adhesive on the surface of a diffusion film to form a first adhesive area, and forming a first air-permeable channel between adjacent coating sites to obtain an adhesive diffusion film; S2. Adsorbing the adhesive diffusion film on the surface of a cut light guide plate substrate through vacuum heating adsorption, so that the diffusion film is connected to the light guide plate substrate to obtain a semi-finished product; S3. Coating an adhesive on the surface of a reflective film to form a second adhesive area, and forming a second air-permeable channel between adjacent coating sites to obtain an adhesive reflective film; S4. Adsorbing the adhesive reflective film on the side of the light guide plate substrate away from the diffusion film and the side of the light guide plate substrate through vacuum heating adsorption, so that the reflective film is connected to the light guide plate substrate to obtain a semi-finished product; S5. Then cutting the semi-finished product with a tool or laser to obtain a light guide plate; The first adhesive area is coated along the edge of the diffusion film and on the surface of the diffusion film, and the width of the first adhesive area does not exceed 10% of the narrowest width of the diffusion film; The second adhesive area is coated along the edge close to the reflective film and on the surface of the reflective film, and the width of the second adhesive area does not exceed 10% of the thickness of the light guide plate; The vacuum degree of the vacuum adsorption in step S2 is -0.01~-5KPa; During the vacuum adsorption in step S2, heating is carried out at the same time, and the heating temperature is 100-150°C; The first adhesive application area is coated with an adhesive by spraying or dotting, and the spraying amount is 10-12 g / m 2 ; The second adhesive application area is coated with an adhesive by spraying or dotting, and the spraying amount is 8-12 g / m 2 ; The adhesive is composed of the following raw materials in weight percentages: Polyether polyol 10-15% Organosilicon-modified polyester resin 2-5% Waterborne acrylic resin solution 5-10% Crosslinking agent 1-2% The balance is a diluent; The organosilicon-modified polyester resin is prepared by the following method: 1) Mix 10-20 parts of polybasic acid, 20-25 parts of polyol and 10-20 parts of diluent by weight, heat up to 200-230°C, add 1-2 parts of catalyst, react for 1-2h, and detect that the acid value is less than 5 to obtain a polyester prepolymer; 2) Stir 5-10 parts of vinyltriisopropenyloxysilane and 3-9 parts of dimethyldiethoxysilane by weight, heat up to 80-90°C, add 1-2 parts of crosslinking agent and the polyester prepolymer, and react for 0.5-1h to obtain an organosilicon-modified polyester resin; the molecular weight of the waterborne acrylic resin solution is 2000-10000, and at 25°C, the viscosity is 4000-1500mpa.s.

2. The manufacturing process of a light guide plate according to claim 1, characterized in that: The adhesive is prepared by the following preparation method: Mix polyether polyol and a solvent, heat up to 80-100°C, add the organosilicon-modified polyester resin and the waterborne acrylic resin solution, stir, and then add the crosslinking agent until the viscosity is 5000-7000mpa.s, and cool to obtain the adhesive.

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