TWI374897B - Light diffusion film - Google Patents

Description

1374897 Amendment date: Patent Document No. 97103043, the first revision of the present invention, the present invention relates to a light diffusing film, and in particular to a high hardness, A light diffusing film that is simplified in process and resistant to yellowing. [Prior Art] Liquid crystal display (LCD) has the advantages of small size, light weight and low operating voltage, and has been widely used in personal mobile communication and home appliances in recent years. Since the liquid crystal panel itself does not emit light, it is necessary to add a backlight module. The general backlight film group includes: a light source, a light guide plate, a light diffusion film and a brightness enhancement film, wherein the light diffusion film function is a line source of a cold cathode tube. Or a point source of a light emitting diode (LED) is converted into a uniform surface source. Due to the increasing demand for large size in the market, the demand for the quality of the liquid crystal display is higher. In order to obtain a more uniform surface light source, the development of the light diffusion film is more important. • In the general light diffusion film process, mainly on a transparent plastic substrate, a layer of a resin containing diffusion particles is coated to form a diffusion layer, and the incident light passes through the diffusion layer due to the difference in refractive index between the resin and the diffusion particles. When it causes optical effects (refracting, reflecting or diffracting). ^Japanese Patent No. 2006126822 provides a light diffusing film comprising a diffusion particle of propylene (tetra) vinegar (10) yl-ne) and a cross-linking of acrylic acid s| (a complex with isocyanate) due to The extension functional group has the same functional group as the resin, so the adhesion is good, and the surface hardness can be improved by adjusting the ratio of the resin. 5 1374897 Patent Specification No. 97103043 Amendment Date: January 10, 2010 U.S. Patent No. 2006/0246233 provides a light diffusing film comprising: (1) diffusing particles; (2) a resin; (3) a leveling agent comprising a fluoroalkyl polymer and an aikyl acryloxy. The polymer can reduce the point defect and effectively improve the quality of the diffused light. However, the current photo-diffusion film is mainly used in a solvent casting process and requires a large amount of organic solvent, which is quite environmentally friendly. The hardness of the light-diffusing film is too low. 'When it comes into contact with the substrate, it is easy to cause fine to trace, and the light-diffusing film will yellow due to heat. The above phenomenon will reduce the quality of the kneading surface. Therefore, the industry needs it urgently. SUMMARY OF THE INVENTION One of the objects of the present invention is to provide a light diffusing film having high picture quality and simplified process. To achieve the above and other objects, the present invention mainly relates to a light diffusing film. Provided is a light diffusing film comprising: a hardening resin which is obtained by crosslinking and hardening a bishexacyclic acryl monomer and a urethane enoic acid monomer, a light diffusing particle and a hardener. And other objects, features, and advantages will be more apparent. The following detailed description of the preferred embodiments, together with the accompanying drawings, will be described in detail as follows: [Embodiment] The present invention provides a hardening resin comprising a double Hexacyclic acryl monomer and mono urethane acrylate monomer. This hardening resin can be combined with light diffusing particles 1374897 No. 97103043. This revision date: January 10, 101 collocation 'forms a light diffusion film. The structure of the decahydronapthyl acrylate (DHA) monomer of the invention is as follows: (:[):

Wherein Ri and the ruler 2 are each independently η or a C1-C5 alkyl group, for example, a 2-cyclododecaphthalene acrylate (2_DHA) monomer. The ring shape of the hexacyclic group in the structure: the structure can improve the hardness of the surface, reduce the slight scratches on the surface, and avoid the occurrence of yellowing.

The structure of the ammonia vinegar acrylic monomer of the present invention is as follows: (D) —|| IIP~~〇R2-c-N- Ί 〇II Η CΝ- ο Η II Ri-Ν-C-R2 〇' \ HC-N-II 〇

H

R-i-N-C-R〇0-C II 2 II O O Formula (Π) wherein the ruler is Cl~C12 aliphatic or aromatic; R2 is Cl~C4^ bond aliphatic. In one embodiment, the urethane acrylate monomer is hexamethylene polyisocyanate triacrylate (HPT) having a structural formula (dish): 7 1374897 Patent Specification No. 97103043, Revision Η h2 C ~ΟΗ2〇Η2〇~C—N~ C-:

〇 II H /C-N- Γ H h2 c- h2 C-N-C· II o

H

Amendment date 〇II: January 10, 101 nc-ch2ch2o-c Η C-C-CH2CH2O~~C^ Formula (in) The urethane acrylate monomer of the present invention has the advantage that the structure has a structure with the substrate Good adhesion. The bishexyl cyanoacrylate monomer of the present invention and the urethane acrylate monomer are mixed in a weight ratio of 5/95 to 50/50, and a hardening agent is added in an amount of about 1 to 7% by weight based on the hardening resin to form a hardening resin. The type of hardener may be a heat hardener or a light hardener. The heat hardener may be an azo compound, a peroxide, and a persulfate compound. The azo compound includes the following compounds: azo compound 2,2·-azobis(4-oxo-2,4-dimercaptophthalonitrile) (2,2'-azobis(4-methoxy-2,4- Dimethylvaleronitrile)), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobisisoheptanenitrile (2,2'-azobis (2) , 4-dimethylvaleronitrile), 2,2'-azobis(isobut;yronitrile) or 2,2'-azo2-methyl-n-butyronitrile (2,2 '-azobis-2-metliylbutyronitrile); peroxides include the following compounds: benzoyl peroxide, acetyl peroxide, lauroyl peroxide, diterpene peroxide Decanoyl peroxide, di-(2-ethylhexyl)peroxydicarbonate or peroxytrimethylglycolic acid t-butyl 1374897 Patent Specification No. 97103043 Revised revision date: 101 T-butylperoxypivalate; January 1st; sulphuric acid compounds include the following compounds: potassium persulfate, s〇dium persulfate or ammonium persulfate ammonium persulfate), the plurality of thermal hardener may be used alone or in combination. The light hardener may be a phenelin-based compound, for example, diethoxyacetophenone, 2-carbo-2-methyl-1-phenylpropan-1-one, benzyldimethyl dimethyl , 1-(4-isopropylphenyl)-2-yl-2-methylpropan-1-yrylate, 4-(2-carbyloxymethyl)phenyl-(2-hydroxy-2 -propyl) ketone, 1-hydroxycyclohexyl benzophenone or 2-hydrazinoyl linyl-(4-thiomethylphenyl)propan-1-one; dehydrogenated benzophenone photopolymerization initiation Agent 'for example: benzophenone, hydrazine benzoyl benzoyl benzoyl benzophenone, 4-4'-dichlorobenzophenone, hydroxydibenzophenone, benzoquinone- 4·'.-Methyl-diphenyl sulfide, acrylated diclofenac, 3_3, _'4, _ tetra(n-butylperoxylated hydroxy)benzophenone or 3-3·,-two Mercapto-4-methoxydibenzophenone, these light hardeners may be used singly or in combination. The light-diffusing particles of the present invention are organic fine particles or inorganic fine particles, for example, such as polystyrene, polymethyl methacrylate, methacrylic acid vinegar and styrene-ethylidene copolymer, polycarbonate, polyethylene, broken Tree vinegar, carbonated feed, cerium oxide, titanium dioxide or a combination of the foregoing. The particle size distribution of the light-diffusing particles is 3 μπι to 25 μιη. The light-diffusing particles of the present invention are mixed with the hardening resin in a weight ratio of 1/99 to 50/50, and then uniformly coated on a substrate, such as a polyethylene terephthalate (PET) substrate, thickness. The resin is hardened by about 10 to 50 μm and then treated by ultraviolet light or heat. The coating method can be a coating technique known in the art, such as: wheel cutter type, gas 9 1374897 Patent No. 97103043, the revision of this revision period.: 101 years, 10 knives, scraper type, reverse direction Roller or slit coating. The method of curing by ultraviolet light is exemplified as follows: the light-diffusing particles and the hardening resin may be mixed in a weight ratio of 1/99 to 50/50, and then a photoinitiator (such as ciba Irgacure 184) is added and uniformly coated on the poly(p-benzoquinone). On a vinyl terephthalate (PET) substrate, it is irradiated with ultraviolet light (6 〇〇W) for about 5 to 30 seconds to obtain a light-diffusing film. By using ultraviolet light irradiation, the process time can be effectively shortened and the solvent usage can be reduced. The heat curing method is exemplified as follows: the light diffusing particles and the hardening resin may be mixed in a ratio of 1/99 to 50/50 by weight, and 2,2,-azobisisobutyronitrile (2,2'-azobis (isobutyronitrile) is added. )) and benzoyl peroxide as a thermal hardener, uniformly coated on a polyethylene terephthalate (PET) substrate at a temperature of 1 〇〇 to 120 ° (: Preferably, the temperature is 120 ° C). After about 3 to 5 hours, the light diffusion film can be obtained. The resin of the present invention has undergone a series of physical property tests, and the data shows that the hardness of the resin can reach a pencil hardness of Ή or more 'best 2H. On the other hand, the surface adhesion (hundredness test) indicates that the resin and the substrate do have good adhesion. From the high-temperature and high-humidity test results, it is known that the resin has anti-yellowing properties. The light-diffusing film of the present invention After a series of qualitative tests, the experimental results show that the penetration is 3 when the added particles are cerium oxide (Si〇2), the penetration is more than 91%, and the haze and diffusion will follow. Adding the type and quantity of light-diffusing particles to influence 'When adding 25% polyphenylene (PS), the haze is up to 83%; when adding 25% of cerium oxide (si〇2), the degree of diffusion can reach 7 or more. From the above information, the light expansion of the invention 1374897 Patent No. 97103043 Amendment of this manual Date of revision: The optical properties of the film on January 10, 101 can meet the requirements of commercial products. I. Examples The measurement methods used in the examples are as follows: 1. Penetration / Haze: Nippon Denshoku NDH2000 is used, and the test method conforms to ASTM D1003. 2. Surface adhesion (100-gauge test): measuring the adhesion of resin to polyethylene terephthalate (PET) substrate, Use ZENHTNER ZCC 2087.5 cross-cut tester in accordance with ASTM D3359-02. 3. Glass transition temperature (Tg): Use model Seiko SSC-5200 DSC, temperature is corrected with Indium, sample volume 5 · 10 mg, scan rate is 10 ° C / min 'Test gas flow rate under nitrogen 1 〇〇 mi / min. 4. Thermal cracking temperature (Td) using Perkin Elmer Pyris I model, operating temperature is 25 ° C ~ 400 (:, the heating rate is UTc/min. 5. Hardness (pencil Degrees): φ using Elcometer 3086M002 electric lead pencil hardness, water-absorbing 6. conform ASTMD3363-05 specification: ASTM D570-98 specifications comply with the operational flow. The test sample was first cut to a size of 5 cm X 5 cm, and the sample was baked in a vacuum atmosphere for 24 hours to remove moisture, and the dry weight Wdry was measured. After the water was removed, the sample was placed in a constant temperature water bath, allowed to stand at 30 ° C for 24 hours, and then taken out, and the surface of the film was lightly pressed with a dry cloth to ensure that the surface water content was accumulated and then the wet weight Wwet was measured. The water absorption rate of the sample can be calculated by the following formula:

Water Absorption Rate = (Wwet - wdry) / wdry χ 100% 7. Refractive Index: Using a Variable Incident Angle Stokes Ellipsometer 1374897 Patent Specification No. 9 03043 Revised Amendment Date: January 1st, 101 ( L116SF), the test method conforms to the ASTM D542 specification. 8. High temperature and high humidity test: Use THS A4L+ /150 model, the conditions are as follows: sample (5cm X 5cm) at a relative humidity of 85%., temperature 6〇t: test for 300 hours, the model conforms to ASTM G154 . 9. Diffusion: NipponDenshokuGC5000L is used, and the test method conforms to the JIS 8113 specification.

Example 1 Preparation of Urethane Acrylic Monomer Process 1

〇

2-bydroxy^hyl acrylate N2,80〇C,8hr II II Η B [B-C-CHzCHaO-C-/ C-〇H2CH2C-C-N-(c]-N

Ο-ι

Take 2,2-hydroethyl acrylate monomer 0.051 mole dissolved in 0.017 mole of 1,6-hexamethylene polyisocyanate trimer (8,6-hexamethylene polyisocyanate trimer) at 8 ( TC was reacted for 8 hours under a nitrogen atmosphere to obtain 1,6-hexamethylene polyisocyanate triacrylate (HPT) 〇12 1374897 Patent specification No. 97103043 Amendment date: January 101 10曰Example 2 Resin formulation and physical property measurement 1,6-hexamethylene polyisocyanate triacrylate (HPT) monomer and 2-cyclododecyl naphthalene acrylate (2 -DHA) The monomers were mixed according to the weight ratio of Table 1, and then a light hardener (Igracure 184, 5 wt%) was added and mixed to obtain a resin coating. The coating was then applied to polyethylene terephthalate (polyethylene). The terephthalate (PET) substrate has a film thickness of about 24 μm, and then irradiated with ultraviolet light (600 W) for about 30 seconds to obtain a hardened resin. The resin is then sequentially measured for its penetration. Haze, surface adhesion, glass turn Temperature (Tg), thermal cracking temperature (Td), hardness, water absorption, refractive index and local temperature and humidity test, the data can be found in Table 1. From the first table, the hardness of the resin is above the grade. It indicates that the resin has good hardness. It is known from the surface adhesion test that the resin has passed the test, indicating that the resin has good adhesion to the substrate. It can be known from the high temperature and high humidity test. Not large, indicating that the tree • lipid has anti-yellowing properties. Table 1 HPT HPT- DHA5 HPT- DHA10 HPT- DHA20 HPT- DHA30 HPT- DHA40 Composition ΗΡΤ (%) 100 95 90 80 70 60 2-DHA (%) 0 5 10 20 30 40 Irgacure 5 5 5 5 5 5 13 1374897

Patent Specification No. 97103043 Amendment This Revision B: 101 j ^ January 10曰184 Basic Properties Penetration 91.22 91.32 91.21 90.98 91.29 91.31 Haze 1.73 1.48 1.32 1.58 1.55 1.67 Surface pass through passing through the passing Tg ( °c) 95.87 94.24 97.02 95.73 88.33 90.02 Td(°C) 338.96 340.66 337.88 332.11 330.63 331.99 Hardness B HB Η 2H 2H Η Water absorption (%) 0.67 0.63 0.63 0.56 0.52 0.47 Refractive index 1.5148 1.5144 1.5145 1.5150 1.5165 0.5163 To warm and wet (0.3106, (0.3105, (0.3105, (0.3105, (0.3104, (0.3104, Test (previous / 0.3166) 0.3164) / 0.3166) / 0.3165) / 0.3164 / 0.3164) / later) (0.3105, (0.3106, (0.3106, ( 0.3105, (0.3105, 0.3165) 0.3166) 0.3165) 0.3165) 0.3165) Example 3 Light-diffusing film formulation and quality measurement sequentially HPT, 2-DHA and light-diffusing particles, such as: polystyrene (PS), polymethyl Methyl methacrylate (PMMA) or cerium oxide (SiO 2 ) was prepared according to the weight ratio of Table 2, and then a light hardening agent (Irgacure 184, 5 wt%) was added to obtain a diffusion film coating. The coating was applied to a polyethylene terephthalate (PET) substrate, and the film thickness was controlled to 24 μm, followed by irradiation with ultraviolet light (600 W) for photopolymerization in about 30 seconds. A light diffusing film is obtained. The transmittance of the diffusing film is measured in sequence, and the properties of the haze and the diffusing degree are corrected by the specification of the patent, and the type and quantity are corrected for the above characteristics: 1〇1 year The first table was obtained on January 1st, and the influence of diffused particle species was discussed. See Table 3-1, the permeability is greater than 75%. The divergence is improved. When adding light diffusing particles of polystyrene (PS), When the ratio of PS is increased and the addition ratio of PS is increased, the haze and expansion can be increased by referring to the third to third 纟, and the light-diffusing particles of the cerium dioxide (si〇2) are added to make the transmittance greater than 9 G%. When the ratio of dioxo addition is increased, both haze and diffusivity can be improved. When 25% of cerium oxide is added, the degree of penetration is greater than 93%, the haze is greater than 63%, and the degree of diffusion is greater than 7 to reach the level of commercial products. Referring to Table 3-3, the addition of poly(meth) methacrylate (PMMa) light-dispersing particles allows for greater than 88% penetration. When the PMMA addition ratio is increased, the haze and the diffusion degree are not helpful because the refractive index of the PMMA (about 1.53) and the refractive index of the resin (about 1.51 to 1.52) are not much different, so the ratio of adding PMMA is increased. It does not increase haze and spread.

Table 2 EX1 EX2 EX3 EX4 EX5 EX6 EX7 EX8 EX9 EXio EXli EX12 Light diffusing particles polystyrene Si02 PMM A 2-DHA 0 5 10 20 30 40 0 10 20 0 10 20 HPT 100 95 90 80 70 60 100 90 80 100 90 80 M84 5 5 5 5 5 5 5 5 5 5 5 5 40 40 40 40 40 40 40 40 40 40 40 40 15 1374897 Patent specification No. 97103043 Amendment date: January 10, 101 曰 3-1 EX1 EX2 EX3 EX4 EX5 EX6 Polystyrene 5 % Penetration (%) 89.28 89.11 89.17 89.11 89.31 89.36 Haze (%) 40.55 37.34 29.23 28.62 27.67 28.37 Diffusion 0.56 0.81 1.09 2.44 0.56 1.19 Polystyrene ισ°/〇 Penetration: (%) 88.75 83.40 84.13 84.15 830.5 83.78 Haze (%) 48.62 70.97 72.04 71.17 69.70 72.61 Diffusion 1.16 3.34 2.51 3.86 6.84 5.63 Polystyrene 15 % Penetration (%) 85.43 76.77 82.61 79.83 79.34 86.64 Haze (%) 86.25 85.47 88.43 82.16 82.95 80.31 Diffusion 2.43 1.54 1.77 3.37 2.79 3.93 Polystyrene 20 % Penetration (%) 85.57 84.56 83.62 84.13 85.58 86.42 Haze (%) 84.90 86.71 86.72 86.70 81.93 80.20 Diffusion 2.58 4.25 2.43 2.92 1.92 2.0 1 Polystyrene 25 % penetration (%) 95.36 94.59 94.71 94.21 93.91 93.94 Haze (%) 90.13 87.48 88.00 85.76 84.20 83.74

10 1374897 Revision date: January 10, 101 Diffusion 4.8 2.7 2.73 2.33 2.13 2.58 Amendment to patent specification No. 97103043

Table 3-2 EX7 EX8 EX9 Si02 Penetration (%) 92.22 91.72 91.53 5% Haze (%) 28.90 25.59 23.22 Diffusion 1.66 2.61 1.68 Si02 Penetration (%) 92.50 92.81 92.35 10% Haze (%) 41.47 44.51 40.49 Diffusion 3.23 3.7 4.42 Si02 Penetration (%) 93.09 93.23 92.12 1.5% Haze (%) 53.72 54.91 46.18 Diffusion 5.48 5.13 4.88 Si02 Penetration (%) 94.22 93.95 94.53 20% Haze (%) 67.63 67.08 69.62 Diffusion 8.38 8.59 7.11 Si〇2 Penetration (%) 93.95 93.62 94.27 25% Haze (%) 68.81 63.92 68.28 Diffusion 9.17 7.11 10.84 Table 3-3 EX 10 EX 11 EX 12 PMMA Penetration (%) 90.21 87.90 89.58 5% Haze (%) 6.00 12.92 9.77 Diffusion 0 0 0 PMMA Penetration (%) 89.22 89.16 89.18 10% Haze (%) 12.07 17.85 18.04 17 1374897 Revision No. 97103043 Modified Muse: January 10, 101 曰 Diffusion 0 0.56 0 PMMA Penetration (%) 88.81 88.86 89.17 15% Haze (%) 18.27 26.41 18.08 Diffusion 0 0 0 PMMA Penetration (%) 88.65 89.27 89.29 20% haze (%) 17.85 16.66 22.46 Diffusion degree 0 0.53 1.63 PMMA Penetration (%) 88.74 89.09 89.46 25% Haze (%) 18.03 24.75 18.77 Diffusion degree 0.47 0.39 0.45 Although the present invention has been disclosed above in several preferred embodiments, it is not In order to limit the invention, any one of ordinary skill in the art can make any changes and refinements without departing from the spirit and scope of the invention, and therefore the scope of the invention is defined by the appended claims. The definition is subject to change. 1374897 Revision No. 97103043 Patent Description Amendment date: January 10, 101. [Simplified illustration] None. [Main component symbol description] None.

19

Claims (1)

I374S9?——η Announcement No. 97103043 Patent Specification Amendment Revision Date: January 10, 2010, Patent Application Range: 1. A light diffusing film comprising: a hardened resin from a bishexacyclic acrylic monomer A light-diffusing particle and a hardener are cross-linked with a urethane acrylate monomer, wherein the bishexa- cyanoacrylate monomer has the structure of formula (I): HC=CH Wherein Ri and R2 are each independently η or a C1-C5 alkyl group, and the weight ratio of the bishexacyclic acryl monomer to the urethane acrylate monomer is 5/95 to 50/50, and the light is diffused. The weight ratio of the particles to the hardened resin is 1/99 to 50/50. 2. The light diffusing film according to claim 1, wherein the bishexacyclic acryl monomer is 2-cyclododecyl acrylate (2-DHA). 3. The light diffusing film according to claim 1, wherein the structure of the urethane acrylic monomer is as follows: Ο 0 II II Η C-OR2——C——N-R. \ Η CN- II 〇Η RI—Ν_C—R2〇_C Ο 〇 (π ) where 艮 is C1~C12 aliphatic or aromatic; R2 is C1~C4 20 1374897 Patent Specification No. 97103043 Amendment Revision Date: 101 January 10, a straight chain aliphatic. 4. The light diffusing film according to claim 3, wherein the urethane acrylate monomer is 1,6-hexamethylene triisocyan acrylate having a structural formula (dish): Η Η2 Η h2 Ρ —Ν— C~"N—C—CH2CH2O c-oh2ch2c-cnc- Η η2 C Ν II II C C C C C C C C C C C C C C C 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光 光Combination of the foregoing. 6. The light diffusing film of claim 1, wherein the light diffusing particles are polystyrene, polymethyl methacrylate, methyl methacrylate and styrene copolymer, polycarbonate, poly Ethylene, eucalyptus, calcium carbonate, cerium oxide, titanium dioxide or a combination of the foregoing. The light-diffusing film according to claim 1, wherein the light-scattering particles have a particle size distribution of from 3 μm to 25 μm. 8. The light diffusing film of claim 1, wherein the hardening agent comprises from 1 to 7% by weight of the hardening resin. 9. The light diffusing film of claim 1, wherein the hardening resin is cured by ultraviolet light. 10. The light diffusing film according to claim 1, wherein the hardening resin is formed by heat hardening. twenty one