Optical device and method of manufacturing the same

Abstract

Disclosed are a silicone composition including polysiloxane and having a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219; and a method of manufacturing an optical device including the silicone composition, wherein the Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition is less than 20.

Description

[0001] OPTICAL DEVICE AND METHOD OF MANUFACTURING THE SAME

[0002] [Technical Field]

[0003] The present invention relates to an optical device including a silicone composition and a method of manufacturing the same.

[0004] [Background Art]

[0005] Optical adhesive formulations are used to improve visibility, readability, and durability by filling an air gap between a screen panel and a display module, or two glasses for a smart window system.

[0006] As materials for optical adhesive formulations, acrylate-based materials, silicone-based materials, urethane-based materials, etc. can be used. In particular, acrylate-based materials have been widely used as optical adhesive formulations for small displays. However, when the size of a display or window is enlarged, an optical device to which an acrylate-based material is applied generates bubbles, the optical degradation such as yellowing etc., and the chemical and mechanical properties thereof are decreased due to the internal and external stress such as heat, UV, electricity etc.

[0007] [Disclosure]

[0008] [Technical Problem]

[0009] Therefore, the present invention has been made given the above problems, and it is one object of the present invention to an optical device including a silicone composition and having excellent workability, mechanical properties, transparency, and light transmission; and a method of manufacturing the optical device.

[0010] [Technical Solution]

[0011] In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of an optical device, including: a first substrate; a functional film formed on the first substrate; a second substrate formed on the functional film; a sealing part configured to fix the first and second substrates; and an adhesive part formed between the first and second substrates, wherein the adhesive part includes a silicone composition, wherein the silicone composition includes polysiloxane and has a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219, and a Shore 00 hardness, measured according to DIN ISO 7619, of a cured product made of the silicone composition is less than 20.

[0012] In an embodiment of the present invention, the functional film may be attached to the first substrate by an optical adhesive film.

[0013] In an embodiment of the present invention, the optical device may be a touch panel display for automobiles.

[0014] In accordance with another aspect of the present invention, there is provided a method of manufacturing an optical device, the method including: preparing first and second substrates; laminating a functional film on the first substrate; introducing a second substrate on the functional film and fixing the first and second substrates; and forming an adhesive layer by injecting a silicone composition between the first and second substrates, wherein the silicone composition is fed by an injection method, the silicone composition includes poly siloxane and has a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219, and a Shore 00 hardness, measured according to DIN ISO 7619, of a cured product made of the silicone composition is less than 20.

[0015] In an embodiment of the present invention, in the laminating, the functional film may be attached onto the first substrate by an optical adhesive film.

[0016] In an embodiment of the present invention, the method may further include, after the laminating of the functional film on the first substrate, forming dams for maintaining an interval between the first and second substrates between the first and second substrates.

[0017] In an embodiment of the present invention, the adhesive layer may be formed by curing the silicone composition at room temperature.

[0018] In accordance with yet another aspect of the present invention, there is provided a silicone composition, including polysiloxane and having a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219, and a Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition is less than 20. In an embodiment of the present invention, the poly siloxane may include: a first organopolysiloxane (a) including an alkenyl group at an end of a main chain thereof; a second organopolysiloxane (b) including a siloxane unit represented by RiR^RsSiOi / ? and SiO4 / 2; and a first organohydrogen polysiloxane (c) including at least one hydrogen group bonded to a silicon atom, wherein Ri, R2 and R3 are each independently a substituted or unsubstituted monovalent hydrocarbon group, and at least one of Ri, R2 and R3 is an alkenyl group.

[0019] In an embodiment of the present invention, the poly siloxane may include: 50 % by weight to 98 % by weight of the first organopolysiloxane (a); 1 % by weight to 10 % by weight of the second organopolysiloxane (b); and 1 % by weight to 40 % by weight of the first organohydrogen polysiloxane (c).

[0020] In an embodiment of the present invention, the first organopolysiloxane may include: a 1-1 organopolysiloxane (a-1) including a siloxane unit having an average chain length of less than 150, the 1-1 organopolysiloxane (a-1) having a weight average molecular weight of 8,000 g / mol or less; and a 1-2 organopolysiloxane (a-2) including a siloxane unit having an average chain length of 150 or more and 1,200 or less, the 1-2 organopolysiloxane (a-2) having a weight average molecular weight of 40,000 g / mol to 80,000 g / mol.

[0021] In an embodiment of the present invention, the first organohydrogen poly siloxane may include: a 1-1 organohydrogen poly siloxane (c-1) containing a hydrogen group at an end of a main chain thereof; and a 1-2 organohydrogen poly siloxane (c-2) containing a hydrogen group in a side chain thereof.

[0022] In an embodiment of the present invention, the 1-1 organohydrogen poly siloxane may include a siloxane unit having an average chain length of greater than 10.

[0023] In an embodiment of the present invention, a content of the 1-2 organohydrogen poly siloxane may be 15 parts by weight or less based on 100 parts by weight of the 1-1 organohydrogen polysiloxane.

[0024] In an embodiment of the present invention, the silicone composition may further include at least one of a tackifier, a reaction inhibitor, and a curing catalyst.

[0025] [Advantageous effects]

[0026] An optical device including a silicone composition according to the present invention and a method of manufacturing the optical device satisfy a certain range of viscosity and hardness.

[0027] Accordingly, the flowability and curability of the silicone composition can be improved, an adhesive layer can be efficiently formed by an injection process at room temperature without a UV process, so it can be applied even when the size of the display is enlarged.

[0028] In addition, yellowing mura, bubble generation, and the like can be suppressed, mechanical properties can be improved while ensuring transparency and light transmission.

[0029] [Description of Drawings]

[0030] FIGS. 1 and 2 schematically illustrate a method of manufacturing an optical device according to the present invention.

[0031] [Best Mode]

[0032] Structural or functional descriptions of embodiments disclosed in the present specification or application are merely illustrated for the purpose of explaining embodiments according to the technical idea of the present invention, embodiments according to the technical idea of the present invention may be implemented in various forms other than the embodiments disclosed in the present specification or application, and it is not to be construed that the technical idea of the present invention is limited to the embodiments described in the present specification or application.

[0033] In the present specification or application, when a certain component is “included,” this indicates that only the component is included or the component may further include another component unless there is no different disclosure. In addition, it should be understood that all numerical ranges representing physical property values, dimensions, etc. of components described in the present specification or application are modified by the term 'about' in all cases unless otherwise specified.

[0034] In this specification or application, the term "upper" may refer to a position in contact with one surface of a certain component, or a position spaced apart from one surface of a certain component. In addition, in this specification or application, the term "lower" may refer to a position symmetrical to the "upper" position and in contact with the other surface of a certain component, or a position spaced apart from the other surface of a certain component.

[0035] The meaning of each term described in the present specification or application is as follows.

[0036] Siloxane: a compound having a Si-O-Si bond.

[0037] Polysiloxane: a compound having a plurality of Si-O-Si bonds.

[0038] Silicone composition refers to a composition composed of only a polysiloxane compound, or a composition including polysiloxane and mixed with additional compounds for implementing specific performance.

[0039] Organopolysiloxane: Polysiloxane having a structure in which an organic group is bonded to a Si atom constituting a Si-O-Si bond.

[0040] Organohydrogen polysiloxane: Polysiloxane having a structure in which a hydrogen group is bonded to a Si atom constituting a Si-O-Si bond.

[0041] Main chain: Relatively longest chain among polysiloxane compounds.

[0042] Side chain: Structure branched from the main chain of polysiloxane compounds.

[0043] Straight-chain polysiloxane: a polysiloxane having a structure in which a siloxane chain is not connected by interposing an atom linking group onto a Si atom of the main chain (-Si-O- Si-O-) of polysiloxane.

[0044] Branched polysiloxane: Polysiloxane containing at least one T-shaped or cross-shaped branch point.

[0045] Hereinafter, an optical device including a silicone composition and a method of manufacturing the same are described in detail.

[0046] A silicone composition according to the present invention includes polysiloxane.

[0047] The polysiloxane may include a first organopolysiloxane having an alkenyl group at an end of a main chain thereof. The silicone composition including the first organopolysiloxane has excellent moldability and may improve viscoelasticity, transparency, and light transmission.

[0048] The alkenyl group may be vinyl, allyl, methallyl, butenyl, pentenyl, or hexenyl. Preferably, the alkenyl group may be vinyl.

[0049] In the main chain of the first organopolysiloxane, a Si-bonded organic group other than the alkenyl group may be a substituted or unsubstituted monovalent hydrocarbon group, specifically methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or halogenated alkyl. Preferably, the Si-bonded organic group may be methyl.

[0050] The first organopolysiloxane may include a 1-1 organopolysiloxane including a siloxane unit with an average chain length of less than 150 and having a weight average molecular weight of 8,000 g / mol or less; and a 1-2 organopolysiloxane including a siloxane unit with an average chain length of 150 or more and 1,200 or less and having a weight average molecular weight of 40,000 g / mol to 80,000 g / mol.

[0051] The first organopolysiloxane may include a 1-1 organopolysiloxane including a siloxane unit having an average chain length of less than 110 and having a weight average molecular weight of 7,800 g / mol or less; and a 1-2 organopolysiloxane including a siloxane unit having an average chain length of 150 or more and 1,100 or less and having a weight average molecular weight of 47,000 g / mol to 76,000 g / mol.

[0052] A weight ratio of the 1-1 organopolysiloxane to the 1-2 organopolysiloxane may be 100:1 to 1 :1, 100: 1 to 1: 1, 100: 1 to 1 : 1, 100: 1 to 1 : 1, or 100:1 to 1 :1. When the range is satisfied, the flowability of the silicone composition may be improved, so an adhesive layer may be efficiently formed by an injection process at room temperature.

[0053] The 1-1 organopolysiloxane may be represented by Formula 1 below:

[0054] [Formula 1]

[0055] In Formula 1, n is 0 to 150.

[0056] The 1-2 organopolysiloxane may be represented by Formula 2 below:

[0057] [Formula 2]

[0058]

[0059] In Formula 2, n is 150 to 1,100.

[0060] Based on a total weight of the polysiloxane, the first organopolysiloxane may be included in a content of 50 % by weight to 98 % by weight, 55 % by weight to 98 % by weight, 60 % by weight to 98 % by weight, or 60 % by weight to 90 % by weight. When the range is satisfied, the silicone composition may have appropriate flowability, so processability may be improved.

[0061] The polysiloxane may include a second organopolysiloxane including a siloxane unit represented by RiR2R3SiOi / 2 and Si O42 The silicone composition including the second organopolysiloxane may have improved toughness, so mechanical properties may be supplemented.

[0062] RiR2R3SiOi / 2 may mean a monofunctional polysiloxane.

[0063] RiR2R3SiOi / 2 may be represented by Formula 3 below:

[0064] [Formula 3]

[0065] R1

[0066] - O - S | i - Ro

[0067] R3

[0068] In Formula 3, Ri, R2 and R3 are each independently a substituted or unsubstituted monovalent hydrocarbon group, and at least one of Ri, R2 and R3 is an alkenyl group.

[0069] SiO4 / 2 may mean a tetrafunctional polysiloxane.

[0070] SiO4 / 2 may be represented by Formula 4 below:

[0071] [Formula 4]

[0072] The second organopolysiloxane may be represented by Formula 5 below:

[0073] [Formula 5]

[0074] In Formula 5, R4and Rs are each independently a substituted or unsubstituted monovalent hydrocarbon group, Re is an alkenyl group, x is an integer from 10 to 2,000, and y is an integer from 10 to 1,000.

[0075] The second organopolysiloxane may have a weight average molecular weight of 1,000 g / mol to 500,000 g / mol, 1,000 g / mol to 300,000 g / mol, 1,000 g / mol to 100,000 g / mol, or 2,000 g / mol to 100,000 g / mol.

[0076] Based on a total weight of the polysiloxane, the second organopolysiloxane may be included in a content of greater than 0 % by weight and 10 % by weight or less, 1 % by weight to 10 % by weight, 2 % by weight to 10 % by weight, or 3 % by weight to 10 % by weight. When the range is satisfied, the silicone composition may have appropriate flowability, and the mechanical properties of a cured product made of the silicone composition may be improved.

[0077] The polysiloxane may include a first organohydrogen polysiloxane including at least one hydrogen group bonded to a silicon atom. The first organohydrogen poly siloxane may act as a crosslinking agent for an alkenyl group of the first organopolysiloxane and / or an alkenyl group of the second organopolysiloxane. The Si-bonded H in the first organohydrogen polysiloxane may undergo an addition reaction with the alkenyl group of the first organopolysiloxane and / or the alkenyl group of the second organopolysiloxane. a curing reaction of the silicone composition may proceed by the addition reaction.

[0078] The first organohydrogen poly siloxane may include 1-1 organohydrogen poly siloxane containing a hydrogen group at an end of a main chain thereof, and 1-2 organohydrogen polysiloxane containing a hydrogen group in a side chain thereof.

[0079] The 1-1 organohydrogen poly siloxane may have an average chain length of greater than 1, greater than 5, greater than 10, or greater than 10 and less than 1,000. The 1-1 organohydrogen polysiloxane may have a weight average molecular weight of 8,000 g / mol to 500,000 g / mol, 8,000 g / mol to 400,000 g / mol, 8,000 g / mol to 300,000 g / mol, or 8,000 g / mol to 100,000 g / mol.

[0080] The 1-2 organohydrogen poly siloxane may have an average chain length of 1 or more, 3 or more, 5 or more, or 1 or more and 1,000 or less. The 1-2 organohydrogen polysiloxane may have a weight average molecular weight of 1,000 g / mol to 300,000 g / mol, 1,000 g / mol to 200,000 g / mol, 1,000 g / mol to 100,000 g / mol, or 1,000 g / mol to 90,000 g / mol.

[0081] Based on 100 parts by weight of the 1-1 organohydrogen poly siloxane, the content of the 1-2 organohydrogen poly siloxane may be 30 parts by weight or less, 20 parts by weight or less, 15 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, or 10 parts by weight or less. When the range is satisfied, the silicone composition may have appropriate flowability and an appropriate curing speed, and change over time may be suppressed.

[0082] The 1-1 organohydrogen poly siloxane may be represented by Formula 6 below:

[0083] [Formula 6]

[0084] In Formula 6, t is 2 to 1,000.

[0085] The 1-2 organohydrogen poly siloxane may be represented by Formula 7 below:

[0086] [Formula 7]

[0087] In Formula 7, p is an integer from 1 to 500, and y is an integer from 1 to 500.

[0088] Based on a total weight of the poly siloxane, the first organohydrogen poly siloxane may be included in a content of 1 % by weight to 40 % by weight, 1 % by weight to 38 % by weight, 5 % by weight to 38 % by weight, 10 % by weight to 38 % by weight, or 10 % by weight to 35 % by weight. When the range is satisfied, the silicone composition may have appropriate flowability and curability.

[0089] The poly siloxane may include 50 % by weight to 98 % by weight of the first organopoly siloxane, 1 % by weight to 10 % by weight of the second organopoly siloxane, and 1 % by weight to 40 % by weight of the first organohydrogen polysiloxane.

[0090] The poly siloxane may include 50 % by weight to 90 % by weight of the first organopoly siloxane, 5 % by weight to 10 % by weight of the second organopoly siloxane, and 5 % by weight to 40 % by weight of the first organohydrogen polysiloxane.

[0091] The poly siloxane may include 50 % by weight to 80 % by weight of the first organopoly siloxane, 5 % by weight to 10 % by weight of the second organopoly siloxane, and 15 % by weight to 40 % by weight of the first organohydrogen poly siloxane.

[0092] When the ranges are satisfied, the flowability and curability of the silicone composition may be improved, and an adhesive layer may be efficiently formed by an injection process at room temperature, so it may be applied even when the size of a display is enlarged.

[0093] The silicone composition may further include at least one of a tackifier, a reaction inhibitor, and a curing catalyst.

[0094] The tackifier may improve the adhesive strength of the silicone composition. The tackifier may include one or more selected from the group consisting of glycidoxypropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, glycidoxypropyltri ethoxy silane or glycidoxypropylmethyldi ethoxy silane, 2-(3- triethoxysilylpropyl)maleic anhydride, N-(3-trimethoxysilylpropyl)urea, N-(3- triethoxysilylpropyl)urea, N-(trimethoxysilylmethyl)urea, N-(methyldimethoxysilylmethyl)urea, O-(methylcarbamatomethyl)methyldimethoxysilane, O- (methylcarbamatomethyl)trimethoxysilane, O-(ethylcarbamatomethyl)methyldiethoxysilane, O- (ethylcarbamatomethyl)triethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, methacryloyloxymethyltrimethoxysilane, methacryloyloxymethylmethyldimethoxysilane, methacryloyloxymethyltri ethoxy silane, methacryloyloxymethylmethyldi ethoxy silane, 3- acryloyloxypropyltrimethoxysilane, acryloyloxymethyltrimethoxysilane, and acryloyloxymethylmethyldimethoxysilane.

[0095] Based on a total weight of the silicone composition, the tackifier may be included in a content of 0.1 % by weight to 10 % by weight, 0.1 % by weight to 5 % by weight, 0.1 % by weight to 3 % by weight, or 0.1 % by weight to 2 % by weight.

[0096] The reaction inhibitor inhibits the increase in viscosity of the silicone composition. The reaction inhibitor may slow down a hydrosilylation addition reaction between Si-bonded H in the first organohydrogen polysiloxane and an alkenyl group of the first organopolysiloxane and / or an alkenyl group of the second organopolysiloxane. The reaction inhibitor may include a vinyl group-containing polysiloxane which is a compound different from the first organopolysiloxane.

[0097] Based on a total weight of the silicone composition, the reaction inhibitor may be included in a content of 0.001 % by weight to 3 % by weight, 0.001 % by weight to 2 % by weight, 0.001 % by weight to 1 % by weight, or 0.01 % by weight to 1 % by weight.

[0098] The curing catalyst may promote an addition reaction between the first organohydrogen polysiloxane and the first organopolysiloxane and / or the second organopolysiloxane. The curing catalyst may include a platinum catalyst, a rhodium catalyst, a palladium catalyst, or a complex compound. The complex compound may be a platinum / alkenylsiloxane complex compound, a platinum / olefm complex compound, or a platinum / carbonyl complex compound.

[0099] Based on a total weight of the silicone composition, the curing catalyst may be included in a content of 0.001 % by weight to 1 % by weight, 0.001 % by weight to 0.5 % by weight, 0.001 % by weight to 0.3 % by weight, or 0.01 % by weight to 0.3 % by weight. A viscosity at 25 °C, measured according to DIN ISO 3219, of the silicone composition is less than 500 mPa.s, and a Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition is less than 20. The viscosity, measured at 25 °C according to DIN ISO 3219, of the silicone composition may be less than 400 mPa.s, and the Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition may be 1 o or more and less than 20. The viscosity, measured at 25 °C according to DIN ISO 3219, of the silicone composition may be greater than 50 mPa.s and less than 400 mPa.s, and the Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition may be 2 or more and less than 10. The cured product of the silicone composition is cured at about 65 °C for about 1 hour and then cooled at room temperature, and may have a thickness of about 6 mm.

[0100] When the ranges are satisfied, the flowability and curability of the silicone composition may be improved, and an adhesive layer may be efficiently formed by an injection process at room temperature, so it may be applied even when the size of a display size is enlarged. In addition, yellowing mura, bubble generation, and the like may be suppressed, and mechanical properties may be improved while ensuring transparency and light transmission.

[0101] A storage modulus, measured by dynamic mechanical analysis according to ASTM E143, ofthe silicone composition may be 0.2 x 103Pa to 8 x 103Pa, 0.5 x 103Pa to 8 x 103Pa, 1 x 103Pa to 8 x 103Pa, 2 x 103Pa to 8 x 103Pa, or 3 x io3Pa to 8 x 103Pa. When the range is satisfied, the mechanical properties of the cured silicone composition do not deteriorate, and rapid changes in a storage modulus may be suppressed.

[0102] A refractive index, measured at the D-line (480 nm, 589 nm) wavelength using an Abbe refractive index meter, of the cured silicone composition may be 1.35 to 1.45, 1.38 to 1.45, 1.38 to 1.43, or 1.39 to 1.42. A light transmittance (based on a wavelength of 450 nm), measured using Specord 200 Plus UV-Vis spectrometer, of the cured silicone composition may be 99 % or more, 99.1 % or more, 99.2 % or more, 99.3 % or more, 99.5 % or more, or 99.6 % or more. A haze of the cured silicone composition according to ASTM D1003-97 may be less than 0.3 %, less than 0.2 %, or less than 0.3 %. A yellowness index of the cured silicone composition according to ASTM D313-73 may be less than 0.5 %, less than 0.4 %, less than 0.3 %, or less than 0.2 %. When the ranges are satisfied, transparency may be improved and light may be smoothly emitted from a light source when the cured silicone composition is used as an adhesive layer of an optical device. A pull strength, measured according to ASTM D2651, of the cured silicone composition may be greater than 1.0 kgf / cm2, greater than 1.5 kgf / cm2, greater than 2.0 kgf / cm2, greater than 2.5 kgf / cm2, or greater than 3.0 kgf / cm2. The silicone composition and the cured silicone composition may have a volumetric shrinkage of less than 0.5 %, less than 0.4 %, less than 0.3 %, less than 0.2 %, or less than 0.1 % according to Equation 1 in accordance with ISO 3521. When the range is satisfied, mechanical properties may be improved while ensuring transparency and light transmission.

[0103] [Equation 1]

[0104] (1 - Volume of silicone composition / volume of cured product) x 100 %

[0105] A method of manufacturing the optical device according to the present invention includes a step of preparing first and second substrates, a step of laminating a functional film on the first substrate, a step of introducing a second substrate on the functional film and fixing the first and second substrates, and a step of forming an adhesive layer by injecting a silicone composition between the first and second substrates, wherein the silicone composition is introduced by an injection method.

[0106] FIGS. 1 and 2 schematically illustrate a method of manufacturing an optical device according to the present invention. Referring to FIGS. 1 and 2, the manufacturing method includes a step of preparing a first substrate 10 and a second substrate 20.

[0107] The first and second substrates 10 and 20 may be substrates in an optical device assembly. The first substrate 10 and a second substrate 20 may be soda lime glass.

[0108] The manufacturing method includes a step of laminating a functional film 30 on the first substrate 10.

[0109] In the laminating step, the functional film 30 may be attached onto the first substrate 10 by an optical adhesive film 40.

[0110] The functional film 30 is a functional film applicable to a liquid crystal display (LCD), an organic light emitting display (OLED), an electronic paper (e-paper) display, a surfaceconduction electron-emitter display (SED), a light emitting diode (LED) display, or an electroluminescent display (ELD). The optical adhesive film 40 may be an optically clear adhesive (OCA) film. The functional film 30 may be fixed onto the first substrate 10 by the optical adhesive film 40. The optical adhesive film 40 may be an optically transparent adhesive film. The optical adhesive film 40 may be a double-sided tape and may have a light transmittance of 99 % or more, 99.3 % or more, or 99.5 %or more.

[0111] The manufacturing method may further include a step of allowing dams 50 for maintaining an interval between the first and second substrates 10 and 20 to be formed between the first and second substrates 10 and 20 after laminating a functional film 30 on the first substrate 10.

[0112] The manufacturing method includes a step of fixing the first and second substrates 10 and 20 after introducing the second substrate 20 onto the functional film 30.

[0113] The first and second substrates 10 and 20 may be fixed by the dams 50. The dams 50 may be removed after the silicone composition is cured. However, the dams 50 may not be removed depending on the purpose of use.

[0114] The manufacturing method includes a step of feeding a silicone composition between the first and second substrates 10 and 20 to form an adhesive layer 70, and the silicone composition is fed by an injection method.

[0115] As the injection method is applied, an adhesive layer may be efficiently formed at room temperature without a UV process even on large displays, yellowing mura and bubble generation may be suppressed after the formation of the adhesive layer, and mechanical properties may be improved while ensuring transparency and light transmission.

[0116] The silicone composition includes poly siloxane and has a viscosity at 25 °C of less than 500 mPa.s measured according to DIN ISO 3219, and the Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition is less than 20. The silicone composition may be the same as the above-described silicone composition. When the range is satisfied, the silicone composition may have appropriate flowability and curing speed, so an adhesive layer may be efficiently formed on a large display by the injection method.

[0117] The adhesive layer 70 may be formed by curing the silicone composition at room temperature. The adhesive layer 70 may be formed by curing the silicone composition at room temperature for about 20 minutes to 600 minutes, about 20 minutes to 500 minutes, about 20 minutes to 400 minutes, about 20 minutes to 300 minutes, or about 20 minutes to 240 minutes. An optical device 100 manufactured according to the manufacturing method includes a first substrate 10, a functional film 30 formed on the first substrate 10, a second substrate 20 formed on the functional film 30, a sealing part 60 for fixing the first and second substrates 10 and 20, and an adhesive part 70 formed between the first and second substrates 10 and 20, wherein the adhesive part 70 includes a silicone composition, the silicone composition includes polysiloxane, a viscosity at 25 °C, measured according to DIN ISO 3219, of the silicone composition is less than 500 mPa.s, and the Shore 00 hardness, measured according to DIN ISO 7619, of a cured product made of the silicone composition is less than 20.

[0118] The silicone composition may be the same as the above-described silicone composition.

[0119] The functional film 30 may be attached onto the first substrate 10 by an optical adhesive film 40.

[0120] The optical adhesive film 40 may be the same as the above-described optical adhesive film.

[0121] The optical device 100 may be a liquid crystal display (LCD), an organic light emitting display (OLED), an electronic paper (e-paper) display, a surface-conduction electron-emitter display (SED), a light emitting diode (LED) display, or an electroluminescent display (ELD).

[0122] Preferably, the optical device 100 may be a touch panel display for automobiles or a curved display.

[0123] When the silicone composition is used as an optical adhesive material of the optical device 100, the optical device 100 may have improved light transmittance, thermal stability and mechanical properties.

[0124] Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are only examples for explaining the present invention in more detail, and the present invention is not limited to the following examples and comparative examples.

[0125] Examples

[0126] Silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were prepared to have components and contents shown in Table 1 below. - Component (A)

[0127] A-l: CH2=CH(CH3)2SiO(Si(CH3)2O)nSi(CH3)2CH=CH2, Mw = 7,000 g / mol, an average chain length = 100

[0128] A-2: CH2=CH(CH3)2SiO(Si(CH3)2O)nSi(CH3)2CH=CH2, Mw = 47,000 g / mol, an average chain length = 600

[0129] A-3: CH2=CH(CH3)2SiO(Si(CH3)2O)nSi(CH3)2CH=CH2, Mw = 76,000 g / mol, an average chain length = 1,100

[0130] - Component (B)

[0131] B-l: M5MviiQ4

[0132] B-2: M7MviiQi2

[0133] Vi refers to a vinyl group, M refers to a monofunctional siloxane unit, and Q refers to a tetrafunctional siloxane unit.

[0134] - Component (C)

[0135] C-l: H-(Si(CH3)2O)nSi(CH3)2-H, Mw = 4,000 g / mol, an average chain length = 20

[0136] C-2: (CH3)3SiO((CH3)2SiO)n(CH3HSiO)mSi(CH3)3, Mw = 5,000 g / mol, an average chain length = 30

[0137] - Component (D)

[0138] D-l: 3-glycididoxy propyltrimethoxy silane (tackifier)

[0139] D-2: Platinum-divinyltetramethyldisiloxane complex (curing catalyst)

[0140] D-3: 1-ethynyl-l -cyclohexanol (reaction inhibitor)

[0141] [Table 1]

[0142] Experimental examples

[0143] Experimental Example 1 - Viscosity

[0144] The viscosity of each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 was measured at 25 °C according to DIN ISO 3219. Results are shown in Table 2 below.

[0145] Experimental Example 2 - Shore 00 hardness

[0146] Each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 was fed into a Teflon-coated mold with a width of 4 cm * length of 5 cm * thickness of 6 mm, and thermally cured at 65 °C for 1 hour, followed by cooling at room temperature. Next, The hardness of the hardened materials was measured with a Shore 00 type tester according to DIN ISO 7619. Results are shown in Table 2 below.

[0147] Experimental Example 3 - Moldability

[0148] The pot life of each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 was measured at 23 °C. Specifically, the initial viscosity of each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 was measured in the same way as in Experimental Example 1, and then the time when the viscosity became twice as high as the initial viscosity was defined as pot life. In addition, the gel time of each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 was measured at 25 °C according to ASTM D4473. Moldability was evaluated based on the following criteria, and results are shown in Table 2 below.

[0149] - Excellent: Pot life of 120 minutes or more and gel time of 600 minutes or less

[0150] - Normal: Pot life of 120 minutes or more or gel time of 600 minutes or less

[0151] - Poor: Pot life of less than 120 minutes and gel time of greater than 600 minutes

[0152] Experimental Example 4 - Volumetric shrinkage

[0153] The volumetric shrinkage of each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 and the hardened products of Examples 1 to 6 and Comparative Examples 1 to 3 according to Experimental Example 2 was measured according to Equation 1 below in accordance with ISO 3521. Results are shown in Table 2 below.

[0154] [Equation 1]

[0155] (1 - volume of silicone composition / volume of cured product) x 100 %

[0156] Experimental Example 5 - Pull strength

[0157] A pull strength was measured according to ASTM D2651. Specifically, each of the silicone compositions of Examples 1 to 6 and Comparative Examples 1 to 3 was coated on a soda lime glass substrate (coating size: 7 cm2). Next, a glass substrate was covered on each of the silicone compositions, and then allowed to stand at room temperature for 24 hours. Next, a pull strength was measured through tests under a condition of 300 mm / min, and results are shown in Table 2 below.

[0158] Experimental Example 6 - Light transmittance

[0159] The transmittance (based on a wavelength of 450 nm) of each of the hardened products of Examples 1 to 6 and Comparative Examples 1 to 3 according to Experimental Example 2 was measured with Specord 200 Plus UV-Vis spectrometer. Results are shown in Table 2 below.

[0160] Experimental Example 7 - Haze

[0161] The haze of each of the hardened products of Examples 1 to 6 and Comparative Examples 1 to 3 according to Experimental Example 2 was measured according to ASTM D1003-97. Results are shown in Table 2 below.

[0162] Experimental Example 8 - Yellowness index

[0163] The yellowness index of each of the hardened products of Examples 1 to 6 and Comparative Examples 1 to 3 according to Experimental Example 2 was measured according to ASTM D313-73. Results are shown in Table 2 below.

[0164] Experimental Example 9 - Refractive index(Refractive index)

[0165] The refractive index of each of the hardened products of Examples 1 to 6 and Comparative Examples 1 to 3 according to Experimental Example 2 was measured at the D line (480 nm, 589 nm) wavelength using an Abbe refractive index meter. Results are shown in Table 2 below.

[0166] Experimental Example 10 - Processability

[0167] A cyclo olefin copolymer (COP) film was laminated on a first substrate using an optically clear adhesive (OCA), and then a second substrate was introduced onto the film, thereby fixing the first and second substrates. Next, Each of the silicone composition of Examples 1 to 6 and Comparative Examples 1 to 3 was fed between the first and second substrates by an injection method, and allowed to stand at room temperature for 24 hours. The processability was evaluated based on the following criteria, and results are shown in Table 2 below.

[0168] - Excellent: The gap between the first and second substrates was filled, and no bubbles or wrinkles were generated.

[0169] - Normal: The gap between the first and second substrates was filled, but some bubbles or wrinkles occurred.

[0170] - Poor: the gap between the first and second substrates was not filled due to poor spreadability of the silicone composition.

[0171] [Table 2]

[0172] As shown in Table 2, the silicone compositions of Examples 1 to 6 satisfy a specific range of viscosity and Shore 00 hardness, compared to the silicone compositions of Comparative Examples 1 to 3, so that the flowability and curability of the silicone compositions can be improved. Therefore, it can be confirmed that an adhesive layer is efficiently formed by an injection process at room temperature, yellowing mura, bubble generation, and the like are suppressed, and mechanical properties are improved while securing transparency and light transmission. [Description of Symbols]

[0173] 10: first substrate

[0174] 20: second substrate

[0175] 30: functional film

[0176] 40: optical adhesive film 50: dams

[0177] 60: sealing part

[0178] 70: adhesive layer

[0179] 100: optical device

Claims

[CLAIMS]

1. An optical device, comprising: a first substrate; a functional film formed on the first substrate; a second substrate formed on the functional film; a sealing part configured to fix the first and second substrates; and an adhesive part formed between the first and second substrates, wherein the adhesive part comprises a silicone composition, wherein the silicone composition comprises polysiloxane and has a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219, and a Shore 00 hardness, measured according to DIN ISO 7619, of a cured product made of the silicone composition is less than 20.

2. The optical device according to claim 1, wherein the functional film is attached to the first substrate by an optical adhesive film.

3. The optical device according to claim 1, wherein the optical device is a touch panel display for automobiles and a smart window system.

4. A method of manufacturing an optical device, the method comprising: preparing first and second substrates;laminating a functional film on the first substrate; introducing a second substrate on the functional film and fixing the first and second substrates; and forming an adhesive layer by injecting a silicone composition between the first and second substrates, wherein the silicone composition is fed by an injection method, the silicone composition comprises polysiloxane and has a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219, and a Shore 00 hardness, measured according to DIN ISO 7619, of a cured product made of the silicone composition is less than 20.

5. The method according to claim 4, wherein, in the laminating, the functional film is attached onto the first substrate by an optical adhesive film.

6. The method according to claim 4, further comprising, after the laminating of the functional film on the first substrate, forming dams for maintaining an interval between the first and second substrates between the first and second substrates.

7. The method according to claim 4, wherein the adhesive layer is formed by curing the silicone composition at room temperature.

8. A silicone composition, comprising polysiloxane and having a viscosity of less than 500 mPa.s measured at 25 °C according to DIN ISO 3219, anda Shore 00 hardness, measured according to DIN ISO 7619, of a cured product of the silicone composition is less than 20.

9. The silicone composition according to claim 8, wherein the polysiloxane comprises: a first organopolysiloxane (a) comprising an alkenyl group at an end of a main chain thereof; a second organopolysiloxane (b) comprising a siloxane unit represented by RiR^RsSiOi / ? and SiO4 / 2; and a first organohydrogen polysiloxane (c) comprising at least one hydrogen group bonded to a silicon atom, wherein Ri, R2 and R3 are each independently a substituted or unsubstituted monovalent hydrocarbon group, and at least one of Ri, R2 and R3 is an alkenyl group.

10. The silicone composition according to claim 8, wherein the polysiloxane comprises:50 % by weight to 98 % by weight of the first organopolysiloxane (a);1 % by weight to 10 % by weight of the second organopolysiloxane (b); and1 % by weight to 40 % by weight of the first organohydrogen poly siloxane (c).

11. The silicone composition according to claim 8, wherein the first organopolysiloxane comprises: a 1-1 organopolysiloxane (a-1) comprising a siloxane unit having an average chain length of less than 150, the 1-1 organopolysiloxane (a-1) having a weight average molecular weight of 8,000 g / mol or less; and a 1-2 organopolysiloxane (a-2) comprising a siloxane unit having an average chainlength of 150 or more and 1,200 or less, the 1-2 organopolysiloxane (a-2) having a weight average molecular weight of 40,000 g / mol to 80,000 g / mol.

12. The silicone composition according to claim 9, wherein the first organohydrogen polysiloxane comprises: a 1-1 organohydrogen poly siloxane (c-1) containing a hydrogen group at an end of a main chain thereof; and a 1-2 organohydrogen poly siloxane (c-2) containing a hydrogen group in a side chain thereof.

13. The silicone composition according to claim 12, wherein the 1-1 organohydrogen polysiloxane comprises a siloxane unit having an average chain length of greater than 10.

14. The silicone composition according to claim 12, wherein a content of the 1-2 organohydrogen poly siloxane is 15 parts by weight or less based on 100 parts by weight of the 1- 1 organohydrogen polysiloxane.

15. The silicone composition according to claim 8, further comprising at least one of a tackifier, a reaction inhibitor, and a curing catalyst.

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