Optical silicone composition and reflective material for optical semiconductor comprising the same

Abstract

This invention relates to an optical polysiloxane composition comprising an organopolysiloxane, an organohydropolysiloxane, a white pigment, and a reaction catalyst, wherein the organopolysiloxane contains at least three alkenyl groups in one molecule, has a viscosity of 20 Pa·s or less at 25°C, and the ratio of the total molar number of the divalent first repeating unit to the molar number of the trivalent second repeating unit to the molar number of the monovalent third repeating unit is from 1:0.3 to 1:3.0; and the organohydropolysiloxane contains at least three silicon-bonded hydrogen groups (SiH) in one molecule, and has a viscosity of 20 Pa·s or less at 25°C.

Description

Technical Field

[0001] This invention relates to an optical polysiloxane composition having excellent dispensing workability as a liquid phase at room temperature, and a reflective material for optical semiconductors comprising an optical polysiloxane composition having high visible light reflectivity and hardness and excellent heat resistance. Background Technology

[0002] Traditional surface mount technology (SMT) optical semiconductor (light-emitting diode, LED) packages (PKGs) are typically constructed by wire bonding the electrodes at the top of the chip to the electrodes at the bottom of the PKG. To protect this optical semiconductor package, the shell and frame are made of highly reflective materials, acting as reflectors. Materials used in SMT optical semiconductor packages include polyphthalamide resin (PPA resin) or condensation resins, but these materials suffer from problems such as discoloration, burrs during cutting, voids, and cracking at high temperatures.

[0003] Furthermore, with the commercialization of flip chips, where electrodes are located only at the bottom of the chip, in response to the recent demand for miniaturization and thinning of optical semiconductor packaging, the need for high-density chip-scale packages (CSPs) that omit frames or have narrower spacing between chips is increasing. Therefore, a method has been proposed in which the spacing between chips is cured by dispensing or molding a highly reflective silicone, and then diced into individual chips to fabricate the package. Various liquid silicones have thus been developed for chip-scale packaging processes, but the cured products formed using them have several problems, such as insufficient hardness, poor moldability due to the short pot life of the composition, and reduced reflectivity at high temperatures due to discoloration of the phenyl groups contained in the silicone composition.

[0004] Traditional silicone resin compositions for semiconductor packaging contain white pigments and inorganic fillers and are solid at room temperature or have high viscosity, making them suitable for injection molding. However, in order to formulate thin-film reflective materials via dispersion or molding processes as described above, the viscosity of the composition must be low. However, when reducing the content of solids (e.g., white pigments) to lower the viscosity of the composition, insufficient white pigment content results in insufficient visible light reflectance of the prepared cured product.

[0005] Therefore, there is a need to study an optical silicone resin composition that is suitable for dispersion or molding in liquid phase at room temperature, can be used for precise molding processes, and has high visible light reflectivity and excellent heat resistance in thin film state. Summary of the Invention

[0006] One aspect of the present invention provides an optical polysiloxane composition that can be dispersed in a liquid phase or molded at room temperature, can be used for precision molding, has high visible light reflectivity in the thin film state, has less burr during cutting due to the high hardness of the cured product, and has excellent heat resistance.

[0007] According to one aspect of the present invention, an optical polysiloxane composition is provided, comprising an organopolysiloxane, an organohydrogenpolysiloxane, a white pigment, and a reaction catalyst, wherein the organopolysiloxane contains at least three alkenyl groups in one molecule, has a viscosity of 20 Pa·s or less at 25°C, and the ratio of the total molar number of divalent first repeating units to the molar number of trivalent second repeating units to the molar number of monovalent third repeating units is from 1:0.3 to 1:3.0, and the organohydrogenpolysiloxane contains at least three silicon-bonded hydrogen groups (SiH) in one molecule, and has a viscosity of 20 Pa·s or less at 25°C.

[0008] According to another aspect of the present invention, a reflective material for optical semiconductors is provided, comprising a cured product prepared by curing the optical polysiloxane composition.

[0009] The optical silicone resin composition according to the present invention can be dispersed or molded in a low-viscosity liquid phase at room temperature, and can be used for precision molding processes. Furthermore, the optical silicone resin composition is ideally suited as a reflective material for optical semiconductors because its cured form has high visible light reflectivity, excellent hardness, does not produce burrs during cutting, and has excellent heat resistance. Detailed Implementation

[0010] The present invention will now be described in detail.

[0011] The relationship between the general structure of polysiloxanes and their common names is shown below.

[0012] (R3SiO 1 / 2 ) a Unit: M unit

[0013] (R2SiO 2 / 2 ) b Unit: D unit

[0014] (RSiO 3 / 2 ) c Unit: T unit

[0015] (SiO 4 / 2 ) d Unit: Q unit

[0016] In this specification, M-cells, D-cells, T-cells, and Q-cells, which are conventionally used in the art, are used in combination.

[0017] Optical Polysiloxane Composition

[0018] The optical polysiloxane composition of the present invention comprises organopolysiloxane, organohydrogenpolysiloxane, white pigment, and reaction catalyst.

[0019] In this example, the white pigment exhibits excellent dispersibility due to the high reactivity and low viscosity of organopolysiloxanes and organohydrogen polysiloxanes at 25°C.

[0020] organopolysiloxanes

[0021] Organopolysiloxanes are used to form the main skeleton of the cured product to be prepared.

[0022] The organopolysiloxane contains at least three alkenyl groups in one molecule, has a viscosity of 20 Pa·s or less at 25°C, and has a total molar ratio of the divalent first repeating unit and the trivalent second repeating unit to the monovalent third repeating unit of 1:0.3 to 1:3.0. Specifically, the organopolysiloxane is represented by the following formula 1 and may include at least one aryl group.

[0023] [Formula 1]

[0024] [R 1 3SiO 1 / 2 ] a [R 2 (R 3 O)SiO] b [R 4 SiO 3 / 2 ] c

[0025] In Equation 1, multiple R 1 Each is independently either substituted or unsubstituted C 2-10 alkenyl or C 1-10 Alkyl group, and at least one R 1 It is an alkenyl group, R 2 R 3 and R 4 Each is independently either substituted or unsubstituted C 1-10 Alkyl group, C 6-14 Aryl or hydrogen, and R 2 R 3 and R 4 At least one of them is an aryl group, a / (b+c) is 0.3 to 3.0, and a+b+c is 1.

[0026] In this example, alkyl and alkenyl groups can be linear, branched, or cyclic.

[0027] For example, multiple R 1 Each is independently either substituted or unsubstituted C 2-6 alkenyl or C 1-6 Alkyl groups, specifically, can each independently be methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, vinyl, allyl, butenyl, pentenyl, or hexenyl. More specifically, multiple R...1 They can be methyl or vinyl, each independently.

[0028] In addition, R 2 R 3 and R 4 Each is independently either substituted or unsubstituted C 1-6 Alkyl, C 6-10 The aryl group or hydrogen, specifically, can each independently be methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, or phenyl. More specifically, R 2 R 3 and R 4 Each can be either phenyl or methyl.

[0029] In Equation 1, [R 1 3SiO 1 / 2 ] represents the third repeating unit (M unit - 1) with a unit price of [R] 2 (R 3 [O)SiO] is a divalent first repeating unit (D unit-1), [R] 4 SiO 3 / 2 [ ] represents a trivalent second repeating unit (T unit-1). That is, a / (b+c) can be 0.3 to 3.0, specifically 0.33 to 3.0. When a / (b+c) is greater than the above range, due to the low molecular weight of the organopolysiloxane, the crosslinking density of the cured product decreases, making it difficult to ensure sufficient hardness. Furthermore, the surface of the cured product becomes very sticky, reducing yield during the cutting and sorting process after curing. In addition, when a / (b+c) is greater than the above range, low-molecular-weight non-reactive components that may not participate in the reaction during curing may volatilize, creating voids on the surface and inside the cured product, adversely affecting reliability. When a / (b+c) is less than the above range, the high molecular weight of the organopolysiloxane and its structurally steric hindrance effect due to its high branching promote the interaction with the inorganic filler components. This increases the viscosity or thixotropy of the composition, thereby reducing the fluidity of the composition at room temperature. Consequently, dispensing and discharging operations may be difficult, and curing shrinkage may occur at high temperatures, which can easily lead to cracks in the prepared cured product, thus reducing reliability.

[0030] Based on R 1 To R 4The total molar amount of the organopolysiloxane may contain less than 40 mol% or 39 mol% or less of aryl groups. In this example, the aryl group may be phenyl. When the content of the aryl group is greater than the above range, there is a difference in refractive index between the white pigment and the interface, thus increasing the transmittance in the prepared cured product with a thickness of 35 μm or less, reducing the visible light reflectance, and causing a significant decrease in visible light reflectance due to discoloration during long-term storage at high temperatures.

[0031] For example, organopolysiloxanes can be (ViMe2SiO) 0.5 ) 0.35 (PhSiO 1.5 ) 0.65 (ViMe2SiO) 0.5 ) 0.6 (PhSiO 1.5 ) 0.4 (ViMe2SiO) 0.5 ) 0.75 (PhSiO 1.5 ) 0.25 (ViMe2SiO) 0.5 ) 0.35 (MeSiO 1.5 ) 0.65 (ViMe2SiO) 0.5 ) 0.6 (MeSiO 1.5 ) 0.4 (ViMe2SiO) 0.5 ) 0.75 (MeSiO 1.5 ) 0.25 (ViMe2SiO) 0.5 ) 0.2 (Me3SiO 0.5 ) 0.15 (PhSiO 1.5 ) 0.65 (ViMe2SiO) 0.5 ) 0.2 (Me3SiO 0.5 ) 0.15 (MeSiO 1.5 ) 0.65 (ViMe2SiO) 0.5 ) 0.175 (Me3SiO 0.5 ) 0.175 (PhSiO 1.5 ) 0.65 (ViMe2SiO) 0.5 ) 0.175 (Me3SiO 0.5 ) 0.175 (MeSiO1.5 ) 0.65 (ViMe2SiO) 0.5 ) 0.25 (Me3SiO 0.5 ) 0.1 (PhMeOSiO) 0.25 (PhSiO 1.5 ) 0.4 (ViMe2SiO) 0.5 ) 0.25 (Me3SiO 0.5 ) 0.1 (PhMeOSiO) 0.2 (PhSiO 1.5 ) 0.1 (MeSiO 1.5 ) 0.35 (ViMe2SiO) 0.5 ) 0.25 (Me3SiO 0.5 ) 0.1 (PhSiO 1.5 ) 0.3 (MeSiO 1.5 ) 0.35 (ViMe2SiO) 0.5 ) 0.35 (PhMeOSiO) 0.1 (PhSiO 1.5 ) 0.55 、or (ViMe2SiO) 0.5 ) 0.25 (PhMeOSiO) 0.1 (PhSiO 1.5 ) 0.3 (MeSiO 1.5 ) 0.35 In this example, Vi is vinyl, Me is methyl, and Ph is phenyl.

[0032] Furthermore, the organopolysiloxane may contain 1.5 mmol / g or more, or 1.6 mmol / g to 9.0 mmol / g of alkenyl groups. When the amount of alkenyl groups is below the above range, the composition may not be able to form a hard-cured product due to its low reactivity, and therefore the surface of the prepared cured product is prone to cracking. In this example, the alkenyl group may be a vinyl group.

[0033] The viscosity of organopolysiloxanes at 25°C can be 20 Pa·s or less, or 18 Pa·s or less. When the viscosity of organopolysiloxanes at 25°C exceeds the above range, the thixotropy of the composition increases due to uneven dispersion of the white pigment, and therefore the discharge stability may decrease.

[0034] Organohydropolysiloxane

[0035] Organohydropolysiloxanes react with organopolysiloxanes to form cured products through crosslinking.

[0036] Organohydropolysiloxanes contain at least three silicon-bonded hydrogen groups (SiH) in one molecule and have a viscosity of 20 Pa·s or less at 25°C. For example, organohydropolysiloxanes can be represented by the following formula 2 and may include at least one aryl group.

[0037] [Equation 2]

[0038] HR 10 2SiO 1 / 2 ] l [R 11 (R 12 O)SiO] m [R 13 SiO 3 / 2 ] n

[0039] In Equation 2, R 10 and R 12 Each is independently either substituted or unsubstituted C 1-10 Alkyl or hydrogen, R 11 Is it substituted or unsubstituted C? 6-14 Aryl, R 13 Each is a substituted or unsubstituted C independently. 1-10 Alkyl or C 6-14 Aryl, l / (m+n) is 0.3 to 3, and l+m+n is 1.

[0040] In this example, the alkyl group can be straight-chain, branched, or cyclic.

[0041] For example, R 10 and R 12 Each is independently either substituted or unsubstituted C 1-6 Alkyl groups, specifically, can each independently be methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, or cyclohexyl. More specifically, R 10 and R 12 It can be methyl.

[0042] In addition, R 11 and R 13 Each is independently either substituted or unsubstituted C 6-10 The aryl group, specifically, can be independently phenyl, naphthyl, or biphenyl. More specifically, R 11 and R 13 It can be phenyl.

[0043] In Equation 2, [HR 10 2SiO 1 / 2 ] represents a repeating unit with a unit price (M units - 2), [R 11 (R 12 [O)SiO] is a divalent repeating unit (D unit-2), [R] 13 SiO 3 / 2 ] represents a trivalent repeating unit (T unit-2).

[0044] Furthermore, l / (m+n) is from 0.3 to 3.0, and specifically from 0.33 to 3.0. When l / (m+n) is less than the above range, the dispensing discharge operation may be difficult due to the high thixotropy of the composition and the reduced flowability at room temperature, or cracks may easily form in the prepared cured product due to curing shrinkage under high temperature conditions, thus reducing reliability.

[0045] Based on R 10 To R 13 The total molar amount of the organohydrogen polysiloxane may contain less than 40 mol% or 39 mol% or less of aryl groups. In this case, the aryl group may be phenyl. When the content of the aryl group is greater than the above range, the following problems may occur: due to the difference in refractive index between the white pigment and the interface, the transmittance of the prepared cured product with a thickness of 35 μm or less increases, resulting in a decrease in visible light reflectance, and the visible light reflectance decreases significantly due to discoloration caused by long-term storage at high temperatures.

[0046] For example, organohydrogen polysiloxanes can be (HMe2SiO) 0.5 ) 0.35 (PhSiO 1.5 ) 0.65 、(HMe2SiO 0.5 ) 0.6 (PhSiO 1.5 ) 0.4 、(HMe2SiO 0.5 ) 0.75 (PhSiO 1.5 ) 0.25 、(HMe2SiO 0.5 ) 0.35 (MeSiO 1.5 ) 0.65 、(HMe2SiO 0.5 ) 0.6 (MeSiO 1.5 ) 0.4 、(HMe2SiO 0.5 ) 0.75 (MeSiO1.5 ) 0.25 、(HMe2SiO 0.5 ) 0.35 (PhMeOSiO) 0.1 (PhSiO 1.5 ) 0.55 or (HMe2SiO) 0.5 ) 0.25 (PhMeOSiO) 0.1 (PhSiO 1.5 ) 0.3 (MeSiO 1.5 ) 0.35 In this example, Me is methyl and Ph is phenyl.

[0047] In addition, the organohydrogen polysiloxane may contain 1.5 mmol / g or more, or 1.8 mmol / g to 10.0 mmol / g of silicon-bonded hydrogen groups (SiH). When the amount of SiH is below the above range, the composition may not be able to form a hard cured product due to its low reactivity, and the surface of the prepared cured product is prone to cracking.

[0048] The viscosity of organohydrogen polysiloxanes at 25°C can be 20 Pa·s or less, or 15 Pa·s or less. When the viscosity of organohydrogen polysiloxanes at 25°C exceeds the above range, the thixotropy of the composition increases due to uneven dispersion of the white pigment, which may reduce emission stability.

[0049] The molar ratio of the alkenyl group to the silicon-bonded hydrogen group (SiH) of the organohydrogen polysiloxane can be in the range of 1:0.5 to 1:2.0 or 1:0.8 to 1:1.5. In this example, the alkenyl group can be vinyl. Furthermore, when the molar ratio of alkenyl group to SiH is less than the above range, the surface of the cured product is sticky due to a large amount of unreacted organosiloxane residue. When the molar ratio of alkenyl group to SiH is greater than the above range, the hardness of the prepared cured product may be reduced due to the residual unreacted organohydrogen polysiloxane, and it is prone to shrinkage due to heat, resulting in cracks.

[0050] White pigment

[0051] White pigments are components that improve reflectivity in the visible light region by reducing the transmittance of the cured product and producing a white color.

[0052] For example, the white pigment may be at least one selected from the group consisting of titanium dioxide, aluminum oxide, zinc oxide, zirconium oxide, magnesium oxide, barium sulfate, and zinc sulfate, and specifically, may include titanium dioxide.

[0053] Furthermore, the white pigment can have an average particle size of 0.05 μm to 10 μm or 0.1 μm to 1.0 μm. When the average particle size of the white pigment is smaller than the above range, the viscosity of the composition tends to increase due to the reduced dispersibility of the pigment. And when the average particle size of the white pigment is larger than the above range, not only will the type of nozzle that can be used in the disperser be limited, but the workability of the composition may also be reduced due to nozzle clogging.

[0054] To improve compatibility with polysiloxanes and dispersibility in compositions, white pigments can be surface-treated with surface treatment agents such as silane coupling agents, silica, alumina, or zirconium.

[0055] Furthermore, based on the total amount of 100 parts by weight of organopolysiloxane and organohydrogen polysiloxane, 60 to 170 parts by weight or 65 to 165 parts by weight of white pigment may be included in the composition. If the amount of white pigment is less than the above range, the transmittance in films with a thickness of less than 35 μm may decrease, and the visible light reflectance may decrease. If the amount of white pigment is greater than the above range, the workability of dispersion, etc., will decrease due to the increased viscosity and thixotropic index of the composition.

[0056] reaction catalyst

[0057] The optical polysiloxane composition according to the present invention includes a reaction catalyst. In this example, the reaction catalyst is a component that promotes the hydrosilylation reaction between the alkenyl group in the organopolysiloxane and the hydrogen group (SiH) bonded to silicon in the organohydropolysiloxane.

[0058] For example, the reaction catalyst may include at least one of the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts. Specifically, platinum-based catalysts may be used as reaction catalysts. Platinum-based catalysts may be finely pulverized platinum powder, chloroplatinic acid, platinum-alkenyl siloxane complex, platinum-olefin complex, or platinum-carbonyl complex, and may include, for example, platinum-alkenyl siloxane complexes.

[0059] Furthermore, when a platinum-based catalyst is used as the reaction catalyst, based on the total amount of organopolysiloxane and organohydropolysiloxane (100 parts by weight), the platinum-based catalyst can contain 0.01 ppm to 100 ppm or 0.1 ppm to 50 ppm of platinum atoms in the composition. If the amount of reaction catalyst is less than the above range, a cured product will not be formed because the composition is difficult to cure. If the amount of reaction catalyst is greater than the above range, the visible light reflectance may decrease because the prepared cured product will change color upon heating.

[0060] additive

[0061] Without prejudice to the purpose of this invention, the optical polysiloxane composition of this invention may further include additives typically found in polysiloxane compositions. For example, additives may be adhesion promoters, inorganic fillers, silicone powder, resin powder, heat resistant agents, antioxidants, free radical scavengers, light stabilizers, flame-retardant additives, silicone-based diluents, or retarding agents.

[0062] In this example, the tackifier may include, for example, an unsaturated or epoxy-functional alkoxysilane, specifically, 3-glycidoxypropyltrimethoxy silane, 3-glycidoxypropyltriethoxy silane, (epoxycyclohexyl)ethyldimethoxy silane, or (epoxycyclohexyl)ethyldiethoxy silane.

[0063] Furthermore, the reaction retarder can be, for example, an alkynyl-containing alcohol compound, specifically 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, or 2-phenyl-3-butyn-2-ol, etc.

[0064] The optical polysiloxane composition according to the present invention, as described above, is a liquid phase at room temperature (e.g., 20°C to 30°C) and has the advantage of being suitable for molding, such as dispersion and injection molding, and can be used in precision molding processes.

[0065] Furthermore, the viscosity of the optical polysiloxane composition at 25°C can be 10 Pa·s or lower, for example, 1 Pa·s to 8 Pa·s, or 2 Pa·s to 6 Pa·s. If the viscosity of the composition at 25°C is greater than the above range, it is difficult to dispense in very small quantities, and it may not easily fill the gaps between chips or electrodes, thus potentially creating voids in the cured surface during the curing process. Conversely, if the viscosity of the composition at 25°C is less than the above range, the initial adhesion between chips or electrodes may be reduced, leading to contamination of the chip surface.

[0066] For optical polysiloxane compositions, in 1s -1 Viscosity measured at 25°C at a shear rate of [value] and at 10 s [value] -1The ratio of viscosity measured at 25°C at the shear rate can be in the range of 1:1 to 2:1 or 1.3:1.0 to 1.9:1.0.

[0067] Reflective materials for optical semiconductors

[0068] Furthermore, the present invention provides a reflective material for optical semiconductors, comprising a cured product prepared by curing an optical polysiloxane composition as described above.

[0069] The shape of the cured product is not particularly limited, and may include, for example, sheet-like, film-like, convex lens-like, concave lens-like, Fresnel lens-like, truncated cone-like, or quadrilateral pyramidal platform, etc.

[0070] Furthermore, the cured product can be processed separately, or it can be processed in a state of covering, sealing, or adhering to optical semiconductor components.

[0071] The cured product can have a hardness of 85 Shore A or higher, and if the cured product has a hardness of less than 85 Shore A, the workability will be reduced because burrs may occur when cutting the molded material.

[0072] Furthermore, the cured product can have an average thickness of 35 μm to 50 μm. When the average thickness of the cured product is within the above range, it can exhibit high visible light reflectance because the visible light transmittance at 450 nm is 3% or less.

[0073] Due to its high visible light reflectivity, excellent hardness resulting in less burr formation during cutting, and excellent heat resistance, the cured product is very suitable as a reflective material for optical semiconductors.

[0074] There are no particular limitations on the applications of reflective materials used in optical semiconductors; for example, they can be used in backlight modules for liquid crystal displays, flash modules for mobile phones, and lighting modules for vehicles.

[0075] The embodiments will be described in detail below to aid in understanding the invention. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the invention thorough and complete, and to fully convey the concept of the invention to those skilled in the art.

[0076] Examples 1 to 6 and Comparative Examples 1 to 10. Preparation of optical polysiloxane compositions.

[0077] The polysiloxane compositions are prepared by mixing the components of the compositions listed in Tables 1 and 2.

[0078] [Table 1]

[0079]

[0080]

[0081] [Table 2]

[0082]

[0083] The manufacturers and product names or material names of the components used in the comparative examples and examples are shown in Table 3. In this example, Vi is vinyl, Me is methyl, and Ph is phenyl.

[0084] Table 3

[0085]

[0086] Experimental Example: Performance Evaluation

[0087] The physical properties of the optical polysiloxane compositions of the examples and comparative examples and the cured products prepared therefrom were measured by the following methods, and the results are listed in Table 4.

[0088] (1) Viscosity and thixotropic index

[0089] Anton Paar GmbH's rheometer (model: MCR301) was used to measure the viscosity of each composition at 25°C at a shear rate of 1 / s or 10 / s. The thixotropic index was then calculated using the following formula.

[0090] Thixotropic index = (viscosity at a shear rate of 1 / s) / (viscosity at a shear rate of 10 / s)

[0091] (2) Hardness (Shore A)

[0092] Each composition was placed in a mold and cured at 150°C for 2 hours to prepare a 6 mm thick sample. The hardness at 25°C was then measured using a Shore A hardness tester.

[0093] (3) Reflectance (%)

[0094] After degassing each composition, a 250 μm thick coating film was formed using a square coater and cured at 150 °C for 2 hours to prepare the cured product.

[0095] Subsequently, the reflectance of the cured product relative to visible light was measured using a Perkin Elmer UV-Vis Spectrometer (Model: Lambda 950). A barium sulfate standard sample provided by the measuring equipment manufacturer was used as a base.

[0096] (4) Dispensing Workability

[0097] After setting the composition per discharge to 0.3 mg using a Vermes piezoelectric 200 μm nozzle robotic disperser, 20 cumulative discharges were set as one group. A group was evaluated as pass when the coefficient of variation (coef.var) for 100 groups was 0.5 or less, and as fail when the coefficient of variation for 100 groups was greater than 0.5.

[0098] (5) Thermal Shock

[0099] After the composition was applied to a glass sample with a thickness of 6 mm using a coater and the sample had dimensions of 50 mm × 50 mm × 0.1 mm (width × length × height), the coating was cured at 150 °C for 2 hours, and 24 evaluation samples (coating thickness: 100 μm) were prepared for each composition.

[0100] The prepared evaluation samples were subjected to a thermal shock tester, with one cycle defined as heating from -25°C to 125°C or cooling from 125°C to -25°C, and 1,000 cycles were performed at 30-minute intervals. Subsequently, the samples were deemed acceptable if no peeling or cracking occurred on the surface, and unacceptable if peeling or cracking occurred in one or more samples.

[0101] (6) Heat reflectivity (%)

[0102] Samples prepared in the same manner as those used to measure the reflectance of item (3) were stored in an oven at 200°C for one week, then cooled to room temperature, and their reflectance (heat-resistant reflectance) relative to visible light was measured using a PerkinElmer UV / Vis spectrometer (model name: Lambda950). A barium sulfate standard sample provided by the measuring equipment manufacturer was used as a reference.

[0103] (7) Heat-resistant crack

[0104] After the heat resistance test in item (6), observe the appearance of the sample to visually confirm whether cracks have appeared. If there are no cracks, it is marked as Good, and if there are cracks, it is marked as Crack.

[0105] Table 4

[0106]

[0107]

[0108] As shown in Table 4, it can be understood that the polysiloxane compositions of Examples 1 to 6 are low-viscosity liquid phases with a viscosity of 10,000 mPa·s or less at 25°C, a thixotropic index of 2.0 or lower, and excellent dispersibility and workability. Furthermore, the cured products prepared from the polysiloxane compositions of Examples 1 to 6 exhibit excellent hardness, visible light reflectance, thermal shock resistance, and heat resistance (heat reflectance and heat crack resistance).

[0109] In contrast, the cured products of Comparative Example 1, which contains a small amount of alkenyl groups (A-4), and Comparative Example 5, which contains a small amount of SiH, have insufficient hardness and thermal shock resistance.

[0110] Furthermore, the cured products of Comparative Example 2, which contained A-5 (where a / (b+c) is 0.25), and Comparative Example 6, which contained B-5 (where l / (m+n) is 0.25), had insufficient heat resistance, and therefore heat-resistant cracks occurred.

[0111] The composition of Comparative Example 3 containing A-6 (with a viscosity of 35,000 mPa·s at 25°C) and the composition of Comparative Example 7 containing B-6 (with a viscosity of 22,000 mPa·s at 25°C) have high thixotropic indexes, and therefore have poor dispersibility.

[0112] Furthermore, the cured products of Comparative Example 4, which contains A-7 (of which the phenyl content is 42.86 mol%), and Comparative Example 8, which contains B-7 (of which the phenyl content is 42.86 mol%), have insufficient visible light reflectance, which is 97% or lower, and also have low heat reflectance, which is 89% or lower.

[0113] The cured product of Comparative Example 9, which contains a small amount of titanium dioxide as a white pigment, has a low visible light reflectance of 93.2% and a low heat reflectance of 84.8%.

[0114] Furthermore, the composition of Comparative Example 10, which contains an excess of titanium dioxide as a white pigment, has a high viscosity of 28,400 mPa·s and a high thixotropic index of 2.3 at 25°C, resulting in very poor dispersibility.

Claims

1. An optical polysiloxane composition, wherein the optical polysiloxane composition comprises an organopolysiloxane, an organohydrogen polysiloxane, a white pigment, and a reaction catalyst. in, The organopolysiloxane contains at least three alkenyl groups in one molecule, has a viscosity of 20 Pa•s or less at 25°C, and is as shown in Formula 1. The organohydrogen polysiloxane contains at least three silicon-bonded hydrogen groups (SiH) in one molecule, and has a viscosity of 20 Pa•s or less at 25°C, as shown in Formula 2. [Chemical Formula 1] [R 1 3SiO 1 / 2 ] a [R 2 (R 3 O)SiO] b [R 4 SiO 3 / 2 ] c In chemical formula 1, Multiple R 1 Each is independently either substituted or unsubstituted C 2-10 alkenyl group or C 1-10 alkyl group, and at least one R 1 It is an alkenyl group. R 2 R 3 and R 4 Each is independently either substituted or unsubstituted C 1-10 alkyl groups, C 6-14 An aryl group or hydrogen, and R 2 R 3 and R 4 At least one of them is an aryl group. a / (b+c) ranges from 0.3 to 3.0, and a+b+c equals 1 [Chemical Formula 2] [HR 10 2SiO 1 / 2 ] l [R 11 (R 12 O)SiO] m [R 13 SiO 3 / 2 ] n In chemical formula 2, R 10 and R 12 Each is independently either substituted or unsubstituted C 1-10 alkyl groups or hydrogen, R 11 Is it substituted or unsubstituted C? 6-14 aryl group, R 13 Each is a substituted or unsubstituted C independently. 1-10 alkyl groups or C 6-14 aryl group, l / (m+n) is between 0.3 and 3, and l+m+n is 1.

2. The optical polysiloxane composition of claim 1, wherein, The optical polysiloxane composition is in the liquid phase at room temperature (20°C to 30°C).

3. The optical polysiloxane composition of claim 1, wherein the organopolysiloxane comprises 1.5 mmol / g or more of alkenyl groups, and The content of the silicon-bonded hydrogen groups (SiH) in the organohydrogen polysiloxane is 1.5 mmol / g or more.

4. The optical polysiloxane composition of claim 1, wherein, Based on all organic groups, the organopolysiloxane contains less than 40 mol% aryl groups.

5. A reflective material for optical semiconductors, comprising a cured product prepared by curing an optical polysiloxane composition as described in any one of claims 1 to 4.

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