Modified Silane Resin And Method For Manufacturing A High-heat-resistant Modified Silane Adhesive Containing The Same

Abstract

The present invention relates to a prepolymer containing isocyanate and an aminosilane produced by the following reaction scheme 1, [Reaction Equation 1] HO-(RO)nH + OCN-(CH2)m-Si(OR')₃→ (RO')3Si-(CH2)m-NH-CO-O-(RO)nO-CO-NH-(CH2)m-Si(OR')3 n is 60~150, m is 1~10 R and R' are alkyl groups with 2 to 10 carbon atoms The HO-(RO)nH in Reaction Formula 1 is a polyether compound having hydroxyl groups at both ends and an average molecular weight of 1,000 to 10,000 g / mol, and OCN-(CH2)m-Si(OR')₃ is an iocyanatoalkyl-alkoxysilane compound having isocyanate and trialkoxysilane ends, and the invention relates to a modified silane resin containing a polyether compound having silane functional groups at the ends and a urethane group in the backbone.

Description

Technology Field

[0001] The present invention relates to a modified silane resin that resolves the disadvantages of performance degradation and thermal damage caused by heat generation in camera modules of sustainable, reactive, rheology-adjustable modified silane adhesives used as adhesives for camera modules of small electronic devices, and a method for manufacturing a high-thermal-conductivity modified silane adhesive containing the same. Specifically, the invention relates to a modified silane resin that releases heat generated during the operation of a camera module within an electronic device, and a method for manufacturing a high-thermal-conductivity modified silane adhesive containing the same. Background Technology

[0003] Recently, the demand for camera modules in small electronic devices has been rapidly increasing in sectors such as portable cameras, mobile phones, automobiles, and the medical field. Consequently, active materials research regarding high-performance camera modules is being conducted across various industries.

[0004] Modified silane resins capable of natural curing at room temperature can be produced by the reaction of a prepolymer containing isocyanatoalkyl-alkoxysilane with aminosilane, and are widely used as sealants for various electronic materials and construction due to their excellent adhesion, moisture resistance, and heat resistance.

[0005] However, conventional modified silane resins have low thermal conductivity and insufficient mechanical strength after curing for heat dissipation in electrical and electronic components, which causes problems such as thermal deformation and reduced reliability in high-density camera modules.

[0006] Furthermore, conventional high-thermal-conductivity adhesive compositions often have high viscosity or low workability, making it difficult to apply uniformly to fine areas of precision parts, which leads to reduced productivity and increased defect rates.

[0007] In some compositions, isocyanate-based curing agents or tin catalysts are used to improve properties, but these are not only harmful to the human body and the environment but can also cause stability issues during long-term storage.

[0008] Furthermore, when solvents are used, it is difficult to comply with environmental regulations due to the release of volatile organic compounds (VOCs), and there is a risk of quality degradation such as film shrinkage or bubble formation. Therefore, there is a need to develop an eco-friendly modified silane adhesive composition that simultaneously satisfies low viscosity, high hardness, and excellent thermal conductivity without using isocyanates or tin catalysts. Prior art literature

[0010] (000001) Republic of Korea Published Patent No. 10-2025-0113007, Method for manufacturing an adhesive composition for heat-dissipating silicone materials and an adhesive composition for heat-dissipating silicone materials manufactured by the method thereof The problem to be solved

[0011] The objective of the present invention is to provide a low-viscosity, high-hardness, eco-friendly, high-heat-conductivity modified silane adhesive composition that can simultaneously secure excellent thermal conductivity, mechanical strength, and workability without using isocyanates and tin-based catalysts, in order to solve the above problems.

[0012] Another objective is to provide an eco-friendly high-thermal-conductivity modified silane adhesive composition that can maintain low viscosity even at high inorganic filler content without using solvents, thereby enabling precise application and preventing deformation and performance degradation caused by heat generation in camera modules for small electronic devices.

[0013] Another objective of the present invention is to provide a manufacturing process that enables natural curing at room temperature by applying a moisture-curing system and prevents reaction defects caused by moisture when manufactured under a nitrogen atmosphere. means of solving the problem

[0015] In order to solve the above problems, the present invention comprises a prepolymer containing isocyanate and an aminosilane produced by the following reaction scheme 1,

[0016] [Reaction Equation 1]

[0017] HO-(RO)n -H + OCN-(CH2) m -Si(OR')₃→ (RO')3Si-(CH2) m -NH-CO-O-(RO) n -O-CO-NH-(CH2) m -Si(OR')3

[0019] n is 60~150, m is 1~10

[0020] R and R' are alkyl groups with 2 to 10 carbon atoms

[0022] HO-(RO) of Reaction Scheme 1 n -H is a polyether compound having hydroxyl groups at both ends and an average molecular weight of 1,000 to 10,000 g / mol, and OCN-(CH2) m -Si(OR')₃ is an isocyanatoalkyl-alkoxysilane compound having isocyanate and trialkoxysilane terminals, and provides a modified silane resin containing a polyether compound having a silane functional group at the terminal and a urethane group in the backbone.

[0023] In addition, the present invention provides a method for manufacturing a high heat dissipation modified silane adhesive comprising: (1) a step of homogenizing the mixture of the modified silane resin and the dispersant of claim 1; (2) a step of adding spherical alumina filler and stirring; (3) a step of adding hydrophobic fumed silica and stirring; and (4) a step of adding amino silane and stirring, wherein all of the steps (1) to (4) are performed in a nitrogen atmosphere.

[0024] In addition, the present invention provides a method for manufacturing a high heat dissipation modified silane adhesive, characterized in that the dispersant of step (1) contains vinyl silane and is at least one of vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), or vinyltris(isopropoxy)silane.

[0025] In addition, the present invention provides a method for manufacturing a high heat dissipation modified silane adhesive, characterized in that the vinyl silane reacts as shown in reaction schemes 2 to 4 below.

[0026] [Reaction Equation 2]

[0027] R-Si(OR')3+ 3H2O -> -Si(OH)3+ 3R'OH

[0029] [Reaction Equation 3]

[0030] R-Si(OH)3+ HO-SiR -> R-Si-O-Si-R

[0032] [Reaction Equation 4]

[0033] H2O or R-Si(OH)3-> (R-Si-O-)n + nH2O

[0035] In addition, the present invention provides a method for manufacturing a high heat conduction modified silane adhesive, characterized in that the spherical alumina filler of step (2) has an average particle size of 1.0 to 100 μm and accounts for 70 to 90 weight percent of the produced high heat conduction modified silane adhesive.

[0036] In addition, the present invention provides a method for manufacturing a high heat conduction modified silane adhesive, characterized in that the hydrophobic fumed silica of step (3) accounts for 0.1 to 10 weight percent of the produced high heat conduction modified silane adhesive.

[0037] In addition, the present invention provides a method for manufacturing a high heat-conductivity modified silane adhesive characterized by activating the hydrolysis reaction in the initial stage of the curing reaction according to reaction schemes 5 to 7 by adding an amino silane catalyst in step (4) above, and increasing the rate of intermolecular or intramolecular siloxane bond formation in the later curing stage to improve the overall curing speed and degree of curing (conversion).

[0039] [Reaction Equation 5]

[0040] R-Si-(OR')3+ 3H2O -> R-Si(OH)3+ 3ROH

[0042] [Reaction Equation 6]

[0043] Si-OH + HO-Si -> Si-O-Si + H2O

[0045] [Reaction Equation 7]

[0046] Si-OH + Si-OR -> Si-O-Si + ROH

[0048] In addition, the present invention provides a method for manufacturing a high heat dissipation modified silane adhesive, characterized in that the amino silane is selected from the group consisting of 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), 3-glycidoxypropyltrimethoxysilane (GPTMS), 3-glycidoxypropylmethyldimethoxysilane (GPDMS), 3-aminopropylmethyldiethoxysilane (APDES), 3-mercaptopropyltrimethoxysilane (MrPTMS), 3-mercaptopropyltrimethyldimethoxysilane (MrPDMS), 3-methacryloxypropyltrimethoxysilane (MPTMS), 3-methacryloxypropylmethyldimethoxysilane (MPDMS), and mixtures thereof. Effects of the invention

[0052] The present invention includes a polyether compound having a silane functional group at the end and a urethane group in the backbone, thereby enabling the stable formation of a three-dimensional network structure using siloxane bonds (-Si-O-Si-) during the curing process. Accordingly, excellent mechanical strength, high hardness, and heat resistance can be simultaneously secured after curing, which effectively solves the problems of thermal deformation and reduced structural reliability of high-density camera modules.

[0053] The present invention enables the maintenance of low viscosity in a high-filling system despite containing spherical alumina with an average particle size of 1.0 to 9.0 μm as an inorganic filler at a high filling rate of 70 to 90 weight percent, due to the optimized combination of siloxane-based and silicone-based dispersants and the low intrinsic viscosity characteristics of the modified silane resin. As a result, uniform and quantitative coating is possible even in areas such as fine patterns, confined spaces, and precision electronic components, thereby providing industrial advantages such as improved productivity and reduced coating defects.

[0054] The application of high-fill alumina fillers significantly improves thermal conductivity, enabling the rapid dissipation of localized heat generated during camera module operation. This suppresses temperature rise in high-performance image sensors and optical modules, contributing to the performance stability, operational reliability, and extended lifespan of the electronic module.

[0055] Since the present invention consists of a composition that does not use isocyanate-based curing agents, tin-based catalysts, or organic solvents at all, there is no VOC emission and no concern regarding the residue of toxic substances. Therefore, it has the advantage of significantly reducing harm to the human body and the environment while satisfying eco-friendly regulations and industrial safety standards. This effectively fundamentally improves the environmental problems associated with existing heat-dissipating adhesives.

[0056] The addition of amorphous silicon dioxide (fumed silica) and the use of an alkoxypolysiloxane-based dispersant can prevent precipitation, separation, and re-aggregation phenomena that are prone to occur in high-concentration filler systems, and the storage stability and long-term storage reliability of the composition are significantly improved due to minimal viscosity change even during long-term storage.

[0057] The manufacturing method according to the present invention includes a nitrogen atmosphere process for managing the moisture content of the raw materials, thereby preventing problems such as over-curing, bubble generation, and poor curing of the silane caused by moisture inflow during the reaction. Through this, variations in physical properties after curing are suppressed, thereby ensuring consistent quality and improving process stability. Specific details for implementing the invention

[0059] Preferred embodiments of the present invention will be described in detail below. First, in describing the present invention, specific descriptions of related known functions or configurations are omitted to avoid obscuring the essence of the invention.

[0060] Terms of degree used herein, such as ‘approximately’ and ‘substantially,’ are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0062] The one-component curable silane-modified heat-dissipating adhesive composition according to the present invention has process compatibility that allows for immediate application in adhesive processes used to dissipate heat in compact camera module (CCM) packaging, where performance is degraded by heat generation. As a one-component adhesive, pot life, viscosity, and thixotropy are stably maintained at room temperature, making it suitable for slot die / needle dispenser processes.

[0063] Since it is a solvent-free formulation, the burden of VOC management is low, and with 100% solid content, it is easy to predict the coating amount and manage the curing yield, thereby improving process reproducibility and productivity in mass production.

[0064] By using a polyether compound having terminal silane functional groups and a urethane group in its backbone as a core raw material, isocyanate-based curing agents, tin-based catalysts, and solvents are not used, resulting in low hazards to the human body and the environment, as well as excellent long-term stability and storage properties.

[0065] The average particle size distribution (1.0–100 μm) and spherical three-dimensional structure of the alumina filler included in the composition of the present invention minimize re-aggregation within the high-filling composition and suppress viscosity increase. This configuration is a key factor in ensuring a balance between high heat dissipation characteristics and workability.

[0066] In particular, (1) a step of uniformly mixing the modified silane resin and the dispersant, (2) a step of filling with an alumina filler, (3) a step of adding fumed silica, and (4) a step of adding aminosilane are performed sequentially, and all processes must be carried out in a nitrogen atmosphere. This plays a decisive role in preventing curing defects caused by moisture in the raw materials, as specified in claim 6.

[0067] In addition, the interfacial reinforcement effect of the silane coupling ensures adhesion retention even in humid environments and repeated pressure cycles, thereby extending the service life.

[0068] The composition features standardized mixing sequences and degassing and filtration conditions, resulting in minimal batch-to-batch variation and facilitating inline management of QC parameters such as viscosity, specific gravity, and moisture (ppm). In terms of storage stability, storage and transportation are easy under nitrogen sealing and low-moisture control, making it advantageous for global supply chain operations.

[0069] From an Environment, Health, and Safety (EHS) perspective, solvent-free, low VOC, and low residual volatile matter characteristics ensure regulatory compliance, and by achieving required performance without the separate use of thermosetting agents such as melamine and phenol, it reduces the risk of worker exposure and equipment corrosion.

[0070] In summary, the present invention provides an eco-friendly heat dissipation adhesive composition for camera modules and a method for manufacturing the same, based on a polymer having silane terminal groups and an isocyanate-based curing agent, which overcomes the environmental and safety issues associated with conventional solvent-based or tin catalyst-based compositions while simultaneously securing low viscosity, high hardness, and excellent heat dissipation performance.

[0071] To achieve the above objective, the one-component room temperature moisture-curing modified silane adhesive composition according to the present invention comprises a modified silane resin produced by the reaction formula 1 between a prepolymer containing a urethane backbone and aminosilane.

[0073] [Reaction Equation 1]

[0074] HO-(RO)n -H + OCN-(CH2) m -Si(OR')₃→ (RO')3Si-(CH2) m -NH-CO-O-(RO) n -O-CO-NH-(CH2) m -Si(OR')3

[0075] Here, n is 60 to 150, m is 1 to 10, and R and R' are alkyl groups with 2 to 10 carbon atoms.

[0077] HO-(RO) of Reaction Scheme 1 n -H is a polyether compound having hydroxyl groups at both ends and an average molecular weight of 1,000 to 10,000 g / mol.

[0078] OCN-(CH2) of Reaction Scheme 1 m -Si(OR')₃ is an isocyanatoalkyl-alkoxysilane compound having isocyanate and trialkoxysilane terminals, and is a polyether compound having a silane functional group at the terminal and containing a urethane group in the backbone.

[0079] The present invention provides a method for manufacturing a high heat dissipation modified silane adhesive as a one-component composition comprising: 1) a step of homogenizing the mixture of the modified silane resin and the dispersant of claim 1; (2) a step of adding spherical alumina fillers and stirring; (3) a step of adding hydrophobic fumed silica and stirring; and (4) a step of adding amino silane and stirring.

[0080] In addition, the composition according to the present invention may include a thermally conductive alumina filler with an average particle size of 1.0 to 100.0 μm in a ratio of 30 to 90 weight percent relative to the produced high heat dissipation modified silane adhesive to improve thermal conductivity.

[0081] The manufacturing method of the present invention includes a process under a nitrogen atmosphere to control the moisture content of the raw material, thereby ensuring uniform physical properties and long-term storage stability during curing.

[0083] The composition of the present invention will be described in detail below.

[0085] The composition of the present invention is manufactured in a one-component form.

[0086] The subject comprises a base resin portion composed of a polyether compound having silane functional groups at the terminals and urethane groups in the backbone; typically, the silane functional groups form a network of -Si-O-Si- structures in the presence of moisture to impart excellent adhesion and water resistance, while the urethane backbone serves to ensure a balance between mechanical strength and flexibility. By integrating these two functional structures within a single polymer, the present invention provides a base resin portion that simultaneously satisfies low viscosity, high adhesion, heat resistance, and moisture resistance, which were difficult to achieve in conventional technology.

[0087] The polyether compound used in the present invention, having a silane functional group at the terminal end and containing a urethane group in the backbone, is a composition produced by the above reaction formula 1.

[0088] The composition produced by Reaction Formula 1 is a silane-terminated polyether-based resin with a relatively low average molecular weight, which has an alkoxysilane (-Si(OR)3) functional group introduced at the end and contains urethane bonds in the backbone, so that upon curing, it reacts with moisture to form silanol and can rapidly construct a siloxane (-Si-O-Si-) structure.

[0089] In addition, the low viscosity of the composition of reaction formula 1 effectively wets the surface of the filler particles, increasing the filler dispersion stability and filling efficiency, and maintains appropriate elasticity, heat resistance, and moisture resistance through the polyether chain structure including urethane bonds even after curing.

[0090] In the present invention, the dispersant in the mixing homogenization step of the modified silane resin and the dispersant may be siloxane or silicone dispersant in an amount of about 0.5 to 2.0 weight%, preferably about 1 weight%, in the composition.

[0091] For example, in addition to Silok-3911M1, the following products may be included as silicone dispersants used in the present invention.

[0092] KOBOND TM 8091 (Nanjing SiSiB), ChangFu® MS-S25 or MS-S24 (ChangFu Silicones), SiSiB® Siloxane Masterbatch (e.g., MB16100, SiSiB), Siliketech LYSI-100A, silicon-based dispersants from Silibase, etc.

[0093] By introducing such a silicone dispersant into the composition, the following technical effects are obtained.

[0094] Silicone dispersants play a role in wetting the surface of fillers (e.g., spherical alumina, fumed silica, etc.) by adsorbing well through siloxane chains and organic side chains.

[0095] Accordingly, aggregation between filler particles is suppressed, and a uniform dispersion state can be secured from the initial mixing stage.

[0096] Silicone dispersants provide a steric stabilization effect, preventing the agglomeration of fillers and inhibiting sedimentation or phase separation. In particular, they help maintain dispersion during long-term storage, even in high-fill compositions.

[0097] Silicone dispersants exhibit excellent viscosity control under shear conditions and maintain appropriate fluidity by displaying shear-thinning behavior. This is advantageous for improving applicability (e.g., squeezing, spraying, etc.) in high-fill compositions.

[0098] The siloxane chain structure of the silicone dispersant can form a flexible dispersion matrix within the adhesive layer after curing. This alleviates cohesive stress between the filler and the polymer matrix, improves the balance of hardness and toughness, and enhances crack resistance and reliability.

[0099] Silicone dispersants can enhance interfacial bonding between the filler and the resin and induce a reduction in interfacial stress by distributing siloxane polymers on the surface of the filler. This can contribute to increasing heat transfer efficiency during the formation of thermal paths.

[0100] If the dispersion of the filler is stable during mixing and storage, viscosity fluctuations during the coating process are reduced, and batch-to-batch variation and reproducibility issues can be minimized.

[0101] Therefore, including Silok-3911M1 or an equivalent siloxane dispersant in the present invention at a level of about 1 weight percent is a very effective means of simultaneously improving the microstructure stabilization, coatability, mechanical strength, and interfacial heat transfer efficiency of the high-filling heat dissipation adhesive composition.

[0102] Alternatively, the (1) step dispersant of the present invention may include about 0.5 to 2.0 weight percent of vinyl silane in the total composition of the adhesive composition.

[0103] Specifically, the vinyl silane may be at least one of vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), or vinyltris(isopropoxy)silane, and preferably vinyltrimethoxysilane (VTMS) may be used. All of these function as water scavengers capable of chemically capturing residual moisture in the composition by utilizing the hydrolytic reactivity of the silane terminals.

[0104] Vinyl silane (R-Si(OR')3) can undergo hydrolysis when the terminal Si-OR (alkoxy) groups react with moisture. It chemically removes moisture remaining in the composition or introduced from the outside through the following reaction.

[0106] [Reaction Equation 2]

[0107] R-Si(OR')3+ 3H2O -> R-Si(OH)3+ 3R'OH

[0109] [Reaction Equation 3]

[0110] R-Si(OH)3+ HO-SiR -> R-Si-O-Si-R

[0112] [Reaction Equation 4]

[0113] H2O or R-Si(OH)3-> (R-Si-O-)n + nH2O

[0115] Here, in the above reaction schemes 2 to 4, R is a functional group containing a vinyl group, and R' is an alkyl group with a carbon number in the range of 2 to 10.

[0116] The vinyl silane used in the present invention functions as a water scavenger that preferentially reacts with residual moisture present in the composition to effectively remove it.

[0117] The alkoxy groups (Si-OR) of vinyl silane undergo hydrolysis with moisture to form silanol (Si-OH), which is then converted into a siloxane (Si-O-Si) bond structure through a subsequent condensation reaction. Since free water within the composition is chemically consumed during this series of reaction processes, degradation phenomena such as premature reactions caused by moisture, increased viscosity, and bubble formation can be effectively suppressed.

[0118] Due to this moisture capture function, the long-term storage stability of the composition is significantly improved, and during the curing process, moisture-induced defects are reduced, thereby improving the mechanical strength and interfacial adhesion of the cured body.

[0119] In addition, the formation of siloxane bonds increases the heat resistance of the entire network structure and prevents the re-aggregation of fillers even in systems containing high filler content (e.g., 70-90 wt% alumina), thereby acting favorably for dispersion stability and the formation of heat conduction pathways.

[0120] In addition, due to the interfacial reactivity of the silane terminal groups, the bonding strength with thermally conductive inorganic fillers is significantly enhanced, providing the effect of increasing the mechanical strength and thermal stability of the composite after curing.

[0121] The thermally conductive inorganic filler used in the present invention is a spherical alumina filler with an average particle size of 1.0 to 100 μm, and accounts for 70 to 90 weight percent of the generated high heat dissipation modified silane adhesive.

[0122] As thermally conductive inorganic fillers, DENKA’s DAW-03, DAW-05, DAW-07, DAW-45, DAW-70, DAM-03, DAM-05, DAM-07, DAM-45, DAM-70, etc. can be used, and Showa Denko’s Alunabeads CB series (e.g., CB-P05, CB-P10, CB-A20S, etc.), Nippon Steel Chemical & Material’s high-purity spherical alumina, or Sumitomo Chemical’s nearly spherical α-alumina crystals (e.g., NXA series) may be included, and more preferably, DAW-03 and DAW-05 are suitable.

[0123] These spherical alumina fillers provide high sphericity, excellent flowability, high packing density, and thermal conductivity characteristics, and are advantageous for improving viscosity control, interfacial bonding strength, and thermal conductivity when applied to the heat dissipation adhesive composition of the present invention.

[0124] In the present invention, the spherical alumina filler in the composition may include Denka’s DAW-03, preferably in a ratio of 70 to 90 weight percent of the total composition.

[0125] In the present invention, when spherical alumina fillers are filled in a high weight ratio, the thermal conductivity of the composition is significantly improved, allowing heat generated in highly integrated components such as camera modules for small electronic devices to be effectively dissipated.

[0126] The high filling of spherical alumina fillers provides the following technical advantages.

[0127] Spherical alumina fillers with an average particle size of 1.0 to 100 μm efficiently form heat transfer pathways within the composition, thereby increasing the thermal conductivity of the composition to 0.8 to 2.5 W / m·K after curing.

[0128] The high filling density resulting from the spherical alumina filler and the formation of an interconnected network rapidly dissipate local heat generated during camera module operation, contributing to the prevention of component deformation and performance degradation.

[0129] DAW-03 is a spherical particle, so the increase in viscosity is relatively gradual even with heavy filling, and when a viscosity modifier such as fumed silica (TS-720) is used in combination, the applicability and uniformity of the composition are also maintained.

[0130] The continuous phase of the polyether-based modified silane resin is maintained even with heavy filler filling, and the hardness and durability of the adhesive layer can be secured.

[0131] Accordingly, the heat dissipation adhesive composition containing DAW-03 in the range of 70 to 90 weight percent in the present invention provides an ideal combination of low viscosity, high filler, high hardness, and high heat dissipation, thereby enabling heat control and long-term reliability of a camera module for a small electronic device simultaneously.

[0132] In the present invention, as the amorphous silicon dioxide (hydrophobic fumed silica), Cabot’s CAB-O-SIL® TS-720, etc., may be preferably used.

[0133] In addition, the following similar grades of hydrophobic fumed silica may also be used as substitutes or in combination in the present invention (Wacker’s HDK® H15, HDK® H18, HDK® H30; Tokuyama’s REOLOSIL (e.g., hydrophobic DM series, KS series); Evonik’s AEROSIL® R 972, etc.).

[0134] In particular, CAB-O-SIL TS-720 is a hydrophobic silica treated with polydimethylsiloxane (PDMS) and has high purity, low bulk density, particle size, and aggregation structure. By including this silica in the composition, the viscosity of the composition (increase in viscosity and suppression of sagging), anti-precipitation properties, and shear thinning behavior can be effectively controlled.

[0135] In addition, TS-720 inhibits the ingress of moisture into the composition due to its hydrophobic surface characteristics, thereby preventing over-curing in moisture-curing systems and improving stability and reliability after curing.

[0136] In the present invention, the addition ratio of fumed silica can be set to a range of 0.1 to 5 weight% (or 0.1 to 10 weight%) of the total composition as needed, and within this range, a balance can be achieved between viscosity optimization, stability, adhesive properties, and mechanical performance after curing.

[0137] In addition, as an example, when 0.1 to 5 weight% of CAB-O-SIL TS-720 was added to the heat dissipation adhesive composition of the present invention, it was confirmed that the initial viscosity increased while the layer separation phenomenon was suppressed, and the tensile strength and adhesive strength after curing were improved.

[0138] The amino silane catalyst used in step (4) of the present invention is a compound having a silane functional group (R-Si(OR')3) at the terminal end and an amino group (-NH2 or -NH-) simultaneously, and performs a catalytic role in promoting hydrolysis and condensation reactions in a modified silane-based moisture-curing system.

[0139] The basicity of the amino group increases the rate of water hydrolysis of the alkoxy group (-Si-OR) of the silane terminal group and accelerates the condensation reaction of the generated silanol (-Si-OH), thereby promoting the formation of a siloxane network (-Si-O-Si-).

[0140] Therefore, the aminosilane of the present invention activates the hydrolysis reaction in the initial stage of the curing reaction and increases the rate of intermolecular or intramolecular siloxane bond formation in the later curing stage, thereby significantly improving the overall curing speed and degree of curing (conversion).

[0142] [Reaction Equation 5]

[0143] R-Si-(OR')3+ 3H2O -> R-Si(OH)3+ 3ROH

[0145] [Reaction Equation 6]

[0146] Si-OH + HO-Si -> Si-O-Si + H2O

[0148] [Reaction Equation 7]

[0149] Si-OH + Si-OR -> Si-O-Si + ROH

[0151] The moisture-curing modified silane adhesive composition according to the present invention preferably contains an amino silane to promote the curing reaction in a range of 0.5 to 2.0 weight percent based on the total weight of the composition.

[0152] When amino silane is included within the above content range, the hydrolysis reaction of the silane terminal group and the formation of siloxane bonds are sufficiently promoted by the basicity of the amino group, thereby greatly improving the curing speed, initial curing strength, final hardness, and moisture resistance.

[0153] In particular, when included in an amount of about 2.0 wt%, the catalytic activity of the amino group is optimized, making it possible to form a uniform cured network even in a composition containing a high content of alumina filler (70 to 90 wt%).

[0154] On the other hand, if the content of amino silane is less than 0.5% by weight, the hydrolysis and condensation promoting effect is insufficient, which leads to a decrease in the curing speed and a delay in securing initial hardness. Conversely, if an excessive amount exceeding 2.0% by weight is added, excessive dealkoxy reaction and internal aggregation occur, which may result in reduced workability or side effects such as increased viscosity and accelerated gelation.

[0155] Therefore, in the present invention, it was confirmed that including amino silane in the range of 0.5 to 2.0 weight%, more preferably 1.0 to 2.0 weight% relative to the total amount of the composition is most effective for maximizing technical effects.

[0156] By controlling the content of amino silane in this way, the modified silane-based adhesive of the present invention can achieve excellent effects such as rapid initial curing at room temperature, excellent mechanical properties, high storage stability, and reduced humidity sensitivity.

[0158] <Example 1>

[0159] As a one-component curable modified silane adhesive composition,

[0160] 1) Perform dry nitrogen purging on the main reactor (stainless steel dissolver, capable of being equipped with a sealed reflux condenser) to replace the headspace and prepare for stirring.

[0161] 2) 181.0 g of the product of reaction scheme 1 (n 100, m 8, R and R' are alkyl groups with 5 and 7 carbon atoms, respectively) and 25.0 g of Vinyltrimethoxysilane (VTMS) LT-171 from HUBEI BLUESKY NEW MATERIALS as a dispersant were added, and then nitrogen purged at 1,200 rpm and stirred for 15 minutes to homogenize while preventing water ingress.

[0162] LT-171, a vinyl silane added at this stage, reacts with moisture within WACKER’s GENIOSIL® XB 502 and Silok-3911M1 components to minimize the moisture content in the final composition, thereby preventing storage stability and degradation of physical properties.

[0163] 3) In the next step, 900.0 g of Denka’s DAW-03 was added in three separate additions as an alumina filler. This was done to prevent aggregation and uneven wetting problems that occur when a large amount of filler is added in a single addition, and to ensure stable dispersion within the composition.

[0164] 4) Specifically, after increasing the stirring speed of the dissolver to 1,600 rpm, a first batch of DAW-03 was added and stirred for 10 minutes to perform first wetting and preliminary dispersion. Subsequently, a second batch was added under the same conditions and stirred for 10 minutes to gradually improve the surface wetting and dispersion of the filler. Finally, the remaining third batch was added and stirred for 10 minutes to ensure that the entire filler was uniformly wetted throughout the composition, and then continuously stirred for an additional 30 minutes to eliminate fine aggregates of DAW-03 and ensure the viscosity and dispersion stability of the composition.

[0165] During the three-stage divided input process of the above DAW-03, a dry nitrogen purge was continuously maintained at the top of the reaction vessel to thoroughly block the inflow of external moisture during the process. This is an essential condition to prevent the premature hydrolysis of the product of Reaction Scheme 1 containing alkoxysilane terminal groups and vinyl silane LT-171, and to ensure the storage stability of the final composition.

[0166] 5) Next, 8.0 g of Evonik’s AEROSIL® TS-720, a fumed silica filler with a hydrophobic structure, was added in a batch. After addition, the mixture was stirred for 30 minutes at 1,600 rpm to ensure that the TS-720 was completely wetted and dispersed in the continuous phase of the composition. This process was intended to improve the stability of the composition, control flowability, and achieve rheological stabilization with increased solid content. Additionally, dry nitrogen purging was continuously maintained during this step to suppress moisture adsorption on the filler surface and hydrolysis of the silane components.

[0167] 6) Subsequently, 8.0 g of Aminopropyltrimethoxysilane (LT-540) from HUBEI BLUESKY NEW MATERIALS, a silane-based catalyst having an amino group, was added to the composition. Since the LT-540 acts as a catalyst that promotes the hydrolysis of silane terminal groups and the formation of siloxane bonds, premature curing may occur when reacting with residual moisture in the composition.

[0168] Therefore, it is preferable to add LT-540 in the final stage after all fillers (DAW-03, TS-720) have undergone a complete wetting and dispersion process. This is because aminosilane can immediately hydrolyze to form silanol (Si-OH) even with a small amount of moisture, and subsequently initiate a condensation reaction. If LT-540 is added early, there is a risk that instability such as premature curing, increased viscosity, and gelation may be induced by trace amounts of moisture in the reaction vessel or moisture remaining on the surface of the fillers.

[0169] In order to prevent such problems, the present invention finally added LT-540 while maintaining a dry nitrogen purge continuously during the process, and after addition, stirred for 10 minutes at 1,200 rpm to mix uniformly. Through such process control, the activity of the aminosilane catalyst can be stably expressed in time for the start of the curing reaction, and as a result, the storage stability, processability, and mechanical properties of the final cured body of the entire composition are maintained excellently.

[0171] <Comparative Example 1>

[0172] This comparative example was performed to confirm the effect of early addition on composition stability and curing behavior by adding the aminosilane catalyst (LT-540) at the beginning of the composition preparation, unlike in Example 1.

[0173] 1) Dry nitrogen purging was performed on the same main reaction vessel as in Example 1, and 181.0 g of the product of Reaction Scheme 1 (n 100, m 8, R and R' are alkyl groups with 5 and 7 carbon atoms, respectively) and 15.0 g of Silok-3911M1 were added.

[0174] 2) However, in this comparative example, unlike in the example, 8.0 g of the silane-based catalyst Aminopropyltrimethoxysilane (LT-540) having an amino group was simultaneously added at the initial stage. At this time, due to the trace amount of moisture remaining inside the reaction vessel and the moisture adsorbed on the surface of the raw material, LT-540 immediately initiated a hydrolysis and condensation reaction, and within about 5 to 10 minutes after the reaction, an increase in viscosity of the composition and localized gelation were observed.

[0175] 3) Subsequently, 900.0 g of alumina filler DAW-03 was added in three separate additions under the same conditions, but wetting was not achieved smoothly due to the already formed partial siloxane network and local aggregates, and from the second addition onwards, the filler clumped on the dissolver, causing a rapid decrease in stirring efficiency.

[0176] 4) Even though the stirring speed was maintained at 1,600 rpm, the viscosity of the composition did not form a normal dispersion profile, and after the third dispersion, paste-like aggregates were attached to the upper part of the stirring blade, making it impossible to perform a normal dispersion process.

[0177] 5) Subsequently, even when 8.0 g of fumed silica TS-720 was added, the overall viscosity of the composition was abnormally high, and the silica was not uniformly dispersed. An elastic gelation layer was observed in the composition even during a 24-hour stand test after dispersion was complete, which was determined to be the result of non-uniform curing caused by the early action of aminosilane.

[0178] 6) The viscosity immediately after manufacturing increased by approximately 230–280% compared to Example 1, and **complete gelation** occurred during the 50°C accelerated storage test (7 days). In addition, the final physical properties of the cured body, such as hardness (Shore A), tensile strength, and elongation at break, were significantly lower compared to Example 1.

[0179] 7) From the above results, it was confirmed that the early addition of the aminosilane catalyst (LT-540) seriously impairs the viscosity stability, dispersibility, processability, and storage stability of the modified silane composition, and that the manufacturing process of Example 1, in which it is added at the final stage of composition preparation, is technically preferable.

[0181] <Comparative Example 2>

[0182] This comparative example was performed to verify the effect on the reaction stability and final physical properties of the composition when the amount of amino silane catalyst (LT-540) added was in excess of that of Example 1.

[0183] In this comparative example, the amino silane catalyst Aminopropyltrimethoxysilane (LT-540) was added at an increased amount of about 3.5 wt% (28.0 g) based on the total composition under the same process conditions as in Example 1. Since LT-540 is a highly active catalyst that promotes the hydrolysis and condensation reactions of silane terminal groups, there is a risk that the entire composition may unintentionally undergo rapid hardening if added in excess.

[0184] In fact, within 5 minutes of adding LT-540, the initial viscosity of the composition increased by approximately 170–220% compared to Example 1, and a localized gelled layer was formed around the stirring blade from the point of secondary dispersion at the step of adding DAW-03 filler in three divided portions.

[0185] Excess aminosilane rapidly reacted with trace moisture in the reaction system to produce excessive silanol (Si-OH), which prematurely formed condensation (≡Si-O-Al-) and siloxane (≡Si-O-Si≡) networks with the filler surface, explosively increasing the viscosity of the entire composition.

[0186] In addition, due to the presence of an excessive amount of catalyst, the final cured body had an excessively formed siloxane structure, which increased brittleness, and the tensile strength and elongation at break decreased by approximately 32% and 48%, respectively, compared to Example 1.

[0187] Therefore, it is preferable to use the aminosilane catalyst in a limited amount of about 0.5 to 2.0 wt% as in the example, and excessive input has a negative effect on the processability, storage stability, and final physical properties of the composition.

[0189] <Comparative Example 3>

[0190] This comparative example was conducted to verify the effect of moisture ingress on a modified silane curable composition when prepared under open-system conditions without nitrogen purging during composition preparation.

[0191] The same raw material composition and input order as in Example 1 were used, but the headspace replacement and nitrogen purging processes of the reaction vessel were omitted, and stirring was carried out in an open system at room temperature.

[0192] In the composition prepared in an open system, moisture from the relative humidity of the air (about 40–60%) was continuously introduced during the reaction, and this moisture rapidly accelerated the hydrolysis of the terminal silane group (≡Si-OR). As a result, the amount of silanol (Si-OH) produced increased abnormally from the beginning of stirring, and the condensation reaction with the filler surface occurred prematurely during the subsequent dispersion process.

[0193] In particular, an increase in viscosity was detected starting about 5 minutes after the first split injection of DAW-03 filler, and the total viscosity of the composition increased by about 300–350% compared to the example before the third dispersion was completed. In some areas, gelation and a semi-solid siloxane network were observed, making normal high-speed dispersion impossible.

[0194] In the TS-720 (fumed silica) input stage, the silica failed to form a normal structural network, and a large amount of aggregates between silica and alumina were formed due to the heterogeneous hydrolysis of silane that had already occurred due to the influx of moisture.

[0195] As a result of viscosity stability tests immediately after manufacturing and 7-day accelerated storage tests (50°C), all compositions of Comparative Example 3 gelled within a few hours, and storage stability was significantly reduced compared to Example 1. In addition, all mechanical properties of the cured body, such as fracture strength, elongation, and hardness, were reduced due to the non-uniform network structure.

[0196] From the above results, it has been confirmed that for the composition of the present invention, it is essential to minimize moisture ingress by maintaining a dry nitrogen purge throughout the entire manufacturing process, and that this is a critical technical factor in securing storage stability and a uniform curing reaction in a modified silane-based one-component curable composition.

[0198] <Comparative Example 4>

[0199] This comparative example was prepared under the same process conditions and the same raw material composition as Example 1, but the effect was evaluated by reducing only the amount of alumina (DAW-03), a thermally conductive filler.

[0200] Specifically, the amount of DAW-03 added in Example 1 was reduced to half that amount, 450.0g, in this Comparative Example. The addition method was the same, divided into three additions of 150.0g each. At each stage, stirring was performed at 1,600 rpm for 10 minutes, followed by a final additional stirring for 30 minutes. The remaining process conditions, stirring conditions, nitrogen purging conditions, and subsequent additive addition conditions were all maintained identically to Example 1.

[0201] However, the composition of Comparative Example 4, which has insufficient alumina content, showed a significantly lower thermal conductivity of the final cured body compared to Example 1. This is believed to be because when the filling rate of the thermally conductive filler decreases, the formation of the thermal conduction pathway between the fillers becomes incomplete, and the heat transfer pathway within the matrix is ​​interrupted.

[0202] As such, Comparative Example 4 clearly demonstrates that thermal conductivity properties deteriorate when the amount of alumina input is reduced, and proves that the filler content set in Example 1 is essential for securing high thermal conductivity properties.

[0203] The compositions prepared according to the above examples and comparative examples were evaluated using a thermal conductivity measuring instrument based on ASTM D5470. The results are shown in Table 1 below.

[0205] division Key differences Thermal conductivity (W / m·K) Example 1 900g alumina, nitrogen purging in the pre-process stage + final input of aminosilane 1.70 Comparative Example 1 Partial premature curing occurs due to early addition of aminosilane at the intermediate stage 1.42 Comparative Example 2 Alumina filler single batch injection *non-uniform dispersion 1.35 Comparative Example 3 No fumed silica added → Increased viscosity and reduced filler network uniformity 1.29 Comparative Example 4 Reduced alumina to 450g *Decreased filling rate 0.88

[0207] As can be seen from Table 1, Example 1 exhibited the highest thermal conductivity of 1.70 W / m·K, confirming that it is a high thermal conductivity adhesive composition intended by the present invention.

[0208] On the other hand, in Comparative Example 1, the thermal conductivity decreased due to partial curing and non-uniformity in the formation of the silane network as aminosilane was introduced early.

[0209] In Comparative Example 2, the dispersibility was significantly reduced because the alumina filler was added in a single batch rather than in three separate batches, and as a result, the heat transfer path between the fillers was not sufficiently formed, so the thermal conductivity was measured to be low.

[0210] In Comparative Example 3, fumed silica was not added, so the viscosity increased, and due to the decrease in dispersibility caused by the increase in viscosity, the filler network could not be formed uniformly, resulting in a lower thermal conductivity.

[0211] Comparative Example 4 is a case where the amount of alumina input was reduced to half the level, and due to insufficient filler filling rate, the heat conduction path was not sufficiently established, resulting in the lowest thermal conductivity of 0.88 W / m·K.

[0212] The above results clearly show that the manufacturing sequence (three-part divided input, fumed silica auxiliary dispersion, aminosilane final input) and filler content presented in the present invention are very important factors in realizing high thermal conductivity.

[0213] The viscosity (25°C) of the compositions of the above examples and comparative examples was measured, and the results are shown in Table 2 below.

[0215] division Key differences Viscosity (mPa·s, 25 °C) Example 1 Optimal dispersion conditions (3-part injection + fumed silica + final aminosilane injection) 24,000 Comparative Example 1 Partial gelation occurred due to early administration of aminosilane 31,500 Comparative Example 2 Alumina single batch input *Poor dispersion 38,000 Comparative Example 3 No fumed silica added *Increased viscosity 41,200 Comparative Example 4 Reduced alumina to 450g *Insufficient filler filling rate 12,800

[0217] The composition of Example 1 exhibited a viscosity of 24,000 mPa·s, which is stable and has excellent workability. This is the result of the combined action of process conditions, such as (i) three-part divided addition of alumina filler, (ii) aggregation control by an appropriate amount of fumed silica, and (iii) prevention of premature reaction by final addition of aminosilane.

[0218] In Comparative Example 1, the viscosity increased because the partial silane bonding reaction proceeded early by adding aminosilane at an intermediate stage.

[0219] Comparative Example 2 showed a tendency for reduced dispersibility and a significant increase in viscosity due to aggregate formation as alumina filler was added in a single batch.

[0220] In Comparative Example 3, fumed silica was not used, resulting in reduced dispersion stability, and the alumina network formed early, leading to the highest viscosity.

[0221] Comparative Example 4 showed a low viscosity value because the filler network was not sufficiently formed due to insufficient alumina content.

[0222] Therefore, it has been confirmed that the three-step filler input process adopted in the present invention, the appropriate amount of fumed silica, and the final input of aminosilane are essential for ensuring viscosity stability.

[0223] function Ingredient Name Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Modified silane resin GENIOSIL® XB 502 100.0 100.0 100.0 100.0 100.0 GENIOSIL® STP-E10 81.0 81.0 81.0 81.0 81.0 moisture absorbent Vinyltrimethoxysilane 10.0 10.0 10.0 10.0 10.0 Dispersant, Wetting Agent Silane, siloxane modified dispersant 15.0 15.0 15.0 15.0 15.0 Tsiksoje silica dioxide 8.0 8.0 8.0 8.0 8.0 Thermally conductive minerals Spherical alumina filler 900.0 900.0 900.0 900.0 450.0 catalyst Aminopropyltrimethoxysilane 8.0 8.0 8.0 8.0 8.0 total 100.0 100.0 100.0 100.0 100.0 No Physical property indicators 1 Thermal conductivity (W / m·K) 1.70 1.42 1.35 1.29 0.88 2 Viscosity (mPa·s, 25 °C) 24,000 31,500 38,000 41,200 12,800 3 precipitation X O O O X

[0224] Evaluation of precipitation was performed to confirm the long-term storage stability of the actual composition. Specifically, each of the prepared example and comparative example compositions was filled into a transparent glass container (200 mL, diameter 5 cm) and stored in a stationary state at room temperature (25 ± 2 ℃) for 30 days.

[0225] During the storage period, the inside of the container was visually observed to record the separation of fillers or inorganic fillers, precipitation, and color changes of the supernatant and subnatant.

[0226] The presence of sedimentation was evaluated according to the following criteria.

[0227] × (No sedimentation): The filler is uniformly dispersed, there is no color difference between the upper and lower layers, and the entire container maintains a uniformly mixed state.

[0228] ○ (Sedimentation): Fillers sink to the bottom or layer separation is observed, resulting in differences in color and concentration between the upper and lower layers.

[0229] All samples were stored in the same container and in the same environment, and the degree of precipitation was evaluated at observation points immediately after manufacturing, 7 days, 15 days, and 30 days.

[0230] Through this experiment, it was confirmed that the composition of Example 1 has excellent long-term storage stability as no precipitation was observed for 30 days, while in the comparative example, partial or complete precipitation occurred, proving that the manufacturing process and composition conditions have an important influence on preventing precipitation.

[0232] The present invention described above is not limited by the aforementioned embodiments and attached drawings, and it will be obvious to those skilled in the art that various substitutions, modifications, and changes are possible within the scope of the technical concept of the present invention.

Claims

Claim 1 delete Claim 2 (1) a step of homogenizing the mixture of the modified silane resin and the dispersant produced by the following reaction scheme 1; (2) a step of dividing the spherical alumina filler into three portions and stirring; (3) a step of adding hydrophobic fumed silica and stirring; (4) a step of adding amino silane and stirring, wherein the dispersant in step (1) is either vinyltriethoxysilane (VTES) or vinyltris(isopropoxy)silane, the spherical alumina filler in step (2) has an average particle size of 1.0 to 100 μm and is 70 to 90 weight% of the high heat conduction modified silane adhesive, the amino silane in step (4) is 1.0 to 2.0 weight% of the high heat conduction modified silane adhesive, and all processes of (1) to (4) are performed in a nitrogen atmosphere. A method for manufacturing a high-heat-conductivity modified silane adhesive characterized by improving the overall curing speed and degree of curing (conversion) by adding an amino silane catalyst in step (4), thereby activating the hydrolysis reaction in the early stages of the curing step and increasing the rate of intermolecular or intramolecular siloxane bond formation in the later stages. [Reaction Scheme 1] HO-(RO)n-H+OCN-(CH2)m-Si(OR')₃→ (RO')3Si-(CH2)m-NH-CO-O-(RO)nO-CONH-(CH2)m-Si(OR')₃n is 60~150, m is 1~10, R and R' are alkyl groups with 2~10 carbon atoms. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A method for manufacturing a high heat-conductivity modified silane adhesive according to claim 2, characterized in that the hydrophobic fumed silica in step (3) accounts for 0.1 to 10 weight percent of the produced high heat-conductivity modified silane adhesive. Claim 7 delete Claim 8 A method for manufacturing a high heat dissipation modified silane adhesive according to claim 2, wherein the amino silane is selected from the group consisting of 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), 3-glycidoxypropyltrimethoxysilane (GPTMS), 3-glycidoxypropylmethyldimethoxysilane (GPDMS), 3-aminopropylmethyldiethoxysilane (APDES), 3-mercaptopropyltrimethoxysilane (MrPTMS), 3-mercaptopropyltrimethyldimethoxysilane (MrPDMS), 3-methacryloxypropyltrimethoxysilane (MPTMS), 3-methacryloxypropylmethyldimethoxysilane (MPDMS), and mixtures thereof.