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CN-121975487-A - Pouring sealant for flexible LED lamp strip and preparation method thereof

CN121975487ACN 121975487 ACN121975487 ACN 121975487ACN-121975487-A

Abstract

The invention provides a pouring sealant for a flexible LED (light-emitting diode) lamp strip and a preparation method thereof, wherein the pouring sealant is prepared by mixing a component A and a component B according to a mass ratio of 2-4:1, and the preparation raw materials of the component A comprise, by weight, 65-80 parts of matrix resin, 5-15 parts of epoxy-polyether grafting modified tackifier, 1-5 parts of boron nitride-graphene hybrid heat-conducting filler and 2-6 parts of hydrophobic fumed silica, and the preparation raw materials of the component B comprise 8-12 parts of methyl hydrogen silicone oil, 0.1-0.3 part of platinum catalyst and 0.05-0.15 part of inhibitor. The pouring sealant provided by the invention has the characteristics of strong adhesive force, high-efficiency heat conduction and excellent mechanical property.

Inventors

  • XU JINSUO

Assignees

  • 浙江冉弘电子有限公司

Dates

Publication Date
20260505
Application Date
20260304

Claims (10)

  1. 1. The pouring sealant for the flexible LED lamp strip is characterized by being prepared by mixing a component A and a component B according to a mass ratio of 2-4:1, and comprising the following components in parts by weight: The preparation raw materials of the component A comprise 65-80 parts of matrix resin, 5-15 parts of epoxy-polyether grafting modified tackifier, 1-5 parts of boron nitride-graphene hybrid heat conducting filler and 2-6 parts of hydrophobic fumed silica; The preparation raw materials of the component B comprise 8-12 parts of methyl hydrogen silicone oil, 0.1-0.3 part of platinum catalyst and 0.05-0.15 part of inhibitor.
  2. 2. The pouring sealant for the flexible LED lamp strip according to claim 1, wherein the matrix resin is formed by compounding 55-60 parts of vinyl-terminated polydimethylsiloxane and 10-20 parts of vinyl MQ silicon resin, the viscosity of the vinyl-terminated polydimethylsiloxane is 3000-8000 mPas (25 ℃), the mol percentage content of vinyl chain links is 0.15-0.25%, the mol percentage content of vinyl of the vinyl MQ silicon resin is 1.5-2.5%, and the M/Q value is 0.7-0.9.
  3. 3. The pouring sealant for the flexible LED lamp strip according to claim 1, wherein the platinum catalyst has a platinum content of 3000-5000ppm, the hydrophobic fumed silica has an average particle size of 10-15nm and a specific surface area of 80-120m 2 /g, and the inhibitor is one or more of ethynyl cyclohexanol, diallyl maleate and 3-methyl-1-butyn-3-ol.
  4. 4. The pouring sealant for the flexible LED lamp strip according to claim 1, wherein the epoxy-polyether graft modification tackifier is prepared from 40-60 parts by weight of side chain vinyl polydimethylsiloxane, 18-22 parts by weight of polyether amine with the number average molecular weight of 1800-2200, 8-12 parts by weight of gamma-glycidyl ether oxypropyl trimethoxy silane, 12-18 parts by weight of phenyl hydrogen silicone oil with the hydrogen content of 0.6-1.0wt%, 0.03-0.07 part by weight of platinum catalyst with the platinum content of 1500-2500ppm and 60-100 parts by weight of anhydrous toluene.
  5. 5. The potting adhesive for flexible LED lamp strips according to claim 4, wherein the preparation method of the epoxy-polyether graft modified tackifier comprises the following steps: 1) Under the protection of dry nitrogen with the flow rate of 0.5-1.5L/min, polyether amine, gamma-glycidyl ether oxypropyl trimethoxy silane and anhydrous toluene are added into a reaction kettle, and stirred and reacted for 2-3h at the temperature of 60-70 ℃ at the speed of 200-400 r/min; 2) Adding side chain vinyl polydimethylsiloxane into the system obtained in the step 1), heating to 80-90 ℃ for heat preservation, dripping the premix liquid into the system at the rate of 5-10mL/min, and stirring for reaction for 4-6h at the speed of 200-300r/min after the dripping is finished; 3) After the reaction is finished, toluene is distilled off under reduced pressure under the conditions of absolute pressure of 5-10kPa and temperature of 80-90 ℃ to obtain the epoxy-polyether graft modified tackifier.
  6. 6. The pouring sealant for the flexible LED lamp strip, which is disclosed in claim 1, is characterized in that the preparation raw materials of the boron nitride-graphene hybrid heat-conducting filler comprise, by weight, 5-7 parts of graphene oxide dispersion liquid with the mass concentration of 1.5-2.5mg/mL, 5-7 parts of hexagonal boron nitride nano-sheet with the thickness of 50-100nm, 2-4 parts of vinyl trimethoxysilane, 0.5-1.0 part of gamma-aminopropyl triethoxysilane, 150-250 parts of absolute ethyl alcohol and 40-60 parts of deionized water.
  7. 7. The pouring sealant for the flexible LED lamp strip according to claim 6, wherein the preparation method of the boron nitride-graphene hybrid heat-conducting filler comprises the following steps: (1) Adding hexagonal boron nitride nano-sheets into a mixed solution of absolute ethyl alcohol and deionized water, and carrying out ultrasonic treatment for 1-2h under the conditions of ultrasonic power of 400-500W and frequency of 20-25 kHz; (2) Adding graphene oxide dispersion liquid and gamma-aminopropyl triethoxysilane into the system obtained in the step (1), and stirring for 2-3h at the temperature of between 40 and 50 ℃ in a water bath at the speed of between 500 and 800 r/min; (3) Dropwise adding 0.5-1.0mol/L glacial acetic acid into the system obtained in the step (2), regulating the pH to 4-5, heating to 60-70 ℃, dropwise adding vinyltrimethoxysilane at the rate of 1-2mL/min, and stirring for reacting for 6-8h at the speed of 300-400r/min after the dropwise adding is finished; (4) Centrifuging the system obtained in the step (3) for 10-15min at 8000-10000r/min, washing the precipitate with ethanol for 3-5 times to neutrality, vacuum drying for 12-24h under the absolute pressure of 5-10kPa and the temperature of 80-90 ℃, grinding, and sieving with a 350-450 mesh sieve to obtain the boron nitride-graphene hybrid heat-conducting filler.
  8. 8. A method for preparing the pouring sealant for the flexible LED lamp strip based on any one of claims 1 to 7, which is characterized by comprising the following steps: the preparation of the component A comprises the steps of adding matrix resin into a planetary stirring kettle, controlling the jacket temperature of the stirring kettle to be 25-30 ℃, stirring and dispersing for 15-20min at 200-300r/min under the condition of absolute pressure of 15-25kPa, sequentially adding an epoxy-polyether grafting modified tackifier, a boron nitride-graphene hybrid heat-conducting filler and hydrophobic fumed silica, stirring and dispersing for 20-30min at 600-800r/min, then defoaming for 20-30min under the absolute pressure of 5-10kPa, releasing vacuum after the defoaming is finished, and filling the obtained component A into a closed container for standby in a dark place; s2, preparing a component B, namely adding methyl hydrogen silicone oil into another stirring container, keeping stirring at the temperature of 20-30 ℃ and normal pressure at the speed of 100-200r/min, adding a platinum catalyst and an inhibitor, then stirring at the speed of 300-400r/min for 20-30min, defoaming for 10-15min under the absolute pressure of 10-20kPa, releasing vacuum after the defoaming is finished, filling the obtained component B into a closed container, and preserving in a dark place for standby; s3, mixing the component A and the component B according to the mass ratio of 2-4:1, and obtaining the pouring sealant for the flexible LED lamp strip after inspection.
  9. 9. The method for preparing the pouring sealant for the flexible LED lamp strip according to claim 8, wherein in the step S3, the step of checking is as follows: For checking and adjusting the light transmittance of the pouring sealant, mixing the component A with the organic silicon color paste according to the mass ratio of 100:0.013-0.017, and stirring for 5-8min at the temperature of 25-30 ℃ at the speed of 300-500 r/min; uniformly mixing the component A and the component B mixed with the organic silicon color paste according to the mass ratio of 2-4:1, taking 8-12g of mixed glue solution, injecting the mixed glue solution into a transparent test box, defoaming for 10-12min under the absolute pressure of 15-25kPa, testing the light transmittance, supplementing the organic silicon color paste if the light transmittance is higher than 56.5%, and supplementing the component A if the light transmittance is lower than 53.5% until the light transmittance reaches 55% +/-1.5%.
  10. 10. The preparation method of the pouring sealant for the flexible LED lamp strip, which is disclosed in claim 8, is characterized in that when the pouring sealant is performed, the pouring sealant for the flexible LED lamp strip is transferred into a vacuum container, defoamed under the absolute pressure of 15-25kPa for 10-12min, the defoamed glue solution is introduced into glue dispensing equipment for pouring the glue, the distance between a glue nozzle and a base material of the LED lamp strip is controlled to be 5-15mm, the glue dispensing speed is controlled to be 15-25mm/s, and the poured LED lamp strip is placed in a clean environment for horizontal standing for 22-26h at the temperature of 25-30 ℃.

Description

Pouring sealant for flexible LED lamp strip and preparation method thereof Technical Field The invention relates to the technical field of pouring sealant, in particular to a pouring sealant for a flexible LED lamp strip and a preparation method thereof. Background The flexible LED lamp strip has the characteristics of light weight, flexibility and uniform light emission, and is widely applied to the fields of decorative lighting, intelligent wearing, automobile interior decoration and the like. The pouring sealant is used as a core packaging material of the flexible LED lamp strip, and has good film forming property, adhesiveness with a base material, thermal conductivity and mechanical property, and has the effects of protecting the inner circuit and the chip of the lamp strip from being corroded by external water vapor and dust, timely leading out heat generated during the working of the LED, and guaranteeing the service life and stable operation of the lamp strip. The existing pouring sealant mostly uses organic silicon, epoxy resin and the like as matrixes, and polyvinyl chloride (PVC) is often used as a base material of the flexible LED lamp strip due to good flexibility and controllable cost, but the pouring sealant using traditional materials such as organic silicon, epoxy resin and the like as matrixes is insufficient in compatibility with the PVC base material, so that the problems of infirm adhesion, delamination, falling off and the like are easy to occur, and the packaging reliability is affected. The LED lamp strip is required to bear repeated bending in the installation and use, and higher requirements are put forward on the heat conduction performance and mechanical properties of the pouring sealant. In the prior art, the pouring sealant is difficult to stably bond with the PVC base material, has high efficient heat conduction and excellent mechanical properties, is insufficient in heat conduction, causes accelerated light pearlescent attenuation, is insufficient in bonding strength, has sealing failure after bending, and is difficult to fully adapt to long-term use requirements of the flexible LED light strip. Disclosure of Invention Aiming at the problems in the prior art, the invention provides a pouring sealant for a flexible LED lamp strip and a preparation method thereof. In order to achieve the above purpose, the invention is realized by the following technical scheme: The invention discloses a pouring sealant for a flexible LED lamp strip, which is prepared by mixing a component A and a component B according to a mass ratio of 2-4:1, wherein the raw materials for preparing the component A comprise, by weight, 65-80 parts of matrix resin, 5-15 parts of epoxy-polyether graft modified tackifier, 1-5 parts of boron nitride-graphene hybrid heat-conducting filler and 2-6 parts of hydrophobic fumed silica, and the raw materials for preparing the component B comprise 8-12 parts of methyl hydrogen-containing silicone oil, 0.1-0.3 part of platinum catalyst and 0.05-0.15 part of inhibitor. According to the technical scheme, the matrix resin can provide basic film forming characteristics for the pouring sealant, the epoxy-polyether grafting modified tackifier can improve the bonding capability of the pouring sealant and the LED lamp strip base material, the boron nitride-graphene hybridized heat conducting filler can improve the heat conducting performance of the pouring sealant, the hydrophobic fumed silica can enhance the mechanical reinforcing effect of the pouring sealant, the methyl hydrogen-containing silicone oil is used as a cross-linking agent, a silicon hydrogen bond in molecules of the methyl hydrogen-containing silicone oil and vinyl in the matrix resin undergo a silicon hydrogen addition cross-linking reaction under the catalysis of a platinum catalyst to form a three-dimensional network structure, the inhibitor can form reversible coordination with the platinum catalyst, the cross-linking reaction rate is regulated and controlled, the operation time of the glue solution is prolonged, and the components are synergistic to enable the pouring sealant to have the basic performance suitable for the packaging requirements of the flexible LED lamp strip. Preferably, the matrix resin is prepared by compounding 55-60 parts of vinyl-terminated polydimethylsiloxane and 10-20 parts of vinyl MQ silicone resin, wherein the viscosity of the vinyl-terminated polydimethylsiloxane is 3000-8000 mPa.s (25 ℃), the mol percentage of vinyl chain units is 0.15-0.25%, the mol percentage of vinyl of the vinyl MQ silicone resin is 1.5-2.5%, and the M/Q value is 0.7-0.9. By adopting the technical scheme, the vinyl-terminated polydimethylsiloxane can endow the pouring sealant with film forming performance and flexibility on the basis, vinyl groups in molecules of the pouring sealant can participate in crosslinking reaction to form a basic network of a curing system, the cage-shaped or branched structure of the