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CN-122011324-A - Polyurethane with sound absorption layer and buffer layer coupled and application of polyurethane in noise reduction earmuffs

CN122011324ACN 122011324 ACN122011324 ACN 122011324ACN-122011324-A

Abstract

The invention discloses polyurethane with a sound absorbing layer and a buffer layer coupled and application of the polyurethane in a noise-reducing earmuff, and belongs to the technical field of polyurethane, wherein the sound absorbing layer comprises isocyanate prepolymer, polysilsesquioxane/polyacrylate hybrid core-shell structure polyol emulsion, a chain extender, a silicone oil foam stabilizer, a delay catalyst, an organotin catalyst and a foaming agent; the buffer layer comprises isocyanate prepolymer, magnolol- (3-mercapto-1, 2-propanediol) adduct, chain extender, hydroxyl-terminated polydimethylsiloxane, polyethylene glycol monomethyl ether, cross-linking agent, silicone oil foam stabilizer, catalyst and foaming agent. According to the invention, polysilsesquioxane/polyacrylate hybrid core-shell structure polyol and magnolol- (3-mercapto-1, 2-propylene glycol) adducts are added into polyurethane of different layers, and interface coupling is performed by combining NCO indexes, so that the triple functions of sound absorption, buffering and antibiosis of double-layer coupling polyurethane are realized.

Inventors

  • LIN TAIQIN

Assignees

  • 广东金海纳实业有限公司

Dates

Publication Date
20260512
Application Date
20260325

Claims (10)

  1. 1. The polyurethane coupling the sound absorption layer and the buffer layer is characterized by comprising, by weight, 100 parts of isocyanate prepolymer, 10-20 parts of polysilsesquioxane/polyacrylate hybrid core-shell structure polyol emulsion, 4-8 parts of chain extender, 1-2 parts of silicone oil foam stabilizer, 0.15-0.2 part of delay catalyst, 0.01-0.05 part of organotin catalyst and 1-2 parts of foaming agent; The raw materials of the buffer layer comprise, by weight, 100 parts of isocyanate prepolymer, 2-4 parts of magnolol- (3-mercapto-1, 2-propylene glycol) adduct, 5-10 parts of chain extender, 2-5 parts of hydroxyl-terminated polydimethylsiloxane, 0.5-1 part of polyethylene glycol monomethyl ether, 0.5-2 parts of cross-linking agent, 1-2 parts of silicone oil foam stabilizer, 0.2-1 part of catalyst and 0.5-2 parts of foaming agent.
  2. 2. The polyurethane of claim 1, wherein the NCO index of the raw materials of the sound absorbing layer is controlled to be 1.05-1.15 and the NCO index of the raw materials of the buffer layer is controlled to be 0.85-0.95.
  3. 3. The polyurethane of claim 1 wherein the sound absorbing layer and the buffer layer are coupled, wherein the polysilsesquioxane/polyacrylate hybrid core-shell structured polyol emulsion is prepared by: S1, mixing methacryloxypropyl trimethoxy silane and dimethyl dimethoxy silane according to the molar ratio of (2-4): 1, and performing hydrolytic polycondensation reaction in the presence of an alkaline catalyst, a surfactant and water to obtain polysilsesquioxane core emulsion with the surface enriched with polymerizable carbon-carbon double bonds; S2, simultaneously dripping an acrylic ester monomer, a terminal hydroxyl monomer and an initiator into the polysilsesquioxane core emulsion at a constant speed, and performing emulsion polymerization at 75-85 ℃ to obtain the polysilsesquioxane/polyacrylate hybrid core-shell structure polyol emulsion, and dehydrating the emulsion until the solid content is 50-60 percent after purification.
  4. 4. The polyurethane of claim 3, wherein the acrylate monomer comprises butyl acrylate and methyl methacrylate in a mass ratio of (75-85): 15-25, the terminal hydroxyl monomer comprises polyethylene glycol acrylate and hydroxyethyl methacrylate in a mass ratio of (40-60): 40-60, the initiator is potassium persulfate, the alkaline catalyst is sodium hydroxide or potassium hydroxide, the surfactant comprises at least one of an ionic surfactant and a nonionic surfactant, the ionic surfactant is selected from one or more of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate, and the nonionic surfactant is selected from one or more of octylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.
  5. 5. The polyurethane of claim 1, wherein the magnolol- (3-mercapto-1, 2-propanediol) adduct comprises one or more of formula 1 or formula 2: Formula 1; Formula 2.
  6. 6. The polyurethane of claim 1, wherein the foaming agent is deionized water.
  7. 7. The polyurethane of claim 1, wherein the catalyst is an organic amine catalyst and an organic tin catalyst, the mass ratio of the organic amine catalyst to the organic tin catalyst is 2:1, the chain extender is one or more of ethylene glycol, 1, 4-butanediol and 1, 6-hexanediol, the crosslinking agent is at least one of trimethylolpropane, glycerol, triethanolamine, pentaerythritol and sorbitol, and the delayed catalyst is at least one of a temperature activated tertiary amine catalyst, a chemically blocked tertiary amine catalyst and a slow release microcapsule catalyst.
  8. 8. The polyurethane of claim 1, wherein the hydroxyl terminated polydimethylsiloxane has a viscosity of 55 to 75cst and the polyethylene glycol monomethyl ether has a molecular weight of 500 to 2000g/mol.
  9. 9. The method for preparing polyurethane coupling the sound absorbing layer and the buffer layer according to any one of claims 1 to 8, comprising the following steps: (1) Pre-mixing and stirring polysilsesquioxane/polyacrylate hybridized core-shell structure polyol emulsion and a chain extender for a period of time, transferring to a reaction kettle with a distillation receiver, heating to 40-60 ℃, starting vacuum dehydration until the moisture content is less than 0.1wt%, mixing with isocyanate prepolymer, silicone oil foam stabilizer, delay catalyst, organotin catalyst and foaming agent, injecting into a mold for foaming, controlling the reaction temperature to be 50-60 ℃, and reacting to a semi-gel state to obtain a sound absorbing layer semi-finished product; (2) Mixing an isocyanate prepolymer, hydroxyl-terminated polydimethylsiloxane, magnolol- (3-mercapto-1, 2-propanediol) adduct, polyethylene glycol monomethyl ether, a chain extender, a cross-linking agent, a silicone oil foam stabilizer, a catalyst and a foaming agent to obtain a buffer layer mixture; (3) Pouring the buffer layer mixture on the surface of the sound absorption layer within a time window of 2-5 minutes after the semi-finished product of the sound absorption layer reaches a semi-gel state, and forming chemical bonding by utilizing the reaction of residual isocyanate groups on the surface of the sound absorption layer and active hydrogen compounds of the buffer layer; (4) And (3) curing the double-layer structure for 20-40 minutes at the temperature of 80-90 ℃ and cooling to room temperature to obtain polyurethane with the sound absorption layer and the buffer layer coupled.
  10. 10. Use of polyurethane with a sound absorbing layer coupled to a buffer layer as claimed in any one of claims 1 to 8 in noise reducing earmuffs or passive noise reducing headphones.

Description

Polyurethane with sound absorption layer and buffer layer coupled and application of polyurethane in noise reduction earmuffs Technical Field The invention relates to the technical field of polyurethane, in particular to polyurethane with a sound absorption layer and a buffer layer coupled and application of the polyurethane in noise reduction earmuffs. Background With the rapid development of industrialization and urbanization, noise pollution has become an important environmental problem affecting human health. Prolonged exposure to high intensity noise conditions can lead to serious consequences such as hearing impairment, sleep disorders, cardiovascular disease, and reduced working efficiency. It is counted that about 4.3 hundred million people worldwide have hearing loss caused by noise exposure, and occupational noise deafness has become one of the most common occupational diseases in China. The noise reduction earmuffs are used as important components of personal hearing protection equipment and are widely applied to high-risk noise environments such as industrial production, military training, aviation ground service, rail transit and the like. In recent years, with the development of consumer electronics markets, both active noise reduction headphones and passive noise reduction earmuffs have made higher demands on acoustic materials, and not only have excellent sound insulation properties, but also have to be compatible with wearing comfort, antibacterial properties and long-term durability. The polyurethane material is a porous polymer, a plurality of-NHCOO-structural units are embedded in a molecular main chain of the porous polymer, the porous polymer is generally obtained through a series of chemical reaction synthesis between binary or polybasic isocyanate and polyalcohol, and the porous polymer has the advantages of high design flexibility, convenient forming construction process, high porosity, light weight, high specific strength, excellent energy absorption capacity and the like, and is extremely wide in application range. The traditional noise-reducing earmuffs mostly adopt polyurethane soft foam with a single formula as a sound absorption material. Although the sound absorption material has a certain sound absorption coefficient, the sound absorption material has the obvious defects of narrow sound absorption frequency band, poor absorption effect on middle-low frequency noise (< 1000 Hz), single cell structure, lack of impedance gradual change design, serious reflection of sound waves on the surface of the material, unadjustable mechanical property, incapability of meeting the dual requirements of acoustic property and wearing comfort, large compression set after long-term use and remarkable attenuation of sound insulation property. Part of high-end products are bonded or physically pressed by adopting a physical superposition mode of multiple layers of foam with different densities, interlayer interfaces are clear, obvious acoustic impedance mutation exists, sound waves are reflected at the interfaces, and the overall sound absorption efficiency is reduced; the adhesive layer becomes an acoustic short plate and is easy to age and lose efficacy, and the layering risk is high after long-term use. In addition, there are researches on filling inorganic nano particles (such as silicon dioxide, calcium carbonate and activated carbon) in a polyurethane matrix for improving the sound absorption performance of polyurethane, but the problems of poor compatibility, easy agglomeration, uneven dispersion, weak interface combination, low stress transmission efficiency, increased brittleness of the material and the like of the physically mixed or physically filled inorganic particles and the organic matrix exist, and the accurate control of the spatial distribution of the particles is lacking, so that an effective sound scattering network is difficult to form. In addition, the polyurethane foam is attached to the face of the ear for a long time, so that the problems of easy bacteria and fungi breeding, easy fatigue damage in the repeated compression-rebound process and the like are solved. Disclosure of Invention Aiming at the defects of the prior art, the application provides polyurethane with a sound absorption layer and a buffer layer coupled and application thereof in noise reduction earmuffs, wherein polysilsesquioxane/polyacrylate hybrid core-shell structure polyol and magnolol- (3-mercapto-1, 2-propylene glycol) adducts are added into polyurethane of different layers, and interface coupling is carried out by combining NCO indexes, so that the triple functions of sound absorption, buffering and antibiosis of the double-layer coupled polyurethane are realized. The invention is realized by the following technical scheme: The polyurethane coupling the sound absorption layer and the buffer layer comprises, by weight, 100 parts of isocyanate prepolymer, 10-20 parts of polysilsesquioxane/polyacrylat