Abstract: The present disclosure discloses a sound absorption material block having a gradient pore diameter from inside to outside, including: an outer portion having a first pore diameter; and an inner portion encapsulated by the outer portion, having a second pore diameter; the first pore diameter is in a range of 20-200 ?m, the second pore diameter is in a range of 1-20 ?m; the sound absorption material block has a thickness in a range of 0.5-5 mm. The sound absorption material block in the present disclosure has lower damping property and higher intensity.

Abstract: A rubber voice diaphragm including distortion improving agent with mass percentage of 0.3% to 60%. The distortion improving agent is macromolecule polymer with hyperbranched structure, and has specific chemical crosslinking points with mass percentage of 0.01% to 15%. Branches of the macromolecule polymer with hyperbranched structure are long or short chain structures prepared by active polymerization. Each distortion improving agent molecule includes at least three long or short chain structures, and number-average molecular weight of the long chain structure or the short chain structure is 200 to 50000. The specific chemical crosslinking points are distributed at the outermost end of the hyperbranched structure, and the adjacent specific chemical crosslinking points are separated by at least six carbon atoms.

Abstract: A method for preparing a sound-absorbing material block, the method includes steps of mixing raw materials to prepare a mixed paste and filling the mixed paste into a speaker rear cavity of a speaker provided in advance, and then sequentially performing drying treatment and dehydration treatment to obtain the sound-absorbing material block. On one hand, the sound-absorbing material block is prepared by mixing the porous material, the gelling agent, the cross-linking agent, the binder, the foaming agent, and the solvent, so that the prepared sound-absorbing material block has high strength, is not prone to breakage, and has good performance. And on an other hand, the sound-absorbing material block adapted to the rear cavity of the speaker is directly prepared, so that steps of cutting and filling can be omitted, and a filling process is simplified.

Abstract: A rubber voice diaphragm is composed of main rubber, distortion improving agent, vulcanizing agent, accelerant, reinforcing filler, and other processing aids. The distortion improving agent is a substance with number-average molecular weight ranging from 1000 to 1000000, and structure of distortion improving agent has special chemical crosslinking points that participate in rubber vulcanization reaction. The special chemical crosslinking points are present in amount of 0.01% to 30% based on mass of distortion improving agent. The distortion improving agent is added in amount of 0.1% to 100% based on mass of main rubber. Frequency bands for improving distortion of distortion improving agent range from 0.1 HZ to 20000 Hz. In the rubber voice diaphragm provided in the present disclosure, a special distortion improving agent is selected, which solves the problems of molecular migration, poor reliability, a high modulus change rate, and poor rubber mechanical properties existing in traditional modified method.

Abstract: A speaker box and an electronic device are provided. The speaker box includes a housing, a speaker unit, and a sound-absorbing foam sheet. The housing includes an accommodating space. The speaker unit is accommodated in the accommodating space. The speaker unit is enclosed with the housing to define a rear cavity. The sound-absorbing foam sheet is adhered to an inner wall of the rear cavity. The sound-absorbing foam sheet includes a foam block and sound-absorbing powders adhered in the foam block. Through the sound-absorbing foam sheet, resonant frequency of the speaker box is effectively reduced, acoustic performance of the speaker box is improved, a structure of the speaker box is stable, and a preparation of the speaker box is simple.

Abstract: The present invention provides a speaker including a chamber filled with the sound absorbing material. The chamber is also filled with expandable foam that is triggered to expand in volume to limit the movement of the sound absorbing material in the chamber. The speaker provided by the present invention improves the reliability of the filled sound absorbing material.

Abstract: A reel mechanism and a winding device for a flexible copper clad laminate includes a rotating roller, a winding belt wound on the rotating roller for winding the flexible copper clad laminate, first and second limit structures arranged one side of the winding belt away from the rotating roller. A space between the first limit structures and the second limit structures accommodates the flexible copper clad laminate. When the winding belt is wound with multiple layers outside the rotating roller, adjacent layers of the winding belt are spaced apart by the first and second limit structures. Since a protruding height of the first limit structures is equal to a protruding height of the second limit structures, and intervals between adjacent layers of a composite coil formed by the winding belt and the flexible copper clad laminate are equal, which avoids adhesion and copper foil surface oxidation.

Abstract: The present invention provides a resin composition, a polyimide preparation method and related products. The resin composition consists of the following components: polyimide which is a soluble product generated by a reaction of monomer groups containing aromatic tetracarboxylic dianhydride and diacid dihydrazide, a main chain of the polyimide containing a hydrazide structure; and a curing agent which comprises one or more of multifunctional epoxy resin, a primary amine compound with three or more functional groups, and polyisocyanate, wherein a mass ratio of the curing agent to the soluble polyimide is 0-20%. The resin composition in the present invention utilizes the hydrazide structure in the polyimide to prepare an adhesive with excellent heat resistance, adhesive performance, and solubility, overcoming the shortcomings of existing polyimide-based adhesives during processing or application.

Abstract: The present disclosure provides a thermally-conductive and sound-absorbing composite material and a preparation method thereof and a speaker. The thermally-conductive and sound-absorbing composite material includes the following components by mass percent: 10-80% of an activated carbon felt, 5-75% of zeolite particles, 1-80% of graphene particles and 5-40% of an adhesive, where the activated carbon felt serves as a skeleton; the graphene particles are bonded to an activated carbon fiber surface of the activated carbon felt through the adhesive; and the zeolite particles are bonded to surfaces of the graphene particles and the activated carbon fiber surface of the activated carbon felt through the adhesive. The thermally-conductive and sound-absorbing composite material provided by the present disclosure has excellent heat conductivity, excellent sound absorption performance, and a desirable mechanical strength.

Abstract: A sound-absorbing material, a manufacturing method thereof and a speaker are provided. The sound-absorbing sheet includes a sheet body and a bonding layer. The sheet body is prepared by coating and freeze-drying a slurry, and the slurry is obtained by mixing sound-absorbing powder, a binder, a thickening agent and a foaming agent with a solvent. The sheet body has thickness of 0.05 mm-2 mm; the sheet body has needle-like pores with a pore size of 1 ?m-100 ?m. The bonding layer is configured to fixedly install the sound-absorbing sheet. By needle-like pores, the sound-absorbing sheet has high sound absorption performance, and low damping performance. The sheet can be designed into different shapes and thicknesses for rear cavities of different speakers, so the application range is wide. Because of bonding layer, while aging risk of a structure in the speaker is lowered, the sound-absorbing sheet has higher strength.

Abstract: The present disclosure provides paste for preparing a capillary structure, a preparation method of the paste, a preparation method of the capillary structure, and a vapor chamber. The paste includes metal powder with a mass fraction of 20-80%, compound powder with a mass fraction of 10-70%, adhesive with a mass fraction of 0.1-20%, and organic solvent with a mass fraction of 5-40%. The organic solvent dissolves the adhesive. The adhesive adheres the metal powder and the compound powder to a vapor chamber. The metal powder forms a matrix of the capillary structure in the vapor chamber after drying. The compound powder forms grooves and through holes on the matrix. The capillary structure has a controllable size to meet size requirements of the vapor chamber. The capillary structure includes the through holes and the grooves, which improves liquid absorption performance and improves heat transfer performance.

Abstract: A molecular sieve material for sound absorption and a method for preparing the same are disclosed. There is a pore structure formed by mesopores with a pore size between 10 and 50 nm on a surface of the molecular sieve material, and the mesopores have a pore volume above 0.25 cm3/g. The molecular sieve material is obtained by etching and modifying a molecular sieve raw powder with an aqueous solution of an inorganic alkali. Since an alkali solution can selectively remove part of silicon elements in a skeleton structure of molecular sieve, more and more pore structures are generated in molecular sieve particles, which can increase the specific surface area and thus enhance the adsorption capacity of the molecular sieve for gases. The frequency reduction performance of the speaker can be significantly improved after the rear cavity of the speaker is filled with the molecular sieve material.

Abstract: The present invention discloses a copper paste for printing a capillary structure and a preparation method thereof. The copper paste consists of copper powder, a high molecular polymer, a solvent, a binder, a dispersant, a leveling agent, a tackifier and an antioxidant. Through the limitation on the copper powder and the high molecular polymer in the copper paste of the present invention, the prepared copper paste can be applied to a carrier of a vapor chamber by blade coating or screen printing, and then used as a wick after binder removal and sintering in hydrogen or hydrogen-nitrogen mixed gas, so as to reduce device investment and cost; and the thickness of the wick can be accurately controlled to be 10-100 ?m, the structural strength is higher, the water absorption performance and the heat transfer performance are better, and the demand for miniaturization of electronic products is met.

Abstract: The present invention discloses a sound absorption material including an organic frame material; a binder; a thickener; and a plurality of sound absorption grains attached to the organic frame material via the binder, having a grain size in a range of 10-100 ?m. The stability and the sound absorption performance of the sound absorption material have been effectively improved.

Abstract: This application provides a benzoxazine resin and a preparation method thereof, and an adhesive. The benzoxazine resin is represented by the following formula: where R1, R2, R3 and R4 are each independently selected from the group consisting of —H, alkyl, alkoxy, cycloalkyl, and aryl, and at least one of R1, R2, R3 and R4 is —H; X1 is an alkyl or/and alkoxy containing a long chain structure in main chain or side chain; X2 is one or more selected from alkyl, ether group, alkoxy, alkyl ester group, carbonyl, sulfone group, and thioether group; and n is 1-150.

Abstract: This application provides a resin composition and an adhesive. The resin composition is composed of benzoxazine and a resin. The benzoxazine is synthesized from a primary amine-capped flexible polyimide oligomer, an aldehyde and a monofunctional phenolic compound. The resin contains one or more of an epoxy resin, a maleimide resin, and a cyanate ester resin containing two or more functional groups. The resin is 0.1%-70% by weight of the benzoxazine.

Abstract: A sound-absorbing material block, a method for preparing the same and application thereof are provided. The sound-absorbing material block includes three-dimensional open-cell foam, sound-absorbing material powder, a binder, a gel, and a cross-linking agent. The sound-absorbing material powder is bonded to each other and connected to the three-dimensional open-cell foam by means of the gel, the cross-linking agent, and the binder, by mass of the sound-absorbing material powder, the gel accounts for 1 wt % to 5 wt % of the sound-absorbing material powder, and the binder accounts for 1 wt % to 8 wt % of the sound-absorbing material powder, and by mass of the gel, the cross-linking agent accounts for 1 wt % to 10 wt % of the gel. The sound-absorbing material block according to the present disclosure reduces an additive amount of the binder, and significantly improves sound-absorbing performance and strength of the material block.

Abstract: A molecular sieve sound-absorbing material, a method for preparing the same, and a speaker. The sound-absorbing material includes a modifying molecular sieve and a binder, the mass of the binder accounts for 2% to 10% of the mass of the modifying molecular sieve, the modifying molecular sieve is obtained by performing phosphorus modification on a molecular sieve, a mass ratio of silicon to aluminum in the molecular sieve is (50-800):1, and a molar ratio of phosphorus to aluminum in the modifying molecular sieve is (0.1-2):1. The sound-absorbing material includes a phosphorus-modifying molecular sieve. Application of the modifying molecular sieve to the sound-absorbing material can ensure that the sound-absorbing material can also maintain good sound absorption performance under high-temperature and high-humidity conditions.

Abstract: Provided is a sound-absorbing material, including a metal-organic framework material having a microporous structure. The metal-organic framework material includes a coordinated metal M and organic framework materials (OFs) coordinated with the coordinated metal. The microporous structure includes a plurality of uniformly distributed micropores, and a diameter of each of the plurality of micropores is within a range of 0.3 nm to 1.2 nm. The sound absorbing material including the metal-organic framework material can be added into a speaker to increase the acoustic compliance of air in a rear cavity of the speaker, thereby improving the performance of the speaker in a low frequency range.

Abstract: A porous composite sound-absorbing material and a method for preparing the same are provided. The porous composite sound-absorbing material includes activated carbon cotton felt, zeolite particles, and an adhesive. The activated carbon cotton felt can bond the zeolite particles to fiber surfaces thereof by means of the adhesive, so that the zeolite particles are evenly dispersed and fixed and achieve optimal sound absorption performance. Meanwhile, a large number of micro-pore structures on surfaces thereof can act synergistically with the zeolite particles, so that the porous composite sound-absorbing material has significantly better sound absorption performance than the two and has extremely high cost performance. During the preparation process, the activated carbon cotton felt after treatments, is successfully compounded with the zeolite particles with more excellent sound absorption performance, so that the sound absorption performance is significantly improved and the cost performance is extremely high.