Loudspeaker cone and preparation method and application thereof

Abstract

The invention provides a loudspeaker cone and a preparation method and application thereof. The loudspeaker cone comprises a first cone layer, a second cone layer and a damping glue layer arranged between the first cone layer and the second cone layer. The inner diameter of the first cone layer is smaller than that of the second cone layer; the preparation raw materials of the first cone layer comprise plant fiber pulp and glass fibers; the preparation raw materials of the damping glue layer comprise damping glue and a thermochromic material; and the mass percentage content of the damping glue layer in the loudspeaker cone is 3-35%. Through the design and mutual compounding of the first paper cone layer, the second paper cone layer and the damping glue layer, the loudspeaker paper cone has high modulus, high strength, high interlayer binding force and appropriate damping characteristics, is excellent in acoustic performance and shows a good visual effect. The loudspeaker cone is used for the loudspeaker, the frequency response range of the loudspeaker can be expanded, the high-frequency segmentation vibration of the loudspeaker is suppressed, and the frequency response curve of the loudspeaker is smoother.

Description

Technical Field

[0001] The invention belongs to the technical field of loudspeakers, and in particular relates to a loudspeaker paper cone and a preparation method and application thereof. Background Art

[0002] The working principle of the speaker is that when an alternating audio current is passed through the voice coil connected to the diaphragm and the centering support, the voice coil vibrates under the action of electromagnetic force in the magnetic field, thereby driving the paper cone to push the air to vibrate and produce sound. The characteristics of the paper cone directly affect the electroacoustic parameters, sound quality and service life of the speaker, and it is a key component of the vibration system.

[0003] The paper cone material should usually meet the following requirements: a. The density of the material should be small; b. The Young's modulus of the material should be large; c. It should have appropriate internal damping. Improving the Young's modulus of the paper cone helps to reduce the split vibration and phase distortion of the unit and improve the frequency response range of the unit. Appropriate internal damping can also suppress the split vibration of the paper cone and make the frequency response characteristics flatter. Therefore, high strength and appropriate damping are the goals pursued by high-quality paper cones.

[0004] The damping of the paper cone is generated by the friction between the fibers to generate heat, which requires that the bonding force between the fibers is weak to generate internal friction. Weak bonding will lead to a decrease in the strength of the paper cone, affecting the performance of the speaker. Therefore, the modulus and damping of the paper cone are two negatively correlated performance indicators. How to achieve high modulus and appropriate damping has always been a research hotspot in the speaker industry.

[0005] CN115897297A discloses a high damping paper cone, which contains the following components: 30-50 parts of bleached sulphate wood pulp, 10-30 parts of Manila hemp pulp, 10-30 parts of bark, and 10-30 parts of Tencel fiber; the paper cone has high strength and appropriate damping. CN117542335A discloses a method for preparing a sound-generating material, which is prepared by using foam metal and / or foam metal alloy as the base material of drum paper or membrane; porous foam metal and its alloy base have low density, light weight, large specific surface area, small vibration inertia, high transient response synchronization, strong impact absorption ability, and can show material characteristics of withstanding large compressive strain under stress, which helps to avoid nonlinear distortion caused by forced vibration. CN205596316U discloses a foamed PP sandwich cone, wherein the cone cone is composed of an inner layer, an outer layer and an intermediate layer, the intermediate layer is a foamed PP layer, the inner layer and the outer layer are both paper cone layers, and the surfaces of the two paper cone layers facing the foamed PP layer are respectively covered with the inner and outer surfaces of the foamed PP layer by a PP special adhesive film; the cone has a large rigidity and can meet the use requirements of high-power speakers. CN106930134A discloses a method for making speaker drum paper, including pulping, batching, papermaking, neck reinforcement, varnish spraying, glue spraying or throwing glue, cutting, molding, edge gluing, laminating and reinforcing steps, so that the fluffiness, damping, rigidity and flexibility of the drum paper obtained are improved to a certain extent, and a better sound effect is obtained.

[0006] In general, the common methods used by technical personnel in the industry to improve the damping and other related properties of paper cones are: ① By adjusting the formula of the paper cone, adding fibers with good damping properties such as wool and Tencel fiber to the paper cone; ② Using porous materials and foaming materials to absorb longitudinal sound waves to improve the damping of the paper cone; ③ Spraying damping glue on the surface of the paper cone. However, the effect of improving the damping performance of the paper cone by adjusting the pulp formula alone is relatively limited; when using sheet-like porous materials and foam materials to hot-press and shape the paper cone, this method is limited by the elongation rate of the porous materials and foam materials, and it is impossible to form a paper cone with a large taper and complex surface; and spraying damping glue will cause the moisture resistance of the paper cone to deteriorate, and it cannot adapt to use in a humid environment; in addition, the glue layer still has a certain viscosity after curing, and the paper cone with the glue layer exposed will adhere to dust, causing the vibration mass of the speaker to increase, affecting the performance of the speaker.

[0007] Therefore, developing a paper cone with high modulus, suitable damping and excellent acoustic properties is an urgent problem to be solved in this field. Summary of the invention

[0008] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a speaker paper cone and a preparation method and application thereof. Through the design and joint action of the first paper cone layer, the second paper cone layer and the damping glue layer, the speaker paper cone has a high modulus and inter-layer bonding strength, moderate damping, good acoustic properties, and can provide good visual effects.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a speaker paper cone, comprising a first paper cone layer, a second paper cone layer, and a damping glue layer arranged between the first paper cone layer and the second paper cone layer; the inner diameter of the first paper cone layer is less than the inner diameter of the second paper cone layer; the raw materials for preparing the first paper cone layer include a combination of plant fiber pulp and glass fiber; the raw materials for preparing the damping glue layer include a combination of damping glue and thermochromic material; the mass percentage of the damping glue layer in the speaker paper cone is 3-35%.

[0011] The speaker paper cone provided by the present invention has a three-layer "sandwich composite structure". By arranging a damping rubber layer between two paper cone layers, on the one hand, suitable damping characteristics are provided, and by adjusting the mass content of the damping rubber layer, the modulus and damping parameters of the speaker paper cone can be controlled; on the other hand, the damping rubber layer is sealed by the two paper cone layers to prevent the damping rubber layer from being directly exposed to the outside and causing moisture absorption and dust adhesion; moreover, the damping rubber layer contains a thermochromic material, which can repeatedly change color with changes in temperature, providing better visual appeal and functionality. The first paper cone layer contains a combination of plant fiber and glass fiber, which can not only increase the strength of the first paper cone layer, but also increase its light transmittance, so that the color of the damping rubber layer and its color change effect can be presented through the first paper cone layer, which has a good visual effect. In addition, the first paper cone layer and the second paper cone layer of the present invention are prepared by wet papermaking, and can form a paper cone blank with a large taper and complex curved surface.

[0012] In summary, the present invention, through the design and mutual compounding of the first paper cone layer, the second paper cone layer, and the damping adhesive layer, makes the speaker paper cone have high modulus, high strength, high-layer bonding force and suitable damping characteristics, excellent acoustic performance, and presents good visual effects, providing users with more personalized and intelligent choices, meeting people's demand for personalized and intelligent products, and expanding the application range of paper cone products, such as smart homes, car interiors and other fields. The speaker paper cone is used for speakers, which can expand the frequency response range of the speakers, suppress the high-frequency segmentation vibration of the speakers, and make the frequency response curve of the speakers smoother.

[0013] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0014] Preferably, the plant fiber pulp includes any one of wood pulp, bamboo pulp, cotton pulp, and hemp pulp, or a combination of at least two of them, and wood pulp and / or cotton pulp are more preferred.

[0015] Preferably, the raw materials for preparing the first paper cone layer also include a first waterproof agent, so as to provide excellent waterproof and moisture-proof properties and prevent the damping glue from penetrating into the interior of the paper layer fibers.

[0016] Preferably, the raw materials for preparing the first paper cone layer include the following components in parts by mass:

[0017]

[0018] Among them, the mass proportion of the first wood pulp is 50-70 parts, for example, it can be 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, 65 parts or 68 parts, as well as specific point values ​​between the above point values. Due to limited space and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0019] The mass proportion of the cotton pulp is 20-35 parts, for example, it can be 22 parts, 25 parts, 28 parts, 30 parts, 32 parts or 34 parts, as well as specific point values ​​between the above point values. Due to limited space and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0020] The mass proportion of the glass fiber is 5-15 parts, for example, it can be 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts or 14 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0021] The mass proportion of the first waterproofing agent is 0.5-3 parts, for example, it can be 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts or 2.8 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0022] Preferably, the first wood pulp comprises bleached kraft pulp and / or unbleached kraft pulp, and more preferably bleached kraft pulp (BKP).

[0023] Preferably, the length of the glass fiber is 2-8 mm, for example, it can be 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, 5 mm, 5.2 mm, 5.5 mm, 5.8 mm, 6 mm, 6.5 mm, 6.8 mm, 7 mm or 7.5 mm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 4-6 mm is further preferred.

[0024] Preferably, the first water repellent comprises cationic styrene acrylic emulsion and / or paraffin emulsion.

[0025] In order to make the sound cone have a significant color development / color change effect, a common method in the prior art is to provide an additional color development / color change coating on the surface of the sound cone after the sound cone is formed, thereby obtaining the color development / color change effect. The present invention disperses the thermochromic material in the damping glue layer, so that the color change is transmitted through the first paper cone layer, thereby greatly reducing the glue content of the entire paper cone.

[0026] Preferably, the raw materials for preparing the damping rubber layer include the following components in parts by mass:

[0027] Damping glue 85-95 parts

[0028] 5-15 parts of thermochromic material.

[0029] Among them, the mass parts of the damping glue are 85-95 parts, for example, it can be 86 parts, 88 parts, 90 parts, 91 parts, 92 parts, 93 parts or 94 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 88-92 parts are further preferred.

[0030] The mass proportion of the thermochromic material is 5-15 parts, for example, it can be 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts or 14 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 8-12 parts are further preferred.

[0031] Preferably, the damping glue comprises water-based acrylic polymer and / or water-based polyurethane.

[0032] Preferably, the thermochromic material includes thermochromic powder.

[0033] As a preferred technical solution of the present invention, the thermochromic material is a product processed by microcapsule technology, has a powdery appearance, and can repeatedly change color as the temperature rises and falls.

[0034] Preferably, the color concentration of the thermochromic material gradually decreases from low temperature to high temperature until it becomes transparent; illustratively, the color of the thermochromic material at low temperature includes red, orange, green, blue, purple, black, etc.; the thermochromic material can adopt a single type / color of thermochromic powder, or a combination of multiple (≥2) different types / colors of thermochromic powder, and its specific color and type can be selected according to appearance requirements.

[0035] Preferably, the initial color change temperature of the thermochromic material is 30-38°C (for example, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, etc.), and the color change completion temperature is 40-48°C (for example, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, etc.); further preferably, the initial color change temperature is 36°C, and the color change completion temperature is 45°C.

[0036] It should be noted that the water-based acrylic polymer, water-based polyurethane and thermochromic powder can all be commercially available products.

[0037] Preferably, the raw materials for preparing the second paper cone layer include a combination of a second wood pulp and a second waterproofing agent. The introduction of the waterproofing agent provides excellent waterproof and moisture-proof properties on the one hand, and can prevent the damping glue spin-coated on the second paper cone blank from penetrating into the paper layer fibers on the other hand.

[0038] Preferably, the raw materials for preparing the second paper cone layer include the following components in parts by mass:

[0039] Second wood pulp 100 parts

[0040] The second waterproofing agent is 0.1-5 parts.

[0041] Among them, based on 100 parts by mass of the second wood pulp, the mass of the second waterproofing agent is 0.1-5 parts, for example, it can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts, 4 parts, 4.2 parts, 4.5 parts or 4.8 parts, as well as specific point values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0.5-3.8 parts is further preferred.

[0042] Preferably, the second wood pulp comprises bleached kraft pulp and / or unbleached kraft pulp, further preferably unbleached kraft pulp (UKP).

[0043] Preferably, the second water repellent comprises a cationic styrene acrylic emulsion and / or a paraffin emulsion.

[0044] As a preferred technical solution of the present invention, the modulus and damping parameters of the paper cone are adjusted by adjusting the mass and thickness of the first paper cone layer, the second paper cone layer, and the damping glue layer, so as to obtain the speaker paper cone having high modulus, high inter-layer bonding strength, suitable damping and excellent acoustic performance.

[0045] Preferably, the mass percentage of the first paper cone layer in the speaker paper cone is 18-38%, for example, it can be 20%, 22%, 25%, 28%, 30%, 32%, 35% or 37%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 20-35% is further preferred.

[0046] In the present invention, the mass percentage of the damping rubber layer in the acoustic paper cone is 3-35%, for example, it can be 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32% or 34%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 5-30% is further preferred.

[0047] Preferably, the mass percentage of the second paper cone layer in the speaker paper cone is 35-65%, for example, it can be 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62% or 64%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range, and 40-60% is further preferred.

[0048] Preferably, the thickness of the first paper cone layer is 0.1-0.35 mm, for example, it can be 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.32 mm or 0.34 mm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0049] And / or, preferably, the thickness of the damping rubber layer is 0.02-0.15 mm, for example, it can be 0.03 mm, 0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm or 0.14 mm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0050] And / or, preferably, the thickness of the second paper cone layer is 0.2-0.5 mm, for example, it can be 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.32 mm, 0.35 mm, 0.38 mm, 0.4 mm, 0.42 mm, 0.45 mm or 0.48 mm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0051] Preferably, the Young's modulus of the speaker cone is ≥3 GPa, for example, it may be 3.2 GPa, 3.5 GPa, 3.8 GPa, 4 GPa, 4.2 GPa, 4.5 GPa, 4.8 GPa or 5 GPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 3.3-4.5 GPa is further preferred.

[0052] Preferably, the loss factor of the speaker cone is ≥0.04, for example, it can be 0.045, 0.048, 0.05, 0.052, 0.055, 0.058, 0.06, 0.062, 0.065, 0.068, 0.07, 0.072, 0.075, 0.078, 0.08, 0.082, 0.085, 0.088, 0.09, 0.092, 0.095, 0.098, 0.1, 0.11 or 0.12, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0.053-0.1 is further preferred.

[0053] Preferably, the Z-direction tensile strength of the speaker cone is ≥ 0.8 N / mm 2 , for example, it can be 0.82N / mm 2 , 0.85N / mm 2 , 0.9N / mm 2 , 0.95N / mm 2 , 1N / mm 2 , 1.05N / mm 2 , 1.1N / mm 2 , 1.15N / mm 2 , 1.2N / mm 2 , 1.25N / mm 2 , 1.3N / mm 2 , 1.35N / mm 2 , 1.4N / mm 2 or 1.45N / mm 2, as well as specific point values ​​between the above point values, due to space limitations and for the sake of brevity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0054] In a second aspect, the present invention provides a method for preparing a speaker cone as described in the first aspect, the preparation method comprising:

[0055] Provide first paper pulp, second paper pulp and damping glue respectively;

[0056] Passing the first paper pulp through a mold to form a first paper cone wet blank, and passing the first paper cone wet blank through a first hot press to obtain a first paper cone blank;

[0057] Passing the second paper pulp through a mold to form a second paper cone wet blank, and passing the second paper cone wet blank through a second hot press to obtain a second paper cone blank;

[0058] Applying the damping adhesive liquid on the surface of the second paper cone blank and drying it to obtain a preform with a damping adhesive layer;

[0059] The first paper cone blank and the preform are assembled and then subjected to a third hot pressing to obtain the speaker paper cone.

[0060] In the preparation method provided by the present invention, the first paper cone blank and the second paper cone blank are prepared by wet papermaking, and a paper cone blank with a large taper and a complex curved surface can be formed; further, the damping glue is applied to the surface of the second paper cone blank, and after the damping glue is dried and solidified, it is assembled and compounded with the first paper cone blank on the upper layer, and hot-pressed in a hot pressing mold for final shaping. The solidified damping glue still has adhesive force after being heated, and can be bonded to the first paper cone blank on the upper layer without the need to add additional adhesive, thereby reducing the overall glue content of the paper cone, so that the speaker paper cone achieves an excellent balance effect in terms of high modulus and damping.

[0061] Preferably, the first pulp comprises a combination of plant fiber pulp and glass fiber, and further preferably comprises a combination of first wood pulp, cotton pulp, glass fiber and a first waterproofing agent.

[0062] Preferably, the preparation method of the first paper pulp comprises: mixing first wood pulp and cotton pulp and beating the mixture to obtain pulp A; and uniformly mixing the pulp A with glass fiber and a first waterproofing agent to obtain the first paper pulp.

[0063] Preferably, the first wood pulp and cotton pulp are dispersed in water and beaten to obtain the slurry A.

[0064] Preferably, the beating degree of the slurry A is 18-40°SR, for example, it can be 20°SR, 22°SR, 24°SR, 25°SR, 28°SR, 30°SR, 32°SR, 34°SR, 35°SR or 38°SR, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0065] Preferably, the slurry A is diluted with water, and then mixed with glass fiber and the first waterproofing agent and stirred evenly to obtain the first paper pulp.

[0066] Preferably, the second pulp comprises a combination of a second wood pulp and a second water-proofing agent.

[0067] Preferably, the method for preparing the second paper pulp comprises: beating the second wood pulp to obtain pulp B; and uniformly mixing the pulp B with a second waterproofing agent to obtain the second paper pulp.

[0068] Preferably, the second wood pulp is dispersed in water and beaten to obtain the slurry B.

[0069] Preferably, the beating degree of the slurry B is 22-30°SR, for example, it can be 23°SR, 24°SR, 25°SR, 26°SR, 27°SR, 28°SR or 29°SR, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0070] As a preferred technical solution of the present invention, the pulping (preparation of slurry A and slurry B) is performed by a Valley pulping machine.

[0071] Preferably, the slurry B is diluted with water, mixed with a second waterproofing agent and stirred evenly to obtain the second paper pulp.

[0072] Preferably, the damping adhesive liquid comprises a combination of damping adhesive and a thermochromic material.

[0073] Preferably, the preparation method of the damping adhesive liquid comprises: mixing and evenly dispersing the damping adhesive and the thermochromic material to obtain the damping adhesive liquid.

[0074] Preferably, the dispersing is performed in a centrifugal homogenizer.

[0075] Preferably, the rotation speed of the centrifugal homogenizer is 500-2000 rpm, for example, it can be 800 rpm, 1000 rpm, 1200 rpm, 1400 rpm, 1500 rpm, 1600 rpm or 1800 rpm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0076] Preferably, the dispersion time is 0.5-10 min, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min or 9 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 1-5 min is further preferred.

[0077] Preferably, the first paper pulp is filtered through a paper basin water filter mold to obtain a first paper basin wet blank; and / or the second paper pulp is filtered through a paper basin water filter mold to obtain a second paper basin wet blank.

[0078] Preferably, the temperatures of the first hot pressing and the second hot pressing are independently 180-230°C, for example, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C or 225°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0079] As a preferred technical solution of the present invention, the first paper basin wet blank is subjected to the first hot pressing to obtain the first paper basin blank, and the second paper basin wet blank is subjected to the second hot pressing to obtain the second paper basin blank. During the hot pressing process, the free water and bound water in the paper basin wet blank evaporate, and hydrogen bonds are formed between the fibers; at the same time, the latex particles in the waterproofing agent spread out due to the thermoplastic effect, forming a film on the fiber surface and between the fibers, giving the paper basin blank excellent waterproofness, while preventing the damping glue coated on the surface of the paper basin blank from penetrating into the paper basin fibers.

[0080] Preferably, the time for the first hot pressing and the second hot pressing is independently 30-80s, for example, it can be 35s, 40s, 45s, 50s, 55s, 60s, 65s, 70s or 75s, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 40-60s is further preferred.

[0081] Preferably, the coating method comprises spin coating.

[0082] Preferably, the spin coating method includes: fixing the second paper cone blank on the base of a glue spreader, placing a damping glue liquid in the middle of the second paper cone blank, and generating centrifugal force and gravity when the base of the glue spreader drives the second paper cone blank to rotate, so that the damping glue liquid placed in the middle of the second paper cone blank is completely distributed on the surface of the second paper cone blank.

[0083] Preferably, the spin coating rotation speed is 400-3200rpm, for example, it can be 500rpm, 600rpm, 800rpm, 1000rpm, 1200rpm, 1500rpm, 1800rpm, 2000rpm, 2200rpm, 2500rpm, 2800rpm or 3000rpm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 500-3000rpm is further preferred.

[0084] In the present invention, by setting different spin coating speeds, the thickness of the damping glue layer on the surface of the second paper cone blank can be controlled. If the spin coating speed is too low (<400rpm), the damping glue cannot flow on the surface of the second paper layer blank, and the damping glue layer cannot be formed; if the spin coating speed is too high (>3200rpm), the damping glue is thrown out due to the excessive centrifugal force, and only a small amount of damping glue remains on the surface of the second paper cone blank, resulting in a lower loss factor of the speaker paper cone and a weaker interlayer bonding force.

[0085] Preferably, the drying temperature is 60-100°C, for example, it can be 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or 95°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 75-85°C is further preferred.

[0086] Preferably, the drying time is 20-120 min, for example, it can be 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min or 110 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0087] Preferably, the temperature of the third hot pressing is 170-230°C, for example, it can be 178°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C or 225°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0088] Preferably, the third hot pressing is performed under the condition of cylinder supercharging.

[0089] In the present invention, the first hot pressing and the second hot pressing rely on the weight of the hot pressing mold and the mold gap to control the thickness of the first paper cone blank and the second paper cone blank. Different from the first hot pressing and the second hot pressing, the third hot pressing needs to be pressurized by a cylinder, so that the damping glue layer and the two paper cone layers have a better bonding effect, giving the speaker paper cone a high modulus and high-layer bonding strength.

[0090] Preferably, the cylinder boost pressure is 0.1-0.4MPa, for example, it can be 0.12MPa, 0.15MPa, 0.18MPa, 0.2MPa, 0.22MPa, 0.25MPa, 0.28MPa, 0.3MPa, 0.32MPa, 0.35MPa or 0.38MPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0.15-0.25MPa is further preferred.

[0091] Preferably, the time of the third hot pressing is 30-80s, for example, it can be 35s, 40s, 45s, 50s, 55s, 60s, 65s, 70s or 75s, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0092] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0093] The first wood pulp and cotton pulp are mixed and then beaten to obtain a slurry A with a beating degree of 18-40° SR; the slurry A is evenly mixed with glass fiber and a first waterproofing agent to obtain a first paper pulp;

[0094] Beating the second wood pulp to obtain a slurry B with a beating degree of 22-30° SR; and uniformly mixing the slurry B with a second waterproofing agent to obtain a second paper pulp;

[0095] The damping glue and the thermochromic material are mixed and dispersed evenly to obtain a damping glue liquid;

[0096] filtering the first paper pulp through a paper basin water filter mold to obtain a first paper basin wet blank, and hot pressing the first paper basin wet blank at 180-230° C. for 30-80 seconds to obtain a first paper basin blank;

[0097] filtering the second paper pulp through a paper basin water filter mold to obtain a second paper basin wet blank, and hot pressing the second paper basin wet blank at 180-230° C. for 30-80 seconds to obtain a second paper basin blank;

[0098] Spin-coating the damping adhesive on the surface of the second paper cone blank at a rotation speed of 400-3200 rpm, and drying and curing at 60-100° C. to obtain a preform with a damping adhesive layer;

[0099] The first paper cone blank and the preform are assembled, and hot pressed for 30-80s at 170-230°C and a cylinder pressure of 0.1-0.4MPa to obtain the speaker paper cone.

[0100] In a third aspect, the present invention provides a speaker, comprising the speaker cone as described in the first aspect.

[0101] Compared with the prior art, the present invention has the following beneficial effects:

[0102] (1) The speaker paper cone provided by the present invention has a "sandwich composite structure" in which a damping rubber layer is arranged between two paper cone layers to provide suitable damping characteristics. At the same time, the damping rubber layer is sealed by the two paper cone layers to prevent the damping rubber layer from being directly exposed to the outside and absorbing moisture and sticking dust. At the same time, the damping rubber layer contains a thermochromic material, which can repeatedly change color with changes in temperature, and the color development / color change effect is presented through the first paper cone layer, providing better visual appeal and functionality.

[0103] (2) The present invention, through the design and joint action of the first paper cone layer, the second paper cone layer, and the damping rubber layer, enables the speaker paper cone to have high modulus, high strength, high-layer bonding force and suitable damping characteristics, excellent acoustic performance, and good visual effects, providing users with more personalized and intelligent choices, meeting people's demand for personalized and intelligent products, and expanding the application range of paper cone products. The speaker paper cone is used for a speaker, which can expand the frequency response range of the speaker, suppress the high-frequency segmentation vibration of the speaker, and make the frequency response curve of the speaker smoother. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Figure 1 A schematic diagram of the structure of a speaker cone provided in a specific embodiment;

[0105] Among them, 11 is a first paper cone layer, 12 is a damping rubber layer, and 13 is a second paper cone layer. DETAILED DESCRIPTION

[0106] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0107] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0108] "Optionally", "optionally" or "either" means that the subsequently described matter or event can or cannot occur, and that the description includes cases where the event occurs and cases where it does not.

[0109] In the present invention, the features defined as "first" or "second" may include one or more of the features explicitly or implicitly, and are used to distinguish and describe the features, without distinction of order or importance. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0110] In a specific embodiment, the structural diagram of the speaker cone is as follows: Figure 1 As shown, it includes a first paper cone layer 11, a second paper cone layer 13, and a damping glue layer 12 disposed between the first paper cone layer 11 and the second paper cone layer 13; the inner diameter of the first paper cone layer 11 is less than the inner diameter of the second paper cone layer 13; the raw material for preparing the first paper cone layer 11 includes a combination of plant fiber pulp and glass fiber; the raw material for preparing the damping glue layer 12 includes a combination of damping glue and thermochromic material. The mass percentage of the damping glue layer 12 in the speaker paper cone is 3-35%.

[0111] In the following specific implementations of the present invention, the testing methods for various parameters of the speaker cone are as follows:

[0112] (1) Thickness of the first paper cone layer, the damping rubber layer, and the second paper cone layer: observed and measured by the VR-3000 microscope.

[0113] (2) The mass of the first cone layer, the damping rubber layer, and the second cone layer: The solid content of the first pulp is tested by the heating weight loss method, and the mass of the first cone wet blank obtained by filtration is weighed. The mass of the first cone layer is obtained by multiplying the mass and the solid content. The mass of the second cone layer is tested and calculated by the same method. The mass of the speaker cone is weighed, and the mass of the damping rubber layer is subtracted from the mass of the two cone layers.

[0114] (3) Young's modulus and loss factor: The strength of the speaker cone is characterized by Young's modulus, and the damping is characterized by the loss factor. The material parameter test module (MPM) in KLIPPEL R&D SYSTEM is used to test the Young's modulus of the cone to characterize its strength.

[0115] (4) Z-direction tensile strength: Indicates the interlayer bonding strength of the speaker cone, and is tested according to the method in ISO 15754 "Paper and paperboard - Determination of tensile strength in the Z direction".

[0116] The speaker paper cone and the preparation method thereof according to the present invention will be described in detail below by taking a plurality of embodiments as examples, but the speaker paper cone and the preparation method thereof according to the present invention are not limited to these embodiments.

[0117] In the following examples of the present invention, the specific information of the materials used is as follows:

[0118]

[0119]

[0120] Example 1

[0121] A speaker paper cone comprises a first paper cone layer, a second paper cone layer and a damping adhesive layer arranged between the first paper cone layer and the second paper cone layer;

[0122] The raw materials for preparing the first paper cone layer include the following components in parts by mass:

[0123]

[0124] The raw materials for preparing the damping rubber layer include, by mass:

[0125] Damping glue TR-16B 92 copies

[0126] 8 parts of thermochromic powder;

[0127] The raw materials for preparing the second paper cone layer include the following components in parts by mass:

[0128] UKP 100 copies

[0129] 3 parts of waterproofing agent;

[0130] The preparation method of the speaker cone is as follows:

[0131] (1) Dispersing BKP and cotton pulp in water according to the above formula, beating with a Wally beater to obtain a slurry A with a beating degree of 30° SR; diluting the slurry A with water, and mixing it with glass fiber and a waterproofing agent to obtain a first paper pulp;

[0132] Filtering the first paper pulp through a paper basin water filter mold to obtain a first paper basin wet blank, placing the first paper basin wet blank in a high-temperature mold, and hot pressing at 190° C. for 50 seconds to obtain a first paper basin blank;

[0133] (2) dispersing UKP in water according to the above formula, beating with a Wally beater to obtain a slurry B with a beating degree of 25° SR; diluting the slurry B with water, and mixing it with a waterproofing agent to obtain a second paper pulp;

[0134] filtering the second paper pulp through a paper basin water filter mold to obtain a second paper basin wet blank, placing the second paper basin wet blank in a high-temperature mold, and hot pressing at 190° C. for 50 seconds to obtain a second paper basin blank;

[0135] (3) Mix the damping glue and the thermochromic powder according to the above formula, and disperse them with a centrifugal homogenizer at a speed of 1000 rpm for 3 minutes to evenly disperse the thermochromic powder to obtain a damping glue solution;

[0136] The second paper cone blank is fixed on the base of the glue roller, the damping glue liquid is placed in the middle of the second paper cone blank, the damping glue liquid is spin-coated on the surface of the second paper cone blank at a speed of 2000 rpm, and dried and cured at 80° C. for 60 minutes to obtain a preform with a damping glue layer;

[0137] (4) The first paper cone blank and the preform are assembled from top to bottom, and after being centered, they are placed together in a hot pressing mold, and hot pressed for 40 seconds at 185° C. and a cylinder pressure of 0.2 MPa to obtain the speaker paper cone. The quality, thickness and performance parameters of each layer are shown in Table 2.

[0138] Examples 2-6, Comparative Examples 1-5

[0139] A speaker paper cone includes a first paper cone layer, a second paper cone layer, and a damping rubber layer disposed between the first paper cone layer and the second paper cone layer. Specific information is shown in Table 1 below; items not shown in Table 1 are the same as those in Example 1; in Table 1, the unit of dosage of each component is "part" (part by mass). The mass, thickness, and performance-related parameters of each layer of the speaker paper cone are shown in Table 2.

[0140] Table 1

[0141]

[0142] Example 7

[0143] A speaker paper cone comprises a first paper cone layer, a second paper cone layer and a damping rubber layer arranged between the first paper cone layer and the second paper cone layer. The raw materials for preparing the speaker paper cone are the same as those in Example 1. The only difference between the speaker paper cone and Example 1 is that the hot pressing molding in step (5) of the preparation method is not performed by cylinder pressurization. The other steps and process parameters are the same as those in Example 1.

[0144] Comparative Example 6

[0145] A speaker paper cone, which differs from Example 1 only in that the damping glue TR-16B in the damping glue layer is replaced with an equal mass of oily solvent glue 1126C (the main component is chloroprene rubber, and the solvent is ethyl acetate and butyl acetate), and the other components, amounts and preparation methods are the same as those in Example 1.

[0146] Comparative Example 7

[0147] A speaker paper cone, which differs from the first embodiment only in that the first paper cone layer is not provided; the materials of the second paper cone layer and the damping rubber layer are the same as those of the first embodiment.

[0148] Comparative Example 8

[0149] A speaker paper cone, which differs from Example 1 only in that no damping rubber layer is provided, and the materials of the first paper cone layer and the second paper cone layer are the same as those of Example 1; the preparation method thereof is as follows:

[0150] The same method as in Example 1 was used to form a first paper cone wet blank and a second paper cone wet blank, respectively. The two were then placed in a high-temperature mold and hot-pressed at 190° C. for 50 seconds to obtain a speaker paper cone.

[0151] In the aforementioned speaker cone, the relevant parameters of the mass, thickness and performance of each layer are shown in Table 2; in Table 2, "m1:m2:m3" represents the mass ratio of the first cone layer, the damping rubber layer and the second cone layer.

[0152] Table 2

[0153]

[0154]

[0155] According to Table 1 and Table 2, the present invention, through the design and compounding of the first paper cone layer, the second paper cone layer, and the damping adhesive layer, combined with a specific preparation method, makes the speaker paper cone have high Young's modulus and strength, high interlayer bonding force, and good damping performance and acoustic performance. The speaker paper cones of Examples 1-6 have a Young's modulus of 3.3-4.5 GPa, a loss factor of 0.053-0.095, and a Z-direction tensile strength of 0.85-1.32 N / mm 2 The speaker cone is applied to the speaker, which can expand the frequency response range of the speaker, suppress the high-frequency segmentation vibration of the speaker, reduce distortion, and make the frequency response curve of the speaker smoother.

[0156] Furthermore, visual observation of the speaker paper cones provided in Examples 1-6 revealed that the color of the surface of each paper cone was uniform and continuous at room temperature, and the color rendering effect was good; each paper cone was placed in a 45°C constant temperature box and kept warm for 30 minutes, and the paper cone could completely fade, showing an excellent color change effect.

[0157] In addition, the present invention designs the preparation method, especially performs the third hot pressing under the condition of cylinder supercharging, so that the damping rubber layer forms a tight and reliable bond with the two paper cone layers. Comparing Example 1 with Example 7, it can be seen that if the third hot pressing is not performed by cylinder supercharging, the bonding effect between the cured damping rubber layer and the first paper cone blank becomes poor, resulting in a decrease in the modulus of the paper cone and a weakening of the interlayer bonding force.

[0158] The present invention adjusts the modulus and damping parameters of the paper cone by adjusting the mass of the first paper cone layer, the second paper cone layer, and the damping adhesive layer, thereby obtaining the speaker paper cone having high modulus, high interlayer bonding strength, suitable damping, and excellent acoustic performance. From the comparison between Example 1 and Comparative Example 1, it can be seen that when the mass of the damping adhesive layer is too large, although the paper cone has good damping performance and high interlayer bonding strength, the strength of the paper cone tends to be significantly reduced; from the comparison between Example 1 and Comparative Example 2, it can be seen that when the mass of the damping adhesive layer is small, the modulus of the paper cone is large, but the loss factor and interlayer bonding strength are significantly reduced, and the acoustic performance is poor.

[0159] The combination of glass fiber in the first paper cone layer of the present invention can not only improve the strength, but also increase the light transmittance of the first paper cone layer, so that the color of the damping rubber layer and its color change effect can be presented through the first paper cone layer. From the comparison between Example 1 and Comparative Example 3, it can be seen that if glass fiber is not added to the first paper cone layer, the strength of the paper cone is reduced, and the light transmittance of the first paper cone layer is reduced, and the color change of the paper cone is not obvious.

[0160] In the present invention, by setting different spin coating speeds, the thickness of the damping glue layer on the surface of the second paper cone blank and the quality of the damping glue layer in the paper cone can be controlled. Comparing Example 1 and Comparative Example 4, it can be seen that when the spin coating speed is too low, the damping glue cannot flow on the surface of the second paper cone blank, so the subsequent steps cannot be completed; from the comparison of Example 1 and Comparative Example 5, it can be seen that when the spin coating speed is too high, the damping glue is thrown out due to the excessive centrifugal force, and only a small amount of damping glue remains on the surface of the second paper cone blank, and the obtained paper cone has a low loss factor and weak interlayer bonding force.

[0161] From the comparison between Example 1 and Comparative Example 6, it can be seen that if the damping glue is replaced by oily solvent glue, although the paper cone has a higher modulus and good interlayer bonding force, the loss factor of the paper cone is low and the acoustic performance is deteriorated.

[0162] From the comparison between Example 1 and Comparative Example 7, it can be seen that if the paper cone has only a double-layer structure of a damping adhesive layer and a second paper cone layer, the damping adhesive layer is exposed to the outside, which will cause the paper cone to absorb moisture, thereby causing the modulus of the paper cone to decrease.

[0163] From the comparison between Example 1 and Comparative Example 8, it can be seen that if a paper cone structure formed by hot-pressing two paper cone layers is used, the loss factor of the paper cone is low and the bonding force between the layers is weak.

[0164] The applicant declares that the present invention uses the above embodiments to illustrate the speaker cone and its preparation method and application, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A speaker cone, characterized in that: The speaker paper cone comprises a first paper cone layer, a second paper cone layer and a damping glue layer arranged between the first paper cone layer and the second paper cone layer; The inner diameter of the first paper cone layer is less than the inner diameter of the second paper cone layer; The raw materials for preparing the first paper cone layer include a combination of plant fiber pulp and glass fiber; The raw materials for preparing the damping glue layer include a combination of damping glue and a thermochromic material; the mass percentage of the damping glue layer in the speaker paper cone is 3-35%.

2. The speaker cone according to claim 1, characterized in that: The plant fiber pulp includes any one of wood pulp, bamboo pulp, cotton pulp, and hemp pulp, or a combination of at least two of them, preferably wood pulp and / or cotton pulp; Preferably, the raw materials for preparing the first paper cone layer include the following components in parts by mass: Preferably, the first wood pulp comprises bleached kraft wood pulp and / or unbleached kraft wood pulp, and more preferably bleached kraft wood pulp; Preferably, the first water repellent comprises cationic styrene acrylic emulsion and / or paraffin emulsion.

3. The speaker cone according to claim 1 or 2, characterized in that: The raw materials for preparing the damping rubber layer include the following components in parts by mass: Damping glue 85-95 parts 5-15 parts of thermochromic material; Preferably, the damping glue comprises water-based acrylic polymer and / or water-based polyurethane; Preferably, the thermochromic material includes thermochromic powder.

4. The speaker cone according to any one of claims 1 to 3, characterized in that: The raw materials for preparing the second paper cone layer include the following components in parts by mass: Second wood pulp 100 parts The second waterproofing agent 0.1-5 parts; Preferably, the second wood pulp comprises bleached kraft wood pulp and / or unbleached kraft wood pulp, and more preferably unbleached kraft wood pulp; Preferably, the second water repellent comprises a cationic styrene acrylic emulsion and / or a paraffin emulsion.

5. The speaker cone according to any one of claims 1 to 4, characterized in that: The mass percentage of the first paper cone layer in the speaker paper cone is 18-38%, preferably 20-35%; Preferably, the mass percentage of the damping glue layer in the speaker cone is 5-30%; Preferably, the mass percentage of the second paper cone layer in the speaker paper cone is 35-65%, and more preferably 40-60%.

6. The speaker cone according to any one of claims 1 to 5, characterized in that: The thickness of the first paper cone layer is 0.1-0.35 mm; And / or, the thickness of the damping rubber layer is 0.02-0.15 mm; And / or, the thickness of the second paper cone layer is 0.2-0.5 mm.

7. A method for preparing a speaker cone as claimed in any one of claims 1 to 6, characterized in that: The preparation method comprises: Provide first paper pulp, second paper pulp and damping glue respectively; Passing the first paper pulp through a mold to form a first paper cone wet blank, and passing the first paper cone wet blank through a first hot press to obtain a first paper cone blank; Passing the second paper pulp through a mold to form a second paper cone wet blank, and passing the second paper cone wet blank through a second hot press to obtain a second paper cone blank; Applying the damping adhesive liquid on the surface of the second paper cone blank and drying it to obtain a preform with a damping adhesive layer; The first paper cone blank and the preform are assembled and then subjected to a third hot pressing to obtain the speaker paper cone.

8. The preparation method according to claim 7, characterized in that: The preparation method of the first paper pulp comprises: mixing first wood pulp and cotton pulp and beating the mixture to obtain pulp A; uniformly mixing the pulp A with glass fiber and a first waterproofing agent to obtain the first paper pulp; Preferably, the beating degree of the slurry A is 18-40°SR; Preferably, the preparation method of the second paper pulp comprises: beating the second wood pulp to obtain pulp B; mixing the pulp B with a second waterproofing agent to obtain the second paper pulp; Preferably, the beating degree of the slurry B is 22-30°SR; Preferably, the preparation method of the damping adhesive liquid comprises: mixing and evenly dispersing the damping adhesive and the thermochromic material to obtain the damping adhesive liquid.

9. The preparation method according to claim 7 or 8, characterized in that: The temperatures of the first hot pressing and the second hot pressing are independently 180-230°C; Preferably, the time of the first hot pressing and the second hot pressing is independently 30-80s; Preferably, the coating method comprises spin coating; Preferably, the spin coating speed is 400-3200 rpm, more preferably 500-3000 rpm; Preferably, the temperature of the third hot pressing is 170-230°C; Preferably, the third hot pressing is performed under the condition of cylinder supercharging, and the pressure of the cylinder supercharging is 0.1-0.4 MPa, and more preferably 0.15-0.25 MPa; Preferably, the third hot pressing time is 30-80s.

10. A loudspeaker, characterized in that: The speaker comprises the speaker cone as described in any one of claims 1-6.

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