Glass fiber composite sound cone and preparation method and application thereof

Abstract

The invention provides a glass fiber composite sound cone and a preparation method and application thereof. The glass fiber composite sound cone is obtained through hot pressing of a first glass fiber prepreg, a foam core layer and a second glass fiber prepreg. The first glass fiber prepreg and the second glass fiber prepreg respectively and independently comprise glass fiber cloth and a resin composition attached to the glass fiber cloth; the resin composition includes a combination of an epoxy resin, a curing agent, and photochromic microcapsules. Through the design and the synergistic effect of the three-layer structure and the material, the composite material has the characteristics of light weight and low density, is high in strength and Young modulus, realizes an excellent photochromic function, and can provide a special appearance visual effect. The glass fiber composite sound cone is used for a loudspeaker, the frequency response range of the loudspeaker can be expanded, high-frequency segmentation vibration of the loudspeaker is restrained, the loudspeaker has high sensitivity, and a product shows high visual attraction and functionality.

Description

Technical Field

[0001] The present invention belongs to the technical field of loudspeakers, and in particular relates to a glass fiber composite sound cone and a preparation method and application thereof. Background Art

[0002] Speakers are important acoustic components in electronic devices. They are used to convert electrical signals into sound signals and are energy conversion devices. Existing speakers are mainly divided into three parts according to their functions: vibration part, magnetic circuit part and suspension part. The vibration part includes the cone and voice coil. The material properties of the cone directly affect the stability and service life of the speaker, as well as the high and low frequency characteristics of the sound. Therefore, developing cone materials with various properties is one of the effective ways to improve the acoustic properties and usage properties of the speaker.

[0003] The cone can be divided into paper cone, metal cone, ceramic cone, polypropylene (PP) cone, composite cone, etc. according to the material. Traditional speaker cones usually use single-layer paper materials, which have the advantages of easy processing and flexible raw material matching, but they often cannot meet the requirements of high-end audio products in terms of rigidity, strength and durability. In order to solve this problem, the concept of sandwich structure cone came into being. The sandwich structure cone usually includes two layers of hard surface materials and one layer of lightweight core material. The adjacent layers are bonded by adhesives, which can not only effectively improve the rigidity and strength of the cone, but also improve the acoustic performance. The researchers further improved the performance of the speaker cone by optimizing the material combination and thickness ratio of the cone structure. For example, CN205596316U discloses a foamed PP sandwich cone, including a folded ring and a cone cone, 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 cone layers, and the surfaces of the two cone layers facing the foamed PP layer are covered with the inner and outer surfaces of the foamed PP layer by a PP special adhesive film. The sound basin disclosed in CN110677784A is made of a composite foam material, which includes a foam base layer and a first surface layer and a second surface layer located on its two surfaces. The material of the first surface layer is any one of polyparaxylene, polymonochloroparaxylene, and polydichloroparaxylene, and the material of the second surface layer is any one of metal material, carbon fiber, aramid fiber, and engineering plastic.

[0004] Generally speaking, the surface layer of the sandwich composite sound cone is made of a hard material with strong rigidity, such as cardboard, carbon fiber prepreg, carbon fiber woven cloth, aramid fiber woven cloth, glass fiber woven cloth, etc. Among them, glass fiber woven cloth is a material woven from slender glass fiber threads. It has excellent strength and is an ideal choice for reinforcing materials. It can strengthen composite materials and other structures and maintain its strength and stability in high temperature environments. CN203416402U discloses a rubber-edged NOMEX paper honeycomb composite sound cone. The front and back sides of the NOMEX paper honeycomb are composited with heat-resistant glue and woven glass fiber cloth to form a NOMEX paper honeycomb cone. It has good rigidity, damping, bending resistance and tear resistance, and can be used in speaker systems such as car audio and professional audio.

[0005] Traditional fiber woven cloth composite sound cones require an adhesive layer between the fiber woven cloth and the middle layer. The adhesive layer will increase the mass and density of the composite sound cone, reduce the Young's modulus of the composite sound cone, and thus have a negative impact on the acoustic performance of the speaker; in addition, traditional composite sound cones can only meet basic functional needs and are difficult to provide additional visual effects or other added value. Therefore, the development of light-weight, low-density, high-modulus sound cones that can provide special visual effects is an urgent problem to be solved in this field. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a glass fiber composite sound basin and a preparation method and application thereof. Through the design and synergistic effect of the three-layer structure, the glass fiber composite sound basin is light in weight, low in density, has high strength and high modulus, and has a photochromic function, which can provide a special appearance visual effect, and provide users with a better quality, personalized and intelligent choice.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a glass fiber composite sound cone, which is obtained by hot pressing a first glass fiber prepreg, a foam core layer and a second glass fiber prepreg; the foam core layer is located between the first glass fiber prepreg and the second glass fiber prepreg.

[0009] The first glass fiber prepreg and the second glass fiber prepreg each independently comprise glass fiber cloth and a resin composition attached to the glass fiber cloth; the resin composition comprises a combination of epoxy resin, a curing agent and photochromic microcapsules.

[0010] The glass fiber composite sound cone provided by the present invention has a three-layer structure, including a foam core layer and a first glass fiber prepreg and a second glass fiber prepreg located on both sides of the foam core layer. The three layers are hot-pressed to form a composite structure. No other adhesive layer is required in the composite structure, thereby avoiding the negative impact of the adhesive layer on the quality of the sound cone and Young's modulus.

[0011] In order to make the speaker cone have different appearance effects, the commonly used method in the prior art is to set an additional color coating on the surface of the cone after the cone is formed, so as to achieve the effect of color development / color change. Different from the conventional method of the prior art, the present invention uses glass fiber prepreg as the outer structure of the cone, and the resin composition attached to the glass fiber cloth contains photochromic microcapsules, so that the photochromic microcapsules are dispersed in the resin composition, so that the surface of the cone can change color through light or environmental changes, and greatly reduce the overall glue content of the glass fiber composite cone. At the same time, the light transmittance of the glass fiber cloth can reach 13%, and the light transmittance is significantly better than that of carbon fiber woven cloth, aramid fiber woven cloth, cardboard and other materials, which can make the color change of the cone perfectly presented, so that the speaker containing it can show higher visual appeal and functionality, and can provide users with more personalized and intelligent choices, meet people's demand for personalized and intelligent products, and at the same time expand the application range of cone products, such as smart homes, car interiors and other fields.

[0012] Through the design of the three-layer structure and materials and their synergistic effect, the present invention makes the glass fiber composite sound basin light in weight, low in density, high in strength and Young's modulus, and has a photochromic function, which can provide a special appearance visual effect. When it is used in a speaker, it can expand the frequency response range of the speaker, suppress the high-frequency split vibration of the speaker, and at the same time make the speaker have higher sensitivity.

[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 raw materials for preparing the glass fiber composite sound cone include the following components in parts by mass:

[0015]

[0016] It should be noted that the preparation raw materials are the preparation raw materials for forming the three-layer structure of the glass fiber composite sound basin, that is, the mass fraction of the foam is the mass fraction of the foam core layer in the glass fiber composite sound basin, the mass fraction of the glass fiber cloth is the total mass fraction of the glass fiber cloth in the first glass fiber prepreg and the second glass fiber prepreg, the mass fraction of the epoxy resin is the total mass fraction of the epoxy resin in the two glass fiber prepregs, and the same applies to the curing agent and photochromic microcapsules. For the sake of brevity, they will not be described one by one.

[0017] As a preferred technical solution of the present invention, by designing the quality of glass fiber cloth, foam, epoxy resin, curing agent and photochromic microcapsules in the preparation raw materials, the glass fiber composite sound basin achieves an excellent balance between low density, high strength, high modulus, high-layer bonding strength, photochromic performance and suitable damping performance.

[0018] Preferably, the mass proportion of the glass fiber cloth is 25-80 parts, for example, it can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts or 75 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 30-70 parts are further preferred.

[0019] Preferably, the mass proportion of the foam is 20-75 parts, for example, it can be 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 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 30-70 parts are further preferred.

[0020] Preferably, the mass parts of the epoxy resin are 6-18 parts, for example, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts or 17 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 7-14 parts are further preferred.

[0021] Preferably, the mass parts of the curing agent are 2-8 parts, for example, it can be 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts or 7.5 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 3-6 parts are further preferred.

[0022] Preferably, the mass fraction of the photochromic microcapsules is 0.2-0.6 parts, for example, it can be 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts or 0.55 parts, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range, and 0.2-0.5 parts is further preferred.

[0023] Preferably, the glass fiber cloth is a glass fiber woven cloth, and the weaving method is preferably plain weave.

[0024] Preferably, the glass fiber cloth comprises alkali-free glass fiber cloth.

[0025] Preferably, the gram weight of the glass fiber cloth is 120-300g / m 2 , for example, it can be 130g / m 2 , 150g / m 2 , 160g / m 2 , 180g / m 2 , 200g / m 2 , 210g / m 2 , 220g / m 2 , 240g / m 2 , 250g / m 2 , 260g / m 2 or 280g / m 2 , and 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. It is further preferred that 125-150g / m 2 .

[0026] Preferably, the foam comprises closed-cell foam, and / or the foam is a rigid foam.

[0027] Preferably, the foam comprises polymethacrylimide (PMI) foam, polyester foam or polyurethane foam.

[0028] Preferably, the closed cell rate of the foam is ≥90%, for example, it can be 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, 99.9% or 100%, 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 enumerates the specific point values ​​included in the range, and it is further preferred that it is ≥95%.

[0029] As a preferred technical solution of the present invention, the foam is a closed-cell foam, preferably with a closed-cell ratio of ≥95%, which can reduce the penetration of epoxy resin in the glass fiber prepreg into the interior of the foam, thereby reducing the mass of the glass fiber composite sound basin.

[0030] Preferably, the density of the foam is 70-200 kg / m 3 , for example, it can be 75kg / m 3 、80kg / m 3 , 90kg / m 3 , 100kg / m 3 , 120kg / m 3 , 140kg / m 3 、150kg / m 3 , 160kg / m 3 or 180kg / m 3, and 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. It is further preferred that 75-200 kg / m 3 .

[0031] Preferably, the foam is polymethacrylimide (PMI) foam.

[0032] As a preferred technical solution of the present invention, the foam is PMI foam with a density of 70-200 kg / m 3 , it is used as the core layer of the glass fiber composite sound basin and compounded with two glass fiber prepregs, so that the glass fiber composite sound basin has low density, high strength, high modulus and excellent processing and forming properties. If the density of the foam is too high, the mass and density of the sound basin containing it will increase; if the density of the foam is too low, its compression strength will decrease, and it will be easy to collapse during the hot pressing process, affecting the processing and forming of the sound basin.

[0033] Preferably, the compression modulus of the PMI foam is 110-300 MPa, for example, it can be 120 MPa, 150 MPa, 180 MPa, 200 MPa, 220 MPa, 250 MPa or 280 MPa, 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.

[0034] Preferably, the flexural modulus of the PMI foam is 85-380 MPa, for example, it may be 90 MPa, 100 MPa, 120 MPa, 150 MPa, 180 MPa, 200 MPa, 220 MPa, 250 MPa, 280 MPa, 300 MPa, 320 MPa, 350 MPa or 370 MPa, 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.

[0035] Preferably, the dimensional change rate of the PMI foam at 130° C. is ≤0.3%, for example, it may be 0, 0.01%, 0.02%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25% or 0.28%, and 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.

[0036] For example, the compression modulus of the PMI foam is measured according to the method in standard GB / T 8813-2008, the flexural modulus is measured according to the method in standard GB / T 8812.2-2007, and the dimensional change rate is measured according to the method in standard GB / T 8811-2008.

[0037] Preferably, based on the total mass of the glass fiber cloth and the foam as 100%, the mass of the glass fiber cloth is 25-80%, for example, it can be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75%, 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 enumerates the specific point values ​​included in the range, and 30-70% is further preferred.

[0038] Preferably, the epoxy resin comprises epoxy laminating resin.

[0039] Preferably, based on the total mass of the glass fiber cloth and the foam as 100%, the mass of the epoxy resin is 5-18%, for example, it can be 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16% or 17%, 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 enumerates the specific point values ​​included in the range, and 7-15% is further preferred.

[0040] In the present invention, the curing agent is an epoxy resin curing agent, which can react with epoxy groups.

[0041] Preferably, the curing agent includes an amine curing agent and / or a phenolic curing agent, more preferably an amine curing agent.

[0042] Preferably, the amine curing agent includes any one of 1,3-cyclohexanedimethylamine, ethylene glycol bis(3-aminopropyl) ether, and polyetheramine (α-(2-aminomethylethyl)-ω-(2-aminomethylethoxy)polyethylene glycol) or a combination of at least two thereof.

[0043] Preferably, the phenolic curing agent includes any one of bisphenol A, bisphenol F, and bisphenol S, or a combination of at least two of them.

[0044] Preferably, the mass ratio of the curing agent to the epoxy resin is 1:(1.5-4), for example, it can be 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.3, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.5 or 1:3.8, and more preferably 1:(2-2.5).

[0045] In the present invention, the epoxy resin and curing agent can be purchased from the market. For example, the epoxy resin uses commercially available epoxy laminating resin EL2, and the curing agent uses commercially available AY30 FAST.

[0046] As a preferred technical solution of the present invention, the photochromic microcapsule is a photochromic powder material obtained by encapsulating a reversible photochromic material in a microcapsule (shell).

[0047] Preferably, the reversible photochromic material includes any one of spiropyran compounds, spirooxazine compounds, diarylethene compounds, and azobenzene compounds, or a combination of at least two of them.

[0048] In the present invention, the specific types of the reversible photochromic material and the photochromic microcapsules are not particularly limited. Photochromic microcapsules with corresponding color changing effects can be selected according to the appearance color requirements of the sound basin product, such as photochromic microcapsules of different colors such as blue, purple, orange, red, orange, green, and yellow.

[0049] In the present invention, the photochromic microcapsules may be commercially available products, such as sunlight-chromic microcapsule powder (MC powder) produced by Tianjin Fuxin Sunshine Technology Co., Ltd.

[0050] Preferably, the thickness of the glass fiber composite sound basin is 1.2-5mm, for example, it can be 1.4mm, 1.5mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm or 4.8mm, 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 1.5-3mm is further preferred.

[0051] Preferably, the thickness of the foam core layer is 1-3 mm, for example, it can be 1.1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.5 mm, 2.6 mm or 2.8 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 1.2-2.3 mm is further preferred.

[0052] Preferably, the first glass fiber prepreg and the second glass fiber prepreg are the same.

[0053] As a preferred technical solution of the present invention, the density of the glass fiber composite sound cone is ≤0.45g / cm 3 , for example, it can be 0.18 g / cm 3 , 0.2g / cm 3 , 0.22g / cm 3 , 0.25g / cm 3 , 0.28g / cm 3 , 0.3g / cm 3 , 0.32g / cm 3 , 0.35g / cm 3 , 0.38g / cm3 , 0.4g / cm 3 or 0.42g / cm 3 , and 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, preferably 0.2-0.4 g / cm 3 .

[0054] As a preferred technical solution of the present invention, the Young's modulus of the glass fiber composite cone is ≥2.5GPa, for example, it can be 2.6GPa, 2.8GPa, 3GPa, 3.2GPa, 3.5GPa, 3.8GPa, 4GPa, 4.2GPa, 4.5GPa or 4.8GPa, 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 range, preferably 2.8-4.5GPa.

[0055] In a second aspect, the present invention provides a method for preparing the glass fiber composite sound cone as described in the first aspect, the preparation method comprising:

[0056] Providing a resin glue, wherein the resin glue comprises a combination of an epoxy resin, a curing agent and photochromic microcapsules;

[0057] The glass fiber cloth is impregnated in the resin glue to obtain a first glass fiber prepreg and a second glass fiber prepreg respectively;

[0058] The first glass fiber prepreg, the foam core layer and the second glass fiber prepreg are stacked in sequence and then hot-pressed to obtain the glass fiber composite sound cone.

[0059] The glass fiber composite sound basin provided by the present invention has a three-layer structure. After the first glass fiber prepreg, the foam core layer and the second glass fiber prepreg are stacked in sequence, the preparation can be completed by one-step hot pressing. During the hot pressing process, the epoxy resin undergoes a curing reaction, and the strength and modulus of the composite sound basin are increased. At the same time, when the epoxy resin is cured, the glass fiber layer and the foam core layer are bonded, eliminating the adhesive layer of the conventional composite sound basin. The glass fiber composite sound basin of the present invention is prepared by a "one-step method", and the process method is simple and feasible, eliminating the tedious process of spraying glue or placing a hot melt adhesive film between each layer of material and then hot pressing and compounding.

[0060] Preferably, the method for preparing the resin glue comprises: first mixing epoxy resin and photochromic microcapsules, and uniformly mixing the obtained mixture with a curing agent to obtain the resin glue.

[0061] Preferably, the first mixing is performed by a centrifugal homogenizer; the photochromic microcapsules have good compatibility with the epoxy resin and are evenly dispersed.

[0062] Preferably, the rotation speed of the first mixing is 500-2000 rpm, for example, it can be 600 rpm, 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.

[0063] Preferably, the first mixing time is 1-10 min, for example, it can be 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 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.

[0064] Preferably, the step of cutting the glass fiber cloth is further included before the impregnation.

[0065] Preferably, the glass fiber cloth is cut into a square slightly larger than the mold, and adhesive tape is attached to four sides of the glass fiber cloth to prevent the fiber bundles of the glass fiber cloth from being separated and / or deformed.

[0066] Preferably, the impregnation is performed under the condition of standing still or using an auxiliary tool (such as a scraper) so that the resin glue can fully and completely penetrate into the pores of the glass fiber cloth.

[0067] Preferably, the hot pressing pressure is 0.1-0.5 MPa, for example, it can be 0.15 MPa, 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, 0.4 MPa or 0.45 MPa, 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.

[0068] Preferably, the temperature of the hot pressing is 80-130°C, for example, it can be 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°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.

[0069] As a preferred technical solution of the present invention, the first glass fiber prepreg, the foam core layer and the second glass fiber prepreg are stacked in sequence and placed in a hot pressing mold for hot pressing. Preferably, the hot pressing pressure is 0.1-0.5MPa and the temperature is 80-130°C, so as to achieve curing and bonding between the foam core layer and the two glass fiber prepregs. If the hot pressing pressure is too low (<0.1MPa), the bonding effect between the glass fiber prepreg and the foam core layer is poor, affecting the interlayer bonding force of the sound basin; when the hot pressing pressure is too high (>0.5MPa), the foam core layer will be squeezed by excessive pressure to deformation or rupture. If the hot pressing temperature is too low (<80°C), the curing rate of the epoxy resin is too slow, resulting in reduced processing efficiency; if the hot pressing temperature is >130°C, the excessively high temperature will affect the temperature resistance stability of the foam core layer, resulting in softening and damage of the foam core layer.

[0070] Preferably, the hot pressing time is 20-60 min, for example, it can be 25 min, 28 min, 30 min, 32 min, 35 min, 38 min, 40 min, 42 min, 44 min, 45 min, 50 min or 55 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 30-45 min is further preferred.

[0071] As a preferred technical solution of the present invention, the method for preparing the glass fiber composite sound cone comprises the following steps:

[0072] Evenly mixing epoxy resin, curing agent and photochromic microcapsules to obtain resin glue;

[0073] Cutting the glass fiber cloth and dipping it into the resin glue to obtain a first glass fiber prepreg and a second glass fiber prepreg respectively;

[0074] The first glass fiber prepreg, the foam core layer and the second glass fiber prepreg are stacked in sequence and placed in a hot pressing mold, and hot pressed at 80-130° C. and 0.1-0.5 MPa for 20-60 minutes to obtain the glass fiber composite sound cone.

[0075] In a third aspect, the present invention provides a loudspeaker, comprising the glass fiber composite cone as described in the first aspect.

[0076] Compared with the prior art, the present invention has the following beneficial effects:

[0077] (1) The glass fiber composite sound cone provided by the present invention has the characteristics of light weight, low density, high strength and Young's modulus, and excellent photochromic function through the design of the three-layer structure and materials and their synergistic effect. It can quickly change color under ultraviolet light or sunlight, and can return to colorless within 30 seconds after the ultraviolet light or sunlight is removed, providing a special appearance visual effect. The glass fiber composite sound cone is used for speakers, which can not only expand the frequency response range of the speakers, suppress the high-frequency split vibration of the speakers, and make the speakers have higher sensitivity, but also make the products show higher visual appeal and functionality, and can provide users with more personalized and intelligent choices, meeting people's demand for personalized and intelligent products.

[0078] (2) The glass fiber composite sound basin provided by the present invention is obtained by "one-step" hot pressing, and no other adhesive layer is required. The tedious process of spraying glue or placing hot melt adhesive film between the layers of materials and then hot pressing and compounding is eliminated, thereby avoiding the negative impact of the adhesive layer on the quality and Young's modulus of the sound basin. The process method is simple and feasible. DETAILED DESCRIPTION

[0079] 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.

[0080] 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.

[0081] "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.

[0082] 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.

[0083] In the following specific implementation of the present invention, the specific information of the materials used is as follows:

[0084] Components Source(Manufacturer) Fiberglass cloth Jining Hongjun Fiberglass Co., Ltd. Foam core: PMI foam Hunan Zhaoheng Materials Technology Co., Ltd. Epoxy resin: Epoxy laminating resin, EL2 Composites Easy Buy (Beijing) Technology Co., Ltd. Curing agent: AY30FAST Composites Easy Buy (Beijing) Technology Co., Ltd. Photochromic microcapsules: sunlight-changing microcapsules MC powder Tianjin Fuxin Sunshine Technology Co., Ltd. Carbon fiber woven cloth: plain 1K Composites Easy Buy (Beijing) Technology Co., Ltd. Hot melt adhesive film: TE95 Shanghai Hengning New Materials Co., Ltd.

[0085] The glass fiber composite sound cone and the preparation method thereof provided by the present invention are described in detail below by taking a plurality of embodiments as examples, but the glass fiber composite sound cone and the preparation method thereof provided by the present invention are not limited to these embodiments.

[0086] Example 1

[0087] A glass fiber composite sound cone is obtained by hot pressing a first glass fiber prepreg, a foam core layer and a second glass fiber prepreg, and the raw materials for preparing the glass fiber composite sound cone include the following components in parts by mass:

[0088]

[0089] The glass fiber cloth has a gram weight of 130 g / m 2 , the density of PMI foam is 100kg / m 3 .

[0090] The preparation method of the glass fiber composite sound cone comprises the following steps:

[0091] (1) mixing epoxy resin and photochromic microcapsules according to the formula amount, dispersing and mixing in a centrifugal homogenizer at a speed of 1000 rpm for 3 minutes to obtain a mixture; and fully mixing the mixture with a curing agent to obtain a resin glue solution;

[0092] (2) cutting the glass fiber cloth and immersing the cloth in the resin adhesive so that the resin adhesive fully enters the pore structure of the glass fiber cloth to obtain a first glass fiber prepreg and a second glass fiber prepreg;

[0093] (3) The first glass fiber prepreg, the foam core layer, and the second glass fiber prepreg are stacked in order to form a sandwich structure, and the sandwich structure is placed in a hot pressing mold. The hot pressing machine is started, and the mold is closed for hot pressing. The hot pressing temperature is 100° C., the pressure is 0.2 MPa, and the time is 45 minutes. Then, the hot pressing is cooled to room temperature to obtain the glass fiber composite sound basin.

[0094] Examples 2-6, Comparative Examples 1-8

[0095] A glass fiber composite sound cone, which differs from Example 1 only in that the raw materials used in the preparation are different, as shown in Table 1; in Table 1, the units of the amounts of the raw materials used in the preparation are "parts by mass"; the items not shown in Table 1 are the same as those in Example 1.

[0096] Table 1

[0097]

[0098] Comparative Example 9

[0099] A composite cone, which differs from Example 1 only in that the glass fiber cloth is replaced with a carbon fiber woven cloth of equal mass (weight 130 g / m2 ), other materials, preparation process and parameters are the same as those in Example 1.

[0100] Comparative Example 10

[0101] A glass fiber composite sound cone, which differs from Example 1 only in that it is obtained by hot pressing a first glass fiber layer, a first hot melt adhesive film, a foam core layer, a second hot melt adhesive film and a second glass fiber layer; the types and weight fractions of the glass fiber cloth, PMI foam, epoxy resin, curing agent and photochromic microcapsules in the preparation raw materials are the same as those in Example 1; and the preparation method comprises the following steps:

[0102] (1) preparing a first glass fiber prepreg and a second glass fiber prepreg according to the same method as in Example 1;

[0103] (2) placing the first glass fiber prepreg in a hot pressing mold, starting a hot pressing machine, closing the mold for hot pressing, the hot pressing temperature is 100° C., the pressure is 0.2 MPa, and the time is 30 min to obtain a first glass fiber layer;

[0104] Hot pressing the second glass fiber prepreg in the same manner to obtain a second glass fiber layer;

[0105] (3) The first glass fiber layer, the first hot melt adhesive film, the foam core layer, the second hot melt adhesive film and the second glass fiber layer are stacked in order to form a sandwich structure, and the sandwich structure is placed in a hot pressing mold, and the hot pressing machine is started, and the mold is closed for hot pressing. The hot pressing temperature is 150° C., the pressure is 0.1 MPa, and the time is 1 min. Then, the hot pressing is cooled to room temperature to obtain the glass fiber composite sound basin.

[0106] The following performance tests were performed on the glass fiber composite cones provided in Examples 1-6 and Comparative Examples 1-10:

[0107] (1) Thickness: observed and measured by the VR-3000 microscope;

[0108] (2) Density: Using the mass / volume method, the mass of the cone is measured by an electronic balance, the thickness of the cone is measured by a micrometer, and the volume of the cone is calculated using its 3D model;

[0109] (3) Young's modulus: tested according to the method in standard GB / T 8812.2-2007;

[0110] The test data is shown in Table 2. In Table 2, "outer layer thickness" refers to the thickness of a single outer layer in the composite cone:

[0111] Table 2

[0112]

[0113]

[0114] According to Table 1 and Table 2, the present invention uses the three-layer structure and material design and the composite synergistic effect, combined with a one-step hot pressing process, to make the density of the glass fiber composite sound cone provided in Examples 1-6 be 0.22-0.38 g / cm 3 , Young's modulus is 2.8-4.2GPa. It has high strength and modulus, low density and light weight. When applied to speakers, the speakers have good transient responsiveness, high energy conversion efficiency and high sensitivity.

[0115] Furthermore, visual observation of the glass fiber composite sound cone provided in Examples 1-6 shows that the color under sunlight is uniform and continuous, with good color development effect, and the surface of the sound cone is smooth and particle-free, indicating that the photochromic microcapsules have a good dispersion effect. Moreover, the surface of the glass fiber composite sound cone can change color through light or environmental changes, and the color changes rapidly under ultraviolet light or sunlight, and can return to colorless within 30 seconds after the ultraviolet light or sunlight is removed, showing a sensitive photochromic effect.

[0116] The glass fiber composite sound basin provided by the present invention is obtained by hot pressing a first glass fiber prepreg, a foam core layer and a second glass fiber prepreg. By further optimizing the design of glass fiber cloth, foam, epoxy resin, curing agent and photochromic microcapsules in the preparation of the raw materials and the quality, the obtained glass fiber composite sound basin can have comprehensive properties such as low density, high modulus and sensitive photochromic effect.

[0117] From the comparison between Example 1 and Comparative Examples 1-2, it can be seen that when the mass fraction of the glass fiber cloth is small and the mass fraction of the PMI foam core layer is large, the thickness of the prepared glass fiber composite sound basin is too thick and the Young's modulus will be attenuated; conversely, when the mass fraction of the glass fiber cloth is large and the mass fraction of the PMI foam core layer is small, the core layer thickness of the glass fiber composite sound basin is small, and although the sound basin has a higher Young's modulus, its density will also increase significantly.

[0118] From the comparison between Example 1 and Comparative Examples 3-4, it can be seen that when the mass fractions of epoxy resin and curing agent are small, the resin composition cannot completely cover the glass fiber cloth, nor can it form a complete and continuous bond between the glass fiber layer and the foam core layer, resulting in separation between the layers of the composite sound basin and the inability to form the composite sound basin. When the mass fractions of epoxy resin and curing agent are large, the glue content of the composite sound basin increases, the modulus decreases, and the density increases.

[0119] The Young's modulus, density and other parameters of the glass fiber composite sound basin prepared in Comparative Example 5 are basically the same as those in Example 1, but because the mass fraction of photochromic microcapsules is small, the color change of the glass fiber composite sound basin in Comparative Example 5 in ultraviolet light or sunlight environment is not obvious, and it is difficult to provide a unique visual effect.

[0120] From the comparison between Example 1 and Comparative Example 6, it can be seen that when the gram weight of the glass fiber cloth is relatively large, the density of the prepared glass fiber composite sound basin increases.

[0121] From the comparison between Example 1 and Comparative Examples 7-8, it can be seen that the density of the PMI foam core layer should be within a reasonable range. When the density of the PMI foam is too small, its compression strength is low, the PMI layer is crushed during hot pressing, and the composite sound basin cannot be formed; when the density of the PMI foam is too large, the density of the glass fiber composite sound basin will increase.

[0122] From the comparison between Example 1 and Comparative Example 9, it can be seen that when carbon fiber woven cloth is used instead of the glass fiber cloth specified in the present invention, the Young's modulus and density of the composite sound basin still maintain the advantages of high strength and light weight, but because the carbon fiber woven cloth is black and has extremely low light transmittance, it cannot show the color change of the surface of the composite sound basin and does not have a unique appearance effect.

[0123] Comparative Example 10 is formed by hot pressing of "first glass fiber layer + first hot melt adhesive layer + PMI foam core layer + second hot melt adhesive layer + second glass fiber layer", which is a traditional method for preparing a composite sound basin. The adhesive layer will cause the Young's modulus of the composite sound basin to decrease and the density to increase.

[0124] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the glass fiber composite sound basin and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of 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 glass fiber composite cone, characterized in that: The glass fiber composite sound cone is obtained by hot pressing a first glass fiber prepreg, a foam core layer, and a second glass fiber prepreg; The first glass fiber prepreg and the second glass fiber prepreg each independently comprise glass fiber cloth and a resin composition attached to the glass fiber cloth; the resin composition comprises a combination of epoxy resin, a curing agent and photochromic microcapsules.

2. The glass fiber composite cone according to claim 1, characterized in that: The raw materials for preparing the glass fiber composite sound basin include the following components by mass:

3. The glass fiber composite sound cone according to claim 1 or 2, characterized in that: The gram weight of the glass fiber cloth is 120-300g / m 2 ; Preferably, the foam comprises a closed-cell foam, further preferably a polymethacrylimide foam, a polyester foam or a polyurethane foam; Preferably, the closed cell rate of the foam is ≥90%, more preferably ≥95%; Preferably, the density of the foam is 70-200 kg / m 3 ; Preferably, based on the total mass of the glass fiber cloth and the foam being 100%, the mass of the glass fiber cloth is 25-80%, more preferably 30-70%.

4. The glass fiber composite sound cone according to any one of claims 1 to 3, characterized in that: The mass of the epoxy resin is 5-18% based on the total mass of the glass fiber cloth and the foam as 100%; Preferably, the curing agent comprises an amine curing agent and / or a phenolic curing agent; Preferably, the mass ratio of the curing agent to the epoxy resin is 1:(1.5-4).

5. The glass fiber composite sound cone according to any one of claims 1 to 4, characterized in that: The thickness of the glass fiber composite sound cone is 1.2-5mm; Preferably, the foam core layer has a thickness of 1-3 mm.

6. The glass fiber composite sound cone according to any one of claims 1 to 5, characterized in that: The density of the glass fiber composite sound cone is ≤0.45g / cm 3 , preferably 0.2-0.4g / cm 3 ; Preferably, the Young's modulus of the glass fiber composite cone is ≥2.5 GPa, and more preferably 2.8-4.5 GPa.

7. A method for preparing a glass fiber composite sound cone according to any one of claims 1 to 6, characterized in that: The preparation method comprises: Providing a resin glue, wherein the resin glue comprises a combination of an epoxy resin, a curing agent and photochromic microcapsules; The glass fiber cloth is impregnated in the resin glue to obtain a first glass fiber prepreg and a second glass fiber prepreg respectively; The first glass fiber prepreg, the foam core layer and the second glass fiber prepreg are stacked in sequence and then hot-pressed to obtain the glass fiber composite sound cone.

8. The preparation method according to claim 7, characterized in that: The method for preparing the resin glue comprises: first mixing epoxy resin and photochromic microcapsules, and uniformly mixing the obtained mixture with a curing agent to obtain the resin glue; Preferably, the first mixing is performed by a centrifugal homogenizer; Preferably, the first mixing speed is 500-2000rpm; Preferably, the first mixing time is 1-10 min.

9. The preparation method according to claim 7 or 8, characterized in that: The hot pressing pressure is 0.1-0.5MPa; Preferably, the temperature of the hot pressing is 80-130°C; Preferably, the hot pressing time is 20-60 min, more preferably 30-45 min.

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

Images