CN113490128A

CN113490128A - Vibrating diaphragm for sound production device and sound production device

Info

Publication number: CN113490128A
Application number: CN202110738074.5A
Authority: CN
Inventors: 王海峰; 王婷; 李春
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2021-10-08
Anticipated expiration: 2041-06-30
Also published as: WO2023273751A1; CN113490128B

Abstract

The invention discloses a vibrating diaphragm for a sound generating device and the sound generating device. The diaphragm is obtained by adding damping additives, fillers, structure control agents and cross-linking agents into a base polymer, mixing and molding at 80-200 ℃, wherein the damping additives are selected from one or more of polysiloxane, and the main chain of the polysiloxane has a structure shown in an average composition formula 1. According to the invention, by adding the damping additive, the damping of the vibrating diaphragm can be improved, and the distortion of the sound generating device is reduced.

Description

Vibrating diaphragm for sound production device and sound production device

Technical Field

The invention relates to the technical field of acoustic products, in particular to a vibrating diaphragm for a sound generating device and the sound generating device.

Background

The prior materials for preparing the vibrating diaphragm of the sound generating device comprise plastic, thermoplastic resin and other elastomer materials; among them, the silicon rubber has good high and low temperature performance, rebound resilience and fatigue resistance, and has a low glass transition temperature, so that it is widely used in the process of manufacturing the diaphragm.

Although the acoustic diaphragm prepared from traditional silicon rubber such as methyl silicon rubber, vinyl silicon rubber and the like can improve the acoustic performance and reliability of the diaphragm at high temperature and high power, the problems of diaphragm folding, diaphragm breaking and the like are avoided; however, conventional silicone rubbers are based on the one hand on the main chain being predominantly Si-O-Si and the side groups being predominantly-CH₃The structure is regular, the steric hindrance is small, the intermolecular friction is small, and the loss is low; on the other hand, the glass transition temperature of the traditional silicone rubber is lower, generally below-100 ℃, and the damping of the material in the glass transition temperature region is highest. Therefore, in the range of the use temperature and the frequency, the damping of the traditional silicon rubber diaphragm is low, generally less than 0.1, so that the Total Harmonic Distortion (THD) of a loudspeaker using the silicon rubber diaphragm is high, the sound is poor, the user experience is poor, and the application of the silicon rubber diaphragm in the field of high-performance sound production devices is limited.

Disclosure of Invention

Based on the above problems, the invention aims to provide a vibrating diaphragm for a sound generating device and the sound generating device, so as to solve the problems of low damping of the traditional silicon rubber vibrating diaphragm, high Total Harmonic Distortion (THD) of the sound generating device using the vibrating diaphragm, poor listening, poor user experience and the like.

The above purpose of the invention is realized by the following technical scheme:

according to one aspect of the present invention, the diaphragm for a sound generating device is obtained by adding a damping additive, a filler, a structure control agent, and a crosslinking agent to a base polymer, mixing, and molding at 80 ℃ to 200 ℃, wherein the damping additive is one or more selected from polysiloxanes, and the polysiloxane main chain has a structure represented by the following average composition formula 1:

[ average composition formula 1]

Wherein R is a group

and-C₃H₆NH₂One of (1); x, y and z are positive integers, x is 1-1000, y is 1-1000, and z is 1-1000.

Optionally, the damping additive is used in an amount of 1% to 50% by weight of the total weight of the base polymer, damping additive, filler, structure control agent and crosslinking agent. Preferably, the amount of the damping additive is 15 to 25% of the total weight of the base polymer, the damping additive, the filler, the structure-controlling agent and the crosslinking agent.

Alternatively, the base polymer is a polysiloxane or a combination of several polysiloxanes comprising in their main chain a member selected from Me₂SiO、MeViSiO、MePhSiO、Ph₂One or more structural units in SiO, and Me as end group₃SiO and/or ViMe₂SiO, wherein Me is methyl, Vi is vinyl and Ph is phenyl.

Further, the base polymer can be one or more of methyl polysiloxane, methyl vinyl polysiloxane, methyl phenyl polysiloxane and vinyl phenyl polysiloxane.

Optionally, the filler is one or more of silica, mica, graphene, clay, calcium carbonate, carbon nanotubes, kaolin, and talc.

Optionally, the structure control agent is one or more of dihydric alcohol, diorganocyclosiloxane, diorganosiloxane, alkoxysilane, low-molar-mass hydroxy silicone oil, an organosilicon compound containing Si-N bonds, and an organosilicon compound containing Si-O-B bonds.

Optionally, the crosslinking agent is one or a mixture of 2, 4-dichlorobenzoyl peroxide, benzoyl peroxide, 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide, di-tert-butyl peroxide and dicumyl peroxide; or the cross-linking agent is one or more of a compound/composition containing platinum element, hydrogen-containing silicone oil and alkynol inhibitor.

Optionally, the damping of the diaphragm is 0.1-0.75.

Optionally, the hardness of the diaphragm is 20A to 95A.

Optionally, the tensile strength of the diaphragm is 1MPa to 15 MPa.

Optionally, the thickness of the diaphragm is 40 μm to 150 μm.

According to another aspect of the present invention, the present invention provides a sound generating apparatus, including a vibration system and a magnetic circuit system cooperating with the vibration system, where the vibration system includes a diaphragm and a voice coil coupled to one side of the diaphragm, the magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to generate sound, and the diaphragm is the diaphragm of the present invention.

The invention also provides another sound production device which comprises a shell, and a magnetic circuit system and a vibration system which are arranged in the shell, wherein the vibration system comprises a voice coil, a first vibration film and a second vibration film, the top of the voice coil is connected with the first vibration film, the magnetic circuit system drives the voice coil to vibrate so as to drive the first vibration film to produce sound, two ends of the second vibration film are respectively connected with the shell and the bottom of the voice coil, and the second vibration film is the vibration film of the invention.

Compared with the prior art, the damping additive is added, and the damping additive, the base polymer, the filler, the cross-linking agent and the structure control agent are subjected to mixing and heating molding to obtain the vibrating diaphragm, so that the damping of the vibrating diaphragm at normal temperature can be improved to be more than 0.10. Use the sound generating mechanism of vibrating diaphragm, under the same performance, can obtain lower Total Harmonic Distortion (THD), THD can be down to about 12% under the low frequency for example, and sound generating mechanism can have better vocal effect, higher definition, fullness, sense of space, brightness and soft degree, and no abnormal sound fidelity is high, and the vibrating diaphragm sways the vibration in-process moreover and shakes less, and the listening is more stable to can improve user experience.

Drawings

Fig. 1 is a schematic view of a process flow for manufacturing a diaphragm of a sound generating device according to an embodiment of the present invention;

FIG. 2 is a graph of a THD test for harmonic distortion of a diaphragm according to an embodiment of the present invention and a diaphragm according to a comparative example;

FIG. 3 is a schematic structural diagram of a sound generating device according to an embodiment of the present invention;

fig. 4 is an exploded schematic view of fig. 3.

In fig. 3-4, 10 cases, 20 magnetic circuits, 31 first diaphragms, 32 second diaphragms, and 33 voice coils.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The vibrating diaphragm for the sound generating device is obtained by mixing and molding a base polymer, a damping additive, a filler, a structure control agent and a cross-linking agent at 80-200 ℃. Wherein the damping additive is selected from one or more modified polysiloxane, and the modified polysiloxane main chain has a structure shown in the following average composition formula 1:

[ average composition formula 1]

Wherein R is a group

and-C₃H₆NH₂One of (1); and x, y and z in the structure are positive integers. Wherein x is 1-1000, y is 1-1000, and z is 1-1000.

It is to be noted that the damping additive of the present invention is a random copolymer,whose average composition is that in formula 1

The three units are randomly distributed and randomly arranged.

Further, the molecular weight of the damping additive can be 5000-200000.

The damping additive is added, so that the damping of the vibrating diaphragm can be improved to be more than 0.1, and the sound production device adopting the vibrating diaphragm has lower Total Harmonic Distortion (THD), better sound production effect, no abnormal sound and high fidelity, and the vibrating diaphragm has less swinging vibration and more stable sound production in the vibration process.

In alternative embodiments, when the R group is-C₃H₆NH₂The compound can be prepared by methyl phenyl siloxane ring, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane under the conditions of a basic catalyst and DMSO (dimethyl sulfoxide). When the R group is

When this is the case, the R group in the structure may be-C₃H₆NH₂The modified polysiloxane of (2) is prepared from phthalic anhydride. When the R group is

When this is the case, the R group in the structure may be-C₃H₆NH₂The modified polysiloxane of (2) and 1, 8-naphthalic anhydride. The damping additive of the present invention may be terminated with methyl groups or vinyl groups, although not limited thereto.

In particular, when R groups are respectively the same as modified polysiloxane used as damping additive

-C₃H₆NH₂The preparation method is as followsThe following steps.

The R group is-C₃H₆NH₂When the average composition formula 1 is

The preparation method comprises the following steps: adding methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane, tetramethyl tetravinylcyclotetrasiloxane, basic catalyst, water, DMSO (dimethyl sulfoxide) and decamethyl tetrasiloxane according to a metering proportion, heating to 80-120 ℃ in a nitrogen atmosphere, stirring for 3-5 hours, vacuumizing for 0.5-8 hours, cooling, adding acetic acid for neutralization, heating to 100-200 ℃, and removing small molecular substances in a system to obtain the damping additive, namely the aminopropyl phenyl silicone oil. The aminopropylphenyl silicone oil may be terminated with a methyl group, a vinyl group or the like. Among them, specific values and/or proportions of raw materials can be determined depending on the modified polysiloxane having a desired structure, for example, specific values of methylphenylsiloxane ring body, aminopropylmethyldiethoxysilane, tetramethyltetravinylcyclotetrasiloxane. The dosage of the alkaline catalyst can be 0.001-0.01 percent of the sum of the three raw materials of methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane. The amount of the water can be 1-10% of the total mass of three raw materials of methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane. The amount of the DMSO is 100-1000% of the sum of the three raw materials of the methyl phenyl siloxane ring body, the aminopropyl methyl diethoxy silane and the tetramethyl tetravinylcyclotetrasiloxane. The dosage of the decamethyltetrasiloxane can be determined according to the modified polysiloxane with a desired structure, and further, the dosage of the decamethyltetrasiloxane can be 0.01-10% of the sum of the three raw materials of the methyl phenyl siloxane ring body, the aminopropyl methyl diethoxy silane and the tetramethyl tetravinyl cyclotetrasiloxane.

R is a group

At that time, i.e. the average compositionFormula 1 is

The preparation method comprises the following steps: dissolving the prepared aminopropyl phenyl silicone oil with dimethylbenzene, adding phthalic anhydride, introducing nitrogen for protection, performing cold flow reflux at 40-120 ℃ for about 2-16 h, cleaning with an aqueous alkali solution to remove unreacted anhydride, separating out an upper-layer organic matter, and performing vacuum decompression to extract dimethylbenzene to obtain the damping additive.

R is a group

When the average composition formula 1 is

The preparation method comprises the following steps: dissolving the prepared aminopropyl phenyl silicone oil by using dimethylbenzene, adding 1, 8-naphthalic anhydride, introducing nitrogen for protection, performing cold flow reflux at 40-120 ℃ for about 2-16 h, cleaning by using an aqueous alkali solution to remove unreacted anhydride, separating out an upper layer organic matter, and performing vacuum decompression to extract the dimethylbenzene to obtain the damping additive.

In particular embodiments, one or more of the three specific modified polysiloxanes described below can be used as a damping additive.

First modified polysiloxane: r is a group

x is 100, y is 50 and z is 30.

Second modified polysiloxane: r is a group

x is 300, y is 200, and z is 90.

Third modified polysiloxane: the R group is-C₃H₆NH₂Is specifically- (CH)₂)₃NH₂X is 200, y is 100, and z is 60.

In the invention, the dosage of the damping additive is 1-50% of the total weight of the base polymer, the damping additive, the filler, the structure control agent and the cross-linking agent. For example, the damping additive may be added in an amount of 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, and the like. In the embodiment, the damping of the diaphragm is improved to 0.1-0.75, for example, 0.1, 0.2, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 and the like, by controlling the adding amount of the damping additive to be 1-50%. The shore hardness of the diaphragm is 20A to 95A, and may be, for example, 20A, 30A, 35A, 40A, 45A, 50A, 55A, 60A, 70A, 80A, 90A, 95A, and the like. The diaphragm may have an elongation at break of 150% to 750%, for example, 150%, 200%, 250%, 300%, 350%, 400%, 450%, 500%, 550%, 600%, 650%, 700%, 750%, or the like. The thickness of the diaphragm is 40-150 μm; for example, it may be 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, or the like. The tensile strength of the diaphragm is 1 to 15MPa, and may be, for example, 1MPa, 5MPa, 10MPa, 15MPa, or the like. Therefore, in the embodiment, the damping of the diaphragm can be improved to 0.1-0.75 by controlling the adding amount of the damping additive to be 1-50%, and the diaphragm has good mechanical property.

In a preferred embodiment, the damping additive is used in an amount of 15% to 25% by weight, for example, 17%, 19%, 21%, 23% by weight, based on the total weight of the five raw materials, i.e., the base polymer, the damping additive, the filler, the structure-controlling agent, and the crosslinking agent. In the embodiment of the invention, by controlling the dosage of the damping additive within the above preferable range, the damping of the diaphragm can be 0.3-0.65, for example, 0.3, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, and the like; the Shore hardness of the diaphragm is 40-70A; the elongation at break of the diaphragm is 230-650%; the tensile strength of the diaphragm is 3MPa to 15MPa, and may be, for example, 3MPa, 6MPa, 9MPa, 13MPa, or the like. Therefore, by optimizing the addition amount of the damping additive, the damping of the vibrating diaphragm can be improved, and the vibrating diaphragm can be ensured to have more excellent mechanical properties.

In the inventionThe base polymer may be selected from conventional silicone polymers. Further, the base polymer may be a polysiloxane or a mixture of several polysiloxanes comprising in its backbone a member selected from Me₂SiO、MeViSiO、MePhSiO、Ph₂One or more structural units in SiO, and Me as end group₃SiO and/or ViMe₂SiO. The base polymer may be one or more selected from non-phenyl containing siloxane polymers, such as polydimethylsiloxane and the like; and may be one or more selected from the group consisting of phenyl siloxane-containing polymers, such as methylphenyl polysiloxane and/or vinylphenyl polysiloxane, and the like; and may include one or more of a phenyl-containing siloxane polymer and a phenyl-containing siloxane polymer.

The non-phenyl containing siloxane polymer may be one including in its backbone a material selected from MeViSiO, Me₂Structural unit of one or two of SiO, the end group of which is Me₃SiO or ViMe₂SiO is terminated by methyl or vinyl; wherein Me is methyl and Vi is vinyl; the molecular weight may be 2000 to 1000000. Further, the base polymer may be polydimethylsiloxane and/or methylvinylpolysiloxane; for example, the base polymer can be one or more of methyl silicone rubber, methyl silicone oil, vinyl silicone rubber and vinyl silicone oil, and the materials can be directly purchased. According to the invention, the polymer without phenyl siloxane is used as a base polymer, so that the vibrating diaphragm can be ensured to have mechanical properties such as high and low temperature resistance, high resilience, fatigue resistance and the like, the acoustic performance of the vibrating diaphragm under high power can be improved, and the probability of the phenomenon of membrane folding or membrane breaking can be reduced to a certain extent.

The phenyl-containing siloxane polymer may be one including Me in its main chain₂SiO/and MeViSiO and selected from MePhSiO and Ph₂Structural unit of one or two of SiO, the end group of which is Me₃SiO or ViMe₂SiO is terminated by methyl or vinyl; wherein Me is methyl, Vi is vinyl, and Ph is phenyl; the molecular weight may be 2000 to 1000000. The present invention is obtained by using the above-mentioned phenyl siloxane-containing polymer as a base polymer, which is incorporatedThe polar phenyl group can destroy the regularity of the siloxane polymer structure, increase the friction force among molecules, reduce the crystallinity of the polymer, and improve the structure of the siloxane polymer, thereby further improving the damping of the vibrating diaphragm. Further, in the phenyl-containing siloxane polymer, the phenyl group content may be 0.5% to 75% by weight, for example, may be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, and the like, and preferably, the phenyl group content is 5% to 15%. The optimal range not only can improve the damping of the vibrating diaphragm, but also can ensure that the mechanical property of the vibrating diaphragm is more excellent.

Further, the siloxane-containing polymer may be one or more selected from methylphenyl polysiloxane, and/or one or more selected from vinylphenyl polysiloxane. For example, the base polymer may be one or more of methyl phenyl silicone rubber, methyl phenyl silicone oil, vinyl phenyl silicone oil, and the materials may be purchased directly.

In the present invention, the methylphenylpolysiloxane includes Me in its main chain₂SiO and selected from MePhSiO and Ph₂One or two structural units in SiO, and the end group is Me₃SiO, wherein Me is methyl and Ph is phenyl. For example, Me may be used₂SiO and MePhSiO as main chain and Me₃SiO-terminated methylphenyl polysiloxane; or may be Me₂SiO and Ph₂SiO as a main chain and Me₃SiO-terminated methylphenyl polysiloxane; or may be Me₂SiO、MePhSiO、Ph₂SiO as a main chain and Me₃SiO-terminated methylphenylpolysiloxanes. The above-mentioned methylphenylpolysiloxane may be used as it is. The methylphenylpolysiloxane in the examples of the invention is Me₂SiO and MePhSiO as main chain and Me₃SiO end group, methyl phenyl polysiloxane with phenyl content of 7%, though not limited thereto.

The vinylphenylpolysiloxane comprises MeViSiO and Me in its backbone₂SiO and selected from MePhSiO and Ph₂One or two structural units in SiO, and the end group is Me₃SiO or ViMe₂SiO, wherein Me is methyl, Vi is vinyl and Ph is phenyl. Specifically, for example, the phenyl-containing siloxane polymer may be represented by MeViSiO, Me₂SiO, MePhSiO as main chain, and ViMe₂Vinyl phenyl polysiloxane with SiO as a terminal group; or may be MeViSiO, Me₂SiO、MePhSiO、Ph₂SiO as a main chain and Me₃Vinyl phenyl polysiloxane with SiO as a terminal group; or may be MeViSiO, Me₂SiO、MePhSiO、Ph₂SiO as main chain and ViMe₂A vinyl phenyl polysiloxane with SiO as a terminal group. The vinylphenylpolysiloxanes mentioned above are all available as such.

In the above examples of the base polymer, Me represents a methyl group (-CH)₃) And Vi represents a vinyl group (-CH ═ CH)₂) Ph represents phenyl

Me₂SiO、MeViSiO、MePhSiO、Ph₂SiO、Me₃SiO、ViMe₂SiO is represented by the structural formula

The materials used as base polymers in the present invention, whether they contain phenylsiloxane polymers or non-phenylsiloxane polymers, may be Me₂SiO、MeViSiO、MePhSiO、Ph₂One or more SiO is/are taken as a main chain, and Me is used₃SiO or ViMe₂A siloxane polymer terminated with SiO; the phenyl group in the phenyl-containing siloxane polymer is MePhSiO or Ph₂The SiO structure exists. Specifically, for example, the base polymer is one or more of methyl polysiloxane, methyl vinyl polysiloxane, methyl phenyl polysiloxane and vinyl phenyl polysiloxane, and all of them can be purchased and used directly from various manufacturers.

In the invention, the filler can be one or more of silicon dioxide, mica, graphene, clay, calcium carbonate, carbon nano tube, kaolin and talcum powder. But not limited thereto, other fillers not listed in the present embodiment but known to those skilled in the art may be used. For example, the filler is silicon dioxide, the silicon dioxide can improve the fatigue resistance and other properties of the material, has better processability and dispersibility, can ensure that the filler and the base polymer are combined more tightly, enhances the reinforcing effect of the filler, and ensures that the diaphragm is not easy to break in the vibration process.

In the embodiment of the invention, the structure control agent can be one or more of dihydric alcohol, diorganocyclosiloxane, diorganosiloxane, alkoxysilane, low-molar-mass hydroxy silicone oil, an organosilicon compound containing Si-N bonds and an organosilicon compound containing Si-O-B bonds. Wherein, the hydroxyl silicone oil with low molar mass generally refers to the hydroxyl silicone oil with molecular weight of less than 100000. More preferably, the structure control agent is hydroxyl silicone oil and/or hydroxyl vinyl silicone oil, wherein the hydroxyl silicone oil with the molecular weight of 50000-60000 is selected as the hydroxyl silicone oil in the embodiment of the invention, and the hydroxyl silicone oil in the molecular weight range can simplify the processing technology of the silicone rubber and improve the process performance; the hydroxy vinyl silicone oil can be used as a structure control agent in the processing of silicone rubber to improve the temperature resistance and weather resistance of the material.

In the present invention, the crosslinking agent may be any of the following two. Wherein the first crosslinking agent is: one or a mixture of several of peroxy group-containing compounds; wherein the compound containing peroxy groups comprises 2, 4-dichlorobenzoyl peroxide, benzoyl peroxide, 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide, di-tert-butyl peroxide and dicumyl peroxide. The second crosslinking agent is a crosslinking agent comprising: one or more compositions of compounds containing platinum element, hydrogen-containing silicone oil and one or more acetylene alcohol inhibitors. The compound containing platinum element may be, for example, an alcohol solution of chloroplatinic acid, platinum (0) -1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane, or the like. The hydrogen-containing silicone oil can be side hydrogenSilicone oil, terminal hydrogen-containing silicone oil or terminal hydrogen-containing silicone oil. The alkynol inhibitor may be, for example, 1-ethynylcyclohexanol or the like. Among them, 2, 5-dimethyl-2, 5-di-tert-butylperoxy hexane is preferably used as the first crosslinking agent. The second cross-linking agent is preferably a mixture of an alcoholic solution of chloroplatinic acid, an alkynol inhibitor and one selected from the group consisting of lateral hydrogen silicone oil, lateral hydrogen silicone oil and terminal hydrogen silicone oil, wherein the amounts of the components are not particularly limited. In the embodiment of the invention, the chloroplatinic acid alcohol solution can be prepared by the following method: 3g of chloroplatinic acid H₂PtCl₆.6H₂Adding O into 100ml of anhydrous isopropanol, fully stirring to dissolve chloroplatinic acid for 4-8 h, and standing the solution for 12-14 h to prepare the chloroplatinic acid and isopropanol complex catalyst.

Fig. 1 schematically shows a process for producing a diaphragm. As shown in fig. 1, the process flow of the diaphragm includes: firstly, carrying out reduced pressure kneading/mixing on a base polymer, a filler, a structure control agent and a damping additive in a kneader/internal mixer at the temperature of 80-150 ℃ to obtain a rubber compound, and cooling to normal temperature for later use; then adding a cross-linking agent for kneading/mixing, and carrying out injection molding or mould pressing vulcanization molding at the temperature of 80-200 ℃ to prepare the vibrating diaphragm. In the preparation process, the raw materials can comprise the following components in percentage by weight: 40% -90% of a base polymer; 3% -60% of filler; 1 to 50 percent of damping additive and 0.5 to 10 percent of cross-linking agent; 1 to 10 percent of structure control agent, and the total content of all raw materials is 100 percent.

The invention also provides a sound production device which can comprise a vibration system and a magnetic circuit system matched with the vibration system, wherein the vibration system comprises a vibrating diaphragm and a voice coil combined on one side of the vibrating diaphragm. When the sound generating device works, the voice coil can vibrate up and down to drive the vibrating diaphragm to vibrate under the action of the magnetic field force of the magnetic circuit system after being electrified, and the vibrating diaphragm can generate sound during vibration. The sound production device such as a loudspeaker prepared by the vibrating diaphragm can obtain lower Total Harmonic Distortion (THD) under the same performance, the THD under low frequency can be as low as 12 percent, the sound production device has better sound production effect, such as good sound quality, higher definition, fullness, space feeling, brightness and softness, no abnormal sound and high fidelity, and has less swing vibration in the vibration process and more stable sound production.

The present invention further provides a sound generating apparatus, as shown in fig. 3 and fig. 4, the sound generating apparatus may include a casing 10, and a magnetic circuit system 20 and a vibration system which are disposed in the casing 10, and the vibration system may include a voice coil 33, a first diaphragm 31 and a second diaphragm 32, wherein a top of the voice coil 33 is connected to the first diaphragm 31, the magnetic circuit system 20 drives the voice coil 33 to vibrate to drive the first diaphragm 31 to generate sound, and two ends of the second diaphragm 32 are respectively connected to the casing 10 and a bottom of the voice coil 33. The second diaphragm 32 may be a diaphragm according to the above embodiment of the present invention.

That is, the first diaphragm 31 may be used to vibrate and generate sound, and the second diaphragm 32 may be used to balance the vibration of the voice coil 33. Specifically, when the sound generating device works, after the voice coil 33 is powered on, under the action of the magnetic force of the magnetic circuit system 20, the voice coil 33 can vibrate up and down to drive the first diaphragm 31 to vibrate, and sound can be generated when the first diaphragm 31 vibrates. The second diaphragm 32 can also vibrate up and down along with the voice coil 33, because the two ends of the second diaphragm 32 are connected with the bottom of the casing 10 and the voice coil 33 respectively, the second diaphragm 32 can balance the vibration of the voice coil 33, and can prevent the voice coil 33 from polarizing, thereby improving the sound production effect of the sound production device.

It should be noted that, the first diaphragm 31 and the second diaphragm 32 may both adopt the diaphragms of the above embodiments of the present invention, or one of the first diaphragm 31 and the second diaphragm 32 may adopt the diaphragm of the above embodiments of the present invention, and the present invention is not limited to this specifically.

The technical solution of the present invention will be further described with reference to the accompanying drawings, embodiments one to five, and comparative examples. It will be appreciated that the following description of exemplary embodiments is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

In the physical property detection of the first comparative example, the first embodiment to the fifth embodiment, a dynamic mechanical analyzer is adopted for damping/tensile strength, and the test frequency is 1 Hz; the hardness detection standard is GB/T1698-2003; detection standard of elongation at break: GB/T1701-2001.

In the first to fifth embodiments, one or more of the following three modified polysiloxanes are used as the damping additive. First modified polysiloxane: r is a group

x is 100, y is 50 and z is 30. Second modified polysiloxane: r is a group

x is 300, y is 200, and z is 90. Third modified polysiloxane: the R group is-C₃H₆NH₂Is specifically- (CH)₂)₃NH₂X is 200, y is 100, and z is 60.

The preparation of three modified polysiloxanes for use as damping additives in the present application is described below using three specific examples.

Preparation of third modified polysiloxane

The R group is-C₃H₆NH₂Aminopropyl phenyl silicone oil with x being 200, y being 100 and z being 60.

Adding methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane, tetramethyl tetravinylcyclotetrasiloxane, a basic catalyst, water, DMSO (dimethyl sulfoxide) and decamethyltetrasiloxane, heating to 90 ℃ in a nitrogen atmosphere, stirring for 3.5 hours, vacuumizing for 1 hour, cooling, adding acetic acid for neutralization, heating to 150 ℃, and removing small molecular substances in a system to obtain a third polysiloxane, namely aminopropyl phenyl silicone oil, wherein the basic catalyst is potassium hydroxide, and the aminopropyl phenyl silicone oil is terminated by methyl. The mass ratio of the methyl phenyl siloxane ring body to the aminopropyl methyl diethoxy silane to the tetramethyl tetravinylcyclotetrasiloxane is 41:29: 30. The dosage of the alkaline catalyst is 0.005 percent of the sum of the mass of three raw materials of methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane. The amount of the water is 1.5 percent of the total mass of three raw materials of methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane. The amount of the DMSO is 200% of the sum of the mass of three raw materials, namely methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane. The dosage of the decamethyltetrasiloxane is 2 percent of the sum of the mass of three raw materials, namely methyl phenyl siloxane ring body, aminopropyl methyl diethoxy silane and tetramethyl tetravinylcyclotetrasiloxane.

First method for preparing modified polysiloxane

R is a group

And x is 100, y is 50, and z is 30.

Dissolving the aminopropyl phenyl silicone oil prepared by the third modified polysiloxane preparation method by using dimethylbenzene, then adding phthalic anhydride with the same mole number as that of aminopropyl methyl diethoxy silane in the aminopropyl phenyl silicone oil, introducing nitrogen for protection, then carrying out cold flow reflux at 80 ℃ for about 3 hours, cleaning by using an aqueous alkali solution to remove unreacted anhydride, then separating out an upper layer organic matter, and carrying out vacuum decompression and xylene extraction to obtain the first modified polysiloxane.

Second method for preparing modified polysiloxane

R is a group

And x is 300, y is 200, and z is 90.

Dissolving aminopropyl phenyl silicone oil prepared by the third modified polysiloxane preparation method by using dimethylbenzene, adding 1, 8-naphthalic anhydride with the same mole number as that of aminopropyl methyl diethoxy silane in the aminopropyl phenyl silicone oil, introducing nitrogen for protection, performing cold flow reflux at 80 ℃ for about 3 hours, cleaning by using an aqueous alkali solution to remove unreacted anhydride, separating out an upper layer organic matter, and performing vacuum pressure reduction to extract the dimethylbenzene to obtain the second modified polysiloxane.

The following describes in detail the preparation methods of the diaphragms in the first comparative example, the first embodiment to the fifth embodiment and the corresponding detection results of the relevant physical properties of the diaphragms.

Comparative example 1

Methyl vinyl polysiloxane is used as a basic polymer, silicon dioxide is used as a filler, hydroxy silicone oil is used as a structure control agent, 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide is used as a crosslinking agent, and a damping additive is not added. Specifically, the materials are prepared according to 65 mass percent of methyl vinyl polysiloxane, 30 mass percent of silicon dioxide, 3 mass percent of hydroxyl silicone oil and 2 mass percent of 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide.

Carrying out reduced pressure mixing on the basic polymer, the filler and the structure control agent in an internal mixer at 100 ℃ to obtain rubber compound, and cooling to normal temperature for later use; then, a cross-linking agent is added into the rubber compound for mixing, and vulcanization molding is carried out at 150 ℃ to obtain the vibrating diaphragm with the thickness of 100 mu m.

Through detection, the Shore hardness of the diaphragm of the comparative example is about 50A, and the damping of the diaphragm is only 0.07; elongation at break is 430%, and tensile strength is 8.5 MPa; the harmonic distortion THD test curve of the loudspeaker adopting the diaphragm is shown in figure 2, and the THD is more than 30% at the frequency of 100 Hz. Therefore, the diaphragm of the comparative example has low damping, higher harmonic distortion and poor sound production effect.

Example one

Polydimethylsiloxane is adopted as a base polymer, silicon dioxide is adopted as a filler, the first modified polysiloxane is added to be used as a damping additive, hydroxy vinyl silicone oil and hydroxy silicone oil are adopted as structure control agents, and 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide is adopted as a cross-linking agent. Specifically, the materials are prepared according to the mass percentage of 80% of polydimethylsiloxane, 9% of silicon dioxide, 3% of damping additive, 3% of hydroxy vinyl silicone oil, 3% of hydroxy silicone oil and 2% of 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide.

Carrying out reduced pressure mixing on a base polymer, a filler, a structure control agent and a damping additive for 6 hours in an internal mixer at 100 ℃ to obtain a rubber compound, and cooling to normal temperature for later use; then, a cross-linking agent is added into the rubber compound for mixing, and vulcanization molding is carried out at 150 ℃ to obtain the vibrating diaphragm with the thickness of 120 mu m.

Through detection, the shore hardness of the diaphragm of the embodiment is about 20A, and the damping of the diaphragm is 0.11; elongation at break of about 721 percent and tensile strength of 5.0 MPa; the THD test curve of the harmonic distortion of the speaker using the diaphragm is shown in fig. 2, and compared to the comparative example, the THD of the example is reduced by about 25% at a frequency of 100 Hz.

Therefore, the embodiment improves the vibration film damping and reduces THD by adding 3% of the first damping additive, and has better mechanical property. The test shows that the loudspeaker adopting the vibrating diaphragm has higher definition, fullness, space sense, brightness and softness, no abnormal sound and high fidelity, and the vibrating diaphragm has less swinging vibration and more stable listening in the vibration process.

Example two

Methyl vinyl polysiloxane is used as a base polymer, silicon dioxide is used as a filler, the first modified polysiloxane is added to be used as a damping additive, hydroxy vinyl silicone oil is used as a structure control agent, and alcohol solution of hydrogen-containing silicone oil, alkynol inhibitor and chloroplatinic acid is used as a cross-linking agent. Specifically, the ingredients are calculated according to the mass percentage of 75 percent of methyl vinyl polysiloxane, 10 percent of silicon dioxide, 10 percent of damping additive, 2 percent of hydroxy vinyl silicone oil, 2.5 percent of end side hydrogen silicone oil and propargyl alcohol inhibitor and 0.5 percent of alcohol solution of chloroplatinic acid.

Carrying out reduced pressure mixing on a base polymer, a filler, a structure control agent and a damping additive in an internal mixer at 150 ℃ to obtain a rubber compound, and cooling to normal temperature for later use; then, a cross-linking agent is added into the rubber compound for mixing, and vulcanization molding is carried out at 180 ℃ to obtain the vibrating diaphragm with the thickness of 110 mu m.

Through detection, the shore hardness of the second vibrating diaphragm of the embodiment is about 35A, and the damping of the vibrating diaphragm is 0.17; elongation at break is about 654%, and tensile strength is 6.5 MPa; the harmonic distortion THD test curve of a speaker using the diaphragm is shown in fig. 2, and the THD is about 21% at a frequency of 100 Hz.

Therefore, the embodiment improves the vibration film damping and reduces THD by adding 10% of the first damping additive, and has excellent mechanical properties. The test shows that the loudspeaker adopting the vibrating diaphragm has higher definition, fullness, space sense, brightness and softness, no abnormal sound and high fidelity, and the vibrating diaphragm has less swinging vibration and more stable listening in the vibration process.

EXAMPLE III

Methyl vinyl polysiloxane is used as a base polymer, silicon dioxide is used as a filler, the third modified polysiloxane is added to be used as a damping additive, hydroxy vinyl silicone oil and hydroxy silicone oil are used as structure control agents, and alcoholic solution containing hydrogen silicone oil, alkynol inhibitor and chloroplatinic acid is used as a cross-linking agent. Specifically, the materials are prepared according to the mass percentage of 60 percent of methyl vinyl polysiloxane, 19 percent of silicon dioxide, 15 percent of damping additive, 2 percent of hydroxyl vinyl silicone oil, 1 percent of hydroxyl silicone oil, 2.5 percent of hydrogen-containing silicone oil and alkynol inhibitor and 0.5 percent of alcohol solution of chloroplatinic acid.

Carrying out reduced pressure mixing on a base polymer, a filler, a structure control agent and a damping additive in an internal mixer at 120 ℃ to obtain a rubber compound, and cooling to normal temperature for later use; and then adding a cross-linking agent into the rubber compound for mixing, and vulcanizing and molding at 120 ℃ to obtain the vibrating diaphragm with the thickness of 90 mu m.

According to detection, the shore hardness of the diaphragm of the first embodiment is about 60A, and the damping of the diaphragm is 0.45; the elongation at break is about 632 percent, and the tensile strength is 9.0 MPa; the harmonic distortion THD test curve of a speaker using the diaphragm is shown in fig. 2, and the THD is about 19% at a frequency of 100 Hz.

Therefore, the embodiment improves the damping of the vibrating diaphragm and reduces THD by adding 15% of the third damping additive, and has excellent mechanical properties. The test shows that the loudspeaker adopting the vibrating diaphragm has higher definition, fullness, space sense, brightness and softness, no abnormal sound and high fidelity, and the vibrating diaphragm has less swinging vibration and more stable listening in the vibration process.

Example four

Methyl vinyl polysiloxane and methyl phenyl polysiloxane are used as basic polymers, silicon dioxide is used as a filler, the first modified polysiloxane and the second modified polysiloxane are added to be used as damping additives together, hydroxy silicone oil is used as a structure control agent, and 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide is used as a cross-linking agent. Specifically, the materials are prepared according to the following mass percent of 25% of methyl vinyl polysiloxane, 25% of methyl phenyl polysiloxane, 16% of silicon dioxide, 9% of first polysiloxane damping additive, 20% of second polysiloxane damping additive, 2% of hydroxy silicone oil and 3% of 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide.

Carrying out reduced pressure mixing on a base polymer, a filler, a structure control agent and a damping additive in an internal mixer at 100 ℃ to obtain a rubber compound, and cooling to normal temperature for later use; and then adding a cross-linking agent into the rubber compound for mixing, and vulcanizing and molding at 150 ℃ to obtain the vibrating diaphragm with the thickness of 85 microns.

According to the detection, the shore hardness of the diaphragm of the embodiment is about 65A, and the damping of the diaphragm is 0.62; the elongation at break is about 232 percent, and the tensile strength is 7.3 MPa; the harmonic distortion THD test curve of a speaker using the diaphragm is shown in fig. 2, and the THD is about 15% at a frequency of 100 Hz.

It can be seen that in this example, with methylvinylpolysiloxane and methylphenylpolysiloxane as base polymers, the addition of 9% of the first damping additive and 20% of the second damping additive increases the diaphragm damping and reduces the THD. The test shows that the loudspeaker adopting the vibrating diaphragm has higher definition, fullness, space sense, brightness and softness, no abnormal sound and high fidelity, and the vibrating diaphragm has less swinging vibration and more stable listening in the vibration process.

EXAMPLE five

Methyl phenyl polysiloxane is used as a base polymer, silicon dioxide is used as a filler, the first modified polysiloxane and the second modified polysiloxane are added to be used as damping additives together, hydroxy silicone oil is used as a structure control agent, and 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide is used as a crosslinking agent. Specifically, the materials are prepared according to the mass percentage of 52 percent of methyl phenyl polysiloxane, 4 percent of silicon dioxide, 9 percent of first polysiloxane damping additive, 30 percent of second polysiloxane damping additive, 2 percent of hydroxyl silicone oil and 3 percent of 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide.

Carrying out reduced pressure mixing on a base polymer, a filler, a structure control agent and a damping additive in an internal mixer at 100 ℃ to obtain a rubber compound, and cooling to normal temperature for later use; and then adding a cross-linking agent into the rubber compound for mixing, and vulcanizing and molding at 150 ℃ to obtain the vibrating diaphragm with the thickness of 90 mu m.

Through detection, the shore hardness of the diaphragm of the first embodiment is about 90A, and the damping of the diaphragm is 0.73; the elongation at break is about 153 percent, and the tensile strength is 7.0 MPa; the harmonic distortion THD test curve of a speaker using the diaphragm is shown in fig. 2, and the THD is about 12% at a frequency of 100 Hz.

It can be seen that in this example, 9% of the first damping additive and 30% of the second damping additive were added to the methylphenyl polysiloxane base polymer to improve the diaphragm damping and reduce the THD. The test shows that the loudspeaker adopting the vibrating diaphragm has higher definition, fullness, space sense, brightness and softness, no abnormal sound and high fidelity, and the vibrating diaphragm has less swinging vibration and more stable listening in the vibration process.

In summary, the damping of the diaphragm in the first to fifth embodiments of the present invention is all above 0.11; also as shown in FIG. 2, the THD of the present invention is much lower than that of comparative example one at a frequency of 100Hz to 1000Hz, for example, the THD of comparative example one is about 32% at a frequency of 100Hz, and the THD of examples one to five of the present invention are about 26%, 22%, 19%, 15%, 12%, respectively; therefore, the damping loss of the vibrating diaphragm is improved and the THD is reduced by adding the damping additive in the first to fifth embodiments of the invention.

In addition, if the total addition amount of the damping additive is too high, the elongation at break and the tensile strength are reduced, and when the damping, the mechanical property and the THD of the vibrating diaphragm are comprehensively considered, the addition amount of the damping is preferably 15-25%, so that the mechanical property of the vibrating diaphragm can be ensured not to be reduced under the condition that the damping of the vibrating diaphragm is increased to be above 0.11, and a sound generating device using the vibrating diaphragm can obtain lower Total Harmonic Distortion (THD) under the same property and has better acoustic property.

The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. The vibrating diaphragm for the sound production device is characterized in that the vibrating diaphragm is obtained by taking polysiloxane as a basic polymer, adding a damping additive, a filler, a structure control agent and a cross-linking agent into the basic polymer, mixing, and molding at 80-200 ℃, wherein the damping additive is selected from modified polysiloxane, and the main chain of the modified polysiloxane has a structure shown in the following average composition formula 1:

[ average composition formula 1]

Wherein R is a group

2. The diaphragm for a sound-emitting device as claimed in claim 1,

the dosage of the damping additive is 1-50% of the total weight of the base polymer, the damping additive, the filler, the structure control agent and the cross-linking agent.

3. The diaphragm for a sound-emitting device according to claim 2,

the dosage of the damping additive is 15-25% of the total weight of the base polymer, the damping additive, the filler, the structure control agent and the crosslinking agent.

4. The diaphragm for a sound-emitting device as claimed in claim 1,

the base polymer is a polysiloxane or a combination of several polysiloxanes, the polysiloxane comprises Me in the main chain₂SiO、MeViSiO、MePhSiO、Ph₂One or more structural units in SiO, and Me as end group₃SiO and/or ViMe₂SiO, wherein Me is methyl, Vi is vinyl and Ph is phenyl.

5. The diaphragm for a sound-emitting device as claimed in claim 4,

the basic polymer is one or more of methyl polysiloxane, methyl vinyl polysiloxane, methyl phenyl polysiloxane and vinyl phenyl polysiloxane.

6. The diaphragm for a sound-emitting device as claimed in claim 1,

the filler is one or more of silicon dioxide, mica, graphene, clay, calcium carbonate, carbon nano tubes, kaolin and talcum powder.

7. The diaphragm for a sound-emitting device as claimed in claim 1,

the structure control agent is one or more of dihydric alcohol, diorganocyclosiloxane, diorganosilanediol, alkoxysilane, low-molar-mass hydroxy silicone oil, an organosilicon compound containing Si-N bonds, and an organosilicon compound containing Si-O-B bonds.

8. The diaphragm for a sound-emitting device as claimed in claim 1,

the cross-linking agent is one or a mixture of more of 2, 4-dichlorobenzoyl peroxide, benzoyl peroxide, 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide, di-tert-butyl peroxide and dicumyl peroxide;

or the cross-linking agent is one or more of a compound/composition containing platinum element, hydrogen-containing silicone oil and alkynol inhibitor.

9. The diaphragm for the sound production device as claimed in claim 1, wherein the damping of the diaphragm is 0.1-0.75.

10. The diaphragm for a sound-emitting device according to claim 1, wherein the diaphragm has a hardness of 20A to 95A.

11. The diaphragm for a sound-producing device as claimed in claim 1, wherein the tensile strength of the diaphragm is 1MPa to 15 MPa.

12. The diaphragm for a sound-emitting device according to claim 1, wherein the thickness of the diaphragm is 40 μm to 150 μm.

13. A sound production device, comprising a vibration system and a magnetic circuit system matched with the vibration system, wherein the vibration system comprises a diaphragm and a voice coil combined on one side of the diaphragm, the magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to produce sound, and the diaphragm is the diaphragm according to any one of claims 1 to 12.

14. A sound production device is characterized by comprising a shell, a magnetic circuit system and a vibration system, wherein the magnetic circuit system and the vibration system are arranged in the shell, the vibration system comprises a voice coil, a first vibrating diaphragm and a second vibrating diaphragm, the top of the voice coil is connected with the first vibrating diaphragm, the magnetic circuit system drives the voice coil to vibrate so as to drive the first vibrating diaphragm to produce sound, two ends of the second vibrating diaphragm are respectively connected with the shell and the bottom of the voice coil, and the second vibrating diaphragm is the vibrating diaphragm in any one of claims 1-12.