阅读说明：本技术 一种扬声器用阻燃纸盆及其制备方法 (Flame-retardant cone for loudspeaker and preparation method thereof ) 是由 司景航 王世伟 谢守华 黄汉雄 陈进 于 2020-05-08 设计创作，主要内容包括：本发明提供一种扬声器用阻燃纸盆及其制备方法。所述扬声器用阻燃纸盆的制备原料包括：未漂白硫酸盐木浆、棉浆、玄武岩纤维、阻燃剂和增硬剂。所述扬声器用阻燃纸盆阻燃性优良,强度高,且纸盆的吸潮性小,音质稳定。(The invention provides a flame-retardant cone for a loudspeaker and a preparation method thereof. The preparation raw materials of the flame-retardant cone for the loudspeaker comprise: unbleached sulfate wood pulp, cotton pulp, basalt fiber, flame retardants, and hardeners. The flame-retardant cone for the loudspeaker is excellent in flame retardance, high in strength, small in moisture absorption and stable in tone quality.)

1. The flame-retardant cone for the loudspeaker is characterized in that the flame-retardant cone for the loudspeaker is prepared from the following raw materials: unbleached sulfate wood pulp, cotton pulp, basalt fiber, flame retardants, and hardeners.

2. The flame-retardant cone for the loudspeaker according to claim 1, wherein the flame-retardant cone for the loudspeaker is prepared from the following raw materials in parts by weight: 40-80 parts of unbleached sulfate wood pulp, 10-50 parts of cotton pulp, 5-20 parts of basalt fiber, 0.1-1 part of flame retardant and 1-3 parts of hardening agent.

3. The flame-retardant cone for speakers according to claim 1 or 2, wherein the monofilament diameter of basalt fiber is 10 to 20 μm;

preferably, the monofilament length of the basalt fiber is 3 to 5 mm.

4. The flame-retardant cone for speakers according to any one of claims 1 to 3, wherein the flame retardant is a phosphorus-based flame retardant;

preferably, the phosphorus flame retardant is ammonium polyphosphate and/or polyphosphoester.

5. The flame retardant cone for speaker as claimed in any one of claims 1 to 4, wherein said hardening agent comprises butyl acetate, acrylic resin and toluene;

preferably, the hardening agent comprises 30-35% of butyl acetate, 8-10% of acrylic resin and 50-60% of toluene by mass percent based on 100% of the hardening agent;

preferably, the viscosity of the hardening agent is 100-300cps at 25 ℃.

6. The method for preparing the flame-retardant cone for the loudspeaker according to any one of claims 1 to 5, wherein the method for preparing the flame-retardant cone for the loudspeaker comprises the following steps: mixing unbleached sulfate wood pulp and cotton pulp, pulping, mixing with basalt fiber, papermaking, hot pressing, soaking in a flame retardant and soaking in a hardening agent to obtain the flame-retardant cone for the loudspeaker.

7. The preparation method according to claim 6, characterized in that the specific steps of beating are as follows: crushing unbleached sulfate wood pulp and cotton pulp, placing the crushed unbleached sulfate wood pulp and cotton pulp in a beater, adding water for dilution, and beating to obtain pulp;

preferably, the beating degree of the slurry is 15-20 ° SR;

preferably, the papermaking method comprises the following specific steps: mixing the pulp obtained by pulping with basalt fibers, diluting with water to obtain a fiber suspension, and filtering the fiber suspension to obtain a cone blank;

preferably, the hot pressing comprises the following specific steps: placing the paper basin blank obtained by papermaking in a high-temperature die, and squeezing and drying to obtain a paper basin blank;

preferably, the drying temperature is 100-150 ℃, and the drying time is 5-20 s.

8. The preparation method according to any one of claims 6 or 7, characterized in that the flame retardant dipping specific steps are as follows: soaking the cone blank obtained by hot pressing in a diluent of a flame retardant to obtain a flame-retardant cone blank;

preferably, the diluent of the flame retardant comprises the flame retardant and a solvent A, and the mass ratio of the flame retardant to the solvent A is 1 (1-4);

preferably, the solvent a is water;

preferably, the concrete steps of the hardening-soaking agent are as follows: soaking the flame-retardant cone blank obtained by soaking the flame retardant into a diluent of a hardening agent to obtain a flame-retardant hardening cone blank;

preferably, the diluent of the hardening agent comprises the hardening agent and a solvent B, and the mass ratio of the hardening agent to the solvent B is (1-3): 5;

preferably, the solvent B is toluene;

preferably, the flame-retardant stiffening cone blank obtained by dipping the stiffening agent needs to be dried at the temperature of 50-60 ℃ for 30-50 min.

9. The production method according to any one of claims 6 to 8, further comprising, after the hardening agent impregnation treatment, a punching treatment: and removing the middle hole and the rim charge of the cone blank treated by the hardening agent by using a punching die to obtain the flame-retardant cone for the loudspeaker.

10. The preparation method according to any one of claims 6 to 9, wherein the preparation method of the flame-retardant cone for the loudspeaker specifically comprises the following steps:

(1) pulping: crushing pulp boards of unbleached sulfate wood pulp and cotton pulp, putting the crushed pulp boards into a beating machine, adding water for dilution, and beating to obtain pulp with a beating degree of 15-20 DEG SR;

(2) papermaking: mixing the slurry obtained in the step (1) with basalt fibers, diluting with water to obtain a fiber suspension, and filtering the fiber suspension to obtain a cone blank;

(3) hot pressing: placing the cone blank obtained in the step (2) in a high-temperature die for squeezing, and drying at the temperature of 100-150 ℃ for 5-20s to obtain a cone blank;

(4) soaking a flame retardant: soaking the cone blank obtained in the step (3) in a diluent of a flame retardant to obtain a flame-retardant cone blank;

(5) dipping hardening agent: soaking the flame-retardant cone blank obtained in the step (4) in a diluent of a hardening agent, taking out the flame-retardant cone blank after soaking, and drying the flame-retardant cone blank for 30-50min at 50-60 ℃ to obtain the flame-retardant hardening cone blank;

(6) punching: and (5) removing the middle hole and the rim charge of the flame-retardant stiffened cone blank obtained in the step (5) by using a punching die to obtain the flame-retardant cone for the loudspeaker.

Technical Field

The invention belongs to the technical field of electroacoustic, and particularly relates to a flame-retardant cone for a loudspeaker and a preparation method thereof.

Background

The loudspeaker cone is a special paper product, which is the most combustible object in television or radio; when the whole machine breaks down, the paper basin can catch fire to cause fire, and potential safety hazards exist. Flame retardant performance is therefore an important issue in the production of speaker cones. And because the water solubility of the flame retardant is limited, the flame retardant effect will be reduced or limited when the paper is wet. At present, the materials of the cone are mainly pulp and other materials, and in recent years, materials with different characteristics enter, such as polypropylene, carbon fiber, metal titanium and the like, and even diamond. But the paper pulp is mainly used, on one hand, the paper pulp is low in cost, and on the other hand, the paper pulp is easy to be made into a complex curved surface required by the loudspeaker diaphragm. The decisive contribution to the sound of the loudspeaker is the formulation of the cone paste. The existing paper pulp production formula is usually composed of wood fibers such as softwood fibers and hardwood fibers to improve the tone quality, and the research on how to improve the flame retardant property of the paper cone while improving the tone quality is less.

CN110219206A discloses a waterproof flame-retardant cone, a loudspeaker and a preparation method of the cone, wherein the waterproof flame-retardant cone is composed of slurry, the front side of the waterproof flame-retardant cone contains a waterproof agent, and the back side of the waterproof flame-retardant cone contains a flame retardant; according to the waterproof and flame-retardant cone, the problem that the mutual reaction influence effect exists when the flame retardant and the waterproof agent are mixed for use is solved, the flame retardant is coated on one surface of the cone, and the waterproof agent is coated on the other surface of the cone, so that the whole cone cannot be guaranteed to have flame retardance and moisture resistance, when the cone is exposed to open fire for a long time, the risk of ignition still exists, and the rigidity of the cone is low.

CN 110644288A discloses a water-resistant flame-retardant paper, a preparation method and application thereof. The water-resistant flame-retardant paper is made by mixing 70-90 wt% of flame-retardant fibers and 10-30 wt% of plant fibers, and has good water resistance and flame retardance. The method has the following defects: the water-resistant flame-retardant paper has low content of plant fibers, greatly limits the selection of cone materials, and is not beneficial to adjusting the tone and the tone quality of the loudspeaker according to actual requirements.

CN106948211A discloses a waterproof flame-retardant paper cone, which is prepared by stirring and mixing paper pulp, a filler, a toughening agent, a regulator, a waterproof agent and a flame retardant, wherein the flame retardant is prepared by mixing and uniformly stirring kaolin, decabromodiphenylethane, antimony trioxide and magnesium hydroxide in proportion. The method has the following defects: the fire retardant is compounded by a plurality of inorganic fillers, the bonding force of the fillers and plant fibers is poor, and the fire retardant is seriously lost when the paper cone is manufactured, so that the fire retardant effect of the paper cone is inevitably influenced.

CN 110318286A discloses a preparation method of halogen-free sound-absorbing flame-retardant paper. The preparation method comprises the following steps: grinding into thick liquid, synthesizing inorganic fire retardant in situ with plant fiber, preparing pulp, making paper, dipping and drying. The pulp comprises 40-70% of softwood pulp, 30-60% of glass fiber and 5-20% of polyvinyl alcohol solution by mass concentration. The prepared paper is green and environment-friendly, and has good sound absorption and flame retardance. The disadvantages of this approach include: a. the slurry contains 30-60% of glass fiber, and is not beneficial to flexibly adjusting the slurry formula to meet the requirements of sound quality and tone quality of the loudspeaker when being applied to the loudspeaker cone; b. the paper flame-retardant treatment method has complicated procedures, and particularly, the consistency is difficult to control when the inorganic flame retardant is synthesized in situ on plant fibers.

Therefore, how to develop the waterproof flame-retardant cone has important significance and value, and the waterproof flame-retardant cone has better moisture resistance and flame retardant property, strong rigidity and good tone quality.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a flame-retardant cone for a loudspeaker and a preparation method thereof. The flame-retardant cone for the loudspeaker is excellent in flame retardance, high in strength, small in moisture absorption and stable in tone quality.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a flame-retardant cone for a loudspeaker, which is prepared from the following raw materials: unbleached sulfate wood pulp, cotton pulp, basalt fiber, flame retardants, and hardeners.

The preparation raw materials of the flame-retardant cone for the loudspeaker comprise: unbleached sulfate wood pulp, cotton pulp, basalt fiber, a flame retardant and a hardening agent are matched with each other, so that the flame retardance and the strength of the cone are effectively improved, and the cone has small moisture absorption and stable tone quality.

The flame-retardant cone paper pulp for the loudspeaker is prepared by compounding unbleached sulfate wood pulp and cotton pulp, and the unbleached sulfate wood pulp and the cotton pulp are combined to form tough fibers, so that the rigidity and toughness of the flame-retardant cone paper for the loudspeaker are improved, and the strength of the flame-retardant cone paper for the loudspeaker is ensured. Among them, Unbleached Kraft Pulp (UKP) has less fiber damage, good toughness and high strength. The fine fibers of the fiber cell walls of the cotton pulp form an angle of 45 degrees with the main fiber shaft, the content of the alpha-cellulose is high, the cotton pulp fibers are long, and the fibers are not easy to swell and longitudinally split during beating.

The paper cone is endowed with flame retardance by adding basalt fibers with good flame retardance into paper pulp and cooperating with a flame retardant, and the basalt fibers and the flame retardant are synergistic, so that the paper cone can be endowed with more excellent flame retardance. The basalt fiber is an inorganic fiber prepared by carrying out centrifugal spinning on industrial waste residues or natural rocks by a melting method, has the advantages of good chemical stability, good mechanical property, high temperature resistance, good flame retardant property and the like, is cylindrical, has a smooth surface, is not easy to adsorb a flame retardant, is mainly distributed on the surface of the plant fiber, and plays a role in protecting the plant fiber from burning.

After the hardening agent is cured, a layer of polymer film is covered on the surface of the cone, so that the moisture absorption of the flame retardant can be effectively prevented, and the effect of improving the strength of the cone is achieved.

Preferably, the preparation raw materials of the flame-retardant cone for the loudspeaker comprise, by weight: 40-80 parts of unbleached sulfate wood pulp, 10-50 parts of cotton pulp, 5-20 parts of basalt fiber, 0.1-1 part of flame retardant and 1-3 parts of hardening agent.

In the preparation raw material of the flame-retardant cone for the loudspeaker, the content of unbleached sulfate wood pulp is 40-80 parts, such as 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts and the like.

The content of the cotton pulp in the raw materials for preparing the flame-retardant cone for the loudspeaker is 10-50 parts, such as 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts and the like.

In the raw material for preparing the flame-retardant cone for the loudspeaker, the content of the basalt fiber is 5 to 20 parts, and for example, the basalt fiber content may be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts and the like.

The flame retardant cone for speakers is prepared from 0.1-1 parts of flame retardant, such as 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, etc.

The content of the hardening agent in the raw materials for preparing the flame-retardant cone for a loudspeaker is 1 to 3 parts, and may be, for example, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts and the like.

Preferably, the basalt fiber has a monofilament diameter of 10 to 20 μm, and may be, for example, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, or the like.

Preferably, the basalt fiber has a monofilament length of 3 to 5mm, and may be, for example, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5mm, or the like.

The monofilament diameter of the basalt fiber is easy to disperse within the range of 10-20 microns, so that slurry and the basalt fiber are mixed more uniformly, the monofilament length of the basalt fiber is 3-5mm, the monofilament length of the basalt fiber is too long, the combination of the basalt fiber and the plant fiber is not good, the reinforcing effect of the basalt fiber on a cone is influenced to a certain extent, and in addition, the surface of a final product is too rough; when the length of the basalt fiber monofilament is too short, the retention rate of a large amount of basalt fibers in paper is not high.

Preferably, the flame retardant is a phosphorus-based flame retardant.

Preferably, the phosphorus flame retardant is ammonium polyphosphate and/or polyphosphoester.

The ammonium polyphosphate and/or the polyphosphate generates a volatile phosphorus compound and phosphoric acid in a combustion state, and the volatile phosphorus compound dilutes combustible gas and oxygen in a gas form to play a role in dilution; phosphoric acid will become metaphosphoric acid and polymetaphosphoric acid again, and a non-volatile phosphoric acid polymer protective film is formed on the surface of the cone. Thereby playing a role of flame retardance.

Preferably, the hardening agent includes butyl acetate, acrylic resin and toluene.

According to the invention, butyl acetate, acrylic resin and toluene are selected to be compounded to obtain the hardening agent, and the hardening agent can cover a layer of polymer film on the surface of the paper cone after being cured, so that the moisture absorption of the phosphorus flame retardant (especially ammonium polyphosphate) can be effectively prevented, and the effect of improving the strength of the paper cone is also achieved.

Preferably, the hardening agent comprises 30-35% of butyl acetate, 8-10% of acrylic resin and 50-60% of toluene by mass percent based on 100% of the hardening agent.

The butyl acetate content may be 30 to 35%, for example, 30%, 31%, 32%, 33%, 34%, 35%, or the like, based on 100% by mass of the hardening agent.

The acrylic resin content may be 8 to 10%, for example, 8%, 8.5%, 9%, 9.5%, 10%, etc., based on 100% by mass of the hardening agent.

The toluene content may be 50 to 60%, for example, 50%, 52%, 54%, 56%, 58%, 60% or the like, based on 100% by mass of the hardening agent.

Preferably, the viscosity of the hardening agent is 100-300cps at 25 ℃, and may be, for example, 100cps, 120cps, 140cps, 160cps, 180cps, 200cps, 220cps, 240cps, 260cps, 280cps, 300cps, or the like.

In a second aspect, the present invention provides a method for manufacturing a flame retardant cone for a speaker according to the first aspect, wherein the method for manufacturing the flame retardant cone for a speaker comprises: mixing unbleached sulfate wood pulp and cotton pulp, pulping, mixing with basalt fiber, papermaking, hot pressing, soaking in a flame retardant and soaking in a hardening agent to obtain the flame-retardant cone for the loudspeaker.

Preferably, the pulping comprises the following specific steps: the method comprises the following steps of crushing unbleached sulfate wood pulp and cotton pulp, putting the crushed unbleached sulfate wood pulp and cotton pulp into a beater, adding water for dilution, and beating to obtain pulp.

Preferably, the degree of beating of the slurry is 15 to 20 ° SR, and may be, for example, 15 ° SR, 16 ° SR, 17 ° SR, 18 ° SR, 19 ° SR, 20 ° SR, or the like.

Preferably, the papermaking method comprises the following specific steps: and mixing the pulp obtained by pulping with basalt fibers, diluting with water to obtain a fiber suspension, and filtering the fiber suspension to obtain a cone blank.

Preferably, the hot pressing comprises the following specific steps: and placing the paper basin blank obtained by papermaking in a high-temperature die, and squeezing and drying to obtain the paper basin blank.

Preferably, the drying temperature is 100-150 ℃, such as 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃ and the like, and the drying time is 5-20s, such as 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, 20s and the like.

Preferably, the flame retardant dipping specific steps are as follows: and soaking the cone blank obtained by hot pressing in a diluent of a flame retardant to obtain the flame-retardant cone blank.

The method is different from the method of directly adding a fire retardant into pulp of paper pulp or preparing a fire retardant solution and then coating, and directly adopts the method of soaking the cone blank obtained by hot pressing into the diluent of the fire retardant for fire retardant treatment, so that the soaking method can ensure that the whole cone has the fire retardant property, and is more beneficial to more uniformly combining the fire retardant with plant fibers so as to further improve the fire retardant property.

Preferably, the diluent of the flame retardant comprises the flame retardant and a solvent A, and the mass ratio of the flame retardant to the solvent A is 1 (1-4), and can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 and the like.

Preferably, the solvent a is water.

Preferably, the concrete steps of the hardening-soaking agent are as follows: and soaking the flame-retardant cone blank obtained by soaking the flame retardant into a diluent of the hardening agent to obtain the flame-retardant hardening cone blank.

The invention is different from the method of directly adding the hardening agent into the pulp of the paper pulp or preparing the pulp into the hardening agent solution for coating, and directly soaks the flame-retardant cone blank obtained by soaking the flame retardant into the diluent of the hardening agent for hardening treatment, and the soaking method is favorable for covering a layer of uniform polymer film on the whole cone and combining the polymer film with the plant fiber, thereby effectively preventing the cone soaked with the phosphorus flame retardant from absorbing moisture and further improving the strength of the cone.

Preferably, the diluent of the hardening agent comprises the hardening agent and the solvent B, and the mass ratio of the hardening agent to the solvent B is (1-3):5, and can be 1:5, 1.2:5, 1.4:5, 1.6:5, 1.8:5, 2:5, 2.2:5, 2.4:5, 2.6:5, 2.8:5, 3:5 and the like.

Preferably, the solvent B is toluene.

Preferably, the flame-retardant stiffening cone blank obtained by dipping the stiffening agent needs to be dried at 50-60 ℃, for example, 50 ℃, 52 ℃, 54 ℃, 56 ℃, 58 ℃, 60 ℃ and the like, and the drying time is 30-50min, for example, 30min, 35min, 40min, 45min, 50min and the like.

Preferably, the hardening agent soaking treatment further comprises a punching treatment: and removing the middle hole and the rim charge of the cone blank treated by the hardening agent by using a punching die to obtain the flame-retardant cone for the loudspeaker.

Preferably, the preparation method of the flame-retardant cone for the loudspeaker specifically comprises the following steps:

(1) pulping: crushing pulp boards of unbleached sulfate wood pulp and cotton pulp, putting the crushed pulp boards into a beating machine, adding water for dilution, and beating to obtain pulp with a beating degree of 15-20 DEG SR;

(2) papermaking: mixing the slurry obtained in the step (1) with basalt fibers, diluting with water to obtain a fiber suspension, and filtering the fiber suspension to obtain a cone blank;

(3) hot pressing: placing the cone blank obtained in the step (2) in a high-temperature die for squeezing, and drying at the temperature of 100-150 ℃ for 5-20s to obtain a cone blank;

(4) soaking a flame retardant: soaking the cone blank obtained in the step (3) in a diluent of a flame retardant to obtain a flame-retardant cone blank;

(5) dipping hardening agent: soaking the flame-retardant cone blank obtained in the step (4) in a diluent of a hardening agent, taking out the flame-retardant cone blank after soaking, and drying the flame-retardant cone blank for 30-50min at 50-60 ℃ to obtain the flame-retardant hardening cone blank;

(6) punching: and (5) removing the middle hole and the rim charge of the flame-retardant stiffened cone blank obtained in the step (5) by using a punching die to obtain the flame-retardant cone for the loudspeaker.

Compared with the prior art, the invention has the following beneficial effects:

(1) the flame-retardant cone for the loudspeaker adopts unbleached sulfate wood pulp and cotton pulp mixed slurry as a main material, and is cooperatively used for providing rigidity and toughness of the flame-retardant cone for the loudspeaker, so that the strength of the flame-retardant cone for the loudspeaker is ensured; the basalt fiber is cooperated with the flame retardant, so that the whole cone has good flame retardance.

(2) According to the flame-retardant cone for the loudspeaker, the surface of the cone is covered with the polymer film by adding the hardening agent, so that the moisture absorption of the flame retardant can be effectively prevented, the weight of the cone can be controlled, and the excellent tone quality and stable and reliable performance of the loudspeaker can be ensured; meanwhile, the strength of the cone is improved, and the loudspeaker can be prevented from being split and vibrated when vibrating at high frequency.

(3) The Young modulus of the flame-retardant cone for the loudspeaker is 3.4-5.0GPa, the afterburning time is 0.9-5.6s, the charring length after burning is 35-69mm, and the water absorption rate is 3-8%.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The raw material sources of the components in the following examples are as follows: unbleached sulfate wood pulp (UKP, Guangzhou City Yunqi electro-acoustic technology development Co., Ltd.), cotton pulp (Guangzhou City Yunqi electro-acoustic technology development Co., Ltd.), basalt fiber (purchased from Jiangsuo Tianlong basalt continuous fiber Co., Ltd.), ammonium polyphosphate (model Doher-6503, purchased from Doer New Material science Co., Ltd., Dongguan City), DJ-17 hardening agent (purchased from Jiangsuo Donggao electro-acoustic accessories Co., Ltd.), and SA-6077H hardening agent (Taijia Industrial materials Co., Ltd.).