JP2002305783A - Speaker component and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent speaker component that needs no primer processing in the case of adhesion because of excellent in the adhesive performance and hardly causes secondary contraction even when subjected to a high temperature environment at a low cost with a lightweight, a high bending strength and excellent size stability. SOLUTION: The speaker component uses an olefin group resin to which 20 wt.% or over and 60 wt.% or below of paper pulps acting like fillers are blended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker component and a method of manufacturing the same.

[0002]

2. Description of the Related Art A loudspeaker is required to output a signal that is highly faithful to an input signal. Therefore, members constituting the loudspeaker are required to have various performances. For example, a speaker frame is required to have excellent strength, heat resistance, adhesiveness, dimensional stability (environmental resistance), and vibration damping properties.

[0003] On the other hand, inexpensive iron has been used, but aluminum has come to be used, for example, in order to respond to the demand for weight reduction in in-vehicle speakers such as automobiles.

Aluminum has high strength and low specific gravity, but has the disadvantage that it is expensive. And so on.

[0005] Although these materials have a low specific gravity and a high internal loss, they are inexpensive compared to aluminum, and various studies have been made to further improve their characteristics.
Fillers such as calcium carbonate, glass fiber, talc or mica are added.

Here, in order to further reduce the weight and cost, members based on olefin resins such as polypropylene have been studied. However, members based on these olefin-based resins are inexpensive and have a low specific gravity, but have poor adhesion and require a primer treatment. In addition, since it has low bending stiffness, a large coefficient of linear expansion, poor dimensional stability, and has crystallinity, after molding, it is exposed to high temperatures that would be expected when mounted on a door or the like, for example, as an in-vehicle speaker. Then, a large amount of filler (generally having a high specific gravity) is added to improve properties such as crystallization progressing and irreversible shrinkage (secondary shrinkage) that does not return to its original state even when the temperature decreases. Is required, and as a result, there is a disadvantage that the original advantage of weight reduction is lost.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, that is, it is inexpensive, lightweight, has excellent adhesiveness, has high bending rigidity, has excellent dimensional stability, and is exposed to a high-temperature environment. It is an object of the present invention to provide an excellent speaker component that is unlikely to cause secondary shrinkage even when it is performed.

[0008]

According to a first aspect of the present invention, there is provided a speaker comprising 20% by weight to 60% by weight of paper pulp as a filler.
It is a component of a speaker using an olefin-based resin compounded below.

According to the present invention, there is provided a speaker comprising:
The loudspeaker according to claim 2, wherein the paper pulp is used as a filler in an amount of 20% by weight to 60% by weight.
It is a component member of a loudspeaker obtained by injection molding the above-mentioned olefin-based resin compounded below.

[0010] With such a configuration, since it is inexpensive, lightweight, low-density, and excellent in adhesiveness, it does not require a primer treatment for bonding, has high rigidity, has excellent dimensional stability, and can be exposed to a high-temperature environment. It is possible to provide an excellent speaker component that is unlikely to cause secondary shrinkage. No harmful gas is generated even if incineration is performed as final disposal.

According to a third aspect of the present invention, there is provided a speaker according to the first or second aspect, wherein the paper pulp includes waste paper pulp. . With such a configuration, it is possible to provide an environmentally-friendly speaker component that can also achieve the effect of resource recycling and, consequently, the conservation of wood resources.

Further, the constituent members of the speaker of the present invention include:
The speaker component according to any one of claims 1 to 3, wherein the olefin resin is polypropylene or polyethylene, as described in claim 4. With such a configuration, a lighter and less expensive component member of the speaker can be provided.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a component member of a speaker, comprising:
After kneading to the olefin resin, after drying if necessary,
This is a method for manufacturing a component of a speaker to be injection-molded, which is inexpensive, lightweight, excellent in adhesiveness, high in bending rigidity, excellent in dimensional stability, and hard to cause secondary shrinkage even when exposed to a high temperature environment. Can be obtained.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the components of a speaker according to the present invention, the blending amount of paper pulp as a filler in the olefin resin used must be 20% by weight or more and 60% by weight or less. If the amount is less than 20% by weight, the adhesiveness is reduced and dimensional stability cannot be obtained. on the other hand,
If the amount is more than 60% by weight, the moldability is reduced, sufficient rigidity is not obtained, and the mechanical performance in a weld portion or the like is reduced.

The filler used as a component of the loudspeaker of the present invention has a lower specific gravity than a commonly used filler (for example, an inorganic filler such as talc). Lighter than the product. For example, when polypropylene is used as the olefin resin and the filler content is 50% by weight, the specific gravity is as follows:
When the filler is glass fiber, it is 1.24, whereas when the filler is paper pulp, it can be reduced to 1.15, that is, 7% or more.

Further, the components of the loudspeaker of the present invention have high adhesiveness, and the components based on the conventional olefin resin generally have low adhesiveness, so that a costly process such as primer treatment is required. However, the components of the speaker of the present invention can be easily bonded by using a normal adhesive, for example, an adhesive such as a chloroprene rubber-based adhesive.

Furthermore, since general olefin resins have crystallinity, crystallization proceeds when exposed to high temperatures after molding, and thereafter irreversible shrinkage (secondary shrinkage) that does not return to its original shape even when the temperature is lowered. However, in the present invention, since the paper pulp is converted into filler, this secondary shrinkage is prevented, and in order to obtain a sufficient secondary shrinkage preventing effect, the amount of the paper pulp is reduced to 20% by weight. Even as described above, as described above, the influence on the specific gravity is small. In addition, when the paper pulp is 51% by weight or more, it is possible to dispose it as paper waste as in the case of paper containers and packaging. Therefore, if possible, the content of the paper pulp is desirably 51% by weight or more. .

A further characteristic of the components of the loudspeaker of the present invention is that it has high load heat resistance. This is a characteristic that is required, for example, when the speaker is installed in a high-temperature place such as a door as an in-vehicle speaker of an automobile.

The paper pulp used as the filler in the present invention is:
New paper may be used, or waste paper pulp may be used. At this time, by using 100% waste paper pulp as the paper pulp, it can be made extremely "environmentally friendly", but new paper pulp may be used in combination as needed according to required performance and the like.

In the present invention, calcium carbonate, glass fiber, talc, mica, etc. other than the above-mentioned paper pulp may be used together for the purpose of improving tensile strength, bending strength, impact strength, heat resistance temperature and flame retardancy. However, it is desirable that the addition amount thereof be in the range of 5% by weight or more and 40% by weight or less and that the sum of the addition amount of paper pulp, that is, the total filler amount be 60% by weight or less.

If the amount is less than 5% by weight, the effect of adding the filler is not sufficient, and if the total amount of filler is more than 60% by weight, the moldability is deteriorated, and the paper pulp may not be formed. If the amount is less than 20% by weight, the effect of the present invention cannot be sufficiently obtained.

The components of the loudspeaker of the present invention can be produced from these materials, for example, as follows. New paper pulp and / or waste paper pulp are beaten, and if necessary, kneaded with an olefin resin together with other fillers, pigments, ultraviolet absorbers (enhancing weather resistance), etc., and extruded into pellets.

The pellets thus prepared absorb moisture when left in a normal environment. However, if they are used while absorbing the moisture, the moldability decreases. For this reason, the components of the speaker of the present invention can be obtained by sufficiently drying as necessary, and then molding by a usual thermoplastic resin product molding method such as injection molding, extrusion molding, or compression molding.

Of these molding methods, molding by injection molding is preferred because of its high fluidity and freedom of molding. The component members of the speaker of the present invention can be used for all parts of the speaker frame made of a resin material, such as a speaker frame, a cabinet, a diaphragm, and the like.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the components of the speaker according to the present invention will be described below. Using raw paper pulp (also referred to as “UP”) beaten as a filler and polypropylene (also referred to as “PP”) as a base resin, kneading and extrusion are performed to produce pellets A to C having the blending (weight ratio) shown in Table 1. did.

Glass fiber (also referred to as "GF") as a filler, and a mixture of acrylonitrile-butadiene-styrene copolymer and polybutylene terephthalate (weight ratio 6: 4, "ABS / PBT") as a base resin
Pellets D to E shown in Table 1 were similarly prepared using calcium carbonate (also referred to as “CC”) as a filler and the same polypropylene as that used above as a base resin.

[0027]

[Table 1]

Using these pellets A to E, speaker frames A to E were respectively manufactured by injection molding. The compressive strength, dimensional change rate, damper adhesive strength, specific gravity, and heat resistance of load of these speaker frames A to E were examined.

As the compressive strength, a stress was applied at a yield point when a load was applied so as to sandwich the upper and lower portions of the frame and the frame was deformed.

The dimensional change was examined by measuring the dimensional change before and after keeping at 100 ° C. for 96 hours. As the damper adhesive strength, a stress value when the damper was adhered to the damper attaching portion with a chloroprene rubber-based adhesive and a load was applied in a vertical direction from the adhesive surface and the damper peeled off from the frame was used. In the case of the frame E, since the adhesive force is weak, the
Was applied to the damper-attached portion, and a sample was prepared by adhering the damper with a chloroprene rubber-based adhesive in the same manner as in frames A to D, and the sample was evaluated ("primer used").

As a heat resistance temperature under load, a load of 300 g was placed in an oven, and the temperature was changed from 100 ° C. to 10 ° C./hour.
The temperature was gradually increased, and the temperature at which deformation was visually confirmed was used. Table 1 also shows these evaluation results.

According to Table 1, the components of the speaker according to the present invention are lightweight, low-density, excellent in adhesiveness, high in rigidity,
It can be seen that the speaker is an excellent speaker having excellent dimensional stability and hardly causing secondary shrinkage even when exposed to a high temperature environment.

[0033]

The components of the speaker according to the present invention are inexpensive,
Lightweight, excellent in adhesiveness, high in bending rigidity, excellent in dimensional stability, hardly causes secondary shrinkage even when exposed to high temperature environment, does not emit harmful gas even when incinerated, and uses waste paper pulp Therefore, it is an environmentally friendly and excellent speaker component.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04R 7/02 H04R 7/02 D 9/02 101 9/02 101A // B29K 23:00 B29K 23:00 B29L 31:38 B29L 31:38 (72) Inventor Masatoshi Sato 1105 Kunomoto Nikko, Oji, Tendo City, Yamagata Prefecture F-term in Tohoku Pioneer Co., Ltd. 4F206 AA01 AA04 AA11 AH39 JA07 JL02 JM01 JM04 JN01 JN11 4J002 AH00XBBW BB12W GN00 GQ00 5D012 BB01 EA04 FA10 GA01 5D016 EC02 5D017 AD04 AE11

Claims (5)

[Claims] 1. A component of a loudspeaker, characterized by using an olefin-based resin obtained by mixing paper pulp as a filler in an amount of 20% by weight or more and 60% by weight or less. 2. The speaker component according to claim 1, wherein the olefin-based resin is blended by mixing paper pulp as a filler in an amount of 20% by weight or more and 60% by weight or less. 3. The speaker component according to claim 1, wherein the paper pulp includes waste paper pulp. 4. The component according to claim 1, wherein the olefin-based resin is polypropylene or polyethylene. 5. A method for producing a speaker component, comprising: beatening paper pulp, kneading the mixture with an olefin resin, drying if necessary, and injection molding.