JPH05125138A - Foamed polyurethane and speaker edge using the same - Google Patents

Abstract

PURPOSE:To provide the foamed polyurethane reduced in its aging deterioration and excellent in the weather resistance, water resistance, etc., by adding a specific amount of a methylpolysiloxane resin or fluororesin to a polyol or polyhydroxy compound and subsequently foaming and curing the mixture. CONSTITUTION:(A) 100 pts. of a polyol or polyhydroxy compound is mixed with (B) >=3 pts. of a methylpolysiloxane resin or fluororesin, and the mixture is subsequently foamed and cured to provide the objective foamed polyurethane. The foamed polyurethane is sliced and subsequently heated and press-formed to give a speaker edge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to urethane foam and a speaker edge using the urethane foam.

[0002]

2. Description of the Related Art Conventional urethane foam is produced by adding a foaming agent when reacting a polyol or a polyhydroxy compound with an isocyanate, and the urethane foam thus obtained has a mattress and a sound absorbing property due to its physical properties. It is used in a wide variety of applications such as materials, heat insulating materials and speaker edges.

The speaker edge is, as is well known,
A function provided between the outer peripheral edge of the speaker diaphragm and the speaker frame to support the voice coil and the speaker diaphragm in the correct position together with the damper, and a function to prevent an acoustic short circuit of sound generated before and after the diaphragm. It has a function as an acoustic end that does not reflect the vibration generated in the voice coil at the edge.

The performance required for the speaker edge is as follows: (1) It has a sufficiently high compliance in the vibration direction of the speaker diaphragm so as not to disturb the vibration of the speaker diaphragm. (2) In order to support the speaker diaphragm in the correct position, it must have sufficient rigidity for lateral movement of the speaker diaphragm. (3) The linearity of the driving force-displacement characteristic is good even in a large amplitude region in order to suppress the occurrence of harmonic distortion particularly in the low range. (4) Do not cause edge resonance or inversion vibration that causes abnormal radiation. (5) Lightweight as a vibration system component. Etc.

In order to satisfy these conditions, a urethane foam sheet is often used because of its excellent rigidity, light weight, excellent vibration absorption and moldability.

[0006]

Such conventional urethane foams are poor in weather resistance and water resistance and hydrolyze due to moisture in the air to destroy the urethane bond, so that the initial physical properties can be maintained for a long period of time. No, the deterioration over time is severe.

Further, the speaker edge formed of the conventional urethane foam sheet has excellent physical properties capable of satisfying the required performance in a high balance, but is poor in weather resistance and water resistance like the conventional urethane foam. However, it has a big defect that it absorbs water and causes hydrolysis, and cannot withstand long-term use. Therefore, for those used in places where water resistance, weather resistance, etc. are required, after-treatment such as providing a film layer having water repellency may be performed, or the acoustic characteristics may be slightly inferior to urethane foam. Weatherability,
They also used speaker edges made of other materials with excellent water resistance.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of the conventional example, to provide urethane foam having little weather deterioration and excellent weather resistance and water resistance, and a speaker edge using the same. ..

[0009]

The urethane foam according to the present invention for achieving the above-mentioned object is foamed by adding 3 parts or more of methylpolysiloxane resin or fluororesin to 100 parts of polyol or polyhydroxy compound. The speaker edge according to the present invention is characterized by being cured, and then foamed urethane obtained by foaming and curing by adding 3 parts or more of methylpolysiloxane resin or fluororesin to 100 parts of polyol or polyhydroxy compound. It is characterized by being heated and pressed.

[0010]

In the urethane foam having such a structure, the mixed methylpolysiloxane resin or fluororesin is
During the foaming step in the manufacturing process, an inactive film is formed on the inner wall of each foam cell of urethane foam to prevent hydrolysis.

Further, in the speaker edge using this, since the urethane foam is heated and pressure-molded, the foam cells are crushed and the open cells are closed, the air permeability is lost, and the fluorine formed in the foam cells is lost. Strong water repellency is exhibited by the resin or methylpolysiloxane resin coating.

It is most effective to add 3 parts or more of the methylpolysiloxane resin or fluororesin to 100 parts of the polyol or polyhydroxy compound. When it is less than 3 parts, The coating film is not formed sufficiently to exhibit water repellency and weather resistance.

[0013]

EXAMPLES Examples of polyether-based and polyester-based urethane foams according to the present invention and speaker edges using these are described in detail below.

[Example 1] Table 1 shows raw materials for polyether foamed urethane.

[0015]

[Table 1] Each of the raw materials shown in Table 1 is weighed for each part, and the foaming agent, dispersant and methylpolysiloxane are mixed and stirred. Next, this, a polyol, an isocyanate and a catalyst were simultaneously mixed, stirred and discharged, and foamed and cured 30 times to obtain a polyether urethane foam according to the present application.

[Example 2] Table 2 shows raw materials for polyester-based urethane foam.

[0017]

[Table 2] Each raw material shown in Table 2 is weighed for each part, and the catalyst and the auxiliary are mixed and stirred, and the water, the dispersant and the fluororesin are mixed and stirred. Next, these, a polyhydroxy compound, and an isocyanate were simultaneously mixed, stirred and discharged, and foamed and cured 30 times to obtain a polyester-based urethane foam according to the present application.

Example 3 The polyether foamed urethane obtained in Example 1 was sliced to a thickness of 8 mm,
The speaker edge according to the present application was obtained by forming the edge shape with a press die at 200 ° C. for about 10 seconds.

Example 4 The polyester foam urethane obtained in Example 2 was molded in the same manner as in Example 3 to obtain a speaker edge according to the present invention.

Although the urethane foam according to the present invention and the speaker edge using the same have been described above in detail based on the examples, the embodiments of the present invention are not limited to the above-mentioned examples. However, each raw material is not limited to that used in the examples, and in the manufacturing process, a fluororesin or a methylpolysiloxane resin may be added to the polyol or the polyhydroxy compound, etc. The present invention can be appropriately modified and implemented as long as it has the constitutional requirements of the above, exhibits the action of the present invention, and has the effects described below.

[0021]

[Effect] The weather resistance of the urethane foam obtained in Examples 1 and 2 and the weather resistance of the conventional urethane foam manufactured without adding the methylpolysiloxane resin in Example 1 as a conventional example to be compared are shown. 3 shows. Further, FIG. 1 shows the weather resistance characteristics of the urethane foam according to the present application with respect to the number of added parts of the fluororesin or the methylpolysiloxane resin.

[0022]

[Table 3] As is clear from Table 3, in the urethane foam according to the present invention, (1) a methylpolysiloxane resin or a fluororesin coating film is formed, and the urethane bond is isolated from the air, so that hydrolysis by water in the air The initial physical properties can be maintained for a long period of time without causing (2) The weather resistance can be imparted without increasing the number of manufacturing steps. It has the effect of. Further, as is clear from FIG. 1, in the formation of the resin coating film sufficient to develop the weather resistance, the number of added portions of the resin becomes substantially saturated when the number of added portions of the resin is approximately 3 parts or more. Is most effective with 3 parts or more.

Next, Table 4 shows the physical properties of the speaker edges obtained in Examples 3 and 4 and the physical properties of the speaker edges formed by heating and pressing the conventional urethane foam as a conventional example to be compared.

[0024]

[Table 4] As is clear from Table 4, the speaker edge according to the present invention is excellent in weather resistance and causes hydrolysis due to (1) the formed chemically inactive fluororesin or methylpolysiloxane resin coating. It is possible to maintain the same physical properties for a long period of time. (2) Since open cells are closed by heat and pressure molding, water is completely impermeable, water droplets are hard to attach, and water resistance is extremely excellent. (3) Since open cells are closed by heating and pressurization, there is almost no air permeation, and it has an excellent function of preventing an acoustic short circuit occurring before and after the diaphragm. (4) No post-treatment is required to provide weather resistance and water resistance. It has the effect of.

[Brief description of drawings]

FIG. 1 is an explanatory view of the weather resistance of the urethane foam according to the present application depending on the number of parts added with a fluororesin or a methylpolysiloxane resin.

Claims (2)

[Claims] 1. A polyol or polyhydroxy compound 1
A urethane foam characterized in that 3 parts or more of a methylpolysiloxane resin or a fluororesin is added to 00 parts and foamed and cured. 2. A polyol or polyhydroxy compound 1
A speaker edge, characterized in that 3 parts or more of methyl polysiloxane resin or fluororesin is added to 00 parts and foamed and cured, and urethane foam is heat-pressed.