JPS5822918B2 - Diaphragm for speakers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides paper made mainly from beaten wood pulp fibers, which is coated with a certain proportion of drying oil, semi-drying oil, boiling oil, the above-mentioned kings or mixtures of the above-mentioned kings. This invention relates to a speaker diaphragm made by pasting and molding sheets of paper that have been immersed in a solution containing natural resins or oil-soluble synthetic resins and then calendered.

Conventional diaphragms for speakers have mostly been made of natural fibers such as wood pulp, synthetic fibers based on natural fibers, carbon fibers, etc., which have been appropriately beaten, paper-formed, and heat-molded depending on the purpose of use.

In this case, the conditions required for the diaphragm in order to reproduce sound faithful to the original sound in the speaker (lightweight, high Young's modulus, large internal loss, and high mechanical strength and elastic force) It was extremely difficult to satisfy all of the requirements, and there were limits.

Furthermore, since they are usually porous, they have the disadvantage that moisture easily penetrates and their physical properties change significantly due to changes in humidity.

Generally speaking, diaphragms for speakers have large mechanical strength and elastic force relative to their weight, and a high Young's modulus can be obtained by compression pressing with high pressure and finishing with high density. Internal losses decreased significantly in inverse proportion.

Therefore, the present invention was obtained as a result of various studies to eliminate the above-mentioned drawbacks.

In other words, paper made mainly from beaten wood pulp fibers is mixed with drying oil, semi-drying oil, boiled oil, a mixture of the above or the three, or in some cases natural resin or oil in addition to the above oils. Mechanical strength, elastic force, and Young's modulus are reduced by dumping the oils that have penetrated into the paper layer by laminating sheets of paper that have been immersed in a solution containing a soluble synthetic resin and then calendered. Therefore, it is possible to manufacture a diaphragm for a speaker which increases internal loss without causing any damage, and which exhibits very little change in physical properties such as expansion and contraction due to changes in humidity.

Next, embodiments of the present invention will be shown and explained in more detail with reference to the drawings, but the present embodiments are not intended to limit the present invention.

First, 2.5% by weight of internal sizing agent, 3.0% by weight of sulfate,
A base paper with a basis weight of 2679/rrt was prepared by mixing 2.0 weight of positive starch and 2.5 weight of dye, and after pre-drying at a low temperature (drying roll temperature of 120 degrees Celsius),
It is impregnated with a drying oil such as linseed oil or a mixed oil in which linseed oil is mixed with soybean oil and tung oil (natural oil).

Then, after squeezing the rolls, calendering is carried out under the conditions of a roll temperature of 40 to 90 degrees, a linear pressure of 30 to 40 kg/cm, and a speed of 10 to 16 m/min.

And finished basis weight 2799/m"s thickness 0.258±
The paper had a density of 0.015 mm, a density of 1.16 ji /cril, and a drying oil content of 12%'.

The internal sizing agent used in this example, sulfate band,
The positive starch and the like are used to obtain normal paper strength, and the dye is used for coloring and has nothing to do with the original function of the diaphragm, so they may be added in appropriate amounts.

The most novel speaker diaphragm according to the present invention, which also forms the basis of the present invention, is produced by drying paper made at low temperatures, and adding drying oil, boiling oil, semi-drying oil, etc. or a mixture of the three, or in some cases a mixture of the above oils with a natural resin or an oil-soluble synthetic resin such as a special epoxy resin, and then calendered.

The soaked oils are adjusted to an appropriate amount using a squeezing roller of a calendar, and excess oil is removed.

Subsequently, the residual moisture is evaporated by the heat of the calender rolls, and the oils that have been dispersed and permeated by the pressure of the rollers are fixed in a saturated state between the fibers inside the paper layer.

The paper finished in this manner is hard and has a high density due to the natural oxidation and polymerization of the soaked oils, but the internal loss is greater than that of the conventional paper.

The speaker diaphragm paper obtained in the above-described embodiments is compared with conventional speaker diaphragm paper (laminated diaphragm paper containing no drying oil or other oils) as shown in the table below.

It is clear that in the case of the embodiment of the present invention, the Young's modulus and mechanical strength were significantly increased, and the internal loss was also increased. In particular, the wet strength, which is a durable characteristic required for a speaker diaphragm, was improved compared to the conventional one. The result was about 20 times better than that, and about 700 times better in terms of durability and strength.

Next, a speaker for bass reproduction with a diameter of 20crrL using a diaphragm made by cutting the paper obtained according to the embodiment of the present invention into a fan shape and bonding and molding the same, and a speaker with a diameter of 20crrL using a conventional diaphragm.
A comparative example of the frequency characteristics with the rrL bass reproduction speaker is as shown in the drawings, and in the case of the embodiment of the present invention, the valleys in the frequency characteristics caused by the divided vibration of the diaphragm in the mid-range characteristics are more pronounced than in the conventional one. Very small.

Furthermore, in the high-pitched sound characteristics, there are few peaks and valleys that occur at high frequencies other than the piston vibration range, and so-called high-frequency peaks do not occur.

The sound pressure attenuation from the treble resonance limit W region to the treble attenuation region is really smooth and rapid.

This fact proves that the present invention has made it possible to obtain a speaker diaphragm with an ideal relative relationship between mass, mechanical strength, Young's modulus, internal loss, etc.

In addition to this example, the content of drying oil and other oils listed above was 7.
The basis weight of ~15% by weight is 100~65 (B9/
The six densities are 0.5 to 1.3. It can be used within the range of F/ffl depending on the type of speaker, purpose, diameter, etc.

Further, depending on the purpose, by mixing known materials for speaker diaphragms with the diaphragm paper of the present invention or coating the surface thereof, it is possible to widen and deepen effects that have not been previously achieved with frequency characteristic materials.

[Brief explanation of the drawing]

The drawing shows the frequency characteristics of a bass speaker with a diameter of 20 cwL incorporating the speaker diaphragm of the present invention and the conventional speaker diaphragm.

Claims (1)

[Claims] 1 Paper made by mixing beaten wood pulp fibers with appropriate amounts of an internal sizing agent, sulfuric acid, positive starch, and dyes, using drying oil, semi-drying oil, boiling oil alone or It is characterized by pasting together and molding paper that has been immersed in the above-mentioned king or a mixture of the three, or in some cases a liquid containing the above-mentioned oils and a natural resin or an oil-soluble synthetic resin, and then finished by calendering. A diaphragm for speakers. 2 The oil content of the diaphragm is 7 to 15% by weight, the density is 0.5 to 1.3 El/cd, and the thickness is 0.1 to 15% by weight.
The diaphragm for a speaker according to claim 1, having a basis weight of 0.5 am and a basis weight of 100 to 550 g/d.