JPS5930858A - Resin composition for molding material for sound device - Google Patents

Abstract

PURPOSE:The titled composition useful for molding cabinet boxes such as especially speaker boxes, etc., having high internal loss, rigidity, and specific gravity, causing slightly vibration, obtained by blending an inorganic filler-containing thermosetting resin with reactive liquid rubber. CONSTITUTION:A thermosetting resin (preferably unsaturated polyester, etc.) is blended with an inorganic filler (e.g., magnesium carbonate, etc.) in an amount to give 1.5-2.5 specific gravity of a molded cured material of the resin composition, usually 50-80wt% filler based on the total resin composition, and 3- 20wt% reactive liquid rubber (especially vinyl-terminated acrylic-butadiene rubber) based on the total resin composition. The composition is further blended with a curing agent and a fiber reinforcing agent usually. The amount of the inorganic filler added can be increased by treating the surface of it with a silane coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition suitable for molding materials for audio equipment, particularly speaker boxes and record player cabinets.

Traditionally, woodblocks, plywood, die-cast aluminum, etc. have been used as materials for audio equipment, but wood boards and plywood are lightweight and easily vibrate, while die-cast aluminum casings have less vibration but low internal loss and are effective at damping. Inferior.

Materials that eliminate the disadvantages of materials for audio equipment as described above (clθ) are used.

However, although this composite plastic material achieves a well-balanced M-'JP effect, it is inferior to wood boards and plywood in terms of internal loss, and the internal loss is large and the overall acoustics may be affected. The emergence of highly effective composite glass materials is eagerly awaited.

The present inventor has conducted various studies on improving composite plastic materials from this point of view, and found that thermosetting resins and inorganic fillers? It has been found that a molded article obtained by molding and curing a resin composition in which the entire reactive liquid rubber is further added has the following properties.

■ Internal loss is a dog.

■ High rigidity.

■ High specific gravity, less likely to cause vibration.

■ Improved water resistance, rigid chemical resistance, thermal stability, etc.0 The present invention has been completed based on the above findings.
Specifically, the present invention provides a 4nl resin for molding materials for audio equipment, which is characterized in that a reactive liquid rubber is blended in the 4Nl fat composition for molding materials for audio equipment, which contains a thermosetting resin and an inorganic filler. It is a composition.

For example, annual salary of 5 fl + polyester resin and epoxy resin can be enumerated as preferred. Further, in addition to the thermosetting resin, the entire thermoplastic resin may be added.

It is essential that the entire reactive liquid rubber be present in the resin composition related to the non-explosion J.

The reactive liquid rubber may be any liquid rubber that is reactive with the thermosetting resin and has a viscosity that allows it to be dispersed in the thermosetting resin. Such reactive liquid rubbers include those having all unsaturated groups (for example, vinyl groups) at the end of the rubber, especially vinyl-terminated acrylic-butadiene rubber (trade name:
Gaagera 2'L.

The amount of the reactive liquid rubber to be blended is approximately 3 to 20 parts, preferably 5 to 15 parts per weight, based on the total weight of 41
By setting 2T ([?i%. Such a mixture t,') to 1.1, the effect of the present invention can be fully exhibited (Jl (
be done.

Examples of semi-filling agents include those conventionally known for use in plastics, such as macanyl carbonate, barium sulfate, and silica, as well as the following.

α) Hollow microscopic inorganic filler: Examples include alumina, silica, zirconia, lath, sodium silicate, etc., which are formed into a hollow shape. The particle +ffi of the hollow spherical filler is preferably 30 to 250μ (sieve fraction is determined by test). As such a filler, for example, Phyllite (manufactured by Fillite, UK) is commercially available, and other hollow spherical fillers are also prepared in the same manner as Phyllite.

■ Acicular inorganic filler with a particle size of 1 to 20 microns measured by the sedimentation method: The preferred particle size is 5 to 15 microns, and is usually acicular crystals, followed by calcium silicate crystals, calcium sulfate crystals, etc. Calcium silicate crystals are used, and what is better than bamboo is calcium silicate crystals.

■ Amorphous inorganic microfibers: ~200 microns), preferably an average length of approximately 120 microns (length distribution 80-140 microns), and an average diameter of approximately 2-200 microns.
12 microns, preferably about 4 microns, and an aspect ratio (length/diameter) of 20 to 40, especially 30 to 40.
An example is shown below.

Examples of such are even if h , S, i 021
, v203, one type of CaOlMgO or a mixture of more than 20% by weight? What is the main ingredient? For example, in the compound exemplified above, the composition ratio is 5i
n2: 40-50:llifk part 1At203:10
~20 parts by weight, Cab: 30-40 parts by weight, MgO:
: Preferably 1 to 4 layers of walls. A specific example of such amorphous inorganic fine fibers is Varnish Fiber FF (manufactured by Nippon Steel Chemical Industry Co., Ltd.).

Such geometric-free MR agents may be used alone or in combination of two or more.

Inorganic J4 content in the 4t=J fat composition according to the present invention
The preferred agent for W1 is the cured product obtained by completely molding and curing the resin composition of the present invention, that is, molding! The specific gravity of the snout is 1.5.
~2.5, and for this purpose it is sufficient to add 50 to 80 Mt:ii1% of the inorganic filler in total, although it depends on the type of filler used. .

The inorganic filler can be used by treating its surface with a silane coupling agent, and by performing such surface treatment, the amount of inorganic filler added to the resin composition can be increased.

The details are described in Japanese Patent Publication No. 44-5094.

The resin composition of the present invention generally further contains a curing agent and a fiber reinforcing agent.

The curing agent may be appropriately selected from known curing agents depending on the characteristics of the thermosetting resin used, such as peroxide (
Benzoyl peroxide, cumene hydroperoxide), amines (diaminophenylmethane), etc. are used alone or in combination.

As the fiber reinforcing agent, those known for use in composite plastic materials, such as glass fiber, carbon fiber, heavy machinery synthetic fiber, and aromatic polyamide fibrous reinforcing material can be used.

As the aromatic polyamide fiber, it is preferable to use a filament having a length of about 2 to 20 mm, for example, a chopped strand. , phenylenediamine such as p-diaminobenzene), and specifically, Kevlar 49 Aramid 0 (manufactured by DuPont, USA) is exemplified as a preferable one.

Such fiber reinforcements, used alone or in combination, are used to increase the overall impact resistance of audio equipment.

The resin composition according to the present invention may optionally contain curing accelerators, pigments, anti-aging agents, etc. that are blended into ordinary resin compositions for molding composite plastic materials. “All resin composition standards.

It also includes additives such as curing agents, fiber reinforcing agents, pigments, curing accelerators, and anti-aging agents.

The resin composition according to the present invention is usually prepared as a premix.

The resin composition of the present invention can be made into a material for audio equipment by a known molding method such as a compression molding method or a cast molding method.

The material for audio equipment made from the resin composition of the present invention has: 1) rigidity that is comparable to that of a woodblock, 2) internal stiffness equivalent to that of a woodblock block or plywood; ■It has excellent mechanical strength such as impact resistance.

Is this invention the following? O Examples Example 1 Example 2 Comparative example 2 Unsaturated polyester 13 parts' 12tf+
+ 14 parts polystyrene 3 parts
3 parts 3 parts Styrene monomer 4
．． 5th part 5.5th part 3rd part VTBN
2 parts 4 parts -benzoyl peroxide 0.5 parts 0.5 parts 0.5 parts stearyl Δryo zinc ]-90 sounds IS 10 parts
1.0 part calcium carbonate 66 parts 64
Parts: 80 parts Glass fiber (1/4”) 10 parts
10 parts 10 parts (Note) Half means jT;Cf, 11 parts.

All of the above compositions were mixed at room temperature in a kneader to obtain a resin composition fc. Using this l;) 5℃, 75 KP/cnf
, a plate-shaped molded product (1,0tx500x5
00y+m)k Heat and pressure molding was performed to obtain a test piece (1). The results were as shown in the table.From this result, it was found that the molded product obtained from the present invention (51 parts fat composition sword) had a specific gravity of 100% and vibration (7), the resonance sharpness was small, and the internal loss was large. It was found to be ideal as a 7M+ equipment receiver.

Claims (3)

[Claims] (1) A resin composition for molding materials for audio equipment, which is characterized in that it contains a thermosetting resin and an inorganic filler, and further contains a reactive liquid rubber. (2) The amount of reactive liquid rubber blended is 3 to 2 based on the total composition.
0% by weight of the resin composition for monthly molding of audio equipment according to claim 1. (3) The specific gravity of the cured product obtained by curing the resin composition for molding audio equipment materials containing reactive liquid rubber is 1.
1. A resin composition for molding a material for an audio equipment as set forth in claim (1), wherein the resin composition is adjusted to have a viscosity of 5 to 2.5.