JPH0333466Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a sheet-like structure in which a non-woven fabric is integrated on at least one side of a sheet made of high-density inorganic powder mainly composed of iron-shaped inorganic powder and ethylene-vinyl acetate copolymer resin. This invention relates to a composite material that has excellent vibration-damping, sound-insulating, and fire-retardant properties, and is made by laminating objects and metal plates.

Currently, there is a need for materials that are inexpensive, easy to process, and have excellent vibration damping and sound insulation properties to reduce or prevent noise and vibration generated in automobiles, ships, aircraft, production equipment, various office equipment, etc. There is.

An object of the present invention is to meet such needs and provide a component that suppresses noise and vibration of the various devices mentioned above.

As a result of many studies, the present inventors integrated a nonwoven fabric on at least one side of a sheet made of 40 to 94% by weight of iron-based inorganic powder and 6 to 30% by weight of ethylene-vinyl acetate copolymer resin. The structural material, which is made by laminating a sheet-like material and a metal plate, has vibration damping, sound insulation,
It was discovered that it has excellent fire resistance.

In the sheet-like material that constitutes the present invention,
Ethylene-vinyl acetate copolymer resins, especially emulsion binders thereof, are preferably used. Ethylene or vinyl acetate homopolymers cannot provide a balanced coagulant, and only ethylene-vinyl acetate copolymers can provide adequate flexibility and flexibility.
It exhibits good tensile strength, elongation, elastic modulus, water resistance, and good adhesion to particles, making it an excellent coagulant. Ethylene acts as an intramolecular plasticizer for vinyl acetate homopolymers.

The composition range of a copolymer exhibiting such properties is a vinyl acetate content of 55% to 92% by weight. If the ethylene content is too high, the copolymer will have low polarity and will not exhibit adhesive strength with particles. If the ethylene content is too low, the copolymer's glass transition point cannot be lowered;
Toughness and flexibility at low temperatures cannot be obtained. Furthermore, in order to impart weather resistance, water resistance, and alkali resistance, modified ethylene-vinyl acetate resins, which are copolymerized with one or more of acrylic acid, acrylic esters, maleic esters, and vinyl versatate, are also preferably used. It is included in the invention.

The iron-based high specific gravity inorganic powder used in this invention includes iron oxide (FeO), diiron trioxide (Fe ₂ O ₃ ),
Triiron tetroxide (Fe ₃ O ₄ ), iron hydroxide (Fe(OH) _o・
nH ₂ O), iron oxyhydroxide (HFeO ₂ / nH ₂ O) as the main components, contains some impurities such as silica and alumina, and has a homogeneous true specific gravity of about 2.5 to 5.5, with a moderate particle size distribution. Examples include high specific gravity inorganic powders with Such powders include iron-based powders, iron ore powders, by-product ferrites, etc. that are produced as by-products during the refining of various non-ferrous metals. Examples of smelting by-product iron-based powder include by-product iron-based powder during copper smelting, by-product iron-based powder during tin smelting, and by-product diiron trioxide powder during aluminum smelting. can. Examples of iron ore powder include magnetite powder (FeO, Fe ₂ O ₃ ), hematite powder (Fe ₂ O ₃ ), limonite powder (Fe(OH) _o・nH ₂ O,
HFeO ₂ .nH ₂ O) can be exemplified. The iron content is preferably 40% by weight or more. The iron-based high-density inorganic powder is the main component of the sheet material of the present invention, and accounts for 40% to 94% by weight.

Furthermore, it is also possible to add 35% by weight or less of mica (scaly powder) to increase sound insulation and vibration damping properties. The sheet of this invention is made by coagulating a small amount of resin with a large amount of high-density inorganic powder, and has excellent fire retardant properties. It is also possible to add aluminum oxide powder, dihydrate gypsum powder, etc. in an amount of 35% by weight or less.

In the present invention, in order to further improve the vibration damping and sound insulation properties of the sheet, a synthetic fiber nonwoven fabric is composited onto at least one side of the sheet. Synthetic fiber nonwoven fabrics are preferred because they are easy to obtain with extremely low areal density (g/m ² ) and there is little deterioration in the fire retardancy of the sheet material. The most preferred type of nonwoven fabric is one made of 100% polyester because it has excellent strength and physical properties, as well as good adhesion to sheet materials, dimensional stability, and chemical resistance. Avoid reducing fire protection performance
It is preferable to use a nonwoven fabric with an areal density of 30 g/m ² or less.

Next, the composition of the sheet of the present invention will be described. The proportion of the ethylene-vinyl acetate copolymer resin as a coagulant is preferably 6 to 30% by weight in the sheet. If the content is too small, the coagulation effect between powder particles will be insufficient, and the strength and physical properties of the sheet will deteriorate.
Furthermore, the fluidity and moldability of the water-containing mixture slurry during sheet manufacturing also become poor, making sheet manufacturing difficult. If the content is too large, the proportion of organic content will increase and the fire resistance will also decrease. In addition, it is not possible to increase the specific gravity of the sheet, resulting in less effective vibration damping and sound insulation.
The iron-based high specific gravity inorganic powder used as a filler has a solid content of
A range of 40-94% by weight is preferred.

To improve sheet strength, vinylon, nylon,
Some short fibers such as glass fibers may also be added. Furthermore, a water-soluble polymer such as carboxymethyl cellulose or epoxidized polyamide polyamine resin may be added as a viscosity modifier for the slurry or a crosslinking agent for the resin. Fiber content is 0.3-10
The content of the water-soluble polymer is preferably in the range of 0.1 to 5% by weight.

In order to provide even better vibration damping properties,
An effective method is to make the sheet-like material porous by foaming and drying the sheet at the time of manufacturing the sheet-like material, thereby increasing the thickness without changing the areal density. This method provides more than twice the vibration damping effect. To make the slurry porous, the slurry of the water-containing mixture is stirred and foamed at high speed while air is injected, the specific gravity is adjusted to an arbitrary value, and the slurry is molded and dried to obtain a sheet-like material with the desired porosity. Excessive foaming is not preferable because it results in a decrease in strength properties, a decrease in sound insulation in a high frequency range, and a decrease in compression resistance. The void ratio of the sheet-like material is preferably 80% or less.

In this invention, the range of the sheet thickness of the sheet-like material is 0.5 to 20 mm, and the range of the sheet apparent specific gravity is
It is 0.6 to 3.5 (g/cm ³ ). The sheet-like material thus obtained is flexible, highly flexible, has heat insulating properties, is easy to process and handle, is inexpensive, and can be combined with a metal plate to provide excellent vibration damping and sound insulation. Show your gender.

This invention improves vibration damping and sound insulation effects,
Metal plates are laminated to improve workability, strength, etc., but in order to combine a sheet-like material and a metal plate, 1
There are composites using adhesives, composites using 2 adhesives, and composites using 3 heat fusions. Adhesives include sodium silicate-based inorganic adhesives, polychloroprene, SBR,
General-purpose adhesives such as synthetic rubbers such as butyl rubber, thermoplastic resin adhesives such as vinyl acetate-based aqueous resin emulsions, and thermosetting resin adhesives such as phenol, urea, and epoxy are used. Examples of adhesives include double-sided adhesive sheets in which a tackifier such as butyral resin, polyisobutylene, polyacrylonitrile, petroleum resin, etc. is coated on a base material such as paper or non-woven fabric. It is possible to bond and combine the two by adhesion. As for the heat fusion method, metal plates are bonded with a gas burner,
There is a method of heating the hot melt film to 130℃ or higher using a heater, etc., sandwiching the hot melt film between a metal plate and a sheet-like object, and crimping it, or sandwiching the hot-melt film between a metal plate and a sheet-like object and applying high frequency Examples include a method of compressing and bonding by locally heating the bonded area to 130°C or higher.

Next, as a metal plate, it is used for structural members.
Iron-based iron plates, galvanized iron plates, colored galvanized iron plates, stainless steel plates, and epoxy resins with a thickness of 0.2 to 3 mm,
In addition to steel sheets painted or laminated with acrylic resin, PVC resin, fluorine resin, etc., copper sheets,
Examples include aluminum plates.

The composite plate-like material thus obtained has a wide range of uses, such as soundproof boxes for compressors, duct covers, and materials for office equipment casings.

Example 800g of ethylene-vinyl acetate copolymer emulsion (purity 400g) with a copolymerization ratio of 17% by weight of ethylene and 83% by weight of vinyl acetate, 10% solution of polyvinyl alcohol as a foaming agent (degree of polymerization 2000, degree of saponification 80) mol%), 40 g of epoxidized polyamide polyamine as a crosslinking agent (purity: 12 g), and 304 g of water were placed in a container No. 10 and mixed with stirring. Next, 3.64 kg of iron concentrate powder (iron content 56%, true specific gravity 3.75, water content 10%), which is a by-product during copper smelting, 320 g of mica powder (35 mesh or less), and 6 g of soda carbonate as a pH adjuster. Gradually add and stir to mix. The water-containing mixture slurry was stirred and foamed at high speed using a foaming machine, and the slurry specific gravity was adjusted to 1.3 to obtain a molding slurry. Next, the molding slurry was coated and cast onto a base sheet with good mold releasability using a doctor blade with a clearance of 5.4 mm. Next, polyester nonwoven fabric (fabric weight 16g/m ² ) was laminated and integrated on the surface, and then heated at 80℃.
Dry in a hot air circulation dryer for 150 minutes to a thickness of 5.0mm.
Obtain a sheet with an apparent specific gravity of 1.0 and an empty ratio of 70%. The obtained sheet is adhered to a metal plate of a type and thickness suitable for the purpose (for example, 0.8 mm) using a chloroprene rubber adhesive.

Comparative example: Ethylene-vinyl acetate copolymer emulsion with a copolymerization ratio of 17% by weight of ethylene and 83% by weight of vinyl acetate.
800g (purity 400g), 200g polyvinyl alcohol 10% solution (polymerization degree 2000, saponification degree 80 mol%) as a foaming agent, 40g epoxidized polyamide polyamine as a crosslinking agent (purity 12g), 304g water in 10 containers and stirred to mix. Next, ethylene with a copolymerization ratio of 20% by weight of ethylene and 80% by weight of vinyl acetate was added.
950 g of vinyl acetate copolymer granules, 320 g of mica powder (35 mesh or less), and 6 g of soda carbonate as a PH regulator are gradually added and mixed with stirring. The water-containing mixture slurry was stirred and foamed at high speed using a foaming machine, and the slurry specific gravity was adjusted to 1.1 to obtain a molding slurry. Next, the molding slurry was coated and cast onto a base sheet having good mold releasability using a doctor blade with a clearance of 5.6 mm. Next, a polyester nonwoven fabric (fabric weight 16 g/m ² ) was laminated and integrated on the surface, and then
Dry in a hot air circulation dryer for 180 minutes at 60℃ to thickness
A sheet with a diameter of 4.9 mm, an apparent specific gravity of 1.0, and a void ratio of 76% was obtained. The obtained sheet is adhered to a metal plate of a type and thickness suitable for the purpose using a chloroprene rubber adhesive.

When the loss coefficient of the sheet-like material obtained in the example was measured by the vibration lead method, it was found to be 0.12, indicating good vibration damping properties. Next, the sound insulation properties of the sheet were measured according to JIS A ^1416-1974 (method for measuring sound transmission loss in a laboratory), and a transmission loss (reduction in generated sound) of 25 dB was observed at a center frequency of 500 Hz, which was good. Data showing excellent sound insulation properties was obtained. Furthermore, when we measured the fire resistance, it met the UL standard.
94V-O, and was found to have good fire resistance.

On the other hand, when the loss coefficient of the sheet-like material obtained in the comparative example was measured in the same manner as the sheet-like material of the example, it was found to be 0.04, indicating that good vibration damping properties could not be obtained. Next, when the sound insulation property of the sheet-like material was measured in the same manner as the sheet-like material of the example, only a transmission loss of 5 dB was observed, and it was found that it did not exhibit good sound insulation property. Furthermore, when the fire resistance was measured in the same way as the sheet material in the example, the sheet did not spread fire.
It has become clear that it does not meet the UL standard of 94V-O.

In this way, the present invention improves vibration damping by coagulating iron-based inorganic powder with high specific gravity with a small amount of ethylene-vinyl acetate copolymer emulsion to form a sheet-like material with high areal density (weight per unit area). It has excellent sound insulation properties, excellent fireproofing properties, and excellent fireproofing properties.

[Brief explanation of the drawing]

1 and 2 are enlarged sectional views showing the structure of the composite plate-like material of the present invention. The symbols in the figure indicate the following. 1...Sheet-like material, 2...Metal plate, 3...Adhesive layer, 4...Nonwoven fabric.

Claims (1)

[Scope of utility model registration request] (b) ethylene-vinyl acetate copolymer resin containing vinyl acetate with a copolymerization ratio of 55% to 92% by weight, (b) iron content of 40% by weight or more as determined by component analysis. Iron-based inorganic powder containing iron 40-94% by weight
A composite material having excellent vibration-damping and sound-insulating properties, in which a sheet-like material 1 having a nonwoven fabric integrated on at least one side of the sheet and a metal plate 2 are laminated.