JPH0873676A - Vibration damping material, master batch pellet for the same, production of vibration damping material and vibration damping structural material comprising the same - Google Patents

Abstract

PURPOSE: To obtain a vibration damping material having large internal loss at nearly room temperature while keeping sufficient strength and hardness. CONSTITUTION: This vibration damping material comprises a blend of 100 pts.wt. of a binder resin consisting of 99-85wt.% of a base resin composed of one or two or more kinds of resins selected from a polypropylene resin, a polystyrene resin, an acrylonitrile-butadiene-styrene copolymer resin, a polycarbonate resin, a polyphenylene ether resin and a modified polyphenylene ether resin and 1-15wt.% of a styrene-isoprene-styrene block copolymer resin with 1-20 pts.wt. of iron oxide particle powder. The vibration damping material is obtained by adding 1-30wt.% of master batch pellets for vibration damping materials obtained by blending 100 pts.wt. of a binding material resin composed of a base resin and a styrene-isoprene-styrene block copolymer resin with 50-300 pts.wt. of oxide particle powder consisting essentially of iron to 99-70wt.% of a base resin and kneading and molding the blend.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping material having a large internal loss near room temperature while maintaining sufficient strength and hardness. Its main use is as a vibration-damping structural material used for structures of electric / electronic / mechanical parts and housings of home electric appliances, OA equipment and audio equipment.

[0002]

2. Description of the Related Art As is well known, damping materials are widely used in various fields to prevent and suppress vibration and noise. The types of vibration and noise include, for example, home appliances such as office automation equipment, washing machines and dryers, audio equipment such as video / audio equipment, electric / electronic machines, precision machine tools, various machine tools such as factory plant machines, and vehicles.・ Vibration and noise caused by the rotation of engines and motors built into ships, etc., vibration and noise caused by conduits such as water and gas in buildings and houses, and air conditioning ducts, and vehicles There are vibrations and noises generated when running on a railroad track, and vibration damping materials are widely used to prevent and suppress these vibrations and noises.

The damping material is generally formed by extruding a filler material such as mica powder or iron oxide powder using a binder resin.
It is molded into various shapes by various molding methods such as calender molding, compression molding, injection molding and cast molding. Examples of the shape include a sheet shape, a block shape, a structure of electric / electronic / mechanical parts, a housing for home electric appliances, office automation equipment and audio equipment, an optical disk, a disk shell of a magnetic disk and a magneto-optical disk, and a cassette tape. There are shapes such as the cassette half and the cartridge tape cartridge half.

The vibration-damping material is used in the form of a sheet-shaped or block-shaped material stuck or sandwiched in a desired portion of the object, or as a molded product having a predetermined shape. There are cases.

In recent years, OA equipment, audio equipment, and the like have been tending to be lighter and smaller, and accordingly, the vibration damping materials used therefor are also required to be lighter, thinner, and smaller. For this reason, high damping characteristics, that is, internal loss is required to be as large as possible, but blending a large amount of inorganic filler material only for the purpose of improving damping characteristics results in use as a binder resin. The strength and hardness of the hard resin used are deteriorated, the workability and the injection moldability are deteriorated, and the specific gravity is increased, which is against the weight reduction. Therefore, it is strongly required to have excellent vibration damping characteristics while maintaining the original strength and hardness of the hard resin. This fact is, for example, disclosed in Japanese Unexamined Patent Publication No. 4-45142, "As a conventional thermoplastic resin having a vibration damping property,
A composition in which a large amount of a filler such as calcium carbonate is mixed with polypropylene is known. However, since these compositions contain a large amount of filler, they have drawbacks such as impairing the original properties of the resin (molding processability, impact strength). Therefore, it has been desired to develop a vibration damping material having the original characteristics of the resin. ".

For example, in home electric appliances and OA equipment,
Many moving parts such as motors, relays, transformers, gears, cams, gearboxes, and electrical, electronic, and mechanical parts that generate vibration are used. These parts may also propagate vibrations to other parts and the entire housing, failing to achieve the intended performance of the product, or in some cases causing malfunction or unpleasant vibration noise. Therefore, a vibration damping material used as a structure for electric / electronic / mechanical parts, a vibration damping structural material such as a housing of home electric appliances or OA equipment, etc., has room temperature while maintaining sufficient strength and hardness. It is required that the internal loss be large.

In addition, in recording media such as optical discs, magnetic discs or magneto-optical discs, data cartridge tapes, optical discs for video / audio, cassette tapes, etc. used in computers, word processors, etc., in recent years, their high reliability and high sound quality have been achieved. There is a strong demand for higher image quality. These recording media are mounted on a recorder or the like, and recording / reproducing is performed by rotationally driving a motor or the like. At this time, vibrations generated inside the cartridge, inside the cassette half, or inside the disk shell (for example, vibration due to play around the axis of the hub for winding the magnetic tape) and from outside the cartridge, outside the cassette half or outside the disk shell Vibration (e.g., vibration from rotation of a motor or the like) adversely affects recording and reproducing, which makes accurate recording and reproducing difficult. Therefore, a vibration damping material used as a vibration damping structural material such as a cartridge half, a cassette half or a disk shell has high internal loss near room temperature while maintaining sufficient strength and hardness. There is a strong demand.

Generally, as a binder resin used for a vibration damping material, a polypropylene resin which is a thermoplastic resin,
Polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin, modified polyphenylene ether resin and the like are used. These hard resins are relatively inexpensive and are particularly well used because of their excellent moldability.

However, the above-mentioned hard resins such as polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin have sufficient internal loss at room temperature as they are. Not big.

Therefore, attempts have been made to improve the vibration damping performance of various hard resins. For example, in JP-A-2-300250, styrene-isoprene-styrene block copolymer is added to polypropylene resin. JP-A-3-45646 discloses a polypropylene composition having improved vibration damping performance by adding a styrene-isoprene-styrene block copolymer to an acrylonitrile-butadiene-styrene copolymer. An ABS resin composition having improved vibration damping performance when added is disclosed. Further, JP-A-3-181552
JP-A-5-70699 discloses a polyphenylene ether resin composition having improved vibration damping performance by adding a styrene-isoprene-styrene block copolymer to polyphenylene ether. A thermoplastic resin composition having improved vibration damping performance by adding a styrene-isoprene-styrene block copolymer to a thermoplastic resin is disclosed.
Japanese Patent No. 59234 discloses a vibration-damping resin in which vibration-damping performance is improved by adding a styrene-isoprene-styrene block copolymer to polypropylene.

Further, Japanese Patent Application Laid-Open No. 3-287652 discloses a vibration damping composition having improved vibration damping performance by adding iron oxide powder as an inorganic filling material.

By the way, in the industry, it is common to directly add an inorganic filler material to a base resin in the production of a vibration damping material containing a thermoplastic resin as a main component. Prepare a masterbatch pellet in which the inorganic filler is dispersed in the base resin at a concentration higher than the intended concentration, and knead and disperse the masterbatch pellet in the base resin to obtain the inorganic filler having a desired concentration. Since it is easier to handle and the composition is easier to prepare, the production using masterbatch pellets has been proposed.

Therefore, there is also a demand for a masterbatch pellet for a vibration damping material, which is easy to handle when manufacturing the vibration damping material and which can impart a sufficient vibration damping effect with an appropriate amount of addition.

[0014]

The vibration-damping material which has a large internal loss in a temperature range which is usually used while maintaining sufficient strength and hardness as a hard resin, particularly in the vicinity of room temperature, is currently most demanded. However, it cannot be said that each damping material according to each of the above-mentioned known technologies sufficiently satisfies these various characteristics.

That is, the above-mentioned JP-A-2-300250, JP-A-3-45646, and JP-A-3-1815.
52, JP-A-5-70699, and JP-A-5-
The vibration damping materials disclosed in Japanese Patent No. 59234 do not have sufficient vibration damping performance because they do not use an oxide powder containing iron as a main component in the inorganic filling material. Since the content is high, the original strength of the hard resin is not sufficiently maintained.

The vibration-damping material according to the technique disclosed in the above-mentioned JP-A-3-287652 has excellent vibration-damping performance in a temperature range from room temperature to a high temperature, but is a styrene-isoprene-styrene copolymer resin. The strength, that is, the flexural modulus is low and the strength is not sufficient as a hard resin.

Therefore, the present invention is to provide a vibration damping material having a large internal loss in a temperature range normally used, particularly near room temperature, while sufficiently maintaining the original strength and hardness of the hard resin. Subject.

[0018]

The above technical problems can be achieved by the present invention as follows.

That is, the present invention is based on one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. Oxide particle powder 1 containing 99 to 85% by weight of resin and 1 to 15% by weight of styrene-isoprene-styrene block copolymer resin as a binder resin, and iron as a main component with respect to 100 parts by weight of the binder resin. It is a vibration-damping material containing about 20 parts by weight.

Further, the present invention is a base comprising one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. 70 to 0% by weight of resin and 30 to 100% by weight of styrene-isoprene-styrene block copolymer resin are used as a binder resin, and oxide particle powder 50 containing iron as a main component with respect to 100 parts by weight of the binder resin is used. It is a masterbatch pellet for a vibration damping material, which is prepared by blending up to 300 parts by weight.

The present invention also provides a base comprising one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. The method for producing a vibration damping material according to claim 1, which comprises adding 1 to 30 weight% of the masterbatch pellet for vibration damping material to 99 to 70 weight% of the resin, kneading and molding.

Further, the present invention is a vibration damping structural material comprising the vibration damping material.

The structure of the present invention will be described in more detail as follows. First, the vibration damping material according to the present invention will be described.

The vibration damping material according to the present invention has a room temperature (24
Loss factor at 0.015 or higher, preferably 0.0
It is 20 or more, and the internal loss is large near room temperature.
When the bending elastic modulus is 100%, the bending elastic modulus is 100%, and is 70% or more, preferably 75%.
As described above, the original strength and hardness of the hard resin are sufficiently maintained. Its specific gravity is 0.95 to 1.40, preferably 0.95 to 1.30, which is close to the original specific gravity of the base resin, and maintains a relatively lightweight state.

The base resin in the present invention is one or more resins selected from polypropylene resin, acrylonitrile-butadiene-styrene block copolymer, polystyrene resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. Can be used. The amount is 9 in the binder resin.
It is in the range of 9 to 85% by weight, preferably 98 to 88% by weight. If it exceeds 99% by weight, the amount of the styrene-isoprene-styrene block copolymer added is too small to obtain the vibration damping effect. 85% by weight
In the case of less than, the strength of the base resin, that is, the flexural modulus is weakened by the added styrene-isoprene-styrene block copolymer, and the original strength of the base resin, that is, the flexural modulus is sufficiently maintained. I can't.

Examples of polypropylene resin include propylene copolymers such as homopolypropylene, propylene-ethylene random copolymer (ethylene content 20% by weight or less), propylene-ethylene block copolymer (ethylene content 20% by weight or less). And modified polypropylene modified with an unsaturated carboxylic acid or its derivative.

The composition of the acrylonitrile-butadiene-styrene block copolymer is 20 to 20% acrylonitrile.
It consists of 30% by weight, 10 to 30% by weight of butadiene and 40 to 70% by weight of styrene.

The polystyrene is preferably high impact polystyrene (HI-PS) obtained by graft-polymerizing styrene on butadiene rubber.

The polycarbonate resin is preferably a resin having a viscosity average molecular weight of 1.8 × 10 ^{4 to} 3.3 × 10 ⁴ .
Examples include Novarex (manufactured by Mitsubishi Chemical), Panlite (manufactured by Teijin Chemicals), Iupilon (manufactured by Mitsubishi Gas Chemical), Tafflon (manufactured by Idemitsu Petrochemical), Lexan (manufactured by GE), and Macron (manufactured by Bayer).

Examples of the polyphenylene ether resin include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether and poly (2-methyl-6-methyl). -1,4-phenylene) ether, poly (2-methyl-6-propyl-)
1,4-phenylene) ether, poly (2,6-dipropyl-1,4-phenylene) ether, and poly (2-ethyl-6-propyl-1,4-phenylene) ether.

As the modified polyphenylene ether, a polymer alloy of polyphenylene ether and a styrene resin (Noryl, (manufactured by Generalel Electric Co.)),
A polymer alloy of polyphenylene ether and a polyamide resin (Noryl GTYX, (manufactured by General Electric Co.)) may be mentioned.

The base resin of the present invention is preferably an acrylonitrile-butadiene-styrene block copolymer, polystyrene resin, polycarbonate resin or modified polyphenylene ether resin.

The styrene-isoprene-styrene block copolymer in the present invention has an anion-polymerizable aromatic vinyl monomer such as styrene, 1-vinylnaphthalene, or 2 as the styrene block of the block copolymer.
-Vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-
Phenyl butyl styrene, etc. Of these, styrene is particularly preferable.

Isoprene or isoprene-butadiene is suitable as the isoprene block of the block copolymer. When other monomers are used, for example,
When butadiene is used alone, even if the vinyl bond content is increased, the temperature at which the vibration damping performance is exhibited is less than 0 ° C, and the function at the temperature actually used cannot be obtained. In the case of isoprene, if the vinyl bond content is 40% or more, the temperature will increase from 0 ° C to 5
The vibration damping performance can be exhibited in a practical temperature range up to around 0 ° C., and it can be applied to a wide range of applications, which is extremely useful in practice. In the case of isoprene-butadiene, if the proportion of isoprene is 40% or more, the vibration damping performance is exhibited at 0 ° C or more. The form of the copolymer in the isoprene block may be random, block or tapered.

The resulting styrene-isoprene-styrene block copolymer has a number average molecular weight of 30,000 to 300.
The range is 000. When the molecular weight is less than 30,000, mechanical properties such as strength and elongation at break of the block copolymer itself are deteriorated and the strength is lowered when used as a material, which is not preferable. Further, when it exceeds 300,000, the workability is deteriorated, which is not preferable. More preferably 80,000-2
It is in the range of 50,000.

The block morphology of the block copolymer is A
It is represented by (BA) _n and (AB) _n . Here, A is a styrene block, B is an isoprene block, and n is an integer of 1 or more. Of these, the form of A (BA) _n is preferable.

The amount of the block copolymer added is 1 to 15% by weight, preferably 2 to 12% by weight in the binder resin.
Range. When it is less than 1% by weight, the improvement of the vibration damping property due to the dispersion of the block copolymer in the base resin is not sufficiently exhibited. When it exceeds 15% by weight, the strength of the base resin is weakened, and the original strength and hardness of the base resin cannot be sufficiently maintained.

The oxide particle powder containing iron as a main component in the present invention includes hematite, maghemite, magnetite,
Iron oxide particle powder such as a beltride compound, magnetoplumbite type ferrite such as strontium ferrite, barium ferrite and spinel type ferrite such as manganese-zinc ferrite and nickel-zinc ferrite can be used. Further, powdered iron oxide hydroxide particles such as goethite, akagenite, and lepidcrosite can also be used.
Particularly, magnetite, strontium ferrite and barium ferrite powder are preferable. The shape thereof may be any of granular, spindle-shaped, needle-shaped, plate-shaped and the like, but the granular shape is particularly preferable. Further, those having a particle size in the range of 0.05 to 10 μm can be used, and those having a particle size in the range of 0.1 to 5 μm are particularly preferable in view of characteristics and economy. BET specific surface area in the case of magnetite particles is 1 to 50 m ² / g, preferably 3~40m ² / g, in the case of barium ferrite particles or strontium ferrite particles is 0.1~30m ² / g, preferably 0.3 to ²⁰ m ² /
g.

The amount of the oxide particle powder containing iron as the main component is 1 to 20 parts by weight with respect to 100 parts by weight of the binder resin. If it is less than 1 part by weight, a large internal loss cannot be obtained. When it exceeds 20 parts by weight, the flexural modulus, which is an index of the strength of the hard resin, is lowered, sufficient strength cannot be obtained, and further, the specific gravity is increased and the original lightness of the resin is lost. It is preferably 3 to 20 parts by weight.

The vibration-damping material according to the present invention contains the base resin, the styrene-isoprene-styrene block copolymer, and the oxide particle powder containing iron as a main component as essential components. It is also possible to blend and use other polymers, compatibilizers, oxidation stabilizers, etc. within a range that does not impair the above. For example, NR, IR, BR,
Examples thereof include SBR, EPDM, EPR, styrene-conjugated diene block copolymers and hydrogenated products thereof. The blending ratio of these polymers is preferably about 30 parts by weight or less, preferably 5 to 25 parts by weight, based on 100 parts by weight of the binder resin.

Next, a method for manufacturing the vibration damping material according to the present invention as described above will be described.

The method for producing a vibration damping material according to the present invention comprises a masterbatch pellet for vibration damping material, polypropylene resin, acrylonitrile-butadiene-styrene block copolymer, polystyrene resin, polycarbonate resin, polyphenylene ether resin, and A base resin composed of one or more resins selected from the modified polyphenylene ether resin is mixed with a mixer such as a ribbon blender, a Nauter mixer, a Henschel mixer, or a super mixer, and then molded with an injection molding machine or the like. It is to get the object.

The masterbatch pellets for vibration damping material according to the present invention used in the above production method will be described.

The masterbatch pellet for vibration damping material according to the present invention has a particle size of 1 to 10 mm, preferably 3 to 7 mm.
Range. If it is less than 1 mm, the workability during pellet production is poor, which is not preferable. If the size exceeds 10 mm, it becomes difficult to sufficiently disperse it in the base resin. In addition, the shape can be various, irregular shape,
It can be cylindrical, spherical, flake-shaped, etc.

As the base resin for the masterbatch pellets, polypropylene resin, acrylonitrile-butadiene-styrene block copolymer, polystyrene resin,
One or more resins selected from polycarbonate resins, polyphenylene ether resins and modified polyphenylene ether resins can be used, and the amount thereof is in the range of 70 to 0% by weight, preferably 65 to 0% by weight in the binder resin. is there. When it exceeds 70% by weight, the content of the styrene-isoprene-styrene block copolymer is small as described later, so that when the vibration damping material is produced, the styrene-isoprene-styrene block copolymer resin is desired. It becomes difficult to obtain the concentration of.

The composition of the base resin in the masterbatch pellets may be the same as or different from the base resin used for kneading the masterbatch pellets.

As the styrene-isoprene-styrene block copolymer resin for the masterbatch pellets, those mentioned above can be used, and the amount thereof is 3 in the binder resin.
It is in the range of 0 to 100% by weight, preferably 35 to 100% by weight. If the amount is less than 30% by weight, the amount of master batch pellets required for producing the vibration damping material increases, which is not preferable.

As the oxide particle powder containing iron as a main component of the masterbatch pellet, the above-mentioned powder can be used, and the amount thereof is 50 to 300 with respect to 100 parts by weight of the binder resin.
Parts by weight, preferably 60 to 250 parts by weight. If the amount is less than 50 parts by weight, the amount of masterbatch pellets required for producing the vibration damping material increases, which is not preferable. If the amount exceeds 300 parts by weight, the content of oxide particle powder containing iron as the main component in the vibration damping material changes greatly due to a slight change in the amount of the master batch pellets added, so the content is adjusted to a desired value. Is difficult and is not preferable. In addition, mechanical wear is severe and unsuitable.

The masterbatch pellets for vibration damping material according to the present invention are polypropylene resin, acrylonitrile-
A butadiene-styrene block copolymer resin, a polystyrene resin, a polycarbonate resin, a polyphenylene ether resin, a base resin composed of at least one resin selected from a modified polyphenylene ether resin, a styrene-isoprene-styrene block copolymer resin, and iron are mainly used. After mixing the oxide particle powder as a component with a mixer such as a ribbon blender, a Nauter mixer, a Henschel mixer, and a super mixer, the mixture is kneaded with a known single-screw kneading extruder or a twin-screw kneading extruder. It is manufactured by cutting after molding or by kneading the mixture with a Banbury mixer, a pressure kneader or the like, crushing, molding, and cutting into a granular material.

The vibration damping material according to the present invention is one or more selected from polypropylene resin, acrylonitrile-butadiene-styrene block copolymer resin, polystyrene resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. 99 to 70% by weight, preferably 95
It is obtained by adding, kneading and molding the master batch pellets for vibration damping materials 1 to 30% by weight to 75% by weight. The amount of masterbatch pellets added is preferably 5 to 25% by weight, more preferably 5 to 20% by weight.
Range. If it is less than 1% by weight, the effect of adding the masterbatch pellets cannot be sufficiently obtained. 30% by weight
If it is added over the range, the original strength and hardness of the base resin may be deteriorated, which is not preferable.

The vibration damping structural material made of the vibration damping material according to the present invention will be described.

The vibration-damping structural material made of the vibration-damping material according to the present invention is a structure of electric / electronic / mechanical parts and a housing for home electric appliances, OA equipment and audio equipment, and in particular, a cassette half. , Cartridge half and disk shell.

The vibration-damping structural material made of the vibration-damping material according to the present invention uses the vibration-damping material according to the present invention as described above. A method of manufacturing a conductive material can be adopted.

The vibration damping structural material made of the vibration damping material according to the present invention has a loss coefficient at room temperature (24 ° C.) of 0.020 or more, preferably 0.025 or more, more preferably 0.0.
It is 30 or more.

[0055]

In the present invention, the reason why a vibration damping material having a high loss coefficient in a normally used temperature range, particularly near room temperature can be obtained while sufficiently maintaining the original strength and hardness of the hard resin, The present inventor thinks as follows.

First, in the vibration damping material, one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. Styrene-isoprene-styrene block copolymer resin is dispersed as a fine lump in a base resin consisting of the styrene-isoprene-styrene block copolymer fine lump and the base resin It is considered that the vibration damping effect is exerted by friction at the interface with etc., and in particular, the smaller the particle size of the dispersed fine agglomerates, the larger the contact area, so that the vibration damping performance, that is, the internal We believe that losses will also increase.

However, when the amount of the styrene-isoprene-styrene block copolymer added is increased, the internal loss increases, but the original strength of the hard resin such as the flexural modulus decreases.

Therefore, as a result of diligent research conducted by the present inventor, the oxide particle powder containing iron as a main component is a well-known inorganic filler.
For example, the loss coefficient is improved compared to the case of using mica, and moreover, the internal loss is efficiently reduced by adding a small amount of styrene-isoprene-styrene block copolymer resin while maintaining the strength and hardness of the hard resin. He found that he could grow.

This is because, among the well-known inorganic filler materials, in particular, the oxide particle powder containing iron as a main component is a lump of styrene-isoprene-styrene block copolymer dispersed in the base resin. It is considered that there is an effect of miniaturization, and as a result, the dispersed state of the agglomerates becomes finer and the damping effect due to friction with the base resin increases, thereby increasing the internal loss.

In the hard resin, styrene-isoprene-
When the oxide particle powder containing iron as the main component is dispersed without adding the styrene block copolymer resin, the vibration damping performance is hardly improved, as shown in Comparative Examples 13 and 14 below.

Moreover, by using the oxide particle powder containing iron as the main component, the addition amount required to obtain the same loss factor as compared with the case of using mica and the like is small,
Further, the addition amount of styrene-isoprene-styrene block copolymer can be suppressed to a small amount, and as a result, while sufficiently maintaining the original strength and hardness of the hard resin,
It is considered that a vibration damping material having a large internal loss in a temperature range normally used, particularly near room temperature, could be obtained.

[0062]

The present invention will be described below with reference to Examples and Comparative Examples.

The loss coefficient η used as an index of the vibration damping performance, that is, for indicating the magnitude of the internal loss of the material, was injection molded into a size of 200 × 12.5 × 3 mm by an injection molding machine, and the loss coefficient η of this test piece was used. Was measured by the cantilever burr type resonance method.
The measurement conditions were 24 ° C. and 1 kHz.

The loss factor η of the cassette half, the gear, and the casing of the OA equipment is the metal sphere (weight 1.05) suspended from the casing by hanging the casing at two points and using the cord (length 250 mm).
g, diameter 6 mm) as a fulcrum above the housing vertically, drop a metal ball pulled up to an angle of 60 ° from the vertical, apply vibration to the center of the housing, and use a vibration pickup installed at the bottom of the housing to vibrate. Transmission was detected, and data processing was performed using a 3550 type FFT analyzer (B & K) to obtain a loss coefficient η.

The flexural modulus, which is an index of the strength of the vibration damping material, was injection-molded by an injection molding machine into 80 × 12.5 × 3 mm, and the flexural modulus of this test piece was measured by ASTM D790.

The specific gravity is a specific gravity meter (EW-120SG: MIR
AGE TRADING CO. , LTD).

<Manufacture of Masterbatch Pellets for Damping Material> Examples 1 to 9 and Comparative Examples 1 and 2; Example 1 High Impact Polystyrene Resin (Sumibrite M57
4: Sumitomo Chemical Co., Ltd.) 50% by weight and styrene-isoprene-styrene block copolymer (VS-1: manufactured by Kuraray Co., Ltd.) 50% by weight, and 100 parts by weight of a binder resin and granular magnetite particles powder (average particle size 0.27 μm). , (VD-803
C: manufactured by Toda Kogyo Co., Ltd.)) and 100 parts by weight of the mixture are kneaded at 160 ° C. by a twin-screw kneader, and then the mixture is extruded through a 3 mmφ die and cut out into about 3 mm units,
A masterbatch pellet A was obtained.

Examples 2 to 9 and Comparative Examples 1 to 2 Table 1 shows the types and amounts of the base resin, styrene-isoprene-styrene block copolymer and iron-based oxide particle powder in the masterbatch pellets. By selecting as shown, master batch pellets B to K for vibration damping materials were obtained.

<Manufacture of vibration damping material> Examples 10 to 23, Comparative examples 3 to 14; Example 10 A high impact polystyrene resin (Sumibrite M574: Sumitomo Chemical Co., Ltd.) was used as a base resin, and 90 high impact polystyrene resins were used. % Of the master batch pellet A and 10% by weight of the master batch pellet A were uniformly blended by a Henschel mixer, and then a strip sample was prepared by an injection molding machine. The loss factor η of this strip sample at room temperature (24 ° C.) is 0.021. The flexural modulus is 254.
It is 00 kgf / cm ² , and maintains 95% of the bending elastic modulus of 100% high-impact polystyrene resin and the original strength and hardness of the hard resin. The specific gravity is 1.09.

Examples 11 to 23, Comparative Examples 3 to 9 Various kinds of masterbatch pellets, kinds of base resins for kneading the masterbatch pellets, mixing ratios of the base resins and masterbatch pellets, etc. were changed as shown in Table 2. A vibration damping material was prepared in the same manner as in Example 1 except that the above was used. Table 4 shows the characteristic values of Examples 11 to 23.
Table 5 shows the characteristic values of Comparative Examples 3 to 9.

Comparative Examples 10 to 14 The base resin, the styrene-isoprene-styrene copolymer resin and the flaky mica were kneaded and molded directly without using the masterbatch pellets to prepare a vibration damping material.
The composition is shown in Table 3. Table 5 for each characteristic value
It was shown to.

<Manufacture of vibration damping structural material made of vibration damping material> Examples 24 to 26, Reference Examples 1 to 3; Example 24 A high impact polystyrene resin (Sumibrite M574: Sumitomo Chemical Co., Ltd.) was used as a base resin. The high-impact polystyrene resin was 90% by weight and the masterbatch pellet A was 10% by weight, and these were uniformly blended by a Henschel mixer, and then a cassette half casing was prepared by an injection molding machine. The loss coefficient η at room temperature (24 ° C.) was 0.031.

Reference Example 1 A cassette half of a commercially available cassette tape was taken out and the loss coefficient was measured by using this as a reference example. Room temperature (24
The loss coefficient at (° C.) was 0.015.

Example 25 A polycarbonate resin (Novarex 7025A (Mitsubishi Kasei)) was used as a base resin, the polycarbonate resin was 93% by weight, the master batch pellet F was 7% by weight, and these were uniformly blended by a Henschel mixer. , Made gears with injection molding machine. The loss coefficient η at room temperature (24 ° C.) was 0.021.

Reference Example 2 A gear was produced by an injection molding machine using only a polycarbonate resin (NOVAREX 7025A (Mitsubishi Kasei)).
The loss coefficient at room temperature (24 ° C.) was 0.008.

Example 26 A modified polyphenylene ether resin (Noryl 731 (manufactured by Japan G-Plastic)) was used as a base resin, and 90% by weight of the modified polyphenylene ether resin and 10% by weight of masterbatch pellet G were used. After blending uniformly, the case (exterior material) of the dot printer was created with an injection molding machine.
The loss coefficient η at room temperature (24 ° C.) was 0.035.

Reference Example 3 A case of a dot printer was produced by an injection molding machine using only a modified polyphenylene ether resin (Noryl 731 (Nippon Gee Plastic)). This room temperature (24
The loss factor η at (° C) was 0.010.

[0078]

[Table 1]

[0079]

[Table 2]

[0080]

[Table 3]

[0081]

[Table 4]

[0082]

[Table 5]

[0083]

The vibration damping material according to the present invention, as shown in the above-mentioned examples, has a temperature range which is usually used while maintaining the original strength and hardness of the hard resin, particularly Since the loss factor around room temperature is high, the vibration damping material can be made lighter, thinner, and smaller, and the structure of electric / electronic / mechanical parts, home electric appliances, OA equipment, audio equipment, etc. Suitable for vibration damping structural materials such as casings, optical disks, disk shells of magnetic disks and magneto-optical disks, cassette halves of cassette tapes, cartridge halves of cartridge tapes, etc., especially disk shells,
It is suitable as a cassette half and a cartridge half.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C08L 71/12 LQP C09K 3/00 P // (C08L 23/10 53:02) (72) Invention Tetsuro Toda 7-1 Yokogawa Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Toda Industrial Co., Ltd.

Claims (4)

[Claims] 1. A base resin 99 to 85 comprising one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin.
% By weight and 1 to 15% by weight of styrene-isoprene-styrene block copolymer resin as a binder resin, and 1 to 20 parts by weight of oxide particle powder containing iron as a main component with respect to 100 parts by weight of the binder resin. Damping material made by blending 2. A base resin 70 to 0 comprising one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin. % By weight and 30 to 100% by weight of styrene-isoprene-styrene block copolymer resin as a binder resin, and 50 to 300 parts by weight of oxide particle powder containing iron as a main component based on 100 parts by weight of the binder resin. A masterbatch pellet for vibration-damping material, which contains 3. A base resin 99 to 70 comprising one or more resins selected from polypropylene resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin and modified polyphenylene ether resin.
The method for producing a vibration damping material according to claim 1, which comprises adding 1 to 30% by weight of the masterbatch pellet for vibration damping material according to claim 2 to the weight%, kneading and molding. 4. A vibration damping structural material comprising the vibration damping material according to claim 1.