JPS6392685A - Vibration absorber for filling hollow member - Google Patents

Abstract

PURPOSE:To provide the title vibration absorber for filling a hollow member of precision mechanical equipment etc. without leaving any space and cured to effectively prevent the occurrence of sound through absorption of vibration and is excellent in moisture resistance and sealing properties and which comprises a liq. compsn. composed of a polyol compd. and a polyisocyanate compd. CONSTITUTION:100pts.wt. polyol compd. (a), such as a liq. diene polymer contg. 0.1-10meq/g of OH group in its molecule or at its molecular end and having a number-average MW of 300-25,000 is compounded with a polyisocyanate compd. (b) having two or more isocyanate groups per molecule (e.g., tolylene diisocyanate) so that the molar ratio of the NCO group of component (b) to the OH group of component (a) is 0.2-25, thereby preparing a liq. compsn. (A). Compsn. (A) is used as a curing component and, if necessary, compound with a reinforcing agent (B) comprising 1-100pts.wt. polyamine compd., 10-1,000pts.wt. bituminous material (C), a viscosity modifier (D) comprising a plasticizer, such as dioctyl phthalate, a curing accelerator (E) comprising dibutyltin dilaurate or the like, and a filler (F) or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for filling hollow members used in OA equipment, measuring equipment, medical equipment (precision instruments such as preceptors), and for vibration-proofing and sound-proofing. The present invention relates to vibration absorbers for use.

[Prior Art 1] Computers, word processors, facsimile machines, copying machines, cameras, and other precision equipment generate various noises as they operate. Among them, for example, printers for computers and word processors that emit loud impact noises can be significantly improved by using soft materials for the printing roll or changing the printing method to an inkjet method or a laser method. It has been.

However, in the current situation where the number of 0A8i machines in use per office station is increasing, regardless of the size of the business, it is difficult to use medium-level VF.
Prevention of the L sound has also become extremely important from the perspective of environmental protection in the workplace.

Most of these noises are caused by the friction noise or shaft that is generated when parts rotate or slide on cylindrical metal hollow members that are often used in precision equipment, such as hollow metal shafts. This includes the rotating sound or vibration sound of the machine itself.

As a general soundproofing measure against this noise, indirect methods such as pasting cushioning material on the inside of the equipment (installing the entire molding on an elastic mat) have been taken, but direct
No Tf elbow prevention measures applied to hollow members have been taken so far.

[Problem to be Solved by the Invention 1] An object of the present invention is to provide a vibration absorber that reduces noise generation in precision instruments by filling the inside of a hollow member.

[Means for Solving the Problem] The present inventors focused on the fact that much of the noise in current precision instruments is caused by hollow members, and as a result of intensive research to eliminate this noise, they found that polyol compounds and polyisocyanate The inventors have discovered that if a liquid composition made of a compound is put into a hollow part and cured, the noise generated by the hollow part can be greatly reduced, and the present invention has been completed.

That is, the present invention achieves the above object with a vibration absorber for filling hollow members, which contains a liquid composition consisting of a polyol compound and a polyisocyanate compound as a curing component.

The polyol compound used in the present invention is firstly a hydroxyl group-containing liquid diene polymer, which has a hydroxyl group in the molecule or at the end of the molecule and has a number average molecular weight of 300.
-25,000, preferably 500-to, ooo, and a hydroxyl group content of 0.1-10 meq/g, preferably 0.3-7 ieq/y is suitably used. can.

The liquid tsene polymer that forms the backbone of these hydroxyl group-containing liquid tsene polymers may be a copolymer of tsene monomers having 4 to 12 carbon atoms, or a copolymer of tsene monomers having 4 to 12 carbon atoms, or a diene monomer with these diene monomers having 2 to 22 carbon atoms. and copolymers with olefin monomers. Specifically, butadiene polymer, imprene polymer, phtadiene-styrene copolymer, butanene-isoprene copolymer, butanoene-7crylonitrile copolymer, butanoene-2-ethylhexyl acrylate fubolymer, butadiene-n-
Examples include octadecyl acrylate fubolimer. These liquid diene polymers can be produced by heating a conjugated diene monomer in a liquid reaction medium in the presence of hydrogen peroxide.

There are no particular limitations on the non-diene polyol compound that can be used in the present invention, and any of primary polyols, secondary polyols, and tertiary polyols can be used. Specifically, for example, 1,2-propylene glycol, dipropylene glycol/1,2-butanediol, 1,
3-butanediol, 2,3-butanediol, 1.
2-bentanediol, 2.3-bentanediol, 2
, 5-hexane diol, 2,4-hexaneol,
At least one of 2-ethyl-1,3-hexane dionopecyclohexane diol, glycerin, N,N-bis-2-hydroxypropylaniline, N,N'-bishydroxyisopropyl-propylene oxide adduct of bisphenol A, etc. Examples include low molecular weight polyols containing hydroxyl groups bonded to two secondary carbons.

Furthermore, as polyol compounds, ethylene glycol, 1,3-
Propylene glycol, 1,4-butanediol, 1,
5-bentanediol, 1,6-hexanediol, etc. can also be used.

As the polyol used in the present invention, diols are usually used, but triols and tetraols can also be used.

Further, in the present invention, polyols having a molecular weight of 50 to 500 can be suitably used as polyol compounds other than the diene polymer.

As the polyisocyanate compound used in the present invention, 1
It is an organic compound that has two or more incyanate groups in its molecule, and has an incyanate group that is reactive with the hydroxyl group of the polyol. Examples of polyisocyanate compounds include the usual aromatic, aliphatic and cycloaliphatic ones, such as) lylene diisocyanate (TDI), hydrogenated TD+
, hexamethylene diisocyanate, nophenylmethane diisocyanate (MDI), hydrogenated MDI, liquid modified diphenylmethane noisocyanate, polymethylene polyphenylisocyanate, xylylene diisocyanate, cyclohexyl diisocyanate, cyclohexanephenylene diisocyanate, naphthalene-1,5-diisocyanate, Examples include isopropylbenzene-2,4-diisocyanate, addition reaction product of polypropylene glycol and tolylene diisocyanate, and especially MDI
, liquid modified nophenylmethanoisocyanate, tolylene diisocyanate and the like are preferred.

There is no particular restriction on the blending ratio of the polyisocyanate compound and polyol compound used in the present invention, but usually the ratio of the isocyanate group (NCO) of the polyisocyanate compound to the hydroxyl group (leaf) of the polyol compound (NCOloH) is The molar ratio should be between 0.2 and 25, preferably between 0.5 and 15. If this molar ratio is outside the above range, it will be difficult to cure, which is not preferable.

The vibration absorber of the present invention is manufactured from a composition containing the above two components as essential components, but depending on the type and blending ratio of these two components and the application of the product, additives such as reinforcing agents may be added. Polyamine compounds, plasticizers, pigments, organic or inorganic fillers, hardening accelerators, anti-aging agents, antifoaming agents and the like can be added to the raw composition.

Further, the polyamine compound used as a reinforcing agent in the present invention may be any of diamine, triamine, and tetraamine. Furthermore, any of primary polyamines, secondary polyamines, and tertiary polyamines can be used.

Examples of polyamine compounds include aliphatic amines such as hexamethylenezamine, 3,3'-dimethyl, 4,4
- Alicyclic amines such as Noami/Nocyclohexylmethane,
Aromatic amines such as 4,4'-diaminonophenyl, 2,
Tetramines such as 4.6-)su(dimethylaminomethyl)7ethyl and the like can be mentioned.

The amount of the polyamine compound as a reinforcing agent is not particularly limited, but it is usually 100% of the polyol compound.
This is added in an amount of 1 to 100 parts by weight, preferably 2 to 50 parts by weight.

In addition, fillers added as desired include fibrous materials such as Japanese hemp, Manila hemp, jute, paper, straw, carbon fiber, and glass fiber, and mica, graphite, vermiculite, talc, calcium carbonate, slate powder, and silica. Powder fillers such as Such a powder filler can adjust the specific gravity of the cured product, thereby changing the natural frequency of the hollow member so that the operation of the device and the hollow member are not synchronized.

In addition, plasticizers such as dioctyl phthalate are added as viscosity modifiers, softeners such as 70 mm oil, naphthenic oil, and paraffin oil are added, and adhesive strength and
Full Kill 7 E/L tJj BW for adhesive strength adjustment
, Terpene 84 Fm, Terpene 7 E/-le tl,
xylene formaldehyde resin, rosin, hydrogenated rosin,
Tackifying resins such as coumaron resins and petroleum resins can be added.

Further, curing accelerators such as dibutyltin dilaurate, stannous octoate, polyethylenenoamine, etc. can also be added. Further, an anti-aging agent may be added to improve weather resistance, and a silicon compound or the like may be added as an antifoaming agent.

Furthermore, a bitumen substance can also be added to this. Bituminous materials include petroleum asphalt, pitch, and tar. In this case, the bituminous substance can be used in an amount of 10 to 1,000 parts by weight per 100 parts by weight of the hydroxyl group-containing tenne polymer. The vibration absorber in the present invention is adjusted as follows.

First, a polyol compound, if desired, a plasticizer, an anti-aging agent, and other additives are blended in predetermined amounts, and the temperature is 10 to 10 degrees.
Stir at 120°C. Then, by adding a predetermined amount of a polyisocyanate compound to this while stirring in the same temperature range, the prepolymer can be obtained.

When using the vibration absorber of the present invention, by injecting it into the hollow part of a hollow member and heating it to 50 to 120°C, the prepolymer will harden and a hollow member that generates less noise can be obtained. . If this part cannot be heated,
After injecting the vibration absorber, if it is left for a long time at room temperature, the vibration absorber will completely harden.

Further, when using the vibration absorber of the present invention, if a foaming agent such as an appropriate amount of water is added and cured, a foamed cured product is generated inside the hollow member. The foaming rate can be selected as appropriate depending on the use of the hollow member, which is advantageous because it can reduce the weight without reducing the damping effect, and when the hollow member itself operates, it can ensure quick operation.

[Effects of the Invention] The vibration absorber of the present invention can be used in hollow members in precision equipment to eliminate noise caused by the hollow members.

When the vibration absorber of the present invention is used, no matter what shape the inside of the hollow member is, it can be filled without leaving any gaps, so that efficient soundproofing can be achieved.

In particular, since liquid rubber, which has better sealing properties than ordinary rubber, constitutes the matrix of the cured product of the vibration absorber of the present invention, it can be suitably used in places that require moisture resistance and sealing properties. Useful.

Furthermore, when applying the vibration absorber of the present invention to a hollow member, it is possible to form a filler with a desired specific gravity in the hollow member simply by adding an inorganic filler or a foaming agent depending on the application. This is advantageous because it allows the natural frequency of the hollow member to be changed.

[Example 1] Next, the present invention will be explained in further detail using an example.

In this example, the preparation of the vibration absorber, the curing reaction, and the measurement of physical properties when applied to a hollow member were carried out as follows.

Examples 1 and 4 [Preparation of vibration absorber and its curing reaction 1 A predetermined amount of polyol compound is placed in a container, and additives such as a curing accelerator are added thereto and mixed. Next, to this,
A predetermined amount of polyisocyanate compound was added and mixed for 2 minutes at a temperature of 20° C. to obtain a vibration absorber.

Next, this vibration absorber was molded using a blurring machine at a molding temperature of 120°C, a molding time of 1 hour, and a molding pressure of 20°C.
Cured and molded under the conditions of 0 kgr/cz2, m: 20
Obtain a plate-shaped cured body of 0xz, width 300ax, and thickness 1u,
The vibration damping properties of this cured body were evaluated.

Separately, this vibration absorber was filled into a computer print head shaft (diameter 25 mm, length 400 zz), and 1
The shaft was cured for 1 hour at 20° C., and the impact sound of the shaft was measured.

Examples 2 and 3 The indicated ingredients except the polyisocyanate compound were placed in a container, stirred at 80°C for 1 hour, then the specified amount of the indicated polyisocyanate compound was added, and stirred at 20°C for 3 hours to form a vibration absorber. Obtained.

This vibration absorber was poured into a glass mold with a width of 200au, a length of 300zz, and a depth of 1zx, and cured at 25°C for 72 hours to obtain a plate-shaped cured body.The vibration damping properties of this cured body were evaluated. did.

Separately, using this vibration absorber, the impact sound of the print head shaft was measured under the same conditions as in Example 1 except for curing conditions at 25° C. for 72 hours.

Example 5: All the listed ingredients were collected in a container and quickly stirred until it became creamy. Using this cream-like vibration absorber, it was filled into the same print head shaft as in Example 1 up to 2/3 of the internal volume of this shaft, and foamed and hardened at 25°C for 15 minutes. In the same manner as above, the impact sound of the print head shaft was measured.

[Test Method 1 Allocability was evaluated using the value of loss tangent (tan δ) as an index.

Regarding the above plate-shaped cured body, the loss tangent was determined by the product manufactured by Toyo Baldwin Co., Ltd., product name DDV-11-C (frequency 11H).
z). The loss tangent is also called a loss coefficient and is defined by loss elastic modulus/storage elastic modulus.

The impact sound was measured in the same way as for dogs.

While holding the above shaft horizontally, separately prepare nine stainless steel wI rods with a diameter of 10zz and a length of 300u, one end of which is rotatably fixed, and the pond end is dropped onto the shaft from a height of 30ON. The impact sound generated at this time was measured. In this measurement, stainless steel f! The fixing point of the 4-piece nine rods is located 30° diagonally above the horizontal and vertical directions with respect to the shaft.

The generated impact sound was measured using an indicator sound level meter 10 manufactured by Denshi Saigi Co., Ltd.
It was measured using a model 15.

These results are shown in the table.

[Comparative Example 1] For comparison, the impact sound was measured for the same shaft without a filling. The noise is 6? It was dB (decibel).

In the above examples, the following raw materials were used.

Hydroxyl group-containing liquid tzene-based polymer manufactured by Idemitsu Ark Co., Ltd., trade name R-45) (Tt-) was used. This is a liquid polybutadiene containing terminal hydroxyl groups, with a number average molecular weight of 2.800 and an OH content of 0.80. 79
meq/g.

Process oil Manufactured by Idemitsu Kosan Co., Ltd., 70mm process oil Product name: AC
-12 Asphalt

Claims (1)

[Claims] 1. A vibration absorber for filling hollow members, which contains a liquid composition consisting of a polyol compound and a polyisocyanate compound as a curing component.