JPS5998121A - Vibration damping material - Google Patents

Abstract

PURPOSE:To provide a vibration damping material having excellent damping property and sound absorbing property even for the sound of low and medium frequency ranges, and suitable as a material for ceiling, floor, etc., by using a specific amount of a foam stabilizer having a specific composition as the stabilizer for the preparation of flexible polyurethane foam. CONSTITUTION:The objective vibration damping material consisting of a flexible polyurethane foam is prepared by reacting a polyol, a polyisocyanate, a foaming agent, a catalyst, a foam stabilizer, a filler, etc. The form stabilizer is a silicone foam stabilizer for rigid polyurethane foam and is composed of a propylene oxide/ethylene oxide copolymer having a propylene oxide content of 5-35mol%. The amount of the stabilizer is 0.5-5pts.wt. per 100pts.wt. of the polyol. Preferably, the filler is a powdery filler such as alumina and the foaming agent is water, and the amounts are 5-120pts.wt. and 1-3.5pts.wt. per 100pts.wt. of the polyol, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foam-shaped damping material that has excellent damping performance, and more particularly to a foam-shaped damping material that has significantly improved damping performance in the low and medium frequency range. ,K
The present invention relates to an extremely practical vibration damping material that has not only excellent vibration damping performance but also excellent sound absorption performance, is much lighter than conventional sheet vibration damping materials, and has a large cost reduction effect.

Conventionally, vibration damping materials have been made of blends of rubber-like substances, thermoplastic resins, or thermosetting tree fertilizers with graphite, mica, and carbon added, and naturally they have a high density, that is, a high weight. It is a big material. For this reason, as a result of the increased need for vehicle noise countermeasures in recent years, lightweight vibration damping materials have attracted attention, but damping performance is proportional to the square of the thickness of the damping material. There is a general rule that if the weight becomes V2.1/3, the vibration damping performance will become 1/4 and 1/9, respectively. :l In the case of conventional damping materials, it has been difficult to use them as lightweight damping materials.

On the other hand, polyurethane foam, which is a typical lightweight material, has rarely been used as a vibration damping material due to its low damping performance. This is essentially due to the low damping performance of the polyurethane itself, and it is clear considering that foaming can result in extremely low-density I-stitching. It is impossible for the inventors of the present invention to trace the research of the present invention.
As a result of evaluating the till vibration performance of general commercially available foams, ■ The vibration damping performance of polyurethane foam is at a low level overall, and the performance is particularly low in the low and medium frequency range below 1000 [z ■ Vibration damping performance A large frequency: jcy, dependence appears.

I discovered this strange phenomenon.

By the way, as is well known, the oscillation frequency of many devices and equipment that require noise countermeasures is 100011z or less [Excitation Sound Genji Techniques Handbook, Volume 1, Chapter 4, pp. 97-171
P, ), 500-600 if possible I! low below z,
There is a strong demand for noise reduction in the medium frequency range.

It goes without saying that the general commercially available polyurethane foam described above is of little use in meeting these requirements, and therefore vibration damping materials based on polyurethane foam materials do not improve overall vibration damping performance. Of course, it is essential to improve damping performance, especially in the low and medium frequency ranges.

As a result of intensive research, the present inventors have found that a silicone foam stabilizer for Koga polyurethane foam with a specific composition can be used as a foam stabilizer when manufacturing the flexible polyurethane foam that forms the foam vibration damping material. We have discovered that this material plays an important role in achieving the above goals, and have obtained a foam-like damping material that has not only poor damping performance in the low and medium frequency ranges but also vague damping performance overall.

Furthermore, with conventional vibration damping materials, the damping performance decreases rapidly as the cylinder temperature increases, so the practical temperature range is very narrow, whereas the foam-shaped damping material of the present invention has a high temperature dependence of damping performance. ”・Accordingly, it is a material that gives young fruits with a damp vibration in a wide temperature absorption range from low temperatures to quite high temperatures.

Another advantage of the foam-shaped damping material of the present invention is that, in addition to the above-mentioned vague damping performance, it also has the characteristic of having excellent sound absorption performance in the low and medium frequency ranges.

That is, although conventional polyurethane foam has good sound absorption properties in the high frequency range, it has the disadvantage that it is not very sound absorbing in the low to medium frequency range, which is the most important for fire applications. The foam-shaped vibration damping material of the present invention has greatly improved this drawback and is an outstanding material that should be noted as a practical material for vibration damping and sound absorbing clothing.

By the way, it is well-known that in order to implement noise countermeasures in a comprehensive and effective manner, in most cases it is necessary to demonstrate both the distribution effect and the dazzling sound motion floor. It has become. For this reason, when commercially available polyurethane foam is used as a sound absorbing material, considering that its damping performance is particularly low in the low and medium frequency ranges as mentioned above, a practical solution is to add solid damping material to polyurethane foam. By bonding (sheets) together and creating a composite material, we are attempting to provide vibration damping and sound absorption performance.

Therefore, in the case of a foam-shaped damping material that has both excellent damping and sound absorption properties as in the present invention, an expensive damping sheet is not required, and the complicated manufacturing process associated with the above-mentioned combination is not required. Since it can be omitted, it is possible to significantly reduce costs and bring about great industrial and academic development.

The vibration damping material of the present invention is a flexible polyurethane foam obtained by reacting a polyol, a polyincyanate, a blowing agent, a catalyst, a foam stabilizer, a filler, etc., in which a silicone foam stabilizer is added with a small amount of propylene oxide. A silicone foam stabilizer for rigid urethane foam having a polymer chain consisting of a copolymer of propylene oxide and ethylene oxide having a molar ratio of 0.5 to 5 parts by weight per 100 parts by weight of polyol. The flexible polyurethane foam obtained by

The present invention will be described in detail below.

The polyol used in the present invention is a polyhydroxyl compound having a molecular weight of 500 to 10,000 and having at least two active hydrogen atoms, and has a hydroxyl/
Polyether polyols with l/ groups.

Polyester polyols and polyether ester polyols, which are copolymers of ether and ester, can be selected arbitrarily to suit the characteristics of the desired flexible polyurethane foam. The present invention particularly uses molecules M800~ which are commonly used in the production of general flexible or half m% polyurethane foams
Poly(oxypropylene) obtained by reacting propylene oxide with glycerin 6000 and performing ring-opening addition.
Active polyols such as triol or poly(oxyethylene-oxypropylene) triol obtained by reacting propylene oxide and ethylene oxide to add a d ring are preferably used.

Moreover, as a polyisocyanate, generally tolylene diinocyanate is mentioned. Among them, the combination ratio of 2,4- and 2.6-H4Q4G of isocyanate groups is 80/2.
Tolylene diisocyanate of 0 or 65/35 (weight ratio) is preferred in terms of low cost and usefulness. Then, the blending amount of this polyisocyanate with respect to the above polyol,
That is, the incyanate index (LAO index) is in the range of 60 to 130, but preferably in the range of 70 to 110 in consideration of the properties of the resulting flexible polyurethane foam.

The catalyst used in the present invention includes known catalysts commonly used in this field, such as tertiary amines and organotin compounds.

The silicone foam stabilizer used in the present invention is poly(oxypropylene-oxyethylene), which is a copolymer of ethylene oxide and propylene oxide.
Among the silicone foam stabilizers for rigid polyurethane foams having a chain, the content of propylene oxide is in the range of 5 to 35 moles, and is usually a poly(oxypropylene-oxyethylene) siloxane copolymer. By setting the amount of propylene oxide in the range of 10 to 30 moles, very preferable young fruits can be obtained. In other words, if the amount of propylene oxide is less than 5 molt, foaming will not be possible! : Nitonashi, cell roughness occurs,
It is not possible to obtain a foam body having the desired foam structure, and if the crack exceeds 357,
The damping performance in the low circumferential square number region deteriorates considerably, making it impossible to achieve the object of the present invention. These silicone foam stabilizers are added in an amount of 0.5 to 5 parts per 100 parts by weight of polyol. If it is less than 0.5 parts by weight, the original function of the foam stabilizer, which is to generate uniform bubbles and adjust the size of the bubbles, will not be achieved, and if it is added in excess of 5 parts by weight, it will not be effective. The effect is not special, and it becomes Neo-U in terms of cost.

As described above, the vibration damping material of the present invention achieves stepped vibration damping in the middle and low frequency ranges below 100011z by applying a specific silicone foam stabilizer for rigid polyurethane foam to flexible polyurethane foam. effect and sound absorption effect 4
It was made to look like G.

The reason for this young fruit is related to the cell structure of the obtained foam: (1) the cell skeleton has a special structure that is convenient for maximizing M25/'a, which will be described later; and (11) This is presumed to be due to the large amount of remaining cell membrane and low air permeability.

Furthermore, in the present invention, it is also possible to further improve the cell uniformity of the foam obtained by adding an organic or inorganic powder filler to each tffl.

Powder fillers used for this include polyvinyl chloride and polyvinyl chloride-vinyl acetate copolymer.

There are zinc oxide, antimony oxide, barium sulfate, calcium carbonate, mica, alumina, etc., and these can be used in one or two buildings.
Yuzu or more can be used in combination. This filler can be used in an amount of 5 to 120 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of the polyol, and the above moving bed cannot be obtained with less than 5 parts by weight.
If it exceeds 120 parts by weight, the viscosity k of the mixed liquid mainly containing polyol increases, making it difficult to foam well. In addition, at this time, a sudden amount of plasticizers such as phthalic acid esters and halogen-containing phosphoric acid esters (the full amount is 10%
By adding (50 parts by weight or less per 0 parts by weight),
It is possible to suppress the increase in viscosity due to mixing, and by doing so, a powder redundant agent can be added to the mixture.

Also, when implementing the present invention! Other additives that may be used include water or low-boiling volatile compounds as blowing agents, which have the effect of controlling the general physical properties and density of the resulting flexible polyurethane foam. There is no particular limitation on the shortness of water as a blowing agent, but as described later, the ratio of the lumka (M2S) to the specific gravity (d) (M25/d) at the time of 25 compression of the obtained foam is determined by the maximum weir. In order to obtain high vibration damping and sound absorption properties, it is desirable to use a 1.0 to 3.5 layer thickness for the polio-Al2O2,i placement portion.

In addition, examples of volatile constituents having a low boiling point include methylene chloride, chloroform, monofluorotrichloromethane, monochlorodifluoromethane, and dichlorodifluoromethane, which may be used alone or in combination.

In addition, there is a light coloring material and brush love agent that is perfect for women.

Plasticizers and the like may be used as appropriate without departing from the purpose of the present invention.

And such an invention? To obtain the tilJ material, a method of operation for producing flexible polyurethane foams, which is currently practiced, is carried out. For example, there is a one-shot method in which polyisocyanate is added to a mixture of polyol, water, a catalyst, a foaming agent, a foaming aid, etc., and reaction foaming is carried out, or a part or all of the polyol is reacted with the entire polyisocyanate in advance. It can be manufactured using a prepolymer method in which the prepolymer thus produced is mixed with other components and foamed.

Among the flexible polyurethane foams having the above-mentioned formulation characteristics, foam materials having the following physical properties exhibit better vibration distribution and sound absorption effects as the vibration damping material of the present invention. In other words, the stress when compressing the foam by 25% (M2S
) is l! j/cTTt or more and 60&/crA or less, and the ratio of the above stress (M2S) to the ratio m ((1)
M2S/'d) is 59/crit or more, 1500
/i/cnt or less, and the air permeability of the foam material at a thickness of 20 degrees is 2 to 1300C, /cIIt-s
The eC foam material has even better vibration damping and sound absorption effects. The above stress (M2S) is 1g/criL6
If it is 4, the rebound modulus of the foam is too low to function as a foam, and if it exceeds 609/aa, the desired allocation performance cannot be obtained, preferably 40 &/'aa or less, and even lower frequency. 3 to improve allocation in the area.
It is desirable that it is 0 g/crIt or more. Further, the foam ratio M(d) is preferably 0.02 or more and 0.5 or less, and more preferably Q is 025 or more and 0.30 or less. If the specific gravity of the foam is /J%, even if its modulus is 1J%, the vibration damping performance will not be exhibited.On the other hand, if the specific gravity is too thick, the force will be too high.

Therefore, the ratio of stress (M2S) to specific gravity (d) (M25
/d) is an important parameter to obtain the specified allocation performance in the low and medium frequency range, and considering the above-mentioned limit range for M2S and d, 1μ of M25/'d is larger than 2g/cTL, Although it is smaller than 3000 g/ci, generally M25/d is in the range of 5 to 1.500 g/cnt, preferably in the range of 5 to 1000 g/cnt. In addition, especially when focusing on the low frequency range, 10 to 600 g/
cnt is included. Stress, specific gravity and the ratio of both (
The 7-ohm fiiiJ4ii material of the present invention whose M25/d) is within the above-mentioned limit range has the following characteristics in terms of vibration distribution performance and sound absorption performance. In other words, regarding the allocation performance, as mentioned above, the foam damping material shows frequency dependence, and when the loss coefficient (η), which is a measure of the size of the allocation performance, is plotted against the frequency, it gives a maximum of η1 dazzle. One or more frequencies are present. Therefore, if j maz is the frequency that gives the maximum one shift among those extreme calms, f wax is less than 100011z, more preferably less than 80011z. On the other hand, in terms of sound absorption performance (c), in order to have sound absorption performance in the low and medium frequency ranges, the ventilation at a thickness of 20 mm must be between 2 and 130 mm.
ec/1-seC.

Preferably, it should be in the range of 2 to 80 cc/'cut·sec.

In this way, by satisfying the above-mentioned physical property conditions, the oscillation material of the present invention has both twisted oscillation performance and sound absorption performance in the low and medium frequency range.Note 1) Molecular weight: 4000
, poly(oxypropylene-oxyethylene) triol with a functional group number of 32) Molecule i 3000, poly(oxypropylene) triol with a functional group number of 33) Copolymerization of propylene oxide and ethylene oxide with a verbal content of propylene oxide of 20 molti Foam stabilizer for rigid urethane foam with polymer chains consisting of polymer chains.

4) A foam stabilizer for flexible urethane foams having a polymer chain consisting of a copolymer of propylene oxide and ethylene oxide containing 50 moles of propylene oxide.

5) A foam stabilizer for flexible urethane foams having a polymer chain consisting of a copolymer of propylene oxide and ethylene oxide with 48 moles of propylene oxide.

6) 2.4-tolylene diisocyanate 80%, 2.6
- A mixture of 20 tolylene diisocyanates.

7) Measured using Dow's airflow measuring device model DA.

8) Poly(oxypropylene-oxyethylene) triol with 11,000 molecules and 3 functional groups.

Comparative Examples 1 and 2 are ordinary commercially available flexible polyurethane foams, using a silicone foam stabilizer for flexible urethane foams containing 48 to 50 moles of propylene oxide, and also containing a large amount of water. Therefore, the obtained form has a large M25/'d, and therefore f+:+ax is considerably reduced at high frequencies. The result is a common polyurethane foam with an overall low loss retention.

In comparison, in Examples 1 and 2, propylene oxide was 20
This is an etherono-based polyurethane foam according to the present invention, which uses Molch's silicone foam stabilizer for rigid urethane foam, has a slightly reduced filler in the piles, and has a considerably lower aquascape. This urethane foam has low M2S and M2S/
A is also quite low. Therefore, it can be seen that f□8 shifts to the low frequency range, and a very sophisticated vibration damping effect can be obtained in the low and medium frequency ranges that are most important for soundproofing. On the other hand, in Example 3, the same silicone foam stabilizer as in Examples 1 and 2 was used, a relatively low molecular weight polyol was used, and N
By lowering the CO index and adding significant filler, it has a deep damping effect.

[Example 4, Comparative Example 3] Soft urethane foam 3001 with the blending composition of Example 1
Example 4 shows the temperature dependence of the loss coefficient at 1z.
Further, a commercially available polyvinyl chloride sheet vibration damping material is shown in FIG. 2 as Comparative Example 3.

7. Swirl pattern dependence of loss coefficient of urethane foam of the present invention
The 1% point, especially the point with a large loss coefficient at high temperatures, should be paid by the hour. In addition, the foam of Example 1 has a weight of about 1/4 compared to the polyvinyl chloride sheet-like damping material used in Comparative Example 3, and is extremely excellent as a lightweight vibration damping material. That is understood.

[Example 5] The foam-shaped distribution material (20 mm thick) of Example 1 was coated with an iron plate (
The sound pressure level was measured when vibrating at 30 degrees Celsius with a 1 mm thick film, and compared with that of a steel plate alone. 3rd result
As shown in the figure. It can be seen that the sound pressure level has decreased significantly corresponding to the frequency dependence of the loss coefficient in FIG. 1, and it can be seen that this material will become a backward soundproofing material.

[Example 6, Comparative Example 4] The sound absorption coefficient was measured using 20 mm thick specimens of the foams of Example 1 and Comparative Example 1 at 30°C using the normal incidence method with rigid wall density. were used as Example 6 and Comparative Example 4 respectively.
Shown in the figure. It can be seen that the foam of Example 1 has significantly improved sound absorption coefficient in the low and medium frequency ranges compared to the foam of Comparative Example 1.

Thus, it can be seen that the foam-shaped damping material of the present invention has ambiguous sound absorption performance, and is a new soundproofing material that has both vibration damping performance and sound absorption performance.

[Brief explanation of drawings]

Fig. 1 is a graph showing the frequency dependence of the loss coefficient of the allocation materials of Examples and Comparative Examples, and Fig. 2 is a graph showing the swirl dependence of the loss coefficient at 300 nz of the allocation materials of the Examples and Comparative Examples. , Fig. 3 is a graph showing the frequency dependence of the sound pressure level of the foam damping material of the present invention laminated on a plate and a steel plate, and Fig. 4 is a graph showing the frequency dependence of the sound pressure level of the foam damping material of the present invention laminated on a plate and a steel plate. It is a graph showing the frequency dependence of the normal incidence sound absorption coefficient of the foam. Applicant: Brideston Tire Co., Ltd. (Hz) (°c) 50 100 200 500 1000 2
000 5000) Tsukasa Shirushi” Utami (Hz
) 400 200 500 1000 2
000 50001it Refutation (Hz) 5th Patent Office 1. Incident display 1982! Igr' = T Application No. 208296 2, Title of invention: Damping side skew 3, Person making the amendment
Yasumi Address 2-1-5 Yaesu, Chuo-ku, Tokyo
Fourth (1) Drawing 6.7 Contents of Yamamasa＼-! ', 7'j J゛- 020406080100 5B-7L ('C) Fig. 3＠Yoshiryo 1 15 [2 () - 1zJ Fig. 4 +00 200 500 1.000 2.0
00 5.0001 @ 3L discount ((HzJ

Claims (3)

[Claims] (1) Can polyols, polyisocyanates, foaming firmness, catalysts, foam breakers, fillers, etc. be removed and Ca? In the vibration damping material made of the ωζ-prize polyurethane foam, the KaM of propylene oxide as the foaming agent is 5.
A silicone pond conditioner for hard bearing foam containing polymers consisting of a propylene oxide-ethylene oxide copolymer having a molar content in the range of 100% by weight of the above polyol, 90.5 to 5 parts was used. An allocating material made of soft shell polyurethane foam. (2) As described in item 1, the scope of special features is characterized in that 5 to 120 parts of a non-denominated or organic powdered light powder is used for polyol 1001 as the filling material 1j. f [i swinging material girder. (3) As the older foam CIJ, water is used as polyol 1θυMJi
The damping material according to item 1 of the patent application, characterized in that 1 to 3.5 parts by weight of the damping material is used.