JPH07188379A - Polyurethane composition - Google Patents

Abstract

PURPOSE:To obtain a polyurethane composition excellent in, e.g. vibration- damping properties in the vicinity of the ordinary temperatures by blending a thin flake-shaped inorganic filler with a polyurethane synthesized by reacting an organic diisocyanate, a high-molecular diol and a chain-lengthening agent containing a specified diol. CONSTITUTION:This polyurethane composition contains (A) a polyurethane synthesized by reacting (i) an organic diisocyanate (e.g. 4,4'-diphenylmethane diisocyanate or tolylene diisocyanate, (ii) a high-molecular diol (e.g. a polyester diol or a polyether diol) and (iii) a chain-lengthening agent containing one or both of a diol of formula I [(m) is 0, 1 or 2] and a diol of formula II [(n) is 0, 1 or 24 and (B) a thin flake-shaped inorganic filler (preferably, having 3 to 100mum weight-average flake size; e.g. mica, glass flake or talk). In addition, the amount of the component (B) is preferably 5 to 70 wt.% based on the component (A).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to polyurethane compositions. More specifically, the present invention relates to a polyurethane composition that has extremely high vibration damping performance at around room temperature, good vibration damping performance in a wide temperature range, and is extremely excellent in vibration absorption and noise prevention.

[0002]

2. Description of the Related Art In recent years, there have been great demands for vibration absorption, noise prevention, quietness, etc. due to changes in lifestyles and increasing demands for environmental improvement, and vibration damping performance (vibration absorption; Noise-preventing materials and molded products are required for housing interior materials and other housing-related fields, fields of transportation equipment such as ships and automobiles, various electrical products, office equipment, building materials for factories and public facilities, etc. Has been. Due to their elastic properties, rubber and elastomers have superior vibration damping properties (vibration absorbing properties) compared to hard materials that do not have elasticity, and have been used as vibration absorbing materials and noise suppressing materials. There is.

The damping performance of an elastic material such as rubber or elastomer is the ratio of the loss elastic modulus (E ″) and the storage elastic modulus (E ′) obtained by measuring the viscoelasticity of the elastic material. The represented mechanical loss factor (tan δ) (ie t
It is widely evaluated that the value of an δ = E ″ / E ′) is large, and it is said that the larger the value of tan δ, the higher the vibration damping performance.

Thermoplastic polyurethane (polyurethane elastomer) excellent in abrasion resistance and other mechanical performance
Has been known to have relatively good vibration damping performance, but the conventional polyurethane elastomer has a very high mechanical loss coefficient (tan δ) at around room temperature where it is often used. However, it is inferior in vibration damping performance (vibration absorption ability; noise prevention ability) at around room temperature and is not sufficiently satisfactory in practical use. In addition, it has been attempted to adjust the type and blending of raw materials so that the peak value of the mechanical loss coefficient (tan δ) of the polyurethane elastomer is around room temperature. In that case, the peak value of tan δ is around room temperature. When set to, the temperature range in which the vibration damping performance can be exhibited becomes narrow, and when the temperature changes, the vibration damping performance is lost, and good vibration damping performance (vibration absorption ability and noise prevention ability) is not exhibited over a wide temperature range. There's a problem.

Further, the above-mentioned mechanical loss coefficient (tan
The storage elastic modulus (E '), which is the base of δ), has an optimum value depending on each application and usage of the vibration damping material. As a method of securing such an optimum value, the filler is used. In general, the storage elastic modulus (E ′) increases while the loss elastic modulus (E ″) does not increase, resulting in the loss elastic modulus (E ″). ) And the storage elastic modulus (E ′) (E ″ / E ′), the value of the mechanical loss coefficient (tan δ) does not increase, but rather decreases, resulting in a reduction in vibration damping performance. There's a problem.

[0006]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a tan at around room temperature, which is most often used.
It has a high δ and is excellent in vibration damping (vibration absorption; noise prevention) near room temperature, and also maintains a high mechanical loss coefficient (tan δ) over a wide temperature range, and good vibration damping even when the temperature changes. It is an object to provide a polyurethane-based material in which performance (vibration absorption capacity; noise prevention capacity) is not lost.

[0007]

[Means for Solving the Problems] Under the above circumstances,
The inventors of the present invention often used t at around room temperature, which is often used.
High an δ, excellent vibration damping (vibration absorption; noise prevention) near room temperature, and high t over a wide temperature range.
Studies have been conducted for the purpose of obtaining a polyurethane that maintains the an δ value and does not lose its good vibration damping performance (vibration absorption ability; noise prevention ability) even when the temperature changes. As a result, when a polyurethane is produced using an organic diisocyanate, a polymer diol and a chain extender, the following formula (I) is used as a chain extender;

[0008]

[Chemical 3] (In the formula, m represents 0, 1 or 2) and the following formula (II);

[0009]

[Chemical 4] When a chain extender containing at least one of the diols represented by the formula (n is 0, 1 or 2) is used, the tan δ value at around room temperature is high and the excellent vibration damping performance is obtained at around room temperature. Having a high ta over a wide temperature range
It was found that a polyurethane capable of maintaining the nδ value can be obtained.

Further research based on the above findings revealed that when a flaky inorganic filler was added to the above-mentioned specific polyurethane produced by the present inventors, its loss elastic modulus (E ″) Was further increased, and as a result, the level of the mechanical loss coefficient (tan δ) itself was further increased, and a polyurethane composition having extremely excellent vibration damping performance was obtained, and the present invention was completed.

That is, the present invention provides (A) an organic diisocyanate, a polymeric diol and the following formula (I);

[0012]

[Chemical 5] (In the formula, m represents 0, 1 or 2) and the following formula (II);

[0013]

[Chemical 6] Polyurethane obtained by reacting a chain extender containing at least one of the diols represented by the formula (wherein n is 0, 1 or 2); and (B) a flaky inorganic filler. Is a polyurethane composition.

The polyurethane used in the present invention can be obtained by using an organic diisocyanate, a high molecular weight diol and the above-mentioned specific chain extender. In this case, the organic diisocyanate is an organic compound conventionally used in the production of thermoplastic polyurethane. Any diisocyanate can be used without any particular limitation. Examples of such organic diisocyanates include 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, 3,3′-dichloro-4,
Aromatic diisocyanates such as 4′-diphenylmethane diisocyanate; hexamethylene diisocyanate,
Examples thereof include aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate. These organic diisocyanates may be used alone or in combination of two or more. You may use together.

As the polymer diol used for producing the polyurethane, any of the polymer diols conventionally used for producing thermoplastic polyurethane can be used, and examples thereof include polyester diol, polyether diol, polycarbonate diol, Examples thereof include polyester polycarbonate diol and polyester polyether diol. More specifically, the polyester diol includes, for example, an aliphatic polyester diol obtained by reacting an aliphatic diol with an aliphatic dicarboxylic acid or an ester-forming derivative thereof, an aliphatic diol with an aromatic dicarboxylic acid or an ester thereof. The aromatic polyester diol obtained by the reaction of the forming derivative, the polyether diol is, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol or a block copolymer thereof, and the polycarbonate diol is an aliphatic diol. A polycarbonate diol obtained by a reaction with a carbonate compound, a polycarbonate diol obtained by a reaction between an aromatic diol such as bisphenol A and a carbonate compound is used. It is possible. The polymeric diols may be used alone or in combination of two or more.

The number average molecular weight of the polymer diol used for producing polyurethane is preferably 500 to 10,000, more preferably 1500 to 6000. When the number average molecular weight of the high molecular weight diol is less than 500, the mechanical properties of the resulting polyurethane tend to deteriorate and become brittle, while when it is more than 10,000, the moldability of the resulting polyurethane and polyurethane composition tends to decrease.

The polyurethane used in the composition of the present invention includes a diol represented by the above formula (I) [hereinafter referred to as "diol (I)"] and a diol represented by the above formula (II) [hereinafter referred to as "the diol (I)"]. It is a polyurethane obtained by using a chain extender containing one or both of the “diol (II)”]. In this case, the diol (I) may be the following formula (Ia), (Ib) or (Ic) depending on the number of m in the formula (I);

[0018]

[Chemical 7] At least one of the diols represented by the formula (II) can be used, and the diol (II) can be represented by the following formulas (IIa), (IIb) or (II) depending on the number of n in the formula (II).
c);

[0019]

[Chemical 8] At least one of the diols represented by The chain extender is one of the above-mentioned diols.
Only one species may be used or two or more species may be contained. In particular, it is preferred to use polyurethanes obtained with a chain extender containing at least a diol of the formula (Ib) and / or a diol of the formula (IIb).

In this case, the content of diol (I) and / or diol (II) in the chain extender [the total amount of both diol (I) and diol (II) when both are contained] is 10 mol% based on the total amount of chain extender
It is preferably at least 30 mol%, more preferably at least 50 mol%, still more preferably at least 50 mol%. Diol (I) and / or diol (II) in polyurethane
The higher the proportion of the structural unit derived from, the higher the mechanical loss factor (tan δ) of polyurethane, and the more excellent the vibration damping performance.

In producing the polyurethane used in the composition of the present invention, other chain extender compounds can be used in combination with the diol (I) and / or the diol (II) as a chain extender. In this case, the type of the other chain extender compound is not limited, and a difunctional low-molecular compound having two isocyanate-reactive active hydrogen atoms, which is conventionally used as a chain extender in the production of polyurethane, is used. can do. Examples of such other bifunctional low molecular weight compounds include ethylene glycol, 1,2-propanediol, 1,4-butanediol, neopentyl glycol, 2,2-diethyl-
1,3-propanediol, 2-butyl-2-ethyl-
Linear or branched aliphatic diols having 2 to 10 carbon atoms such as 1,3-propanediol and 3-methyl-1,5-pentanediol; bis (hydroxymethyl) tricyclo [5.2.1.0] ^{2, 6]} alicyclic diols such as decane; 1,4-bis (beta-hydroxyethoxy) aromatic ring-containing diols such as benzene; ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine, phenylenediamine, Examples thereof include diamines such as tolylenediamine; hydrazine, adipic acid dihydrazide, and isophthalic acid dihydrazide. These bifunctional compounds may be used alone or in combination of two or more.

Among the above-mentioned bifunctional compounds, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1. , 5-aliphatic diol having a branched such as pentanediol, bis (hydroxymethyl) tricyclo [5.2.1.0 ^{2, 6]} alicyclic diols such as decane are preferably used. In some cases, the polyfunctional compound having three or more isocyanate-reactive hydrogen atoms is less than 5 mol% based on the total amount of the polymer diol and the chain extender within a range that does not reduce the vibration damping performance of the polyurethane. You may use it in the ratio of.

The polyurethane used in the composition of the present invention preferably has a nitrogen atom content of 2.5 to 3.2% by weight, and the polyurethane having such a nitrogen atom content is a polymer diol used. It can be obtained by adjusting the number average molecular weight, the use ratio of the polymer diol, the organic diisocyanate and the chain extender, and the like.

In producing the polyurethane used in the composition of the present invention, isocyanate groups are added per equivalent of active hydrogen atoms based on the total amount of active hydrogen atoms contained in the polymer diol, chain extender and other components. It is preferable to use an organic diisocyanate so that the equivalent weight is about 0.90 to 1.30, preferably 0.95 to 1.10, in order to obtain a thermoplastic polyurethane excellent in various physical properties.

Depending on the type of organic diisocyanate to be used, the polymer diol, the content (type) and the molecular weight of the chain extender, and the ratio of their use, the molecular weight and viscosity of the polyurethane obtained by reacting them will differ. But 0.
It is preferable to use a polyurethane having a logarithmic viscosity of 0.5 to 2.0 dl / g as measured at 30 ° C. as a 5 g / dl dimethylformamide solution from the viewpoint of mechanical performance and moldability.

In the production of the polyurethane used in the composition of the present invention, catalysts, reaction accelerators and the like which are commonly used in the production of polyurethane may be used, and in some cases, colorants and flame retardants. , UV absorbers, antioxidants, anti-hydrolysis agents, anti-mold agents, various additives such as internal release agents, various fibers such as glass fibers and organic fibers, talc, silica, other inorganic fillers, various cups A ring agent or the like may be appropriately added before, during, or after the polymerization.

The polyurethane used in the composition of the present invention is
It can be produced by any of the known prepolymer method and one-shot method. For example, an organic diisocyanate, a polymer diol, a chain extender and, if necessary, other components are simultaneously added to a single-screw or multi-screw extruder. Alternatively, by continuously and almost simultaneously supplying and performing continuous melt polymerization at 190 to 280 ° C., preferably 200 to 260 ° C., the target polyurethane can be smoothly produced by a simple operation.

The polyurethane produced as described above by using the chain extender containing the diol (I) and / or the diol (II) is, at its ordinary temperature and at a temperature other than that of the conventional thermoplastic polyurethane. It has a high mechanical loss factor (tan δ) at temperature and tan
The peak of δ is near room temperature, and it has good vibration damping performance.However, in the present invention, by blending a flaky inorganic filler with such a polyurethane to obtain a polyurethane composition, the mechanical properties are improved. The material obtained has a higher dynamic loss coefficient (tan δ) and is superior in vibration damping performance. In that case, as the flaky inorganic filler suitable for use in the polyurethane composition of the present invention, mica, glass flakes, talc, kaolin and the like can be mentioned, and among them, mica is preferable. There is no limitation on the type of mica used, and various types of mica such as muscovite (muscovite), phlogopite (biotite), biotite, synthetic fluorophlogopite can be used. . Even if only one type of flaky inorganic filler is used,
Alternatively, two or more kinds may be used in combination.

Further, in the polyurethane composition of the present invention,
The weight average flake diameter of the flaky inorganic filler is 3 to 100μ.
It is preferably m, and more preferably 5 to 75 μm. The weight average flake diameter of the flaky inorganic filler is 3μ
When it is less than m, it becomes difficult to uniformly disperse in polyurethane, and the mechanical loss coefficient (ta) based on the flaky inorganic filler is
It becomes difficult to increase nδ), and it becomes difficult to obtain the effect of improving the vibration damping performance. On the other hand, when the weight average flake diameter of the flaky inorganic filler is larger than 100 μm, the molded article obtained from the polyurethane composition is likely to have irregularities on its surface, resulting in poor appearance and poor practical utility. In addition,
The weight average flake diameter of the flaky inorganic filler here is
It means the value when measured as follows.

Weight-average flake diameter (L) : Wet classification of flaky inorganic filler using various sieves of micro sieve or standard sieve, and the results are plotted on a Rosin-Ramlar diagram and used for measurement. The opening L ₅₀ of the microsieve or standard sieve through which 50% by weight of the flaky inorganic filler passes is determined. From this value, when the microsieve is used, the following formula (i) is used and a standard sieve is used. If it does, the weight average flake diameter (L) is calculated by the following formula (ii).

[0031]

[Equation 1] L = L ₅₀ (i)

[0032]

[Equation 2] L = 2 ^1/2 L ₅₀ (ii)

Here, the weight average flake diameter is about 40 μm.
In the case of the following flaky inorganic filler having a relatively small particle size, it is appropriate to determine the weight average flake diameter (L) by the above formula (i) using a microsieve, while the weight average flake diameter is about 40 μm. In the case of the above-mentioned flaky inorganic fillers having a relatively large particle size, the above formula (i
It is appropriate to obtain the weight average flake diameter (L) by i).

The polyurethane composition of the present invention is
Based on the weight of polyurethane, the flaky inorganic filler is added to 5
It is preferably contained at a ratio of 70 to 70% by weight.
More preferably, it is contained in an amount of ˜60% by weight. When the content of the flaky inorganic filler is less than 5% by weight, the effect of improving the vibration damping performance [mechanical loss coefficient (tan δ)] is small,
On the other hand, when it exceeds 70% by weight, the moldability of the polyurethane composition is deteriorated.

If necessary, the polyurethane composition of the present invention further comprises various conventionally known additives such as flame retardants, antioxidants, ultraviolet absorbers, hydrolysis inhibitors, crystal nucleating agents, antistatic agents, and coloring agents. Agents (dyes and pigments), release agents, plasticizers, lubricants,
It may contain a dispersant, an inorganic filler, and a thermoplastic elastomer.

The method for preparing the polyurethane composition of the present invention is not particularly limited, and any of the known methods conventionally used for preparing thermoplastic polyurethane compositions can be adopted.
For example, after thoroughly drying and dehumidifying pelletized polyurethane, a flaky inorganic filler and, if necessary, other additives are mixed in advance using a mixer such as a tumbler or a Henschel mixer, and then uniaxially mixed. Alternatively, the polyurethane composition of the present invention in the form of pellets or other forms can be obtained by supplying it to a twin-screw extruder, melt-kneading it, extruding it, and then cutting it into an appropriate size.

The polyurethane composition of the present invention can be molded by using a molding method and a molding apparatus that are generally used for thermoplastic polyurethane and the composition thereof, for example, injection molding, extrusion molding, press molding, A molded product having an arbitrary shape and size can be obtained by blow molding or the like. By doing so, molds, pipes, sheets,
A wide variety of products such as films and laminates can be obtained. In addition, various products having excellent vibration damping properties may be manufactured by other methods instead of molding. The product obtained from the polyurethane composition of the present invention has excellent vibration damping performance (vibration absorbing ability; noise preventing ability), and thus is related to housing-related products, daily necessities, electric / electronic parts, mechanical parts, automobile parts,
It can be effectively used for various applications such as packaging materials.

[0038]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following examples, the nitrogen atom content of polyurethane, the loss modulus of polyurethane (E ″), the peak value of the mechanical loss coefficient (tan δ), the temperature (peak temperature) at that time, and tan δ are 0.2 or more. The temperature range was determined as follows.

[Nitrogen Atom Content of Polyurethane] Polyurethane pellets which had been melt-polymerized and then dehumidified and dried at 80 ° C. for 20 hours were analyzed by an elemental analyzer (“240 Perkin Elmer”).
0-2 type ”) and subjected to elemental analysis to determine the nitrogen atom content rate.

[Loss modulus of polyurethane (E ″); ta
Peak value of nδ; peak temperature; temperature range of tan δ ≧ 0.2] The polyurethane obtained in each example was press-molded using a hot press at 220 ° C. to produce a film having a thickness of 0.1 mm. Test piece from this film (length x width = 5 mm x
30 mm) was sampled and the storage elastic modulus of the test piece at each temperature was sequentially changed at a frequency of 11 Hz using a dynamic viscoelasticity measuring device [“DVE Rheospectler” manufactured by Rheology Co., Ltd.) ( E ′) and loss elastic modulus (E ″) are measured, and the mechanical loss coefficient (tan δ) is calculated from these values based on the following mathematical formula, and a graph showing the distribution state of the tan δ value with respect to temperature is created. did. From the resulting graph, the value at which tan δ shows a peak and the temperature at that time, and the temperature range where tan δ was 0.2 or more were determined. This tan δ is used as a measure of vibration damping,
The larger this value, the greater the vibration damping performance (vibration absorption capacity).

[0041]

[Equation 3] Mechanical loss coefficient (tan δ) = [(Loss elastic modulus
(E ″) / storage modulus (E ′)]

The abbreviations and contents of each component used in the following Examples and Comparative Examples and Table 2 below are summarized in Table 1 below.

[0043]

[Table 1]

Example 1 (1) Polyester diol (PMPA; number average molecular weight 3500), decahydro-1, represented by formula (Ib),
4: 5,8-Dimethanonaphthalene-2,3-dimethanol (MNDM) and 4,4′-diphenylmethane diisocyanate (MDI) in a molar ratio of 1: 4.8: 5.8 (per 1 equivalent of active hydrogen atom). Isocyanate group equivalent of
1.00), while being heated, it is continuously supplied to a twin-screw extruder (L / D = 34; φ = 30 mm) in a liquid state all at once by a constant-rate pump, polymerized at 260 ° C., and then extruded. Polyurethane pellets were produced. The nitrogen atom content of the polyurethane obtained here was 2.7% by weight.

(2) The polyurethane pellets obtained in the above (1) were heated at 80 ° C. for 10 hours to be dehumidified and dried, and then fed to a twin-screw extruder (φ = 30 mm), together with muscovite [K. Kuraray's “muscovite 400W-K1”; weight average flake diameter 16 μm] is used as polyurethane pellets 100
30 parts by weight per part by weight was supplied to the twin-screw extruder, melt-kneaded at a cylinder temperature of 160 to 210 ° C., extruded, and cut to produce pellets of the polyurethane composition.

(3) The polyurethane composition pellets obtained in (2) above were heated at 80 ° C. for 2 hours to dehumidify and dry, and then press-molded by a hot press at 220 ° C. to a thickness of 0.
A 1 mm film was prepared, and a test piece taken from this film was used to prepare a graph showing the relationship between temperature and tan δ by the method described above. The value of loss elastic modulus (E ″) at 25 ° C. of tan δ Peak value and temperature at that time
(Peak temperature) and the temperature range where tan δ is 0.2 or more were determined. The results are shown in Table 2 below.

Example 2 A polyurethane composition was produced in the same manner as in Example 1 except that the amount of muscovite supplied to the twin-screw extruder was changed to 50 parts by weight per 100 parts by weight of polyurethane pellets. In the same manner as in 1, the loss elastic modulus (E ″) value at 25 ° C., the peak value of tan δ and the temperature at that time (peak temperature), and the temperature range in which tan δ is 0.2 or more were determined. The results are shown in Table 2 below.

Example 3 PEA (number average molecular weight 3500) was used as polyester diol instead of PMPA.
And decahydro-1,4 as the chain extender:
MNDM and BD instead of using 5,8-dimethanonaphthalene-2,3-dimethanol (MNDM) alone
A polyurethane composition was produced in the same manner as in Example 1 except that (1,4-butanediol) was used at a ratio of 80:20 (molar ratio), and loss elastic modulus at 25 ° C. was obtained in the same manner as in Example 1. The value of (E ″), the peak value of tan δ and the temperature at that time (peak temperature), and the temperature range in which tan δ is 0.2 or more were determined. The results are shown in Table 2 below.

Example 4 PEA (number average molecular weight 3500) was used as polyester diol instead of PMPA.
And MNDM and NPG 60:40 (molar ratio) instead of using MNDM alone as a chain extender.
A polyurethane composition was produced in the same manner as in Example 1 except that the ratio was used, and the value of loss elastic modulus (E ″) at 25 ° C., the peak value of tan δ and the temperature at that time were the same as in Example 1. (Peak temperature) and the temperature range where tan δ is 0.2 or more were determined. The results are shown in Table 2 below.

Comparative Example 1 A polyurethane composition was produced in the same manner as in Example 1 except that BD was used alone instead of using MNDM as a chain extender, and at 25 ° C. in the same manner as in Example 1. Loss modulus (E '') value, ta
The peak value of nδ, the temperature at that time (peak temperature), and the temperature range in which tan δ was 0.2 or more were determined. The results are shown in Table 2 below.

Reference Example 1 A polyurethane was produced in the same manner as in Example 1 except that muscovite was not used, and the resulting polyurethane had a loss elastic modulus (E ″) value at 25 ° C. and a peak of tan δ. The value, the temperature at that time (peak temperature), and the temperature range in which tan δ is 0.2 or more were determined in the same manner. The results are shown in Table 2 below.

[0052]

[Table 2]

From the results shown in Table 2 above, 1,
The polyurethane composition of Comparative Example 1 consisting of a conventional polyurethane produced using only 4-butanediol (BD) has a tan δ peak temperature of -35 ° C, which is extremely low.
The peak value of tan δ at that time was 0.45, and tan
The δ value level itself is extremely low, and tan δ is 0.2.
The temperature range shown above is as narrow as 50 ° C, and the vibration damping performance (vibration absorption ability; noise prevention ability) at room temperature and other temperatures is inferior, whereas diol (Ib) is used as the chain extender. The polyurethane of Reference Example 1 produced as described above has a tan δ peak temperature of 27 ° C. and is at room temperature, has a tan δ peak value of 1.25 at that time, and has a high tan δ value itself, and tan δ It can be seen that the temperature range showing 0.2 or more is as wide as 102 ° C., and that it has excellent vibration damping performance (vibration absorption ability; noise prevention ability) at room temperature and other temperatures.

From the results shown in Table 2 above, the invention of Examples 1 and 2 obtained by further blending mica with the polyurethane of Reference Example 1 produced using diol (I) [diol (Ib)] In the case of the polyurethane composition of No. 1, the loss elastic modulus, and by extension, the peak value of tan δ, are higher than those of Reference Example 1 having excellent vibration damping performance, and the vibration damping performance (vibration absorbing capacity; noise) of Reference Example 1 is further increased. It can be seen that the prevention ability) is further improved. Similarly, in the polyurethane compositions of the present invention of Examples 3 and 4, obtained by blending mica with polyurethane produced by using diol (I) [diol (Ib)] in combination with another chain extender. Also has a high loss elastic modulus, and has a tan δ peak value, a tan δ peak temperature, and ta.
Excellent data are shown in the temperature range in which nδ is 0.2 or more, and it can be seen that the material has excellent vibration damping performance at room temperature and other temperatures.

[0055]

The polyurethane composition of the present invention has the peak value of the mechanical loss coefficient (tan δ) near room temperature, and the tan δ value itself is extremely high. Therefore, it is most often used. It has excellent vibration damping performance (vibration absorption capacity; noise prevention capacity) at around room temperature. Furthermore, since the polyurethane composition of the present invention maintains a high tan δ value over a wide temperature range, its good vibration damping performance (vibration absorption ability; noise prevention ability) is not lost even when the temperature changes, and it is effective. Can be used.

Claims (3)

[Claims] 1. An organic diisocyanate (A), a polymeric diol and the following formula (I); (In the formula, m represents 0, 1 or 2) and the following formula (II); (In the formula, n represents 0, 1 or 2) A polyurethane obtained by reacting a chain extender containing at least one of diols represented by the formula; and (B) containing flaky inorganic filler. A polyurethane composition comprising: 2. The polyurethane composition according to claim 1, containing 5 to 70% by weight of a flaky inorganic filler based on the weight of the polyurethane. 3. The polyurethane composition according to claim 1, wherein the flaky inorganic filler has a weight average flake diameter of 3 to 100 μm.