JP2000038432A - Expanded polyurethane elastomer composition and damping material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in moldability while having a sufficient compressive stress, a small compression set and sufficient load and flex resistances even when an inexpensive isocyanate is used by including a specific isocyanate group-terminated prepolymer and a specified foaming component. SOLUTION: This composition comprises (A) an isocyanate group-terminated prepolymer composed of (i) an isocyanate which is 4,4'-diphenylmethane diisocyanate and (ii) a polyol component and (B) a foaming component composed of water, a foam stabilizer and a catalyst. The component A (ii) is a polyol containing a polyether ester polyol obtained from a triol compound (e.g. trimethylolpropane), a compound forming an ether unit represented by formula I [(m) is an integer] (e.g. polytetramethylene glycol), a compound forming an ester unit represented by formula II [(n) is an integer] (e.g. ε-caprolactone) and an aliphatic dibasic acid and having 2.1-2.5 average number of functional groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in compressive stress,
Compression set is small and has sufficient durability, excellent storage stability of prepolymer, and at the time of elastomer production,
The present invention relates to a foamed polyurethane elastomer composition having excellent molding workability.

[0002]

2. Description of the Related Art Foamed polyurethane elastomers are widely used as auxiliary rubbers and cushioning materials for vibration dampers for automobile suspensions due to their excellent bending fatigue characteristics and mechanical strength. Conventionally, foamed polyurethane elastomers having excellent performance include 1,5-naphthalenediisocyanate (hereinafter abbreviated as NDI) and 3,3′-dimethyl-4,
It is manufactured by mixing a foaming agent comprising an isocyanate group-terminated prepolymer obtained by reacting 4′-biphenylenediisocyanate (hereinafter abbreviated as TODI) with a polyester polyol, water, a catalyst and a silicone-based foam stabilizer, followed by foaming and curing. ing.

[0003] However, those using the above-mentioned NDI or TODI have excellent performance such as small settling when repeatedly subjected to compression set and high load, and have sufficient durability, but have a prepolymer pot. There is a drawback that the prepolymer has to be prepared each time because the life is short, the viscosity increases with time, and the storage stability is poor. In addition, the disadvantage that NDI and TODI are extremely expensive is always mentioned as a problem in practical use. However, when the isocyanate is replaced with inexpensive 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), a product having excellent storage stability and good workability can be obtained, but the conventional NDI or TODI is used. It is inferior in dynamic characteristics and compression set when a very large load of 50 to 80% is applied from the initial state, and has a disadvantage that it is swollen or cracked when it is released from the mold. Therefore, studies have been made to obtain a foamed polyurethane elastomer which can solve the drawbacks caused when MDI is used, but it has not been put to practical use.

[0004] For example, JP-A-7-224139 discloses that the mechanical properties obtained by reacting an isocyanate group-terminated prepolymer with a blowing agent composed of water, a low molecular weight diol and a polyether polyol having a number average molecular weight of 5,000 to 10,000 are disclosed. There have been proposals for fine foamed polyurethane elastomers having excellent compression set and small compression set. However, in this case, the compatibility between water in the foaming agent and the polyether polyol is not always good, and physical property deterioration due to uneven reaction and foaming is expected.

[0005] JP-A-7-252340 discloses an MD
There has been proposed a foamed polyurethane elastomer obtained by foaming and curing an isocyanate-terminated prepolymer, a hydroxyl-terminated prepolymer, and a foaming component using I. However, TODI is used as a diisocyanate component for the hydroxyl-terminated prepolymer. Thus, an inexpensive microcellular foamed polyurethane elastomer cannot be obtained.
Further, in this case, since the hydroxyl group-terminated prepolymer is contained in the foaming agent, the crosslinking and curing reaction is slow, and a long time is required for demolding, which may reduce the workability.

Japanese Unexamined Patent Publication (Kokai) No. 60-235824 discloses that the mixing ratio (EG / BG) of ethylene glycol (EG) and butylene glycol is 70/30 to 30/7.
There is a proposal for a urethane elastomer sponge characterized by containing 2,2-bis (4′-oxyphenyl) propane in adipate adjusted to be 0, but the adipate is composed of 2,2-bis ( Depending on the content of 4'-oxyphenyl) propane, it was impossible to obtain a product having excellent molding workability such that the viscosity of the obtained prepolymer was increased and cracks were generated during foaming and curing.

Further, Japanese Patent Application Laid-Open No. 61-250019 discloses that a copolymer of polytetramethylene glycol and ε-caprolactone and, if necessary, an adipic acid-based polyester are used in combination to form an NCO-terminated NCO prepolymer obtained from MDI. There is an example in which a foaming agent containing water as a main component is used as an anti-vibration material capable of sufficiently withstanding repeated compression under a high load, and producing a microcellular polyurethane elastomer excellent in cold resistance and hydrothermal hydrolysis resistance. However, even in this case, all of the polyol components have an average number of functional groups of 2.0, are linear, and are not necessarily in terms of mechanical strength and moldability as compared with those using NDI or TODI when used as an anti-vibration material. Satisfactory performance cannot be obtained. Also, simply mixing a copolymer of polytetramethylene glycol and ε-caprolactone and an adipic acid ester is inferior in compatibility depending on the composition and may cause a problem during prepolymerization,
Moreover, the moldability of the obtained elastomer is inferior and the mechanical strength is reduced.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an inexpensive MD.
Provided is a foamed polyurethane elastomer composition having sufficient compressive stress, small compression set, sufficient load resistance and bending resistance when using I, and excellent moldability during elastomer production. The purpose is to do.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve these objects, and as a result, they can be widely used as vibration damping materials including auxiliary rubbers for vibration damping materials for automobile suspensions. It has been found that a foamed polyurethane elastomer can be obtained, and the present invention has been completed.

That is, the present invention relates to (A-1) an isocyanate
(A-2) In a foamed polyurethane elastomer composition comprising an isocyanate group-terminated prepolymer (A) comprising a polyol component and a foaming component (B) comprising water, a foam stabilizer and a catalyst, an isocyanate group-terminated prepolymer ( A) is that (A-1) is 4,4′-diphenylmethanediisocyanate and (A)
-2) is (A-2-1) a triol compound, (A-2-2) a compound forming an ether unit represented by Formula 1,

[0011]

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(A-2-3) a compound forming an ester unit represented by the formula 2:

[0013]

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(A-2-4) A foamed polyurethane elastomer composition characterized by being a polyol containing a polyetherester polyol having an average functional group number of 2.1 to 2.5 obtained from an aliphatic dibasic acid, preferably Is (A-) in the polyetherester polyol in the polyol (A-2).
The ether unit derived from 2-2) has 20
At 90% by weight, preferably 5 to 70% by weight of the ester unit derived from (A-2-3) in the polyol, and preferably the ester unit derived from (A-2-3) is a terminal of the polyol. , Preferably having an average molecular weight of 1500 to 4000, preferably (A-1) / (A-2) = NCO / OH (equivalent ratio) of the prepolymer (A). The present invention provides a vibration damping material characterized in that the ratio is 1.6 / 1 to 5.0 / 1 and the foamed polyurethane elastomer composition is used.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A-1) of the present invention comprises 4,4 ′
-Diphenylmethane diisocyanate is mainly used, but other diisocyanates may be used in a range that does not impair the effects of the present invention, preferably less than 50% by weight, and examples thereof include aromatic, alicyclic, and aliphatic. Any of the following, for example, 1,5-naphthalenediisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, polymethylene polyphenylisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate Isocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3
-Diisocyanate, p-phenylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, and the like, but are not limited thereto.

The polyetherester polyol (A-2) contained in the polyol component (A-2) of the present invention is preferably 20 to 100% by weight, more preferably 50 to 100% by weight in the polyol component (A-2). 100% by weight. This polyetherester polyol (A-2) is a compound which forms an ether unit represented by the formula (A-2-2) with a (A-2-1) triol compound,

[0017]

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(A-2-3) a compound forming an ester unit represented by the formula 2:

[0019]

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(A-2-4) Polyetherester polyol having a terminal hydroxyl group comprising an aliphatic dibasic acid.
The number average molecular weight is preferably from 1500 to 40
00.

The triol compound (A-2-1) of the present invention includes, for example, trimethylolpropane, trimethyloloctane, glycerin and the like. These can be used alone or in combination of two or more. Particularly preferred is trimethylolpropane.

The content of the triol compound in the polyetherester polyol (A-2) is basically determined by the target average number of functional groups and the number average molecular weight of the obtained polyetherester polyol (A-2). . The amount of the triol compound (A-2-1) used is adjusted so that the average number of functional groups of the entire polyol (A-2) is 2.1 to 2.5.

As the compound (A-2-2) which forms the ether unit represented by the formula 1, for example, polyteratomethylene glycol obtained by ring-opening polymerization of tetrahydrofuran by a commonly used method is preferably exemplified. If Equation 1
When polytetramethylene glycol is used as the compound (A-2-2) which forms the ether unit of the formula (I), the number average molecular weight is preferably from 300 to 3,000, more preferably from 500 to 2,000. However, as long as the polyetherester polyol of the component (A-2) has the average functional group number and molecular weight of the present invention, it is not particularly limited to polytetramethylene glycol.

The compound (A-2-3) forming an ester unit represented by the formula 2 is, for example, ε-caprolactone, which can be formed into a ester unit by a ring-opening polymerization method. That is, ε-caprolactone is subjected to ring-opening polymerization of a compound having active hydrogen at the terminal in the reaction system in the presence of a ring-opening catalyst. In the polyetherester polyol (A-2), the ester unit derived from (A-2-3) is
It is preferably from 5 to 70% by weight in the polyol.

When the amount is less than 5% by weight, the characteristic of improving the durability of the urethane elastomer is not exhibited. On the other hand, when the content is more than 70% by weight, the internal heat storage amount of the urethane elastomer increases when a continuous load is applied, and the compression set becomes large, and finally, the deformation is completely caused.

In addition to (A-2-1), (A-2-2) and (A-2-3), as a raw material for polyetheresterol (A-2),
Normally used short-chain diols may be used preferably in an amount of 0 to 50% by weight as long as the effects of the present invention are not impaired.

The short-chain diol includes an aliphatic short-chain diol having 2 to 18 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and 1,2-butanediol. , 1,3-butanediol, 2-methyl-1,3-propanediol,
1,4-butanediol, neopentyl glycol,
1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-
Trimethyl 1,3-pentanediol, 2-ethyl 1,
3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, and the like, and these may be used alone or in combination of two or more. Can be.

The aliphatic dibasic acids (A-2-4) of the present invention include, for example, succinic acid, glutaric acid, adipic acid, pimelic acid, shuberic acid, azelaic acid, sebacic acid,
Examples thereof include 1,10-decanedicarboxylic acid and 1,12-dodecanedicarboxylic acid, which can be used alone or in combination of two or more.

The polyetherester polyol of the present invention
The method for producing (A-2) is not particularly limited. For example, a compound (A) that forms an ether unit of the formula 1 such as the triol compound (A-2-1) and polytetramethylene glycol may be used. -2-2) A predetermined amount is mixed in accordance with the desired average functional group number of 2.1 to 2.5, and a polyol compound is synthesized by a dehydration condensation reaction in the presence of an aliphatic dibasic acid and a commonly used esterification catalyst, Subsequently, a method of producing a compound (A-2-3) which forms an ester unit of the formula 2 consisting of ε-caprolactone by ring-opening addition polymerization using the esterification catalyst or the polymerization catalyst as required is mentioned. Preferred are mentioned.

As another production method, any one of a compound (A-2-2) forming an ether unit of the formula 1 such as polytetramethylene glycol and a triol compound (A-2-3) is used.
Alternatively, a compound (A-2-3) forming an ester unit of the formula 2 consisting of ε-caprolactone is simultaneously or individually subjected to a ring-opening addition reaction, and then the polyol compound and an aliphatic dibasic acid ( A-2-4) to obtain a polyetherester polyol by a dehydration condensation reaction. However, a polyol in which the ester unit represented by the formula 2 is added to the end of the polyol by a block is more preferable because the operation steps are not complicated and the obtained polyurethane elastomer has excellent durability.

The average number of functional groups of the obtained polyetherester polyol (A-2) is preferably in the range of 2.1 to 2.5. Of course, the polyol (A-2) having an average functional group number of 2.0 and the polyol (A-2) having an average functional group number exceeding 2.0 can be prepared in advance and used by mixing. The average number of functional groups in the mixture is 2.1 to 2.
It is necessary to be prepared in the range of 5.

If the polyetherester polyol (A-2) has an average number of functional groups of 2, for example, as obtained from a polyoxyalkylene glycol and an aliphatic dibasic acid.
When it is smaller than 1, the compression set of the obtained foamed polyurethane elastomer becomes large, which is not practical. When the average number of functional groups exceeds 2.5, a gel is generated at the stage of synthesizing the prepolymer (A) having terminal isocyanate groups, or the viscosity of the prepolymer (A) is significantly increased, and the Is poorly mixed and cracks occur during foam molding.

The polyetherester polyol (A-2) shown above preferably accounts for 20 to 100% by weight of the polyol component. If less than 20% by weight,
The characteristic of urethane elastomer having a small compression set is not exhibited, resulting in poor durability.

Other polyols that can be used in combination with the polyetherester polyol (A-2) include ordinary polyesterether polyols composed of an acid component of a dibasic acid such as adipic acid and the above-mentioned short-chain polyol components, and short polyols. Examples include polyester polyols obtained by ring-opening polymerization of lactones using chain glycol as a reaction initiator, and polyether polyols such as polytetramethylene glycol and polypropylene glycol. of course,
These combined polyols may have an average number of functional groups exceeding 2.0, and may be used in a range that does not impair the effect.

As a means for obtaining the terminal isocyanate group-terminated prepolymer (A) from the polyetherester polyol (A-2) and the MDI (A-1), a conventionally known production method can be used. The equivalent ratio of (A-1) / (A-2) between the MDI (A-1) and the polyetherester polyol to be used is preferably NCO / OH = 1.6 to 5.0. NCO /
When the OH ratio is less than 1.6, the viscosity of the isocyanate group-terminated prepolymer (A) increases, the workability decreases, and when the NCO / OH ratio exceeds 5.0, the resulting foamed polyurethane elastomer is obtained. Is impaired, making it unsuitable for practical use.

In the present invention, if necessary, stabilizers and additives such as a reactivity modifier and an antioxidant may be added during prepolymerization.

The ratio between the isocyanate group equivalent of the isocyanate group-terminated prepolymer (A) of the present invention and the hydroxyl equivalent in the foaming component (B) is preferably 1.0 / 0.9 to 1.0 / 1.
It is necessary to prepare in the range of 1. Outside the above range, the physical properties and durability of the obtained foamed polyurethane elastomer are reduced. The amount of water contained in the foaming component (B) is not particularly limited, but the ratio of the isocyanate group-terminated prepolymer (A) to the foaming component (B) is preferably in the range of 100: 1 to 50 by weight. It is prepared and used so that

The water used in the foaming component (B) of the present invention is preferably pure water or ion-exchanged water. As the catalyst, known organic metal compounds and amines can be used as long as they promote foaming and curing, and amines are preferable. These include, for example, tertiary amines such as triethylamine and triethylenediamine, nitrogen compounds such as morpholine and N-methylmorpholine, metal salts such as potassium acetate and zinc stearate, and organic metal compounds such as dibutyltin dilaurate and dibutyltin oxide. And the like. Further, the foam stabilizer is preferably a silicone surfactant, and a known surfactant such as SH-193 (Toray Dow Corning Silicone Co., Ltd.) can be used.

If necessary, an organic chain extender can be added simultaneously with the polyol component or stepwise during preparation of the prepolymer or during foaming of the elastomer in order to obtain desired physical properties. Examples of the organic chain extender include aliphatic short-chain diols such as 1,4-butanediol, ethylene glycol, diethylene glycol, 1,3-butanediol, and diethanolamine; aromatic diols such as hydroquinone bishydroxyethyl ether;
Aromatic diamines such as 4'-diaminodiphenylmethane,
Examples thereof include an alkylene oxide adduct of bisphenol A and bisphenol F.

As the foaming component (B), an aqueous solution containing a commercially available fatty acid such as ricinoleic acid modified with sodium sulfate can also be used. Examples of such a foaming agent include Agiti SV (manufactured by Sumitomo Bayer Urethane Co., Ltd.).

In the foaming component (B) of the present invention, an auxiliary agent can be added, if necessary, in addition to water, a foam stabilizer and a catalyst. Examples of such an auxiliary include an antioxidant, an ultraviolet absorber, and a flame retardant. Known auxiliaries can be used.

The operation of mixing and stirring the above foaming component (B) and the above-mentioned isocyanate group-terminated prepolymer (A) and injecting and foaming it into a mold can be sufficiently performed by a known technique. As a method for producing a molded article using the polyurethane elastomer composition of the present invention, the component (A) and the component (B) are preferably heated and mixed at 50 to 100 ° C, and preferably heated to 50 to 100 ° C. A molded product is obtained by injecting foaming, curing, and heating and aging in the formed molding die.

The foaming of the present invention preferably means that the density of the obtained polyurethane elastomer is from 0.3 to 0.7 g / cm.
³ , wherein closed cells and open cells are formed in the polyurethane elastomer.

The anti-vibration material of the present invention is a material used for preventing vibration of automobiles, vehicles, civil engineering buildings, electric and electronic products, mechanical devices and the like. For example, it is used as a vibration damping material for automobile suspensions, auxiliary rubber, and the like.

[0045]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should not be construed that the invention is limited thereto. In the following description, “parts” and “%” are based on weight unless otherwise specified.

(A-1) MDI: "Millionate MT" manufactured by Nippon Polyurethane Industry Co., Ltd. TODI: "Trizine diisocyanate" manufactured by Nippon Soda

(A-2) (Synthesis Example 1) Polyetheresterol (A) Polytetramethylene glycol (molecular weight: 1000)
-A polyetherester polyol (A) having an average number of functional groups of 2.00 and a hydroxyl value of 74.8 (mg KOH / g) (hereinafter abbreviated to unit) obtained by ring-opening polymerization of caprolactone.

(Synthesis Example 2) Polyester polyol (B) An average number of functional groups obtained by ring-opening polymerization of ε-caprolactone with trimethylolpropane is 2.00, and a hydroxyl value is 7
4.8 polyester polyol (B).

Polyetherester polyol (c) Polytetramethylene glycol (molecular weight: 1,000), trimethylolpropane, and adipic acid are charged at once and subjected to a dehydration condensation reaction to give an average number of functional groups of 2.40 and a hydroxyl value of 5
A polyetherester polyol of 4.0 is obtained. Subsequently, polyetherester polyol (c) having an average number of functional groups of 2.40 and a hydroxyl value of 45.0, which is obtained by charging ε-caprolactone and subjecting it to ring-opening polymerization.

Polyetherester polyol (d) The polyetheresterpolyol (A) obtained in Synthesis Example 1, trimethylolpropane, and adipic acid are collectively charged, and the average number of functional groups obtained by the dehydration condensation reaction is 2.40. And a polyetherester polyol (d) having a hydroxyl value of 44.5.

Polyetherester polyol (e) Polytetramethylene glycol (molecular weight: 1000) and polyester polyol (B) obtained in Synthesis Example 2,
A polyetherester polyol (e) having an average number of functional groups of 2.40 and a hydroxyl value of 44.7, obtained by collectively charging adipic acid and performing a dehydration condensation reaction.

Polyetherester Polyol (f) The polyetheresterpolyol (A) obtained in Synthesis Example 1, the polyester polyol (B) obtained in Synthesis Example 2, and adipic acid are collectively charged and subjected to a dehydration condensation reaction. The obtained polyetherester polyol (f) having an average number of functional groups of 2.40 and a hydroxyl value of 44.6.

Polyetherester polyol (g) ε is added to polytetramethylene glycol (molecular weight: 1400).
-A polyetherester polyol (g) having an average number of functional groups of 2.00 and a hydroxyl value of 56.2, obtained by subjecting caprolactone to ring-opening polymerization.

Polyetherester polyol (h) ε is added to polytetramethylene glycol (molecular weight: 1,000).
-A polyetherester polyol (h) having an average number of functional groups of 2.00 and a hydroxyl value of 56.4, obtained by ring-opening polymerization of caprolactone.

Polyester polyol (i) Average number of functional groups obtained by the dehydration condensation reaction of ethylene glycol, 1,4-butanediol and adipic acid
00, polyesterol (i) having a hydroxyl value of 56.5.

Polyetherester polyol (j) Polytetramethylene glycol (molecular weight: 1000), trimethylolpropane, and adipic acid are charged at once, and the average number of functional groups obtained by dehydration condensation reaction is 2.40, and the hydroxyl value is 56.0. A polyetherester polyol (j).

Polyetherester polyol (k) Polytetramethylene glycol (molecular weight: 1,000) and 1,4-butanediol are used in a mixture at a molar ratio of 85/15, and adipic acid is charged at a time to carry out a dehydration condensation reaction. To obtain a polyetherester polyol having an average number of functional groups of 2.00 and a hydroxyl value of 44.9. Subsequently, ε-caprolactone was charged and subjected to ring-opening polymerization to obtain a polyetherester polyol (k) having an average number of functional groups of 2.00 and a hydroxyl value of 37.5.

Example 1 An NCO content of 6.5 was added to 4,4'-diphenylmethane diisocyanate after the reaction.
The above polyetherester polyol (c) was added so as to be 0%, and reacted at 80 ° C. for 30 hours in a nitrogen stream to synthesize a urethane prepolymer.

Table 1 shows the amount of the unit derived from (A-2-2) in the polyol used and the weight content in the total charged amount of the unit derived from (A-2-3). The decimal places have been rounded. Table 1 shows the average number of functional groups. The content of the triol compound is naturally determined based on the target average number of functional groups and molecular weight.

As the foaming agent, 150 parts of water and a silicone foam stabilizer SH-193 (manufactured by Dow Corning Toray Silicone Co., Ltd.)
It was prepared by mixing 100 parts and 5 parts of triethylenediamine.

Prepolymer 1 previously heated to 80 ° C.
2 parts of a foaming agent was added to 00 parts, and the mixture was rapidly stirred at 6000 rpm for about 10 to 20 seconds, poured into a mold heated to about 80 ° C, and then aged at 80 ° C with a heating device. After aging for 40 minutes, the molded product was taken out of the mold, annealed at 110 ° C. for 15 hours, and then subjected to a density of 0.54 (g / cm ³ ) to 0.55.
(G / cm ³ ) was obtained. The compression set, compression stress, flexural durability and storage stability of this molded product were measured,
The results are shown in Table 2.

[Examples 2 to 5] Table 1 as polyols
The molded articles produced by the same method as in Example 1 were evaluated except that they were used as shown in Table 2, and the results are shown in Table 2.

[Comparative Examples 1 to 5] Table 3 as polyols
A prepolymer was synthesized in the same manner as in Example 1, except that the prepolymer was used as shown in Example 1. The molded article produced by the same method as in Example 1 was evaluated, and the results are shown in Table 4.

Comparative Example 6 3,3′-dimethyl-4,
4'-biphenylenediisocyanate added with NC after reaction
All except that the urethane prepolymer was synthesized by adding the above-mentioned adipic acid-based polyester polyol (e) having an average functional group number of 2.0 so that the O content became 4.50% and reacting at 80 ° C. for 30 hours in a nitrogen stream. The molded article produced by the same method as in Example 1 was evaluated, and the results are shown in Table 4.

<Physical Property Test> (1) Compression set (compliance with JIS K-6301) The compression set after heat treatment at 80 ° C. for 70 hours under 25% compression was measured.

(2) Compressive stress A sample having an outer diameter of 28 mm and a thickness of 12.7 mm was compressed at a compression speed of 5 m.
The third 60 when the 60% compression is repeated 3 times at m / min.
% The stress at the time of compression was measured.

(3) Bending Durability A durability test was performed on a sample having a length of 150 mm, a width of 25 mm and a thickness of 6 mm using a dematcher bending tester, and the number of times until cracks, cracks and cracks were generated was measured.

(4) Moldability The state of the elastomer at the time of demolding and the shape of the elastomer after demolding and after secondary curing are visually confirmed.

：: State in which no deformation, swelling, cracking, or crack has occurred. ×: State in which deformation, swelling, cracking, or cracking is observed.

(5) Storage stability The NCO% was measured before and after the isocyanate group-terminated prepolymer was heated at 100 ° C. for 24 hours, and the following formula was used.
The storage stability was evaluated.

The lower the storage stability (%), the better the stability.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

[0076]

The present invention relates to a foamed polyurethane elastomer using MDI, comprising a triol compound represented by the formula 1
By using, as a raw material, a specific polyol having a specific average number of functional groups consisting of a compound forming an ether unit and a compound forming an ester unit represented by Formula 2, and an aliphatic dibasic acid. It has low compression set, has sufficient load-bearing capacity, excellent storage stability of prepolymer, and can be used to produce an inexpensive foamed polyurethane elastomer with excellent molding workability during elastomer production. It has high utility value in many industrial fields.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 75:04 F term (reference) 4F074 AA79 AA83 AA84 AB01 BA34 BC01 BC05 CA12 DA02 DA08 DA40 4J034 BA08 CA04 CA05 CB03 CB04 CC03 DH02 DH05 DH06 HA07 HC12 HC13 HC64 HC67 HC71 HC73 JA42 KA01 KB02 KB05 NA03 QA03 QC01 RA15

Claims (7)

[Claims] 1. A foam comprising an isocyanate group-terminated prepolymer (A) comprising (A-1) isocyanate and (A-2) a polyol component, and a foaming component (B) comprising water, a foam stabilizer and a catalyst. In the polyurethane elastomer composition, the isocyanate group-terminated prepolymer (A) is (A-1) is 4,4′-diphenylmethanediisocyanate, and the (A-2) is (A-2-1) a triol compound. (A-2-2) a compound forming an ether unit represented by the formula 1, (A-2-3) a compound forming an ester unit represented by the formula 2, (A-2-4) average functional group number obtained from aliphatic dibasic acid 2.1
A foamed polyurethane elastomer composition, which is a polyol containing a polyetherester polyol of from 2.5 to 2.5. 2. The polyetherester polyol in the polyol (A-2), wherein the unit derived from (A-2-2) accounts for 20 to 90% by weight of the polyol. Foamed polyurethane elastomer composition. 3. The polyetherester polyol in the polyol (A-2), wherein the unit derived from (A-2-3) accounts for 5 to 70% by weight of the polyol. Foamed polyurethane elastomer composition. 4. The polyetherester polyol in the polyol (A-2) according to the above (1), wherein the unit derived from (A-2-3) is a polyol having a block added to its terminal. The foamed polyurethane elastomer composition according to claim 1. 5. The foamed polyurethane elastomer composition according to claim 1, wherein the average molecular weight of the polyetherester polyol in the polyol (A-2) is from 1500 to 4000. 6. The prepolymer (A) of (A-1) / (A-2) = NCO
The foamed polyurethane elastomer composition according to claim 1, wherein / OH (equivalent ratio) is from 1.6 / 1 to 5.0 / 1. 7. A vibration-insulating material comprising the foamed polyurethane elastomer composition according to any one of claims 1 to 4.