JPH08231676A - Highly elastic polyurethane foam manufacturing method - Google Patents

Abstract

PURPOSE: To improve comfortableness and moldability by allowing a specific high molecular weight active hydrogen compound to react with a polyisocyanate compound inn the presence of a catalyst and a blowing agent. CONSTITUTION: To prepare a polyoxyalkylene polyol having 2-6 hydroxyl groups and 3-25wt.% oxyethylene groups at the terminal by ring-opening polymerization of a cyclic ether in the presence of an initiator as a high molecular weight active hydrogen compound having two or more active hydrogen functional groups reactive with a isocyanate group, a mixture of the polyols having a total unsaturation value of at most 0.08meg/g in which (A) a polyol made with a K or Na catalyst and having a hydroxyl value of 20-60 and (B) a polyol made with a composite metal cyanide complex or a cesium catalyst and having a hydroxyl value of 5-35 are mixed at a weight ratio of (A)/(B)=5/95-90/10 is allowed to react with a polyisocyanate compound in the presence of a catalyst and a blowing agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a highly elastic polyurethane foam.

[0002]

2. Description of the Related Art In recent years, various studies have been newly made to improve the characteristics of polyurethane elastic foam. For example, in order to improve the riding comfort of seat cushions as automobiles become more sophisticated, impact resilience, durability,
Improvement of vibration characteristics is desired. Regarding the vibration characteristics, the relationship between the vehicle body vibration and human beings is not uniform, but it is possible to improve the riding comfort by taking particularly large attenuation in the frequency range where humans are particularly sensitive (for example, said to be 4 to 8 Hz or 6 to 20 Hz). Has been proposed to be effective.

In order to improve these characteristics, it has been considered effective to produce a seat cushion by using a polyoxyalkylene polyol having a higher molecular weight that has been conventionally produced.

Generally, a polyoxyalkylene polyol used as a raw material for polyurethane is prepared by using a sodium or potassium catalyst such as sodium hydroxide or potassium hydroxide to open an alkylene oxide such as propylene oxide in an initiator such as a polyhydric alcohol. It is produced by ring polymerization.

In this production method, a monool having an unsaturated group is produced as a by-product, and the amount of the unsaturated monool produced increases as the molecular weight of the polyoxyalkylene polyol increases (the hydroxyl value decreases). In the polyoxyalkylene polyol having a hydroxyl value of about 56, which is widely used as a raw material for polyurethane elastic foam, the presence of the unsaturated monool was not a problematic amount. However, the presence of this unsaturated monol may be a problem in a low hydroxyl value polyoxyalkylene polyol having an increased molecular weight.

For example, in a polyoxyalkylene polyol having a hydroxyl value of about 34, the total degree of unsaturation is usually 0.
It becomes 1 meq / g or more. Even if an elastic foam is produced using a polyoxyalkylene polyol having a high total degree of unsaturation, problems such as a decrease in hardness, a decrease in rebound resilience, a deterioration in compression set, and a decrease in cure property during foam molding occur. Further, even if an attempt is made to produce a polyoxyalkylene polyol having a low hydroxyl value by using a sodium or potassium catalyst, it is practically impossible because the total unsaturation degree becomes extremely high.

For the purpose of improving the riding comfort performance, a polyurethane elastic foam is prepared by using a polyoxyalkylene polyol having a low total unsaturation and synthesized by ring-opening polymerization of alkylene oxide using a complex metal cyanide complex as a catalyst. Manufacturing is described in JP-A-3-45613. Further, as a method of reducing the total unsaturation degree of the high molecular weight polyoxyalkylene polyol, a method of using cesium hydroxide as a polymerization catalyst is described in US Pat. No. 3,393,243. However, in recent years, due to the increase in size and the complicated shape of seat cushions, in addition to the riding comfort performance, it has been required to improve performance called moldability such as fluidity, air void resistance, and communication.

[0008]

The present invention is the following invention which solves the above-mentioned problems. That is, in producing a highly elastic polyurethane foam by reacting a high molecular weight active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group and a polyisocyanate compound in the presence of a catalyst and a blowing agent, a high molecular weight The active hydrogen compound is a polyoxyalkylene polyol (A) obtained by ring-opening polymerization of a cyclic ether using a sodium- or potassium-based catalyst in the presence of an initiator, and a complex metal cyanide complex catalyst or a cesium-based catalyst in the presence of an initiator. Polyoxyalkylene polyol (B) obtained by ring-opening polymerization of cyclic ether using (A) /
(B) (weight ratio) is a mixed polyol mixed at 10/90 to 95/5, which is a method for producing a highly elastic polyurethane foam.

In recent years, high molecular weight polyoxyalkylene polyols having a low total degree of unsaturation synthesized by using a complex metal cyanide complex or a cesium hydroxide catalyst have been prepared.
It has been clarified that the riding comfort of the seat cushion is improved when used as a raw material for forming the seat cushion.

Further, the present inventor blended this polyol with a polyoxyalkylene polyol synthesized using a commercially available sodium- or potassium-based catalyst in a specific ratio to lower the viscosity of the reaction stock solution. It is possible, liquidity is greatly improved, total unsaturation is low,
We have discovered an unprecedented high molecular weight polyoxyalkylene polyol. While maintaining the riding comfort of the seat cushion that has been greatly improved by using this high molecular weight polyoxyalkylene polyol, defective molding of a seat cushion with a large and complicated shape (air void, shrink,
Etc.) has been dramatically improved.

The polyoxyalkylene polyol obtained by ring-opening polymerization of a cyclic ether using a sodium or potassium catalyst according to the present invention, and the polyoxyalkylene polyol obtained by ring-opening polymerization of a cyclic ether using a cesium catalyst or a complex metal cyanide complex catalyst. The oxyalkylene polyol may be a mixture of two or more kinds, and in that case, the average number of hydroxyl groups and the range of the hydroxyl value are as described above.

The cyclic ether is preferably an alkylene oxide having 2 or more carbon atoms, specifically, ethylene oxide, propylene oxide, 1,2-butylene oxide,
2,3-butylene oxide and styrene oxide are exemplified. In particular, it is preferable to use ethylene oxide in combination with at least one selected from propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide.

The polyoxyalkylene polyol of the present invention preferably contains an oxyethylene group. The polyoxyalkylene polyol containing an oxyethylene group at its terminal is obtained by adding an alkylene oxide having 3 or more carbon atoms such as propylene oxide or 1,2-butylene oxide to a polyvalent initiator and then adding ethylene oxide.

Further, ethylene oxide and an alkylene oxide having 3 or more carbon atoms are sequentially or mixed and added to the polyvalent initiator, and ethylene oxide is added at the last stage to give a polyoxyalkylene having an oxyethylene group inside. A polyol is obtained.

The content of oxyethylene groups is preferably 3% by weight or more, particularly preferably 5% by weight or more. The total oxyethylene group content in the polyoxyalkylene polyol, including the oxyethylene groups present at the terminals and inside, is 2
It is 5% by weight or less. In that case, it is preferable that most of the oxyethylene group is present in the terminal portion of the molecular chain.

The polyhydric initiators used in the production of the polyoxyalkylene polyols include polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines and the like. The number of active hydrogens in the initiator is 2
6 is preferable, and the number of hydroxyl groups of the polyoxyalkylene polyol produced from such an initiator is 2 to 6.

For example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, diglycerin, dextrose, choux. Examples include claose, bisphenol A, ethylenediamine, and polyoxyalkylene polyol having a lower molecular weight than the target product obtained by adding alkylene oxide to these.

These initiators may be used alone or in combination of two or more. A particularly preferred polyhydric initiator is a polyhydric alcohol.

The sodium or potassium catalyst used in the production of the polyol (A) in the present invention includes sodium metal, potassium metal, sodium methoxide, sodium ethoxide, sodium propoxide, potassium methoxide, potassium ethoxide and potassium propoxy. Sodium, potassium alkoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and the like.

The hydroxyl value of the polyol (A) is 20 to 60.
It is preferred that

The cesium-based catalyst used in the production of the polyol (B) in the present invention is selected from cesium-based metals, cesium alkoxides such as cesium methoxide, cesium ethoxide and cesium propoxide, cesium hydroxide and cesium carbonate. The thing which has a thing as a main component is preferable. Those containing cesium hydroxide as a main component are particularly preferable.

The complex metal cyanide complex is preferably a complex containing zinc hexacyanocobaltate as a main component,
The ether and / or alcohol complex is preferred. The composition thereof can be essentially that described in JP-B-46-27250. As the ether, ethylene glycol dimethyl ether (glyme), diethylene glycol dimethyl ether (diglyme) and the like are preferable, and glyme is preferable among the handling during the production of the complex. Alcohol is disclosed in JP-A-4-14512.
The t-butanol described in Japanese Patent No. 3 is preferable.

The polyol (B) is preferably a polyoxyalkylene polyol obtained by subjecting a cyclic ether to ring-opening polymerization using a cesium-based catalyst.

The hydroxyl value of the polyol (B) is preferably 5 to 35. Total unsaturation of polyol (B) is 0.05m
It is preferably eq / g or less.

The polyol (A) and the polyol (B) are mixed at a ratio (A) / (B) (weight ratio) of 5/95 to 90/10. The total unsaturation of the mixed polyol obtained by mixing the polyol (A) and the polyol (B) is 0.08 me.
It is preferably q / g or less.

The mixed polyol may be a polymer-dispersed polyol containing polymer particles.

The polymer-dispersed polyol is a dispersion in which fine polymer particles are stably dispersed in a polyoxyalkylene polyol matrix, and examples of the polymer include addition polymerization type polymers and condensation polymerization type polymers.

Polymer-dispersed polyols whose matrix is a conventional polyol are known and are widely used as polyols for polyurethane elastic foams. The polymer-dispersed polyol in the present invention can be produced by a conventional method using the above-mentioned polyol (A), polyol (B) or mixed polyol as a matrix.

The polymer particles in the polymer-dispersed polyol are acrylonitrile, styrene, methacrylate,
It is composed of addition polymerization type polymers such as acrylates and other homopolymers and copolymers of vinyl monomers, and condensation polymerization type polymers such as polyester, polyurea, polyurethane and melamine resin. Due to the presence of the polymer particles, the hydroxyl value of the polymer-dispersed polyol as a whole is generally lower than the hydroxyl value of the matrix polyol.

The content of the fine polymer particles in the mixed polyol is usually preferably 50% by weight or less. The amount of the polymer fine particles does not need to be particularly large, and even if it is too large, it is not inconvenient except for the economic aspect. Often 3
~ 35 wt% is preferred. Further, the presence of polymer fine particles in the polyol is not essential, but the presence thereof is effective for improving the hardness, air permeability and other physical properties of the foam.

As the high molecular weight active hydrogen compound other than the above-mentioned mixed polyol, a primary amino group or a secondary amino group is used as a secondary compound.
High molecular weight polyamine or primary amino group or 2 having the above
A high molecular weight compound having one or more primary amino groups and one or more hydroxyl groups can be used in combination.

The molecular weight per functional group of these high molecular weight active hydrogen compounds is 400 or more, particularly 800 or more, and the number of functional groups per molecule is preferably 2-8. The molecular weight per functional group is preferably 10,000 or less.

Examples of such compounds include compounds obtained by converting a part or all of the hydroxyl groups of the polyoxyalkylene polyol as described above into amino groups, and polyisocyanates in excess equivalent to the polyoxyalkylene polyol as described above. There is a compound obtained by hydrolyzing an isocyanate group of a prepolymer having an isocyanate group at the terminal obtained by reacting with a compound and converting it into an amino group.

When a high molecular weight active hydrogen compound that can be used in combination with the above-mentioned mixed polyol is used, the amount used is preferably 40% by weight or less, and particularly preferably 20% by weight or less, based on the total amount of both.

In the present invention, a crosslinking agent may be used if necessary. As the cross-linking agent, a compound having two or more functional groups selected from a hydroxyl group, a primary amino group and a secondary amino group, having a molecular weight of 1800 or less and having 2 to 8 active hydrogen-containing groups, at least one compound Is preferably used. You may use together 2 or more types of crosslinking agents.

The crosslinking agent having a hydroxyl group preferably has 2 to 8 hydroxyl groups. There are polyols such as polyhydric alcohols, low molecular weight polyoxyalkylene polyols obtained by adding alkylene oxides to polyhydric alcohols, or polyols having a tertiary amino group.

Specific examples include, but are not limited to, the following exemplified compounds. Ethylene glycol, 1,
4-butanediol, neopentyl glycol, 1,6
-Hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, monoethanolamine, diethanolamine, triethanolamine, N-alkyldiethanol, bisphenol A-alkylene oxide adduct, glycerin-alkylene oxide adduct, trimethylolpropane-alkylene oxide Adduct, pentaerythritol-alkylene oxide adduct, sorbitol-alkylene oxide adduct,
Examples include sucrose-alkylene oxide adducts, aliphatic amine-alkylene oxide adducts, alicyclic amine-alkylene oxide adducts, heterocyclic polyamine-alkylene oxide adducts, aromatic amine-alkylene oxide adducts, and the like.

The heterocyclic polyamine-alkylene oxide adducts are piperazine, 2-methylpiperazine, 2-ethylpiperazine, 2-butylpiperazine, 2-hexylpiperazine, 2,5-, 2,6-, 2,3- or 2, 2
-Dimethylpiperazine, 2,3,5,6- or 2,
It can be obtained by adding an alkylene oxide to a C-lower alkyl-substituted piperazine such as 2,5,5-tetramethylpiperazine or an aminoalkyl-substituted piperazine such as 1- (2-aminoethyl) piperazine.

As the amine-based crosslinking agent having a primary amino group or a secondary amino group, there are aromatic polyamines, aliphatic polyamines, alicyclic polyamines and the like.

The aromatic polyamine is preferably an aromatic diamine. The aromatic diamine is preferably an aromatic diamine having one or more substituents selected from an alkyl group, a cycloalkyl group, an alkoxy group, an alkylthio group and an electron-withdrawing group in the aromatic nucleus to which an amino group is bound. ,
Particularly, a diaminobenzene derivative is preferable. The above-mentioned substituents other than the electron-withdrawing group are 2 to 4 in the aromatic nucleus to which the amino group is bound.
It is preferable that they are individually bonded, and particularly, that they are bonded to one or more, preferably all of the ortho positions with respect to the binding site of the amino group.

It is preferable that one or two electron-withdrawing groups are bonded to the aromatic nucleus to which the amino group is bonded. The electron withdrawing group and the other substituent may be bonded to one aromatic nucleus. The alkyl group, alkoxy group, and alkylthio group preferably have 4 or less carbon atoms, and the cycloalkyl group is preferably a cyclohexyl group. As the electron-withdrawing group, a halogen atom, a trihalomethyl group, a nitro group, a cyano group,
Alkoxycarbonyl group and the like are preferable, especially chlorine atom,
A trifluoromethyl group and a nitro group are preferred.

Examples of the aliphatic polyamines include diaminoalkanes having 6 or less carbon atoms, polyalkylene polyamines, and polyamines obtained by converting some or all of the hydroxyl groups of low molecular weight polyoxyalkylene polyols into amino groups. Furthermore, a polyamine having an aromatic nucleus such as an aromatic compound having two or more aminoalkyl groups, an aromatic compound having a total of two or more aminoalkyl groups, and these aromatic compounds having the above substituents is also used. it can. The alicyclic polyamine includes cycloalkane having two or more amino groups and / or aminoalkyl groups.

Specific examples of the amine chain extender are shown below, but the invention is not limited thereto. Particularly preferred is diethyltoluenediamine [ie 1-methyl-3,5-diethyl-2,4 (or 2,6) -diaminobenzene 1
Seed or mixture], dimethylthiotoluenediamine, monochlorodiaminobenzene, trifluoromethyldiaminobenzene, and other diaminobenzene derivatives.

1-methyl-3,5-diethyl-2,4
(Or 2,6) -diaminobenzene (DETDA),
2-chloro-p-phenylenediamine (CPA), 1-
Methyl-3,5-dimethylthio-2,4 (or 2,
6) -diaminobenzene, 1-trifluoromethyl-
3,5-diaminobenzene, 1-trifluoromethyl-
4-chloro-3,5-diaminobenzene, 2,4-toluenediamine, 2,6-toluenediamine, bis (3,3
5-dimethyl-4-aminophenyl) methane, 4,4-
Diaminodiphenylmethane, ethylenediamine, m-xylenediamine, 1,4-diaminohexane, 1,3-
Bis (aminomethyl) cyclohexane, isophoronediamine.

The polyisocyanate compound is an aromatic, alicyclic or aliphatic polyisocyanate having two or more isocyanate groups, a mixture of two or more kinds thereof, and a modified polyisocyanate obtained by modifying them. There is. Specifically, for example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (common name: crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HM).
DI) and the like, and their prepolymer type modified products, nurate modified products, urea modified products, carbodiimide modified products, and the like.

In the present invention, it is preferable to use at least one foaming agent selected from water and an inert gas as the foaming agent. As the inert gas, specifically, air,
Nitrogen etc. are illustrated. The amount of these foaming agents used is not particularly limited, and when using only water, up to 10 parts by weight, particularly 0.1 to 100 parts by weight of the high molecular weight active hydrogen compound is used.
8 parts by weight is suitable. Other foaming agents can also be used in appropriate amounts according to the requirements such as foaming ratio.

When reacting the polyol and the polyisocyanate compound, it is usually necessary to use a catalyst. In recent years, in order to prevent the fog phenomenon of automobile glass, amine compounds, organometallic compounds having low sublimation properties, or a part of the structure of amine compounds are hydroxylated or aminated so as to react with isocyanate. You may use what you have done to the minimum necessary. Further, a polymerizing catalyst for reacting isocyanate groups such as carboxylic acid metal salt is used depending on the purpose.

Examples of the reactive amine catalyst include dimethylethanolamine, trimethylaminoethylethanolamine, dimethylaminoethoxyethoxyethanol and the like.

The amount of the amine compound catalyst used is up to 1.0 part by weight based on 100 parts by weight of the high molecular weight active hydrogen compound.
In particular, 0.05 to 1.0 part by weight is preferable.

Examples of the organometallic compound catalyst include organotin compounds, organobismuth compounds, organolead compounds, organozinc compounds and the like.

For example, di-n-butyltin oxide,
Di-n-butyltin dilaurate, di-n-butyltin, di-n-butyltin diacetate, di-n-octyltin oxide, di-n-octyltin dilaurate,
There are monobutyltin trichloride, di-n-butyltin dialkylmercaptan, di-n-octyltin dialkylmercaptan, and the like. The amount of the organometallic compound catalyst used is 1.
Up to 0 parts by weight, particularly 0.005 to 1.0 parts by weight is preferred.

Further, foam stabilizers for forming good bubbles are often used. Examples of the foam stabilizer include a silicone-based foam stabilizer and a fluorine-containing compound-based foam stabilizer. Other compounding agents that can be optionally used include, for example, fillers, stabilizers, colorants, flame retardants, and defoamers.

The molding of the high-elasticity polyurethane foam is carried out by directly injecting the reactive mixture into a mold using a low-pressure foaming machine or a high-pressure foaming machine (that is, reaction injection molding method), or by reacting the reactive mixture in an open mold. Is preferably used. The high-pressure foaming machine is preferably a type in which two ordinary liquids are mixed, one of which is a polyisocyanate compound, and the other liquid is a mixture of all raw materials other than the polyisocyanate compound. In some cases, a catalyst or a defoaming agent (usually used by being dispersed or dissolved in a part of high molecular weight polyol) as a separate component to form a reactive mixture with a total of three components can be injected.

[0054]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto (parts represent parts by weight).

Examples (Examples 1-11, 18-28, 35-35)
40, 46-52) and comparative examples (Examples 12-17, 29).
To 34, 41 to 45, 53), the molecular weights of the polyoxyalkylene polyols (a) to (h), the number of hydroxyl groups,
Oxyethylene (EO) group content (% by weight), polymerization catalyst, hydroxyl value (mgKOH / g), and degree of unsaturation (m
eq / g) is shown in Table 1. Polyols a to s were obtained by mixing A to C with the composition shown in Table 2. Table 3 shows prescription components other than the polyol.

(Examples 1 to 17) 70 parts of the polyols a to s shown in Tables 4 to 5, 30 parts of the polyol y, 1.0 part of the foam stabilizer v, and 3.4 parts of the foaming agent x. , Amine catalyst t
Was mixed with 0.03 part of the amine catalyst u to prepare a polyol liquid. The polyol liquid was put into one raw material tank of the reaction injection molding apparatus (high pressure foaming machine), and the liquid temperature was adjusted to 25 to 30 ° C. As the polyisocyanate liquid, polyisocyanate α was put in the other raw material tank of the reaction injection molding apparatus, and the liquid temperature was adjusted to 25 to 30.
The temperature was adjusted to ° C.

Both of them were mixed and injected at a ratio of the isocyanate index shown in the table. Isocyanate index means total active hydrogen compounds 10
It refers to the number of equivalents of the isocyanate compound with respect to 0 equivalent.
The injection conditions are as follows: injection pressure 140 kg / cm ² , injection amount 30
It was set to 0 g / sec. Mold 400 mm x 400 mm x
A mold having an inner size of 100 mm (t) was used, and the mold temperature was adjusted to 58 to 62 ° C. The mold release from the mold was performed 5 minutes after the raw material was injected.

The foam physical properties, vibration characteristics and moldability of the obtained high elastic polyurethane foam are shown in Tables 4 to 5.
Physical properties of foam are total density (unit: kg / m ³ ), 25% I
LD (unit: kg / 314 cm ² ), compression set (%), wet heat compression set (%), impact resilience (%) and air permeability (ft ³ / min) were evaluated. Vibration characteristics are 6H
The transmissivity of z and the resonance frequency (unit: Hz) were evaluated. Moldability was evaluated for fluidity and crushing property.
The fluidity was evaluated as ⊚, ◯ as slightly good, and Δ as poor, and the crushing property evaluation as ⊚, ◯ as slightly good, and Δ as poor.

(Examples 18 to 34) 65 parts of polyols a to s shown in Tables 6 to 7, 35 parts of polyol y,
A mixture of 1.0 part of the foam stabilizer v, 3.25 parts of the foaming agent x, 0.35 part of the amine catalyst t and 0.04 part of the amine catalyst u was used as a polyol liquid, and a polyisocyanate liquid was used. Examples 1 to 1 except that polyisocyanate β is used
The same procedure as 16 was performed. The isocyanate index is shown in Tables 6-7. The foam physical properties, vibration characteristics and moldability of the obtained foam are shown in Tables 6 to 7.

(Examples 35 to 53) 70 parts of the polyols a to s shown in Tables 8 to 10 and 30 parts of the polyol y.
Parts, 4.0 parts of crosslinking agent s, 1.0 part of foam stabilizer v, 2.7 parts of foaming agent x, 0.60 parts of amine catalyst t and 0.10 parts of amine catalyst u. The same procedure was performed as in Examples 1 to 16 except that the polyol solution was used, and the polyisocyanate z was used as the polyisocyanate solution. The isocyanate index was 100. The foam physical properties, vibration characteristics and moldability of the obtained foam are shown in Tables 8 to 10.
Shown in

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

[0065]

[Table 5]

[0066]

[Table 6]

[0067]

[Table 7]

[0068]

[Table 8]

[0069]

[Table 9]

[0070]

[Table 10]

[0071]

The highly elastic polyurethane foam produced by the production method of the present invention has the effect of greatly improving the riding comfort and moldability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Hasegawa 2 474, Tsukoshi, 3 Saidaku, Kawasaki-shi, Kanagawa Asahi Glass Co., Ltd. Tamagawa branch room

Claims (7)

[Claims] 1. A method for producing a highly elastic polyurethane foam by reacting a high molecular weight active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group, and a polyisocyanate compound in the presence of a catalyst and a blowing agent. , A high molecular weight active hydrogen compound obtained by ring-opening polymerization of a cyclic ether using a sodium or potassium catalyst in the presence of an initiator, and a complex metal cyanide complex catalyst in the presence of an initiator Alternatively, the polyoxyalkylene polyol (B) obtained by ring-opening polymerization of a cyclic ether using a cesium-based catalyst has a ratio (A) / (B) (weight ratio) of 5 /
A method for producing a highly elastic polyurethane foam, which is a mixed polyol mixed at 95 to 90/10. 2. The method according to claim 1, wherein the polyol (A) is a polyol having 2 to 6 hydroxyl groups, a hydroxyl value of 20 to 60, and 3 to 25% by weight of an oxyethylene group at the terminal portion. 3. The polyol (B) is a polyol having a hydroxyl number of 2 to 6, a hydroxyl value of 5 to 35 and an oxyethylene group of 3 to 25% by weight at the end portion.
Manufacturing method. 4. The total unsaturation of the mixed polyol is 0.08 m.
The production method according to any one of claims 1 to 3, which is eq / g or less. 5. The total unsaturation of the polyol (B) is 0.05.
The manufacturing method according to any one of claims 1 to 4, which is not more than meq / g. 6. The method according to claim 1, wherein the mixed polyol is a polymer-dispersed polyol containing fine polymer particles. 7. The method according to claim 1, wherein the foaming agent is at least one foaming agent selected from water and an inert gas.