JP2002179756A - Method for producing polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a low density polyurethane foam of 20 kg/m3 or lower density, having good adhesion with an adherend without shrinking of the foam or formation of voids inside for a formulation using abundant water as a foaming agent, capable of producing the polyurethane foam in good conditions of working environment reducing bad smell due to a catalyst for producing polyurethane. SOLUTION: This method for producing a polyurethane foam having 20 kg/m3 or lower density comprises reacting a polyol component with an isocyanate component in the presence of a catalyst for producing polyurethane, a foaming agent and a foam stabilizer, wherein the catalyst comprises a tertiary amine expressed by the formula (I) (where n is an integer of 2 to 4) and an imidazole compound expressed by the formula (II) (where R1 represents a C1-6 linear or branched alkyl group or a C1-6 linear or branched hydroxyalkyl group; and R2 represents a hydrogen atom, a C1-6 linear or branched alkyl group or a C1-6 linear or branched hydroxyalkyl group).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a polyurethane foam. More specifically, building materials, insulation materials such as bathtubs, dew condensation prevention materials for detached houses / condominiums, industrial piping, etc., lightweight cores that are packed inside building materials such as bay windows and sashes to maintain product shape The present invention relates to a method for producing a polyurethane foam which can be suitably used as a material or the like.

[0002]

2. Description of the Related Art From the viewpoint of global environmental protection, CFC-11 is used.
The ban on production and use of specific CFCs has already been taken. In recent years, reduction of alternative chlorofluorocarbons such as hydrochlorofluorocarbon has been called for, and in Japan, the use of HCFC-141b has been banned from 2004.

Under such circumstances, a system using a larger amount of water than the conventional formulation as a foaming agent for a polyurethane foam and a system using a formulation in which all the foaming agent is water are being studied.

[0004] However, when a large amount of water is used as a foaming agent, there is a disadvantage that the polyurethane foam becomes brittle because the amount of urea bonds in the polyurethane foam increases. In particular, the bonding surface between the polyurethane foam and the adherend such as a steel plate becomes brittle, which causes a problem that the adhesiveness is deteriorated. Further, in the low density region where the density is 20 kg / m ³ or less, the strength of the polyurethane foam becomes relatively small and a large amount of water is used, so that the foaming reaction (reaction between isocyanate groups and water) and the resin formation Since the balance of the reaction (reaction between the isocyanate group and the hydroxyl group) is lost, there arises a problem that voids are generated inside the polyurethane foam and the polyurethane foam shrinks with time.

[0005] In view of the above, it has been proposed to use an N-substituted imidazole as a catalyst for producing polyurethane to suppress the deterioration of surface brittleness and improve the adhesion to an adherend. (Japanese Unexamined Patent Publication No. 3-9521
No. 2, JP-A-4-161417).

However, since N-substituted imidazoles are catalysts that give priority to the resinification reaction, water as a blowing agent is used in a large amount in a low density region having a density of 20 kg / m ³ or less. In addition, there is a disadvantage that the balance between the foaming reaction and the resinification reaction is lost, and cells are broken during the formation of the polyurethane foam, so that a satisfactory foam cannot be produced or a large void is generated inside the polyurethane foam.

Further, since N-substituted imidazoles emit a peculiar odor, the working environment is deteriorated by the odor at the time of premixing or foaming of polyurethane foam, and the N-substituted imidazoles are converted from polyurethane foam after production. It has the disadvantage of emitting a characteristic odor.

[0008]

SUMMARY OF THE INVENTION The present invention has a density of 20.
When producing a low-density polyurethane foam of kg / m ³ or less, in a formulation using a large amount of water as a foaming agent, the polyurethane foam does not shrink and voids are not formed inside. It is an object of the present invention to provide a method capable of producing a polyurethane foam having good adhesiveness to a material in a state in which the working environment is good, by reducing malodor based on a polyurethane production catalyst.

[0009]

The present invention provides a compound of the formula (I): (CH ₃ ) ₂ N (CH ₂ CH ₂ O) _n -H (I) wherein n is an integer of 2 to 4. And a tertiary amine of the formula (II):

[0010]

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Wherein R ¹ is a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms or a straight-chain or branched-chain hydroxyalkyl group having 1 to 6 carbon atoms, R ² is a hydrogen atom, , A straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms or a straight-chain or branched-chain hydroxyalkyl group having 1 to 6 carbon atoms). The present invention relates to a method for producing a polyurethane foam having a density at which a polyol component and an isocyanate component are reacted in the presence of 20 kg / m ³ or less.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a catalyst for producing a polyurethane containing a tertiary amine represented by the formula (I) and an imidazole compound represented by the formula (II) is used. There is one major feature.

In the tertiary amine represented by the formula (I), n is an integer of 2-4. Among the tertiary amines, 2- (2-dimethylaminoethoxy) ethanol and 2- [2- (2-dimethylaminoethoxy) ethoxy] ethanol give priority to a foaming reaction which is a reaction between an isocyanate group and water. It has high catalytic activity and can be suitably used from the viewpoint of odor characteristics. Such tertiary amines can be used alone or in combination.

In the imidazole compound represented by the formula (II), R ¹ is a linear or branched alkyl group having 1 to 6 carbon atoms or a linear or branched hydroxyalkyl group having 1 to 6 carbon atoms. . Among these, from the viewpoint of catalytic activity, R ¹ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched hydroxyalkyl group having 1 to 4 carbon atoms.

R ² is a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms or a linear or branched hydroxyalkyl group having 1 to 6 carbon atoms. Among these, from the viewpoint of catalytic activity, R ² is preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

Preferred imidazole compounds among the imidazole compounds include 1-methylimidazole, 1,1, and 2, from the viewpoints of catalytic activity and industrial availability.
2-dimethylimidazole, 1-isobutyl-2-methylimidazole and 1- (2-hydroxyethyl) -2
One or more selected from the group consisting of -methylimidazole. In particular, 1- (2-hydroxyethyl)-
Since 2-methylimidazole has a hydroxyl group in a molecule and is taken into a polyurethane foam, 2-methylimidazole is excellent in odor characteristics and can be suitably used.

As described above, the tertiary amine represented by the formula (I) and the imidazole compound represented by the formula (II) are used in combination in the catalyst for producing polyurethane used in the present invention. Not only are the drawbacks of these catalysts supplemented, but also in systems using a large amount of water as a blowing agent, the reaction between the isocyanate groups and water is promoted, and good flow characteristics with good balance are obtained. The density of the foam can be reduced. Furthermore, since the odor based on the catalyst is reduced during the production of the polyurethane foam,
The working environment is improved, and the odor derived from the catalyst from the polyurethane foam after production can be reduced.

Further, even in a system using a large amount of water as a foaming agent, the cell shape tends to be uniform because the balance between foaming and resinification is good.
The polyurethane foam does not shrink and voids are not formed therein, and furthermore, excellent properties such as improved flyability characteristics such as surface brittleness and adhesiveness are exhibited.

Further, in the present invention, water as a foaming agent efficiently contributes to the reaction by the combined use of the tertiary amine and the imidazole compound. Despite the generation of water vapor, a particularly remarkably excellent effect is obtained in that the odor based on the catalyst can be suppressed without relatively scattering the catalyst.

The tertiary amine / imidazole compound [weight ratio] is preferably 30 from the viewpoint of lowering the density of the polyurethane foam, suppressing internal voids, improving the working environment from the viewpoint of odor, and improving the adhesion to the adherend. / 70-95 / 5, preferably 40 / 60-90 / 10, more preferably 60/40.
It is desirably about 90/10.

The total amount of the tertiary amine and the imidazole compound cannot be determined unconditionally because it depends on the reactivity of the polyol component and the isocyanate component used, the use of the polyurethane foam, and the like. Usually, the total amount is based on 100 parts by weight of the polyol component, which is a raw material of the polyurethane foam, from the viewpoint of increasing the reactivity between the polyol component and the isocyanate component.
0.3 parts by weight or more, preferably 0.5 parts by weight or more, and from the viewpoint of maintaining the strength and odor characteristics of the polyurethane foam, 10 parts by weight or less, preferably 100 parts by weight, based on 100 parts by weight of the polyol component. It is desirable that the content be 8 parts by weight or less. Therefore, in consideration of these circumstances, a desirable total amount is 0.3 to 10 parts by weight, preferably 0.5 to 8 parts by weight based on 100 parts by weight of the polyol component.

The polyurethane-producing catalyst of the present invention contains a tertiary amine and an imidazole compound. In addition to these, other polyurethane-producing catalysts may be used as long as the object of the present invention is not impaired. Can be used.

As other catalysts for producing polyurethane, for example, 1,4-diazabicyclo (2.2.2) octane, 2-methyl-1,4-diazabicyclo (2.2.
2) Octane, N-methylmorpholine, N-ethylmorpholine, N- (2-dimethylaminoethyl) morpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetra Methylpropylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, N, N′-dimethylpiperazine, N,
N ', N'-trimethylaminoethylpiperazine, tris (3-dimethylaminopropyl) amine, N, N-dimethylcyclohexylamine, N, N-dimethylbenzylamine, N, N, N', N ", N"- Pentamethyldiethylenetriamine, bis (2-dimethylaminoethyl) ether, 1,8-diazabicyclo (5.4.0)
Undecene-7, N, N ', N "-tris (3-dimethylaminopropyl) hexahydro-s-triazine, 6
-Dimethylamino-1-hexanol, 5-dimethylamino-3-methyl-1-pentanol, N, N-dimethylethanolamine, N- (3-dimethylaminopropyl) -N-methylaminoethanol, N- (2 Tertiary amine catalysts such as -dimethylaminoethyl) -N-methylaminoethanol and derivatives thereof; salts of these with acids such as carboxylic acid and carbonic acid; organometallic compounds represented by organotin compounds; Can be

For the purpose of imparting flame retardancy to the polyurethane foam, a catalyst for producing a polyisocyanurate represented by a potassium salt such as potassium acetate or potassium octylate or a quaternary ammonium salt may be used in combination. Good.

The amount of other polyurethane-producing catalyst and polyisocyanurate-producing catalyst used is not particularly limited.
Usually, it may be appropriately adjusted within a range in which the object of the present invention is not hindered.

The polyol component may be any of those conventionally used when producing a polyurethane foam.
There is no particular limitation.

Representative examples of the polyol component include polyester polyols and polyether polyols having 2 to 8 functional groups.

The average hydroxyl value of the polyol component is from 150 to 800 mg KOH from the viewpoint of improving the fluidity of the obtained polyurethane foam, maintaining strength and shrinking characteristics over time.
/ G, preferably 200 to 600 mgKOH / g.

The polyester polyol can be produced by a condensation reaction between a dicarboxylic acid and a polyhydric alcohol.

Examples of the dicarboxylic acid used for the polyester polyol include a saturated aliphatic dicarboxylic acid such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid; a saturated aliphatic dicarboxylic acid such as cyclohexanedicarboxylic acid; Aromatic dicarboxylic acids such as phthalic acid, terephthalic acid and isophthalic acid; unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid; halogen-containing dicarboxylic acids such as tetrabromophthalic acid; These acid anhydrides and the like can be mentioned, and these can be used alone or in combination of two or more. The dicarboxylic acid may optionally contain a tribasic or higher polybasic acid such as trimellitic acid.

Examples of the polyhydric alcohol constituting the polyester polyol include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, methylpentanediol-1,6-hexanediol, and trimethylol. Examples thereof include propane, glycerin, pentaerythritol, diglycerin, dextrose, and sorbitol, and these can be used alone or as a mixture of two or more.

Representative examples of the polyether-based polyol include a polyoxypropylene-based polyol, polyoxytetramethylene glycol, and a mixture thereof.

The polyoxypropylene-based polyol is composed of 2
Starting from a compound having at least two active hydrogen-containing groups, ethylene oxide, propylene oxide, 1,2-
It can be produced by a ring-opening addition reaction of an alkylene oxide such as butylene oxide, 1,3-butylene oxide, and styrene oxide.

Compounds having two or more active hydrogen-containing groups include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol,
Neopentyl glycol, 1,4-butanediol,
Dihydric alcohols such as 1,6-hexanediol; trihydric or higher alcohols such as glycerin, trimethylolpropane, pentaerythritol, diglycerin, dextrose, sorbitol, and sucrose; polyhydric alcohols such as resorcinol, hydroquinone, and bisphenol A Phenol;
Polyamines such as ethylenediamine, tolylenediamine, 1,3-propanediamine, and isophoronediamine; alkanolamines such as diethanolamine and triethanolamine; and modified products thereof. These may be used alone or in combination of two or more. Can be used in combination.

Polyoxytetramethylene glycol is
It can be produced by ring-opening polymerization of tetrahydrofuran.

As the polyol component, the polyester polyol and the polyether polyol can be used alone or in combination of two or more.

As the isocyanate component, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate,
Aromatic polyisocyanates such as 2,4'-diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate, naphthylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate and lysine diisocyanate; hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate Alicyclic polyisocyanates such as isocyanate and isophorone diisocyanate; and the above-mentioned modified polyisocyanates containing one or more of urethane bond, carbodiimide bond, uretoimine bond, allophanate bond, urea bond, buret bond, isocyanurate bond and the like. These can be used alone or in combination of two or more.

The ratio between the polyol component and the isocyanate component is usually 20 to 3 for the isocyanate index.
00, preferably 30-110, more preferably 30-
It is preferable to adjust so as to be 80.

Examples of the foaming agent include water, low-boiling hydrocarbons such as isopentane, normal pentane and cyclopentane, nitrogen gas, air and gas such as carbon dioxide, and HCFC.
-141b, HCFC-142b, HCFC-22, H
FC-134a, HFC-152a, HFC-245f
a, HFC-245ca, HFC-236ea, HFC
-365mfc and the like, and these can be used alone or in combination of two or more. Among these,
From the viewpoint of being inexpensive and suppressing the effect on the global environment, water alone or a combination of water and another blowing agent is preferable, and water alone is more preferable.

The amount of the foaming agent to be used cannot be unconditionally determined because it varies depending on the type and the density of the intended polyurethane foam. Normally, the amount of water used alone or in combination with another blowing agent cannot be determined unconditionally because it varies depending on the type and amount of the other blowing agent used in combination, but it does not affect the global environment. From the viewpoint of minimizing the effects of the present invention and maximizing the effects of the present invention, the amount is 8 to 30 parts by weight, preferably 10 to 30 parts by weight, more preferably 15 to 25 parts by weight based on 100 parts by weight of the polyol component. It is desirable.

The foam stabilizer can be used as needed, but may be any one which is generally used when producing a polyurethane foam. Representative examples of foam stabilizers include silicone surfactants such as dimethylpolysiloxane and polyoxyalkylene-modified dimethylpolysiloxane, and anionic surfactants such as fatty acid salts, sulfate esters, phosphate esters, and sulfonates. Is mentioned. Since the amount of the foam stabilizer differs depending on the type and the density of the target polyurethane foam, it cannot be unconditionally determined. Therefore, it is desirable to appropriately adjust the amount according to the kind of the foam stabilizer.

Further, optional components other than those described above, for example,
Other auxiliaries such as a cross-linking agent, a flame retardant, and a filler can be used as long as the object of the present invention is not hindered.

Examples of the crosslinking agent include a hydroxyl group, a primary amino group,
Low molecular weight compounds having two or more active hydrogen-containing groups capable of reacting with a secondary amino group or another isocyanate group are exemplified. Examples thereof include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolpropane, triethanolamine, and alkylene oxides of bisphenol A. Examples thereof include polyhydric alcohols such as adducts, and polyamines such as diethyltoluenediamine, chlorodiaminobenzene, ethylenediamine, and 1,6-hexanediamine. These can be used alone or in combination of two or more.

Examples of the flame retardant include tricresyl phosphate, tris (2-chloroethyl) phosphate, tris (2-chloropropyl) phosphate, and tris (1,3
-Dichloropropyl) phosphate, tris (2,3-
And halogen-based flame retardants such as dibromopropyl) phosphate.

Examples of the filler include inorganic compounds such as silica-based fine particles and alumina-based fine particles, and organic compounds such as melamine-based resin and phenol-based resin.

For example, a polyurethane foam is prepared by mixing a polyol component, a foaming agent, a catalyst for producing polyurethane, a foam stabilizer, and other auxiliaries as necessary, and mixing the obtained polyol mixture with an isocyanate component. Etc.
It can be manufactured by mixing, stirring, pouring into a mold, and foaming. More specifically, for example,
The temperature of the polyol mixture is adjusted to about 20 ° C. using a tank or the like, and then the polyurethane foam is reacted with an isocyanate component using a foaming machine such as an automatic mixing injection type foaming machine and an automatic mixing injection foaming machine to form a polyurethane foam. Can be manufactured.

The density (core density) of the polyurethane foam obtained by the production method of the present invention is 20 kg /
m ³ or less, but from the viewpoint of economy and maintenance of physical properties of the polyurethane foam, it is desirably 8 to 20 kg / m ³ , preferably 8 to 15 kg / m ³ .

The polyurethane foam obtained by the production method of the present invention is used as a heat insulating material for building materials, bathtubs, etc., a dew condensation preventing material for detached houses / condominiums, industrial pipes, etc., a bay window, a sash, etc. for maintaining the product shape. It can be suitably used as a lightweight core material or the like to be packed inside a building material part or the like.

[0049]

Examples 1 to 8 Catalysts for polyurethane production and polyol components [ethylenediamine-based polyether polyol (hydroxyl value: 768 mgKOH / g, manufactured by Mitsui Chemicals, Inc., trade name: polyol AE-300)] shown in Table 1 are shown in Table 1. % By weight and glycerin-based polyether polyol (hydroxyl value: 56 mg KO
H / g, manufactured by Dow Chemical Co., Ltd., trade name: Boranol 3
010) 50% by weight] 100 parts by weight, 4 parts by weight of a silicone-based foam stabilizer [manufactured by Toray Dow Corning Silicone Co., Ltd., trade name: SF2938F], a halogenated phosphate ester-based flame retardant [Daihachi Chemical Industry Co., Ltd. Co., Ltd., product name: TMC
PP] and 20 parts by weight of water as a foaming agent were mixed with a laboratory mixer to obtain a polyol mixture.

Next, the obtained polyol mixture and an isocyanate component (Sumitomo Bayer Urethane Co., Ltd., trade name: Sumidur 44V20) are mixed and stirred with a lab mixer at 20 ° C. so that the isocyanate index becomes 40. Then, a polyurethane foam was produced using the obtained mixture, and the following physical properties were examined.

(1) Reactivity The mixture 3 stirred in a 300 mL polycup was used.
0 g of cream time in free foaming (hereinafter referred to as CT
) And rise time (hereinafter, referred to as RT) were measured.

(2) Shrinkage Characteristics of Polyurethane Foam Mixture 12 of Polyol Mixture and Isocyanate Component
0g in a mold (inner size: 150mm × 150mm × 300
mm (height)] to form a polyurethane foam free foam. After leaving the free foam of the obtained polyurethane foam for one day, its shrinkage characteristics were evaluated for appearance. The evaluation criteria are as follows.

[Evaluation Criteria] A: No shrinkage was observed. ：: slight shrinkage △: small shrinkage ×: large shrinkage

(3) Internal state of polyurethane foam After leaving the free form of the polyurethane foam obtained in the above “(2) Shrinkage properties of polyurethane foam” for one day, it was cut at the center along the foaming direction. The cut surface was visually observed and evaluated based on the following evaluation criteria.

[Evaluation Criteria] A: The inside of the foam is extremely good and the cell size is uniform. ：: The inside of the foam was good, and there was some disturbance in the cells at the center of the foam. Δ: Cell coarseness occurred in the center of the foam, or small voids occurred. X: Large voids are generated inside the foam.

(4) Core Density After leaving the polyurethane foam free foam obtained in the above “(2) Shrinkage characteristics of polyurethane foam” for one day, the core portion was measured to be 100 mm × 100 mm × 1
A test piece having a size of 00 mm was cut out. The weight of the test piece was measured, and the core density was determined based on the formula: [core density] = [weight of test piece] ÷ [volume of test piece].

(5) Evaluation of Adhesive Strength and Adhesiveness (Surface Condition) A vertical mold (aluminum, inner dimensions: 300 mm × 300 mm × 15 mm) adjusted to 40 ° C. However, wax was applied to one surface of the inner wall of the mold. Paste release paper,
A polyethylene sheet is attached to the other surface), and a mixture of a polyol mixture and an isocyanate component is cast therein.
After 5 minutes in the state of free foaming, the mold was released.

50 m from the obtained polyurethane foam
A test piece of mx 50 mm x 15 mm was cut out, and the adhesive strength between the release paper and the polyurethane foam was measured using a tensile tester (manufactured by Shimadzu Corporation, model number: AGS-500G) under the following measurement and analysis conditions. Therefore sought.

[Measurement and Analysis Conditions] Measurement conditions: The entire surface of the polyurethane foam opposite to the release paper was fixed to a flat jig under the tester, and the release paper was rotated at a 90 ° angle at a speed of 50 mm / min. And the adhesive strength was measured continuously. Analysis conditions: Moving distance 10 to 50 m for 10 test pieces
m was measured and divided by the width of the test piece (5 cm). The unit is kgf / cm.

Next, the surface condition of the test piece and the release paper after measuring the adhesive strength was observed, and the adhesiveness of the polyurethane foam was evaluated based on the following evaluation criteria.

[Evaluation Criteria] A: The polyurethane foam is broken from the inside, and the polyurethane foam adheres to the entire surface of the release paper. ：: Most of the polyurethane foam was broken from the inside, and polyurethane foam was attached to most of the release paper. Δ: Most of the polyurethane foam was peeled off from the interface with the release paper, and the polyurethane foam was attached to a part of the release paper. ×: The entire surface was peeled off at the interface between the polyurethane foam and the release paper, and the polyurethane foam did not adhere to the release paper.

(6) Odor originating from catalyst from polyurethane foam When the reactivity was examined in the above “(1) Reactivity”, R
The odor of the polyurethane foam in free foaming immediately after T was directly sensory-evaluated by olfaction. The evaluation criteria are as follows.

[Evaluation Criteria] Bad odor: Imidazole odor is remarkably recognized. Amine odor: A tertiary amine odor is remarkably observed. Slight odor: Slight odor derived from the catalyst. None: Almost no odor from the catalyst is observed.

Comparative Examples 1 to 10 Using the catalysts for polyurethane production shown in Table 2,
A polyurethane foam was produced in the same manner as in Example 8, and its physical properties were examined. Table 2 shows the results.

[0065]

[Table 1]

[0066]

[Table 2]

From the results shown in Table 1, in Examples 1 to 8, since a tertiary amine and an imidazole compound were used in combination as the catalyst for producing polyurethane, a large amount of water was used as the blowing agent. The polyurethane foam does not shrink, the internal condition is good, the density is easy to be reduced, the adhesive strength with the adherend is high, and the polyurethane foam peels off It can be seen that is hard to occur.

Further, the polyurethane foams obtained in each of the examples have almost no odor derived from the catalyst or a slight odor, which is a level that does not cause any problem.

Furthermore, in each of the examples, since the CT is relatively long, it can be estimated that the formability is improved by adapting to the complicated inner surface shape of the mold.

On the other hand, from the results shown in Table 2, in Comparative Examples 1 to 10, the tertiary amine and the imidazole compound were not used in combination, and the tertiary amine or the imidazole compound was used alone. This indicates that a polyurethane foam that satisfies all of the shrinkage characteristics, internal state, adhesiveness, and odor characteristics of the polyurethane foam at the same time cannot be obtained.

[0071]

According to the production method of the present invention, the density is 20 k
g / m ³ or less when producing a low-density polyurethane foam, in a formulation using a large amount of water as a foaming agent,
A polyurethane foam that does not shrink or form voids inside and has good adhesion to the adherend. The effect that it can manufacture in a proper state is produced.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masayoshi Morii 1334 Minato, Wakayama-shi Kao Corporation Research Institute F-term (reference) 4J034 CA04 CA05 CA15 CB03 CB04 CC03 CC08 CC12 CC61 CC62 CC67 CD01 CD04 CD13 DA01 DB03 DB07 DF16 DF20 DF22 DF29 DG02 DG03 DG04 DG05 DG06 DG14 DG15 DG16 DG22 GA55 HA01 HA06 HA07 HB06 HB07 HB08 HB09 HB12 HC03 HC09 HC12 HC13 HC17 HC22 HC25 HC26 HC34 HC35 HC44 HC46 HC52 HC61 HC63 HC64 HC67 HC02 NA01 NA03 KB01 NA03 KB QC01 RA15

Claims (5)

[Claims] 1. A tertiary compound represented by the formula (I): (CH ₃ ) ₂ N (CH ₂ CH ₂ O) _n -H (I) wherein n is an integer of 2 to 4. Amine and formula (II): (Wherein, R ¹ is a linear or branched alkyl group having 1 to 6 carbon atoms or a linear or branched hydroxyalkyl group having 1 to 6 carbon atoms, R ² is a hydrogen atom, A straight-chain or branched-chain alkyl group or a straight-chain or branched-chain hydroxyalkyl group having 1 to 6 carbon atoms) in the presence of a polyurethane-producing catalyst, a foaming agent and a foam stabilizer containing an imidazole compound represented by the formula: And the density at which the polyol component is reacted with the isocyanate component is 20 kg / m.
Method for producing polyurethane foam of ³ or less. 2. The method of claim 2, wherein the tertiary amine is 2- (2-dimethylaminoethoxy) ethanol and / or 2- [2- (2-
2. The production method according to claim 1, which is [dimethylaminoethoxy) ethoxy] ethanol. 3. The imidazole compound is selected from the group consisting of 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole and 1- (2-hydroxyethyl) -2-methylimidazole. 3. The method according to claim 1, wherein the method is at least one kind. 4. The method according to claim 1, wherein the blowing agent contains water, and the amount of water is 8 to 30 parts by weight based on 100 parts by weight of the polyol component. 5. The method according to claim 1, wherein the tertiary amine / imidazole compound (weight ratio) is 30/70 to 95/5.