JP5026896B2 - Polyol composition and method for producing rigid polyurethane foam - Google Patents

Description

  The present invention relates to a polyol composition for rigid polyurethane foam using water as a foaming agent, and a method for producing a rigid polyurethane foam using the polyol composition.

  Conventionally, glass wool has been the most commonly used heat insulating material for buildings mainly in detached houses, but glass wool applied in the wall gradually sinks downward over the years, reducing the thermal insulation of the wall. In addition, there is also a problem that the construction thickness is increased in order to satisfy the demand for high heat insulating properties required in recent years.

  Rigid polyurethane foam with spray foaming method that sprays on the inner wall of the outer wall or inner wall as a heat insulating material for buildings that has higher heat insulation than glass wool insulation and does not cause sinking over the years. In addition, a rigid polyurethane foam of an injection method in which a foaming stock solution is injected into a wall formed by an outer wall surface and an inner wall surface is known. As a foaming agent for rigid polyurethane foam, chlorofluorocarbon compounds have been used in the old days, but production is prohibited because it is a substance that causes environmental problems such as destruction of the ozone layer. Currently usable foaming agents are HFC compounds, Pentane, carbon dioxide and water. Among these foaming agents, HFC compounds are expensive, and pentane is a highly flammable compound and cannot be used for rigid polyurethane foams with spray foam. Further, when carbon dioxide is used as a foaming agent, an apparatus for pressurizing and mixing carbon dioxide with the polyol composition is necessary, and an apparatus for producing a rigid polyurethane foam becomes expensive. On the other hand, water is easy to handle at low cost, and for example, a water-foamed rigid polyurethane foam that can be used for spray foaming is known (for example, Patent Document 1).

Japanese Patent No. 3272971

  The technology disclosed in Patent Document 1 is a water-foamed rigid polyurethane foam excellent in dimensional stability and flame retardancy, which can be produced by spray foaming, and connects the aromatic ester polyol and foam cells (cells). The communicator to be used is used as a raw material component.

  However, the polyol composition disclosed in Patent Document 1 has low compatibility with water as a foaming agent, and may have poor storage stability or foam stability, resulting in a decrease in the dimensional stability of the rigid polyurethane foam obtained. It has the problem of being easy.

  The present invention has been made in view of the above-mentioned problems of the known art, and uses a polyol as a foaming agent for rigid polyurethane foams having excellent storage stability and foaming stability, and excellent long-term dimensional stability. An object of the present invention is to provide a method for producing a rigid polyurethane foam using a polyol composition.

The present invention for solving the above problems is as follows.
1. A polyol composition for a rigid polyurethane foam comprising a polyol compound, polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester, a catalyst, water as a foaming agent, mixed with a polyisocyanate compound and reacted to form a rigid polyurethane foam.
2. The polyol compound contains a polyether polyol. The polyol composition for rigid polyurethane foams described in 1.
3. 1. The polyether polyol contains an aromatic polyether polyol. The polyol composition for rigid polyurethane foams described in 1.
4). 2. The aromatic polyether polyol is a Mannich-modified polyether polyol. The polyol composition for rigid polyurethane foams described in 1.
5. 2. The aromatic polyether polyol is a Mannich modified polyether polyol and has a hydroxyl value of 200 to 400 mgKOH / g. Or 4. The polyol composition for rigid polyurethane foams described in 1.
6). 1. The polyether polyol is contained in an amount of 10% by weight or more in the total amount of the polyol compound. To 5. The polyol composition for rigid polyurethane foam according to any one of the above.
7). The polyol compound contains an aromatic ester polyol. To 6. The polyol composition for rigid polyurethane foam according to any one of the above.
8). 6. The total amount of the polyol compound contains 10 to 90% by weight of an aromatic ester polyol and 10 to 90% by weight of a polyether polyol. The polyol composition for rigid polyurethane foams described in 1.

9. The polyoxyethylene sorbitan fatty acid ester has a total number of repeating units of ethylene oxide units constituting a polyoxyethylene group of 15 or more and an HLB of 10 or more. To 8. The polyol composition for rigid polyurethane foam according to any one of the above.
10. The sorbitan fatty acid ester has an HLB of 5 or less. To 9. The polyol composition for rigid polyurethane foam according to any one of the above.
11. 1. The mixing ratio of the polyoxyethylene sorbitan fatty acid ester and the sorbitan fatty acid ester is a weight ratio of polyoxyethylene sorbitan fatty acid ester: sorbitan fatty acid ester = 1: 0.5 to 1: 2. To 10. The polyol composition for rigid polyurethane foam according to any one of the above.
12 1. The total amount of the polyoxyethylene sorbitan fatty acid ester and the sorbitan fatty acid ester is 10 to 1000 parts by weight with respect to 100 parts by weight of water. To 11. The polyol composition for rigid polyurethane foam according to any one of the above.
13. 0.01 to 10% by weight of an alkoxysilane condensate having a three-dimensional crosslinked structure is contained in the total amount of the polyol composition. To 12. The polyol composition for rigid polyurethane foam according to any one of the above.
14.1. To 13. The manufacturing method of the rigid polyurethane foam which mixes the polyol composition in any one of these, and a polyisocyanate compound, and makes it react and makes it a rigid polyurethane foam.

  The polyol composition of the present invention uses water as a foaming agent, has excellent storage stability, and is excellent in foaming stability, dimensional stability and heat insulation.

The polyol composition of the present invention contains water as a polyol compound, polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester, catalyst, and foaming agent.
The viscosity of the polyol composition of the present invention is preferably 1000 mPa · s (20 ° C.) or less, and preferably 500 mPa · s (20 ° C.) or less, from the viewpoint of easily producing a rigid polyurethane foam by a spray method. More preferred.

  Although it does not specifically limit as a polyol compound which comprises the polyol composition of this invention, The thing containing polyether polyol and / or aromatic ester polyol is preferable.

  Examples of polyether polyols include aromatic polyether polyols, glycerin polyether polyols, tertiary amino group-containing polyether polyols, and the like.

As the aromatic polyether polyol, bisphenol A type polyether polyol obtained by adding alkylene oxide such as ethylene oxide and propylene oxide with bisphenol A as an initiator, and aromatic amines, that is, toluenediamine, diethyltoluenediamine 4,4'-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, naphthalenediamine, triethanolamine, Mannich condensation products, etc. as initiators, and obtained by adding alkylene oxides such as ethylene oxide and propylene oxide. And aromatic amine-based polyether polyols.
In the present invention, an aromatic amine-based polyether polyol, particularly a Mannich-modified polyether polyol obtained by adding an alkylene oxide to a formalin condensate of a phenol and an amine compound is preferable.
As such an aromatic polyether polyol, a hydroxyl value of 200 to 400 mgKOH / g is preferable in terms of foam flame retardancy and dimensional stability. When deviating from this range, the flame retardancy and dimensional stability of the resulting foam may be reduced.

  The glycerin-based polyether polyol is preferably a polyether polyol obtained by ring-opening addition of at least one alkylene oxide such as ethylene oxide and propylene oxide using glycerin as an initiator. Furthermore, the hydroxyl value of the glycerin-based polyether polyol is preferably 350 to 600 mg KOH / g in terms of storage stability of the polyol composition, adhesion to the casing surface, and the like. When deviating from this range, there is a fear that the storage stability and the adhesion of the polyol composition may be lowered.

  Examples of the tertiary amino group-containing polyether polyol include low molecular weight amines such as alkylene diamine and alkanol amine, that is, ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, neopentyl diamine and the like having 2 to 8 carbon atoms. And those obtained by ring-opening addition of at least one alkylene oxide such as ethylene oxide and propylene oxide.

  Examples of polyether polyols include glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexylene glycol, and cyclohexanedimethanol. Or a polyether polyol obtained by ring-opening addition of at least one of alkylene oxides such as ethylene oxide and propylene oxide using trimethylolpropane, sorbitol, sucrose, etc. as an initiator.

  In particular, the polyether polyol used in the present invention preferably contains an aromatic polyether polyol. By using an aromatic polyether polyol, in particular, to obtain a rigid polyurethane foam excellent in storage stability of the polyol composition, foamability, curability, flame retardancy of the foam, dimensional stability and heat insulation. Can do.

  The aromatic polyether polyol is used in the polyether polyol in an amount of 50 to 100% by weight, more preferably 70 to 100% by weight. The storage stability of the polyol composition, the foamability, the flame retardancy of the foam, and the dimensional stability It is suitable in terms of the above. When the amount is less than 50% by weight, foamability, flame retardancy of the obtained foam, and the like may be lowered.

  The aromatic ester polyol includes at least one glycol selected from ethylene glycol, diethylene glycol, 1,6-hexanediol, and the like, and at least one aromatic dicarboxylic acid selected from phthalic acid, isophthalic acid, terephthalic acid, and the like. The ester polyol.

  Such an aromatic ester polyol is preferably used in an amount of 10 to 90% by weight, more preferably 15 to 85% by weight in the total amount of the polyol compound, in terms of flame retardancy and dimensional stability. If it is less than 10% by weight, the flame retardancy may be lowered. If it is more than 90% by weight, the foaming property of the foam may be lowered. The hydroxyl value of such an aromatic ester polyol is preferably 100 to 400 mgKOH / g.

  Examples of the aromatic ester polyol include those having as a main component an ester skeleton obtained by dehydration condensation of a dicarboxylic acid having a phthalic acid skeleton and a glycol compound.

  The polyoxyethylene sorbitan fatty acid ester used in the present invention is a compound having a chemical structure represented by the chemical formula (Chemical Formula 1).

(Chemical formula 1)
O (CH ₂ CH ₂ O) mH
│
CH
/ \
_{H (CH 2 CH 2 O)} pO─CH CHO (CH 2 CH 2 O) nH
│ │
CH ₂ CHCH ₂ OCOR ₁
\ /
O

R ₁ is an alkyl group, alkenyl group or alkadienyl group having 8 to 18 carbon atoms, and specifically R ₁ has 8 or more carbon atoms such as octyl group, stearyl group, lauryl group, oleyl group, palmityl group, etc. And an alkyl group, an alkenyl group, and an alkadienyl group. m + n + p is 15 or more, more preferably 20 or more (provided that m + n is 1 or more), and HLB is preferably 10 or more, more preferably 13 or more, and even more preferably 15 or more.
In addition, HLB is hydrophilic-lipophilic balance, and is a value calculated by the Griffin method in the present invention.

As the polyoxyethylene sorbitan fatty acid ester, the total amount (m + n + p) of repeating units of ethylene oxide units constituting the polyoxyethylene group is 15 or more, more preferably 20 or more, HLB is 10 or more, further 13 or more, By being 15 or more, it becomes advantageous in terms of dimensional stability, recoatability, adhesion, and the like.
When the total number of repeating units of ethylene oxide units constituting the polyoxyethylene sorbitan fatty acid ester is less than 15, or when the HLB is less than 10, the dimensional stability of the formed rigid polyurethane foam is not satisfactory, There is a tendency to be inferior in recoatability and adhesiveness.
Among polyoxyethylene sorbitan fatty acid esters, it is particularly preferable to use a polyoxyethylene sorbitan monofatty acid ester having a monoalkyl group, a monoalkenyl group or a monoalkadienyl group, and in particular, polyoxyethylene sorbitan monolaurate, polyoxyethylene Ethylene sorbitan monooleate is preferred. In this case, since the polyoxyethylene sorbitan monofatty acid ester is introduced into the polyol skeleton, the dimensional stability of the foam is particularly excellent.

  The sorbitan fatty acid ester used in the present invention is a compound having a chemical structure represented by the chemical formula (Chemical Formula 2).

(Chemical formula 2)
OH
│
CH
/ \
HO-CH CHOH
│ │
CH ₂ CHCH ₂ OCOR ₂
\ /
O

R ₂ is an alkyl group having 8 to 18 carbon atoms, an alkenyl group, or an alkadienyl group. Specifically, R ₂ has 8 or more carbon atoms such as an octyl group, a stearyl group, a lauryl group, an oleyl group, and a palmityl group. And an alkyl group, an alkenyl group, and an alkadienyl group. HLB is preferably 5 or less.

  Among sorbitan fatty acid esters, it is particularly preferable to use a sorbitan monofatty acid ester having a monoalkyl group, a monoalkenyl group or a monoalkadienyl group. In this case, since the sorbitan monofatty acid ester is introduced into the polyol skeleton, the dimensional stability of the foam is particularly excellent.

  By using such a sorbitan fatty acid ester, the compatibility with the aromatic ester polyol can be enhanced.

The present invention is characterized by using polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester in combination. By using polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester in combination, water is more uniformly dissolved in the polyol composition, and the balance of bubbles (cells) at the time of foaming is excellent, foaming stability and dimensional stability. In addition, it has excellent properties and heat insulation properties, and also has an excellent foam regulating effect.
The mixing ratio of the polyoxyethylene sorbitan fatty acid ester and the sorbitan fatty acid ester is a weight ratio, and the polyoxyethylene sorbitan fatty acid ester: sorbitan fatty acid ester is 1: 0.5 to 1: 2, and further 1: 0.7 to 1. : It is preferable that it is 1.5.

  The total amount of polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester is preferably 10 to 1000 parts by weight, more preferably 50 to 500 parts by weight, with respect to 100 parts by weight of water. By being in such a range, it becomes possible to improve the solubility of the water which is a foaming agent in a polyol composition. By being within such a range, water is more uniformly dissolved in the polyol, so that a foam having excellent balance of cells (cells) during foaming and excellent foaming stability and dimensional stability can be obtained.

  The polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester used in the present invention have effects similar to those of the compatibilizer and foam stabilizer. In the present invention, the content of the compatibilizer and foam stabilizer is small. Even if it is not contained, it is possible to produce a rigid polyurethane foam excellent in foaming stability, dimensional stability, heat insulation, and foam regulating effect.

  Water as the foaming agent is 3 to 12 parts by weight, preferably 4 to 10 parts by weight with respect to 100 parts by weight of the polyol compound. If the amount is less than 3 parts by weight, the resulting foam may be densified. If the amount is more than 12 parts by weight, the foam is brittle and the adhesion to the housing surface may be reduced.

  As the catalyst, known catalysts such as tertiary amine catalysts, imidazole catalysts, and fatty acid alkali metal salt catalysts can be used without limitation.

  As the tertiary amine catalyst, specifically, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine (Kaorizer No. 1), N, N-alkylpolyalkylenepolyamines such as N, N ′, N ′, N ″ -pentamethyldiethylenetriamine (Kaorizer No. 3), diazabicycloundecene (DBU), bis (β-dimethylaminoethyl) ether, N And tertiary amine catalysts such as N, N-dimethylaminopropylhexahydrotriazine.

Examples of the imidazole catalyst include 1-isobutyl-2-methylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, and examples of the fatty acid alkali metal salt catalyst include potassium octylate and potassium acetate. it can.
In addition to these catalysts, an amine catalyst or an organometallic catalyst may be used in combination.
The addition amount of the catalyst is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight with respect to 100 parts by weight of the total polyol compound.

Furthermore, the polyol composition of the present invention preferably contains a flame retardant.
Examples of the flame retardant include organic phosphoric acid esters. As the organic phosphoric acid esters, halogenated alkyl ester of phosphoric acid, alkyl phosphoric acid ester, aryl phosphoric acid ester, phosphonic acid ester and the like can be used. Specific examples include tris (β-chloroethyl) phosphate, tris (β-chloropropyl) phosphate, tributoxyethyl phosphate, tributyl phosphate, triethyl phosphate, cresylphenyl phosphate, dimethylmethylphosphonate, etc. More than species can be used. In the present invention, it is preferable to use tris (β-chloropropyl) phosphate because it exhibits flame retardancy and an effect as a viscosity reducing agent, but is not limited thereto.
The amount of the flame retardant added is 5 to 120 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the polyol compound. When deviating from this range, there may be a problem that the flame retardancy effect and the viscosity reduction effect cannot be sufficiently obtained, or the mechanical properties of the foam are lowered.

Furthermore, the polyol composition of the present invention preferably contains an alkoxysilane condensate having a three-dimensional crosslinked structure.
Such an alkoxysilane condensate can be obtained, for example, by mixing and condensing alkoxysilane compounds 1 to 4 represented by the following formula by a known method.

(Alkoxysilane compound 1)
OR ₁
│
_{R 2 O- (Si-O)} n-R 4
│
OR ₃
R _{1 to} R ₄ represent a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms and hydrogen, and R _{1 to} R ₄ may be the same or different. n is an integer of 1 or more (preferably n is 1).
Some of carbon atoms and hydrogen atoms may be replaced with nitrogen atoms, halogen atoms, or the like.

  Examples of the alkoxysilane compound 1 include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-butoxysilane, and tetra-t-butoxy. Silane, dihydroxydimethoxysilane, dihydroxydiethoxysilane, dihydroxydi-n-propyloxysilane, trihydroxymethoxysilane, trihydroxyethoxysilane, trihydroxy-n-propyloxysilane, diphenoxydiethoxysilane, etc., or these Examples include condensates.

(Alkoxysilane compound 2)
R ₅
│
_{R 6 O- (Si-O)} n-R 8
│
OR ₇
R ₅ represents a linear, branched, or cyclic alkyl group having 1 to 18 carbon atoms, an amino group, an epoxy group, or a halogen.
R _{6 to} R ₈ represent a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms and hydrogen, and R _{6 to} R ₈ may be the same or different. n is an integer of 1 or more (preferably n is 1).
Some of carbon atoms and hydrogen atoms may be replaced with nitrogen atoms, halogen atoms, or the like.

  Examples of the alkoxysilane compound 2 include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, and propyl. Trimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltributoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltripropoxysilane, butyltributoxysilane, isobutyltrimethoxysilane, phenyltrimethoxysilane, phenyl Triethoxysilane, phenyltributoxysilane, hexyltrimethoxysilane, cyclohexyltriethoxysilane, decyltrimethoxy Lan, naphthyltriethoxysilane, 4-chlorophenyltriethoxysilane, 4-cyanophenyltriethoxysilane, 4-aminophenyltriethoxysilane, 4-nitrophenyltriethoxysilane, 4-methylphenyltriethoxysilane, 4-hydroxyphenyl Triethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltri-n-propyloxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxy Silane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltri Toxisilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxyepoxypropyltrimethoxysilane, 3-glycidoxyepoxypropyltriethoxysilane, hydroxytrimethoxysilane, hydroxytriethoxysilane, hydroxy Tri-n-propyloxysilane, methylhydroxydimethoxysilane, phenylhydroxydimethoxysilane, methyl (phenoxy) diethoxysilane, phenyl (phenoxy) diethoxysilane, triphenoxyethoxysilane, methyl (diphenoxy) ethoxysilane, phenyl (diphenoxy) An ethoxysilane etc. or these condensates are mentioned.

(Alkoxysilane compound 3)
R ₉
│
_{R 10 - (Si-O)} n-R 12
│
OR ₁₁
R _{9 to} R ₁₀ represent a linear, branched, or cyclic alkyl group having 1 to 18 carbon atoms, an amino group, an epoxy group, or a halogen, and R _{9 to} R ₁₀ may be the same or different. .
R _{11 to} R ₁₂ represent a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms and hydrogen, and R _{11 to} R ₁₂ may be the same or different. n is an integer of 1 or more (preferably n is 1).
Some of carbon atoms and hydrogen atoms may be replaced with nitrogen atoms, halogen atoms, or the like.

  Alkoxysilane compound 3, such as dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, dipropyldimethoxysilane, Dipropyldiethoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldibutoxysilane, methylethyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, methylcyclohexyldiethoxy Silane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-glycidoxyepoxypropyl Chill diethoxy silane, dimethyl (phenoxy) ethoxysilane, diphenyl (phenoxy) ethoxysilane, methyl (phenyl) (phenoxy) ethoxysilane and the like, or the like condensates thereof and the like.

(Alkoxysilane compound 4)
R ₁₃
│
_{R 14 - (Si-O)} n-X
│
R ₁₅
X represents a linear, branched, or cyclic alkyl group having 1 to 18 carbon atoms, hydrogen, or —Si (R ₁₆ ) ₃ . n is an integer of 1 or more (preferably n is 1).
R _{13 to} R ₁₆ represent a linear, branched, or cyclic alkyl group having 1 to 18 carbon atoms, an amino group, an epoxy group, or a halogen, and R _{13 to} R ₁₆ may be the same or different. n is an integer of 1 or more (preferably n is 1).
Some of carbon atoms and hydrogen atoms may be replaced with nitrogen atoms, halogen atoms, or the like.

  Alkoxysilane compound 4, for example, trimethylmethoxysilane, trimethylethoxysilane, trimethyl-n-propyloxysilane, dimethyl (ethyl) ethoxysilane, dimethyl (cyclohexyl) ethoxysilane, dimethyl (phenyl) ethoxysilane, methyl (diphenyl) ethoxysilane Or condensates thereof (for example, disiloxanes such as hexamethyldisiloxane). In the present invention, a compound in which n is 1 can be suitably used.

The alkoxysilane condensate used in the present invention can be obtained by mixing and reacting at least one selected from the alkoxysilane compound 1 and the alkoxysilane compound 2, and such an alkoxysilane condensate can be obtained by three-dimensional crosslinking. It has a structure.
Although the details of such an alkoxysilane condensate are unknown, the polyoxyethylene sorbitan fatty acid ester and the sorbitan fatty acid ester are efficiently dispersed in the polyol composition while being incompatible with the polyol compound. Therefore, it is considered that the foaming stability is excellent. Furthermore, it is considered that the alkoxysilane condensate is efficiently incorporated into the polyurethane skeleton, and a rigid polyurethane foam excellent in long-term dimensional stability can be obtained by the action of the incorporated alkoxysilane condensate.
Furthermore, in this invention, the 1 or more types chosen from the alkoxysilane compound 1 and the alkoxysilane compound 2, and the alkoxysilane condensate obtained by mixing and making the alkoxysilane compound 4 react can be used conveniently.

  Moreover, when obtaining an alkoxysilane condensate, a known catalyst can be used. For example, as specific examples, organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, tin octylate, phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, mono Phosphate ester such as decyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate, propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxy Silane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyl Dimethoxysilane, addition reaction product of epoxy compound and phosphoric acid and / or monoacidic phosphate, maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, phthalic acid, trimetic acid, pyromet Acid compounds such as acids, acid anhydrides thereof, and p-toluenesulfonic acid are exemplified. Also included are mixtures or reactants of these acidic catalysts and amines.

  The addition amount of the alkoxysilane condensate is suitably 0.01 to 10% by weight, preferably 0.1 to 5% by weight, more preferably 0.3 to 3% by weight, based on the total amount of the polyol composition. When the amount is less than 0.01% by weight, long-term dimensional stability may not be obtained. When the amount is more than 10% by weight, long-term stability may not be obtained.

  In the production of the rigid polyurethane foam of the present invention, in addition to the above components, colorants, antioxidants, foam stabilizers, compatibilizers, surfactants and the like well known to those skilled in the art can be used.

As the foam stabilizer, a known silicone foam stabilizer for rigid polyurethane foam, that is, a graft copolymer (polyether-modified silicone compound) of polydimethylsiloxane and polyoxyethylene glycol or polyoxyethylene-propylene glycol is used without limitation. be able to. Such foam stabilizers include SH-193, L-5420, L-5340, SZ-1698, SZ-1704, SZ-1923, SZ-1932 (Toray Dow Corning), F-502, F-506 (Shin-Etsu Chemical). Industrial) and the like.
In the present invention, by using the above alkoxysilane condensate, polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester in combination with a silicone foam stabilizer, in particular, a rigid polyurethane foam excellent in storage stability of a polyol composition is obtained. Can do.

  The polyisocyanate compound that forms a rigid polyurethane foam by mixing and reacting with the polyol composition is easy to handle, fast in reaction, excellent in the physical properties of the resulting rigid polyurethane foam, and low in cost. For this reason, liquid MDI is usually used. As the liquid MDI, crude MDI (c-MDI) or the like is used. In addition to liquid MDI, other polyisocyanate compounds may be used in combination. As the polyisocyanate compound used in combination, a polyisocyanate compound known in the technical field of polyurethane can be used without limitation.

In the rigid polyurethane foam of the present invention, the polyol composition and the polyisocyanate compound are adjusted to have an NCO / OH ratio (equivalent ratio) of 1.0 to 3.0, preferably about 1.0 to 2.0, It can be obtained by reacting.
Moreover, it is preferable to adjust the temperature at the time of manufacture of a rigid polyurethane foam so that the temperature of the said polyol composition and the said polyisocyanate compound may be about 30-80 degreeC, respectively.
In the production of such a rigid polyurethane foam, there is no particular limitation as long as the polyol composition and the polyisocyanate compound can be uniformly mixed, and a known apparatus can be used. For example, low pressure and high pressure foaming machines for injection foaming, low pressure and high pressure foaming machines for slab foaming, low pressure and high pressure foaming machines for continuous lines, and spraying work used when manufacturing small mixers and ordinary urethane foam. For example, a spray foaming machine can be used.

(Polyol composition)
Using the raw materials described in Table 1, a polyol composition was prepared with the formulation described in Table 2.

(Examples and comparative examples)
In Examples and Comparative Examples, a polyol composition was prepared by a conventional method with the formulation described in Table 2. In the production of rigid polyurethane foam, a commercially available rigid polyurethane foam spray foaming device is used, and the polyol composition and the polyisocyanate compound are adjusted so that the isocyanate index (NCO / OH equivalent ratio) is 2.0. A rigid polyurethane foam was formed on the test face material. The obtained rigid polyurethane foam was evaluated as described below, and the results are shown in the lower part of Table 2.

(Evaluation)
1) Foaming stability Using a commercially available rigid polyurethane foam spray foaming device, the polyol composition and the polyisocyanate compound are adjusted so that the isocyanate index (NCO / OH equivalent ratio) is 2.0. The form of the foam when sprayed on was visually evaluated. Evaluation results were carried out according to the following criteria.
A: No shrinkage on appearance.
○: Almost no shrinkage on appearance.
Δ: Partial shrinkage on appearance
X: Shrinkage on appearance.

2) Dimensional stability An evaluation sample prepared by cutting a rigid polyurethane foam into 100 mm × 100 mm × 30 mm was visually evaluated for the presence or absence of shrinkage after standing at 25 ° C. and 50 ° C. for 3 days. Evaluation results were carried out according to the following criteria.
A: No shrinkage on appearance.
○: Almost no shrinkage on appearance.
Δ: Partial shrinkage on appearance
X: Shrinkage on appearance.

3) Foam density An evaluation sample prepared by cutting a rigid polyurethane foam into 100 mm × 100 mm × 30 mm was left at 25 ° C. for 3 days and then weighed to calculate the density (kg / m ³ ).

4) Storage stability After storing the polyol composition at 50 ° C. for one month, using a commercially available rigid polyurethane foam spray foaming device, the polyol composition and the polyisocyanate compound have an isocyanate index (NCO / OH equivalent ratio). The form of the foam when it was adjusted to 2.0 and sprayed onto the test face was visually evaluated.
Evaluation results were carried out according to the following criteria.
A: No abnormality.
○: Almost no abnormality.
Δ: Partial phase separation was observed.
X: Phase separation was observed.

5) Flame retardancy For an evaluation sample prepared by cutting a rigid polyurethane foam into 180 mm × 255 mm, the skin surface of the sample was heated with a propane gas burner flame for about 5 minutes, and the carbonized layer forming ability by heating and the combustion of the foam Shrinkage was confirmed visually. The results are shown in Table 2. The evaluation was performed in a five-step evaluation, with 5 being no shrinkage due to foam combustion and 1 being a shrinkage due to foam combustion.

Claims (14)

  A polyol composition for a rigid polyurethane foam comprising a polyol compound, polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester, a catalyst, water as a foaming agent, mixed with a polyisocyanate compound and reacted to form a rigid polyurethane foam.   The polyol composition for rigid polyurethane foam according to claim 1, wherein the polyol compound contains a polyether polyol.   The polyol composition for rigid polyurethane foam according to claim 2, wherein the polyether polyol contains an aromatic polyether polyol.   The polyol composition for rigid polyurethane foam according to claim 3, wherein the aromatic polyether polyol is a Mannich-modified polyether polyol.   The polyol composition for rigid polyurethane foam according to claim 3 or 4, wherein the aromatic polyether polyol is Mannich-modified polyether polyol and has a hydroxyl value of 200 to 400 mgKOH / g.   The polyol composition for rigid polyurethane foam according to any one of claims 1 to 5, wherein the polyol compound contains 10% by weight or more of polyether polyol in the total amount of the polyol compound.   The polyol composition for rigid polyurethane foam according to any one of claims 1 to 6, wherein the polyol compound contains an aromatic ester polyol.   The polyol composition for a rigid polyurethane foam according to claim 7, wherein the total amount of the polyol compound contains 10 to 90% by weight of an aromatic ester polyol and 10 to 90% by weight of a polyether polyol. The polyoxyethylene sorbitan fatty acid ester has a total amount of repeating units of ethylene oxide units constituting a polyoxyethylene group of 15 or more, and HLB is 10 or more. The polyol composition for rigid polyurethane foam according to any one of the above. The polyol composition for rigid polyurethane foam according to any one of claims 1 to 9 , wherein the sorbitan fatty acid ester has an HLB of 5 or less.   The mixing ratio of the polyoxyethylene sorbitan fatty acid ester and the sorbitan fatty acid ester is a weight ratio of polyoxyethylene sorbitan fatty acid ester: sorbitan fatty acid ester = 1: 0.5 to 1: 2. The polyol composition for rigid polyurethane foam according to claim 10.   The total amount of the polyoxyethylene sorbitan fatty acid ester and the sorbitan fatty acid ester is 10 to 1000 parts by weight with respect to 100 parts by weight of water, according to any one of claims 1 to 11. Polyol composition for rigid polyurethane foam.   The polyol for rigid polyurethane foam according to any one of claims 1 to 12, wherein 0.01 to 10% by weight of an alkoxysilane condensate having a three-dimensional crosslinked structure is contained in the total amount of the polyol composition. Composition.   A method for producing a rigid polyurethane foam, wherein the polyol composition according to any one of claims 1 to 13 and a polyisocyanate compound are mixed and reacted to form a rigid polyurethane foam.