JP2011157528A - Polyol composition for rigid polyurethane foam and manufacturing method for rigid polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyol composition for a rigid polyurethane foam which can form a rigid polyurethane foam excellent in flame retardancy and dimensional stability and has low viscosity and excellent workability, and to provide a manufacturing method for the rigid polyurethane foam. <P>SOLUTION: In the polyol composition for a rigid polyurethane foam, a polyol compound includes: a polyester polyol of polyoxyethylene glycol whose average molecular weight is 100-300 and an aromatic dicarboxylic acid in which the molar ratio of orthophthalic acid (O) to terephthalic acid (P) O/P is 20/80-60/40; and a mannich polyether polyol. When the total amount of the polyol compound is made 100 pts.wt., the polyester polyol is 40-80 pts.wt., and the mannich polyether polyol is 20-40 pts.wt. <P>COPYRIGHT: (C)2011,JPO&INPIT

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.

  Rigid polyurethane foam is a well-known material as a heat insulating material, a lightweight structural material, and the like. Such a rigid polyurethane foam is formed by mixing a polyol composition containing a polyol compound and a foaming agent as essential components and a polyisocyanate component, and foaming and curing. In the past, chlorofluorocarbon compounds such as CFC-11 were used as blowing agents, but they were prohibited because CFC compounds caused destruction of the ozone layer, and switched to HCFC-141b. Although switching to an HFC compound having a coefficient of zero has been performed, the HFC compound has a problem that the GWP (global warming potential) is large.

  A technique using pentanes such as n-pentane, iso-pentane, and cyclopentane as a low-cost blowing agent instead of a halogenated hydrocarbon compound such as an HFC compound is known. However, pentanes are highly flammable. In addition, there is a problem that a large amount of cost is required for the equipment for fire prevention.

  In the following Patent Documents 1 and 2, a rigid urethane foam using water and an HFC compound in combination as a foaming agent is described. However, as described above, the HFC compound is expensive, and it is difficult to adjust the reactivity mildly as compared with the conventional formulation using HCFC-141b. There is a problem that workability is poor because it cannot be smoothly blown in the required refrigerated warehouse.

  There is no problem in the working environment and the global environment, and water is known as a low-cost foaming agent, and many rigid polyurethane foams using water as a foaming agent have been reported. However, when water is used as the foaming agent, the polyester polyol as a raw material reacts with the water of the foaming agent to cause hydrolysis, resulting in a reaction delay. Further, since carbon dioxide is used as the foaming gas, the diffusion of carbon dioxide is fast, the foam after foaming is in a reduced pressure state, the foam shrinks, and the dimensional stability tends to deteriorate. Therefore, when water is used as the foaming agent, it is necessary to devise the formulation of the polyol composition to prevent the above problems from occurring.

  As a result of intensive studies on the above problems when water is used as a blowing agent, the present inventors have mainly found a polyol compound containing an ester polyol of polyoxyethylene glycol and an aromatic dicarboxylic acid and a polyether polyol containing resin fine particles. It has been found that a rigid polyurethane foam obtained by mixing and reacting a polyol composition as a component and a polyisocyanate component is excellent in dimensional stability and flame retardancy (Patent Document 3 below). However, when a rigid polyurethane foam is applied by, for example, a spray method, there is a request that the viscosity of the polyol composition should be further reduced. In the invention described in such literature, further improvement in terms of the viscosity of the polyol composition is required. There was room. Moreover, when the polyol composition contains resin fine particles, the quality regulation of the obtained rigid polyurethane foam is satisfied, but it is easily subjected to viscosity restrictions. Furthermore, when the storage stability of the polyol composition is emphasized, it is preferable not to contain resin fine particles.

  In the following Patent Document 4, a water-foamed hard polyisocyanurate foam-forming composition containing an organic polyisocyanate composition containing an isocyanate group-terminated prepolymer and a polyol composition containing a phthalic polyester polyol. Is described. However, this document does not describe or suggest a reduction in the viscosity of the polyol composition described above or an improvement in the dimensional stability of the foam.

JP 2004-51693 A JP 2004-59900 A JP 2008-138137 A WO 2007/7577

  The present invention has been made in view of the above circumstances, and its purpose is to form a rigid polyurethane foam excellent in flame retardancy and dimensional stability, and to have low viscosity and workability and storage stability. An object is to provide an excellent polyol composition for rigid polyurethane foam and a method for producing the rigid polyurethane foam.

  The above object can be achieved by the present invention as described below. That is, the polyol composition for rigid polyurethane foam according to the present invention contains a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst, and is mixed with and reacted with a polyisocyanate component to form a rigid polyurethane foam. A polyol composition for foam, wherein the polyol compound contains a polyester polyol of polyoxyethylene glycol and an aromatic dicarboxylic acid and a Mannich polyether polyol, and the average molecular weight of the polyoxyethylene glycol is 100 to 300 The aromatic dicarboxylic acid is composed of orthophthalic acid and terephthalic acid, and the molar ratio of the orthophthalic acid (O) and the terephthalic acid (P) is O / P = 20/80 to 60/40, 100 weight of all polyol compounds And when 40 to 80 parts by weight of the polyester polyol, characterized in that it contains the Mannich polyether polyol 20 to 40 parts by weight.

  When the above polyol composition is used as a raw material, a rigid polyurethane foam having excellent dimensional stability and excellent flame retardancy can be formed even when water is used as a foaming agent. Moreover, the viscosity of the polyol composition itself is low, and the workability when forming a rigid polyurethane foam is excellent. Furthermore, since resin fine particles are not contained in the polyol composition, it is possible to prevent deterioration of storage stability accompanying sedimentation and separation of the resin fine particles in the polyol composition.

  In the polyol composition for rigid polyurethane foam, it is preferable that the plastic composition further contains a water-soluble organic solvent having no active hydrogen group in an amount of 5 to 20 parts by weight based on 100 parts by weight of the polyol compound. In this case, since the viscosity of the polyol composition is further lowered, the workability when forming the rigid polyurethane foam is particularly excellent. When the rigid polyurethane foam contains a plasticizer, the flame retardancy of the foam generally seems to deteriorate, but the combination of a specific polyol compound and a water-soluble organic solvent having no active hydrogen group in the present invention is used. In the rigid polyurethane foam obtained by use, the deterioration of flame retardancy can be prevented.

  Another aspect of the present invention is a method for producing a rigid polyurethane foam, which comprises mixing and reacting a polyol composition containing a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst, and a polyisocyanate component to form a rigid polyurethane foam. The polyol compound contains a polyester polyol of polyoxyethylene glycol and an aromatic dicarboxylic acid and a Mannich polyether polyol, the polyoxyethylene glycol has an average molecular weight of 100 to 300, and the aromatic dicarboxylic acid is orthophthalic It comprises an acid and terephthalic acid, the molar ratio of the orthophthalic acid (O) and the terephthalic acid (P) is O / P = 20/80 to 60/40, and the total amount of the polyol compound is 100 parts by weight. When the polyester polyol is 40 80 parts by weight, characterized by containing the Mannich polyether polyol 20 to 40 parts by weight.

  By the method for producing a rigid polyurethane foam, a rigid polyurethane foam having excellent dimensional stability and excellent flame retardancy can be formed. Moreover, since the viscosity of the polyol composition itself as a raw material is low, it is excellent in workability when forming a rigid polyurethane foam.

  In the manufacturing method of the said rigid polyurethane foam, it is preferable to contain 5-20 weight part of water-soluble organic solvents which do not have an active hydrogen group as a plasticizer with respect to 100 weight part of said polyol compounds. In this case, since the viscosity of the polyol composition is further lowered, the workability when forming the rigid polyurethane foam is particularly excellent.

  The polyol composition of the present invention contains a polyol compound, water as a foaming agent, a foam stabilizer, and a catalyst, and contains a polyester polyol of polyoxyethylene glycol and an aromatic dicarboxylic acid and a Mannich polyether polyol as the polyol compound. To do. In consideration of workability when used in a continuous production method, a spray method, etc., the viscosity of the polyol composition of the present invention is preferably 500 mPa · s (20 ° C.) or less, and is 200 to 300 mPa · s. Is more preferable.

  The polyester polyol is a polyester polyol of polyoxyethylene glycol and aromatic dicarboxylic acid, the aromatic dicarboxylic acid is composed of orthophthalic acid and terephthalic acid, and the molar ratio of orthophthalic acid (O) and terephthalic acid (P). However, O / P = 20 / 80-60 / 40 and polyoxyethylene glycol has an average molecular weight of 100-300.

  When the molar ratio of orthophthalic acid increases beyond the above range, the flame retardancy of the rigid polyurethane foam tends to deteriorate, and when the molar ratio of terephthalic acid increases beyond the above range, the storage stability of the polyol composition is increased. There is a tendency to get worse. Considering the viscosity of the polyol composition and the flame retardancy of the rigid polyurethane foam, the molar ratio of orthophthalic acid (O) to terephthalic acid (P) is O / P = 30/70 to 50/50. Preferably, O / P = 35/65 to 45/55 is more preferable.

  Moreover, when the average molecular weight of the polyoxyethylene glycol used when manufacturing the polyester polyol exceeds 300, the viscosity of the polyol composition increases as the viscosity of the polyester polyol increases. In consideration of the viscosity of the polyol composition, it is preferable to use at least one of diethylene glycol (DEG) and triethylene glycol (TEG) as the polyoxyethylene glycol, and diethylene glycol (DEG) and / or triethylene glycol (TEG). It is more preferable to use only

  The polyester polyol used in the present invention preferably has a hydroxyl value (OHV) of 150 to 200 mgKOH / g.

  Mannich polyether polyol is obtained by ring-opening addition polymerization of at least one of ethylene oxide and propylene oxide to an active hydrogen compound obtained by Mannich reaction of phenol and / or its alkyl-substituted derivative, formaldehyde and alkanolamine. Is an active hydrogen compound obtained by The Mannich polyether polyol used in the present invention preferably has a hydroxyl value (OHV) of 200 to 300 mgKOH / g, and preferably 2 to 4 functional groups.

  The polyol composition according to the present invention contains 40 to 80 parts by weight of polyester polyol and 20 to 40 parts by weight of Mannich polyether polyol when the total amount of the polyol compound is 100 parts by weight. Furthermore, it is preferable to contain 55 to 70 parts by weight of polyester polyol and 25 to 35 parts by weight of Mannich polyether polyol.

  The polyol composition according to the present invention comprises, as a polyol compound, at least one hydroxyl value of 200 selected from other polyols other than polyester polyol and Mannich polyether polyol, specifically, aliphatic amine polyol and aromatic amine polyol. It may contain ˜500 mg KOH / g polyol compound. Examples of the aliphatic amine polyol include alkylene diamine polyols and alkanol amine polyols. These polyol compounds are polyfunctional polyol compounds having a terminal hydroxyl group obtained by ring-opening addition of at least one of ethylene oxide and propylene oxide using alkylene diamine or alkanol amine as an initiator. As the alkylene diamine, known compounds can be used without limitation. Specifically, use of alkylene diamine having 2 to 8 carbon atoms such as ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, and neopentyl diamine is preferable. Among these, the use of alkylenediamine having a small number of carbon atoms is more preferable, and the use of a polyol compound having ethylenediamine or propylenediamine as an initiator is particularly preferable. In the alkylene diamine-based polyol, the alkylene diamine as the initiator may be used alone or in combination of two or more. Examples of the alkanolamine include monoethanolamine, diethanolamine, and triethanolamine. The number of functional groups of the polyol compound using alkylene diamine as the initiator is 4, and the number of functional groups of the polyol compound using alkanolamine as the initiator is 3.

  The aromatic amine-based polyol is a polyfunctional polyether polyol compound having a terminal hydroxyl group obtained by ring-opening addition of at least one of ethylene oxide and propylene oxide using an aromatic diamine as an initiator. As the initiator, known aromatic diamines can be used without limitation. Specific examples include 2,4-toluenediamine, 2,6-toluenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, naphthalenediamine and the like. Of these, the use of toluenediamine (2,4-toluenediamine, 2,6-toluenediamine, or a mixture thereof) is particularly preferable because the properties such as heat insulation and strength of the rigid polyurethane foam obtained are excellent.

  You may use a crosslinking agent as a component which comprises the polyol composition for rigid polyurethane foams of this invention. As the crosslinking agent, low molecular weight polyhydric alcohols used in the technical field of polyurethane can be used. Specifically, trimethylolpropane, glycerin, pentaerythritol, triethanolamine and the like are exemplified.

  In the polyol composition according to the present invention, the plasticizer preferably contains 5 to 20 parts by weight of a water-soluble organic solvent having no active hydrogen group with respect to 100 parts by weight of the polyol compound, and contains 8 to 12 parts by weight. More preferred is If the content of the water-soluble organic solvent having no active hydrogen group is less than 5 parts by weight, the viscosity of the polyol composition may increase. If the content exceeds 20 parts by weight, the flame retardancy of the rigid polyurethane foam deteriorates. In addition, physical properties such as foam strength may deteriorate.

  The water-soluble organic solvent having no active hydrogen group is preferably at least one selected from the group consisting of γ-butyrolactone, ε-caprolactone, N-methylpyrrolidone and ethylene glycol derivatives having a molecular weight of 100 to 400. .

  The ethylene glycol derivative is, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group at both ends of polyethylene glycol having an average molecular weight of 400 or less such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, Those having a substituent that is not an active hydrogen group, such as an acyl group such as an acetyl group, a propionyl group, and a butyryl group. The substituents bonded to both ends of the ethylene glycol derivative may be the same as or different from each other. Specific examples of the ethylene glycol derivative include ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, ethylene glycol methyl ethyl ether, ethylene glycol methyl propyl ether, ethylene glycol methyl butyl ether, ethylene glycol ethyl propyl ether, ethylene Glycol ethyl butyl ether, ethylene glycol propyl butyl ether, ethylene glycol diacetate, ethylene glycol dipropionate, ethylene glycol dibutyrate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol propyl ether acetate, ethylene glycol butyl ether Acetate, ethylene glycol methyl ether propionate, ethylene glycol ethyl ether propionate, ethylene glycol propyl ether propionate, ethylene glycol butyl ether propionate, ethylene glycol methyl ether butyrate, ethylene glycol ethyl ether butyrate, ethylene glycol propyl Ethylene glycol derivatives such as ether butyrate and ethylene glycol butyl ether butyrate; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl propyl ether, diethylene Recall methyl butyl ether, diethylene glycol ethyl propyl ether, diethylene glycol ethyl butyl ether, diethylene glycol propyl butyl ether, diethylene glycol diacetate, diethylene glycol dipropionate, diethylene glycol dibutyrate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol propyl ether acetate, diethylene glycol butyl ether acetate, diethylene glycol Methyl ether propionate, diethylene glycol ethyl ether propionate, diethylene glycol propyl ether propionate, diethylene glycol butyl ether propionate, diethylene glycol Diethylene glycol derivatives such as recall methyl ether butyrate, diethylene glycol ethyl ether butyrate, diethylene glycol propyl ether butyrate, diethylene glycol butyl ether butyrate; triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tridiethylene glycol dipropyl ether, triethylene glycol dibutyl ether, Triethylene glycol methyl ethyl ether, triethylene glycol methyl propyl ether, triethylene glycol methyl butyl ether, triethylene glycol ethyl propyl ether, triethylene glycol ethyl butyl ether, triethylene glycol propyl butyl ether, triethylene glycol dia Tate, triethylene glycol dipropionate, triethylene glycol dibutyrate, triethylene glycol methyl ether acetate, triethylene glycol ethyl ether acetate, triethylene glycol propyl ether acetate, triethylene glycol butyl ether acetate, triethylene glycol methyl ether propionate , Triethylene glycol ethyl ether propionate, triethylene glycol propyl ether propionate, triethylene glycol butyl ether propionate, triethylene glycol methyl ether butyrate, triethylene glycol ethyl ether butyrate, triethylene glycol propyl ether butyrate , Triethylene glycol butyl ether Triethylene glycol derivatives such as terbutylate; tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetradiethylene glycol dipropyl ether, tetraethylene glycol dibutyl ether, tetraethylene glycol methyl ethyl ether, tetraethylene glycol methyl propyl ether, tetraethylene glycol methyl butyl ether , Tetraethylene glycol ethyl propyl ether, tetraethylene glycol ethyl butyl ether, tetraethylene glycol propyl butyl ether, tetraethylene glycol diacetate, tetraethylene glycol dipropionate, tetraethylene glycol dibutyrate, tetraethylene glycol methyl ether acetate , Tetraethylene glycol ethyl ether acetate, tetraethylene glycol propyl ether acetate, tetraethylene glycol butyl ether acetate, tetraethylene glycol methyl ether propionate, tetraethylene glycol ethyl ether propionate, tetraethylene glycol propyl ether propionate, Examples include tetraethylene glycol derivatives such as tetraethylene glycol butyl ether propionate, tetraethylene glycol methyl ether butyrate, tetraethylene glycol ethyl ether butyrate, tetraethylene glycol propyl ether butyrate, and tetraethylene glycol butyl ether butyrate. Among the ethylene glycol derivatives, the diethylene glycol derivative is preferable in consideration of the effect of reducing the viscosity and the flame retarding effect of the foam, and diethylene glycol ethyl ether acetate is particularly preferable.

In the present invention, as the foam stabilizer, a foam stabilizer known in the field of rigid polyurethane foam can be used. (A) Cyclic dialkylpolysiloxane containing 4 to 5 Si—O bonds, (b) (R ¹ ) Si (OR ² ) ₃ , Si (OR ² ) ₄ and at least one selected from the group consisting of Si (OR ² ) ₃ , (R ¹ ) ₂ Si (OR ² ) ₂ and (R ¹ ) ₃ Si (OR ² ) Silicone polymer which is a hydrolysis-condensation product (R ¹ is an alkyl group having 1 or 2 carbon atoms or phenyl group, R ² is an alkyl group having 1 or 2 carbon atoms, R ¹ and R ² may be the same, It is preferable to use those containing two types of the above as foam stabilizers. When (a) and (b) are used in combination as a foam stabilizer, shrinkage is effectively suppressed even if the resulting rigid polyurethane foam has a low density, and its dimensional stability is excellent. In addition, it is excellent in adhesion to the object to be applied by a face material or a spray method. Here, as the foam stabilizer, when the above (a) and (b) are used in combination, the reason why the shrinkage of the foam is prevented is not clear, but the use of a polyol having a specific composition and the cyclic dialkylpolysiloxane (a) And the use of silicone polymer (b), extremely fine pores are formed in the foamed polyurethane bubbles, and the shrinkage caused by the pressure drop due to the diffusion of carbon dioxide in the bubbles is prevented without impairing the heat insulation. Presumed to be. The mixing ratio of (a) cyclic dialkylpolysiloxane and (b) silicone polymer is preferably 1/9 to 8/2, more preferably 1/4 to 4/1 in weight ratio. More preferably, it is 1/2 to 2/1.

The (b) silicone polymer is at least selected from the group consisting of (R ¹ ) Si (OR ² ) ₃ , (R ¹ ) ₂ Si (OR ² ) ₂ , (R ¹ ) ₃ Si (OR ² ). One type and Si (OR ² ) ₄ can be produced by cohydrolytic condensation using water and a catalyst to form a polysiloxane bond. R ¹ and R ² may be the same or different and are preferably a methyl group or an ethyl group. Further, (a) cyclic dialkylpolysiloxane can also be produced by a known method, and is preferably cyclic dimethylsiloxane.

  In the present invention, a copolymer silicone compound may be included as a foam stabilizer. The copolymerized silicone compound is a compound used as a foam stabilizer in the technical field of polyurethane foam. In the present invention, among these known foam stabilizers, the Si content is 10 to 40% by weight, that is, the content of the copolymerized polyoxyalkylene glycol is small, and generally the activity is low. It is preferable to use a foam stabilizer. Specifically, it is possible to use foam stabilizers such as S-824-02 (Si = 25 wt%; manufactured by Toray Dow Corning), SZ-1704 (Si = 25 wt%; manufactured by Toray Dow Corning). it can. Two or more kinds of foam stabilizers (copolymerized silicone compounds) having polyoxyalkylene glycol may be used, or (a) a cyclic dialkylpolysiloxane may be contained.

  As the silicone compounds (a) and (b), commercially available products can be used. Specifically, compositions containing (a) and (b) are suitable for use. As described above, (a) cyclic dialkylpolysiloxane and (b) silicone polymer are preferably mixed in advance and used as a foam stabilizer composition in the production of a polyol composition.

  Examples of the catalyst include N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine (Kaorizer No. 1), N, N, N ′, N ′, N-alkylpolyalkylenepolyamines such as N ″ -pentamethyldiethylenetriamine (Kaorizer No. 3), diazabicycloundecene (DBU), N, N-dimethylcyclohexylamine (Polycat-8), triethylenediamine, N— It is preferable to use tertiary amines such as methylmorpholine and NIAX-A1.

  It is also preferable to use a catalyst that forms an isocyanurate bond that contributes to improving the combustion resistance in the structure of the polyurethane molecule. For example, as a trimerization catalyst such as potassium acetate or potassium octylate, or a quaternary ammonium salt catalyst, Examples thereof include catalysts disclosed in Japanese Patent No. 104734, commercially available products Dabco-TMR, Dabco-TMR-2 (Air Products), and the like. Some of the above-mentioned tertiary amine catalysts also promote the isocyanurate ring formation reaction. A catalyst that promotes the formation of isocyanurate bonds and a catalyst that promotes the formation of urethane bonds may be used in combination.

  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 used. As liquid MDI, Crude MDI (c-MDI) (Sumijoule 44V-10, Sumijoule 44V-20, etc. (manufactured by Sumika Bayer Urethane Co., Ltd.), Millionate MR-200 (Nippon Polyurethane Industry)), uretonimine-containing MDI (Millionate) MTL (manufactured by Nippon Polyurethane Industry), prepolymer-modified crude MDI and the like are 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 polyol composition for rigid polyurethane foam of the present invention, in addition to the above components, flame retardants, colorants, antioxidants and the like known to those skilled in the art may be blended.

  Examples of suitable flame retardants include metal compounds such as halogen-containing compounds, organophosphates, and aluminum hydroxide. Among these, organophosphates can be preferably used.

  As the organic phosphates, halogenated alkyl esters of phosphoric acid, alkyl phosphate esters, aryl phosphate esters, phosphonate esters and the like can be used. Specifically, tris (β-chloroethyl) phosphate (CLP, large Eight Chemical), Tris (β-chloropropyl) phosphate (TMCPP, manufactured by Daihachi Chemical), Tributoxyethyl phosphate (TBXP, manufactured by Daihachi Chemical), Tributyl phosphate, Triethyl phosphate, Cresyl phenyl phosphate, Dimethylmethylphosphonate, etc. And one or more of these can be used. The addition amount of the organic phosphates is 40 parts by weight or less, preferably 5 to 40 parts by weight, based on 100 parts by weight of the total polyol compound. Exceeding this range may cause problems such as insufficient plasticization and flame retardant effects and reduced foam mechanical properties.

  In the above-mentioned method for producing a rigid polyurethane foam, the isocyanate group / active hydrogen group equivalent ratio (NCO index) in the mixing of the polyol composition and the polyisocyanate component is 1.0 to 4.0, more preferably 1.2. It is -3.5, More preferably, it is 1.3-2.0. It is also a more preferable aspect that the NCO index is 1.3 or more and the catalyst contains a trimerization catalyst.

  With such a configuration, it is possible to produce a rigid polyurethane foam in which many isocyanurate bonds are formed in the resin constituting the rigid polyurethane foam and the combustion resistance is further improved.

The density of the rigid polyurethane foams produced by the present invention is preferably from 20 and 100 kg / ^{m 3,} more preferably from 20 to 50 kg / ^{m 3.}

(Polyol composition)
A polyol composition was prepared with the composition described in the upper part of Table 1. The contents and characteristics of the raw materials used are as follows.

a-1) Polyol A
According to a conventional method, an aromatic dicarboxylic acid having a molar ratio of orthophthalic acid (O) to terephthalic acid (P) of O / P = 40/60, a mixture of diethylene glycol (DEG) and triethylene glycol (TEG) , Polyester polyol produced by Hitachi Chemical Co., Ltd .; hydroxyl value = 250 mgKOH / g
a-2) Polyol B
Mannich polyether polyol (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) obtained using a Mannich initiator; hydroxyl value 290 mgKOH / g
a-3) Polyol C
Polyether polyol (manufactured by Asahi Glass Co., Ltd.) obtained by adding (glycerin) / (monoethanolamine) = 70/30 (molar ratio) as an initiator and adding propylene oxide thereto: hydroxyl value 185 mgKOH / g
a-4) Polyol D
Polyether polyol (manufactured by Mitsui Chemicals) obtained by adding propylene oxide to triethanolamine as an initiator: hydroxyl value 350 mgKOH / g
a-5) Polyol E
According to a conventional method, an aromatic dicarboxylic acid having a molar ratio of orthophthalic acid (O) to terephthalic acid (P) of O / P = 50/50 and polyfunctional ethylene oxide (PEG) having an average molecular weight of 400. And polyester polyol (manufactured by Hitachi Chemical Co., Ltd.); hydroxyl value = 150 mgKOH / g
a-6) Polyol F
Polyol in which resin fine particles are dispersed in a Mannich polyether polyol compound (manufactured by Asahi Glass Co., Ltd.); hydroxyl value = 300 mgKOH / g

b) Plasticizer Diethylene glycol ethyl ether acetate c) Flame retardant Phosphorus flame retardant (“TMCPP”, manufactured by Daihachi Chemical Industry Co., Ltd.)
d) Catalyst (i): Potassium octylate ("Perlon 9540", manufactured by Perlon)
(Ii): ("Polycat 41", manufactured by Air Products)
(Iii): 1-isobutyl-2-methylimidazole (“Kaorizer No. 120”, manufactured by Kao Corporation)
(Iv): ("Toyocat TT", manufactured by Tosoh Corporation)
e) foam stabilizer (i): 1: 1 (weight ratio) mixture of (a) cyclic dialkylpolysiloxane and (b) silicone polymer (ii): a copolymer of polydimethylsiloxane and polyoxyalkylene glycol Copolymer silicone compound f) Polyisocyanate component: (“V-460”, manufactured by Sumika Bayer Urethane Co., Ltd.), NCO% = 30.0%
g) Foaming agent: water

(Examples 1-5 and Comparative Examples 1-2)
The polyol compositions according to Examples 1 to 5 and Comparative Examples 1 and 2 were prepared with the formulation described in the upper part of Table 1. The polyol composition was prepared by first stirring and mixing the components excluding water and the foam stabilizer, and then adding and mixing the foam stabilizer. In the production of rigid polyurethane foam, the polyol composition and the polyisocyanate component are blended and adjusted to have the NCO index (NCO / OH equivalent ratio) shown in Table 1, and mixed and reacted with a laboratory stirrer. To produce a rigid polyurethane foam. The evaluation described below was performed, and the results are shown in the lower part of Table 1.

(Evaluation)
1) Viscosity of polyol composition (mPas / 20 ° C.)
The viscosity of the polyol composition was measured at a temperature of 20 ° C. using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.).

2) Two-component mixing (polyol component / isocyanate component stirring)
The case where the difference in viscosity between the polyol component and the isocyanate component was less than 200 (mPs / 20 ° C.) was evaluated as “good”, and the case where it was 200 (mPs / 20 ° C.) or more was evaluated as “bad”. In addition, when the viscosity difference between these two components is 200 (mPs / 20 ° C.) or more (in the case of “poor”), the agitation becomes poor and the quality is deteriorated, and the discharge pressure balance of the two components easily breaks down. It is easy to cause a problem called.

3) Spray pattern properties (spreading / stability)
The case where the rigid polyurethane foam after spraying by the spray method is a perfect circle having a diameter of approximately 15 to 25 cm is defined as a “proper / stable” spray pattern, and the one having a diameter of 15 cm or less is defined as a “narrow” spray pattern. In addition, a case where the rigid polyurethane foam after spraying by the spray method is not a perfect circle but a crescent shape or a distorted ellipse is defined as an “unstable” spray pattern. In the spray method, it is preferable to obtain a spray pattern in an “appropriate / stable” state.

4) Foam density (kg / m ³ )
A 10 cm × 10 cm × 10 cm sample was cut out from the produced rigid polyurethane foam and measured for weight.

5) Storage stability of the polyol composition A sample having the same shape as the sample used for measuring the foam density by creating a free-foam foam by leaving the polyol composition in a sealed state at a temperature of 40 ° C for 1 month. Was left for 48 hours under high temperature and high humidity conditions (temperature 70 ° C., relative humidity 95%), and the dimensional change rate (%) of the core in the vertical direction of foaming was measured. When a polyol composition having poor storage stability is used, the dimensional change rate increases. Evaluations were made with a dimensional change rate of −5% to + 10% as “◯” and a value outside this range as “X”.

6) Dimensional stability A foam sample obtained by spraying a urethane plate with a thickness of 20 to 30 mm on a concrete plate with a length and width of 300 mm is cut out for 3 days in a 40 ° C.-95% humidity atmosphere. An exposure test was performed, and the rate of change in thickness was measured to obtain a dimensional change rate. The evaluation results were evaluated as ◯ when the rate of dimensional change was within ± 5%, and x when out of this range.

7) Flame retardancy by corn calorie test (corn calorie flame retardant test)
For foamed rigid polyurethane foam, a sample of (99 ± 1) mm × (99 ± 1) mm is cut out and the maximum heat generation rate when heated for 5 minutes at a radiant heat intensity of 50 kW / m ² in accordance with ISO-5660 (Heat generation rate) and total calorific value were measured. This measuring method is a test method stipulated by the public organization stipulated in Article 108-2 of the Building Standard Law Enforcement Ordinance as corresponding to the standard by the corn calorimeter method. In this test, under the above conditions, the maximum heat generation rate does not exceed 200 kW / m ² continuously for 10 seconds or more, and there is no harmful deformation for fire prevention, and the total calorific value for 5 minutes is less than 8 MJ / m ² . In some cases, it was evaluated as x (failed) when either (acceptable) or any of the maximum heat generation rate and the total calorific value exceeded the above range.

  From the result of Table 1, compared with the polyol composition of Comparative Example 1, the polyol compositions of Examples 1 to 5 have low viscosity, excellent workability and storage stability, and polyol compositions of Examples 1 to 5. It can be seen that the rigid polyurethane foam obtained by using is excellent in flame retardancy and dimensional stability. On the other hand, it can be seen that the polyol composition of Comparative Example 2 has a high viscosity and the workability deteriorates.

Claims (4)

A polyol composition for a rigid polyurethane foam comprising a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst, mixed with a polyisocyanate component and reacted to form a rigid polyurethane foam,
The polyol compound contains polyester polyol and Mannich polyether polyol of polyoxyethylene glycol and aromatic dicarboxylic acid,
The polyoxyethylene glycol has an average molecular weight of 100 to 300;
The aromatic dicarboxylic acid comprises orthophthalic acid and terephthalic acid, and the molar ratio of the orthophthalic acid (O) and the terephthalic acid (P) is O / P = 20/80 to 60/40,
A polyol composition for rigid polyurethane foam, comprising 40 to 80 parts by weight of the polyester polyol and 20 to 40 parts by weight of the Mannich polyether polyol when the total amount of the polyol compound is 100 parts by weight.   The polyol composition for rigid polyurethane foam according to claim 1, further comprising 5 to 20 parts by weight of a water-soluble organic solvent having no active hydrogen group as a plasticizer with respect to 100 parts by weight of the polyol compound. A method for producing a rigid polyurethane foam comprising mixing a polyol composition, a polyol composition containing a foaming agent, water, a foam stabilizer and a catalyst, and a polyisocyanate component to react to form a rigid polyurethane foam,
The polyol compound contains polyester polyol and Mannich polyether polyol of polyoxyethylene glycol and aromatic dicarboxylic acid,
The polyoxyethylene glycol has an average molecular weight of 100 to 300;
The aromatic dicarboxylic acid comprises orthophthalic acid and terephthalic acid, and the molar ratio of the orthophthalic acid (O) and the terephthalic acid (P) is O / P = 20/80 to 60/40,
A method for producing a rigid polyurethane foam comprising 40 to 80 parts by weight of the polyester polyol and 20 to 40 parts by weight of the Mannich polyether polyol when the total amount of the polyol compound is 100 parts by weight.   Furthermore, the manufacturing method of the rigid polyurethane foam of Claim 3 which contains 5-20 weight part of water-soluble organic solvents which do not have an active hydrogen group as a plasticizer with respect to 100 weight part of said polyol compounds.