JP2006016562A - Polyol composition for rigid polyurethane foam and method for producing rigid polyurethane foam - Google Patents

Abstract

【選択図】 なし[PROBLEMS] To provide a polyol composition for rigid polyurethane foam having improved flame retardancy and adhesive strength to a face material without lowering heat insulation by using pentane as a foaming agent component, and a method for producing the rigid polyurethane foam. provide.
SOLUTION: The blowing agent contains pentanes, and when the total amount of the polyol compound is 100 parts by weight, the aromatic amine polyether polyol is 5 to 40 parts by weight and the aromatic polyester polyol is 10 to 50 parts by weight. And a polyol composition for rigid polyurethane foam containing 35 to 70 parts by weight of a polyether polyol represented by a chemical formula (Chemical Formula 4) having 2 to 4 average functional groups.
[Formula 4]

[Selection figure] None

Description

  The present invention relates to a polyol composition for a rigid polyurethane foam that uses pentanes as a foaming agent component and is excellent in flame retardancy, and a method for producing a water-foamed rigid polyurethane foam.

  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 and reacting a polyol composition containing a polyol compound and a foaming agent as essential components with a polyisocyanate component, followed by foaming and curing. In the past, chlorofluorocarbon compounds such as CFC-11 were used as foaming agents, but CFC compounds were prohibited because they 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 it is expensive.

  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 (for example, Patent Documents 1 and 2).

Patent Document 1 discloses that a foamed stock solution composition obtained by mixing a polyol composition and a polyisocyanate compound has good fluidity, good adhesion to a face material, and an aromatic group concentration in a polyurethane foam constituent resin is 32. A pentane foamed rigid polyurethane foam with reduced thermal conductivity, characterized by being greater than or equal to weight percent, is disclosed. Patent Document 2 discloses a polyether polyol having a trimethylol alkane as an initiator, in which both the polyol composition and the polyisocyanate compound are stable in storage, the flowability of the foamed stock solution composition is small, and the curing shrinkage is small. A rigid polyurethane foam with a pentane foam is disclosed.
Japanese Patent Application Laid-Open No. 8-208779 JP-A-11-343326

  However, in the rigid polyurethane foams disclosed in Patent Documents 1 and 2, the polyol compound used was substantially a polyether polyol, and was obtained because the pentane as a blowing agent was highly flammable. The flame retardancy of the foam is not sufficient compared to the case where an HFC compound is used as a foaming agent.

  As a technique for increasing the flame retardancy of the polyurethane resin itself constituting the rigid polyurethane foam, a method of using a large amount of aromatic polyester polyol for the rigid polyurethane foam or a method of increasing the concentration of isocyanurate groups can be considered.

  However, pentanes have poor compatibility with aromatic polyester polyols, and according to the method in which the amount of aromatic polyester polyol added is increased, phase separation of the blowing agent occurs in the polyol composition, bubbles are large, and There is a problem that it becomes a rigid polyurethane foam with poor uniformity.

  In contrast, an NCO / active hydrogen group equivalent ratio (NCO index) at the time of reaction is 2.0 using a polyether polyol compound having good compatibility with the blowing agent as disclosed in Patent Documents 1 and 2. When trying to make a foam with a high isocyanurate group concentration by setting it as high as ~ 3.5, the amount of pentane added must be increased to form a foam with a predetermined density, and separation of the blowing agent still occurs. However, the curability is lowered, causing problems such as a decrease in adhesive strength with the face material and a decrease in foam strength.

  An object of the present invention is to provide a polyol composition for a rigid polyurethane foam having improved flame retardancy and adhesion strength to a face material without reducing heat insulation by using pentanes as a foaming agent component, and a rigid polyurethane foam. It is to provide a manufacturing method.

The polyol composition for rigid polyurethane foam of the present invention is a polyol composition comprising a polyol compound, a foaming agent, a catalyst and a foam stabilizer, and mixed with a polyisocyanate component to form a rigid polyurethane foam,
The foaming agent contains pentanes,
When the total amount of the polyol compound is 100 parts by weight, 5 to 40 parts by weight of an aromatic amine polyether polyol having a hydroxyl value of 200 to 500 mgKOH / g and 10 to 50 aromatic polyester polyol having a hydroxyl value of 150 to 400 mgKOH / g. It contains 35 to 70 parts by weight of a polyether polyol represented by a chemical formula (Chemical Formula 3) having a hydroxyl value of 250 to 550 mgKOH / g and an average functional group number of 2 to 4.

（Ｒは炭素数１〜４のアルキル基、Ｘはオキシエチレン基、オキシプロピレン基の少なくとも１種を含む有機基、Ｙはエチレン基又はプロピレン基、ｍは０又は１、ｑは１又は２、ｍ＋ｑ＝２、ｎの平均値は１〜４である。）
上記構成のポリオール組成物を使用して得られた硬質ポリウレタンフォームは、ペンタン類を発泡剤成分として使用しつつ断熱性が良好であり、しかも難燃性と面材との接着強度が改善された硬質ポリウレタンフォームである。係る効果が得られる理由は明らかではないが、化学式（化３）にて示されるポリオール化合物の使用により、芳香族ポリエステルポリオールをポリオール化合物中１０重量％以上配合してもペンタン類とポリオール組成物との相溶性が改善され、得られるフォームの難燃性も向上することによるものと推測される。

(R is an alkyl group having 1 to 4 carbon atoms, X is an organic group containing at least one of oxyethylene group and oxypropylene group, Y is an ethylene group or propylene group, m is 0 or 1, q is 1 or 2, m + q = 2, and the average value of n is 1 to 4.)
The rigid polyurethane foam obtained by using the polyol composition having the above structure has good heat insulation while using pentanes as a foaming agent component, and has improved flame retardancy and adhesive strength with a face material. Rigid polyurethane foam. The reason why such an effect is obtained is not clear, but by using the polyol compound represented by the chemical formula (Chemical Formula 3), even if the aromatic polyester polyol is blended in an amount of 10% by weight or more in the polyol compound, the pentane and the polyol composition It is presumed that this is due to the improvement in the compatibility and the flame retardancy of the resulting foam.

  The compounding amount of the aromatic amine polyol is more preferably 10 to 30 parts by weight, and the compounding amount of the aromatic polyester polyol is more preferably 20 to 30 parts by weight. When the blending amount of the aromatic polyester polyol is small, the flame retardancy of the foam is lowered, and when it is too much, the compatibility between the foaming agent and the polyol composition is lowered. Further, the blending amount of the polyol compound represented by the chemical formula (Chemical Formula 3) is more preferably 40 to 60 parts by weight. When the blending amount of the polyol compound is small, the compatibility between the polyol composition and the foaming agent is lowered, and when it is too much, the flame retardancy of the foam is lowered.

  In the above polyol composition, the catalyst preferably contains a trimerization catalyst.

  By using the trimerization catalyst, an isocyanurate bond is formed in the rigid polyurethane foam produced using the polyol composition, and the flame retardancy is further improved.

Another aspect of the present invention is a rigid polyurethane foam in which a polyol composition containing a polyol compound, a foaming agent, a catalyst and a foam stabilizer and a polyisocyanate component are mixed to form a foamed stock solution composition, and the foamed stock solution composition is foamed and cured. A manufacturing method of
The foaming agent contains pentanes,
When the total amount of the polyol compound is 100 parts by weight, 5 to 40 parts by weight of an aromatic amine polyether polyol having a hydroxyl value of 200 to 500 mgKOH / g and 10 to 50 aromatic polyester polyol having a hydroxyl value of 150 to 400 mgKOH / g. And 35 to 70 parts by weight of a polyether polyol represented by the above chemical formula (Chemical Formula 3) having a hydroxyl value of 250 to 550 mgKOH / g.

  With the above-described configuration, it is possible to produce a rigid polyurethane foam that uses pentanes as a foaming agent component, has good heat insulation properties, and has improved flame retardance and adhesive strength between face materials. In terms of flame retardancy, it was possible to produce a foam equivalent in terms of ignitability of rigid polyurethane foam using HCFC-141b as a foaming agent.

  In the above-described 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 1.5 to 3.5, and the catalyst is three. It is preferable to contain a quantification 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 flame retardancy is further improved. The density of the rigid polyurethane foams produced by the present invention ^is preferably ^{25kg / m 3 ~130kg / m 3} .

  The polyol compound represented by the above chemical formula (Chemical Formula 3) used in the present invention is an active hydrogen compound obtained by Mannich reaction of phenol, formaldehyde and alkanolamine, or at least one of ethylene oxide and propylene oxide is opened to this compound. This is an active hydrogen compound obtained by cycloaddition polymerization. As a commercial item of such a polyol compound, for example, DK-3776 (Daiichi Kogyo Seiyaku Co., Ltd.) is available. As for the compounding quantity of the polyol compound shown by Chemical formula (Formula 3), it is more preferable that it is 40-60 weight part.

  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 preferred in that the obtained rigid polyurethane foam has excellent properties such as heat insulation and strength.

  Examples of the aromatic polyester polyol having a hydroxyl value of 150 to 400 mgKOH / g which is a polyol compound constituting the polyol composition of the present invention include an aromatic polycarboxylic acid and a polyhydric alcohol, particularly a polyol compound which is an ester of glycol. Is done.

  As the ester of aromatic polycarboxylic acid and polyhydric alcohol, known aromatic polyester polyol compounds for resin foam can be used without limitation, phthalic acids such as terephthalic acid, phthalic acid, isophthalic acid and trimellitic acid Specific examples thereof include ester polyols having a hydroxyl group terminal with polyhydric alcohols such as ethylene glycol, diethylene glycol, 1,4-butanediol, dipropylene glycol, and polyoxyalkylene glycol. The average functional group number of the aromatic polyester polyol compound is preferably 2 to 4, more preferably 2 to 3, and still more preferably 2 to 2.5. The hydroxyl value of the aromatic polyester polyol is more preferably 200 to 300 mgKOH / g.

  As the polyol compound constituting the polyol composition for rigid polyurethane foams of the present invention, other polyether polyol compounds may be used in addition to the above-described polyol compound as long as the object of the present invention is not impaired. Examples of such other polyether polyol compounds include known polyether polyols such as aliphatic amine-based polyether polyols, aliphatic polyether polyols, and aromatic polyether polyols. Among these, the use of an aromatic polyether polyol is preferable from the viewpoint of improving flame retardancy.

  Examples of the aliphatic amine-based polyether polyol include alkylene diamine-based polyols and alkanolamine-based 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 and diethanolamine.

  The aliphatic polyether polyol is obtained by ring-opening addition polymerization of at least one of propylene oxide and ethylene oxide to a polyfunctional active hydrogen compound, that is, an aliphatic or alicyclic polyfunctional active hydrogen compound as a polyol initiator. Is a multifunctional oligomer.

  Examples of the polyol initiator include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexylene glycol, cyclohexanedimethanol and other glycols, Examples include triols such as methylolpropane and glycerin, tetrafunctional alcohols such as pentaerythritol, polyhydric alcohols such as sorbitol and sucrose, and water.

  The aromatic polyether polyol is produced in the same manner as the above polyether polyol, using an aromatic compound such as hydroquinone, bisphenol A, and xylylene glycol as an initiator.

  The pentane used as the foaming agent is appropriately selected from one or more of n-pentane, isopentane, and cyclopentane. The foaming agent is more preferably a combination of water and pentane.

  You may use a crosslinking agent as an active hydrogen group containing 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 production of the rigid polyurethane foam of the present invention, foam stabilizers, catalysts, plasticizers or flame retardants, colorants, antioxidants and the like well known to those skilled in the art can be used.

  Examples of the catalyst include triethylenediamine, N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine (Kaorizer No. 1), diaza It is preferable to use tertiary amines such as bicycloundecene (DBU) and N, N-dimethylcyclohexylamine (Polycat-8).

  In the present invention, it is also preferable to use a trimerization catalyst that forms an isocyanurate bond that contributes to an improvement in flame retardancy in the structure of the polyurethane molecule in addition to the urethanization reaction promoting catalyst. For example, potassium acetate, potassium octylate (trade names) Examples thereof include aliphatic carboxylic acid potassium salts and quaternary ammonium salts such as Perlon 9540). As the quaternary ammonium salts, conventionally known quaternary ammonium salts can be used without limitation. For example, tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetra Examples thereof include tetraalkylammonium organic acid salts such as methylammonium 2-ethylhexanoate, 2-hydroxypropyltrimethylammonium formate, and 2-hydroxypropyltrimethylammonium 2-ethylhexanoate. Commercially available products can be used as the quaternary ammonium salt-containing catalyst. For example, Kaolizer No. Examples include 400, 410, 420 (manufactured by Kao). Some of the above-mentioned tertiary amine catalysts also promote the isocyanurate ring formation reaction. A suitable blending ratio of the tertiary amine catalyst and the trimerization catalyst is 3/1 to 1/2, preferably 2/1 to 1/1 in the weight ratio of [tertiary amine catalyst] / [trimerization catalyst]. It is.

  In the present invention, addition of a flame retardant is also a preferred embodiment, and examples of suitable flame retardants include metal compounds such as halogen-containing compounds, organophosphates, antimony trioxide, and aluminum hydroxide. .

  However, when an excessive amount of powdery flame retardant such as antimony trioxide is added excessively, there may be a problem that the foaming behavior of the foam is affected.

  Organophosphates are suitable additives because they also have an action as a plasticizer and thus have an effect of improving the brittleness of rigid polyurethane foam. It also has the effect of reducing the viscosity of the polyol composition. Examples of the organic phosphate esters include halogenated alkyl esters of phosphoric acid, alkyl phosphate esters, aryl phosphate esters, phosphonate esters, and the like. Specifically, tris (β-chloroethyl) phosphate (CLP, Daihachi Chemical), Tris (β-chloropropyl) phosphate (TMCPP, Daihachi Chemical), Tributoxyethyl phosphate (TBXP, Daihachi Chemical), Tributyl phosphate, Triethyl phosphate, Cresyl phenyl phosphate, Dimethyl methylphosphonate 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, and more preferably 10 to 30 parts by weight with respect to 100 parts by weight of the total polyol compound. If this range is exceeded, problems such as insufficient plasticization and flame retardant effects and deterioration of the mechanical properties of the foam may occur.

  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) or the like is used. In addition to liquid MDI, other polyisocyanate compounds may be used in combination. As the polyisocyanate compound to be used in combination, polyisocyanate compounds well known in the technical field of polyurethane can be used without limitation.

  In the production of the rigid polyurethane foam of the present invention, the equivalent ratio (NCO index) of isocyanate groups to active hydrogen groups is 1.5 to 4.0, more preferably 2.0 to 3.5.

  The polyol composition for rigid polyurethane foams and the method for producing rigid polyurethane foams of the present invention can be used for the production of continuously produced foams such as slabstock foams and sandwich panels.

  The method for producing a rigid polyurethane foam of the present invention will be described by taking as an example the production of a heat insulating panel in which paper materials are laminated on both sides. In the method for producing a rigid polyurethane foam of the present invention, a face material supply device, a conveyor device, a polyol composition and a polyisocyanate component, which are generally used for producing a slab foam or a sandwich panel, are mixed on the bottom material. A known continuous foaming apparatus equipped with a foaming machine (mixer) to be fed to a heating oven, a heating oven, and a cutting machine for cutting a rigid polyurethane foam formed into a continuous shape into an appropriate length can be used.

The manufacturing process of the sandwich panel is generally composed of the following processes.
1) The lower sheet surface material is rewound from the original roll and supplied to the conveyor.
2) A foaming stock solution composition formed by mixing a polyol composition and a polyisocyanate component in a foaming machine on a lower paper surface material is uniformly supplied in the width direction of the paper surface material.
3) Supply the upper paper surface material. After supplying the top surface material, it passes through a nip device such as a nip roll to diffuse the foamed stock solution composition in the width direction, make the thickness of the solution uniform, and make the top and bottom surface material and the foamed stock solution composition compatible.
4) It is sent to a heating oven and heated to cause a foaming / curing reaction, thereby obtaining a rigid polyurethane foam having paper materials laminated on both sides. In order to obtain a predetermined thickness, a double conveyor that holds the upper and lower surfaces of the foam may be used.
5) The rigid polyurethane foam continuously coming out of the heating oven is cut into a predetermined length by a cutting machine.

  The rigid polyurethane foam sandwich panel has a width of 600 to 1500 mm, a thickness of 10 to 55 mm when it is thin, and a thickness of 55 to 150 mm when it is thick. The face material to be used is not particularly limited. In the case of a paper face material, kraft paper having a thickness of 0.3 to 2.0 mm is used.

<Raw compound used>
(1) Polyol compound / GR-40A: Aromatic amine-based polyol compound (ring-opening addition polymer of propylene oxide of toluenediamine); functional group number 4, hydroxyl value 400 mgKOH / g (manufactured by Mitsui Takeda Polychemical Co., Ltd.)
DK-3776: a polyol compound having a chemical structure represented by the chemical formula (Chemical Formula 3); R is a methyl group, X is an oxypropylene group, Y is a propylene group, and a hydroxyl value is 350 mgKOH / g (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
T-24: aromatic polyester polyol; number of functional groups 2, hydroxyl value 260 mgKOH / g (manufactured by Toho Rika Kogyo Co., Ltd.)
PL-135: aromatic polyester polyol; number of functional groups 2, hydroxyl value 250 mgKOH / g (manufactured by Toho Rika Kogyo Co., Ltd.)
GR-84: Aliphatic polyether polyol (propylene oxide ring-opening addition polymer using sucrose / glycerin mixture as an initiator); hydroxyl value 450 mgKOH / g (manufactured by Mitsui Takeda Polychemical Co., Ltd.)
EX-600ED: Aliphatic polyether polyol (propylene oxide ring-opening addition polymer using ethylenediamine as an initiator); functional group number 4, hydroxyl value 600 mgKOH / g (manufactured by Asahi Glass Co., Ltd.)
(2) Plasticizer TMCPP: manufactured by Daihachi Chemical Industry Co., Ltd. (3) Foam stabilizer, SH-193, SF-2945F: manufactured by Toray Dow Corning Silicon Co., Ltd., S824-02: manufactured by Nippon Unicar Co., Ltd. (4) foaming agent: pentane (5) Isocyanate compound: Sumidur 44V-20 (manufactured by Sumika Bayer Urethane Co., Ltd.) is used.

<Example of rigid polyurethane foam production>
A polyol composition was prepared by the formulation described in the upper part of (Table 1), and a thick kraft paper having a thickness of 0.5 mm was used as a face material by the above-described sandwich panel manufacturing method using the polyol composition and polyisocyanate. Sandwich panels having a length of 20 mm and a width of 1200 mm were continuously produced, and the foam density, adhesive strength with the face material, flame retardancy, and thermal conductivity were measured. The mixing ratio of the polyol composition and the isocyanate component was set so that the NCO index was a numerical value described in Table 1. The NCO index was set to 1.0 for the added water.

<Evaluation method>
(1) Viscosity of polyol composition excluding pentane Viscosity at a temperature of 20 ° C. was measured using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) in a composition without adding pentane in the composition of (Table 1).
(2) Foam density A 100 mm × 100 mm foam excluding the face material was cut out from the sandwich panel, and the weight was measured and calculated.
(3) Adhesive strength with the face material As shown in FIG. 1, a 5 cm wide notch was formed in the face material, and the peel strength was measured by pulling the face material with the end peeled in the direction of the arrow with a spring balance. .
(4) Flame retardance A sample with a width of 100 mm and a length of 100 mm was cut out from a sandwich panel, and the above sample was placed at the tip of a propane gas Bunsen burner with the inner flame height adjusted to 20 mm and the outer flame height adjusted to 38 mm. The tip was brought into contact for 10 seconds, and it was visually observed whether or not the foam burned. The case where the foam did not burn was evaluated as ◯, the case where ignition was performed but the combustion was not sustained was evaluated as Δ, and the case where the foam was burned was evaluated as x.
(5) Thermal conductivity A thermal conductivity measuring device AUTO-Λ HC-074 (manufactured by Eihiro Seiki Co., Ltd.) was used, and the measurement conditions were measured in accordance with JIS A 9511.

<Evaluation results>
The evaluation results are shown in the lower part of (Table 1). From the results of this table, the polyol composition of the present invention has a low viscosity, and it is possible to produce a rigid polyurethane foam sandwich panel using a production apparatus equipped with a conventional mixer. It was possible to produce a rigid polyurethane foam having excellent adhesive strength between the material and foam, low thermal conductivity, excellent heat insulation, and excellent flame retardancy even when pentane was used as a foaming agent. The foam strength was also equivalent to the conventional foam using HCFC-141b. In contrast, a foam having a low content of a polyol compound having a structure represented by the chemical formula (Chemical Formula 3) was not satisfactory in flame retardancy.

The figure which showed the measuring method of the adhesive strength of the face material and foam of rigid polyurethane foam sandwich panel

Claims (4)

A polyol composition comprising a polyol compound, a blowing agent, a catalyst and a foam stabilizer, mixed with a polyisocyanate component and reacted to form a rigid polyurethane foam,
The foaming agent contains pentanes,
When the total amount of the polyol compound is 100 parts by weight, 5 to 40 parts by weight of an aromatic amine polyether polyol having a hydroxyl value of 200 to 500 mgKOH / g and 10 to 50 aromatic polyester polyol having a hydroxyl value of 150 to 400 mgKOH / g. A polyol composition for rigid polyurethane foam, comprising 35 parts by weight and a polyether polyol represented by a chemical formula (Chemical Formula 1) having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 .

(R is an alkyl group having 1 to 4 carbon atoms, X is an organic group containing at least one of oxyethylene group and oxypropylene group, Y is an ethylene group or propylene group, m is 0 or 1, q is 1 or 2, m + q = 2, and the average value of n is 1 to 4.)   The polyol composition for rigid polyurethane foam according to claim 1, wherein the catalyst contains a trimerization catalyst. In a method for producing a rigid polyurethane foam, a polyol composition containing a polyol compound, a foaming agent, a catalyst and a foam stabilizer and a polyisocyanate component are mixed and reacted to form a foamed stock solution composition, and the foamed stock solution composition is foamed and cured. There,
The foaming agent contains pentanes,
When the total amount of the polyol compound is 100 parts by weight, 5 to 40 parts by weight of an aromatic amine polyether polyol having a hydroxyl value of 200 to 500 mgKOH / g and 10 to 50 aromatic polyester polyol having a hydroxyl value of 150 to 400 mgKOH / g. A method for producing a rigid polyurethane foam, comprising 35 parts by weight of a polyether polyol represented by a chemical formula (Chemical Formula 2) having 2 parts by weight and a hydroxyl value of 250 to 550 mgKOH / g and having 2 to 4 functional groups.

(R is an alkyl group having 1 to 4 carbon atoms, X is an organic group containing at least one of oxyethylene group and oxypropylene group, Y is an ethylene group or propylene group, m is 0 or 1, q is 1 or 2, m + q = 2, and the average value of n is 1 to 4.)   The isocyanate group / active hydrogen group equivalent ratio (NCO index) in the mixture of the polyol composition and the polyisocyanate component is 1.5 to 3.5, and the catalyst contains a trimerization catalyst. Item 4. A method for producing a rigid polyurethane foam according to Item 3.

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