JP2010018818A - Method for producing rigid foamed synthetic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing lightweight rigid foam having excellent adhesivity and appearance of the foam by using only water as a foaming agent. <P>SOLUTION: The method for producing the rigid foam comprises reacting a polyol compound with a polyisocyanate compound, wherein a polyoxyethylene polyol produced by subjecting only ethylene oxide to ring-opening addition polymerization by using at least one kind selected from the group consisting of aliphatic amines and alicyclic amines as an initiator and having a hydroxyl value of 150-800 mgKOH/g is used as the polyol compound, and only water is used as the foaming agent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a rigid foam synthetic resin. More specifically, the present invention relates to a method for producing a rigid foam synthetic resin such as rigid polyurethane foam, wherein only water is used as a foaming agent.

  Production of rigid foamed synthetic resins (hereinafter referred to as rigid foam) such as rigid polyurethane foam and rigid polyisocyanurate foam by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent or the like is widely performed. ing. Here, various compounds are known as a foaming agent for producing a rigid foam. Previously, low-boiling fluorine-containing compounds have been mainly used. However, considering the burden on the environment, it is desirable to reduce the use of fluorine-containing compounds. Therefore, in order to reduce the amount of use, techniques for using a large amount of water as a blowing agent have been studied. Water reacts with the polyisocyanate compound to generate carbon dioxide, which acts as a blowing agent. When a large amount of water is used, a relatively lightweight rigid foam can be obtained at low cost.

  However, when a rigid foam is produced using a large amount of water, the compatibility between the polyol compound and water is generally not so high, and therefore water tends to be sufficiently dispersed and difficult to dissolve in the polyol compound. As a result, the reaction between water and the polyisocyanate compound does not proceed sufficiently, and as a result, it is difficult to reduce the density of the rigid foam produced. In particular, when producing a rigid foam in a low temperature environment, it is difficult to control the density of the rigid foam low. Specifically, when manufacturing a rigid foam by spray foaming at a construction site in winter, temperature control is difficult, and the density of the manufactured rigid foam cannot be controlled low.

  In addition, the low compatibility between water and the polyol compound results in a decrease in compatibility and miscibility between the polyisocyanate compound and the mixed liquid (polyol system liquid) of the polyol compound, water, and other additives. . As a result, it is difficult to form fine bubbles uniformly during the production of the rigid foam, and cell roughness and striped patterns are likely to appear in the obtained rigid foam.

  In addition, rigid foams produced using a large amount of water increase the proportion of urea bonds formed by the reaction of water and polyisocyanate compounds, making the resulting foams brittle, thus reducing the adhesiveness of the rigid foams. There is a problem of doing.

  Among these problems, a polyoxyalkylene polyol produced using piperazines such as 1- (2-aminoethyl) piperazine as an initiator is used as a method for producing a lightweight rigid foam using a large amount of water. Has been proposed (see, for example, Patent Documents 1 and 2).

JP-A-6-87943 JP-A-8-100044

  However, in the techniques proposed in Patent Documents 1 and 2, etc., the compatibility between a specific polyol and water is not sufficiently high, the density of the rigid foam to be produced is kept low, the adhesiveness is increased, and the good The problem of obtaining a good appearance has not been sufficiently solved.

  That is, the present invention solves the above-mentioned problems, can be produced stably even in a low temperature environment using only water as a foaming agent, and the resulting rigid foam is lightweight, excellent in adhesiveness, and exhibits a good appearance. The purpose is to provide a manufacturing method.

  In the method for producing a rigid foamed synthetic resin by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent, a foam stabilizer and a catalyst, the present invention comprises the following polyol (A) as a polyol compound, Provided is a method for producing a rigid foam synthetic resin, wherein a polyol mixture having a value of 100 to 700 mgKOH / g is used and only water is used as a foaming agent. However, the polyol (A) is produced by ring-opening addition polymerization of only ethylene oxide using at least one selected from the group consisting of aliphatic amines and alicyclic amines as an initiator, and has a hydroxyl value of 150 to 800 mgKOH. / G of polyoxyethylene polyol.

  Here, it is preferable to use piperazine as an initiator of the polyol (A). Moreover, it is preferable that the said polyol mixture contains the following polyol (BA) and / or polyol (BB). However, the polyol (BA) is a polyoxyalkylene polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by ring-opening addition polymerization of alkylene oxide using an aromatic compound as an initiator. The polyol (BB) is a polyester polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by polycondensation of a monomer containing an aromatic compound. Here, it is preferable to use at least one selected from the group consisting of a Mannich condensation product, diaminotoluene and bisphenol A as an initiator for the polyol (BA). Furthermore, it is preferable that the manufacturing method of a hard foam synthetic resin is spray foaming.

  According to the present invention, it is possible to produce a rigid foam that uses only water as a foaming agent and is lightweight, excellent in adhesiveness and good in appearance. In addition, it has become possible to produce a rigid foam by spray foaming stably even in a low temperature environment.

  In the method for producing a rigid foam of the present invention, a rigid foam synthetic resin is produced by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent, a foam stabilizer and a catalyst. The details will be described below.

(Polyol compound)
In the present invention, the polyol (A) is produced by ring-opening addition polymerization of only ethylene oxide using at least one selected from the group consisting of aliphatic amines and alicyclic amines as an initiator and having a hydroxyl value of 150. It is a polyoxyethylene polyol which is ˜800 mg KOH / g. By using this polyol (A), the dissolution stability of water and the polyol compound is improved, the reactivity of water and the polyisocyanate compound is also improved, and an effect such that a lower density rigid foam can be produced is obtained. It is done.

  The initiator used for the production of the polyol (A) is at least one selected from the group consisting of aliphatic amines and alicyclic amines. Here, as the initiator, an alicyclic amine is more preferable. Examples of the aliphatic amine include alkylamines and alkanolamines. Examples of alkylamines include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetraamine. Examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, 1-amino-2-propanol, and aminoethylethanolamine. Examples of the alicyclic amines include piperidines, piperazines, pyrrolidines, etc., piperazines are particularly preferred, and piperazines substituted with aminoalkyl groups are most preferred. Piperazine has a high effect as a catalyst for promoting the urethane bond formation reaction, and by using it as an initiator of the polyol (A), an effect of increasing the reactivity at the time of producing the rigid foam can be obtained. Examples of piperidines include 1- (2-aminoethyl) piperidine. Examples of piperazines include piperazine, N-aminomethylpiperazine, 1- (2-aminoethyl) piperazine and the like. Examples of pyrrolidines include 1- (2-aminoethyl) pyrrolidine.

  Moreover, as an alkylene oxide used for manufacture of a polyol (A), only ethylene oxide is used. By using only ethylene oxide, the affinity between the polyol (A) and water is improved, and the dissolution stability of water and polyol is improved. Further, by using only ethylene oxide, the hydroxyl group of the polyol (A) becomes a primary hydroxyl group, the reactivity of the polyol (A) is increased, and the adhesiveness is improved.

  The hydroxyl value of the polyol (A) is 150 to 800 mgKOH / g, preferably 250 to 700 mgKOH / g. When the hydroxyl value of the polyol (A) is within the above range, the compatibility between the polyol compound and water can be secured, the reactivity of the polyol compound can be increased, and the adhesiveness of the rigid foam can be easily secured, which is preferable. Moreover, 2-8 are preferable and, as for the average functional group number of a polyol (A), 2-6 are more preferable. Here, the average number of functional groups means the average number of active hydrogen atoms in the initiator.

  5-100 mass% is preferable and, as for the ratio of a polyol (A) among the polyol mixtures used for this invention, 15-80 mass% is more preferable. If the proportion of the polyol (A) is less than 5% by mass, the adhesive property of the rigid foam tends to deteriorate, such being undesirable.

  In the present invention, the polyol mixture preferably contains a polyol (BA) and / or a polyol (BB). By using this polyol (BA) and / or polyol (BB), flame resistance can be imparted to the resulting rigid foam.

  In the present invention, the polyol (BA) is a polyoxyalkylene polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by ring-opening addition polymerization of alkylene oxide using an aromatic compound as an initiator.

  As an initiator used for the production of the polyol (BA), an aromatic compound is used, but it is preferable to use at least one selected from the group consisting of a Mannich condensation product, diaminotoluene and bisphenol A. Here, the aromatic compound means a compound having an aromatic ring. Here, the aromatic ring may be a ring composed of only carbon atoms or a ring containing atoms (heteroatoms) other than carbon atoms such as nitrogen atoms. Examples of the ring consisting of only carbon atoms include a benzene ring and a naphthalene ring. Examples of the ring containing an atom other than a carbon atom include a pyridine ring. However, the presence or absence of a heteroatom in these rings is not considered.

  The aromatic compound may be a condensed compound or a non-condensed compound. The condensation compound includes a Mannich condensation product, which is a reaction product of phenols, alkanolamines and aldehydes, a resol-type initial condensate obtained by condensation-bonding phenols with an excess of formaldehyde in the presence of an alkali catalyst. Examples include a benzylic type initial condensate reacted in a non-aqueous system when synthesizing a type initial condensate, a novolak type initial condensate obtained by reacting excess phenols with formaldehyde in the presence of an acid catalyst, and the like. The molecular weight of these initial condensates is preferably about 200 to 10,000. In the above, examples of phenols include phenol, cresol, nonylphenol, bisphenol A, resorcinol, and examples of aldehydes include formalin and paraformaldehyde. Examples of non-condensable compounds include polyphenols such as bisphenol A and resorcinol, diaminotoluene, diethyldiaminotoluene, diaminodiphenylmethane, and the like.

  Examples of the alkylene oxide used for producing the polyol (BA) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and styrene oxide. Of these, propylene oxide and ethylene oxide are preferred.

  The hydroxyl value of the polyol (BA) is 100 to 700 mgKOH / g, preferably 200 to 600 mgKOH / g. When the hydroxyl value of the polyol (BA) is within the above range, it is preferable because sufficient flame retardancy can be imparted while maintaining the mixing property of the polyol compound. Moreover, 2-8 are preferable and, as for the average functional group number of a polyol (BA), 2-6 are more preferable.

  In the present invention, the polyol (BB) is a polyester polyol having a hydroxyl value of 100 to 700 mgKOH / g produced by polycondensation of a monomer containing an aromatic compound. That is, as a monomer used for producing this polyol (BB), a diol having an aromatic ring or a dicarboxylic acid having an aromatic ring is used. Examples of the diol having an aromatic ring include a diol obtained by adding ethylene oxide to bisphenol A. Examples of the dicarboxylic acid having an aromatic ring include phthalic acids such as terephthalic acid. The hydroxyl value of the polyol (BB) is 100 to 700 mgKOH / g, preferably 200 to 600 mgKOH / g. When the hydroxyl value of the polyol (BB) is within the above range, it is preferable because sufficient flame retardancy can be imparted while maintaining the mixing property of the polyol compound.

  7-90 mass% is preferable and, as for the ratio of the sum total of a polyol (BA) and a polyol (BB) among the polyol mixtures used for this invention, 20-70 mass% is more preferable. If the total ratio of the polyol (BA) and the polyol (BB) is within the above range, an appropriate flame retardancy can be imparted to the obtained rigid foam, and other mechanical properties and the like are not impaired. Moreover, there is no restriction | limiting in particular in the ratio of a polyol (BA) and a polyol (BB).

  In the present invention, a polyol mixture containing the above-described polyol (A) and having a hydroxyl value of 100 to 700 mgKOH / g is used as the polyol compound. Here, the hydroxyl value of the polyol mixture is 100 to 700 mgKOH / g, preferably 100 to 420 mgKOH / g. When the hydroxyl value is within this range, a rigid foam having good physical properties can be obtained.

  As said polyol mixture, a polyol (A) and the polyol (BA) and / or polyol (BB) which were mentioned above may be mixed depending on the case, and another polyol may be further mixed. Here, the other polyol is a polyol other than the above-described polyol (A), polyol (BA), and polyol (BB), and examples thereof include polyether polyol, polyester polyol, and polycarbonate polyol. Examples of the initiator for the polyether polyol include polyhydric alcohols such as propylene glycol, glycerin, pentaerythritol, sorbitol, and sucrose. The polyol mixture may contain a small amount of an active hydrogen-containing compound such as polyamine.

(Foaming agent)
In the present invention, only water is used as the foaming agent. As a result, a rigid foam can be produced without using a fluorine-containing compound or the like, which is a concern for the environment. The amount of water used as the foaming agent is preferably 1 to 15 parts by mass, particularly preferably 2 to 13 parts by mass with respect to 100 parts by mass of the polyol compound. When the amount of water used is less than 1 part by mass, the obtained rigid foam is not preferred because it is difficult to lighten. Moreover, when there is much usage-amount exceeding 15 mass parts, the miscibility of water and a polyol compound tends to deteriorate, and it is not preferable.

(Polyisocyanate compound)
In the present invention, the polyisocyanate compound is not particularly limited, but aromatic, alicyclic and aliphatic polyisocyanates having two or more isocyanate groups; mixtures of two or more of the above polyisocyanates; And modified polyisocyanates obtained by modifying. Specific examples include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (common name: crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), and the like. These polyisocyanates or their prepolymer-modified products, nurate-modified products, urea-modified products, carbodiimide-modified products, and the like. Of these, TDI, MDI, crude MDI, or modified products thereof are preferred.

  The amount of the polyisocyanate compound used is represented by 100 times the number of isocyanate groups with respect to the total number of active hydrogens of the polyol compound and other active hydrogen compounds (usually, the value represented by 100 times is referred to as the isocyanate index), 300 is preferred. Here, in the urethane prescription which mainly uses a urethanization catalyst as a catalyst, the usage-amount of a polyisocyanate compound is an isocyanate index | exponent, 50-140 are preferable and 60-130 are more preferable. Moreover, in the isocyanurate prescription which mainly uses the catalyst which accelerates | stimulates the trimerization reaction of an isocyanate group as a catalyst, the usage-amount of a polyisocyanate compound is an isocyanate index, 120-300 are preferable and 150-250 are more preferable.

(catalyst)
The catalyst used in the present invention is not particularly limited as long as it is a catalyst that promotes the urethanization reaction. Examples thereof include tertiary amines such as triethylenediamine, bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine; and organometallic compounds such as dibutyltin dilaurate. Moreover, you may use together the catalyst which accelerates | stimulates the trimerization reaction of an isocyanate group, and carboxylic acid metal salts, such as potassium acetate and potassium 2-ethylhexanoate, etc. are mentioned. When spray foaming is adopted as a method for producing a rigid foam, it is preferable to use an organometallic catalyst such as lead 2-ethylhexanoate in order to complete the reaction in a short time. As for the usage-amount of a catalyst, 0.1-10 mass parts is preferable with respect to 100 mass parts of polyol compounds.

(Foam stabilizer)
In the present invention, a foam stabilizer is used to form good bubbles. Examples of the foam stabilizer include silicone foam stabilizers and fluorine-containing compound foam stabilizers. Although the usage-amount of a foam stabilizer may be selected suitably, 0.1-10 mass parts is preferable with respect to 100 mass parts of polyol compounds.

(Other ingredients)
In the present invention, any compounding agent can be used in addition to the above-described polyol compound, polyisocyanate compound, foaming agent, catalyst, and foam stabilizer. Compounding agents include fillers such as calcium carbonate and barium sulfate; anti-aging agents such as antioxidants and UV absorbers; flame retardants, plasticizers, colorants, anti-fungal agents, foam breakers, dispersants, discoloration prevention Agents and the like.

(Foaming device)
As a manufacturing method of the rigid foam of the present invention, normal hand foaming or a foaming apparatus may be used. As the foaming apparatus, either a high pressure foaming apparatus or a low pressure foaming apparatus can be used. The reaction conditions may be appropriately selected, but the reaction temperature is preferably 0 to 50 ° C, more preferably 15 to 45 ° C.

  As a method for producing the rigid foam of the present invention, spray foaming is particularly preferable. This is because high reactivity can be obtained by using the polyol (A). Various methods for producing by spray foaming are known. Of these, airless spray foaming is preferred, in which the compounded liquid is mixed and foamed by a mixing head. Here, spray foaming is a foaming method in which a polyol system solution and a polyisocyanate compound are reacted while sprayed, and the reaction is completed in a short time by selecting a catalyst or the like. Spray foaming is often employed when constructing hard foam insulation on walls, ceilings, etc. at construction sites. Spray foaming has advantages such as manufacturing rigid foams directly at the construction site, thus reducing the construction cost, and being able to construct even on uneven construction surfaces. Specific construction examples include heat insulating materials for condominiums, office buildings, prefabricated refrigerated warehouses, etc. In recent years, they are also being used as heat insulating materials for highly airtight detached houses.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Of the following examples, Examples 1 to 6 represent production examples of rigid polyurethane foam, and Examples 7 to 9 represent production examples of rigid urethane-modified polyisocyanurate foam. However, Examples 1-3, 7, and 8 represent Examples, and Examples 4 to 6 and 9 represent Comparative Examples. Moreover, the unit of the numerical value of the part which showed prescription in the table | surface is a mass part. The raw materials used in Examples and Comparative Examples are as shown in each table, and the details are as follows.

(Polyol compound)
Polyol A1: Polyoxyethylene polyol having a hydroxyl value of 350 mgKOH / g, obtained by reacting only ethylene oxide as an alkylene oxide using ethylenediamine as an initiator.
Polyol A2: A polyoxyethylene polyol having a hydroxyl value of 350 mgKOH / g, obtained by reacting only ethylene oxide as alkylene oxide using 1- (2-aminoethylpiperazine) as an initiator.
Polyol BA1: A polyoxyethylene polyol having a hydroxyl value of 280 mgKOH / g, obtained by reacting only ethylene oxide as an alkylene oxide using bisphenol A as an initiator.
Polyol BA2: Polyoxyethylene having a hydroxyl value of 350 mgKOH / g and a proportion of oxyethylene groups of 25% by mass, obtained by mixing and reacting ethylene oxide and propylene oxide as alkylene oxide using diaminotoluene as an initiator Polyoxypropylene polyol.
Polyol Z1: Polyoxypropylene polyol having a hydroxyl value of 350 mgKOH / g, obtained by reacting only propylene oxide as alkylene oxide using ethylenediamine as an initiator.
Polyol Z2: Polyoxyethylene polyol having a hydroxyl value of 350 mgKOH / g, obtained by reacting only propylene oxide as alkylene oxide using 1- (2-aminoethylpiperazine) as an initiator.
Polyol Z3: Polyoxypropylene having a hydroxyl value of 300 mgKOH / g, obtained by reacting only propylene oxide as alkylene oxide using a mixture of sucrose and glycerin as the initiator (mixing ratio is 1: 1 by mass) Polyol.

(Examples 1-6)
The polyols shown in Table 1 were mixed and used. Further, water was used in the amount shown in Table 1 as a foaming agent. The following foaming agent, catalyst, foam stabilizer and flame retardant were added to and mixed with the polyol mixture and water to obtain a polyol composition. As the catalyst, N, N-dimethylcyclohexylamine (trade name: Kaulizer No. 10, manufactured by Kao Corporation) was used. The amount used was such that the gel time was 25 seconds. However, since Example 3 has high reactivity of the polyol compound, no catalyst was added. As the foam stabilizer, 2.0 parts by mass of a silicone foam stabilizer (trade name: SH-193, manufactured by Toray Dow Corning Silicone) was used. As the flame retardant, 20 parts by mass of tris (2-chloropropyl) phosphate (trade name: TMCPP, manufactured by Daihachi Chemical Co., Ltd.) was used. As the polyisocyanate compound, polymethylene polyphenyl polyisocyanate (trade name: C-1155, manufactured by Nippon Polyurethane Industry Co., Ltd.) was used. The amount of the polyisocyanate compound used was such that the polyol composition and the polyisocyanate compound were 1: 1 in volume ratio.

  The polyol composition and the polyisocyanate compound were mixed at a liquid temperature of 20 ° C., and placed in a wooden box having a length of 200 mm × width of 200 mm × height of 200 mm to produce a rigid polyurethane foam by foaming.

(Examples 7 to 9)
The polyols shown in Table 1 were mixed and used. Further, water was used in the amount shown in Table 1 as a foaming agent. The following foaming agent, catalyst, foam stabilizer and flame retardant were added to and mixed with the polyol mixture and water to obtain a polyol composition. As the catalyst, N, N ′, N ″ -tris (dimethylaminopropyl) hexahydro-S-triazine (trade name: Polycat 41, manufactured by Air Products) and diethylenglycol solution of potassium 2-ethylhexanoate (potassium concentration 15) %, Trade name: PACCAT 15G, manufactured by Nippon Kagaku Sangyo Co., Ltd.) in a ratio of 2 parts by mass to 3 parts by mass, and the amount used was such that the gel time was 25 seconds. As the agent, 2.0 parts by mass of SH-193 was used, as the flame retardant, 30 parts by mass of TMCPP, and as the polyisocyanate compound, polymethylene polyphenyl polyisocyanate (trade name: C-1155, Japan). The amount of the polyisocyanate compound used was a polyol composition, a polyisocyanate compound, and a polyisocyanate compound. The volume ratio was 1: 1.

  The polyol composition and the polyisocyanate compound were mixed at a liquid temperature of 20 ° C. and placed in a wooden box having a length of 200 mm × width of 200 mm × height of 200 mm, and a rigid urethane-modified polyisocyanurate foam was foamed and produced.

(Evaluation 1)
The obtained rigid foam was evaluated for core density (unit: kg / m ³ ), initial adhesiveness, cell appearance and self-extinguishing property. The initial adhesiveness was evaluated as “Good” and “Poor” when the laminate paper was peeled off after 30 minutes after foaming and stirring, after laminating paper was spread in a box before foaming. The appearance of the cells was evaluated by evaluating the inside cell state and the rough state of the bottom surface of the foam by ◯: good and x: bad when the manufactured foam was cut. About the self-extinguishing property, the distance (unit: mm) measured according to JIS A-9511 and burned was measured.

  As shown in Table 1, each of the rigid foams produced by the method for producing a rigid foam according to the present invention had a low density and exhibited good initial adhesiveness, cell appearance, dimensional stability, and self-extinguishing properties. .

(Evaluation 2)
Next, a mineral spirit solution of lead 2-ethylhexanoate (lead concentration: 20%, trade name: Nikka Octix Lead 20%, Nippon Chemical Industry Co., Ltd.) was added to the polyol composition used in Examples 1, 2, 3, 7 and 8. 1.0 parts by mass) was further added and mixed. This liquid and C-1155 as a polyisocyanate compound were sprayed onto the wall surface by spray foaming using a gasmer foaming machine at a liquid temperature of 35 ° C. and a room temperature of 10 ° C.

The resulting foam showed a good foaming process even though it was manufactured at room temperature of 10 ° C. and a low temperature assuming wintertime. The density of the rigid foam obtained was a core density of 37 kg / m ³ or less. It was sufficiently low and showed good cell appearance, initial adhesion, and self-extinguishing properties.

  For the rigid foams of Examples 7 and 8 which are production examples of rigid urethane-modified polyisocyanurate foam, the core portion is cut out to a thickness of 15 mm, and a corn calorimeter (manufactured by Toyo Seiki Seisakusho Co., Ltd.) is used as a combustion test in accordance with ISO 5600 Part 1 Carried out. As a result, it was found that the prescribed flame retardancy was satisfied.

  The manufacturing method of the rigid foam which is lightweight and excellent in adhesiveness based on this invention is suitable for construction of the rigid foam by spray foaming constructed | assembled at a construction site.

Claims (5)

In a method for producing a rigid foam synthetic resin by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent, a foam stabilizer and a catalyst,
The manufacturing method of the hard foam synthetic resin characterized by using the following polyol (A) as a polyol compound, the polyol mixture whose hydroxyl value is 100-700 mgKOH / g, and using only water as a foaming agent.
Polyol (A): produced by ring-opening addition polymerization of only ethylene oxide using at least one selected from the group consisting of aliphatic amines and alicyclic amines as an initiator, and having a hydroxyl value of 150 to 800 mgKOH / g A certain polyoxyethylene polyol.   The manufacturing method of the hard foam synthetic resin of Claim 1 which uses piperazine as an initiator of the said polyol (A). The method for producing a rigid foam synthetic resin according to claim 1 or 2, wherein the polyol mixture contains the following polyol (BA) and / or polyol (BB).
Polyol (BA): A polyoxyalkylene polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by ring-opening addition polymerization of alkylene oxide using an aromatic compound as an initiator.
Polyol (BB): Polyester polyol produced by polycondensation of a monomer containing an aromatic compound and having a hydroxyl value of 100 to 700 mgKOH / g.   The method for producing a rigid foam synthetic resin according to claim 3, wherein at least one selected from the group consisting of a Mannich condensation product, diaminotoluene and bisphenol A is used as the initiator of the polyol (BA).   The method for producing a rigid foam synthetic resin according to claim 1, 2, 3, or 4, wherein the production method for the rigid foam synthetic resin is spray foaming.