JP4677709B2 - Manufacturing method of rigid foam synthetic resin - Google Patents

Description

  The present invention relates to a hard foam synthetic resin and a method for producing the same. More specifically, the present invention relates to a hard foam synthetic resin such as an open-cell hard polyurethane foam characterized by using a relatively large amount of water as a foaming agent and a method for producing the same.

  It is widely performed to produce a rigid foamed synthetic resin (hereinafter referred to as a rigid foam) such as a rigid polyurethane foam and a rigid polyisocyanurate foam by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent or the like. ing. The state of air bubbles in the rigid foam is roughly divided into closed cells and open cells. Among these, open cells are connected to individual cells, and a rigid foam having many open cells (open cell type) is highly breathable. Such an open-celled rigid foam has a characteristic that it has a low thermal insulation performance but is excellent in dimensional stability under severe temperature conditions.

  On the other hand, various compounds are known as foaming agents for producing rigid foams. 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, a technique of using a large amount of water as a foaming agent has been proposed (see, for example, Patent Documents 1 to 3).

  However, a rigid foam using a large amount of water has a problem that the resulting foam tends to be brittle because the ratio of urea bonds generated by the reaction of water and the polyisocyanate compound increases. In addition, when a large amount of water is used, the stability of a solution (polyol system liquid) in which water or the like is mixed with a raw material polyol compound tends to deteriorate, and the polyol system liquid becomes cloudy and is likely to be separated. Furthermore, the compatibility and mixing properties of the polyol system liquid and the isocyanate compound are likely to be poor, and it is difficult to form fine bubbles uniformly during the production of the rigid foam, and the resulting rigid foam is liable to be broken and depressed. There is also.

  In the aforementioned Patent Documents 1 to 3, a proposal has been made to produce an open-celled rigid foam by using a mixed polyol of a low molecular weight polyol and a high molecular weight polyol, and using a lot of water by further improvement. . However, none of the proposals show a formulation that can produce a rigid foam that is sufficiently light and exhibits good open-cell properties when produced by pouring into a mold, and that the raw material exhibits good storage stability.

JP-A-6-25375 JP 2001-342237 A JP 2002-128855 A

  Therefore, an object of the present invention is to provide a method for producing an open-celled rigid foam that is sufficiently lightweight and excellent in storage stability of raw materials.

  That is, this invention provides the manufacturing method of the following rigid foams.

In the method for producing an open-celled 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 following polyol (A) is used as a polyol compound in a range of 40 to 70: % By weight, a polyol mixture containing 20 to 50% by weight of the following polyol (B) and 1 to 20% by weight of the following monool (C), water as a blowing agent , and 6 to 15 with respect to 100 parts by weight of the polyol compound. Provided is a method for producing a rigid foam synthetic resin, characterized by using a mass part . Polyol (A): The average number of functional groups is 2 to 8, the hydroxyl value is 20 to 120 mgKOH / g, the oxyethylene group content is 0 to 5% by mass, and the proportion of primary hydroxyl groups is 15 mol% or less based on the total hydroxyl groups. , Polyoxyalkylene polyols. Polyol (B): The average number of functional groups is 3 to 8, the hydroxyl value is 200 to 800 mgKOH / g, the oxyethylene group content is 0 to 5% by mass, and the proportion of primary hydroxyl groups is 15 mol% or less based on the total hydroxyl groups. , Polyoxyalkylene polyols. Monool (C): obtained by reacting an alkylene oxide using a monool having 7 to 22 carbon atoms as an initiator , the oxyethylene group content is 70 to 100% by mass, and the hydroxyl value is 30 to 350 mgKOH / g. Is a polyoxyalkylene monool.

Here, the polyol (A) is obtained by reacting an alkylene oxide with at least one initiator selected from water, ethylene glycol, propylene glycol, glycerin, trimethylolpropane, diglycerin, pentaerythritol, sorbitol and sucrose. The polyoxyalkylene polyol obtained is preferable. The polyol (B) is preferably a polyoxyalkylene polyol obtained by reacting an alkylene oxide with an amine compound as an initiator. Moreover, it is preferable that the usage-amount of the said polyisocyanate compound is 50-250 by an isocyanate index | exponent . Moreover, it is preferable that the hydroxyl value of the said polyol mixture is 150-300 mgKOH / g.

  Moreover, this invention provides the hard foam synthetic resin manufactured by said manufacturing method. Here, the rigid foam synthetic resin preferably has a closed cell ratio of 50% or less.

  According to the present invention, even when a large amount of water is blended, a formulation with excellent raw material storage stability can be achieved. In addition, since a large amount of water can be used, it is possible to produce a lighter rigid foam. Moreover, the cells of the rigid foam produced at the same time are fine, and bubbles are not broken and the cells are not roughened, the occurrence of depression can be suppressed, and excellent dimensional stability and good strength can be obtained.

  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, a polyol mixture containing 40 to 70% by mass of the following polyol (A), 20 to 50% by mass of the following polyol (B) and 1 to 20% by mass of the following monool (C) is used as the polyol compound. .

  In the present invention, the polyol (A) means an average functional group number of 2 to 8, a hydroxyl value of 20 to 120 mgKOH / g, an oxyethylene group content of 0 to 5% by mass, and a ratio of primary hydroxyl groups to 15 of all hydroxyl groups. It is a polyoxyalkylene polyol having a mol% or less. That is, the polyol (A) is a polyoxyalkylene polyol (polyether polyol) produced by ring-opening addition polymerization reaction of an alkylene oxide as an initiator. The polyol (A) may be only one kind of polyol satisfying the characteristics described below, or may be a polyol mixture in which two or more kinds are mixed.

  As an initiator used for manufacture of a polyol (A), water and a polyhydric alcohol are preferable. Specific examples of the polyhydric alcohols include ethylene glycol, propylene glycol, glycerin, trimethylolpropane, diethylene glycol, diglycerin, pentaerythritol, sorbitol, sucrose, and the like. Here, as the initiator, at least one selected from water, ethylene glycol, propylene glycol, glycerin, trimethylolpropane, diglycerin, pentaerythritol, sorbitol and sucrose is particularly preferable.

  Examples of the alkylene oxide used for producing the polyol (A) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and styrene oxide. Among these, it is preferable to use propylene oxide alone or a mixture of propylene oxide and a small amount of ethylene oxide. That is, the oxyethylene group content of the polyol (A) is 0 to 5% by mass, preferably 0 to 2% by mass, and particularly preferably 0% by mass (excluding oxyethylene groups). Here, the oxyethylene group content in the polyol means the content of a portion derived from ethylene oxide in the alkylene oxide reacted with the initiator. When the content of the oxyethylene group exceeds 5% by mass, the activity of the polyol (A) is increased, and the obtained rigid foam is not preferable because it is difficult to be open-celled.

  The ratio of the primary hydroxyl group of the polyol (A) is 15 mol% or less with respect to the total hydroxyl groups of the polyol (A), preferably 10 mol% or less, particularly preferably 5 mol% or less. When the proportion of the primary hydroxyl group exceeds 15 mol%, the activity of the polyol (A) is increased, and the obtained rigid foam is not preferable because it is difficult to become open-celled.

  Moreover, although the average functional group number of a polyol (A) is 2-8, 2-6 are more preferable. Here, the average number of functional groups means the average number of active hydrogen atoms in the initiator. If the average functional group number is less than 2, the strength of the obtained rigid foam tends to be insufficient, which is not preferable. On the other hand, when the average number of functional groups exceeds 8, the viscosity of the polyol (A) becomes too high, and the mixability of the raw materials tends to decrease, which is not preferable.

  Moreover, although the hydroxyl value of a polyol (A) is 20-120 mgKOH / g, 25-100 mgKOH / g is preferable and 30-80 mgKOH / g is more preferable. When the hydroxyl value is less than 20 mgKOH / g, the viscosity of the polyol (A) becomes too high, which is not preferable. On the other hand, if it exceeds 120 mgKOH / g, the resulting rigid foam is not preferred because it is difficult to be open-celled.

  Although the ratio of a polyol (A) is 40-70 mass% among the polyol mixtures used for this invention, 40-60 mass% is preferable. When the proportion of the polyol (A) is less than 40% by mass, the obtained rigid foam is not preferable because it is difficult to become open-celled. On the other hand, when the proportion of the polyol (A) is more than 70% by mass, the cells of the obtained rigid foam tend to be rough (cell roughness tends to occur), and the rigid foam tends to be insufficient in strength.

  In the present invention, the polyol (B) means an average number of functional groups of 3 to 8, a hydroxyl value of 200 to 800 mgKOH / g, an oxyethylene group content of 0 to 5% by mass, and a ratio of primary hydroxyl groups to 15 of all hydroxyl groups. It is a polyoxyalkylene polyol having a mol% or less. That is, polyol (B) is a polyoxyalkylene polyol produced by subjecting an alkylene oxide to a ring-opening addition polymerization reaction as an initiator. The polyol (B) may be only one kind of polyol satisfying the characteristics described below, or may be a polyol mixture in which two or more kinds are mixed.

  As an initiator used for manufacture of a polyol (B), an amine compound is preferable. Examples of amine compounds include aliphatic amines, alicyclic amines, and aromatic amines. Examples of the aliphatic amines include alkylamines such as ethylenediamine, hexamethylenediamine, and diethylenetriamine, and alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine. Examples of the alicyclic amines include aminoethylpiperazine. Examples of aromatic amines include diaminotoluene and Mannich reaction products. The Mannich reaction product is a reaction product of phenols, alkanolamines and aldehydes, and examples thereof include reaction products of nonylphenol, monoethanolamine and formaldehyde.

  Examples of the alkylene oxide used for producing the polyol (B) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and styrene oxide. Among these, it is preferable to use propylene oxide alone or a mixture of propylene oxide and a small amount of ethylene oxide. That is, the oxyethylene group content of the polyol (B) is 0 to 5% by mass, preferably 0 to 2% by mass, and particularly preferably 0% by mass (excluding oxyethylene groups). When the content of the oxyethylene group exceeds 5% by mass, the activity of the polyol (B) becomes high, and the obtained rigid foam is not preferred because it is difficult to become open-celled.

  The ratio of the primary hydroxyl group of the polyol (B) is 15 mol% or less with respect to the total hydroxyl groups of the polyol (B), preferably 10 mol% or less, particularly preferably 5 mol% or less. If the proportion of the primary hydroxyl group exceeds 15 mol%, the activity of the polyol (B) is increased, and the obtained rigid foam is not preferred because it is difficult to be open-celled.

  Moreover, although the average functional group number of a polyol (B) is 3-8, 3-6 are more preferable and 4-5 are especially preferable. If the average number of functional groups is less than 3, the strength of the obtained rigid foam tends to be insufficient, which is not preferable. On the other hand, if the average number of functional groups exceeds 8, the viscosity of the polyol (B) becomes too high, and the mixing property of the raw materials tends to decrease, which is not preferable.

  Moreover, although the hydroxyl value of a polyol (B) is 200-800 mgKOH / g, 300-700 mgKOH / g is preferable and 400-600 mgKOH / g is more preferable. When the hydroxyl value is less than 200 mgKOH / g, the strength (particularly compressive strength) of the obtained rigid foam tends to be insufficient, which is not preferable. On the other hand, if it exceeds 800 mgKOH / g, the miscibility with the polyol (A) tends to be poor, and the obtained rigid foam is not preferred because it tends to be open-celled.

  Although the ratio of a polyol (B) is 20-50 mass% among the polyol mixtures used for this invention, 25-45 mass% is preferable and 30-40 mass% is especially preferable. When the ratio of the polyol (B) is less than 20% by mass, the strength of the obtained rigid foam tends to be insufficient, which is not preferable. Moreover, when the ratio of a polyol (B) exceeds 50 mass%, the obtained rigid foam becomes difficult to become open-cell property, and is unpreferable.

  In the present invention, the monool (C) is a polyoxyalkylene monool having a hydroxyl value of 20 to 400 mgKOH / g obtained by reacting an alkylene oxide using a monool having 7 to 22 carbon atoms as an initiator. . That is, the monool (C) is a polyoxyalkylene monool produced by ring-opening addition polymerization reaction of an alkylene oxide with an initiator. The monool (C) may be a single monool satisfying the characteristics described below or a monool mixture in which two or more types are mixed.

  The initiator used for production of monool (C) is a monool having 7 to 22 carbon atoms. However, compounds having phenolic hydroxyl groups are not included. Here, as the initiator, an alkyl monool having 7 to 22 carbon atoms is preferable. Specific examples of the alkyl monool having 7 to 22 carbon atoms include heptanol, octanol, decanol, dodecanol (lauryl alcohol), hexadecanol (cetyl alcohol), octadecanol (stearyl alcohol), (Z) -9-octadecene. -1-ol (oleyl alcohol) and the like. In particular, monool mixtures include animal and vegetable oil-based alcohols such as beef tallow alcohol. The average functional group number of monool (C) is 1.

Examples of the alkylene oxide used for the production of the monool (C) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and styrene oxide. Of these, it is preferable to use ethylene oxide alone or a mixture of ethylene oxide and propylene oxide. That is, the oxyethylene group content of the monool (C) is preferably 50 to 100% by mass, preferably 70 to 100% by mass, and particularly preferably 100% by mass (only the oxyethylene group). When the oxyethylene group content is less than 50% by mass, water and the polyol compound are easily separated, and the raw material stability is likely to deteriorate, which is not preferable.
The oxyethylene group content of monool (C) in the present invention is 70 to 100% by mass.

Moreover, although the hydroxyl value of monool (C) is 20-400 mgKOH / g, 30-350 mgKOH / g is preferable and 50-300 mgKOH / g is more preferable. When the hydroxyl value is less than 20 mgKOH / g, the strength (particularly compressive strength) of the obtained rigid foam tends to be insufficient, which is not preferable. On the other hand, if it exceeds 400 mgKOH / g, the mixing property of water and the polyol compound tends to deteriorate, which is not preferable.
The hydroxyl value of monool (C) in the present invention is 30 to 350 mgKOH / g.

  Although the ratio of monool (C) is 1-20 mass% among the polyol mixtures used for this invention, 3-17 mass% is preferable and 5-15 mass% is especially preferable. If the proportion of monool (C) is less than 1% by mass, the miscibility of water and the polyol compound is likely to deteriorate, such being undesirable. Moreover, when the ratio of monool (C) exceeds 20 mass%, the strength of the obtained rigid foam tends to be insufficient, which is not preferable.

  The hydroxyl value of the polyol mixture used in the present invention is preferably 150 to 300 mgKOH / g, more preferably 160 to 280 mgKOH / g, and particularly preferably 170 to 250 mgKOH / g. When the hydroxyl value is less than 150 mgKOH / g, the strength of the obtained rigid foam tends to be insufficient, which is not preferable. On the other hand, if the hydroxyl value exceeds 300 mgKOH / g, the resulting rigid foam is not preferred because it is difficult to become closed-celled.

  The polyol mixture used in the present invention contains the above-mentioned polyol (A), polyol (B) and monool (C), but may contain other active hydrogen compounds. Examples of other active hydrogen compounds include polyols other than polyol (A) and polyol (B), polyhydric phenols, and aminated polyols. Examples of polyols other than polyol (A) and polyol (B) include polyether polyol, polyester polyol, and polycarbonate polyol. As polyhydric phenols, non-condensable compounds such as bisphenol A and resorcinol, resol-type initial condensates obtained by condensation-bonding phenols with excess formaldehyde in the presence of an alkali catalyst, and this resole-type initial condensate are synthesized. Examples thereof include a benzylic type initial condensate reacted in a non-aqueous system, 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, phenols include phenol, cresol, bisphenol A, resorcinol, and the formaldehydes include formalin and paraformaldehyde.

(Foaming agent)
In the present invention, water is used as the foaming agent. As the blowing agent, a low boiling point hydrocarbon compound, a low boiling point fluorine-containing compound, and an inert gas can be used in combination. However, in the present invention, it is preferable to use only water or a combination of water and an inert gas as the foaming agent, and use of only water is particularly preferable because it has a low environmental impact. The amount of water used as the foaming agent is preferably 6 to 15 parts by mass, particularly preferably 8 to 13 parts by mass with respect to 100 parts by mass of the polyol compound. If the amount of water used is less than 6 parts by mass, the resulting 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.
In this invention, 6-15 mass parts is used for 100 mass parts of polyol compounds as water as a foaming agent.

  Examples of the low-boiling hydrocarbon compound include butane, pentane, hexane, and cyclohexane. Examples of the low boiling point fluorine-containing compound include 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1,1,3,3-pentafluoropropane (HFC-245fa). It is done. Examples of the inert gas include air, nitrogen, carbon dioxide gas and the like.

(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), 250 is preferred. Here, in the urethane formulation mainly using a urethanization catalyst as the catalyst, the amount of the polyisocyanate compound used is an isocyanate index, preferably 50 to 120, more preferably 60 to 100, and particularly preferably 60 to 90. 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 | exponent, 120-250 are preferable and 150-200 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. 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. Among these, a silicone type foam stabilizer used for the production of a highly breathable flexible urethane foam is particularly preferable. 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 40 ° C.

(Rigid foam)
The present invention relates to an open-celled rigid foam produced by the production method described above. Here, the open cell property means that there are few closed cells. The closed cell ratio of the rigid foam produced in the present invention is preferably 50% or less, more preferably 20% or less, and particularly preferably 10% or less. By having high open cell properties (low closed cell ratio), the dimensional stability is improved and the foaming pressure is reduced. Here, the closed cell ratio is measured in accordance with ASTM D2856.

Moreover, the rigid foam manufactured by this invention is lightweight. In particular its density is preferably 30kg / ^{m 3} or less, more preferably 25 kg / ^{m 3.}

  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 8 represent Examples, and Examples 9 to 12 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 Tables 1 and 2, and the details are as follows.

(Polyol compound)
Polyol A1: Polyoxypropylene triol obtained by reacting only propylene oxide as alkylene oxide using glycerin as an initiator. The hydroxyl value is 33 mgKOH / g, the oxyethylene group content is 0% by mass, and the proportion of primary hydroxyl groups is 0%.
Polyol A2: Polyoxypropylene triol obtained by using glycerin as an initiator and reacting only propylene oxide as alkylene oxide. The hydroxyl value is 56 mgKOH / g, the oxyethylene group content is 0% by mass, and the proportion of primary hydroxyl groups is 0%.
Polyol B1: Polyoxypropylene tetraol obtained by reacting only propylene oxide as an alkylene oxide using ethylenediamine as an initiator. The hydroxyl value is 500 mgKOH / g, the oxyethylene group content is 0% by mass, and the proportion of primary hydroxyl groups is 0%.
Polyol B2: A polyoxypropylene polyol obtained by reacting only propylene oxide as alkylene oxide using a Mannich reaction product obtained by reacting nonylphenol, diethanolamine and formaldehyde as an initiator. The average number of functional groups is 5, the hydroxyl value is 470 mgKOH / g, the oxyethylene group content is 0% by mass, and the proportion of primary hydroxyl groups is 0%.
Monool C1: Polyoxyethylene monool obtained by reacting only ethylene oxide as alkylene oxide using dodecanol as an initiator. The hydroxyl value is 100 mgKOH / g, and the oxyethylene group content is 100% by mass.
Monool C2: Polyoxypropylene polyoxyethylene monool obtained by using butanol as an initiator and mixing and reacting propylene oxide and ethylene oxide as alkylene oxide. The hydroxyl value is 249 mgKOH / g, and the oxyethylene group content is 28.5% by mass.

(Raw materials other than polyol compounds)
Flame retardant: Tris (β-chloropropyl) phosphate.
Foam stabilizer: Silicone foam stabilizer (trade name: SZ-1136, manufactured by Nihon Unicar).
Catalyst 1: Pentamethyldiethylenetriamine (Toyocat DT, manufactured by Tosoh Corporation).
Catalyst 2: N, N, N ′, N′-tetramethylhexamethylenediamine (Toyocat MR, manufactured by Tosoh Corporation).
Polyisocyanate compound: General-purpose crude MDI (trade name: MR-200, manufactured by Nippon Polyurethane Industry Co., Ltd.).

(Reaction conditions, evaluation)
Tables 1 and 2 show the manufacturing formulation and evaluation results. Polyol compounds in combination shown in the table (the total is 100 parts by mass. Tables 1 and 2 show the average hydroxyl value (unit: mg KOH / g)), foaming agent (water), foam stabilizer, An amine catalyst and a flame retardant were mixed and used as a polyol system liquid. This polyol system liquid and polyisocyanate compound (crude MDI) are mixed at a liquid temperature of 20 ° C. so that the ratio of isocyanate groups to active hydrogen groups is 0.75 (isocyanate index 75), and is 200 mm × 200 mm × The reaction was carried out in a 200 mm wooden box. The reactivity at this time was measured by cream time (unit: second), gel time (unit: second), and tack free time (unit: second).

  In addition, the closed cell ratio (unit:%) of the manufactured rigid foam was measured using a high-precision automatic volume meter VM-100 (manufactured by STEC). The storage stability was evaluated by storing the polyol system solution in a refrigerator at 0 ° C. for 1 month, and determining that there was no liquid separation and that the liquid was separated. In addition, flowability was evaluated as a measure of productivity. The method comprises the above-described reactive mixed liquid in the center of a rectangular parallelepiped aluminum mold having a length of 80 cm, a width of 40 cm, and a thickness of 1.7 cm with two width directions adjusted to 40 ° C. 100 g was injected and the average flow length was measured. Moreover, in order to evaluate the open-cell property of the manufactured rigid foam, smoothness was evaluated. In this method, the produced flat plate was stored at 25 ° C., the surface smoothness after 1 week was observed, and the one without shrinkage was good and the one with shrinkage was regarded as shrinkage. The compressive strength (unit: MPa) was measured according to JIS K-7220. Specifically, the measurement was performed using an auto tensilon measuring apparatus manufactured by A & D. The cell appearance was evaluated based on the criteria of good: the cells were fine and uniform, and there was no problem in use. Defect: the cells were non-uniform and rough and unusable.

  As is clear from the above examples, in the examples of the present invention, the storage stability of the polyol system liquid is excellent. Moreover, the density is light, and it is excellent in productivity (flowability), smoothness, strength, adhesiveness, and cell appearance. On the other hand, Example 9 is an example in which the monool (C) was not used, and the storage stability of the polyol system liquid was inferior, and a good rigid foam could not be produced. Example 10 is an example in which the amount of monool (C) used is large, and shrinkage was observed in the manufactured rigid foam. This is presumably because the crosslink density of the resin was lowered. Example 11 is an example in which the amount of the polyol (A) used is small. The produced rigid foam has a high closed cell ratio, and the rigid foam was contracted. Example 12 is an example in which the carbon number of the monool (C) initiator is short, but the storage stability of the polyol system was not good.

The rigid foam obtained by the present invention is excellent in productivity, light weight, and excellent in adhesiveness and strength. Therefore, it is suitably used as a building material for panels, boards and the like.

Claims (7)

In a method for producing an open-celled 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,
As the polyol compound, a polyol mixture containing 40 to 70% by mass of the following polyol (A), 20 to 50% by mass of the following polyol (B) and 1 to 20% by mass of the following monool (C) is used.
6-15 mass parts of water is used as a foaming agent with respect to 100 mass parts of polyol compounds, The manufacturing method of the hard foam synthetic resin characterized by the above-mentioned.
Polyol (A): The average number of functional groups is 2 to 8, the hydroxyl value is 20 to 120 mgKOH / g, the oxyethylene group content is 0 to 5% by mass, and the proportion of primary hydroxyl groups is 15 mol% or less based on the total hydroxyl groups. , Polyoxyalkylene polyols.
Polyol (B): The average number of functional groups is 3 to 8, the hydroxyl value is 200 to 800 mgKOH / g, the oxyethylene group content is 0 to 5% by mass, and the proportion of primary hydroxyl groups is 15 mol% or less based on the total hydroxyl groups. , Polyoxyalkylene polyols.
Monool (C): obtained by reacting an alkylene oxide with a monool having 7 to 22 carbon atoms as an initiator , the oxyethylene group content is 70 to 100% by mass, and the hydroxyl value is 30 to 350 mgKOH / g. a polyoxyalkylene mono-ol.   Polyoxyl obtained by reacting alkylene oxide with at least one initiator selected from the group consisting of water, ethylene glycol, propylene glycol, glycerin, trimethylolpropane, diglycerin, pentaerythritol, sorbitol and sucrose. The method for producing a rigid foam synthetic resin according to claim 1, which is an alkylene polyol.   The method for producing a rigid foam synthetic resin according to claim 1 or 2, wherein the polyol (B) is a polyoxyalkylene polyol obtained by reacting an alkylene oxide with an amine compound as an initiator.   The manufacturing method of the hard foam synthetic resin in any one of Claims 1-3 whose usage-amount of the said polyisocyanate compound is 50-250 by an isocyanate index | exponent. The manufacturing method of the hard foam synthetic resin in any one of Claims 1-4 whose hydroxyl value of the said polyol mixture is 150-300 mgKOH / g.   The hard foam synthetic resin manufactured by the manufacturing method in any one of Claims 1-5.   The rigid foam synthetic resin according to claim 6, wherein the closed cell ratio is 50% or less.