JP5049658B2 - Rigid polyurethane foam composition and rigid polyurethane foam obtained using the same - Google Patents

Description

  The present invention relates to a composition for rigid polyurethane foam and a rigid polyurethane foam obtained therefrom, and in particular, for the purpose of heat insulation of buildings such as buildings, condominiums and frozen warehouses, prevention of condensation, and heat insulation of infusion pipes. Rigid polyurethane foam formed by foaming method (spraying foaming method) and rigid polyurethane foam formed by injection method foaming method (injection foaming method) for the purpose of imparting heat insulation to electric refrigerators, panels, and inner and outer wall materials And a rigid polyurethane foam obtained by foaming and curing the rigid polyurethane foam composition by a spray foaming method.

  Conventionally, rigid polyurethane foam (hereinafter, also simply referred to as foam) has been used as a heat insulating material in various structures such as buildings and electric refrigerators. A polyol component, a foaming agent, and a curing catalyst as necessary. A composition for rigid polyurethane foam prepared by mixing a premix liquid (polyol composition) containing various auxiliaries such as flame retardant and foam stabilizer with an isocyanate component using a mixing device (hereinafter, foaming property). For example, it is manufactured by a method of spraying or injecting an undiluted solution) into a heat insulating part such as a building or an electric refrigerator, and foaming and curing.

  In such foaming stock solutions, alternative chlorofluorocarbons (for example, HFC-245fa, HFC-365mfc, etc.) corresponding to the environmental problem of destruction of the stratospheric ozone layer have been used as foaming agents. Furthermore, from the viewpoint of preventing global warming, carbon dioxide (hereinafter referred to as carbon dioxide) generated by a chemical reaction between a polyisocyanate component and water is used as a substitute for part or all of an alternative fluorocarbon foaming agent. A so-called “water foaming method” has been proposed as a method for producing a non-fluorocarbon-oriented rigid polyurethane foam (see Patent Document 1).

  However, in such a water foaming method, instead of substitute chlorofluorocarbon having a thinning effect, water having no thinning effect is blended, so that the viscosity of the foaming stock solution is adjusted to the extent that it can be used in a foaming machine. In general, low-viscosity polyols such as polyether polyols are used as the polyol component for the purpose of reducing the viscosity of the foamable stock solution. Thus, although the viscosity of the foamable stock solution itself can be reduced by using a low-viscosity polyol, on the contrary, the adhesiveness of the foamable stock solution is lowered and adhesion to the adherend surface is reduced. There is a tendency to deteriorate. In particular, hard polyurethane foam is applied to the surface of adherends such as concrete frames, walls, ceilings, and roofs at construction sites such as buildings under low-temperature environments (eg, -5 to -15 ° C) such as severe cold seasons in winter. When formed, there was a problem that the foam formed easily peeled off from the adherend after construction. For this reason, in order to compensate for the decrease in reactivity such as foaming / curing in a low-temperature environment, prior to spraying, the bottom surface is treated by thinly spraying the foaming stock solution on the adherend surface, which is necessary for the foaming / curing reaction. Although measures are taken to prevent the decrease in reactivity by preventing heat from being taken away by a cold adherend exposed to a low-temperature environment, the work efficiency increases due to the lower blowing treatment, and the work efficiency is improved. The problem was that the density of the foam was increased with the worsening.

  In addition, foams formed by the water foaming method generally have a surface hardness that is higher than the surface hardness of foams formed by the alternative Freon foaming method using alternative Freon as a foaming agent and lack flexibility. ing. Therefore, the tapping process (the work of cutting and smoothing the surface of the sprayed foam), which is performed after the spraying work and before the inner wall material (board) is pasted on the sprayed surface, may be difficult and the work efficiency is improved. There was a problem of lowering. In particular, in a low temperature environment, the foam obtained is high in density and hard due to poor initial foamability, and has poor machinability.

  On the other hand, in the case of rigid polyurethane foams, heat resistance and flame resistance are strongly demanded from the viewpoint of foam fires at the construction site and prevention of similar firing. For this reason, in order to achieve heat resistance and flame retardancy, for example, as the polyol component, a polyol having heat resistance such as polyester polyol is used, a flame retardant such as a phosphoric acid flame retardant is used, or a curing catalyst is used. Various measures have been taken, such as introducing a new cross-linked structure (isocyanurate structure) into the obtained polyurethane using an isocyanurate catalyst (hereinafter referred to as a nurate catalyst) together with a certain urethanization catalyst. . As such a nurating catalyst, Patent Documents 2 to 5 exemplify fatty acid alkali metal salts. However, it is clarified that the fatty acid alkali metal salt is used as a foaming agent. No.

  Patent Document 6 proposes a method for producing a rigid polyurethane foam using water as a foaming agent source, in which an amine-based foaming catalyst is used to promote the reaction between polyisocyanate and water. ing. Furthermore, Patent Document 7 proposes a completely water-foamed rigid polyurethane foam using carbon dioxide gas generated by the reaction of water and polyisocyanate as a foaming agent, where the harmfulness to the human body is pointed out. For example, it has been clarified that bismuth organic acid salts are effective as catalysts instead of lead-based catalysts such as lead octylate and lead naphthenate. Patent Document 8 proposes a non-foaming polyurethane composition for use in waterproofing materials, flooring materials, sealing materials, etc., in which an organic acid bismuth salt and a fatty acid alkali metal salt or fatty acid alkali are used as a catalyst. Combinations of earth metal salts and basic compounds have been found useful. However, these publications do not discuss any of the above-mentioned problems caused when the water foaming method is performed in a low temperature environment such as a severe cold season.

JP-A-4-227645 JP 2004-175773 A JP 61-81420 A JP 2004-339468 A JP 2000-169542 A JP 2001-302756 A JP 2005-307145 A JP 2003-40962 A

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is that in a composition for rigid polyurethane foam using water as a foaming agent source, a low temperature environment (for example, -5 to -15 [deg.] C.) to improve the initial foamability and adhesion to the adherend, and to achieve low density of the foam and prevention of foam peeling from the adherend, A composition for rigid polyurethane foam capable of imparting appropriate flexibility to polyurethane foam and improving work efficiency in cutting after foaming (after foaming and curing), and a composition for such rigid polyurethane foam Another object of the present invention is to provide a rigid polyurethane foam which is foamed and cured by a spray foaming method.

  And in order to solve the said subject, this inventor repeated the earnest examination about the composition for hard polyurethane foams (foamable undiluted | stock solution) useful for the water foaming method in a severe cold season, As a result of specific aliphatic carboxylic acid Foaming due to the soap function of alkali metal salts, acceleration of curing (resinification) by containing a highly reactive Mannich polyol as a polyol component at a predetermined ratio, and carbon dioxide gas by an amine foaming catalyst It was found that the early foaming property is improved by the interaction between the early generation of the compound and the initial problem of foaming, and the above-mentioned problems are solved. Thus, the present invention has been completed.

  That is, the present invention includes (A) a polyisocyanate component, (B) a polyol component containing a Mannich polyol in a proportion of 50% by mass or more, (C) water, and (D) a fat having 12 to 18 carbon atoms. Comprising at least one foaming agent selected from the group consisting of alkali metal salts of group carboxylic acids, and (E) an amine-based foaming catalyst that promotes the reaction between the polyisocyanate component and the water. The gist of the composition for rigid polyurethane foam is as follows.

  In addition, according to the preferable aspect of the composition for rigid polyurethane foams according to this invention, the ratio of the Mannich-type polyol in the said polyol component shall be 70 mass% or more, Furthermore, 80 mass% or more.

  Moreover, according to one of the other preferable aspects in the composition for rigid polyurethane foams according to this invention, the said polyol component contains the glycerol polyether polyol.

  Furthermore, according to one of the desirable aspects in the composition for rigid polyurethane foams according to this invention, the said polyol component contains glycol type polyether polyol further.

  In addition, according to another preferred embodiment of the composition for rigid polyurethane foam according to the present invention, a potassium salt of the aliphatic carboxylic acid can be employed as the foaming agent, and the aliphatic carboxylic acid As the potassium salt, at least one selected from the group consisting of potassium ricinoleate, potassium castor oil fatty acid and potassium oleate can be suitably employed.

  According to another preferred embodiment of the rigid polyurethane foam composition according to the present invention, an organic acid bismuth salt is further contained as a curing catalyst.

  Furthermore, according to one of the desirable embodiments of the composition for rigid polyurethane foam according to the present invention, a phosphoric acid-based flame retardant and / or a silicone-based surfactant is further contained.

  The gist of the present invention is also a rigid polyurethane foam obtained by foaming and curing a composition for a rigid polyurethane foam as described above by a spray foaming method.

  Thus, in the composition for rigid polyurethane foams according to the present invention, since the constituent components (A) to (E) are used in combination, the effects of the constituent components are combined. Even if the water foaming method is performed in a low temperature environment, the initial foamability can be advantageously increased, and the foam can be reduced in density, which makes it possible to omit the conventional bottom blowing treatment. The construction efficiency can be improved, the adhesion to the adherend can be advantageously enhanced, the foam can be effectively prevented from peeling off the adherend, and the resulting rigid polyurethane foam can be softened moderately. In other words, the surface hardness of the rigid polyurethane foam is lowered and the cutting workability is advantageously improved.

  Moreover, in the composition for rigid polyurethane foam according to the present invention, since the Mannich polyol is contained in a proportion of 50% by mass or more as a polyol component, the flame resistance of the obtained rigid polyurethane foam is also advantageous. It is enhanced.

  In addition, in the rigid polyurethane foam according to the present invention, the composition for a rigid polyurethane foam as described above is foamed and cured by the spray foaming method, and thus, various effects as described above are enjoyed. Even if it is constructed in a low temperature environment, peeling from the adherend can be advantageously prevented, and the surface hardness is moderately reduced, and the workability of the cutting process is excellent. It has become a thing.

  In the present invention, the reason why the above-described excellent effects are manifested is not fully elucidated, but according to the inventor's inference, the foaming agent and water are mixed and contacted. Due to physical foaming of the foamable stock solution caused by the above, contact between the foamable stock solution and the adherend is prevented as much as possible. That is, when the foamable concentrate is sprayed on the surface of the adherend, the foamable concentrate is physically foamed on the sprayed adherend surface, and the amount of contact between the foamable concentrate and the adherend can be reduced as much as possible. . The reaction heat generated by the curing reaction (resinification) and the foaming reaction (generation of carbon dioxide gas) promoted by the highly reactive Mannich polyol and amine-based foaming catalyst blended in the foaming stock solution. However, it is advantageously prevented from shifting to the adherend exposed to a low temperature environment and being taken away by the adherend. As a result, the generated heat of reaction can be used for further curing reaction and foaming reaction, and the initial foamability can be improved. Therefore, the balance between the curing reaction and the foaming reaction in the initial foaming stage is extremely high. It will be kept good. Therefore, when the foaming stock solution is sprayed on the adherend in a low temperature environment, the initial foaming state and the adhesion to the adherend are extremely effectively improved. The foam can be advantageously prevented from being peeled off, the foam density is reduced, and not only the construction cost is reduced (the amount of foaming concentrate used is reduced), but also a foam having an appropriate surface hardness or flexibility. Be able to. As a result, even if blowing and foaming is performed in a low temperature environment, it is easy to cut the foam obtained, and no bottom blowing work is required, so that the construction efficiency can be remarkably improved.

  Hereinafter, the rigid polyurethane foam composition according to the present invention and the rigid polyurethane foam obtained by using the composition will be described in detail.

  First, as described above, the composition for rigid polyurethane foam according to the present invention includes at least (A) a polyisocyanate component, (B) a polyol component containing a Mannich polyol in a proportion of 50% by mass or more, and (C And (D) at least one foaming agent selected from the group consisting of alkali metal salts of aliphatic carboxylic acids having 12 to 18 carbon atoms, and (E) a reaction between the polyisocyanate component and the water. An amine-based foaming catalyst to be promoted is contained.

  Of the constituent components of the rigid polyurethane foam composition, the (A) polyisocyanate component is not particularly limited as long as it is an isocyanate compound having two or more isocyanate groups (NCO groups) in the molecule. Thus, various known polyisocyanates are appropriately selected and used. Examples of such polyisocyanates include diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate (crude MDI), tolylene diisocyanate, polytolylene polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, and other aromatic polyisocyanates, hexamethylene. In addition to aliphatic polyisocyanates such as diisocyanates, cycloaliphatic polyisocyanates such as isophorone diisocyanate, isocyaninate group-terminated prepolymers (urethane prepolymers) using the above polyisocyanates, isocyanurate modified carbodiimide modified products of polyisocyanate, etc. These polyisocyanates may be used alone or in combination of two or more. It may be used in the I.

  On the other hand, as the polyol component (B) used in the present invention, among various polyols, those containing a Mannich polyol having a high reaction activity and effective for flame retardancy in a proportion of at least 50% by mass or more. In this case, the polyol component contains a Mannich polyol in a proportion of 50 to 100% by mass, which effectively enhances the reaction in a low-temperature environment, and immediately after spraying. The foamability (initial foamability) and curability at the interface of adherends such as building enclosures are improved, and the adhesion to the adherend is effectively improved. Flame retardancy or fire resistance is also advantageously increased. Among them, when the ratio of the Mannich polyol in the polyol component is preferably 70% by mass or more, more preferably 80% by mass or more, the workability and the flame retardancy are further improved.

  Here, the Mannich polyol is a Mannich condensation product having two or more hydroxyl groups in a molecule obtained by utilizing a Mannich reaction, or a Mannich polyether polyol obtained by adding an alkylene oxide to the Mannich condensation product, or It is a mixture of these. Among these, Mannich polyols based on phenols, such as Mannich condensation products obtained by reacting phenols, aldehydes and secondary amines, or Mannich polyether polyols obtained by adding alkylene oxide to the Mannich condensation products, preferable. Specific examples of such preferred Mannich polyols include Mannich condensation products produced based on the method described in JP-A-10-298258, and the latter include commercial products. Examples thereof include Mannich polyether polyols that can be obtained in the public domain, such as EXCENOL-200R, EXCENOL-400R, and EXCENOL-FB800 (trade name) manufactured by Asahi Glass Co., Ltd.

  As such a Mannich polyol, a Mannich polyol having a hydroxyl value of 300 to 800 mg-KOH / g and a viscosity at 25 ° C. of 500 to 7000 mPa · s is more preferably used. Among Mannich polyols, phenolic Mannich condensation products are superior in terms of reaction activity and flame retardancy compared to Mannich polyether polyols, but because of their high viscosity, emphasis is placed on workability in the water foaming method. Then, Mannich polyether polyol is more suitable.

  By the way, the (B) polyol component can be composed of only the Mannich polyol as described above (the ratio of the Mannich polyol in the polyol component: 100% by mass). In such a range, a combination of other polyols is preferably employed. In this case, the polyol used in combination is not particularly limited as long as it is a compound having two or more hydroxyl groups in the molecule, but the foam physical properties (adhesiveness and flame retardancy) are improved, It is desirable to select a polyol according to the purpose such as improving curability and reducing the viscosity of the polyol component.

  Examples of the polyol used in combination include various polyether polyols such as glycerin-based, sorbitol-based, ethylenediamine-based, tolylenediamine-based, phenolic resin-based, glycol-based, etc. Depending on the choice, the polyol component other than the Mannich polyol may be used alone or in combination of two or more. Among these polyether polyols, in particular, glycerin-based polyether polyols are effective for improving adhesiveness at low temperatures, and glycol-based polyether polyols have a viscosity suitable for the water foaming method. Since it is effective as a viscosity modifier for adjusting, it can be suitably employed. That is, as the polyol component, among various combinations, a combination of a Mannich polyol and a glycerin polyether polyol (a mixture of two kinds of polyols) is preferably used, and more preferably, a Mannich polyol, A combination of glycerin-based polyether polyol and glycol-based polyether polyol (a mixture of three types of polyols) is more advantageously used from the viewpoint of workability.

  Here, as the glycerin-based polyether polyol, those having a hydroxyl value of 20 to 100 mg-KOH / g and a viscosity at 25 ° C. of 200 to 2000 mPa · s are more suitably used, and are commercially available. As an article, Asahi Glass Co., Ltd. EXCENOL-3030 (brand name), ADEKA G3000B (brand name), etc. can be mentioned, for example. On the other hand, examples of the glycol-based polyether polyol include polyethylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polypropylene glycols such as dipropylene glycol, tripropylene glycol, and tetrapropylene glycol. . These can be used alone or in combination of two or more.

  The blending ratio of the (A) polyisocyanate component and the (B) polyol component is determined depending on the type of foam (polyurethane, isocyanurate-modified polyurethane, urethane-modified polyisocyanurate, polyisocyanurate), and water blending described later. The NCO / OH index (equivalent ratio) indicating the ratio of the number of isocyanate groups to the number of hydroxyl groups is generally set in the range of about 0.8 to 3.0, depending on the amount, physical properties and the like. In the case of the polyurethane type, the range is about 0.8 to 1.3, and in the case of the isocyanurate type, the range is about 1.3 to 3.0.

  In addition, water (C), which is one of the other components of the rigid polyurethane foam composition according to the present invention, is a foaming agent source that generates carbon dioxide gas that functions as a foaming agent by reaction with the polyisocyanate component. . In the present invention, the reaction between the water and the polyisocyanate component is promoted by the catalytic action of the (E) amine-based foaming catalyst described later, so that early generation of carbon dioxide gas can be achieved. The amount of water is appropriately set according to the desired foam density. However, when the amount is less than 1 part by mass, the amount of carbon dioxide generated is not sufficient, and the foam density becomes high. On the other hand, when the amount exceeds 10 parts by mass, the foam density is extremely lowered and may cause weakening of the foam. It can be appropriately set in the range of 10 to 10 parts by mass, preferably 2 to 8 parts by mass, more preferably 3 to 7 parts by mass.

  Furthermore, as the foaming agent (D) which is one of the other components of the composition for rigid polyurethane foam according to the present invention, the foaming agent having both high foaming property and good foam stability, so-called soap function is excellent. In the present invention, at least one selected from the group consisting of alkali metal salts of aliphatic carboxylic acids having 12 to 18 carbon atoms, or a combination of two or more types is employed. By using such a specific foaming agent, the initial foamability in a low temperature environment and the adhesion to an adherend can be advantageously improved. More specifically, such a foaming agent comes into contact with water contained in the foaming stock solution and foams on the surface of the sprayed adherend, whereby carbon dioxide gas is produced by the reaction between the water and the isocyanate component. Until this occurs, it is prevented that the foaming stock solution comes into contact with the cold adherend surface exposed to a low temperature environment and the reaction heat generated in the foaming stock solution is taken away. It becomes possible to effectively use the foaming stock solution for foaming and curing reaction, thereby promoting foaming and curing in a well-balanced manner, and when blowing the foaming stock solution to the adherend in a low temperature environment, The initial foamed state and the adhesion to the adherend can be improved extremely effectively. In addition, when the carbon number of the foaming agent is less than the above range or exceeds the above range, the foaming force and the holding force thereof are insufficient, and a desired effect can be obtained. Disappear.

  Further, the foaming agent is used in combination with a Mannich polyol as described above, an amine foaming catalyst described later, etc. The magnification can be increased, and the density of the entire foam can be advantageously reduced. As a result, the hardness of the skin layer on the foam surface is lowered, the flexibility is increased, and the effect of increasing the efficiency of the cutting work after the construction can be enjoyed.

  Here, as an alkali metal salt of an aliphatic carboxylic acid having 12 to 18 carbon atoms (carbon atoms) used as the foaming agent, for example, fatty acid sodium salt (solid soap) or fatty acid potassium salt (liquid soap) Among them, in view of adaptability to the water foaming method, those having good solubility or mixing in the polyol component or water are desirable, and the fatty acid potassium salt is more preferably used. Furthermore, suitable examples of such fatty acid potassium salts include potassium salts such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, and castor oil fatty acid potassium (main component: Among these, potassium oleate, potassium ricinoleate, and castor oil fatty acid potassium mainly composed of potassium ricinoleate have an excellent soap function. In view of the fact that foaming is satisfactorily formed on the surface of the adherend in a low-temperature environment, it is more preferably used. In addition, although the said fatty acid potassium salt is conventionally used for manufacture of a polyurethane foam as a nurating catalyst, in this invention, the outstanding foaming power of the predetermined fatty acid potassium salt is another component. Combined with the reaction promoting effect of the above, the initial foamability, adhesion to the adherend, and the like are effectively improved.

  And generally the said foaming agent is mix | blended in the ratio used as 0.01-5 mass parts with respect to 100 mass parts of a polyol component, Preferably it is 0.1-3 mass parts, More preferably, it is 0.1. ˜2 parts by mass, more preferably 0.3 to 1 part by mass. If the blending amount is less than 0.01 parts by mass with respect to 100 parts by mass of the polyol component, a sufficient foaming effect cannot be obtained. The effect cannot be further improved, and it is not economical.

  Further, (E) the amine foaming catalyst which is one of the other components of the composition for rigid polyurethane foam according to the present invention is a catalyst for promoting the reaction between the polyisocyanate component and water, This is for advancing the generation time of carbon dioxide gas in the liquefaction reaction and realizing a good balance between the curing (resinization) reaction and the foaming reaction of the foamable stock solution containing each component as described above. Examples of such amine-based foaming catalysts include triethylenediamine, pentamethyldiethylenetriamine, bis (dimethylaminoethyl) ether, N, N, N′-trimethylaminoethylethanolamine, N, N-dimethylaminoethoxyethanol, and the like. These may be used alone or in combination of two or more. Among these, considering adverse effects on workers and the environment, a reactive amine-based foaming catalyst having at least one hydroxyl group in the molecule that reacts with the polyisocyanate component and is incorporated into the polyurethane structure (for example, N, N-dimethylaminoethoxyethanol, N, N, N′-trimethylaminoethylethanolamine) are preferably used from the viewpoint of preventing the generation of odor caused by amine compounds, and particularly amine-based compounds. The ratio of the reactive amine-based foaming catalyst in the foaming catalyst is preferably 90 to 100% by mass.

  In addition, the compounding quantity of the said amine type foaming catalyst is suitably set according to the catalyst activity of the amine type foaming catalyst to be used, and generally it is the range of 1-20 mass parts with respect to 100 mass parts of a polyol component. However, it is preferably 3 to 15 parts by mass, more preferably 3 to 10 parts by mass. If the blending amount is less than 1 part by mass, the catalytic effect in the foaming reaction cannot be sufficiently obtained. Conversely, even if it exceeds 20 parts by mass, the catalytic effect can be further improved. It is not economical.

  Further, in the composition for rigid polyurethane foam according to the present invention, a curing catalyst such as a urethanization catalyst or a nuration catalyst can be advantageously blended with the components (A) to (E) as described above, Thereby, the effect exhibited by combining the components (A) to (E) can be more remarkably enjoyed. Examples of such curing catalysts include metal catalysts such as dibutyltin dilaurate, dibutyltin diacetate, potassium octylate, and organic acid bismuth salt, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine, methylmorpholine, trimethylaminoethylpiperazine, Examples include amine catalysts such as bis (dimethylaminotyl) ether, methylimidazole, isobutylmethylimidazole, dimethylimidazole, and tris (dimethylaminopropyl) hexahydrotriazine. These may be used alone or in combination of two or more. Can do. Among these, the organic acid bismuth salt is excellent in the reaction promoting effect in a low temperature environment, so that the foamability at the initial stage of spraying and the adhesion to the adherend can be improved more effectively, and the foam obtained Since the density can be further reduced and the machinability of the foam can be further improved, and since the catalyst conforms to the tendency to lead-free, it is particularly preferably used.

  Examples of such organic acid bismuth salts include alicyclic organic acid bismuth salts such as bismuth abietic acid, aromatic organic acid bismuth salts such as bismuth benzoate and bismuth oxycinnamate. Resin acid bismuth salts, fatty acid bismuth salts having 8 to 20 carbon atoms and the like may be mentioned, and these may be used alone or in combination of two or more. Among these, fatty acid bismuth salts having 8 to 20 carbon atoms are advantageously used from the viewpoint of adaptability to the water foaming method. Examples of the fatty acid bismuth salt include bismuth octylate, bismuth 2-ethylhexylate, bismuth neodecanoate, bismuth neododecanoate, and bismuth naphthenate, one of which is singly or in combination of two or more. Are used in combination.

  In addition, when a curing catalyst such as bismuth salt of organic acid is blended, the blending amount is the same as that for producing a conventional rigid polyurethane foam, depending on the catalytic activity of the curing catalyst used. Generally, the amount is appropriately set in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyol component. In particular, when an organic acid bismuth salt is used, it is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polyol component from the viewpoint of reducing the heavy metal content and obtaining a sufficient blending effect. Is desirable. If the blending ratio is less than 0.01 parts by mass with respect to 100 parts by mass of the polyol component, the effect of addition cannot be obtained. Conversely, if it exceeds 10 parts by mass, the curing reaction is accelerated. It tends to be too much, and the balance between foaming and curing by carbon dioxide gas becomes worse.

  Furthermore, a flame retardant is advantageously blended with the rigid polyurethane foam composition according to the present invention from the viewpoint of flame retardancy of the foam. As such a flame retardant, conventionally known flame retardants can be used, and among them, in the case of phosphate esters such as trischloroethyl phosphate, trischloropropyl phosphate, triethyl phosphate, etc. Therefore, it can be used advantageously as a flame retardant suitable for the water foaming method. In addition, when mix | blending this phosphate ester, the compounding quantity can be suitably determined according to the objective foam characteristic, the kind of flame retardant to use, etc., Preferably, with respect to 100 mass parts of a polyol component 10 to 60 parts by mass, and more preferably about 10 to 40 parts by mass. Moreover, aluminum hydroxide can be illustrated as a suitable flame retardant other than this phosphate ester. These flame retardants can be used alone or in combination of two or more.

  In addition, a foam stabilizer is advantageously blended in the rigid polyurethane foam composition according to the present invention from the viewpoint of heat insulation. Nonionic surfactants are preferably used as such foam stabilizers. Specific examples include polyoxyethylene sorbitan fatty acid ester, castor oil ethylene oxide adduct, lauryl fatty acid ethylene oxide adduct, dimethylpolysiloxane, polyoxysiloxane. Examples thereof include oxyalkylene-modified dimethylpolysiloxane, polysiloxane oxyalkylene copolymer, and the like, and one of these is used alone or in combination of two or more. Among these, silicone surfactants are particularly preferably used because they can reinforce the cell walls of the foamed cells formed in the rigid polyurethane foam. In addition, when the foam stabilizer is blended, the blending amount can be appropriately determined according to the desired foam characteristics, the type of foam stabilizer to be used, etc., but preferably with respect to 100 parts by mass of the polyol component. And about 0.1-5 parts by mass.

  Furthermore, in the present invention, in addition to the essential components (A) to (E) described above, a curing catalyst that is advantageously added, a flame retardant, and a foam stabilizer, as necessary, urea, melamine, and the like. Formaldehyde scavengers, bubble refining agents such as trimethylmethoxysilane, plasticizers, reinforcing base materials and the like can be appropriately blended.

  By the way, the composition for rigid polyurethane foam according to the present invention is composed of water, a foaming agent, an amine-based foaming catalyst, and other curing catalysts, flame retardants, and regulators, as necessary, with respect to the polyol component as described above. A premix liquid (polyol composition) containing various auxiliary agents such as foaming agents and a polyisocyanate component, and these various raw material components are stirred and mixed in a known mixing device. This is a foaming stock solution prepared.

  Among such hard polyurethane foam compositions (foamable stock solutions), for example, foamable stock solutions prepared by high-speed stirring and mixing with a mixing head are suitably applied to the injection foaming method, for example, electric refrigerators and the like. The foamable stock solution prepared by high-pressure impingement mixing by nozzle injection is suitable for the spray foaming method, while it is injected and filled into the honeycomb structure of heat insulation parts and heat insulation boards, foamed and cured, and made into rigid polyurethane foam. Applied, sprayed directly from the spray gun head to the adherend, foamed and cured, and made into a rigid polyurethane foam. As described above, the rigid polyurethane foam composition according to the present invention can be used in both the injection foaming method and the spray foaming method, and the initial foamability in a low temperature environment can be advantageously improved. However, in the present invention, it is particularly suitably used as a hard polyurethane foam composition for on-site construction employing a spray foaming method.

  In addition, the rigid polyurethane foam obtained by foaming and curing by the above blowing foaming method has a low density, excellent adhesiveness, hardly peels off from the adherend, and substitutes Freon foam. It has the same flexibility or surface hardness as the foam formed by the method, and has excellent machinability. And since it is formed using the polyol component which contains a Mannich-type polyol in the ratio of 50% or more, a flame retardance is also improved.

  Some examples of the present invention will be shown below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Needless to say. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific description described above. It should be understood that improvements and the like can be added.

Example 1
In a polybeaker having a capacity of 500 ml, as a polyol component, 80 parts by mass of Mannich polyol (trade name: EXCENOL-200R, manufactured by Asahi Glass Co., Ltd.), 10 parts by mass of glycerin-based polyether polyol (trade name: G3000B, manufactured by ADEKA), And 10 parts by mass of polyethylene glycol (number average molecular weight: 400) acting as a viscosity modifier, and further 5 parts by mass of N, N-dimethylaminoethoxyethanol as an amine foaming catalyst and dibutyltin as a curing catalyst 0.7 parts by weight of dilaurate, 33% castor oil fatty acid potassium aqueous solution (trade name: FR-25, manufactured by Kao Corporation) as a foaming agent, 3 parts by weight (active ingredient: 1 part by weight), water as a foaming agent source 5.5 parts by mass, as a foam stabilizer, a polysiloxane oxyalkylene copolymer (trade name: SH 93, manufactured by Toray Dow Corning Co., Ltd.) 1 part by mass, 20 parts by mass of tris (chloropropyl) phosphate as a flame retardant, and then thoroughly mixed by hand, a premix solution containing a polyol component (polyol composition) Product) (see Table 1 below).

  And the premix liquid (polyol composition) prepared as described above and crude MDI (trade name: M11S, manufactured by BASF INOAC Polyurethane Co., Ltd.) as a polyisocyanate component were adjusted to a liquid temperature of 10 ° C., respectively. Thereafter, each was weighed into a paper cup (capacity 500 ml) so that NCO / OH = 1.05, and then immediately used a homodisper (high-speed stirring mixer, rotation speed: 8000 rpm, manufactured by Tokushu Kika Kogyo Co., Ltd.) Then, the mixture was stirred and mixed until the foaming start cream time to prepare a hard polyurethane foam composition (foamable stock solution). Then, the composition for rigid polyurethane foam was obtained by making the prepared foamable undiluted solution foam-harden at normal temperature as it is.

Moreover, in order to judge the reactivity of a foaming undiluted | stock solution, when cream time (CT), gel time (GT), and rise time (RT) were measured, those time is shown in following Table 2. As shown, C.I. In order from T, they were 4 seconds, 8 seconds and 15 seconds. Here, C.I. T is the time from the start of mixing the premix liquid (polyol composition) and the isocyanate component to the start of foaming. T is the time from the start of mixing of the above components until the foam surface exhibits sticky adhesiveness, and R.T. T indicates the time from the start of mixing of the components to the end of foaming. Furthermore, when the density (free density) of the obtained rigid polyurethane foam was measured according to JIS K 7222, it was 26.0 kg / m ³ as shown in Table 2 below.

  On the other hand, a premix solution containing a polyol component prepared by the procedure as described above and a crude MDI (trade name: M11S, manufactured by BASF INOAC Polyurethane Co., Ltd.) as a polyisocyanate component are used in an on-site spray foaming machine (trade name: FF-1600 (manufactured by Gasmer) was mixed with stirring to prepare a foaming stock solution. And, by blowing this foaming undiluted solution on the surface of the concrete plate (adhered body) which is a casing under the respective conditions of the atmospheric temperature: 5 ° C., −5 ° C. or −15 ° C., foaming and hardening, Thickness: A foamed layer made of a rigid polyurethane foam having a thickness of about 30 mm was formed. In addition, the foaming state of the foamable stock solution immediately after the start of spraying was observed during the spraying, and “initial foamability” was evaluated according to the evaluation criteria described later. The obtained results are shown in Table 2 below.

  In addition, after 5 minutes from spraying, the end of the rigid polyurethane foam protruding from the concrete plate was cut with a cutter knife along the peripheral edge of the concrete plate, and the following evaluation criteria, according to the touch at that time, Atmosphere temperature: The “foam machinability” of the foam formed at −15 ° C. was evaluated. Furthermore, by visually observing the cut surface after cutting, particularly the adhesive surface between the concrete plate and the polyurethane foam, and confirming whether or not the hard polyurethane foam was peeled off, the “adhesiveness” was evaluated according to the following evaluation criteria. . Moreover, the density of the rigid polyurethane foam produced at each environmental temperature was measured according to JIS K7222. Further, a combustion test piece (300 mm × 200 mm × 30 mm) was cut out from each rigid polyurethane foam (foam formed at ambient temperature: −15 ° C.), and the combustion test piece was set at a position about 100 mm away from the gas torch. Thereafter, flame was directly applied to the combustion test piece for 30 seconds, and the flame retardancy was evaluated according to the following evaluation criteria. These results are also shown in Table 2 below.

  The evaluation criteria for the above-mentioned “initial foamability” are: x: liquid sag occurs, surface is not smooth, Δ: liquid sag occurs slightly, surface is smooth, ◯: liquid sag occurs And the surface was smooth, ◎: better than ◯. In addition, the evaluation criteria for “form machinability” are: x: a large force is required for cutting, and smoothing work is difficult, Δ: some force is required for cutting, and some smoothing work is required. There is a difficulty, ○: It can be easily cut, and smoothing work is easy. Furthermore, the evaluation criteria for “adhesiveness” are: x: peeling of the foam from the concrete board is recognized and there is a difficulty in adhesion, Δ: peeling of the foam from the concrete board is slightly recognized, but the adhesiveness is No problem, ○: No exfoliation of the foam from the concrete board was observed, and there was no problem in adhesion. Furthermore, the evaluation criteria for “flame retardant” were: X: large penetration, Δ: slight penetration, ○: no penetration in the test piece after the test.

(Examples 2-7 and Comparative Examples 1-3)
In Example 1, Examples 2 to 7 and Comparative Examples were performed in the same manner as in Example 1 except that the blending ratio of each component in the premix solution containing the polyol component and the blending components were changed to those shown in Table 1 below. Nine types of premix solutions according to 1 to 3 were prepared. In Example 2, the Mannich condensation product described below was used as the Mannich polyol, and bismuth octylate (trade name: Puccat 25, manufactured by Nippon Chemical Industry Co., Ltd.) was used as the curing catalyst. Moreover, in Example 4, potassium oleate is used as a foaming agent, and in Comparative Example 2, potassium octylate (trade name: PACCAT 15G, manufactured by Nippon Chemical Industry Co., Ltd.) is used as a curing catalyst. Using.

  In addition, as the Mannich condensation product, one produced as follows was used. That is, first, 1222 parts by mass of phenol and 819 parts by mass of diethanolamine were charged into a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, and 498 parts by mass of 47% by mass formalin was added at 40 ° C. under stirring. The solution was dropped while controlling the heat generation so as not to exceed. After completion of the dropwise addition, the temperature was raised to 60 ° C., the mixture was reacted at the same temperature for 1 hour, and then cooled to 30 ° C. Subsequently, 380 parts by mass of diethylamine was added, and 332 parts by mass of 47% by mass formalin was added dropwise by the same operation as described above, followed by reaction at 60 ° C. for 1 hour and then cooling to 40 ° C. Next, the pressure inside the reaction system was reduced to about 20 to 60 mmHg under stirring, and the Mannich condensation product was produced by heating and concentrating to 100 ° C. The Mannich condensation product thus obtained has a moisture content (Karl Fischer method) of 0.4 mass%, a hydroxyl value measured according to JIS K 0070 of 500 mg KOH / g, and a cone plate viscometer CV-1S. (Trade name, manufactured by Toa Kogyo Co., Ltd., viscosity is a numerical value calculated by multiplying the display value 30 seconds after starting rotation of corn type rotor No. 5 at 94 rpm by 8) with an initial viscosity at 30 ° C. It was 4450 mPa · s.

  Thus, using the premix solution prepared above and the polyisocyanate component (trade name: M11S), C.I. T, G. T, R.M. Measure density at T and normal temperature (free density), spray on concrete board with on-site spray foaming machine, evaluate initial foamability, foam adhesion, adhesion and flame retardancy, and measure density The results obtained are also shown in Table 2 below.

  As apparent from Table 2, in the hard polyurethane foam compositions according to Examples 1 to 7, the initial foamability, adhesiveness, foam cutting property and flame retardancy were all It turns out that it is (circle) or (triangle | delta) and it is favorable. In particular, in Example 2 to which bismuth octylate was added, the initial foamability at 5 ° C. and −5 ° C. was ◎, and the respective densities at 5 ° C., −5 ° C. and −15 ° C. were It is low compared to other examples, and it is recognized that the machinability is excellent.

On the other hand, in Comparative Example 1 and Comparative Example 2 in which no foaming agent is blended, initial foamability, adhesiveness, and foam machinability under a low temperature environment (−5 ° C., −15 ° C.) are not good. I understand. Further, even in Comparative Example 3 in which only 45% of the Mannich polyol is blended in the polyol component, the initial foamability, adhesiveness, and foam cutting property in a low temperature environment (−5 ° C., −15 ° C.) It turns out that it is not favorable and is also inferior in flame retardance compared with the other Examples.

Claims (10)

(A) a polyisocyanate component;
(B) a polyol component containing a Mannich polyol in a proportion of 50% by mass or more;
(C) water and
(D) at least one foaming agent selected from the group consisting of alkali metal salts of aliphatic carboxylic acids having 12 to 18 carbon atoms;
(E) an amine-based foaming catalyst that promotes the reaction between the polyisocyanate component and the water;
A composition for rigid polyurethane foam, comprising:   The composition for rigid polyurethane foam according to claim 1, wherein the ratio of Mannich polyol in the polyol component is 70% by mass or more.   The composition for rigid polyurethane foam according to claim 2, wherein the ratio of the Mannich polyol in the polyol component is 80% by mass or more.   The composition for rigid polyurethane foam according to any one of claims 1 to 3, wherein the polyol component contains a glycerin-based polyether polyol.   The composition for rigid polyurethane foam according to claim 4, wherein the polyol component further contains a glycol polyether polyol.   The composition for rigid polyurethane foam according to any one of claims 1 to 5, wherein the foaming agent is a potassium salt of the aliphatic carboxylic acid.   The composition for a rigid polyurethane foam according to claim 6, wherein the potassium salt of the aliphatic carboxylic acid is at least one selected from the group consisting of potassium ricinoleate, potassium castor oil fatty acid and potassium oleate.   The composition for rigid polyurethane foam according to any one of claims 1 to 7, further comprising an organic acid bismuth salt as a curing catalyst.   The composition for rigid polyurethane foam according to any one of claims 1 to 8, further comprising a phosphoric acid-based flame retardant and / or a silicone-based surfactant. A rigid polyurethane foam obtained by foaming and curing the composition for rigid polyurethane foam according to any one of claims 1 to 9 by a spray foaming method.