JP2020070410A - Method for producing polyurethane foam - Google Patents

Abstract

To provide a method for producing a polyurethane foam capable of advantageously forming a polyurethane foam having excellent flame retardancy and a uniform density distribution.SOLUTION: In producing a polyurethane foam by mixing and reacting a composition A mainly composed of a polyol and a composition B mainly composed of a polyisocyanate, followed by foaming and curing, the objective polyurethane foam is produced by 1) incorporating at least an aromatic polyester polyol into the composition A, 2) incorporating a foaming agent I composed of red phosphorus into the composition A and/or the composition B, and 3) in the production site of the polyurethane foam, adding a foaming agent I composed of critical, subcritical or liquid carbon dioxide to the composition A and/or the composition B at a predetermined ratio, followed by proceeding the reaction.SELECTED DRAWING: None

Description

  TECHNICAL FIELD The present invention relates to a method for producing a polyurethane foam, and more particularly to a method capable of advantageously producing a polyurethane foam having excellent flame retardancy and having a uniform density distribution.

  BACKGROUND ART Conventionally, polyurethane foam has been used mainly as a heat insulating material by utilizing its excellent heat insulating properties, adhesiveness, lightweight properties, and the like, as a heat insulating material for building interior and exterior wall materials and panels, metal siding, electric refrigerators, etc. It is used for heat insulation, insulation of building walls, ceilings, roofs, etc. of buildings, condominiums, frozen warehouses, etc., prevention of dew condensation, insulation of infusion pipes, etc., and backing material for filling voids generated in civil engineering work, civil engineering work It is also in practical use as a reinforcing material for such occasions. In addition, such a polyurethane foam is generally a composition comprising a polyol compounding liquid (premix liquid) in which a foaming agent is further mixed with a polyol and, if necessary, various auxiliary agents such as a catalyst, a foam stabilizer and a flame retardant. A and a composition B containing polyisocyanate as a main component are continuously or intermittently mixed by a mixing device to obtain a foamable composition for polyurethane foam, which is slab foaming method, injection foaming method, It is manufactured by foaming and curing by a method such as a spray foaming method, a laminate continuous foaming method, a lightweight embankment method, and an injection backfilling method.

  By the way, since the polyurethane foam formed as described above is required to have flame retardancy in view of its application, it is described in, for example, paragraph [0046] of Patent Document 1 (JP 2002-47325A). As described above, it is known that flame retardancy is imparted to a polyurethane foam obtained by using a flame retardant added to a polyol component or the like. Particularly, in recent years, where polyurethane foam is required to have more excellent flame retardancy than ever before, it is proposed to use red phosphorus as a flame retardant in order to exhibit more excellent flame retardancy in polyurethane foam. Has been done. For example, in Patent Document 2 (JP-A-2015-193839), a polyisocyanate compound, a polyol compound, an additive and the like are contained, and an additive is added to 100 parts by weight of a urethane resin composed of the polyisocyanate compound and the polyol compound. A flame-retardant urethane resin composition characterized by containing 3.5 to 20 parts by weight of red phosphorus has been proposed, and in Patent Document 3 (JP-A-2015-63675), a polyisocyanate is proposed. A urethane resin composition containing a compound, a polyol compound having a weight average molecular weight of 1,000 to 20,000, a foaming agent, and an additive containing red phosphorus as an essential component has been proposed.

  However, the composition containing red phosphorus as disclosed in Patent Document 2 or Patent Document 3 is applied to a target adherend (structure) from a spray gun head of an in-situ foaming machine according to, for example, a spray foaming method (spray foaming method). When a polyurethane foam is manufactured by spraying, foaming and curing, the following problems may occur. That is, 1) the granular or powdery substance of red phosphorus may hinder the progress of the urethane reaction, and 2) the specific gravity of red phosphorus is larger than the specific gravity of the entire composition, Due to the low dispersibility of the powdery substance of phosphorus, etc., in the finally obtained polyurethane foam, the powdery substance of red phosphorus, etc. will be present in a biased state, resulting in a biased density. There is an inherent problem of producing polyurethane foam with a distribution.

JP-A-2002-47325 JP, 2005-193839, A JP, 2005-63675, A

  Here, the present invention has been made in view of such circumstances, and the problem to be solved is that it is difficult to foam and cure by any conventionally known foaming method. It is an object of the present invention to provide a method for producing a polyurethane foam which has an excellent flammability and is advantageous in polyurethane foam having a uniform density distribution.

  And in order to solve the above-mentioned subject, the present invention can be suitably carried out in the various modes enumerated below. It is understood that the aspects and technical features of the present invention are not limited to those described below and can be recognized based on the inventive idea that can be understood from the description of the specification. Should be.

(1) When a polyurethane foam is produced by mixing a composition A containing a polyol as a main component with a composition B containing a polyisocyanate as a main component and reacting them to foam and cure the mixture,
As the polyol, at least an aromatic polyester polyol is contained in the composition A,
Flame retardant I made of red phosphorus is contained in the composition A and / or the composition B,
At the production site of the polyurethane foam, a blowing agent I consisting of carbon dioxide in a critical, subcritical or liquid state is added to the composition A and / or the composition B, and the reaction is immediately performed after the addition. Can proceed,
A method for producing a polyurethane foam, comprising:
(2) A flame retardant II comprising at least one of a phosphate ester, a phosphate-containing flame retardant, a stannate-containing flame retardant, a bromine-containing flame retardant, a boron-containing flame retardant and a metal hydroxide, The method for producing a polyurethane foam according to the aspect (1), which is contained in the composition A and / or the composition B.
(3) The method for producing a polyurethane foam according to the aspect (1) or the aspect (2), wherein the proportion of the aromatic polyester polyol in the polyol is 30% by mass or more.
(4) The method for producing a polyurethan foam according to any one of the aspects (1) to (3), wherein a polyether polyol is further contained in the composition A as the polyol.
(5) The method for producing a polyurethane foam according to any one of the above aspects (1) to (4), wherein the aromatic polyester polyol has a number average molecular weight of 200 to 1,000.
(6) The flame retardant I composed of red phosphorus is contained in the composition A and / or the composition B at a ratio of 1 to 70 parts by mass with respect to 100 parts by mass of the polyol in the composition A. The method for producing a polyurethane foam according to any one of the above aspects (1) to (5), which is caused.
(7) The flame retardant II is contained in the composition A and / or the composition B in a proportion of 3 to 90 parts by mass with respect to 100 parts by mass of the polyol in the composition A. A method for producing a polyurethane foam according to any one of aspects (2) to (6).
(8) A foaming agent II made of at least one of water, hydrocarbon, hydrofluorocarbon and halogenated olefin is at least one of the composition A, the composition B and the foaming agent I. The method for producing a polyurethane foam according to any one of the above aspects (1) to (7), which is contained in one of the two.
(9) Any one of the above aspects (1) to (8) in which the polyurethane foam is produced by a blowing foaming method after adding the foaming agent I to the composition A and / or the composition B 1. The method for producing a polyurethane foam according to one.
(10) Polyurethane according to any one of the aspects (1) to (9), wherein a polyurethane foam having a difference between the overall density and the core density of 0.1 to 12 kg / m ³ is obtained. Form manufacturing method.
(11) Polyurethane foam having a total calorific value of 8 MJ / m ² or less after 10 minutes when heated at a radiant heat intensity of 50 kW / m ² according to the test method specified in ISO-5660. The method for producing a polyurethane foam according to any one of the above aspects (1) to (10), wherein
(12) Polyurethane foam having a total calorific value of 8 MJ / m ² or less after 20 minutes when heated at a radiant heat intensity of 50 kW / m ² according to the test method specified in ISO-5660. The method for producing a polyurethane foam according to any one of the above aspects (1) to (11), wherein

  As described above, in the method for producing a polyurethane foam according to the present invention, at least a part of the polyol in the composition A is an aromatic polyester polyol that contributes to the improvement of the flame retardancy of the polyurethane foam, and the critical and subcritical values are used. Alternatively, the blowing agent I made of liquid carbon dioxide is added to the composition A and / or the composition B at the production site of the polyurethane foam, and then the composition A and the composition B are immediately reacted with each other. Therefore, in the production method of the present invention, the mixture of the composition A and the composition B (reactant) is formed by the effective foaming of the foaming agent I from the start to the end of the reaction between the polyol and the polyisocyanate. In that case, the red phosphorus is dispersed in a good state, in other words, the red phosphorus is uniformly present in the mixture (reactant) without being unevenly distributed. As a result, the red phosphorus and the aromatic polyester polyol exhibit excellent flame retardancy, and the density distribution becomes uniform. Further, when the present invention is applied to perform two-layer spraying (two-stage spraying) especially in winter when the ambient temperature is low, the first-layer foam (foam formed by the first spray) and the second-layer foam The finally obtained polyurethane, since the difference in density between the foam (foam formed by the second spraying) is small and therefore the occurrence of the difference in shrinkability between the layers is effectively suppressed. The foam as a whole has suppressed warpage.

  In the method for producing a polyurethane foam according to the present invention, the composition A containing a polyol as a main component and the composition B containing a polyisocyanate as a main component are mixed, foamed and cured to give a desired polyurethane foam. The polyol, which is the main component constituting the composition A used therein, is at least a part or all of the aromatic polyester polyol. By using the aromatic polyester polyol, the finally obtained polyurethane foam exhibits excellent flame retardancy.

  Here, in the present invention, any conventionally known aromatic polyester polyol can be used. Preferably, orthophthalic acid, isophthalic acid, terephthalic acid, or a phthalic acid-based compound obtained by decomposing a phthalic acid-based polyester molded product such as condensed polyester polyol or polyethylene terephthalate obtained by reacting phthalic anhydride with a polyhydric alcohol A phthalic acid type polyester polyol such as a recovered polyester polyol is used, and a terephthalic acid type polyester polyol is more preferably used. In the present invention, one kind or two or more kinds of aromatic polyester polyols can be used.

  The number average molecular weight (Mn) of the aromatic polyester polyol used in the present invention is preferably 200 to 1000, more preferably 250 to 900, and most preferably 300 to 800. By using an aromatic polyester polyol having a number average molecular weight (Mn) within these ranges, a polyurethane foam having excellent dimensional stability can be advantageously produced.

  The proportion of the above-mentioned aromatic polyester polyol in the polyol contained in the composition A of the present invention is preferably 30% by mass or more, more preferably 40 to 100% by mass, and 50 to 90% by mass. % Is most preferred. When the proportion of the aromatic polyester polyol in the polyol in the composition A is less than 30% by mass, the polyurethane foam finally obtained may not exhibit sufficient flame retardancy.

  On the other hand, in the present invention, as the polyol which is the main component of the composition A, it is preferable to use a polyether polyol together with the above-mentioned aromatic polyester polyol. By using a polyether polyol with an aromatic polyester polyol, the difference between the overall density and the core density of the foam can be further reduced while maintaining the flame retardancy of the finally obtained polyurethane foam, and the dimensional stability of the foam. It is possible to improve.

  The polyether polyol that can be used in the present invention is not particularly limited, but for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol. , Dipropylene glycol, neopentyl glycol, glycerin, trimethylol bropan, pentaerythritol, methyl glucoside, sorbitol, sucrose and other polyhydric alcohols; pyrogallol, hydroquinone and other polyhydric phenols; bisphenol A, bisphenol S, bisphenol F, bisphenols such as low-condensation products of phenol and formaldehyde; propylenediamine, hexamethylenediamine, ethylenediamine, diethylenetriamine, triethylenethene Aliphatic amines such as lamin, pentamethylenehexamine, ethanolamine, diethanolamine, triethanolamine, aminoethylethanolamine; aromatic amines such as aniline, phenylenediamine, xylylenediamine, methylenedianiline, diphenyletherdiamine; isophorone Alicyclic amines such as diamine and cyclohexylenediamine; Heteroalicyclic amines such as aminoethylpiperazine; Activity of the polyhydric phenol, Mannich polyol (compound obtained by reaction of the aliphatic amine and formalin), etc. The compound etc. which added the alkylene oxide to the hydrogen compound can be mentioned. In addition, these active hydrogen compounds may be a mixture of two or more kinds. Further, the alkylene oxide added to the active hydrogen compound is not particularly limited, and examples thereof include ethylene oxide, propylene oxide, butylene oxide and the like, and two or more of these may be used in combination. May be. Preferable alkylene oxide is ethylene oxide, propylene oxide, or a combination thereof.

  In the present invention, among the conventionally known polyether polyols, ethylenediamine-based polyether polyol, Mannich-based polyether polyol, sucrose-based polyether polyol, and glycerin-based polyether polyol are advantageously used. It is also possible to use two or more polyether polyols.

  Further, in the present invention, even polyols other than the above-mentioned polyether polyols can be used together with the aromatic polyester polyol. Examples of such polyols include polyester polyols and polymer polyols.

  Polyester polyol used in the present invention is not particularly limited, for example, polybasic acids such as succinic acid, adipic acid, sebacic acid, maleic acid, dimer acid, trimellitic acid, and polyhydric alcohols. Examples thereof include condensed polyester polyols obtained by the reaction and polylactone polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone.

  Further, the polymer polyol is not particularly limited, and for example, the polyether polyol and the ethylenically unsaturated monomer (for example, butadiene, acrylonitrile, styrene, etc.) described above may be used in the presence of a radical polymerization catalyst. Examples thereof include polymer polyols obtained by reacting with.

  On the other hand, the polyisocyanate, which is the main component of the composition B, is blended with the composition A and reacts with the polyol in the composition A to form a polyurethane (resin). Is an organic isocyanate compound having two or more isocyanate groups (NCO groups) in, for example, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, tolylene diisocyanate, polytolylene triisocyanate, xylylene diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, Aromatic polyisocyanates such as dimethyldiphenylmethane diisocyanate and triphenylmethane triisocyanate, methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate , Tetramethylene diisocyanate, aliphatic polyisocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, dicyclohexylmethane diisocyanate, alicyclic polyisocyanate such as dimethyldicyclohexylmethane diisocyanate, and isocyanate at the molecular end Examples thereof include urethane prepolymers having a group, isocyanurate modified products of polyisocyanates, and carbodiimide modified products. These polyisocyanate compounds may be used alone or in combination of two or more kinds. Generally, polymethylene polyphenylene polyisocyanate (polymeric MDI) is preferably used from the viewpoints of reactivity, economy, handleability, and the like.

  The proportion of the polyisocyanate in the composition B and the polyol in the composition A described above is appropriately determined depending on the type of foam to be formed (for example, polyurethane or polyisocyanurate). However, generally, the NCO / OH index (equivalent ratio) showing the ratio of the isocyanate group (NCO) of the polyisocyanate to the hydroxyl group (OH) of the polyol is 0.9 to 4.5, preferably 1.5 to 4.0. It will be appropriately determined so as to be within the range of the degree.

  Then, in the present invention, the composition A and the composition B as described above are mixed and reacted with each other, and at the same time, foamed by a foaming agent and cured to form a hard polyurethane foam. However, in the reaction between the composition A and the composition B, a catalyst is generally used. In the present invention, preferably a trimerization catalyst, in other words, a catalyst (isocyanurate-forming catalyst) that reacts with an isocyanate group of a polyisocyanate to trimerize and promotes the formation of an isocyanurate ring is added to the composition A. It will be included. As this trimerization catalyst, it is possible to appropriately select and use various known ones, but it is preferable to use a quaternary ammonium salt, potassium octylate, potassium 2-ethylhexanoate, sodium acetate. Carboxylic acid alkali metal salts such as; trinitromethyl aromatic compounds such as tris (dimethylaminomethyl) phenol, 2,4-bis (dimethylaminomethyl) phenol, tris (dimethylaminopropyl) hexahydrotriazine; trimethylammonium salt, triethyl Examples thereof include tertiary ammonium salts such as ammonium salts and triphenylammonium salts. Among these, it is preferable to use a quaternary ammonium salt from the viewpoint of improving flame retardancy, and in particular, it is more preferable to use a quaternary ammonium salt and an alkali metal carboxylic acid salt together. From the viewpoint of improvement, it is particularly preferable.

  The quaternary ammonium salt advantageously used here is tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, propyltrimethylammonium, butyltrimethylammonium, pentyltrimethylammonium, hexyltrimethylammonium, heptyltrimethylammonium, octyltrimethylammonium, Nonyl trimethyl ammonium, decyl trimethyl ammonium, undecyl trimethyl ammonium, dodecyl trimethyl ammonium, tridecyl trimethyl ammonium, tetradecyl trimethyl ammonium, heptadecyl trimethyl ammonium, hexadecyl trimethyl ammonium, heptadecyl trimethyl ammonium, octadecyl trimethyl ammonium Aliphatic ammonium compounds, hydroxyammonium compounds such as (2-hydroxypropyl) trimethylammonium, hydroxyethyltrimethylammonium, trimethylaminoethoxyethanol, hydroxyethyl-2-hydroxypropyldimethylammonium, 1-methyl-1-azania-4- Examples thereof include alicyclic ammonium compounds such as azabicyclo [2,2,2] octanium, 1,1-dimethyl-4-methylpiperidinium, 1-methylmorpholinium, and 1-methylpiperidinium. Among these, excellent catalytic activity, from industrially available, tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, butyltrimethylammonium, hexyltrimethylammonium, octyltrimethylammonium, decyltrimethylammonium, dodecyltrimethylammonium, Tetradecyltrimethylammonium, hexadecyltrimethylammonium, octadecyltrimethylammonium, (2-hydroxypropyl) trimethylammonium, hydroxyethyltrimethylammonium, hydroxyethyl-2-hydroxypropyldimethylammonium, 1-methyl-1-azania-4-azabicyclo [ 2,2,2] Octanium, and 1,1-dimethyl-4-methyl Peridinium is, so that the preferably used.

  Examples of the organic acid group or the inorganic acid group constituting the quaternary ammonium salt as described above include, for example, formic acid group, acetic acid group, octylic acid group, oxalic acid group, malonic acid group, succinic acid group, glutaric acid group, Organic acid groups such as adipic acid group, benzoic acid group, toluic acid group, ethyl benzoic acid group, methyl carbonate group, phenol group, alkylbenzene sulfonic acid group, toluene sulfonic acid group, benzene sulfonic acid group, and phosphoric acid ester group, Inorganic acid groups such as a halogen group, a hydroxyl group, a hydrogen carbonate group and a carbonic acid group can be mentioned. Among these, formic acid groups, acetic acid groups, octylic acid groups, methyl carbonate groups, halogen groups, hydroxyl groups, hydrogen carbonate groups, and carbonate groups are preferable because they have excellent catalytic activity and are industrially available.

  Further, various catalysts composed of such a quaternary ammonium salt are commercially available, for example, U-CAT 18X, U-CAT 2313 (manufactured by San-Apro Co., Ltd.), Kaorizer No. 410, Kaurizer No. 420 (manufactured by Kao Corporation) and the like can be mentioned.

  In addition, as described above, the amount of the trimerization catalyst used as one of the catalysts is 0 with respect to 100 parts by mass of the entire polyol in the composition A in order to effectively exhibit the function as the catalyst. 1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, more preferably 1 to 6 parts by mass. If the amount of the trimerization catalyst used is less than 0.1 parts by mass, the trimerization of the polyisocyanate cannot be sufficiently realized, which makes it difficult to sufficiently achieve the flame retardancy improving effect. On the other hand, when the amount is more than 10 parts by mass, the reaction proceeds too much and the solidification is accelerated, which makes spraying difficult.

  In the present invention, it is also possible to use a urethanization catalyst which is a resinization catalyst together with such a trimerization catalyst. Examples of the urethane-forming catalyst include known ones such as dibutyltin dilaurate, bismuth octylate (bismuth 2-ethylhexylate), bismuth neodecanoate, bismuth neododecanoate, bismuth naphthenate and other fatty acid bismuth salts, lead naphthenate and the like. I can.

  The amount of the resinification catalyst used is 0.1 to 10 parts by mass, preferably 0 to 100 parts by mass of the entire polyol in the composition A, so that the function as a catalyst can be effectively exhibited. It will be selected in the range of 0.5 to 8 parts by mass, more preferably 1 to 6 parts by mass. If the amount of the resinification catalyst used is less than 0.1 parts by mass, the resulting foam may be sticky, dust, etc. may adhere to the foam, and the appearance may be deteriorated. There is a problem that the workability deteriorates because the droplets that adhere to the surface become sticky. On the other hand, if it exceeds 10 parts by mass, the heat generated during the resinification reaction will increase and the appearance of the foam will become yellow, etc. However, the catalyst containing the quaternary ammonium salt contained in the droplets generated during foaming may deteriorate the work environment at the work site where the spraying work is performed.

  On the other hand, in the present invention, either of the above-described composition A containing a polyol as a main component or composition B containing a polyisocyanate as a main component, or both of the composition A and the composition B, Red phosphorus (flame retardant I) is added. In the present invention, any conventionally known red phosphorus can be used, and usually, it is appropriately selected from commercial products and used. In addition, the addition amount of red phosphorus in the present invention (when it is used by adding to both the composition A and the composition B, the total amount) is 1 to 100 parts by mass of the polyol in the composition A. 70 parts by mass, preferably 10 to 60 parts by mass, more preferably 20 to 55 parts by mass. When the amount of this red phosphorus added is too small, the resulting polyurethane foam may not be able to exhibit sufficient flame retardancy, and when the amount added is too large, the composition of the composition in which it is added In addition to increasing the viscosity and causing problems such as poor stirring, there is a risk of causing problems such as reduced workability and the fact that the polyurethane foam becomes rather flammable.

  Further, in the present invention, the coated red phosphorus is advantageously used among the red phosphorus from the viewpoints of safety and easy handling. The coated red phosphorus is a red phosphorus that is surface-treated with an inorganic substance and / or an organic substance, and commercially available coated red phosphorus is Novarred (trade name, manufactured by Rin Kagaku Kogyo Co., Ltd.) Excel (trade name, manufactured by Rin Kagaku Kogyo Co., Ltd.), Hishiguard (trade name, manufactured by Nippon Kagaku Kogyo Co., Ltd.) and the like can be exemplified. As the coated red phosphorus, one having a high red phosphorus content contributes more effectively to the improvement of the flame retardancy of the polyurethane foam, and therefore the red phosphorus component is 80% or more, preferably 80 to 99%, Coated red phosphorus, preferably 90-98%, is advantageously used.

  As the red phosphorus used in the present invention, those exhibiting a granular body or a powdery body are advantageously used similarly to the red phosphorus conventionally used when producing a polyurethane foam. Further, in order to obtain a good dispersion state in the finally obtained polyurethane foam, red phosphorus particles or powders having an average particle diameter of 1 to 50 μm, preferably 5 to 45 μm, and more preferably 10 to 40 μm. The body is used advantageously.

  On the other hand, in the method for producing a polyurethane foam according to the present invention, it is possible to use other flame retardants known in the related art together with the above red phosphorus. By using another flame retardant together with red phosphorus, it is possible to further improve the flame retardancy of the finally obtained polyurethane foam. When red phosphorus and other flame retardants are used in combination, the amount of red phosphorus used can be suppressed to a small amount, which effectively suppresses the uneven distribution of red phosphorus in the foam, resulting in a density distribution. Can be advantageously obtained (in other words, the difference between the overall density and the core density is small). In the present invention, examples of the flame retardant that can be used with red phosphorus include phosphoric acid ester, phosphate-containing flame retardant, stannate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant and metal hydroxide. You can do it. Advantageously, at least one or more of the various flame retardants described below (flame retardant II), together with red phosphorus (flame retardant I) or separately from red phosphorus (flame retardant I), the composition A and / or composition B.

-Phosphate ester-
Examples of the phosphoric acid ester include monophosphoric acid ester and condensed phosphoric acid ester.

  The monophosphate ester is not particularly limited, and examples thereof include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl. Phosphate, tris (isopropylphenyl) phosphate, tris (phenylphenyl) phosphate, trinaphthylphosphate, cresyldiphenylphosphate, xylenyldiphenylphosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenylphosphate, monoisodecyl Phosphate, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl Cid phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine oxide, tricresylphosphine oxide, diphenyl methanephosphonate, phenylphosphone Examples thereof include diethyl acid, resilcinol bis (diphenyl phosphate), bisphenol A bis (diphenyl phosphate), phosphaphenanthrene, tris (β-chloropropyl) phosphate and the like.

  Further, the condensed phosphoric acid ester is not particularly limited, and examples thereof include trialkyl polyphosphate, resorcinol polyphenyl phosphate, resorcinol poly (di-2,6-xylyl) phosphate (trade name, manufactured by Daihachi Chemical Industry Co., Ltd.). : PX-200), hydroquinone poly (2,6-xylyl) phosphate, condensates of these, and the like. Examples of commercially available condensed phosphates other than those mentioned above include resorcinol polyphenyl phosphate (trade name: CR-733S), bisphenol A polycresyl phosphate (trade name: CR-741), aromatic condensed phosphate ester. (Trade name: CR747), resorcinol polyphenyl phosphate (made by ADEKA, trade name: ADEKA STAB PFR), bisphenol A polycresyl phosphate (trade names: FP-600, FP-700) and the like can be mentioned.

  In the present invention, it is possible to appropriately select and use one or two or more kinds from among the conventionally known phosphoric acid esters including the monophosphoric acid ester and the condensed phosphoric acid ester described above. is there. Further, among the above monophosphates and condensed phosphates, it is possible to use a monophosphate in that the effect of lowering the viscosity of the composition before curing and the effect of reducing the initial calorific value are high. It is more preferable to use tris (β-chloropropyl) phosphate.

-Phosphate-containing flame retardant-
The phosphate-containing flame retardant is one that contains a phosphate and has flame retardancy. The phosphoric acid used in the phosphate-containing flame retardant is not particularly limited, and various phosphoric acids such as monophosphoric acid, pyrophosphoric acid and polyphosphoric acid can be exemplified.

  Further, as the phosphate-containing flame retardant, for example, the above-mentioned various phosphoric acids, and at least one metal selected from the metals of groups IA to IVB of the periodic table, ammonia, aliphatic amines, aromatic amines or compounds thereof. Mention may be made of phosphates consisting of salts with. Examples of the metal of Group IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron (II), iron (III), aluminum and the like. Examples of the aliphatic amine include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, piperazine and the like, and examples of the aromatic amine include pyridine, triazine, melamine, ammonium and the like. The phosphate-containing flame retardant used in the present invention may be one to which a known water resistance improving treatment such as silane coupling agent treatment or coating with a melamine resin has been added, and melamine, pentaerythritol, etc. A known foaming auxiliary agent may be added.

  Specific examples of the phosphate constituting the phosphate-containing flame retardant used in the present invention include monophosphate, pyrophosphate and polyphosphate.

  The monophosphate is not particularly limited, and examples thereof include ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, monosodium phosphate, disodium phosphate, and trisodium phosphate. , Monosodium phosphite, disodium phosphite, sodium salts such as sodium hypophosphite, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, Potassium salts such as potassium hypophosphite, lithium lithium phosphate, dilithium phosphate, trilithium phosphate, lithium lithium phosphite, dilithium phosphite, lithium salts such as lithium hypophosphite, diphosphate Barium hydrogen, barium hydrogen phosphate, tribarium phosphate, barium salt such as barium hypophosphite, magnesium monohydrogen phosphate, Magnesium hydrogen phosphate, trimagnesium phosphate, magnesium hypophosphite and other magnesium salts, calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, calcium hypophosphite and other calcium salts, zinc phosphate and phosphorus Examples thereof include zinc salts such as zinc acid salt and zinc hypophosphite.

  The polyphosphate salt is not particularly limited, and examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium polyphosphate amide, and aluminum polyphosphate.

  In the present invention, it is possible to appropriately select and use one kind or two or more kinds from the conventionally known phosphate-containing flame retardants including those mentioned above. Among the above-mentioned phosphates, monophosphates are advantageously used, and ammonium dihydrogenphosphate is more advantageously used, in terms of excellent self-extinguishing properties.

-Stannate-containing flame retardant-
The stannate-containing flame retardant is a flame retardant containing a metal stannate salt. Here, examples of the stannate metal salt contained in the stannate-containing flame retardant include zinc stannate, barium stannate, sodium stannate, potassium stannate, cobalt stannate, and magnesium stannate. Of these, zinc stannate is preferably used.

-Bromine-containing flame retardant-
The bromine-containing flame retardant used in the present invention is not particularly limited as long as it is a compound containing bromine in its molecular structure, and examples thereof include various aromatic brominated compounds. Specifically, hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis (pentabromophenoxy) ethane, ethylene-bis ( Monobromoorganic compounds such as tetrabromophthalimide) and tetrabromobisphenol A; brominated polycarbonates such as polycarbonate oligomers produced from brominated bisphenol A as a raw material, copolymers of the above-mentioned polycarbonate oligomer and bisphenol A; brominated bisphenols A diepoxy compound prepared by the reaction of A with epichlorohydrin, obtained by the reaction of brominated phenols with epichlorohydrin Brominated epoxy compound such as monoepoxy compound; poly (brominated benzyl acrylate); brominated polyphenylene ether; condensate of brominated bisphenol A, cyanuric chloride and brominated phenol; brominated (polystyrene), poly (brominated styrene) ), Brominated polystyrene such as cross-linked brominated polystyrene; and halogenated bromine compound polymers such as cross-linked or non-cross-linked brominated poly (-methylstyrene).

  In the present invention, it is possible to appropriately select and use one kind or two or more kinds from the conventionally known bromine-containing flame retardants including those mentioned above. Among the above-mentioned bromine-containing flame retardants, brominated polystyrene, hexabromobenzene, etc. are advantageously used, and hexabromobenzene is more advantageously used, from the viewpoint of controlling the calorific value in the early stage of combustion.

-Boron-containing flame retardant-
Examples of the boron-containing flame retardant used in the present invention include borax, boron oxide, boric acid, borate and the like. Specific examples of the boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, tetraboron pentaoxide and the like. Further, examples of the borate include alkali metal, alkaline earth metal, elements of Group 4, Group 12, and Group 13 of the periodic table, ammonium borate, and the like. More specifically, lithium borate, sodium borate, potassium borate, cesium borate, and other alkali metal borate salts; magnesium borate, calcium borate, barium borate, and other alkaline earth metal borate salts; Examples thereof include zirconium borate, zinc borate, aluminum borate, ammonium borate and the like.

  In the present invention, it is possible to appropriately select and use one kind or two or more kinds from the conventionally known boron-containing flame retardants including those mentioned above. Among the above-mentioned boron-containing flame retardants, borate is preferably used, and zinc borate is more preferably used.

-Metal hydroxide-
In the present invention, examples of the metal hydroxide used as the flame retardant include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide and zinc hydroxide. , Copper hydroxide, vanadium hydroxide, tin hydroxide and the like. One or two or more of these known materials are appropriately selected and used.

  In the present invention, the above-mentioned phosphate ester, phosphate-containing flame retardant, stannate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant and a metal hydroxide containing at least one or more flame retardant. When II is used together with red phosphorus (flame retardant I), the amount used (total amount of flame retardant II used) is 3 to 90 parts by mass based on 100 parts by mass of the polyol in composition A. It is preferably within the range, and more preferably within the range of 10 to 80 parts by mass. If the amount of flame retardant II used is too small, it may not be possible to enjoy the effect of using it in combination with red phosphorus (flame retardant I). On the other hand, if the amount used is too large, flame retardant II was added. The viscosity of the composition increases and problems such as deterioration of workability are caused.

  Further, in the production method of the present invention, the foaming agent I composed of critical, subcritical or liquid carbon dioxide is used as the foaming agent.

Here, as is well known, critical, subcritical or liquid carbon dioxide (hereinafter, abbreviated as liquefied CO ₂ ) means that supercritical carbon dioxide is obtained by pressurizing carbon dioxide gas at a predetermined temperature. It is in a state, a subcritical state, or a liquid state. Specifically, liquid carbon dioxide is liquefied under a temperature and pressure conditions of a triple point or higher, and carbon dioxide in a subcritical state has a pressure of a critical pressure or higher and a temperature of lower than the critical temperature. Liquid state carbon dioxide, which is a liquid state carbon dioxide whose pressure is below the critical pressure and whose temperature is above the critical temperature, or whose temperature and pressure are below the critical point but which are close to this Further, the carbon dioxide in the supercritical state is a carbon dioxide in a fluid state in which both the pressure and the temperature exceed the critical point of the critical pressure or the critical temperature or higher.

Since the liquefied CO ₂ described above exerts an effective foaming action immediately after addition to the composition A or the like, the composition A and the composition A are treated from the start to the end of the reaction between the polyol and the polyisocyanate. It improves the dispersibility of red phosphorus in the mixture (reactant) with B, contributes to the thinning of the skin layer in the obtained polyurethane foam, and advantageously realizes its low density. is there. Further, since liquefied CO ₂ is used, for example, when the present invention is applied to the spray foaming method using a spray gun (spray foaming method), the sprayability of the mixture of the composition A and the composition B is improved. In addition, the occurrence of clogging in the spray gun due to red phosphorus (flame retardant I) is advantageously suppressed. In the present invention, if the amount of liquefied CO ₂ used is too small, the effect of addition cannot be sufficiently exhibited, and in particular, foaming immediately after spraying by spray foaming method (spray foaming method) becomes insufficient. However, since the difference in density between the core layer and the skin layer becomes large, problems such as a decrease in compressive strength and an increase in the dimensional change rate are caused. On the other hand, if the amount of the liquefied CO ₂ used is too large, the gas (carbon dioxide) generated in the initial stage of the reaction becomes excessive, which adversely affects the foaming characteristics, and, for example, in the spraying foaming method (spray foaming method). At this time, problems such as difficulty in obtaining a good foam are caused. Therefore, in the present invention, the amount of the liquefied CO ₂ used needs to be in the range of 0.1 to 4 parts by mass with respect to 100 parts by mass of the polyol in the composition A, preferably. It will be within the range of 0.2 to 3 parts by mass.

Such liquefied CO ₂ is produced in the composition of the composition A containing a polyol as a main component by a carbon dioxide supply device as disclosed in, for example, JP 2011-247323 A, at the production site of polyurethane foam. It is supplied to the flow channel or the flow channel of the composition B containing polyisocyanate as a main component and mixed, and contributes to the foaming of polyurethane generated by the reaction between the polyol and the polyisocyanate. Of course, such liquefied CO ₂ is supplied directly to the position where the composition A and the composition B are brought into contact and mixed with each other, and the liquefied CO ₂ is supplied to both of them. It is also possible to do so.

In the present invention, it is preferable to use a foaming agent II composed of at least one of water, hydrocarbon, hydrofluorocarbon, and halogenated olefin together with the above-mentioned liquefied CO ₂ (foaming agent I). Water produces carbon dioxide by the reaction with polyisocyanate, and the carbon dioxide functions as a foaming agent. Further, heat of reaction is generated during the reaction between water and polyisocyanate, and the heat can cause the urethanization reaction and the isocyanurate-forming reaction to proceed effectively, and the compression strength of the resulting polyurethane foam can be increased. There is also an advantage that it can be further enhanced. However, when the amount of such water used is too large, the strength is rather lowered. That is, the urea bond generated by the reaction between water and polyisocyanate increases in the resin, and the polyisocyanate used for the isocyanurate-forming reaction is consumed by the reaction with water, and the polyisocyanate in the reaction system decreases. This is because. From the above, in the present invention, water as a foaming agent is preferably contained in the composition A containing a polyol as a main component, and the content (usage) is 100 parts by mass of the polyol in the composition A. On the other hand, the amount is preferably 5 parts by mass or less, preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and in order to sufficiently exert the effect of the presence of water, 0.1 parts by mass or more, preferably It is desirable that the amount is 0.5 parts by mass or more, and more preferably 1 part by mass or more. In addition, such water is added and blended separately as a blending component for forming the composition A, and is also added and blended as water contained in other blending components such as polyol, and The water contained due to moisture absorption during the storage of the composition A is also taken into consideration, and the total amount thereof is adjusted to be a ratio within the range specified above.

Then, due to the presence of water in the composition A as described above, the composition A containing a polyol as a main component and the composition B containing a polyisocyanate as a main component are mixed and reacted with each other. Carbon dioxide is generated by the reaction with polyisocyanate, and this carbon dioxide also contributes to the foaming of polyurethane. Therefore, in the present invention, carbon dioxide generated by the reaction between those water and polyisocyanate is used. The composition is such that the content of the organic foaming agent described below is more than 1 mol and not more than 20 mol with respect to 1 mol of the total amount with carbon dioxide used as the liquefied CO ₂ described above. It is made to exist in the mixture of the substance A and the composition B.

  In the present invention, as the blowing agent II, instead of or together with the above-mentioned water, an organic blowing agent such as hydrocarbon (HC), hydrofluorocarbon (HFC), hydrofluoroolefin (HFO) or hydrochlorofluoroolefin ( Halogenated olefins (halogenated alkenes) called HCFO) are used. HFC is classified as a chlorofluorocarbon foaming agent, and HC, HFO, and HCFO are classified as a non-fluorocarbon foaming agent.

  Examples of the hydrocarbon (HC) that can be used in the present invention include propane, normal pentane, isopentane, cyclopentane, butane, isobutane, hexane, isohexane, neohexane, heptane, isoheptane, and the like. Examples of the fluorocarbon (HFC) include difluoromethane (HFC32), 1,1,1,2,2-pentafluoroethane (HFC125), 1,1,1-trifluoroethane (HFC143a), 1,1,2. , 2-tetrafluoroethane (HFC134), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1-difluoroethane (HFC152a), 1,1,1,2,3,3,3-heptafluoro Propane (HFC227ea), 1,1,1,3 3-pentafluoropropane (HFC245fa), 1,1,1,3,3-pentafluorobutane (HFC365mfc), and 1,1,1,2,2,3,4,5,5,5-decafluoropentane (HFC4310mee), dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride and the like can be mentioned.

  The halogenated olefins (halogenated alkenes) that can be used in the present invention include those called hydrofluoroolefins (HFO) and hydrochlorofluoroolefins (HCFO), and generally, chlorine or fluorine is used as halogen. Is an unsaturated hydrocarbon derivative having about 2 to 6 carbon atoms, which is bonded and contained. For example, tetrafluoropropene, pentafluoropropene, hexafluorobutene and other propenes having 3 to 6 fluorine substituents, butene, pentene and hexene, and fluorochloropropene, trifluoromonochloropropene, fluorochlorobutene. And the like, and unsaturated hydrocarbons having a fluorine substituent and a chlorine substituent, and mixtures of two or more thereof. Examples of the hydrofluoroolefin (HFO) include pentafluoropropene such as 1,2,3,3,3-pentafluoropropene (HFO1225ye), 1,3,3,3-tetrafluoropropene (HFO1234ze), 2, Tetrafluoropropenes such as 3,3,3-tetrafluoropropene (HFO1234yf) and 1,2,3,3-tetrafluoropropene (HFO1234ye), trifluoropropenes such as 3,3,3-trifluoropropene (HFO1243zf) , Tetrafluorobutene isomers (HFO1354), pentafluorobutene isomers (HFO1345), 1,1,1,4,4,4-hexafluoro-2-butene (HFO1336mzz), and other hexafluorobutene isomers ( HFO1336), hepta Ruorobuten isomers (HFO1327) include, heptafluoro pentene isomers (HFO1447) include, octafluoro pentene isomers (HFO1438) include, nonafluorobutyl pentene isomers (HFO1429), and the like can be mentioned. In addition, as hydrochlorofluoroolefin (HCFO), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), Dichlorotrifluoropropene (HCFO1223), 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd), 1-chloro-1,3,3-trifluoropropene (HCFO-1233zb), 2-chloro- 1,3,3-Trifluoropropene (HCFO-1233xe), 2-chloro-2,2,3-trifluoropropene (HCFO-1233xc), 3-chloro-1,2,3-trifluoropropene (HCFO-) 1233ye), 3-chloro-1,1,2-trifluoropropene (HCF) -1233yc), etc. can be mentioned.

  In particular, the above-mentioned hydrofluoroolefin (HFO) and hydrochlorofluoroolefin (HCFO) have a low global warming potential and are attracting attention as an environmentally friendly foaming agent, and thus are advantageously used in the present invention.

  The amount of the above-mentioned organic foaming agent (hydrocarbon, hydrofluorocarbon, halogenated olefin) used is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the polyol in the composition A. It is preferably part. When the amount of the organic foaming agent used exceeds 50 parts by mass, the core density of the finally obtained polyurethane foam becomes low, which may lead to decrease in the strength of the foam and eventually deterioration of dimensional stability. There is. There is also a problem in terms of cost. On the other hand, when the amount of the organic foaming agent used is less than 5 parts by mass, the function as the foaming agent cannot be sufficiently exhibited, and the density of the obtained foam may increase, and the composition When it is used by adding it to A, if the addition amount is too small, the viscosity of the composition A as a whole becomes high and the mixing property with the composition B deteriorates. For example, in the blowing foaming method using a spray gun. However, it causes a problem that a good spray pattern cannot be obtained.

In the present invention, the blowing agent II serving organic blowing agent (hydrocarbon, hydrofluorocarbon, halogenated olefin), the composition A, composition B or the foaming agent I (liquefied CO ₂ type: critical, subcritical or liquid is the addition of carbon dioxide), the place to be used, the use by adding an organic blowing agent in a liquefied CO ₂ include, the boiling point of the mixture of liquefied CO ₂ compound and an organic foaming agent is liquefied CO ₂ such boiling point ( Since the temperature is higher than −78.5 ° C.), there is an advantage that a device or equipment for cooling the liquefied CO ₂ is unnecessary. As the organic blowing agent used is added to the liquefied CO ₂ include, preferably halogenated olefin in terms of impact on the environment, also, the mixing ratio (weight ratio) relative to the liquefied CO ₂ class is liquefied CO ₂ Class: organic foaming agent = 1: 9 to 9: 1, preferably liquefied CO ₂ class: organic foaming agent = 2: 8 to 8: 2.

  Furthermore, when an organic foaming agent (hydrocarbon, hydrofluorocarbon, halogenated olefin) and water are used together as the foaming agent II in the present invention, the organic foaming agent and water are in a mass ratio of 60:40 to 99. It is desirable to use it in a ratio of 9: 0.1, preferably 70:30 to 99: 1, and more preferably 80:20 to 98: 2. If the proportion of water exceeds 40 in this range, brittleness may develop as the reaction progresses, the adhesiveness to the body surface may deteriorate, and problems such as peeling may occur. Further, carbon dioxide generated by the reaction with isocyanate lowers the thermal conductivity, and there is a possibility that a foamed layer having insufficient thermal conductivity is formed. When water is used as the foaming agent II, water is preferably added to the composition A or the foaming agent I.

  As described above, the composition used for producing a polyurethane foam according to the production method of the present invention has been described in detail for each component. Any additives can be used as long as they do not impair the object of the present invention. A foam stabilizer can be illustrated as such an additive. The foam stabilizer is used for uniformly adjusting the cell structure of polyurethane foam, and in the present invention, a silicone type or a nonionic surfactant is preferably adopted. Specific examples include polyoxyalkylene-modified dimethyl polysiloxane, polysiloxane oxyalkylene copolymer, polyoxyethylene sorbitan fatty acid ester, castor oil ethylene oxide adduct, lauryl fatty acid ethylene oxide adduct, and the like. One type may be used alone, or two or more types may be used in combination. The blending amount of the foam stabilizer is appropriately determined according to the desired foam characteristics, the type of the foam stabilizer used, etc., but is 100 parts by mass of the total polyol in the composition A. On the other hand, it is selected in the range of 0.1 to 10 parts by mass, preferably 1 to 8 parts by mass.

The compositions described above A, composition B and a blowing agent I: using (liquefied CO ₂ such critical carbon dioxide subcritical or liquid), blowing agent I compositions of the predetermined amount in the manufacturing site of a polyurethane foam It is added to A and / or composition B. Immediately after such addition, the reaction between the polyol and polyisocyanate is started to cause foaming and curing, whereby the desired polyurethane foam is produced.

Here, in the case of reacting a polyol and a polyisocyanate to foam and cure, various known polyurethane foam manufacturing methods can be adopted. For example, 1) Composition A, Composition B and a foaming agent. Laminate continuous foaming method in which the mixture of I is applied on a face material to foam and cure in a plate shape. 2) The mixture is used in a space such as an electric refrigerator where heat insulation performance is required, or a lightweight and high strength board. Injection foaming method of injecting and filling into the honeycomb structure of 3) to foam / cure, 3) Spraying foaming method (spray foaming) of spraying the above mixture from the spray gun head of the in-situ foaming machine to the adherend to foam / cure Method) or the like, and foamed and cured to form a desired polyurethane foam. In the present invention, the blowing agent I is added to the composition A and / or the composition B, and the reaction of the polyol and the polyisocyanate immediately after the addition means that the blowing agent I is added to the composition. It merely excludes intentionally storing (leaving) the substance A and the like and allowing the reaction to proceed after such storing (leaving). Therefore, at the production site of polyurethane foam, the foaming agent I (liquefied CO ₂ ) is supplied to the flow path of the composition A or the like by a conventionally known carbon dioxide supply device, and then the composition A and the composition B are mixed. In the case of mixing and reacting, and foaming / curing, the time for flowing through the flow path is required, but it is included in "immediately" in the present invention.

In particular, the present invention is preferably applied to a spray foaming method (spray foaming method) in which foaming is performed in situ at an ambient temperature (ambient temperature). By applying to such in-situ blowing foaming method, it is possible to advantageously realize low density of polyurethane foam and good dispersibility of red phosphorus, and the difference between the overall density of the foam and the core density is 1 to 12 kg / m ^3. And the total calorific value after 10 minutes when heated at a radiant heat intensity of 50 kW / m ² in accordance with the test method specified in ISO-5660, preferably 8 MJ / m ² or less, A polyurethane foam having excellent properties such as dimensional stability, which also has a total calorific value after 8 minutes of 8 MJ / m ² or less, can be advantageously obtained. Further, when performing two-layer spraying (two-stage spraying) particularly in winter when the environmental temperature is low, in the conventional manufacturing method, the density of the foam of the first layer formed on the surface of the adherend is There is a problem that the density of the foam formed on the second layer is higher than that of the second layer, and a difference in shrinkage occurs between the layers, so that the resulting foam (foam) tends to warp as a whole. .. However, when the production method of the present invention is applied to the blowing and foaming method, the density of the foam of the first layer can be suppressed to a low level, so that the occurrence of warpage can be suppressed in the finally obtained polyurethane foam. It becomes.

  Hereinafter, some examples of the present invention will be shown to clarify the characteristics of the present invention more specifically, but the present invention is subject to any restrictions by the description of such examples. Not to mention that. In addition to the following embodiments, the present invention further includes various modifications based on the knowledge of those skilled in the art, in addition to the above specific description, without departing from the spirit of the present invention. It should be understood that modifications, improvements, etc. may be made. All the percentages and parts shown below are based on mass.

First, each component is contained in the ratio shown in Tables 1 to 7 below (however, liquid CO ₂ and liquid CO ₂ and HFO-1234ze represented as “liquid CO ₂ + HFO-1234ze” in the table). And a composition B containing a polyol as a main component, and a composition B consisting of polyisocyanate (polymeric MDI, manufactured by Wanka Kagaku Japan Co., Ltd., product name: Wannate PM-130), Got ready. The raw materials used in the preparation of the composition A are as follows.
・ Polyol: terephthalic acid type polyester polyol
(Kawasaki Kasei Co., Ltd. product name: RFK505, Mn = 448)
・ Polyol: terephthalic acid type polyester polyol
(Kawasaki Kasei Co., Ltd. product name: RLK035, Mn = 747)
-Polyol: succinic acid type polyester polyol
(Kawasaki Kasei Co., Ltd. product name: SDK145, Mn = 1244)
-Polyol: Mannich type polyether polyol
(Product name: EXCENOL FB800, Mn = 530, manufactured by AGC Corporation)
・ Foam stabilizer: Silicone-based foam stabilizer
(Product made by Toray Dow Corning Co., Ltd., product name: SH-193)
・ Red phosphorus: Nova Excel 140
(Product name, manufactured by Rin Kagaku Kogyo Co., Ltd., average particle size: 30 μm, with surface coating treatment, red phosphorus content: 92% or more)
・ Flame retardant: Phosphate ester
[TMCPP: tris (1-chloro-2-propyl) phosphate, manufactured by Daihachi Kagaku Kogyo Co., Ltd.]
・ Flame retardant: Phosphate-containing flame retardant
(Ammonium dihydrogen phosphate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
・ Flame retardant: Flame retardant containing stannate
(Zinc stannate, manufactured by Nippon Light Metal Co., Ltd., product name: Flamtard S)
・ Flame retardant: Flame retardant containing bromine
(Hexabromobenzene, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
・ Flame retardant: Boron-containing flame retardant
(Zinc borate, manufactured by Mizusawa Chemical Co., Ltd., product name: ALCANEX FR-100)
・ Flame retardant: Metal hydroxide
(Aluminum hydroxide, manufactured by Nippon Light Metal Co., Ltd., product name: B1403)
・ Trimerization catalyst: quaternary ammonium salt
(Kao Corporation, product name: Kaorizer No. 420)
-Resinization catalyst: N, N-dicyclohexylmethylamine
(Evonik Japan KK, product name: Polycat 12)
Blowing agent: HCFO-1233zd
(Honeywell, 1-chloro-3,3,3-trifluoropropene)
Blowing agent: HFO-1336mzz
(1,1,1,4,4,4-hexafluoro-2-butene manufactured by Chemours)
・ Foaming agent: HFC245fa
(Central Glass Co., Ltd., 1,1,1,3,3-pentafluoropropane)
・ Foaming agent: HFC365mfc
(1,1,1,3,3-pentafluorobutane manufactured by SOLVAY Co., Ltd.)
Blowing agent: liquid CO ₂ + HFO-1234ze (mixture)
(Tokyo high Yamazaki Co., liquid _{CO 2: HFO-1234ze = 3} : 7 ( weight ratio))

-Manufacture of polyurethane foam-
Using the composition A and the composition B (polymeric MDI) prepared above, with an in-situ foaming spraying device (manufactured by Asahi Organic Materials Co., Ltd., product name: AYK-1000 series) equipped with a liquefied carbon dioxide supply device, First, composition A was supplied with liquid carbon dioxide in the proportions shown in Tables 1 to 4, or a mixture of liquid carbon dioxide and HFO-1234ze, and after mixing, the obtained liquid carbon dioxide was obtained. The composition A containing (liquid CO ₂ ) or the like was contact-mixed with the composition B at a volume ratio of 1: 1. Continuously from such contact mixing, the surface of the flexible board (910 mm × 910 mm), which is the body, is sprayed once downward and twice upward, and reacted on the board to foam and cure. , The bottom blown layer is 5 mm or less and the two upper blown layers are each 30 mm or less, foamed layer made of various rigid polyurethane foam according to Examples 1 to 25 and Comparative Examples 1 to 9 (total thickness: about 60 mm ) Were each formed.

  Then, using each polyurethane foam thus obtained as a sample, the overall density and core density were measured (calculated), and dimensional stability (shrinkage), dimensional stability (warpage) and flame retardancy were evaluated. The measurements and evaluations were performed according to the procedures shown below. The obtained results are shown in Tables 1 to 7 below.

-Measurement (calculation) of overall density and core density-
The thickness of the polyurethane foam having a skin layer (surface layer) formed by spraying on the flexible board was measured at 13 points vertically and horizontally equidistantly, and the average of the thicknesses at the 13 points was used to determine the polyurethane. While determining the volume of the foam, the mass of the flexible board sprayed with polyurethane foam is measured, and the mass of the flexible board measured in advance is subtracted to calculate the mass of the polyurethane foam, thereby calculating the overall density. .. Further, the skin layer (surface layer) is removed from the foam layer formed on the flexible board to expose the core layer, and a 100 mm × 100 mm × 25 mm polyurethane foam is cut out, and its mass is determined to determine the core density. To calculate. The “difference between the overall density and the core density” shown in Tables 1 to 4 below is obtained by subtracting the numerical value of the core density from the numerical value of the overall density.

-Evaluation of dimensional stability (shrinkage)-
From each of the obtained polyurethane foams, a test piece having a size of 100 mm × 100 mm × 25 mm including an internal skin layer (skin layer formed by the first upper blowing) is cut out. The cut-out test piece was allowed to stand in an environment of −30 ° C. for 48 hours, after which the size of the test piece was measured with a caliper, and the measurement result was used to calculate the dimensional change rate (shrinkage) from the following formula (1). ) Is calculated.
Dimensional change rate (%)
= ([Dimension of test piece after test]-[Dimension of test piece before test])
/ [Dimension of test piece before test] × 100
The calculated dimensional change rate (shrinkage) is evaluated according to the following criteria. In addition, the evaluation of ◎ and ○ is passed.
A: The dimensional change rate is less than 1%.
◯: The dimensional change rate is 1% or more and less than 3%.
Δ: The dimensional change rate is 3% or more and less than 7%.
X: The dimensional change rate is 7% or more.

-Evaluation of dimensional stability (warpage)-
From each of the obtained polyurethane foams, a test piece having a size of 100 mm × 100 mm × 25 mm including an internal skin layer (skin layer formed by the first upper blowing) is cut out. The cut-out test piece was allowed to stand for 48 hours in an environment of −30 ° C., then the test piece was placed on a horizontal table, and the presence or absence of warpage in the test piece was visually confirmed and checked. Check the presence or absence of sticking and evaluate according to the following criteria.
◯: No warp or rattling is observed.
X: Either warpage or rattling is recognized.

-Evaluation of flame retardancy-
From each of the obtained polyurethane foams, a 100 mm × 100 mm × 50 mm size cone calorimeter test sample was cut out, in accordance with the combustion test method specified in ISO-5660, at a radiant heat intensity of 50 kW / m ² , The maximum heat generation rate and the total heat generation amount after heating for 10 minutes, and the total heat generation amount after heating for 20 minutes (the maximum heat generation amount is the same value as that during 10 minutes) are measured. The flame retardancy of the measurement results is evaluated according to the following criteria. In the following, the total calorific value after heating for 10 minutes is shown as the total calorific value (10 minutes), and the total calorific value after heating for 20 minutes is shown as the total calorific value (20 minutes).
⊚: The maximum heat generation rate is 80 kW / m ² or less, and both the total heat generation amount (10 minutes) and the total heat generation amount (20 minutes) are 7 MJ / m ² or less.
◯: The maximum heat generation rate is 80 kW / m ² or less, and both the total heat generation amount (10 minutes) and the total heat generation amount (20 minutes) are 8 MJ / m ² or less.
Δ: Maximum heat generation rate is 80 kW / m ² or less and total heat generation amount (10 minutes) is 8 MJ / m ²
And the total calorific value (20 minutes) exceeds 8 MJ / m ² .
X: The maximum heat generation rate exceeds 80 kW / m ² , or both the total heat generation amount (10 minutes) and the total heat generation amount (20 minutes) exceed 8 MJ / m ² .

  As is clear from the results of Tables 1 to 5, all of the polyurethane foams (Examples 1 to 25) manufactured according to the manufacturing method of the present invention have excellent flame retardancy and overall density. Since the difference between the core density and the core density is small, it is recognized that the density distribution is uniform and the dimensional stability is also excellent.

On the other hand, as is clear from the results of Tables 6 and 7, the polyurethane foam according to Comparative Example 1 in which only water was used as the foaming agent and liquid CO ₂ was not used, the overall density and the core density were It is recognized that there is a variation in the density distribution and the dimensional stability is also inferior because the difference in is extremely large. Further, the polyurethane foam in which the aromatic polyester polyol is not used (Comparative Examples 2 and 3) and the polyurethane foam in which red phosphorus is not used at all (Comparative Examples 4 to 9) are flame retardant. It is recognized that it is inferior to.

Claims (12)

When a polyurethane foam is produced by mixing a composition A containing a polyol as a main component and a composition B containing a polyisocyanate as a main component and reacting them to foam and cure,
As the polyol, at least an aromatic polyester polyol is contained in the composition A,
A flame retardant I made of red phosphorus is contained in the composition A and / or the composition B,
At the production site of the polyurethane foam, a blowing agent I consisting of critical, subcritical or liquid carbon dioxide is added to the composition A and / or the composition B, and the reaction is allowed to proceed immediately after the addition. Be
A method for producing a polyurethane foam, comprising:   A flame retardant II comprising at least one or more of a phosphate ester, a phosphate-containing flame retardant, a stannate-containing flame retardant, a bromine-containing flame retardant, a boron-containing flame retardant and a metal hydroxide, wherein the composition is The method for producing a polyurethane foam according to claim 1, which is contained in A and / or the composition B.   The method for producing a polyurethane foam according to claim 1 or 2, wherein the proportion of the aromatic polyester polyol in the polyol is 30% by mass or more.   The method for producing a polyurethane foam according to any one of claims 1 to 3, wherein a polyether polyol is further contained in the composition A as the polyol.   The number average molecular weight of the said aromatic polyester polyol is 200-1000, The manufacturing method of the polyurethane foam of any one of Claim 1 thru | or 4.   The flame retardant I consisting of the red phosphorus is contained in the composition A and / or the composition B in a ratio of 1 to 70 parts by mass with respect to 100 parts by mass of the polyol in the composition A. The method for producing the polyurethane foam according to claim 1.   The flame retardant II is contained in the composition A and / or the composition B in a ratio of 3 to 90 parts by mass with respect to 100 parts by mass of the polyol in the composition A. The method for producing the polyurethane foam according to claim 6.   A foaming agent II comprising at least one of water, hydrocarbon, hydrofluorocarbon and halogenated olefin is contained in at least one of the composition A, the composition B and the foaming agent I. The method for producing a polyurethane foam according to any one of claims 1 to 7, wherein the method is used.   The polyurethane foam according to any one of claims 1 to 8, wherein the polyurethane foam is produced by a blowing foaming method after adding the foaming agent I to the composition A and / or the composition B. Manufacturing method. The method for producing a polyurethane foam according to claim 1, wherein a polyurethane foam having a difference between the overall density and the core density of 0.1 to 12 kg / m ³ is obtained. A polyurethane foam having a total calorific value of 8 MJ / m ² or less after 10 minutes is obtained when heated at a radiant heat intensity of 50 kW / m ² according to the test method specified in ISO-5660. Item 11. A method for producing a polyurethane foam according to any one of items 1 to 10. A polyurethane foam having a total calorific value of 8 MJ / m ² or less after 20 minutes is obtained when heated at a radiant heat intensity of 50 kW / m ² in accordance with the test method specified in ISO-5660. Item 12. A method for producing a polyurethane foam according to any one of items 1 to 11.