JP6978396B2 - Polyurethane foam manufacturing method - Google Patents

Description

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 a uniform density distribution.

Conventionally, polyurethane foam has been mainly used as a heat insulating material for heat insulating materials such as interior and exterior wall materials for buildings, heat insulation of panels, metal siding, electric refrigerators, etc. by utilizing its excellent heat insulating properties, adhesiveness, and light weight. It is used for heat insulation, heat insulation of building walls, ceilings, roofs, etc., and prevention of dew condensation, heat insulation of infusion pipes, etc. It is also practically used as a reinforcing material for the case. Further, such a polyurethane foam is generally composed of a polyol compounding liquid (premixed liquid) in which a polyol is mixed with a foaming agent and, if necessary, various auxiliaries such as a catalyst, a foam stabilizer and a flame retardant. A and the 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 obtained by a slab foaming method, an injection foaming method, or the like. It is manufactured by foaming and curing by a method such as a spray foaming method, a laminated continuous foaming method, a lightweight filling method, and an injection backfilling method.

By the way, since the polyurethane foam formed as described above is required to have flame retardancy due to its use, for example, it is described in paragraph [0046] of Patent Document 1 (Japanese Unexamined Patent Publication No. 2002-47325). As described above, it is known that a flame retardant is added to a polyol component or the like and used to impart flame retardancy to the obtained polyurethane foam. In particular, in recent years, polyurethane foam has been required to have better flame retardancy than before, and it has been proposed to use red phosphorus as a flame retardant in order to develop more excellent flame retardancy in polyurethane foam. Has been done. For example, in Patent Document 2 (Japanese Unexamined Patent Publication No. 2015-193839), an additive is contained with respect to 100 parts by weight of a urethane resin composed of the polyisocyanate compound and the polyol compound, which contains a polyisocyanate compound, a polyol compound, an additive and the like. A flame-retardant urethane resin composition characterized by containing 3.5 to 20 parts by weight of red phosphorus is proposed, and in Patent Document 3 (Japanese Unexamined Patent Publication No. 2015-63675), polyisocyanate is used. A urethane resin composition containing a compound, a polyol compound having a weight average molecular weight in the range of 1000 to 20000, a foaming agent, and an additive containing red phosphorus as an essential component has been proposed.

However, a composition containing red phosphorus as disclosed in Patent Document 2 and 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 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 inhibit the progress of the urethane reaction, and 2) the specific gravity of red phosphorus is larger than the specific gravity of the entire composition, and red in the composition. Due to the low dispersibility of phosphorus powder and the like, red phosphorus powder and the like are present in a biased state in the finally obtained polyurethane foam, and as a result, the density is biased. There is an inherent problem of producing polyurethane foams with a distribution.

Japanese Unexamined Patent Publication No. 2002-47325 Japanese Unexamined Patent Publication No. 2015-193839 Japanese Unexamined Patent Publication No. 2015-63675

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

The present invention can be suitably carried out in various aspects as listed below in order to solve the above-mentioned problems. It is understood that the aspects or technical features of the present invention are not limited to those described below and can be recognized based on the invention idea that can be grasped from the description of the specification. Should be.

(1) When producing a polyurethane foam by mixing and reacting a composition A containing a polyol as a main component and a composition B containing a polyisocyanate as a main component to foam and cure them.
The polyol contained in the composition A contains an aromatic polyester polyol in a proportion of 25% by mass or more.
The flame retardant I made of red phosphorus is contained in the composition A and / or the composition B at a ratio of 10 to 70 parts by mass with respect to 100 parts by mass of the polyol.
At the production site of the polyurethane foam, the composition of the foaming agent I composed of critical, subcritical or liquid carbon dioxide at a ratio of 0.1 part by mass or more with respect to 100 parts by mass of the polyol according to the spray foaming method. object a and / or added to the composition B, after such addition, immediately the polyurethane emissions form the reaction is allowed to proceed is produced,
A method for manufacturing polyurethane foam.
(2) The flame retardant II composed of at least one of phosphoric acid ester, phosphate-containing flame retardant, stannate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant and metal hydroxide. The method for producing a polyurethane foam according to the aspect (1) contained in the composition A and / or the composition B.
(3) The method for producing a polyurethane foam according to the embodiment (1) or the embodiment (2), wherein the composition A further contains a polyether polyol as the polyol.
(4) The method for producing a polyurethane foam according to any one of the above-described embodiments (1) to (3), wherein the aromatic polyester polyol has a number average molecular weight of 200 to 1000.
(5) The flame retardant II is contained in the composition A and / or the composition B at 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 a polyurethane form according to any one of aspects (2) to (4).
(6) The foaming agent II composed 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-mentioned mode (1) to the above-mentioned aspect (5) contained therein.
(7) The polyuretan foam according to any one of the above aspects (1) to (6) , wherein a polyurethane form having a difference between the total density and the core density of 0.1 to 12 kg / m ^{3 can be obtained.} Manufacturing method.
(8) Polyurethane foam ^{having a total calorific value of 8 MJ / m 2} or less after 10 minutes when heated to a radiant heat intensity of ^{50 kW / m 2} in accordance with the test method specified in ISO-5660. The method for producing a polyurethane foam according to any one of the obtained aspects (1) to (7).
(9) A polyurethane foam ^{having a total calorific value of 8 MJ / m 2} or less after 20 minutes when heated to a radiant heat intensity of ^{50 kW / m 2} in accordance with the test method specified in ISO-5660. The method for producing a polyurethane foam according to any one of the obtained aspects (1) to (8).

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 improving the flame retardancy of the polyurethane foam, and is also critical or subcritical. Alternatively, the foaming 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. Therefore, in the production method of the present invention, a mixture (reactant) of the composition A and the composition B is produced 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 the resulting polyurethane foam, the dispersed state of red phosphorus is good, in other words, red phosphorus is uniformly present in the mixture (reactant) without uneven distribution. As a result, the red phosphorus and the aromatic polyester polyol exhibit excellent flame retardancy, and the density distribution becomes uniform. Further, especially in winter when the environmental temperature is low, when the present invention is applied to perform two-layer spraying (two-stage spraying), the first layer foam (foam formed by the first spraying) and the second layer. The final polyurethane is obtained from the fact that the difference in density between the foam (the foam formed by the second spray) is small and therefore the generation of shrinkage differences between those layers is effectively suppressed. The foam is one in which the occurrence of warpage is suppressed as a whole.

In the method for producing a polyurethane foam according to the present invention, a composition A containing a polyol as a main component and a composition B containing a polyisocyanate as a main component are mixed, foamed and cured to obtain the desired polyurethane foam. However, at least a part or all of the polyol which is a main component constituting the composition A used therefor is an aromatic polyester polyol. By using an 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, it is phthalic acid-based obtained by decomposing a phthalic acid-based polyester molded product such as orthophthalic acid, isophthalic acid, terephthalic acid, condensed polyester polyol obtained by reacting anhydrous phthalic acid with polyhydric alcohol, or polyethylene terephthalate. A phthalic acid-based polyester polyol such as a recovered polyester polyol is used, and more preferably a terephthalic acid-based polyester polyol is 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. Most preferably. If the proportion of the aromatic polyester polyol in the polyol in the composition A is less than 30% by mass, the finally obtained polyurethane foam may not exhibit sufficient flame retardancy.

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

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, and triethylene glycol. , Dipropylene glycol, neopentyl glycol, glycerin, trimethylolbropan, pentaerythritol, methylglucoside, sorbitol, shoe cloth and other polyvalent alcohols; pyrogallol, hydroquinone and other polyvalent phenols; bisphenol A, bisphenol S, bisphenol Bisphenols such as F, a low condensate of phenol and formaldehyde; propylenediamine, hexamethylenediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, pentamethylenehexamine, ethanolamine, diethanolamine, triethanolamine, aminoethylethanolamine, etc. Aliphatic amines; aromatic amines such as aniline, phenylenediamine, xylylene diamine, methylenedianiline, diphenyletherdiamine; alicyclic amines such as isophoronediamine and cyclohexylenediamine; complex alicyclic amines such as aminoethylpiperazine. Formula amines; Examples include compounds in which an alkylene oxide is added to an active hydrogen compound such as the polyvalent phenol and the Mannig polyol (a compound obtained by the reaction of the aliphatic amine with formarin). In addition, these active hydrogen compounds may be a mixture of two or more kinds. 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, in which two or more of these are used in combination. May be. Preferred alkylene oxides are ethylene oxide, propylene oxide, or a combination thereof.

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

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

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

Further, the polymer polyol is not particularly limited, and for example, the above-mentioned polyether polyol and an ethylenically unsaturated monomer (for example, butadiene, acrylonitrile, styrene, etc.) are 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), which is in the molecule. It is an organic isocyanate compound having two or more isocyanate groups (NCO groups), for example, diphenylmethane diisocyanate, polymethylenepolyphenylene polyisocyanate, tolylene diisocyanate, polytolylene triisocyanate, xylylene diisocyanate, naphthalene diisocyanate, phenylenedi isocyanate, etc. Aromatic polyisocyanates such as dimethyldiphenylmethane diisocyanate and triphenylmethane triisocyanate, aliphatic polyisocyanates such as methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate and hexamethylene diisocyanate, isophorone diisocyanate, cyclohexylene diisocyanate and methylcyclohexylene. Examples thereof include alicyclic polyisocyanates such as diisocyanate, dicyclohexylmethanediisocyanate, and dimethyldicyclohexylmethanediisocyanate, urethane prepolymers having an isocyanate group at the molecular terminal, isocyanurate-modified polyisocyanates, and carbodiimide-modified products. These polyisocyanate compounds may be used alone or in combination of two or more. In general, polymethylene polyphenylene polyisocyanate (polymeric MDI) is preferably used from the viewpoint of reactivity, economy, handleability and the like.

The ratio of the polyisocyanate in the composition B to the polyol in the composition A described above will be appropriately determined depending on the type of foam to be formed (for example, polyurethane or polyisocyanurate). However, in general, the NCO / OH index (equivalent ratio) indicating 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 decided appropriately 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, and are foamed and cured by a foaming agent 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, the composition A preferably contains a trimerization catalyst, in other words, a catalyst (isocyanurate-forming catalyst) that reacts with an isocyanate group of polyisocyanate to tritrate and promote the formation of an isocyanurate ring. It will be contained. As the trimerization catalyst, various known catalysts can be appropriately selected and used, but a quaternary ammonium salt, potassium octylate, potassium 2-ethylhexanoate, sodium acetate are preferable. Carboxylic acid alkali metal salts such as; nitrogen-containing 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. Of these, it is preferable to use a quaternary ammonium salt from the viewpoint of improving flame retardancy, and in particular, using a quaternary ammonium salt and a carboxylic acid alkali metal salt in combination is further flame retardant. Especially preferable from the viewpoint of improvement.

Examples of the quaternary ammonium salt advantageously used here include tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, propyltrimethylammonium, butyltrimethylammonium, pentyltrimethylammonium, hexyltrimethylammonium, heptyltrimethylammonium, and octyltrimethylammonium. Aliphatic ammonium such as nonyltrimethylammonium, decyltrimethylammonium, undecyltrimethylammonium, dodecyltrimethylammonium, tridecyltrimethylammonium, tetradecyltrimethylammonium, heptadecyltrimethylammonium, hexadecyltrimethylammonium, heptadecyltrimethylammonium, octadecyltrimethylammonium, etc. Compounds, hydroxyammonium compounds such as (2-hydroxypropyl) trimethylammonium, hydroxyethyltrimethylammonium, trimethylaminoethoxyethanol, hydroxyethyl-2-hydroxypropyldimethylammonium, 1-methyl-1-azania-4-azabicyclo [2, 2,2] Examples thereof include alicyclic ammonium compounds such as octanium, 1,1-dimethyl-4-methylpiperidinium, 1-methylmorpholinium, and 1-methylpiperidinium. Among these, tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, butyltrimethylammonium, hexyltrimethylammonium, octyltrimethylammonium, decyltrimethylammonium, dodecyltrimethylammonium, because of their excellent catalytic activity and industrial availability, 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-methylpiperidinium will be preferably used.

Examples of the organic acid group or inorganic acid group constituting such a quaternary ammonium salt include formic acid group, acetic acid group, octyl acid group, oxalic acid group, malonic acid group, succinic acid group and 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, phosphoric acid ester group, etc. Examples thereof include inorganic acid groups such as halogen groups, hydroxyl groups, hydrogen carbonate groups and carbon dioxide groups. Among these, a formic acid group, an acetic acid group, an octylate group, a methyl carbonate group, a halogen group, a hydroxyl group, a hydrogen carbonate group and a carbonic acid group are preferable because they have excellent catalytic activity and are industrially available.

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

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 exert the function as the catalyst. It will be selected within the range of 1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, and 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 polyisocyanate cannot be sufficiently realized, and therefore it becomes difficult to sufficiently achieve the effect of improving flame retardancy. On the other hand, if the amount exceeds 10 parts by mass, the reaction proceeds too much and the solidification becomes faster, which makes spraying work difficult.

Further, in the present invention, it is also possible to use a urethanization catalyst, which is a resinification catalyst, in combination with such a quantification catalyst. Examples of the urethanization catalyst include known fatty acid bismuth salts such as dibutyltin dilaurate, bismuth octylate (bismuth 2-ethylhexylate), bismuth neodecanoate, bismuth neododecanoate, and bismuth naphthenate, and lead naphthenate. I can.

The amount of the resinification catalyst used is 0.1 to 10 parts by mass, preferably 0, based on 100 parts by mass of the entire polyol in the composition A in order to effectively exert its function as a catalyst. It will be selected within the range of 5 to 8 parts by mass, more preferably 1 to 6 parts by mass. If the amount of this resinification catalyst used is less than 0.1 parts by mass, the obtained foam may become sticky, dust or the like may adhere to the resin, resulting in a poor appearance. In the spray foaming operation, the floor or the like may be used. Since the droplets adhering to the salt become sticky, there is a problem that workability deteriorates. On the other hand, if the amount exceeds 10 parts by mass, heat generation increases during the resinification reaction, and the appearance is abnormal such as yellowing of the foam. The catalyst containing the quaternary ammonium salt contained in the droplets generated during foaming may worsen the work environment at the work site where the spraying work is performed.

On the other hand, in the present invention, with respect to either one of the above-mentioned composition A containing a polyol as a main component or the 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 commercially available products and used. The amount of red phosphorus added in the present invention (when added to both composition A and composition B, the total amount thereof) is 1 to 100 parts by mass of the polyol in composition A. It is determined in the range of 70 parts by mass, preferably 10 to 60 parts by mass, and more preferably 20 to 55 parts by mass. If the amount of this red phosphorus added is too small, the resulting polyurethane foam may not exhibit sufficient flame retardancy, and if the amount of red phosphorus added is too large, the composition to which it is added may not be exhibited. In addition to increasing the viscosity and causing problems such as poor stirring, there is a risk of causing problems such as a decrease in workability and a problem such as the polyurethane foam becoming more flammable.

Further, in the present invention, coated red phosphorus is advantageously used among red phosphorus from the viewpoint of safety and ease of handling. Coated red phosphorus is red phosphorus that has been surface-treated with an inorganic substance and / or an organic substance, and commercially available coated red phosphorus includes Novaled (trade name, manufactured by Rinkagaku Kogyo Co., Ltd.) and Nova. Excel (trade name, manufactured by Rinkagaku Kogyo Co., Ltd.), Hishigard (trade name, manufactured by Nippon Kagaku Kogyo Co., Ltd.) and the like can be exemplified. As the coated red phosphorus, the one having a high content ratio of red phosphorus contributes more effectively to the improvement of the flame retardancy of the polyurethane foam. 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 having a granular form or a powdery form are preferably used in the same manner as the red phosphorus conventionally used for producing polyurethane foam. In addition, a granular or powdery red phosphorus having an average particle size of 1 to 50 μm, preferably 5 to 45 μm, and more preferably 10 to 40 μm so that the dispersed state is good in the finally obtained polyurethane foam. The body is used to advantage.

On the other hand, in the method for producing polyurethane foam according to the present invention, it is possible to use other conventionally known flame retardants together with the above-mentioned 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. In addition, when red phosphorus is used in combination with other flame retardants, the amount of red phosphorus used can be suppressed to a small amount, so that the uneven distribution of red phosphorus in the foam can be effectively suppressed, and the density distribution. It is possible to advantageously obtain a polyurethane foam having a uniform (in other words, a small difference between the total density and the core density). In the present invention, examples of the flame retardant that can be used together with red phosphorus include 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. Can be done. Advantageously, at least one or more of the various flame retardants described below (flame retardant II) is composed with or separately from red phosphorus (flame retardant I). A and / or added to composition B.

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

The monophosphoric acid ester is not particularly limited, and is not particularly limited, for example, trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl. Phosphonate, Tris (isopropylphenyl) Phosphonate, Tris (Phenylphenyl) Phosphonate, Trinaphthyl Phosphonate, Cresyldiphenyl Phosphonate, Xylenyldiphenyl Phosphonate, Diphenyl (2-Ethylhexyl) Phosphonate, Di (Phenylphenyl) Phosphonate, Monoisodecyl Phosphonate, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine Oxide, tricresylphosphine oxide, diphenyl methanephosphonate, diethyl phenylphosphonate, resylsinol bis (diphenyl phosphate), bisphenol A bis (diphenyl phosphate), phosphaphenanthrene, tris (β-chloropropyl) phosphate, etc. , Can be mentioned.

The condensed phosphoric acid ester is also not particularly limited, and for example, trialkylpolyphosphate, resorcinolpolyphenyl phosphate, resorcinol poly (di-2,6-kisilyl) phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., trade name). : PX-200), hydroquinonepoly (2,6-kisilyl) phosphate, and condensates thereof can be mentioned. Examples of commercially available condensed phosphate esters other than those described above include resorcinol polyphenyl phosphate (trade name: CR-733S), bisphenol A polycresyl phosphate (trade name: CR-741), and aromatic condensed phosphate ester. (Product name: CR747), resorcinol polyphenyl phosphate (manufactured by ADEKA, trade name: Adecastab PFR), bisphenol A polycresyl phosphate (trade names: FP-600, FP-700) and the like can be mentioned.

In the present invention, one or two or more kinds of conventionally known phosphate esters such as the above-mentioned monophosphate ester and condensed phosphate ester can be appropriately selected and used. be. Further, among the above-mentioned monophosphoric acid esters and condensed phosphoric acid esters, monophosphoric acid esters can be used in that they have a high effect of reducing the viscosity in the composition before curing and the effect of reducing the initial calorific value. Preferably, it is more preferred to use tris (β-chloropropyl) phosphate.

-Phosphate-containing flame retardant-
The phosphate-containing flame retardant is one containing phosphate and having 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, at least one metal selected from the above-mentioned various phosphoric acids, metals of Group IA to IVB of the Periodic Table, ammonia, aliphatic amines, and aromatic amines or compounds thereof. Phosphate consisting of the salt of and can be mentioned. Examples of the metals of Group IA to Group IVB of the Periodic Table include lithium, sodium, calcium, barium, iron (II), iron (III), and aluminum. 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 and ammonium. The phosphate-containing flame retardant used in the present invention may be treated with a known water resistance improving treatment such as a silane coupling agent treatment or a melamine resin coating, and may be melamine, pentaerythritol or the like. A known foaming aid 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 for example, ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate, monosodium phosphate, disodium phosphate, and trisodium phosphate. , Sodium phosphate, disodium phosphite, sodium salts such as sodium hypophosphite, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, Potassium salts such as potassium hypophosphite, monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphate, dilithium phosphite, lithium salts such as lithium hypophosphite, diphosphate Barium salts such as barium hydrogen, barium hydrogen phosphate, tribarium phosphate, barium hypophosphite, magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, magnesium salts such as magnesium hypophosphite, phosphorus Calcium salts such as calcium dihydrogen acid, calcium hydrogen phosphate, tricalcium phosphate, calcium hypophosphite, zinc salts such as zinc phosphate, zinc phosphite, zinc hypophosphite and the like can be mentioned.

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

In the present invention, one or more of the conventionally known phosphate-containing flame retardants such as those described above can be appropriately selected and used. Among the above-mentioned phosphates, monophosphate is advantageously used and ammonium dihydrogen phosphate is more preferably used in that it is excellent in self-extinguishing property.

-Stannate-containing flame retardant-
The stannate-containing flame retardant is a flame retardant containing a tin acid metal salt. Here, examples of the metal salt of tin contained in the stannate-containing flame retardant include zinc tinate, barium tinate, sodium tinate, potassium tintin, cobalt tintate, magnesium tint, and the like. Among them, 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 ( Tetrabromophthalimide), monomer organic bromine compounds such as tetrabromobisphenol A; polycarbonate oligomers produced from brominated bisphenol A as raw materials, brominated polycarbonates such as copolymers of the above polycarbonate oligomers and bisphenol A; brominated bisphenols. Bromine epoxy compounds such as diepoxy compounds produced by the reaction of A with epichlorohydrin, monoepoxy compounds obtained by the reaction of brominated phenols with epichlorohydrin; poly (bromineed benzyl acrylate); brominated polyphenylene ether; brominated. Condensations of bisphenol A, cyanur chloride and brominated phenols; brominated polystyrenes such as brominated (polystyrene), poly (bromineed styrene), crosslinked brominated polystyrene; crosslinked or non-crosslinked brominated poly (-methylstyrene), etc. Examples thereof include halogenated bromine compound polymers.

In the present invention, one or more of the conventionally known brominated flame retardants such as those described above can be appropriately selected and used. Among the above-mentioned brominated flame retardants, brominated polystyrene, hexabromobenzene and the like are advantageously used, and hexabromobenzene is more preferably used from the viewpoint of controlling the calorific value at the initial 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, and tetraboron pentoxide. Examples of borates include alkali metals, alkaline earth metals, elements of Groups 4, 12, and 13 of the Periodic Table, and ammonium borates. More specifically, alkali metal borate salts such as lithium borate, sodium borate, potassium borate, and cesium borate; alkaline earth metal borate salts such as magnesium borate, calcium borate, and barium borate; Examples thereof include zirconium borate, zinc borate, aluminum borate, and ammonium borate.

In the present invention, one or more of the conventionally known boron-containing flame retardants such as those described above can be appropriately selected and used. 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 a 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 more of these known substances are appropriately selected and used.

In the present invention, a flame retardant composed of at least one of the above-mentioned phosphoric acid ester, phosphate-containing flame retardant, stannate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant and metal hydroxide. When II is used with red phosphorus (flame retardant I), the amount used (total amount of flame retardant II used) is 3 to 90 parts by mass with respect to 100 parts by mass of the polyol in the 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, the effect of using it in combination with red phosphorus (flame retardant I) may not be enjoyed, while if the amount used is too large, flame retardant II is added. The viscosity of the composition increases, which causes problems such as deterioration of workability.

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

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

Liquefied CO ₂ such as described above, the period from exerting an effective foaming action immediately after addition to the composition A or the like, until the end of the reaction the start of a polyol and a polyisocyanate, the composition and the composition A 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 further realizes the reduction in density advantageously. be. Further, by using liquefied CO ₂ , for example, when the present invention is applied to a spray foaming method using a spray gun (spray foaming method), the sprayability of a mixture composed of composition A and composition B becomes high. 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 adding the liquefied CO 2 cannot be sufficiently exhibited, and in particular, foaming immediately after spraying by the spray foaming method (spray foaming method) becomes insufficient. Since the density difference 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 such liquefied CO 2} used is too large, the gas (carbon dioxide) generated at the initial stage of the reaction becomes excessive, which adversely affects the foaming characteristics. At that time, problems such as difficulty in obtaining a good foam are caused. Therefore, in the present invention, the _{amount of the liquefied CO 2} to be 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, which is preferable. It will be in the range of 0.2 to 3 parts by mass.

Then, such liquefied CO ₂ class is the manufacturing site of polyurethane foams, for example, by such carbon dioxide supply apparatus is elucidated in JP 2011-247323 Laid, composition A composed mainly of polyol It is supplied to the flow path or the flow path of the composition B containing polyisocyanate as a main component and mixed, and contributes to the foaming of polyurethane caused 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 contacted and mixed, and the liquefied CO ₂ is supplied to both of them. It is also possible to be done.

In the present invention, preferably, liquefied CO _2's mentioned above with (blowing agent I), water, hydrocarbon, blowing agent II comprising at least one or more ones of hydrofluorocarbons and halogenated olefins are used. Water produces carbon dioxide by reacting 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 effectively promote the urethanization reaction and the isocyanurate formation reaction, and the compression strength of the obtained polyurethane foam can be increased. There is also the advantage that it can be further enhanced. However, if the amount of such water used becomes too large, the strength will rather decrease. The reason is that 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 in the reaction with water, so that the polyisocyanate in the reaction system decreases. 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 amount) thereof is 100 parts by mass of the polyol in the composition A. On the other hand, it is desirable that the amount is 5 parts by mass or less, preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and 0.1 parts by mass or more, preferably 0.1 parts by mass or less so that the effect due to the presence of water can be sufficiently exerted. It is desirable that the amount is 0.5 parts by mass or more, more preferably 1 part by mass or more. In addition, such water can be added and blended separately as a blending component for forming the composition A, and can also be added and blended as water contained in other blending components such as a polyol. Water contained by moisture absorption during storage of composition A is also taken into account and will be adjusted so that the total amount thereof is 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 such water. 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, the carbon dioxide generated by the reaction between the water and the polyisocyanate The composition is such that the organic foaming agent described later has a content of more than 1 mol and 20 mol or less with respect to 1 mol of the total amount of carbon dioxide used as the above-mentioned liquefied CO _{2 class.} It is present in the mixture of the substance A and the composition B.

In the present invention, the foaming agent II is an organic foaming agent such as hydrocarbon (HC), hydrofluorocarbon (HFC), hydrofluoroolefin (HFO) or hydrochlorofluoroolefin (instead of or together with water described above). A halogenated olefin (alkene halide) called HCFO) is used. HFC is classified as a chlorofluorocarbon-based foaming agent, and HC, HFO and HCFO are classified as non-chlorofluorocarbon-based foaming agents.

Examples of the hydrocarbon (HC) that can be used in the present invention include propane, normal pentane, isopentane, cyclopentane, butane, isopentane, 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 Examples thereof include 3,4,5,5,5-decafluoropentane (HFC4310mee), dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride and the like.

Further, the halogenated olefin (alkene halide) that can be used in the present invention includes those called hydrofluoroolefin (HFO) and hydrochlorofluoroolefin (HCFO), and generally, chlorine and fluorine are used as halogens. It is an unsaturated hydrocarbon derivative having about 2 to 6 carbon atoms, which is bonded to and contains the above. For example, propene, butene, pentene and hexene having 3 to 6 fluorine substituents, including tetrafluoropropene, pentafluoropropene and hexafluorobutene, as well as fluorochloropropene, trifluoromonochloropropene, fluorochlorobutene. Such as unsaturated hydrocarbons having a fluorine substituent and a chlorine substituent, and a mixture of two or more thereof can be mentioned. Examples of the hydrofluoroolefin (HFO) include pentafluoropropene such as 1,2,3,3,3-pentafluoropropene (HFO1225ye), 1,3,3,3-tetrafluoropropene (HFO1234ze), 2, Tetrafluoropropene such as 3,3,3-tetrafluoropropene (HFO1234yf), 1,2,3,3-tetrafluoropropene (HFO1234ye), trifluoropropene 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 (HFO1336mzz). HFO1336), heptafluorobutene isomer (HFO1327), heptafluoropentene isomer (HFO1447), octafluoropentene isomer (HFO1438), nonafluoropentene isomer (HFO1429) and the like can be mentioned. Examples of the hydrochlorofluoroolefin (HCFO) include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), and the like. 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 (HCFO-1233yc) and the like can be mentioned.

In particular, the above-mentioned hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs) have a low global warming potential and are attracting attention as environmentally friendly foaming agents, and are therefore advantageously used in the present invention.

The amount of the organic foaming agent (hydrocarbon, hydrofluorocarbon, halogenated olefin) used is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the polyol in the composition A. It is preferably a 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 cause a decrease in the strength of the foam and a deterioration in dimensional stability. There is. There is also a problem of disadvantage in terms of cost. On the other hand, if the amount of the organic foaming agent used is less than 5 parts by mass, the function as a foaming agent cannot be fully exerted, the density of the obtained foam may increase, and the composition When added to A and used in an amount too small, the viscosity of the entire composition A becomes high and the mixing property with the composition B deteriorates. For example, in a spray foaming method using a spray gun. , Will cause the problem of not being able to obtain a good spray pattern.

Further, in the present invention, the organic foaming agent (hydrocarbon, hydrofluorocarbon, halogenated olefin) as the foaming agent II is the composition A, the composition B or the foaming agent I (liquefied CO ₂ : 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 equipment and facilities for cooling _{liquefied CO 2 are not required.} 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 : Organic foaming agent = 2: 8 to 8: 2.

Further, when the organic foaming agent (hydrocarbon, hydrofluorocarbon, halogenated olefin) and water are used in combination as the foaming agent II in the present invention, the mass ratio of the organic foaming agent and water is 60:40 to 99. It is desirable to use at 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 outside this range, brittleness develops as the reaction progresses, the adhesiveness to the skeleton surface decreases, and problems such as peeling may occur. In addition, carbon dioxide generated by the reaction with isocyanate may lower the thermal conductivity and form a foam layer having an insufficient thermal conductivity. When water is used as the foaming agent II, it is preferable that the water is added to the composition A or the foaming agent I.

As described above, the composition used for producing polyurethane foam according to the production method of the present invention has been described in detail for each component, but in the present invention, in addition to the above-mentioned components, conventionally, when producing polyurethane foam, Any material used as an additive can be used as long as it does not impair the object of the present invention. As such an additive, a defoaming agent can be exemplified. The foam stabilizer is used to uniformly arrange the cell structure of the polyurethane foam, and in the present invention, a silicone-based surfactant or a nonionic surfactant is preferably adopted. Specific examples include polyoxyalkylene-modified dimethylpolysiloxane, polysiloxaneoxyalkylene 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 this defoaming agent is appropriately determined according to the desired foam characteristics, the type of the defoaming agent to be used, and the like, but it is included in 100 parts by mass of the entire 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.

Then, using the above-mentioned composition A, composition B and foaming agent I (liquefied CO ₂ : critical, subcritical or liquid carbon dioxide), a predetermined amount of foaming agent I is added to the composition at the polyurethane foam manufacturing site. The target polyurethane foam is produced by being added to A and / or composition B, and immediately after such addition, the reaction between the polyol and the polyisocyanate is started to foam and cure.

Here, in reacting the polyol with the polyisocyanate to foam and cure, various known methods for producing polyurethane foam 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 the face material to foam and cure in the form of a plate. Injection foaming method that injects and fills into the honeycomb structure of the above, and foams and cures. By the method) or the like, it is foamed and cured to form the desired polyurethane foam. In the present invention, the composition to which the foaming agent I is added means that the foaming agent I is added to the composition A and / or the composition B, and the reaction between the polyol and the polyisocyanate proceeds immediately after such addition. It merely excludes the intentional storage (leaving) of the substance A or the like and the progress of the reaction after such storage (leaving). Therefore, at the polyurethane foam manufacturing site, 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. Even when the mixture is mixed and reacted to foam and cure, it requires time to flow through the flow path, but it is included in "immediately" as referred to in the present invention.

In particular, the present invention is suitably applied to a spray foaming method (spray foaming method) in which foaming is performed on-site at an ambient temperature (ambient temperature). By applying to such an in-situ spray foaming method, the polyurethane foam has a low density and good dispersibility of red phosphorus is advantageously realized, and the difference between the total density of the foam and the core density is 1 to 12 kg / m ^{3. When heated to a radiant heat intensity of 50 kW / m 2} in accordance with the test method specified in ISO-5660, the total calorific value after 10 minutes is 8 MJ / m ² or less, preferably. A polyurethane foam having excellent characteristics such as dimensional stability, which also has a characteristic that the total calorific value after 20 minutes has elapsed is 8 MJ / m ^{2 or less, can be advantageously obtained.} Further, in the case of 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 first layer foam formed on the surface of the adherend is the first layer. There is a problem that the resulting foam (foam) tends to warp as a whole because the density is higher than that of the second layer foam formed on the top and a difference in shrinkage occurs between the layers. .. However, when the production method of the present invention is applied to the spray foaming method, the density of the foam of the first layer can be suppressed to a low level, so that the polyurethane foam finally obtained can suppress the occurrence of warpage. It becomes.

Hereinafter, some examples of the present invention will be shown to clarify the features of the present invention more specifically, but the present invention is subject to any restrictions due to the description of such examples. Needless to say, this is not the case. Further, in addition to the following examples, the present invention is further modified in various ways based on the knowledge of those skilled in the art, as long as it does not deviate from the gist of the present invention, in addition to the above-mentioned specific description. It should be understood that modifications, improvements, etc. can be made. In addition, all of% and part shown below are based on mass.

First, each component is contained in the ratios 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. (Excluding the mixture with), a composition A containing a polyol as a main component, and a composition B composed of polyisocyanate (Polymeric MDI, manufactured by Mangekagaku Japan Co., Ltd., product name: Wannate PM-130) were prepared. Got ready. The raw materials used in the preparation of the composition A are as follows.
-Polyol: Terephthalic acid-based polyester polyol
(Made by Kawasaki Kasei Chemicals Co., Ltd., Product name: RFK505, Mn = 448)
-Polyol: Terephthalic acid-based polyester polyol
(Made by Kawasaki Kasei Chemicals Co., Ltd., Product name: RLK035, Mn = 747)
-Polyol: Succinic acid-based polyester polyol
(Made by Kawasaki Kasei Chemicals Co., Ltd., Product name: SDK145, Mn = 1244)
-Polyol: Mannich-based polyether polyol
(Manufactured by AGC Inc., product name: EXCENOL FB800, Mn = 5 30)
・ Defoaming agent: Silicone-based defoaming agent
(Manufactured by Toray Dow Corning Co., Ltd., product name: SH-193)
・ Red phosphorus: Nova Excel 140
(Product name, manufactured by Rinkagaku 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 Wako Pure Chemical Industries, Ltd.)
-Flame retardant: Stannate-containing flame retardant
(Zinc tinate, manufactured by Nippon Light Metal Co., Ltd., product name: Fram Tard 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 Industrial Chemicals Co., Ltd., product name: ALCANEX FR-100)
-Flame retardant: Metal hydroxide
(Aluminum hydroxide, manufactured by Nippon Light Metal Co., Ltd., product name: B1403)
・ Triquantization catalyst: quaternary ammonium salt
(Made by Kao Corporation, Product Name: Kaorizer No. 420)
-Resination catalyst: N, N-dicyclohexylmethylamine
(Made by Evonik Japan Co., Ltd., Product name: Polycat 12)
-Effervescent agent: HCFO-1233zd
(Honeywell, 1-chloro-3,3,3-trifluoropropene)
-Effervescent agent: HFO-1336mzz
(Chemours, 1,1,1,4,4,4-hexafluoro-2-butene)
・ Foaming agent: HFC245fa
(Manufactured by Central Glass Co., Ltd., 1,1,1,3,3-pentafluoropropan)
・ Foaming agent: HFC365mfc
(Manufactured by SOLVAY Co., Ltd., 1,1,1,3,3-pentafluorobutane)
・ Foaming agent: Liquid CO ₂ + HFO-1234ze (mixture)
(Made by Tokyo High Pressure Yamazaki Co., Ltd., Liquid CO ₂ : HFO-1234ze = 3: 7 (weight ratio))

-Manufacturing of polyurethane foam-
Using the composition A and composition B (polymeric MDI) prepared above, an in-situ foam spraying device (manufactured by Asahi Organic Materials Co., Ltd., product name: AYK-1000 series) equipped with a liquefied carbon dioxide supply device is used. First, liquid carbon dioxide in the proportions shown in Tables 1 to 4 or a mixture of liquid carbon dioxide and HFO-1234ze is supplied to composition A and mixed, and then the obtained liquid carbon dioxide is obtained. Composition A containing (liquid CO ₂ ) and the like was contact-mixed with 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 skeleton, is sprayed once with one bottom blow and two times with top blow, and reacted on the board to foam and cure. A foamed layer made of various rigid polyurethane foams according to Examples 1 to 25 and Comparative Examples 1 to 9, wherein the bottom blowing layer is 5 mm or less and the two top blowing layers are 30 mm or less, respectively (total thickness: about 60 mm). ) Was formed respectively.

Then, using each polyurethane foam thus obtained as a sample, the overall density and the core density were measured (calculated), and the dimensional stability (shrinkage), the dimensional stability (warp), and the flame retardancy were evaluated. The measurement or evaluation was performed according to the procedure 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 the skin layer (surface layer) formed by spraying on the flexible board was measured at 13 points located at approximately equal distances in the vertical and horizontal directions, and the average thickness at the 13 points was used to measure the polyurethane. While obtaining the volume of the foam, the mass of the flexible board sprayed with the polyurethane foam is further measured, and the total density is calculated by obtaining the mass of the polyurethane foam by subtracting the mass of the flexible board measured in advance. .. Further, the skin layer (surface layer) is removed from the foam layer formed on the flexible board to reveal the core layer, a polyurethane foam of 100 mm × 100 mm × 25 mm is cut out, and the mass thereof is determined to obtain the core density. Is calculated. The "difference between the total density and the core density" shown in Tables 1 to 4 below is the value obtained by subtracting the value of the core density from the value of the total 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 top blowing) is cut out. The cut out test piece is allowed to stand in an environment of -30 ° C for 48 hours, then the size of the test piece is measured with a caliper, and the measurement result is used to obtain the dimensional change rate (shrinkage) from the following formula (1). ) Is calculated.
Dimensional change rate (%)
= ([Dimensions of test piece after test]-[Dimensions of test piece before test])
/ [Dimensions of test piece before test] x 100
The calculated dimensional change rate (shrinkage) is evaluated according to the following criteria. The evaluations of ◎ and ○ are acceptable.
⊚: 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 (warp)-
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 top blowing) is cut out. The cut out test piece was allowed to stand in an environment of -30 ° C for 48 hours, and 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 then rattled. Check for stickiness and evaluate according to the following criteria.
○: No warping or rattling is observed.
X: Either warpage or rattling is observed.

-Evaluation of flame retardancy-
From each of the obtained polyurethane foams, a sample for a cone calorimeter test having a size of 100 mm × 100 mm × 50 mm was cut out and subjected to a radiant heat intensity of 50 kW / m ² in accordance with the combustion test method specified in ISO-5660. The maximum heat generation rate and total heat generation amount when heated for 10 minutes, and the total heat generation amount when heated for 20 minutes (the maximum heat generation amount is the same value as in 10 minutes) are measured, respectively. The flame retardancy of these measurement results is evaluated according to the following criteria. In the following, the total calorific value when heated for 10 minutes is shown as the total calorific value (10 minutes), and the total calorific value when heated 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: The maximum heat generation rate is 80 kW / m ² or less, and the total heat generation amount (10 minutes) is 8 MJ / m ^2.
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 in Tables 1 to 5, all of the polyurethane foams (Examples 1 to 25) produced according to the production method of the present invention are excellent in flame retardancy and have an overall density. Since the difference between the 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 in Tables 6 and 7, the _{polyurethane foam according to Comparative Example 1 in which only water was used as the foaming agent and no liquid CO 2} was used had the overall density and the core density. Since the difference between the two is very large, it is recognized that there are variations in the density distribution and the dimensional stability is also inferior. Further, the polyurethane foams in which no aromatic polyester polyol is used (Comparative Example 2 and Comparative Example 3) and the polyurethane foams in which red phosphorus is not used at all (Comparative Examples 4 to 9) are both flame-retardant. It is recognized that it is inferior to.

Claims (9)

When producing a polyurethane foam 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 them.
The polyol contained in the composition A contains an aromatic polyester polyol in a proportion of 25% by mass or more.
The flame retardant I made of red phosphorus is contained in the composition A and / or the composition B at a ratio of 10 to 70 parts by mass with respect to 100 parts by mass of the polyol.
At the production site of the polyurethane foam, the composition of the foaming agent I composed of critical, subcritical or liquid carbon dioxide at a ratio of 0.1 part by mass or more with respect to 100 parts by mass of the polyol according to the spray foaming method. It is added to the substance A and / or the composition B, and immediately after such addition, the reaction is allowed to proceed to produce the polyurethane foam .
A method for manufacturing polyurethane foam. The composition is the flame retardant II comprising at least one of a phosphoric acid 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 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 a polyether polyol is further contained in the composition A as the polyol. The method for producing a polyurethane foam according to any one of claims 1 to 3, wherein the aromatic polyester polyol has a number average molecular weight of 200 to 1000. Claims 2 to 2 in which the flame retardant II is contained in the composition A and / or the composition B at 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 a polyurethane foam according to any one of claims 4. The foaming agent II composed of 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 5, which is being sought after. The method for producing a polyurethane foam according to any one of claims 1 to 6 , wherein a polyurethane foam having a difference between the total density and the core density of 0.1 to 12 kg / m ^{3 can be obtained.} Claims that a polyurethane foam having a total calorific value of 8 MJ / m ^{2 or less after 10 minutes can be obtained when heated at a radiant heat intensity of 50 kW / m 2} in accordance with the test method specified in ISO-5660. The method for producing a polyurethane foam according to any one of items 1 to 7. Claims that a polyurethane foam having a total calorific value of 8 MJ / m ^{2 or less after 20 minutes can be obtained when heated at a radiant heat intensity of 50 kW / m 2} in accordance with the test method specified in ISO-5660. The method for producing a polyurethane foam according to any one of items 1 to 8.