JP2022030314A - Method for producing polyurethane foam - Google Patents

Abstract

To provide a method for producing a polyurethane foam that prevents the boiling of a polyol composition and facilitates the control of reaction with a polyisocyanate.SOLUTION: A method for producing a polyurethane foam causes a polyol composition containing a polyol, a foamer, and a catalyst to react with a polyisocyanate to be foamed, the foamer containing a hydrofluoroolefin with a boiling point of 30°C or lower, and the temperature of the polyol composition to be set to 30°C or lower before the reaction.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a polyurethane foam.

Polyurethane foam is used as a heat insulating material for buildings such as condominiums and other condominiums, detached houses, various school facilities, and commercial buildings because of its excellent heat insulating properties and adhesiveness. Polyurethane foam is obtained by mixing a polyol composition and polyisocyanate and foaming them.
Examples of the foaming agent include various ones, and hydrofluoroolefins (hereinafter, may be referred to as “HFO”) having no environmental problems such as global warming and ozone layer depletion have been proposed (for example, they may be referred to as “HFO”). See Patent Document 1).

As a construction method, a method such as mixing a polyol composition and a polyisocyanate, reacting them, foaming them, and spraying them at a construction site is adopted. Therefore, the polyol composition and the polyisocyanate are separately stored in a container, a drum, or the like and mixed immediately before construction (see, for example, Patent Document 2).

Further, when the filler is contained in the polyol composition, the polyol composition may be stirred immediately before the construction in order to disperse the filler and the like.

Japanese Unexamined Patent Publication No. 2018-21199 Japanese Unexamined Patent Publication No. 2016-145360

As described above, the polyol composition and the polyisocyanate are stored in a drum or the like before the construction, but the polyol composition may boil before being mixed with the polyisocyanate, which is particularly remarkable in the summer. In addition, it may be boiled by stirring to disperse the filler in the polyol composition.
When the polyol composition boils, it becomes difficult to control the reaction with the polyisocyanate, and there is a problem that the construction becomes insufficient.

In view of the above-mentioned problems, it is an object of the present invention to provide a method for producing a polyurethane foam that suppresses boiling of a polyol composition.

As a result of diligent studies to solve the above problems, the present inventor has found that the cause of boiling is the low boiling point foaming agent contained in the polyol composition, and the polyol composition is prepared before being mixed with the polyisocyanate. We have found that the above problems can be solved by cooling, and have completed the present invention. That is, the present invention provides the following [1] to [8].

[1] A method for producing a polyurethane foam in which a polyol composition containing a polyol, a foaming agent, and a catalyst is reacted and foamed with a polyisocyanate, wherein the foaming agent contains a hydrofluoroolefin having a boiling point of 30 ° C. or lower and is foamed. A method for producing a polyurethane foam, which comprises lowering the temperature of the polyol composition to 30 ° C. or lower before the reaction.
[2] The method for producing a polyurethane foam according to the above [1], wherein the polyol composition further contains a filler.
[3] The method for producing a polyurethane foam according to the above [1] or [2], wherein the catalyst contains a trimerization catalyst.
[4] The method for producing a polyurethane foam according to the above [3], wherein the quantification catalyst contains a quaternary ammonium salt.
[5] The method for producing a polyurethane foam according to any one of the above [1] to [4], wherein the catalyst contains a metal catalyst containing at least one selected from the group consisting of bismuth and tin.
[6] The method for producing a polyurethane foam according to any one of the above [1] to [5], wherein the catalyst contains an imidazole derivative.
[7] Production of the polyurethane foam according to any one of the above [1] to [6], wherein the hydrofluoroolefin having a boiling point of 30 ° C. or lower is trans-1-chloro-3,3,3-trifluoropropene. Method.
[8] The method for producing a polyurethane foam according to any one of the above [1] to [7], which has an isocyanate index of 200 or more.

According to the present invention, it is possible to provide a method for producing a polyurethane foam, which can suppress boiling of a polyol composition, facilitate control of reaction with polyisocyanate, and can be satisfactorily applied.

It is a conceptual diagram which shows one aspect of the cooling method which concerns on this invention.

The present invention is a method for producing a polyurethane foam in which a polyol composition containing a polyol, a foaming agent, and a catalyst is reacted and foamed with polyisocyanate, wherein the foaming agent contains a hydrofluoroolefin having a boiling point of 30 ° C. or lower. Moreover, the temperature of the polyol composition is set to 30 ° C. or lower before the reaction.
Hereinafter, the present invention will be described in detail.
[Polyform composition]
The polyol composition of the present invention contains a polyol, a foaming agent, and a catalyst. Each component in the polyol composition will be described in detail below.

<Polyol>
The polyol composition of the present invention contains a polyol as a raw material for polyurethane foam.
Examples of the polyol used in the present invention include polylactone polyols, polycarbonate polyols, aromatic polyols, alicyclic polyols, aliphatic polyols, polyester polyols, polymer polyols, and polyether polyols. The polyol usually becomes a liquid at normal temperature (23 ° C.) and normal pressure (1 atm).

Examples of the polylactone polyol include polypropiolactone glycol, polycaprolactone glycol, polyvalerolactone glycol and the like.
Examples of the polycarbonate polyol include a polyol obtained by a dealcohol reaction between a hydroxyl group-containing compound such as ethylene glycol, propylene glycol, butanediol, pentandiol, hexanediol, octanediol, and nonanediol and ethylene carbonate, propylene carbonate, or the like. And so on.

Examples of the aromatic polyol include bisphenol A, bisphenol F, phenol novolac, cresol novolak and the like.
Examples of the alicyclic polyol include cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, dimethyldicyclohexylmethanediol and the like.
Examples of the aliphatic polyol include alkanediols such as ethylene glycol, propylene glycol, butanediol, pentandiol, and hexanediol.

Examples of the polyester polyol include a polymer obtained by dehydrating and condensing a polybasic acid and a polyhydric alcohol, and a condensate of a hydroxycarboxylic acid and the polyhydric alcohol and the like.
Examples of the polybasic acid include adipic acid, azelaic acid, sebacic acid, isophthalic acid (m-phthalic acid), terephthalic acid (p-phthalic acid), succinic acid and the like. Examples of the polyhydric alcohol include bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexaneglycol, neopentyl glycol and the like.
Examples of the hydroxycarboxylic acid include castor oil and reaction products of castor oil and ethylene glycol.

Examples of the polymer polyol include a polymer obtained by graft-polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene, methyl acrylate, and methacrylate with an aromatic polyol, an alicyclic polyol, an aliphatic polyol, a polyester polyol, or the like. , Polybutadiene polyols, or their hydrogenated additives and the like.

As the polyether polymer, for example, at least one kind of alkylene oxide such as ethylene oxide, propylene oxide and tetrahydrofuran is ring-opened in the presence of at least one kind such as a low molecular weight active hydrogen compound having two or more active hydrogens. Examples thereof include a polymer obtained by polymerization. Examples of the low molecular weight active hydrogen compound having two or more active hydrogens include diols such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol and 1,6-hexanediol, and triols such as glycerin and trimethylolpropane. , Pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol, etc., sucrose, glucose, mannose, fructose, methyl glucoside and its derivatives, tetra-octavalent alcohols, ethylenediamine, butylene diamine, etc. Examples of amines and the like.

The polyol used in the present invention is preferably at least one selected from the group consisting of polyester polyols and polyether polyols. Polyester polyols are more preferred from the standpoint of foamability and reactivity. Further, a polyol having two hydroxyl groups is preferable. Of these, aromatic polyester polyols, which are polyester polyols having an aromatic ring, are preferable from the viewpoint of enhancing flame retardancy. Examples of the aromatic polyester polyol include polybasic acids having an aromatic ring such as isophthalic acid (m-phthalic acid) and terephthalic acid (p-phthalic acid), bisphenol A, ethylene glycol, 1,2-propylene glycol and the like. An aromatic polyester polyol obtained by dehydration condensation with the dihydric alcohol of No. 1 is more preferable. By using an aromatic polyester polyol, flame retardancy can be easily improved.

The hydroxyl value of the polyol is preferably 20 to 350 mgKOH / g, more preferably 50 to 300 mgKOH / g, and even more preferably 100 to 250 mgKOH / g. When the hydroxyl value of the polyol is not more than the upper limit, the viscosity of the polyol composition tends to decrease, which is preferable from the viewpoint of handleability and the like. On the other hand, when the hydroxyl value of the polyol is at least the above lower limit value, the crosslink density of the polyurethane foam is increased and the strength is increased.
The hydroxyl value of the polyol can be measured according to JIS K 1557-1: 2007.

The content of the polyol in the polyol composition of the present invention is preferably 15 to 80% by mass, more preferably 20 to 70% by mass, and further preferably 25 to 60% by mass. When the content of the polyol is at least the above lower limit value, the polyol and the polyisocyanate are likely to react with each other, which is preferable. On the other hand, when the content of the polyol is not more than the upper limit, the viscosity of the polyol composition does not become too high, which is preferable from the viewpoint of handleability.

<Effervescent agent>
The polyol composition of the present invention contains a hydrofluoroolefin having a boiling point of 30 ° C. or lower (hereinafter, may be referred to as “low boiling point HFO”) as a foaming agent. HFO has high stability as a foaming agent, its catalytic activity is less likely to decrease, and its environmental load is also reduced. The HFO is not particularly limited as long as it has a boiling point of 30 ° C. or lower, and examples thereof include fluoroalkenes having about 3 to 6 carbon atoms. Further, the HFO may be a hydrochlorofluoroolefin having a chlorine atom, and therefore may be a chlorofluoroalkene having about 3 to 6 carbon atoms.
Examples of the low boiling point HFO include trifluoropropene, tetrafluoropropene such as HFO-1234, pentafluoropropene such as HFO-1225, chlorodifluoropropene, chlorotrifluoropropene such as HFO-1233, and chlorotetrafluoropropene. Can be mentioned.
More specifically, 3,3,3-trifluoropropene (HFO-1243zf, boiling point: -18 ° C.), trans-1,3,3,3-tetrafluoropropene (HFO-1234ze (E), boiling point: -18 ° C.). -19 ° C.), cis-1,3,3,3-tetrafluoropropene (HFO-1234ze (Z), boiling point: 10 ° C.), 2,3,3,3-tetrafluoropropene (HFO-1234yf, boiling point: 10 ° C.) −29 ° C.), 1,1,3,3-tetrafluoropropene (boiling point: 4 ° C.), trans-1,2,3,3,3-pentafluoropropene (HFO-1225ye (E), boiling point: -10). ° C.), cis-1,2,3,3,3-pentafluoropropene (HFO-1225ye (Z), boiling point: -19 ° C.), 1,1,3,3,3-pentafluoropropene (HFO-1225zc). , Boiling point: -21 ° C.), 1,1,2,3,3-pentafluoropropene (HFO-1225yc, Boiling point: 2 ° C.), Trans-1-chloro-3,3,3-trifluoropropene (HFO-) 1233zd (E), boiling point: 19 ° C.) and the like. Among these, HFO-1233zd (E) is preferable.
These low boiling point hydrofluoroolefins may be used alone or in combination of two or more.

The lower limit of the boiling point of the low boiling point HFO is not particularly limited, but is preferably 0 ° C. or higher from the viewpoint of easy handling. Therefore, the low boiling point HFO according to the present invention preferably has a boiling point of 0 to 30 ° C. Further, from the viewpoint of suppressing boiling of the polyol composition and good handling property, the boiling point of the low boiling point HFO is more preferably in the range of 10 to 25 ° C.

The content of the low boiling point HFO is preferably 20 to 70 parts by mass, more preferably 25 to 60 parts by mass, and even more preferably 30 to 50 parts by mass with respect to 100 parts by mass of the polyol. When the content of the hydrofluoroolefin is at least the above lower limit value, foaming is promoted, foamability is improved, and the density of the obtained polyurethane foam can be reduced. On the other hand, when the content of the hydrofluoroolefin is not more than the above upper limit value, it is possible to suppress the excessive progress of foaming.

The polyol composition of the present invention may contain a hydrofluoroolefin having a boiling point of more than 30 ° C. as a foaming agent as long as the effects of the present invention are not impaired. For example, cis-1,3,3,3-tetrafluoropropene (HFO-1234ze (Z), boiling point: 39 ° C.), 1,1,1,4,4,4-hexafluorobut-2-ene (HFO). -1336 mzz, boiling point: 33 ° C.) and the like.

Further, the polyol composition of the present invention may contain a foaming agent other than the hydrofluoroolefin. Examples of the foaming agent other than the hydrofluoroolefin include water, an organic physical foaming agent, and an inorganic physical foaming agent. Examples of the organic physical foaming agent include low boiling hydrocarbons such as propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane: dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, and the like. Chlorinated aliphatic hydrocarbon compounds such as isobutyl chloride, pentyl chloride, and isopentyl chloride: ether compounds such as dimethyl ether and diisopropyl ether can be mentioned. Examples of the inorganic physical foaming agent include nitrogen gas, oxygen gas, argon gas, carbon dioxide gas and the like. Among these, water, oxygen gas, and carbon dioxide gas are preferable from the viewpoint of handleability, and water is more preferable from the viewpoint of adjusting the isocyanate index and from the viewpoint of ease of handling.

The content of the foaming agent other than the low boiling point HFO is preferably 0.01 to 25 parts by mass, more preferably 0.1 to 20 parts by mass, and further preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the polyol. preferable. When the content of the foaming agent is at least the above lower limit value, foaming is promoted and the density of the obtained polyurethane foam can be reduced. On the other hand, when the content of the foaming agent is not more than the upper limit, it is possible to prevent the foaming from progressing excessively.

<Catalyst>
<< Metal catalyst (resinized metal catalyst) >>
The catalyst used in the polyol composition of the present invention preferably contains a metal catalyst containing at least one selected from the group consisting of bismuth and tin. This metal catalyst is generally called a resinified metal catalyst. In the present invention, the inclusion of the metal catalyst promotes the reaction between the polyol and the polyisocyanate. Further, if a filler described later is contained in a certain amount or more, the reactivity of the polyurethane foam is hindered and the foamability tends to decrease, but by containing a metal catalyst, the foamability of the polyurethane foam can be easily maintained. The metal catalyst more preferably contains bismuth from the viewpoint of foamability and the like.

The resinized metal catalyst is preferably a metal salt selected from bismuth and tin, and more preferably a bismuth salt. The metal salt is preferably an organic acid metal salt, more preferably a metal salt of a carboxylic acid having 5 or more carbon atoms. When the carboxylic acid has 5 or more carbon atoms, its stability with respect to a foaming agent, particularly a hydrofluoroolefin, becomes good. The carbon number of the carboxylic acid is preferably 18 or less, more preferably 12 or less, from the viewpoint of catalytic activity and the like. The carboxylic acid is preferably an aliphatic carboxylic acid, more preferably a saturated aliphatic carboxylic acid. The carboxylic acid may be linear or may have a branched structure, but it is preferable that the carboxylic acid has a branched structure.
Specific examples of the carboxylic acid include octyl acid, lauryl acid, versatic acid, pentanic acid, acetic acid and the like, and among these, octyl acid is preferable. That is, the transition metal salt is preferably a metal salt of octylic acid. These carboxylic acids may be linear as described above, but may have a branched structure. Examples of the octyl acid having a branched structure include 2-ethylhexanoic acid.
As the metal salt of carboxylic acid, a bismuth salt of carboxylic acid and a tin salt of carboxylic acid are preferable, and a bismuth salt of octyl acid is particularly preferable. Further, the metal salt of the carboxylic acid may be a carboxylate of an alkyl metal. For example, the carboxylic acid tin salt may be a dialkyltin carboxylate or the like, preferably a dioctyltin carboxylate or the like.
Specific examples of the metal salt of the carboxylic acid include bismuth trioctate, dioctyl tin versate, dibutyl tin dilaurate, dioctyl tin dilaurate, tin dioctylate and the like, preferably bismuth trioctate, dioctyl tin versate and more preferably. Bismuth Trioctate.

The content of the metal catalyst in the polyol composition is preferably 0.1 to 10 parts by mass, more preferably 1 to 8 parts by mass, still more preferably 1.5 to 6 parts by mass with respect to 100 parts by mass of the polyol. 2 to 5 parts by mass is even more preferable. When the content of the metal catalyst is at least the above lower limit value, the curing reaction speed of the effervescent polyurethane composition is improved and the effervescent property is improved. On the other hand, when the content of the metal catalyst is not more than the upper limit value, the reaction can be easily controlled.

《Imidazole derivative》
The catalyst used in the polyol composition of the present invention preferably contains a resinified amine catalyst, and more preferably contains an imidazole derivative as the resinified amine catalyst.
The imidazole derivative is less susceptible to the influence of hydrofluoroolefins, and makes it easier for the polyol to react with the polyisocyanate while increasing the stability of the polyol composition. Therefore, when the polyol composition contains an imidazole derivative in addition to the above-mentioned metal catalyst, the reactivity between the polyol and the isocyanate is enhanced, and the foamability is further improved.
The imidazole derivative is preferably an imidazole in which the 1-position and the 2-position are independently substituted with an alkyl group having 8 or less carbon atoms, and the alkyl group preferably has 6 or less carbon atoms, and more preferably 4 or less carbon atoms. A suitable specific example of the imidazole derivative is represented by the following general formula (1).

（一般式（１）中、Ｒ^１及びＲ^２は、それぞれ独立に炭素数１～８のアルキル基又は炭素数２～８のアルケニル基を表す。）

(In the general formula (1), R ¹ and R ² independently represent an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, respectively.)

R ¹ and R ² in the general formula (1) independently represent an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, respectively. The alkyl group and the alkenyl group may be linear or have a branched structure.
Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, isopentyl group, sec-pentyl group, hexyl group and heptyl. Groups, octyl groups and the like can be mentioned.
Specific examples of the alkenyl group include a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group and the like.
When the carbon number of the alkyl group or alkenyl group of R ¹ and R ² is at least the above lower limit value, steric hindrance becomes large and it is less likely to be affected by a foaming agent such as a hydrofluoroolefin, which is preferable. On the other hand, when the carbon number of the alkyl group of R ¹ and R ² is not more than the above upper limit value, the steric hindrance does not become extremely large, so that the reaction between the polyol and the polyisocyanate can be rapidly promoted, and the foamability becomes foamy. Will also be good.
From these viewpoints, R ¹ and R ² are each independently preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and further preferably a methyl group.

Examples of the imidazole derivative represented by the general formula (1) include 1,2-dimethylimidazole, 1-ethyl-2-methylimidazole, 1-methyl-2-ethylimidazole, 1,2-diethylimidazole, and 1-isobutyl. Examples thereof include -2-methylimidazole, among which 1,2-dimethylimidazole and 1-isobutyl-2-methyl are used from the viewpoint of improving the activity of the catalyst in the presence of hydrofluoroolefin and promptly advancing the reaction. Imidazole is preferred. Further, 1,2-dimethylimidazole is more preferable from the viewpoint of further enhancing the stability.

The content of the imidazole derivative in the polyol composition is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, still more preferably 2 to 15 parts by mass, and 3 to 3 to 100 parts by mass with respect to 100 parts by mass of the polyol. 10 parts by mass is particularly preferable. When the content of the imidazole derivative is at least the above lower limit value, the formation of urethane bonds is likely to occur, the reaction proceeds rapidly, and the foamability becomes good. On the other hand, when the content of the imidazole derivative is not more than the above upper limit value, the reaction rate can be easily controlled, which is preferable.

《Triquantization catalyst》
The polyol composition of the present invention preferably further contains a trimerization catalyst. The trimerization catalyst is a catalyst that promotes the formation of an isocyanurate ring by reacting an isocyanate group contained in polyisocyanate to trimerize it. The inclusion of the trimerization catalyst has the advantage that a good foam can be obtained by completing the reaction of the unreacted isocyanate group. Examples of the trimerization catalyst include metal catalysts and ammonium salts.
Examples of the metal catalyst used as the trimerization catalyst (trimerization metal catalyst) include potassium organic acid, preferably potassium octylate such as potassium 2-ethylhexanoate, potassium acetate, potassium propionate, potassium butanoate, and the like. It is potassium carboxylate having 2 to 8 carbon atoms such as potassium benzoate.
As the ammonium salt, a tertiary ammonium salt such as triethylammonium salt and triphenylammonium salt, a quaternary ammonium salt such as tetramethylammonium salt, tetraethylammonium salt and tetraphenylammonium salt can be used. Of these, a quaternary ammonium salt is preferable. The ammonium salt is, for example, an ammonium salt of a carboxylic acid. Examples of the carboxylic acid in the ammonium salt include saturated fatty acids having 1 to 10 carbon atoms, preferably 2 to 8 carbon atoms. The saturated fatty acid may have a linear hydrocarbon group or may have a branch, but it is preferable that the saturated fatty acid has a branch. Specific examples of the carboxylic acid include 2-ethylhexanoic acid, 2,2-dimethylpropionic acid, acetic acid, and formic acid, and among these, 2,2-dimethylpropionic acid is preferable. The trimerization catalyst may be used alone or in combination of two or more. When two or more kinds are used in combination, it is preferable to use a quaternary ammonium salt and a metal catalyst in combination.

The content of the trimerization catalyst in the polyol composition is preferably 0.5 to 30 parts by mass, more preferably 1 to 25 parts by mass, and even more preferably 2 to 20 parts by mass with respect to 100 parts by mass of the polyol. ~ 18 parts by mass is even more preferable. When the content of the trimerization catalyst is at least the above lower limit value, there is no big difference in the activity between the resinification and the trimerization, the foaming can be suppressed from being in two stages, and the foaming property is improved. On the other hand, when the content of the quantification catalyst is not more than the above upper limit value, the resinification reaction proceeds to the activity, so that the activity of the quantification can be assisted by the heat of the resinification reaction, and the foaming property becomes good, which is good. A foam can be formed.

<Filler>
The polyol composition of the present invention preferably contains a filler. The filler is contained as a solid component in the polyol composition, and is a component generally present as a granular or powdery component in the polyol composition. In the present invention, by containing a filler, it becomes easy to improve various physical properties such as flame retardancy and mechanical properties of the obtained polyurethane foam.

The filler may be a component that is solid at room temperature (23 ° C.) and normal pressure (1 atm) and does not dissolve in the polyol composition. The filler preferably has no hygroscopicity and deliquescent property from the viewpoint of reducing the water absorption rate of the polyurethane foam.
Specifically, as the filler, it is preferable to use a solid flame retardant that is solid at normal temperature (23 ° C.) and normal pressure (1 atm). The solid flame retardant is selected from red phosphorus flame retardants, phosphate-containing flame retardants, bromine-containing flame retardants, boric acid-containing flame retardants, antimony-containing flame retardants, chlorine-containing flame retardants, metal hydroxides, needle-like fillers, etc. It is preferably at least one of the above. By using a solid flame retardant as a filler, the flame retardancy of urethane foam is improved. The solid flame retardant may be used alone or in combination of two or more.
Further, as the filler, an inorganic filler other than the solid flame retardant may be used. The inorganic filler other than the solid flame retardant is preferably used in combination with the solid flame retardant from the viewpoint of flame retardancy, but the inorganic filler other than the solid flame retardant may be used alone as the filler. Of course, the solid flame retardant may be used alone.

(Red phosphorus flame retardant)
The red phosphorus-based flame retardant used as a filler may be composed of red phosphorus alone, may be red phosphorus coated with a resin, a metal hydroxide, a metal oxide, or the like, or may be a red phosphorus coated with a resin or a metal. It may be a mixture of hydroxide, metal oxide and the like. The resin coated with red phosphorus or mixed with red phosphorus is not particularly limited, and examples thereof include thermosetting resins such as phenol resin, epoxy resin, unsaturated polyester resin, melamine resin, urea resin, aniline resin, and silicone resin. Be done. As the film or the compound to be mixed, a metal hydroxide is preferable from the viewpoint of flame retardancy. As the metal hydroxide, those described later may be appropriately selected and used.

(Phosphate-containing flame retardant)
The phosphate-containing flame retardant is at least selected from various phosphates, metals of the Group IA to IVB of the Periodic Table, ammonia, aliphatic amines, aromatic amines, and heterocyclic compounds containing nitrogen in the ring. Phosphates consisting of salts with one metal or compound can be mentioned. The term "various phosphoric acids" is a concept that includes not only phosphoric acid but also phosphorous acid, hypophosphoric acid and the like.
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. Examples of the aromatic amine include aniline, o-triidin, 2,4,6-trimethylaniline, anicidin, 3- (trifluoromethyl) aniline and the like. Examples of the heterocyclic compound containing nitrogen in the ring include pyridine, triazine, melamine and the like.

Specific examples of the phosphate-containing flame retardant include monophosphate, polyphosphate and the like. The monophosphate is not particularly limited, but for example, ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, monosodium phosphate, disodium phosphate, trisodium phosphate, and phosphite. Sodium salts such as monosodium, disodium phosphite, sodium hypophosphite, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, hypophosphite Potassium salts such as potassium, monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphate, dilithium phosphate, lithium salts such as lithium hypophosphite, barium dihydrogen phosphate, phosphorus Barium salts such as barium hydrogen phosphate, tribarium phosphate, barium hypophosphite, magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, magnesium salts such as magnesium hypophosphite, calcium dihydrogen phosphate , Calcium hydrogen phosphate, tricalcium phosphate, calcium salts such as calcium hypophosphite, zinc salts such as zinc phosphate, zinc phosphite, zinc hypophosphite and the like.
Here, the polyphosphate is not particularly limited, and examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium polyphosphate, aluminum polyphosphate, and the like.
The phosphate-containing flame retardant may be used alone from the above-mentioned ones, or may be used in combination of two or more.

(Brominated flame retardant)
The bromine-containing flame retardant is not particularly limited as long as it is a compound containing bromine in its molecular structure and is solid at room temperature (23 ° C.) and normal pressure (1 atm). Examples include compounds.
Examples of the brominated aromatic ring-containing aromatic compound include hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis (pentabromophenoxy) ethane, and ethylenebis (pentabromophenoxy). Examples thereof include monomer-based organic bromine compounds such as pentabromophenyl), ethylene bis (tetrabromophthalimide), and tetrabromobisphenol A.

Further, the brominated aromatic ring-containing aromatic compound may be a bromine compound polymer. Specifically, a polycarbonate oligomer produced from brominated bisphenol A as a raw material, a brominated polycarbonate such as a copolymer of this polycarbonate oligomer and bisphenol A, and a diepoxy compound produced by the reaction of brominated bisphenol A with epichlorohydrin. And so on. Furthermore, brominated epoxy compounds such as monoepoxy compounds obtained by the reaction of brominated phenols with epichlorohydrin, condensates of brominated phenols of brominated polyphenylene ether, brominated bisphenol A and cyanur chloride, uncrosslinked or crosslinked. Examples include brominated polystyrene.
Further, it may be a compound other than a brominated aromatic ring-containing aromatic compound such as hexabromocyclododecane.
These brominated flame retardants may be used alone or in combination of two or more.

(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. Examples of the boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, tetraboron pentoxide and the like.
Examples of the borate include alkali metals, alkaline earth metals, elements of Groups 4, 12, and 13 of the Periodic Table, and ammonium borates. Specifically, an alkali metal borate salt such as lithium borate, sodium borate, potassium borate, and cesium borate, an alkaline earth metal salt borate such as magnesium borate, calcium borate, and barium borate, boro Examples thereof include zirconium acid, zinc borate, aluminum borate, and ammonium borate.
The boron-containing flame retardant may be used alone or in combination of two or more.
The boron-containing flame retardant used in the present invention is preferably borate, more preferably zinc borate.

(Antimony-containing flame retardant)
Examples of the antimony-containing flame retardant include antimony oxide, antimony acid salt, pyroantimony acid salt and the like. Examples of antimony oxide include antimony trioxide and antimony pentoxide. Examples of the antimonate include sodium antimonate, potassium antimonate and the like. Examples of the pyroantimonate include sodium pyroantimonate, potassium pyroantimonate and the like.
The antimony-containing flame retardant may be used alone or in combination of two or more. The antimony-containing flame retardant used in the present invention is preferably antimony oxide.

(Chlorine-containing flame retardant)
Examples of the chlorine-containing flame retardant include those commonly used for polyurethane foam, such as polynaphthalene chloride, chlorendic acid, and dodecachlorododecahydrodimethanodibenzocyclooctene sold under the trade name of "Dechloran Plus". Be done.

(Metal hydroxide)
Examples of the metal hydroxide used in the present invention include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, and copper hydroxide. Examples thereof include vanadium hydroxide and tin hydroxide. The metal hydroxide may be used alone or in combination of two or more. As the metal hydroxide, aluminum hydroxide is preferable.

(Needle-shaped filler)
Examples of the needle-shaped filler include potassium titanate whisker, aluminum borate whisker, magnesium-containing whisker, silicon-containing whisker, wollastonite, sepiolite, zonolite, elestadite, boehmite, rod-shaped hydroxyapatite, glass fiber, carbon fiber, and graphite fiber. , Metal fiber, slag fiber, gypsum fiber, silica fiber, alumina fiber, silica alumina fiber, zirconia fiber, boron nitride fiber, boron fiber, stainless fiber and the like.
These needle-shaped fillers may be used alone or in combination of two or more.
The range of the aspect ratio (length / diameter) of the needle-shaped filler used in the present invention is preferably in the range of 5 to 50, and more preferably in the range of 10 to 40. The aspect ratio can be obtained by observing the needle-shaped filler with a scanning electron microscope and measuring its length and width.

As the filler, an inorganic filler other than the above-mentioned flame retardant may be used. Such inorganic fillers include alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dosonite, hydrotalcite. , Calcium sulfate, barium sulfate, calcium silicate, talc, mica, montmorillonite, bentonite, active white clay, imogolite, sericite, glass beads, aluminum nitride, boron nitride, silicon nitride, various metal powders, magnesium sulfate, zirconic acid titanate Lead, molybdenum sulfide, silicon carbide, various magnetic powders, fly ash and the like can be appropriately used. These inorganic fillers may be used alone or in combination of two or more.
These fillers may be used alone or in combination of two or more.

The content of the filler in the polyol composition is preferably, for example, 10 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 40 parts by mass or more with respect to 100 parts by mass of the polyol. , 50 parts by mass or more is particularly preferable. By setting the content of the filler to the above lower limit value or more, it becomes easy to impart various performances such as flame retardancy to the polyurethane foam. The content of the filler is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, and further preferably 90 parts by mass or less with respect to 100 parts by mass of the polyol. By setting the content of the filler to these upper limit values or less, it becomes easy to obtain good foamability without lowering the reactivity.

<Phosphate ester>
The polyol composition of the present invention may have a flame retardant other than the above-mentioned solid flame retardant. Examples of such a flame retardant include flame retardants that are liquid at normal temperature (23 ° C.) and normal pressure (1 atm), and specific examples thereof include phosphoric acid esters. By using the phosphoric acid ester, it becomes easy to improve the flame retardancy of the urethane foam without lowering the fluidity of the polyol composition.

As the phosphoric acid ester, a monophosphate ester, a condensed phosphoric acid ester and the like can be used. The monophosphate ester is a phosphate ester having one phosphorus atom in the molecule. Examples of the monophosphate include trialkyl phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate and tri (2-ethylhexyl) phosphate, halogen-containing phosphate esters such as tris (β-chloropropyl) phosphate, and tributoxyethyl phosphate. Arocyclic-containing phosphoric acid esters such as trialkoxy phosphate, tricredyl phosphate, trixilenyl phosphate, tris (isopropylphenyl) phosphate, cresyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, monoisodecyl phosphate, diisodecyl, etc. Examples thereof include acidic phosphoric acid esters such as phosphate.

Examples of the condensed phosphate ester include aromatic condensed phosphate esters such as trialkylpolyphosphate, resorcinol polyphenyl phosphate, bisphenol A polycresyl phosphate, and bisphenol A polyphenyl phosphate.
Commercially available products of condensed phosphoric acid ester include, for example, "CR-733S", "CR-741" and "CR747" manufactured by Daihachi Chemical Industry Co., Ltd., and "ADEKA STUB PFR" and "FP-600" manufactured by ADEKA. And so on.

As the phosphoric acid ester, one of the above-mentioned ones may be used alone, or two or more of them may be used in combination. Among these, a monophosphate ester is preferable from the viewpoint of facilitating the appropriate viscosity of the polyol composition and the viewpoint of improving the flame retardancy of the polyurethane foam, and a halogen-containing phosphoric acid ester such as tris (β-chloropropyl) phosphate is preferable. Is more preferable.
The content of the phosphoric acid ester in the polyol composition is preferably 5 to 100 parts by mass, more preferably 12 to 90 parts by mass, further preferably 20 to 75 parts by mass, and 30 to 60 parts by mass with respect to 100 parts by mass of the polyol. The part is more preferable.

<Foam control agent>
The polyol composition of the present invention may contain a defoaming agent. By containing a foam stabilizer, the foamability of the polyurethane foam can be improved, and for example, foaming can be promoted when reacting with polyisocyanate in a spray spray.
Specific examples of the defoaming agent include a surfactant, more specifically, a nonionic surfactant, a cationic surfactant, an anionic surfactant and the like. Specific examples of the nonionic surfactant include a polyoxyalkylene defoaming agent such as polyoxyalkylene alkyl ether and a silicone defoaming agent such as organopolysiloxane. The defoaming agent used in the present invention is not particularly limited, but a silicone defoaming agent is preferable from the viewpoint of foamability. The foam stabilizer may be used alone or in combination of two or more.

The content of the defoaming agent in the polyol composition of the present invention is preferably 0.1 to 12 parts by mass, more preferably 1 to 10 parts by mass, and further preferably 2 to 8 parts by mass with respect to 100 parts by mass of the polyol. preferable. When the content of the defoaming agent is at least the above lower limit value, it becomes easy to foam the mixture of the polyol composition and the polyisocyanate, so that a homogeneous polyurethane foam can be obtained. Further, when the content of the defoaming agent is not more than the upper limit value, the balance between the manufacturing cost and the obtained effect is optimized.

<Other ingredients>
The polyol composition may be a phenol-based, amine-based, sulfur-based or other antioxidant, heat stabilizer, metal damage inhibitor (metal inactivating agent), and antistatic agent, if necessary, as long as the object of the present invention is not impaired. It can contain one or more selected from additives such as inhibitor, stabilizer, cross-linking agent, lubricant, softener, pigment, tackifier resin, and tackifier such as polybutene and petroleum resin.

The method for preparing the polyol composition of the present invention is not particularly limited, and can be produced, for example, by stirring each component at about 20 to 40 ° C. using a homodisper or the like for about 30 seconds to 20 minutes.

<Manufacturing method of polyurethane foam>
The method for producing a polyurethane foam of the present invention is prepared as described above, and the temperature of the polyol composition stored in a container such as a drum is set to 30 ° C. or lower before being reacted with polyisocyanate. It is characterized by that. The polyol composition may boil at a temperature of 30 ° C. or higher, and the boiling may become remarkable particularly by stirring for dispersing the filler in the polyol composition. Such boiling can be suppressed by lowering the temperature of the polyol composition to 30 ° C. or lower.
The method for cooling the temperature of the polyol composition to 30 ° C. or lower is not particularly limited, and for example, a method for cooling the drum for storing the polyol composition with cold air, a method for cooling with a cold insulating agent, a wet towel, or the like. A method of cooling by using the heat of vaporization of water by using water or by pouring water on a drum, a method of storing for a certain period of time in a refrigerator, etc., a chiller that circulates and cools while controlling the temperature of a heat medium such as water. A method using a cooling method, a method using a dedicated drum jacket for cooling, and the like can be mentioned.

The case of cooling by cold air is not particularly limited, but is performed by covering the outside of the container such as a drum with a sheet material such as a resin sheet or a resin film and sending cold air to the gap between the sheet material and the container such as a drum. It is good. By using the sheet material in this way, the container and the polyol composition filled therein can be efficiently cooled. Further, the sheet material such as a resin sheet may be a bag body, or a container may be arranged inside the bag body and cold air may be blown from the opening of the bag body.

Further, a container such as a drum generally has an opening for putting in and taking out the contents, and the opening is closed by a stopper, but cooling of the polyol composition is a container in a state where the stopper is closed. It is good to do it for. According to such a cooling method, it is possible to prevent boiling of the polyol composition that occurs when the stopper is opened when the temperature of the polyol composition is higher than 30 ° C.

The timing for lowering the temperature of the polyol composition to 30 ° C. or lower may be performed before stirring for dispersing the filler or the like contained in the polyol composition, and after the temperature is lowered to 30 ° C. or lower, the mixture is rapidly stirred. It is preferable to do. It is not necessary to cool during stirring, but it may be cooled during stirring.
As a method for measuring the temperature of the polyol composition, a usual method can be used, for example, the temperature of the polyol composition may be directly measured using a thermocouple.

The method for stirring the polyol composition is not particularly limited as long as the compound such as the filler can be dispersed in the polyol composition, but it may be carried out by a stirrer or by shaking the container. It is preferable to use a stirrer. The stirrer is preferably provided with a stirring blade, and it is preferable to arrange the stirring blade in the polyol composition and rotate the stirring blade to stir the polyol composition.
More specifically, the stirrer includes a shaft portion, a stirrer blade attached to the shaft portion, and a stirrer that rotates around the shaft portion. Such a stirrer is, for example, a container such as a drum. The stirring blade can be placed in the polyol composition by inserting it into the container through the opening. As the stirrer, for example, a commercially available drum mixer may be used.
Further, the stirring of the polyol composition depends on the stirring method, but as described above, when stirring using a stirrer, it is preferable to stir after opening the container.

Further, when the outside air temperature is higher than 30 ° C. such as in summer, the polyol composition may be cooled to 30 ° C. or lower by the above cooling.
When cooling to 30 ° C. or lower, the lower limit of the temperature is not particularly limited, but it is preferable to cool to a temperature of 20 ° C. or higher, for example. By cooling to a temperature of 20 ° C. or higher, the cooling time can be shortened and the process can be simplified. In addition, it is possible to prevent the viscosity of the polyol composition from becoming too low and dew condensation.

The polyol composition stirred as described above is then mixed with polyisocyanate in a foaming machine or the like, and the obtained mixed liquid (foamable polyurethane composition) is reacted and foamed to produce a polyurethane foam. good. As the foaming machine, it is preferable to use a spray device or the like having a spray gun.
More specifically, the polyol composition is sent to the foaming machine in a state where the composition such as the filler is dispersed by stirring, and collides with the polyisocyanate sent from another container or the like inside the foaming machine. It is good to mix. Then, the mixed liquid (foamable polyurethane composition) may be discharged from a discharge port of a spray gun or the like, and the polyurethane foam may be molded by the discharged foamable polyurethane composition.
This manufacturing method can be applied to, for example, spraying applications. Therefore, the mixed liquid discharged from the foaming machine may be sprayed on the construction target surface at a constant discharge pressure to foam, thereby forming a polyurethane foam on the construction target surface.
Further, in the present invention, a polyurethane foam may be obtained by mixing a polyisocyanate and a polyol composition, and then injecting the polyisocyanate into a container such as a mold or a frame material and curing the mixture.

[Effervescent polyurethane composition and polyurethane foam]
The effervescent polyurethane composition according to the present invention contains the above-mentioned polyol composition and polyisocyanate, and is obtained by mixing these. The polyurethane foam of the present invention is a reaction product obtained by reacting and foaming a foamable polyurethane composition.

<Polyisocyanate>
Examples of the polyisocyanate include aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates.
Examples of the aromatic polyisocyanate include phenylenediocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate (polymeric MDI). Will be.

Examples of the alicyclic polyisocyanate include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate.

Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate and the like.

Among these, aromatic polyisocyanates are preferable from the viewpoint of ease of use and availability, and diphenylmethane diisocyanate, polypeptide MDI, or a mixture thereof is more preferable. As the polyisocyanate, one type may be used alone, or two or more types may be mixed and used.
Further, the polyisocyanate may be appropriately blended with a known additive to be blended with the polyisocyanate before being mixed with the polyol composition.

It is preferable that the volume of the polyol composition and the polyisocyanate mixed in the polyol composition are substantially the same. Specifically, the volume ratio of the polyisocyanate to the polyol composition is preferably 0.8 to 1.2, more preferably 0.9 to 1.1, and even more preferably 0.95 to 1.05.

The content of the filler in the polyurethane foam is, for example, 4 parts by mass or more, preferably 6 parts by mass or more, more preferably 8 parts by mass or more, and 10 parts by mass with respect to 100 parts by mass of the urethane resin. It is more preferable that the amount is more than one part. By setting the content of the filler in the foamable polyurethane composition to the above lower limit value or more, the proportion of the filler in the polyurethane foam becomes sufficient, the water absorption rate of the polyurethane foam can be reduced, and hydrolysis is satisfactorily suppressed. be able to. The filler content is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, based on 100 parts by mass of the urethane resin. By setting the value to the upper limit or less, it becomes easy to obtain a polyurethane foam having good foamability. The total amount of the polyol and the polyisocyanate contained in the foamable polyurethane composition can be regarded as the amount of the urethane resin.

<Isocyanate index>
The isocyanate index of the polyurethane foam of the present invention is not particularly limited, but is preferably 200 or more. When the isocyanate index is at least the lower limit value, the amount of polyisocyanate with respect to the polyol becomes excessive, and isocyanurate bonds are easily generated by the trimericized polyisocyanate, and as a result, the flame retardancy of the polyurethane foam is improved. It is also possible to impart nonflammability. Further, when the above lower limit value or more is set, a polyurethane foam having a sufficient isocyanurate bond, that is, a polyurethane foam having a high level of flame retardancy and heat insulating property, is produced in combination with the combined use of the above-mentioned various catalysts. Easy to manufacture. From these viewpoints, the isocyanate index is more preferably 250 or more, further preferably 300 or more, further preferably 350 or more, and particularly preferably 400 or more.
The isocyanate index is preferably 1,000 or less, more preferably 800 or less, and even more preferably 600 or less. When the isocyanate index is not more than the upper limit value, flame retardancy sufficiently commensurate with the manufacturing cost can be obtained.

The isocyanate index can be calculated by the following method.
Isocyanate index = equivalent number of polyisocyanate ÷ (equivalent number of polyol + equivalent number of water) × 100
Here, each equivalent number can be calculated as follows.
Equivalent number of polyisocyanate = amount of polyisocyanate used (g) x NCO content (mass%) / molecular weight of NCO (mol) x 100
Equivalent number of polyol = OHV × amount of polyol used (g) ÷ molecular weight of KOH (mmol)
OHV is the hydroxyl value (mgKOH / g) of the polyol.
Equivalent number of water = molecular weight of water (g) / molecular weight of water (mol) x number of OH groups of water In each of the above formulas, the molecular weight of NCO is 42 (mol) and the molecular weight of KOH is 56,100 (mmol). ), The molecular weight of water is 18 (mol), and the number of OH groups in water is 2.

<Use of polyurethane foam>
The use of the polyurethane foam of the present invention is not particularly limited, but since it is excellent in flame retardancy and heat insulating property, it can be suitably used for buildings such as walls, ceilings, roofs, and floors of buildings. Polyurethane foam may be molded using the roof, floor, etc. as the spray target surface. Further, it can be suitably used as a member for filling an arbitrary opening generated in a building, including joints and holes generated between structural materials of the building.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
[Material used]
<Polyform composition>
[Polyol]
-P-Phthalic acid polyester polyol (manufactured by Kawasaki Kasei Chemicals, product name: Maximol RLK-087, hydroxyl value = 200 mgKOH / g)

〔catalyst〕
-Resinylated amine catalyst, 1,2-dimethylimidazole (manufactured by Tosoh Corporation, product name: TOYOCAT (registered trademark) -DM70) concentration 65-75% by mass
・ Resinized metal catalyst, bismuth trioctate (manufactured by Nitto Kasei Co., Ltd., product name: Neostan U-600) concentration 55-58% by mass
・ Resinized metal catalyst, dioctyl tin versatate (manufactured by Nitto Kasei Co., Ltd., product name: Neostan U-830) concentration approx. 99% by mass
-Ammonium salt (triquantization catalyst), 2,2-dimethylpropanoic acid tetramethylammonium salt (Air Products, Chemicals, product name: DABCO (registered trademark) TMR7) concentration 45-55% by mass
-Metal catalyst (triquantization catalyst), potassium 2-ethylhexanoate (manufactured by Air Products and Chemicals, product name: DABCO (registered trademark) K-15) concentration 70-80% by mass

[Effervescent agent]
-Hydrofluoroolefin (HFO, manufactured by Honeywell Japan Co., Ltd., product name: Solstice LBA, trans-1-chloro-3,3,3-trifluoropropene)
·water

〔Flame retardants〕
-Tris (β-chloropropyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., product name: TMCPP)

[Filler]
・ Wollastonite (SiO ₂・ CaO) (manufactured by Kinsei Matek Co., Ltd., product name: SH-1250)

<Polyisocyanate>
・ 4,4'-Diphenylmethane diisocyanate (4,4'-MDI) (manufactured by Manka Chemical Japan Co., Ltd., product name: PM200)

Example 1
Each component was mixed according to the formulation shown in Table 1 to prepare a polyol composition. The polyol composition was placed in a drum and stored at 32 ° C. for 24 hours.
The drum 1 was entirely covered with a bag body 3 as shown in the conceptual diagram in FIG. 1, and cooled by cold air using a spot cooler 2 (“TRUSCO spot air conditioner TS-20ES-1” manufactured by TRUSCO NAKAYAMA). The cooling nozzle 4 was inserted into the cold air insertion port so that no gap was formed, and cold air was directly applied to the drum to cool the drum. The temperature of the polyol composition was measured with a thermocouple (not shown), and it was confirmed that the mixture had been cooled to 28 ° C., and cooling was completed.
Next, the small mouth of the drum was opened, and a mixer for drums (“Air-driven agitator for drums with 3-stage wings, product number: NUE035B-1” manufactured by Nippon Urethane Engineering Co., Ltd. was set. After that, the large mouth of the drum was opened. The mixture was stirred with a drum mixer for 30 minutes, and it was visually observed whether or not the contents boiled and overflowed from the large mouth. The evaluation criteria were as follows.
〇: No overflow ×: Overflow The evaluation results are shown in Table 1.

Example 2
By cooling, the polyol composition was cooled in the same manner as in Example 1 except that the temperature of the polyol composition was cooled to 25 ° C. The results are shown in Table 1.

Examples 3-12
As shown in Table 1, the test was carried out in the same manner as in Example 1 except that the amount of water as a foaming agent, the composition of the catalyst, and the final cooling temperature were changed. The results are shown in Table 1.

Comparative Examples 1 to 3
The test was carried out in the same manner as in Example 1, Example 3 and Example 11, respectively, except that cooling was not performed. The results are shown in Table 1.

As is clear from the results of the above Examples and Comparative Examples, the boiling was suppressed by cooling the polyol composition stored in the drum and lowering the temperature to 30 ° C. or lower. It was found that the content of water, which is a foaming agent, has no effect and depends on the temperature of the polyol composition.
Further, from the test results of the comparative example, when the temperature of the polyol composition was 32 ° C., boiling was observed regardless of the water content. From the above, it was found that there is a critical point near 30 ° C., and the boiling can be remarkably suppressed at this critical point.

1. 1. Drum 2. Spot cooler 3. Bag body 4. Cooling nozzle

Claims (8)

A method for producing a polyurethane foam in which a polyol composition containing a polyol, a foaming agent, and a catalyst is reacted and foamed with a polyisocyanate, wherein the foaming agent contains a hydrofluoroolefin having a boiling point of 30 ° C. or lower and before the reaction. A method for producing a polyurethane foam, which comprises setting the temperature of the polyol composition to 30 ° C. or lower. The method for producing a polyurethane foam according to claim 1, wherein the polyol composition further contains a filler. The method for producing a polyurethane foam according to claim 1 or 2, wherein the catalyst comprises a trimerization catalyst. The method for producing a polyurethane foam according to claim 3, wherein the quantification catalyst contains a quaternary ammonium salt. The method for producing a polyurethane foam according to any one of claims 1 to 4, wherein the catalyst contains a metal catalyst containing at least one selected from the group consisting of bismuth and tin. The method for producing a polyurethane foam according to any one of claims 1 to 5, wherein the catalyst contains an imidazole derivative. The method for producing a polyurethane foam according to any one of claims 1 to 6, wherein the hydrofluoroolefin having a boiling point of 30 ° C. or lower is trans-1-chloro-3,3,3-trifluoropropene. The method for producing a polyurethane foam according to any one of claims 1 to 7, wherein the isocyanate index is 200 or more.

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