JP6130426B2 - Method for producing rigid polyurethane foam - Google Patents

Description

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

Rigid polyurethane foam is used in a wide range of heat insulating materials such as building materials, refrigerators, freezers, structural materials, and on-site building construction sprays because of its heat insulating performance, dimensional stability at low temperatures, and workability. .
Conventionally, chlorofluorocarbons have been used as foaming agents used in the production of rigid polyurethane foams. However, as indicated in the Kyoto Protocol, etc., conventional chlorofluorocarbons are subject to regulation, and hydrofluorocarbons are required to comply with them. Hydrofluoroolefins, low boiling point hydrocarbons and the like are being used as blowing agents.

  On the other hand, a flame retardant is used for the purpose of improving flame retardancy (see Non-Patent Document 1). However, the use of a large amount of a flame retardant has a problem that the heat insulating property (thermal conductivity) of the polyurethane foam deteriorates.

Formulation design and flame retardant technology and practical examples in polyurethane foam (Technical Information Association)

  An object of the present invention is to provide a method for producing a rigid polyurethane foam capable of obtaining a foam excellent in heat insulation (thermal conductivity) without deteriorating the flammability (flame retardancy) of the rigid polyurethane foam. .

As a result of intensive studies, the present inventor has reached the present invention.
That is, the present invention provides an active hydrogen-containing compound (A) having no vinyl polymerizable functional group, an organic polyisocyanate (B) and a vinyl polymerizable compound (Z) in the presence of a foaming agent (C) or a foaming agent. (C) and a method for producing a rigid polyurethane foam by reacting in the presence of a flame retardant (D), wherein (Z) has a vinyl polymerizable functional group represented by the following general formula (1), a molecule It is one or more vinyl polymerizable compounds selected from the group consisting of the following (z1) to (z3) whose concentration of the vinyl polymerizable functional group is 0.5 to 20 (mmol / g), and contains active hydrogen above 70% by weight of the compound (a) is an aromatic polyester diol, Ri less than 20 wt% der based on the total weight of the amount of flame retardant (D) is (a) and (Z), the vinyl polymerizable compound Between (Z) and the active hydrogen-containing compound (A) Ratio (Z) / (A) is from 0.5 / 99.5 to 30/70 a method for producing a rigid polyurethane foam which; is; and urethane foam for building materials obtained by the above production method.
R
｜
CH ₂ = C- (1)
[In General Formula (1), R represents hydrogen, a C1-C15 alkyl group, or a C6-C21 aryl group. ]
(Z1) Unsaturated carboxylic acid ester or unsaturated alkyl ether of polyol (z2) Unsaturated carboxylic acid amidation or unsaturated alkylation product of amine (z3) Unsaturated carboxylic acid thioester or unsaturated alkylthioether of polythiol

  The rigid polyurethane foam produced by the method of the present invention is superior in heat insulation (thermal conductivity) without deteriorating flammability (flame retardancy) as compared with conventional rigid polyurethane foam.

  As the active hydrogen-containing compound (A) having no vinyl polymerizable functional group in the present invention, a polyhydric alcohol (A1), a polyether polyol (A2), a polyester polyol (A3), other polyols (A4), and A mixture of two or more of these may be mentioned.

  As the polyhydric alcohol (A1), a dihydric alcohol having 2 to 20 carbon atoms (hereinafter abbreviated as C) [aliphatic diol (ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, 1, 6-hexanediol, neopentylglycol, etc., alicyclic diol (cyclohexanediol, cyclohexanedimethanol, etc.); C3-20 trihydric alcohol [aliphatic triol (glycerin, trimethylolpropane, trimethylolethane, hexanetriol, etc.) Etc.]; C5-20 tetrahydric to octahydric or higher polyhydric alcohols [aliphatic polyols (pentaerythritol, sorbitol, mannitol, etc.), intramolecular dehydrates of aliphatic polyols (sorbitan, etc.), aliphatic polyols Intermolecular dehydrates (diglycerin, dipenta Risuritoru etc.); and saccharides and derivatives thereof (sucrose, glucose, mannose, fructose, methyl glucoside, etc.) and the like.

(A2) is an alkylene oxide (hereinafter referred to as a compound) containing at least 2 (preferably 3 to 8) active hydrogen atoms (polyhydric alcohol, polyhydric phenol, ammonia, amine, polycarboxylic acid, phosphoric acid, etc.). , Abbreviated as AO) and adducts, and mixtures thereof.
Examples of the polyhydric alcohol include those described above.

  Polyvalent (divalent to octavalent or higher) phenols include monocyclic polyhydric phenols (hydroquinone, resorcinol, pyrogallol, phloroglucin, etc.); polycyclic polyhydric phenols (dihydroxynaphthalene, etc.); bisphenol compounds (bisphenol A, − F and S); condensates of phenol and formaldehyde (novolak, resol, etc.) and the like.

  Examples of amines include aliphatic amines [monoamines (C1-20, such as n-butylamine, octylamine), diamines (C2-10, such as ethylenediamine, propylenediamine, hexamethylenediamine), polyalkylene polyamines (C4-20, such as diethylenetriamine). , Triethylenetetramine, pentaethylenehexamine, etc.]; aromatic (aliphatic) amines (C6-20 mono- and polyamines such as aniline, phenylenediamine, tolylenediamine, xylylenediamine, diethyltoluylenediamine, methylenedianiline) , Diphenyl ether diamine); cycloaliphatic amines (C4-20, such as isophorone diamine, cyclohexane diamine, dicyclohexylmethane diamine); heterocyclic amines (C4-20, such as pyridine). Rajin, those aminoethylpiperazine and Sho 55-21044 JP); alkanolamines (C2-20, such as mono-, - di - and triethanolamine, isopropanol amine and the like) and the like.

  Examples of the poly (divalent to tetravalent or higher) carboxylic acid include aliphatic polycarboxylic acids (C4-18, such as succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid), aromatic polycarboxylic acids ( C8-18, such as terephthalic acid, isophthalic acid, orthophthalic acid, trimellitic acid, pyromellitic acid), alicyclic polycarboxylic acids (C8-15, such as cyclohexane 1,4-dicarboxylic acid), and two or more thereof And the like.

AO added to the active hydrogen-containing compound may be C2-12 or more (preferably 2-8), such as ethylene oxide, 1,2-propylene oxide, 1,2-, 2,3- and 1,3-butylene. Oxide, tetrahydrofuran and 3-methyl-tetrahydrofuran (hereinafter abbreviated as EO, PO, BO, THF and MTHF, respectively), 1,3-
Propylene oxide, isoBO, C5-12 α-olefin oxide, substituted AO, such as styrene oxide and epihalohydrin (such as epichlorohydrin), and combinations of two or more thereof (random addition and / or block addition) are included.
Of these, PO and a combination of EO / PO are more preferable from an industrial viewpoint.
The addition amount of AO is preferably 1 to 10 mol, more preferably 2 to 6 mol, per active hydrogen atom.

  Preferable specific examples of polyether polyols include glycerin, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol and sucrose PO adducts, EO / PO adducts, and mixtures thereof.

The number average molecular weight (Mn) of (A2) is preferably 150 to 3,000, more preferably 200 to 2,500, and particularly preferably 250 to 1,500 from the viewpoint of mechanical properties of the polyurethane foam.
In addition, Mn in this invention is molecular weight converted from the active hydrogen value mentioned later.

  As the polyester polyol (A3), the polyhydric alcohol and / or the polyether polyol, the polycarboxylic acid, its anhydride, and an ester-forming derivative such as a lower alkyl (alkyl group is C1-4) ester (adipine) Acid, sebacic acid, maleic anhydride, phthalic anhydride, dimethyl terephthalate, etc.), AO adduct of the carboxylic anhydride; AO adduct of the condensation reaction; polylactone polyol [the polyvalent polyol A product obtained by ring-opening polymerization of a lactone (C4-10, for example, ε-caprolactone, δ-valerolactone) using an alcohol as an initiator; a polycarbonate polyol [the polyhydric alcohol and an alkylene carbonate (ethylene carbonate, etc.); And the like.

Specific examples of (A3) include poly (1,4-butanediol adipate), poly (1,4-butanediol terephthalate), poly (ethylene glycol terephthalate), poly (diethylene glycol terephthalate), polyε-caprolactone. Polyol and the like.
Among (A3), from the viewpoint of flame retardancy, an aromatic polyester polyol (A31) is preferable, an aromatic polyester diol is more preferable, terephthalic acid or a lower alkyl (1 to 4 carbon atoms) ester thereof and 2 carbon atoms. A condensation reaction product with an aliphatic diol of ˜20 is particularly preferred.
Mn of (A3) is preferably 150 to 3,000, more preferably 200 to 2,500, and particularly preferably 250 to 1,500, from the viewpoint of mechanical properties of the polyurethane foam.

Examples of the other polyol (A4) include a polymer polyol (hereinafter abbreviated as P / P) and a hydroxyl group-containing vinyl polymer (polybutadiene polyol, partially saponified ethylene / vinyl acetate copolymer, etc.).
P / P is obtained by in-situ polymerization of ethylenically unsaturated monomers in a polyol (the OH-terminated polyether polyol and / or polyester polyol, or a mixture thereof with the polyhydric alcohol).
Ethylenically unsaturated monomers include acrylic monomers [(meth) acrylonitrile, alkyl (C1-20 or higher) (meth) acrylate (methyl methacrylate, etc.)], hydrocarbon (hereinafter abbreviated as HC) monomer [aromatic unsaturated Saturated HC (styrene, etc.), aliphatic unsaturated HC (C2-20 or higher alkenes, alkadienes, etc. (α-olefins, butadiene, etc.)), and combinations of two or more of these [acrylonitrile / styrene combinations ( Weight ratio 100/0 to 80/20) and the like.
P / P has, for example, a polymer content of 5 to 80% by weight or more, preferably 30 to 70% by weight.

  Among the hydroxyl group-containing vinyl polymers, polybutadiene polyol includes OH-terminated butadiene homopolymers and copolymers (styrene / butadiene copolymers, acrylonitrile / butadiene copolymers, etc.) [having 1,2-vinyl structures, 1,4-trans structures. , Those having a 1,4-cis structure, and those having two or more of these], and hydrogenated products thereof (hydrogenation rate is, for example, 20 to 100%).

Mn of (A4) is preferably 150 to 3,000, more preferably 200 to 2,500, and particularly preferably 250 to 1,500 from the viewpoint of mechanical properties of the polyurethane foam.

  In the production method of the present invention, from the viewpoint of flame retardancy, it is necessary that 50% by weight or more of the active hydrogen-containing compound (A) having no vinyl polymerizable functional group is the aromatic polyester polyol (A31), It is preferable that 70% by weight or more of (A) is (A31).

The active hydrogen value of (A) is preferably from 50 to 1900, more preferably from 160 to 1850, particularly preferably from 200 to 1000, from the viewpoint of flame retardancy and foam physical properties.
Here, the active hydrogen value means “56100 / molecular weight per active hydrogen”, and corresponds to the hydroxyl value when the group having active hydrogen is a hydroxyl group. The hydroxyl value is mg of KOH corresponding to neutralizing 1 g of a sample and means “56100 / molecular weight per hydroxyl group”. Here, 56100 represents the mg number of 1 mol of KOH. The method for measuring the active hydrogen value is not particularly limited as long as it is a method that can measure the value defined above, but in the case of the hydroxyl value, for example, the method described in JIS K1557-1 can be mentioned.

The vinyl polymerizable compound (Z) used in the production method of the present invention has a vinyl polymerizable functional group represented by the following general formula (1), and the concentration of the vinyl polymerizable functional group in the molecule is 0.5-20. 0.0 (mmol / g), which is at least one vinyl polymerizable compound selected from the group consisting of the following (z1) to (z3).

R
｜
CH ₂ = C- (1)

[In General Formula (1), R represents hydrogen, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 21 carbon atoms. ]
(Z1) Unsaturated carboxylic acid ester or unsaturated alkyl ether of polyol (z2) Unsaturated carboxylic acid amidation or unsaturated alkylation product of amine (z3) Unsaturated carboxylic acid thioester or unsaturated alkylthioether of polythiol Carbon in R above Examples of the alkyl group having 1 to 15 include a methyl group and an ethyl group. Examples of the aryl group having 6 to 21 carbon atoms include a phenyl group and a p-methylphenyl group.

The concentration of the vinyl polymerizable functional group in (Z) is represented by the number of moles of the vinyl polymerizable functional group in the molecule, and is represented by the following formula [1].
Concentration of vinyl polymerizable functional group =
(Number of vinyl polymerizable functional groups in the molecule / molecular weight) × 1000 [1]
The concentration (mmol / g) of the vinyl polymerizable functional group in the molecule is 0.5 to 20.0, preferably 7.0 to 15.0, and more preferably 7.5 to 14.0. When the concentration of the vinyl polymerizable functional group in the molecule is less than 7.0, the flame retardancy of the resulting foam is insufficient. If it exceeds 15.0, the reactivity is lowered and the curing of the rigid urethane foam is delayed.
When the composition of (Z) is not single, the average number is used as the number of the above-mentioned vinyl polymerizable functional groups, and the calculated value from the composition is used as the molecular weight.

  Examples of the vinyl polymerizable functional group represented by the general formula (1) include one or more selected from the group consisting of a (meth) acryloyl group, an allyl group, a propenyl group, and a 1-butenyl group. Among these, from the viewpoint of flame retardancy of the foam, a (meth) acryloyl group, an allyl group and a propenyl group are preferable, and a (meth) acryloyl group and an allyl group are more preferable. Here, the (meth) acryloyl group means an acryloyl group and / or a methacryloyl group, and the same description method is used hereinafter.

The vinyl polymerizable compound (Z) is a compound selected from the group consisting of the following (z1) to (z3), and two or more kinds may be used in combination.
(Z1) Unsaturated carboxylic acid ester of polyol or unsaturated alkyl ether As the polyol, polyhydric alcohol, polyhydric phenol, polyhydric alcohol or polyhydric phenol AO adduct, amine AO adduct, polyhydric alcohol and polyhydric alcohol And polyester polyols derived from divalent carboxylic acids or lactones.
Examples of unsaturated carboxylic acid esters include (meth) acrylic acid esters.
An example of the unsaturated alkyl ether is allyl ether.
(Z2) Unsaturated carboxylic acid amidated or unsaturated alkylated product of amine Examples of the unsaturated carboxylic acid amide include (meth) acrylamide.
Unsaturated alkyl includes allyl.
(Z3) Unsaturated carboxylic acid thioester or unsaturated alkyl thioether of polythiol Examples of the unsaturated carboxylic acid thioester include (meth) acrylic thioester.
Examples of unsaturated alkyl thioethers include allyl thioether.

  Examples of the polyhydric alcohol used in the production of (z1) include dihydric alcohols having 2 to 18 carbon atoms (preferably 2 to 12) [ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4- and 1 , 3-butanediol, 1,6-hexanediol, neopentyl glycol, etc.], 3 to 5 polyhydric alcohols having 3 to 18 carbon atoms (preferably 3 to 12) [alkane polyol and its intramolecular or intermolecular] Dehydrates such as glycerin, trimethylolpropane, pentaerythritol, sorbitan and diglycerin; sugars and derivatives thereof such as α-methylglucoside, xylitol, glucose and fructose], and 5 to 18 carbon atoms (preferably 5 to 5) 12) 6 to 10 or more polyvalent Lucol [6 to 10 valent alkane polyol, and intramolecular or intermolecular dehydration of 6 to 10 valent alkane polyol or 3 to 5 valent alkane polyol, such as dipentaerythritol; saccharides and derivatives thereof such as sorbitol, Mannitol, sucrose, etc.] and combinations of two or more thereof.

  Examples of the polyhydric phenol used in the production of (z1) include polyhydric phenols (monocyclic polyhydric phenols (hydroquinone, etc.), bisphenols (bisphenol A, bisphenol F, etc.), etc. Ring polyhydric phenols (pyrogallol, phloroglucin, etc.), formalin low condensates (number average molecular weight 1000 or less) of 3-5 valent polyhydric phenol compounds (novolak resin, intermediate of resole, etc.), 6-10 valences or more The above polyhydric phenols [formal low polycondensate of polyhydric phenol compound (number average molecular weight 1000 or less) (novolak resin, intermediate of resol) etc., etc.] etc.], formalin condensate of polyhydric phenol and alkanolamine (Mannich polyol) and combinations of two or more of these may be mentioned.

  Among the polyols used for the production of (z1), examples of amines in amine AO adducts include ammonia; alkanolamines having 2 to 20 carbon atoms [mono-, di- or triethanolamine, isopropanolamine, and aminoethylethanol. An amine etc.]; an alkylamine having 1 to 20 carbon atoms [methylamine, ethylamine, n-butylamine and octylamine etc.]; an alkylenediamine having 2 to 6 carbon atoms [ethylenediamine and hexamethylenediamine etc.]; 2-6 polyalkylene polyamines (degree of polymerization 2-8) [diethylenetriami and triethylenetetramine, etc.]; C6-C20 aromatic amines [aniline, phenylenediamine, tolylenediamine, xylylenediamine, methylenedi Aniline, di Phenyl ether diamine, naphthalene diamine, anthracene diamine, etc.]; C 4-15 alicyclic amine [isophorone diamine, cyclohexylene diamine, etc.]; C 4-15 heterocyclic amine [piperazine, N-aminoethylpiperazine And 1,4-diaminoethylpiperazine etc.] and combinations of two or more thereof.

  As AO added to polyhydric alcohol, polyhydric phenol, or amine, EO, PO, 1,2-, 1,3-, 1,4- or 2,3-butylene oxide, α-olefin oxide (carbon number) 5-30 or more), styrene oxide and the like, and a combination of two or more of these (in the case of combination, random addition, block addition, or a combination thereof may be used). Among these AOs, those having 2 to 8 carbon atoms are preferred, and those containing PO and / or EO as the main component and optionally containing other AO of 20% by weight or less are more preferred. The addition reaction can be performed by a conventionally known ordinary method. The number of moles of AO added per molecule is preferably 1 to 70, more preferably 1 to 50.

Among the polyols used for the production of (z1), examples of the polyhydric alcohol used for the polyester polyol include those described above. Examples of the polyvalent carboxylic acid include aliphatic polycarboxylic acids having 4 to 18 carbon atoms [succinic acid]. Acid, adipic acid, sebacic acid, maleic acid, fumaric acid, etc.], aromatic polycarboxylic acids having 8 to 18 carbon atoms [phthalic acid or its isomers, trimellitic acid, etc.], ester formation of these polycarboxylic acids Derivatives [acid anhydrides, lower alkyl esters having 1 to 4 carbon atoms in the alkyl group, etc.] and combinations of two or more of these may be mentioned. Examples of the lactone include ε-caprolactone, γ-butyrolactone, γ-valerolactone, and combinations of two or more of these.
The polyol used for the production of (z1) preferably has 3 to 10 hydroxyl groups, more preferably 3 to 6 hydroxyl groups.

  Taking (z1) as an example of a (meth) acrylic acid ester and an allyl ether, for example, the above-mentioned polyol is halogenated (meth) acrylic or halogenated at an equivalent ratio such that the hydroxyl group remains unreacted. It is obtained by (meth) acryloylation or allylation using allyl bromide. As halogenated (meth) acrylic, (meth) acryloyl chloride, (meth) acryloyl bromide, (meth) acryloyl iodide, and allyl halide include allyl chloride, allyl bromide, allyl iodide, and these two types The above combination is mentioned. Moreover, you may esterify by a normal method using the said polyol and (meth) acrylic acid by the equivalent ratio that a hydroxyl group does not remain unreacted.

  (Z2) reacts, for example, a polyvalent amine or alkanolamine with the halogenated (meth) acrylic or allyl halide in an equivalent ratio such that the amino group and hydroxyl group (in the case of alkanolamine) remain unreacted. Is obtained.

As polythiol used for manufacture of unsaturated carboxylic acid thioester of polythiol or unsaturated alkyl thioether (z3), those having 2 to 4 thiol groups and having 2 to 18 carbon atoms are preferable. For example, ethanedithiol, 1, 2-propanedithiol, 1,3-propanedithiol, 1,4-propanedithiol, 1,4-benzenedithiol, 1,2-benzenedithiol, bis (4-mercaptophenyl) sulfide, 4-t-butyl-1, Examples include 2-benzenedithiol, ethylene glycol dithioglycolate, trimethylolpropane tris (thioglycolate) thiocyanuric acid, di (2-mercaptoethyl) sulfide, di (2-mercaptoethyl) ether, and combinations of two or more thereof. It is done.
(Z3) is obtained by reacting these polythiols with the above-mentioned halogenated (meth) acrylic or allyl halide in an equivalent ratio such that no unreacted thiol group remains.
Among these vinyl polymerizable compounds (Z), an unsaturated carboxylic acid ester of a polyol or an unsaturated alkyl ether (z1) is preferable.

  From the viewpoint of heat resistance, an unsaturated carboxylic acid ester having 2 to 8 number-average active hydrogen-containing functional groups of the vinyl polymerizable compound (Z) is preferable, and more preferably 3 to 6.

  The active hydrogen value of the vinyl polymerizable compound (Z) is preferably 0 to 1200, and more preferably 0 to 500, from the viewpoint of flame retardancy of the urethane foam.

  The weight ratio of the vinyl polymerizable compound (Z) and the active hydrogen-containing compound (A) is preferably 0.5 / 99.5 to 99/1, more preferably 2/98 to 60 /, from the viewpoint of foam physical properties. 40, particularly preferably 5/95 to 35/65, most preferably 10/90 to 30/70.

  As organic polyisocyanate (B) used by this invention, what is necessary is just a compound which has two or more isocyanate groups in a molecule | numerator, and what is normally used for manufacture of a polyurethane foam can be used. Examples of such isocyanates include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, and modified products thereof (for example, urethane groups, carbodiimide groups, allophanate groups, urea groups, burettes). Group, an isocyanurate group, or an oxazolidone group-containing modified product) and a mixture of two or more thereof.

As aromatic polyisocyanate, C6-C16 aromatic diisocyanate, C6-C20 aromatic triisocyanate, and crude products of these isocyanates (excluding carbon in the NCO group; the following isocyanates are also the same), etc. Is mentioned. Specific examples include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and / or 4, Examples thereof include 4′-diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI), naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate and the like.
Examples of the aliphatic polyisocyanate include aliphatic diisocyanates having 6 to 10 carbon atoms. Specific examples include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and the like.
Examples of the alicyclic polyisocyanate include alicyclic diisocyanates having 6 to 16 carbon atoms. Specific examples include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate, and the like.
Examples of the araliphatic polyisocyanate include araliphatic diisocyanates having 8 to 12 carbon atoms. Specific examples include xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.

Specific examples of the modified polyisocyanate include urethane-modified MDI, carbodiimide-modified MDI, sucrose-modified TDI, castor oil-modified MDI, and the like.
Of these, aromatic polyisocyanates are preferred from the viewpoint of foam physical properties, and more preferably 2,4′- and / or 4,4′-diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate and their modified products. It is 1 or more types chosen from more.
From the viewpoint of the physical properties of the foam, the content of one or more selected from the group consisting of 2,4′- and / or 4,4′-diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate and their modified products in (B) is: It is preferably 40% by weight or more, more preferably 80% by weight or more.

  In the production method of the present invention, the isocyanate index (NCO INDEX) [(NCO group / active hydrogen atom-containing group) equivalent ratio × 100] in the production of rigid polyurethane foam is from the viewpoint of general physical properties and flame retardancy of urethane foam. It is preferably 70 or more and less than 300, more preferably 80 to 298, particularly preferably 90 to 295, and most preferably 100 to 290.

As the foaming agent (C) used in the production method of the present invention, water, hydrogen atom-containing halogenated hydrogen, low-boiling hydrocarbon, liquefied carbon dioxide or the like is used, and two or more kinds may be used in combination.
Specific examples of the hydrogen atom-containing halogenated hydrocarbon include HCFC (hydrochlorofluorocarbon) type (for example, HFC-245fa and HFC-365mfc), HFO (hydrofluoroolefin) type (for example, HFO-1336mzzZ). Etc.
Examples of the low boiling point hydrocarbon include hydrocarbons having a boiling point of −5 to 70 ° C., and specific examples thereof include butane, pentane, and cyclopentane. Of these, pentane and cyclopentane are preferable, and cyclopentane is more preferable.

In the manufacturing method of this invention, a flame retardant (D) can be used as needed.
Examples of the flame retardant (D) include phosphate ester, halogenated phosphate ester, aluminum hydroxide, antimony oxide, boron compound, bromine compound, chlorinated paraffin, and cyclic fatty acid. Among these, phosphoric acid esters and rogenated phosphoric acid esters are preferable.

  The amount of the flame retardant (D) used in the production method of the present invention is less than 20% by weight based on the total weight of the active hydrogen-containing compound (A) and the vinyl polymerizable compound (Z) from the viewpoint of the heat insulation performance of the urethane foam. Preferably 0 to 15% by weight, more preferably 1 to 10% by weight.

In the production method of the present invention, other additives (E) can be used as necessary.
As the radical polymerization initiator (E1) in (E), azo compounds (for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 1,1 '-Azobis (1-acetoxy-1-phenylethane, etc.), organic peroxides (eg dibenzoyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, etc.), peroxides and dimethylaniline And a water-soluble radical polymerization initiator such as a combination with (redox catalyst).
The amount of the radical polymerization initiator (E1) is preferably 10% by weight or less, more preferably 0.001 to 5% by weight, based on the total weight of the active hydrogen-containing compound (A) and the vinyl polymerizable compound (Z). Particularly preferably, it is 0.005 to 3% by weight, and most preferably 0.01 to 2.5% by weight. If it is 10% by weight or less, it is easy to proceed the polymerization reaction simultaneously with the urethanization reaction, and if it is 0.001% by weight or more, a rigid polyurethane foam having good curing properties can be obtained.

  As other additives (E), foam stabilizer (E2) (dimethylsiloxane, polyether-modified dimethylsiloxane, etc.), isocyanuration catalyst (E3) (for example, potassium octylate, quaternary ammonium salt), Urethane catalyst (E4) (tertiary amine catalyst such as triethylenediamine, N-ethylmorpholine, diethylethanolamine, N, N, N ′, N′-tetramethylhexamethylenediamine, tetramethylethylenediamine, pentamethyldiethylenetriamine, diamino Bicyclooctane, 1,2-dimethylimidazole, 1-methylimidazole, 1-isobutyl-2-methylimidazole, bis (dimethylaminoethyl) ether and 1,8-diazabicyclo- [5,4,0] -undecene- 7 etc. and / or metal catalyst, For example, stannous octylate, dibutylstannic dilaurate, lead octylate, etc.), colorants (dyes, content, etc.), plasticizers (phthalate esters, adipates, etc.), organic fillers (synthetic short fibers, Hollow microspheres made of thermoplastic or thermosetting resins, etc.), antioxidants (hindered phenols, hindered amines, etc.), anti-aging agents (triazoles, benzophenones, etc.), mold release agents (waxes, metals) The reaction can be carried out in the presence of a known additive such as a soap system or a mixed system thereof.

Based on the total weight of the active hydrogen-containing compound (A) and the vinyl polymerizable compound (Z), the amount added is preferably 10% by weight or less, more preferably 0.01% for the foam stabilizer (E2). -7% by weight, particularly preferably 0.05-5% by weight, most preferably 0.1-3% by weight. The urethanization catalyst (E4) is preferably 15% by weight or less, more preferably 0.01 to 10% by weight, particularly preferably 0.02 to 5.0% by weight, and most preferably 0.1 to 3.5% by weight. It is. When the amount of the urethanization catalyst (E4) is 10% by weight or less, it is easy to cause the polymerization reaction to proceed simultaneously with the urethanization reaction.
The colorant is preferably 2% by weight or less, more preferably 1% by weight or less. The plasticizer is preferably 50% by weight or less, more preferably 20% by weight or less, and particularly preferably 10% by weight or less. The organic filler is preferably 50% by weight or less, more preferably 40% by weight or less, and particularly preferably 30% by weight or less. The antioxidant is preferably 1% by weight or less, more preferably 0.01 to 0.5% by weight. The anti-aging agent is preferably 1% by weight or less, more preferably 0.01 to 0.5% by weight. The mold release agent is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 3% by weight or less.

  In the method for producing a rigid polyurethane foam of the present invention, the active hydrogen-containing compound (A), the organic polyisocyanate (B), and the vinyl polymerizable compound (Z) are reacted.

A specific example of the method for producing the rigid polyurethane foam of the present invention is as follows.
First, a predetermined amount of the active hydrogen-containing compound (A), the vinyl polymerizable compound (Z), the foaming agent (C), and, if necessary, the flame retardant (D) and other additives (E) are mixed. Next, using a polyurethane foaming machine or a stirrer, a mixture (foaming stock solution) obtained by rapidly mixing the mixture and the organic polyisocyanate (B) is poured into a mold, cured for a predetermined time, and then demolded to obtain a rigid polyurethane foam. The mold may be either an open mold (free foaming) or a closed mold (mold foaming), and may be at room temperature or under heating (for example, 30 to 80 ° C.). Moreover, either spray foaming or continuous foaming may be used. The urethanization reaction is preferably a one-shot method in the prepolymer method because the viscosity of the stock solution in which each component is mixed increases.
The method of the present invention can be applied to slab foam and molding by RIM (reaction injection molding) method, and can also be used to obtain rigid polyurethane foam by mechanical flossing method.

The density (kg / m ³ ) of the rigid polyurethane foam obtained by the production method of the present invention is preferably 80 or less, more preferably 15 to 78, particularly preferably 20 to 75, in the mold foaming. Most preferably, it is 25-70. In free foaming, the core density is preferably 50 or less, more preferably 10 to 65, particularly preferably 15 to 63, and most preferably 20 to 61.

The vinyl polymerizable functional group concentration (mmol / g) in the rigid polyurethane foam obtained by the production method of the present invention is preferably 0.05 or more, more preferably 0.06 to 10.0, from the viewpoint of flame retardancy. More preferably, it is 0.07-8.00, Especially preferably, it is 0.08-5.00, Most preferably, it is 0.10-2.50.
The vinyl polymerizable functional group concentration (mmol / g) in the rigid polyurethane foam is obtained from the blending amount of the raw material by the following calculation.
Vinyl polymerizable functional group concentration in rigid polyurethane foam (mmol / g)
= [(Z) number of vinyl polymer groups in one molecule / number average molecular weight of (Z)] × (Z) blending amount / ((A) blending amount + (Z) blending amount + (D) blending amount) + (E) blending amount + (B) blending amount] × 1000

The total calorific value (MJ / m ² ) of the rigid polyurethane foam obtained by the production method of the present invention is preferably 8.0 or less, more preferably 5.0 or less, particularly preferably from the viewpoint of flame retardancy. 3.0 or less.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited by this.

The raw materials for the rigid polyurethane foam in Examples 1 to 23 and Comparative Examples 1 to 8 are as follows.
(1) Active hydrogen-containing compound (A)
(A3-1) Polyester polyol obtained from phthalic acid and ethylene glycol (number average active hydrogen-containing functional group number 2, hydroxyl value 250)
(A-2) PO adduct of bisphenol A (hydroxyl value 280)
(A-3) PO adduct of glycerin (hydroxyl value 280)
(2) Vinyl polymerizable compound (Z)
(Z1-1) A vinyl polymerizable compound obtained by reacting pentaerythritol and acrylic acid and having a vinyl polymerizable functional group in the molecule of 10.1 (mmol / g).
(Z1-2) A vinyl polymerizable compound having a vinyl polymerizable functional group in the molecule of 11.4 (mmol / g) obtained by reacting pentaerythritol and acrylic acid.
(Z1-3) A vinyl polymerizable compound having a vinyl polymerizable functional group in the molecule of 10.1 (mmol / g), obtained by reacting trimethylolpropane and acrylic acid.
(Z1-4) A vinyl polymerizable compound in which 1-hexanol and acrylic acid are reacted and the vinyl polymerizable functional group in the molecule is 6.4 (mmol / g).

(3) Foaming agent (C)
(C-1) Water (C-2) HFC-245fa
(4) Flame retardant (D)
(D-1) Trichloropropyl phosphate (manufactured by Daihachi Chemical Co., Ltd.)
(5) Other additives (E)
(E-1) Polyethersiloxane polymer (foam stabilizer) (“SH-193” manufactured by Toray Dow Corning Co., Ltd.)
(E3-1) Catalyst (DabcoK-15 manufactured by Air Products Japan Co., Ltd.)
(E3-2) Catalyst (DabcoTMR manufactured by Air Products Japan Co., Ltd.)
(E4-1) Catalyst (Dabco33LV manufactured by Air Products Japan Co., Ltd.)
(6) Organic polyisocyanate (B)
(B-1) Crude MDI (“MR-200” manufactured by Nippon Polyurethane Industry Co., Ltd.), NCO% = 31.5

[Examples 1 to 23, Comparative Examples 1 to 8]
The manufacturing method of the rigid polyurethane foam of Examples 1-23 and Comparative Examples 1-8 is as follows.
The active hydrogen-containing compound (A), vinyl polymerizable compound (Z), foaming agent (C), flame retardant (D) and other components adjusted to 20 ± 5 ° C. in the number of parts shown in Tables 1 and 2 A predetermined amount of additive (E) was blended to prepare a polyol premix. An organic polyisocyanate (B) whose temperature was adjusted to 20 ± 5 ° C. was added to this polyol premix so as to have a predetermined isocyanate index, and rapidly mixed at 8000 rpm × 7 seconds with a stirrer [Homodisper: manufactured by Primex]. Thereafter, the temperature is adjusted to 60 ° C., and the mixed solution is immediately poured into a 300 × 300 × 40 mm mold in which 250 × 250 × 0.5 mm steel plate panels are set on the upper and lower surfaces of the mold, and the mold is foamed to form a rigid polyurethane. Got a form.

  Tables 1 and 2 show the measurement results of the molded product density, the heat insulating property (thermal conductivity), and the combustibility of the foamed polyurethane foam obtained in each example and comparative example.

<Measurement method of molded product density>
After molding by the above method, the following formula was used. Unit is kg / m ³
Density of molded product (kg / m ³ ) = (Weight of molded product with steel plate panel (g) −Total weight (g) of two steel plate panels) / Volume of molded product (cm ³ ) × 1000

<Measurement method of thermal conductivity>
According to JIS A1412-2, a rigid polyurethane foam of 300 (length) x 300 (width) x 40 (thickness) mm obtained by mold foaming was changed to 200 (length) x 200 (width) x 40 (thickness) mm. Cut to size. Thereafter, the thermal conductivity was measured using a thermal conductivity measuring device “AUTO-Λ HC-074” by Eihiro Seiki Co., Ltd.

<Measurement method of flammability (corn calorimeter)>
Two sample pieces of 990 (length) × 990 (width) × 400 (height) mm were obtained from the center of the molded product, and the total calorific value (unit: MJ / m ² ) was measured in accordance with ISO5660. .

As shown in Tables 1 and 2, the foams of Examples 1, 2, 5-11, and 18-23 having an NCO index of 200 and a molded article density of about 50 kg / m ³ have the same NCO index and molded article. Compared to the foams of density comparative examples 1 and 8, the heat insulation (thermal conductivity) is excellent. Furthermore, the foam of Comparative Example 8 in which the content of the aromatic polyester polyol (A31) in the active hydrogen-containing compound (A) is less than 50% by weight is inferior in combustibility (total calorific value).
The foams of Examples 3 and 4 having an NCO index of 110 and a molded article density of about 50 kg / m ³ are more thermally insulating (thermal conductivity) than the foam of Comparative Example 2 having the same NCO index and molded article density. Excellent.
The foams of Examples 12 and 13 having an NCO index of 200 and a molded article density of about 35 kg / m ³ are more thermally insulating (thermal conductivity) than the foam of Comparative Example 4 having the same NCO index and molded article density. Excellent.
The foams of Examples 14 and 15 having an NCO index of 200 and a molded article density of about 68 kg / m ³ are more thermally insulating (thermal conductivity) than the foams of Comparative Examples 5 and 6 having the same NCO index and molded article density. ).
The foams of Examples 16 and 17 having an NCO index of 290 and a molded article density of about 50 kg / m ³ are more thermally insulating (thermal conductivity) than the foam of Comparative Example 3 having the same NCO index and molded article density. Excellent.
In Comparative Example 7 not containing the active hydrogen-containing compound (A), the foam collapsed and a foam capable of measuring physical properties was not obtained.

  The rigid polyurethane foam of the present invention is excellent in heat insulating properties (thermal conductivity), and therefore can be suitably used, for example, in applications such as architectural heat insulating agents, and particularly suitable for sandwich panels, boards, siding or spray applications. Can be used.

Claims (4)

The active hydrogen-containing compound (A), the organic polyisocyanate (B) and the vinyl polymerizable compound (Z) having no vinyl polymerizable functional group in the presence of the foaming agent (C) or the foaming agent (C) and difficult A method for producing a rigid polyurethane foam by reacting in the presence of a flame retardant (D), wherein (Z) has a vinyl polymerizable functional group represented by the following general formula (1), It is at least one vinyl polymerizable compound selected from the group consisting of the following (z1) to (z3) having a functional group concentration of 0.5 to 20 (mmol / g), and the active hydrogen-containing compound (A) 70 wt% or more are aromatic polyester diols are based on the total weight of less than 20% by weight of the flame retardant (D) is (a) and (Z), the isocyanate index is Ri der less than 300 70 or more , Vinyl polymerizable compound (Z) and Sex hydrogen-containing compound weight ratio of (A) (Z) / ( A) The method for producing a rigid polyurethane foam is from 0.5 / 99.5 to 30/70.

R
｜
CH ₂ = C- (1)

[In General Formula (1), R represents hydrogen, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 21 carbon atoms. ]
(Z1) Unsaturated carboxylic acid ester or unsaturated alkyl ether of polyol (z2) Unsaturated carboxylic acid amidation or unsaturated alkylation product of amine (z3) Unsaturated carboxylic acid thioester or unsaturated alkylthioether of polythiol   The method for producing a rigid urethane foam according to claim 1, wherein the active hydrogen value of the vinyl polymerizable compound (Z) is 0 to 1200.   The method for producing a rigid urethane foam according to claim 1 or 2, wherein the active hydrogen-containing compound (A) has an active hydrogen value of 50 to 1900.   The organic polyisocyanate (B) contains one or more selected from the group consisting of 2,4'- and / or 4,4'-diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate and their modified products. 4. The method for producing a rigid urethane foam according to any one of 3 above.