JPH09194559A - Production of flame retardant polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject polyurethane excellent in flame retardance and physical properties by reacting an active hydrogen compound partially containing a specific phosphorus compound having a hydroxyl group as a flame retardance-imparting component with a polyisocyanate. SOLUTION: This polyurethane is produced by reacting (B) an active hydrogen compound with (C) a polyisocyanate optionally in the presence of a catalyst, a foaming agent, a foam-controlling agent, etc. The component B contains at least partly (A) a compound obtained by esterifying (i) a polyhydroxy compound having at least two hydroxyl groups in a molecule with (ii) a phosphinic acid derivative of the formula (R<1> is ethylene or 1,2-propylene; R<2> is a 1-10C alkylene; R<3> is a 1-10C alkyl, phenyl or an alkyl-substituted phenyl). The component A is preferably used at least 0.5wt.% in the polyurethane in terms of a phosphorus content.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a flame-retardant polyurethane. More specifically, the present invention relates to a method for producing a polyurethane foam having excellent flame retardancy and physical properties.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a flame-retardant polyurethane, a method of reacting a polyol with a polyisocyanate in the presence of tris (2-chloroethyl) phosphate (for example, JP-B-41-13154); triphenyl phosphate A method of reacting a polyol with a polyisocyanate in the presence of such an aromatic phosphate as described above (for example, Japanese Patent Publication No. 62-79218) is known.

[0003]

However, in the above method, tris (2-chloroethyl) phosphate acts as a plasticizer and reduces the hardness of foams and elastomers, so that the amount used is limited, resulting in sufficient flame retardancy. However, the other method has a problem that internal heat generation is high and scorch is likely to occur.

An object of the present invention is to provide a method for producing a polyurethane having the above-mentioned problems, excellent flame retardancy and good physical properties.

[0005]

The inventors of the present invention have conducted extensive studies on a method for producing a polyurethane having excellent flame retardancy and good physical properties, and as a result, have identified a hydroxyl group-containing component as a flame retardancy-imparting component. The inventors have found that the above-mentioned problems can be solved by using the above phosphorus-containing compound, and have reached the present invention.

That is, the present invention provides an active hydrogen compound (A)
And polyisocyanate (B) as necessary, catalyst, foaming
To produce polyurethane by reacting in the presence of agents and foam stabilizers
The method of
Polyhydroxy having at least two hydroxyl groups in the child
At least a part of the hydroxyl groups of the compound (c1) and
General formula (1) [Wherein, R¹Is an ethylene group or 1,2-propylene
Group, R^TwoIs an alkylene group having 1 to 10 carbon atoms, R^ThreeIs the carbon number
1-10 alkyl groups, phenyl groups or alkyl substitutions
Represents a phenyl group. ] The phosphinic acid derivative represented by
Obtained by subjecting (c2) to an esterification reaction
Flame-retardant polyuret characterized by using compound (C)
It is a tongue manufacturing method.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As a polyhydroxyl compound (c1) having at least two hydroxyl groups in the molecule, which is used in the synthesis of the compound (C) which is an essential constituent of the active hydrogen compound (A) used in the present invention. Dihydric or higher alcohols and phenols, alkylene oxide adducts thereof, alkylene oxide adducts of amines and polycarboxylic acids, polyester polyols, polybutadiene polyols and the like can be used. Examples of dihydric or higher alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose and di-. Alternatively, triethanolamine and the like can be mentioned. Examples of the divalent or higher phenols include hydroquinone, catechol and bisphenol A. Ammonia as the amines; alkanolamines [monoethanolamine,
Isopropanolamine, aminoethylethanolamine, etc.]; C1-C20 alkylamines [methylamine, ethylamine, etc.]; C2-C6 alkylenediamines [ethylenediamine, hexamethylenediamine, etc.]; polyalkylenepolyamines [ Diethylenetriamine, triethylenetetramine, etc.]; Aromatic amines [aniline, phenylenediamine, diaminotoluene,
Xylylenediamine, methylenedianiline, diphenyletherdiamine, etc.]; alicyclic amines [isophoronediamine, cyclohexylenediamine, etc.]; and aminoethylpiperazine, heterocyclic amines described in JP-B-55-21044. . Examples of the polycarboxylic acids include aliphatic polycarboxylic acids [succinic acid, adipic acid, sebacic acid, maleic acid, fumaric acid, etc.]; aromatic polycarboxylic acids [phthalic acid, terephthalic acid, trimellitic acid, etc.]. As alkylene oxide,
Examples thereof include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,4- or 2,3-butylene oxide, and combinations of two or more thereof. Of these, preferred is PO alone, EO alone, or a combination of EO and PO, and the addition form in the case of combined use may be either block or random.

Examples of the polyester polyols include condensed polyester polyols and lactones [ε-caprolactam, etc.] obtained by reacting low molecular weight polyols [the above dihydric alcohol, trimethylolpropane, glycerin, etc.] with the above polycarboxylic acids. And a recovered polyester polyol obtained by decomposing a polyester molded product into a glycol.

In the above general formula (1) showing the phosphinic acid derivative (c2) used in the synthesis of the (C), R ¹
Is an ethylene group or a 1,2-propylene group, preferably an ethylene group. R ² is an alkylene group having 1 to 10 carbon atoms, preferably an ethylene group. R ³ is an alkyl group having 1 to 10 carbon atoms, a phenyl group or an alkyl (normally 1 to 4 carbon atoms) substituted phenyl group, preferably a methyl group and a phenyl group. If the carbon number of R ² or R ³ exceeds 10, the effect of imparting flame retardancy becomes insufficient.

The method for producing (c2) is not particularly limited and can be produced, for example, by the method described in JP-A-4-364196.

The method for producing (C) is not particularly limited, but, for example, (c1) and (c2) may be produced at 150 ° C. to 18 ° C.
A method of performing an esterification reaction while dehydrating at 0 ° C can be mentioned.

The amount of (C) in (A) in the present invention is
The phosphorus content based on (C) in the resulting polyurethane is usually at least 0.5% by weight, preferably at least 1% by weight. When the phosphorus content based on (C) is less than 0.5% by weight, the flame retardancy of polyurethane becomes insufficient.

In the present invention, as (A), a known polyol conventionally used in the production of polyurethane can be used together with (C), if necessary. Examples of such polyols include polyether polyols, polyester polyols, polybutadiene polyols, acrylic polyols, polymer polyols modified with a polymer of ethylenically unsaturated monomers, and the like.

Examples of the polyether polyol include alkylene oxide adducts such as alcohols, phenols, amines and polycarboxylic acids. Examples of alcohols include dihydric alcohols [ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and the like]; and trihydric or higher alcohols [glycerin , Trimethylolpropane,
Pentaerythritol, sorbitol, sucrose and the like]. Examples of the phenols include alkylphenols [phenol and nonylphenol, etc.], bisphenol A, catechol, hydroquinone and the like. As amines, ammonia; alkanolamines [mono-, di- or triethanolamine, isopropanolamine, aminoethylethanolamine, etc.]; C1-C20 alkylamines [methylamine, ethylamine, etc.]; 2 to 6 alkylenediamines [ethylenediamine, hexamethylenediamine, etc.]; polyalkylenepolyamines [diethylenetriamine, triethylenetetramine, etc.]; aromatic amines [aniline, phenylenediamine, diaminotoluene,
Xylylenediamine, methylenedianiline, diphenyletherdiamine, etc.]; alicyclic amines [isophoronediamine, cyclohexylenediamine, etc.]; and aminoethylpiperazine, heterocyclic amines described in JP-B-55-21044. . Examples of the polycarboxylic acids include aliphatic polycarboxylic acids [succinic acid, adipic acid, sebacic acid, maleic acid, fumaric acid, etc.]; aromatic polycarboxylic acids [phthalic acid, terephthalic acid, trimellitic acid, etc.]. As alkylene oxide,
EO, PO, 1,2-, 1,4- or 2,3-butylene oxide and the like and a combination of two or more of these are included. Of these, preferred is PO alone or a combination of EO and PO, and the addition form in the case of combination may be either block or random.

Examples of the polyester polyols include condensed polyester polyols and lactones [ε-caprolactam, etc.] obtained by reacting low molecular weight polyols [the above dihydric alcohol, trimethylolpropane, glycerin, etc.] with the above polycarboxylic acids. And a recovered polyester polyol obtained by decomposing a polyester molded product into a glycol.

Examples of the polymer polyol include those obtained by polymerizing and stably dispersing vinyl monomers such as acrylonitrile and styrene in at least one of the above-exemplified polyols in the presence of a radical initiator. The content of the vinyl polymer in the polymer polyol is usually 50% by weight or less.

Among the above-exemplified polyols, preferred are polyether polyols, polyester polyols, and combinations thereof.

The average number of functional groups of (A) is usually at least 2, preferably at least 2.3. The average hydroxyl value is usually at least 10, preferably 20 to 10.
00. When the average number of functional groups is less than 2 or the average hydroxyl value is less than 10, the strength of the foam is reduced and the foam is likely to shrink.

As the polyisocyanate (B) used in the present invention, those conventionally used for producing polyurethane can be used. Examples of such isocyanates include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, and modified products thereof (for example, carbodiimide-modified, allophanate-modified, urea-modified, buret-modified, isosinurate-modified, oxazolidone-modified). , Isocyanate group-terminated prepolymers and mixtures of two or more thereof.

Specific examples of aromatic polyisocyanates include 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and 4,4 '
-Diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (crude MDI),
Examples thereof include naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate.
Specific examples of the aliphatic isocyanate include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and xylylene diisocyanate.
Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,4-cyclohexane diisocyanate. Specific examples of the modified polyisocyanate include carbodiimide-modified MDI, sucrose-modified TDI, castor oil-modified MDI, and the like. Preferred among these are MDI, crude MDI, sucrose modified TDI and carbodiimide modified MDI.

In the production method of the present invention, the ratio of the active hydrogen compound (A) and the polyisocyanate (B) can be variously changed, but (B Equivalent number x 100] is usually 50 to 500, preferably 90 to
300.

In the method of the present invention, an inorganic flame retardant (D) may be used in combination for the purpose of further improving the flame retardancy of polyurethane. Examples of the (D) include aluminum hydroxide, magnesium hydroxide, antimony oxide, zinc oxide, ammonium bromide, barium metaborate, zinc borate,
Examples include magnesium carbonate, magnesium sulfate, hydrated gypsum and the like. When used in combination, the amount of the (D) used is
Usually at least 10 relative to the total weight of (A) and (B)
%, Preferably 15-100% by weight.

In the present invention, a hydrogen atom-containing halogenated hydrocarbon blowing agent (alternative CFC) may be used if necessary. Specific examples of the CFC substitute include HCFC type ones (for example, HCFC-123 and HCFC-141).
b, HCFC-22 and HCFC-142b); HF
C type (eg HFC-134a, HFC-1
52a, HFC-356mff, HFC-236ea,
HFC-245ca, HFC-245fa and HFC
-365 mcf) and the like. Among these, preferable ones are HCFC-141b, HFC-134a,
HFC-356mff, HFC-236ea, HFC-
245ca, HFC-245fa, HFC-365mc
f and mixtures of two or more thereof. If necessary, water or a low boiling point hydrocarbon may be used in combination with these alternative CFCs. Furthermore, water alone can be used as the foaming agent without using the above-mentioned CFC alternatives and low boiling point hydrocarbons. The low boiling point hydrocarbon is a hydrocarbon having a boiling point of usually 0 to 50 ° C., and specific examples thereof include propane, butane,
Mention may be made of pentane and mixtures thereof. When a blowing agent is used in the method of the present invention, the amount used is usually 5 to 50 parts by weight, preferably 10 to 45 parts by weight, per 100 parts by weight of the polyol component when using the CFC substitute alone. When water alone is used as the foaming agent, it is usually 0.5 to 10 parts by weight per 100 parts by weight of the polyol component.
It is preferably 1 to 8 parts by weight. When the CFC substitute and water are used in combination, they are appropriately combined within the above range depending on the physical properties of the desired foam. The amount of low-boiling hydrocarbons used is usually 0 to 40 parts by weight, preferably 0 to 30 parts by weight, per 100 parts by weight of the polyol component.

In the present invention, if necessary, a catalyst usually used in a polyurethane reaction, for example, an amine-based catalyst (triethylenediamine, N-ethylmorpholine, diethylethanolamine, 1-isobutyl-2-methylimidazole, 1,8-diazabicyclo-) is used. [5,4,0] -undecene-7 etc.) and metal catalysts (stannous octylate, dibutyl stannate dilaurate, lead octylate etc.) can be used. The amount of the catalyst used is usually 0.001 to 5% by weight based on the weight of (A).

In the present invention, if necessary, an organic flame retardant (tris-chloroethyl phosphate, tris-chloropropyl phosphate, chlorinated paraffin, etc.) usually used for polyurethane may be used in combination.
The amount of the organic flame retardant used is usually 1 to 10% by weight based on the total weight of (A) and (B).

Further, if necessary, known additives such as a foam stabilizer, a colorant (dye or pigment), a plasticizer, a filler, an antioxidant and an antioxidant can be used.

The method of the present invention can be suitably used for producing flame-retardant urethane elastomers, rigid, semi-rigid and flexible polyurethane foams.

An example of the method for producing a flame-retardant polyurethane foam according to the method of the present invention is as follows. First, a predetermined amount of a polyol component, a foaming agent, a foam stabilizer, a catalyst and other additives are mixed. A polyurethane foamer or stirrer is then used to rapidly mix the mixture with the polyisocyanate component. The obtained mixture is poured into a mold. After curing, the mold is removed to obtain a flame-retardant polyurethane foam.

[0029]

EXAMPLES The present invention will be further described with reference to examples below, but the present invention is not limited to these examples. In the following, “parts” and “%” are based on weight, respectively.

Composition of raw materials used in Examples and Comparative Examples,
The symbols are as follows. (1) Polyol Polyol a1: Polyether polyol having a hydroxyl value of 450 in which PO is added to a mixture of glycerin (1 mol) and sugar (0.5 mol) Polyol a2: Sorbitol (1 mol) is supplemented with PO (6 mol) Added polyether polyol having a hydroxyl value of 635 Polyol a3: Pentaerythritol (1 mol) is added to P
Polyether polyol having a hydroxyl value of 374 added with O (8 mol) Polyol a4: "Phantol PL-305" [polyester polyol manufactured by Toho Rika Co., Ltd.]

(2) Flame retardant: "Phiroll CEF"
[Akzo Japan Ltd.] (3) Foam stabilizer: "Silicone SH-193" [Tolesi
Recone Co., Ltd.] (4) Foaming agent: "HCFC-141b" [Central Glass
Child Co., Ltd.] (5) Catalyst: "U-CAT1000" [SAN APPRO]
(6) Compound (C) Compound C-1: phosphine represented by the following chemical formula (2)
Acid compound 516g (2mol) and ethylene glycol 62
g (1 mol) in the presence of paratoluenesulfonic acid 15
Obtained by esterification reaction for 3 hours while dehydrating at 0 ° C.
A compound having a hydroxyl value of 207Compound C-2: phosphine represented by the following chemical formula (3)
Acid compound 858g (3mol) and polyol a3 600
g (1 mol) in the presence of paratoluenesulfonic acid 15
Obtained by esterification reaction for 3 hours while dehydrating at 0 ° C.
Compound with a hydroxyl value of 160Compound C-3: phosphine represented by the following chemical formula (4)
580 g (3 mol) of acid compound and 530 of polyol a2
g (1 mol) in the presence of paratoluenesulfonic acid 15
Obtained by esterification reaction for 3 hours while dehydrating at 0 ° C.
Hydroxyl number 301 compound (7) Polyisocyanate: "Millionate MR-10
0 "[manufactured by Nippon Polyurethane Industry Co., Ltd.]

Examples 1 to 4 and Comparative Examples 1 to 4 A polyol and a polyisocyanate compounded according to the composition shown in Table 1 and adjusted to a temperature of 25 ° C. and a homoisper (stirring machine manufactured by Tokushu Kiki) at 3000 rpm for 10 seconds. After stirring and mixing, the temperature was adjusted to 25 ° C, and the temperature was adjusted to 1000 mm (length) x 10
A 0 mm (width) x 100 (height) mm small side surface is injected into the opposite end of the open mouth of a horizontally long box-shaped mold, one side of which is an open system, and after 10 minutes, it is demolded and a polyurethane foam is formed. Obtained. Table 1 shows the evaluation results of physical properties and flame retardancy (combustion rate) of these foams.

[0033]

[Table 1]

The evaluation method of the physical properties of foam in Table 1 is as follows. Density (Kg / m ³ ): Compliant with JIS K6310 Compressive strength: (Kg / cm ² ): Compliant with JIS A9514 Burning speed: (cm / min): Compliant with JIS A9514

As is clear from Table 1, the polyurethane foams of Examples 1 to 4 have higher flame retardancy and higher compression strength than those of Comparative Examples.

[0036]

EFFECT OF THE INVENTION By using the flame retardant polyurethane production method of the present invention, a urethane foam having a lower flammability and a higher foam strength can be obtained, in particular, as compared with a foam using a conventionally known flame retardant. be able to.
Due to the above effects, the polyurethane foam obtained by the method of the present invention is extremely useful particularly as a refrigerator, a freezer, a heat insulating material for building materials, an interior material for automobiles, furniture and the like.

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Claims (5)

[Claims] 1. An active hydrogen compound (A) and polyisocyanate
If necessary, a catalyst, foaming agent, foam stabilizer, etc.
In the method of producing polyurethane by reacting under ambient conditions
And at least a part of (A), at least in the molecule
Is a polyhydroxyl compound having two hydroxyl groups (c
At least a part of the hydroxyl groups of 1) and the following general formula (1) [Wherein, R¹Is an ethylene group or 1,2-propylene
Group, R^TwoIs an alkylene group having 1 to 10 carbon atoms, R^ThreeIs the carbon number
1-10 alkyl groups, phenyl groups or alkyl substitutions
Represents a phenyl group. ] The phosphinic acid derivative represented by
Obtained by subjecting (c2) to an esterification reaction
Flame-retardant polyuret characterized by using compound (C)
Tongue manufacturing method. 2. The process according to claim 1, wherein (C) is used in an amount such that the phosphorus content based on the (C) in the polyurethane is at least 0.5% by weight. 3. The method according to claim 1, wherein the inorganic flame retardant (D) is used in an amount of at least 10% by weight based on the total weight of (A) and (B). 4. (D) is selected from the group consisting of aluminum hydroxide, magnesium hydroxide, antimony oxide, zinc oxide, ammonium bromide, barium metaborate, zinc borate, magnesium carbonate, magnesium sulfate and hydrated gypsum. The manufacturing method according to claim 3, which is at least one kind. 5. The production method according to claim 1, wherein the flame-retardant polyurethane is a flame-retardant polyurethane foam.