JPH09151231A - Preparation of flame-retardant polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a flame-retardant polyurethane which has excellent flame retardancy and strength by using a particular comps. as a part of an active H compd. in a reaction of an active H compd. with a polyisocyanate to prepare a polyurethane. SOLUTION: A phosphinic acid deriv. represented by formula I [ R<1> represents a methylene or 1,2-propylene group; R<2> represents a 1-10C alkyl; R<3> represents R<2> or an (alkyl-substd.) phenyl; R<4> represents a 2-12C alkylene; and m is 1 to 15] and/or formula II (R<5> represents a 1-10C alkylene; and (n) is 0 to 15) are used as at least a part of an active H compd. in a reaction of an active H compd. (e.g. a polyether polyol prepared. by adding propylene oxide to sorbitol) with a polyisocyanate (e.g. a crude MDI) optionally in the presence of a catalyst, a forming agent, a foam stabilizer or the like to prepare a polyurethane. The amt. of the phosphinic acid deriv. used is pref. such that the content of P based on the deriv. is not less than 0.5wt.% in the polyurethane.

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 the foam or elastomer, so that the amount used is limited, resulting in a sufficient difficulty. There is a problem that flammability cannot be obtained, and in the other method, there is a problem that internal heat generation becomes 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 made extensive studies as to a method for producing a polyurethane having excellent flame retardancy and good physical properties, and as a result, as a flame retardant, a specific compound having an active hydrogen group is contained. The inventors have found that the above problems can be solved by using a phosphorus 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
In at least a part of (A),
Represented by the general formula (1) and / or the general formula (2)
A phosphinic acid derivative (C) is used.
It is a manufacturing method of polyurethane. [Wherein, R¹Is an ethylene group or 1,2-propylene
Group, R^TwoIs an alkyl group having 1 to 10 carbon atoms, R^ThreeIs 1 carbon
-10 alkyl groups, phenyl groups or alkyl-substituted groups
Phenyl group, R^FourRepresents an alkylene group having 2 to 12 carbon atoms
And m represents an integer of 1 to 15. ] [Wherein, R¹, R^ThreeAnd R^FourIs the same as in the case of general formula (1)
Like, R^FiveRepresents an alkylene group having 1 to 10 carbon atoms
However, n represents the integer of 0-15. ]

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the above general formula (1) and general formula (2) showing the phosphinic acid derivative (C) which is an essential constituent of the active hydrogen compound (A) used in the present invention, R ¹ is ethylene. Group or 1,2-propylene group, preferably ethylene group. R ³ has 1 to 1 carbon atoms
It is a 10-alkyl group, a phenyl group or an alkyl (usually 1 to 4 carbon atoms) -substituted phenyl group, preferably a methyl group and a phenyl group. If the carbon number of R ³ exceeds 10, the effect of imparting flame retardancy becomes insufficient. R ⁴ has 2 carbon atoms
To 12 alkylene groups, preferably ethylene groups. If the carbon number of R ⁴ exceeds 12, the effect of imparting flame retardancy will be insufficient. R ² in the general formula (1) is an alkyl group having 1 to 10 carbon atoms, and particularly preferably a methyl group. If R ² has more than 10 carbon atoms, the flame retardancy-imparting effect is reduced. In addition, R ⁵ in the general formula (2) is
Is an alkylene group having 1 to 10 carbon atoms, preferably an ethylene group. If the carbon number of R ⁵ exceeds 10, the flame retardancy-imparting effect is reduced. Further, m in the general formula (1) is an integer of usually 1 to 15, preferably 1 to 5.
N in the general formula (2) is usually 0 to 15, preferably 1
Is an integer of up to 5. When m in the general formula (1) and n in the general formula (2) exceed 15, the effect of imparting flame retardancy decreases.

The method for producing (C) is not particularly limited, and it can be produced, for example, by the method described in Japanese Patent Application Laid-Open No. 4-364196.

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 the alcohols include monohydric alcohols [methanol, ethanol, n- or iso-propanol, butanol, 2-ethylhexyl alcohol, cyclohexanol, benzyl alcohol, etc.]; dihydric alcohols [ethylene glycol, propylene glycol, , 4
-Butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, etc.]; and trihydric or higher alcohols [glycerin, trimethylolpropane, pentaerythritol, sorbitol,
Sucrose, etc.]. Examples of phenols include alkylphenols [phenol and nonylphenol and the like]. Examples of amines include ammonia; alkanolamines [mono-, di- or triethanolamine, isopropanolamine, aminoethylethanolamine, etc.]; alkylamines having 1 to 20 carbon atoms [trimethylamine, triethylamine, etc.]; And alkylene diamines [ethylenediamine, hexamethylenediamine, etc.]; polyalkylenepolyamines [diethylenetriamine, triethylenetetramine, etc.]; aromatic amines [aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, diphenyl ether] Diamines and the like]; alicyclic amines [isophoronediamine, cyclohexylenediamine and the like]; and aminoethylpiperazine, JP-B-55
Heterocyclic amines described in JP-A-21044. As polycarboxylic acids, aliphatic polycarboxylic acids [succinic acid, adipic acid, sebacic acid, maleic acid,
Fumaric acid and the like]; aromatic polycarboxylic acids [phthalic acid, terephthalic acid, trimellitic acid and the like]. Examples of the alkylene oxide include ethylene oxide (hereinafter referred to as EO).
Abbreviation), propylene oxide (hereinafter abbreviated as 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 polyol include low molecular weight polyols [the above-mentioned dihydric alcohols, trimethylolpropane, glycerin and the like] and the above-mentioned polycarboxylic acids and condensed polyester polyols and lactones [e-caprolactam and the like]. And the recovered polyester polyol obtained by subjecting a polyester molded product to glycol decomposition.

Examples of the polymer polyol include at least one of the polyols exemplified above, in which a vinyl monomer such as acrylonitrile or styrene is polymerized and stably dispersed 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 examples of the polyol, 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) to the polyisocyanate (B) can be variously changed, but the ratio (B to 1 equivalent of active hydrogen group of the polyol component having the isocyanate index [(A) is 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) can 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)
% By weight, preferably 10 to 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 usually a hydrocarbon having a boiling point of 0 to 50 ° C, and specific examples thereof include propane, butane,
Mention may be made of pentane and mixtures thereof. The amount of the blowing agent in the method of the present invention is usually 5 to 5 per 100 parts by weight of the polyol component when using the CFC substitute alone.
It is 0 part by weight, preferably 10 to 45 parts by weight. When water alone is used as the foaming agent, it is usually 0.5 to 10 parts by weight, preferably 1 to 8 parts by weight, per 100 parts by weight of the polyol. When the CFC substitute and water are used in combination, they may be appropriately combined and used 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 polyol.

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, ordinarily used for polyurethane,
Chlorinated paraffin, etc.) can be used. 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 polyurethane foam.

[0026]

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) Phosphinic acid derivative Phosphinic acid derivative 1: Chemical formula represented by the following chemical formula (3)
CompoundPhosphinic acid derivative 2: Compound represented by the following chemical formula (4)
CompoundPhosphinic acid derivative 3: a compound represented by the following chemical formula (5)
Compound (7) Polyisocyanate: "Millionate MR-10
0 "[manufactured by Nippon Polyurethane Industry Co., Ltd.]

Examples 1 to 4 and Comparative Examples 1 to 3 Polyol and polyisocyanate were blended with the composition shown in Table 1 and adjusted to a temperature of 25 ° C., and homodisper (stirrer manufactured by Tokushu Kiki) at 3000 rpm. After stirring for 10 seconds, the temperature was adjusted to 25 ° C. and 1000 mm (length) × 10
A 0 mm (width) × 100 (height) mm mold was poured into the opposite end of the opening of a mold whose opening direction was vertical to the floor surface, and the mold was removed after 10 minutes to obtain a polyurethane foam. Table 1 shows the evaluation results of physical properties and flame retardancy (combustion rate) of these foams.

[0030]

[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 described in Examples 1 to 4 are characterized by high flame retardancy and high compression strength.

[0033]

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.

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
Then, as at least a part of (A), the following general formula (1)
And / or the phosphinic acid derivative represented by the general formula (2)
Flame-retardant polyureta characterized by using conductor (C)
Manufacturing method. [Wherein, R¹Is an ethylene group or 1,2-propylene
Group, R^TwoIs an alkyl group having 1 to 10 carbon atoms, R^ThreeIs 1 carbon
-10 alkyl groups, phenyl groups or alkyl-substituted groups
Phenyl group, R^FourRepresents an alkylene group having 2 to 12 carbon atoms
And m represents an integer of 1 to 15. ] [Wherein, R¹, R^ThreeAnd R^FourIs the same as in the case of general formula (1)
Like, R^FiveRepresents an alkylene group having 1 to 10 carbon atoms
However, n represents the integer of 0-15. ] 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.