JPH10168154A - Production of flame retardant flexible polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject foam, excellent in balance between heat resistance and physical characteristics and flame retardance and useful as a sheet for automatic seats, pieces of furniture, etc., by using a bromine compound having a specific structure and a condensed type phosphoric ester compound. SOLUTION: A condensed type phosphoric ester [e.g. a halide having >=150 plasticizing efficiency when that of the dioctyl phthalate is 100 and >=200 deg.C temperature for 1wt.% weight loss according to the thermogravimetric measurement] and an oxyalkylene ether of a polybrominated bisohenol A such as a compound represented by the formula [R is a 2-3C alkylene; (m) and (n) are each 1-50] are used in respective amounts of 1-30wt.% based on a component F as (A) a flame retardant when reacting (E) a polyisocyanate with (F) a polyol in the presence of the flame retardant A, (B) foam stabilizer, (C) a catalyst and (D) a foam stabilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a flame-retardant flexible polyurethane foam, and more particularly to a method for producing a flame-retardant flexible polyurethane foam having excellent heat resistance and physical properties.

[0002]

2. Description of the Related Art Flexible polyurethane foams have excellent cushioning properties and are very widely used in furniture such as automobile seats, beds and sofas. However, since polyurethane foam is an organic compound,
It has the disadvantage that it is easy to burn. Therefore, there are various flame retardant regulations, the most typical of which is FMVSS-
Section 302 (US Federal Motor Vehicle Safety Standards). And
Various techniques for flame retarding polyurethane foam to satisfy these requirements have been proposed, and there are various specialized books such as "Flame retardation of polymers = science and practical technology = Taiseisha (1992)".

The most widely used means for making a flexible polyurethane foam flame retardant is a method of adding various flame retardants when reacting a polyisocyanate with a polyol. Examples of the flame retardant include phosphate esters, chlorinated phosphate esters, bromine compounds, bromine compounds having active hydrogen, and the like. However, when these flame retardants are used alone, it is difficult to solve problems such as lack of flame retardancy, decrease in heat resistance, deterioration of physical properties due to the foam structure of the foam, and the like. Are widely used.

For example, Japanese Patent Publication No. 58-22044 uses dibromoneopentyl glycol and a halogenated phosphate ester plasticizer in combination, and Japanese Patent Publication No. 5-79688 discloses a bromine compound having a divalent active hydrogen group and an aromatic compound. A phosphate ester is used in combination. However, in these combined production methods, non-condensation type compounds having a relatively low molecular weight are used as the phosphorus compounds, and problems such as heat resistance and volatility have not been completely solved. Also,
In order to solve the problem derived from the phosphorus compound, when the addition ratio of the bromine compound having a divalent active hydrogen group is increased,
Problems derived from bromine compounds, such as a bubble structure, are emphasized. Moreover, if the amount of the flame retardant used is reduced in order to avoid these problems, the desired sufficient flame retardancy cannot be provided. Therefore, there is a need for a method for producing a flame-retardant flexible polyurethane having excellent heat resistance and physical properties that can solve both problems by using a combined system of a phosphorus compound and a bromine compound having an active hydrogen group.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide the above-mentioned heat-resistant and physical properties, and at the same time, FMVSS-3.
Another object of the present invention is to provide a method for producing a flexible polyurethane foam exhibiting flame retardancy conforming to No. 02.

[0006]

Means for Solving the Problems In view of such circumstances, the present inventors have found that by using a bromine compound and a condensed phosphate compound having a specific structure, heat resistance and physical properties can be balanced, and The present inventors have found a method for producing a flexible polyurethane foam capable of imparting the desired flame retardancy, and have completed the present invention.

That is, the present invention relates to a method for producing a flexible polyurethane foam by reacting a polyisocyanate with a polyol in the presence of a flame retardant, a foaming agent, a catalyst and a foam stabilizer. 1 to 30 parts by weight of the condensed phosphate ester, and 1 to 30% by weight of the polyol is an oxyalkylene ether of polybrominated bisphenol A.
This is a method for producing a flame-retardant flexible polyurethane foam.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The condensed phosphoric ester compound used as a flame retardant in the present invention is a phosphoric ester containing two or more phosphorus atoms in one molecule. More specifically, it refers to a phosphate compound having a chemical structure in which two or more units of a phosphoric ester and / or a phosphite are crosslinked by a polyhydric alcohol, a phenol, an alkyl group, an aryl group, or the like. . These can be selected from the industrially used condensed phosphate esters and used. Further, the condensed phosphate ester may be a non-halogen compound or a halogen-containing compound, but the halogenated condensed phosphate ester is more excellent for imparting sufficient flame retardancy.

[0009] The condensed phosphate compound used in the present invention is required to have a lower plasticizing efficiency than DOP. Specifically, when DOP is 100, 1
Desirably, it is 50 or more. In general, the plasticizing efficiency is often obtained from the amount of other plasticizers that exhibit the same effect as the 100% modulus of a blend obtained by adding 50 parts by weight of DOP to a vinyl chloride resin. 1
0), 745 (1957) and the Japan Vinyl Industry Association Conference Material No. 9, 1952 and the like. The plasticization efficiency indicates that the smaller the value, the lower the plasticity.If the plasticization efficiency is less than 150, the plasticity of the condensed phosphate ester used is too high, and the physical properties of the obtained polyurethane foam after the reaction, In particular, it has a bad effect on compression set.

[0010] The condensed phosphate compound used in the present invention is required to satisfy the above-mentioned plasticization efficiency and at the same time, satisfy a low heating loss. Specifically, the 1% by weight reduction temperature by TG (thermogravimetry) is 200 ° C. or more. When the 1% by weight reduction temperature in TG is less than 200 ° C., the performance of the condensed phosphate ester used for heat loss is insufficient, and the heat resistance of the polyurethane foam obtained after the reaction, specifically, heat aging resistance and scorch Properties, flame retardancy after heat treatment, etc. are significantly reduced.

The condensed phosphate compound used in the present invention can be arbitrarily selected from various condensed phosphate esters that are currently industrialized and widely used, as long as they satisfy the above-mentioned plasticization efficiency and TG heat loss. Can be selected. Specifically, examples of the non-halogenated condensed phosphoric acid ester include Ajinomoto's Leophos RDP and Daihachi Chemical's C
Examples of halogenated condensed phosphate esters such as R-735 and CR-741 include Ajinomoto's Amgard V-6 and Daihachi Chemical's CR-530 and CR-504.
Also, a mixture of two or more of these condensed phosphate esters may be used.

The condensed phosphate ester used in the present invention is
The polyisocyanate and the polyol are added prior to the reaction and used. However, since they are basically non-reactive phosphate esters, they may be added to either the polyisocyanate or the polyol. Regarding the addition amount, when the weight of the polyol is used as a guide, it is preferably 1 to 30 parts by weight. If the amount is less than 1 part by weight, the flame retardancy of the obtained polyurethane foam becomes insufficient. On the other hand, when the amount exceeds 30 parts by weight, the physical properties of the obtained polyurethane foam, particularly the compression set, are adversely affected.

In the method for producing a flexible polyurethane foam according to the present invention, a flame retardant other than those described above can be optionally used as an auxiliary in a range that does not adversely affect the physical properties of the obtained polyurethane foam. Flame retardants that can be used are flame retardants that are widely used for industrial purposes. Specifically, brominated flame retardants (decabromodiphenyl oxide, hexabromobenzene, hexabromocyclododecane, dibromoneopentyl glycol, tribromoneopentyl glycol, Bromoneopentyl alcohol, etc.), chlorine-based flame retardants (chlorinated paraffin, chlorinated polyethylene, etc.), phosphorus-based flame retardants (triphenyl phosphate, tricresyl phosphate,
Tris (isopropylphenyl) phosphate, tris (chloropropyl) phosphate, tris (dichloropropyl) phosphate, trioctylphosphate, tris (tribromoneopentyl) phosphate, red phosphorus, ammonium polyphosphate, etc., inorganic flame retardants (trioxide Antimony, zinc borate, aluminum hydroxide, magnesium hydroxide, etc.), nitrogen-based flame retardants (melamine, melamine cyanurate, guanidine, etc.), and the like.
These mixtures may be used.

The catalyst used in the present invention includes:
Catalysts usually used for producing polyurethane foams can be used. Specifically, organic tin compounds (such as dibutyltin dilaurate and stannas octoate) and amines (such as trimethylamine, triethylenediamine, dimethylpiperazine, and diethylaminoethanol) are added in an amount of 0.1%.
One or more of them may be used as needed in the range of 001 to 10% by weight.

As the foaming agent used in the present invention, a foaming agent usually used for producing a polyurethane foam can be used. Specifically, one or more kinds of organic fluorohydrocarbons such as monofluorotrichloroethane and difluorodichloroethane, which are usually used in general, such as water, in the range of 0.1 to 40% by weight, if necessary, may be used. Can be used.

As the foam stabilizer used in the present invention, a foam stabilizer usually used for producing a polyurethane foam can be used. Specific examples include widely used silicone surfactants and the like.
It is used in the range of 20% by weight.

The polyisocyanate used in the present invention comprises 1
Industrially flexible polyurethane foams having two or more isocyanate groups in the molecule, such as aromatic polyisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.) and aliphatic polyisocyanates (hexamethylene diisocyanate, isophorone diisocyanate, etc.) What is used for manufacture can be used.

Examples of the polyol used in the present invention include polyether polyols and polyester polyols. In order to achieve the object of the present invention, 1 to 30% by weight of the total polyol contains oxyalkylene ether of polybrominated bisphenol A. It is important to use

The oxyalkylene ether of the polybrominated bisphenol A is an alkylene oxide adduct of the polybrominated bisphenol A, and is disclosed in JP-A-63-314231.
It can be manufactured by the method described. Here, the polybrominated bisphenol A is a compound in which a hydrogen atom on a benzene ring of bisphenol A is substituted with 2 to 8 bromine atoms. Examples of the alkylene oxide include ethylenoxide and propylene oxide. The oxyalkylene ether of the polybrominated bisphenol A is also a component of the polyurethane foam in the production of the flexible polyurethane foam of the present invention, but since it has flame retardancy itself, it also functions as a flame retardant.

When an alkylene oxide is added to polybrominated bisphenol A, it is produced by reacting 100 mol or less of alkylene oxide with respect to 1 mol of polybrominated bisphenol A. 100 alkylene oxides
When the reaction is performed in excess of the mole, the flame retardancy of the obtained polyurethane foam decreases. For example, when the polybrominated bisphenol A is produced using tetrabromobisphenol A, which is widely used industrially, the alkylene oxide adduct can be represented by the following general formula (I).

[0021]

Embedded image

(In the formula, R represents an alkylene group having 2 to 3 carbon atoms, and m and n each represent an integer of 1 to 50.)

M and n in the above general formula, that is,
The number of moles of the alkylene oxide added to the polybrominated bisphenol A is 5 to 1 mole equivalent of the phenolic hydroxyl group.
0 molar equivalent or less. The reason is as already explained.

The oxyalkylene ether of the polybrominated bisphenol A used in the present invention is used as a part of a polyol and reacts with a polyisocyanate. As described above, the content of the polybrominated bisphenol A oxyalkylene ether in the polyol is preferably 1 to 30% by weight. If it is less than 1%, the flame retardancy of the obtained polyurethane foam is insufficient, and if it exceeds 30% by weight, the physical properties of the obtained polyurethane foam deteriorate due to the influence on the cell structure.

As described above, as the polyol other than the oxyalkylene ether of the polybrominated bisphenol A, a polyether polyol or a polyester polyol can be used. Polyether polyols are adducts of alkylene oxides to active hydrogen containing compounds. Examples of the active hydrogen-containing compound include polyhydric alcohols (ethylene glycol, 1,3-propanediol, 1,4-butanediol, glycerin, trimethylolpropane, pentaerythritol, etc.), amines (ethylamine, monoethanolamine, ethylenediamine) , Diethylenetriamine, phenylenediamine and the like), and polyhydric phenols (hydroquinone, resorcin, bisphenol A and the like). Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and epichlorohydrin. These may be used alone or in combination of two or more. Examples of the polyester polyol include those obtained by reacting the polyhydric alcohol and / or the polyether polyol with a derivative such as a polycarboxylic acid or an acid anhydride thereof, a lactone, or the like. The hydroxyl value of the above polyol is usually 20 to 2
00, preferably 30 to 200. When the hydroxyl value is less than 20 or more than 200, the cell structure and the like are affected, and the physical properties of the foam deteriorate.

In the production of the flexible polyurethane foam of the present invention, there are no particular restrictions on the method of compounding and the order, and the foaming method can also be applied to slabs, hot molds, sprays and the like. In the present invention, various additives such as pigments and the like usually used in the production of flexible polyurethane foams may be used as long as the effects of the present invention are maintained.

The flexible polyurethane foam obtained according to the present invention has sufficient flame retardancy and, at the same time, has excellent heat resistance and physical properties. The flame-retardant flexible polyurethane foam according to the present invention can be usefully used for furniture such as automobile seats, beds and sofas.

[0028]

EXAMPLES In order to further clarify the features of the present invention, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

The components used in Examples and Comparative Examples are shown below. 1. 1. Polyol Polyol A: trifunctional propylene-based polyether polyol (average molecular weight 3000) Polyol B: trifunctional polyester ether polyol (average molecular weight 3000) Brominated flame retardant TBA-PEO2: Tetraboromobisphenol A,
Diol reacted with 2 molar equivalents of ethylene oxide TBA-PEO80: Tetraboromobisphenol A
Diol TBA-PEO120: tetraboromobisphenol A reacted with 2 mole equivalents of ethylene oxide
2. A diol DBNP: dibromoneopentyl glycol which was reacted with 120 mole equivalents of ethylene oxide. Phosphorus flame retardant Reophos RDP: Ajinomoto Co., Ltd., non-halogen condensed phosphate ester (plasticization efficiency 158, TG1% by weight reduction temperature 280 ° C) Amgard V-6: Ajinomoto Co., chlorinated condensate type Phosphate ester (plasticization efficiency 165, TG 1% by weight reduction temperature 210 ° C.) Clonitex CDP: Ajinomoto Co., Ltd., cresyl diphenyl phosphate (plasticization efficiency 111, TG 1% by weight
3. Decrease temperature: 120 ° C.) Amgard TMCP: manufactured by Ajinomoto Co., Inc., tris (chloropropyl) phosphate (plasticization efficiency: 110, TG: 1% by weight, decrease temperature: 190 ° C.) 4. Polyisocyanate TDI: Sumitomo Bayer Urethane Co., Ltd., Tolylene diisocyanate (2,4- / 2,6-isomer ratio = 80/20) Others Foaming agent: CFC 141B Catalyst: Stanas octate, DABCO (triethylenediamine) Foam stabilizer: Silicone foam stabilizer F-258 manufactured by Shin-Etsu Chemical Co., Ltd.

(Examples 1 to 6, Comparative Examples 1 to 8) Based on the formulations shown in Table 1, flexible polyurethane foams were produced. Polyol: dissolving flame retardant: 2 and / or 3: in water, water, blowing agent, catalyst, foam stabilizer,
Add TDI: 4 and add a homomixer (7000 rpm) for 5 seconds.
m), the mixture was poured into a mold and foamed for 5 minutes to produce a polyurethane foam. The obtained polyurethane foam was subjected to various tests, and its performance was compared. The results are shown in the table.

Various test methods are described below. 1 Combustion test: carried out according to FMVSS302. The initial flame retardancy and the flame retardancy after the heat treatment (100 ° C. × 200 hours) were measured. 2 Compression residual strain: Implemented in accordance with JIS K-6382. 3 Scorch property: A foam was prepared, and after 24 hours, the occurrence of scorch at the center of the foam was observed. ◎: no scorch was generated. わ ず か: slight scorch was generated. X: scorch was generated. 4 Fogging property: Implemented in accordance with DIN75201. After heating the foam at 110 ° C. for 3 hours, the weight of the deposit on the glass plate was measured.

[0032]

[Table 1]

[0033]

According to the method for producing a flexible polyurethane foam of the present invention, by using a specific bromine compound and a condensed phosphoric ester, a polyurethane foam having excellent heat resistance, physical properties, and sufficient flame retardancy. Can be manufactured.

Claims (4)

[Claims] 1. A polyisocyanate and a polyol are reacted in the presence of a flame retardant, a foaming agent, a catalyst and a foam stabilizer,
In producing a flexible polyurethane foam, 1 to 30 parts by weight of a condensed phosphoric acid ester based on the weight of the polyol is added as a flame retardant to 1 to 3 parts by weight of the polyol.
A method for producing a flame-retardant flexible polyurethane foam, wherein 0% by weight of an oxyalkylene ether of polybrominated bisphenol A is used. 2. An oxyalkylene ether of a polybrominated bisphenol A is represented by the following general formula (I): The method for producing a flame-retardant flexible polyurethane foam according to claim 1, wherein R is an alkylene group having 2 to 3 carbon atoms, and m and n each represent an integer of 1 to 50. 3. The plasticization efficiency of the condensed phosphate ester is as follows:
The flame retardancy according to claim 1 or 2, wherein, when dioctyl phthalate (DOP) is used as a reference (100), the flame retardancy is 150 or more, and the TG 1% by weight reduction temperature of the condensed phosphate ester is 200 ° C or more. A method for producing a flexible polyurethane foam. 4. The method for producing a flame-retardant flexible polyurethane foam according to claim 1, wherein the condensed phosphate ester is a chlorinated condensed phosphate ester.