JPS581690B2 - Method for manufacturing flame-retardant polyurethane foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing flame retardant polyurethane foam.

Conventional methods for making polyurethane foam flame retardant include:
Broadly speaking, there are reaction methods, addition methods, dipping methods, and methods that combine these methods. Phosphate esters, halogenated phosphate esters, alkyl halides, etc. are used as flame retardants, but phosphorus-halogen These substances generally contain many poisonous or deleterious substances, and generate a large amount of toxic gas when burned, while reacting with water or moisture at high temperatures and decomposing, producing hydrochloric acid, etc. It also causes corrosion of metals, etc.

A method of adding inorganic salts is also known, but it is rarely practiced because of problems such as adverse effects on reactivity or non-uniformity due to differences in specific gravity.

Furthermore, methods such as immersing the foam in a concentrated solution of these inorganic salts or spray coating the foam are also known, but these methods have problems in terms of durability and are not common.

Examples of non-reactive additives containing phosphorus and halogen include tris(chloropropyl) phosphate, tris(
2,3-dibromopropyl) phosphate, tris)chloroethyl)phosphate, tris(2,3-dichloropropyl) phosphite, etc., and reactive additives include tris(diglopylene glycol) phosphite, phosphoric acid, etc. Compounds made by reacting alkylene oxide with a partial ester are known.

On the other hand, there is a method of adding ammonium polyphosphate to polyurethane, as disclosed in Japanese Patent Publication No. 49-15046, but since ammonium polyphosphate itself is relatively easily soluble in water, it cannot be said to be sufficient in terms of water resistance.

As a result of various studies in view of the above circumstances, the inventors of the present invention have found that by adding polyphosphoric acid amide, which is substantially insoluble in water, as a flame retardant, there is no generation of poisonous gas during combustion as described above, and there is no hydrolysis. It has been discovered that it is possible to obtain flame-retardant polyurethane foam that does not corrode metals and has superior flame-retardant effects compared to conventionally used flame retardants.

That is, the present invention is a flame retardant material characterized by adding substantially water-insoluble polyphosphoric acid amide when producing polyurethane foam from polyol and polyisocyanate in the presence of a catalyst, a blowing agent, a foam stabilizer, etc. This is a method for producing polyurethane foam.

The substantially water-insoluble polyphosphoric acid amide used in the method of the present invention refers to ammonium orthophosphate, orthophosphoric acid, condensed phosphoric acid, phosphoric anhydride, urea phosphate, and mixtures thereof as a phosphoric acid source and as a nitrogen source. As a condensing agent, cyanamide derivatives such as melamine, dicyandiamide, and guanidine, and mixtures thereof are used to conduct a heating condensation reaction in the presence of phosphorus, urea phosphate, and mixtures thereof as condensing agents. It is a polyphosphate (amide polyphosphate) containing.

However, urea and urea phosphate as condensing agents may also serve as a nitrogen source.

This polyphosphoric acid amide is prepared by using one or more phosphoric acid sources as shown above, one or more cyanamide derivatives as a nitrogen source, urea or phosphate urea or a mixture thereof as a condensing agent. /phosphoric acid (H3PO
4)/cyanamide derivative=0.8-1.5/1/
1 in an atmosphere of ammonia gas at a molar ratio of 0.05 to 1
It can be produced by heating and condensing at 50 to 350°C.

In addition, "substantially insoluble in water" means that polyphosphoric acid amide is
When added to 00cc of water at 25℃, the solubility is approximately 1g.
/ 100cc or less of water (usually about 0.2g/100cc of water)
It means.

Since the solubility of ammonium polyphosphate, which is generally known to be poorly soluble in water, is 1 to 3 g/100 cc of water,
Even in comparison, the solubility of polyphosphoric acid amide is extremely low.

In order to produce flame-retardant polyurethane foam in the present invention, the amount of the polyphosphoric acid amide used is 0.5 to 35 wt%, preferably 1 to 30 wt%, as the amount contained in the foam.

If the amount of polyphosphoric acid amide added is less than this range, the flame retardance will not be sufficient, and if it is too much, the foam properties will deteriorate, such as poor fluidity, failure to foam, or brittleness even when foamed.

The above polyphosphoric acid amide can be used in combination with other flame retardants.

Any method can be used to add polyphosphoric acid amide, but basically, fine powder of polyphosphoric acid amide is mixed with polyol in advance, and then ordinary foaming agents, foam stabilizers, catalysts, and other additives for polyurethane are added. It is desirable to add and foam a substance containing incyanate groups in the presence of.

Any known polyol, polyisocyanate, blowing agent, foam stabilizer, and catalyst can be used in the present invention.

Typical polyols used in the present invention include ethylene glycol, glycerin, propylene glycol, trimethylolpropane, α-methylglucoside, pentaerythritol, sorbitol, sucrose, polyols such as saccharides, diethanolamine, triethanolamine, and triethanolamine. Obtained by addition polymerizing oxides such as ethylene oxide or propylene oxide to a base material of amino alcohols such as propanolamine, amines such as ethylenediamine, triethylenetetramine, and mixtures of these in the presence of an alkali catalyst (KOH, NaOH, etc.). Examples include nitrogen-containing polyether polyols.

Other examples include halogen-containing polyether polyols and polyester polyols.

Typical polyisocyanates used in the present invention include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), and 4,4',4'-triphenylmethane triisocyanate. , m-xylylene diisocyanate (MXDI), hexamethylene diisocyanate, phenyl ether diisocyanate, and mixtures or crude products thereof can be used.

Examples of catalysts for promoting the polyurethanization reaction include organic tin compounds such as dibutyltin laurate, and amine-based compounds such as triethylamine, triisopropylamine, triethylenediamine, dimethylcyclohexylamine, and tetramethylpropanediamine.

As the blowing agent, water may be used in addition to low boiling point compounds such as Freon (a fluorinated hydrocarbon manufactured by DuPont) and methylene chloride.

A silicone-based foam stabilizer is used.

Examples are shown below to explain the present invention in more detail.

The minimum oxygen concentration index (LOI) shown in the table has a length of 1.
The minimum oxygen concentration required for a test piece with a size of 5 cm, width 6.5 mm, and thickness 3.0 mm to continue burning for 5 cm in a mixture of oxygen and nitrogen was determined in volume ratio % (ASTMD2863
-70), and the degree of corrosion and the pH of the immersion liquid are as follows:
Two pieces of carbon steel of 0mm x 25mm are sized 30mm x 30
Corrosion degree of carbon steel (g/m2hr) when attached to a mm x 140mm urethane foam specimen and immersed for one month
) and the pH of the immersion liquid were measured.

The blank in the table is the result when only carbon steel was immersed in distilled water.

Example 1 Sumifene TS380 (manufactured by Sumitomo Bayer Urethane ■, sucrose-based polyether polyol, hydroxyl value 380) and Sumifene PM (manufactured by Sumitomo Chemical ■; urea phosphate and melamine were combined into a mixture of urea/phosphoric acid (as H3po4)/melamine = Substantially water-insoluble polyphosphoric acid amide (
N: 31.48% by weight, P2O5: 47.27% by weight,
Solubility 0.2g/100cc water, pH of 1% aqueous solution: 8
．． 3) 10.0 parts by weight of a uniform mixture of 1:1 (weight ratio), 1.0 parts by weight of water, 20.0 parts by weight of trichlorofluoromethane, and 1.0 parts by weight of N-N-dimethylcyclohexylamine. 2 parts by weight and 12 parts by weight of a silicone foam stabilizer were added to 100.0 parts by weight of SUMIFUEN TS380, stirred and mixed thoroughly, and then 123.0 parts by weight of MDI was added and stirred in a lab mixer for about 20 seconds, then placed in a container and foamed. A flame-retardant polyurethane foam was obtained by this process.

Table 1 shows the minimum oxygen concentration index, corrosion degree, and pH value of the immersion liquid of the flame-retardant polyurethane foam obtained.

Example 2 Same as Example 1 Sumifen TS380 and Sumsafe PM
Uniformly mixed at a ratio of 1:1 (weight ratio) 20.0
1.0 parts by weight of water, 20 parts by weight of trichlorofluoromethane
．． 5 parts by weight, N-N-dimethylcyclohexylamine 1
．． 2 parts by weight and 1.2 parts by weight of a silicone foam stabilizer were added to 100.0 parts by weight of Sumifen TS380 and thoroughly stirred and mixed, and then 130.0 parts by weight of MDI was added,
A flame-retardant polyurethane foam was obtained by stirring the mixture for about 20 seconds using a lab mixer, then placing it in a container and foaming it.

Measured values of the obtained flame-retardant polyurethane foam are shown in Table 1.

Example 3 Same as Example 1 Sumifen TS380 and Sumsafe PM
50.0 parts by weight of a 1:1 (weight ratio) mixture of 1.0 parts by weight of water and 25.0 parts by weight of trichlorofluoromethane N.N'
- After adding 100.0 parts by weight of Sumifene TS380 with 1.2 parts by weight of dimethylcyclohexylamine and 1.2 parts by weight of a silicone foam stabilizer, and stirring and mixing thoroughly,
After adding 14.50 parts by weight of MDI and stirring with a lab mixer for about 20 seconds, the mixture was placed in a container and foamed to obtain a flame-retardant polyurethane foam.

Measured values of the obtained flame-retardant polyurethane foam are shown in Table 1.

Example 4 Same as Example 1 Sumifen TS380 and Sumsafe PM
200.0 parts by weight of a 1:1 (weight ratio) mixture of 1.0 parts by weight of water
Parts by weight, 35.0 parts by weight of trichlorofluoromethane, N.
After adding 1.2 parts by weight of N-dimethylcyclohexylamine and 1.2 parts by weight of a silicone foam stabilizer and thoroughly stirring and mixing, 11.50 parts by weight of MDI was added, and after stirring with a lab mixer for about 20 seconds, the container was poured. A flame-retardant polyurethane foam was obtained by foaming.

Measured values of the obtained flame-retardant polyurethane foam are shown in Table 1.

Comparative Example 1 100.0 parts by weight of Sumifen TS38 as in Example 1
0, 1.0 parts by weight of water, 18.0 parts of trichlorofluoromethane
Parts by weight, N-N-dimethylcyclohexylamine 1.2
After adding parts by weight and 1.2 parts by weight of a silicone foam stabilizer and stirring and mixing thoroughly, 115.0 parts by weight of MDI was added, and after stirring with a lab mixer for about 20 seconds, the mixture was placed in a container and foamed. A polyurethane foam was obtained.

The measured values of the obtained polyurethane foam are shown in Table 1.

Comparative Example 2 100.0 parts by weight of Sumifen TS38 as in Example 1
Tris(2-chloroethyl)phosphate (TC
EP) 20.0 parts by weight, 1.0 parts by weight of water, 20.0 parts by weight of trichlorofluoromethane, 1.2 parts by weight of N.N'-dimethylcyclohexylamine and 1.2 parts by weight of a silicone foam stabilizer were added. After stirring and mixing thoroughly, MDI11
．． After adding 50 parts by weight and stirring with a lab mixer for about 20 seconds, the mixture was placed in a container and foamed to obtain a flame-retardant polyurethane foam.

The measured values of the obtained flame-retardant polyurethane foam were
Shown in the table.

Example 5 Same as Example 1 Sumifen TS380 and Sumsafe PM
Tris (2-
chloroethyl) phosphate 100 parts by weight, water 1.0
Part by weight, trichlorofluoromethane (TCEP) 20.0
Add 1.2 parts by weight of N・N-dimethylcyclohexylamine and 1.2 parts by weight of a silicone foam stabilizer, stir in a lab mixer for about 20 seconds, then pour into a container and foam to produce flame-retardant polyurethane. I got it.

Measured values of the obtained flame-retardant polyurethane are shown in Table 1.

As is clear from the table, by adding substantially water-insoluble polyphosphoric acid amide to polyurethane foam,
Excellent flame retardant effects can now be obtained, and even when added in small amounts, it has an effect comparable to that of the conventionally used flame retardant TCEP.

On the other hand, no effect on corrosion was observed when adding a flame retardant such as TCEP.

Claims (1)

[Claims] 1. A method for producing a flame-retardant polyurethane foam, which comprises containing a substantially water-insoluble polyphosphoric acid amide.