DE1694428B2 - PROCESS FOR THE MANUFACTURING OF FLAME RETARDANT POLYURETHANE FOAM - Google Patents

Description

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The invention relates to the production of diisocyanate, aromatic diisocyanates such as toluene

flame retardant polyurethane foams. 2,4-diisocyanate, toluene-2,6-diisocyanate, diphenyl

The production of polyurethane foams methane-4,4'-diisocyanate, 3-methyldiphenylmethane

by reacting an organic polyisocyanate with 4,4'-diisocyanate, m-or p-phenylene diisocyanate, chlorine

a polyether polyol in the presence of a propellant 5 phenylene-i ^ -diisocyanate, naphthalene-1,5-diisocyanate,

means is well known. Diphenyl-4,4'-diisocyanate, 3,3'-dimethyl-diphenyl-

The foams are in flexible form and in 4,4'-diisocyanate or diphenyl ether diisocyanate, or

hard form many uses. Cycloaliphatic diisocyanates such as dicyclohexyl

which they use as upholstery materials in the furniture industry, methane diisocyanate. Examples of usable tri-

in the transport industry, as carpet underlays, as io isocyanates are: aromatic triisocyanates, such as

thermal insulation materials in refrigerators and 2,4,6-triisocyanatotoluene or 2,4,4'-triisocyanatodi-

Cold storage containers, as sound insulation materials in phenyl ether. Examples of other suitable organic

Buildings and as transport units as well as construction polyisocyanates are the reaction products from one

parts used in ¹ buildings or ships. Unfortunate excess of a diisocyanate with polyvalent alcohol

It is clear that polyols such as trimethylolpropane and uretdione dimers are widely used

urethane foams in many of these applications are or isocyanurate polymers of diisocyanates such as

restricts, since they are flammable, which despite the fact of toluene-2,4-diisocyanate. Mixtures of poly

that they are less flammable than comparable material isocyanates can also be used. At-

materials pose a serious problem. Games for suitable mixtures are the mixtures

It is already known to use tris-2-chloroethyl phosphate as 20 toluene-2,4- and -2,6-diisocyanates and the crude flame retardant agents in rigid polyurethane polyisocyanate compositions, which are branched polynation of the phosfoams crude polyamines such as B. the raw toether included. When this substance is added as a flame-luylenediamine mixture or the crude diaminodiaryl-inhibiting agent, the foams often have un-methanes, which have been obtained,
desired cracks and voids. This is in particular 25 As examples of polyether polyols which are produced for the Herder case if foams with a density of the position of the polyurethane foams are suitable, 0.080 g / cm ³ or higher. should be mentioned: hydroxyl-capped poly-

It is also known in polyurethanes as _me re or copolymers of cyclic oxides, such as

flame retardants tris (dichloropropyl) phosphate 1,2-propylene oxide, 1,2-butylene oxide, or 2,3-butylene

or to use tris (2,3-dibromopropyl) phosphate ^. 30 oxide, oxacyclobutane or substituted oxabutane or

However, it has been found that the flame-retardant tetrahydrofuran. Such polyethers can be linear

Menden properties of the last-mentioned substances be polyether glycols, such as those caused by

not sufficient in all cases. Polymerization of an alkylene oxide in the presence of a

The invention is based on the object of a ver-basic catalyst, such as potassium hydroxide, and drive for the production of polyurethane foams 35 of a glycol or a primary monoamine create what polyurethane foams have been made with. On the other hand, you can also unite high flame resistance and without voids and branched polyether polyols, for example by Ritzen supplies. Polymerization of an alkylene oxide in the presence of a

The invention therefore relates to a process for the basic catalyst and a substance with more

Manufacture of flame-retardant polyurethane foam 40 as two active hydrogen atoms per molecule

substances have been made by reacting an organic polyiso- such. B. ammonia, hydrazine or

cyanate and a polyether polyol in the presence of a polyhydroxy compounds such as glycerol, trimethylol

Propellant and in the presence of a trishaloalkyl propane or other hexanetriols, trimethylolethane,

phosphate as a flame retardant, thereby triethanolamine, pentaetythritol, sorbitol, sucrose or

is characterized that as a flame retardant 45 phenol-formaldehyde reaction products, amino alcohol

Tris-chloropropyl phosphate is used. bring, like monoethanolamine or diethanolamine, or

It has generally been found that it is advantageous to use polyamines such as ethylenediamine, tolylenediamine or most of the amounts of trischloropropylphosphate to add diaminodiphenylmethane. Branched ethers can apply that 2 to 40 percent by weight, preferably also by copolymerization of a cyclic oxide 5 to 15 percent by weight, in the polyurethane foam 50 of the type mentioned with cyclic oxides, which are present. Larger amounts can have an additional functionality greater than two, such as B. lent flame resistance, they can diepoxyde, glycidol or 3-hydroxymethyloxacyclo, but a detrimental effect on the physicalibutane, have been produced.
see properties, while smaller men- The polyethers usually have a molecular gene sometimes an insufficient effect result in weight from 200 to 8000. Mixtures of linear and can. branched polyethers can optionally

The tris-chloropropyl-phosphate can be turned into the foam.

forming reaction mixture in any convenient manner be incorporated. If necessary, special flame-retardant additives such as e.g. B. Antimony 60 foams suitable, with branched polyethers oxide, can be used together with the tris-chloropropyl phosphate, which usually uses 3 to 8 hydroxyl will. groups per molecule and hydroxyl values from 200 to

Which in the process according to the invention contain 750 mg KOH / g. In particular, poly-

turning starting materials are those, as they are called ether, which contain three to eight hydroxyl

65 groups per molecule and molecular weights of 75 are described in the literature on polyurethane production

been practicing. have up to 150 units per hydroxyl group.

Examples of suitable organic polyisocyanates The compound in the process according to the invention : aliphatic diisocyanates, depending on the hexamethylene propellant used, can be water or an inert one

Low boiling point liquid which is under the influence of the exothermic polyurethane formation reaction evaporates. It is often beneficial to use both types together.

If water is used, then it is preferably used in amounts of 1 to 10 percent by weight, based on the polyether polyol applied.

Suitable low-boiling liquids are those liquids against the polyurethane foam-forming units are inert and have boiling points at atmospheric pressure of not having preferably more than 75 ⁰ C and between -40 ° and 50 ° C. Examples of such liquids are halogenated hydrocarbons, such as. B. methylene chloride, vinylidene chloride or partially fluorinated hydrocarbons, such as. B. trichloromonofluoromethane, dichloromonofluoromethane, monochlorodifluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethane, l, l, 2-trichloro-1,2,2-trifluoroethane, dibromodifluoromethane or monobromotrifluoroethane. Mixtures of these low-boiling liquids with one another or with other substituted or unsubstituted hydrocarbons can also be used. Such liquids are usually used in amounts of 1 to 100 percent by weight, preferably 5 to 50 percent by weight, based on the polyether polyol.

If desired, a catalyst can be incorporated into the polyurethane-forming reaction mixture. Suitable catalysts are well known in the art and in particular include tertiary amines. Examples of suitable tertiary amines are: triethylamine, dimethylethylamine, dimethylbenzylamine, Dimethylcyclohexylamine, dimethylphenylethylamine, tetramethyl-l, 3-butanediamine, triethylenediamine, N-alkylmorpholines, N-alkylpyrrolidines, N-alkylpiperidines, pyrrolizidine, 1,1'-dimethyl-4,4'-bipiperidyl or fully N-substituted 4-aminopyridines, such as. B. 4-dimethylaminopyridine. Amine salts, such as B. dimethylbenzylamine lactate are also suitable. Other suitable catalysts are z. B. the non-basic organic compounds of metals, such as. B. dibutyltin dilaurate, dibutyltin diacetate, Iron acetylacetonate, manganese acetylacetonate, tin (II) carboxylates, such as. B. Tin (II) octoate, or lead carboxylates, such as. B. lead acetate or lead octoate. Mixtures of catalysts are often special advantageous.

The method according to the invention can be carried out using the customary methods described in the literature the manufacture of polyurethane foams are described. So they can foam-forming ingredients are mixed continuously or discontinuously, and the reaction mixture can in addition to those already described Materials contain other common additives. Examples of such additives are: surface-active Means such as B. oxyethylated fatty alkylphenols, oxyethylated fatty alcohols, salts of sulfuric acid derivatives of high molecular weight organic compounds or alkyl or aryl polysiloxanes or Copolymers of the same with alkylene oxides, foam stabilizers, such as. B. ethyl cellulose, Colorants, plasticizers, or antioxidants.

The invention is explained in more detail with reference to the following examples. All parts and percentages are expressed in weight.

Example 1

A hard foam is made by mixing the following materials:
5

50 parts of oxypropylated triethanolamine with a

Hydroxyl value of 530 mg KOH / g,
50 parts of oxypropylated tolylenediamine with a hydroxyl value of 490 mg KOH / g,
2 parts water,

1 part r ^ N-dimethylcyclohexylamine,

3 parts of a siloxane-oxyalkylene copolymer, 40 parts of trichlorofluoromethane,
30 parts of tris-chloropropyl-phosphate,
173 parts of a crude diisocyanatodiphenyl methane composition.

The foam obtained has a density of 0.032 g / cm ³ and is classified as “non-burning” according to the ASTM 1692/59-T test method.

Example 2

A soft polyurethane foam is made by mixing the following ingredients:

Parts of oxypropylated glycerine with a hydroxyl value of 56 mg KOH / g,
0.8 parts of tin (II) octoate,
25 parts of tris-chloropropyl-phosphate,
0.4 parts 1,4-diazabicyclo [2.2.2] octane,
7 parts water,

2 parts of a siloxane-oxyalkylene mixed poly-

meren,

91 parts of toluene diisocyanate (80:20 mixture of 2,4 / 2,6 isomers).

The foam obtained is classified as "self-extinguishing" according to the ASTM 1692/59-T test method.

Example 3

A foam is made by mixing the following ingredients:

100 parts of oxypropylated trimethylolpropane with

a hydroxyl value of 540 mg KOH / g, 2 parts water,

2 parts dimethylbenzylamine lactate,
1 part siloxane-oxyalkylene copolymer,
33 parts of tris-chloropropyl-phosphate,
179 parts of a crude Diisocyanatodiphenylmethanzusammensetzung containing approximately 55 ° / ₀ Diisocyanatodiphenylmethanisomere, the remainder being largely polyiso

cyanates higher functionality.

Mix for 90 seconds; the foam obtained has a density of 0.083 g / cm ³ and is completely free of cracks. According to the ASTM 1692/59-T test method, the foam is classified as "non-burning".

In a foam production for comparison, the 33 parts of tris-chloropropyl phosphate are replaced by 30 parts of tris-2-chloroethyl phosphate, the batch being otherwise unchanged. The foam obtained has a density of 0.083 g / cm ³ , but contains numerous cracks throughout the structure.

Example 4

A hard foam is made by mixing the following ingredients:

70 parts of oxypropylated triethanolamine with a

Hydroxyl value of 520 mg KOH / g,
30 parts of oxypropylated glycerine with a hydroxyl value of 540 mg KOH / g,
2 parts l ^ -Diazabicycloß ^^ joctan,
20 parts of triisopropanolamine,
1.5 parts water,
2 parts of a siloxane-oxyalkylene mixed poly-

meren,

20 parts of trichlorofluoromethane,
33 parts of tris-chloropropyl-phosphate,
183 parts of a 50:50 mixture of a crude toluene diisocyanate with an NCO content of 39.4 ° / ₀ and of a crude di-

isocyanatodiphenylmethane with an NCO content of 29.2%, which is approximately Contains 55% diisocyanatodiphenylmethane isomers.

and the following results were obtained:

Tris (2,3-dibromopropyl) phosphate

, Parts per 100 parts of poly-

ether 15 20 25

Fire spread

in cm / min 12.95 10.18 5.41

Classification burning self-extinguishing

Tris (chloropropyl) phosphate

Parts per 100 parts poly-

ether 15 20 25

Fire spread

in cm / min 11.99 5.84 4.59

Classification all self-extinguishing

From these comparative tests it can be seen that the expansion of fire in the case of the use of Tris (2,3-dibromopropyl) phosphate is greater than when using that proposed according to the invention Additive tris (chloropropyl) phosphate. The values are averages of ten samples in each case.

Mix for 9 seconds; the foam obtained has a density of 0.035 g / cm ³ and is completely free of cracks. According to the ASTM 1692/59-T test method, the foam is classified as "non-burning".

When the 33 parts of tris-chloropropyl phosphate are replaced by 30 parts of tris-2-chloroethyl phosphate and the approach remains otherwise unchanged, a foam with a large number of cracks is obtained.

Example 5

35

This example illustrates the flame retardant properties of polyurethane foams made in accordance with the invention compared with such polyurethane foams, which are used as a flame-retardant additive, tris (dichloropropyl) phosphate or tris (2,3-dibromopropyl) phosphate contain.

(a) Tris (2,3-dibromopropyl) phosphate

The following approach was made:

Parts by weight

Oxypropylated glycerin (molecular weight 3000) 100

Water 3.5

Diazabicyclo [2.2.2] octane 0.1

Tin (II) octoate 0.4

. Siloxane-oxyalkylene copolymer 1.0

Flame retardants 15 to 25

Tolylene diisocyanate (80:20 mixture of
2,4- and 2,6-isomers) 44.5

These compositions of matter were made into flexible polyurethane foams by the usual mixing process manufactured using three different concentrations of the additives tris (2,3-dibromopropyl) phosphate and tris (chlorpropyi) phosphate were used.

Samples of these foams were tested using the ASTM D 1692/59-T method (Flammability of Plastics Foams and Sheeting), published by the American Society for Testing and Materials, under-

(b) tris (dichloropropyl) phosphate
The following approach was made:

Parts by weight

Oxypropylated glycerin (molecular weight 3000) 100

Water 3.5

Diazabicyclo [2.2.2] octane 0.1

Tin (II) octoate 0.6

Siloxane-oxyalkylene copolymer 1.0

Flame retardants 15 to 25

Tolylene diisocyanate (80:20 mixture of
2,4- and 2,6-isomers) 45.5

These compositions of matter became flexible polyurethane foams by the usual mixing process manufactured using three different concentrations of the additives tris (dichloropropyl) phosphate and tris (chloropropyl) phosphate were used.

Samples of these foams were tested using the ASTM D 1692/59-T method (Flammability of Plastics Foams and Sheeting), published by American for Testing and Materials, investigated, and the following results were achieved:

Tris (2,3-dichloropropyl) phosphate

Parts per 100 parts poly-

ether 15 20 25

Fire spread

in cm / min 3.81 4.16 5.76

Tris (chloropropyl) phosphate

Parts per 100 parts poly-

ether 15 20 25

Fire spread

in cm / min 3.76 3.96 3.58

It can be seen that the expansion of fire in the polyurethane foam produced according to the invention is less.

Claims (4)

Patent claims: 1. Process for the production of flame-retardant polyurethane foams by implementing a organic polyisocyanate and a polyether polyol in the presence of a blowing agent and in Presence of a trihaloalkyl phosphate as a flame retardant, characterized in that that as a flame retardant 5 tris-chloropropyl phosphate is used. 2. The method according to claim 1, characterized in that the tris-chloropropyl phosphate is tris-2-chloropropyl phosphate is used. 3. The method according to claim 1 or 2, characterized in that a tris-chloropropyl phosphate is used, which is obtained by reacting propylene oxide with phosphorus oxychloride or phosphorus oxybromide been prepared in the presence of a titanium or zirconium halide as a catalyst is. 4. The method according to any one of the preceding claims, characterized in that such Amount of tris-chloropropyl phosphate is used that in the polyurethane foam 2 to 40 percent by weight, preferably 5 to 15 percent by weight. 109511/385