DD232712A1 - PROCESS FOR PREPARING A FLAME-RESISTANT POLYMER COMPOSITION - Google Patents

Abstract

The invention relates to a process for the preparation of a flame-retardant polyol composition which is suitable for the production of polyurethanes, preferably flexible polyurethane foam. The invention has for its object to develop a process for preparing a flame retardant polyol with low Viskositaet, high stability and density and good solubility. According to the invention, the object is achieved by reacting reactive compounds consisting of halogen and / or phosphorus and / or nitrogen in a per se known polyol with a deficit of isocyanates.

Description

Explanation of the essence of the invention

The invention has for its object to develop a process for preparing a flame retardant polyol composition with low viscosity, high stability and density and good solubility.

According to the invention the object is achieved in that reactive flame retardant components containing halogen and / or phosphorus and / or nitrogen are reacted with a stoichiometric deficit of isocyanates in a known per se, a polyolic medium. Depending on the molecular weight and solubility in the base polyol, the reaction products of reactive flame retardant component and isocyanate are present as a clear solution or a stable finely divided dispersion of low viscosity is formed.

The polyols used are polyether and / or polyester alcohols.

As polyether alcohols alkoxylation and condensation products having molecular weights between 300 and 7000 are used. It is also possible to use polyester alcohols with predominantly terminal hydroxyl groups and molecular weights between 500 and 4000.

For carrying out the process according to the invention, all difunctional and polyfunctional isocyanates, such as diphenylmethane diisocyanate, toluylene diisocyanate and their NCO-containing prepolymers are suitable.

The flame retardant component consists of halogen, in particular bromine or chlorine and / or phosphorus and / or nitrogen-containing compounds.

With dehTerfindungsgemäßen process, it is also possible to Halogenpolyalkohole, such as. B. Dibromobuten- (2) -diol (1.4), Dibromneopentylglykol, brominated OH-functional 2-Methylstyrenoligomere to convict in a polyol compatible flame retardant form. The reaction of the reactive flame retardant component with the deficiency of isocyanate in polyolischem medium is in a temperature range from 2O ⁰ C to 200 ° C, preferably 4O ⁰ C to 140 ⁰ C, in conventional production facilities, such as stirring apparatus is performed. The process of the invention has the advantage that stable polyol compositions containing high density particulates can be prepared. This result was not to be expected since, in analogy to the dispersions with inorganic fillers or to dispersions based on organic substances of higher density, such as aminoplasts, considerable stability problems occur. In view of the stoichiometric deficit of isocyanate-that is, the low probability of a grafting reaction on the OH groups of the polyol-on the contrary, the formation of highly unstable products was very likely.

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The use of products having such hydroxyl groups as in bis (chloroalkyl) N, N'-alkanoiaminomethylphosphonates, whose reactivity is adversely affected by the heteroatoms present in the molecule, in competition with the unimpaired hydroxyl groups of the polyol, achieves a preferred reaction with isocyanates and produces low viscosity Products. Furthermore, it is possible by the process according to the invention halopolyalcohols such as 2,3 Dibrombuten- (2) -diol (1,4), Dibromneopentylglykol, brominated OH-functional 2-Methylstyrenoligomere to convert into a polyol compatible form. It was not expected that reaction products from o.g. halogenated compounds and a stoichiometric deficiency of isocyanates in the polyol were prepared, have a large compatibility range with the polyol, because these reaction products are indeed a mixture of pure form anyway insoluble halogenated alcohols and insoluble polyurethanes.

The main advantage of the process is that the compatibility and processing problems of many reactive flame retardants are overcome by the reaction of the invention resulting in stable dispersions or solutions of the reaction products in the polyol composition

 The invention will be explained in more detail below to 8 exemplary embodiments.

Embodiment 1

In a stirred apparatus with temperature display and reflux cooling 54200 g of a Polyetheralkohls the OHZ = 47.6 mg KOH / g at 25 ° C with 4035 g Bisfchlorpropyll-NN diethanolaminomethylphosphonat intimately mixed. To 1980g tolylene diisocyanate are added and the reaction temperature increased to 80 ⁰ C. After a reaction time of 10 hours, the reaction is complete and there is a stable Polyolkomposition with the following characteristics: hydroxyl number = 43.7mg KOH / g water content = 0.17% acid number = 0.47 mg KOH / g

Viscosity = 1641 m Pas at 25 ⁰ C.

Solids content = 10%

Comparative Example 1 a

46530 g of a polyether alcohol of OHN = 47.6 mg KOH / g are intimately mixed with 3245 g of bis (chloropropyl) -NN-diethanolaminomethylphosphonate at room temperature in a stirring apparatus with thermometer and reflux cooling. After addition of 1925 g of tolylene diisocyanate, the reaction temperature is raised to 8O ⁰ C and the reaction is completed after a period of 10 hours. The resulting dispersion is characterized by the following characteristic values: hydroxyl number = 41.9 mg KOH / g acid number = 0.56 mg KOH / g

Water content = 0.094% viscosity = 2028 m Pas

Solid content = 10%

Embodiment 2

In a laboratory stirred apparatus 200 g of a polyether alcohol OHZ = 48.3 mg KOH / g at 25 ⁰ C with 34 g of bis (chloropropyl) -NN-diethanolaminomethylphosphonat well.

To this is added 16 g of tolylene diisocyanate and the reaction mixture is heated to a temperature of 70 ⁰ C. After the content of free isocyanate has dropped to zero%, a stable polyol composition with the following quality parameters is obtained:

Hydroxyl number = 38.6 mg KOH / g

Acid number = 0.771 mg KOH / g

Water content = 0.09%

Viscosity = 5100mPasbei25 ° C

Solids content = 20%

Embodiment 3

2125 g of a polyether alcohol of OHN = 47.2 mg KOH / g are mixed in a stirred apparatus with thermometer and reflux condenser with 255 g of a bis-l-chloropropyl-N-dipropanolaminomethylphosphonate and to this 120 g of tolylene diisocyanate are metered. Subsequently, the reaction mixture is reacted for 9 hours at a temperature of 90 ⁰ C. The stable slightly yellow colored polyol composition has the characteristic values:

Hydroxyl number = 41.4 mg KOH / g

Acid number = 0.623 mg KOH / g

Water content = 0.06%

Viscosity = 3990m Pas at 25 ⁰ C.

Solids content = 15% _

Exemplary embodiment 4

In a stirred apparatus, 7125 g of a polyether alcohol OHZ = 45.2 mg KOH / g with 255 g of bis (chloropropyl) NN diethanolaminomethylphosphonat stirred at 25 ⁰ C and then 120 g of toluene diisocyanate are added. The reaction, which is carried out at a temperature of 100 ⁰ C for 8 hours, provides a stable Polyolkomposition following quality:

OH = 43 mg KOH / g

SZ = 0.77 mg KOH / g

H ₂ O = 0.07%

Viscosity = 1 312 m Pas at 25 ° C

Solids content = 5%

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Embodiment 5

In a sulfonating flask equipped with thermometer, stirrer and reflux condenser, 481 g of a polyether alcohol OHZ = 46.2 mg KOH / g at 25 ° C mixed with 80g Bis-lchlorpropyO-N, N-diethanolaminomethylphosphonat. 17.4 g of tolylene diisocyanate added with stirring. The reaction mixture is brought to a temperature of 90 ° C and the reaction is complete after 9 hours. The result is a white polyol composition with the characteristics:

Hydroxyl number = 40.2 mg KOH / g

Acid number = 0.7 mg KOH / g

Water content = 0.1%

Viscosity = 3900 m Pas at 25 ° C

Solids content = 17%

Embodiment 6>

In a sulphonation flask, 420 g 2,3Dibrombuten- (2) -diol (1.4) are dissolved at a temperature of 110 ° C in 1785 g of a polyalkylene glycol having a hydroxyl value of 46.8 mg KOH / g. After cooling the reaction product to a temperature of 80 ⁰ C, 280 g of tolylene diisocyanate are added and there is formed after 10 hours of reaction time, a brown clear highly viscous solution with the following characteristics:

Hydroxyl number = 39.5 mg KOH / g

Acid number = 0.52 mg KOH / g

Water content = 0.065%

Viscosity = 24280 m Pas at 25 ° C

Bromine content = 11.1%

Exemplary embodiment 7

In 357 g of a polyester alcohol OHZ = 51.4 mg KOH / g are dissolved in a sulfonation flask with a thermometer and reflux condenser 84g 2.3 Dibrombuten- (2) -diol (1.4) at 120 ° C. After cooling the product to 90 ⁰ C, 50 g of toluene diisocyanate are added and the temperature is increased again to 150 ⁰ C. After a reaction time of 8.5 hours, a clear high-viscosity product of the following quality is obtained: hydroxyl number = 49.8 mg KOH / g acid number = 0.82 mg KOH / g

Water content = 0.1% viscosity = 18940m Pas

Bromine content = 10.2%

Embodiment 8

252g 2,3Dibrombuten- (2) -diol (1,4) in 714g of a polyether alcohol OHZ = 46.8mg KOH / g at 120 ⁰ C are completely dissolved in a 1,51 Sulfierkoiben. 118 g of tolylene diisocyanate are added while stirring and the reaction is carried out over a period of 8 hours. The result is a viscous clear brown solution with the following parameters:

Hydroxyl number =

Acid number =

Water content

Viscosity =

Bromine content

53.4 mg KOH / g

0.8 mg KOH / g

0.09%

21,000 m Pas at 25 ° C

13.9%

Claims (3)

-1- 715 Invention claims: 1. A process for the preparation of flame retardant polyol compositions with low viscosity, good stability or solubility, characterized in that reactive compounds consisting of halogen and / or phosphorus and / or nitrogen are reacted in a per se known Polyoi with a deficit of isocyanates. 2. The method according to item 1, characterized in that the reaction product of reactive compound and isocyanate dispersed in Polyoi present. 3. The method according to item 1, characterized in that the reaction product of reactive compound and isocyanate is present dissolved in Polyoi. Field of application of the invention The invention relates to a process for the production of a flame-retardant polyol composition which is suitable for the production of polyurethanes, preferably flexible polyurethane foam Characteristic of the known technical solutions It is known, by using reactive and additive flame retardants, by using raw material compositions specific structure, appropriate applications of the material and use of special fillers (various inorganic and organic substances, which may also be applied in the form of dispersions) polyurethane to flameproof equip. The abovementioned possibilities often lead to a deterioration of the mechanical parameters in the production of polyurethanes with specific property requirements. Therefore, the commercial production of flame retardant materials with a high level of mechanical properties is still a largely unsolved problem today. This applies in particular to the production of high-quality polyurethanes. Causes of this deficiency of the prior art are the negative influence of the polyurethane reaction by some otherwise flame-retardant suitable flame retardants, often insufficient solubility of flame retardants in the polyol, the impairment of the stability of dispersions, especially of polymer polyols and polyurea dispersion polyols , by addition of flame retardants and insufficient flame-retardant effect of dispersion polyether alcohols, for example in aminoplast dispersions. Reaction products of the above-mentioned type are described many times. The use of heteroatoms such as phosphorus or halogen provided solid components does not lead to stable dispersions due to the high density of this compound. The use of such classes of compounds to prepare stable dispersions requires the use of special grafting and / or stabilizing products which always result in high viscosity and hence a deterioration of processability. The possibility of using a grafting technology to prepare stable dispersions is described e.g. described in DE-OS 2513815. Furthermore, there are substances with flame retardancy, which do not adversely affect the polyurethane reaction due to their chemical structure, such as halogenated diols, which are unfortunately insufficiently soluble in the polyol. One way to bring about the solubility would be the preparation of mixed OH-functional prepolymers of diisocyanates, the base polyol and the halogenated diol. The incorporation of polyether alcohol molecules into prepolymers improves the solubility of the halogenated compound. The main disadvantage consists in an impermissible increase in the viscosity of the prepolymers and thereby difficult processability. Object of the invention The aim of the invention is to develop a technologically simple and therefore economically favorable process for the production of a flame-retardant polyol composition.