EP4658695A1 - Isocyanate-reactive and isocyanate-terminated phosphanylcarboxamides and their production and use for producing phosphorous polyurethanes and polyisocyanurates - Google Patents

Abstract

The present invention relates to isocyanate-reactive and isocyanate-terminated phosphanylcarboxamides as novel monomers and prepolymers for producing plastics, which can, for example, be used for the production of polyurethanes or polyurethane/polyisocyanurate polymers.

Description

Isocyanate-reactive and isocyanate-terminated phosphanylcarboxamides and their preparation and use for the production of phosphorus-containing polyurethanes and polyisocyanurates

The present invention relates to novel monomers and prepolymers for the production of plastics which can be used, for example, for the production of flame-retardant polyurethanes or polyurethane/polyisocyanurate polymers (hereinafter referred to individually or jointly as PUR/PIR).

Many plastics, like most organic substances, are highly flammable. For a large number of applications, it is therefore necessary to equip them with flame retardants. This also applies to PUR/PIR polymers, particularly those used in the construction sector or in certain coatings. PUR/PIR foams are often used as insulation materials and the use as foam in general increases the fire risk due to the large surface area per unit mass. In many areas where PUR/PIR foams are used, fire protection equipment using added flame retardants is therefore essential.

Halogen-containing compounds as well as nitrogen and phosphorus compounds are preferred as flame retardants. Compounds containing halogens and low-valent phosphorus compounds are considered typical representatives of flame retardants that extinguish flames. Higher-valent phosphorus compounds are said to cause a catalytic splitting of the polyurethanes and thus lead to the formation of a solid, polyphosphate-containing, charred surface. This intumescent layer protects the material from further combustion.

Low molecular weight flame retardant additives such as tris(2-chloroisopropyl) phosphate (TCPP) or triethyl phosphate (TEP) are chemically unbound in the polymer matrix and can act as plasticizers, affecting the product and leaching out over time.

An interesting alternative to phosphorus-containing flame retardant additives is the use of phosphorus-containing, reactive building blocks such as monomers and prepolymers for the production of inherently flame-retardant polymers. For example, hydroxy-terminated organic phosphonates or phosphates, which are available under the trade names Exolit® OP560 or Nofia® OLIOOO, can be used to produce phosphorus-containing polyurethanes and polyurethane/polyisocyanurates. The phosphonate- or phosphate-containing monomers or prepolymers are incorporated into the polyurethane via a polyaddition, which influences the polyurethane-characteristic structure and thus the properties of the polyurethane.

The increasing demands on safety, costs and sustainability of organic polymers in general and PUR/PIR in particular therefore require the development of new flame retardants. A class of organic phosphorus-containing compounds that has not yet been used commercially are phosphanylcarboxamides (Figure 1, I) and phosphorus(III) acid carboxamides (Figure 1, II). The groups show a strong structural analogy to the urea, urethane, biuret and isocyanurate binding motifs found in polyurethanes and polyisocyanurate.

I II

Figure 1: general structures of phosphanylcarboxamides (I) and phosphorus(III) acid carboxamides (II); with R = independently selected from (optionally substituted with heteroatoms) organyl radicals and hydrogen radicals

Certain phosphanylcarboxamides and phosphorus(III) acid carboxamides each containing one phosphanyl or phosphorus(III) acid and one amide function as shown in Figure 1 are already known.

Compounds of structure I can be prepared from the corresponding starting compounds using known synthesis processes. This includes the direct reaction of primary or secondary phosphines or phosphine oxides with monofunctional isocyanates and cyanates (eg US 3,116,316 A). The reaction of phosphines and phosphine oxides with difunctional isocyanates to form a polymeric structure has also been described (US 3,213,042 A). The reaction of primary amines with the 1,4-dioxane adduct consisting of Na(OCP)(l,4-dioxane) _x with varying 1,4-dioxane content (eg x = 2.5) is also described. However, the synthesis and isolation of Na(OCP)(l,4-dioxane) _x is cumbersome because several organic solvents have to be used simultaneously (DME, 1,4-dioxane, THF), the organic solvents used have to be removed in a vacuum, which is energy-intensive, and a time-consuming (6-12 h) filtration process and recrystallization process with 1,4-dioxane is necessary. In addition, the 1,4-dioxane adduct Na(OCP)(l, 4-dioxane) _x obtained in this way contains non-reproducible amounts of 1,4-dioxane, so that the 1,4-dioxane content of each product batch has to be quantified by NMR spectroscopy. Due to these disadvantages, the synthesis route via the adduct consisting of Na(OCP)(l,4-dioxane) _x is not well suited for the production of larger quantities of the compounds with structures I or II, and a simplified production process would be of great interest. Two examples of bifunctional, primary bis(phosphanylcarboxamides) of structure III are also described in the literature (Figure 2, structure III, R = ethylene and R = 1,2-cyclohexylene, Y.-H. Wu, Z.-F. Li, W.-P. Wang, X.-C. Wang, Z.-J. Quan, Eur. J. Org. Chem. 2017, 2017, 5546-5553; EN Faria, AR Jupp, JM Goicoechea, Dalton Trans. 2021, 50, 6991-6996.). Bifunctional hydroxy(phosphanylcarboxamides) (IV, with X = OH) and bis(phosphoric acid carboxamides) (V) are not yet known in the literature.

III IV V

Figure 2: Structures of bis(phosphanylcarboxamides) (III); bifunctional phosphanylcarboxamides with X = NCO-reactive group (IV) and bis(phosphoric acid carboxamides) (V); with R = independently selected from organyl radicals (optionally substituted with heteroatoms)

The use of phosphanylcarboxamide- or phosphorus(III) acid carboxamide-containing structures as reactive, phosphorus-containing building blocks, e.g. for incorporation into polyurethanes or polyisocyanurates, has not yet been disclosed.

As reactive monomeric building blocks (“monomers”) for the production of plastics, e.g. as a reactant for the polyaddition reaction with the NCO function of an isocyanate compound in the formation of polyurethane or polyisocyanurate, compounds that are of particular interest are those that firstly have one or more phosphanylcarboxamide structures and/or phosphoric acid carboxamide structures and secondly have at least two functional groups that are isocyanate-reactive (“NCO-reactive groups”). These compounds are referred to below individually or together as “PCA”.

The invention relates to PCA compounds of the general structure VI or VII (see Figure 3), which have at least two NCO-reactive groups and can thus be used as monomers, e.g. for the polyaddition to polyisocyanates, with the proviso that the compounds with the structure III and R = ethylene or R = 1,2-cyclohexylene are excluded.

The invention also relates to the use of PCAs as monomers for the production of phosphorus-containing prepolymers and polymers, e.g. PUR/PIR. The invention further relates to prepolymers, polymers and NCO-terminated compounds which can be prepared using PCA compounds and polyfunctional isocyanates.

The invention further relates to novel processes for preparing the PCA, wherein a) a Na(OCP) reaction solution is reacted with an amine in the presence of a Brönsted acid and optionally an oxidizing agent in a multi-step synthesis (Figure 4a) or alternatively b) red phosphorus, sodium, organic carbonates, tert-butanol, amines are reacted in the presence of a Brönsted acid and optionally an oxidizing agent in a one-pot reaction (Figure 4b).

Connections PCA

The novel PCA compounds are selected from the group of organic phosphorus compounds which have a structure VI or a structure VII and which have at least two isocyanate-reactive groups, with the proviso that compounds of structure III with R = ethylene or R = 1,2-cyclohexylene are excluded.

VI VII

Figure 3: Structures of phosphanylcarboxamides (VI) and

Phosphorus(III) acid carboxamides (VII)

In the phosphanylcarboxamides VI or phosphorus(III) acid carboxamides VII, X is an NCO-reactive group, m = 0-3, n = 1-4, m+n > 2; and R is an organyl radical (optionally substituted with heteroatoms).

In particular, the isocyanate-reactive groups of the PCA compounds are at least two groups selected from the group consisting of -PH ₂ , -PHR, -P(O)H ₂ , -P(O)HR, -P(O)(H)OH, -P(OH)H, -P(OH)R (where R = organyl radical optionally substituted by heteroatoms), -OH, -NH ₂ , -NHR' (where R' = organyl radical optionally substituted by heteroatoms, excluding para-substituted aniline radical), - SH and oxirane.

Particularly preferred are PCA compounds which are selected from the group of compounds consisting of PCA compounds with the structures VI and VII, and wherein the organyl radicals R are preferably selected from the group consisting of trimethylene, Tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, optionally heteroatom-containing cyclohexylene, phenylene, diphenylene, dimethylphenylene, 2-methylpentamethylene, 2,2,4-trimethylhexamethylene, dodecamethylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 5-(l-methylene-(l,3,3-trimethylcyclohexane)), all regioisomers of methylenebiscyclohexylene, all regioisomers of methylenebisphenylene, methylenebis-(3,3'-dimethylcyclohexane-l,4-diyl), propane-2,2-diyl)bis(cyclohexane-4,l-diyl), Propane-2,2-diyl-bis-4,l-phenylene, polyhexamethylene, tolylene, poly(propylene glycol)tolylene, poly(ethylene adipate)tolylene, 2,4,6-trimethyl-l,3-phenylene, 4-chloro-6-methyl-l,3-phenylene, poly[l,4-phenylene], co-[poly(l,4-butanediol)], poly(tetrafluoroethylene oxide-co-difluoromethylene oxide), l,3-bis(l-methylethyl)benzene, 3,3'-dimethyl-4,4'-biphenylene, naphthalene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,4- or 2,5- or 2,6- tolylene and their isomer mixtures, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures, 4,4'-, 2,4'- or 2,2'- 2,2'-diphenylpropane-p-xylylene and a,a,a',a' -tetramethyl- m- or -p-xylylene. The organyl radical R is very particularly preferably selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures.

The NCO-reactive radical X is in particular selected from the group consisting of -PH ₂ , -PHR', - P(O)H ₂ , -P(O)HR', -P(O)(H)OH, -OH, -NH ₂ , -NHR', - NHC(O)PH2, -NHC(O)PHR', - NHC(O)P(O)H2, -NHC(O)P(O)HR', -NHCOOH, -NHC(O)NH2, - NHC(O)NHR' (where R' = organyl radical optionally substituted by heteroatoms).

Particularly preferred compounds of structure VI or VII are characterized in that m = 0, 1, n = 1, 2, m+n = 2;

R is selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures and

X = OH.

Manufacturing process of isocyanate-reactive compounds PCA The preparation of the PCA compounds can be carried out as described above from the corresponding starting compounds using known synthesis methods, which, however, are not particularly suitable for the synthesis of larger quantities.

The invention further relates to new processes for producing PCA, whereby a) a Na(OCP) reaction solution is reacted with an amine in the presence of a Brönsted acid and optionally an oxidizing agent in a multi-stage synthesis (Figure 4a) or b) alternatively, red phosphorus, sodium, organic carbonates, tert-butanol, naphthalene, amines can be reacted in the presence of a Brönsted acid and optionally an oxidizing agent in a one-pot reaction (Figure 4b). a) Compounds VI and VII can be prepared using a newly developed process via a Na(OCP) ("sodium phosphaethynolate") reaction solution according to the following reaction scheme:

Naphthalene (cat.) Solvent

1 P + 3 Na + 2 tBuOH + 1 Org. Carbonate Na(OCP) reaction solution

+ 2 tBuONa

+ Brönsted acid

+ Brönsted acid

+ Oxidizing agents

Figure 4a: Reaction scheme for the preparation of PCA VI and VII via a Na(OCP) reaction solution.

The synthesis includes the following steps:

(i) starting from elemental phosphorus, elemental sodium, tert-butanol (tBuOH), naphthalene and organic carbonates, a 1,4-dioxane-free, storage-stable Na(OCP) reaction solution is prepared in a solvent (Figure 4a). This contains sodium tert-butoxide (tBuONa) and alcohols as non-interfering co-products. The Na(OCP) reaction solution is strongly basic due to the tBuONa co-product, which promotes storage stability. Several Filtration steps and solvent changes are not necessary. Alternatively, the Na(OCP) reaction solution can be directly processed further without further processing.

An ether is preferably used as the solvent, with ethylene glycol dimethyl ether being particularly preferred. Dioxane is preferably not used as the solvent, which means that the Na(OCP) remains in solution and does not precipitate, unlike previously known methods. The OCP anion content can be quantified during and/or after the reaction using IR spectroscopy.

(ii) In the next step, the Na(OCP) reaction solution is then reacted with a suitable amine (X) _m - R-(NH ₂ ) _n in the presence of a suitable Brönsted acid to give PCA of structure VI. The Brönsted acid is added in excess. Instead of the combination of amine (X) _m -R-(NH ₂ ) _n and Brönsted acid, the corresponding hydrochloride of the amine can also be used.

(iii) When an additional oxidizing agent is used during or after step (ii), PCAs of structure VII are obtained.

b) Alternatively, the PCA can be prepared by the direct reaction of red phosphorus, sodium, organic carbonates, tert-butanol, naphthalene, amines, a Brönsted acid and, if necessary, an oxidizing agent (Figure 4b) in a one-pot reaction (Figure 4b).

1. + 1/n (X) _m R(NH ₂ ) _n

2. + Brönsted acid

3. if necessary + oxidizing agent

1 P + 3 Na + 2 tBuOH + 1 Org. Carbonate > ... > ....

+ Naphthalene *"

Figure 4b: Reaction scheme for the preparation of PCA VI and VII in a one-pot reaction

The amine used for processes a) and b) is selected from the group of compounds consisting of organic amines of the structural formula (X) _m -R-(NH ₂ ) _n , where the substituent R is selected from organyl radicals (optionally substituted by heteroatoms), preferably from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene optionally heteroatom-containing cyclohexylene, phenylene, diphenylene, dimethylphenylene, 2-methylpentamethylene, 2,2,4-trimethylhexamethylene, dodecamethylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 5-(l-methylene-(l,3,3-trimethylcyclohexane)), all regioisomers of methylenebiscyclohexylene, all regioisomers of methylenebisphenylene, methylenebis-(3,3'-dimethylcyclohexane-l,4-diyl), propane-2,2-diyl)bis(cyclohexane-4,l-diyl), propane-2,2-diyl-bis-4,l-phenylene, polyhexamethylene, tolylene, poly(propylene glycol)tolylene, Poly(ethylene adipate)tolylene, 2,4,6-trimethyl-l,3-phenylene, 4-chloro-6-methyl-l,3-phenylene, poly[l,4-phenylene], co-[poly(l,4-butanediol)], poly(tetrafluoroethylene oxide-co-difluoromethylene oxide), l,3-bis(l-methylethyl)benzene, 3,3'-dimethyl-4,4'-biphenylene, naphthalene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,4- or 2,5- or 2,6- tolylene and their isomer mixtures, methylene-4,4'- or 2,4'- or 2,2'- bisphenylene and their isomer mixtures, 4,4'-, 2,4'- or 2,2'- 2,2'-diphenylpropane-p-xylylene and a,a,a',a'-tetramethyl- m- or -p-xylylene; and R is very particularly preferably selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures; and wherein X is selected from -PH ₂ , -PHR', -P(O)H ₂ , -P(O)HR', -P(O)(H)OH, -OH, -NH ₂ , -NHR', - NHC(O)PH ₂ , -NHC(O)PHR', - NHC(O)P(O)H ₂ , -NHC(O)P(O)HR', -NHCOOH, -NHC(O)NH ₂ , - NHC(O)NHR' (with R' = organyl radical optionally substituted by heteroatoms).

The organic carbonate (Figures 4a / 4b: “Org. Carbonate”) is preferably selected from the group of compounds consisting of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, glycerol carbonate and mixtures thereof.

Brönsted acid (Figures 4a / 4b: “Brönsted acid”) is one or more acids, in particular selected from the group consisting of organic carboxylic acids, in particular acetic acid and/or formic acid, dihydrogen carbonate, sodium hydrogen carbonate, phosphoric acid, sodium dihydrogen phosphate,

Hydrochloric acid, sulfuric acid, sodium hydrogen sulfate, ammonium hydrohalides, where the halide is selected from Cl', Br, T, in particular ammonium chloride (NHzi)Cl, triethylammonium chloride (Et3NH)Cl, or corresponding hydrochlorides of the amines (X) _m -R-(NH ₂ ) _n .

The oxidizing agent is an oxygen transfer reagent that is able to convert phosphanylcarboxamides VI to phosphoric acid carboxamides VII. Particularly suitable for this purpose are hydrogen peroxide (H ₂ O ₂ ), oxygen (O ₂ ), ozone (O3), peroxyacetic acid, Peroxysulphuric acid, nitrous oxide (N ₂ O), nitrogen dioxide (NO ₂ ), organic peroxides such as tert-butyl peroxide, peroxybenzoic acid, chloroperoxybenzoic acid, pyridine-N-oxide. Hydrogen peroxide (H ₂ O ₂ ) or oxygen (O ₂ ) is particularly preferred.

The compound PCA can be obtained as a pure substance after processing. Isolation is achieved, for example, by removing all volatile components from the reaction mixture in a vacuum, followed by extraction of the residue if necessary. Alternatively, the residue can be washed with water beforehand.

Isocyanate-terminated compounds VIII, IX and X:

The PCAs can be used to prepare NCO-terminated phosphanylcarboxamides of structures VIII, IX and X (Figure 5), or their equivalent compounds with oxidized phosphorus.

Figure 5 : NCO-terminated phosphanylcarboxamides VIII, IX and X

In the NCO-terminated phosphanylcarboxamides VIII, IX and X, m = 1, 2; n = 2-4; o = 1-3; the substituted R ¹ is an organyl radical (optionally substituted by heteroatoms) and is selected from the group consisting of the substituents hydrogen, methyl, ethyl, butyl, propyl, pentyl, hexyl, heptyl, oxytyl, phenyl, tolyl, cyclohexyl and cyclopentyl, and the substituents R are independently selected organyl radicals (optionally substituted by heteroatoms) and are preferably selected from the group consisting of from the substituents methylene, dimethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, optionally heteroatom-containing cyclohexylene, phenylene, diphenylene, dimethylphenylene, 2-methylpentamethylene, 2,2,4-trimethylhexamethylene, dodecamethylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 5-(l-methylene-(l,3,3-trimethylcyclohexane)), all regioisomers of methylenebiscyclohexylene, all regioisomers of methylenebisphenylene, methylenebis-(3,3'-dimethylcyclohexane-l,4-diyl), Propane-2,2-diyl)bis(cyclohexane-4,l-diyl), propane-2,2-diyl-bis-4,l-phenylene, polyhexamethylene, tolylene, poly(propylene glycol)tolylene, poly(ethylene adipate)tolylene, 2,4,6-trimethyl-l,3-phenylene, 4-chloro-6-methyl-l,3-phenylene, poly [1,4-phenylene], co-[poly (1,4-butanediol)], poly (tetrafluoroethylene oxide-co- difluoromethylene oxide), l,3-bis(l-methylethyl)benzene, 3,3'-dimethyl-4,4'-biphenylene, naphthalene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,4- or 2,5- or 2,6- tolylene and their isomer mixtures, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures, 4,4'-, 2,4'- or 2,2'- 2,2'-diphenylpropane-p-xylylene and a,a,a',a' -tetramethyl- m- or -p-xylylene; and very particularly preferably selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures.

Particularly preferred for further use in the production of polymers are compounds of the structures VIII, IX and/or X with m = 2; n = 1, 2; o = 1, where R ¹ is selected from the group consisting of hydrogen, phenyl and tolyl, and where R is selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures.

The isocyanate-terminated phosphanylcarboxamides of the formulas VIII, IX and X preferably have an average molecular weight determined by gel permeation chromatography of at least 300 g/mol and at most 10,000 g/mol, particularly preferably of at least 300 g/mol and at most 2000 g/mol.

The isocyanate-terminated phosphanylcarboxamides of the formula VIII, IX or X according to the invention are particularly preferably liquid and have a dynamic viscosity at 23°C, determined with a cone-plate viscometer, of at most 30,000 mPa*s, particularly preferably of at most 20,000 mPa*s.

Preparation process of the isocyanate-terminated phosphanylcarboxamides VIII, IX and X:

The phosphanylcarboxamides VI or phosphorus(III) acid carboxamides VII can be reacted with a (molar) excess of at least one di- or polyisocyanate, optionally in the presence of a catalyst, to isocyanate-terminated phosphanylcarboxamides VIII, IX or X and VIII,

IX or X equivalent compounds are reacted with oxidized phosphorus. Preferably, at least 2 times the amount of at least one di- or polyisocyanate compared to the phosphanylcarboxamide or phosphorus(III) acid carboxamide is used. The reaction can be carried out in solvent or solvent-free (e.g. with excess diisocyanate or polyisocyanate as (reactive) diluent). The product is obtained after distilling off the solvent or the excess diisocyanate or polyisocyanate.

For the preparation of isocyanate-terminated phosphanylcarboxamides with the structures VIII, IX or

X preferably uses phosphanylcarboxamides of structure VI, with m = 0-3, n = 1-4, m+n > 2; and wherein the substituent R is selected from organyl radicals (optionally substituted with heteroatoms), preferably from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, optionally heteroatom-containing cyclohexylene, phenylene, diphenylene, dimethylphenylene, 2-methylpentamethylene, 2,2,4-trimethylhexamethylene, dodecamethylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 5-(l-methylene-(l,3,3-trimethylcyclohexane)), all regioisomers of methylenebiscyclohexylene, all regioisomers of methylenebisphenylene, Methylenebis-(3,3'-dimethylcyclohexane-l,4-diyl), propane-2,2-diyl)bis(cyclohexane-4,l-diyl), propane-2,2-diyl-bis-4,l-phenylene, polyhexamethylene, tolylene, poly(propylene glycol)tolylene, poly(ethyleneadipate)tolylene, 2,4,6-trimethyl-l,3-phenylene, 4-chlorine o-6-methyl-l,3-phenylene, poly[l,4-phenylene], co-[poly(l,4-butanediol)],

Poly(tetrafluoroethylene oxide-co-difluoroethylene oxide), 1,3-bis(l-methyl)benzene, 3,3'-dimethyl-4,4'-biphenylene, naphthalene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,4- or 2,5- or 2,6-tolylene and their isomer mixtures, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures, 4,4'-, 2,4'- or 2,2'- 2,2'-diphenylpropane-p-xylylene and a,a,a',a'-tetramethyl- m- or -p-xylylene; and very particularly preferably is selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and isomer mixtures thereof; and wherein X is selected from -PH ₂ , -PHR', -P(O)H ₂ , -P(O)HR', -P(O)(H)OH, -OH, -NH ₂ , -NHR', - NHC(O)PH ₂ , -NHC(O)PHR', - NHC(O)P(O)H ₂ , -NHC(O)P(O)HR', -NHCOOH, -NHC(O)NH ₂ , - NHC(O)NHR' (with R' = organyl radical optionally substituted by heteroatoms). Particularly preferred compounds are those of structure VI where: m = 0, 1, n = 1, 2, m+n = 2;

R is selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures; and

X = OH.

The following polyisocyanates are preferably used for the production of isocyanate-terminated phosphanylcarboxamides VIII, IX and X:

Methylene diphenyl diisocyanate (MDI), tolyl diisocyanate (TDI), naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), pentramethylene diisocyanate (PDI), isophorone diisocyanate (IPDI), methylenedicyclohexyl diisocyanate (H12MDI), as well as their oligomers and derivatives, such as prepolymers.

The molar ratio of isocyanate groups to isocyanate-reactive groups of the compounds having the structures VI or VII in the reaction mixture for preparing the isocyanate-terminated phosphanylcarboxamides VIII, IX or X is > 1 and is preferably at least 2:1 and at most 40:1, particularly preferably at least 2:1 and at most 10:1.

After reaction, the excess isocyanate can either remain in the product mixture as a reactive diluent or be distilled off.

The isocyanate-terminated phosphanylcarboxamides VIII, IX and X prepared in this way have in particular an average molecular weight determined by gel permeation chromatography of at least 300 g/mol and at most 10,000 g/mol, particularly preferably of at least 300 g/mol and at most 2000 g/mol. They are very particularly preferably liquid and have a dynamic viscosity determined with a cone-plate viscometer of at most 30,000 mPa*s, particularly preferably of at most 20,000 mPa*s at 23 °C.

For the production of the isocyanate-terminated phosphanylcarboxamides VIII, IX and X, nitriles such as acetonitrile, propionitrile and ethers such as tetrahydrofuran, diethyl ether and dioxane are preferably used as solvents. The same polyisocyanates such as methylenediphenyl diisocyanate (MDI), tolyl diisocyanate (TDI), naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), pentramethylene diisocyanate (PDI), isophorone diisocyanate (IPDI), methylenedicyclohexyl diisocyanate (H12MDI) and their oligomers and prepolymers with which the phosphanylcarboxamide VI is reacted are particularly suitable as reactive diluents. Lewis bases, such as amine bases, in particular tertiary amines, particularly preferably triethylamine, are preferably used as catalysts. Alternatively, the reaction can also be carried out without a catalyst.

For the preparation of the compounds with oxidized phosphorus equivalent to VIII, IX or X, the PCAs of structures VII are used accordingly.

Production of polymers

The di- and multifunctional PCAs with structures VI and VII as well as the isocyanate-terminated compounds VIII, IX and X can be used as monomers and prepolymers for the production of new phosphorus-containing polymers, in particular for the production of phosphorus-containing polyurethanes and polyisocyanurates.

To produce PUR/PIR from the isocyanate-reactive compounds VI or VII, these are reacted with polyisocyanates.

The isocyanate-terminated compounds VIII, IX and X and their equivalents with oxidized phosphorus and their mixtures with polyisocyanates as reactive diluents can also be converted to PUR/PIR with corresponding isocyanate-reactive compounds, e.g. polyols.

The reactions can be carried out in the presence or absence of a suitable catalyst, with or without an additional solvent.

To produce the phosphorus-containing polyurethanes or polyisocyanurates, preference is given to using isocyanate-reactive phosphanylcarboxamides VI or phosphorus(III) acid carboxamides VII with m = 0-3, n = 1-4, m+n > 2, where the substituent R is selected from organyl radicals (optionally substituted with heteroatoms), preferably from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, optionally heteroatom-containing cyclohexylene, phenylene, diphenylene, dimethylphenylene, 2-methylpentamethylene, 2,2,4-trimethylhexamethylene, dodecamethylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 5-(l-methylene-(l,3,3-trimethylcyclohexane)), all regioisomers of methylenebiscyclohexylene, all regioisomers of methylenebisphenylene, methylenebis-(3,3'-dimethylcyclohexane-l,4-diyl), propane-2,2-diyl)bis(cyclohexane-4,l-diyl), propane-2,2-diyl-bis-4,l- phenylene, polyhexamethylene, tolylene, poly(propylene glycol)tolylene, poly(ethylene adipate)tolylene, 2,4,6-trimethyl-l,3-phenylene, 4-chloro-6-methyl-l,3-phenylene, Poly [1,4-phenylene], co-[poly(l,4-butanediol)], poly(tetrafluoroethylene oxide-co-difluoromethylene oxide), l,3-bis(l-methylethyl)benzene, 3,3'-dimethyl-4,4'-biphenylene, naphthalene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,4- or 2,5- or 2,6-tolylene and their isomer mixtures, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures, 4,4'-, 2,4'- or 2,2'- 2,2'-diphenylpropane-p-xylylene and a,a,a',a' -tetramethyl- m- or -p-xylylene; and wherein X is selected from -PH ₂ , -PHR', -P(O)H ₂ , -P(O)HR', -P(O)(H)OH, -OH, -NH ₂ , -NHR', - NHC(O)PH ₂ , -NHC(O)PHR', - NHC(O)P(O)H ₂ , -NHC(O)P(O)HR', -NHCOOH, -NHC(O)NH ₂ , - NHC(O)NHR' (with R' = organyl radical optionally substituted by heteroatoms).

Particularly preferred compounds are those of structure VI or VII, characterized in that m = 0, 1, n = 1, 2, m+n = 2;

R is selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures and

X = OH.

To produce PUR/PIR, the PCAs are reacted with polyisocyanates, i.e. isocyanates with an NCO functionality of > 2, alone or with other isocyanate-reactive reactants and, if necessary, other formulation components commonly used in polyurethane chemistry. Examples of such suitable polyisocyanates are 1,4-butylene diisocyanate,

1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4- and/or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis(4,4'-isocyanatocyclohexyl)methanes or their mixtures with any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and/or 2,6-toluene diisocyanate (TDI),

1,5-naphthylene diisocyanate, 2,2'- and/or 2,4'- and/or 4,4'-diphenylmethane diisocyanate (MDI) and/or higher homologues, 1,3- and/or l,4-bis-(2-isocyanato-prop-2-yl)-benzene (TMXDI), 1,3-bis-(isocyanatomethyl)benzene (XDI), and alkyl-2,6-diisocyanatohexanoates (lysine diisocyanates) with C1 to C6 alkyl groups. In a preferred embodiment, mixtures of the isomers of diphenylmethane diisocyanate (“monomeric MDI”, abbreviated “mMDI”) and its oligomers (“oligomeric MDI”) are used. Mixtures of monomeric MDI and oligomeric MDI are generally referred to as “polymeric MDI” (pMDI). The oligomers of MDI are higher-nuclear polyphenyl-polymethylene polyisocyanates, ie mixtures of the higher-nuclear homologues of diphenyl-methylene diisocyanate, which have an NCO functionality f > 2 and can be described by the following molecular formula: CisHioWD^CsHsNOJn , where n = integer > 0, preferably n = 1, 2, 3 and 4. Higher-nucleus homologues Ci5Hi ₀ N ₂ O2[C ₈ H5NO]m, m = integer > 4) can also be present in the mixture of organic polyisocyanates. Further preferred polyisocyanate component A) are mixtures of mMDI and/or pMDI with a maximum of up to 20% by weight, more preferably a maximum of 10% by weight, of other aliphatic, cycloaliphatic and in particular aromatic polyisocyanates known for the production of polyurethanes, very particularly TDI.

In a further embodiment, the phosphorus-containing polyurethanes (PUR) / polyisocyanurates (PIR) are prepared by reacting the isocyanate-terminated compounds of structures VIII, IX and / or X or their equivalents with oxidized phosphorus with m = 1, 2; n = 1-4; o = 1-3 and

R is selected from organyl radicals (optionally substituted by heteroatoms), preferably selected from the group consisting of ethyl, butyl, propyl, pentyl, hexyl, isosorbide, methylenediphenyl, tolyl, aromatic radicals based on lignin, such as dimethoxyphenyl, organyl radicals based on furan and very particularly preferably selected from the group consisting of propyl, butyl and pentyl, hexyl, methylenediphenyl, tolyl, used to completely or partially replace the commonly used isocyanate component in PUR/PIR reaction mixtures.

Particularly preferred compounds are VIII, IX or X with m = 2; n = 1, 2; n = 1 and where R is selected from the group consisting of propyl, butyl and pentyl, hexyl, methylenediphenyl, tolyl, for the production of PUR/PIR.

The new polymers have intrinsic flame retardancy due to the built-in phosphorus and are therefore particularly suitable for applications where good and permanent flame resistance is important, e.g. PUR/PIR rigid foam applications in the construction industry.

The PCA compounds and the polymers produced from them can also be used as additives for polymers, in particular as flame retardant additives. Compounds with decomposition temperatures of > 150 °C are particularly suitable for this purpose, especially > 155 °C and < 250 °C. Examples

Raw materials:

Red phosphorus (99%, amorphous powder), sodium (99%, rods in paraffin oil), ethylene carbonate (99%), diethyl carbonate (99%), tert-butanol (99.5%), triethylammonium hydrochloride (99+%), hexamethylene diisocyanate (HDI) (99%), 6-aminohexanol (98%), 1,6-

Diaminohexane dihydrochloride (99%), 5-aminopentanol (92%), 1,5-diaminopentane (99%), 1,4-diaminobutane dihydrochloride (99+%), 1,3-diaminopropane (99%), ethanolamine hydrochloride (99+%), diethylamine (99.5%), 4,4'-diaminodiphenylmethane (97%), meta-chloroperbenzoic acid (m-CPBA, 77+%), 1,4-diazabicyclo[2.2.2]octane (DABCO, 99+%), 1,4-butanediol (99%) and hydrogen peroxide (aqueous solution, 30%) were used without further purification. Naphthalene (99%) was sublimed before use. 1,6-Diaminohexane dihydrochloride was synthesized according to literature procedures (Neumann, L; Bomschein, C.; Jiao, H.; Junge, K.; Beller, M. Hydrogenation of Aliphatic and Aromatic Nitriles Using a Defined Ruthenium PNP Pincer Catalyst. European J. Org. Chem. 2015, 2015 (27), 5944-5948 (https://doi.org/10.1002/ejoc.201501007); Armarego, W. L. F.; Perrin, D. D. Purification of Laboratory Chemicals Eighth Edition', 2017). 6-Aminohexanol hydrochloride,

5-aminopentanol hydrochloride, 1,5-diaminopentane dihydrochloride, 1,3-

Diaminopropane dihydrochloride, ethylenediamine dihydrochloride and 4,4 -

Diaminophenylmethane dihydrochloride was prepared analogously by reacting the corresponding amino alcohols or amines with ethereal or aqueous HCl solution in suitable solvents. The solvents 1,2-dimethoxyethane (DME), tetrahydrofuran (THF), 1,4-dioxane, diethyl ether (Et20), dichloromethane (CH2CI2) and acetonitrile ( _CH3CN ) were distilled before use and stored under protective gas over molecular sieves (3 Ä: CH3CN, 4 Ä: DME, THF, 1,4-dioxane, Et20, CH2Q2). NaOCP(l,4-dioxane) _x (X = 2 - 3) was prepared according to a literature procedure (Heift, D.; Benko, Z.; Grützmacher, H. Coulomb Repulsion versus Cycloaddition: Formation of Anionic Four-Membered Rings from Sodium Phosphaethynolate, Na(OCP). Dalt. Trans. 2014, 43 (2), 831-840. https://doi.org/10.1039/C3DT52359D). The dioxane content of the individual batches was determined by NMR methods and elemental analysis. Sodium sand was prepared by melting bare sodium pieces in xylene under protective gas and finely dispersing them with a KPG stirrer.

Measurement methods:

Nuclear magnetic resonance experiments were performed on the A VANCE III HD Nanobay 400 MHz Ultrashield device from Broker. Infrared (IR) spectra were recorded at room temperature with a Broker Vertex 70 spectrometer with RAM II module (d-YAG laser, 1064 nm). Elemental analyses were carried out using a Vario MICRO cube elemental analyzer (Elementar Analysatorsysteme GmbH) in CHNS mode. TGA measurements were carried out using a TG 50 from Mettler Toledo in ceramic crucibles. Viscosity measurements: The dynamic viscosities were determined using an MCR 501 rehometer (Anton Paar) at 23 °C in accordance with DIN EN ISO 3219:1994-10. Measurements at different shear rates ensured that Newtonian flow behavior can be assumed. Information on the shear rate can therefore be omitted.

Preparation of phosphanylcarboxamides (PCA) (VI, VII)

Method 1: Starting from the salts of amines and amino alcohols and NaOCP(l,4-dioxane) ₂ .4

The starting material diamine dihydrochloride (1 eq.) or amino alcohol hydrochloride (2 eq.) (see Table 1) and Na(OCP)(dioxane) ₂ ,4 (2.1 eq.) were suspended in acetonitrile (CH ₃ CN) and stirred overnight at RT. Depending on the diamine dihydrochloride or amino alcohol hydrochloride used, the mixture was worked up accordingly:

Example 1 - 4: The resulting beige suspension was filtered and the filter residue was washed with CH ₃ CN or warm CH ₃ CN. The product crystallized from the concentrated filtrate at reduced temperature (eg -30 °C) or by adding suitable solvents such as diethyl ether (Et ₂ O). The product was obtained as a solid after single or multiple recrystallization, filtration and drying in vacuo.

Example 5a, Example 8: The resulting beige suspension was filtered and the product was obtained as a white solid by Soxhlet extraction of the filter residue with CH ₂ C1 ₂ and subsequent drying in vacuo.

Example 7: The resulting beige suspension was filtered, the filter residue was washed with CH ₃ CN and the filtrate was dried in vacuo to obtain the product as a yellow oil.

The respective starting materials for the PCAs, the structures, melting points and ³¹ P NMR signals of the corresponding products are given in Table 1.

Method 2: Starting from the salts of amines and amino alcohols and with a dioxane-free NaOCP reaction solution a) Preparation and quantification of a NaOCP reaction solution

Red phosphorus (3 g, 97 mmol, 1 eq.), naphthalene (620 mg, 5 mmol, 0.05 eq.) and sodium sand (6.68 g, 291 mmol, 3 eq.) were suspended in 420 mL DME and stirred with a KPG stirrer for 4 h at RT. The resulting black suspension was cooled to 0 °C and 30 °C warm water was added. Cert-butanol (18.53 mL, 194 mmol, 2 eq.) was slowly added. The gray suspension was stirred for a further hour at RT, cooled to 0 °C and then a solution of ethylene carbonate (8.53 g, 97 mmol, 1 eq.) in 90 mL DME was added dropwise over an hour. The green-yellow suspension was stirred overnight at RT, then filtered through a Schlenk frit and the green filter residue was washed with DME (3 x 30 mL) to obtain a clear, yellow NaOCP solution. The NaOCP content of this solution was determined using a calibration line using IR spectroscopy. The NaOCP solution is stable for at least 6 weeks when cooled and stored under protective gas and can be used for the preparation of the PC As without further treatment. b) Creation of the calibration grades for the quantification of the NaOCP content of the NaOCP reaction solution

To create the calibration curves, a NaOCP standard solution was prepared in DME/CH ₃ CN (70/30) (purity and dioxane content of the NaOCP(l,4-dioxane)22 ₃ used were determined by NMR spectroscopy and elemental analysis). The absorbance of the CO stretching vibration of the NaOCP (1760 cm ¹ ) was determined in a thin-layer liquid cuvette by a transmission measurement. The method was validated by a standard addition method. For further samples, an aliquot of the reaction solution was taken, diluted and measured in the same way.

Example 5b: Preparation of PCA-5 starting from the NaOCP reaction solution using the example of the synthesis of N,N’-(hexane-l,6-diyl)bis(phosphanylcarboxamide)

To the NaOCP reaction solution (0.105 M, 80 mL, 8.34 mmol, 2 eq.) from a) at room temperature, first 1,6-diaminohexane dihydrochloride (0.78 g, 4.17 mmol, 1 eq.) and then triethylammonium hydrochloride (2.02 g, 7.30 mmol, 1.75 eq.) were rapidly added with vigorous stirring. The initially yellow suspension turned light brown when stirred overnight. The suspension was filtered, the pale brown filter residue was washed with CH ₃ CN (3 x 5 mL) and dried in vacuo. The product was obtained as a colorless solid by Soxhlet extraction of the filter residue with CH2Q2 and subsequent drying in vacuo.

Method 3: Preparation without filtration of the NaOCP reaction solution (one-pot reaction)

Example 8b: Preparation of PCA-8 starting from the NaOCP reaction solution using the example of the synthesis of (N-(6-hydroxyhexyl)phosphinocarboxamide)

Red phosphorus (0.5 g, 16 mmol, 1 eq.), naphthalene (103 mg, 1 mmol, 0.05 eq.) and sodium sand (1.14 g, 48 mmol, 3 eq.) were suspended in 200 mL DME and stirred for 12 h at RT. The resulting black suspension was cooled to 0 °C and warm tert-butanol (3.1 mL g, 32 mmol, 2 eq.) was slowly added. The grey suspension was stirred for one hour at RT, to 0 °C and a solution of ethylene carbonate (1.421 g, 16 mmol, 1 eq.) in 10 mL DME was added dropwise over 1 hour. The green-yellow suspension was stirred overnight at RT. To the NaOCP suspension (0.038 M, 215 mL, 8.3 mmol, 1.04 eq.) at RT, first 6-aminohexanol (0.96 mL, 8 mmol, 1 eq.) and then triethylammonium hydrochloride (6.7 g, 48 mmol, 6 eq.) were quickly added. The suspension turned light brown when stirred overnight. The suspension was filtered and the pale brown filter residue was washed with CH ₃ CN (3 x 5 mL). The product was precipitated from the filtrate at -30 °C as a colorless solid.

Example 5c: Preparation of PCA-5 in one step using the example of the synthesis of N,N’-(hexane-l,6-diyl)bis(phosphanylcarboxamide) (work-up by Soxhle extraction)

Red phosphorus (250 mg, 8 mmol, 1 eq.), naphthalene (52 mg, 0.4 mmol, 0.05 eq.) and sodium sand (557 mg, 24 mmol, 3 eq.) were suspended in 15 mL DME and stirred vigorously for 16 h at RT. The resulting black suspension was cooled to 0 °C and a solution of tert-butanol (1.55 mL, 16 mmol, 2 eq.) and diethyl carbonate (0.98 mL, 8 mmol, 1 eq.) in 15 mL DME was added dropwise. The green-yellow suspension was stirred for 16 h at RT. The NaOCP content of the supernatant yellow solution was determined by IR spectroscopy using a calibration curve. The required amounts of 1,6-diaminohexanedihydrochloride and triethylammonium hydrochloride were determined according to the NaOCP concentration. First 1,6-diaminohexanedihydrochloride (565 mg, 2.98 mmol, 0.37 eq.) and then triethylammonium hydrochloride (2.51 g, 18.25 mmol, 2.26 eq.) were rapidly added to the suspension with vigorous stirring. The suspension quickly turns black upon addition of triethylammonium hydrochloride and changes color to brown-orange a few seconds after the end of the addition. The suspension was stirred overnight at RT and then dried in vacuo to obtain a brown solid. The product was obtained as a pale yellow solid by Soxhlet extraction with CH2Q2 and subsequent drying in vacuo.

Example 5d: Preparation of PCA-5 in one step using the example of the synthesis of N,N '-(hexane-l,6-diyl)bis(phosphinocarboxamide)

Red phosphorus (7.03 g, 0.23 mol, 1 eq.), naphthalene (1.45 g, 0.4 mmol, 0.05 eq.) and sodium (15.7 g, 0.68 mol, 3 eq.) were suspended in 120 mL DME and stirred vigorously for 16 h at RT. The resulting black suspension was cooled to 0 °C and a solution of tert-butanol (43.43 mL, 0.46 mol, 2 eq.) and diethyl carbonate (27.5 mL, 0.23 mol, 1 eq.) in 120 mL DME was added dropwise. The green-yellow suspension was stirred for 16 h at RT. The NaOCP content of the supernatant yellow solution was determined by IR spectroscopy using a calibration curve. The required amounts of 1,6-diaminohexane dihydrochloride and triethylammonium hydrochloride were determined according to the NaOCP concentration. To NaOCP suspension (0.538 M, 310 mL, 0.167 mol, 0.74 eq.) was added first 1,6-diaminohexanedihydrochloride (15.8 g, 0.084 mol, 0.37 eq.) and then triethylammonium hydrochloride (70.7 g, 0.51 mmol, 2.26 eq.) with vigorous stirring. The suspension rapidly turns black upon addition of triethylammonium hydrochloride and changes color to brown-orange a few seconds after the end of the addition. The suspension was stirred overnight at RT and then dried in vacuo to obtain a brown solid. The dried suspension was washed with water and extracted by Soxhlet extraction with CH2Q2 to obtain the product PCA-5.

Table 1: Compounds prepared PCA (structure VI)

Method for the preparation of bis(phosphoric acid carboxamides) (VII)

Bis(phosphinocarboxamide) (1 eq.) or hydroxy-R-phosphinocarboxamide (2 eq.) was dissolved or suspended in CEbCh (only for meta-chloroperbenzoic acid (m-CPBA)), CH3CN or water and an oxidizing agent such as m-CPBA or aqueous hydrogen peroxide solution (H2O2; 2 or 4 eq.) was added. The product was obtained as a colorless oil by filtration of the colorless precipitate (when using m-CPBA) and removal of the solvent and water in vacuo.

Preparation of N,N'-(hexane-l,6-diyl)bis(phosphoric acid carboxamide (PCA-9)

Example 9a: By oxidation of PCA-5 with meta-chloroperbenzoic acid (m-CPBA):

To a suspension of PCA-5 (100 mg, 0.42 mmol, 1 eq.) in CH2Q2 (5 mL) was added meta-chloroperbenzoic acid (m-CPBA; 146 mg, 0.84 mmol, 2 eq.). The white suspension was stirred for 12 h at RT. The reaction solution was filtered and the filtrate was dried in vacuo to afford the product as a colorless oil.

Example 9b: By oxidation of PCA-5 with aqueous H2O2 solution:

An aqueous solution of H2O2 (0.4 mL, 4.31 M, 1.68 mmol, 4 eq.) was added dropwise to a suspension of PCA-5 (100 mg, 0.42 mmol, 1 eq.) in deionized water (5 mL) with stirring. The pH of the reaction mixture was kept between pH 8 and pH 10 by the addition of NEt;. The suspension was stirred for 12 h at RT and the excess H2O2 was quenched by the addition of manganese(IV) oxide. The clear reaction solution was filtered and the filtrate was dried in vacuo at 60°C to obtain the product as a colorless oil.

Example 10: Preparation of (N-(6-hydroxyhexyl)phosphoric acid carboxamide (PCA-10) by oxidation of PCA-8 with aqueous H2O2 solution:

An aqueous solution of H2O2 (106 pL, 4.31 M, 0.46 mmol, 2 eq.) was added dropwise to a solution of PCA-8 (40.5 mg, 0.23 mmol, 1 eq.) in deionized water (4 mL) with stirring. The reaction mixture was stirred for 12 h at RT. The excess of H2O2 was quenched by the addition of manganese(IV) oxide and the reaction solution was filtered. The product was obtained from the filtrate after drying in vacuo at 60 °C as a colorless oil.

Preparation of isocyanate-terminated bis(phosphanylcarboxamides) and hydroxyphosphanylcarboxamides (IX, X)

Example 11: Isocyanate-terminated NCO-PCA-5 (structure IX) :

A suspension of PCA-5 (12.36 g, 0.05 mol, 1 eq.) and NEts (0.3 mL) in 400 mL CH3CN was very slowly added dropwise into an excess of hexamethylene diisocyanate (HDI) (528.2 g, 503 mL, 3.08 mol, 60 eq.) under vigorous stirring with a KPG stirrer. The colorless Suspension was stirred for 16 h at RT and filtered to remove a very small amount (<20 mg) of solid. Solvent and excess HDI were removed from the filtrate by distillation. The product was obtained as a liquid. NCO number: 18.6%, viscosity: 3600 mPas; refractive index (nD20): 1.5299; ³¹ P NMR (CD ₃ CN, 300K, in ppm): 5 = - 46.6.

Example 12: Isocyanate-terminated NCO-PCA-8 (structure X):

A solution of PCA-8 (12.85 g, 0.07 mol, 1 eq.) and NEt ₃ (0.3 mL) in 200 mL CH ₃ CN was very slowly added dropwise into an excess of HDI (365.9 g, 348.6 mL, 2.18 mol, 30 eq.) with vigorous stirring using a KPG stirrer. The colorless, clear solution was stirred for 16 h. The solvent and the excess HDI were removed by distillation. The product was obtained as a liquid. NCO number: 17.3%, viscosity: 2350 mPas; refractive index (nD20): 1.5113; ³¹ P NMR (CD ₃ CN, 300K, in ppm): 5 = - 45.8.

Example 13: Use of NCO-PCAs to produce polyurethane thermosets

A formulation consisting of 1,4-butanediol (2 mL), NCO-PCA-8 (0.3 mL) and water (0.02 mL) was heated to 70 °C and then catalytic amounts of DABCO (1,4-diazabicyclo[2.2.2]octane) were added. The reaction mixture hardened to a white polyurethane-containing solid. The formation of urethane bonds was demonstrated using IR spectroscopy.

T GA analyses (decomposition temperatures)

T GA analyses were carried out under protective gas. The decomposition temperatures of PCA-5 and PCA-8 are approximately 160 °C, which is lower than those of NCO-PCA-5 (T _d = 180 °C) and NCO-PCA-8 (190 °C). HDI was measured for comparison and has a decomposition temperature of 180 °C.

Table 2: Decomposition temperatures (T _d ) of selected PCAs and NCO-PCAs

Td given at 5% mass loss (± 5%)

Flame retardant tests

The tests were carried out in accordance with DIN EN ISO 15025 (vertical flame test).

Cotton Lawn Rubbing Fabric (BS EN ISO 105-109) test strips in 20 cm x 8 cm strips were prepared. For impregnation, the cotton strips were dipped in CH ₃ CN solutions of the samples. The cotton samples were dried at 60 °C for 1 h before and after impregnation and conditioned in atmosphere for 24 h. Samples and loadings are summarized in Table 3. Blank samples were treated with pure CH ₃ CN. For the other samples, solutions of HDI (approx. 4.00 g), NCO-PCA-8 (approx. 4.00 g) and NCO-PCA-5 (approx. 2.00 g) in 30 - 50 mL CH ₃ CN were used. HDI apparently evaporated completely during the treatment of the samples. Table 3 shows the mass fraction of phosphorus as well as the masses of selected samples before and after combustion.

Table 3: Overview of samples.

* Mass of the impregnated and dried sample.

** Fraction of the mass of P to the total mass of the sample.

The samples were exposed to flames for 10 seconds in accordance with the DIN standard. The HDI and blank samples ignited quickly and burned completely within about 30 seconds. As soon as the flame had consumed the entire surface of the sample and reduced in size again, the shrunken remains glowed for about 15 seconds. Small amounts of very light gray ash flakes remained from the samples, which could not be collected.

The samples impregnated with NCO-PCA-5 and NCO-PCA-8 also ignited quickly and the flames spread over the entire surface within about 20 seconds. However, the samples did not burn completely. The flames extinguished very quickly and without afterglow, leaving the blackened samples in a recognizable (rectangular) shape. The residual mass of the charred samples was on average 30 mg.

Production of translucent foams

Components used:

Trimerization catalysts: Desmorapid® 30HB14 (36 wt.% potassium formate, 64 wt.% ethylene glycol)

Catalyst: Dimethyltin neodecanoate (Formrez UL-28)

Polyols/ alcohols used A): Ethylene glycol Foam stabilizers (polyether-polydimethylsiloxane copolymers): Tegostab® B8490

Iso- and polyisocyanates B used): Desmodur® N3600 (polyisocyanate containing isocyanurate groups based on 1,6-diisocyanatohexane (HDI) with an NCO content of 23.2% by weight, an average NCO functionality of 3.2 (according to GPC), a monomeric HDI content of maximum 0.2% by weight and a viscosity of 1200 mPas (23 °C)), Bayhydur® 3100 (hydrophilic polyisocyanate containing isocyanurate groups based on 1,6-diisocyanatohexane (HDI) with an NCO content of 17.4% by weight, an average NCO functionality of 3.2 (according to GPC), a monomeric HDI content of maximum 0.1% by weight and a viscosity of 2800 mPa*s (23 °C)), NCO-PCA-5 (viscosity of 3600 mPa*s (23 °C))

Example 14: Translucent foam containing NCO-PCA-5

An isocyanate-reactive composition of 0.18 g ethylene glycol, 0.22 g water, 0.18 g foam stabilizer Tegostab B8490 and 0.38 g catalyst Desmorapid® 30HB14 as well as 0.13 g Formrez UL-28 was mixed with an isocyanate mixture of 10.76 g Desmodur® ultra N3600, 2.39 g Bayhydur® 3100 and 10.76 g NCO-PCA-5 for 15 seconds with a speed mixer at 3540 rpm until virtually bubble-free and carefully poured into a mold. The mold was then placed in an oven at 74°C. The foam had set after 240 seconds. The foam was then annealed in the oven at 74° for a further 120 minutes.

The cell size was approximately 1 to 3 mm.

Example 15 (comparative example): Translucent foam without NCO-PCA-5

An isocyanate-reactive composition of 0.34 g ethylene glycol, 0.22 g water, 0.18 g foam stabilizer Tegostab B8490 and 0.38 g catalyst Desmorapid® 30HB14 as well as 0.13 g Formrez UL-28 was mixed with an isocyanate mixture of 21.38 g Desmodur® ultra N3600 and 2.38 g Bayhydur® 3100 for 15 seconds with a speed mixer at 3540 rpm until virtually bubble-free and carefully poured into a mold. The mold was then placed in an oven at 73°C. The foam had set after 540 seconds. The foam was then annealed in the oven at 74° for a further 120 minutes.

The cell size was approximately 1 to 3 mm.

Fire test / Determination of heat release according to ISO 5660-1

The heat release rate of the product to be tested is determined in the “Cone Calorimeter” test device according to ISO 5660-1. Table 3: Fire test results

Heat flux: Irradiance with which the respective sample was irradiated

HRR (Heat Release Rate): Heat release HRRpeat: Maximum heat release

HRR _a vera _g e: medium heat release

THR (Total Heat Release): Total heat release

The data show that the NCO-PCA-5, which is active as a flame retardant in Example 1, is not active at the beginning of the experiment: The time until self-ignition is the same, the heat of the first flare-up is even slightly more intense than in the comparison example without NCO-PCA-5. But then The NCO-PCA-5 in Example 1, which is active as a flame retardant, self-extinguishes surprisingly quickly. This does not occur through improved carbonization (the mass loss is comparable), but rather through very effective interruption of the oxidation reactions in the flame. This corresponds to the lower effective heat release. The NCO-PCA-5 in Example 1, which is active as a flame retardant, thus improves the overall heat release, which is one of the important criteria for the approval of materials in the construction industry.

Claims

Expectations 1. Organic phosphorus compounds PCA, characterized in that they have one of the isocyanate-reactive group-containing structures VI or VII where X is an NCO-reactive group, m = 0, 1, 2 or 3, n = 1, 2, 3 or 4 and m+n > 2 and R is an organyl radical (optionally substituted with heteroatoms), with the proviso that compounds with the structure III and R = ethylene or R = 1,2-cyclohexylene are excluded. 2. Organic phosphorus compounds according to claim 1, characterized in that the isocyanate-reactive groups of the PCA compounds are at least two groups selected from the group consisting of -PH ₂ , -PHR, -P(O)H ₂ , -P(O)HR, -P(O)(H)OH, -P(OH)H, -P(OH)R (where R = organyl radical optionally substituted by heteroatoms), -OH, -NH ₂ , -NHR' (where R' = organyl radical optionally substituted by heteroatoms, excluding para-substituted aniline radical), - SH and oxirane. 3. Organic phosphorus compounds according to claim 1 or 2, characterized in that m = 0 or 1 and n = 1 or 2, where in each case m+n = 2, and R is selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures, and X = OH. 4. Process for the preparation of organic phosphorus compounds according to claims 1 to 3, characterized in that red phosphorus, sodium, organic carbonates, tert-butanol, amines are reacted with one another in the presence of a Bronsted acid and optionally an oxidizing agent in a one-pot reaction. 5. Process for the preparation of organic phosphorus compounds PCA which have one of the structures VI or VII where X is an NCO-reactive group, m = 0, 1, 2 or 3, n = 1, 2, 3 or 4 and m+n > 2 and R is an organyl radical (optionally substituted with heteroatoms), comprising the steps (i) starting from elemental phosphorus, elemental sodium, tert-butanol (tBuOH), naphthalene and organic carbonates in a solvent, preparation of a 1,4-dioxane-free, storage-stable Na(OCP) reaction solution, and (ii) this is reacted in a further step with an amine or the hydrochloride of an amine in the presence of a suitable Brönsted acid, and (iii) optionally oxidation with an oxidizing agent. 6. The method according to claim 5 comprising in or after step (i) quantifying the OCP anion content in the Na(OCP) solution by means of IR spectroscopy. 7. Process for the preparation of isocyanate-terminated compounds by reacting an organic phosphorus compound according to one of claims 1 to 3 with a molar Excess of at least one di- or polyisocyanate, which after reaction can either remain in the product mixture as a reactive diluent or be distilled off. 8. Isocyanate-terminated compounds obtainable by a process according to claim 7. 9. Isocyanate-terminated compounds having one of the structures VIII, IX, X: with m = 1, 2; n = 2-4; o = 1-3; R ¹ = an organyl radical (optionally substituted by a heteroatom), and preferably selected from the group consisting of the substituents hydrogen, methyl, ethyl, butyl, propyl, pentyl, hexyl, heptyl, oxytyl, phenyl, tolyl, cyclohexyl and cyclopentyl; and R = independently selected organyl radicals (optionally substituted with heteroatoms), and are preferably selected from the group consisting of the substituents methylene, dimethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, optionally heteroatom-containing cyclohexylene, phenylene, diphenylene, dimethylphenylene, 2-methylpentamethylene, 2,2,4-trimethylhexamethylene, dodecamethylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 5-(l-methylene-(l,3,3-trimethylcyclohexane)), all regioisomers of methylenebiscyclohexylene, all regioisomers of methylenebisphenylene, Methylenebis-(3,3'-dimethylcyclohexane-l,4-diyl), propane-2,2-diyl)bis(cyclohexane-4,l-diyl), propane-2,2-diyl-bis-4,l-phenylene, polyhexamethylene, tolylene, poly(propylene glycol)tolylene, Poly(ethylene adipate)tolylene, 2,4,6-trimethyl-l,3-phenylene, 4-chloro-6-methyl-l,3-phenylene, poly[l,4-phenylene], co-[poly(l,4-butanediol)], poly(tetrafluoroethylene oxide-co-difluoromethylene oxide), 1,3-bis(l-methyl)benzene, 3,3'-dimethyl-4,4'-biphenylene, naphthalene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,4- or 2,5- or 2,6- tolylene and their isomer mixtures, methylene-4,4'- or 2,4'- or 2,2'- bisphenylene and their isomer mixtures, 4,4'-, 2,4'- or 2,2'- 2,2'-diphenylpropane-p-xylylene and a,a,a',a'-tetramethyl- m- or -p-xylylene; R is very particularly preferably selected from the group consisting of trimethylene, tetramethylene, pentamethylene, hexamethylene, methylene-4,4'- or 2,4'- or 2,2'-bisphenylene and their isomer mixtures, or one of the structures of the compounds equivalent to VIII, IX or X with oxidized phosphorus. 10. Use of phosphanylcarboxamides and phosphorus(III) acid carboxamides according to one of claims 1 to 3 as monomer for the preparation of polymers, in particular for polymers having a phosphorus content >1%. 11. Process for the preparation of polymers, preferably polyurethane (PUR) or polyurethane/polyisocyanurate (PUR/PIR), particularly preferably PUR/PIR rigid foam, by reacting isocyanate-terminated compounds according to one of claims 8 and 9 with isocyanate-reactive compounds, e.g. polyols. 12. Process according to claim 11, characterized in that the reaction is carried out in the presence of di- and/or polyisocyanates. 13. Polymers obtainable using phosphanylcarboxamides and phosphorus(III) acid carboxamides according to one of claims 1 - 4 and/or isocyanate-terminated compounds according to claim 8 or 9. 14. Polymer according to claim 12, characterized in that it is a polyurethane (PUR) or a polyurethane/polyisocyanurate (PUR/PIR), in particular a PUR/PIR rigid foam. 15. Use of a compound according to one of claims 1 to 4, 8 and 9 and/or a polymer according to one of claims 13 - 14 as a flame retardant additive.