EP4337709A1 - Alkoxylates of methylol-organyl-phosphine oxides, process for manufacture thereof, flame-retardant polymers and use thereof - Google Patents

Abstract

Disclosed are mixtures comprising at least two phosphine oxides of formula (I) wherein R1 is a monovalent organic group, R2, R3, R4 and R5 independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms, n and m independently of one another are integers between 0 and 10. These phosphine oxides can be used to manufacture flame-retardant polymers.

Description

1

Alkoxylates of methylol-organyl-phosphine oxides, process for manufacture thereof, flame-retardant polymers and use thereof

The present invention relates to alkoxylates of methylol-organyl-phosphine oxides, to a process for the preparation thereof and to their use in the manufacture of flame-retardant polymers.

The flame retardancy of polymers and polymer foams can be achieved by addition of various substances. A majority of these substances are halogenated, especially brominated organic compounds. However, the regulatory pressure on these materials is growing every year due to toxicological and ecotoxicological effects. Therefore, there is an urgent need to find alternative non-halogenated flame retardants for polymers.

Among these non-halogenated flame retardants phosphorus-based flame retardants are one of the most efficient species in terms of flame retardation.

These phosphorus-based compounds can be further differentiated by their oxidation state.

Industrially available flame retardants may be phosphates, phosphonates or phosphinates, which all contain phosphorus-oxygen-carbon bonds, i.e. ester linkages. These ester linkages are all - to a certain degree - prone to hydrolysis, thus leading either to detrimental effects during processing of the polymers, such as foam production (as hydrolytically formed acid deactivates catalysts, the latter being essential for proper foaming), or to deteriorating polymer properties, especially polymer foam properties (three-dimensional network being destroyed as covalent bonds are cleaved). In this regard phosphine oxides are very favorable over all other phosphorus species.

Moreover, the compatibility of the flame retardant with the polymer - or, to be more precise - with the polyol system is highly important. On the one hand, only a well-dispersed compound allows a homogeneous distribution of said flame 2 retardant in the polymer and on the other hand a stable dispersion is desired, which can also be stored from minutes to days to months.

From the prior art phosphine oxide compounds are known exhibiting flame retardancy, but low compatibility with the polymer system, thus being technically unfeasible in such applications.

Reactions between tris-(chloromethyl)- and bis-(chloromethyl) methyl phosphine oxide with vicinal diols are disclosed by G. Borisov at al. in Phosphorus and Sulfur, 1984, Vol. 21, pp. 59-65. The products are linear or cyclic. As linear products bis- (ethylene glycol) methyl phosphine oxide and bis-(propylene glycol)methyl phosphine oxide are disclosed. These compounds are characterized by boiling point, melting point and refractive index. No mixtures of different phosphine oxides and no applications for phosphine oxides are disclosed.

US 3,445,405 discloses flame-resistant polyurethane compositions which are produced by using condensation products of at least one alkylene oxide and tris(hydroxymethyl)phosphine oxide in the reaction involving a polyisocyanate and a polyether polymer. In this document tris-functionalized phosphine oxides are disclosed as flame retardants for polyurethanes.

US 5,985,965 A discloses flame-resistant polyurethanes. These contain mixtures of oligomeric phosphoric acid esters which carry hydroxyalkoxy groups. No phosphine oxides are mentioned herein.

From CN 105801833 A1 reactive halogen-free flame-retardant polyether polyols are known. These are prepared from trimethylol phosphorus oxide by addition reaction with propylene oxide / ethylene oxide. The product is a polyvalent reactive halogen-free flame-retardant polyether which can be used in the manufacture of flame-retardant rigid foam materials. In this document tris-functionalized phosphine oxides are disclosed.

K. Zhang et al. in Journal of Applied Polymer Science, 135(5), 1-10 (2018) 3 disclose a flame retardant polyurethane foam prepared from compatible blends of soybean oil-based polyol and phosphorus containing polyol. The phosphorus containing polyether polyol was synthesized by polymerization between tris- (hydroxymethyl) phosphine oxide and propylene oxide. A soybean oil-based polyol was synthesized from epoxidized soybean oil by ring-opening reaction with lactic acid. Polyurethane foams were prepared by mixing soybean oil-based polyol with phosphorus containing polyether polyol. Several properties of the polyurethane foams, such as their density and thermal degradation property were investigated.

One major application for flame retarded flexible polyurethane foams is seat liners or head liners in the automotive sector. However, technical demand is not limited to flame retardancy, but another very important demand from the industry - and ultimately from the end-customer - is a very low emission of volatile organic substances (VOC), which can be harmful. Typically, flame retardants are small and unreactive molecules with a tendency to migrate and evaporate, i.e. leading to leaching and emission of VOC. There are two concepts on to achieve the demand for low emission by either employing reactive or polymeric flame retardants or small reactive molecules. The latter having the advantage of being usually less viscous and thus easier to process.

Additionally, the molecular architecture can play a decisive role in foam production. In fact, for flexible foam a low cross-linking density is mandatory to allow a defect-free formation of an open-porous structure of the foam. The phosphine oxides disclosed in the prior art for polyurethane foam applications have one major drawback of being three-functional (i.e. each molecule carrying three hydroxy groups) thus each acting as a cross linker in the polymerization reaction (see e.g. US 3,445,405 A or CN 105801833 A or K. Zhang et al. article mentioned above).

US 6,380,273 B1 discloses a process for the production of polyurethane foams containing halogen-free flame retardants and having high oxidative thermal resistance during foaming. The process is usable for the manufacture of flexible ester and ether foams and for rigid foams and facilitates the production of 4 polyurethane foams having low fogging values. Moreover, the process gives polyurethane foams having high aging resistance of the flame resistance, i.e. the polyurethane foam still has effective flame resistance after corresponding storage duration, even at elevated temperature. The disclosed process for the production of flame-resistant flexible polyurethane foams having a low susceptibility to core discoloration comprises employing hydroxyalkyl phosphonates as halogen-free flame retardants and as core discoloration inhibitors.

US 2001/0034388 A1 discloses a halogen-free, water-blown, flame-retardant rigid polyurethane foam which meets the necessary and prescribed requirements for flame retardancy, ease of production, low smoke density and low smoke toxicity. The polyurethane foam described in this document comprises alkoxylated alkyl- phosphonic acids as a flame retardant.

US 2004/0077741 A1 discloses flame-retardant flexible polyurethane foams with high aging resistance, and a process for their production. This document describes reduced-halogen-content, low-emission polyurethane foams which, when compared with a halogen-free flame-retardant polyurethane foam, has improved resistance to hydrolysis aging, and, when compared with a prior-art polyurethane foam, has lower halogen content. The flame-retardant flexible polyurethane foams disclosed in this document comprise a mixture composed of hydroxyalkyl phosphonates and chlorinated phosphoric esters.

Summarizing, there are solutions available for each of the technical challenges present in the production of flame-retardant polymers, such as flexible polyurethane foams.

It is an object of the present invention to provide halogen-free flame-retardant compounds which can be used to prepare flame-retardant polymers having low VOC emission as well as non-hydrolyzing, high compatibility and open-pore-foam- forming properties. Said compounds and the flame-retardant polymers prepared therefrom shall have these different properties in one single compound. 5

Another object of the present invention is the provision of a polymer composition having an excellent flame-retardancy combined with very low VOC emission as well as resistance against hydrolysis when subjected to high temperatures, preferably in polymers made from monomers having reactive hydroxyl groups, amino groups or epoxy groups. Furthermore, the polymer compositions shall show an excellent extrudability and moldability in different plastic articles.

These objects are achieved by providing phosphine oxide compounds and by providing polymer compositions disclosed hereinafter.

The present invention relates to phosphine oxides comprising at least two structurally different compounds of formula (I) wherein

R¹ is a monovalent organic group,

R², R³, R⁴ and R⁵, each being same or different and independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms, n and m independently of one another are integers between 0 and 10.

The term “structurally different” shall broadly encompass any difference in formula (I) of the phosphine oxides, including any difference in the nature of the groups R¹ to R⁵ and/or in the integers m and n in formula (I). 6

Preferred are mixtures of structurally different phosphine oxides of formula (I), wherein one of R² or R³ is hydrogen and the other one of R² or R³ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms and wherein one of R⁴ or R⁵ is hydrogen and the other one of R⁴ or R⁵ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms.

More preferred are mixtures of structurally different phosphine oxides of formula (I), wherein one of R² or R³ is hydrogen and the other one of R² or R³ is hydrogen or an alkyl group having between one and two carbon atoms, preferably methyl, and wherein one of R⁴ or R⁵ is hydrogen and the other one of R⁴ or R⁵ is hydrogen or an alkyl group having between one and two carbon atoms, preferably methyl.

These preferred mixtures of phosphine oxides comprise at least two structurally different compounds of formula (la) (lb) and/or (lc). 7 wherein

R¹, m and n are as hereinbefore defined,

R^2a and R^3a each being same or different and independently of one another is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon, preferably selected from hydrogen and methyl, and R^4a and R^5a each being same or different and independently of one another is an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon, and preferably selected from hydrogen and methyl.

In these preferred mixtures at least two structurally different compounds of formula

(la) may be present, or at least two structurally different compounds of formula

(lb), or at least two structurally different compounds of formula (lc), or at least two structurally different compounds of formulae (la) and (lb), or at least two structurally different compounds of formulae (la) and (lc), or at least two structurally different compounds of formulae (lb) and (lc).

Very preferred are phosphine oxides, wherein R², R³, R⁴ and R⁵ independently of one another are selected from hydrogen, Ci-C6-alkyl and phenyl, more preferred from hydrogen and Ci-Ce-alkyl, and still more preferred from hydrogen and Ci-C₃-alkyl, and most preferred from hydrogen and methyl.

Very preferred is a mixture of phosphine oxides comprising structurally different compounds of formula (I), wherein R¹ is Ci-Ce-alkyl, cyclohexyl or phenyl, preferred Ci-C₃-alkyl, and most preferred methyl.

Very preferred are phosphine oxides comprising at least one compound of formula (II), wherein R¹ is Ci-Ce-alkyl, cyclohexyl or phenyl, preferred Ci-C₃-alkyl, and most preferred methyl. 8

Still other very preferred mixtures of phosphine oxides comprise compounds of formula (I), wherein the sum n+m is a number between 1 and 15 and most preferred between 4 and 12.

Unless otherwise indicated, the term "monovalent organic group" as used herein includes a monovalent organic radical derived from an organic group by removal of one hydrogen atom. Organic groups may be saturated or unsaturated straight- chain, branched-chain or mono- or multicyclic hydrocarbons or saturated or unsaturated heterocyclic groups, having - besides the ring carbon atoms - one or more ring-heteroatoms, such as oxygen, nitrogen or sulfur.

Unless otherwise indicated, the term "alkyl" as used herein includes a saturated monovalent aliphatic hydrocarbon radical with straight or branched moieties, preferably a Ci-Ci2-alkyl radical and most preferred a Ci-C₆-alkyl radical. Examples of alkyl radicals are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl, preferably methyl or ethyl and most preferred methyl.

Unless otherwise indicated, the term "alkylene" as used herein includes a saturated divalent aliphatic hydrocarbon radical with straight or branched moieties, preferably a C2-Ci2-alkylene radical and most preferred a C2-C6-alkylene radical. Examples of alkylene radicals are ethylene, propylene, isopropylene, butylene, isobutylene, tert-butylene, pentene or hexene, preferably ethylene, propylene, isopropylene or butylene and most preferred ethylene, propylene or isopropylene.

Unless otherwise indicated, the term "cycloalkyl" as used herein includes a cyclic saturated monovalent hydrocarbon radical with five to seven ring carbon atoms.

An example of a cycloalkyl group is cyclohexyl.

Unless otherwise indicated, the term "aryl" as used herein includes an aromatic radical derived from an aromatic hydrocarbon by removal of one hydrogen, such as, but not limited to, phenyl or naphthyl. 9

Unless otherwise indicated, the term "aralkyl" as used herein signifies an "aryl- alkyl-" group such as, but not limited to benzyl (C6H5-CH2-) or methylbenzyl (CH3-C6H4-CH2-).

Unless otherwise indicated, the term "alkyl-aryl" as used herein signifies an "alkyl- aryl-" group such as, but not limited to: methylphenyl (CH3-C6H4-), dimethylphenyl ((CH3)2-C6H3-) or isopropylphenyl ((CH3)2C-C6H4-).

R¹ is a monovalent organic group. This is preferably selected from alkyl, cycloalkyl, aryl, aralkyl or alkyl-aryl, more preferred selected from Ci-Ce-alkyl, cyclohexyl or phenyl. Still more preferred R¹ is Ci-C3-alkyl, most preferred methyl.

Examples of R¹ are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, cyclohexyl or phenyl.

R², R³, R⁴ and R⁵ independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms,

R², R³, R⁴ and R⁵ preferably are selected from hydrogen, C-i-Cs-alkyl and phenyl, more preferred from hydrogen and Ci-Ce-alkyl, and still more preferred from hydrogen and Ci-C3-alkyl, and most preferred from hydrogen and methyl.

Examples of R², R³, R⁴ and R⁵ as C-i-Cs-alkyl are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl and octyl.

R⁶, R⁷ and R⁸ independently of one another are hydrogen or a group of formula (III) which is derived from glycidol.

The chain length of the alkylene oxide units in the individual molecules of formula (I) in the mixture is characterized by integers n and m. 10

Integers m and n independently of one another have values between 0 and 10, preferably between 1 and 10 and more preferred between 1 and 8 and still more preferred between 2 and 6.

Preferred are mixtures comprising single compounds with the same groups R¹ to R⁵ which differ in the values of n and/or m, more preferred in the values of (n+m). In the mixture comprising compounds of formula (I) the sum n+m of a single compound in said mixture is a number between 0 and 20, preferably between 1 and 15 and most preferred between 4 and 12.

In the mixture comprising compounds of formula (I) at least two structurally different compounds must be present. These comprise different compounds of formula (I), for example compounds of formulae (la), (lb) and/or (lc) mentioned above.

The alkylene oxide moieties in the single compounds of the mixture of structurally different compounds of formula (I) may have different chain lengths (= different values of n and/or m or of the sum of m+n).

One particularly preferred example is a mixture of structurally different phosphine oxides of formula (I), wherein R¹ is Ci-C3-alkyl, R², R³, R⁴ and R⁵are each hydrogen, and the alkylene oxide moieties in the single compounds have different chain lengths (= different values of n and/or m or of the sum of m+n).

In another preferred embodiment of the present invention the mixture or phosphine oxides contains besides at least two structurally different compounds of formula (I), at least one compound of formula (VI) 11 wherein

R², R³, R⁴, R⁵, m and n are defined as above,

R¹⁴ and R¹⁵ each being same or different and independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms, and r independently of n and m is an integer between 0 and 10, preferably between 1 and 10.

Very preferred are mixtures of phosphine oxides comprising besides at least two structurally different compounds of formula (I), at least one compound of formula (VI), wherein one of R² or R³ is hydrogen and the other one of R² or R³ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms and wherein one of R⁴ or R⁵ is hydrogen and the other one of R⁴ or R⁵ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms and wherein one of R¹⁴ or R¹⁵ is hydrogen and the other one of R¹⁴ or R¹⁵ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms.

Still more preferred are mixtures of phosphine oxides comprising at least two structurally different compounds of formula (I) and at least one compound of formula (VI). 12

Compounds of formula (VI) are similar to compounds of formula (I), but the former carries a group -0-(CHR¹⁴-CHR¹⁵-0)_r-H instead of a group R¹ (= trifunctional compounds carrying three alkylene oxide groups).

Preferably, the content of bifunctional compounds of formulae (I) is from 50 to 100, more preferred from 90 to 100 and still more preferred from 90 to 99.5 % by weight, referring to the total amount of the mixture of compounds of formulae (I) and (VI).

Preferably, the content of trifunctional compounds of formula (VI) is from 50 to 0, more preferred from 10 to 0 and still more preferred from 10 to 0.5 % by weight, referring to the total amount of the mixture of compounds of formulae (I) and (VI).

The mixtures of structurally different compounds of formula (I) and may be prepared by standard reactions known to the skilled artisan.

Alkylene oxides of formula (I) may be produced by reacting bis-methylol- phosphine oxide of formula (VII) with one or more epoxides of formula (VIII) wherein R¹, R² and R³ are as defined hereinbefore.

The amounts of bis-methylol-phosphine oxide and epoxides are selected in a manner so that the desired number of recurring alkylene oxide units is obtained.

The reaction between compounds of formulae (VII) and (VIII) may be initiated by mixing said compounds and by heating these compounds in the presence of a basic compound, for example an alkali hydroxide, such as sodium hydroxide or potassium hydroxide. The reaction temperature may be varied in a broad range, 13 for example between 50 and 200°C. During reaction the reaction mixture is preferably agitated, e.g. by using a stirrer.

The reaction may be carried out at atmospheric pressure, preferably at reduced pressure, for example in the pressure range between 1 and 10⁵ Pa, preferably between 10 and 10⁴ Pa.

The reaction may also be carried out in solution using an organic solvent which is inert under reaction conditions. Examples of solvents are aprotic organic solvents, such as dimethyl sulfoxide, dimethyl formamide or dimethyl acetamide, or aromatic hydrocarbons, such as benzene, toluene or xylene.

Phosphine oxide starting materials of formula (VII) are known compounds or can be produced using standard procedures of phosphorus-organic chemistry.

Epoxy starting materials of formula (VIII) are known compounds or can be produced using standard procedures of organic chemistry.

Examples of preferred epoxy starting materials are ethylene oxide, propylene oxide, styrene oxide or glycidol.

Surprisingly, it has been found that alkoxylated phosphine oxide compounds of formula (I) as defined above, can be used for the manufacture of flame-retardant polymers. Single compounds of formula (I) or mixtures of structurally different compounds of formula (I) may be used in the manufacture of polymers.

Surprisingly, a compound of formula (I) when incorporated into a polymer provides excellent flame-retardancy combined with very low VOC emission as well as resistance against hydrolysis when subjected to high temperatures, preferably in polymers prepared from monomers having reactive hydroxyl groups, amino groups or epoxy groups, such as polyesters, polycarbonates, polyamides, polyurethanes and polyureas. Furthermore, the polymer compositions comprising 14 flame-retardant polymers made from compounds of formula (I) show an excellent extrudability and moldability in different plastic articles.

The invention also relates to flame retardant polymers comprising structural units of form u la (X) wherein R¹, R², R³, R⁴ , R⁵, n and m are as defined hereinabove.

Preferably a flame retardant polymer comprises different structural units of formula (X), more preferred structural units of formulae (Xa), (Xb) and/or (Xc) optionally in combination with structural units of formula (Via) 15 wherein R¹, R^2a, R^3a, R^4a, R^5a, R², R³, R⁴, R⁵, R¹⁴, R¹⁵, n and m are as aforesaid defined.

The amount of structural unit of formula (X) in the polymer of the invention may vary in a broad range. Typically, the amount of structural units of formula (X) is from 0.5 to 30 mol.-%, preferably from 0.5 to 20 mol.-% and most preferred from 1 to 10 mol.-%, referring to the total amount of the polymer.

The polymers of the invention comprising structural units of formula (X) may be prepared by standard reactions known to the skilled artisan.

Thus, polymer-forming mixtures of polymerizable compounds are subjected to polymerization conditions, wherein said mixtures comprises at least one compound of formula (I) and at least one compound copolymerizable with said compound of formula (I).

The polymers of the invention can be any natural polymer including modifications by chemical treatment or any synthetic polymer. Polymer blends may also be used. Suitable polymers include thermoplastic polymers, thermoplastic elastomeric polymers, elastomers or duroplastic polymers.

Preferred are thermoplastic polymers. Thermoplastic polymers may be selected from the group consisting of polyamides, polycarbonates, polyesters, polyvinyl 16 esters, polyvinyl alcohols, polyurethanes and polyureas. Preferred thermoplastic polymers are prepared from monomers having functional groups which can react with hydroxyl groups. These are preferably selected from the group consisting of polyamides, polycarbonates, polyesters, polyvinyl alcohols, polyurethanes and polyureas.

Another preferred group of polymers are duroplastic polymers. More preferred, these are selected from the group consisting of polyurethanes, epoxy resins, phenolic resins, melamine resins and unsaturated polyester resins.

Still another preferred group of polymers are thermoplastic elastomeric polymers. These constitute different types and are known to the skilled person.

Examples of thermoplastic elastomeric polymers include thermoplastic and elastomeric polyurethanes (TPE-U), thermoplastic and elastomeric polyesters (TPE-E), and thermoplastic and elastomeric polyamides (TPE-A).

Thermoplastic elastomeric polymers can be derived from different monomer combinations. As a rule, these contain blocks of so-called hard and soft segments. The soft segments are typically derived from polyalkoxy glycol ethers in the TPE-U and TPE-E and from amino-terminated polyalkoxy glycol ethers in the TPE-A. The hard segments are typically derived from short-chain diols or diamines in the TPE-U, TPE-A and TPE-E. In addition to the diols or diamines, the thermoplastic elastomeric polymers are derived from aliphatic, cycloaliphatic and / or aromatic dicarboxylic acids or diisocyanates.

Also, mixtures of two or more polymers, in particular thermoplastics and/or thermosets may be used.

Examples of polymers are:

Hydrocarbon resins including hydrogenated modifications thereof (e.g. tackifier resins) and mixtures of polyalkylenes and starch. 17

Polymers derived from alpha-, beta-unsaturated acids and derivatives thereof, such as polyacrylates and polymethacrylates, butyl acrylate-impact-modified polymethyl methacrylates, polyacrylamides and polyacrylonitriles and copolymers of the cited monomers with one another or with other unsaturated monomers, for example acrylonitrile-butadiene copolymers, acrylonitrile-alkyl acrylate copolymers, acrylonitrile-alkoxyalkyl acrylate copolymers, acrylonitrile-vinyl halide copolymers or acrylonitrile-alkyl methacrylate-butadiene terpolymers.

Polymers derived from unsaturated alcohols and amines or from the acyl derivatives or acetals thereof, such as polyvinyl alcohol, polyvinyl acetate, stearate, benzoate or maleate, polyvinyl butyral, polyallyl phthalate, polyallylmelamine; and copolymers thereof with olefins.

Homo- and copolymers of cyclic ethers, such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or copolymers thereof with bisglycidyl ethers.

Polyacetals, such as polyoxymethylene, and those polyoxymethylenes which comprise comonomers, for example ethylene oxide; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS.

Polyphenylene oxides and sulfides and mixtures thereof with styrene polymers or polyamides.

Polyurethanes deriving from polyethers, polyesters or polybutadienes having both terminal hydroxyl groups and aliphatic or aromatic polyisocyanates, and the precursors thereof.

Polyamides and copolyamides which derive from diamines and dicarboxylic acids and/or from aminocarboxylic acids or the corresponding lactams, such as nylon 2/12, nylon 4, nylon 4/6, nylon 6, K122, Zytel 7301, Durethan B 29, nylon 6/6 Zytel 101, Durethan A30, Durethan AKV, Durethan AM, Ultramid A3, nylon 6/9. Nylon 6/9, nylon 6/10, nylon 6/12, nylon 6/66, nylon 7, nylon 7,7, nylon 8, 18 nylon 8,8, nylon 9, nylon 9,9, nylon 10, nylon 10,9, nylon 10,10, nylon 11, nylon 12, Grillamid L20, aromatic polyamides proceeding from m-xylene, diamine and adipic acid; polyamides prepared from hexamethylenediamine and iso- and/or terephthalic acid (polyhexamethyleneisophthalamide, polyhexamethyleneterephthalamide) and optionally an elastomer as a modifier, e.g. poly-2, 4, 4-trimethylhexamethylene-terephthalamide or poly-m- phenyleneisophthalamide. Block copolymers of the abovementioned polyamides with polyolefins, olefin copolymers, ionomers or chemically bonded or grafted elastomers; or with polyethers, for example with polyethylene glycol, polypropylene glycol or polytetramethylene glycol. In addition, EPDM- or ABS-modified polyamides or copolyamides; and polyamides condensed during processing ("RIM polyamide systems").

Polyureas, polyimides, polyamide-imides, polyetherimides, polyesterimides, poly- hydantoins and polybenzimidazoles.

Polyesters which derive from dicarboxylic acids and dialcohols and/or from hydroxycarboxylic acids or the corresponding lactones, such as polyethylene terephthalate, polybutylene terephthalate, poly-1 ,4-dimethylolcyclohexane terephthalate, polyhydroxybenzoates, and block polyether esters which derive from polyethers with hydroxyl end groups; and also polyesters modified with polycarbonates or MBS.

Polycarbonates, polyester carbonates, polysulfones, polyether sulfones and polyether ketones.

Duroplastic or thermoset polymers or resins are preferably polyurethane resins, epoxy resins, phenol-formaldehyde resins, melamine-formaldehyde resins, urea- formaldehyde resins and/or unsaturated polyesters.

The thermoset resins are preferably polyurethane resins, epoxy resins or unsaturated polyester resins. 19

Thermoset polymers preferably find use in electrical switch components, components in automobile construction, electrical engineering, electronics, printed circuit boards, prepregs, potting compounds for electronic components, in boat and rotor blade construction, in outdoor GFRP applications, domestic and sanitary applications, engineering materials and further products.

Other polymers of the present invention are duroplastic polymers which derive from aldehydes and from phenols, urea or melamine, such as phenol- formaldehyde, urea-formaldehyde and melamine-formaldehyde resins.

Other polymers of the invention comprise crosslinkable acrylic resins which derive from substituted acrylic esters, for example from epoxy acrylates, urethane acrylates or polyester acrylates.

Still other preferred polymers of the invention are epoxy resins which derive from aliphatic, cycloaliphatic, heterocyclic or aromatic glycidyl compounds, for example products of bisphenol A diglycidyl ethers, bisphenol F diglycidyl ethers, which may be are crosslinked by means of customary hardeners, for example anhydrides or amines, with or without accelerators.

Still other preferred thermosets are polymers from the class of the cyanate esters, cyanate ester/bismaleimide copolymer, bismaleimide/triazine epoxy blends and butadiene polymers.

Epoxy resins are preferably polyepoxide compounds. Epoxy resins preferably originate from the group of polyglycidyl-formaldehyde resins, polyglycidyl-urea- formaldehyde resins, polyglycidyl-melamine-formaldehyde resins and bisphenol resins.

Preferred epoxy resins are bisphenol A diglycidyl esters, bisphenol F diglycidyl esters, polyglycidyl esters of phenol formaldehyde resins and cresol-formaldehyde resins, polyglycidyl esters of phthalic acid, isophthalic acid and terephthalic acid, and of trimellitic acid, N-glycidyl compounds of aromatic amines and heterocyclic 20 nitrogen bases, and di- and polyglycidyl compounds of polyhydric aliphatic alcohols.

Suitable hardeners are aliphatic, cycloaliphatic, aromatic and heterocyclic amines or polyamines, such as ethylenediamine, diethylenetriamine, triethylenetetramine, propane-1 ,3-diamine, hexamethylenediamine, aminoethylpiperazine, isophorone- diamine, polyamidoamine, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, aniline-formaldehyde resins, 2, 2, 4-trimethylhexane-1 ,6- diamine, m-xylylenediamine, bis(4-aminocyclohexyl)methane, 2,2-bis(4-amino- cyclohexyl)propane, 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophorone- diamine), polyamidoamines, cyanoguanidine and dicyandiamide, and likewise polybasic acids or anhydrides thereof, for example phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride, and also phenols, for example phenol-novolac resin, cresol-novolac resin, dicyclopentadiene-phenol adduct resin, phenol aralkyl resin, cresolaralkyl resin, naphtholaralkyl resin, biphenol-modified phenolaralkyl resin, phenol- trimethylolmethane resin, tetraphenylolethane resin, naphthol-novolac resin, naphthol-phenol cocondensate resin, naphthol-cresol cocondensate resin, biphenol-modified phenol resin and aminotriazine-modified phenol resin. All hardeners can be used alone or in combination with one another.

Suitable catalysts or accelerators for the crosslinking in the polymerization are tertiary amines, benzyldimethylamine, N-alkylpyridines, imidazole, 1-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethyl-4- methylimidazole, 2-phenylimidazole, 2-heptadecylimidazole, metal salts of organic acids, Lewis acids and amine complex salts.

Other preferred polymers of the invention are crosslinked polymers which derive from aldehydes on the one hand, and phenols, urea or melamine on the other hand, such as phenol-formaldehyde, urea-formaldehyde and melamine- formaldehyde resins. The polymers preferably comprise crosslinkable acrylic 21 resins which derive from substituted acrylic esters, for example from epoxy acrylates, urethane acrylates or polyester acrylates.

Very preferred polymers of the invention are polyurethanes and polyureas. Most preferred are polyurethanes.

Polyurethanes are polymers composed of organic units joined by carbamate (urethane) links while polyureas contain carbamide links. Polyurethanes and polyureas may be thermosetting polymers that do not melt when heated; but thermoplastic polyurethanes and polyureas are also available.

Polyurethanes are commonly formed by reacting a di- or triisocyanate with a polyol. Both the isocyanates and polyols used to make polyurethanes contain, on average, two or more functional groups per molecule. Diols and diisocyanates lead to linear polyurethanes, crosslinked polyurethanes can be produced e.g. by converting triisocyanate diisocyanate mixtures with triol-diol mixtures. The properties of polyurethanes can be varied in a wide range. Depending on the degree of crosslinking and/or isocyanate or OH component used, thermosets, thermoplastics or elastomers are obtained. In terms of quantity, polyurethane foams are most important as soft or hard foam. However, polyurethanes are also used as molding compounds for molding, as casting resins (isocyanat resins), as (textile) elastic fibers, polyurethane coatings and as polyurethane adhesives.

Properties of a polyurethane resin are greatly influenced by the types of isocyanates and polyols used for manufacture thereof. Long, flexible segments, contributed by the polyol, give soft, elastic and/or thermoplastic polyurethane. Higher amounts of crosslinking monomers give tough or rigid polyurethanes. Short chains with many crosslinks produce a hard and thermoset polyurethane. Crosslinked polyurethanes comprise a three-dimensional network and have very high molecular weight. Duroplastic polyurethanes do not soften or melt when they are heated; thus they are thermosetting polymers. 22

Polyols are compounds having on average two or more hydroxyl groups per molecule. Polyol chain length and functionality contribute much to the polyurethane properties. Polyols used to make rigid or thermosetting poly urethanes have molecular weights in the hundreds, while those used to make flexible or thermoplastic polyurethanes have molecular weights in the thousands.

Thermoset polyurethanes are preferably derived from polyols, preferred aliphatic polyols with low molecular weights having two, three or four hydroxyl groups, e.g. from ethylene glycol, propylene glycol, trimethylol propane or pentaerythritol, and from aliphatic or aromatic polyisocyanates, and the precursors thereof.

Starting materials used for producing polyurethanes are, for example, aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates (see, for example, W. Siefken in Justus Liebigs Annalen der Chemie, 562, pp. 75-136), for example those of the formula Q(NCO)_r, where r= from 2 to 4, preferably from 2 to 3, and Q is an aliphatic hydrocarbon radical having from 2 to 18 carbon atoms, preferably from 6 to 10 carbon atoms, a cycloaliphatic hydrocarbon radical having from 4 to 15 carbon atoms, preferably from 5 to 10 carbon atoms, an aromatic hydrocarbon radical having from 6 to 15 carbon atoms, preferably from 6 to 13 carbon atoms, or an araliphatic hydrocarbon radical having from 8 to 15 carbon atoms, preferably from 8 to 13 carbon atoms. Suitable polyisocyanates are aromatic, alicyclic and/or aliphatic polyisocyanates having at least two isocyanate groups and mixtures thereof. Preference is given to aromatic polyisocyanates such as tolyl diisocyanate, methylene diphenyl diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, tris(4-isocyanatophenyl)methane and polymethylene- polyphenylene diisocyanates; alicyclic polyisocyanates such as methylenediphenyl diisocyanate, tolyl diisocyanate; aliphatic polyisocyanates and hexamethylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, 1,1-methylenebis(4- isocyanatocyclohexane-4,4'-diisocyanatodicyclohexylmet hane isomer mixture,

1 ,4-cyclohexyl diisocyanate, Desmodur products (Bayer) and lysine diisocyanate and mixtures thereof. 23

Particular preference is generally given to the polyisocyanates readily available industrially and derived from toluene 2,4- and/or 2,6-diisocayanate or from diphenylmethane 4,4'- and/or 2,4'-diisocyanate.

Suitable polyisocyanates are modified products which are obtained by reaction of polyisocyanate with polyol, urea, carbodiimide and/or biuret.

Other starting materials for producing polyurethanes or polyureas of the invention are compounds having at least two hydrogen atoms capable of reaction with isocyanates and having a molecular weight of from 400 to 10,000 ("polyol component"). These are compounds having amino groups, thio groups or carboxyl groups, and preferably compounds having hydroxyl groups, in particular from 2 to 8 hydroxyl groups, and specifically those of molecular weight from 1000 to 6000, preferably from 2000 to 6000, and are generally polyethers or polyesters dihydric to octahydric, preferably dihydric to hexahydric, or else polycarbonates or polyesteramides, as known per se for the production of homogenous or of cellular polyurethanes, and as described in DE-A 2832253, for example.

Preferred polyester polyols are obtained by polycondensation of a polyalcohol such as ethylene glycol, diethylene glycol, propylene glycol, 1 ,4-butanediol,

1 ,5-pentanediol, methylpentanediol, 1 ,6-hexanediol, trimethylolpropane, glycerol, pentaerythritol, diglycerol, glucose and/or sorbitol, with a dibasic acid such as oxalic acid, malonic acid, succinic acid, tartaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid and/or terephthalic acid. These polyester polyols can be used alone or in combination.

Other starting materials which may be used are compounds having at least two hydrogen atoms capable of reaction with isocyanates and with a low molecular weight, such as from 30 to 500. In this case, again, these are compounds having hydroxyl groups and/or amino groups and/or thio groups and/or carboxyl groups, preferably compounds having hydroxyl groups and/or amino groups and serving as chain extenders or crosslinkers. These compounds generally have from 2 to 8, preferably from 2 to 4, hydrogen atoms capable of reaction with isocyanates. 24

Still other preferred thermoset polymers of the invention are unsaturated polyester resins (UP resins) which derive from copolyesters of saturated and unsaturated dicarboxylic acids with polyhydric alcohols, and vinyl compounds as crosslinking agents.

UP resins are cured by free-radical polymerization with initiators (e.g. peroxides) and accelerators.

Unsaturated polyesters may contain the ester group as a connecting element in the polymer chain.

Preferred unsaturated dicarboxylic acids and derivatives for preparation of unsaturated polyesters are maleic acid, maleic anhydride and fumaric acid, itaconic acid, citraconic acid, mesaconic acid. These may be blended with up to 200 mol %, based on the unsaturated acid components, of at least one aliphatic saturated or cycloaliphatic dicarboxylic acid.

Preferred saturated dicarboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, dihydrophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, adipic acid, succinic acid, sebacic acid, glutaric acid, methylglutaric acid, pimelic acid.

Preferred polyhydric, especially dihydric, optionally unsaturated alcohols are the customary alkanediols and oxaalkanediols having acyclic or cyclic groups.

Preferred unsaturated monomers copolymerizable with monomers for the production of unsaturated polyesters preferably bear vinyl, vinylidene or allyl groups, for example preferably styrene, but also, for example, ring-alkylated or -alkenylated styrenes, where the alkyl groups may contain 1-4 carbon atoms, for example vinyltoluene, divinylbenzene, alpha-methylstyrene, tert-butylstyrene; vinyl esters of carboxylic acids having 2-6 carbon atoms, preferably vinyl acetate, vinyl propionate, vinyl benzoate; vinylpyridine, vinylnaphthalene, vinylcyclohexane, 25 acrylic acid and methacrylic acid and/or esters thereof (preferably vinyl, allyl and methallyl esters) having 1-4 carbon atoms in the alcohol component, amides and nitriles thereof, maleic anhydride, maleic monoesters and diesters having 1-4 carbon atoms in the alcohol component, maleic mono- and -diamides or cyclic imides, such as butyl acrylate, methyl methacrylate, acrylonitrile, N-methylmaleimide or N-cyclohexylmaleimide; allyl compounds such as allylbenzene and allyl esters such as allyl acetate, diallyl phthalate, diallyl isophthalate, diallyl fumarate, allyl carbonates, diallyl phthalates, diallyl carbonates, triallyl phosphate and triallyl cyanurate.

A preferred vinyl compound for crosslinking is styrene.

Preferred unsaturated polyesters may bear the ester group in the side chain as well, for example polyacrylic esters and polymethacrylic esters.

Preferred hardener systems for unsaturated polyesters are peroxides and accelerators.

Preferred accelerators are metal coinitiators and aromatic amines and/or UV light and photosensitizers, for example benzoin ethers and azo catalysts such as azoisobutyronitrile, mercaptans such as lauryl mercaptan, bis(2-ethylhexyl) sulfide and bis(2-mercaptoethyl) sulfide.

In one process for preparing flame-retardant copolymers, at least one ethylenically unsaturated dicarboxylic anhydride derived from at least one C4-C8-dicarboxylic acid, at least one vinylaromatic compound and at least one polyol are copolymerized and then reacted with the flame retardants of formula (I) and/or (II).

The invention also relates to polymer compositions comprising the flame-retardant polymers of the present invention as component a) and optionally additives as component b). 26

The amount of component b) may vary in a broad range. Typical amounts of component(s) b) are between 0 and 60 % by weight, preferably between 1 and 50 % by weight and more preferred between 5 and 30 % by weight, referring to the total amount of the flame-retardant polymer composition.

Examples of additives b) are antioxidants, blowing agents, further flame retardants, light stabilizers, heat stabilizers, impact modifiers, processing aids, glidants, processing aids, nucleating agents and clarifiers, antistatic agents, lubricants, such as calcium stearate and zinc stearate, viscosity and impact modifiers, compatibilizers and dispersing agents, dyes or pigments, antidripping agents, additives for laser marking, hydrolysis stabilizers, chain extenders, softeners and/or plasticizers, fillers and/or reinforcing agents.

The flame-retardant polymer composition of the present invention preferably contains additional fillers as component b). These are preferably selected from the group consisting of metal hydroxides and/or metal oxides, preferably alkaline earth metal, e.g. magnesium hydroxide, aluminum hydroxide, silicates, preferably phyllosilicates, such as bentonite, kaolinite, muscovite, pyrophyllite, marcasite and talc or other minerals, such as wollastonite, silica such as quartz, mica, feldspar and titanium dioxide, alkaline earth metal silicates and alkali metal silicates, carbonates, preferably calcium carbonate and talc, clay, mica, silica, calcium sulfate, barium sulfate, pyrite, glass beads, glass particles, wood flour, cellulose powder, carbon black, graphite and chalk.

The flame-retardant polymer composition of the present invention preferably contains reinforcing agents as component b), more preferred reinforcing fibers. These are preferably selected from the group consisting of glass fibers, carbon fibers, aramid fibers, potassium titanate whiskers, glass fibers being preferred. The incorporation of the reinforcing agents in the molding compositions can be done either in the form of endless strands (rovings) or in cut form (short glass fibers). To improve the compatibility with the polymer matrix, the reinforcing fibers used can be equipped with a size and an adhesion promoter. The diameter of commonly used glass fibers is typically in the range of 6 to 20 microns. 27

These additives b) can impart other desired properties to the polymer composition of the invention. In particular, the mechanical stability can be increased by reinforcement with fibers, preferably with glass fibers.

The flame-retardant polymer compositions of the invention are preferably prepared by providing components a) and optionally b), e.g. by mixing or by incorporation into a masterbatch, and by incorporating components a) and optionally b) into the polymer or polymer mixture.

The components a) and optionally b) can be incorporated into the polymer composition by premixing all components as powder and/or granules in a mixer and then homogenizing them in the polymer melt in a compounding unit (e.g. a twin-screw extruder). The melt is usually withdrawn as a strand, cooled and granulated. The components a) and optionally b) can also be introduced separately via a metering system directly into the compounding unit. It is also possible to admix the components a) and optionally b) to a finished polymer granulate or powder and to process the mixture directly to form parts, e.g. on an injection molding machine.

The process for the production of flame-retardant polymer compositions is characterized by incorporating and homogenizing components a) and optionally b), into polymer pellets in a compounding assembly at elevated temperatures. The resulting homogenized polymer melt is then formed into a strand, cooled and portioned. The resulting granules are dried, e.g. at 90 °C in a convection oven.

It is likewise possible to admix components a) and optionally b) with prepared polymer pellets/powder and to process the mixture directly, for example, on a film blowing line or a fiber spinning line.

Preferably, the compounding equipment is selected from the group of single-screw extruders, multizone screws, or twin-screw extruders. 28

The flame-retardant polymer compositions according to the invention are suitable for the production of moldings, e.g. films, sheets, threads and fibers, for example by injection molding, extrusion, blow molding or press molding.

The invention also relates to a shaped part prepared from a composition containing components a) and optionally b).

The shaped parts produced are preferably of rectangular shape with a regular or irregular base, or of cubic shape, cuboidal shape, cushion shape or prism shape.

The polymer compositions according to the invention are particularly suitable for the manufacture of foams, preferably of polyurethane foams.

The invention furthermore relates to the use of a compound of formula (I) and/or (II) as aforesaid defined as a monomer in the manufacture of flame-retardant polymers.

Moreover, the invention relates to the use of the polymer composition comprising components a) and optionally b) for the manufacture of high-resilience foam seating, rigid foam insulation panels, microcellularfoam seals and gaskets, durable elastomeric wheels and tires, automotive suspension bushings, electrical potting compounds, high-performance adhesives, surface coatings and sealants, synthetic fibers, carpet underlay, hard-plastic parts and hoses.

Finally, the invention relates to the use of the polymer composition comprising components a) and optionally b) for the manufacture of electrical switch components, components in automobile construction, electrical engineering or electronics, printed circuit boards, prepregs, potting compounds for electronic components, in boat and rotor blade construction, in outdoor GFRP applications, domestic and sanitary applications and engineering materials. 29

Examples

Methods / Tests + Standards

Compatibility with standard polyols

Flame retardant was dispersed in respective polyol in different ratios using a mechanical stirrer. The dispersion was stored at 23 °C for 48 h. Afterwards, the homogeneity of the dispersion was assessed visually.

Following criteria were applied (see “Table of Properties XY”), with the more “x” the better

Hydrolytic stability test of flame retardant substances

A 10 wt.-% solution of the respective compound in water is stirred for 2 hours at 100 °C. The solution is then analyzed via ³¹ P NMR and titration to see whether changes in the spectra or acid value did occur.

Hydrolytic stability test of polyol compositions for PUR manufacture Hydrolytic stability was determined by measuring the development of the acid value of polyol-FR-water blends at increased temperature over time. For this purpose, 90 g of polyol, 9 g of FR (10 %(w/w)) and 4,5 g of water (5 %(w/w)) were homogenized by stirring at 1500 rpm for 2 min. The samples were then stored at 40 °C and the acid values were determined after given periods of time. Samples were homogenized before analysis by stirring at 1500 rpm for 2 min. As a reference, development of acid value of a polyol-water blend with no added FR was carried out. 30

Raw materials and origin 31

Synthesis Examples

Example 1: Manufacture of BMPO-PO with 1 equivalent PO The BMPO-PO was prepared by the reaction between BMPO and propylene oxide. In a process, 234 g propylene oxide, 500 g BMPO (90% purity), and 5.5 g potassium hydroxide were charged into a 3000 ml_ glass reactor which was equipped with a magnetic stick. The glass reactor was heated in a thermostatic oil bath for 48 h at 150 °C. The unreacted PO and small molecules were removed under reduced pressure at 100 °C to obtain a slightly yellow, transparent liquid. The mixture comprises 30% (n = 0, m = 0), 40% (n = 1 , m = 0), 15% (n = 1 , m = 1), 5% higher oligomers and 10% non-Phosphorus glycols.

Example 2: Manufacture of BMPO-PO with 2 equivalent PO The BMPO-PO was prepared by the reaction between BMPO and propylene oxide. In a process, 470 g propylene oxide, 500 g BMPO (90% purity), and 5.5 g 32 potassium hydroxide were charged into a 3000 ml_ glass reactor which was equipped with a magnetic stick. The glass reactor was heated in a thermostatic oil bath for 48 h at 150 °C. The unreacted PO and small molecules were removed under reduced pressure at 100 °C to obtain a slightly yellow, transparent liquid. The mixture comprises 10% (n = 0, m = 0), 25% (n = 1 , m = 0), 40% (n = 1 , m = 1), 10% (n = 2, m = 1), 5% higher oligomers and 10% non-Phosphorus glycols.

Example 3: Manufacture of BMPO-PO with 3 equivalent PO The BMPO-PO was prepared by the reaction between BMPO and propylene oxide. In a process, 700 g propylene oxide, 500 g BMPO (90% purity), and 5.5 g potassium hydroxide were charged into a 3000 ml_ glass reactor which was equipped with a magnetic stick. The glass reactor was heated in a thermostatic oil bath for 48 h at 150 °C. Unreacted PO and small molecules were removed under reduced pressure at 100 °C to obtain a slightly yellow, transparent liquid. The mixture comprises 10% (n = 1, m = 0), 40% (n = 1, m = 1), 30% (n = 2, m = 1), 10% higher oligomers and 10% non-Phosphorus glycols

Example 6: Manufacture of BMPO-EO with 3 equivalent EO The BMPO-EO was prepared by the reaction between BMPO and ethylene oxide. In a process, 213 g ethylene oxide, 100 g BMPO (90% purity), and 0.5 g potassium hydroxide were charged into a 1000 ml_ glass reactor which was equipped with a magnetic stick. The glass reactor was heated in a thermostatic oil bath for 6 h at 150 °C. The unreacted ethylene oxide and small molecules were removed under reduced pressure at 100 °C to obtain a slightly yellow, transparent liquid. The mixture comprises 10% (n = 1, m = 0), 40% (n = 1, m = 1), 30% (n = 2, m = 1), 10% higher oligomers and 10% non-Phosphorus glycols

Properties of flame retardants of this invention compared to reference materials 33

Table 1 : Properties of flame retardant material, regarding stoichiometry of their syntheses, Phosphorus content and miscibility with polyols.

34

In table 1 selected synthetic (equivalents of alkylene oxide) and elemental (Phosphorus) details of examples of this invention are disclosed together with their miscibility in polyether-type (Arcol 1104) and polyester-type (Desmophen 60WB01) polyols. One trend to be illustrated is the better miscibility of BMPO-PO with increasing equivalents of PO employed in their synthesis, i.e. BMPO-PO (entry 3) is completely miscible even at 30% concentration in polyester polyol, whereas less PO leads to inhomogeneities at these high concentrations.

Compared to PO, EO yields, with identical synthetic parameters, alkoxylated products of BMPO with less miscibility (entry 6 vs. entry 3). Also compared to reference materials (Ref-1 to Ref-3) BMPO-PO (entry 3) performs better in those miscibility experiments in polyester-type polyol. In polyether-type polyols Ref-1 and Ref-2 show the best miscibility of all selected examples.

Application Examples

Hydrolytic stability of neat flame retardant material

Table 2: Hydrolytic stability of neat flame retardant material in boiling water

In Table 2 the hydrolytic stability of BMPO-PO compared to commercial reference materials Exolit OP 550 and Exolit OP 560 is shown. As expected, the propoxylated phosphine oxide shows no tendency to hydrolyze even after being exposed to boiling water for 4 h, whereas both reference materials show a significant increase in acid value after the same treatment. The effect of the latter can be assigned to the phosphoric acid-type (OP 550) or phosphonic acid-type 35

(OP 560) oxidation state of the respective reference materials. The alkoxylated acids, i.e. phosphoric / phosphonic acid esters, have a much higher tendency to hydrolyze compared to phosphine oxide-alkyoxylates. Furthermore, on hydrolysis the former release free acid, while the latter release methylol-moieties with a much lower acidity.

Hydrolytic stability of flame retardant material in polyol/water mixture

Table 3: Hydrolytic stability test: Development of the acid value of mixtures of polyols with 10 %(m/m) of flame retardant and 5 %(m/m) of water during storage at 40 °C.

Table 3 shows the same trend as in Table 2 - only in a more application-like environment - that entry 3 does not significantly contribute to an increase of the acid value as compared to the pure polyol, indicating similarly high hydrolytic stability of FR 1 during storage as the polyol. After 28 d of storage the acid value of pure polyol is at 0.1 and at 0.5 with added FR1 in Arcol® 1104 (Polyether polyol) - those numbers indicate no to negligible hydrolysis of the FR. In comparison, Exolit OP 550 shows a significantly increased acid value of >40 after 11 d, which can be explained by hydrolysis of the FR. The same experiment in Desmophen^® 60WB01 (Polyester polyol) shows similar results. The acid value of pure polyol and the system with added FR1 show the same acid value of 1.9, indicating no 36 contribution of FR1 -hydrolysis to the increase of acid value. Exolit OP 550 shows a rapid rise of acid value at same conditions (94.7 after 28 d) indicating a rapid hydrolysis of this material. Polyurethane flexible foam formulations and application test results

Table 4: Polyurethane formulations with flame retardants for flexible foams with a bulk density of 30 kg/m³. ^*TCPP= Tris(1-chloro-2-propyl) phosphate Application in PUR foam 37

Table 5: Application test results of flexible polyurethane foams.

Table 5 indicates that all formulations can be processed to stable flexible foams except for Ref.FM-3, where the trifunctional polyol TMPO-PO leads to pronounced cross-linking and as a consequence to the collapse of the foam. Of course, a collapse is the worst case scenario for foam production. It was not possible to find a non-collapsing formulation in this polyether-type system, thus showing the difficulties of using TMPO-PO.

In contrast to Ref.FM-1 (TCPP) and FM-2 (BMPO-EO), 4 parts are sufficient in FM-1 (BMPO-PO) to achieve rating “SE” in the FMVSS 302 test. The reason for the inferior flame retardancy performance of BMPO-EO - in comparison to its propoxylated analogue - lies in the low compatibility of the material with the polyol, where it is dispersed in. The de-mixing leads to inhomogeneous distribution of the flame retardant in the final foam specimens. Flence, some specimens perform well while others fail (burn) completely, resulting in an overall bad rating of B. 38

Compared to Ref.FM-2 the air permeability of FM-1 is better, and a lower value of compression set can be achieved. Both characteristics are beneficial for the latter application. Both emission indicators “fogging” and “VOC” show the successful covalent bonding of BMPO-PO into to polyurethane matrix, lead to values that are below the threshold for automotive applications. The impact of “non-reactive” flame retardants can be seen in Ref. FM-1 , where TCPP leads to very high fogging and VOC values, which are not acceptable for such automotive applications.

Claims

39 Patent claims

1 . Phosphine oxides comprising a mixture of at least two structurally different compounds of formula (I) wherein

R¹ is Ci-C₆-alkyl, cyclohexyl or phenyl,

R², R³, R⁴ and R⁵, each being same or different and independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms, n and m independently of one another are integers between 0 and 10.

2. The phosphine oxides of formula (I) according to claim 1 , wherein one of R² or R³ is hydrogen and the other one of R² or R³ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms and wherein one of R⁴ or R⁵ is hydrogen and the other one of R⁴ or R⁵ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms.

3. The phosphine oxides of formula (I) according to claim 2, wherein one of R² or R³ is hydrogen and the other one of R² or R³ is hydrogen or an alkyl group having between one and two carbon atoms, preferably methyl, and wherein one of R⁴ or R⁵ is hydrogen and the other one of R⁴ or R⁵ is hydrogen or an alkyl group having between one and two carbon atoms, preferably methyl. 40

4. The phosphine oxides according to at least one of claims 1 to 3, wherein R², R³, R⁴ and R⁵ independently of one another are selected from hydrogen, Ci-C₆-alkyl and phenyl, more preferred from hydrogen and Ci-Ce-alkyl, and still more preferred from hydrogen and Ci-C3-alkyl, and most preferred from hydrogen and methyl.

5. The phosphine oxides according to at least one of claims 1 to 4, wherein R¹ is Ci-C3-alkyl, and preferred methyl.

6. The phosphine oxides according to at least one of claims 1 to 5, wherein the sum n+m in each of the phosphine oxides of formula (I) contained in the mixture is a number between 1 and 15 and most preferred between 4 and 12.

7. The phosphine oxides according to at least one of claims 1 to 6, wherein the mixture comprises besides at least two structurally different compounds of formula (I) at least one compound of formula (VI) wherein R¹⁴ and R¹⁵ independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms, and r independently of n and m is an integer between 0 and 10, preferably between 1 and 10. 41

8. The phosphine oxides of formula (I) according to claim 7, wherein one of R² or R³ is hydrogen and the other one of R² or R³ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms and wherein one of R⁴ or R⁵ is hydrogen and the other one of R⁴ or R⁵ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms and wherein one of R¹⁴ or R¹⁵ is hydrogen and the other one of R¹⁴ or R¹⁵ is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon atoms.

9. The phosphine oxides according to at least one of claims 1 to 8, wherein the alkylene oxide moieties in the single compounds of the mixture of structurally different compounds of formula (I) have different values of n and/or m or of the sum of m+n.

10. A flame retardant polymer comprising structural units of formula (X) wherein

R¹ is Ci-C₆-alkyl, cyclohexyl or phenyl,

R², R³, R⁴ and R⁵ each beinig same or different and independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms, n and m independently of one another are integers between 0 and 10. 42

11. The flame retardant polymer according to claim 10, wherein the polymer comprises different structural units of formula (X).

12. The flame retardant polymer according to claim 11 , wherein the polymer comprises at least two structural units of formulae (Xa), (Xb) and/or (Xc) optionally in combination with structural units of formula (Via) wherein

R^2a and R^3a independently of one another is hydrogen, an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon, 43

R^4a and R^5a independently of one another is an alkyl group having between one and eight carbon atoms or an aryl group having between six and eighteen carbon, and

R¹⁴ and R¹⁵ independently of one another are hydrogen, alkyl groups having between one and eight carbon atoms or aryl groups having between six and eighteen carbon atoms.

13. The flame retardant polymer according to at least one of claims 10 to 12, wherein the amount of structural units of formula (X) in the polymer is from 0.5 to 30 mol.-%, preferably from 0.5 to 20 mol.-% and most preferred from 1 to 10 mol.- %, referring to the total amount of the polymer.

14. The flame retardant polymer according to at least one of claims 10 to 13, wherein the polymer is a thermoplastic polymer, preferably selected from the group consisting of polyamides, polycarbonates, polyesters, polyvinyl esters, polyvinyl alcohols, polyurethanes and polyureas.

15. The flame retardant polymer according to at least one of claims 10 to 13, wherein the polymer is a duroplastic resin, preferably selected from the group consisting of polyurethane resins, epoxy resins, phenol-formaldehyde resins, melamine-formaldehyde resins, urea-formaldehyde resins and/or unsaturated polyesters.

16. The flame retardant polymer according to at least one of claims 10 to 15, wherein the polymer is a polyurethane.

17. A composition comprising a) a flame retardant polymer according to at least one of claims 10 to 16, and optionally b) at least one adjuvant.

18. A composition according to claim 17, wherein the additive is selected from the group consisting of antioxidants, blowing agents, further flame retardants, light 44 stabilizers, heat stabilizers, impact modifiers, processing aids, glidants, processing aids, nucleating agents and clarifiers, antistatic agents, lubricants, such as calcium stearate and zinc stearate, viscosity and impact modifiers, compatibilizers and dispersing agents, dyes or pigments, antidripping agents, additives for laser marking, hydrolysis stabilizers, chain extenders, softeners and/or plasticizers, fillers and/or reinforcing agents.

19. A shaped part prepared from a composition according to at least one of claims 17 to 18.

20. Use of a compound of formula (I) as defined in claim 1 as a monomer in the manufacture of flame-retardant polymers.

21. Use of the polymer composition according to at least one of claims 17 to 18 for the manufacture of high-resilience foam seating, rigid foam insulation panels, microcellularfoam seals and gaskets, durable elastomeric wheels and tires, automotive suspension bushings, electrical potting compounds, high-performance adhesives, surface coatings and sealants, synthetic fibers, carpet underlay, hard- plastic parts and hoses.

22. Use of the polymer composition according to at least one of claims 17 to 18 for the manufacture of electrical switch components, components in automobile construction, electrical engineering or electronics, printed circuit boards, prepregs, potting compounds for electronic components, in boat and rotor blade construction, in outdoor GFRP applications, domestic and sanitary applications and engineering materials.