Method for producing flame retardant polyurethane foams using halogen-free flame retardants

Abstract

The present invention relates to a process for producing flame-retarded polyurethane foams, in particular flexible polyurethane foams, using halogen-free flame retardants, wherein the resulting flame-retarded polyurethane foams exhibit low emission values coupled with good mechanical properties. The present invention further relates to halogen-free flame retardants.

Claims

1. A flame-retarded polyurethane foam obtainable by reacting a reaction mixture comprising a component which comprises a) at least one compound which comprises isocyanate-reactive hydrogen atoms, b) water and/or a physical blowing agent, c) auxiliary and additive substances, d) at least one halogen-free flame retardant comprising d.2) a phosphoric ester of formula (II) ##STR00007## wherein: n represents an integer from 1 to 4, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 each independently represent a hydrogen atom, a straight-chain, branched or cyclic C.sub.1- to C.sub.10-alkyl radical, a C.sub.6- to C.sub.12-aryl radical, a C.sub.2H.sub.2Ph radical, an O-alkyl radical having C.sub.1 to C.sub.5-carbon atoms, an O-aryl radical having C.sub.6 to C.sub.12-carbon atoms and/or COOR.sub.11 wherein R.sub.11 represents a C.sub.1- to C.sub.5-alkyl radical, with e) at least one di- and/or polyisocyanate, to form a foam, wherein the reaction mixture is free from halogen-containing flame retardants.

2. The flame-retarded polyurethane foam as claimed in claim 1, wherein the polyurethane foam is a flexible polyurethane foam.

3. An article comprising the polyurethane foam as claimed in claim 1 in the automobile, construction and/or furniture industries.

4. The article of claim 3, wherein said article comprises an automobile part, a construction part or a furniture part.

Description

DETAILED DESCRIPTION

(1) To produce the polyurethane foams, the reaction components are reacted by the one-step process known per se, often using mechanical means, for example those described in EP-A 355 000. Details of processing means also contemplated in accordance with the invention are reported in Kunststoff-Handbuch, volume VII, edited by Vieweg and Hchtlen, Carl-Hanser-Verlag, Munich 1993, for example on pages 139 to 265.

(2) The polyurethane foams are preferably in the form of flexible polyurethane foams and may be produced as molded foams or else as slabstock foams, preferably as slabstock foams. The invention therefore provides a process for producing the flame-retarded polyurethane foams, the flame-retarded polyurethane foams produced by these processes, the flame-retarded flexible polyurethane slabstock foams and flame-retarded flexible polyurethane molded foams produced by these processes, and also for the use of the flame-retarded flexible polyurethane foams.

(3) The components employed in the process according to the invention are more particularly described hereinbelow.

(4) Component a)

(5) Compounds according to component a) are compounds comprising isocyanate-reactive hydrogen atoms having a hydroxyl number (OH number) according to DIN 53240 of 5 mg KOH/g to 250 mg KOH/g, preferably of 9 mg KOH/g to 112 mg KOH/g, particularly preferably of 28 mg KOH/g to 60 mg KOH/g.

(6) Production of the compounds according to component a) is effected in a manner known per se by addition of alkylene oxides onto starter compounds having isocyanate-reactive hydrogen atoms under base catalysis or by using double metal cyanide compounds (DMC compounds). The starter compounds usually have functionalities of 2 to 8, preferably of 2 to 6, particularly preferably of 3, and are preferably hydroxy-functional. Examples of hydroxy-functional starter compounds are propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, hexanediol, pentanediol, 3-methyl-1,5-pentanediol, 1,12-dodecanediol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, sucrose, hydroquinone, catechol, resorcinol, bisphenol F, bisphenol A, 1,3,5-trihydroxybenzene, methylol-containing condensates of formaldehyde and phenol or melamine or urea. Preferably employed starter compounds are glycerol and/or trimethylolpropane.

(7) Suitable alkylene oxides are, for example, ethylene oxide, propylene oxide, 1,2-butylene oxide/2,3-butylene oxide and styrene oxide. It is preferable when propylene oxide and ethylene oxide are supplied to the reaction mixture individually, in admixture or successively. When the alkylene oxides are metered in successively the products produced (polyether polyols) comprise polyether chains having block structures. Products having ethylene oxide end blocks are characterized, for example, by elevated concentrations of primary end groups which impart advantageous isocyanate reactivity to the systems.

(8) The functionality of the polyether polyols is determined by the functionality of the starting compounds employed for producing the polyether polyols.

(9) In one embodiment of the invention component a) has a hydroxyl number (OH number) according to DIN 53240 of 5 mg KOH/g to 250 mg KOH/g, preferably of 9 mg KOH/g to 112 mg KOH/g, particularly preferably of 28 mg KOH/g to 60 mg KOH/g, a hydroxyl functionality of 2 to 8, preferably of 2 to 6, particularly preferably of 2 to 3. It is preferable when propylene oxide and/or ethylene oxide are supplied individually, in admixture or successively in the addition reaction of alkylene oxide onto suitable starter compounds.

(10) In a preferred embodiment component a) has an OH number according to DIN 53240 of 28 mg KOH/g to 60 mg KOH/g, a hydroxyl functionality of 2 to 3 and a proportion of 75 wt %, preferably 85 wt %, particularly preferably 95 wt %, of propylene oxide.

(11) Component b)

(12) Water and/or physical blowing agents are employed as component b). Physical blowing agents employed as blowing agents are for example carbon dioxide and/or volatile organic substances.

(13) Component c)

(14) Used as component c) are auxiliary and additive substances such as c.1) catalysts (activators), c.2) surface-active additive substances (surfactants), such as emulsifiers and customary foam stabilizers c.3) additives such as reaction retardants (for example acidic substances such as hydrochloric acid or organic acyl halides), cell regulators (for example paraffins or fatty alcohols or dimethylpolysiloxanes), pigments, dyes, optionally further flame retardants, stabilizers against aging and weathering effects, plasticizers, fungistatic and bacteriostatic substances, fillers (for example barium sulfate, kieselguhr, carbon black or whiting) and separating agents.

(15) These auxiliary and added substances for optional use are described for example in EP-A 0 000 389, pages 18-21. Further examples of auxiliary and added substances for optional use according to the invention and also details concerning ways these auxiliary and added substances are used and function are described in Kunststoff-Handbuch, volume VII, edited by G. Oertel, Carl-Hanser-Verlag, Munich, 3rd edition, 1993, for example on pages 104-127.

(16) Preferred as catalysts are aliphatic tertiary amines (for example trimethylamine, tetramethylbutanediamine), cycloaliphatic tertiary amines (for example 1,4-diaza[2.2.2]bicyclooctane, aliphatic amino ethers (for example dimethylaminoethyl ether and N,N,N-trimethyl-N-hydroxyethylbisaminoethyl ether), cycloaliphatic amino ethers (for example N-ethylmorpholine), aliphatic amidines, cycloaliphatic amidines, urea, derivatives of urea (for example aminoalkylureas; see, for example, EP-A 0 176 013, especially (3-dimethylaminopropylamino)urea), and tin catalysts (for example dibutyltin oxide, dibutyltin dilaurate, tin octoate).

(17) Particularly preferred as catalysts c.1) are c.1.1) urea, derivatives of urea and/or c.1.2) tin catalysts, preferably dibutyltin oxide, dibutyltin dilaurate, tin octoate, particularly preferably tin octoate and/or c.1.3) tertiary amines (for example 1,4-diaza(2,2,2)bicyclooctane), aliphatic amino ethers (for example dimethylamino ethyl ether).
Component d)

(18) Employed in accordance with the invention is at least one halogen-free flame retardant comprising d.1) a phosphoric ester of formula (I)

(19) ##STR00005## in which m represents an integer from 1 to 3, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 each independently represent H, a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, a C.sub.2H.sub.2Ph radical (styryl), an O-alkyl radical having C.sub.1 to C.sub.5-carbon atoms, preferably having C.sub.1 to C.sub.3-carbon atoms, particularly preferably having C.sub.1-carbon atoms, an O-aryl radical having C.sub.6 to C.sub.12-carbon atoms, preferably having C.sub.6-carbon atoms, and/or COOR.sub.11 where R.sub.11C.sub.1- to C.sub.5-alkyl radical, preferably C.sub.1- to C.sub.3-alkyl radical, particularly preferably C.sub.1-alkyl radical, and wherein at least one of the radicals R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 is distinct from H, or d.2) a phosphoric ester of formula (II)

(20) ##STR00006## in which n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 each independently represent H, a straight-chain, branched or cyclic C.sub.1- to C.sub.10-alkyl radical, preferably C.sub.1- to C.sub.6-alkyl radical, a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, a C.sub.2H.sub.2Ph radical (styryl), an O-alkyl radical having C.sub.1 to C.sub.5-carbon atoms, preferably having C.sub.1 to C.sub.3-carbon atoms, particularly preferably having C.sub.1-carbon atoms, an O-aryl radical having C.sub.6 to C.sub.12-carbon atoms, preferably having C.sub.6-carbon atoms, and/or COOR.sub.11 where R.sub.11C.sub.1- to C.sub.5-alkyl radical, preferably C.sub.1- to C.sub.3-alkyl radical, particularly preferably C.sub.1-alkyl radical.

(21) In one embodiment d) comprises a component d.1) according to formula (I), wherein m=3, one of the radicals R.sub.1, R.sub.2, R.sub.3, R.sub.4 or R.sub.5 is a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and the remaining radicals represent an H-Atom, or wherein m is an integer from 1 to 3 and R.sub.1, R.sub.3 and R.sub.5 are identical and represent a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H.

(22) In a further embodiment d) comprises a component d.1) according to formula (I), wherein m=3, one of the radicals R.sub.1, R.sub.2, R.sub.3, R.sub.4 or R.sub.5 is a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and the remaining radicals represent an H-Atom, or wherein m is an integer from 1 to 3 and R.sub.1, R.sub.3 and R.sub.5 represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H.

(23) In a further embodiment d) comprises a component d.1) according to formula (I), wherein m=3, R.sub.3 is a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, and R.sub.1, R.sub.2, R.sub.4 and R.sub.5 represent H, or wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H.

(24) In a further preferred embodiment d) comprises a component d.1) according to formula (I), wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H.

(25) In a further embodiment d) comprises a component d.1) according to formula (I), wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H.

(26) In a further embodiment the halogen-free flame retardant d) comprises a mixture of compounds d.1) according to formula (I), where m=1, m=2 and m=3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2, R.sub.4 represent H,

(27) In a further embodiment d) comprises a component d.1) according to formula (I), wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H, wherein component d.1) is in the form of a mixture of compounds where m=3 in an amount of 20 to 26 wt %, where m=2 in an amount of 25 to 35 wt % and where m=1 in an amount of 45 to 55 wt %.

(28) In one embodiment of d.2) according to formula (II) n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably 1, represent and one of the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 is selected from the group consisting of H, straight-chain, branched or cyclic C.sub.1- to C.sub.10-alkyl radical, preferably C.sub.1- to C.sub.6-alkyl radical, a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, a C.sub.2H.sub.2Ph radical (styryl), an O-alkyl radical having C.sub.1 to C.sub.5-carbon atoms, preferably having C.sub.1 to C.sub.3-carbon atoms, particularly preferably having C.sub.1-carbon atoms, an O-aryl radical having C.sub.6 to C.sub.12-carbon atoms, preferably having C.sub.6-carbon atoms, or COOR.sub.11 where R.sub.11C.sub.1- to C.sub.5-alkyl radical, preferably C.sub.1- to C.sub.3-alkyl radical, particularly preferably C.sub.1-alkyl radical, and the remaining radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 represent an H atom.

(29) In a further embodiment of d.2) according to formula (II) n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably 1, one of the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 is selected from the group consisting of H, O-alkyl radical having C.sub.1 to C.sub.5-carbon atoms, preferably having C.sub.1 to C.sub.3-carbon atoms, particularly preferably having C.sub.1-carbon atoms, or COOR.sub.11 where R.sub.11C.sub.1- to C.sub.5-alkyl radical, preferably C.sub.1- to C.sub.3-alkyl radical, particularly preferably C.sub.1-alkyl radical, and the remaining radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 represent an H atom.

(30) In a preferred embodiment of d.2) according to formula (II) n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, and the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 are identical and represent H.

(31) In a further preferred embodiment of d.2) according to formula (II) n represents an integer of 1 and the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 are identical and represent H.

(32) In one embodiment the halogen-free flame retardant d) comprises a compound d.1) according to formula (I), wherein m=3, one of the radicals R.sub.1, R.sub.2, R.sub.3, R.sub.4 or R.sub.5 is a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and the remaining radicals represent an H atom, or wherein m is an integer of 1 to 3 and R.sub.1, R.sub.3 and R.sub.5 are identical and represent a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or a C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H, or a compound d.2) according to formula (II), in which n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, and one of the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 is selected from the group consisting of H, straight-chain, branched or cyclic C.sub.1- to C.sub.10-alkyl radical, preferably C.sub.1- to C.sub.6-alkyl radical, a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, a C.sub.2H.sub.2Ph radical (styryl), an O-alkyl radical having C.sub.1 to C.sub.5-carbon atoms, preferably having C.sub.1 to C.sub.3-carbon atoms, particularly preferably having C.sub.1-carbon atoms, an O-aryl radical having C.sub.6 to C.sub.12-carbon atoms, preferably having C.sub.6-carbon atoms, or COOR.sub.11 where R.sub.11C.sub.1- to C.sub.5-alkyl radical, preferably C.sub.1- to C.sub.3-alkyl radical, particularly preferably C.sub.1-alkyl radical, and the remaining radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 represent an H atom, employed.

(33) In a further embodiment the halogen-free flame retardant d) comprises a compound d.1) according to formula (I), wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent a C.sub.6- to C.sub.12-aryl radical, preferably C.sub.6-aryl radical, or C.sub.2H.sub.2Ph radical (styryl) and R.sub.2 and R.sub.4 represent H, or a compound d.2) according to formula (II), in which n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, one of the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 is selected from the group consisting of H, O-alkyl radical having C.sub.1 bis C.sub.5-carbon atoms, preferably having C.sub.1 to C.sub.3-carbon atoms, particularly preferably having C.sub.1-carbon atoms, or COOR.sub.11 where R.sub.11C.sub.1- to C.sub.5-alkyl radical, preferably C.sub.1- to C.sub.3-alkyl radical, particularly preferably C.sub.1-alkyl radical, and the remaining radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 represent an H atom.

(34) In a further embodiment the halogen-free flame retardant d) comprises a compound d.1) according to formula (I), wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2, R.sub.4 represent H, or a compound d.2) according to formula (II), in which n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, and the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 are identical and represent an H atom.

(35) In a further embodiment the halogen-free flame retardant d) comprises a mixture of compounds d.1) according to formula (I), where m=1, m=2 and m=3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2, R.sub.4 represent H, or a compound d.2) according to formula (II), in which n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, and the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 are identical and represent an H atom.

(36) In a further embodiment the halogen-free flame retardant d) comprises a compound d.1) according to formula (I), wherein m is an integer from 1 to 3, R.sub.1, R.sub.3 and R.sub.5 are identical and represent C.sub.2H.sub.2Ph radical (styryl) and R.sub.2, R.sub.4 represent H, and wherein component d.1) is in the form of a mixture of compounds where m=3 in an amount of 20 to 26 wt %, where m=2 in an amount of 25 to 35 wt % and where m=1 in an amount of 45 to 55 wt %, or a compound d.2) according to formula (II), in which n represents an integer from 1 to 4, preferably from 1 to 2, particularly preferably of 1, and the radicals R.sub.6, R.sub.7, R.sub.8, R.sub.9 or R.sub.10 are identical and represent an H atom.

(37) Component d) may be employed in an amount of 1 to 30 pphp (pphp=parts per hundred parts polyol), preferably of 5 to 25 pphp and particularly preferably of 8 to 20 pphp.

(38) Component e)

(39) Employed as component e) are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic di- or polyisocyanates, such as are described for example by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example those of the formula (III)
Q(NCO).sub.n(III)

(40) in which

(41) n=2-4, preferably 2-3,

(42) and

(43) Q represents an aliphatic hydrocarbon radical having 2-18, preferably 6-10, carbon atoms, a cycloaliphatic hydrocarbon radical having 4-15, preferably 6-13, carbon atoms or an araliphatic hydrocarbon radical having 8-15, preferably 8-13, carbon atoms.

(44) The polyisocyanates are for example those described in EP-A 0 007 502, pages 7-8. Particular preference is generally given to the readily industrially obtainable polyisocyanates, for example 2,4- and 2,6-tolylene diisocyanate and any desired mixtures of these isomers (TDI); polyphenylpolymethylene polyisocyanates as prepared by aniline-formaldehyde condensation and subsequent phosgenation (crude MDI), and polyisocyanates having carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups (modified polyisocyanates), especially those modified polyisocyanates which derive from 2,4- and/or 2,6-tolylene diisocyanate or from 4,4- and/or 2,4-diphenylmethane diisocyanate. It is preferable when at least one compound selected from the group consisting of 2,4- and 2,6-tolylene diisocyanate, 4,4- and 2,4- and 2,2-diphenylmethane diisocyanate and polyphenyl polymethylene polyisocyanate (polycyclic MDI) is employed as component e). It is particularly preferable when an isomer mixture of 2,4- and 2,6-tolylene diisocyanate is employed as component e). Particularly preferably employed as component e) is an isomer mixture of 2,4- and 2,6-tolylene diisocyanate in a weight ratio 80:20.

(45) The NCO content of employed component e) may be in the range of 15-54%, preferably of 28-51% and particularly preferably of 47-49%.

(46) To produce the polyurethane foams, the reaction components are reacted by the one-step process known per se, often using mechanical means, for example those described in EP-A 355 000. Details of processing means also contemplated in accordance with the invention are reported in Kunststoff-Handbuch, volume VII, edited by Vieweg and Hchtlen, Carl-Hanser-Verlag, Munich 1993, for example on pages 139 to 265.

(47) The index indicates the percentage ratio of the actually employed isocyanate amount to the stoichiometric, i.e. calculated for the conversion of the OH equivalents, amount of isocyanate groups (NCO) amount.
Index=[(isocyanate amount employed):(isocyanate amount calculated)].Math.100(VIII)

(48) In one embodiment the reaction of the isocyanate-reactive components A with the isocyanate component B is effected with an index of 50 to 250, preferably with an index of 90-125.

(49) The polyurethane foams produced by the process according to the invention are preferably flexible polyurethane foams. These feature not only flame retardant properties but also low emission characteristics. Thus, the fogging value according to DIN 75201 B of the polyurethane foams produced according to the invention is 0.70 mg. The overall sum of the omissions according to VDA 278 (VOC value+FOG value) is 1250 mg/kg.

(50) The polyurethane foams produced according to the invention may be employed inter alia in the construction, automobile and/or furniture industries.

EXAMPLES

(51) d-1: tris(phenoxyethyl) phosphate

(52) d-2: tris(tristyrylphenyl) phosphate

(53) d-3: Fyrol PCF from ICL Industrial Products: tris(2-chloroisopropyl) phosphate

(54) d-4: Phosflex 71B from ICL Industrial Products: mixture of butylated triphenylphosphate ester

(55) Polyether polyol a-1: DMC-catalyzed, glycerol- (90.2%) and monopropylene-glycol-started (9.8%) polyether polyol comprising 99% propylene oxide and 1% ethylene oxide, having an OH number of 56 mg KOH/g.

(56) c-1: Niax L620 from Momentive Performance Chemicals, Germany (catalyst)

(57) c-2: Dabco 33LV from Air Products, Germany (catalyst)

(58) c-3: Niax A1 from Momentive Performance Chemicals, Germany (catalyst)

(59) c-4: Dabco T-9 (Tin (II) 2-ethylhexanoate) from Air Products, Germany (catalyst)

(60) e-1: Mixture of 2,4- and 2,6-TDI in a weight ratio of 80:20 and having an NCO content of 48 wt %.

(61) The phosphoric esters d-1, and d-2 were produced as follows:

(62) d-1: tris(phenoxyethyl) phosphate

(63) Under a dry nitrogen atmosphere, 477.00 g of phenoxyethanol (3.45 mol) in 4.6 l of dry toluene are initially charged into a 10 l four-necked flask stirring apparatus and heated to 80 C. 621.00 g of sodium methoxide solution (30 wt % in methanol; 3.45 mol) are added dropwise via a dropping funnel and the dropping funnel is then rinsed out with 20 g of dry methanol. 3.8 l of methanol/toluene are distilled off via a distillation bridge up to a tops temperature of 110 C. Two 1 l portions of dry toluene are further metered in during the distillation. After cooling of the reaction mixture to 90 C. a further 500 mL of dry toluene are metered in and a solution of 176.53 g of phosphoryl chloride (1.15 mol) in 400 mL of dry toluene are added dropwise. The reaction is allowed to react for 4.5 h under reflux and then cool to room temperature. The obtained solution is filtered off from the precipitated solid, divided among two separating funnels and in each case extracted four times with 400 mL of water. Concentrating at 50 C. under vacuum affords 278.0 g (53% of theory) of the high-viscosity target compound from the combined toluene solutions.

(64) .sup.31P{.sup.1H} NMR (toluene, 25 C.): 2.0 ppm [s]

(65) d-2: tris(tristyrylphenyl) phosphate

(66) Under a dry nitrogen atmosphere, 669.20 g of tristyrylphenol (1.8 mol) in 4 l of dry toluene are initially charged into a 10 l four-necked flask stirring apparatus and heated to 80 C. 324.00 g of sodium methoxide solution (30 wt % in methanol; 1.8 mol) are added dropwise via a dropping funnel and the dropping funnel is then rinsed out with 20 g of dry methanol. 2.1 l of methanol/toluene are distilled off via a distillation bridge up to a tops temperature of 110 C. After cooling of the reaction mixture to 80 C. a further 1 lL of dry toluene is metered in and a solution of 92.10 g of phosphoryl chloride (0.6 mol) in 500 mL of dry toluene are added dropwise. The reaction is allowed to react for 1.5 h under reflux and then cool to room temperature. The obtained solution is filtered off from the precipitated solid and in a separating funnel extracted with 100 mL of 1 M HCl and subsequently four times with 200 mL of water. Concentrating at 50 C. under vacuum affords 446.6 g (64% of theory) of a high-viscosity residue. The residue comprises about 23% tris(tristyrylphenyl) phosphate, about 28% bis(tristyrylphenyl) phosphate and about 49% mono(tristyrylphenyl) phosphate. .sup.31P{.sup.1H} NMR (toluene, 25 C.): 5.1 ppm [m, mono(tristyrylphenyl) phosphate]; 7.6 ppm [m, bis(tristyrylphenyl) phosphate]; 14.8 ppm [m, tris(tristyrylphenyl)phosphate]

(67) Tristyrylphenol: produced by Tanatex Chemicals; mixture of about 70% 2,4,6-tristyrylphenol, about 25% 2,6-distyrylphenol and tetrastyrylphenol.

(68) The starting components according to table 1 are processed in a single-stage process by slabstock foaming under the processing conditions customary for the production of polyurethane foams. Indications concerning the input materials (pphp) are based on 100 parts of polyether polyol b-1. Table 1 reports the index for the processing stage (this determines the amount of component B to be employed relative to component A). The index (isocyanate index) indicates the percentage ratio of the actually employed isocyanate amount to the stoichiometric, i.e. calculated, isocyanate groups (NCO) amount.
Index=[(isocyanate amount employed):(isocyanate amount calculated)].Math.100(IV)

(69) Apparent density was determined according to DIN EN ISO 3386-1-98.

(70) Indentation hardness (CLD 40%) was determined according to DIN EN ISO 3386-1-98 at 40% deformation, 4th cycle.

(71) Fogging was determined by gravimetric means according to DIN 75201B.

(72) The VOC value (Volatile Organic Compounds) in mg/kg (toluene equivalent) and FOG value in mg/kg (hexadecane equivalent) was determined according to VDA 278 (October 2011).

(73) The fire test was performed according to Directive 95/28/EC.

(74) .sup.31P{.sup.1H} NMR was measured in toluene with 85% aqueous phosphoric acid as external standard on a Bruker DPX 400 spectrometer at 25 C.

(75) TABLE-US-00001 Example Unit 1 2 3 (comp.) 4 (comp.) 5 (comp.) a-1 pphp 100 100 100 100 100 Water pphp 3.5 3.5 3.5 3.5 3.5 d-1 pphp 8.0 d-2 pphp 8.0 d-3 pphp 8.0 d-4 8.0 c-1 pphp 0.30 0.30 0.30 0.30 0.30 c-2 pphp 0.24 0.24 0.24 0.24 0.24 c-3 pphp 0.04 0.04 0.04 0.04 0.04 c-4 pphp 0.22 0.22 0.22 0.22 0.22 Index 102 102 102 102 102 e-1 pphp 43.54 43.54 43.54 43.54 43.54 Apparent density kg/m.sup.3 33.2 26.7 36.2 33.0 35.7 Indentation hardness kPa 3.9 2.5 4.04 4.6 4.2 Fogging DIN75201B mg 0.29 0.56 22.6 0.04 0.72 VOC value (VDA278) mg/kg 412 542 1256 160 496 FOG value (VDA278) mg/kg 99 632 3931 2 829 Sum of VOC + FOG values mg/kg 511 1174 5187 162 1325 Directive 95/28/EC fire test passed yes yes yes no yes (comp.): Comparison

(76) The inventive examples 1 and 2 exhibit markedly lower fogging values (gravimetric) compared to polyurethane foams produced with the conventional halogen-containing flame retardants (comparative example 3) or with butylated triphenylphosphate ester as flame retardant (comparative example 5).

(77) Moreover, the polyurethane foams produced with the flame retardants according to the invention exhibit markedly fewer emissions of high- and low-volatility organic constituents (sum of VOC and FOG value according to VDA 278).