WO2009078725A1

WO2009078725A1 - Fire retardant composition

Info

Publication number: WO2009078725A1
Application number: PCT/NL2008/050833
Authority: WO
Inventors: Henri Jacobus Gruenbauer; Martin Moeller; Karin Peter; Sylwia Szkudlarek; Ronald Van Den Bosch
Original assignee: Dow Global Technologies Inc.
Priority date: 2007-12-19
Filing date: 2008-12-19
Publication date: 2009-06-25

Abstract

The invention relates to the use of a functionalized polyalkoxysilane or alkoxysilane as a fire retardant. The invention relates further to a composition comprising at least one polyol and at least one (poly)alkoxysilane, wherein the (poly)alkoxysilane comprises functional groups capable of reacting with an isocyanate. The invention further relates to a polyurethane-(poly)alkoxysilane copolymer derived from substances comprising one or more polyols, one or more functionalised (poly)alkoxysilanes and one or more isocyanates.

Description

Title: Fire retardant composition

The invention relates to a composition comprising alkoxysilane or polyalkoxysilane and being suitable for preparing a polymer, to a copolymer, a polymeric material comprising such copolymer and to the use of said silane as a fire retardant.

The development of a fire can be characterized by three phases (J. Tritzsch, "International Plastics Flammability Handbook", 2nd edition, Carl Hanser Verlag, Munich, 1990, hereafter "Tritzsch"): (1) an initial, "smouldering" phase where an ignition source causes local decomposition of polymers yielding, amongst others, highly reactive liquid and gaseous organic radicals via an essentially endothermic reaction. Eventually, this phase leads to combusion of the polymer in phase (2), the "flame spread" phase when the gaseous mixtures of volatilized, degraded polymer fragments in air are within the flammability limits and above the ignition temperature. This phase ends with a so-called flash-over when the exothermic energy produced by the thermal oxidation in both the gas phase and the condensed phase has become sufficient to compensate the endothermic supply of combustibles to the flame by the ongoing thermal degradation of the polymer. The flash-over marks the start of phase (3), the "fully developed fire" which is self-sustaining until extinction occurs due to a lack of fuel or oxygen (A.F. Grand; CA. Wilkie, eds, "Fire Retardancy of Polymeric Materials", 1st edition, Marcel Dekker, Inc., New York, 2000, hereafter "Grand"). In order to improve the resistance of ignitable polymeric materials against fire, it is common practice to provide such materials with a variety of fire retardant agents, to provide fire retardant activity within the above phases.

Suitable fire-retardant molecules interrupt development of fires either by a physical action (e.g. by cooling, formation of protective layers or, for fillers, dilution) or by a chemical action in the gas phase (eg. radical scavenging) or in the condensed phase (e.g. radical scavenging, charring or formation of an intumescent layer) (Tritzsch, supra.). In the latter case compounds with designed thermal degradation profiles are frequently used, such that fire-retardant active species are released by a parent compound at the temperature regime where they are most needed. It is for example well- known that, amongst the rather popular radical scavenging organic halogen compounds, fluorines are too stable to release radical scavenging F' groups in time whereas, in contrast, iodine compounds are too unstable for that purpose. As a result, compounds containing bromine and chlorine are most frequently used as halogen-containing fire retardants, often in combination with phosphorous. In practice, one or more fire retardants acting in the gas phase are being combined with one or more fire retardants acting in the condensed phase to ensure that fire retardancy takes place during all the above phases of fire develpoment. Examples of fire retardants acting in the gas phase are triethylphosphate (TEP) and diethyl ethylphosphonate (DEEP) whereas Tris(2-chloroisopropyl)phosphate (TCPP) provides a good example of a fire retardant acting both in the gas phase and in the condensed and. All of these fire retardants are thought to act primarily by a radical scavenging mechanism. In contrast, fire retardants of higher thermal stability, such as melamines, are thought to act at later stages of the fire, either by a charring or intumescent mechanism. Combinations of all these different types of fire retardants are commonly used.

Or gano- silicon compounds have been proposed for use as a smoke- retardant in a polyisocyanurate foam. US 4,133,781 relates to a smoke-retardant polyisocyanurate foam containing 2-30 wt. % of an organosilicate containing a hydroxypolyoxyalkylene group.

DE-A 26 10 640 relates to a method for preparing a smoke-retardant polyisocyanurate foam, using an organopolysiloxane-poly-oxyalkylene compolymer surfactant. This surfactant is typically present in concentration of 0.5-6 wt. %.

DE-A 26 09 181 relates to a method for preparing a smoke-retardant polyisocyanurate foam, using an organosilicate with the formula Si(OR)4 or R_nSi(OR')4-n wherein R and R' are hydrocarbon groups and n is an integer from 1-3. The organo-silicate is typically used in a concentration of 0.2-3 wt. %. These noted publications only relate to isocyanurate foams (PIR foams). Isocyanurate foams tend to intrinsically have a relatively high fire retardancy, compared to polyurethane foams (PUR). Further, the concentrations of the organo-silicate are relatively high, which may, e.g., be detrimental to a mechanical product property.

In addition, these organo- silicates may be relatively volatile, which can be an undesirable trait when forming the polyisocyanurate foam. Further, these organo-silicates may have a relatively high migratability in a cured polymer composition. Thus, they may leach out of the polymer relatively easy and thus become ineffective.

In view of the complexity of improving the fire retardant properties of ignitable materials there is a continuous need for ways of accomplishing such improvement. In view of the expected increase in regulatory pressure on halogen- containing industrial products, there is a also a need to replace halogen- containing fire retardant agents, in particular volatile halogen-containing fire retardants with environmentally less harmful materials without sacrificing fire retardant properties and cost performance. It has now been found that a specific group of silanes is capable of acting as a fire retardant agent in an ignitable polyurethane-based material.

Accordingly the present invention relates to the use of a alkoxysilane (AOS) or a polyalkoxysilane (PAOS) as a fire retarandant. Polyalkoxysilane may also be referred to as polyalkylorthosilicate and refers specifically to poly(alkoxysilane). The term alkoxysilane is used herein for a alkoxysilane compound having a single Si, whereas polyalkoxysilane comprises a plurality of Si's. As further explained below, certain elements other than Si, C, O and H may be present in the polyalkoxysilane molecule as long as at least one, preferably at least two, and even more preferably more than two, Si atoms are present.

The alkoxysilane may in particular be represented by the structural formula (RiO)3-Si-R2, or (RiO)3-Si-O-R2 where Ri and R2 are alkyl, wherein the alkyl group may be straight or branched chain, or cyclic, and has at least 1, preferably at least 2, up to 16, preferably up to 12, more preferably up to 6, and even more preferably up to 2, carbon atoms. Alkoxysilane may also be referred to as alkylorthosilicate.

The PAOS preferably comprises at least one branched unit within a PAOS molecule having the chemical structure of formula (1):

wherein Ri has the same meaning as defined above.

More preferably, the PAOS comprises at least one branched unit within a PAOS molecule having the chemical structure of formula (2):

wherein Ri and R2 have the same meaning as defined above. A PAOS molecule preferably has multiple branched units of formula

(1). More preferably, a PAOS molecule has multiple units of formula (2).

The PAOS preferably has a weight- average molecular weight (M _w) of at least 5 x 10², more preferably at least 1 x 10^, even more preferably at least 2 x 10^ up to 1 x 10⁴, more preferably up to 7 x 10^. Typically, the PAOS or AOS bears isocyanate-reactive (X) moieties. Such functionalised polyalkoxysilane, respectively alkoxysilane, may herein after be referred to as PAOS-X respectively AOS-X. An isocyanate reactive group may be attached indirectly to a Si atom, e.g. via an alkylene moiety or another organic moiety, or directly to a Si atom, e.g. AOS or PAOS may be provided with -OH groups by (partially) hydrolysing the AOS or PAOS, whereby -OH groups directly attached to Si are formed

AOS-X may be represented by the chemical structure of formula (3):

(R₁O)₃ Si— A— X ₍₃₎ wherein —A— represents a covalent bond, —A'— or — 0— A'— , wherein A' represents a straight or branched alkylene group having at least one, preferably at least two, up to 16, preferably up to 12, more preferably up to six, and even more preferably up to two, carbon atoms.

PAOS-X preferably comprises at least one branched unit within a PAOS-X molecule having the chemical structure of formula (4):

wherein A and X are defined as above.

PAOS-X preferably comprises at least one branched unit within a

PAOS-X molecule having the chemical structure of formula (4) and the same PAOS-X molecule preferably further comprises at least one unit having the chemical structure of formula (1). More preferably, the same PAOS-X molecule further comprises at least one unit having the chemical structure of formula (2).

The same PAOS-X molecule preferably comprises multiple units (at least 2, preferably at least 4) of formula (1). More preferably, the same PAOS-

X molecule comprises multiple units (at least 2, preferably at least 4) of formula (2). Even more preferably, the same PAOS-X molecule comprises multiple units of formula (4).

The PAOS-X preferably has a M_w of at least 5 x 10², more preferably at least 1 x 10^, even more preferably at least 2 x 10^ up to 1 x 10⁴, more preferably up to 7 x 10^.

An aspect of this invention is the use of AOS and/or PAOS, or a corresponding residue of AOS-X and/or PAOS-X in a polyurethane polymer, as a fire-retardant in an ignitable material. As a fire retardant, PAOS is in particular preferred, inter alia for its reduced volatility compared to AOS. In particular the invention relates to a polyol composition comprising (a) one or more polyols bearing at least two isocyanate reactive hydrogen atoms, and (b) one of more adjuvants, wherein at least one adjuvant is a polyalkoxysilane (PAOS), or alkoxysilane (AOS), substance bearing isocyanate-reactive (X) moieties. The invention further relates to a polyurethane-(poly)alkoxysilane copolymer at least composed of one or more polyols, at least one PAOS or AOS substance bearing isocyanate-reactive moieties, and one or more isocyanates.

The invention further relates to a two component system suitable for the manufacture of polyisocyanate-based polymer which comprises (a) a first component, being an aliphatic or aromatic polyisocyanate; and

(b) a second component, being a polyol composition according to the invention. Such a system may for instance suitably be used to prepare a PUR or PIR foam or an elastomer.

The invention further relates to a polyisocyanate-based polymer obtainable by a reaction of a polyisocyanate with a polyol composition of the invention. Preferably such polymer is obtainable by intimately mixing under reaction conditions an organic polyisocyanate with a polyol composition according to the invention.

The invention further relates to a polymeric material, in particular a foam, comprising a polymer of the invention. The invention further relates to an article having a laminate structure wherein at least one lamella is a polyisocyanate-based polymer according to the invention.

The invention further relates to an insulation panel comprising a polyisocyanate-based polymer according to the invention.

The invention further relates to a method of providing a polyisocyanate-based polymer with a retarded flammability or combustibility performance which comprises preparing the polymer by reacting a polyisocyanate with a polyol in the presence of an effective amount of a fire retarding adjuvant wherein, the adjuvant comprises a PAOS or AOS substance bearing isocyanate-reactive (X) moieties. The reaction is preferably carried out by continuously mixing a polyisocyanate, a polyol and a AOS-X or PAOS-X and allowing the mixture to react. The mixing is preferably carried out by impingement mixing or mixing in a static mixer. Figure 1 shows a preferred reaction scheme for the preparation of

PAOS.

Figures 2A and 2B show a further reaction scheme for the preparation of functionalized PAOS via, respectively, transesterification or co- condensation. Figure 3 shows yet another reaction scheme for the preparation of

PAOS.

It has been found that, in particular, when the PAOS-X or AOS-X is incorporated in the backbone of a isocyanate based polymer, fire retardancy, as determined by a fire retardant test such as the German DIN 4102 B2 test (in particular for rigid foams) or the CAL 117-Al "Vertical Burning" test, as described in California Technical Bulletin 117 Section A Part 1 (in particular for flexibile foams), is improved.

In particular (incorporated) PAOS-X or AOS-X may act as an intumescent, i.e. a moiety which takes part in forming a protective coating (a polysilicate coating) that prevents access of oxygen. Depending upon the functionality X one or more gaseous compounds are formed (when a polymer material comprising at least one PAOS-X or AOS-X component is exposed to excessive heat, e.g. fire). Such gaseous compound may contribute to fire retardancy. For instance, ammonia and water may be formed in case the polyurethane is exposed to extreme heat, such as from a fire, if the PAOS-X or AOS-X comprises amine functionalities.

It has been found that the ability of the PAOS-X or AOS-X to be incorporated into the polymer provides the advantage to the observed fire retardant activity. Further, as will be explained below, the decomposition temperature of PAOS-X, can be modified by modifying the backbone structure of the silane by incorporating Si-C linkages for increased thermal stability and/or to incorporate or graft one ore more fire retardant atoms or groups, for instance phosphates, phosphonates or phenyl groups.

In particular, a PAOS-X or AOS-X may be provided with a decomposition temperature, as measured by thermal gravimetric analysis

(TGA), in a particular range, such as in the range of about 50-350 ⁰C. Factors that may have an effect on the decomposition temperature, such as degree of branching, the presence of specific functional groups, etc. will be discussed in more detail below. As used herein, the decomposition temperature is the decomposition temperature as determinable by TGA-Mass Spectrometry (TGA-MS), using the following conditions: temperature scan rate: 10 °C/min minimum temperature: 25 ⁰C - maximum temperature: 700 ⁰C detector: multiplier, scan speed 0.1 sec sample holder: Pt Open sample weight: 5 mg atmosphere: inert (e.g. noble gas, such as helium, nitrogen, a mixture of noble gas and nitrogen) Thus, it has for instance been found possible to provide PAOS-X or AOS-X that can be used to partially or fully replace halogen containing fire retardants having an intermediately high decomposition temperature, such as TCPP. Thus, in an embodiment, the invention provides a polymeric material which is essentially free of halogenated fire-retardants.

Besides contributing to fire retardancy, in particular PAOS-X may contribute to an improved mechanical property in a polymer material, compared to a polymer material comprising a conventional fire retardant, at a concentration having a similar fire retardant effect. For example in a foamed rigid polyurethane polymer, wherein PAOS-X is incorporated, compressive strength and/or cell anisotropy may be improved. With respect to improved cell anisotropy, in particular the difference between the compressive strength in the parallel direction to the compressive strength in the perpendicular direction may be smaller, i.e. the ratio of the compressive strength in the parallel direction to the compressive strength in the perpendicular direction may be closer to 1.

This is particularly surprising, because application as fire retardants of known organo- silicon compounds, such as tetraethoxylsilane is usually accompanied by poor compatibilities with polyols, at effective concentrations. Poor compatibility may subsequently lead to inferior foam physical properties. The inventors also found (as part of an internal research) that in particular PAOS-X is better miscible with a polyol than unfunctionalised PAOS, due to a better compatibility. Thus, mixtures comprising polyol and PAOS-X tend to be more homogenous, such that a mechanical property is improved.

Thus, in a particular advantageous embodiment, the invention provides a composition for preparing a polyurethane, with good fire retardancy and good mechanical properties, wherein the content of halogen containing fire retardants is low or even essentially absent, and wherein the content of volatile/migratable fire retardants is low or even essentially absent. It is further an advantage, that in particular PAOS-X or AOS-X (when incorporated) in a polymer according to the invention show an improved effect on fire retardancy at a relatively low concentration. In particular when compared to the above identified prior art organo-silicates, fire retardancy is improved at the same or even at a lower concentration. Thus the fire retardant may be used at a lower concentration for a similar fire retardant effect or even better effect. In fact, PAOS-X or AOS-X may contribute more to fire retardancy at a specific concentration than known halogenated fire retardants. Thus, it may be used at a lower concentration than such halogenated fire retardants to achieve a similar effect or at the same concentration for an improved effect.

The concentration of PAOS-X or AOS-X may be chosen within a wide range, depending upon factors such as indicated above, in particular the desired level of fire retardance, desired mechanical properties, the extent to which it is desirable to reduce the halogen containing fire retardant content and/or the extent to which it is desirable to reduce the volatile fire retardant content.

Usually, a composition according to the invention comprises at least 0.1 parts by weight (pbw) PAOS-X or AOS-X per 100 pbw polyol. In particular the composition may comprise at least 0.2 pbw PAOS-X or AOS-X /100 pbw polyol, more in particular at least 0.5 pbw PAOS-X or AOS-X /100 pbw polyol or at least 1.0 pbw PAOS-X or or AOS-X /100 pbw polyol.

For practical reasons, the composition according to the invention usually comprises 20 pbw PAOS-X or AOS-X per 100 pbw polyol or less. Preferably, the concentration is 10 pbw PAOS or AOS-X -X per 100 pbw polyol or less. In a particularly preferred composition, the concentration is 5 pbw

PAOS-X or AOS-X per 100 pbw polyol or less, more in particular 3 pbw PAOS- X or AOS-X per 100 pbw polyol or less.

In addition to PAOS-X or AOS-X , optionally PAOS or AOS may be present, in particular residual PAOS or AOS that has not been functionalised when preparing PAOS-X or AOS-X . The PAOS or AOS concentration is generally less than the PAOS-X or AOS-X concentration, preferably at least 10 times less.

For the copolymer of the invention analogous ranges apply for the PAOS-X or AOS-X based units per 100 polyol based units of which the polymer is composed.

As indicated above, PAOS-X or AOS-X contains functional groups that are capable of reacting with an isocyanate. The functional group usually comprises a so called active hydrogen moiety. This term is generally known in the art. For the purposes of this invention, an active hydrogen moiety refers to a moiety containing a hydrogen atom which, because of its position in the molecule, displays significant activity according to the Zerewitnoff test described by Kohler in the Journal of American Chemical Society, Vol. 49, page 3181 (1927). In particular the functional groups X may be selected from the group of -COOH, -OH, -SH, -CONH₂, glycidyl, epoxy, -NH₂, -CONHR and - NHR. In the moiety NHR, R is an organic moiety, in particular an optionally substituted hydrocarbon moiety, more in particular an alkyl, a cycloalkyl, an alkenyl or an aryl, preferably an unsubstituted or substituted alkyl. The substituent, if present, is usually different from halogen atoms. R usually comprises 1-12 carbons, in particular 1-6 carbons. In a preferred embodiment, PAOS-X or AOS-X comprises at least one moiety selected from the group of -CONH₂, -NH₂, -CONHR and -NHR'. Herein R' is as identified above, and in particular R' may be selected from unsubstituted and substituted alkyls, more in particular from C1-C6 alkyls. A PAOS-X or AOS-X comprising such a moiety may in particular show good stability, compared to e.g. PAOS-OH or AOS-OH , with respect to degradation due to hydrolysis. Of these compounds, a PAOS-X or AOS-X comprising -NH₂ groups is particularly preferred.

The PAOS or AOS may in particular comprise alkoxygroups comprising 1-16 carbon atoms, more in particular 2-12 carbon atoms even more in particular 2-6. PAOS-X usually is branched. The extent to which PAOS-X is branched may influence its thermal stability (decomposition temperature). Thus, depending on a desired decomposition temperature a more or less branched PAOS-X may be used. For a high thermostability, PAOS-X preferably is hyperbranched.

Hyperbranched macromolecules are highly branched macromolecules, generally with a three-dimensional dentritic architecture. Their structure is in general essentially randomly branched (as opposed to true dendrimers). Hyperbranched macromolecules may normally be obtained from AB_n monomers with n is 2, where only the reaction between A and B is normally possible (Jaumann et al, Macromol. Chem. Phys. 2003, 204, 7, pp. 1014-1026).

As used herein, the term hyperbranched is generally used for a PAOS respectively PAOS-X having a degree of branching (DB) of at least 0.2. Preferably DB is at least 0.3, at least 0.4 or at least 0.5. DB usually is 0.9 or less. In particular DB may be 0.8 or less, more in particular 0.7 or less.

DB is defined as follows:

DB = [2Q₄+Q₃)]/[2/3(3Q4+2Q₃ +Q₂)] wherein - Q₂ is the fraction of silicon atoms bearing two alkoxy groups, or other substituents {i.e. linear units, linked to two other silicon atoms via an oxygen)

Q3 is the fraction of silicon atoms bearing one alkoxy group, or other substituent {i.e. semi -dendritic units, linked to three other silicon atoms via an oxygen)

Q4 is the fraction of silicon atoms bearing no alkoxy group, or other substituent {i.e. dendritic units, linked to four other silicon atoms via an oxygen) A remainder of the silicons may form fraction Qi (terminal units, linked to one other silicon atom via an oxygen) or Qo (monosilicate unts, not linked to any other silicon atom via an oxygen.

Qo to Q4 can be determined with ²⁹Si NMR (See Zhu et al. Macromolecules, 2006, 39, 1701-1708).

In particular, for a hyperbranched PAOS-X, Q4 usually is at least 1 %. In particular for increased thermal stability, Q4 preferably is at least 3 %, or at least 4 %. Depending upon the desired decomposition temperature, Q4 preferably is 30 % or less, 20 % or less, or 15 % or less. In particular for a hyperbranched PAOS-X, Q3 usually is at least

15 %. In particular for increased thermal stability, Q3 preferably is at least 20. Depending upon the desired decomposition temperature, Q3 preferably is 60 % or less, 50 % or less, or 40 % or less.

The sum of Q3 and Q4 preferably is at least 16 %, at least 25 %, at least 30 %, or at least 35 %. Usually, the sum of Q3 and Q4 is less than 90 %, in particular 75 % or less, more in particular 60 % or less, 50 % or less, or 45 % or less.

Q2 usually is 50 % or less. The lower the Q2 (compared to the sum of Q3 and Q4), the higher the degree of branching. In particular, Q2 may be 40 % or less, or 30 % or less. In practice, Q2 usually is at least 10 %.

The balance of the fractions is usually formed by Qi₁ and optionally (residual) Qo. Qi is usually 30 % or less. In particular, Qi may be at least 1 % or at least 10 %.

Qo does not actually form part of PAOS-X, as it relates to (unreacted) monoorganosiloxane. Some (residual) monoorganosiloxane may be present (as an impurity), e.g. forming a fraction Qo of less than 4 %, in particular of less than 2 %. PAOS-X that is essentially free of a fraction Qo (less than 1 %) may be obtained, e.g., by distillation.

In another embodiment which may or may not be hyperbranched, PAOS-X preferably has the following preferred Q values: TABLE A Preferred PAOS-X Q Values

PAOS, AOS, PAOS-X or AOS-X may be commercially obtained, e.g. from Wacker Chemie AG, or made based on a method which is known in the art per se.

For instance, Xiamin Zhu et al., in Macromolecules 2006, 39; 1701- 1708 describe a method to prepare a hyperbranched polyethoxysiloxane, using tetraethoxysilane . Jaumann et al. describe methods to prepare PAOS including hyperbranched polyethoxysiloxane, using tetraethoxysilane, in Macromol. Chem. Phys. 2003, 204, No 7, page 1014-1026. A preferred method for producing PAOS as described by Jaumann et al., as depicted in Figure 1. PAOS used herein is a room temperature liquid silica precursor polymer. It has a low content of volatiles which can be fully removed using a thin-film evaporator. The product is stable upon storage due to its high hydrophobicity and lack of reactive groups like silanol and acetoxysilane. It is miscible with most organic solvents. Furthermore, it can be easily functionalized due to the versatility of organosilicon chemistry. PAOS can be solidified by moisture in the presence of a suitable catalyst, or by reaction with metal (or semi-metal) hydroxides and acetates. It can be prepared via a controllable one-pot synthetic route based on catalytic condensation of tetraethoxysilane with acetic anhydride (Figure 1, wherein "Et" is a an alkyl group, e.g. an ethyl, it will be understood that other organo- silicon polymers can be provided analogously). It should be noted that the Siθ2 content as well as the molecular weight of the product can easily be controlled varying the molar ratio of the reactants.

Next PAOS can be modified, e.g., by transesterification of PAOS with a functional alcohol. This is schematically illustrated in Figures 2A . wherein "Et" is a an alkyl group, e.g. an ethyl, it will be understood that other organo- silicon polymers can be provided analogously. Herein for at least part of the XR-OH molecules, R is a linear or branched organic moiety attached to the functional group X, e.g. NH2-C_nH2_n, wherein n usually is 1-16, in particular 2-12, more in particular 2-6. One or more functional groups, other than a group X, e.g. a hydrocarbon, may also be incorporated by transesterification (wherein R is such functional group). Such hydrocarbon may be linear, branched, cyclic or a combination thereof. The hydrocarbon may be substituted or unsubstituted. The hydrocarbon may contain one or more heteroatoms (e.g. O, S). Examples of suitable hydrocarbons include alkyls, alkenyls, alkynyls, cycloalkyls, aryls, glycidyls, alkoxylated moieties (CH3-(OCH2)_n-) etc. The functional group may in particular comprise 1-30 carbons, more in particular 1-16 carbons. In particular an aryl group (which may comprise substituents, e.g. alkyl groups or heteroatom containing substituents), may be provided for further improving fire retardancy. An aryl group for group R may in particular be selected from from the group of optionally functionalised phenyl , mono-alkyl phenyl and di- alkyl phenyl.

Suitable reaction conditions may be based on those known in the art, e.g. on Jaumann et al or Zhu et al., of which the contents are incorporated by reference, in particular with respect to the reaction conditions.

It is also possible to prepare PAOS by co-condensation, using a trialkoxysilane as co-monomer in PAOS synthesis. This is schematically shown in Figure 2, B. Herein R is as defined for R when discussing the transesterification method to prepare PAOS(-X) (see also Figure 2, A). Herein "Et" is a an alkyl group, e.g. an ethyl, it will be understood that other organo- silicon polymers can be provided analogously.

This co-condensation method also allows the formation of a PAOS wherein one or more functional groups X are coupled to the silicon directly via an alkylene group (Si-(ClHb)_n-X), wherein "n" represents a number in the range from at least 1, preferably at least 2, up to at least 16, preferably up to 12, morepreferably up to 6, and even more preferably up to 2. This may be advantageous in case a relatively high thermostability and hydrolytical stability is desired. It should be noted though that a too high fraction of Si-C bonds in a branched organosilicon compound may lead to a decomposition temperature that is too high for providing a substitute for halogenated fire retardants acting in the gas or condensed phase. Preferably less than 20 percent, more preferably less than 10 percent, and even more preferably less than 5 percent, of the covalent bonds to Si per molecule are Si-C bonds. PAOS-OH may, e.g., be prepared by at least partially hydrolysing

PAOS, e.g. at elevated temperature {e.g. about 50 ⁰C or higher) in an organic solvent (e.g. an alcohol, such as ethanol) by adding water comprising a catalytic amount of an acid (e.g. HCl).

The hydrophobicity/hydrophilicity balance of PAOS can be tuned. For instance, to increase hydrophilicity, PAOS may be pre-hydrolyzed in a controlled manner using a mixture of ethanol and water to forming reactive hydroxyl groups.

In addition to modification of PAOS end groups for fine-tuning of miscibility and reactivity, a modification of PAOS core is also possible. One or more heteroatoms may be incorporated inside the silicate backbone or at a terminal position (end-capped), such that these heteroatoms form an oxide structure, such as phosphate or metal oxide; this may be done to increase thermal stability, hydrolytic stability, and/or to improve activity in the vapour phase. An element selected from Group 13, 14 (other than Si), 15, 16 (period 3 and higher) and transition metal elements. Of Group 13, B and Al are preferred. Of group 14 Ge, Sn and Pb are preferred. Of Group 15 P, As and Sb are preferred. Of group 16 S is preferred. Particularly suitable transitional elements are Ti, V, Cr, Fe, Zr and Hf.

Incorporation of at least one hetero element selected from the group of phosphorous, aluminium and magnesium is in particular preferred.

In particular, PAOS may comprise at least one branched unit within a PAOS molecule having the chemical structure of formula (IA):

wherein Ei and E2 each independently represent a multivalent element selected from Group 13, 14, 15, 16 (period 3 and higher), and the transition elements and m and n each independently represent the number of bonds available based on the valence of Ei and E2, respectively, wherein m > 1, preferably m > 2, and n > 0, preferably n > 1, and at least one, preferably both, of Ei and E2 represents Si.

The preferences for Groups 13, 14, 15, 16 (period 3 and higher) and the transition elements are the same as described above. More preferably, PAOS comprises at least one branched unit within a PAOS molecule having the chemical structure of formula (2A):

wherein E₁, E2, Ri and R2 have the same meaning as defined above.

In one embodiment, the same PAOS molecule preferably has multiple branched units having a chemical structure of formula (IA). More preferably, the same PAOS molecule has multiple branched units having a chemical structure of formula (2A). The PAOS preferably has a M_w of at least 5 x 10², more preferably at least 1 x 10^, even more preferably at least 2 x 1O^ up to 1 x 10⁴, more preferably up to 7 x 10³.

In a preferred embodiment, the same PAOS molecule comprises at least one branched unit having a chemical structure represented by formula (IAl) and/or formula (1A2):

wherein Ri has the same meaning as described above.

In a more preferred embodiment, the same PAOS molecule comprises at least one branched unit having a chemical structure represented by formula (2Al) and/or formula (2A2):

wherein Ri and R2 have the same meaning as described above.

PAOS-X therefore may comprise at least one branched unit within a PAOS-X molecule having the chemical structure of formula (4A):

wherein E₁, E2, A, X, m and n have the same meaning as described above. The preferences for E₁, E2, A and X are the same as described above.

In a preferred embodiment, the same PAOS-X molecule comprises at least one branched unit having a chemical structure represented by formula (4Al) and/or formula (4A2):

wherein A and X have the same meaning as described above. In a preferred embodiment, the same PAOS-X molecule comprises at least one branched unit having a chemical structure represented by formula (4Al) and at least one branched unit having a chemical structure represented by formula (4A2).

In the same or in another preferred embodiment, the same PAOS-X molecule comprises at least one branched unit having the chemical structure of formula (4A), or a preferred embodiment thereof, and multiple branched units (at least 2, preferably at least 4) having the chemical structure of formula (IA) or, more preferably, multiple branched units (at least 2, preferably at least 4) having the chemical structure of formula (2A). Such PAOS-X preferably has a M_w of at least 5 x 10², more preferably at least 1 x 10^, even more preferably at least 2 x 10^ up to 1 x 10⁴, more preferably up to 7 x 10^.

Suitable reaction conditions may be based on those known in the art, for instance making use of suitable heteroatom alkoxylate or heteroatom-alkyl compounds, as described in e.g. on Jaumann et al or Zhu et al., of which the contents are incorporated by reference, in particular with respect to the reaction conditions.

Foams containing both a phosphorous modified PAOS and a mixture of PAOS and triethylphosphate have been made, based on a reaction as schematically shown in Figure 3, wherein Et is an alkyl, e.g. ethyl, or another suitable organic moiety. Suitable catalysts are known in the art and include amines and organo tin compounds.

The number average molecular mass (Mn) of the PAOS(-X) usually is at least 500 g/mol. Preferably, Mn is at least 1000 g/mol. An Mn of at least 1 600 g/mol or at least 2 000 g/mol is particular preferred. For providing a liquid PAOS(-X), Mn usually is less than 20 000 g/mol. For having good dispersibility of solubility in the composition, Mn is preferably 15 000 g/mol or less. In a particularly preferred embodiment Mn is 10 000 g/mol or less or 8 000 g/mol or less.

Preferably, the PAOS(-X) is a liquid at room temperature. The intrinsic viscosity (at 25 ⁰C) is usually about between 100 cps and the gelation point of the PAOS(-X). The viscosity as used herein is the value as determined by the cone and plate method viscosities, as measured on an Advanced Rheometer AR2000 from TA Instruments, at 25 ⁰C under exclusion of moisture (from air).

As indicated above, a composition according to the invention further comprises at least one polyol. Polyols useful in the present invention are compounds which contain two or more isocyanate reactive groups, generally active-hydrogen groups. Active-hydrogen groups in particular include -OH, primary amines, secondary amines, and -SH. Representative of suitable polyols are generally known and are described in such publications as High Polymers, Vol. XVI; "Polyurethanes, Chemistry and Technology", by Saunders and Frisch, Interscience Publishers, New York, Vol. I, pp. 32-42, 44-54 (1962) and VoI II. Pp. 5-6, 198-199 (1964); Organic Polymer Chemistry by K. J. Saunders, Chapman and Hall, London, pp. 323-325 (1973); and Developments in Poly ur ethanes, Vol. I, J. M. Burst, ed., Applied Science Publishers, pp. 1-76 (1978). Representative of suitable polyols include polyester, polylactone, polyether, polyolefin, polycarbonate polyols, and various other polyols. Illustrative of the polyester polyols are the poly(alkylene alkanedioate) glycols that are prepared via a conventional esterification process using a molar excess of an aliphatic glycol with relation to an alkanedioic acid. Illustrative of the glycols that can be employed to prepare the polyesters are ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol and other butanediols, 1,5-pentanediol and other pentane diols, hexanediols, decanediols, dodecanediols and the like. Preferably the aliphatic glycol contains from 2 to about 8 carbon atoms. Illustrative of the dioic acids that may be used to prepare the polyesters are maleic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 2-methyl-l,6- hexanoic acid, pimelic acid, suberic acid, dodecanedioic acids, and the like.

Preferably the alkanedioic acids contain from 4 to 12 carbon atoms. Illustrative of the polyester polyols are poly(hexanediol adipate), poly(butylene glycol adipate), poly(ethylene glycol adipate), poly(diethylene glycol adipate), poly(hexanediol oxalate), poly(ethylene glycol sebecate), and the like. Polylactone polyols useful in the practice of this invention are the di- or tri- or tetra-hydroxyl in nature. Such polyol are prepared by the reaction of a lactone monomer; illustrative of which is δ-valerolactone, ε-caprolactone, ε- methyl-ε-caprolactone, ξ-enantholactone, and the like; is reacted with an initiator that has active hydrogen-containing groups; illustrative of which is ethylene glycol, diethylene glycol, propanediols, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, and the like. The production of such polyols is known in the art, see, for example, United States Patent Nos. 3,169,945, 3,248,417, 3,021,309 to 3,021,317. The preferred lactone polyols are the di-, tri-, and tetra-hydroxyl functional ε-caprolactone polyols known as polycaprolactone polyols. The polyether polyols include those obtained by the alkoxylation of suitable starting molecules with an alkylene oxide, such as ethylene, propylene, butylene oxide, or a mixture thereof. Examples of initiator molecules include water, ammonia, aniline or polyhydric alcohols such as dihyric alcohols having a molecular weight of 62-399 g/mol, especially the alkane polyols such as ethylene glycol, propylene glycol, hexamethylene diol, glycerol, trimethylol propane or trimethylol ethane, or the low molecular weight alcohols containing ether groups such as diethylene glycol, triethylene glycol, dipropylene glyol or tripropylene glycol. Other commonly used initiators include pentaerythritol, xylitol, arabitol, sorbitol mannitol and the like. Preferably a poly(propylene oxide) polyols include poly(oxypropylene- oxyethylene) polyols is used. Preferably the oxyethylene content should comprise less than about 40 weight percent of the total and preferably less than about 25 weight percent of the total weight of the polyol. The ethylene oxide can be incorporated in any manner along the polymer chain, which stated another way means that the ethylene oxide can be incorporated either in internal blocks, as terminal blocks, may be randomly distributed along the polymer chain, or may be randomly distributed in a terminal oxyethylene- oxypropylene block. These polyols are conventional materials prepared by conventional methods.

Other polyether polyols include the poly(tetramethylene oxide) polyols, also known as poly(oxytetramethylene) glycol, that are commercially available as diols. These polyols are prepared from the cationic ring-opening of tetrahydrofuran and termination with water as described in Dreyfuss, P. and M. P. Dreyfuss, Adv. Chem. Series, 91, 335 (1969).

Polycarbonate containing hydroxyl groups include those known per se such as the products obtained from the reaction of diols such as propanediol- (1,3), butanediols-(l,4) and/or hexanediol-(l,6), diethylene glycol, triethylene glycol or tetraethylene glycol with diarylcarbonates, e.g. diphenylcarbonate or phosgene. Illustrative of the various other polyols suitable for use in this invention are the styrene/allyl alcohol copolymers; alkoxylated adducts of dimethylol dicyclopentadiene; vinyl chloride/vinyl acetate/vinyl alcohol copolymers; vinyl chloride/vinyl acetate/hydroxypropyl acrylate copolymers, copolymers of 2-hydroxyethylacrylate, ethyl acrylate, and/or butyl acrylate or 2-ethylhexyl acrylate; copolymers of hydroxypropyl acrylate, ethyl acrylate, and/or butyl acrylate or 2-ethylhexylacrylate, and the like.

The polyol or blends thereof present in a composition of the invention depends upon the end use of the polyurethane product to be produced. The molecular weight or hydroxyl number of the base polyol may thus be selected so as to result in flexible, semi-flexible, integral-skin or rigid foams, elastomers or coatings, or adhesives when the polymer/polyol produced from the base polyol is converted to a polyurethane product by reaction with an isocyanate, and depending on the end product, optionally in the presence of a blowing agent. The hydroxyl number and molecular weight of the polyol or polyols employed can vary accordingly over a wide range. In general, the hydroxyl number of the polyols employed may range from about 20 to about 800 mg/KOH/g.

In an embodiment the polyol component in the composition has an average equivalent weight of more than about 500 g/mol, e.g. up to about 10 000 g/mol, in particular up to about 7 000 g/mol, more in particular up to 3000 g/mol. Such a composition is in particular suitable to provide a flexible polyisocyanate-based polymer.

In the production of a flexible polyurethane foam, the polyol is preferably a polyether polyol and/or a polyester polyol. The polyol generally has an average polyol functionality ranging from 1.5 to 5, preferably from 1.8 to 5, in particular from 2.0 to 4. The average hydroxyl number preferably ranges from 20 to 100 mg KOH/g, more preferably from 20 to 70 mgKOH/g, for a flexible foam. As a further refinement, the specific foam application will likewise influence the choice of base polyol. As an example, for moulded foam, the hydroxyl number of the base polyol may be on the order of about 20 to about 60 with ethylene oxide (EO) capping, and for slabstock foams the hydroxyl number may be on the order of about 25 to about 75 and is either mixed feed EO/PO (propylene oxide) or is only slightly capped with EO. For elastomer applications, it will generally be desirable to utilize relatively high molecular weight base polyols, from about 2,000 to 8,000 g/mol, having relatively low hydroxyl numbers, e.g., about 20 to about 50 mgKOH/g. Polyols suitable for elastomer end applications typically have an average functionality of from 2 to 3. In an embodiment the polyol component in the composition has an average equivalent weight of from more than about 250 to about 500 g/mol. Such a composition is in particular suitable to provide a semi-rigid polyisocyanate-based polymer. For the production of semi-rigid foams, it is preferred to use a trifunctional polyol with a hydroxyl number of 30 to 80. Typically polyols suitable for preparing rigid polyurethanes include those having a number average molecular weight of at least 30 g/mol, at least 100 g/mol, at least 200 g/mol or at least 500 g/mol. The number average weight usually is 10,000 g/mol. or less, in particular 7,000 g/mol or less, more in particular 5,000 g/mol or less. In an embodiment the polyol component in the composition has an average equivalent weight of from about 30 to about 250 g/mol. Such a composition is in particular suitable to provide a rigid polyisocyanate-based polymer.

Polyols for preparing a rigid polyurethane advantageously have a functionality of at least 2, preferably of at least 3 active hydrogen atoms per molecule. Usually said functionality is up to 8, preferably up to 6. The polyols used for rigid foams preferably have a hydroxyl number of about 200 to about 1,200 mg KOH/g and more preferably from about 300 to about 800 mg KOH/g.

For the preparation of polyurethane, the composition is further provided with an isocyanate. The isocyanate generally is a polyisocyanate, i.e. comprising two or more isyanate groups. In particular, the isocyanate may comprise two or three isocyananate groups. In particular one or more isocyanates selected from the group of methylene diphenyl diisocyanate, toluene diisocyanate (2,4-and/or 2,6-isomer), hexamethylenediisocyanate, isophoronediisocyanate, dicyclohexylmethanediisocyanate, methyl cyclohexanediisocyanate , bitolylenediisocyanate, naphthylenediisocyanate (such as 1,5-naphthylenediisocyanate), triphenylmethanetriisocyanate, dianisidinediisocyanate, xylylenediisocyanate, oligomers comprising any of these monomers and polymers comprising any of these monomers, may be present. The organic polyisocyanate(s) and the isocyanate reactive compound(s) are usually reacted in such amounts that the isocyanate index, defined as the number or equivalents of NCO groups divided by the total number of isocyanate reactive hydrogen atom equivalents multiplied by 100, ranges from 50 to less than 500. In particular for a rigid foam the isocyanate index usually ranges from 80 to less than 500, preferably from 90 to 100 in the case of polyurethane foams, and from 100 to 300 in the case of combination polyurethane- polyisocyanurate foams. For semi-rigid and flexible foams, this isocyanate index is generally between 50 and 120 and preferably between 75 and 110. A product (used in a method) of the invention may comprise one or more other adjuvants different from PAOS and PAOS-X, in particular one or more adjuvants selected from the group of surfactants, additional fire retarding agents and substances able to confer a reduced density or cellular structure. Substances able to confer a reduced density or cellular structure include physical blowing agents, chemical blowing agents, microspheres (e.g. of glass or polymeric material) and the like.

The applications for foams produced by the present invention include those known in the industry. Flexible and viscoelastic foams are mainly used in applications such as furniture and automobile seating. Other applications may include sun visors, steering wheels, packaging applications, armrests, door panels, noise insulation parts, other cushioning and energy management applications, carpet backing, dashboards and other applications for which conventional flexible polyurethane foams are used.

The composition may further comprise one or more components selected from the group of additional fire retardants, surfactants, solvents, polymerisation catalysts, surfactants. Suitable components and concentrations are known in the art. Hereinbelow several particularly suitable additional components will be mentioned.

Processing for producing polyurethane products are well known in the art. In general components of the polyurethane-forming reaction mixture may be mixed together in any convenient manner, for example by using any of the mixing equipment described in the prior art for the purpose such as described in "Polyurethane Handbook", by G. Oertel, Hanser publisher. In general, the polyurethane foam is prepared by mixing the polyisocyanate and polyol composition in the presence of the blowing agent, catalyst(s) and other optional ingredients as desired, under conditions such that the polyisocyanate and polyol composition react to form a polyurethane and/or polyurea polymer while the blowing agent generates a gas that expands the reacting mixture.

As a blowing agent used in the polyurethane-forming composition in particular at usually at least one physical blowing agent is used selected from the group of hydrocarbons, hydrofluorocarbons, hydrochlorofluorocarbons, fluorocarbons, dialkyl ethers, fluorine- substituted dialkyl ethers. Blowing agents of these types include propane, isopentane, n-pentane, n-butane, isobutene, isobutene, cyclopentane, dimethyl ether, 1,1-dichloro-l-fluoroethane (HCFC-UIb), chlorodifluoromethane (HCFC-22), l-chloro-l,l-difluoroethane (HCFC-142b), 1,1,1,2-tetrafluoroethane (HFC- 134a), 1,1,1,3,3- pentafluorobutane (HFC-365mfc), 1,1-difluoroethane (HFC-152a), 1,1,1,2,3,3,3- heptafluoropropane (HFC-227ea) and 1,1,1,3,3-pentafluoropropane (HFC- 245fa), trans-dichloroethylene, methylformate, formic acid, actone, and hydrofluoroolefins. The hydrocarbon and the hydrofluorocarbon blowing agents are preferred. It is generally preferred to further include water in the formulation, in addition to the physical blowing agent. Blowing agent(s) are preferably used in an amount sufficient such that the formulation cures to form a foam having a density of from 16 to 160 kg/m³, preferably from 16 to 64 kg/m³ and especially from 20 to 48 kg/m³. To achieve these densities, the hydrocarbon or hydrofluorocarbon blowing agent conveniently is used in an amount ranging from about 10 to about 40, preferably from about 12 to about 35, parts by weight per 100 parts by weight polyol(s). Water reacts with isocyanate groups to produce carbon dioxide, which acts as an expanding gas. Water is suitably used in an amount within the range of 0.5 to 3.5, preferably from 1.5 to 3.0 parts by weight per 100 parts by weight of polyol(s). The polyurethane-forming composition typically will include at least one catalyst for the reaction of the polyol(s) and/or water with the polyisocyanate. Suitable urethane-forming catalysts include those described by U.S. Pat. No. 4,390,645 and in WO 02/079340, both incorporated herein by reference. Representative catalysts include tertiary amine and phosphine compounds, chelates of various metals, acidic metal salts of strong acids; strong bases, alcoholates and phenolates of various metals, salts of organic acids with a variety of metals, organometallic derivatives of tetravalent tin, trivalent and pentavalent As, Sb and Bi and metal carbonyls of iron and cobalt. Tertiary amine catalysts are generally preferred. Among the tertiary amine catalysts are dimethylbenzylamine (such as Desmorapid® DB from Rhine Chemie), 1,8-diaza (5,4,0)undecane-7 (such as Polycat® SA-I from Air Products), pentamethyldiethylenetriamine (such as Polycat® 5 from Air Products), dimethylcyclohexylamine (such as Polycat® 8 from Air Products), triethylene diamine (such as Dabco® 33LV from Air Products), dimethyl ethyl amine, n-ethyl morpholine, N-alkyl dimethylamine compounds such as N-ethyl N,N-dimethyl amine and N-cetyl N,N-dimethylamine, N-alkyl morpholine compounds such as N-ethyl morpholine and N-coco morpholine, and the like. Other tertiary amine catalysts that are useful include those sold by Air Products under the trade names Dabco® NE1060, Dabco® NE1070, Dabco® NE500, Dabco® TMR-2, Dabco® TMR 30, Polycat® 1058, Polycat® 11, Polycat 15, Polycat® 33 Polycat® 41 and Dabco® MD45, and those sold by Huntsman under the trade names ZR 50 and ZR 70. In addition, certain amine-initiated polyols can be used herein as catalyst materials, including those described in WO 01/58976 A. Mixtures of two or more of the foregoing can be used.

The catalyst is used in catalytically sufficient amounts. For the preferred tertiary amine catalysts, a suitable amount of the catalysts is from about 1 to about 4 parts, especially from about 1.5 to about 3 parts, of tertiary amine catalyst(s) per 100 parts by weight of the polyol(s). Various methods exist to produce the foam. The foam may be formed by the so-called prepolymer method, as described in U.S. Pat. No. 4,390,645, for example, in which a stoichiometric excess of the polyisocyanate is first reacted with the high equivalent weight polyol(s) to form a prepolymer, which is in a second step reacted with a chain extender and/or water to form the desired foam. Frothing methods, as described in U.S. Patents 3,755,212; 3,849,156 and 3,821,130, for example, are also suitable. So-called one- shot methods, such as described in U.S. Patent 2,866,744, are preferred. In such one- shot methods, the polyisocyanate and all polyisocyanate-reactive components are simultaneously brought together and caused to react. Three widely used one-shot methods which are suitable for use in this invention include slabstock foam processes, high resiliency slabstock foam processes, and moulded foam methods.

Slabstock foam is conveniently prepared by mixing the foam ingredients and dispensing them into a trough or other region where the reaction mixture reacts, rises freely against the atmosphere (sometimes under a film or other flexible covering) and cures. In common commercial scale slabstock foam production, the foam ingredients (or various mixtures thereof) are pumped independently to a mixing head where they are mixed and dispensed onto a conveyor that is lined with paper or plastic. Foaming and curing occurs on the conveyor to form a foam bun. The resulting foams are typically from about from about 10 kg/m³ to 80 kg/m³, especially from about 15 kg/m³ to 60 kg/m³, preferably from about 17 kg/m³ to 50 kg/m³ in density.

A preferred slabstock foam formulation contains from about 3 to about 6, preferably about 4 to about 5 parts by weight water are used per 100 parts by weight high equivalent weight polyol at atmospheric pressure. At reduced pressure these levels are reduced.

High resilience slabstock (HR slabstock) foam is made in methods similar to those used to make conventional slabstock foam but using higher equivalent weight polyols. HR slabstock foams are characterized in exhibiting a Ball rebound score of 45% or higher, per ASTM 3574.03. Water levels tend to be from about 2 to about 6, especially from about 3 to about 5 parts per 100 parts (high equivalent) by weight of polyols.

Moulded foam can be made according to the invention by transferring the reactants (polyol composition including copolyester, polyisocyanate, blowing agent, and surfactant) to a closed mould where the foaming reaction takes place to produce a shaped foam. Either a so-called "cold- moulding" process, in which the mould is not preheated significantly above ambient temperatures, or a "hot- moulding" process, in which the mould is heated to drive the cure, can be used. Cold-moulding processes are preferred to produce high resilience moulded foam. Densities for moulded foams generally range from 30 to 50 kg/m³. Moulding is in particular useful for preparing a flexible foam, which may also suitably be made in a process wherein the foam is allowed to rise freely (a free rise process), or for preparing a microcellular elastomer. Two or more production techniques, e.g. as described above, may be combined. For instance, for producing rigid foams, the known one- shot prepolymer or semi-prepolymer techniques may be used together with conventional mixing methods including impingement mixing. The rigid foam may also be produced in the form of slabstock, mouldings, cavity filling, sprayed foam, frothed foam or as a laminate with other material such as paper, metal, plastics or wood-board.

Preferred embodiments

1. A polyol composition comprising (a) one or more polyols bearing at least two isocyanate reactive hydrogen atoms, and (b) one of more adjuvant wherein at least one adjuvant is a polyalkoxysilane (PAOS) or alkoxysilane (AOS) substance bearing isocyanate-reactive (X) moieties.

2. The polyol composition of embodiment 1, wherein the polyalkoxysilane or alkoxysilane substance and the polyol comprises one or more isocyanate-reactive hydrogen atoms forming part of a moiety selected from the group of -COOH, -OH, -NH₂, NHR', -CONH₂, -SH, epoxy groups, glycidyl groups, and -CONH-.

3. The polyol composition of embodiment 2, wherein the isocyanate- reactive moiety is -OH or -NH₂. 4. The polyol composition of embodiment 1 wherein the polyalkoxysilane or alkoxysilane substance is present in a concentration of from 0.1 to 20 parts by weight per 100 parts of the polyol.

5. The polyol composition of any of the embodiments 1 to 4 wherein the polyol component (a) comprising one or more polyols has a number average equivalent weight of from about 30 to about 250 g/mol.

6. The polyol composition of any of the embodiments 1 to 4, wherein the polyol component (a) comprising one or more polyols has a number average equivalent weight of from more than about 250 to about 500 g/mol. 7. The polyol composition of any of the embodiments 1 to 4 wherein the polyol component (a) comprising one or more polyols has a number average equivalent weight of from more than about 500 to about 3000 g/mol.

8. A two component system suitable for the manufacture of polyisocyanate-based polymer which comprises

(a) a first component, being an aliphatic or aromatic polyisocyanate; and

(b) a second component, being a polyol composition as claimed in any of the embodiments 1-7.

9. A polyisocyanate-based polymer obtainable by intimately mixing under reaction conditions an organic polyisocyanate with a polyol composition as claimed in any of the embodiments 1 to 7.

10. The polyisocyanate-based polymer of embodiment 9 prepared in the presence of a substance able to confer a reduced density or cellular structure.

11. A rigid polyisocyanate-based polymer obtainable by reaction of a polyisocyanate with a polyol composition of embodiment 5.

12. A semi-rigid polyisocyanate-based polymer obtainable by reaction of a polyisocyanate with a polyol composition of embodiment 6.

13. A flexible polyisocyanate-based polymer obtainable by reaction of a polyisocyanate with a polyol composition of embodiment 7. 14. An article having a laminate structure wherein at least one lamella is a polyisocyanate-based polymer of embodiment 9.

15. An article having a laminate structure wherein at least one lamella is a polyisocyanate-based polymer of embodiment 11.

16. An insulation panel comprising a polyisocyanate-based polymer as claimed in any one of embodiments 9-12.

17. A method of providing a polyisocyanate-based polymer with a retarded flammability or combustibility performance which comprises preparing the polymer by reacting a polyisocyanate with a polyol in the presence of an effective amount of a fireretarding adjuvant wherein, the adjuvant comprises a polyalkoxysilane or alkoxysilane substance bearing isocyanate-reactive hydrogen atoms.

18. A method according to embodiment 17 comprising continuously mixing a polyisocyanate, a polyol and a mono- or polyalkoxysilane substance bearing isocyanate-reactive moieties and allowing the mixture to react.

19. A method according to embodiment 18, wherein the mixing involves impingement mixing or mixing in a static mixture.

20. Polyurethane-polyalkoxysilane copolymer at least composed of one or more polyols, one or more isocyanates and one or more polyalkoxysilane or alkoxysilane substances, as defined in any one of embodiments 1 to 7.

21. Use of a polyalkoxysilane or alkoxysilane bearing isocyanate- reactive hydrogen atoms, as defined in any one of embodiments 1-4, or a corresponding residue thereof in a polyurethane polymer, as a fire-retardant in an ignitable material. The invention will now be illustrated by the following examples.

Examples

A description of the raw materials used in the examples is as follows.

Dabco 33 LV is an amine catalyst, 33% triethylene diamine in dipropylene glycol.

Dabco Kl 5 is 70% potassium octoate in diethylene glycol.

Niax Al is an amine catalyst; available from Crompton-Witco.

Specflex NE- 150 is a MDI based isocyanate prepolymer available from The

Dow Chemical Company.

Stepanpol PS 2352 is a ortho phthalate-diethylene glyol base aromatic polyester polyol with a reported hydroxyl value of 240 available from Stephan Company. Saytex RB 79 is a reactive bromine-containing diester/ether diol of tetrabromophthalic anhydride available from Abermale Corporation.

Tegostab B8408 is a polyether- modified polysiloxane surfactant available from Degussa-Goldschmidt AG.

Tegaostab B8469 is a polysiloxane-polyoxylakylenealkylate copolymer surfactant available from Degussa-Goldschmidt AG.

Tegostab B8715 is a silicon-based surfactant available from Degussa- Goldschmidt AG.

Tercarol T5902 is an ortho-toluene diamine initiated PO polyol with 30 wt% EO cap having a molecular weight of about 600.

VORANATE M600 is a polymeric-MDI having an isocyanate content of aboubt 30.3% and an average functionality of about 2.85 available from The Dow Chemical Company.

VORANOL E600 is a 600 molecular weight ethylene oxide polyol.

VORANOL IP 585 is an aromatic resin-initiated oxypropylene-oxyethylene polyol with hydroxyl number of 195 and average functionality of 3.3 available from The Dow Chemical Company.

VORANOL CP 1421 is glycerine initiated polyoxypropylene polyoxyethylene polyol having an average hydroxyl number of 32 available from The Dow Chemical Company.

VORANOL CP 6001 is a glycerine initiated PO polyol with a 15 wt% EO cap and having an average molecular weight of about 6120. VORANOL RN482 is a sorbitol inititated PO polyol having a molecular weight of about 700.

Synthesis of PAOS-X

PAOS was made using the acetoxy route based on the method described by Jaumann et al, Macromol. Chem. Phys. 2003, 204, 7, pp. 1014- 1026.

In a 2 L three- neck round-bottom flask equipped with a mechanical stirrer and a 30 cm dephlagmator connected with a distillation bridge, equimolar amounts of tetraethoxysilane (TEOS) and acetic anhydride were mixed with titanium trimethylsil oxide (0.3 mol %) under an argon atmosphere

Under intensive stirring the mixture was heated to 135 ⁰C using a silicon oil bath. The ethyl acetate released was continuously distilled off. Heating was continued until the distillation of ethyl acetate stopped (about 8 hrs).

Afterwards the product was cooled down to room temperature and dried in vacuum for 5 hrs. A yellowish oily liquid was obtained. Complete removal of volatile compounds was achieved using a vacuum thin film evaporator (type S 51/31; Nor mag; Germany) equipped with a rotary vane vacuum pump (model RZ-5; Vacubrand; Germany), magnetic coupling

(Buddelberg; Germany) for the stirrer (model RZR2020, Heidoplh, Germany) operating at the highest level 10 and a heating device. Operating temperature was 150 ⁰C;

Synthesis of functionalised PAOS derivatives (PAOS-X) from PAOS was accomplished as a second step in a one-pot setup. The non- exhaustive listing given below includes PAOS-NH2 and PAOS-OH from, (respectively, monoethanolamine and ethanol). PAOS coupled to n- propanol-amine, octanol and CH₃(OC2H₄)7-OH (indicated by PAOS-DEG) were prepared in ananalogous manner as PAOS-NH2 and PAOS-OH PAOS-NH₂ was synthesized from PAOS as follows. In a 250 ml two-neck round-bottom flask equipped with a magnetic stirrer and a 22 cm dephlagmator connected with a distillation bridge, 5Og (0,67MoEt) of PAOS (polyethoxysiloxan) was mixed with 31, 5g (0,5M) monoethanolamine under a nitrogen atmosphere. Under intensive stirring the mixture was heated to 130 ⁰C using a silicon oil bath. Resulting ethanol was continuously distilled off. Heating was continued until the distillation of ethanol stopped, The reaction was finished within 4 hrs. Afterwards the product was cooled down and dried in vacuum for 4 hrs. (oil bath temperature 40-60⁰C). A yellowish oily liquid (yield about 57g) was obtained, NMR analysis showed that 68% of the ethanol groups are replaced with amine end groups.

The synthesis of PAOS-OH proceeded via a simple hydrolysis of PAOS. In a 100 ml two-neck round-bottom flask equipped with magnetic stirrer and reflux condenser 28,Og (0,37MoEt) of PAOS was mixed with 17,02g (0,37M) ethanol under a nitrogen atmosphere. Under intensive stirring the mixture was heated to 50⁰C using a silicon oil bath. Then 4,Og (0,22M) of water was added to the solution with the syringe pump. The water contained a catalytic amount of HCl (pH = 4-5). The addition rate of water was 2ml/h. After reaction, a product with about 60% hydroxyl group with 55,3 wt% of ethanol was obtained.

Tests

Fire retardancy of rigid foams was tested according to the DIN 4102 B2 test. The flexible foams were tested using the CAL 117-Al "Vertical Burning" test, as described in California Technical Bulletin 117 Section A Part 1. These tests are standard in the industry.

Compressive strength in the parallel (Cstr //)respectively perpendicular (Cstr ±.) direction was determined according to DIN 18164. Foam formulations

All reference formulations used to test fire retardancy performance of various PAOS derivatives are summarized in their standard form by Table 1. Formulations I and II were employed for rigid PIR and PUR foam, respectively. Formulations according to the invention were based on the same formulation, albeit that one or more fire retardant agents may have been replaced by a PAOS-X as will be indicated below.

Table 1: ingredients

Table 1: ingredients (continued)

Notes: ¹Trademark of the Dow Chemical Company; ²Diethanolamine, 85% in water; ³Trademark of Chemtura (Crompton-Witco); ⁴Trademark of Air Products; ⁵Trademark of Degussa-Goldschmidt; ⁶Tris(chloroisopropyl)- phosphate; ⁷Trademark of Stepan Company; ⁸Trademark of Albemarle Corporation; ⁹Triethyl phosphate; ¹⁰Dimethyl Cyclohxylamine; ⁿDimethyl benzylamine; ¹²Triethanolamine; ¹³Diethyl ethylphosphonate

Rigid foam tests

Rigid PUR foam was compared in a manner known per se, in the presence of fire retardants in a concentration as indicated in Tables 2 to 9. Concentrations are in parts by weight per 100 parts polyol. Table 2: Examples of TCPP replacement in a rigid PUR foam using PAOS modified with 3-aminopropyltriethoxysilane (APTS)

Table 3: Examples of TCPP replacement in a rigid PUR foam using TEOS modified with n-propanolamine and ethanolamine

Table 4: Examples of TCPP replacement in a rigid PUR foam using PAOS modified with n-propanolamine

Table 5: Examples of TCPP replacement in a rigid PUR foam using PAOS modified with iso-propanolamine

Table 6: Examples of TCPP replacement in a rigid PUR foam using PAOS modified with n-pentanolamine and n-hexanolamine

Table 7: Examples of TCPP replacement in a rigid PUR foam using Ethylsilicate from Wacker Chemie modified with ethanolamine

Table 8: Examples of TCPP replacement in rigid PUR foam using Ethylsilicate from Wacker Chemie modified with n-propanolamine

Table 9: Examples of TCPP replacement in rigid PUR foam using; phosphate modified PAOS

Table 10: Examples of TCPP replacement in rigid PUR foam using hydroxyl modified PAOS

60 % hydrolysed 2 30 % hydrolysed

Rigid PIR foam test

Table 11: Example of TCPP or Saytex RB 79 replacement in rigid PIR foam using amine functionalised PAOS

1 60 % functionalised (60 % of O-Et end caps replaced using monoethanol amine)

Flexible foam tests

In the Examples according to the invention TCPP (90 pbw, per 100 pbw polyol was fully replaced by PAOS-X (9 pbw), as shown in Table 12

Claims

ClaimsWhat is claimed is:

1. A polyol composition comprising (a) one or more polyols bearing at least two isocyanate reactive hydrogen atoms, and (b) one of more adjuvants wherein at least one adjuvant is PAOS-X, which represents a polyalkoxysilane (PAOS) bearing isocyanate-reactive (X) moieties or AOS-X. which represents an alkoxysilane (AOS) bearing isocyanate-reactive (X) moieties, wherein

PAOS-X comprises at least one branched unit within a PAOS-X molecule having a chemical structure of formula (4A):

wherein

—A— represents a covalent bond, —A'— or — 0— A'— , wherein A' represents a straight or branched alkylene group having from 1 to 16 carbon atoms;

Ei and E2 each independently represent a multivalent element selected from Group 13, 14, 15, 16 (period 3 and higher), and the transition elements; m and n each independently represent the number of bonds available based on the valence of Ei and E2, respectively; m > 1; and at least one of Ei and E2 represents Si and AOS-X is represented by a chemical structure of formula (3):

(R₁O)₃ Si— A— X ₍₃₎ wherein —A— represents a covalent bond, —A'— or — 0— A'— , wherein A' represents a straight or branched alkylene group having from 1 to 16 carbon atoms.

2. The polyol composition of claim 1, wherein X represents -COOH, -OH, -NH₂, NHR', -CONH₂, -SH, epoxy groups, glycidyl groups, and -CONH-.

3. The polyol composition of claim 2, wherein X is -OH or -NH₂.

4. The polyol composition of claim 1 wherein the polyalkoxysilane or alkoxysilane substance is present in a concentration of from 0.1 to 20 parts by weight per 100 parts of the polyol.

5. A two component system suitable for the manufacture of polyisocyanate- based polymer which comprises (a) a first component, being an aliphatic or aromatic polyisocyanate; and

(b) a second component, being a polyol composition as claimed in any one of the claims 1-4.

6. A polyisocyanate-based polymer obtainable by intimately mixing under reaction conditions an organic polyisocyanate with a polyol composition as claimed in any one of the claims 1 to 4.

7. The polyisocyanate-based polymer of claim 6 prepared in the presence of a substance able to confer a reduced density or cellular structure.

8. A rigid polyisocyanate-based polymer obtainable by reaction of a polyisocyanate with a polyol composition according to any one of claims 1 to 4, wherein polyol component (a) has a number average equivalent weight of from about 30 to about 250 g/mol.

9. A semi-rigid polyisocyanate-based polymer obtainable by reaction of a polyisocyanate with a polyol composition according to any one of claims 1 to 4, wherein the polyol component (a) has a number average equivalent weight of from more than about 250 to about 500 g/mol.

10. A flexible polyisocyanate-based polymer obtainable by reaction of a polyisocyanate with a polyol composition according to any one of claims 1 to 4, wherein the polyol component (a) has a number average equivalent weight of from more than about 500 to about 3000 g/mol .

11. An article having a laminate structure wherein at least one lamella is a polyisocyanate-based polymer as claimed in claim 6 or 8.

12. An insulation panel comprising a polyisocyanate-based polymer as claimed in any one of the claims 6 to 9.

13. A method of providing a polyisocyanate-based polymer with a retarded flammability or combustibility performance which comprises preparing the polymer by reacting a polyisocyanate with a polyol in the presence of an effective amount of a fire-retarding adjuvant, wherein the adjuvant comprises at least one PAOS-X, which represents a polyalkoxysilane (PAOS) substance bearing isocyanate-reactive hydrogen atoms (X) and/or at least one AOS-X, which represents an alkoxysilane (AOS) substance bearing isocyanate-reactive hydrogen atoms (X), wherein

wherein

Ei and E2 each independently represent a multivalent element selected from Group 13, 14, 15, 16 (period 3 and higher), and the transition elements; m and n each independently represent the number of bonds available based on the valence of Ei and E2, respectively; m > 1; and at least one of Ei and E2 represents Si and

AOS-X is represented by a chemical structure of formula (3):

(R₁O)₃ Si— A— X ₍₃₎ wherein —A— represents a covalent bond, —A'— or — 0— A'— , wherein A' represents a straight or branched alkylene group having from 1 to 16 carbon atoms..

14. Polyurethane-polyalkoxysilane copolymer derived from substances comprising one or more polyols, one or more isocyanates and one or more PAOS-X and/or AOS-X as defined in any one of the claims 1 to 4.

15. Use of PAOS-X and/or AOS-X as defined in any one of the claims 1 to 4, or a corresponding residue thereof in a polyurethane polymer, as a fire-retardant in an ignitable material.