WO1992002567A1

WO1992002567A1 - Polymer modified polyols

Info

Publication number: WO1992002567A1
Application number: PCT/EP1991/001383
Authority: WO
Inventors: Jitka Jenc; Jose Godoy
Original assignee: Polyol International B.V.
Priority date: 1990-07-31
Filing date: 1991-07-24
Publication date: 1992-02-20
Also published as: CA2048129A1; AU8233091A; GB9016726D0

Abstract

A polymer modified polyol is prepared by polymerizing an olphosphine with a polyisocyanate in the presence of a polyol. The resulting polymer modified polyol may constitute a stable dispersion and is particularly useful in the manufacture of polyurethane foams.

Description

POLYMER MODIFIED POLYOLS

The present invention relates to novel polymer modified polyols and methods for the preparation thereof. To the extent that the novel polymer modified polyols are useful in the manufacture of polyurethane foams, the present invention also relates to poly¬ urethane foams and processes for the manufacture thereof.

Polyurethane foam is manufactured by reacting a polyol with a polyisocyanate in the presence of a blowing agent and usually also one or more additives.

Despite the variety of physical and chemical properties obtainable by proper selection of the conditions under which the reaction is carried out, there are definite limitations in selecting components for desirable properties in the resulting polyurethane foam.

A great deal of art has grown up reflecting the extensive efforts made to improve physical properties of the polyurethane foam. In recent years an extensive effort has been made to modify the physical properties of the polyurethane foam in a desired manner by using pre-formed polymer modified polyols (polyols containing additional polymeric material) in the polyurethane- forming reaction.

One type of the polymer modified polyol which is produced in a dispersed form in the base polyol comprises for example the polyaddition reaction product of a polyamine, or hydrazine with a mono or poly- functional isocyanate. These polymer modified polyols are known as PHD polymer polyols and are described in British Patent No. 1,501,172.

10 Another type of polymer modified polyols, known as polymer (copolymer) polyol, is thought to comprise a polymer or a copolymer of a monomer at least partially grafted to the polyol. These polymer modified polyols

•,cr are produced by polymerizing or copolymerizing at least one ethylenically unsaturated monomer in the base polyol at elevated temperature in the presence of a free- radical initiator. Preferred ethylenically unsaturated monomers include styrene and acrylonitrile. This type of 0 polymer modified polyols is described in U.S. Patent No. 3,304,273.

Still another type of polymer modified polyols is describes in British Patent No. 2,072,204. This 5 patent describes a polymer modified polyol obtained by polymerizing an olamine (i.e., a compound containing at least one hydroxyl group and at least one amino group, whether primary, secondary or tertiary amino group) with an organic polyisocyanate in the presence of a polyol. 0 Modified polymer polyol dispersions generated in this manner are known as PIPA dispersion polymer polyols.

Despite of variety of known polymer modified- polyols used in the manufacture of a polyurethane foam, there still remains a need for additional polymer modified polyols which, when used in the manufacture of a polyurethane foam, will result in a polyurethane foam having one or more physical properties improved in the desired manner.

Accordingly, the present invention concerns a process for making a novel polymer modified polyol which process comprises polymerizing an olphosphine with a polyisocyanate in the presence of a polyol.

In another aspect, the present invention concerns a novel polymer modified polyol produced by polymerizing an olphosphine with a polyisocyanate in the presence of a polyol.

Still in another aspect, the present invention concerns a polymer modified polyol comprising a polyol and a polyaddition product resulting from the polymerization of an olphosphine with a polyisocyanate.

Yet in another aspect, the present invention concerns a process for the manufacture of a polyurethane material which process comprises reacting a polyol with a polyisocyanate in the presence of a catalyst for the urethane forming reaction and, optionally, a blowing agent and/or one or more other additives, characterized in that said polyol is the polymer modified polyol of the type described hereinbefore.

Still in another aspect the present invention concerns a polyurethane foam produced by the process described hereinbefore. As used herein the term olphosphine means an organic compound having at least one hydroxyl group and at least one phosphine group. While olphosphines having, hydroxyl and phosphine groups attached to an aliphatic group are most suitable in the practice of the present invention, olphosphines having hydroxyl and phosphine groups attached to alicyclic, aromatic or heterocyclic nuclei or combination thereof with each other and/or aliphatic groups can also be used.

Whether active hydrogens in the olphosphine are derived from both hydroxyl and phosphine groups having such hydrogens or only by hydroxyl groups, all these active hydrogens may be reactive with respect to isocyanate groups.

The preferred olphosphines are represented by the following formula

wherein each R independently is hydrogen, an alkyl group or hydroxyalkyl group with the proviso that at least one R is hydroxyalkyl group; X is oxygen, sulfur, selenium or a chemical entity which when bonded to the phosphorous atom forms a phosphonium compound; and n is 0 or 1.

By the term hydroxyalkyl group is meant (a) a hydroxy functionalized alkyl group of the formula

-(CR¹R-^-OH (||)

wherein R¹ independently in each occurence is hydrogen or an alkyl group; R² independently in each occurence is hydrogen or an alkyl group; and m is an integer of 1 to 6; or (b) a hydroxy functionalized poly(oxyalky- lene)group of the formula

wherein R³ independently in each occurrence is hydrogen or an alkyl group; and p is an integer of 1 to 6.

Alkyl groups contemplated by R, R¹, R² and R³ in Formulae I, II, and III hereinbefore are straight or branched chain alkyl groups of from 1 to 16, preferably 1 to 12, most preferably 1 to 6, carbon atoms. The alkyl groups may have one or more hydrogen atoms substituted by halogen atoms. Halogen atoms which are suitable as the alkyl group substituents are fluorine, chlorine, bromine and iodine.

Olphosphines of Formula I above in which n is 0 and each R independently is hydrogen, alkyl, or the hydroxy functionalized alkyl group of Formula II above wherein R¹, R² and n are defined as hereinbefore are further preferred. Examples of these olphosphines are hydro¬ xyalkyl phosphines such as trimethanolphosphine, mono- ethanolphosphine, diethanolphosphine, triethanolphos- phine, monoisopropanolphosphine, diisopropanolphosphine, triisopropanolphosphine, methyldiethanolphosphine, n-bu- tyldiethanolphosphine, t-butyldiethanolphosphine, halo¬ gen substituted derivatives thereof and the like. These olphosphines are known and can be readily prepared by methods described in the art. See, for example, German Patent No. 2,158,823; U.S. Patent No. 3,704,325; U.S.S.R. Patent No. 1,145,022; Doklady Akad. S.S.S.R. 56, 49-52 (1947); Z. Chem 19, 252-53 (1979); Z Obsc. Kh. 37, 2269-73 (1967); and Z Obsc. Kh. 37, 2522-24 (1967) .

Olphosphines of Formula I above in which n is 0 and each R is independently hydrogen or the hydroxy functionalized alkyl group of Formula III above wherein R³ and p are defined as hereinbefore are known. These compounds can be readily prepared by known methods using formaldehyde or a suitable alkoxylating agent. Suitable alkoxylating agents are C₂ to C₆ alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide or a mixture thereof.

Olphosphines of Formula I above in which n is 1 and X is oxygen or sulfur are also known. See, for example, U.S. Patent No. 4,007,229; ^~_^ Obsc. Kh. 44 (7); 1440-43 (1974); and German Patent No. 2,511,932. Olphosphines of Formula I above in which X is oxygen are preferred. Olphosphines of Formula I above in which X is selenium can be prepared in analogous manner as the olphosphines in which X is oxygen or sulfur.

Olphosphines of Formula I above in which n is 1 and X is a chemical entity which when bonded to the phosphorus atom forms a phosphonium compound are also known. Details of the preparation of these phosphonium compounds will be familiar to the skilled person.

In the practice of the present invention a single olphosphine or a mixture of two or more olphos- • phines can be used.

Suitable polyisocyanates for use in the present invention include aliphatic, cycloaliphatic and aromatic polyfunctional, particularly bifunctional, isocyanates. These include: aliphatic diisocyanates such as ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexa- methylene diisocyanate and 1,12-dodecane diisocyanate; cycloaliphatic diisocyanates such as cyclohexane-1,3- diisocyanate, cyclohexane-l,4-diisocyanate as well as any desired mixture thereof, l-isocyanato-3, 3 , 5-tri- methyl-5-isocyanatomethylcyclohexane; 2,4- and 2,6-hexa- hydrotoluene diisocyanate as well as any desired mixture of these isomers; 4,4'- and 2,4 '-diisocyanatodicyclo- hexylmethane; aromatic diisocynates such as 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-toluene diiso¬ cyanate as well as any desired mixture of these isomers, 2,2'-, 2,4'- and 4,4 '-diphenylmethane diisocyanate as well as any desired mixture of these isomers, and naphthylene-l,5-diisocyanate; aromatic polyisocyanates such as 4,4 ' ,4 ' '-triphenylmethane triisocyanate, 2,4,6- triisocyanatobenzene and polyphenylene polymethylene polyisocyanates.

Modified polyisocyanates such as carbodiimide group containing polyisocyanates (e.g., German Patent No. 1,292,007, allophanate group-containing polyiso¬ cyanates (e.g., British Patent No. 994,890 and Belgian Patent No. 761,626), isocyanurate group containing polyisocyantes (e.g., German Patent No. 1,022,789) ure- thane group containing polyisocyanates (e.g. British Patent No. 752,261 and U.S. Patent No. 3,394,164), biuret group-containing polyisocyanates (e.g. German Patent No. 1,101,394 and British Patent No. 889,050) and ester group-containing polyisocyanates (e.g. British Patent No. 964,474) may also be used in the practice of the present invention. Further preferred are the readily available aromatic di- and polyisocyanates such as 2,4- and 2,6- toluene diisocyanates (TDI) as well as any desired mixtures thereof; 2,2'-, 2,4'- and 4,4 '-diphenylmethane diisocyanates (MDI) as well as any desired mixture of these isomers with polyphenylene polymethylene polyisocyanates (crude MDI); mixtures of 2,4- and 2,6- toluene diisocyanates and crude MDI, and carbodiimide-, urethane-, allophanate-, isocyanurate-, urea- and biuret group-containing polyisocyanates. These di- and poly¬ isocyanates may be used individually or in mixtures or as prepolymers.

In the practice of the present invention any base polyol and any kind of polymer polyol can be used as the polyol.

The base polyol includes polyether polyols such as those described in British Patent No. 1,482,213 and polyester polyols. Suitable polyether polyols are those having a hydroxyl number in the range of 10 to 150, preferably in the range of 20 to 60, and a molecular weight in the range of from 200 to 16,000, preferably 500 to 10,000

Polymer polyols useful in the present invention as the polyol include PHD polymer polyols, PIPA polymer polyols and copolymer polyols.

Mixtures of base polyols or mixtures of base polyols and any kind of polymer polyols can also be used as the polyol in the present invention.

Polymerization of olphosphines with poly¬ isocyanates is carried out in the presence of the polyol. Amines and alkanolamines such as those used for PHD and PIPA polymer polyols production may be present during the polymerization reaction.

It is believed that the polymerization reaction (i.e., the polyaddition reaction) produces straight and/or branched chains by combination of isocyanate and hydroxyl groups to form urethane linkages (-0-CO-NH-) and by combination of isocyanate and phosphine groups, to form linkages of the type -PH-CO-NH- or >P-CO-NH- as appropriate.

10 The polyaddition product obtained may be mixed and/or chemically combined (as by copolymerization) with the polyol and it is to be understood that the term polymer modified polyol as used herein is intended to

•_jc encompass both physical and chemical combinations and also mixtures thereof. A solution or a stable dispersion of the polyaddition product in the base polyol or polymer polyol is obtained depending on the polymerization conditions and the ratio 0 olphosphine/polyisocyanate used.

Preferably-, the olphosphine and the polyisocyanate are reacted in the molar ratio of about 1.0/0.1 to 1.0/1.5 in the presence of base polyol having e a molecular weight in the range of 200 to 16,000 preferably 500 - 10,000. The resulting polymer modified polyol is normally a stable dispersion having the total solids content in the range of 0.1% to 45% by weight, preferably 2% to 30% by weight, most preferably 5% to 0 20% by weight, based on the weight of the polyol.

The polymerization of olphosphines with polyisocyanates can also be carried out in presence of primary monophosphines R-PH₂ or polyphosphines containing two or more primary or secondary phosphine groups in all proportions.

It is to be understood that not all hydroxyl/phosphine groups of the olphosphine used in the polyaddition reaction of the invention need react in all circumstances with the isocyanate groups and thus the olphosphine may react monofunctionally in some instances thereby acting itself as a chain terminator.

Other chain terminators such as, but not restricted to, monofunctional isocyanates, dialkyla- mines, diarylamines, N,N-dialkylalkanolamines, N,N-dia- ryalkanolamines, dialkylphosphines, diarylphosphines, and dialkylalkanolphosphines, diarylakanolphosphines may also be used in order to adjust the average molecular weight of the polyaddition products.

The polymer modified polyols of this invention may be also produced in presence of a catalyst. Same type of catalyst as used for polyurethane production such as organometallic compounds, amines etc can be used.

In general the olphosphine and the polyisocya¬ nate may be reacted at temperatures from 0°C to 150°C. Preferably the reactants are reacted at the temperature at which the reactants are in a liquid state.

The polyaddition reaction is slightly exother¬ mic and the temperature rise is proportional to the amount or polyaddition product made.

Although a simple batch process may be used whereby one of the olphosphine and polyisocyanate^* reactants is first of all dissolved or dispersed in the polyol, followed by the addition of the other reactant into the zone of maximum agitation, a continous process may also be used. The addition of the second reactant can be made instantaneously or progressively in time.

In situ polymerization, ( i . e . , the polymerization of the olphosphine with polyisocyanate concomitantly with the foaming reaction) is also possible.

The polymer modified polyols of this invention may be used either immediately after completion of the reaction or after a prolonged period of time.

Depending on the polymerization conditions and the ratio olphosphine/polyisocyanate used, the polymer modified polyols produced can take a form of a stable dispersion or solution.

In the case where the polyaddition product is in the form of a stable polyol dispersion, that is a dispersion which does not settle out or at least will remain in dispersion during mixing with other foam forming ingredients, the dispersed polyaddition product is particularly effective as a polymeric filler in the production of highly resilient conveniently processable foam.

The polymer modified polyols of this invention are useful for making polyurethane materials such as a polyurethane foams, elastomers and coatings.

Polyisocyanates and catalysts for the urethane forming reaction and, optionally, blowing agents and/or one or more other additives conventionally used in the manufacture of polyurethanes can be used with the polymer modified polyols of the present invention in amounts which will vary with the type of the polyurethane material desired. For the preparation of a polyurethane foam, polyisocyanates, blowing agents, foam stabilisers, catalysts, cross-linking agents, fillers, pigments, flame retardants and other additives familiar to the skilled person can be used in amounts which will vary with the type of the polyurethane material desired.

Organic polyisocyanates which may be used in the preparation of the polyurethane naterial are well known in the art and may be the same as the polyiso-

10 cyanates described hereinbefore for the reaction with the olphosphine.

All types of flexible, semi-flexible or rigid polyurethane foams can be produced using the polymer ic* modified polyol of the present invention provided that the polyurethane foam forming reactants and additives are selected and processed in an appropriate known manner.

All types of combustion modified foams can also 0 be prepared with the polymer modified polyol of this invention. Melamine or any other flame retardant or combinations thereof can be added before or during the polymer modified polyol preparation or just dispersed in 5 the polymer modified polyol before the foaming process.

Advantage of using polymer modified polyols of the present ^* invention resides in their inherent fire retardant and antioxidant properties. Consequently, polyurethane foams formulated with the polymer modified 0 polyols of this invention have fire retardant properties and high resistance to thermal ageing. Generally, these polyurethane foams would not require any other fire retardant additive for complying with existing flammability standards such as California Technical Bulletin 117 and MVSS 302.

In some cases in which polyurethane foams are required to comply with more severe flammability standards such as British Standard 5852, Part 2, Crib 5, additional fire retardant additives such as melamine may be required. In such cases, lower levels of such additional fire retardant additives are required than conventionally used for imparting the desired degree of fire retardancy to the foam.

Additional advantage of using polymer modified polyols of this invention in the preparation of polyurethane foams resides in the fact that these polyurethane foams retain fire retardant properties longer than foams prepared with non-reactive fire retardant additives which are often volatile.

Furthermore, it is believed that polymer modified polyols of the present invention have capability of bonding stoichiometrically carbon dioxide at atmospheric pressure, which carbon dioxide can be released during the foaming process and used as a blowing agent aid. The present invention is illustrated but not limited by the following Examples. In the Examples, the properties of the polyurethane foam were determined by the following tests:

Viscosity: measured at 25°C with Brookfield viscometer using number 3 spindle at 12-30 rpm after 24 hours.

Density: expressed in terms of kilograms per cubic meter. Hardness: determined in accordance with ISO 3386.1-79.

Tensile Strength:, determined in accordance with ASTM D-3574-77. Elongation: determined in accordance with ASTM

D-3574-77.

Tear Strength: determined in accordance with ASTM D-3574-77. Resilience: ball rebound (%).

Air Flow: determined in accordance with NOPCO.

Compression Set: determined in accordance with ISO 1856-72.

Fire Retardancy: determined in accordance with California Bulletin 117A (Cal 117) or British Standard 5852 Part 2 Crib 5 (BS 5852).

The abbreviations used in the Examples have the followng meanings:

Polyol A is a reactive trifunctional polyether polyol with an hydroxyl number of 35 and a primary hydroxyl group content of about 80%. Polyol B is a reactive diol with an hydroxyl number of 40 and a primary hydroxyl group content of about 80%.

Polyol C is a 50:50 styrene-acrylonitrile copolymer polyol with 8% solids content, the hydroxyl number of 32 and primary hydroxyl group content of about 75%.

Dabco 33 LV is a commercial amine catalyst for polyurethane foam production based on triethylene diamine supplied by Air Products and Chemicals Inc. Niax A-l is bis(2-dimethylaminoethyl)ether, an amine catalyst for polyurethane production available from Union Carbide Corporation.

SH-209 is a commercial silicone surfactant available from Union Carbide Corporation.

DBTDL is dibutyl tin dilaurate.

VORANATE M 220 is a po1ymethy1ene polyphenyleneisocyanate (polymeric MDI) supplied by The Dow Chemical Company.

T-80/20 is toluene diisocyanate (blend of 80% 2,4- and 20% 2,6-diisocyanate)

DEOA is diethanolamine. pbw is parts by weight.

Examole 1

A mixture of Polyol A (300 g) and liquid trimethanol phosphine (13.3 g) was stirred (2000 rpm) at a temperature of about 22°C for about 10 seconds. T- 80/20 (14.3 g) was added to the stirred mixture, the resulting mixture stirred for about 10 more seconds and then the stirring was discontinued. Within about 1 minute after discontinuance of the stirring, the temperature of the reaction mixture had risen from 22°C to 39°C. The resulting polymer modified polyol is a white dispersion which has a calculated solids content of 8.4%, and viscosity of 3200 cps.

Example 2

The polymer modified polyol obtained in Example was diluted with polyol A to the calculated solids content of 4.5% and used for preparing a polyurethane foam. The following formulation was prepared and allowed to foam and cure.

Foam Formulation

A non shrinking, highly resilient foam with the following properties was obtained.

Density (kg/m³) 29.5

Hardness (CFD 40%, kPa) 1.1

Tensile Strength (kPa) 89

Elongation (%) 147

Tear Strength (N/m) 223

Resilience (%) 63

Air Flow (cfm) 7.6

Compression Set 75 (%) 6

Cal 117 pass

Example 3

A mixture of Polyol B (135 g) and liquid trimethanolphosphine (6 g) was stirred (2000 rpm) at a temperature of about 22°C for about 5 seconds. T-80/20 (6.45 g) was added to the stirred mixture, the resulting mixture stirred for about 5 more seconds and then the stirring discontinued.

Within minutes after discontinuance of the stirring, the temperature of the reaction mixture had risen from 22°C to 39°C. The resulting polymer modified polyol is a stable white dispersion which has a calculated solids content of 8.4% and viscosity of 950 cps.

Example 4

A mixture of Polyol C (135 g) and liquid trimethanolphosphine (6 g) was stirred (2000 rpm) at a temperature of about 22°C for about 5 seconds. T-80/20 (6.45 g) was added to the stirred mixture, the resulting mixture stirred for about 5 more seconds and then the stirring discontinued.

Within minutes after discontinuance of the stirring, the temperature of the reaction mixture had risen from 22°C to 40°C. The resulting polymer modified polyol is a stable dispersion which has a calculated solids content of 16% and viscosity of 4300 cps.

Example 5

Polyol -A (90 g), liquid trimethanolphosphine (4. g) and hydrazine (1 g) were mixed at a temperature of about 22°C and stirred (2000 rpm) for about 10 seconds. T-80/20 (7.3 g) was added to the stirred mixture, the resulting mixture stirred for about 5 more seconds and then the stirring discontinued.

Within minutes after discontinuance of the stirring, the temperature of the reaction mixture had risen from 22°C to 45°C. The resulting polymer modified polyol is a stable white dispersion which has a calculated solids content of 12% and viscosity of 3100 cps.

Example 6

Polyol A (135 g), liquid trimethanolphosphine (3 g) and triethanolamine (3.65 g) were mixed at a temperature of about 22°C (2000 rpm) for about 5 seconds. T-80/20 (7.06 g) was added to the mixture, the resulting mixture stirred for about 5 more seconds and then the stirring discontinued.

Within minutes after discontinuance of the stirring, the temperature of the reaction mixture had risen from 22°C to 40°C. The resulting polymer modified polyol is a stable dispersion which has a calculated solids content of 9.2% and viscosity of 1700 cps.

Example 7

A mixture of Polyol A (90 g), liquid trimethanolphosphine (3 g) and DBTDL (0.03 g) was stirred (2000 rpm) at a temperature of about 22°C for about 10 seconds. VORANATE M 220 (5 g) was added to the stirred mixture, the resulting mixture stirred for about 20 more seconds and then the stirring discontinued.

Within minutes after discontinuance of the stirring, the temperature of the reaction mixture had risen from 22°C to 36°C. The resulting polymer modified polyol is a stable yellowish dispersion which has a calculated solids content of 8% and viscosity of 4000 cps.

Example 8

A mixture of Polyol A (90 g), liquid (previously melted at a temperature above 110°C) trimethanolphosphine oxide (4 g) and DBTDL (0.03 g) was stirred at a temperature of about 22°C for about 10 seconds. T-80/20 (3 g) was added to the stirred mixture, the stirring continued for another 10 seconds and then the stirring discontinued.

The resultant polymer modified polyol is a stable light yellowish dispersion which has a calculated solids content of 7.2 and viscosity of 5000 cps.

Example 9 The diluted polymer modified polyol as described in Example 2 was used for preparing a polyure¬ thane foam according to the formulation given in Example 2 hereinbefore except that melamine (15 php) was included in the formulation. A non-shrinking, highly resilient polyurethane foam of 32 kg/m³ density was obtained.

This polyurethane foam was tested according to BS 5852 and passed the test.

Claims

PATENT CLAIMS:

1. A process for preparing a polymer modified polyol which process comprises polymerizing an olphosphine with a polyisocyanate in the presence of a polyol.

2. A process according to Claim 1 wherein said olphosphine has the following formula

R—P(X)„ (i)

wherein each R independently is hydrogen, an alkyl group or hydroxyalkyl group with the proviso that at least one R is hydroxyalkyl group; X is oxygen, sulfur, selenium or a chemical entity which when bonded to the phosphorus atom forms a phosphonium compound; and n is 0 or 1.

3. A process according to Claim 2 wherein R in Formula I is hydroxy functionalized alkyl group of the formula ^■iC R^' R^--OH (ID

wherein R¹ independently in each occurence is hydrogen or an alkyl group; R² independently in each occurence is hydrogen or an alkyl group; and m is an integer of 1 to 6.

4. A process according to Claim 2 wherein R in Formula I is hydroxy functionalized poly(oxyalkylene) group of the formula

5. A process according to any one of Claims 1 to 4 wherein said polyol is a base polyol selected from a polyether polyol, polyester polyol and mixtures thereof.

6. A process according to any one of Claims 1 to 4 wherein said polyol is a polymer modified polyol ~ _n O 9

23

selected from PHD polymer polyols, PIPA polymer polyols and copolymer polyols.

7. A process according to any one of Claims 1 to 6 wherein polymerization of said olphosphine with said polyisocyanate is carried out at a temperature from 0°C to 150°C.

10 8. A process according to any one of Claims 1 to 7 wherein polymerization of said olphosphine with said polyisocyanate is carried out in the presence of a catalyst for the urethane forming reaction.

15

9. A process according to any one of Claims 1 to 8 wherein polymerization of said olphosphine with said polyisocyanate is carried out in the presence of an amine or an alkanolamine.

20

10. A process according to any one of Claims 1 to 9 wherein said olphosphine and said polyisocyanate are reacted in the molar ratio of 1.0/0.1 to 1.0/1.5.

25

11. A process according to any one of Claims 1 to 10 wherein the obtained polymer modified polyol is in the form of a dispersion which has a solids content of 0 from 0.1 to 45 percent by weight.

12. A process according to any one of Claims 1 to 11 wherein at least one additive is mixed with said olphosphine and said polyisocyanate.

13. A process according to Claim 12 wherein said at least one additive is a fire retardant additive.

14. A polymer modified polyol comprising a polyol and i a polyaddition product resulting from the polymerisation of an olphosphine with a polyisocyanate.

15. A polymer modified polyol according to Claim 14 which is a stable dispersion.

16. A process for preparing a polyurethane material wherein a polyisocyanate is reacted with a polyol characterised in that said polyol comprises a polymer modified polyol as claimed in Claim 14 or Claim 15.

17. A process according to Claim 16, wherein the polyisocyanate which reacts with the polyol is the same as that used in preparing the polymer modified polyol.

18. A process according to Claim 16 or Claim 17, wherein said polyurethane forming reaction between the polyisocyanate and the polyol is carried out in the presence of at least one additive selected from blowing agents, catalysts, stabilisers, cross-linking agents, flame retardant agents, pigments and fillers.

19. A process for producing a polyurethane material comprising reacting together a polyol, a polyisocyanate and an olphosphine.