Phosphorous containing materials, their preparation and use

1. A process for preparing a phosphorus-containing polymer precursor which polymer precursor is substantially halogen-free and is a radiation-curable polyester, the process comprising the steps of

(a) mixing together:

(i) a compound containing at least one hydrocarbylidenically unsaturated group and a plurality of carbonyloxy groups;

(ii) optionally a compound having a plurality of carbonyloxy groups and optionally free of hydrocarbylidenically unsaturated groups,

(iii) a polyol, and

(iv) an oxyphosphorous-containing compound (component (iv)) in which the phosphorous atom has at least one P—C bond which is resistant to hydrolysis or transesterification under the reaction conditions herein; such component (iv) comprising compounds of formula (I) and/or (II) and/or effective isomers, salts and mixtures thereof:

R 1 R 2 R 3 P═O

 where,

in formula (I): at least R 1 and R 2 independently represents C 1-20 organo group substituted by one or more hydroxy and/or carboxy group; R 3 represents H or optionally substituted C 1-20 organo group;

in formula (II): the phosphorous atom is substituted with at least one carbon atom to form at least one P—C bond; the P—O bond forms part of an organo ring, the ring being optionally substituted with one or more organo groups and/or optionally fused to one or more other organo rings;

(b) initiating polymerisation of the mixture to form a hydroxy and/or carboxy terminated phosphorous containing polyester oligomer (“First Polymer”),

(c) reacting the First Polymer with at least one acrylating agent to form a radiation-curable polymer precursor (“Second Polymer”).

2. A process as claimed in claim 1 , in which a catalyst is present during step (a) which catalyst (component (v)) comprises a tin complex catalyst.

3. A process as claimed in claim 1 , wherein the oxyphosphorous-containing compound of formula (I) comprises at least one of:

bis(hydroxymethyl)isobutylphosphineoxide, bis(hydroxypropyl)isobutylphosphine oxide and trishydroxymethylphosphine oxide.

4. A process as claimed any claim 1 , wherein the oxyphosphorous-containing compound of formula (II) comprises:

in which

R 2 to R 5 independently represent H or optionally substituted C 1-18 organo group(s), a plurality of which may together represent one or more rings optionally fused to the oxyphosphorous ring to which they are attached.

5. A process as claimed in claim 1 , wherein the oxyphosphorous-containing compound of formula (II) comprises:

9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide.

6. A process as claimed in claim 1 , which comprises a further step (step (d)) where the reaction product is neutralised with a base and water is removed from the reaction mixture before the resultant product is isolated.

7. A process as claimed in claim 1 , wherein the “First Polymer” is reacted with an oxiranating and/or isocyanating agent.

8. A polymer obtained or obtainable from the process as claimed in claim 1 .

9. A polymer as claimed in claim 8 comprising optionally substituted phosphorous containing polyester urethane (meth)acrylates.

10. A process comprising a polymerisation method for preparing a phosphorus-containing polyester derived polymer by initiating polymerisation in the presence of the polymer as claimed in claim 8 , and which optionally may be used as a reagent, and/or co-monomer in combination with other ingredients selected from (co)monomers, polymer precursors, catalysts, initiators, cross-linkers, flame retardant additives and/or other additives.

11. A polymer (“Third Polymer”) obtained or obtainable from the process as claimed in claim 10 .