Thermosetting composition

1. A thermosetting composition comprising

(a) 50-90 wt % of at least one phosphorous-free bis(dihydrobenzoxazine) of formula (I),

wherein

each R 1 is independently C 1 -C 18 alkyl, C 3 -C 12 cycloalkyl, C 3 -C 12 cycloalkyl which is unsubstituted or substituted with a C 1 -C 4 -alkyl, or C 6 -C 18 aryl which is unsubstituted or substituted by one or more C 1 -C 6 alkyl groups or C 1 -C 6 alkoxy groups;

each R 2 is independently hydrogen, dialkylamino, alkylthio, alkylsulfonyl, C 1 -C 18 alkyl, C 1 -C 18 alkenyl, C 1 -C 18 alkoxy, C 1 -C 18 alkoxy-C 1 -C 18 -alkylene, C 5 -C 12 cyclo alkyl which is unsubstituted or substituted by one or more C 1 -C 6 alkyl groups or C 1 -C 6 alkoxy groups, C 6 -C 12 aryl which is unsubstituted or substituted by one or more C 1 -C 6 alkyl groups or C 1 -C 6 alkoxy groups, or C 6 -C 12 aryl-C 1 -C 18 -alkylene wherein the aryl moiety is unsubstituted or substituted by one or more C 1 -C 6 alkyl groups or C 1 -C 6 alkoxy groups;

X 1 is a bivalent bridging group selected from —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, —N(R 3 )—, —O—C(O)—, —O—C(O)—O—, —S(O) 2 —O—, —O—S(O) 2 —O—, C 1 -C 18 alkylene, C 2 -C 18 alkenediyl, C 3 -C 12 cycloalkylene, C 5 -C 12 cycloalkenediyl, —Si(OR 3 ) 2 — or —Si(R 3 ) 2 —; and

R 3 is H, C 1 -C 12 alkyl, C 5 or C 6 cycloalkyl, C 5 or C 6 cycloalkyl substituted with methyl, ethyl, or phenyl, benzyl or phenyleth-2-yl;

(b) 1-13 wt % of at least one quaternary ammonium salt comprising

i) a cation of an aromatic-N-heterocyclic compound which comprises one or two nitrogen atoms and

ii) an anion;

(c) 1-15 wt % of a thermal radical initiator selected from a pinacol or an ether, ester or silyl derivative thereof; and

(d) 15-40 wt % of a compound comprising at least one epoxy group

wherein the wt % is based on the entire weight of the thermosetting composition.

2. A thermosetting composition according to claim 1 wherein the quaternary ammonium salt (b) comprises a cation of a substituted or unsubstituted aromatic-N-heterocyclic compound which is selected from pyridine, pyrimidine, pyridazine, pyrazine, picoline, lutidine, quinoline, isoquinoline, quinoxaline, phthalazine, quinazoline, acridine, phenanthridine and phenanthroline.

3. A thermosetting composition according to claim 1 wherein the quaternary ammonium salt (b) comprises a cation of formulae (XIII), (XIV) and (XV):

wherein R 7 is C 1 -C 18 alkyl; aryl-C 1 -C 8 alkylene wherein the aryl moiety is unsubstituted or substituted by one or more linear or branched C 1 -C 12 alkyl, C 1 -C 8 alkoxy-C 1 -C 8 alkylene, C 1 -C 12 alkyloxy, C 1 -C 12 alkylcarbonyl, halogen or hydroxyl; C 3 -C 15 alkoxy-C 1 -C 8 alkylene or benzoyl-methylene;

each of R 8 , R 9 , R 10 , R 11 and R 12 independently of the other is hydrogen, C 1 -C 4 alkyl or phenyl, or R 8 and R 9 or R 9 and R 10 or R 10 and R 11 or R 11 and R 12 , together with the two carbon atoms to which they are attached, are a fused benzo, naphtho, pyridino or quinolino radical.

4. A thermosetting composition according to claim 3 , wherein R 7 is selected from the group consisting of methyl, ethyl, n-propyl, iso-butyl, sec-butyl, test-butyl, dodecyl, octadecyl, benzyl, phenyleth-2-yl, acetyl and benzoyl.

5. A thermosetting composition according to claim 1 wherein the quaternary ammonium salt (b) comprises a cation selected from one or more of the formulae (XVI) to (XXIV) wherein Y is either-CH═ or a nitrogen atom:

wherein R 7 is C 1 -C 18 alkyl; aryl-C 1 -C 8 alkylene wherein the aryl moiety is unsubstituted or substituted by one or more linear or branched C 1 -C 12 alkyl, C 1 -C 8 alkoxy-C 1 -C 8 alkylene, C 1 -C 12 alkyloxy, C 1 -C 12 alkylcarbonyl, halogen or hydroxyl; C 3 -C 15 alkoxy-C 1 -C 8 alkylene or benzoyl-methylene.

6. A thermosetting composition according to claim 1 wherein the quaternary ammonium salt (b) comprises a cation of the following formula:

wherein each R 13 independently of the other is C 1 -C 18 alkyl; aryl-C 1 -C 8 alkylene wherein the aryl moiety is unsubstituted or substituted by one or more linear or branched C 1 -C 12 alkyl, C 1 -C 8 alkoxy-C 1 -C 8 alkylene, C 1 -C 12 alkyloxy, C 1 -C 12 alkylcarbonyl, halogen or hydroxyl; C 3 -C 15 alkoxy-alkylene or benzoyl-methylene.

7. A thermosetting composition according to claim 1 wherein the quaternary ammonium salt (b) comprises an anion ii) selected from the group consisting of BF 4 − , PF 6 − , SbF 6 − and SbF 5 (OH) − .

8. A thermosetting composition according to claim 1 wherein weight ratio of component (a) to quaternary ammonium salt (b) is 100:1 to 10:2.

9. Process for the manufacturing of an article comprising the steps:

a) providing a fabric

b) impregnating the fabric with a thermosetting composition according to claim 1 and

c) curing the impregnated fabric.