Photo-reactive binder

1. A process for the synthesis of a compound having the following formula (I),

comprising reacting:

a) a benzophenone derivative of the following general formula

b) a linker comprising from 4 to 300 hydroxyl groups, and

c1) a (meth)acrylating compound comprising at least one (meth)acrylate group and at least one reactive group capable to react with an hydroxyl group, or

c2) a linker comprising at least two reactive groups capable to react with a hydroxyl, then a (meth)acrylating compound comprising at least one (meth)acrylate group and at least one hydroxyl,

wherein in the formulas:

L is a linker,

R 5 is a reactive group capable to react with a hydroxyl group to form an ester,

R, R″ and R′″ are independently selected from the group consisting of H, C 1-8 alkyl, C 1-10 alkoxy and halogen,

m is from 1 to 100,

n is from 1 to 100,

G is a linker comprising a number p of unreacted hydroxyl groups comprised between 0 and 100, and is a residue of a polyhydroxy compound having at least 4 hydroxyl groups, and

M is a group comprising a number z of (meth)acrylate groups equal to at least one.

2. The process according to claim 1 , wherein the compound has the following formula (II),

3. The process according to claim 2 , wherein the compound has the following formula (IV),

4. The process according to claim 3 , wherein the compound has the following formula (VI),

5. The process according to claim 1 , wherein

the linker b) comprises from 4 to 92 hydroxyl groups,

n and m are independently from 1 to 31, and

p is from 0 to 30.

6. The process according to claim 5 , wherein the linker b) comprises from 4 to 40 hydroxyl groups and n and m are independently from 1 to 5.

7. The process according to claim 5 , wherein the linker b) comprises from 4 to 66 hydroxyl groups and p is from 0 to 4.

8. The process according to claim 1 , wherein n is from 2 to 100.

9. The process according to claim 8 , wherein the linker b) comprises from 4 to 205 hydroxyl groups and n is from 2 to 5.