UV-transparent pressure sensitive adhesive

1. A UV-transparent pressure sensitive adhesive having a UV transparency at 300 nm of more than 95%, comprising:

(a) a copolymer of

(a1) from 75 to 99.8% by weight of acrylic esters and/or methacrylic esters of the formula CH 2 ═CH(R 1 )(COOR 2 ), where R 1 is H or CH 3 and R 2 is an alkyl chain having 1 to 20 carbon atoms;

(a2) from 0 to 10% by weight of acrylic acid and/or methacrylic acid of the formula CH 2 ═CH(R 1 )(COOH), where R 1 is H or CH 3 ;

(a3) from 0.2 to 5% by weight of olefinically unsaturated monomers which contain at least one UV-crosslinking functional group per monomer; and

(a4) from 0 to 20% by weight of olefinically unsaturated monomers which are different than the olefinically unsaturated monomers (a3) and which contain at least one functional group per monomer; said copolymer having a molecular weight Mw of less than 300,000 g/mol and

(b) from 2 to 20% by weight, based on the weight of the copolymer, of a silicate filler, the silicate filler having a maximum particle diameter of 50 nm;

the U-V-transparent pressure sensitive adhesive having a residual solvent fraction of less than 1%, based on the weight of the U-V transparent pressure sensitive adhesive.

2. A pressure sensitive adhesive as claimed in claim 1 , wherein said amount of component (a1) is from 86 to 90% by weight.

3. A pressure sensitive adhesive as claimed in claim 1 , wherein said amount of component (a2) is from 4 to 6% by weight.

4. A pressure sensitive adhesive as claimed in claim 1 , wherein said amount of component (a3) is from 0.5 to 1.5% by weight.

5. A pressure sensitive adhesive as claimed in claim 1 , wherein said amount of said silicate filler is 5 to 10% by weight.

6. A pressure sensitive adhesive as claimed in claim 1 , wherein the silicate filler has a particle diameter of from 10 to 30 nm.

7. An adhesive tape comprising the pressure sensitive adhesive of claim 1 .