PVB film containing a plastifying agent

1. A plasticized foil based on a partially acetalized polyvinyl alcohol and suitable as an intermediate layer in a laminated safety glass, comprising:

a) 60–85% by weight of partially acetalized polyvinyl alcohol,

b) 14–39% by weight of a plasticizer, and

c) 1–10% by weight of one or more non-ionic surfactants as an additive increasing the solubility of the plasticizer in the partially acetalized polyvinyl alcohol, wherein all weight percents are based on the total foil.

2. The foil as claimed in claim 1 , wherein the ratio of the plasticizer to the non-ionic surfactant—based on the parts by weight in the foil—is greater than 2.7:1.

3. The foil as claimed in claim 1 , wherein the amount of the plasticizer is sufficient to be incompatible with the partially acetalized polyvinyl alcohol without addition of the non-ionic surfactant.

4. The foil as claimed in claim 1 , wherein the amount of the non-ionic surfactant(s) is 2–4% by weight, based on the total foil.

5. The foil as claimed in claim 1 , wherein the partially acetalized polyvinyl alcohol comprises a partially butyralized polyvinyl alcohol with a polyvinyl alcohol content >19.5% by weight.

6. The foil as claimed in claim 1 , wherein the plasticizer comprises triethylene glycol di-2-ethylhexanoate.

7. The foil as claimed in claim 1 , wherein the non-ionic surfactant comprises a polyethoxylated aliphatic or aromatic alcohol having at least 6 carbon atoms in its alcohol fraction, with an average degree of ethoxylation greater than or equal to 2.

8. The foil as claimed in claim 7 , wherein the non-ionic surfactant comprises a polyethoxylated aliphatic or aromatic alcohol having 8–20 carbon atoms in its alcohol fraction, with an average degree of ethoxylation of 3–10.

9. A laminated safety glass, comprising at least one glass pane and at least one foil as claimed in claim 1 adjoining this glass pane.

10. A process for increasing the solubility of a plasticizer in a partially acetalized polyvinyl alcohol, comprising adding to the partially acetalized polyvinyl alcohol one or more non-ionic surfactants of a polyethoxylated aliphatic or an aromatic alcohol containing at least 6 carbon atoms in the alcohol fraction, with an average degree of ethoxylation greater than or equal to 2 with an average degree of ethoxylation of 3–10.

11. A process according to claim 10 , wherein the plasticizer is triethylene glycol di-2-ethylhexanoate.

12. A process according to claim 10 , wherein the amount of non-ionic surfactants is 2–10%, based on a total foil.

13. A process according to claim 10 , wherein the polyethoxylated aliphatic or aromatic alcohol contains 8–20 carbon atoms in the alcohol fraction.

14. A plasticized foil based on a partially acetalized polyvinyl alcohol for an intermediate layer in a laminated safety glass, comprising:

a) 60–85% by weight of partially acetalized polyvinyl alcohol,

b) 14–39% by weight of a plasticizer, and

c) 1–10% by weight of one or more non-ionic surfactants as an additive increasing the solubility of the plasticizer in the partially acetalized polyvinyl alcohol, wherein all weight percents are based on the total foil and the ratio of plasticizer to the non-ionic surfactant is greater than 2.7:1 based on the parts by weight in the foil.

15. The foil as claimed in claim 1 , wherein the amount of the non-ionic surfactant(s) is 1–9% by weight, based on the total foil.

16. The foil as claimed in claim 1 , wherein the ratio of the plasticizer to the non-ionic surfactant—based on the parts by weight in the foil—is greater than 3:1 but less than 10:1.