Sealant for floor joints with a high resistance to fuels
A polyurethane composition having a) 5 to 40 wt. %, based on the total polyurethane composition, of at least one polyol P; b) 25 to 75 wt. %, based on the total polyurethane composition, of at least one filler F; c) 0.5 to 10 wt. %, based on the total polyurethane composition, of at least one polyisocyanate I; and d) 10 to 40 wt. %, based on the total polyurethane composition, of at least one plasticizer W. The plasticizer W has at least one sulfonamide. Compositions according to the invention are suitable in particular as adhesives or sealants, in particular joint sealants, and have an excellent resistance against fuels.
1. A polyurethane composition consisting of:
a) 10 to 40 wt %, based on the overall polyurethane composition, of a polyol P comprising a polyether polyol or a polyester polyol;
b) 25 to 75 wt %, based on the overall polyurethane composition, of a filler F;
c) 0.5 to 10 wt %, based on the overall polyurethane composition, of a polyisocyanate I;
d) 10 to 40 wt %, based on the overall polyurethane composition, of a plasticizer W made exclusively of a sulfonamide selected from the group consisting of: an N-alkylated para-toluenesulfonamide, N-alkylated ortho-toluenesulfonamide, N-alkylated benzenesulfonamide, and combinations thereof, and
optionally at least one further additive selected from the group consisting of: a silane adhesion promoter, a reactive plasticizer, a urea compound, a polyamide wax, a bentonite, fumed silica, an adhesion promoter resin, a surface-active substance, a drying agent, a stabilizer to counter heat, light, UV light, and oxidation, a flame-retardant additive, a biocide, a fiber, a dye, a pigment, and a catalyst for crosslinking polyurethanes,
wherein the composition is fuel resistant.
2. The polyurethane composition as claimed in claim 1 , wherein the composition is substantially free from asphalt, bitumen, or tar oils.
3. The polyurethane composition as claimed in claim 1 , wherein the plasticizer W consists of N butylbenzenesulfonamide.
4. The polyurethane composition as claimed in claim 1 , wherein the polyisocyanate I comprises monomeric, oligomeric and/or polymeric diphenylmethane diisocyanate (MDI) or tolylene diisocyanate (TDI).
5. The polyurethane composition as claimed in claim 1 , wherein:
the composition is a single component composition, and the catalyst is present in an amount in a range of from 0 to 2 wt %, based on the overall polyurethane composition; and
the polyol P and the polyisocyanate I are present in a pre-reacted form as an isocyanate-functional polyurethane polymer PR having a free isocyanate content in a range of from 0.1 and 5 wt. %.
6. The polyurethane composition as claimed in claim 1 , wherein the composition is formed of two components: a first component KA comprising the polyol P, and a second component KB comprising the polyisocyanate I.
7. The polyurethane composition as claimed in claim 6 , wherein:
the first component KA comprises:
a) 10 to 50 wt %, based on KA, of the polyol P;
b) 10 to 50 wt %, based on KA, of the plasticizer W;
c) 25 to 75 wt %, based on KA, of the filler F; and
d) 0 to 2 wt %, based on KA, of the catalyst for the crosslinking of polyurethanes; and
the second component KB comprises:
e) 10 to 100 wt %, based on KB, of the polyisocyanate I;
f) 0 to 60 wt %, based on KB, of the plasticizer W; and
g) 0 to 60 wt %, based on KB, of the filler F;
with a mass mixing ratio of the first and second components KA:KB being between 8:1 and 12:1.
8. A method comprising applying an adhesive or a sealant consisting of the polyurethane composition as claimed in claim 1 onto a substrate.
9. A method comprising bonding and/or sealing a substrate comprising concrete with an adhesive or a sealant consisting of the polyurethane composition as claimed in claim 1 .
10. The method according to claim 9 , wherein the substrate comprises a garage or a building of a filling station, a tank farm, a fuel container, or an airport.
11. A method comprising applying a sealant consisting of the polyurethane composition as claimed in claim 1 for ground joints in civil engineering.
12. A building or article of manufacture, comprising concrete, which has been bonded or sealed with the polyurethane composition as claimed in claim 1 .
13. The building or article of manufacture according to claim 12 , wherein the polyurethane composition has been cured on the building or article of manufacture and is in contact with fuel after application and curing.
14. The polyurethane composition as claimed in claim 1 , wherein the composition is cured.
15. A sealant or adhesive consisting of the polyurethane composition as claimed in claim 1 , wherein the sealant or adhesive is fuel-resistant.
16. The sealant or adhesive as claimed in claim 15 , wherein the sealant or adhesive is in contact with fuel after application and curing.
17. A method comprising:
applying a sealant or adhesive consisting of the polyurethane composition according to claim 1 to a substrate; and
curing the sealant or adhesive on the substrate,
wherein the sealant or adhesive is in contact with fuel after application and curing.
18. The polyurethane composition according to claim 1 , wherein the polyol P is the polyester polyol.
19. The polyurethane composition according to claim 1 , wherein the polyol P is the polyether polyol.