Phthalate-free isocyanurate formulations
View Patent ↗The present invention relates to novel low-monomer low-viscosity high-activity formulations composed of isocyanurate containing isocyanate groups, exclusively based on 2,4-diisocyanatotoluene and phthalate-free plasticizers, to the use thereof as adhesion promoters with improved adhesion for coating compositions based on plasticized polyvinyl chloride, and to coatings and coated substrates.
1. A composition comprising:
A) from 15 to 50% by weight isocyanurate containing isocyanate groups,
B) from 84.99 to 49.99% by weight n-alkyl monobenzoates or isoalkyl monobenzoates, and
C) from 0.01 to 0.099% by weight 2,4-toluene diisocyanate (2,4-TDI),
wherein the composition has a viscosity of 5,000 mPas/23° C. to 18,000 mPas/23° C., with the proviso that:
i) the isocyanurate containing isocyanate groups is produced by trimerization of 2,4-TDI and
ii) the total of all the percentages by weight is 100%.
2. The composition of claim 1 , wherein the n-alkyl monobenzoates or isoalkyl monobenzoates comprise greater than 90% by weight n-nonyl benzoate or isononyl benzoate.
3. The composition of claim 1 , comprising 20 to 35% by weight isocyanurate containing isocyanate groups and 79.99 to 64.99% by weight of n-alkyl monobenzoates or isoalkyl monobenzoates.
4. An adhesion promoter for coating compositions based on plasticized polyvinyl chloride comprising the composition of claim 1 .
5. A substrate comprising the adhesion promoter of claim 4 .
6. An article comprising the substrate of claim 5 , wherein the article is selected from the group consisting of tarpaulins, billboards, air-supported structures and other textile structures, flexible containers, polygonal roofs, awnings, protective apparel, conveyor belts, flock carpets and foamed synthetic leather.
7. The substrate of claim 5 , wherein the substrate has an underlying structure comprising textiles or fabrics.
8. The substrate of claim 7 , wherein the fabrics are textile polyester fabrics or textile polyamide fabrics.
9. A process for production of the composition of claim 1 , comprising trimerizing 2,4-TDI to produce component A) at a temperature of 40° C. to 140° C. in the presence of component B) without solvent and in the presence of at least one Mannich base functioning as catalyst, and terminating the trimerization with complete or partial deactivation of the catalyst by thermal decomposition of the catalyst or by addition of at least one catalyst poison as soon as the content of free 2,4-TDI in the reaction mixture is below 0.1% by weight.
10. The process of claim 9 , wherein the amount of the Mannich base is from 0.01 to 2.0% by weight of the total composition.
11. The process of claim 9 , wherein the catalyst poison is selected from the group consisting of protic acids, acyl chlorides, dibutyl phosphate and methyl toluenesulfonate.
12. A coating composition comprising the composition of claim 1 .