Low VOC construction primer

Abstract

The present disclosure relates to a primer composition. The primer composition comprises: a tert butyl acetate solvent; an organometallic reagent selected from organotitanates, organozirconates, aluminum organometallic compounds, and any combination thereof; an organotin compound; a silane with at least 3 hydrolyzable groups; and a polyorganosiloxane resin. Optionally, the primer composition further comprises a second solvent different from the tert butyl acetate solvent.

What is claimed is: 
     
       1. A primer composition for application to a substrate, the primer composition comprising:
 (i) a tert butyl acetate solvent; 
 (ii) an organometallic reagent selected from organotitanates, organozirconates, aluminum organometallic compounds, and any combination thereof; 
 (iii) an organotin compound; 
 (iv) a silane with at least three hydrolyzable alkoxy groups; and 
 (v) a polyorganosiloxane resin; and 
 (vi) optionally, a second solvent; 
 wherein adhesion of a material applied to the substrate is improved via priming of the substrate with the primer composition; and 
 wherein ingredient (v) is an MQ resin having hydroxyl groups and comprised substantially of M units (R 1 R 2 R 3 SiO 1/2 ) and Q units (SiO 4/2 ), with each R 1 -R 3  independently selected from monovalent hydrocarbon groups. 
 
     
     
       2. The primer composition of  claim 1 , including:
 between about 20 percent by weight and about 99.5 percent by weight of ingredient (i); and 
 between about 0 percent by weight and about 80 percent by weight of ingredient (vi). 
 
     
     
       3. The primer composition of  claim 1 , including:
 between about 0.05 percent by weight and about 5 percent by weight of ingredient (ii); and/or 
 between about 0.05 percent by weight and about 10 percent by weight of ingredient (iii); and/or 
 between about 0.05 percent by weight and about 10 percent by weight of ingredient (iv); and/or 
 between about 0.1 percent by weight and about 5 percent by weight of ingredient (v). 
 
     
     
       4. The primer composition of  claim 1 , wherein ingredient (vi) is present and selected from VOC exempt solvents or any combination thereof. 
     
     
       5. The primer composition of  claim 1 , wherein ingredient (ii) is selected from tetrabutyl titanate, tetrapropoxy titanate, zirconium acetylacetonate, tetraethoxy titanate, tetraamyl titanate, titanium di-isopropoxy bis ethylacetoacetate, di-isopropoxy bis acetylacetonate, aluminum acetylacetonate, and any combination thereof. 
     
     
       6. The primer composition of  claim 1 , wherein ingredient (iii) is selected from dimethyl tin di-neodecyl ester, dibutyltin dilaurate, dibutyl tin laulate, dibutyl tin acetate, dibutyl tin 2-ethyl hexanoate, and any combination thereof. 
     
     
       7. The primer composition of  claim 1 , wherein ingredient (iv) includes a phenyltrimethoxysilane and an (ethylenediaminepropyl)trimethoxysilane. 
     
     
       8. The primer composition of  claim 1 , wherein ingredient (iv) is selected from phenyltrimethoxysilane, (ethylenediaminepropyl)trimethoxysilane, vinyl trimethoxysilane, tetraalkylorthosilicate having the general formula SiOR 4 , tetraethoxysilane, mercapto functional-silanes, glycidyloxypropyl trimethoxysilane, and any combination thereof. 
     
     
       9. The primer composition of  claim 1 , wherein R 1 -R 3  do not include acrylate functional groups. 
     
     
       10. The primer composition of  claim 1 , wherein ingredient (v) has a molar ration of M units to Q units of 8:1 and/or an average of 2.1 mass % hydroxyl groups. 
     
     
       11. The primer composition of  claim 1 , being configured to have a VOC content of below about 250 g/l, optionally below about 100 g/l. 
     
     
       12. The primer composition of  claim 1 , wherein application of the primer to a painted substrate is configured to allow the paint to remain intact and does not cause surface marring or run-off of the paint. 
     
     
       13. The primer composition of  claim 1 , wherein ingredients (i) and (vi) are fully miscible with ingredients (ii), (iii), (iv), and (v), either alone or in combination. 
     
     
       14. A method for improving adhesion of silicone-based sealants to painted substrates, comprising priming a painted substrate with the primer composition as defined in  claim 1 . 
     
     
       15. A method of providing an improved cohesive failure mode of silicone-based sealants within the sealant matrix, comprising priming a substrate with the primer composition as defined in  claim 1 . 
     
     
       16. The method of providing an improved cohesive failure mode of silicone-based sealants within the sealant matrix as set forth in  claim 15 , wherein cohesive failure mode of silicone-based sealants within the sealant matrix is increased to above about 70%. 
     
     
       17. A method of priming a painted substrate surface, comprising the steps of:
 optionally, cleaning the painted substrate surface to remove contaminants and drying the painted substrate surface; 
 applying a primer composition to the painted substrate surface, the primer composition comprising: 
 (i) a tert butyl acetate solvent; 
 (ii) an organometallic reagent selected from organotitanates, organozirconates, aluminum organometallic compounds, and any combination thereof; 
 (iii) an organotin compound; 
 (iv) a silane with at least three hydrolyzable alkoxy groups; and 
 (v) a polyorganosiloxane resin; and 
 (vi) optionally, a second solvent selected from VOC exempt solvents or any combination thereof; 
 allowing the primer composition to dry; and 
 applying a silicone-based sealant to the painted substrate; 
 wherein adhesion of the silicone-based sealant to the painted substrate is improved via application of the primer composition to the painted substrate; and 
 wherein ingredient (v) is an MQ resin having hydroxyl groups and comprised substantially of M units (R 1 R 2 R 3 SiO 1/2 ) and Q units (SiO 4/2 ), with each R 1 -R 3  independently selected from monovalent hydrocarbon groups. 
 
     
     
       18. A primer composition for application to a substrate, the primer composition comprising:
 (i) a tert butyl acetate solvent; 
 (ii) an organometallic reagent selected from organotitanate, organozirconate, aluminum organometallic compounds, and any combination thereof; 
 (iii) an organotin compound; 
 (iv) an alkoxy-functional silane; and 
 (v) a polyorganosiloxane resin; and 
 (vi) optionally, a second solvent selected from VOC exempt solvents or any combination thereof; 
 optionally, wherein ingredient (iv) has at least one amine group; 
 wherein ingredient (v) is an MQ resin having hydroxyl groups and comprised substantially of M units (R 1 R 2 R 3 SiO 1/2 ) and Q units (SiO 4/2 ), with each R 1 -R 3  independently selected from monovalent hydrocarbon groups, the MQ resin having weight-average molecular weight between about 1,000 and about 100,000 on a standard polystyrene basis by gel permeation chromatography; and 
 wherein adhesion of a material applied to the substrate is improved via priming of the substrate with the primer composition. 
 
     
     
       19. The primer composition of  claim 18 , wherein ingredient (v) has a Molar Ratio of M Units to Q units of 8:1 and/or an average of 2.1 mass % hydroxyl groups. 
     
     
       20. The primer composition of  claim 18 , wherein ingredient (iv) includes a phenyltrimethoxysilane and an (ethylenediaminepropyl)trimethoxysilane.