Dr. Frank Groß 13th of November 2013 licon cross-linking premium clear coats
Structure of lixan U binders lixan U via silicon groups cross-linking urethane binder with high abrasion and chemical resistance
Application fields of lixan U Formulation of high quality clear coats with good abrasion resistance and high chemical resistance - temperature drying coatings (80-200 C, shortly 250 C) - at room temperature with moisture curing systems Improvement of the properties of 2K-PUR systems Increase of the mechanical resistance of silicone resin systems Combination with epoxy formulations or with melamine resin Source: BMW AG
Curing mechanism of 2K PU State of the art 2-pack polyurethane isocyanate + polyol isocyanate + polyol urethane (PU) Free isocyanate => problems for health: skin, lung, eyes Good chemical stability of formed urethane group Flexible polyurethane films with moderate chemical stability
= = = = = = Curing mechanism of lixan U lixan U clear coat Base varnish plus hardener licon cross-linking polyurethane (R) 3 (R) 3 N-C- H (R) 3 (R) 3 (R) 3 (R) 3 (R) 3 (R) 3 (R) 3 N-C- H (R) 3 (R) 3 N-C- H (R) 3 N-C- H N-C- H 2 nano silica N-C- H N poisonous or harmful isocyanate in liquid varnish N nanoparticles in liquid varnish UV- and chemical stable urethane groups already in the coating liquid => no free crosslinking organic groups Inorganic crosslinking via hardener (catalyst) to a scratch resistant 2 network in the cured clear coat => nano silica domains in the dry film
Clear coat raw materials lixan U 300-60/X/M/PA silicon cross-linking urethane for automobile clear coat, generation 1 lixan U 500-70/X fluorinated silicon cross-linking urethane, generation 2.1 lixan U 400 silicon cross-linking urethane based on natural raw materials, generation 2.2 lixan U 100 as additive for 2K-PU clear coat
Clear coat guide formulations No. U300-1001 / generation 1 K1 base varnish Mass [g; %] lixan U 300-60/X/M/PA 89,13 lixan, binder Butylgylcol 4,86 solvent lixan A 110 5,66 lixan, UV absorber additive Byk 301 Byk 088 0,25 BYK Chemie, leveling additive 0,10 BYK Chemie, defoamer Total 100,00 K2 hardener Mass [g; %] lixan Cat 200 88,89 lixan, curing catalyst lixan Cat 220 11,11 lixan, curing catalyst Total 100,00 Mixing ratio K1 : K2 100 : 4,5 Solid content 60 %wt. No. U500-3006 / generation 2.1 K1 base varnish Mass [g; %] lixan U 500-70/X 99,58 lixan, fluorinated binder Byk 301 0,30 BYK Chemie, leveling additive Byk 088 0,12 BYK Chemie, defoamer Total 100,00 K2 hardener Mass [g; %] lixan Cat 200 56,00 lixan, curing catalyst Diethylenglycol diethylether 44,00 solvent Total 100,00 Mixing ratio K1 : K2 100 : 10 Solid content 73 %wt. No. U400-1003 / generation 2.2 K1 base varnish Mass [g; %] lixan U 400 79,75 lixan, binder Xylol 19,95 solvent Byk 301 0,30 BYK Chemie, leveling additive Total 100,00 K2 hardener Mass [g; %] lixan Cat 200 100,00 lixan, curing catalyst Total 100,00 Source: VMA-Getzmann Mixing ratio K1 : K2 100 : 4,0 Solid content 80 %wt.
Acid resistance Chemical resistance with 36% sulfuric acid according to DIN EN IS 4628-1 Test U300-1001 2K PU clear coat ref2 Acid resistance Swelling Acid resistance Etching 12 min 6 min 16 min 8 min lixan U 300 / generation 1
Chemical resistance Gradient oven test according to DIN EN IS 4628-1 Test substance U300-1001 2K PUR clear coat ref2 Sulfuric acid 1,0% 42 C 49 C Hydrochloric acid 10,0% 42 C 41 C Caustic soda 5% 37 C 60 C Tree resin solution 37 C 43 C Pancreatin / Deionized water 47 C 37 C Deionized water 52 C 65 C lixan U 300 / generation 1
% gloss/20 Mechanical properties Scratch resistance - Crockmeter test with 10 double strokes of polishing paper (9 µm) according to BMW testing method AA-P 259 Mechanical resistance by Crockmeter-Test 100 96 89 lixan U 300 / generation 1 80 60 68 Crockmeter stress before weathering of coated test panels 40 Crockmeter stress after 3000 hours Xenon of coated test panels 20 21 0 guide formulation 2-K PUR clear coat ref2 fjgögki U300-1001 => Very good residual gloss after mechanical stress and weathering U300-1001 2K-PU
Delta E UV stability / weathering Total colour change ΔE (DIN 6174) after Xenon exposure (SAE J 1960) with different basecoats and guide formulation U300-1001 1,4 Delta E after weathering 1,2 2K PUR clear coat 2-K PUR clear coat Guide "lixan" formulation clear coat U300-1001 lixan U 300 / generation 1 1 0,8 0,6 t=500h t=1000h t=1500h t=2000h t=2500h t=3000h 0,4 0,2 0 black silver white black silver white basecoat => Good test results passing automotive requirements in color change and visual assessment
gloss 20 UV stability / weathering Gloss measurement (DIN 67530) after Xenon exposure (SAE J 1960) with different basecoats and guide formulation no. 1001 89 88 87 Gloss 20 after Xenon weatering up to 3000 h with different basecoats 2-K PUR clear coat Guide "lixane" clear formulation coat no. 1001 lixan U 300 / generation 1 86 85 84 83 t=0h t=500h 82 t=1000h t=1500h 81 t=2000h t=2500h 80 t=3000h black silver white black silver white basecoat => Test results passing automotive requirements in gloss and visual assessment
Summary Properties of U300-1001 High stiffness but flexible No etching under environmental stress High appearance and gloss High scratch resistance Reflow properties Excellent UV stability: 3 years Florida approval High solid formulation, low VC emission Isocyanate free! => High potential as automotive clear coat
Comparative results on lixan U 300-60/X/M/PA Generation 1 lixan U 500-70/X Generation 2.1 lixan U 400 Generation 2.2 lixan U 100 Additive for 2K-PU
Acid resistance Sulfuric acid drop test lixan U 400 lixan U 500 lixan U 300 2K-PU GS index value 36% Sulfuric acid Etching 36% Sulfuric acid Swelling 0 10 20 30 40 50 60 70 Time [min] Guide formulation based on lixan U 500 is best in sulfuric acid drop test
Chemical resistance lixan U 400 lixan U 500 lixan U 300 2K-PU GS index value Gradient oven test Gradient oven Deionised water Gradient oven Pancreatin / deionised water 1:1 Gradient oven Tree resin solution Gradient oven Caustic soda 5% Gradient oven Hydrochloric acid 10% Gradient oven Sulfuric acid 1% 0 20 40 60 80 100 Temperature [ C] lixan U 500 is the best sample in the tree resin test lixan U 400 shows good resistance against 5% caustic soda lixan U 400 shows good resistance against 10% hydrochloric acid & 1% sulfuric acid
Abrasion test lixan U Crockmeter residual gloss at 20 [%] lixan U 400 lixan U 500 lixan U 300 2K-PU %gloss after reflow GS index value %gloss before reflow 0 20 40 60 80 100 120 %
Chemical resistance - additive for 2K PU Gradient oven test Gradient oven Deionised water 2K-PU + U 100/13% Cat150 2K-PU + U 100/7% Cat150 2K-PU + U 300 2K-PU Gradient oven Pancreatin / deionised water 1:1 Gradient oven Tree resin solution Gradient oven Caustic soda 5% lixan U 300 0 10 20 30 40 50 60 Temperature [ C] Gradient oven Sulfuric acid 1%
Abrasion test additive for 2K PU Crockmeter residual gloss at 20 [%] 2K-PU + U 100/13% Cat150 2K-PU + U 100/7% Cat150 lixan U 100 is an effective additive for 2K-PU 2K-PU + U 300 %gloss after reflow 2K-PU %gloss before reflow lixan U 300 0 20 40 60 80 100 120 %
You re welcome! lixan GmbH Next Generation Resins Theodor-Heuss-Straße 11a D-66130 Saarbrücken (Germany) E-mail: Web: info@silixan.de www.silixan.de Tel.: +49 (0)681 876105 23 Fax: +49 (0)681 876105 31 Contact: Dr. Frank Groß Managing director (CE)