Mastertitelformat. bearbeiten. One component waterborne coating system developments

Transcription

1 One component waterborne coating system developments Mastertitelformat industrial furniture applications (Authors : Thom Hermens, Jerome Caron, Guy Clamen) bearbeiten European Coating Conference, February 2014 G.Clamen The Dow Chemical Company

2 Summary Objectives, challenges and tool box Testing protocols Polymer definition and results Conclusion

3 Trend and challenges High chemical resistance 2K water borne binders High performance 1K water borne binders High mechanicals (block, scratch) High performance Furniture Topcoats User friendly (Low VOC) 2K solvent based binders

4 High chemical resistance properties High EtOH resistance in clear formulations High coffee resistance in pigmented formulations IKEA R2 Water resistance (24 hrs)* IKEA R4 Alcohol resistance (1 hr)* No chemical resistance

5 Starting point

6 Tool box 1. Polymer architecture 2. Polymer cross-linking 3. Binder <-> pigment interaction

7 Polymer cross-linking 2K Mechanisms Organic 1K Inorganic

8 Reference binders properties Commercial high performance Furniture topcoat binders Properties TA OXA MXA R1 R2 R3 R4 Solids (%) MFT ( C) ph Metal self-crosslinked binder Organic self-crosslinked binder Thermoplastic un-crosslinked binder

9 Testing protocols Chemical resistance Early block 150 µ WFT drawdowns on Al plates 4 min drying at 40 C 200 g/cm2 pressure Reference to EN and IKEA Rating : 5 : No damage (no visible damage) 4 : Slight gloss change, visible only when the panel is observed under one angle. 3 : Slight mark visible in many directions of observation 2 : Heavy mark, however the structure of the surface is unchanged. 1 : The structure of the surface has changed. The coating has been partially removed. 0 : The coating has been totally removed.

10 Properties of EXP. EXA1 in clear closs topcoat applications Properties OXA MXA R1 R2 R3 EXA1 Water (24H) Ethanol 50 % (1H) Block resistance (6mn at 40 C) 3.5 m 4 mok 4 m 3 mm 4 m 4 m VOC (g/l) Hardness Development : Koenig hardness MXA R1 R2 Properties EXA1 Solids (%) 40.5 MFT ( C) 42 ph EXA Time (days)

11 Properties of EXP. EXA1 in clear matt topcoat applications 20 % Silica based matting agent in water Acemat TS IW3311+TS100-2 Silica matting agent in EXP. EXA Micronized (D50 = 8µ) PE wax Particle Diameter (µm.) Matting agent chemistry Level (%) Silica based 2 2 Wax based 4 TA MXA R1 R2 R3 EXA1 EXA1 Water (24H) Ethanol 50 % (1H) Gloss (%)

12 Properties of EXP. EXA1 in clear matt topcoat applications Properties TA MXA R2 R3 R4 EXA1 Water (24H) Ethanol 50 % (1H) Gloss (2 x 200µm WFT) Formulation for a matt clear top coat for conventional spray applications Material Experimental acrylic EXA Pre-mix: - Water Dowanol PnB Dowanol DPnB 22.5 Byk TEGO Airex 902W 3.5 Ceraflour Adjust ph 8.1 with ammonia 3.7 Water 35.3 Total Weight solids: 38% ph: ~8.1 Density 1.04 g/l Parts by weight Properties Requirement definition Specification details Measured gloss at 60 : 70 <20 Mar/Scratch resistance Aluminium strip 3N, 5N 5 4 Early Block resistance Alu, 40 C after 4, 6 min 4 4 Sanding ability After 2 hrs at RT Fat on scratch IKEA 2N, 3N (24 hrs) 5 5 Chemical resistance IKEA Water (24 hrs) 5 5 IKEA Ethanol 50% (1 hr) 5 4 IKEA Coffee (1 hr) 5 5 IKEA Fat (24 hr) 5 5 Dry heat IKEA 70 C, 20 min Hot block resistance IKEA Alu, 4 weeks drying, 70 C 5 4 VOC Formulator g/l of total formulation 45 g/l 45 g/l

13 Properties of EXP. EXA1 in pigmented topcoat applications Starting formulation for a matt pigmented top coat Material Parts by weight A) Grind Water 56.1 Orotan Surfynol 104E 3.9 Byk Ti-pure R Minex Grind total Grind in Cowles at high speed for about 20 mins B) Let down Experimental acrylic polymer EXA Grind above Pre-mix: - Water Dowanol PnB Dowanol DPnB 22.2 Byk Aquacer Acematt TS Acrysol RM Total OXA MXA EXA1 Water (24H) Ethanol 50 % (1H) Coffee (1H) Block resistance 6mn 4 m 4 mok 4 mok VOC (g/l) Weight solids: 48% Volume solids: 35% Pigment Volume Conc: 24% Density 1.25 g/l Gloss 60 (%) 30

14 Intermediate conclusions A conventional themoplastic polymer is unable to deliver acceptable chemical resistance properties The inorganic crosslinking chemistry helps improve chemical resistance but at the expense of higher VOC A new acrylic polymer equipped with the proper organic crosslinking package has been developed that shows excellent solvent resistance properties in low VOC varnish systems A specific development is required to address the chemical resistance to coffee in pigmented systems

15 Coffee pause! Coffee contains more than 700 ingredients out of which caffeine is only 1 to 2 % : Caffeine Tannin Thiamin Xanthine Spermidine Guaiacol Citric Acid Chlorogenic acid Acetaldehyde Spermine Putrescine Scopoletin Theobromine Theophylline Trigonelline Hypoxanthine Aroma and color components : 4-Ethylphenol 2,4-Methylenephenol 2, 3, 5-Trimethylphenol 4-Methoxy-4-Vinylphenol 2-Ethylphenol

16 Binder chemical species most sensitive to polyphenols Extractables from topcoat surface Amidoamine species?

17 EXP. EXA2 for improved coffee resistance properties Properties EXA2 Solids (%) 44 MFT ( C) 36 ph 8 Key advantage : Tighter more impervious film

18 EXP. EXA2 properties in pigmented topcoat applications Parts by weight Water 4.75 Orotan Tego Airex 902W 0.45 Ti-Pure R Subtotal PVC (%) 18 EXA Gloss 60 (%) 17 Ammonia (14%) 0.20 Water 7.77 VOC (g/l) 67 Dowanol PnB 2.80 Alcohol resistance 4 Dowanol DPnB 2.80 Coffee resistance 4 BYK Block resistance 4 BYK Ceraflour RM-12W 0.23 RM Water

19 Conclusions 2 new one component water borne acrylic binders have been developed that show innovative chemical resistance properties targeting IKEA R2 requirements EXP. EXA1 shows outstanding alcohol resistance properties across a wide range of glossy, matt varnishes and pigmented applications EXP. EXA2 delivers the level of coffee resistance properties in pigmented applications up to now essentially achievable with 2K systems

20 The most difficult part is not to develop polymers

21 Mastertitelformat Thank you your attention bearbeiten!