Automotive coatings Improving efficiency, enhancing aesthetics. Eastman cellulose esters ADD-COAT-7954

Transcription

1 Automotive coatings Improving efficiency, enhancing aesthetics Eastman cellulose esters ADD-COAT-7954

2 Agenda Cellulose esters overview Desired attributes for automotive coatings Improving application and appearance Cellulose esters in basecoats Conventional low/medium solids solventborne basecoats Higher solids solventborne basecoats Cellulose esters in clear and top coats High solids clear coats

3 Introduction to cellulose esters Eastman supplies free flowing powders Produced from renewable sustainable raw materials CAB/CAP solution Eastman cellulose esters come from renewable sources and have unique properties that enhance the application and aesthetics of automotive coatings

4 Cellulose esters A product of the reaction between organic acids and anhydrides with cellulose: Acetic acid/anhydride Butyric acid/anhydride Propionic acid/anhydride Cellulose acetate (CA) Cellulose acetate butyrate (CAB) Cellulose acetate propionate (CAP) Eastman cellulose esters are available in a wide variety of formats and dispersions for versatility in use to achieve desired formulation and coatings attributes.

5 Code designation Example Eastman cellulose acetate butyrate - - CAB Cellulose acetate butyrate Approximate butyrl content at trimester stage (wt%) Falling-ball viscosity (s) Number of OH-groups per four anhydroglucose units Use solubility and molecular weight details for effective formulation and solvent choices

6 Chain packing CA vs. CAB Acetate molecule Butyrate molecule Understanding chain packing impacts solubility parameters and solvent choice

7 Eastman cellulose esters for coatings application R1,R2,R3 Acetyl, butyryl/propyl or H Pharmaceutical and other products Cellulose acetate Cellulose acetate propionate Cellulose acetate butyrate Automotive coatings: Cellulose esters enable high quality, compliant systems with higher solids

8 Segment Overview

9 Needs in automotive applications Improving application and aesthetics Automotive OEM needs Flow and leveling (gloss/smoothness) Metallic flake alignment (brightness) Reduced drying time (throughput) Automotive refinish needs Improved atomization (uniformity) Reduced surface defects (1 st pass yield) Rheology (application and appearance)

10 Metallic basecoats Details and desired attributes Designers use metallic paint and special effect pigments to enhance flow lines in body panels and other components. Metallic basecoats allow the use of a mixture of materials on a vehicle which all have the same appearance. Body coloured plastic components bumpers, wing mirrors, and more. Coated alloy wheels or plastic wheel trims Coated plastic components are generally cheaper, lighter, and more versatile than using actual metal components. Coatings can be given different tactile qualities such as soft feel and visual effects such as matt/glossy appearance. Consistent appearance across all vehicle components is crucial and can be impacted by ingredient and formulation choices

11 Segment Challenges Addressed by CAB and CAP

12 How CAB functions in metallic basecoats Viscosity of CAB permits application of heavy basecoat Aluminum pigment (flakes) As solvent evaporates, film shrinks, flake orientation begins Clear coat CAB prevents solvents in clear topcoat from redissolving basecoat

13 Solution viscosity With CAB No CAB Solution viscosity V T 1 Time T 2 With CAB, solution viscosity increases more rapidly

14 Comparing metallic flake orientation Coatings with and without CAB With Eastman CAB viscosity changes more quickly, allowing for better metallic flake orientation at the right time of the drying process Without Eastman CAB metallic flake orientation is hindered based on less desirable viscosity during drying

15 Improved flake orientation Indications of ideal flip flop 90 Highest coating brightness at direct view 45 Coating appears progressively darker at angle view With CAB Without CAB

16 Tuning the properties of coatings What if Attributes increase Attributes decrease Butyryl content of cellulose esters increases? Hydroxyl content of cellulose esters increases? Cellulose ester viscosity increases? Flexibility Solubility Hydrocarbon tolerance Compatibility Water tolerance Alcohol tolerance Hardness Reactivity Melting point Toughness Chemical resistance Grease resistance Hardness Moisture resistance Alcohol resistance Compatibility (very slightly) Solubility (slightly) Solution nonvolatile at fixed viscosity Cellulose esters are versatile problem solvers that offer formulators many options to achieve desired application and coating attributes

17 Results for cellulose esters in metallic base coats Conventional solventborne basecoats Solus 2300 in higher solids solventborne basecoats Cellulose esters in clear coat and topcoat systems

18 Eastman cellulose acetate butyrate for conventional solventborne basecoats

19 Typical metallic basecoat formulation Component Weight Description Supplier Alpate 7106 NS 61.0 Metallic pigment Toyal Europe Butyl acetate 61.0 Xylene 35.5 Cerafak Wax Byk-Chemie Setal SS Polyester resin Nuplex Resins Dow corning 56 (10%) in butyl acetate) Eastman Chemical Company Butyl acetate 35.0 Total Butyl acetate till application viscosity Technical data Property Value Test method Application viscosity at 23 C sec DIN cup 4 Solids content 20%

20 Typical components of a basecoat explained Ingredient Typical amount Function Binder (polyester or acrylic) Cellulose ester 40 60% of total solids 15 35% of total solids Appearance, depth of image (DOI), physical properties Flake orientation, fast drying, prevents re-dissolve by top coat Melamine resin 15 30% of total solids Inter-coat adhesion Polyethylene wax dispersion 5 10% of total solids Helps appearance, reduces mottling Metallic flake (aluminium) 10 15% of total solids Metallic effect, substrate hiding Solvent To application viscosity (20 Sec. DIN 4 flow cup) Fluidity, regulates drying time; solids at application viscosity typically > 20% Additives As needed Flow, levelling

21 Flake orientation Confocal microscopy Without CAB With CAB With CAB, metallic flakes align flat and reflect more light, enhancing appearance

22 Visual affect of metallic flake orientation

23 Resistance to redissolve by clear coat With CAB No color change Without CAB Visual color change CAB in the basecoat allows wet on wet application of clear coat without redissolve, which can alter appearance

24 Reducing redissolve SEM images of basecoat/clearcoat interphase Without CAB With CAB Diffuse interphase due to solvent migration into the basecoat layer Poorer alignment of Al flakes Clean interphase indicating lower redissolve of the basecoat layer Redissolve can negatively impact appearance

25 Effect of increasing the level of CAB Delivers enhanced aesthetic properties Improves appearance Smoother, more uniform paint film More consistent metallic flake orientation Improved color consistency

26 Solus 2300 for higher solid automotive solventborne basecoats

27 Eastman Solus 2300 performance additive Automotive OEM basecoat performance Generic OEM basecoat formulation Formulation Wt % Formulation/application data Polyester polyol (60% NV) 40.7 Solids as prepared (%) prior to reducing to spray viscosity Melamine resin (70% NV) 17.2 Application viscosity (#4 Ford cup), seconds Solus 2300 (40% in n-butyl acetate) 9.4 Theoretical solids (%) Wax dispersion (5% NV) 19.8 Measured solids (%) at application Flow additive Aluminum flake (70% NV) 11.2 Density (g/l) 989 Solvent blend 1.0 Total: NV = Non-volatile

28 Automotive OEM basecoat With Solus 2300 Control Solus 2300 Solus 2300 / microgel Top view Side view Avg RMS : 4.69 um FI : 7.1 Avg RMS = 2.36 um FI : 10.1 Avg RMS = 2.08 um FI : 13.4 With Solus, metallic flakes align flat and reflect more light, enhancing appearance

29 Eastman Solus 2300 Additional benefits to basecoats Helps in lowering volatile organic compounds (VOC) Superior performance Optimized flake control/face brightness Enhanced distinctness of image (DOI) Reduced dry-to-touch times Improved re-dissolve/strike-in resistance Smoother films Greater productivity by enabling higher solids Reduced defects during and after coatings application

30 Cellulose esters in clear and top coat systems

31 Automotive clear coat Desired application and appearance attributes Application Faster dry to touch Improved flow and leveling and sag resistance Improved hardness development Appearance Improved distinctness of image (DOI) Reduced defects

32 Clear coat formulation 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Acrylic +10% Cellulose ester Solvent Additives Curing agent Cellulose ester Polyol Control Novel approach Acrylic resin (75% n-ba) Solus 2100 (55% MIAK) n-butyl acetate MIAK Catalyst (1% in n-ba) Part A subtotal HDI trimer (90% n-ba) n-butyl acetate PM Acetate Part B subtotal Thinner (n-butyl acetate/1-ethoxy propanol acetate 60/40) Total

33 Enhanced drying performance With Solus 2100 Sand free free dry dry time time (mins) (min) minute drying time reduction Control Fast Drying drying Acrylic acrylic Fast drying Drying Acrylic acrylic +10% cellulose Cellulose Ester ester Reducing trying time is significant and decreases the chance of airborne contaminants to settle on wet paint and negatively impact appearance

34 Enhanced sagging performance With Solus Dry film sag point (µm) Spray application 40 Fast Drying Acrylic Fast drying acrylic Fast drying acrylic Fast Drying Acrylic +10% cellulose ester +10% Cellulose Ester With Solus, higher Tg and faster solvent release mean top coats can be applied in thicker films, improving appearance and productivity

35 Enhanced König hardness development With Solus 2100 Konig seconds Hardness of 2K clearcoat based after baking (60 C/30min) Fast Drying Acrylic Fast drying acrylic Fast Fast Drying drying acrylic Acrylic +10% cellulose ester Cellulose Ester Time (hr) Solus can decrease drying time while achieving desired hardness, improving productivity

36 Enhanced pot life With Solus Viscosity double time (mins) Fast Fast Drying drying Acrylic acrylic Fast Fast Drying drying Acrylic acrylic +10% +10% Cellulose cellulose ester Ester Increased pot life improves productivity and eliminates unnecessary waste of materials

37 Minimal VOC impact With Solus VOC (g/l) Fast Fast Drying drying acrylic Acrylic Fast Fast Drying drying acrylic Acrylic +10% cellulose ester +10% Cellulose Ester With Solus, productivity and appearance can be improved while also meeting stringent VOC limits

38 Gloss Gloss 20 (%) Fast drying acrylic Fast Drying Acrylic Fast drying acrylic Fast Drying Acrylic +10% cellulose ester +10% Cellulose Ester With Solus, there is insignificant impact to gloss compared to control

39 Appearance measured by Wavescan Horizontal (Wavescan profile) Horizontal (Short and long wave) Fast Fast Drying drying Acrylic acrylic Fast drying acrylic Fast Drying Acrylic + 10% +10% cellulose ester Cellulose Ester du Wa Wb Wc Wd We 0.0 SW LW With Solus, there is measurable appearance improvement

40 Appearance Acrylic +10% cellulose ester

41 Cellulose esters reduce coating defects Picture framing Crater Pin hole Coating Substrate

42 Improved flow and leveling with CAB Pencil reflection in a coating Without CAB Poor flow / leveling Poor reflection With Eastman CAB Good flow / leveling High reflection

43 CAB reduces flooding and floating in paint Solvent evaporation leads to localized surface cooling With CAB, rapid viscosity rise after application effectively locks pigments in position, delivering more even color and appearance

44 Similar mechanism for silica matting aids Light Reflected Light Scattered Silica particle Silica particle Without CAB Higher solids Lower film shrinkage Higher gloss With CAB Lower solids Higher film shrinkage Lower gloss With CAB, the performance of matting aids such as silica is increased due to higher film shrinkage

45 60 Gloss 2K acrylic urethane coating With silica matting aid at different film thicknesses 30 Acrylic control 25 Gloss : 0.3 Acrylic: CAB 10 1: 0.8 Acrylic: CAB Thickness (Microns) With CAB, constant gloss levels are exhibited as dry film thickness increases.

46 Conclusion

47 Cellulose esters for automotive coatings Enhancing application and appearance Improves application Faster drying time Improved flow and leveling Increases solution viscosity faster Improved hardness development Smoother, more uniform paint film Improves appearance More consistent metallic flake orientation Improved color consistency Delivers compliance No negative impact to VOC Derived from renewable sources