Tailored surface modification of substrates by atmospheric plasma for improved compatibility with specific adhesive Nicolas Vandencasteele

Transcription

1 1 oating Plasma Innovation Tailored surface modification of substrates by atmospheric plasma for improved compatibility with specific adhesive Nicolas Vandencasteele

2 2 Plasma Applications Adhesion improvement Release Liners

3 3 Plasma 4 th state of matter: ionized gas

4 4 old atmospheric plasma old: T gas < 100 T ions,neutrals < 100 T electrons Hot: T gas T ions,neutrals T electrons 10 4 <T<10 8 Atmospheric: Plasma gas is at atmospheric pressure Open reactor, high density of particles Energetic electrons chemistry

5 5 orona High Voltage Used for activation or cleaning Flat substrate Most of the time need to be used inline with other process Gas used: none (ambient air) Ambient air Filamentary discharge

6 6 Plasma DBD High Voltage Used for activation or cleaning and deposition Flat substrate Used online or offline Gas used:n 2, (Ar, He) ontrolled atmosphere Homogeneous discharge

7 7 Plasma vs orona Surface energy measurements on BOPP film ontrolled chemistry Stable treatment

8 8 Plasma vs orona Microscopy (AFM) image of BOPP film 1 µm x 1 µm images (Tapping) Untreated Plasma DBD orona Es 30 mn/m Es = 60 mn/m Es = 38 mn/m Identical discharge power ontrolled chemistry, homogenous discharge no surface damage

9 9 Process Plasma gas + dopant Dopant: ppm of reactive gases mixed with plasma gas (only safe gas green top bottles)

10 10 APPLIATIONS

11 11 Applications: leaning Plasma O 2, H 2 O ontaminated surface Surface contamination leaned sample Removal of surface contamination without substrate degradation

12 12 Applications: Grafting O O O O H O O O O O H O Amine Amide Imide N H H 2 O NH O O N H Gas: N 2 + dopants Surface functionalization

13 Atomic % (XPS) Quantity (a.u.) 13 Applications: Grafting Plasma 1 Standard Plasma 2 Advanced Dopant 11 Plasma 3 Advanced Dopant Amine Amide Imide Grafting of nitrogen containing groups Tunable surface functionalization

14 14 Applications:oating Specific molecules (precursor ) are added to the plasma gas. Those molecules are activated ( ) by the plasma and react with the sample surface to form a thin film. HMDSO precursor SiO x film (hydrophilic) Si y O x film (hydrophobic) oating nature dependend on precursor AND plasma chemistry

15 15 ADHESION IMPROVEMENT

16 16 ETFE Surface energy increase Very limited ageing after 3 weeks

17 Peel Force [N/m] Surface energy [mn/m] ETFE Adhesion increase ETFE laminate (Araldite 2028) Untreated orona Plasma 1 Plasma 2 Plasma 3 Peel Force Surface Energy Different plasma chemistries Surface energy is not the main factor improving adhesion

18 Peel Force [N/m] at. % N 18 ETFE Adhesion increase ETFE laminate (Araldite 2028) Untreated orona Plasma 1 Plasma 2 Plasma 3 Peel Force %N grafted hemistry, not SE, is the main factor improving adhesion

19 Peel Force [N/m] Surface Enrgy [mn/m] 19 PET Adhesion increase PET thermoset adhesive Untreated orona Plasma a Plasma b Plasma c Peel force Surface Energy Adhesion not always directly related to surface energy

20 Peel Force [N/m] At. % Nitrogen 20 PET Adhesion increase PET thermoset adhesive Untreated orona Plasma a Plasma b Plasma c Peel force Surface omposition hemistry, not SE, is the main factor improving adhesion

21 21 Adhesion increase Acrylic PET Untreated vs orona 15% Untreated vs Plasma Up to 85% orona vs Plasma 35% Thermoset PET Untreated vs orona 200% Untreated vs Plasma Up to 2300% orona vs Plasma 800% Araldite 2028 ETFE Untreated vs orona 1000% Untreated vs Plasma Up to 4870% orona vs Plasma 350% Results depend on adhesive and plasma chemistries

22 22 RELEASE LINERS

23 23 Release coating Plasma allow deposition of nanometer thick coatings. Release liner developed for electronic industry Moderate to high release force Extremely low level of extractible silicone Recyclable oating 10 nm TEM crosssection image

24 24 Release coating Peel force (N/m) SA (%) Extractible Silicone (ng/cm²) Silicone RL Silicone RL Silicone RL Silicone RL Non silicone RL 1* Non silicone RL 2* n.d. Plasma n.d. *Not resistant to solvant Peel force measured with solvent based acrylic tape SA measured with Nitto 31b tape Extratible silicone measured based on IDEMA M 7 98 standard

25 RF [N/m] 25 Release coating ontrolled Release Solvent based acrylic PSA, 180 peel test at 300 mm/min Experimental parameter [a.u.] Release level can be adjusted by experimental parameters

26 26 onclusion Plasma treatment enables stable modification of surface energy Plasma allows to tailor the surface modifications to specific adhesive and substrate combination Level of adhesion can be controlled over a large range Plasma treatment can be applied to almost any materials (PEEK, Fluorinated polymers, PI ) Plasmas allow to produce very clean release liners (no silicone contamination) with tunable release force