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Arkema Coating Resins
Welcome to the 2014 ACR Webinar Series!!
November 21, 2014
Invest one hour with us and we’ll help you grow your business with products and technology from Arkema Coating Resins
2014 ACR Webinar Series
Today’s Topic: Taking the Fear out of Wood Coatings: Understanding Wood for Better Coatings Choices
Speaker: Doug Mall
Title: Senior Technical Service Chemist
3 3
Our Training Goal
Give you the knowledge necessary to answer your customer’s questions concerning wood coatings with confidence: ● A high level overview of wood coatings applications,
formulation, and testing. ● Review the various types of woods and relevant
properties ● Discuss formulating and testing of wood primers and
finishes ● Highlight several Arkema products and describe their
performance benefits
4
Overview Wood as a Substrate ● Benefits, challenges of using wood as a substrate ● Decline of Wood as siding in single family homes.
Defining Wood Coatings ● Types of coatings for wood ● Testing of wood coatings ● What goes into a wood coating?
ACR product overview and product spotlight ● Paints and stains ● Specialty finishes
– Primers – Varnishes
● Industrial finishes
Recap
What Are The Issues With Wood Coatings?
6
Wood as a Substrate
Wood is a renewable resource that has been used for construction and decorative purposes for a long time.
A well maintained and preserved wood structure can last for centuries!
Photo of 1700’s US mill courtesy of Sam Williams of the USDA Forest Products Laboratory, Madison WI
7
Wood as a Substrate
Keys to achieving long time durability: ● Protecting the wood from UV light. ● Keeping the wood from getting wet.
Images courtesy of USDA Forest Products Laboratory, Madison WI
Erosion of wood due to UV and weathering
Raised grain, end grain view, same panel cut in two. Differences due to moisture difference!
8
Moisture Content Cycle – Coated & Uncoated
6
9
12
15
18
21
Moi
stur
e co
nten
t of w
ood,
g H
2O /
100g
OD
Woo
d Unfinished1 Coat3 Coats
*Forest Products Labs study on effect of relative humidity on moisture contedt of Ponderosa Pine. From “Finishes for Exterior Wood,” Williams, Knaebe & Feist, Published 1996
90%RH 30%RH 90%RH 30%RH 90%RH 30%RH
Ponderosa Pine
9
Not All Wood Is The Same! Different species: ● Softwood (conifers) – Typically used for exterior substrates
– Cedar – Redwood – Cypress – Pine
- Southern Yellow - White - Ponderosa
– Fir – Spruce
● Hardwood – Better for interior uses such as furniture.
– Cottonwood – Maple – Luan – Oak – Mahogany – Cherry
Usually the best choice for exterior siding
Typically pressure treated for better stabilization and insect repellency for decks
10
For Most Up-To-Date Performance Data…
11
There Are Even Differences On The Same Tree!
Image courtesy of USDA Forest Products Laboratory, Madison WI
12
Not All Wood Is The Same! – Continued…
Differences in where the wood is cut! ● Vertical grain (best; old time boards) ● Flat grain (typical of wood today)
– Bark side – Pith side
● Vertical grain with pith – Juvenile wood from center of log – Poor properties!
● Texture of wood
– Smooth sawn – Rough sawn
Differences in moisture level ● Straight from saw mill ● Kiln dried – typical moisture level 6-12% (best)
Figure courtesy of USDA Forest Products Laboratory, Madison WI
13
Not All Wood Is The Same! – Continued…
Differences in board quality ● Clear (no knots) ● Some knots (1-2 knots/board) ● Knotty wood (>2 knots/board) ● Juvenile wood (Pith included)
Image above – shows use of knotty and flat-grain boards where finish problems may arise.
Image to left – shows mixed use of flat and edge grain wood, leading to performance issues.
Photos by Doug Mall, 1994, Subdivision in Milwaukee, WI
14
Not All Wood Is The Same! - Composites Finger-Jointed Lumber ● Brings utility to knotty wood, cutting
out knots and dove-tailing pieces together
● However, one board could have various grain patterns and be from various trees, leading to localized board differences
T1-11 Plywood ● Sheets of layered and treated
plywood with a bead to simulate a board pattern used for barns and sheds.
Hardboard ● Also called high-density fiberboard
(HDF), is a type of fiberboard, which is an engineered wood product. Part of a class-action lawsuit in 1996, although homes still exist that have this type of siding.
Not used as exterior siding: ● Oriented strand board
T111 Siding Image courtesy of Home Depot
Finger Jointed lumber Image courtesy of woodgears.ca
15
Issues Of Using Wood
Proper preparation and finishing of wood can help prevent: ● Warping ● Weathering ● Extractive staining ● Early peeling of finish ● Wood degradation due to UV ● Wood rot due to high moisture content
– (>20%)
16
Pre-Weathering Effects on Paint Durability
0 1 2 3 4 5 6 7 8 9 10 11 12 14 16 17
0123456789
10
Cra
ckin
g R
atin
g
Years Exposure
Rating during 17 Years Ext Exposure on Latex Top-coat / Latex Primer on WRC
0 Wks PW1 Wk PW16 Wks PW
Correlation Of Adhesive Strength With Service Life Of Paint Applied To Weathered Wood, RS Williams, JE Winandy, WC Feist, Proceedings of the 9th Durability of Building Materials and Components Conference held 17-20, March 2002 in Brisbane Australia
No P
re-
weat
herin
g Pr
e-we
athe
red
1 wk
Pre-
weat
here
d 16
wks
17
Pre-Weathering Headaches For Paints, etc.:
Wood grain on back of peeling paint is a key indicator of pre-weathering!
18
Total Primary Siding Trends – USA
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
Hom
es [
000'
s]
Aluminum SidingFiber CementOther (Cinder block, Stone, etc.)StuccoBrickWood & Wood SubstratesVinyl Siding
US Census Bureau, The Official Statistics, June 2014 http://www.census.gov/pub/const/C25Ann/sftotalexwallmat.pdf
Wood market share went from 35% in 1992 to 5% in 2013
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So, Do We Need Exterior Wood Coatings?
Yes! Customers in the architectural coatings business still see wood as a major substrate that needs to be addressed by their coatings business.
There is still a large stock of wood based homes that require regular maintenance and repainting.
Wood is also still used for decks, fences, railings, doors and windows.
A coat of paint as thin as a sheet of paper can help extend the lifetime of wood.
What are Wood Coatings?
21
Wood Coatings Are Any Finish Used For Either New Or Previously Finished Wood Substrates
Used for both interior and exterior surfaces
Exterior and interior finishes have different challenges that need to be met: ● Different substrate issues ● Different moisture resistance ● Different chemical resistance ● Different abrasion resistance
Some industrial wood finishes have been developed to better address the wide variability of substrates and finish application encountered with DIY finishes
22
Defining Categories Exterior Wood Coatings
Coatings to wood surfaces that will be outside that are applied on-site, either by a homeowner or a contractor.
Typically applied with a brush or roller.
Coating system must hold up to ● Weathering (UV and moisture) ● A wide extreme of temperatures ● Dirt, mildew and algae
Coating system must resist ● Grain cracking and peeling ● Blistering ● Extractive stain bleeding ● Moisture
Interior Wood Coatings
Coatings to wood surfaces that will be inside that are applied on-site, usually by a homeowner.
Typically applied with a brush or roller.
Coating system must hold up to ● Occasional UV light exposure ● Abrasion or household chemicals
Industrial Wood Coatings
Coatings typically applied at a factory with specialized equipment, where control of the substrate, finish and drying conditions are key.
23
Defining Wood Coatings Types
For Siding, Furniture, Fences, etc.:
Paint ● Typically a flexible finish that offers liquid water resistance, fade and
mildew resistance. ● The coating (45-65% solids) will hide the wood grain. ● Most quality finish systems suggest the use of a primer and two topcoats. ● Durability of a properly prepared and applied system can reach 20 years
before repainting required. (One coat = 7-10 years)
● Paints come in a range of finishes, from flat to gloss.
● Typically the wood siding is painted flat to satin. Wood trim paints are a higher gloss.
24
Wood Coatings Types - Continued
For Siding, Furniture, Fences, Decks, etc.: Solid-Color Stain ● Lower solids than a paint (35-50%), but very similar in performance. Will use
same binders as found in paints, but usually formulated to a flat finish. ● Market has demanded this category for decks, but will peel if not properly
maintained and renewed. ● Refinish after 3-7 years (siding); 2-5 years (decks)
Semi-Transparent Stain ● Lower solids finish (20-35%) that has enough pigment to partially obscure
the grain of the wood. Can be either penetrating or film-forming. ● Refinish after 2-5 years (siding); 1-3 years (decks)
Penetrating/transparent stain (Toner) ● A low solids finish (15-35%) that changes the color of the wood. ● Typically is refinished every 6-24 months. Fails by erosion.
25
Examples of Commercial Deck Stains
Transparent Stains (Toners)
Semi-Transparent Stains
Solid Color Stains
26
Conventional Thinking About Deck Finishes
● “A penetrating finish applied to wood decks provides better overall performance and is easier to reapply than a film-forming finish (e.g., paint, solid-color stain).
● “In addition to the continuous shrinking and swelling of the wood caused by changes in the moisture content, film-forming finishes are subjected to excessive wear, especially in high-traffic areas.
● “For these reasons, penetrating finishes, not film-forming finishes, should be used on wood decks. “
Commercial products today defy this train of thought by proper maintenance and early refinishing!
“Penetrating finishes are recommended for use on wood decks.
“These finishes include: – Water repellent preservatives, – Colored water-repellent preservatives, and – Semi-transparent stains.”
- R. Sam Williams, USDA Forest Products Lab. “The Finish Line – Finishes for Wood Decks.” October 1995
27
0% 20% 40% 60% 80% 100%
Northeast (n=95)
Midwest (n=90)
South (n=117)
West (n=66)
Overall US (n=372)
Tropical HardwoodWestern Red CedarRedwoodPressure Treated Lumber
Wood Plastic CompositePlastic/Vinyl
From most recent CINTRAFOR* market survey - 2009 *Center for International Trade in Forest Products, College of Forest Resources, University of Washington
Majority of Decking used is either PT Pine or Wood/Plastic Composite
WPC grew from 2% market share in 1997 to 18.8% in 2004, and to 30.3% in 2009.
2004 residential market demand for decking materials estimated at 3,060 mm board feet. At 250 ft2/gal, market opportunity is over 6mm gallons of deck stain!
Deck Substrate Market Share – 2009*
28
Wood Coatings Types - Specialty
Specialty Wood Coatings: Primer/Sealer ● A first coat that helps stabilize the wood and serves as a tie-coat for the
topcoat(s). ● Many wood primers are also stain-blocking primers, used to reduce the
amount of extractive that can bleed through the finish. ● A wood sealer can be pigmented or unpigmented, and helps close up some
of the wood grain, helping reduce grain-raising, or extractive bleed-through, or improving the gloss potential of the finish applied to it. – Wood sealers need to be hard enough to sand without gumming sandpaper.
Varnish ● A clear, film-forming topcoat that comes in a variety of finishes, from matte
to gloss, typically enhancing the stained wood underneath ● Very rarely used exterior, due to UV degradation of the wood underneath.
29
This Is Why Most Varnishes Not Used Exterior.
What Kind Of Tests Are Performed On Wood Coatings?
31
Typical Wood Coatings Performance Testing Wet Adhesion ● Required for application over glossy alkyd
substrates (especially trim paints)
Chalk Adhesion ● Required for application on chalky
substrates
Dirt Pick-up Resistance ● Run to see how prone soft exterior
finishes collect dirt
Swell-o-meter ● Measures how well a coating system
withstands water penetration
Tannin Stain Resistance ● Measures how well a coating system
withstands tannin stain penetration
Cyclic Accelerated Weathering ● Exposes to calibrated UV light and water
– QUV Cabinet – Weather-O-Meter
Adhesion Testing
Accelerated Testing
Edge Grain
Rough Side
Micrographs
32
Accelerated Testing Is No Substitute For Real World Exposures Testing Exterior Durability
Arkema Coating Resins maintains an extensive exterior coatings testing program in Cary, NC
Statistics: ● Over 3,000 panels on test at the site ● About 60 new test series added every year ● Mix tests roughly 1/3 developmental and new products, 1/3 customer
support or technical service, and 1/3 commercial product benchmarking
33
Exterior Durability Must Be Assessed On Various Substrates
Paints applied in-lab to a variety of substrates ● New or weathered wood ● Stable (cedar) or unstable wood (pine) ● Glossy or chalky substrate panels for adhesion
Monitored over time ● Gloss or color change ● Dirt pickup and mildew ● Cracking ● Loss of adhesion ● Extractive bleed-thru
What Goes Into Wood Coatings?
Paints Are Complex Mixtures Of Raw Materials
Latex Polymer(s)
Coalescent
Primary Pigments
Extender Pigments
Functional Pigments
Dispersants & Surfactants
Defoamer
Preservative/Mildewcide
Thickener/Rheo. Mod.
Misc. Additives
− Film Former, Adhesion
− Plasticizer/Open Time
− Color, Hiding Power
− Control Gloss
− Reduce Mildew Growth, Stain-blocking
− Wetting And Flow
− Reduces/Eliminates Foam
− Microbial Protection
− Application, Anti-settling
− UV Absorbers, Water Repellants, Etc.
35
Component Function
Pigments Provide Color, Hiding, Functionality
Prime – Hiding and color ● Main white pigment: TiO2
– Too much can serve as a catalyst for polymer degradation.
– Will show up on exposure as excessive chalking
● For toners and semi-transparent stains: transparent iron oxides.
Functional – imparts specific properties ● Zinc oxide: Used primarily in
primers and exterior paints, it provides mildew resistance and stain blocking properties.
● Barium Metaborate: Used in wood coatings for stain blocking
36
37
Pigments Control Appearance & Performance
Extender choice can impact film performance ● Some mineral extenders can lead to frosting and color fade
– Calcium carbonate ● Other mineral extenders are inert but lack hiding
– Silica, feldspar ● Smaller particle size of the extender can lead to chalking and fading ● Selection may impact UV and moisture resistance or durability ● For stains and varnishes, some fumed silica may prevent settling.
Pigment Volume Concentration (PVC) in wood coating determines paint finish ● Higher PVC systems are flat and low sheen ● Lower PVC systems are semi-gloss to gloss
Solids Content helps classify paints vs. stains ● Higher solids are paints ● Lower solids are stains
The Proportion Of Raw Materials Affects Quality
For the specific type of coating, higher quality coatings have more binder, less pigment and higher volume solids
38
Gloss Quality Flat Low-cost Flat
Liquid
Binder
Pigment
Liquid
Binder
Pigment
Liquid
Binder Pigment
PVC Tells Us About The Nature Of The Paint Film
Critical Pigment Volume Concentration (CPVC) ● CPVC marks the transition from a system in which the pigment is dispersed
in a continuous binder matrix to one where there is insufficient binder to completely encapsulate all the pigments.
39
paint film
substrate
Low PVC Film(< CPVC)
CPVC Film High PVC Film(> CPVC)
pigment
Whitewash
15
25
35
45
55
65
75
Semigloss
Interior Satin
Exterior Sheen
Exterior Flat
High Gloss Enamel
Gloss Trim
40
Pigment Volume Concentration
Paint Finishes
How Wood Coatings Fit Into The PVC Range
Interior Flat
Transparent Stain
Semi-Transparent Stain
Varnish
Solid-Color Stain
Stains & Clear Finishes
Additives Are Critical To Coating Properties
Enhancing numerous properties ● Rheology modifiers – HASE, HEUR, Cellulosic, HEURASE, ASE ● Preservatives, Algaecides and Mildewcides ● Dispersant and Surfactants ● Mar and Slip additives ● Coalescing solvent – aids in film formation ● Glycol – freeze thaw protection and open time extension
For clear finishes ● UV Absorbers ● Hindered amine light stabilizers (HALS) ● Waxes
41
42
As Discussed In Previous Webinars, Polymer & Latex Characteristics Impact Performance
POLYMER
Composition ● durability ● water resistance ● adhesion
Glass Transition Temp (Tg) ● “hardness” ● dirt pick up resistance ● tensile/elongation ● coalescent/plasticizer demand
Molecular weight ● exterior durability ● “toughness”
LATEX
Particle size/ Distribution/ Morphology ● thickener efficiency ● rheology ● freeze/thaw stability ● binding efficiency ● adhesion
Surfactant package ● stability ● water sensitivity
Most ACR Waterborne Products can be used for wood coatings.
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ACR Offers A Broad Range Of Products For This Segment With Our Polymer Tool Box
Broadest technology platform ● NEOCAR® Acrylic polymers ● Acrylic polymers ● Styrene acrylic polymers ● NEOCAR® polymers ● Vinyl acrylic polymers ● Vinyl acetate ethylene polymers ● SYNAQUA® Waterborne Alkyds
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Arkema Coating Resins self certification program
Demonstrates commitment to sustainable formulated products ● Helping support “Green” initiatives ● Reduction of air pollution ● Meeting VOC (Volatile Organic Compounds) ● Reducing environmental impact ● Enabling sustainable formulating
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No added alkyl phenol ethoxylate (APEO) surfactants
No added formaldehyde or formaldehyde donors
Total latex VOC <5 g/L
Below regulatory reporting limits for carcinogens, reproductive toxins and ozone depleting compounds
Low residual monomer levels ● Total monomer <500 ppm
Minimal use of Hazardous Substances ● Green Seal™ hazardous components
– <0.01% per component ● California Prop 65 substances
– Minimized and documented with data available upon request ● Hazardous Air Pollutants (HAPS) < 0.1% ● No known added phthalates, triphenyl or tributyl tins, 1,2-dichlorobenzene
Interior/Exterior Paints and Stains for Wood Substrates
47
ACR Has An Extensive Acrylic Product Line
General Performance Characteristics
Durability for exterior exposure
Grain crack resistance
Color fade resistance
Dirt pick-up resistance
Good washability
Flexibility and elongation
48
ACR Offers A Full Range Of Acrylic Options
SELECTION GUIDELINES ● ENCOR 657, 626 and 644 are versatile general use acrylics
– Products have good exterior durability performance – Select 626 or 644 where exterior wet adhesion is a requirement, or blending is desired
● ENCOR 627 and CL36 for stainblocking primers, and exterior wood stains. ● ENCOR 631 for improved film toughness over 626 and 657
– Self Crosslinking for enhanced performance – Zero VOC formulation capable for Flat through Semi-Gloss levels
● SNAP 720 or 728 for high gloss enamels. The two products offer similar features; SNAP 728 offers the broadest formulation capability
Acrylic Technology for Paints & Stains for Wood
% Solids
Tg [ºC]
MFT [ºC]
VOC Potential
[g/L] Pai
nts
Solid
Col
or S
tain
s
Sem
i-Tr
ansp
aren
t St
ains
Tone
rs
Target Application Key Feature
Value ENCOR 657 58 14 16 100 x x Interior/Exterior Basic Use Good acrylic starter for wood paint
ENCOR 651 65 12 9 100 x x x x Good for porch paints and solid color deck stains
Strong durability and wear resistance
ENCOR CL36 49 20 18 150 x x x xStainblocking Primer. Also good for Paints & Stains
Tannin blocking and zinc oxide stable
ENCOR 626 50 29 20 150 x x Interior/Exterior Non-Flat Wet Adhesion, gloss development, and grain crack resistance.
ENCOR 627 43.5 15 9 50 x x x xStainblocking Primer. Also good for Solid Color Stains
Tannin blocking and zinc oxide stable
ENCOR 631 50 N/A 0 0 x x x x Interior/Exterior General Use Strong scrub resistance, Zero VOC capable
ENCOR 644 50 4 0 0 x x Interior/Exterior General Use Strong scrub resistance, Zero VOC capable
SNAP 720 50 <4 0 0 x x x x Interior/Exterior Enamels (Trim Paints)
Excellent film hardness, High gloss capable
Premium SNAP 728 50 <4 0 0 x x x xInterior/Exterior Enamels (Trim Paints)
Excellent film hardness, High gloss capable
49
ENCOR 627 / ENCOR 631 Has Performance Superior To Many Commercial Offerings
627/631
Weathered White Pine exposed on South 45 for 1.5 years
Sections 30A, 31A and 32A – represent a system based on ENCOR 627 primer & internal control topcoat
Section 31C is ENCOR 627 primer with ENCOR 631 topcoat. All other systems in sections B, C and D are various combinations of commercially available primers and topcoats
Conclusion: The exposure demonstrates ENCOR 631 with ENCOR 627 as the primer can be formulated to give outstanding adhesion, excellent dirt pickup resistance and grain crack resistance equal to or better than several commercial primer and topcoat paints
50
Other ACR Technologies for Wood Coatings
General Performance Characteristics
Durability for exterior exposure
Grain crack resistance
Color fade resistance
Dirt pick-up resistance
Good washability
Improved hydrophobicity
Good penetration into wood
51
ACR Offers A Range Of Other Technologies
SELECTION GUIDELINES ● NEOCAR 2535 is a general use NEOCAR Latex for exterior flat-eggshell finishes
– Good for exterior paints, solid color finish for siding. ● NEOCAR 820 is a high performance ultra-small hydrophobic binder that is excellent
for use in exterior wood stains due to water repellency. – Can be used to modify other binders at 10-20% on solids to give additional water resistance
● SYNAQUA 4804 can be used to formulate high gloss trim paints, as well as high performance interior or exterior transparent, semi-transparent wood stains. – Low VOC formulation capable, APEO-free.
● Also, many interior or second-line paints are formulated with vinyl acrylics (such as
ENCOR 379G) blended with an acrylic (such as ENCOR 626 or 644) at a 75:25 ratio
Polymer Type
Other Technology for Paints & Stains for Wood
% Solids
Tg [ºC]
MFT [ºC]
VOC Potential
[g/L] Pai
nts
Solid
Col
or S
tain
s
Sem
i-Tr
ansp
aren
t St
ains
Tone
rs
Target Application Key Feature
NEOCAR Latex NEOCAR 2535 53.5 10 8 50 x x Paints and Solid color stains Economical, general purpose binder for flats.
NEOCAR Acrylic NEOCAR 820 45 20 17 50 x x Exterior Stains and SealersUltra-small particle size, excellent hydrophobicity. Can be used to enhance water resistance in other binders at 10-20% modification
Waterborne Alkyd SYNAQUA 4804 50 N/A N/A N/A x x x Trim paints and wood stains Good wood penetration, high gloss potential.
52
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C
CH3
O
C
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CH2
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O
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CH3H3C
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O
C
CH3
O
O
C
C
CH2
CH
Cn
CH3
CH3H3C
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C
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O
C
CH3
O
C
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Cn
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O
C
CH3
O
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C
C
CH2
CH
Cn
CH3
CH3H3C
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C
CH3
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NEOCAR® Technology Enhances Performance
Vinyl Acrylic NEOCAR Latex Acrylic Styrene Acrylic NEOCAR Acrylic
Hydrophobicity
In Wood Coatings Vinyl versatate modification enables: • Exceptional water resistance • Improves chemical resistance • Exceptional flexibility and elongation
53
NEOCAR 820 as a Modifier in S/T Stains
NEOCAR 820 is well-suited for use on exterior wood substrates in a semi-transparent or transparent stain finish.
Because of its outstanding hydrophobicity, the option of blending in NEOCAR 820 at 10% of the binder solids can give long-term improved water repellency over the same finish without the NEOCAR 820.
The systems shown here have been exposed for 30 months.
Stain with 10% NEOCAR 820
Stain without NEOCAR 820
54
SYNAQUA® 4804 An APEO and ammonia free short oil alkyd emulsion designed for use in a wide variety of coatings in which performance similar to solvent based alkyds are desired. It offers the coatings formulator a low VOC option to develop the highest gloss products while giving the application feel of a solvent based alkyd ● High gloss trim paints ● Interior/ exterior primers for wood and metal ● Direct-to-metal coatings with anticorrosive properties ● Transparent and semi-transparent stains
Performance benefits: ● High gloss potential and excellent gloss retention ● Very good hardness ● Quick dry time ● Low yellowing ● Good stability with anticorrosive pigments ● Good application characteristics ● Outstanding resin for blending with other technologies, including styrene
acrylics, acrylics and polyurethane dispersions
55
SYNAQUA® 4804 Offers High 20º Gloss Potential
40
50
60
70
80
90
100
SA 4804 Comp A Comp B
Gloss @ 60º Gloss @ 20º
Competitive A: PU-modified alkyd emulsion Competitive B: Alkyd-acrylic hybrid
Interior/Exterior Specialty Finishes for Wood Substrates
57
Specialty Finishes for Wood
Primer/Sealer A first coat that helps stabilize the wood and serves as a tie-coat for the topcoat(s).
Many (but not all) wood primers are also stain-blocking primers, used to reduce the amount of extractive that can bleed through the finish.
● Primer – pigmented ● Sealer – may or may not be
pigmented.
Varnish: A clear finish that is used as a top coat once the wood has been stained to the desired finish.
Most varnishes are glossy, although specialty finishes can include satin and flat finishes.
Can involve 2-5 coats of varnish with sanding in between coats.
58
ACR Offers A Range Of Technologies for Wood Primers/Sealers and Varnishes
SELECTION GUIDELINES ● ENCOR 627 and CL36 are good general starting points for stain-blocking primers
– Will require formulating with zinc oxide. ● ENCOR 2722 is good for stain-blocking primer without need of zinc oxide ● ENCOR 461 is a small particle flexible binder good for use as a standard wood primer ● SYNAQUA 4804 can be used to formulate sandable primers that penetrate wood.
– Will also work as a varnish, giving good wood warmth to the finish. ● SNAP 720 and 728 may be used as a general purpose varnish with good block and
print resistance
Technology for Primers & Specialy for Wood
% Solids
Tg [ºC]
MFT [ºC]
VOC Potential
[g/L] Pri
mer
Stai
n B
lock
er
Sand
ing
Seal
er
Var
nish
Target Application Key Feature
Acrylic ENCOR CL36 49 20 18 150 x x x x Stainblocking Primer. Also good for Paints & Stains
Tannin blocking and zinc oxide stable
Acrylic ENCOR 627 43.5 15 9 50 x x Stainblocking Primer. Also good for Solid Color Stains
Tannin blocking and zinc oxide stable
Acrylic ENCOR 2722 42 N/A 5 50 x x x Stainblocking Primer. Also good for Solid Color Stains
Tannin blocking without need for zinc oxide. Hard enough for use as a sanding sealer
Styrene Acrylic ENCOR 461 47 -3 <0 100 x x Wood Primer. Good adhesion and flexibility
Waterborne Alkyd SYNAQUA 4804 50 N/A N/A N/A x x x Wood primer and varnish Good wood penetration, warmth, excellent gloss
Acrylic SNAP 720 50 <4 0 0 x Interior/Exterior Enamels Excellent film hardness, High gloss capable
Acrylic SNAP 728 50 <4 0 0 x Interior/Exterior Enamels Excellent film hardness, High gloss capable
59
Stain-Blocking Primer Performance Example
Anti-stain Effect In A PVC 17% Primer Without Zinc Oxide
Standard emulsion ENCOR 2722
Two coats
One coat
60
Product Descriptions
ENCOR 627 ● Good starting point 100% acrylic
binder for stain-blocking wood primers.
● 43.5% solids, 9ºC MFFT. ● Needs to be formulated with ZnO.
– Also stable with Barium Metaborate. ● Good thickener response.
● Can also be formulated into solid
color stain formulations.
ENCOR 2722 ● For premium stain-blocking wood
primers. ● 43% solids, 15ºC MFFT. ● Can be formulated without ZnO. ● Good Sandability.
Formulation tips: ● No alkaline salts.
– dispersants, surfactants... ● Neutralization with ammonia.
– Not Na+ salts ● Avoid water soluble co-solvents.
ENCOR 2722 has a higher Tg and therefore is more suitable for industrial primers because of its better sandability.
Industrial Wood Coatings
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Industrial Coatings
Factory applied finishes ● Requires equipment above and beyond the standard homeowner. ● May include pretreatment of substrates.
– Sanding, control of moisture content, etc. ● Could be applied by spray, dip, or flow-coating.
– In some cases a rotating brush wheel to simulate brush application. ● May include heat drying/baking in order to process more quickly. ● Typically requires quick handling and stacking.
● More precise control of substrates and finish system. ● May require higher performance properties
– Example: Kitchen Cabinet Manufacturer’s Association (KCMA) durability
● Many of the finishes (and binders) described for do-it-yourself projects are also used in the industrial coating segment.
● However, can also include (or require) higher-end binder systems such as
UV-cured finishes or polyurethane clear coats.
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Why is Factory Finishing of Wood Better? Industrial settings ● Requires a level of expertise
Controlled feedstock ● Type and grade of lumber ● Moisture content ● No pre-weathering
Controlled surface preparation ● Proper sanding and cleaning
Controlled finishes ● Large batches ● Precise application levels ● Quality control checks
Controlled environment
Controlled drying conditions.
But for field applied OEM wood, will still need to have field applied finish
Image courtesy of University of British Columbia Department of Wood Science
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ENCOR 2721 Properties
A new emulsion approach with the early handling properties necessary to achieve a significant productivity gain.
Low MFFT self-crosslinking acrylic emulsion with high Tg sequential polymerization with unique morphology
Wood coatings with low coalescent level
Quick hardening and sanding in thick films ● low coalescent retention ● high crosslinking level
High chemical resistance
Early blocking resistance
APEO free
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Type of polymer Acrylic, dispersed in water
Viscosity, mPa.s <100
Solids content,% 43
MFFT(C) <5
pH 7.5
Mean particle size, nm 80
ENCOR 2721 - Typical Characteristics
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Drying at room temperature (20ºC) and 65% RH • Application of ~3.0 mils of sealer
25 minutes to sand
• Application of ~4.5 mils of sealer
40 minutes to sand
ENCOR 2721 - Sandability
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CHEMICAL RESISTANCES ACCORDING TO EN12720 Chemical Time Rating
Water 16h 5 Ethanol (48% in water) 16h 4-5 Ethanol 16h 4-5 Coffee 16h 5 Acetone 10s 5 Hand cream 16h 4-5 Ammonia (10% in water) 2 min 5
Spray application of 100 g/m2 of sealer + 100 g/m2 of topcoat on sapelli veneer.
Evaluation after 12 days
Can be used for KCMA type finishes
ENCOR 2721 Chemical Resistance
Summary
Highlights of Today’s Webinar
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Recap – Wood Coatings
Today’s session was intended to provide you with a historical view of wood coatings, a technical overview in coating performance, and product selection for wood coatings.
Exterior wood coatings are still a viable key market need.
Interior wood coatings, while not requiring the durability under weather extremes, require durability that allows for cleaning.
Key to the performance of any finish on exterior wood is the ability of the finish system to protect the wood from: ● Moisture (which leads to expansion and contraction of the wood) ● UV Light (which causes the weathering of the surface of the wood) NOTE: Regular maintenance of finish will prevent finish failure 69
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Recap – Product Offering
ACR offers products that can be used for interior and exterior applications.
ACR offers products for use in primers ● From ENCOR 627 – Good first stop for stain-blocking wood primer (+ stains) ● To ENCOR 2722 – High performance zinc free stain-blocking systems, sandable
ACR offers products for use in stains ● From ENCOR 651 – Acrylic for solid color stains, good abrasion resistance. ● To SYNAQUA 4804 – Waterborne alkyd with good penetration (+ paints and varnishes) ● And NEOCAR 820 – Alone or as modifier for improved water resistance
ACR offers products for use in paints ● From NEOCAR 2535 – General purpose binder for flats and eggshells ● To ENCOR 631 – High performance int/ext acrylic for flats to semi-gloss (+ stains) ● And SNAP 720 + 728 – Low VOC, high performance gloss paints and varnishes with excellent
block and low odor properties. Can be formulated to close to zero VOC.
ACR offers products for industrial wood finishes ● ENCOR 2721 - Low MFFT self-crosslinking acrylic emulsion with early block resistance and
sandability, plus excellent chemical resistance.
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Questions? Please Contact The Account Team
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Mary Chervenak mary.chervenak@arkema.com
Marlene Hernandez marlene.hernandez@arkema.com
Mark Piggott mark.piggott@arkema.com
Commercial Questions
Latin America
Commercial Questions
USA & Canada
Technical Questions
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2014 ACR Webinar Series
Next Month’s Topic: Traffic Paint
Speaker: Mike Kaufman
Title: Sr. Application Development Leader
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Arkema Coating Resins
Thank You for Joining Us!!
See you in December !!
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