green additives for the coatings industry

Report
Protecting the Environment
Green Additives for the Coatings Industry
David Torocsik – Borchers OM Group
Content
 Environment in the 21st century reasons for being Green
 Definitions of Being Green
 “Green” Solutions to Being Environmentally Friendly
 Raw Materials from Nature as Building Blocks
 Environmentally Friendly Alternatives to Hazardous Chemicals
 Conclusion
2
Environment in the 21st Century- Good Reason for Being
Green
Europian heat wave 2003
Pakistan floods 2010
Katrina 2005
Pictures source: Wikipedia
3
Several Definitions of “Green” Products
Low or No VOC’s
Bio-based AND Non-hazardous
The product contains a high percentage of bio-based
components either as supplied, or 100% of the active
substance is bio-based
4
How to Become More Environmentally Friendly?
 Use more Renewable or Sustainable Non-Hazardous raw materials
 Reduce VOC Content by making Higher Solids formulations
 Convert our Solventborne formulations to Waterborne with Equivalent
Properties
 Product Stewardship – Cradle to Grave Awareness
 Recycle and Rework Paint Waste whenever possible
5
Use More Raw Materials from Nature as Potential Building Blocks
Vegetable Oils – Triglycerides
O
O
O
O
O
O
Glycerol-Based Alkyds
O
O
O
R=
O
Chain of linoleic acid
n
O
R
O
Chain of a-linolenic acid
6
Use More Raw Materials from Nature as Potential Building Blocks
Fatty acids can be a source for metal soaps and alkyd binders
OH
Stearinic acid
O
OH
-Linolenic acid
O
Alcohols can be used to make non-ionic surfactants and PU compounds
OH
OH
Stearyl alcohol
Lauryl alcohol
O
O
O
O
OH
Ethoxylated cetyl alcohol
7
Use More Raw Materials from Nature as Potential Building Blocks
Polyols: glycerol and sugar derivatives
H2C
OH
HC
OH
H2C
OH
HOOC
O
HC
OH
H2C
OH
(Poly)ester
Reaction with
OCN
O
H2C
R
C
R
HO
(Poly)urethane
OH
O
C17H35
Glycerol monostearate
APG – Alkyl
Polyglycosides
(biodegradable surfactants)
O
O
C17H33
OH
Sorbitan monooleate
OH
H
O
O
HO
OH
n
O CH2
CH3
m
8
Use More Raw Materials from Nature as Potential Building Blocks
Epoxy Hardeners from Cashew Nutshell Liquid (CNSL)
Anacardic acid C15:3
OH
Cardanol
O
Phenalkamine
OH
OH
OH
H2N
R
(CH2)n
R
NH
R
R=
Acrylic Compounds
O
O
O
O
Furfuryl acrylate
O
C 18 H 37
Stearyl methacrylate
9
What are Environmentally Friendly Additives?
 Additives that help make High Solids, Bio-Based or Waterborne
Binder alternatives possible
 What options are available?
 Cobalt Free Driers
 Additives that contribute Zero VOC’s
 Tin Free Catalysts
 Additives Containing Sustainable Raw Materials
 Additives with Universal Applications – Waterborne, Solventborne
and Solvent Free Coatings that result in fewer Specialized
Additives
10
History of Bio-Renewable Systems
The original bio-renewable binder systems were based on natural and
synthetic oils (alkyds). However, they had two major flaws that were
driving them to extinction:
1. They needed to be dissolved in petroleum based solvents that
contain (VOC’s)
2. Also that they needed hazardous metal based catalysts to
accelerate crosslinking
Over time Alkyd binders have been developed that are soluble in water
or exempt solvents. However, most still rely on metal based driers, which
then face us with an even tougher challenge of “how replace metal
catalysts considered to be hazardous?”
11
Cobalt Driers – Regulatory Concerns
 Cobalt has been the metal drier of choice for binders that cure via
oxidation for over 100 years. However, Cobalt carboxylates are on
the verge of being labeled more hazardous in Europe which will
eventually affect all countries that sell products to Europe making it a
global concern
 Cobalt carboxylates promote surface dry in coatings and without
these surface driers – bio-based binders that cure via oxidation will
not dry properly
12
Labeling of Cobalt-Carboxylates
Current Labeling Cobalt-bis(2-ethylhexanoate),
Cobalt 2 neodecanoate, Cobalt naphthenate
CAS Nr. 136-52-7, EINECS Nr. 205-250-6
 DSD:
Repr. Cat. 3; R62 - Possible risk of impaired fertility
Xn; R65 - lung damage if swallowed
R43 - May cause sensitization by skin contact
N; R50/53 - Very toxic to aquatic organisms, may cause
long-term adverse effects in the aquatic environment
R66 – Repeated exposure may cause skin dryness or cracking
 CLP:
Repr. 2; H361f,
Skin sens. 1; H317,
Eye Irrit. 2; H319,
Aquatic Acute 1; H400,
Aquatic Chronic 1; H410
13
What are some Cobalt Drier Alternatives?
 Manganese driers by itself used in waterborne and solvent-borne
alkyd systems
 Accelerated Manganese driers
 Also available are Iron-based complex compounds that work well in
waterborne and solventborne alkyd systems, and some contain Zero
VOC’s
14
Performance Advantages Involving Cobalt Alternatives
Co
Co replacement #1
Co replacement #2
10°C – 80RH
10°C – 30RH
23°C – 55RH
(standard
conditions)
0
0
2
4
2
4
6
6
8
8
10
10
12
12
14
Improved dry in cool damp
conditions and less
yellowing over time
Lightness (L value)
Tack Free Dry Time (in hours)
82
80
78
76
74
72
70
68
66
64
62
dark
light
Lightness (L value)
after 2 months of
storage in the dark
and in the light
without
drier
0.079% Co
Co, Zr drier
Cobalt Free
0.00065%
Fe
Driers
new
catalyst
15
Why Use Anti-Skinning Additives?
 Coatings that cure via oxidation require additives to prevent skinning
in the can during storage
 The most common anti-skinning additive for Cobalt containing
systems is the volatile complexing agent methyl ethyl ketoxime
(MEKO)
What are some of the issues with MEKO?
 Its toxicity and corresponding labeling issues
 It doesn’t always work well with a number of cobalt replacement
driers
16
Anti-Skinning Additives that are possible replacements for
MEKO
 Phenolic based anti-skinning additives
Product Issues:
 slow evaporation
 the radical absorber stays in the film and may cause yellowing
 Other slow evaporating Anti-Skinning additives are aminic
compounds dissolved in Fatty acid esters or glycolic solvents
Advantages:
 Works for all metal types
 Reduced toxicity
Disadvantages:
 Dosage has to be experimentally determined to avoid excessive
amounts causing prolonged drying time
17
Catalysts in Polyurethane Based Coatings and Additives

+
R-N=C=O
+
R`-OH
catalyst
H O
R-N-C-O-R´

MLn -
polyisocyanate
polyol
polyurethane
 Function to increase chemical reactivity of polyurethane systems
 Polyurethanes are used in highly durable coatings, gel coats and other
additives like rheology modifiers and dispersants
18
Catalyst Options Types Used in Coatings
Catalysts
alkylated tin compounds
(e.g. Dibutyltin dilaurate)
metal carboxylates
(e.g. Bismuth or Lithium)
tertiary amines
Mechanism
Application
Lewis-acid-mechanism
polarization of isocyanate
improves electrophilic properties of
carbonyl group
1K & 2K polyurethanes
blocked isocyanates
Lewis-acid-mechanism
polarization of isocyanate
improves electrophilic properties of
carbonyl group
Insertion mechanism
after formation of alcoholate
1K & 2K polyurethanes
blocked isocyanates
Lewis-base-mechanism
increase nucleophilic properties of
OH compound
2K polyurethanes
epoxy resins
19
Tin Catalysts: Hazardous Chemical for the Production of
Polyurethane Coatings and a Conflict Mineral
 HMIS rating: DBTL on the ECHA (European Chemicals Agency Reach) website has been registered with a GHS 1B reproductive
toxicity classification as well as STOT (Specific Target Organ Toxicity)
– single and STOT – Repeated Class 1 which could lead to a 3* HMIS
rating as they are both chronic endpoints
 The Dodd-Frank Act targets the sources of Cassiterite/Tin. There are
many unrestricted sources of Tin available but proving the source of
Tin is a continuous concern
20
PU Catalysts: Tin Based Compared to Bismuth Based on the
Organic Components
the OH-NCO reaction:
influence on
catalystBismuth
The Effect of different
carboxylates
on OH-NCO reaction:
N 3300);
(D'dur
Isocyanurate
/
870)
A
(D'phen
[OH-Acrylic
OH-Acrylic (Desmophen A 870) / Isocyanurate ( Desmodur
N 3300)
concentration: 0.003% metal / binder]
[catalyst concentration: 0.003% metal / solid binder]
0,14
NCO-absorption
0,12
0,1
0,08
0,06
0,04
0,02
0
0:00
2:24
DBTL
Acid Blend
Kat 24
Borchi
4:48
Neodecanoate
315
catalyst
7:12
Octoate
320
catalyst
9:36
Other322
catalyst
12:00
14:24
time [h]
21
Bismuth Catalysts - Extending Pot Life
pot-Life of different catalyzed clear coats
based on Desmophen A VP LS 2383
60
viscosity [s]
50
40
30
20
10
0
0h
DBTL
1h
2h
Octoate
Borchi
Kat 24
3h
4h
Neodecanoate
Borchi Kat 0243
5h
6h
7h
time [h]
22
The Smart Choice - Dispersants Based on Sustainable
Raw Materials
Branched polyurethane oligomer
For waterborne systems
Contains sugar, fatty alcohol and acid
More than 50% sustainable RM
90% active in water
23
Dispersants Based on Sustainable Raw Materials (SRM)
SRM Dispersant
Conventional
Conventional
SRM Dispersant
24
Dispersants Based on Sustainable Raw Materials
SRM Dispersant
Conventional
Conventional
SRM Dispersant
25
Summary
 The coatings industry uses huge amounts of raw materials and is
facing the challenge to switch to renewable resources
 Recent alternative additives support the continued use of biorenewable resin systems where only hazardous materials were
effective before
 Many sustainable raw materials are already available
 New “green” additives can generate equal or better properties to
current hazardous agents
 Cost effective alternative formulations are possible
26
Thank you for your attention
Questions?
OMG Americas, Inc.
811 Sharon Drive
Westlake, Ohio 44145-1522
USA
440-889-2950
880-321-9696
eMail: [email protected]
 www.borchers.com
 www.omgi.com
27

similar documents