Leather and soiling: an exploration of current anti-soiling technologies Dr. Dietrich Tegtmeyer Vice...
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Transcript of Leather and soiling: an exploration of current anti-soiling technologies Dr. Dietrich Tegtmeyer Vice...
Leather and soiling: an exploration of current anti-soiling technologies
Dr. Dietrich TegtmeyerVice President
Product Development and Application
Business Unit Leather
SLTC; September 26th, 20092
Antisoiling Systems
For A Change In Leather
- leather is a classic yet highly fashionable article
- leather undergoes a continuous development with regards to its longevity
- due to the consumer’s requirements the color shades of leather goods have changed over the past
- color shades have become lighter
SLTC; September 26th, 20093
Antisoiling Systems
The Challenge
- bright colors are by nature more sensitive to soiling and staining
- enhanced anti-soiling / anti-staining and cleaning behavior are of need
- performance and esthetics of leather must be maintained
- leather must remain leather with all its desirable properties
SLTC; September 26th, 20094
Antisoiling Systems
• Basics Definitions and Theory
• Differentiation of Performance Characteristics
• Testing of Antisoiling Characteristics
• Chemistry of the New Antisoiling Technology
• Test Results
• Summary / Conclusions
Today’s Agenda
SLTC; September 26th, 20095
Antisoiling Systems
Nano foam
Nano particles
1 Nanometer = 0,0000000001 meter
= 1 * 10 EXP-9 meter
1 nm : 1 mm
football : earth
Picture: GNU Free Documentation License
Nano colloids
Nano tubes
Basics – Definition of Nano Technology
SLTC; September 26th, 20096
Antisoiling Systems
bis 160 °
Pictures: GNU Free Documentation License
Basics – Definition of Lotus Effekt
SLTC; September 26th, 20097
Antisoiling Systems
Basics – Lotus Effect means a self cleaning capability of the surface
Pictures: GNU Free Documentation License
SLTC; September 26th, 20098
Antisoiling Systems
Aesthetical properties
• Touch• Feel • Smell
Many requirements for a finishing chemistry
Fastenessproperties
• Hydrolysis• Lightfastness• Color Strength
Physicalproperties
• Abrasion• Adhesion• Flex• Antisqueek
Processproperties
• Recoatability• Flow out• Drying• Staking
SLTC; September 26th, 20099
Antisoiling Systems
binder elasticitylow high
flex
General problem: if you optimize one of the properties, you are sacrifying others
A lot of criteria are behaving complementary
Challenge for chemistry: we have to look for the best compromise or
for the application: we have to formulate around weaknesses
SLTC; September 26th, 200910
Antisoiling Systems
Aesthetical properties
ANTISOILING • Touch• Feel • Smell
Anti-soiling is one additional category, also complementary to important other requirements
?
Fastenessproperties
• Hydrolysis• Lightfastness• Color Strength
Physicalproperties
• Abrasion• Adhesion• Flex• Antisqueak
Processproperties
• Recoatability• Flow out• Drying• Staking
Anti-soiling
Recoatability
SLTC; September 26th, 200911
Antisoiling Systems
• matting system • binder chemistry
• degree of X-linking • additives e.g. thickener
• embossing • drying conditions
Anti-soiling is a very complex requirementand influenced mainly by surface parameters of the leather
Surface
Morphologyphysics
Substancechemistry
Marcro Scale> 1 µm
Micro Scale10 – 1000 nm
Hydrophobicity Oleophobicity
SLTC; September 26th, 200912
Antisoiling Systems
Macro Scale: Surface Porosity of a conventional top coat
A high amount of holes visible on the surface in a range of 5 µm
5.5 µm
SLTC; September 26th, 200913
Antisoiling Systems
A small amount of holes visible on the surface in a range of 5 µm
Macro Scale: Surface Porosity of a conventional top coatwith good anti-soiling perforance
SLTC; September 26th, 200914
Antisoiling Systems
Surface Porosity of a top coat of the new PTFE Copolymer
Basically zero holes visible on the surface in a range of 5 µm
Less penetration of soil can be easier cleaned away, but after soiling
it also appears more dirty on the surface!
SLTC; September 26th, 200915
Antisoiling Systems
e.g. little pins on the surfacein nano rangecould lead to a self cleaning effect
Micro Scale: Surface structure of a lotus leave
Pictures: GNU Free Documentation License
SLTC; September 26th, 200916
Antisoiling Systems
• matting system • binder chemistry
• degree of X-linking • additives e.g. thickener
• embossing • drying conditions
Surface
Morphologyphysics
Substancechemistry
Marcro Scale> 1 µm
Micro Scale10 – 1000 nm
Hydrophobicity Oleophobicity
Anti-soiling is a very complex requirementand influenced mainly by surface parameters of the leather
SLTC; September 26th, 200917
Antisoiling Systems
A good antisoiling performance is not the result of one single additive -
but one wrong single additive could have a very negative impact
• for some tests acrylic chemistry is better suited than PU chemistry
• low concentration of emulsifier
• only special silicons are required
• special matting agents, which generate a small surface and have a low porosity
• high X-linking, not only for the permanence, even for the antisoiling effect
• special additives can improve the anti-soiling performance
The right formulation is one of the important basics
SLTC; September 26th, 200918
Antisoiling Systems
Adhesion of dirt is determined by the surface chemistry
Hydrophobicity
Oleophobicity
Silicon Area
PTFE Area
Parafin Area
the best anti-soiling characteristicshould be in the right upper square
Additives and binder chemistrydo influence the surface properties
SLTC; September 26th, 200919
Antisoiling Systems
• Basics Definitions and Theory
• Differentiation of Performance Characteristics
• Testing of Antisoiling Characteristics
• Chemistry of the New Antisoiling Technology
• Test Results
• Summary / Conclusions
Today’s Agenda
SLTC; September 26th, 200920
Antisoiling Systems
Requirements
Anti-Staining:
- mainly required by the furniture industry
Anti-Soiling:
- mainly required by the automotive industry
Cleanabilty:
- required by both furniture and automotive industry
SLTC; September 26th, 200921
Antisoiling Systems
1. Dirt ≠ Dirt
The contamination of leather must be differentiated by different pollutants:
Staining:
- accidental and occasional contamination of leather
- wine, coffee, lipstick, ball pen etc.
before soiling after soilingSoiling
Soiling:
- constant exposure of leather to dirt throughout daily use
- ambient dust, dyestuffs from garment, carbons, oils etc.
Staining
SLTC; September 26th, 200922
Antisoiling Systems
What is soiling / cleanability about ? We differentiate between …
Cleanability:
- The behavior of leather surfaces to cleaning after a contamination has occured
- Can the contaminant(s) be removed ?
- How easily can the contaminant(s) be removed ?
- How much residue remains on the leather surface ?
Durability of anti-soiling finishes:
- Gives an indication about the “longevity” of anti-soiling finishes
- How many times can a leather be soiled and cleaned
maintaining it anti-soiling / cleanability performance ?
2. Cleaning ≠ Cleaning
SLTC; September 26th, 200923
Antisoiling Systems
3. Testing ≠ Testing
Different kinds of “dirt” are applied and cleaned by different test methods.
Staining:
- is tested by applying the contaminants onto the leather directly
- subsequently the dirt is wiped off with common household cleaners
- cleaning efficacy is evaluated and rated
after staining after cleaning
SLTC; September 26th, 200924
Antisoiling Systems
Testing ≠ Testing
Soiling:
- standardized fabrics, contaminated with different pollutants are rubbed over the leather by means of the Martindale abrasion tester
- after 2.000 cycles the degree of color change on the leather is measured
- subsequently the dirt is wiped off by means of common leather cleaners and the color change is measured again
Conventional
Finish
after soiling
after cleaning
Attentio
n: diffe
rent testin
g procedures do result in
different d
ata !
SLTC; September 26th, 200925
Antisoiling Systems
How is soiling tested ?
Anti-Soiling 1 ( VDA Test ):
- Contaminants are applied on the leather by
standardized soiling clothes*.
*EMPA 104:
polyester/cotton, soiled with carbon black / olive oil
*EMPA 128:
cotton jeans with indigo/sulfur black, soiled with carbon black / olive oil
EMPA 104
EMPA 128
without X-Shield top with X-Shield top
before after
cleaning
before after
cleaning
EMPA 104
with X-Shield topwithout X-Shield top
before after
cleaning
before after
cleaning
EMPA 128
Different contamination
SLTC; September 26th, 200926
Antisoiling Systems
How is soiling tested ?
Anti-Soiling 1 ( VDA Test ):
- Testing is done by Martindale abrasion tester:
- 1.000 cycles, weight 12Kpa,
large Lissajous figure with:
- Pilling holder* ( Ø 140 mm ) or
- Abrasion holder* (Ø 38 mm )
( *depending on specification )
- Degree of soiling before cleaning:
Requirement: ≥ 3 ( grey scale )
- Degree of soiling after cleaning:
Requirement: ≥ 4-5 ( grey scale )
Abrasion holder, Ø 38 mm
without X-Shield top with X-Shield top
before after
cleaning
before after
cleaning
Pilling holder, Ø 140 mm
without X-Shield top with X-Shield top
before after
cleaning
before after
cleaning
Different holders/conditions
SLTC; September 26th, 200927
Antisoiling Systems
How is soiling tested ?
Anti-Soiling 2 ( Dye Ingress Test ):
- Contaminants are applied on the leather by
a standardized “soiling cloth*”.
*standard JLR denim fabric with indigo dye,
soaked in alkaline sweat solution ( BS1006 E04 )
soiling cloth
cleaning cloth
Different testing fabrics/conditions
SLTC; September 26th, 200928
Antisoiling Systems
How is soiling tested ?
Anti-Soiling 2 ( Dye Ingress Test ):
- Testing is done by Martindale abrasion tester:
- 1.000 cycles, weight 12Kpa, large Lissajous figure
- Abrasion holder
( small specimen holder, 38 mm )
- Degree of soiling before cleaning:
Requirement: ≥ 4 ( grey scale )
- Degree of soiling after cleaning ( 1.000 cycles as
described above; cleaning cloth soaked in
cleaner; e.g. “Leather Master” car interior
leather cleaner:
Requirement: ≥ 4-5 ( grey scale )
Standard PU Top
after cleaning
LXS Acrylic Top
after cleaning
Different testing fabrics/conditions
SLTC; September 26th, 200929
Antisoiling Systems
• Basics Definitions and Theory
• Differentiation of Performance Characteristics
• Testing of Antisoiling Characteristics
• Chemistry of the New Antisoiling Technology
• Test Results
• Summary / Conclusions
Today’s Agenda
SLTC; September 26th, 200930
Antisoiling Systems
Individualized Systems
- a wide variety of potential contaminants along with an even bigger number of different leather properties require different anti- soiling systems
- the goal is to achieve the best possible spectrum of efficacy
- TFE ( tetrafluoroethene ) based products have proven to be the best suitable substances for those applications
SLTC; September 26th, 200931
Antisoiling Systems
Polytetrafluorethene ( PTFE ), The Solution
PTFE
- provides hydrophobic and oleophobic effects at the same time
- thermo stable from -200°C to +260° C
- chemically inert and resistant against UV radiation
- provides low friction and excellent release properties
- has extremely low surface energy
SLTC; September 26th, 200932
Antisoiling Systems
TFE Containing Copolymers, Different Options
1. Comb Polymer
Advantages:
- excellent dirt repellency
- excellent initial cleanability
TFE containing side chains
TFE protection top
2. Linear Polymer
Advantages:
- excellent dirt repellency
- excellent cleanability and durability
TFE groups are built into the monomer
TFE copolymer binder
TFE groups can be incorporated in two different ways
SLTC; September 26th, 200933
Antisoiling Systems
Comb Polymer Structure
AQUADERM® X-Shield L facts:
- used as an additive in special top coats
- cross-linking of pure product not possible ( limited durability )
- outstanding dirt repellency
- outstanding initial cleanability
AQUADERM® X-Shield L
Important note:
- PFOS (perfluoroctylsulfonic acid)
- PFOA (perfluoroctanoic acid)
Analysis of leather finished with AQUADERM® X-Shield L have proven that neither PFOS nor PFOA are detectable.
SLTC; September 26th, 200934
Antisoiling Systems
SLTC; September 26th, 200935
Antisoiling Systems
With And Without....
Conventional Finish
AQUADERM® X-Shield LFinish
after soiling after soilingafter cleaning after cleaning
SLTC; September 26th, 200936
Antisoiling Systems
Linear Polymer Structure
- TFE copolymers + different functional groups offer a versatile application field to the leather industry
Protection coats which consist of AQUADERM® X-Shield G / M2
- can be pigmented- can be cross-linked with isocyanate- are film forming- allow to adjust different gloss levels- can be fine tuned by the addition of
feel agents- provide superior and long lasting
abrasion resistance
AQUADERM® X-Shield G / M2
SLTC; September 26th, 200937
Antisoiling Systems
Linear Polymer Structure
R1
|CH - CH a CF2 - CF2 c CH2 - CH d CH2 - CH e
|CH - CH b
|X Y ZCOO-
HN+R3
||
R2
|
COO-
HN+R3
|
film formation /transparency
antisoiling /cleanability
cross-linking /adhesion
pigmentdispersibility
dispersionstability
- functional groups: approx. 50 % in total
- built-in PTFE segments: approx. 50 % in total
SLTC; September 26th, 200938
Antisoiling Systems
Different To Conventional Fluorine Systems
- the X-Shield system is based on a new concept providing permanent protection
- the integrated PTFE segments in a polymer backbone are stable against hydrolytic attack ( bound by stable C-C bonds )
- additional segments provide film formation and reactivity
- long lasting protection along with environmental soundness
R
Leather Surface
PTFE segment
non fluorinated segment
TFE -copolymer
R NCO
OCN
OCN
cross-linking reaction
+
R
R
RR
SLTC; September 26th, 200939
Antisoiling Systems
Cleanability performance as a function of cycles
Only one cycle is currently part of automotive specs!Long term cleanability is a new challenge.
0
1
2
3
4
5
before cleaningafter cleaning
complementaryAntisoiling system conventional
PTFE binder
1. 2. 3. 4. cleaning cycle
poor
excellent
SLTC; September 26th, 200940
Antisoiling Systems
Consistancy of Cleanability performance is an issue
Only one cycle is currently part of automotive specs!Long term cleanability is a new challenge.
1. 2. 3. 4. cleaning cycle
0
1
2
3
4
5
before cleaningafter cleaning
Antisoiling system conventional
PTFE binder
poor
excellent
SLTC; September 26th, 200941
Antisoiling Systems
1. 2. cleaning cycle
Cleanability performance suffers after pre-treatment
A tough pre-treatment influences the anti-soiling performance.
0
1
2
3
4
5
before cleaningafter cleaningPre-treatment
3.000 cyclesMartindale
w/clean cloth
48 h Hydrolysis Antisoiling system
Typ A
Typ B
poor
excellent
SLTC; September 26th, 200942
Antisoiling Systems
Special protection top doesn‘t show soiling at allin all EMPA tests. It is however not a long lasting effect
1 cleaning cycle
0
1
2
3
4
5
before cleaningafter cleaning
Comparison of soiling performance of X-Shield G and L
Anti-soiling system conventional
PTFE binder
PTFE protection top
poor
excellent
SLTC; September 26th, 200943
Antisoiling Systems
final antisoiling performance depends on article characteristics
The Finishing System is playing an important role
Gloss level
Recoatability
Anti squeek
Flex Performance
Impact on Antisoilingperfomance
dull…….medium……….glossy
high…….…..medium……...poor
excellent…… regular …....… poor
excellent..…..good …...… medium
decreasing improving
Adjustments of
certain parameters / physical properties
have an impact
on antisoiling performance
SLTC; September 26th, 200944
Antisoiling Systems
• Basics Definitions and Theory
• Differentiation of Performance Characteristics
• Testing of Antisoiling Characteristics
• Chemistry of the New Antisoiling Technology
• Test Results
• Summary / Conclusions
Today’s Agenda
SLTC; September 26th, 200945
Antisoiling Systems
Two main conclusions
1.) There is no universal system which fullfills overall best performance
in terms of
• Antistaining
• Antisoiling
• Cleanability
You have to chose the best system for you specific application requirements
2.) You have to minimize the negative impacts of other properties such as
dulling, anti squeek, etc.
SLTC; September 26th, 200946
Antisoiling Systems
Best systems for Antisoiling
In dependence of the leather goods manufacturers’ requirements the X-Shield system allows the individual customization of all kinds of leather articles.
AQUADERM® X-Shield L
- for optimized anti-soiling and initial cleanability performance in EMPA test
HYDRHOLAC AD1 and CL1
- for optimized anti-soiling in Dye Ingress test
X-Shield ProtectedConventional Finish
SLTC; September 26th, 200947
Antisoiling Systems
AQUADERM® X-Shield G,( gloss component )
in combination with
AQUADERM® X-Shield M2,( matting component )
- for efficient and long lasting anti-staining protection and long term cleanability
Conventional Finish
before cleaning after cleaning
X-Shield Protected
before cleaning after cleaning
Best systems for Antistaining and Cleanability
SLTC; September 26th, 200948
Antisoiling Systems
Individual systems for individual specifications
Product Staining Anti-Soiling VDA
Anti-Soiling Dye Ingress
AQUADERM X-Shield G x x
AQUADERM X-Shield M 2 EXP 2002 x
AQUADERM X-Shield L EXP 2001 x
HYDRHOLAC AD-1 x x
AQUADERM Matt HPM-N x
HYDRHOLAC CL-1 x x
HYDRHOLAC AQS x
AQUADERM Additive GF x x x
AQUADERM Additive SF x x x
ROSILK 2229 FM x x
Different systems for different requirements
SLTC; September 26th, 200949
Antisoiling Systems
Summary
The AQUADERM® X-Shield range:
- functional products providing additional performance
and value to leather industry
- unique chemistry for leather
- strong effect
- significant extra value of the leather article
A special labeling is offered to the industry
SLTC; September 26th, 200950
Antisoiling Systems
Thank you for your attention