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Paints
 Coatings are materials that are applied to a surface which form a

continuous film in order to beautify and/or protect the surface
...
”
 Pigments: Provide color, UV protection and hiding to

coatings
...

 Resins: Synthetic or vegetable materials that are used
as a base for coatings
...


Paints & Coatings
 Paint
 Enamel

 Varnish
 Stains
 Sealants

Stain vs
...

 Stains penetrate into the
wood, don’t form a film
...

 Recoat every 3-5 years

 Paints form a film on the





surface and protect the
substrate
...

Available in variety of gloss
levels: flat, satin, semigloss and gloss
...

Recoat every 7-10 years
...

 Solvent
 Effectively thins the paint
 It carries the pigment and binder
 Used to regulate how much a paint flows
 Called a “thinner” when used with lacquer
 Called a “reducer” when used with enamel

Paint:Interesting Facts

A jumbo jet needs 2 tons of paint
...
g
...

Glass transition influences
mechanical properties such
as flexibility, hardness, etc
...


Consideration of UV, thermal,
oxidative stability depends on
application (primer, topcoat)
...


Thermosetting Binders: Epoxy and Polyurethane Resins
 Epoxy resins are two-component paints formulated from epoxide functionalized

monomer and (usually) amine hardeners
...


 Polyurethanes afford superiour abrasion and chemical resistance, as well as a fast,

low-temperature cure
...

COOH

2

+

CH2
n

H
Acid functionalized
acrylic resin

OH
O CH2
O C
CH2

CH2

CH Resin CH CH2
O

O
Epoxy resin

OH

CH Resin CH CH2 O
C O

CH

CH2 CH
n

n

Thermosetting Binders: Cured Polyesters and Acrylics
 Unsaturated polyesters and acrylic resins of low molecular weight can be

polymerized by free radical addition chemistry to generate a stable, crosslinked
film
...


 Free radical polymerization initiated by an organic peroxide generates a networked

structure of high molecular weight by addition through unsaturation in the polymer
backbone
...

 Oils are first transformed into monoglycerides:

 Film formation results
 from condensation
 polymerization with

 diacid as well as
 oxidative cure
...

 Water is the continuous phase, which results in a very low viscosity
coating
...


•Most emulsion paints contain some solvent/plasiticizer
to modify the Tg of the polymer
...

–Organic solvents assist with film formation, and
evaporate to leave a solid coating
...


Thermoplastic Binders: Emulsions
 Household emulsion paints are usually comprised of
 poly(vinyl acetate-co-ethyl acrylate) or poly(acrylate-co-acrylic

acid) resins
 pigment is dispersed in the continuous aqueous phase with
suitable surfactants and water-soluble thickener
...

AFM of latex

n
O

Me
O

O

OEt

n
HO
O

O

OEt

Thermoplastic Binders: Lacquers


Lacquers harden quickly at all practical temperatures, are supplied in one pack and do not suffer
from shelf or pot life problems
...
Plasticizers and
copolymerization alters Tg
...

 Oils are frequently used in conjunction with other resins to modify
drying properties and film structure
...

Unsaturated oils are valued for
their relatively rapid oxidative curing
...

O2

OOH

O

OH

+ ROH

Polyurethanes

Low

 One part polyurethane
 Moisture cured polyurethane
 Acrylic polyols-aliphatic linear isocyanate two part

polyurethanes
 Polyester polyols-aliphatic isocyanate two part
polyurethane
High
component 1

component 2
O

n
O

OH

n-m

m
OH

O

NH
R
NH

OCN R NCO
O

OH

m

O
n-m

n-m

n
O

O

O

OMe

O
OCN R NCO

O
MeO

O
HO

O

HN R N
H

O

O
O

O
O

Epoxy Paints

Epoxy coating

Coating Formulations: Solvent Selection Criteria
 Solvating Capacity:

Miscibility of polymer/solvent systems are dictated by
thermodynamics, as approximated by solubility parameters and
hydrogen bonding groupings
...

 Volatility:

Rate of solvent evaporation influences drying time as well as film
aesthetic qualities
...

 Toxicity and smell
...


Coating Formulations: Extenders and others
 Extenders provide no colour to a film, but their use is an inexpensive method of

improving adhesion, ease of sanding, film strength and opacity
...


•(2) White and
•
black paints

Inorganic

The purest white pigment is TiO2
and the most jet black, carbon
...
Some organics
are very insoluble
...


•(5) Heat stability
•

Inorganic

Very few organic compounds are
stable above 300°C
...

 Dependent on refractive
index of fillers relative
to the polymeric
binder
...

 Color
 Inorganic and organic colourants that are soluble or dispersed
in the film (may or may not provide opacity)
...
Viscosity can be defined as the resistance of a liquid to flow
...

so the paint does not splatter or drip on the user
so no brush marks can be seen
to prevent settling of the paint in the can during storage
so that a "good" film can be formed can be formed

Coating processes: Coil Coating
•Coat sheet metal from
coils before shaping
• Calendar or knife
delivery

• Also electrocoat &
spray

Spraying (charged particles)

Curing
(Infrared oven)

Electrocoating or E-coat
The Electrocoating Process
...


Functional pigments (e
...
, for corrosion protection) are
discussed to some extent
...
0510 pm, that of transparent pigments 0
...
05 pm
...


White Pigments
The most important white pigment for surface coatings is titanium
dioxide [13463-67-7] with a worldwide consumption in 1996 of ca
...
0 x lo6 t (60 YO of total consumption)
...
The
brookite modification has no economic importance
...
80,
anatase n = 2
...
When
combined with

White Pigments
colored pigments, titanium dioxide exhibits the highest
brightening power of all industrially produced white
pigments
...


White Pigments
Commercial products
Bayertitan (Bayer), Kemira (Kemira Pigments Oy),
Hombitan (Sachtleben),
Kronos (Kronos Titan),
Tibras (Titanio do Brad),
Tiona (Millenium Chem
...

Tioxide (Tioxide Group),
Tipaque (Ishihara S
...
), Tipure (Du Pont), Tronox (Kerr
McGee), and
Rhoditan (Rhone Poulenc)
...
200000 t), zinc oxide/zinc
white (ZnO produced from metallic zinc by oxidation of metal vapors,
worldwide production capacity ca
...
Pb(OH),)
...
Special
properties of zinc sulfide and lithopone are their low absorption in the
near UV range; they can therefore be used to color UV-curable paints
...


The luster of lithopone is used to advantage in
wallpaper coatings
...

Also, the lower abrasivity in comparison to TiO,
pigments can be of importance
...

pigments may be natural or synthetic, the synthetic
oxides have a wider color range and more uniform quality
...
The color range includes
the basic colors red (a-Fe,O,, hematite), black (Fe,O,, magnetite), yellow (aFeOOH, goethite), and orange (y-FeOOH, lepidocrocite)
...

Manganese- and chromium-containing iron oxide phases are important as
heat-stable brown pigments (e
...
, for stoving enamels)
...

Only micronized pigments should be used in paints
because they have better dispersion properties
...
g
...

Commercial products include Bayferrox (Bayer), Harcros
(Harrison & Crosfield), Ferrofin (Laporte
PLC), Mapico (Columbian Chem
...


Chromium Oxide Pigments
Chromium Oxide Pigments are composed of chromium(II1) oxide
[1308-38-91, Cr,O,, crystallized in a corundum lattice
...

On account of their excellent colorfastness and insolubility in
solvents, acid, and alkali,
chromium oxide pigments have successfully competed against more
brilliant organic green pigments
...

Pure chromium oxide pigments are not toxic
...


Complex Inorganic Colour
Pigments

...

Substitution of metal ions in the host lattice by other chromophoric metal ions
opens up a broad color spectrum
...

Heavy-metal ions can only exert their toxic effects in dissolved form
Since these pigments are sparingly soluble, they may be classified as
toxicologically innocuous
...
25 000
t in 1995 was processed into coating materials
...
H
...
and Sicopal
...
, Shephard Chem
...
and Ishihama SK
...
Bismuth pigments are
also produced as the two-phase system BiV0,- Bi,MoO, to
improve their colorfastness
...
Worldwide production in 1995 is estimated at
500 t
...


Organic pigment
Organic pigments are used to color and/or cover a substrate
...

Organic pigments have a high light absorption and a low
scattering power, whereas
inorganic pigments have a low light absorption and high scattering
power
...

Organic pigments are therefore often advantageous
...


Organic pigments tend to dissolve at high temperature and
in binders and solvents (migration)
...

Transparent pigments are used in glazes and in combination
with inorganic pigments including special-effect pigments
...

Other important pigment classes include metal-complex
pigments (e
...
,
copper phthalocyanine) and higher polycyclic compounds
(e
...
, anthraquinone, quinacridone, isoindolinone, and
perylene)
...
The powder
consists of agglomerates of pigment particles
...

These steps are described in detail in Chapter 7
...


Organic pigments
Properties
...
The organic pigments should be colorfast and stable towards
radiation, heat, and atmospheric substances
...
g
...

Migration should not occur when organic pigments are used in paints that are
applied in differently colored layers on top of each other
...

The pigment should be heat stable because it may be subject to increasing temperature
during dispersion, stoving, or use
...
Most organic pigments on the market are suitable for use in
paint
systems
...
Favorable rheology (i
...
, low viscosity) allows higher pigment and binder
concentrations at equal application viscosity
...

Pigments can also influence other coating properties (e
...
, film gloss) as a result
of complex interactions between the pigment, binder, and solvent, and the
method
of application
...

Pigment manufacturers have therefore produced
pattern cards and information describing their
properties and areas of application
...


Varnish
 Varnish is a transparent, hard, protective finish or film primarily







used in wood finishing but also for other materials
...

Varnish finishes are usually glossy but may be designed to
produce satin or semi-gloss sheens by the addition of
"flatting" agents
...

Varnishes are also applied over wood stains as a final step to
achieve a film for gloss and protection
...


Components of classic varnish
 Drying oil
 There are many different types of drying oils,

including linseed oil , tung oil and walnut oil
...


Types of varnishes
 Resin
 Resins that are used in varnishes include amber, kauri gum,

dammar, copal, rosin (pine resin), sandarac, balsam, elemi,
mastic, and others
...
In the 1900s in
Canada, resins from local trees were used to finish pianos
...
Solvent (traditionally turpentine)
 Traditionally, natural (organic) turpentine was used as the
thinner or solvent, but has been replaced by several mineralbased turpentine substitutes such as white spirit or "paint
thinner", also known as "mineral spirit"
...
Some systems use a drying oil
varnish as described below, while others use spirit (or
solvent) varnish
...


Resin
 Most resin or "gum" varnishes consist of a natural, plant- or insectderived substance dissolved in a solvent, called spirit varnish or solvent
varnish
...

Some resins are soluble in both alcohol and turpentine
...
e
...
The resins include amber, dammar, copal,
rosin, sandarac, elemi, benzoin, mastic, balsam, shellac, and a
multitude of lacquers
...

 Over centuries, many recipes were developed which involved the
combination of resins, oils, and other ingredients such as certain waxes
...

 The interaction of different ingredients is difficult to predict or
reproduce, so expert finishers were often prized professionals
...
It is not used for outdoor surfaces or where it will
come into repeated contact with water, such as around a sink or
bathtub
...

Shellac is the basis of French polish, which for centuries has been the
preferred finish for fine furniture
...


shellac
 Prepared shellac is typically available in "clear" and "amber" (or

"orange") varieties, generally as "three-pound cut" or three
pounds dry shellac to one US gallon of alcohol
...

 Dry shellac is available as refined flakes, "sticklac," "button lac,"
or "seedlac
...
Shellac clean-up may be done
either with pure alcohol or with ammonia cleansers
...

 Alkyds are chemically modified vegetable oils which operate
well in a wide range of conditions and can be engineered to
speed up the cure rate and thus harden faster
...

 Various resins may also be combined with alkyds as part of the
formula for typical "oil" varnishes that are commercially
available
...
Spars bend
under the load of their sails
...

 Elasticity was a pre-condition for weatherproofing too, as
a finish that cracked would then allow water through, even
if the remaining film was impermeable
...

Modified tung oil and phenolic resins are often used
...

Even after more modern synthetic resins did become resistant,
a true spar varnish maintained its elasticity above other
virtues, even if this required a compromise in its UVresistance
...

Despite this, the widespread perception of "marine products" as
"tough" led to domestic outdoor varnishes being branded as
"Spar varnish" and sold on the virtue of their weather- and UVresistance
...
Only relatively recently
have spar varnishes been available that can offer both effective
elasticity and UV-resistance
...
They are popular for hardwood floors but are considered by some
wood finishers to be difficult or unsuitable for finishing furniture or other
detailed pieces
...
Compared to simple oil or shellac varnishes, polyurethane varnish
forms a harder, decidedly tougher and more waterproof film
...

 This tendency increases with long exposure to sunlight or when it is

applied over soft woods like pine
...

Various priming techniques are employed to overcome this problem,
including the use of certain oil varnishes, specified "de-waxed" shellac,
clear penetrating epoxy sealer, or "oil-modified" polyurethane designed
for the purpose
...


Lacquer
 The word lacquer refers to quick-drying, solvent-based varnishes

or paints
...
Lacquer
is dissolved in lacquer thinner, which is a highly flammable
solvent typically containing butyl acetate and xylene or toluene
...

 Outside America, the rule of thumb is that a clear wood finish
formulated to be sprayed is a lacquer, but if it is formulated to be
brushed on then it is a varnish
...

 Lacquer may be considered different from varnish because it can
be re-dissolved later by a solvent (such as the one it was dissolved
in when it was applied) and does not chemically change to a solid
like other varnishes
...

They resist yellowing
...
They sometimes lack the
brushability and self-leveling qualities of solvent-based
varnishes
...


Drying oils
 By definition, drying oils, such as linseed and tung oil, are not true

varnishes though often in modern terms they accomplish the same
thing
...
Originally,
the term "varnish" referred to finishes that were made entirely of resin
dissolved in suitable solvents, either ethanol (alcohol) or turpentine
...
By
contrast, untreated or "raw" oils may take weeks or months to cure,
depending on ambient temperature and other environmental factors
...
However, certain non-toxic by-products of the curing
process are emitted from the oil film even after it is dry to the touch
and over a considerable period of time
...

Often, the two parts are of equal volume and are
referred to as "part A" and "part B"
...
All two-part
epoxies have a "pot-life" or "working time" during
which the epoxy can be used
...

Both water-borne and solvent-based epoxies are
used
...

 Comes in two parts: a resin and an acid catalyst
...
The acid catalyst is
added right before application in a set ratio determined by
the manufacturer
...
There are, however, two
downsides to this finish
...
The second
is that the finish can crack or craze if too many coats are
applied

History, Types, and Applications

Outline
 Conventional Coatings
 Powder Coating History

 Types of Powder Coatings
 Advantages/ Disadvantages

 Applications

Lacquers

+ Fast

Drying
+Deep shine

-Lack of durability
-High maintenance
-High VOC content

+ Good

flexibility and
durability
+ Cross-linking

- Long drying times
- Oxidation

+ Dry fast
+ Very durable and
flexible

- Isocyanate
component is
highly toxic

History
 Late 1940’s- Flame spraying of thermoplastic powder developed
 1955- Dr
...
Formulation
The formulation of powder coatings involves the use of 4 key raw material
types: resins, pigments, curing agents and additives
...

2
...
These raw materials are then blended together, either by
mixing or tumbling, to ensure a consistent dispersion of raw materials
throughout the mixture
...
Extrusion
The mixed raw materials are then fed into an extruder
...
The extrudate is then cooled and
chipped
...
Grinding
Once the extrudate has been cooled and chipped, it is ready to be ground into a fine
powder
...
Particles that are under 10 micrometers or over 120 micrometers can
cause application problems and are restricted by the sieving and classification
process
...


Epoxy
H2
C O
O

+ Excellent flexibility
- Fair resistance to overbaking
- Poor exterior
durability (low UV
resistance)
 Epoxy-urethane hybrids
• Similar to epoxy
+ Improved flow
properties
- Lower hardness

H2 OH H2
O C C C O
H

H2
O C
O

Urethane Polyesters
+ Very good

flexibility and
weatherability
+ outstanding thin film
appearance

*

C
O

N

R

N

C
O

O

R' O
n

Polyurethane

O
N
O

O

C

N
N

O
O
R O C R' C O

O

N

N

N

C

C

n

O

O
tris(6-isocyanatohexyl) isocyanurate

Polyester

Powders used in Spray Coating
Epoxies-More durable, but more
light sensitive (chalking)
HO

HO

O

O

H
N

NH
N

H
N

O
O
OH

OH
NH

N
N
H

N

O
OH
O

Polyesters-More light stable
O
O
O

O
O
O
O

Polymer
+
Binder

HO

Me

Me O
O
O

O

O

O

O
Me

Pigment + Filler

+

Antioxidant

Acrylics
+ Excellent color, gloss,

weather ability
+ Excellent thin film
appearance
- Fair flexibility and
corrosion resistance

CH3
*

H
C C
*
n
H
C O
O
CH3

Poly(methyl methacrylate)

The crosslinking during the cure
O
N

O
N

O

O

O

O

n

O

N

O

O

O

HO2C

tri-glycidyl-iso-cyanurate
powder

Polyester milled into powder

O

O
O

O
O

O

O
n

O

O

O

O

O

OH
O

O
O
O

O

CO2H

O

O

O

O

N
O
HO

O
O

N

O

O

O

OH

N

O

O
HO

O

O

O

O

O

N

O
O

O
HO
O

O

O

O

N
N

O
O

O

OH
O
O

O

TGIC Polyesters
Excellent exterior
durability
- Exposure limits when
spraying due to TGIC
+

O

O
N
N

O
N

O
O

O
TGIC

O
O
R O C R' C O
n
Polyester

Powder Coating versus Paint
no solvent

(toxic) solvent

recycles
unused coating

overspray wasted

single layer
sufficient

several layers
required

conflicting flow
requirements

viscosity adjusted
separately

now dominates for coating of parts

Advantages of Powder Coating
 No VOC emissions
 Improved durability
 Over-spray may be reused
 Lower operating and maintenance costs for

finishing lines

Disadvantages
 Material must be able to withstand curing






temperatures, >260º F (~125ºC)
Forming films thinner than 1
...

Test steps :
Steering the paint carefully in its package by using
the glass rode
...

 Test Criteria :
 The paint must be suitable, homogenous and easy to
use
...
Referring to the
basic Newtonian model, when a shear is applied to a
fluid it is deformed such that the material layers move
according to a velocity gradient in relation with the
force imposed
...
shear rate
...


Viscosity
Newtonian vs
...
g
...

This dependency can lead to a thinning effect where the deformation
reduces the viscosity, or
correspondingly thickening where the viscosity increases
...
TEST REQUIREMENT
 The specimen of the paint to be tested should be visibly









homogeneous and free from any foreign materials or air
bubbles
...
4
...

3 Stop watch
...

2: The analyst should has a mask and gloves during the test
...

2 Close the orifice of the ford cup by holding rubber or by
using hand
...

4- Scrape off the excess with straight edge
...


 7- Measure the temperature of the fluid in the efflux






stream
...
and record it in the data
presentation Appendix 1
...

3
...

2
...

3
...

2 Tapered Gage : hardened stainless steel block
...

2 Do not allow any hard materials to come in contact with the gage surface
...

4 The tested specimen must be free from any bubble

Fineness- Procedures
1 -Place a gage in horizontal flat
2- Place the specimen in the deep end of two bathes of the gage
...

4- Draw the specimen down the length of the two path toward the shallow
end of the gage
...

5 -Within 10 Sec of placing the specimen on the gage , make the reading as
follows:
A- View the gage from the side
...

B- Keeping the gage between the operator and the light source
...


7- Observe the point where the material first shows a defined
speckled pattern , not just isolated specks
...

9-Take the average values in the two paths to nearest
micrometer
10- Record the reading in the data presentation 1ppendix 1
...

Fineness for glossy ≥ 25 µm
...

b : Non glossy (matt ) paint
...


Color
(104)
Color measurements conducted by using the ˝Gardenr
1953 Standard
Colours˝
...
The material in which color
matched inserted inside
clear glass color tubes 10
...
25 mm inside diameter
and 114 -+1 mm
out side length
...


Color
The transparent sample solution poured (at temperature
of 25 + 5 ºC) into an empty color tube
...
The rack containing the standards held the
standard and sample reported in terms of one of the 18
Gardner standards
...
If it closer to the lower of the two
standards, it will be reported as ˝ + ˝
...
Any
sample darker than 18 was reported as ˝ >18 ˝
...
ENVIRONMENT
The environment required for this test is 25 ±2°C according to standard
ES 761/2005
...
TEST REQUIREMENT
the specimen of the materials to be tested shall be visibly homogeneous
and free of any foreign materials or air bubbles
...

2 Digital Balance
3 Ceramic crucible
...
PRECAUTIONS
1: The used oven must be forced – ventilation type
...
and adjust its
temperature at 25 ±2°C
2 Weight the empty crucible (W1), and record it in appendix 1
...
1 gm of the specimen in the
crucible
...

5 Put the crucible with the specimen in the oven at 105 ± 2 °C for
2 Hr
...

7 Calculate the weight of nonvolatile
T = W nonvolatile % = [(W3-W1)/ [(W2-W1) ]* 100
...

Where W1: Weight of the empty crucible, g
...

W3: Weight of the crucible with the specimen after drying , g
...
ENVIRONMENT
The environment required for this test is 25 ±2°C temperature and
relative humidity 55±5 % Hr
...

2
...

3
...

2 Test cup with thermometer graduated (10°C to 60°C)
...
with thermometer graduated (35°C to
88°C)
...


PROCEDURES
1 Fill the cup with the specimen to prevent the possibility of loss
of volatile contents and close the container tightly
...

3 Adjust temperature of the specimen at degree between 0 to 10
°C
...

5 After the temperature of the water bath equal 55 °C
...

6 Light the flame by opening the slide of the water bath in the
test vessels when the temperature of the specimen equal 19 °C
until
...
5 ±0
...
and record the
reading temp
...

Digital Stop Watch hh: mm: ss
...

Watch the surface of the paint after 3 Hr and 16 Hr
...


KEEPING THE PROPARTIES DURING STORAGE:
 Test steps :

 Take two package from the paint under test
...

 Compare between the results for the first and second
package
...


Density

...
2 Thermometers, graduated in 0
...
3 Constant-Temperature Bath, held at 25 6 0
...


...


...

6
...
1 Determine the volume of the container at the specified temperature
by employing the following steps:

...


...


...


...


Density

...
6 Obtain the mean of at least three determinations
...
Procedure
Repeat the steps in Section 8, substituting the sample for the reagent
water and a suitable nonresidual solvent for the acetone or alcohol
Record the weight of the filled container, W, and the weight of the
empty container, w, in grams
...
2 Calculate the density in grams per milliliter as follows:
Dm 5 ~W 2 w!/V (2)
where: Dm = density, g/mL
...
3 Calculate the density in pounds per gallon as follows:
D 5 ~W 2 w!K/V (3)
where:
D = density, lb/gal,
K = 8
...


...
40 µm – 0
...

2) Small Brushes
...

4) Oven

b) Test steps:
Prepare a film with thickness 50
...
0 µm on the steel sheet by
the specimen
...

3) Put the steel sheet after drying in the oven at
temperature 80°C for 4 hr
...
to cooling
...


SCRATCH HARDNESS TEST:
6) Operate the scratching machine 6 times to make 6
different scratch with the machine needle
...

8) Record your watching in the data presentation
appendix 1
...


Bending test (flexibility)
1
...


3
...


The test performed to determine the adhesion power of the
varnish to the substrate by bending apparatus
...

The panel placed into the bending apparatus (0
...

The apparatus then opened and the panel examined carefully
to find out any cracking or dislodging of the film as criterion of
loss of consistency of the film
...


Adhesion
Adhesion is a very important property of a paint system, and some useful
empirical information can obtain by the crosshatch test
...

These test methods cover procedures for assessing the adhesion of coating
films to substrates by applying and removing pressure- sensitive tape
(25mm wide semi transparent tape) over cuts in the film
...

· This test method for coatings having a DFT up to and including 50 μm, For
coatings having a DFT between 50 μm and 125 μm,
the space cuts 2mm
...
Motor driven blade film applicator
...
Glass sheet 10 x 15 cm
...
Micrometer
...
Water bath
...
1 Clean the base plate of the motor and place the glass
sheet on it
...

 3 Place a suitable amount of the coating material on the
glass sheet in front of the blade
...

 5 Remove the coated glass sheet and let or dying for 3
days in the room temperature
...

7 Let the film to dry for 7 days (168 Hr)
...

2) Measure the thickness of the applied coating
...

5) Record your watching in the data presentation appendix 1
c) Test criteria:
The sample is passing if no any effect on the color of water
and the film
...
1 ASTM D823-95 – practice C “ Motor driven blade film application ” for

producing a film of uniform thickness of paint
...

 3 Glass sheet 10 x 15 cm
...


PRECAUTIONS
1: Before using the gloss meter ensure that it is calibrated
...
Clean the
applicator blade
...
1 Preparation the test specimen
1 -Clean the base plate of the motor (6
...
3) on it
...

3- Place a suitable amount of the paint material on the glass sheet at front of the
blade
...

5- Remove the coated glass sheet and let or dying for 7 days
...

2 Measuring the thickness :
1 Measure the thickness of the applied coating by using the micrometer in
accordance with the test method ASTM D 1005-95
3 Testing the specimen
...
R
...

1 Position the specimen on gloss meter
...

3 Take 3 different reading for the gloss of specimen
...

5 Record the final gloss reading
...
1 Glossy and semi glossy synthetic air drying paint
...

Gloss ≥ 70
Drying for 7 Days
For Semi glossy paint at 60º
30 ≤ Gloss ≤ 70 Drying for 24 Hr or 7 days
...

For Glossy plastic at 60° = Gloss ≥ 62
For Semi glossy plastic at 60° = 31 ≤ Gloss ≤ 62

= Gloss 7±1
11 SAMPLING REQUIREMENTS :
The EOS sampling department provide the Paints & Varnishes
laboratory with the samples to be tested
...

2) Steel sheet (15 X 10 cm)
...

4) Soap solution 0
...


WASHABILITY TEST:
b) Test steps:
1) Prepare a film on the steel panel by specimen with the thickness
100 µm
...

3) Put the brushes of the washability equipment in distilled water
with depth 13 mm at temperature 25-30°C for 30 min
...
50% for 5 min
...

6) Adjust the washability equipment to let the 10 mm distance from
each edge of the steel panel , and keep the amount of the soap
solution at 10 -12 point /min at the brushes direction
...


WASHABILITY TEST:
c) Test criteria:
1) The appearance of the tested panel must be free from
any cracking
...


Analysis of Paint
Colour layer analysis
Requires cross section of paint chip
Cannot be done on paint smears
Same number and order of layers
Relative thickness must be same
Is a class test (but see case at end of lecture)

Solubility
Use solvents such as acetone, dichloromethane, pyridine
...


Analysis of Paint
FTIR

Will determine type of film former
Does not show pigments unless they are organic
Is a bulk method: if more than one layer is
present, IR will be a composite

Analysis of Paint
Electron microscopy
Inorganic pigments
Excellent for single, top layer analysis and paint smears

UV-visible spectrophotometry
Must be able to separate pigment from film former and
dissolve it

Smart Coatings

Smart Coatings and Materials

Materials, which are capable of adapting
dynamically their properties to an external
stimulus, are called responsive or “smart
...

- Reshaping, reorganization and rebuilding-- bones
- Dynamic and responsive– cell membranes

Smart Coatings and Materials
• One-way systems: Already in use
-Corrosion sensing
-Conductive coatings
-Anti-inflammatory coatings

• Two-way systems: More challenging
-Shape-memory materials
-Hydrophobic/hydrophilic switching
-Thermochromic pigmented coatings

Smart Coatings and Materials
 Adaptive materials
-Properties endure as long as the signal is present
-Permanent signal

 Switchable materials
-Momentary signal

Smart Coatings
Stimuli
Chemical Signals

Physical Signals

 Acid-base reactions
 Complexation
 Bond formation/breaking
 Electrochemical reactions
 Photochemical reactions

 pH
 Ionic strength
 Temperature
 Pressure/mechanical
 Surface tension
 Light and acoustic
 Electrical/magnetic fields

Examples of Smart Coatings












Antimicrobial and Hygienic
Antifouling
Bio-catalytic
Color shifting
Conductive
Corrosion sensing
Defect/degradation sensing
Light sensing
Molecular electronics
Nanotechnology-based
Optically active

 Photo-catalytic
 Pressure sensing
 Shape-memory polymers
 Self-lubricating
 Self-repair and healing
 Super hydrophobic
 Thermally triggered

Smart Coatings
Smart coating is not just a dream
some are already in use
...
2, 2005)-- Nissan Motor Co
...
Aksay, Peng Jiang, Dudley A
...


Smart Coatings

Smart Coatings

Smart Coatings

Smart Coatings
Alternative Approach:
H2O

hv,

Selfhealing

T

Chemical reactions

J
...
, work in progress



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