Flame Retardant Additives for
Coatings, Plastics, and Adhesives
by
Walter Conti
BUCKMAN LABORATORIES, INC.
1256 North McLean Blvd.
Memphis, TN 38108-1241
1-800-282-5626
Mission
• “We, the associates of Buckman
Laboratories, will excel in providing
measurable, cost-effective improvements in
output and quality for our customers by
delivering customer-specific services and
products, and the creative application of
knowledge”
Buckman Laboratories
Flame Retardant Additives for
Coatings, Plastics, and
Adhesives
Definition of FIRE
• Fire is one of the 4 Elements: EARTH,
AIR, FIRE and WATER.
• By Webster, Fire is defined as:
– A Rapid, persistent chemical reaction that
releases heat and light, esp. the exothermic
combustion of a combustible substance with
oxygen.
Fire Flashover
Upholstered Chair Fire
(elapsed time 4:50 min/sec)
TV/ Low Level Ignition
(not flame retarded)
TV/ Low Level Ignition
(flame retarded)
Introduction
• Almost anything will burn.
• The objective of flame retarding is to
increase the resistance of a product to
ignition and to reduce flame spread. Thus,
the use of a flame retardant may prevent a
small fire from becoming a major
catastrophe.
Introduction
(con't.)
• A National Bureau of Standards (U.S.)
study comparing fire retarded and non-fire
retarded products concluded that fire
retardant additives decreased the overall fire
hazard of their host products.
FIRE Statistics
• US has one of the highest fire death rates in the industrialized world
• More than 2 million fires reported each year / cost of 8.1 billion dollars
• Where fires occur in the home:
– Kitchen 29%
– Bedroom 13%
– Living Room/Den 8%
– Chimney 8%
– Laundry Area 4%
• Top causes of residential fires:
–
–
–
–
Careless Smoking
Arson
Alternative heaters
Cooking
Determining the Fire Hazard of a
Product
• Factors needed to be considered in
determining the fire hazard of a product are
–
–
–
–
–
–
Ignitability
Flammability
Heat released when burned
Heat release rate
Smoke obscuration
Toxicity of the smoke generated
Flame Retardant Market
• The overall market for flame retardant
chemicals is controlled by government
regulations, insurance underwriters, national or
local building codes, special regulations and
compliance with existing and anticipated
standards.
• Without these regulatory actions or mandatory
standards, flame retardant chemicals probably
would not be used to an appreciable extent.
Flame Retardant Market
• Fire Retardant additives in
–
–
–
–
Plastics
Adhesives
Paints and Coatings
Other
9.4%
0.2%
4.8%
8.1%
(con't.)
Desired Properties of a Flame
Retardant
•
•
•
•
•
High Decomposition Temperature
Low volatility
Non-blooming or plate-out
Minimal effect on final physical properties
Low toxicity
(no single additive meets all these
requirements)
3 Things are Needed to Sustain
FIRE
• Flame
• Oxygen
• Fuel
Phases in the course of a Fire
Fire triangle (according to Emmons)
Mechanisms of Flame Retardants
• Endothermicity
• Char former
• Vapor phase
ENDOTHERMICITY
• Mode of action - heat absorber
– Primarily utilize evaporative cooling provided
by chemically bound water and diluting the
oxygen in the gas-phase reaction
• Examples
– Alumina trihydrate and magnesium hydroxide
• They are relatively inefficient
• High use levels required comprimise
products physical properties
CHAR FORMER
• Mode of action - Char former
– As the material is broken down a char or carbon
layer is formed. This char acts as a physical
barrier excluding oxygen and fuel for the fire.
• Examples
– Barium/Calcium metaborates, phosphorus
compounds, zinc borate. These products work
best with a halogen donor of some sort
(chlorinated resin, chlorinated wax, other
synergistic flame retardant)
VAPOR PHASE
• Mode of action - Chemically inhibit flame
– Free radicals generated during combustion are
scavenged by halogens (which compete with
oxygen - no oxygen, no flame) stopping the
chain reaction of combustion.
• Inexpensive
• Examples
– Halogenated materials (deca-brome type,
chlorinated paraffin wax, phosphate esters,
antimony tri and pentoxide)
Major US Producers of Flame Retardant
Chemicals
•
Product
Alumina Trihydrate
•
Antimony Oxide
•
•
Boron Compounds
Brominated Phosphates
•
Chlorinated Cmpds
•
Chlorinated Phosphates
•
Molybdenum Cmpds
•
Phosphate Esters
Company
Alcoa
LaRoche Chemical
Reynolds Metals
Solem
Albermarle
Anzon
Cookson
Laurel
Buckman Laboratories
Climax
US Borax
Ameribrom / Dead Sea Bromine
Albermarle
Ferro
Great Lakes Chemical
FMC
Ferro
Dover Chemical
Occidental
Pearsall
Akzo
Albright and Wilson
AMAX
Sherwin William
Akzo
Monsanto
Tradename
FlameGaurd
Fireshield, Thermogaurd
Flamebloc
Firebrake
Saytex
Firemaster, Smokebloc
Characteristics of Other Most
Widely Used FR’s
• Antimony Tri/Pentoxide (Sb2O3)– Pros
• Inexpensive Commodity (large price swings $1 - $3)
• Fine particle size
• Track Record in many materials and applications
– Cons
•
•
•
•
•
May Cause “Antimony Measles” in workers
Halogen needed for optimal performance
High loading levels, possibly decreased physical properties
Higher product density
Most supply is imported (commodity, large price swings)
– See Technical Data Sheet Example
Characteristics of Other Most
Widely Used FR’s
• Zinc Borate (ZnBO3) – Pros
• Inexpensive
• Similar RI of most thermoplastics (lower pigment levels)
• Track Record in many materials and applications
– Cons
• High loading levels, possibly decreasing final physical
properties
• Halogen needed for optimal performance
• High product density
• Water of hydration
Characteristics of Other Most
Widely Used FR’s
• Brominated Flame Retardant (BFR's) – Pros
• Cost Effective
• Track Record in many materials and applications
– Cons
• Halogen (Bromine)
• Brominated materials under scrutiny in Europe, US may follow
• Not readily biodegradable - environmental issues
Primary Industries Where Flame
Retardants are Used
•
•
•
•
•
•
•
Wire and cable (electronic and other)
Appliances
Textiles
Coatings
Adhesives
Carpet Backing
Other
Successes with Flamebloc
Products in Plastics/Coatings
• PVC (wire and jacketing)
• Chlorinated Polyethylene (riser cable)
• Nylon other engineering resins (part of FR
package)
• Polyester Pultrusion
• Coatings / Intumesent coatings
Benefits of Flamebloc Flame
Retardants/Smoke Suppressants
(con’t)
• Flame Retardant / Smoke Suppressor
– Data has shown that the smoke suppressant
effectiveness can be as great as 50% or better
(see data)
• Four particle sizes to choose from
– The theory is that you will get better dispersion
in your polymer with a smaller particle size
and more uniform distribution curve. Also, the
increased surface area helps create more char.
Benefits of Flamebloc Flame
Retardants/Smoke Suppressants
(con’t)
• Does not noticeably degrade final physical
properties of most finished products
• Heat Stabilization Effect
– Unlike products like Zinc Borate, that significantly
degrade a polymer’s final physical properties, the
Barium and Calcium Metaborates act as stabilizers and
do not degrade the polymer’s final properties to that
degree
• Safer product (MSDS) than many of its
competitors
Benefits of Flamebloc Flame
Retardants/Smoke Suppressants
(con’t)
• Reduced toxic smoke emissions and total
smoke
– The Flamebloc products keep the Peak Rate of
Heat Release and Total Heat Release (cone
calorimeter) low thus creating less
combustibles and less smoke. Also the
byproducts of BMB and CMB are less toxic
than some of its counterparts.
• Non-halogen
Test Methods
• There are many different tests for determining the
degree of flame retardancy of materials.
• The correlation of performance between test
methods is poor. Therefore, a system that passes
one test, might not pass or may need modification
in order to pass a different test.
• Following is a list of some of the more common
test.
Measuring Flammability/Smoke
• The two most popular laboratory methods of
measuring flammability are
– UL -94
– Limited Oxygen Tests
• While such small scale tests are useful for
comparative studies, they do not predict the level
of hazard in an actual room fire.
Measuring Flammability/Smoke
UL-94
• The UL-94 requirements cover tests for
flammability of plastic materials used to
manufacture parts in devices and appliances.
They are intended to provide an indication of a
resin’s flammability , and therefore acceptability
for a particular application.
• Tests:
– Horizontal Burning Test; 94HB 20MM
– Vertical Burning Test; 94V-0, 94V-1, or 94V-2
Measuring Flammability/Smoke
UL-94
(con't)
Measuring Flammability/Smoke
UL-94
(con't)
Measuring Flammability/Smoke
UL-94
(con't)
Measuring Flammability/Smoke
UL-94
(con't)
• Tests:
– Horizontal Burning Test; 94HB
– 20 MW Vertical Burning Test; 94V-0, 94V-1,
or 94V-2
– 500 MW Vertical Burning Test; 94-5VA or
94-5VB
– Thin Material Vertical Burning Test;
94VTM-0, or 94VTM-2…
– Horizontal Burning Foamed Materials Test;
934HBF, 94HBF-1, or 94HBF-2
Measuring Flammability/Smoke
Oxygen Index
• Oxygen index is the consumption of oxygen
of a fire system related to a numerical value.
The higher the value the better the flame
retardant system may be.
• Buckman Laboratories has this apparatus
available in the lab.
Measuring Flammability/Smoke
Oxygen Index
(con't)
Measuring Flammability/Smoke
(con’t)
• Methods for measuring smoke
– Cone colorimeter
– UL Steiner Tunnel Test (larger scale)
• Although toxic gases are the major cause of
fire deaths, it has been suggested that heat
release rate is the single most important
variable in characterizing flammability.
Measuring Flammability/Smoke
Cone Calorimeter
• The cone calorimeter is an apparatus that
measures the rate of heat release using the
‘oxygen consumption principle’, ignitability
and smoke production.
Measuring Flammability/Smoke
UL Steiner Tunnel Test
• This test analyzes the smoke produced by
the burning of a material.
Flame Retardant Chemicals
Market
• Projected Growth is 4% per year over the
next five years
• Flame retardants in the electronics market
segment will grow the fastest at about 7.5%
Current and Future Trends
• Europe has moved to ban or curtail the use
of brominated diphenyl oxide flame
retardants because of the potential
formation of highly toxic brominated furans
and dioxins during combustion.
• Reformulation to replace halogenated flame
retardants with non-halogenated flame
retardants.
Current and Future Trends
(con’t)
• New co-polymerization of engineering
thermoplastics
• More rigid flame retardant requirements
have been established for the upholstered
furniture industry
• Better flame and smoke reduction using
non-halogen chemistry in the polyolefin
arena
Current and Future Trends
(con’t)
• Flame retardant blends (synergism's
between different FR mechanism products)
– i.e. Flamebloc products and antimony oxide
Data Review
Buckman Laboratories Cone
Calorimeter Data on Plenum Wire
and Cable Formulation
PVC Cone Colorimeter Data and Graphs
Heat and Visible Smoke Release Rates of Plasticized PVC
Test Results:
ASTM 1354
Heat and Visible Smoke Release Rates for Materials and Products Using an
Oxygen Consumption Calorimeter
Heat Flux: 35 kW/m2
Exhaust Flow Rate: 24.0 I/s
Sample
A
Q
N
K
H
B
D
E
G
K
Initial Mass (g)
Final Mass (g)
Avg. % wt. Loss (g)
13.4
2.9
78.4
14.0
3.5
75.0
13.2
3.1
76.5
12.6
3.3
70.0
12.0
2.8
76.7
12.3
3.3
73.2
11.0
3.3
70.0
9.9
2.6
73.7
9.8
2.6
73.4
11.3
3.6
68.1
Time to Sustained Ignition (s)
Time to Flame-out (s)
Peak Rate of Heat Release (kW/m2)
Total Heat Released (MJ/m m2 )
19
112
244.1
10.89
18
171
178.9
10.58
18
139
215.0
10.32
17
148
196.9
10.03
16
122
204.9
9.85
20
104
198.0
9.40
15
98
185.3
8.88
16
89
173.2
7.48
28
96
174.7
6.71
36
99
199.6
7.02
Total Smoke Released (m2 )
10.88
9.34
10.14
9.95
9.62
6.65
7.70
5.87
5.10
6.55
Legend:
A – Control
Q – Flamebloc 381
N – Zinc Borate
K – Flamebloc
H – Busan 11-M1
(10phr)
(10phr)
(10phr)
(10phr)
B – Antimony (10phr)
D – Flamebloc 428 (10phr)
E – Flamebloc 428/Antimony /5/5phr)
G – Busan 11-M1/Antimony (5/5phr)
K – Flamebloc/Antimony (5/5phr)
Test Formulation
Base Formulation
Material
poly(vinyl chloride)
dioctylphthalate
epoxidized soybean oil
CaCO3
TiO2
barium-zinc salts
stearic acid
Product Name
Geon Resin 103EPF-76
Eastman DOP
Plas-Chek 775
Duramite
Ti-Pure R-900
Therm-check 144
A292-500
Company
The Geon Company
Eastman Chemical
Ferro
ECC
DuPont
Ferro
Fisher Chemical
Function
Parts
resin
100
primary plasticizer
35
secondary plasticizer
5
filler pigment
10
colorant
10
thermal stabalizer
3
lubricant
0.5
Heat Release Rate
Control
300
ZnBO4 10 phr
250
SbO3 10 phr
Flamebloc 428 10 phr
Flamebloc 428~SbO3 5~5 phr
150
100
50
Seconds
117
113
109
105
101
97
93
89
85
81
77
73
69
65
61
57
53
49
45
41
37
33
29
25
21
17
13
9
5
0
1
Kw /m 2
200
Effective Heat
Control
ZnBO4 10 phr
40.00
SbO3 10 phr
35.00
Flamebloc 428 10 phr
30.00
Flamebloc 428~SbO3 5~5 phr
20.00
15.00
10.00
5.00
Seconds
117
113
109
105
101
97
93
89
85
81
77
73
69
65
61
57
53
49
45
41
37
33
29
25
21
17
13
9
5
0.00
1
MJ/k g
25.00
Control
ZnBO4 10 phr
SbO3 10 phr
Flamebloc 428 10 phr
Flamebloc 428~SbO3 5~5 phr
Extinction Area
4000
3500
3000
2000
1500
1000
500
Seconds
117
113
109
105
101
97
93
89
85
81
77
73
69
65
61
57
53
49
45
41
37
33
29
25
21
17
13
9
5
0
1
m 2/k g
2500
Smoke
Control
0.25
ZnBO4 10 phr
SbO3 10 phr
0.2
Flamebloc 428 10 phr
Flamebloc 428~SbO3 5~5 phr
m 2/s
0.15
0.1
0.05
Seconds
117
113
109
105
101
97
93
89
85
81
77
73
69
65
61
57
53
49
45
41
37
33
29
25
21
17
13
9
5
1
0
Total Smoke
12.00
10.00
6.00
Control
4.00
ZnBO4 10 phr
SbO3 10 phr
2.00
Flamebloc 428 10 phr
117
113
109
105
101
93
89
85
81
77
73
69
65
61
53
49
45
41
37
33
29
25
21
17
13
9
5
57
Seconds
97
Flamebloc 428~SbO3 5~5 phr
0.00
1
m2
8.00
Summary Review of Data
• Flamebloc 428/Antimony and the
Busan 11-M1/Antimony combination had:
1. Longer times to sustained ignition
2. Lower Heat Release Rates
3. Lower Total Heat Released
4. Lower Total Smoke Generation
5. Better part physical properties
than the control or competitive materials
(zinc borate or antimony)
• All the above contribute to superior performance for
Buckman products in plenum cable applications.
Buckman Laboratory Products
for Flame and Smoke Reduction
• Barium Metaborate Based
– BUSAN 11M1
– BULAB FLAMEBLOC
– BULAB FLAMEBLOC 440
• Calcium Metaborate Based
– BULAB FLAMEBLOC 381
– BULAB FLAMEBLOC 428
– BULAB FLAMEBLOC 451
Buckman Laboratory Products for
Flame and Smoke Suppression
• This is a strategic business area for
BUCKMAN LABORATORIES, Inc. We
are committed to keeping our customers on
the cutting edge of FR and SS with new
products and technologies.
BUCKMAN!
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Expect!
1-800-BUCKMAN
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