Page 140 - Engineering Plastics Handbook

Acrylonitrile-Butadiene-Styrene (ABS) Resin 113

TABLE 6.3 Properties and Characteristics of Flame-Retardant ABS
ASTM Flame-retardant
test
Unit method TBBA BEO FF-680
Mechanical
2
Tensile strength (5 mm/min) kg f /cm D638 420 430 400
Elongation at break % D638 28 26 18
2
Flexural strength (1.3 mm/min) kg f /cm D790 685 700 670
Flexural modulus kg f D790 23,500 24,500 21,000
Izod impact (notched, 23°C) cm/cm D256 29 22 25
Rockwell hardness R-scale D785 104 102 104
Thermal
Heat deflection temperature
2
(18.5 kg f /cm ) °C D648 82 86 78
Flowability
Melt index (220°C, 10 kg) g/10 min D1238 50 38 48
Flame rating
UL-94 (1/16 in) V-0 V-0 V-0
NOTE: TBBA is tetra-bromo-bisphenol A, BEO is brominated epoxy oligomer, and FF-680 is
1,2-bis(tribromophenyl) ethane.

Since flame-retardant ABS has excellent properties and processability
(Table 6.3), the application field has been expanded to the parts of various
kinds of electric and electronic equipment as well as computer monitor
housings. As safety is emphasized, the flame-retardant standard has been
strengthened, and the environmental problem is an issue, as the harmful
effect of halogen-based flame retardant has been criticized. Therefore, for
flame-retardant ABS it is necessary to abide by the uses and regulations
according to the safety and environmental issues in each country.
The movement to regulate flame retardants was led by the Green Party
in Germany in the middle of the 1980s, and it then came to be noticed by
the public through participation of other European countries. Accordingly,
as the risk assessment depending on the kinds of flame retardants is
established, the regulation of some flame retardants has been envisioned.
Recently, even in the United States, which has held on to a generous policy
for flame retardants, the movement to regulate some flame retardants has
arisen, centering on California. However, since the flame retardant used
for flame-retardant ABS has been classified as a relatively safe material,
its use has not been regulated up to now. Self-imposed control has been
practiced by establishing the ecolabel mainly in European countries. See
Table 6.4.
The flame-retardant ABS resins are mainly used in the parts and hous-
ings of various kinds of electric and electronic products that require the
flame-retardant property. Specific applications have been made in various
fields including cathode-ray tube (CRT) and LCD monitor housings, TV