USES AND FORMULATIONS
largest use of antimony oxide is in a synergistic flame retardant system for
plastics and textiles. Normal applications include upholstered chairs, rugs,
television cabinets, business machine housings, electrical cable insulation,
laminates, coatings, adhesives, circuit boards, electrical appliances, seat
covers, car interiors, tape, aircraft interiors, fiberglass products, carpeting,
etc. There are numerous other applications for antimony oxide that are discussed
Polymer formulations are
generally developed by the user. Dispersion of the antimony oxide is extremely
important to get the maximum effectiveness. The optimum amount of either
chlorine or bromine must also be used.
FLAME RETARDANT APPLICATIONS IN HALOGENATED
No halogen addition is necessary in polyvinyl
chloride (PVC), polyvinylidene chloride, chlorinated polyethylene (PE),
chlorinated polyesters, neoprenes, chlorinated elastomers (i.e.,
chlorosulfonated polyethylene ).
Polyvinyl Chloride (PVC). - Rigid PVC.
products (unplasticized) are essentially flame retarded due to their chlorine
content. Plasticized PVC products contain flammable plasticizers and must be
flame retarded. They contain a high enough chlorine content so that an
additional halogen is usually not necessary, and in these cases 1 % to 10%
antimony oxide by weight is used. If plasticizers are used that reduce the
halogen content, the halogen content can be increased by using halogenated
phosphate esters or chlorinated waxes.
Polyethylene (PE). - Low-density polyethylene
(LDPE). burns rapidly and must be
flame retarded with as much as 8% to 16% antimony oxide and 10% to 30% of a
halogenated paraffin wax or a halogenated aromatic or cycloaliphatic compound.
Brominated aromatic bisimides are useful in PE used in electrical wire and cable
- Halogenated polyester resins are flame retarded with approximately 5% antimony
FLAME RETARDANT APPLICATIONS IN NON
A halogen synergist must be added to polyolefins,
polystyrene, polyesters, epoxies, acrylonitrilebutadiene-styrene (ABS),
polyurethanes (PU), natural rubber, and polypropylene (PP).
- ABS is processed at high temperatures-and requires the use of a stable flame
retardant. Up to 25% of a chlorinated cycloaliphatic compound or an organic
brominated compound are used with 5% to 12% antimony oxide.
- PP is generally processed by injection molding or etrusion at 4000
to 4500 F and requires a flame retardant that is stable at these
temperatures, not, for instance, a chlorinated paraffin. Normally a combination
of 5% to 15% antimony oxide and up to 40% of a brominated chlorinated
cycloaliphatic or aromatic compound is used. Generally more flame retardant
additives are needed for applications above 4500 F. Heating over
prolonged periods should be avoided to prevent the decomposition of the
chlorinated compounds. A fine antimony oxide particle size is more desirable to
improve the physical properties.
- Basically there are three types of polystyrene. Crystal polystyrene, or
general purpose polystyrene, can be flame retarded with a brominated flame
retardant with small amounts of antimony oxide. High impact polystyrene contains
an elastomer and must be flame retarded with a significant amount of a
brominated compound and approximately 10% antimony oxide. Expanded beads of
polystyrene are flame retarded with a brominated compound with an activator such
as an organic peroxide.
- Epoxy resins are best flame retarded with a brominated organic compound and a
fine particle antimony oxide.
Styrene butadiene rubber, ethylene propylene rubber, and other elastomers can be
flame retarded with halogenatecj compounds and 5% to 30% antimony oxide.
- Rubber processors use antimony oxide and a
halogen in hose, belting, carpet backing,
PU is flame retarded with a brominated hydrocarbon and up to 10% antimony
FLAME RETARDANT APPLICATION FOR COATINGS AND
- Paints can be made flame retardant by
providing a halogen, usually chlorinated paraffin or rubber, and 10% to 25%
antimony trioxide. Additionally antimony oxide is used as a color "fastener" in
paint subject to ultraviolet radiation that tends to deteriorate colors. As a
color fastener it is used in yellow striping on highways and in yellow paints
for school buses.
- Antimony oxide and a suitable halogen
are used to render paper flame retardant. Since antimony oxide is insoluble in
water, it has an added advantage over other flame retardants.
- Modacrylic fibers and halogenated
polyesters are rendered flame retardant by using the antimony oxide- halogen
synergistic system. Drapes, carpeting, padding, canvas and other textile goods
are flame retarded using chlorinated paraffins and (or) polyvinyl chloride latex
and approximately 7% antimony oxide. The halogenated compound and antimony oxide
are applied by rolling, dipping, spraying, brushing, or padding operations.
- Antimony oxide is used as a catalyst for the production of polyester resins
for fibers and film.
Polyethylene Terephthalate (PET).
Resins and Fibers.- Antimony oxide is used as a catalyst in the esterification
of high-molecular-weight polyethylene terephthalate resins and fibers. High
purity grades of Montana Brand Antimony Oxide are available for food
- Micropure and high tint are used as opacifiers in vitreous enamel frits. They
have the added advantage of acid resistance. Antimony oxide is also used as a
brick colorant; it bleaches a red brick to a buff color.
- Antimony oxide is a fining agent
(degasser) for glass; especially for television bulbs, optical glass, and in
fluorescent light bulb glass. It is used also as a decolorizer in amounts
ranging from 0.1
to 2%. A nitrate is also used
in conjunction with antimony oxide to help oxidation. It is an antisolorarant
(the glass will not change color in sunshine) and is used in heavy plate glass
exposed to the sun. Glasses with antimony oxide have excellent light
transmitting properties near the infrared end of the spectrum.
- Besides being used as a flame
retardant in paints, it is also used as a pigment that prevents "chalk wash
down" in oil base paints.
- Antimony oxide is used as a chemical intermediate for the production of a wide
variety of other antimony compounds, i.e. sodium antimonate, potassium
antimonate, antimony pentoxide, antimony trichloride, tartar emetic, antimony
Fluorescent Light Bulbs
- Antimony oxide is used as a phosphorescent agent in fluorescent light bulbs.
Antimony oxide is added to fluid lubricants to increase stability. It is also
added to molybdenum disulfide to decrease
friction and wear.