what chemicals are found at the tip of a match head that cause it to ignite?

ellenbon,

The following is an excerpt from http://www.pitara.com/discover/5wh/26.htm:

What do present day matches contain? Red phosphorus is the main
substance used in the match industry. Matches are of two types:
Lucifer or friction matches and Safety matches.Lucifer or friction
matches light when rubbed against any rough surface. The match is
basically a wood splint slightly longer than a normal matchstick. The
tips are of two colours - red and white or blue and white.

The tip of the wooden strip is first dipped in molten sulphur or
paraffin wax. The small white tip is made from the paste of phosphorus
trisulphide. The red tip is made of various chemicals and substances -
antimony trisulphide (to act as kindling material), potassium chlorate
(to support combustion), glass or silica powder (to cause friction)
and gum (to act as binder).

Lucifer matches can be struck against any hard surface that provides
friction. When the stick is rubbed, the white tipped portion first
ignites the match and when the tip has caught fire the red or blue
part of the tip burns and carries the flame up the rest of the
matchstick.

In the case of safety matches they can only be ignited by striking
them against a special surface usually located on the match box. In
addition red phosphorous is used to ignite the matchstick instead of
phosphorous trisulphide.

Because of the fact that they easily burst into flames, Lucifer
matches are no longer in general use. However, they are very popular
in Westerns where cowboys are seen lighting the match on their boots,
on the seat of the pants and even lighting it from their nails!

The link is: http://www.pitara.com/discover/5wh/26.htm

ellenbon,
        Here is some useful information I found for you on a web site
called "The Naked Scientist", this is an excerpt from a post found
there.

Here is the post location.

http://www.thenakedscientists.com/forum/topic.asp?whichpage=8&TOPIC_ID=350&#16228


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Matches were invented by the English apothecary John Walker in 1826-7
when he made a mixture of antimony sulphide and potassium chlorate for
a client. He accidentally dropped some of the mixture which, upon
impact, promptly ignited. Adding a stick and refining the recipe he
produced the world's first friction matches, containing antimony
sulfide, potassium chlorate, gum, and starch.

Walker was not an astute businessman and made no money from his
invention. Indeed, it was another individual - Samuel Jones - who was
already into matchmaking - who realised the huge commercial potential
of a readily available source of fire and patented the invention under
his own name. His brand of matches, based on the same recipe, were
called Lucifers and were a runaway success.

But the problem with Walker and Jones's matches was that they were not
terribly safe - they ignited in an explosive manner, produced a
terrible smell when lit, and were poisonous ! They were, however, a
runaway success and sales rocketed (pardon the pun).

Then, in 1832, Richard Bell established the first British match
factory in London. He began producing a new phosphorus-containing
match that had been invented by Frenchman Charles Sauria. The match
head contained a mixture of sulphur, potassium chlorate, antimony
sulphide, and white phosphorus. The addition of phosphorus made
striking the match much easier to accomplish, but had the downside of
poisoning people. The workers in the match factory developed
phossy-jaw (an erosive disease of the lower jaw caused by long term
exposure to white phosphorus), and children developed other bony
abnormalities. A match box also contained enough white phosphorous to
kill someone, and the matches kept setting fire to things they
shouldn't - largely because all the chemicals needed for ignition were
jammed together into the match head and all that was needed to
kick-start the reaction was some energy.

This problem was solved in 1844 when the Swedish chemist Gustav Pasch
began separating the chemicals in a match head, placing some on the
side of the matchbox, and the rest on the match head. The match could
then only be struck against the side of the box - and that's the
safety match. Another safety measure, which came later, was the
subsitution of the less reactive red phosphorus for its more violent
white counterpart.

The present day recipe for a match comprises a wooden or cardboard
splint impregnated with ammonium phosphate (to stop it smouldering
after being blown out), coated on the end with a mixture of gum,
potassium chlorate, glass powder (to create the friction on striking),
and sulphur.

The sulphur is the fuel which consumes the oxygen released by the
potassium chlorate. The red phosphorus on the matchbox kickstarts the
reaction rather than being used as a fuel (as in the early match
recipes).

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I hope that helps