GB2044748A

GB2044748A - Improvement to Coloured Pyrotechnic Flare Compositions

Info

Publication number: GB2044748A
Application number: GB7909476A
Authority: GB
Original assignee: BROCKS FIREWORKS Ltd
Current assignee: BROCKS FIREWORKS Ltd
Priority date: 1979-03-19
Filing date: 1979-03-19
Publication date: 1980-10-22
Also published as: GB2044748B

Abstract

A coloured pyrotechnic flare composition which comprises a chlorinated resin or a mixture of chlorinated resins as a combined binder and chlorine donor. Preferred chlorinated resins include chlorinated polyester, alkyd and polyether resins, and mixtures thereof. The compositions may further comprise an additional chlorine donor, for example polyvinyl chloride powder.

Description

SPECIFICATION Improvement to Coloured Pyrotechnic Flare Compositions The present invention relates to flare compositions, and more particularly relates to coloured pyrotechnic flare compositions containing a chlorinated resin which acts both as a binder and as a chlorine donor.

Some prior art flare compositions have employed a chlorinated organic compound such as P.V.C. or chlorinated rubber together with a suitable solvent, as a combined chlorine donor/binder. Such compositions have, however, the disadvantage that when a volatile solvent is employed, extending drying time is required to remove the solvent from the compacted mass, and when a non-volatile solvent is employed, the binder in effect never sets due to the solvent remaining within the composition, and maximum mechanical strength cannot be achieved.

Other conventional flare compositions have employed two separate compounds for the two functions, for example, boiled linseed oil or polyester resin as a binder, and P.V.C. powder as a chlorine donor.

The above prior art compositions require considerable pressure for consolidation, and although the pressure required can be decreased by increasing the percentage weight of binder present, the increased amount of binder can impair the efficiency and the colour of the composition. In particular, the colour of green flares may be impaired since too much carbonaceous material imparts a yellow tinge to the flame.

It has now been found that the above disadvantages may be overcome by using a chlorinated resin, such as a chlorinated polyester resin, a chlorinated alkyd resin, a chlorinated polyether resin or mixtures thereof as a combined binder and chlorine donor.

Accordingly the present invention provides a coloured pyrotechnic flare composition which comprises a chlorinated resin or a mixture of chlorinated resins as a combined binder and chlorine donor.

The chlorinated resin is generally present in an amount of from 3 to 16% by weight of the total flare composition, although it is preferable that it is present in an amount of approximately 10% by weight.

The chlorinated resin binders can be used in relatively large amounts in the compositions of the present invention since they contain a relatively smaller amount of carbon and are less likely to impair the colour of the flares. In addition, the chlorine they contain either partially or completely removes the need for any additional chlorinated material. If desired, however, another chlorine donor such as P.V.C. powder, which contains approximately 5/8ths chlorine, may be present in the compositions of the present invention.

The present invention is further illustrated in the following Example.

Example Standard Green Flare Composition Component (% by weight) Magnesium grade 4 42% Potassium perchlorate 27% Barium Nitrate 17% P.V.C. powder 8% Boiled Linseed Oil 6% Compositions of the Present Invention:- (1) (Green) Component (% by weight) Magnesium grade 2, 3 or 4 42% Potassium perchlorate 27% Barium Nitrate 17% P.V.C. powder 4% Chlorinated polyester resin 10% (3) (Green) Component (% by weight) Magnesium grade 3 42% Potassium perchlorate 27% Barium nitrate 17% Chlorinated polyester resin* 14% (4) (Red) Component (% by weight) Magnesium grade 3 42% Potassium perchlorate 14% Strontium nitrate 30% Chlorinated polyester resin 14% *R884O chlorinated polyester resin from B.I.P.

chemicals containing 25% by weight chlorine.

Small quantities of standard accelerator and hardener are mixed with the resin just before use, for example 0.2% by weight, based on the weight of the resin, of a 6% solution of cobalt naphthenate, and 1% by weight, based on the weight of the resin of a 5% solution of methyl ethyl ketone.

The above standard green flare composition contains 5% by weight of chlorine from the P.V.C.

(disregarding chlorine available from the perchlorate).

The composition of the present invention numbered 1 above, also contain 5% by weight chlorine from the chlorinated resin and the P.V.C.

together. Both of the above compositions have similar burning characteristics.

Claims

1. A coloured pyrotechnic flare composition which comprises a chlorinated resin or a mixture of chlorinated resins as a combined binder and chlorine donor.

2. A composition as claimed in claim 1 in which the chlorinated resin or mixture of chlorinated resins is present in an amount of from 3 to 16% by weight of the total flare composition.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvement to Coloured Pyrotechnic Flare Compositions The present invention relates to flare compositions, and more particularly relates to coloured pyrotechnic flare compositions containing a chlorinated resin which acts both as a binder and as a chlorine donor. Some prior art flare compositions have employed a chlorinated organic compound such as P.V.C. or chlorinated rubber together with a suitable solvent, as a combined chlorine donor/binder. Such compositions have, however, the disadvantage that when a volatile solvent is employed, extending drying time is required to remove the solvent from the compacted mass, and when a non-volatile solvent is employed, the binder in effect never sets due to the solvent remaining within the composition, and maximum mechanical strength cannot be achieved. Other conventional flare compositions have employed two separate compounds for the two functions, for example, boiled linseed oil or polyester resin as a binder, and P.V.C. powder as a chlorine donor. The above prior art compositions require considerable pressure for consolidation, and although the pressure required can be decreased by increasing the percentage weight of binder present, the increased amount of binder can impair the efficiency and the colour of the composition. In particular, the colour of green flares may be impaired since too much carbonaceous material imparts a yellow tinge to the flame. It has now been found that the above disadvantages may be overcome by using a chlorinated resin, such as a chlorinated polyester resin, a chlorinated alkyd resin, a chlorinated polyether resin or mixtures thereof as a combined binder and chlorine donor. Accordingly the present invention provides a coloured pyrotechnic flare composition which comprises a chlorinated resin or a mixture of chlorinated resins as a combined binder and chlorine donor. The chlorinated resin is generally present in an amount of from 3 to 16% by weight of the total flare composition, although it is preferable that it is present in an amount of approximately 10% by weight. The chlorinated resin binders can be used in relatively large amounts in the compositions of the present invention since they contain a relatively smaller amount of carbon and are less likely to impair the colour of the flares. In addition, the chlorine they contain either partially or completely removes the need for any additional chlorinated material. If desired, however, another chlorine donor such as P.V.C. powder, which contains approximately 5/8ths chlorine, may be present in the compositions of the present invention. The present invention is further illustrated in the following Example. Example Standard Green Flare Composition Component (% by weight) Magnesium grade 4 42% Potassium perchlorate 27% Barium Nitrate 17% P.V.C. powder 8% Boiled Linseed Oil 6% Compositions of the Present Invention:- (1) (Green) Component (% by weight) Magnesium grade 2, 3 or 4 42% Potassium perchlorate 27% Barium Nitrate 17% P.V.C. powder 4% Chlorinated polyester resin 10% (3) (Green) Component (% by weight) Magnesium grade 3 42% Potassium perchlorate 27% Barium nitrate 17% Chlorinated polyester resin* 14% (4) (Red) Component (% by weight) Magnesium grade 3 42% Potassium perchlorate 14% Strontium nitrate 30% Chlorinated polyester resin 14% *R884O chlorinated polyester resin from B.I.P. chemicals containing 25% by weight chlorine. Small quantities of standard accelerator and hardener are mixed with the resin just before use, for example 0.2% by weight, based on the weight of the resin, of a 6% solution of cobalt naphthenate, and 1% by weight, based on the weight of the resin of a 5% solution of methyl ethyl ketone. The above standard green flare composition contains 5% by weight of chlorine from the P.V.C. (disregarding chlorine available from the perchlorate). The composition of the present invention numbered 1 above, also contain 5% by weight chlorine from the chlorinated resin and the P.V.C. together. Both of the above compositions have similar burning characteristics. Claims

3. A composition as claimed in claim 2 in which the chlorinated resin or mixture of chlorinated resins is present in an amount of approximately 10% by weight.

4. A composition as claimed in any of claims 1 to 3 in which the chlorinated resin is a chlorinated polyester resin, a chlorinated alkyd resin, a chlorinated polyether resin or a mixture thereof.

5. A composition as claimed in any of claims 1 to 4 which further comprises an additional chlorine donor.

6. A composition as claimed in claim 5 in which the additional chlorine donor is polyvinyl chloride powder.

7. A coloured pyrotechnic flare composition substantially as herein described with reference to the Example.