JPS5827236B2 - Fireworks composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in compositions for fireworks.

More specifically, the present invention provides a composition for fireworks that has improved performance, which is vital for fireworks, such as ignitability, burning rate, flame brightness, color clarity, and safety.

A fireworks composition basically contains an oxidizing agent, a flame coloring agent, and a binder as main components, and metal powder or the like may be added as necessary.

It is well known that potassium perchlorate or the like is used as the oxidizing agent, and metal salts, oxides, etc. that exhibit a flame reaction are used as the flame coloring agent.

Binders vary depending on the purpose and form of fireworks, but for example, for fireworks, starch-based binders (such as ground starch), which have been used in the past, are still mainly used today.

Nitrocellulose solutions are also used as a binder in some fireworks.

However, such conventional binders use water as a solvent in the manufacturing process, making it time-consuming and labor-intensive to dry, making it difficult to control the burning speed of fireworks, and lacking sufficient impact resistance. , there were several difficulties to be overcome, such as the need for special care in handling and transporting the product.

On the other hand, the development of binder technology in the technical field of explosives and propellants has been remarkable, and polyvinyl, polyester,
Cured polymers such as epoxy resins, polyurethanes, and polysulfides have been proposed, and many of these are actually used as binders.

This is because explosives and propellants containing these polymerized and cured products are highly safe and stable against the effects of friction, impact, vibration, moisture absorption, and the like.

There are various reasons why the synthetic yarn binders used in gunpowder and propellants as described above have not been used in firework compositions to date, but from a performance standpoint, it is difficult to use these synthetic binders in firework compositions. In this case, it is thought that the burning speed of the fireworks becomes smaller, that is, the burning time becomes longer.

Another problem is that the ignitability deteriorates significantly.

The present inventors have studied various types of synthetic binders mentioned above, and have found that in order to maintain the function of the binder, which is to give appropriate hardness and flexibility to fireworks, many synthetic binders cannot be used in compositions for fireworks. It was found that approximately 30φ or more had to be added to the material.

However, fireworks compositions containing such a large amount of binder have poor combustion conditions, resulting in inadequate combustion speed, flame brightness, color clarity, etc. necessary for fireworks.
It's not practical.

However, fireworks compositions obtained by mixing polysulfide liquid prepolymers with oxidizing agents, flame coloring agents, etc. and polymerizing and curing them using curing agents have excellent flammability and require a relatively small amount of binder. It was a small amount.

This is thought to be due to the fact that polysulfide contains sulfur atoms, so it also acts as a combustion aid, and that polysulfide has elasticity after curing, which is a characteristic of polysulfide.

As described above, by using a polymerized cured product of polysulfide as a binder for fireworks compositions, it is possible to obtain fireworks compositions that are far superior to conventional starch-based binders as well as other synthetic binders. found.

Moreover, since cured polysulfide polymers generally have excellent elasticity, the vibration stability of fireworks is significantly improved.

The present invention was completed based on the above findings,
A fireworks composition containing an oxidizing agent, a flame coloring agent, and a binder as main components, characterized in that a cured polysulfide polymer is used as the binder.

As the oxidizing agent and flame coloring agent in the firework composition of the present invention, those conventionally used in firework compositions can be used without limitation.

For example, nitrates, perchlorates, or chlorates are used as oxidizing agents, and flame-coloring agents include salts, oxides, or Alloys are used.

Furthermore, various metal powders can be used if desired.

In the present invention, as the polysulfide-based cured polymer used as a binder, a cured polymer containing sulfur in the main chain is used, preferably a cured polysulfide liquid prepolymer, and more preferably a cured polysulfide prepolymer. A copolymerized cured product obtained by mixing, polymerizing, and curing two components of a polysulfide liquid prepolymer and an epoxy resin is used.

Polysulfide liquid prepolymers are not particularly limited, but are available from Thiokol Co., Ltd. in the United States or Toshi Thiokol Co., Ltd., which are sold with LP numbers such as Thiokol LP-3.
The following products are mentioned as suitable examples.

As the epoxy resin, any ordinary epoxy resin containing an epoxy group can be used without particular limitation.

When polymerizing and curing a mixture of polysulfide liquid polymer and epoxy resin, their mixing ratio is 1.
It is preferable to select an appropriate ratio within the range of 0:1 to 1:10 (weight ratio), and particularly preferably 2:1 to 1:2 (weight ratio).

The amount of the cured polysulfide polymer added is approximately 10 to 20φ (weight ratio) based on the total amount of the composition.

Next, an example of a method for producing the composition of the present invention will be described.

A curing agent is added to a polysulfide liquid prepolymer or, if necessary, an epoxy resin mixed therein.

Various known curing agents can be used, but in consideration of the clarity of color development and the brightness of the flame, organic compounds are preferable.

In particular, when polymerizing and curing a mixed system of polysulfide liquid prepolymer and epoxy resin, it is desirable to use an amine curing agent that generates little reaction heat, especially imidazole or its derivatives (e.g. 2-ethyl-4-methylimidazole). .

This is due to constraints in the production of fireworks, ie, the need to carry out the polymerization and curing reaction at as low a temperature as possible (room temperature to 50° C.) for safety reasons.

The amount of resin with hardener added is about 10 to 2
0φ (weight ratio), add a volatile solvent if necessary for molding, and mold with a molding machine.

Curing to complete the polymerization and curing reactions varies depending on the raw materials used and their quantitative relationship, but is generally carried out at room temperature for one to several days and at 500C for 4 to 8 hours.

The composition for fireworks according to the present invention, that is, the fireworks composition containing as a binder a cured polysulfide polymer, especially a cured copolymer of a liquid polysulfide prepolymer and an epoxy resin, has excellent moldability, such as a cylindrical shape, a plate shape, etc. The product can be reliably molded into shapes that could only be formed insufficiently using conventional techniques, and the product also has excellent strength and flexibility.

The fireworks composition of the present invention will be explained in more detail with reference to Examples below.

EXAMPLE A fireworks composition having the following formulation was manufactured using the general molding method described above.

The numbers in the table represent parts by weight.

The compositions in all Examples showed excellent moldability,
It showed a bright color upon ignition.

Example 1: Red flame, Example 2: Green flame, Example 3: Yellow flame, Example 4: Blue flame, Example 5: Blue flame, Example 6: Yellow flame.

Furthermore, the compositions in all Examples were excellent in ignitability, flammability, brightness of flame, and clarity of color development.

Claims (1)

[Scope of Claims] 1. A fireworks composition containing an oxidizing agent, a flame coloring agent, and a binder as main components, characterized in that a cured polysulfide polymer is used as the binder. 2. The composition for fireworks according to claim 1, wherein the cured polysulfide polymer is a cured copolymer of a polysulfide liquid prepolymer and an epoxy resin. 3. Fireworks according to claim 2, wherein the copolymerized cured product of polysulfide liquid prepolymer and epoxy resin is obtained by using imidazole or a derivative thereof as a polymerization curing agent. Composition.