JPS591959B2 - Method for manufacturing a combustible cylinder for burnout cartridges or burnout tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a combustible cylinder for use in burnout agents or burnout tubes, which has improved water resistance by impregnating it with synthetic rubber latex.

More specifically, a water-based binder is added to a slurry consisting of nitrocellulose and reinforcing fibers (internal addition of the binder) to form a slurry mixture, and the slurry mixture is then processed by suction dehydration molding or centrifugal dehydration molding. A combustible cylinder for burnout cartridges or burnout large tubes, characterized by forming a cylinder and further impregnating the formed cylinder with a binder made of at least synthetic rubber latex (external addition of binder). It concerns the method of manufacturing the body.

Generally, a gun shell consists of a bullet and a cartridge that fires it.

As shown in the cross-sectional explanatory view including a fractured view in FIG. The ignition device 3 consists of a case bottom 22, an ignition device 3, and a propellant (not shown) loaded in the corpus luteum.The ignition device 3 uses, for example, only a detonator 3a for small guns for external use, but for large guns for external use, it uses a point ignited by the detonator 3a. Fire tube 3 filled with gunpowder
b is used by inserting it into the corpus luteum 1.

The thallus of such a cartridge 1. Cap bottom 2. Conventionally, fire tubes 3b and the like have been made of metal.

However, since the cartridge remains in the turret or combat station after the bullet is fired, there are problems in processing the empty cartridge, problems in handling the metal cartridge as a heavy object, and problems in manufacturing economy. .

Therefore, recently, cartridges made of materials that can burn out the shell and fire tube at the same time as the bullet is fired have come into use.

Those used for this purpose are called burnout cartridges and burnout tubes.

The main component of the leaf part of the burnout cartridge or the tube part of the burnout tube is the combustible cylinder as defined in the present invention.

As a method for manufacturing such a combustible cylinder, the present inventors previously completed and filed the invention shown below (Japanese Patent Application No.
No. 124781).

That is, nitrocellulose as a combustible fiber and reinforcing fibers such as kraft valve and cotton linters are mixed and stirred in water to form a slurry, and an anionic synthetic resin emulsion or anionic synthetic resin as a binder is added to the slurry. Add a resin aqueous solution and a cationic synthetic resin aqueous solution or a cationic synthetic resin emulsion (that is, add a binder internally), and further add nitrocellulose stabilizers such as diphenylamine and ethyl centralit as necessary. The water is separated from the slurry mixture by a conventionally known suction dehydration molding method or centrifugal dehydration molding method, and the solid content is formed into a cylindrical shape.Then, after drying the cylindrical body, the cylinder is After the body is immersed in a bath of a binder, which is a water emulsion of vinyl acetate resin, ethylene-vinyl acetate copolymer, etc., to impregnate the body with the binder (i.e., the binder is added externally), the cylinder is re-immersed. This method of manufacturing a combustible cylinder for a burnt-out cartridge case or burnt-out large tube is characterized by drying the body and finishing it.

The combustible cylinder for burnout cartridges or burnout tubes produced by the above manufacturing method has excellent mechanical strength due to the action of the binder, and is made using an easily combustible binder. Therefore, when the outside of the gun is fired, most of the leaf or tube burns as the propellant burns inside the gun, and even if a small amount of combustion residue is generated, it easily escapes outside the gun and disappears. It had the characteristic of causing

However, the combustible cylinder for burnout cartridges or burnout tubes manufactured by the above manufacturing method has room for improvement in terms of water resistance.

That is, when placed in a humid environment, the combustible cylinder absorbs moisture, which tends to reduce mechanical strength and increase the amount of combustion residue.

Therefore, the present inventors conducted intensive research to improve this water resistance, and surprisingly, they found that water resistance could be significantly improved by using at least synthetic rubber latex as an externally added binder. They discovered this and completed the present invention.

That is, in the present invention, nitrocellulose and reinforcing fibers are mixed and stirred in water to form a slurry, a binder is added to the slurry, and a stabilizer is further added as necessary to form a slurry mixture, which is then suctioned. Water is separated from the slurry mixture by dehydration molding or centrifugal molding to form a cylinder, and after drying, the cylinder is further immersed in a binder bath to impregnate the cylinder with binder. In the method of manufacturing a combustible cylinder by drying a cylinder impregnated with a binder, synthetic rubber latex or a mixture of synthetic rubber latex and synthetic resin emulsion may be used as the binder to be impregnated into the cylinder. This is a method for manufacturing a combustible cylinder for a burnt-out cartridge case or a burnt-out large tube.

As for the anionic or cationic synthetic resin emulsion, which is an example of the internally added binder used in the present invention, the main component synthetic resin is, for example, acrylic ester resin, vinyl acetate-acrylic copolymer, styrene. Water emulsions include resins, styrene-butadiene copolymers, styrene-acrylic copolymers, ethylene-vinyl acetate copolymers, modified acrylic resins, synthetic rubber-modified resins, vinyl propionate resins, acrylamide resins, and the like.

Similarly, examples of aqueous solutions of cationic synthetic resins, which are examples of binders for internal addition, include aqueous solutions of polyamide-epichlorohydrin copolymers, polyethyleneimine, modified acrylamide resins, and other examples. Examples of anionic synthetic resin aqueous solutions include acrylamide resin aqueous solutions.

The amount of binder used for internal addition is 5 to 20 parts of the combustible cylinder (based on weight, the same applies hereinafter) as the synthetic resin component.
This is the amount.

In the present invention, the method for forming the cylinder from the slurry mixture is based on the conventionally known suction dehydration molding method or centrifugal dehydration molding method. Using a device consisting of an inner tank, the slurry mixture is placed between the outer tank and the inner tank, and the water in the slurry mixture is dehydrated by suctioning the inside of the inner tank, and the fibrous solids are removed from the inside. It is a method in which a solid layer is formed by adhering to the outer wall of the tank, and the desired cylinder is obtained by removing the solid layer. Using a device, the slurry mixture is placed in the inner tank and the inner tank is rotated at high speed.The water is removed from the porous wall of the inner tank by centrifugal force, and the fibrous solids adhere to the inner wall of the inner tank. In this method, a solid layer is formed, and the desired cylinder is obtained by removing the solid layer.

In the present invention, the formed cylinder is immersed in a binder bath after drying to impregnate the cylinder with binder (external addition of binder). The binder is synthetic rubber latex or a mixture of synthetic rubber latex and synthetic resin emulsion.

Synthetic rubber latexes include those whose main components exhibit so-called rubber elasticity, such as styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, butadiene-styrene-acrylonitrile ternary copolymer latex, butyl rubber. There are latex, glolobrene latex, etc.

Furthermore, as synthetic resin emulsions, there are water emulsions in which the main component synthetic resin is, for example, vinyl acetate resin, ethylene-vinyl acetate copolymer, acrylic ester resin, vinyl acetate-acrylic copolymer, etc. It can be either anionic or nonionic.

The amount of these externally added binders used is such that the amount of impregnated synthetic rubber, or the total amount of synthetic rubber and synthetic resin, is 5 to 20 times the amount of the combustible cylinder.

If the total amount of impregnated synthetic rubber or synthetic rubber and synthetic resin is less than 5 parts of the combustible cylinder, there will be no water resistance effect, and if the total amount of impregnated synthetic rubber or synthetic rubber and synthetic resin is less than 5 parts, there will be no water resistance effect, and the content of the synthetic resin in the binder for internal addition will not be effective. If the total amount exceeds 40 parts of the combustible cylinder, combustibility will deteriorate.

In the present invention, the cylinder impregnated with a binder for external addition is dried and then used as a combustible cylinder, or the cylinder is cut and cut to a predetermined size, or the cylinder is further finished into a desired shape. This is done by press working to make a combustible cylinder.

The effects of the method for manufacturing a combustible cylindrical body according to the present invention as described above are as follows.

(a) Since synthetic rubber latex is used as a binder, the synthetic rubber latex itself has excellent water resistance, so the obtained combustible cylinder has extremely excellent water resistance.

(b) Since the obtained combustible cylinder has excellent water resistance, its mechanical strength such as tensile strength and impact strength is excellent even under high humidity, and it can be used in unexpected situations such as dropping or being handled roughly. It can also withstand

(c) Synthetic rubber latex, synthetic resin aqueous solution, synthetic resin emulsion, etc. using water as a binder are used as a binder, and since they do not contain solvents, they are extremely effective in terms of manufacturing workability, safety, and environmental hygiene. Are better.

Next, the manufacturing method of the present invention and its effects will be specifically explained using Examples and Comparative Examples.

All parts and percentages in each example are based on weight.

Example 1 A mixture consisting of 50 parts of nitrocellulose, 50 parts of Kraft Harz and 900 parts of water was beaten for about 2 hours using a beater, and then mixed and stirred using a stirrer.
33 parts of a polyamide-epichlorohydrin copolymer aqueous solution, which is an aqueous cationic resin solution with a concentration of 20 parts, was gradually added at room temperature, and after stirring for 5 minutes, 50 parts of an acrylic resin aqueous solution, which was an aqueous anionic resin solution with a concentration of 20 parts, was gradually added. Then, 2 parts of finely powdered ethyl centralite was added as a stabilizer and thoroughly stirred to obtain a slurry mixture.

Next, a cylinder was molded from this slurry mixture by a suction dehydration molding method.

After drying this cylinder at 60°C,
It was immersed in a bath of butadiene copolymer latex.

After soaking, dry at 60°C and process this cylinder into specified dimensions.
A combustible cylinder having a molded article composition as shown in Table 1 was obtained.

This combustible cylinder was left in a tank with a relative humidity of 90% for one day, and the amount of water absorbed was measured.

In addition, the combustible cylinders and the combustible cylinders that were not placed in the tank were burned in a combustion tester, and the amount of residual combustion in each was measured to examine the combustibility.

Mechanical strength was measured using sample pieces of the combustible cylindrical body that had been left in the tank at a relative humidity of 90% for one day, and the sample pieces of the combustible cylindrical body that had not been placed in the tank.

The results of these measurements are shown in Table 2.

Example 2 Diphenylamine was used instead of ethyl centralite as a stabilizer, and 10 parts of an acrylic acid ester resin emulsion with a concentration of 40% was used instead of an acrylamide resin aqueous solution as a caking agent for internal addition. A combustible cylinder having a molded article composition as shown in Table 1 was prepared in accordance with Example 1, except that an acrylonitrile-butadiene copolymer latex with a concentration of 4 was used as the agent instead of a styrene-butadiene copolymer latex. Obtained.

The water absorption, mechanical strength, and amount of residual combustion of this combustible cylinder were determined in the same manner as in Example 1, and the results are shown in Table 2.

Example 3 A mixed solution of styrene-butadiene copolymer latex and vinyl acetate resin emulsion (4-fiber concentration) was used instead of styrene-butadiene copolymer latex as a binder for external addition without using a stabilizer. Combustible cylindrical bodies having molded article compositions shown in Table 1 were obtained in accordance with Example 1 except that the following examples were used.

The water absorption, mechanical strength, and amount of residual combustion of this combustible cylinder were determined in the same manner as in Example 1, and the results are shown in Table 2.

Example 4 Except for using acrylonitrile-butadiene copolymer latex with a concentration of 4 instead of a styrene-butadiene copolymer as a binder for external addition, and using a centrifugal dehydration molding method instead of a water absorption dehydration molding method. According to Example 1, a combustible cylinder having a molded article composition as shown in Table 1 was obtained.

The water absorption, mechanical strength, and amount of residual combustion of this combustible cylinder were determined in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 1 A mixture consisting of 50 parts of nitrocellulose, 50 parts of Kraftharz and 900 parts of water was beaten for about 2 hours using a beater, and then mixed and stirred using a stirrer.
17 parts of a polyamide-epichlorohydrin copolymer aqueous solution, which is a cationic resin aqueous solution with a concentration of Then, 2 parts of finely powdered ethyl centralite was added as a stabilizer and thoroughly stirred to obtain a slurry mixture.

Next, a cylinder was molded from this slurry mixture by a suction dehydration molding method.

After drying this cylindrical body at 60° C., the cylindrical body was immersed in a tank containing a vinyl acetate resin emulsion having a concentration of 4 parts.

After immersion, it was dried at 60° C., and the cylinder was processed into predetermined dimensions to obtain a combustible cylinder having a molded article composition as shown in Table 1.

The water absorption amount, mechanical strength, and amount of residual combustion of this combustible cylinder were determined in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2 As a binder for internal addition, 33 parts of polyamide-epichlorohydrin copolymer was used instead of 17 parts, and 10 parts of an acrylic acid ester resin emulsion with 4 different concentrations was used instead of the acrylamide resin aqueous solution, and molding was carried out. A combustible cylindrical body having a molded article composition shown in Table 1 was obtained in accordance with Comparative Example 1, except that the centrifugal dehydration molding method was used instead of the suction dehydration molding method.

The water absorption, mechanical strength, and amount of residual combustion of this combustible cylinder were determined in the same manner as in Example 1, and the results are shown in Table 2.

1. As is clear from the test results of the above Examples and Comparative Examples, the water resistance of the combustible cylinders (Examples 1 to 4) obtained by the manufacturing method of the present invention is As compared to the fusible gun cylinders not impregnated with synthetic rubber latex (Comparative Examples 1 and 2), the amount of water absorbed is about half, and the amount of residual combustion produced is about 1/3.

Further, the rate of decrease in tensile strength due to water absorption is about 30 degrees in the case of the combustible cylinder obtained by the manufacturing method of the present invention, whereas it is twice that in the comparative example, about 60 degrees.

Furthermore, the combustible cylinder obtained by the manufacturing method of the present invention is
Compared to that of the comparative example, its mechanical strength even before water absorption shows that it is a dog.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view including an exploded view showing a general example of a cartridge outside a gun. 1... Leaf body, 2... Cap bottom, 3... Ignition device, 3a
...detonator, 3b...fire tube.

Claims (1)

[Claims] 1 Mix and stir nitrocellulose and reinforcing fibers in water to form a slurry, add a binder to the slurry to form a slurry mixture, and separate water from the slurry mixture by suction dehydration molding or centrifugal dehydration molding. After drying, the cylinder is further immersed in a vat of binder to impregnate the cylinder with binder, and the cylinder impregnated with the binder is dried to form a combustible cylinder. A method for manufacturing a combustible cylinder for burnout cartridges or burnout tubes, characterized in that synthetic rubber latex or a mixture of synthetic rubber latex and synthetic resin emulsion is used as a binder to be impregnated into the cylinder. Manufacturing method.