JPH09272752A - Stabilized tetrazole foaming agent for resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable tetrazole foaming agent which decomposes completely and is used as a foaming agent for the precision molding of a synthetic resin or for producing a molding having a reduced weight or used as a smoking agent for dispersing a chemical, by converting an azobistetrazole into an amine salt. SOLUTION: A tetrazole derivative which is any of the various amine salts of an azobistetrazole represented by the formula is useful as a foaming or smoking agent for use in, synthetic resin molding. The agent decomposes completely and is highly stable. In the formula, Z is any of various amines including primary monoamines such as monomethylamine, monoethylamine, propylamine, dicyandiamide, guanidine, aminoguanidine, and aminotriazole and primary diamines such as ethylenediamine, hexamethylenediamine, phenylenediamine, xylylenediamine, acetoguanamine, hydrazine, urea, carbohydrazide, thiocarbohydrazide, and N,N'-bis(3aminopropyl)piperazine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a foaming agent for precision molding of a resin or for reducing the weight of a molded article, or as a smoke agent for diffusing a drug. The present invention relates to a tetrazole-based resin foaming agent using an amine salt of azobistetrazole.

[0002]

2. Description of the Related Art Conventionally, crystalline resins naturally undergo crystallization in the cooling process after molding. As a result, it is difficult to obtain a molded product according to the mold due to shrinkage, and these precision moldings have empirically avoided apparent shrinkage by devising the mold. However, complete precision molding is difficult, and some measures have been taken to prevent the shrinkage by physically blowing gas into the core of the molded product (Japanese Patent Publication No. 48-41264, Japanese Patent Publication No. 57-1).
4968), the addition of expensive chemical foaming agents has been proposed (JP-A-50-129563, JP-A-53-1286).
4, JP-A-56-61435, USP. 487186
1). Also generally azodicarbamide (ADCA)
Has been used for a long time and widely for the purpose of molding and foaming a resin. In addition, it is essential that the smoke agent is odorless in terms of harm to humans and animals. However, the smoke agent currently used does not always satisfy these conditions.

[0003]

The above-mentioned (ADCA), which is widely and generally used at present, has a wide decomposition temperature range and is not always sufficiently satisfactory for precision molding or high foaming for weight reduction. . In addition, the decomposed gas or its decomposed residue discharges ammonia, urea and the like, and therefore, it cannot be said that it is friendly to humans or the environment. Further, the decomposed residue stains the mold, which lowers the molding efficiency and the yield. Although tetrazole solves all of the above problems because it completely decomposes, there is a trade-off between complete decomposition and stability, and high physical sensitivity such as friction sensitivity and drop hammer sensitivity makes it unsafe for use. Met. In view of the above, it is an object of the present invention to develop an amine salt of azobistetrazole, which has a large stability and is completely decomposed only by temperature to generate a clean gas as a resin foaming agent or a smoke agent. .

[0004]

In order to achieve the above-mentioned object, the present invention uses azobistetrazole which does not leave a residue when thermally decomposed, and a tetrazole resin foaming agent stabilized with an organic amine. Was successfully developed. That is, the first aspect of the present invention is a stabilization characterized in that an amine salt of azobistetrazole represented by the following chemical formula (1) is used as a gas generating agent which is highly decomposed and highly stable with respect to a synthetic resin. Is a tetrazole resin foaming agent.

[0005]

[Chemical Formula (1)] Here, Z is the following various amines.
That is, monomethylamine, monoethylamine, propylamine, dicyandiamide, guanidine, aminoguanidine, aminotriazole as primary monoamines. 1
Ethylenediamine, hexamethylenediamine, phenylenediamine, xylylenediamine, as primary diamines
Acetoguanamine, hydrazine, urea, carbohydrazide, thiocarbohydrazide, N-N'-bis (3-aminopropyl) piperazine. Melamine as a primary triamine. Pyridine, piperazine and piperidine as secondary monoamines or diamines. The tertiary amines are triethylamine, N, N, N ', N'-tetramethylethylenediamine, hexamethylenetetramine,

Second, the stabilized tetrazole resin foam according to the first aspect of the invention is characterized in that the gas generating agent is used as a smoke agent for foaming a resin molded product or diffusing a drug. It is related to agents.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As a method for synthesizing an organic amine salt of azobistetrazole of the present invention, azobistetrazole
It can be produced by dissolving a salt such as an alkali metal salt of alcohol in water or alcohol, adding an equimolar amount of carbonate or halide of each amine, and stirring. Using the amine salt of azobistetrazole prepared as above, if the metal halide is selected to be water-soluble or alcohol-soluble, the crystals are filtered to easily obtain the amine salt of azobistetrazole. To be The present invention uses the organic amine salt of azobistetrazole thus produced in an amount of 5 to 2% by weight based on the synthetic resin.
First, adjust the master chip by adding the degree, use a test mold, and 200 ~ 300 ℃ depending on the kind of synthetic resin.
A foamed product was manufactured by injection molding at the temperature of.

[0008]

EXAMPLES The present invention will be described with reference to examples, but the present invention is not limited to the examples. The present invention synthesizes amine salts of azobistetrazole according to the following [Synthesis Examples] 1, 2 and 3 to prepare master chips according to the preparation method of master chips, and add them to various synthetic resins. And molded under heating to produce a foam.

[0009]

[Synthesis Example 1] A 500-ml four-necked flask equipped with a stirrer and a thermometer was set in an oil bath, and azobistetrazole soda salt (molecular weight: 210.072) of 33.
02 g (0.157 mol) were charged, followed by 300 ml of water. When the temperature was raised, it was completely dissolved at 40 ° C. With stirring, 25 g (0.157 mol) of chloride of piperazine (molecular weight: 159.06) was added. Crystals precipitated at the same time as the addition, and the reaction solution became slightly yellow. After cooling to room temperature with stirring, suction filtration was carried out using No. 2 filter paper to give a piperazine salt of azobistetrazole (molecular weight: 252.2).
5) was collected by filtration. The yield was 85%. The detonation properties of the soda salt of azobistetrazole were completely eliminated.

[0010]

Synthesis Example 2 As in Example 1, 19.3 g (0.092 mol) of soda salt of azobistetrazole, 25 g of a carbonate of aminoguanidine corresponding to 2 equivalents (molecular weight: 0.1
84 mol) was added to obtain a 2-aminoguanidine salt of azobistetrazole in a yield of 85%. The detonation properties of the soda salt of azobistetrazole were completely eliminated.

[0011]

Synthesis Example 3 As in Example 1, 14.6 g (0.070 mol) of soda salt of azobistetrazole and 25 g of guanidine carbonate corresponding to 2 equivalents (molecular weight: 0.139 mol) were added. As a result, the 2-guanidine salt of azobistetrazole could be obtained in a yield of 98%. The detonation properties of the soda salt of azobistetrazole were completely eliminated. The representative amine salts thus obtained and the results of measuring their decomposition temperature, friction sensitivity and drop hammer sensitivity are shown in the table below.

[0012] As shown above, the amine salt of the present invention has a lower decomposition temperature than the 2-Na salt, complete decomposition is expected, and
Friction sensitivity of a salt is JIS, first grade, drop hammer sensitivity is JIS, 2
On the contrary, all of the amine salts of the present invention have friction sensitivity, JIS, 7th grade, drop hammer sensitivity, JIS, 8th grade and 2-N grade.
It is a tetrazole-based resin foaming agent which has significantly higher stability than the salt a and is stabilized.

[0013]

[Preparation of Master Chip 1] Crystals of the 2-aminoguanidine salt of azobistetrazole obtained in Synthesis Example 2 were pulverized in a mortar and 5% by weight of low density polyethylene (melting point 90 ° C) was impregnated and extruded. Machine temperature 1
It was extruded at 40 ° C. to prepare a master chip having a diameter of 3 mm and a length of 3 mm.

[0014]

[Preparation of master chip 2] The master chip was prepared in the same manner for 2 guanidine salts.

[0015]

[Example 1] Adjustment of the master chip 2% by weight was added to the polypropylene resin to be molded into the master chip prepared by the method 1, and the thickness of 3 mm x width 100 mm x length 100 mm was 4 mm, 5 mm, 6 mm. Injection molding was performed at 220 ° C. using a test mold provided with three types of ribs. The effect was confirmed in comparison with a blank molded product without a foaming agent. The blank product had no commercial value with sink marks on the back of the rib, but the sink product was completely restored in the product of the present invention to which the foaming agent was added.

[0016]

[Example 2] Adjustment of master chip 2% by weight was added to the polypropylene resin from which the master chip prepared in step 2 was to be molded, and the thickness of 3 mm x width 100 mm x length 100 mm was 4 mm, 5 mm, 6 mm. Injection molding was performed at 280 ° C. using a test mold provided with three types of ribs. The effect was confirmed in comparison with a blank molded product without a foaming agent. The blank product had a sink mark on the back of the rib and had no commercial value, but the product of the present invention to which the foaming agent was added had the sink mark completely restored and the skin layer was beautiful.

[0017]

Example 3 Preparation of Master Chip 10% by weight was added to the polypropylene resin to be molded into a master chip prepared by the procedure 1 and molded at 180 ° C. into a sheet having a thickness of 2 mm. Width 200 mm × length 200
Gear cut into 10 mm, prepared in a test mold with a thickness of 10 mm × width of 200 mm and length of 200 mm and set to 220 ° C in advance.
When exposed to an oven for 10 minutes, a beautiful foam having a cell diameter of several tens of microns was obtained.

[0018]

The detonation property of azobistetrazole or soda salt is eliminated, and azodicarbamide (ADCA)
It is possible to avoid the toxicity of decomposition gas and decomposition residue that can be seen in Fig. 3 and has a great stability and complete decomposition, so there is no sink or warp molding with a beautiful skin layer that is not seen in azodicarbonamide etc. in injection molding etc. In addition, the present invention has succeeded in developing a smoke agent having a toxicity lower than ever before.

Embedded image

Claims (2)

[Claims] 1. A stabilized tetrazole characterized by using an amine salt of azobistetrazole represented by the following chemical formula (1) as a gas generating agent which is highly decomposed and highly stable to a synthetic resin. Resin foaming agent. [Chemical Formula (1)] Here, Z is the following various amines.
That is, monomethylamine, monoethylamine, propylamine, dicyandiamide, guanidine, aminoguanidine, aminotriazole as primary monoamines. 1
Ethylenediamine, hexamethylenediamine, phenylenediamine, xylylenediamine, as primary diamines
Acetoguanamine, hydrazine, urea, carbohydrazide, thiocarbohydrazide, N-N'-bis (3-aminopropyl) piperazine. Melamine as a primary triamine. Pyridine, piperazine and piperidine as secondary monoamines or diamines. Triethylamine, N, N, N ', N'-tetramethylethylenediamine and hexamethylenetetramine as tertiary amines. 2. The stabilized tetrazole-based resin foaming agent according to claim 1, wherein the gas generating agent is used as a smoke agent for foaming a resin molded product or diffusing a drug.