KR20120101322A

KR20120101322A - Gas-generating agent

Info

Publication number: KR20120101322A
Application number: KR1020127001460A
Authority: KR
Inventors: 노리카즈 마야마
Original assignee: 미츠비시 가스 가가쿠 가부시키가이샤; 에이와 가세이 고교 가부시키가이샤
Priority date: 2009-06-19
Filing date: 2010-06-11
Publication date: 2012-09-13
Also published as: CN102803424A; KR101768431B1; DE112010002570A5; WO2010147067A1; JP5647606B2; CN102803424B; JPWO2010147067A1

Abstract

Gas generation obtained by combining (A) nitrogen-containing compounds (compounds having urea bonds such as urea and hydrazodicarbonamide, etc.) that produce ammonia gas by heating, (B) nitrite and (C) hydrotalcite By mixing the agent with a synthetic resin material or a rubber material to form a foaming composition, and heating and molding the foam to form a foam, nitrogen gas can be generated while suppressing generation of ammonia or nitrite gas, thus having uniform and fine bubbles. High magnification foams with high whiteness can be obtained.

Description

Gas-generating agent

TECHNICAL FIELD This invention relates to the gas generating agent used for manufacture of foams, such as a thermoplastic resin and rubber | gum.

Chemical foaming agents, such as azodicarbonamide (ADCA), and foaming aids, such as urea, are used for manufacture of foams, such as a thermoplastic resin and rubber | gum. In addition, azodicarbonamide is known to produce cyanuric acid, biurea (hydrazodicarbonamide), urea and the like as a decomposition residue during thermal decomposition. Moreover, when heating temperature is 220 degreeC or more, it is known that a part of biurea decomposes and produces ammonia (refer nonpatent literature 1-3).

Urea compounds generate ammonia by heating, but ammonia gas does not contribute to the expansion ratio, and in order to produce high magnification foams, it is necessary to increase the amount of blowing agent added. It becomes necessary.

In order to increase the amount of gas generated by the chemical blowing agent, a method of adding molybdenum and molybdate compounds to the blowing agent (see Patent Document 1), or a method of supporting fatty acid alkaline earth metal salts and quaternary ammonium salts (see Patent Document 2) is known. In such a method, biurea (hydrazodicarbonamide) or ammonia produced at the time of pyrolysis cannot be used as nitrogen gas, and it is difficult to suppress odor. In addition, Patent Document 3 discloses a method of decomposing and removing organic nitrogen by adding nitrite to water containing organic nitrogen, but is not applicable to the foam production field by the decomposition treatment of organic nitrogen in an aqueous solution.

Japanese Laid-Open Patent Publication No. 2001-139928 Japanese Laid-Open Patent Publication No. 2000-336337 Japanese Patent Application Laid-Open No. 9-122690

Handbook, Rubber-Plastic Compounding Chemicals, p.266 to 267, issued March 30, 1989, Rubber Digest Co., Ltd. Waki Kunio Yamatata Tadaka, "Pyrolysis of Azodicarbonamide," Journal of the Japanese Chemical Society, 1972, p. 2359 to 2364 (Non-Patent Literature 3) Waki Kunio, Mitsuki Haraguchi, and Yamashita Tadaka, “Pyrolysis of Hydrazodicarbonamide,” Japanese Chemical Society, 1974, p. 1668-1672

An object of the present invention is to produce a foam, such as a resin material or rubber, by using a compound that generates ammonia gas by heating, thereby suppressing the generation of ammonia and nitrite gas and generating nitrogen gas, thereby producing uniform and fine bubbles. It is to provide a gas generating agent which can have a high magnification foam with a high magnification.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining about the said subject, it turned out that the said subject can be solved by using nitrite and hydrotalcite.

That is, this invention relates to the gas generating agent shown below.

(1) A gas generating agent for use in producing a foam, comprising (A) a nitrogen-containing compound that generates ammonia gas by pyrolysis, (B) nitrite, and (C) hydrotalcite. Generator.

(2) The gas generator according to (1), wherein the nitrogen-containing compound (A) is a compound having urea bonds.

(3) 0.5-95 weight% of nitrogen-containing compound (A) with respect to the total whole quantity of nitrogen-containing compound (A), nitrite (B), and hydrotalcite (C) in (1) or (2), A gas generator, characterized by containing 0.5 to 60% by weight of nitrite (B) and 1 to 40% by weight of hydrotalcite (C).

(4) The gas generator according to any one of (1) to (3), wherein the nitrite (B) is at least one member selected from the group consisting of sodium nitrite, potassium nitrite and barium nitrite.

(5) The gas generator according to any one of (1) to (4), wherein the hydrotalcite (C) is represented by the following general formula (1).

In Formula 1,

And M ⁺ ² is a divalent metal ion of a metal selected from the group consisting of Mg, Mn, Fe and Zn,

M ⁺ ³ is the metal 3 is selected from the group consisting of Al, Fe and Cr metal ion,

A ⁿ ^- is an n-valent anion of a group selected from the group consisting of OH, F, Cl, Br, NO ₃ , CO ₃ and SO ₄ ,

x is in the range of 0 <x≤0.33,

n is an integer,

m is zero or more.

According to (6) (5), M 2 + in the formula 1 is a Mg ⁺ ^2, M ³ ⁺ is Al ³ ⁺ a, gas is generated.

(7) The composition for foaming which mix | blends the gas generating agent in any one of (1)-(6) with a to-be-foamed material.

(8) The foaming composition according to (7), wherein the material to be foamed is a synthetic resin material or a rubber material.

(9) A method for producing a foam, comprising the step of heating the foaming composition according to (7) or (8).

According to the present invention, in the foam molding temperature range of the synthetic resin material or rubber material, it is possible to suppress the generation of ammonia or nitrite gas and to generate nitrogen gas, and to obtain a foam having uniform and fine bubbles and high whiteness at high magnification. Can be. In addition, the urea compound normally used as a foaming aid, such as urea, can be used as a foaming agent, such as a synthetic resin material or a rubber material, and when it is used as a foaming aid of a chemical foaming agent, the adjustment function of the decomposition temperature of a chemical foaming agent is used. While holding, in addition to the generation of chemical blowing agent gas, the amount of generated gas can be increased by the blowing aid generating nitrogen gas. As a result, when manufacturing a foam of thermoplastic resin or rubber, it is possible to produce a foam of high magnification without increasing the chemical blowing agent, and in order to suppress ammonia, the ammonia odor countermeasure at the manufacturing site is also unnecessary. Very advantageous.

Further, in the present invention, high magnification can be achieved without requiring odor countermeasure because ammonia generated in pyrolysis of the nitrogen-containing compound is reacted with nitrous acid to be replaced with nitrogen gas as a foaming gas. It is considered that the use of the site increases the reactivity of nitrous acid to ammonia and suppresses the generation of nitrous acid gas. In addition, the whiteness is improved, according to the method of using the nitrous acid and hydrotalcite of the present invention, such as azodicarbonamide, such as azodicarbonamide, the foaming agent is yellowish after decomposition (degradation problem when the thermal decomposition is insufficient). Occurrence) is thought to be due to the fact that the thermal decomposition is accelerated and the afterimage disappears.

The gas generating agent of this invention contains a nitrogen containing compound (A), nitrite (B), and hydrotalcite (C), It is characterized by the above-mentioned.

The nitrogen-containing compound (A) of this invention produces | generates ammonia gas by thermal decomposition. Here, as generating the ammonia gas by pyrolysis, even if the main component of the gas generated by the pyrolysis is ammonia gas, the main component of the gas generated by the pyrolysis is gas other than ammonia gas such as nitrogen gas, In addition, a small amount of ammonia gas may be produced by-product.

As the nitrogen-containing compound (A), urea bonds such as urea, hydrazodicarbonamide (hereinafter may be referred to as HDCA), biuret, urazol (for example, -NHCONH ₂ , -NRCONH ₂ , -NHCONHR, -NRCONHR and the like; wherein R is an organic group, azodicarbonamide (hereinafter sometimes referred to as ADCA), guanidines, 4,4'-oxybis (benzenesulfonylhydrazide) ( Hereinafter, OBSH may be called), N, N'-dinitrosopentamethylenetetramine (hereinafter may be called DNPT), and p-toluenesulfonylhydrazide (hereinafter, may be called TSH). ), 2,2'- azoisobutyronitrile (hereinafter may be referred to as AIBN), and the like.

In the present invention, one type of these may be used alone, or two or more types may be used in combination. Among these, the compound which has a urea bond is preferable, and urea and HDCA can be used suitably. Moreover, as urea, you may use the fine powder urea which the hygroscopicity improved by surface treatment agents, such as a commercially available fine powder urea, a fatty acid, a fatty acid metal salt, a fatty acid ester, and a silane coupling agent.

Here, "pyrolysis" in the nitrogen-containing compound (A) of the present invention means heating when kneading the foam production raw material containing the nitrogen-containing compound (A), and heating when the kneaded product is foamed ( For example, when using a press die for foaming, pyrolysis by heating in the press die) or the like can be exemplified. For example, as heating temperature at the time of foam manufacture, it is about 130-250 degreeC.

Examples of the nitrite (B) used in the present invention include sodium nitrite, potassium nitrite, calcium nitrite, and the like. One of them may be used alone or in combination of two or more thereof. In addition, these nitrites are preferably ground fine powder.

Hydrotalcite (C) used for this invention is a crystalline composite metal hydroxide, The hydrotalcite represented by following General formula (1) is preferable.

Formula 1

In Formula 1,

M ³ ⁺ is a metal of the 3 selected from the group consisting of Al, Fe and Cr metal ion,

x is in the range of 0 <x≤0.33,

n is an integer,

m is zero or more.

Here, m is preferably 0, but fluctuates depending on the dry state or storage state of the hydrotalcite, and m is not particularly limited as long as it does not impair the effects of the present invention. n is a valence of an anion, Preferably it is 1 or 2, More preferably, it is 2.

Among these, M is Mg ⁺ ² and ² ^+, M ³ ⁺ is Al ⁺ ³ of hydrotalcite is preferable, Al: Mg molar ratio of the two in the ease of retrieving: 5 to 2:10 is preferred. For example, when the molar ratio of Al: Mg is 2: 5, the mole fraction x of Al (x = Al / (Mg + Al)) is 0.29, and the molar ratio of Al and Mg is 2:10. The mole fraction x of Al is 0.17.

The hydrotalcite of this invention has the effect | action which improves the reactivity of nitrite. By blending hydrotalcite, the decomposition of ammonia produced when the nitrogen-containing compound (A) is thermally decomposed, and the reactivity of the nitrite is suppressed to suppress the generation of nitrite gas, promote the production of nitrogen gas, and improve the foamability. You can. Although the particle diameter of the hydrotalcite of this invention is not specifically limited, In order to make it effective to react with nitrogen-containing compound (A) and nitrite, it is preferable to improve dispersibility in a gas generating agent, and the maximum particle diameter is 80 Preference is given to finely divided hydrotalcites of up to micrometers.

The gas generating agent of this invention contains nitrogen containing compound (A), nitrite (B), and hydrotalcite (C) which generate | occur | produce a gas by pyrolysis and generate | generate ammonia gas.

About the ratio of each component in the gas generating agent of this invention, the compounding quantity with respect to the nitrogen-containing compound (A) of the said nitrite (B) and hydrotalcite (C), for example depends on the amount of ammonia gas which generate | occur | produces In addition, since the amount of ammonia gas to be generated varies greatly depending on the type of the nitrogen-containing compound (A) to be used, the amount of ammonia gas to be generated cannot be limited collectively.

However, when the sum total of the said nitrogen-containing compound (A), nitrite (B), and hydrotalcite (C) is 100 weight%, nitrogen-containing compound (A) becomes like this. Preferably it is 0.5 to 95 weight%.

In addition, although the compounding quantity of a nitrite (B) changes with the amount of ammonia gas which generate | occur | produces, Preferably it is 0.5 to 60 weight%. Although the compounding quantity of hydrotalcite (C) changes also with the amount of ammonia gas which generate | occur | produces, Preferably it is 1-40 weight%.

When there are too few nitrogen containing compounds (A), nitrous acid gas may leak. When there is too little nitrite (B), ammonia gas may leak.

In addition, as a component other than (A), (B), and (C) in the gas generating agent of this invention, if it does not impair the effect of this invention, it will not be limited, The compounding quantity is also not limited. Specific examples of the constituents other than (A), (B) and (C) include salts of fatty acids such as stearic acid or fatty acids such as calcium stearate.

Although the gas generating agent of this invention can be used when manufacturing foams, such as various synthetic resin materials and rubber | gum materials, a suitable foam can be obtained, but the gas generator of this invention is mix | blended with the conventional thermal decomposition type chemical foaming agent, and a composite gas is produced. It can also be used as a generator.

As a thermal decomposition type chemical blowing agent which can be used in a composite gas generating agent, the general chemical blowing agent which produces | generates nitrogen gas or a carbon dioxide gas by thermal decomposition is mentioned, For example, azodicarbonamide, 4,4'-oxybis ( Benzenesulfonylhydrazide), chemical blowing agents such as N, N'-dinitrosopentamethylenetetramine, 5-phenyl-1,2,3,4-tetrazole, and organic acids such as monosodium citrate and sodium tartarate Inorganic chemical blowing agents such as organic chemical blowing agents of metal salts and sodium hydrogencarbonate. You may use these individually by 1 type or in combination of 2 or more types.

The blending ratio of the gas generating agent of the present invention and the thermally decomposable chemical blowing agent in the composite gas generating agent is not particularly limited, but preferably [the gas generating agent of the present invention]: [pyrolysis type chemical blowing agent] = 5 to 95: 95 to 5 (weight ratio).

In addition, when the gas generator of the present invention is used in combination with a pyrolytic chemical blowing agent, the pyrolysis chemical blowing agent first generates a decomposition foaming gas according to the increase in the heating temperature, and then the gas generator of the present invention generates nitrogen gas ( Or vice versa), by selecting and combining gas generating agents having different gas generating temperatures, a two-stage decomposition type blowing agent can be obtained. By using such a two-stage decomposition type foaming agent, it becomes possible to manufacture the characteristic foam which has a high foaming ratio.

The manufacturing method of the gas generating agent of this invention is not specifically limited, A general mixing method can be used. For example, a nitrogen-containing compound (A), nitrite (B) and hydrotalcite (C) are uniformly subjected to a temperature of 60 ° C. or less and a time of about 5 minutes using a high speed mixer, ribbon blender, corn blender or the like. Mix so that it is dispersed.

The manufacturing method of the composite gas generating agent of this invention is not specifically limited, A general mixing method can be used. When manufacturing the gas generating agent of this invention, you may mix a thermal decomposition type chemical blowing agent together, and after manufacturing the gas generating agent of this invention, you may mix a thermal decomposition type chemical blowing agent. In the mixing of the composite gas generating agent, for example, a high-speed mixer, a ribbon blender, a cone blender, or the like may be mixed so as to be uniformly dispersed under a condition of about 60 ° C. or less for about 5 minutes.

The gas generating agent or composite gas generating agent of this invention can be used suitably for foam molding of a synthetic resin material or a rubber material. The gas generator or the composite gas generator of the present invention can suppress the generation of ammonia or nitrite gas and generate nitrogen gas at a foam molding temperature (for example, about 130 to 250 ° C) of a synthetic resin material or a rubber material. In this regard, it is possible to obtain a foam having uniform and fine bubbles and high whiteness at high magnification.

The composition for foaming of this invention mix | blends the gas generating agent of above-mentioned this invention with the to-be-foamed material. Examples of the material to be foamed include a synthetic resin material or a rubber material.

As a synthetic resin material of this invention, the polyolefin copolymer resin, the polystyrene resin, the acrylonitrile- butadiene-styrene copolymer illustrated by vinyl chloride resin, a vinyl chloride copolymer resin, polyethylene, a polypropylene, an ethylene-propylene copolymer, for example Although (ABS resin) etc. are mentioned, It is not limited to these.

As a method for producing a foam by blending the gas generator or the composite gas generator of the present invention with a synthetic resin material, a general method for producing a foam can be used. For example, the synthetic resin material, the crosslinking agent, and the gas generator or composite gas generator of the present invention can be kneaded with a heated kneading roll to prepare a foaming composition (unfoamed resin composition). The kneading temperature is preferably 90 to 130 ° C.

The non-foamed resin composition thus obtained is filled into a mold and pressurized with a press to obtain a foam of a synthetic resin material. The metal mold | die thickness, pressurization conditions, etc. are not restrict | limited, The conventionally well-known foam molding method can be employ | adopted suitably according to the kind of a synthetic resin, a use, etc .. For example, 100% filling is carried out in the mold of thickness 5-30 mm, and it pressurizes for 5 to 60 minutes on the conditions of 145-170 degreeC, and 150 kg / cm <2> with a press machine, and the foam of a resin composition is obtained.

Although the compounding ratio of each component in a foaming composition is not restrict | limited, Preferably, a crosslinking agent is 0.1-10 weight part, More preferably, 0.5-1.5 weight part is mix | blended with respect to 100 weight part of synthetic resin materials. If the blending ratio of the crosslinking agent is too small, the crosslinking under will occur, and foaming shortage due to gas leakage may occur. If the amount of the crosslinking agent is excessively large, the crosslinking over may occur, resulting in cracks or bubble roughness in the foam.

Although the usage-amount of the gas generating agent of this invention can be suitably selected according to the objective expansion ratio, although it does not have a restriction | limiting in particular, Preferably 1-7 weight part is mix | blended with respect to 100 weight part of synthetic resin materials.

When using the composite gas generating agent containing the gas generating agent of this invention, although the usage-amount of a composite gas generating agent can be suitably selected according to the objective expansion ratio, there is no restriction | limiting in particular, Preferably it is 100 weight of synthetic resin materials 1-7 weight part with respect to a part.

Since the nitrogen-containing compound (A) contained in the gas generator of this invention uses what has conventionally been used as a foaming aid of a chemical foaming agent, also in the composite gas generator containing the gas generator of this invention, The decomposition temperature adjustment function with respect to the chemical foaming agent as foaming aid is maintained.

On the other hand, although the urea-based foaming aid has not contributed to foaming even if ammonia is generated by thermal decomposition, the gas generating agent of the present invention can contribute to foaming by generating nitrogen gas by combining nitrite and hydrotalcite. Therefore, in addition to the foaming gas derived from a chemical blowing agent, the nitrogen gas derived from a foaming aid can also be made into foaming gas, and it becomes possible to increase the generated gas by the same chemical blowing agent use amount. In other words, a foam having the same expansion ratio can be produced with a smaller amount of chemical blowing agent than before.

Thus, combining the gas generating agent of this invention with the conventional chemical foaming agent can exhibit the improvement effect of foaming magnification, demonstrating the decomposition temperature adjustment function of a chemical foaming agent.

The ratio of the gas generating agent of this invention in the said composite gas generating agent is not specifically limited, It can select suitably according to the objective foaming ratio. For example, it can use according to the ratio of foaming aid with respect to the chemical blowing agent in the case of combining a conventional chemical blowing agent and a foaming adjuvant.

As the crosslinking agent, for example, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, 2,5-dimethyl-2,5 -Di (t-butylperoxy) hexyn-3, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclo Hexane, n-butyl-4,4-bis (t-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butylperoxybenzoate, t -Butyl perbenzoate, t-butyl peroxy isopropyl carbonate, diacetyl peroxide, lauroyl peroxide, t-butyl cumyl peroxide, etc. can be used.

As the rubber material of the present invention, natural rubber (NR), polyisoprene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, butadiene rubber, etc. Although these are mentioned, It is not limited to these.

As a method of preparing the foaming composition by blending the gas generating agent or the composite gas generating agent of the present invention with a rubber material, thereby producing a foam, general production conditions for the foam can be used. For example, the rubber material, the vulcanizing agent, the filler, the vulcanizing accelerator, and the gas generator or the composite gas generator of the present invention are uniformly dispersed with a kneading roll to obtain a foaming composition. The obtained foaming composition is introduced into an extruder heated at about 70 to 90 ° C to prepare an unvulcanized molded body. The obtained unvulcanized molded body is heated in an oven heated at about 60 to 220 ° C. for about 5 to 15 minutes to vulcanize and foam to obtain a foam of rubber material.

Although the compounding ratio of each component in a foaming composition is not restrict | limited, Preferably, a vulcanizing agent is mix | blended with 0.1-10 weight part with respect to 100 weight part of rubber materials. The filler is preferably blended from 10 to 150 parts by weight with respect to 100 parts by weight of the rubber material. The vulcanization accelerator is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the rubber material.

Although the usage-amount of the gas generating agent of this invention can be suitably selected according to the objective foaming ratio, there is no restriction | limiting in particular, Preferably 1-20 weight part is mix | blended with respect to 100 weight part of rubber materials. When using the composite gas generator containing the gas generator of this invention, the usage-amount of a composite gas generator can be suitably selected according to the objective expansion ratio, Although it does not have a restriction | limiting in particular, Preferably 100 weight part of rubber materials It is 1-20 weight part with respect to.

Sulfur is mentioned as a specific example of the vulcanizing agent used by this invention.

Specific examples of the filler used in the present invention include heavy and hard calcium carbonate.

Specific examples of the vulcanization accelerator used in the present invention include DM (dibenzylthiazole-disulfide).

The gas generating agent of this invention is economical because it is possible to manufacture the foam of the same magnification with the addition amount less than a conventional product. At the same time, ammonia odors generated from chemical blowing agents and urea compounds, and by-products such as urea compounds and biurea (hydrazodicarbonamide) are nitrogen gas, so that the problem of adhesion failure or fogging of resin foams caused by urea compounds You can also improve fogging problems.

Example

Although an Example and a comparative example are given to the following and this invention is demonstrated more concretely, this invention is not limited to this Example. In the examples and comparative examples shown below, evaluation of the amount of generated gas, the amount of nitrous acid generated, the amount of ammonia generated, the specific gravity of the foam, and the bubble state of the foam was carried out by the following methods, respectively.

1 g of a gas generator or a composite gas generator is added to a test tube, and 10 ml of liquid paraffin is added as a heat medium, and the test tube is connected to a test tube, a sodium hydroxide aqueous solution bottle, a boric acid aqueous solution bottle, and a gas burette in order. It was immersed in the oil bath. The oil bath was then heated to 220 ° C. at a rate of temperature rise of 2 ° C./min. The gas generated during heating was collected by the gas burette, and the amount of generated gas was determined.

The gas generated at the time of pyrolysis was absorbed into an absorption bottle containing 400 ml of 1N sodium hydroxide aqueous solution, and then the amount of nitrous acid gas generated in the absorbent liquid was measured according to JIS-K0102 (naphthylethylenediamine absorbance photometric method).

After absorbing the gas passing through the absorption bottle containing the aqueous sodium hydroxide solution into the absorption bottle containing 400 ml of 0.5 N boric acid aqueous solution, the amount of ammonia generated in the absorption liquid was measured according to JIS-K0102 (Indophenol Blue Absorption Spectrophotometry).

The specific gravity of the foam of the resin composition and the rubber composition was determined by an electronic hydrometer (manufactured by Alpha Mirage, product name MD-200S).

SEM (Keyence Corporation make, VE-7800) was used for evaluation of the bubble state of a resin composition and a rubber composition. The foamed molded article was sliced in parallel in the thickness direction, and the slice cross section was observed by SEM to observe the bubble state and bubble diameter.

Measuring instrument: Cul fischer moisture meter MKC-210 made in Kyoto Denshi

&Lt; Example 1 >

60 g (1 mol) of urea (Mitsugagaku Co., Ltd. industrial urea), 69 g of sodium nitrite (1 mol) (manufactured by Nissan Chemical Co., Ltd., sodium nitrite (wet phase)), hydrotalcite ([Mg ²⁺ _0.83 Al ³⁺ _{^{0.17 (OH) 2] 0.17+ [}} (CO 3) 2- 0.17 / 2 0.33H 2 0] 0.17-, Al:? Mg molar ratio = 2: a 10) 6g, at room temperature, using a polyethylene bag 5 minutes After mixing, the mixture was ground to a 150 mesh pass (using JIS8801 sieve) using a ball mill to obtain a gas generating agent.

The amount of generated gas was measured using 1 g of the obtained gas generator. At the time of measuring the amount of generated gas, gas generation was confirmed from 120 ° C, gas was suddenly generated at 155 ° C, and sudden gas generation was terminated at 158 ° C, but gentle gas generation was confirmed up to 180 ° C, and then to 220 ° C. Gas generation was not confirmed. Table 1 shows the measurement results of the amount of generated gas, the amount of nitrous acid gas and the amount of ammonia generated.

Next, 100 parts by weight of an ethylene-vinyl acetate copolymer (EVA) (trade name "Ultrasen 630" manufactured by Tosoh Corporation) was kneaded with a mixing roll heated to 90 to 100 ° C, and then 5 parts by weight of the gas generator was added thereto. The mixture was kneaded for 5 minutes, then 0.8 parts by weight of dicumyl peroxide (DCP) was added to knead for 3 minutes, and the mixture was taken out from the mixing roll. The kneaded material was thrown in so that the internal volume of the metal mold | die (200 mm x 200 mm x 10 mm) of the press apparatus heated to 160 degreeC could be 100% filled, and it pressurized for 10 minutes by 150 Kg / cm <2> of press pressures. After 10 minutes the press pressure was opened to normal pressure at once to obtain a foam. The compounding quantity and evaluation result of the obtained foam were shown in Table 2.

&Lt; Comparative Example 1 &

Except having changed the hydrotalcite into the zeolite deodorant (Zeoram A-4 by Toso Corporation), the amount of gas generated, the amount of nitrous acid gas produced, and the amount of ammonia produced were measured like Example 1, and the foam was manufactured. The compounding quantity and evaluation result of a gas generating agent are shown in Table 1, and the compounding quantity and evaluation result of a foam are shown in Table 2. The obtained foam was colored in light yellow and had a low degree of crosslinking, so the foam adhered to the mold and could not be taken out.

60 g (1 mol) urea (Mitsugagaku Co., Ltd. industrial urea), sodium nitrite (Nissan Gakuku Co., sodium nitrite (wet phase)) 69 g (1 mol), hydrotalcite ([Mg ²⁺ _0.71 Al ³⁺ _{^{0.29 (OH) 2] 0.29+ [}} (CO 3) 2- 0.29 / 2 0.57H 2 0] 0.29-, Al: Mg molar ratio of = 2: 5) 18g, calcium stearate (from Nippon oil suggest production, calcium stearate 6g) was mixed at room temperature for 5 minutes using a polyethylene bag, and then ground by a ball mill to 150 mesh pass to obtain a gas generating agent.

Using 1 g of the gas generating agent, the amount of gas generated, the amount of nitrous acid gas generated, and the amount of ammonia generated were measured as in Example 1 to prepare a foam. The compounding quantity and evaluation result of a gas generating agent are shown in Table 1, and the compounding quantity and evaluation result of a foam are shown in Table 2.

Comparative Example 2

Except for hydrotalcite, the amount of gas generated, the amount of nitrous acid gas generated, and the amount of ammonia generated were measured in the same manner as in Example 2 to prepare a foam. The compounding quantity and evaluation result of a gas generating agent are shown in Table 1, and the compounding quantity and evaluation result of a foam are shown in Table 2. The obtained foam adhered to the mold in light yellow color and could not be taken out.

60 g (1 mol) of urea (Mitsugagaku Co., Ltd. industrial urea), sodium nitrite (Nissan Chemical Co., Ltd., sodium nitrite (wet phase)) 69 g (1 mol), hydrotalcite ([Mg ²⁺ _0.83 Al ³⁺ _{^{0.17 (OH) 2] 0.17+ [}} (CO 3) 2- 0.17 / 2 0.33H 2 0] = 2 molar ratio of ^{0.17-, Al / Mg:? 10} ) to 18g, at room temperature, using a polyethylene bag 5 minutes After mixing, the mixture was ground up to a 150 mesh pass using a ball mill. To this pulverized sample, 200 g of chemical blowing agents azodicarbonamide (ADCA) (brand name "beanie hall AC # 3" manufactured by Eiwa Chemical Co., Ltd.), zinc oxide (manufactured by Sakai Chemical Co., Ltd., two kinds of zinc oxide) 53 g The mixture was mixed at room temperature for 5 minutes using a polyethylene bag, and a gas generating agent was obtained. Using 1 g of the gas generator thus obtained, the amount of gas generated, the amount of nitrous acid gas generated, and the amount of ammonia generated were measured as in Example 1. Table 1 shows the compounding amounts of the gas generating agents and the evaluation results.

Next, 100 parts by weight of low-density polyethylene (trade name "Novatech PE YF30" manufactured by Nippon Polyethylene Co., Ltd.), 10 parts by weight of the gas generator, and dicumyl peroxide (DCP) in a kneader heated to 110 to 120 ° C. 1 part by weight was added and kneaded. The kneaded material was thrown in and pressurized at the press pressure of 150 Kg / cm <2> so that the internal volume of the metal mold | die (200 mm x 200 mm x 10 mm) of the press apparatus heated to 155 degreeC may be 100% filled. After 15 minutes the press pressure was opened to normal pressure at once to obtain a foam. Table 2 shows the compounding amounts of the foams and the evaluation results.

&Lt; Comparative Example 3 &

The chemical blowing agent azodicarbonamide (ADCA) (brand name "Vinihole AC # 3", Eiwa Kasei Kogyo Co., Ltd.) was carried out similarly to Example 3 except having changed hydrotalcite into aluminum silicate (made by Wako Pure Chemical Industries, Ltd., aluminum silicate). Kaisha) and zinc oxide (manufactured by Sakai Chemical Co., Ltd., zinc oxide, two kinds) were mixed to obtain a gas generator. The amount of gas generated, the amount of nitrous acid gas generated, and the amount of ammonia generated were measured in the same manner as in Example 1, and then a foam was produced in the same manner as in Example 3. The compounding quantity and evaluation result of a gas generating agent are shown in Table 1, and the compounding quantity and evaluation result of a foam are shown in Table 2. The foam obtained was colored pale yellow, and the bubbles inside the foam were also nonuniform.

60 g (1 mol) of urea (Mitsugagaku Co., Ltd. industrial urea), sodium nitrite (Nissan Chemical Co., Ltd., sodium nitrite (wet phase)) 69 g (1 mol), hydrotalcite ([Mg ²⁺ _0.83 Al ³⁺ _{^{0.17 (OH) 2] 0.17+ [}} (CO 3) 2- 0.17 / 2 0.33H 2 0] 0.17-, Al: Mg molar ratio of a = 2: 10) 12g, magnesium stearate (Sakai the flexors manufacture, SM- 1000 g of 6 g was mixed at room temperature for 5 minutes using a polyethylene bag, and then ground to a 150 mesh pass using a ball mill. 62.6 g of azodicarbonamide (ADCA) (brand name "Vinihole AC # 3" manufactured by Eiwa Chemical Co., Ltd.), the chemical blowing agent N, N'-dinitrosopentamethylenetetramine (DNPT) (Brand name `` Cellular D '', manufactured by Eiwa Chemical Co., Ltd.) 93.8 g, zinc oxide (manufactured by Sakai Chemical Co., Ltd., two types of zinc oxide) was mixed at room temperature for 5 minutes using a polyethylene bag, and then gas. A generator was obtained. Using the obtained gas generating agent, the amount of generated gas, the amount of nitrous acid generated, and the amount of ammonia generated were measured as in Example 1. The compounding quantity of each formulation and the evaluation result are shown in Table 1.

Next, 60 parts by weight of NR (RSS # 1) and 40 parts by weight of SBR (1502) were kneaded with a kneader, 50 parts by weight of calcium carbonate (made by Bihoku-Hunka Co., Ltd., Whiteton SB), white carbon (manufactured by DSL Japan), 20 parts by weight of caprex # 80, titanium dioxide (manufactured by Wako Pure Chemical Industries, Ltd., titanium oxide), 5 parts by weight of zinc oxide (manufactured by Sakai Chemical Co., Ltd., zinc oxide), 5 parts by weight of stearic acid (manufactured by Kao Corporation, Lunak S-20) 3 parts by weight and 5 parts by weight of naphthene oil (Sansen 410, manufactured by Nihon San Seki Oil Co., Ltd.) were added, kneaded and taken out again. This kneaded material was wound on a mixing roll, and 2.5 parts of sulfur (Tsurumi Chemical Co., Pulverized Sulfur) as a vulcanizing agent and 1 part of vulcanization accelerator DM were added and kneaded for 3 minutes, and then 15 parts of blowing agent mixture was added and kneaded for 3 minutes. It was.

The kneaded material was thrown in and pressurized at the press pressure of 150 Kg / cm <2> so that the internal volume of the metal mold | die (124 mm x 124 mm x 11 mm) of the press apparatus heated to 150 degreeC could be 100% filled. After 15 minutes the press pressure was opened to atmospheric pressure at once to give a foam. Table 2 shows the compounding amounts of the foams and the evaluation results.

&Lt; Comparative Example 4 &

Except for removing hydrotalcite from the formulation of Example 4, the same operation as in Example 4 was carried out to measure the amount of generated gas, the amount of nitrous acid gas generated, and the amount of ammonia generated to prepare a foam. The compounding quantity and evaluation result of a gas generating agent are shown in Table 1, and the compounding quantity and evaluation result of a foam are shown in Table 2. The bubbles inside the foam were nonuniform.

118 g (1 mol) of biurea (hydrazodicarbonamide, Ewagase Kogyo Co., Ltd., FE-823), 42.5 g (0.5 mol) of potassium nitrite (made by Wako Pure Chemical Co., Ltd., Wako high grade potassium nitrite), hydro hydrotalcite ^{_{^{_{([Mg 2+ 0.83 Al 3+ 0.17}}}} (OH) 2] 0.17+ [(CO 3) 2- 0.17 / 2 0.33H 2 0?] 0.17-, Al: Mg molar ratio = 2.10) to 12g, polyethylene After mixing for 5 minutes at room temperature using a bag, the ball mill was milled up to 150 mesh pass to obtain a gas generator.

The amount of gas generated, the amount of nitrous acid gas generated, and the amount of ammonia generated were measured in the same manner as in Example 1, except that the oil bath temperature 220 ° C was changed to 250 ° C in the measurement of the amount of generated gas by using 1 g of the obtained gas generator. Table 1 shows the compounding amounts of the gas generating agents and the evaluation results.

Next, 1 part by weight of liquid paraffin and 3 parts by weight of the gas generator obtained above were added and mixed with 100 parts by weight of polypropylene (trade name "Novatech PP MA3" manufactured by Nippon Poly). The mixture was put into an extruder (Toyo Seiki Raboplast Mill 50C150, extrusion machine type D2025), and the set temperature C1; 200 ° C., C2; 240 ° C., C3; 200 ° C., die; It was made into 180 degreeC and extruded at the screw speed of 80 rpm, and obtained foam seat | seet. Table 2 shows the compounding amounts of the foams and the evaluation results.

&Lt; Comparative Example 5 &

Except for removing hydrotalcite from the formulation of Example 5, the amount of generated gas, the amount of nitrous acid generated and the amount of ammonia generated were measured in the same manner as in Example 5 to prepare a foam. The compounding quantity and evaluation result of a gas generating agent are shown in Table 1, and the compounding quantity and evaluation result of a foam are shown in Table 2. The foam obtained was colored pale yellow and bubbles were hardly observed.

As shown in Table 1, in Examples 1 to 5, the amount of generated gas was improved, the amount of detected nitrite gas was decreased, and ammonia was not detected in all gas generating agents. Therefore, in Examples 1 to 5, it was confirmed that nitrite gas was reduced by hydrotalcite, and nitrite gas was reduced, and ammonia was decomposed to increase the amount of nitrogen gas generated at the time of foaming.

As shown in Table 2, it was confirmed that Examples 1-5 are excellent in the whiteness of foam, the bubble inside a foam is a micro uniform bubble, and foaming magnification improves as can be understood from the specific gravity of foam. .

Industrial availability

According to the present invention, when manufacturing a thermoplastic resin or rubber foam, it is possible to produce a high magnification foam without increasing the chemical foaming agent, and the ammonia odor countermeasure in the manufacturing site is also unnecessary since the ammonia can be suppressed. It is very advantageous industrially.

Claims

A gas generator used for producing a foam, comprising (A) a nitrogen-containing compound that generates ammonia gas by pyrolysis, (B) nitrite, and (C) hydrotalcite.

The gas generator according to claim 1, wherein the nitrogen-containing compound (A) is a compound having a urea bond.

The nitrogen-containing compound (A) is 0.5 to 95% by weight and the nitrite (B) according to claim 1 or 2, based on the total amount of the nitrogen-containing compound (A), nitrite (B) and hydrotalcite (C). ) 0.5 to 60% by weight, hydrotalcite (C) 1 to 40% by weight, characterized in that the gas generator.

The gas generator according to any one of claims 1 to 3, wherein the nitrite (B) is at least one member selected from the group consisting of sodium nitrite, potassium nitrite and barium nitrite.

The gas generator according to any one of claims 1 to 4, wherein hydrotalcite (C) is represented by the following formula (1).
Formula 1

In Chemical Formula 1,
And M ⁺ ² is a divalent metal ion of a metal selected from the group consisting of Mg, Mn, Fe, and Zn,
M ³ ⁺ is a metal of the 3 selected from the group consisting of Al, Fe and Cr metal ion,
A ⁿ ^- is an n-valent anion of a group selected from the group consisting of OH, F, Cl, Br, NO ₃ , CO ₃ and SO ₄ ,
x is in the range of 0 <x≤0.33,
n is an integer,
m is zero or more.

The method of claim 5, wherein the formula is M ² ⁺ in the Mg ² ⁺ 1, M ³ ⁺ is Al ³ ⁺ a, gas is generated.

The composition for foaming which mix | blends the gas generating agent of any one of Claims 1-6 with a to-be-foamed material.

The foaming composition according to claim 7, wherein the material to be foamed is a synthetic resin material or a rubber material.

The manufacturing method of a foam containing the process of heating the foaming composition of Claim 7 or 8.