JP3095355B2 - Foaming composition and foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a foaming agent composition and a foam. More specifically, the present invention relates to a synthetic resin,
The present invention relates to a foaming agent composition useful for producing foams such as natural rubber and synthetic rubber, and a foam obtained using the foaming agent composition.

[0002]

2. Description of the Related Art Foams such as synthetic resins, natural rubbers and synthetic rubbers (hereinafter simply referred to as "foams") are lightweight and highly elastic.
Because it has excellent heat insulation, shock absorption, soundproofing, decorativeness, etc.,
In a wide range of industrial fields, such as civil engineering, agriculture, forestry and fisheries, automobiles, electric and electronic equipment, and household goods, it is widely used as a heat insulating material, an interior material, a seal material, a cushion material, and the like.
In order to produce a foam, a method is generally used in which a foaming agent is added to a material to be foamed such as a synthetic resin, natural rubber, or synthetic rubber, and the foaming agent is decomposed to generate gas. Examples of the foaming agent include inorganic chemical foaming agents such as sodium bicarbonate and ammonium carbonate, azo compounds (azodicarbonamide, azobisisobutyronitrile, diazoaminobenzene, barium azodicarboxylate, etc.), nitroso compounds (N , N'-Dinitrosopentamethylenetetramine, N,
Organic chemical blowing agents such as N'-dinitroso-N, N'-dimethyl terephthalamide), sulfonyl hydrazide compounds (p, p'-oxybis (benzenesulfonyl hydrazide), p-toluenesulfonyl hydrazide, etc.), butane,
Evaporation-type physical foaming agents such as pentane, hexane, and fluorinated aliphatic hydrocarbons are used.

[0003]

Conventionally, when foaming synthetic rubber, natural rubber, thermoplastic polyurethane and the like (hereinafter referred to as "rubbers" for convenience), N, N'-dinitrosopenta, which is a nitroso compound, is used. Methylenetetramine (hereinafter referred to as “DPT”) is widely used. D
PT is about 1% by blending urea as a foaming aid.
It begins to decompose at a relatively low temperature of 30 ° C., has a high decomposition rate, is sharply decomposed, and has a large amount of gas generated, and thus is suitable for foaming rubbers. Urea has the effect of accelerating the decomposition of DPT and reacting with odorous substances generated by the decomposition of DPT to eliminate odor. However, DPT is difficult in terms of safety and toxicity, and in the current situation where emphasis is placed on environmental preservation and the safety of workers and users, it is increasingly recognized as an undesirable chemical substance. Therefore, development of a foaming agent having a foaming performance equal to or higher than that of DPT and safe for the environment and the human body is desired. On the other hand, azodicarbonamide has a practical decomposition onset temperature of about 180 ° C., which is higher than DPT, and is mainly used for foaming polyvinyl chloride.
Because of its high safety to the human body, it has been studied to substitute it for DPT.

[0004] The decomposition temperature of azodicarbonamide is determined by using, for example, zinc oxide, zinc chloride, zinc carbonate,
Zinc compounds such as zinc acetate, zinc laurate, zinc stearate, zinc 2-ethylhexoate, and zinc benzoate;
Lead compounds such as lead stearate, dibasic lead phthalate, and tribasic lead sulfate; cadmium compounds such as cadmium stearate and cadmium laurate; organic acids such as oxalic acid, lactic acid, succinic acid, malic acid, and citric acid; It is known that the temperature can be lowered to about 150 to 160 ° C. by adding urea or the like, but the decomposition temperature is still high for foaming rubbers. Furthermore, Japanese Patent Publication No. 50-36861 describes a benzenesulfinic acid derivative represented by the general formula (1) and a salt thereof as an azodicarbonamide foaming aid.

[0005]

Embedded image [Wherein R ^{1 to} R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group or a halogen atom. M represents a hydrogen atom, an ammonium nitrogen-containing group, or a metal cation. When M represents a hydrogen atom or an ammonium nitrogen-containing group, n represents 1, and when M represents a metal cation, n represents the valence of the metal cation. ]

The derivative is said to be effective in lowering the decomposition temperature of azodicarbonamide and sharply performing the decomposition. However, in practice, the lowering of the decomposition temperature is insufficient, and the same degree of decomposition sharpness as DPT has not been achieved. An object of the present invention is to reduce the decomposition temperature of azodicarbonamide, increase the decomposition rate, sharpen the decomposition reaction, and achieve a foaming agent composition capable of achieving the same or higher foaming performance as DPT and An object of the present invention is to provide a foam obtained by using the foaming agent composition.

[0007]

The present invention relates to (1) azodicarbonamide, (2) at least one selected from benzenesulfinic acid derivatives and salts thereof, and (3) at least one selected from urea compounds. It relates to a foaming agent composition as an active ingredient. Further, the present invention relates to a foam obtained by adding the blowing agent composition of the present invention to a material to be foamed and decomposing a foaming component contained in the foaming agent composition to generate gas.

In the present invention, the benzenesulfinic acid derivative or the urea compound is not added to the azodicarbonamide alone, but is used in combination with the azodicarbonamide. Occurs and the decomposition state becomes sharper. That is, from the attached FIG. 1, the foaming agent composition of the example generates 200 ml of gas during a temperature rise of only 10 ° C. from 130 to 140 ° C., whereas the decomposition temperature is closest to that of the example. The foaming agent composition of the comparative example weighed only 63 ml, and the blowing agent composition of the present invention showed 3.2 times the gas generation amount as compared with the conventional closest foaming agent composition. It is clear that a synergistic effect based on the combined use of urea compounds is exhibited. ADVANTAGE OF THE INVENTION According to this invention, the foaming agent useful for foaming various materials, such as synthetic resin, natural rubber, and synthetic rubber, especially the material which needs vulcanization and / or crosslinking, for example, rubbers, is provided.
In the foam provided by the present invention, fine and uniform cells are uniformly dispersed, and various properties required for the foam (for example, elasticity, heat insulation, shock absorption, soundproofing, decorativeness, etc.) are obtained. Excellent foam filled with high standards. Although the reason why the blowing agent composition of the present invention exhibits such excellent effects as described above is not sufficiently clear, the benzenesulfinic acid derivative and the urea compound show a synergistic effect, and the benzenesulfinic acid derivative is not only azodicarbonamide but also It also acts as a foaming aid for the urea compound, and it is considered that the decomposition temperature decreases and the amount of generated gas increases, resulting in sharper decomposition.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The blowing agent composition of the present invention comprises (1)
Essential components are at least one selected from azodicarbonamide, (2) a benzenesulfinic acid derivative and a salt thereof, and (3) at least one selected from a urea compound. In the blowing agent composition of the present invention, azodicarbonamide serving as a main blowing agent is a blowing agent widely used industrially as described above, has high safety to the human body, and has good storage stability. And various favorable characteristics such as low cost. As the azodicarbonamide, those produced by various methods and commercial products can be used. The particle size of the azodicarbonamide is not particularly limited and can be appropriately selected from a wide range. However, from the viewpoint of further improving the foaming performance, it is usually about 30 μm or less, preferably about 10 μm or less, more preferably 7 μm.
It is good to be less than about. As the second component of the blowing agent composition of the present invention, benzenesulfinic acid and salts thereof are not particularly limited, and known ones can be used, and examples thereof include a compound represented by the general formula (1). .

[0010]

Embedded image [Wherein R ^{1 to} R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group or a halogen atom. M represents a hydrogen atom, an ammonium nitrogen-containing group, or a metal cation. When M represents a hydrogen atom or an ammonium nitrogen-containing group, n represents 1, and when M represents a metal cation, n represents the valence of the metal cation. ]

In the above formula (1), lower alkyl groups represented by R ^{1 to} R ⁵ include, for example, methyl, ethyl, n
Linear or branched alkyl groups having about 1 to 4 carbon atoms, such as -propyl, iso-propyl, n-butyl, iso-butyl and tert-butyl. Examples of the halogen atom include chlorine, bromine, fluorine, iodine and the like. Examples of the metal of the metal cation represented by M include alkali metals such as Li, Na, and K;
Examples thereof include alkaline earth metals such as a, Mg, Ca and Sr, Group IIb elements such as Zn and Cd, and Group IVb elements such as Pb. Among the benzenesulfinic acid derivatives represented by the general formula (1) and salts thereof, a compound in which M is a metal cation is preferable. Specific examples of the benzenesulfinic acid derivative metal salt in which M is a metal cation include, for example, sodium benzenesulfinate, potassium benzenesulfinate, lithium benzenesulfinate,
Zinc benzenesulfinate, calcium di-benzenesulfinate, lead di-benzenesulfinate, barium di-benzenesulfinate, cadmium dibenzenesulfinate, magnesium di-benzenesulfinate, p
-Sodium toluenesulfinate, potassium p-toluenesulfinate, lithium p-toluenesulfinate, zinc bis-p-toluenesulfinate, bis-p-
Calcium toluenesulfinate, lead bis-p-toluenesulfinate, barium bis-p-toluenesulfinate, cadmium bis-p-toluenesulfinate, magnesium bis-p-toluenesulfinate,

Sodium p-chlorobenzenesulfinate, potassium p-chlorobenzenesulfinate, lithium p-chlorobenzenesulfinate, zinc bis-p-chlorobenzenesulfinate, calcium bis-p-chlorobenzenesulfinate, lead bis-p-chlorobenzenesulfinate Barium bis-p-chlorobenzenesulfinate, cadmium bis-p-chlorobenzenesulfinate, magnesium bis-p-chlorobenzenesulfinate, sodium 2,4-dimethylbenzenesulfinate, potassium 2,4-dimethylbenzenesulfinate, 2, Lithium 4-dimethylbenzenesulfinate,
Zinc bis-2,4-dimethylbenzenesulfinate, calcium bis-2,4-dimethylbenzenesulfinate, lead bis-2,4-dimethylbenzenesulfinate,
Barium bis-2,4-dimethylbenzenesulfinate, cadmium bis-2,4-dimethylbenzenesulfinate, magnesium bis-2,4-dimethylbenzenesulfinate, sodium 2,5-dimethylbenzenesulfinate, bis-2, Zinc 5-dimethylbenzenesulfinate,

Sodium 3,4-dimethylbenzenesulfinate, zinc bis-3,4-dimethylbenzenesulfinate, sodium 2-chloro-4-methylbenzenesulfinate, zinc bis-2-chloro-4-methylbenzenesulfinate Sodium 2-methyl-4-chlorobenzenesulfinate, zinc bis-2-methyl-4-chlorobenzenesulfinate, sodium p-fluorobenzenesulfinate, zinc bis-p-fluorobenzenesulfinate, sodium p-bromobenzenesulfinate , Zinc bis-p-bromobenzenesulfinate, p-
Sodium tert-butylbenzenesulfinate, bis-
zinc p-tert-butylbenzenesulfinate, bis-
Zinc 2,3,4,5,6-pentamethylbenzenesulfinate, zinc bis-2,3,4,5,6-pentachlorobenzenesulfinate and the like can be mentioned. From the viewpoint of further lowering the decomposition temperature of azodicarbonamide and performing the decomposition more sharply, among these metal salts, sodium salt, potassium salt, calcium salt,
Zinc salts and the like are preferred, zinc salts are particularly preferred, and among the zinc salts, zinc benzenesulfinate is preferred.

The particle size of the benzenesulfinic acid derivative and the salt thereof is not particularly limited and can be appropriately selected from a wide range. However, from the viewpoint of further lowering the decomposition temperature of azodicarbonamide and sharpening the decomposition. Is usually about 30 μm or less, preferably about 15 μm or less, and more preferably about 7 μm or less. The amount of the benzenesulfinic acid derivative and the salt thereof is not particularly limited and can be appropriately selected from a wide range. However, from the viewpoint of further lowering the decomposition temperature of azodicarbonamide and sharply decomposing it, azodicarbonamide 100
Usually about 5 to 200 parts by weight, preferably 1 to 5 parts by weight
The amount is preferably about 0 to 100 parts by weight. If the amount is less than 5 parts by weight, the decomposition temperature may be lowered or the sharpness of decomposition may be insufficient. If the amount is more than 200 parts by weight, the decrease in decomposition temperature is the same as up to 200 parts by weight. This is uneconomical, and the resulting foam may have coarse cells and cause surface roughness, and may not be a good foam.

The urea compound as the third component of the blowing agent composition of the present invention is not particularly limited, and known compounds can be used. Examples thereof include urea, biuret, and triuret. Urea is preferred. One urea compound can be used alone, or two or more urea compounds can be used in combination. As the urea compound, both those produced by various production methods and those commercially available can be used. The urea compound is desirably subjected to a surface treatment with a surface treatment agent to prevent moisture absorption. As the surface treatment agent, for example,
Fatty acids such as lauric acid, palmitic acid, stearic acid, and oleic acid; fatty acid metal salts such as calcium stearate, zinc stearate, and barium stearate; aliphatic hydrocarbons such as liquid paraffin, polyolefin wax, and microcrystalline wax; and higher aliphatics Examples thereof include alcohols, fatty acid esters, soybean oil, coconut oil, and polyvinyl chloride plasticizer, and one or more kinds can be used.

The particle size of the urea compound is not particularly limited and can be appropriately selected from a wide range. However, from the viewpoint of further lowering the decomposition temperature of azodicarbonamide and further sharply decomposing it, it is usually about 30 μm or less, and preferably about 30 μm or less. 20 μm
It is good to be less than about. The blending amount of the urea compound is not particularly limited and can be appropriately selected from a wide range. However, from the viewpoint of further lowering the decomposition temperature of azodicarbonamide and sharply decomposing it, azodicarbonamide 1
The amount is usually about 5 to 200 parts by weight, preferably about 10 to 100 parts by weight, based on 00 parts by weight. If the amount is less than 5 parts by weight, the decomposition temperature may be lowered or the decomposition sharpness may be insufficient. On the other hand, if it exceeds 200 parts by weight,
Despite the increase in the amount used, the decomposition temperature is reduced to the same extent as 200 parts by weight, and the resulting foam may have coarse cells and rough surfaces, and may not be a good foam. Known foaming agents, foaming aids, compounding agents, and the like may be added to the foaming agent composition of the present invention as long as the effects are not impaired.

Examples of the foaming agent include inorganic chemical foaming agents such as sodium bicarbonate and ammonium carbonate, organic chemical foaming agents such as azobisisobutyronitrile and p-toluenesulfonyl hydrazide, aliphatic hydrocarbons and chlorinated fats. Physical foaming agents such as aromatic hydrocarbons, fluorinated aliphatic hydrocarbons, carbon dioxide gas, and nitrogen gas. Examples of the foaming aid include metal oxides such as zinc oxide, lead oxide, and magnesium oxide; metal carbonates such as zinc carbonate and barium carbonate; metal chlorides such as zinc chloride and potassium chloride; lithium stearate; and stearic acid. Magnesium, aluminum stearate, calcium stearate, barium stearate, zinc stearate, cadmium stearate, lead stearate, dibasic lead stearate, calcium laurate, zinc laurate, zinc 2-ethylhexoate, dibasic phthalic acid Inorganic acid salts such as metal soaps such as lead, tribasic lead sulfate, dibasic lead phosphite, and basic lead sulfite; organic tin compounds such as dibutyltin dilaurate and dibutyltin dimaleate; dibutyltin dilaurate; dibutyltin Dimalate type, calcium-zinc type, barium-
Examples thereof include zinc-based composite stabilizers for PVC, metal sulfonic acid compounds, and the like.

Examples of the compounding agent include a plasticizer, a stabilizer, a vulcanizing agent, a vulcanization accelerator, a crosslinking agent, an anti-scorch agent, an antioxidant, an antioxidant, a softener, a tackifier, and an ultraviolet absorber. , Coloring agents, flame retardants, dispersants, antistatic agents, reinforcing materials,
Examples include a curing agent, an adhesive, a fluorescent whitening agent, and a release agent. The foaming agent composition of the present invention can be produced by mixing the above three essential components and other components as necessary according to a usual method. For mixing, a usual mixer such as a Henschel mixer or a ribbon mixer can be used. In addition, when adding the foaming agent composition of the present invention to the material to be foamed, a mixture of the above three essential components may be added, or the three essential components may be separately added.

The most preferred embodiment of the blowing agent composition of the present invention is a composition containing azodicarbonamide, zinc benzenesulfinate and urea as essential components. The foaming agent composition of the present invention can be applied to various materials to be foamed, similarly to a conventional foaming agent. The material to be foamed is not particularly limited, and examples thereof include a synthetic resin, a synthetic rubber, a natural rubber, and a mixture of two or more of these. The synthetic resin is not particularly limited, and known resins can be used.For example, polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, polyacrylonitrile, acrylonitrile-butadiene-styrene terpolymer, polyurethane, urethane-vinyl chloride Copolymers and the like can be mentioned. The synthetic rubber is not particularly limited, but examples thereof include styrene butadiene rubber, nitrile butadiene rubber, chloroprene rubber, isobutylene rubber, isoprene rubber, butadiene rubber, acrylic rubber, chlorinated butyl rubber, and ethylene-propylene-diene terpolymer. it can. The blowing agent composition of the present invention is a thermoplastic polyurethane,
It is particularly effective for foaming synthetic rubber, natural rubber and the like.

In foaming the material to be foamed using the foaming agent composition of the present invention, any of the known methods conventionally used for producing foams can be employed. That is, the foaming agent composition of the present invention is added to and mixed with the material to be foamed,
A gas may be generated by decomposing the foaming component contained in the foaming agent composition. More specifically, for example, a foaming agent composition and a material to be foamed are kneaded with a roll, an extruder or the like, the obtained mixture is filled in a mold, and the foamed component is pressed and heated with a press to form a foamed component. Decomposition method (press pressure foam molding method), method of molding a mixture of foaming agent composition and material to be foamed by an extruder (extrusion foam molding method, injection foam molding method), foaming agent composition and material to be foamed After forming the mixture with an arbitrary shape such as a sheet or coating on paper, release paper, cloth, board, etc., the mixture is placed in a heating device such as a hot-air foaming furnace or an infrared heating foaming furnace to form a foaming agent. A method of decomposing components (normal pressure foam molding method) and the like can be mentioned. When producing a foam using the foaming agent composition of the present invention, the amount of the foaming agent composition added to the material to be foamed is determined by various factors such as the material of the material to be foamed and the use of the foam to be obtained. It may be appropriately selected from a wide range according to the conditions, but usually, the material to be foamed 100
0.2 to 30 parts by weight, preferably 0.2 to 30 parts by weight with respect to parts by weight.
It may be about 3 to 25 parts by weight. Foam obtained by using the foaming agent composition of the present invention, like conventional foams,
It can be used as a heat insulating material, an interior material, a sealing material, a cushioning material, and the like in a wide range of fields such as civil engineering construction, agriculture, forestry and fisheries, transportation equipment such as automobiles, electric and electronic equipment, and daily necessities.

[0021]

The present invention will be specifically described below with reference to examples and comparative examples. Example 1 and Comparative Examples 1 to 3 Azodicarbonamide [trade name: Uniform AZ V-45, manufactured by Otsuka Chemical Co., Ltd., the same applies unless otherwise specified] in the mixing ratio (parts by weight) shown in Table 1 below, Zinc benzenesulfinate (average particle diameter 3.5 μm, unless otherwise specified) and urea [trade name: Uniform AZ 0
1, manufactured by Otsuka Chemical Co., Ltd., unless otherwise specified] were mixed with a Henschel mixer (except for Comparative Example 1), and the blowing agent composition of the present invention (Example 1) and a mixture for comparison were prepared. Blowing agent compositions (Comparative Examples 1 to 3) were produced.

[0022]

[Table 1]

With respect to these foaming agent compositions, an amount at which the azodicarbonamide content becomes 1 g is collected in a test tube.
Further, 10 ml of liquid paraffin was added to the test tube and stirred, and the foaming agent composition was dispersed in liquid paraffin. Using this as a sample, an automatic gas amount measuring device [trade name: CT-
1. Cell Techno Co., Ltd.] and a measurement start temperature of 80
The decomposition state was measured at a temperature of 2 ° C. and a heating rate of 2 ° C./min.
The results are shown in FIG. From FIG. 1, it is clear that the foaming agent composition of the present invention is decomposed at a low temperature and the decomposition state is sharper than the comparative foaming agent composition.
That is, the foaming agent composition of Example 1 generates 200 ml of gas during a temperature rise of only 10 ° C. from 130 ° C. to 140 ° C., whereas the decomposition temperature of the comparative example is closest to that of the example. The foaming agent composition of Comparative Example 2 weighed only 63 ml, and the blowing agent composition of the present invention showed 3.2 times the gas generation amount as compared with the conventional closest foaming agent composition. A synergistic effect based on the combined use of an acid derivative and a urea compound. On the other hand, the foaming agent compositions of Comparative Examples 1 and 3 have decomposition temperatures of 160 ° C. and 200 ° C., respectively.
° C, and the decomposition temperature was not lowered at all.

Example 2 and Comparative Examples 4 to 6 100 parts of polyvinyl chloride (trade name: ZEST P35J, manufactured by Shin-Daiichi PVC Co., Ltd.), 70 parts of plasticizer (dioctyl phthalate), stabilizer [trade name: mark] FL-30, manufactured by Asahi Denka Kogyo Co., Ltd.] 2.5 parts, a filler (calcium carbonate) 60 parts, a pigment (titanium dioxide) 5 parts and a foaming agent composition having a blending ratio (part) shown in Table 2 below. Was mixed with a propeller-type stirrer to produce a paste-like foamable resin composition. Next, using a knife coater for flameproof paper for wallpaper,
The foamable resin composition is coated to a thickness of 0.2 mm,
It was placed in a hot air oven at 110 ° C. and heated for 50 seconds to gel the polyvinyl chloride. Then, in a hot air oven at 155 ° C,
The foam was heated for 4 minutes to foam, and the expansion ratio of the obtained foam was determined according to the following equation. Expansion ratio = thickness of foamable resin composition after foaming (mm) / thickness of foamable resin composition after gelation (mm) The results are also shown in Table 2.

[0025]

[Table 2]

Example 3 and Comparative Examples 7 to 8 100 parts of EPDM (trade name: Mitsui EPT 4095, manufactured by Mitsui Petrochemical Industries, Ltd.), 5 parts of zinc oxide, 1.5 parts of stearic acid, 80 parts of FEF carbon black, Light calcium carbonate 20 parts, paraffinic process oil 4
5 parts and a foam inhibitor [CML- # 21, manufactured by Omi Chemical Industry Co., Ltd.] were mixed in a kneader to obtain a composition. 1.5 parts of vulcanization accelerator BZ (zinc di-n-butyldithiocarbamate) and TRA
(Dipentamethylenethiuram tetrasulfide) 1
Part, vulcanization accelerator M (2-mercaptobenzothiazole)
1 part, 0.5 parts of a vulcanization accelerator TET (tetraethylthiuram disulfide), 1.5 parts of sulfur, and the components (parts) shown in Table 3 are added, and the components are roll-kneaded to produce a rubber composition. did. This rubber composition was extruded at 70 ° C. with an extruder, heated at 220 ° C. for 10 minutes with a HAV foaming apparatus,
Vulcanization and foaming were performed. Specific gravity of the obtained foam (g / cm ³ )
Was measured, and the bubble state (cell uniformity) was visually observed. The results are also shown in Table 3.

[0027]

[Table 3]

Example 4 and Comparative Examples 9 to 10 Chloroprene rubber on a roll after the mastication operation was completed [trade name: Skyprene R-22, manufactured by Tosoh Corporation] 100
Parts, HAF carbon black 10 parts, factice 2
0 parts, petrolatum 2 parts, stearic acid 2 parts, MgO 5
Parts, 3.5 parts of ZnO, 10 parts of crown clay, 0.7 parts of an antioxidant, 30 parts of a naphthenic process oil, and each component having a compounding ratio (part) shown in Table 4 were sequentially compounded to obtain a rubber sheet. A composition was prepared. These rubber compositions were charged into a mold, subjected to primary foaming at 140 ° C. for 8 minutes, and subjected to 165 ° C.
For 8 minutes to produce a rubber foam. The specific gravity (g / cm ³ ) of the obtained foam was measured, and the state of air bubbles (cell uniformity) was visually observed. The results are also shown in Table 4.
However, the average particle size of zinc benzenesulfinate is 4 μm
It is.

[0029]

[Table 4]

Example 5 and Comparative Examples 11 to 12 NBR / PVC rubber on a roll after mastication was completed [trade name: JSR NV72, manufactured by Nippon Synthetic Rubber Co., Ltd.]
100 parts, HAF carbon black 3 parts, stearic acid 2 parts, ZnO 5 parts, hydrated silica 15 parts, hard clay 30 parts, soft clay 20 parts, plasticizer (DOP)
13 parts, tackifier [trade name: process resin C-6]
1. Kobe Yuka Kogyo Co., Ltd.] 5 parts, sulfur 2 parts and Table 5
The components in the mixing ratios (parts) described in (1) were sequentially compounded to produce a sheet-like rubber composition. These rubber compositions were charged into a mold and subjected to primary foaming at 145 ° C. for 6.5 minutes.
Secondary foaming was performed at 0 ° C. for 10 minutes to produce a rubber foam. The specific gravity (g / cm ³ ) of the obtained foam was measured, and the state of air bubbles (cell uniformity) was visually observed. The results are also shown in Table 5.

[0031]

[Table 5]

Example 6 and Comparative Examples 13 to 14 Silicon rubber [trade name: KE904] was added to the mixing roll.
FU, manufactured by Shin-Etsu Chemical Co., Ltd.]
0.1 parts of benzoyl peroxide (50% product), 3 parts of dicumyl peroxide (20% product) and each component having the compounding ratio (part) shown in Table 5 were sequentially compounded to obtain a sheet-like rubber composition. Manufactured. Each of these rubber compositions was charged into a mold, and foamed and vulcanized at 165 ° C. for 10 minutes.
Secondary vulcanization was performed at 00 ° C. for 3 hours to produce a rubber foam. The specific gravity (g / cm ³ ) of the obtained foam was measured, and the state of air bubbles (cell uniformity) was visually observed. The results are also shown in Table 6. In Table 6, DPT is trade name: CellMike A [manufactured by Sankyo Chemical Co., Ltd.].

[0033]

[Table 1]

[0034]

In the present invention, a benzenesulfinic acid derivative or a urea compound is not added to azodicarbonamide alone, but is added in combination with the azodicarbonamide, whereby the azodicarbonamide can be used as compared with a conventional blowing agent composition. It is possible to obtain a foaming agent composition in which decomposition occurs at a low temperature and the decomposition state is sharper. In other words, FIG. 1 shows that the foaming agent composition of the example has a temperature rise of only 130 ° C. to 140 ° C. for only 10 ° C.
The foaming composition of the comparative example, in which the decomposition temperature is closest to that of the example, is only 63 ml, whereas the gas of 00 ml is generated.
ml, the blowing agent composition of the present invention shows 3.2 times the gas generation amount as compared with the conventional closest blowing agent composition,
It is clear that a synergistic effect based on the combined use of the benzenesulfinic acid derivative and the urea compound is exhibited.

[Brief description of the drawings]

FIG. 1 is a graph showing the decomposition state of a foaming agent composition of the present invention (Example 1) and a conventional foaming agent composition (Comparative Examples 1 to 3) based on a relationship between a gas generation amount and a temperature.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-30834 (JP, A) JP-A-3-199244 (JP, A) JP-A-57-36133 (JP, A) 148242 (JP, A) JP-A-2-86634 (JP, A) JP-B-50-36861 (JP, B2) "Polymer", 1970, Vol. 19, No. 224, p. 1038-1044 (58) Field surveyed (Int. Cl. ⁷ , DB name) C09K 3/00 111 C08J 9/04-9/10 CA (STN) REGISTRY (STN)

Claims (6)

(57) [Claims] 1. A blowing agent composition comprising (1) azodicarbonamide, (2) at least one selected from benzenesulfinic acid derivatives and salts thereof, and (3) at least one selected from urea compounds as active ingredients. . 2. The benzenesulfinic acid derivative and a salt thereof are compounds represented by the following general formula (1).
The foaming agent composition according to the above. Embedded image [Wherein R ^{1 to} R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group or a halogen atom. M represents a hydrogen atom, an ammonium nitrogen-containing group, or a metal cation. When M represents a hydrogen atom or an ammonium nitrogen-containing group, n represents 1, and when M represents a metal cation, n represents the valence of the metal cation. ] 3. The urea compound is at least one selected from urea, biuret and triuret.
The foaming agent composition according to the above. 4. The blowing agent composition according to claim 1, comprising azodicarbonamide, zinc benzenesulfinate and urea as active ingredients. 5. A benzenesulfinic acid derivative or a salt thereof is added in an amount of 5 to 2 parts per 100 parts by weight of azodicarbonamide.
2. The blowing agent composition according to claim 1, wherein the urea compound is contained in an amount of 5 to 200 parts by weight. 6. A foam obtained by adding the foaming agent composition of claim 1 to a material to be foamed and decomposing a foaming component contained in the foaming agent composition to generate a gas.