JPH10298535A - Foaming agent composition containing azoalkane derivative and foamed material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition free from the problems of the emission of ill odor such as acetic acid odor, the deterioration of working environment and the impartment of the foamed product with acetic acid odor by compounding an azoalkane derivative with an alkaline earth metal oxide and a phosphoric acid compound. SOLUTION: This composition contains (A) an azoalkane derivative of the formula (R<1> and R<2> are each a lower alkyl or an aryl; R<3> is an alkyl or an aryl), (B) an alkaline earth metal oxide and (C) a phosphoric acid compound. The component A is preferably 1,1'-azobis(1-acetoxy-1-phenylethane), etc., the component B is preferably calcium oxide or magnesium oxide and the component C is preferably sodium dihydrogen phosphate or potassium dihydrogen phosphate. The amounts of the components B and C are 0.1-5 mol each based on 1 mol of the component A. The deodorizing effect can be improved as necessary by compounding an alkali metal or alkaline earth metal hydroxide, carbonate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a blowing agent composition containing an azoalkane derivative and a foam obtained using the same.

[0002]

2. Description of the Related Art 1,1'-Azobis (1-acetoxy-1)
Α-α-diacetoxyazoalkanes such as -phenylethane) exhibit excellent ability as a polymerization initiation catalyst for a polymerizable double bond-containing compound such as styrene, methyl methacrylate, and vinyl acetate. USP 3,28
2,912, Mem. Fac. Eng., 1980, 21, 141-9. Α, α'-diacetoxyazoalkanes are one of the currently widely used polymerization initiation catalysts.
Since the azo compound does not have the cyano group, the azo compound has lower toxicity than general-purpose azo compounds, and is very preferable in the current situation where environmental issues are emphasized.

The above-mentioned azoalkanes are also useful as a foaming agent for synthetic resins, and are substances which decompose when heated to generate gas. These foaming agents are kneaded in synthetic resin and heated to form a foam. Have gained. Some synthetic resins are cured by gelation or cross-linking reaction, but are mixed with a foaming agent in advance and heated for gelation and foaming. Gaining body. These foaming agents are selected and used according to the size of the cell diameter, the expansion ratio, the operating temperature and the like. For example, α, α′-diacetoxyazoalkanes such as 1,1′-azobis (1-acetoxy-1-phenylethane) are used as a foaming agent for polyester resins, silicone rubbers and the like in US Pat.
9,615 and JP-A-8-134250.

[0004] However, the difficulty in producing azoalkanes limits its use as a polymerization initiation catalyst or a blowing agent. Therefore, the applicant of the present invention has disclosed in Japanese Patent Application Laid-Open No. Hei 7-206798 the production of azoalkane derivatives containing these α, α′-diacetoxyazoalkanes in a high yield with easy reaction operation and almost no by-products. Provided a method.

[0005]

However, in the case of α, α′-diacetoxyazoalkane, for example, when this azoalkane derivative is thermally decomposed, it is derived from an acetic acid group (—OAc) in the molecule together with nitrogen gas. Acetic acid (AcOH) was generated, and the odor of acetic acid deteriorated the working environment and caused a problem that the odor adhered to the obtained foam. An object of the present invention is to prevent a foaming agent containing an azoalkane derivative as a main component from generating an odor such as an acetic acid odor, and thus not deteriorating the working environment or causing the acetic acid odor or the like to adhere to the obtained foam. An object of the present invention is to provide a foaming agent composition and a foam obtained using the same.

[0006]

The present invention provides a foaming agent composition comprising an azoalkane derivative represented by the general formula (1), an alkaline earth metal oxide and a phosphoric acid compound, and uses the same. The present invention relates to a foam obtained by the above method.

[0007]

Embedded image [In the formula, R ¹ and R ² are the same or different and represent a lower alkyl group or an aryl group, and R ³ represents an alkyl group or an aryl group. ]

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The azoalkane derivative of the present invention is a known compound, for example, as described in JP-A-7-2067.
No. 98 can be produced. That is, α, α′- represented by the general formula (2) in the presence of an amine
It can be obtained by reacting a dihalogenoazoalkane with a carboxylic acid represented by the general formula (3) and / or a metal salt thereof.

[0009]

Embedded image [In the formula, R ¹ and R ² are the same or different and are a lower alkyl group or an aryl group, and X represents a halogen atom. R ³ COOH (3) wherein R ³ represents an alkyl group or an aryl group. ]

In the above, the lower alkyl groups represented by R ¹ and R ² include, for example, those having about 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and isobutyl. A straight-chain or branched alkyl group can be mentioned. The alkyl group represented by R ³ is not particularly limited, and examples thereof include a linear or branched alkyl group having about 1 to 8 carbon atoms. In the above general formulas (1) to (3), R
Examples of the aryl group represented by ¹ , R ² and R ³ include phenyl, tolyl, xylyl, naphthyl and the like.

In the production method of the present invention, the α, α′-dihalogenoazoalkanes of the above general formula (2), which are raw materials, are known compounds, and their production methods are also known. For example, it can be produced by reacting ketone with hydrated hydrazine to obtain ketazine, and reacting ketazine with a halogen such as chlorine or bromine.

In the present invention, as the carboxylic acid of the above general formula (3), which is another raw material, a known linear or branched carboxylic acid having about 1 to 8 carbon atoms in the alkyl moiety is used. Among them, among them, for example, acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-pivalic acid, isopivalic acid, tert-pivalic acid, etc. The carboxylic acid which is an alkyl can be preferably used. Examples of the carboxylic acid in which R ³ is an aryl group include benzoic acid, methylbenzoic acid, dimethylbenzoic acid, and naphthoic acid. In the present invention, examples of the metal salt of carboxylic acid include alkali metal salts such as sodium salt and potassium salt.

As the amine to be present in the reaction system of the present invention, known amines can be widely used, and examples thereof include primary amines represented by the formula R ⁴ NH ₂ such as ethylamine and propylamine, dimethylamine and diethylamine. Secondary amines represented by (R ⁴ ) ₃ N such as secondary amines represented by (R ⁴ ) ₂ NH, trimethylamine and triethylamine
Primary amines (each R ⁴ represents an alkyl group having 1 to 10 carbon atoms), heterocyclic amines such as piperidine, pyridine and pyrrole, and condensed amines such as DBU and DBN can be exemplified.

Specific examples of the azoalkane derivative represented by the general formula (1) of the present invention include, for example, 1,1'-azobis (1-acetoxy-1-phenylethane) and 1,1'-azobis (1-acetoxy-1-). Phenylpropane), 1,1'-
Azobis (1-acetoxy-1-phenylbutane),
2,2'-azobis (2-acetoxypropane), 2,2 '
-Azobis (2-acetoxybutane), 2,2′-azobis (2-acetoxy-3-methylbutane), 2,2′-azobis (2-acetoxy-4-methylpentane),
2'-azobis (2-acetoxy-3,3-dimethylbutane), 1,1'-azobis (1-propionoxy-1-phenylethane), 2,2'-azobis (2-propionoxy-3,3-dimethylbutane) ), 2,2'-azobis (2
-Propionoxy-4-methylpentane), 2,2'-azobis (2-propionoxypropane), 2,2'-azobis (2-propionoxybutane), 2,2'-azobis (2-propionoxy- 3-methylbutane),

1,1'-azobis (1-isobutyroxy-
1-phenylethane), 2,2′-azobis (2-isobutyroxy-3,3-dimethylbutane), 2,2′-azobis (2-isobutyroxy-4-methylpentane), 2,
2'-azobis (2-isobutyroxypropane), 2,
2'-azobis (2-isobutyroxybutane), 2,2 '
-Azobis (2-isobutyroxy-3-methylbutane), 1,1'-azobis (1-pivaloxy-1-phenylethane), 2,2'-azobis (2-pivaloxy-3,
3-dimethylbutane), 2,2'-azobis (2-pivaloxy-4-methylpentane), 2,2'-azobis (2-
Pivaloxypropane), 2,2'-azobis (2-pivaloxybutane), 2,2'-azobis (2-pivaloxy-3
-Methylbutane), 2,2′-azobis (2-benzoyloxy-3,3-dimethylbutane), 2,2′-azobis (2-benzoyloxy-4-methylpentane) and the like. Among them, 1,1′-azobis (1-acetoxy-1-phenylethane), 2,2′-azobis (2-acetoxy-4-methylpentane),
2'-Azobis (2-acetoxy-3,3-dimethylbutane) is particularly preferably used.

The blowing agent of the present invention is characterized by containing the azoalkane derivative, an alkaline earth metal oxide and a phosphate compound. As alkaline earth metal oxides,
For example, magnesium oxide, calcium oxide, barium oxide and the like can be mentioned, and magnesium oxide and calcium oxide are preferable. The amount of the alkaline earth metal oxide is usually about 0.01 to 10 mol, preferably about 0.1 to 5 mol, per 1 mol of the azoalkane derivative.

Examples of the phosphate compound include primary phosphates such as sodium dihydrogen phosphate, potassium dihydrogen phosphate, magnesium dihydrogen phosphate and calcium dihydrogen phosphate;
Examples include secondary phosphates such as disodium hydrogen phosphate, dipotassium hydrogen phosphate, dimagnesium hydrogen phosphate, and dicalcium hydrogen phosphate, with sodium dihydrogen phosphate and potassium dihydrogen phosphate being preferred. The amount of the phosphoric acid compound is usually 0.01 to 1 mol of the azoalkane derivative.
About 10 to 10 mol, preferably about 0.1 to 5 mol is good.

The use of an alkaline earth metal oxide alone does not completely suppress the generation of acetic acid odor, but the combined use of an alkaline earth metal oxide and a phosphoric acid compound completely suppresses the generation of acetic acid odor. This is presumably because the phosphoric acid compound has an action of suppressing secondary decomposition accompanied by generation of acetic acid.

In the present invention, the deodorizing effect can be further improved by blending an alkali metal or alkaline earth metal hydroxide, carbonate, bicarbonate, silicate or the like, if necessary. Examples of the alkali metal include sodium and potassium, and examples of the alkaline earth metal include calcium, magnesium, and barium.
The amount of these compounds is usually about 0.01 to 10 mol, preferably about 0.1 to 5 mol, per 1 mol of the azoalkane derivative.

The foaming agent of the present invention may contain known foaming agents, foaming assistants, compounding agents, etc. as long as the effects are not impaired. As the foaming agent, for example, sodium bicarbonate, inorganic foaming agents such as ammonium carbonate, azobisisobutyronitrile, organic foaming agents such as p-toluenesulfonyl hydrazide, aliphatic hydrocarbons, chlorinated aliphatic hydrocarbons,
Physical blowing agents such as fluorinated aliphatic hydrocarbons, carbon dioxide gas, and nitrogen gas can be used.

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, and lithium stearate. , Magnesium stearate, aluminum stearate, calcium stearate, barium stearate, zinc stearate, cadmium stearate, lead stearate, dibasic lead stearate, calcium laurate, zinc laurate, zinc 2-ethylhexoate, dibasic Metallic soaps such as basic lead phthalate, inorganic salts such as tribasic lead sulfate, dibasic lead phosphite and basic lead sulfite, organic tin compounds such as dibutyltin dilaurate and dibutyltin dimaleate, dibutyltin dilaurate , Dibutyltin dimaleate, calcium-zinc, burr Beam - PVC composite stabilizer zinc, etc., can be mentioned sulfonic acid metal compounds.

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 blowing agent composition of the present invention can be produced by mixing the above-mentioned azoalkane derivative, a compound which generates ammonia by heating, and if necessary, other components according to a usual method. For mixing, a usual mixer such as a Henschel mixer or a ribbon mixer can be used.

The blowing agent composition of the present invention can be applied to various materials to be foamed in the same manner as the conventional blowing agent composition. 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 a known resin can be used.
Polyvinyl chloride, polyethylene, polypropylene, polymethyl acrylate, polymethyl methacrylate, ethylene-vinyl acetate copolymer, ethylene propylene terpolymer, acrylonitrile-butadiene-styrene terpolymer, polystyrene, polyacrylonitrile, polyurethane, urethane-vinyl chloride copolymer, and the like. be able to. Although not particularly limited as a synthetic rubber, for example, styrene butadiene rubber, nitrile butadiene rubber, silicone rubber, chloroprene rubber, isobutylene rubber, isoprene rubber, butadiene rubber, acrylic rubber, chlorinated butyl rubber, ethylene-propylene-diene terpolymer, etc. Can be mentioned. The foaming agent of the present invention is particularly effective for foaming thermoplastic polyurethane, 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 a foaming component contained in the foaming agent. 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 foaming component is pressed and heated with a press to reduce the foaming 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 to be mixed with 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, and is usually about 0.01 to 50 parts by weight, preferably about 0.1 to 30 parts by weight, per 100 parts by weight of the material to be foamed.

The temperature at the time of producing the foam is preferably at least 50 ° C. lower than the decomposition temperature of the foaming agent, more preferably at least 20 ° C. lower. In addition, foaming can be performed while causing a curing reaction or a crosslinking reaction. Foams obtained by using the foaming agent composition of the present invention, like conventional foams, civil engineering, agricultural, forestry and fisheries, automobiles and other transport equipment, electrical and electronic equipment, life-related products and a wide range of fields, It can be used as heat insulating material, interior material, sealing material, cushioning material, etc.

[0026]

The present invention will be described in more detail with reference to the following examples. Example 1 100 g of vinyl chloride resin, 5 g of 2,2'-azobis (2-acetoxy-4-methylpentane), 2 g of calcium oxide, 2 g of dipotassium hydrogen phosphate, 50 g of dioctyl phthalate (DOP), zinc stearate 2.5g
And kneaded at 150 ° C. with a calender roll to mold. The obtained sheet was placed in an oven at 220 ° C. and heated and foamed for 4 minutes. At that time, no acetic acid odor was generated. The obtained sheet had dense cells and was a foam having a thickness 3.5 times that of the unfoamed sheet and no acetic acid odor.

Example 2 100 g of vinyl chloride resin for paste resin, 2,2'-azobis (2-acetoxy-3,3-dimethylbutane) 5
g, calcium oxide 2 g, calcium dihydrogen phosphate 2
g, dioctyl phthalate (60 g), calcium stearate (3 g), calcium carbonate (50 g), and titanium dioxide (3 g) were thoroughly mixed and spread on a cotton cloth. 130-140
Heat to 1 ° C. for 1 minute to gel. Then 180 ~ 19
The mixture was foamed by heating at 0 ° C. for 2 minutes. At that time, no acetic acid odor was generated. The resulting sheet had homogeneous cells and was 2.3 times the foam of the non-foamed sheet without acetic acid odor.

EXAMPLE 3 5 g of 1,1'-azobis (1-acetoxy-1-phenylethane), 2 g of magnesium oxide, 2 g of potassium dihydrogen phosphate and 100 g of benzoyl peroxide were added to 100 g of the thermosetting silicone rubber compound. 5 g and 0.6 g of dicumyl peroxide were added and mixed with a calender roll until uniform. This was supplied to an extruder and extruded into a tube having an inner diameter of 10 mm and an outer diameter of 20 mm. This tube was cut into a length of 30 cm and placed in an oven at 220 ° C. for 10 minutes to heat and foam. At that time, no acetic acid odor was generated. The obtained sheet had dense cells, a specific gravity of 0.35, and was a foam having a smooth surface and no odor of acetic acid.

Comparative Example 1 In the same manner as in Example 1, foaming was carried out by heating without adding 2 g of calcium oxide and 2 g of dipotassium hydrogen phosphate. Although the obtained sheet had dense cells, acetic acid odor remained. In addition, an odor of acetic acid was generated during the foaming operation, the working environment was poor, and a local exhaust device and a gas mask were required.

[0030]

According to the present invention, acetic acid odor and the like are not generated,
Therefore, it is necessary to obtain a foaming agent composition which does not deteriorate the working environment and does not cause acetic acid odor or the like to adhere to the obtained foam, and a foam having a smooth surface and fine uniform cells obtained by using the same. Can be.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 101/00 C08L 101/00

Claims (3)

[Claims] 1. A blowing agent composition comprising an azoalkane derivative represented by the general formula (1), an alkaline earth metal oxide and a phosphoric acid compound. Embedded image [In the formula, R ¹ and R ² are the same or different and represent a lower alkyl group or an aryl group, and R ³ represents an alkyl group or an aryl group. ] 2. The blowing agent composition according to claim 1, wherein the azoalkane derivative is 1,1′-azobis (1-acetoxy-1-phenylethane). 3. A foam obtained by foaming using the foaming agent composition according to claim 1.