JPH0748467A - Expandable polyolefinic resin composition containing inorganic filler - Google Patents

Abstract

PURPOSE:To deodorize ammonia formed as a by-product and detoxify the ammonia in thermally expanding an expandable polyolefinic resin composition containing a large amount of an inorganic filler and azodicarbonamide as a foaming agent. CONSTITUTION:This expandable polyolefinic resin composition containing an inorganic filler is obtained by comprising 50-250 pts.wt. inorganic filler, a decomposable foaming agent consisting essentially of azodicarbonamide and a reactive deodorizing agent for deodorizing ammonia in 100 pts.wt. polyolefinic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamable polyolefin resin composition containing a large amount of inorganic filler.

[0002]

BACKGROUND OF THE INVENTION Inorganic filler-containing expandable polyolefin in which a large amount of inorganic filler is contained in a polyolefin resin such as polyethylene or polyethylene, and a decomposable foaming agent containing azodicarbonamide as a main component is contained therein. -Based resin compositions are known (for example, JP-A-57-115).
432).

When such an inorganic filler-containing expandable polyolefin resin composition is heated and foamed, a nitrogen gas effective for foaming is generated by thermal decomposition of azodicarbonamide to obtain a foam. Gas is a byproduct. The gas produced as a by-product contains ammonia. This ammonia occurs remarkably when foaming a resin composition containing a large amount of inorganic filler.

The large amount of ammonia produced not only smells bad, but corrodes the foaming device. Further, it remains in the foam, and when the foam is used for various purposes, there is a problem that the metal parts used together with the foam are corroded.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and heat-foams a foamable polyolefin resin composition containing a large amount of an inorganic filler and containing azodicarbonamide as a foaming agent. The purpose of this is to deodorize the ammonia produced as a byproduct to make it harmless.

[0006]

The above object is to provide a decomposable foaming agent containing 50 to 250 parts by weight of an inorganic filler in 100 parts by weight of a polyolefin resin and further containing an azodicarbonamide as a main component and an ammonia. This can be achieved by the inorganic filler-containing expandable polyolefin resin composition containing a reactive deodorant for deodorizing.

In the present invention, the polyolefin resin contains a relatively large amount of inorganic filler. As the polyolefin resin, various polyolefin copolymers such as ethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer and ethylene-propylene copolymer are used.

As the inorganic filler, calcium carbonate, magnesium carbonate, calcium oxide, magnesium oxide, calcium hydroxide is added in order to impart various performances such as rigidity, flame retardancy, earthquake resistance or mass feeling, depending on the purpose. , Magnesium hydroxide, calcium silicate, magnesium silicate,
Various inorganic powders such as talc, clay, mica, dawsonite and antimony trioxide are used.

These inorganic fillers are used in an amount of 50 to 250 with respect to 100 parts by weight of the polyolefin resin, depending on the purpose.
It is contained in a large amount in a range of 70 parts by weight, preferably 70 to 150 parts by weight. These inorganic fillers may be blended with the polyolefin resin as they are, but it is desirable to pretreat the inorganic filler with stearic acid, a silane coupling agent or the like. By such treatment, the resin composition is easily molded, the appearance of the product is improved, and the mechanical properties are improved.

Further, a decomposing type foaming agent containing azodicarbonamide as a main component is contained. Azodicarbonamide is an excellent blowing agent for polyolefin resins, and it is preferable to use this azodicarbonamide alone, but benzenesulfonyl hydrazide, N,
Decomposition type foaming agents used for polyolefin resins such as N'-dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide, p, p'-oxybis (benzenesulfonylhydrazide) namide may be used in combination.

The decomposable foaming agent containing azodicarbonamide as a main component is contained in an appropriate amount depending on the expansion ratio, but is generally contained in the range of 3 to 50 relative to 100 parts by weight of the polyolefin resin. To be done.

Further, it contains a reactive deodorizing agent for deodorizing ammonia. This reactive deodorant is one that eliminates the ammonia odor by reacting with ammonia, and polyphenol condensate, sodium hypochlorite, chlorine dioxide and the like are used. In particular, polyphenol condensates are preferable in terms of handling workability and deodorizing effect. The content of these reactive deodorants depends on the amount of azodicarbonamide used, but it is generally preferable to add them in the range of 1 to 5 parts by weight with respect to 100 parts by weight of the polyolefin resin.

The expandable polyolefin resin composition containing an inorganic filler of the present invention usually contains the above-mentioned various materials in a required amount and, if necessary, a flame retardant, an antioxidant, a cross-linking agent, an antistatic agent. A known additive such as a lubricant or a colorant is mixed and uniformly mixed, and the resin is foamed by melt-kneading the mixture with an extruder or the like at a temperature equal to or higher than the decomposition temperature of the foaming agent and extruding from a mold, or It is made into a product by melt-kneading at a temperature at which the foaming agent does not decompose to once form a foamable molded article, and then thermally decomposing the foaming agent to foam the resin.

[0014]

When 100 to 100 parts by weight of the polyolefin resin is mixed with 50 to 250 parts by weight of the inorganic filler and this is foamed by using the decomposing type foaming agent containing azodicarbonamide as a main component, when the azodicarbonamide is decomposed. In addition, a large amount of ammonia is by-produced due to the influence of a large amount of inorganic filler.

Therefore, if the above-mentioned expandable polyolefin resin composition containing a large amount of inorganic filler contains an appropriate amount of reactive deodorant for deodorizing ammonia,
The ammonia produced as a by-product reacts with this reactive deodorant to eliminate the ammonia odor. When an adsorptive deodorizing agent such as zeolite is used instead of the reactive deodorizing agent, the above-mentioned action does not occur and the ammonia odor cannot be eliminated.

[0016]

EXAMPLES Examples and comparative examples of the present invention will be shown below. Example 1 Ethylene-vinyl acetate copolymer (Evaflex 36
0: Mitsui DuPont Polychemical Co., Ltd.) 100 parts by weight,
Aluminum hydroxide as an inorganic filler (Higilite H
32: Showa Denko KK) 150 parts by weight, 20 parts by weight of azodicarbonamide as a foaming agent, and 3 parts by weight of polyphenol condensate (Pancil: manufactured by Lily Kasei) as a reactive deodorant.

This mixture was melt-kneaded with a mixing roll at 130 ° C. and pressed to form a foamable sheet having a thickness of 2 mm, which was irradiated with a high energy electron beam at a dose of 5 Mrad. Crosslink the resin and add 2
A foamed sheet was obtained by heating and foaming in a gear oven at 40 ° C.

This foamed sheet is placed in a closed glass container.
After leaving it for a while, a sensory evaluation was performed on the ammonia odor in the glass container, and no ammonia odor was felt.

Comparative Example 1 In Example 1, no polyphenol condensate as a reactive deodorant was added. Other than that was performed like Example 1. In this case, a very strong ammonia odor that could not be sucked was generated.

Comparative Example 2 In Example 1, 3 parts by weight, 5 parts by weight, and 10 parts by weight of zeolite were blended as an adsorption type deodorant in place of the polyphenol condensate of the reaction type deodorant. Other than that was performed like Example 1. In this case, any combination of
Similar to Comparative Example 1, a very strong ammonia odor that could not be sucked was generated.

[0021]

As described above, the expandable polyolefin resin composition containing an inorganic filler of the present invention contains 50 to 250 parts by weight of the inorganic filler in 100 parts by weight of the polyolefin resin, and further contains azodicarbonamide as a main component. It contains a decomposing foaming agent as a component and a reactive deodorizing agent for deodorizing an ammonia, which makes it possible to deodorize and detoxify the ammonia generated during foaming by heating.

Therefore, according to the expandable polyolefin resin composition containing an inorganic filler of the present invention, a foam to which various properties such as rigidity, flame retardancy, earthquake resistance, and mass feeling are imparted by the inorganic filler is obtained. be able to. Moreover, since ammonia does not occur, it does not corrode not only the working environment, but also the foaming device, and since ammonia does not remain in the foam, it can be used in various applications. The advantage is that it does not corrode the metal parts used together.

Claims (1)

[Claims] 1. A decomposable foaming agent containing 50 to 250 parts by weight of an inorganic filler in 100 parts by weight of a polyolefin resin, and further containing azodicarbonamide as a main component, and a reactive deodorizing agent for deodorizing ammonia. An expandable polyolefin-based resin composition containing an inorganic filler, which comprises: