JPH08269223A - Expandable flame-retardant olefin resin composition - Google Patents

Abstract

PURPOSE: To obtain an expandable flame-retardant olefin resin composition which can give a high-expansion-degree noncross-linked olefin resin foam having uniformly distributed fine cells, exhibiting high flame retardancy in spite of no use of a halogenated compound and being stably produced because of easy temperature control in the expansion step. CONSTITUTION: This expandable flame-retardant olefin resin composition is prepared by adding 5-100 pts.wt. ternary flame retardant comprising polyammonium phosphate, a metal oxide and a nitrogen compound represented by the formula (wherein R<1> to R<3> are each hydrogen or 1-16C hydroxyalkyl, dihydroxyalkyl, hydroxyaryl or dihydroxyaryl) to 100 pts.wt. olefin resin component comprising 99-80wt.% noncross-linked olefin resin having a weight-average molecular weight of M1 and 1-20wt.% noncross-linked olefin resin having a weight-average molecular weight of M2 and satisfying the conditions: (1) M1 =50000-500000, M2 /M1 =5-100, and M2 <=7000000 or (2) M1 =50000-500000, M2 -M1 =300000 and M2 <=7000000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant olefin resin composition for foaming, and more specifically, a non-crosslinked flame-retardant olefin resin composition suitable for the production of high-magnification foamed flame-retardant olefin resin composition. Regarding things.

[0002]

2. Description of the Related Art Olefin resins such as polyethylene and polypropylene are used in various products in a wide variety of fields by utilizing their chemical and physical properties, from low molecular weight wax-like substances to ultra high molecular weight engineering plastics. Is used as.

In particular, low-boiling organic solvent type foaming agents such as dichlorotetrafluoroethane, thermal decomposition type foaming agents such as azodicarbonamide, or inert gas type foaming agents such as carbon dioxide are added to these olefin resins. BACKGROUND ART A foamed body obtained by mixing and uniformly dispersing it and heating it to foam an olefinic resin is extremely widely used as a heat insulating material, a cushioning material, a soundproofing material and the like.

However, the olefin resin is a crystalline resin, and when the olefin resin is heated to a temperature higher than the melting point, the viscoelasticity of the resin is rapidly lowered, and the olefin resin foam is easily broken in the foaming process of the olefin resin. Since it is in a state, it is difficult to stably produce a high-magnification foam having fine texture uniformly formed, for example, foamed 10 to 40 times and having a good texture. Conventionally, most foams obtained from non-crosslinked olefin resins have only coarse cells, and in general, most of them are used for packaging materials with little consideration given to appearance.

Since the olefin resin has a narrow temperature range showing viscoelasticity suitable for foaming, extremely severe temperature control of the foaming process is required regardless of which of the above-mentioned foaming agents is used.

Therefore, in order to stably produce a high-magnification foam in which fine bubbles are uniformly dispersed, an olefin resin is previously cross-linked by irradiation with an organic peroxide or ionizing radiation, and is suitable for foaming. In addition, a method of foaming is adopted after modification so that the temperature range exhibiting viscoelasticity is expanded.

However, in order to crosslink the olefinic resin, as described above, a crosslinking means such as irradiation with an organic peroxide or ionizing radiation is required, and a large apparatus for that purpose and an organic peroxide which is troublesome to handle are required. Since a material such as an oxide is used, the manufacturing cost is increased, and the cross-linked olefin resin is difficult to reuse.

Most of the above-mentioned olefin-based resins are originally resins that easily burn, and in particular, when an olefin-based resin foam expanded at a high ratio is used as a building material for roofs and walls, it is flame-retardant. There is a strong demand for sex.

As a method of making an olefin resin flame-retardant, a method of adding a halogen-containing compound has been generally used. Although they certainly show a high degree of flame retardancy, and the deterioration of molding processability and the mechanical strength of molded products are relatively small, a large amount of irritation occurs during molding and when incinerated as waste. Generated fumes, corroded the equipment and required detoxification equipment.

Therefore, development of a halogen-free flame retardant having a high degree of flame retardancy is eagerly awaited, but at present, a halogen-free flame retardant exhibiting flame retardancy comparable to that of a halogen flame retardant has not been obtained.

Under these circumstances, studies on flame-retardant olefin resins by adding hydrated metal oxides such as aluminum hydroxide, magnesium hydroxide, and basic magnesium carbonate which do not generate harmful gas during combustion have been made. Has been done.
However, a large amount of the above hydrated metal oxide must be added in order to impart sufficient flame retardancy to the olefin resin that is flammable with these hydrated metal oxides, and as a result, these Various products obtained from the olefin-based resin composition have a problem that their mechanical strength is remarkably lowered and they cannot be put to practical use.

As a non-halogen flame retardant, Japanese Patent Laid-Open No.
JP-A-3-61055 discloses that polyolefins include ammonium polyphosphate and tris- (2-hydroxyethyl).
-A two-component flameproofing agent comprising isocyanurate is disclosed.

However, even in the case of the two-component flame retardant composed of ammonium polyphosphate and tris- (2-hydroxyethyl) -isocyanurate, the olefin resin foam having a high porosity and a high expansion ratio is used. When used as a building material for roofs and walls, sufficient flame retardancy cannot be expected.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to foam a non-crosslinked olefin resin foam which is foamed at a high magnification and fine bubbles are uniformly dispersed. To provide a flame-retardant olefin resin composition for foaming, which imparts a high degree of flame retardancy to the body without using a halogen-containing compound, and can be manufactured stably with easy temperature control in the foaming step. is there.

[0015]

The present invention provides a compounding ratio of 99 to 80% by weight of a non-crosslinked olefin resin having a weight average molecular weight M _{1 and 1} to 20% by weight of a noncrosslinked olefin resin having a weight average molecular weight M _2. , (1) M ₁ = 50,000 to 500,000, M ₂ /
M ₁ = 5 to 100, M ₂ ≦ 7 million, or (2) M ₁
= 50000 to 500000, M ₂ -M ₁ = 30 million in, M ₂ ≦ 700
With respect to 100 parts by weight of the olefin resin component which is 10,000,
A flame-retardant olefin resin composition for foaming, comprising 5 to 100 parts by weight of a three-component flame retardant of ammonium polyphosphate, a metal oxide and a nitrogen compound represented by the following structural formula.

Embedded image (In the formula, R ^{1 to} R ³ are each hydrogen or C ^{1 to} C 1.
It represents 6 hydroxyalkyl groups, dihydroxyalkyl groups, hydroxyaryl groups having 1 to 16 carbon atoms, and dihydroxyaryl groups. ) Is the gist.

Weight average molecular weight M of the above olefin resin
₁ and M ₂ are gel permeation chromatography (hereinafter,
It is abbreviated as GPC. ) Is measured.

If the weight average molecular weight M ₁ is less than 50,000, the viscosity of the olefin resin composition blended with the weight average molecular weight at the time of melting becomes too low and the bubbles are broken (foaming) in the foaming step remarkably. It is difficult to form bubbles and evenly disperse the bubbles. On the other hand, if the weight average molecular weight M ₁ exceeds 500,000, the fluidity of the olefin resin composition blended with the weight average molecular weight remarkably deteriorates, and molding cannot be performed by a usual extruder. Weight average molecular weight M of one component of the olefin resin
₁ is preferably 50,000 to 200,000 when polyethylene is used, and 300,000 to 50 when polypropylene is used.
10,000 is preferable.

The other components of the olefin resin and the relationship between them are as follows: (1) M ₁ = 50,000 to 500,000, M ₂ / M ₁ = 5
˜100, M ₂ ≦ 7,000,000, or (2) M ₁ = 50,000˜
500,000, M ₂ -M ₁ = 30 million in, M ₂ ≦ 700 million in, in but indicated by the value of M ₂ / M ₁ is M ₂ / M ₁ = 5~100, preferably M ₂ / M ₁ = 6 to 80.

That is, the weight average molecular weight M₂But 50,000
When the weight is full, the weight average molecular weight M₁For the reasons mentioned in section
Not preferable, but the above weight average molecular weight M₂But above (1)
M ₂/ M₁= 5 to 100, and M of (2)₂-M₁=
If any of the conditions of 300,000 is exceeded, the above weight average
Molecular weight M₁Can be uniformly dispersed with the olefin resin component of
In addition, the expansion ratio of the resulting foam varies and the air bubbles are coarse.
And the surface condition of the foam itself was very rough.
Will be things. Furthermore, the weight average molecular weight M₂≤ 7 million
Then, the fluidity of the olefin resin composition containing this
Is significantly reduced, and molding cannot be performed with a normal extruder.

When the blending ratio of the non-crosslinked olefin resin having the weight average molecular weight M ₂ is less than 1% by weight, the olefin resin composition blended with the resin has a small melt tension, foams at a high ratio and is fine. A foam having uniformly dispersed cells cannot be obtained. On the other hand, if the blending ratio of the non-crosslinked olefin resin having the weight average molecular weight M ₂ exceeds 20% by weight, the melt tension of the olefin resin composition blended with it becomes too large, and sufficient foaming cannot be achieved.

Three-component flame retardant of ammonium polyphosphate / metal oxide / nitrogen compound represented by the following structural formula 5
To 100 parts by weight of a flame-retardant olefin resin composition for foaming,

Embedded image (In the formula, R ^{1 to} R ³ are each hydrogen or C ^{1 to} C 1.
It represents 6 hydroxyalkyl groups, dihydroxyalkyl groups, hydroxyaryl groups having 1 to 16 carbon atoms, and dihydroxyaryl groups. In the three-component flame-retardant system consisting of), ammonium polyphosphate has a general formula (NH ₄ P
O ₃ ) _{n, in} which n = 200 to 1000 or so, is preferable, and the surface thereof is coated with a melamine / formaldehyde resin or the like to be used in the form of a free-flowing, poorly water-soluble powder. It is preferable.

The metal oxide may be an oxide having any valence and is not particularly limited. For example, magnesium oxide, aluminum oxide, zinc oxide,
Examples thereof include titanium oxide, cobalt oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide and nickel oxide. Above all, titanium dioxide is preferably used.

Examples of the nitrogen compound represented by the above structural formula include, for example, isocyanuric acid, mono (hydroxymethyl) isocyanurate, bis (hydroxymethyl) isocyanurate, tris (hydroxymethyl) isocyanurate, mono (dihydroxy). Methyl) isocyanurate, bis (dihydroxymethyl) isocyanurate, tris (dihydroxymethyl) isocyanurate, mono (2-hydroxyethyl) isocyanurate, bis (2
-Hydroxyethyl) isocyanurate, tris (2-
Hydroxyethyl) isocyanurate, tris (1,2)
-Dihydroxyethyl) isocyanurate, tris (3
-Hydroxypropyl) isocyanurate, tris (2,3-dihydroxypropyl) isocyanurate,
Tris (4-hydroxybutyl) isocyanurate, Tris (3,4-dihydroxybutyl) isocyanurate, Tris (8-hydroxyoctyl) isocyanurate, Tris (4-hydroxyphenyl) isocyanurate, Tris (2,4-dihydroxyphenyl) ) Isocyanurate, tris (2,3-dihydroxyphenyl) isocyanurate and the like can be mentioned. These nitrogen compounds represented by the above structural formulas may be used alone, and 2
One or more species may be used in combination. Above all, tris (2-hydroxyethyl) isocyanurate is preferably used because of its flame retardant effect.

The addition amount of the ammonium polyphosphate / metal oxide / nitrogen compound represented by the above structural formula of the three-component flame retardant is such that ammonium polyphosphate and metal oxide are added to 100 parts by weight of the olefin resin component. And 5 to 100 parts by weight of a three-component flame retardant of a nitrogen compound represented by the following structural formula. The compounding ratio in the three-component flame retardant is 40 to 94.9% by weight of the above ammonium polyphosphate, metal oxide. 5 to 40% by weight, and the nitrogen compound represented by the above structural formula is preferably used in the range of 0.1 to 20% by weight, and sufficient flame retardancy cannot be obtained at a compounding ratio outside the above range. .

If the amount of the three-component flame retardant added in the above range is less than 5 parts by weight based on 100 parts by weight of the olefin resin component, sufficient flame retardancy cannot be obtained.
If it exceeds 0 parts by weight, a uniform foam cannot be obtained.

In the present invention, in addition to the above-mentioned three-component flame retardant, for example, a flame retardant aid made of a hydrated metal oxide such as aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate and dawsonite is the above-mentioned olefin-based flame retardant. It may be added to the resin. The amount of the flame-retardant auxiliary agent composed of the hydrated metal oxide varies depending on the amount of the three-component flame retardant added, but is preferably 100 parts by weight or less relative to 100 parts by weight of the olefin resin component. If the amount added exceeds 100 parts by weight, the flame retardancy is enhanced, but the foaming characteristics of the olefin resin composition are impaired, and foaming cannot be performed at a high magnification,
Also, a cell structure in which fine bubbles are uniformly dispersed cannot be obtained,
Both appearance and mechanical strength are reduced.

Further, if necessary, a foam control agent, an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a colorant and the like may be added to the flame-retardant olefin resin composition for foaming of the present invention. Good.

In order to produce a non-crosslinked flame-retardant olefin resin foam using the flame-retardant olefin resin composition for foaming of the present invention, the foaming method is not particularly limited, and it is an extrusion foaming method. Known foaming methods such as a pressure foaming method and a normal pressure foaming method can be applied.

In addition to the above-mentioned foaming method and foaming agent, the extrusion foaming method is, for example, melt-kneading the above-mentioned flame-retardant olefin resin composition for foaming in an extruder, and in the middle of the kneading part of the extruder. An inflatable liquid type foaming agent such as dichlorotetrafluoroethane or an inert gas type foaming agent such as carbon dioxide gas is pressed into a molten resin through a foaming agent injection port provided in This is a method in which a resin composition preliminarily mixed with a thermal decomposition type foaming agent such as azodicarbonamide is melt-kneaded with an extruder and extruded from an extrusion mold while foaming into an appropriate shape.

In the pressure foaming method, for example, the above flame-retardant olefin resin composition for foaming is melt-kneaded by an extruder, a roll or the like, and the kneaded material is extruded, pressed, or formed into a sheet by an appropriate means. Preform into any other suitable shape, put the preform in a pressure chamber such as an autoclave and heat it under pressure, and expandable liquid type foaming agent such as dichlorotetrafluoroethane or inert gas type foaming such as carbon dioxide. In this method, the surface of the preform is impregnated with the agent, and then the pressure in the pressure chamber is released to cause foaming.

In the normal pressure foaming method, for example, a composition obtained by previously mixing a thermal decomposition type foaming agent such as azodicarbonamide with the above flame-retardant olefin resin composition for foaming is used in an extruder or at a temperature at which the foaming agent does not decompose. Melt and knead with rolls, etc., and preform the kneaded material into a sheet or other appropriate shape by extrusion molding, press molding or other appropriate means, and then introduce the preformed product into a heating chamber such as a hot air oven or a heating bath. It is a method of foaming under normal pressure.

The foaming agent used in each of the above foaming methods also comprises
It is not particularly limited, and may be a low-boiling organic solvent, an expanding liquid type foaming agent such as a swelling agent, an inert gas type foaming agent, a foaming agent prepared for an olefin resin such as a thermal decomposition type foaming agent. Any foaming agent can be used.

The flame-retardant olefin resin composition for foaming of the present invention is preferably used as a non-crosslinked flame-retardant olefin resin foam which is foamed at a foaming ratio of about 10 to 40 times, but has excellent properties. Is maintained even outside the range of the expansion ratio.

[0034]

The flame-retardant olefin resin composition for foaming of the present invention is a non-crosslinked olefin resin 99 having a weight average molecular weight of M _1.
In 80% by weight and the weight average molecular weight non-crosslinked olefin resin 1 to 20% by weight of the blend ratio of _{M 2, (1) M 1} = 5 million in to 50 million _{in, M 2 / M 1 = 5~100} , M 2 ≤ 7 million,
Or, (2) M ₁ = 50,000 to 500,000, M ₂ −M ₁ = 30
Olefin-based resin component 10 with M ₂ ≦ 7 million
Ammonium polyphosphate, metal oxide, and nitrogen compound represented by the following structural formula relative to 0 parts by weight

[0035]

[Chemical 4]

(In the formula, R ^{1 to} R ³ each represent hydrogen or a hydroxyalkyl group having 1 to 16 carbon atoms, a dihydroxyalkyl group, a hydroxyaryl group having 1 to 16 carbon atoms, or a dihydroxyaryl group.)

Since 5 to 100 parts by weight of the three-component flame retardant of (3) is added, a non-crosslinked olefin resin foam which is foamed at a high ratio and in which fine bubbles are uniformly dispersed is prepared by using a halogen-containing compound. A high degree of flame retardancy can be imparted without using.

Further, since the flame-retardant olefin resin composition for foaming of the present invention has a broad temperature range suitable for foaming in the foaming step, it is a high-magnification, non-crosslinking olefin resin composition in which fine bubbles are uniformly dispersed. Since it is possible to stably produce a resin foam, and it is not necessary to use a special device for crosslinking an olefin resin or a dangerous material such as an organic peroxide, which is troublesome to handle, It can greatly contribute to the cost reduction of the olefin resin foam.

[0039]

Embodiments of the present invention will be described below.

(Weight average molecular weight M₁Uncrosslinked olefins
Resin) M₁-1: Low density polyethylene (product of Mitsubishi Chemical Co., Ltd.
Name: LF440HB, M ₁= 710,000) M₁-2: Polypropylene (product of Mitsui Petrochemical Co., Ltd.
Name: F601, M₁= 180,000) M₁-3: Polypropylene (trade name: E, manufactured by Mitsubishi Chemical Corporation)
C8, M₁= 460,000)

[0041] (weight average molecular weight M uncrosslinked olefin resin ₂₎ M ₂ -1: low-density polyethylene (manufactured by Mitsubishi Chemical Corporation, trade _{name: ZC-30B, M 2 =} 14 million in) M ₂ -2: density Polyethylene (Mitsui Petrochemical Co., Ltd., trade name: HiZex Million 240M, M ₂ = 230
Ten thousand) M ₂ -3: high-density polyethylene (Mitsui Petrochemical Co., Ltd., trade name: Hizex Million 320M, M ₂ = 280
10,000) M ₂ -4: Polypropylene (manufactured by Mitsubishi Chemical Co., trade name: E
C9, M ₂ = 50,000,000)

(Three-component flame retardant) Ammonium polyphosphate: manufactured by Sumitomo Chemical Co., Ltd., trade name: SUMISsafe P tris (2-hydroxyethyl) isocyanurate: abbreviation THEIC TiO ₂ : rutile titanium dioxide

(Antioxidant) ADEKA ARGUS CORPORATION, trade name: Mark328

(Examples 1 and 2) With the compounding ratios shown in Table 1,
A non-crosslinked olefin resin M ₁ and M ₂ , a three-component flame retardant and an antioxidant were dry blended to prepare a flame retardant olefin resin composition for foaming. Using the flame-retardant olefin resin composition for foaming, a 65 mmφ extruder (L / D = 35) having a foaming agent pressure inlet in the middle of the cylinder was used, and 90 kg / kg of a carbon dioxide blowing agent was introduced from the foaming agent pressure inlet.
While continuously injecting at a pressure of cm ^2, the mixture is heated and kneaded at 140 ° C., and a rod-shaped non-crosslinked olefin resin foam is extruded at a rate of 15 kg / hr from a rod mold having a diameter of 2 mmφ set to 113 ° C. Was produced by the extrusion foaming method.

The non-crosslinked olefin resin foam obtained was evaluated by the following method. The evaluation results are shown in Table 1.

1. Expansion Ratio The specific gravity of the flame-retardant olefin resin composition for foaming and the obtained non-crosslinked olefin resin foam was measured and calculated from the ratio.

2. Flame retardance According to JIS D 1201, oxygen index is measured,
◯: Oxygen index of 28 or more, x: less than oxygen index of 28 were evaluated in two stages.

3. Cell Structure and Appearance Visually observe the surface and cut surface of the obtained non-crosslinked olefin resin foam, and ○: the cell structure is finely and uniformly dispersed, and the appearance can be judged to be good with a smooth surface. No, there is a defect such as non-uniform cell structure, x:
Or / and, there are some defects such as rough appearance, 2
The grade was evaluated.

(Example 3) Flame-retardant olefin resin composition for foaming by dry blending non-crosslinking olefin resins M ₁ and M ₂ , ternary flame retardant and antioxidant at the compounding ratio shown in Table 1. Was prepared. The flame-retardant olefin resin composition for foaming was heated and kneaded using a roll at 140 ° C., and then a sheet having a thickness of 2 mm was formed by pressing. Then, the non-crosslinked olefin resin sheet is heated to 110 ° C. in an autoclave, and 90 kg / c of carbon dioxide blowing agent is added.
Flame-retardant olefin resin composition for foaming ^{1 at} a pressure of m ^2.
After impregnating 5 parts by weight with respect to 00 parts by weight and sufficiently dissolving it, the pressure valve of the autoclave is opened to foam the foamable flame-retardant olefin resin composition, and a sheet-shaped non-crosslinked olefin resin foam The body was made by the pressure foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Example 4) Non-crosslinked polypropylene M ₁ −
3 and after an equal weight of non-crosslinked polyethylene M ₂ -3 uniformly dissolved in hot xylene and dried in vacuo at 80 ° C., and grinding the resulting resin mixture, non-crosslinked polypropylene M in the pulverized pieces 20 parts by weight _1-3, 80 parts by weight, a three-component flame retardant and an antioxidant were dry-blended at the compounding ratio shown in Table 1 to prepare a flame-retardant olefin resin composition for foaming. The flame-retardant olefin resin composition for foaming was prepared by using the same extruder as in Example 1, using an extruder side of 195 ° C. and a mold 16
A rod-shaped non-crosslinked olefin resin foam was produced by an extrusion foaming method at an extrusion rate of 15 kg / hr at 0 ° C. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 5 The same flame-retardant olefin resin composition for foaming as in Example 4 was used, except that the blowing agent was changed to Freon 114 (dichlorotetrafluoroethane), and the injection pressure was set to 50 k.
g / cm ² , the same extruder as in Example 1 was used, and as in Example 4, the extruder side was 195 ° C. and the mold 160 was used.
A rod-shaped non-crosslinked olefin resin foam was produced by an extrusion foaming method at an extrusion rate of 15 kg / hr at 0 ° C. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0052]

[Table 1]

(Examples 6 and 7) With the compounding ratios shown in Table 2,
Non-crosslinked olefin resin M ₁ and M ₂ , three-component flame retardant, antioxidant, and 10 parts by weight of azodicarbonamide (foaming agent) based on 100 parts by weight of the polyethylene component.
Was dry-blended to prepare a foamable flame-retardant olefin resin composition. The foamable flame-retardant olefin resin composition was used using an extruder having a diameter of 65 mmφ (L / D = 35),
The mixture was heated and kneaded at 135 ° C., and a foamable non-crosslinking olefin resin sheet having a thickness of 2 mm was produced from a mold set at 115 ° C. at an extrusion rate of 15 kg / hr. The above-mentioned foamable non-crosslinked olefin resin sheet was prepared in a foaming furnace at 240 ° C. by a normal pressure foaming method to produce a non-crosslinked olefin resin foamed sheet. The resulting non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 8 A non-crosslinking olefin resin M ₁ and M ₂ , a three-component flame retardant and an antioxidant were dry-blended at a blending ratio shown in Table 2 to prepare a foamable flame-retardant polyethylene composition. did. The foamable flame-retardant olefin resin composition was produced in the same manner as in Example 1 by producing a rod-shaped non-crosslinked olefin resin foam by an extrusion foaming method. The resulting non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 2.

[0055]

[Table 2]

(Comparative Examples 1 to 4) With the compounding ratios shown in Table 3,
A non-crosslinked olefin resin, a flame retardant and an antioxidant were dry blended to prepare a flame retardant olefin resin composition for foaming. The flame-retardant olefin resin composition for foaming was produced in the same manner as in Example 1 by producing a rod-shaped non-crosslinked olefin resin foam by an extrusion foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 3.

(Comparative Examples 5 and 6) With the compounding ratios shown in Table 3,
A non-crosslinked olefin resin, a flame retardant and an antioxidant were dry blended to prepare a flame retardant olefin resin composition for foaming. The flame-retardant olefin resin composition for foaming was produced in the same manner as in Example 3 to prepare a rod-shaped non-crosslinked olefin resin foam by a pressure foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 3.

[0058]

[Table 3]

(Comparative Examples 7 and 8) With the compounding ratios shown in Table 4,
A non-crosslinked olefin resin, a flame retardant, and an antioxidant were dry-blended to prepare flame-retardant olefin resin compositions for foaming. The flame-retardant olefin resin composition for foaming,
In the same manner as in Example 5, rod-shaped non-crosslinked olefin resin foams were produced by the extrusion foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 4.

(Comparative Examples 9 to 11) Non-crosslinking olefin resin, flame retardant and antioxidant were dry blended at the compounding ratios shown in Table 4 to prepare flame retardant olefin resin compositions for foaming. The flame-retardant olefin resin composition for foaming,
In the same manner as in Example 5, a rod-shaped non-crosslinked olefin resin foam was produced by an extrusion foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 4.

Comparative Example 12 A flame-retardant olefin resin composition for foaming was prepared by dry blending a non-crosslinking olefin resin, a flame retardant and an antioxidant at the compounding ratio shown in Table 4. The flame-retardant olefin resin composition for foaming was produced in the same manner as in Example 1 by producing a rod-shaped non-crosslinked olefin resin foam by an extrusion foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 4.

[0062]

[Table 4]

Comparative Examples 13 and 14 Non-crosslinking olefin resins, flame retardants and antioxidants were dry blended at the compounding ratios shown in Table 5 to prepare foaming flame retardant olefin resin compositions. The flame-retardant polyethylene composition for foaming was produced in the same manner as in Example 1 by producing a rod-shaped non-crosslinked olefin resin foam by an extrusion foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1,
The results are shown in Table 5.

(Comparative Example 15) A non-crosslinking olefin resin, a flame retardant and an antioxidant were dry blended at the compounding ratio shown in Table 5 to prepare a flame retardant olefin resin composition for foaming. The flame-retardant olefin resin composition for foaming was produced in the same manner as in Example 3 to prepare a rod-shaped non-crosslinked olefin resin foam by a pressure foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 5.

(Comparative Example 16) A non-crosslinked olefin resin was prepared in the same manner as in Examples 6 and 7 with the compounding ratios shown in Table 5.
A flame retardant olefin resin composition for foaming was prepared by dry blending a flame retardant and an antioxidant. Using the flame-retardant olefin resin composition for foaming, a non-crosslinked olefin resin foam sheet was produced in the same manner as in Example 6 by an atmospheric pressure foaming method. The obtained non-crosslinked olefin resin foam was evaluated in the same manner as in Example 1, and the results are shown in Table 5.

[0066]

[Table 5]

[0067]

Since the flame-retardant olefin resin composition for foaming of the present invention is constructed as described above, it is a non-crosslinked olefin resin foam which is foamed at a high ratio and in which fine bubbles are uniformly dispersed. Without the use of halogen-containing compounds,
A high degree of flame retardancy can be imparted.

Further, since the flame-retardant olefin resin composition for foaming of the present invention has a broad temperature range suitable for foaming in the foaming step, it is a high-magnification, non-crosslinked olefin resin composition in which fine bubbles are uniformly dispersed. Since it is possible to stably produce a resin foam and it is not necessary to use a special device for crosslinking an olefin resin or a dangerous material such as an explosive organic peroxide, It can greatly contribute to the cost reduction of the olefin resin foam.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Qi Shirato 2-2 Kamitobaue Tonkocho, Minami-ku, Kyoto City Sekisui Chemical Co., Ltd. -2 Sekisui Chemical Co., Ltd.

Claims (1)

[Claims] In 1. A weight average molecular weight non-crosslinked olefin resin 99 to 80 wt% and a weight average molecular weight non-crosslinked olefin resin 1 to 20% by weight of the blending ratio of M ₂ of M _1, (1)
M ₁ = 50,000 to 500,000, M ₂ / M ₁ = 5 to 100, M ₂ ≦
7 million or (2) M ₁ = 50,000 to 500,000, M ₂ -M
_{5 to} 100 parts by weight of three-component flame retardant of ammonium polyphosphate, metal oxide and nitrogen compound represented by the following structural formula, based on 100 parts by weight of olefin resin component with ₁ = 300,000 and M ₂ ≦ 7 million. A flame-retardant olefin-based resin composition for foaming. Embedded image (In the formula, R ^{1 to} R ³ are each hydrogen or C ^{1 to} C 1.
It represents 6 hydroxyalkyl groups, dihydroxyalkyl groups, hydroxyaryl groups having 1 to 16 carbon atoms, and dihydroxyaryl groups. )