JPH0770348A - Foamable organic polymer composition and production of foam - Google Patents

Abstract

PURPOSE:To obtain the title composition which is highly expandable and does not cause problems of, e.g. ozonosphere depletion by mixing a foamable compound comprising an organic polymer and a chemical foaming agent with a physical foaming agent, e.g. a rare gas. CONSTITUTION:A physical foaming agent selected from rare gases and carbon dioxide is injected into a compound which comprises an organic polymer (e.g. polyethylene) and a chemical foaming agent (e.g. azodicarbonamide) and is for use in producing a foam having an expansion ratio of 50% or higher. Thus, the title composition is produced. This composition may further contain a non- foamable organic polymer (e.g. polyethylene). The composition is foamed to obtain a highly expanded foam which has almost the same ultrahigh expansion ratio as foams produced with a chloro fluorocarbon and has a homogeneous and fine foam structure. When the composition is used for forming the insulating foam layer of a foam-insulated conductor, e.g. an electric wire, in which especially high insulating properties are required, the insulated conductor can be free from buckling etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a foamable organic polymer composition which is uniform, fine and has a high foamability of, for example, 75% or more, and which can be suitably used particularly for an insulating layer of a coaxial cable. And a method for producing a foam using the same.

[0002]

2. Description of the Related Art Conventionally, various freon gases have been used as a foaming agent in order to obtain a foam having a high degree of foaming.
Its use tends to be regulated for environmental protection because it causes destruction of the ozone layer.

[0003]

At present, various foaming agents have been studied in place of CFC gas, but all of them have a problem that it is difficult to obtain a highly foamed product having uniform foaming. Therefore, it is possible to obtain a foam having a high degree of foaming, a uniform and fine foam structure without using CFC gas, and a method for producing a foam that does not cause an environmental problem such as destruction of the ozone layer, or a foam such as this. There is a need for foamable compositions that can be provided.

[0004]

The present invention comprises a compound (A) for foaming containing 50% or more of an organic polymer (A-1) and a chemical foaming agent (A-2), a rare gas and a physical foaming agent, and The present invention relates to a foamable organic polymer composition containing at least one (B) selected from carbon dioxide gas, and a method for producing a foam using the composition to obtain a foam having a high degree of foaming.

The physical blowing agent (B) used in the present invention is
At least one selected from helium, neon, argon, krypton, noble gases of xenon and radon, and carbon dioxide gas. Among them, argon has a higher degree of foaming and a more uniform foam, does not destroy the ozone layer like CFC gas, is extremely stable and does not show a chemical reaction, and explodes. It is particularly preferable in that there is no danger such as. The degree of foaming is measured by the specific gravity method and is defined by the following formula.

[0006]

[Equation 1]

(In the formula, ρ ₀ is the density of the resin before foaming, and ρ is the density of the foam.)

When a mixture of rare gas and carbon dioxide is used as the component (B), the component ratio (volume ratio) is 30:
70 to 70:30 (rare gas: carbon dioxide gas) is preferable, and 4
0:60 to 60:40 is more preferable. The rare gas and / or carbon dioxide gas may be used in combination with a small amount, preferably 30% by volume or less of nitrogen based on the rare gas and / or carbon dioxide gas.

The purity of the component (B) is preferably 99.9% or more, more preferably 99.99% or more.

The 50% or more foaming compound (A) used in the present invention means an organic polymer (A-) to be foamed.
1) and a large amount of the chemical foaming agent (A-2), the compound was foamed under the well-known extrusion foaming conditions by the action of the chemical foaming agent contained without using the physical foaming agent. In some cases, a foam having a degree of foaming of 50% or more can be obtained. In the present invention, with the same definition, 6
0% or more foaming compounds, particularly 70% or more foaming compounds are preferred.

The organic polymer (A- used for the component (A)
As 1), olefin resin, polystyrene, polyvinyl chloride, polyamide, polyurethane elastomer,
The target is a thermoplastic resin such as a fluororesin. Of these, olefin resins are preferable, and polyethylene is particularly preferable. These may be used alone or as a mixture.

As polyethylene, ultra low density polyethylene (V-LDPE), low density polyethylene (LDP)
Any of E), high density polyethylene (HDPE), ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, a mixture thereof and the like can be used. Particularly, HDPE alone, LDPE alone, and a mixture of HDPE and LDPE are very preferable.

LDPE has a density of 0.89-0.
935, in particular, 0.91 to 0.926, and HDPE refers to one having a density in the range of 0.94 to 0.96.

The preferable range of melt flow rate (hereinafter abbreviated as MFR) of the above-mentioned olefin resin is, for example, 0.1 to 5 g / 10 minutes in the case of polyethylene, preferably 0.
5 to 3.0 g / 10 minutes, 0.1 for polypropylene
-10 g / 10 minutes, preferably 0.3-5.0 g / 10
Min, 0.1 to 1 for propylene / ethylene copolymer
It is 0 g / 10 minutes, preferably 0.3 to 5.0 g / 10 minutes. In the present invention, MFR is a value measured according to JIS K7210. The measurement conditions are a load of 2.16 kg and a temperature of 190 ° C. for polyethylene, and a load of 2.16 kg and a temperature of 230 ° C. for polypropylene or propylene / ethylene copolymer.

The swelling ratio (swelling degree) of the component (A-1) is preferably about 30 to 80%, more preferably 45 to 80%, and particularly preferably 50 to 70%. Here, the swelling ratio is a value defined in Japanese Examined Patent Publication No. 61-11412 (columns 3, 4 and lines 1 to 20) and the like, and is measured under the conditions shown in the publication. It is something.

The olefin resin having a broader molecular weight distribution than the sharp one is preferable because it has a large melt tension and thus tends to easily obtain a uniform and high foam.

Suitable MFR of HDPE / LDPE mixture
Range of 0.1 to 5.0 g / 10 minutes, preferably 0.5
~ 3.0 g / 10 minutes.

As the chemical foaming agent (A-2), which is another constituent of the component (A), an organic foaming agent, an inorganic decomposable compound, or the like is decomposed by heat to generate a gas. Stuff used. The chemical foaming agent (A-2) is appropriately selected from known foaming agents according to the melting temperature, melt viscosity, etc. of the resin used, and is used alone or as a mixture. For example, azodicarbonamide (ADCA),
Azobisisobutyronitrile (AIBN), N, N'-
Dinitrosopentamethylenetetramine (DPT), p-
Toluenesulfonyl hydrazide (TSH), 4,4'-oxybisbenzenesulfonyl hydrazide (OBSH), sodium bicarbonate, ammonium carbonate and the like can be used. Among them, when polyethylene is used, OBSH, ADCA or a mixture thereof is preferable because a particularly high foaming degree can be obtained.

The components (A-1) and (A- in the component (A)
The content of component 2) varies depending on the type of organic polymer or chemical blowing agent used and cannot be generally stated. Generally, in a foaming compound of 50% or more, the amount of the component (A-2) is 1.5 to 20.0% by weight, preferably 1.6 to 18.0, relative to the component (A-1). % By weight. Specifically, the amount of the component (A-2) with respect to the component (A-1) is
If the foaming compound has a foaming degree of 50% or more and less than 60%, 1.5 to 10.0% by weight, preferably 1.6 to
If the compound is 5.0% by weight and the degree of foaming is 60% or more and less than 70%, it is 1.6 to 15.0% by weight, preferably 1.8 to 10.0% by weight, and 70% or more. If it is a foaming compound, it is 1.9 with respect to the component (A-1).
~ 20.0 wt%, preferably 2.0-18.0 wt%
Is.

A specific example of the component (A) is WN866 manufactured by Nippon Unicar Co., Ltd. as a 70% foaming compound.
UBEC-481 and UBEC-485 manufactured by Ube Industries, Ltd. as a 60% foaming compound, and DFDJ- manufactured by Nippon Unicar Co., Ltd. as a 50% foaming compound.
4960 etc. are mentioned.

By injecting the component (B) into the above component (A) and foaming it, it is possible to obtain a dense foam having a high foaming degree of 75% or more and a uniform foaming structure. it can.

According to the present invention, when the non-foaming organic polymer (C) is added to the component (A) and the component (B) is added to the mixture, the resulting foam has a high degree of foaming and a smooth surface. And the hardness increases. Therefore, a foam having further improved buckling resistance and heat resistance can be obtained.

As the component (C), an olefin resin,
Examples thereof include thermoplastic resins such as polystyrene, vinyl chloride, polyamide, polyurethane elastomer, and fluororesin, and the same or different kinds as the component (A-1) are used. Among them, preferable results can be obtained by using the same type of organic polymer as the component (A-1). That is, when the component (A-1) is polyethylene,
The component (C) is also preferably polyethylene. In addition, (A-1),
When polyethylene is used together with the component (C), (A-
When using LDPE as 1), HDP as (C)
When HDPE is used as E, (A-1), (C)
When LDPE is used as the above and HDPE or LDPE is used as both (A-1) and (C), it is preferable to use those having different densities. Particularly, (A-1) having a lower density than that of (C) is preferably used.

The mixing ratio of the component (A) and the component (C) varies depending on the type of resin and foaming agent used and the desired degree of foaming, and cannot be determined unconditionally, but the component (A) :( C )
The weight ratio of the components is usually 100: 10 to 10: 100, preferably 100: 15 to 15: 100, more preferably 100: 20 to 20: 100.

When the component (C) is mixed, the swelling ratio of the mixture of the component (A-1) and the component (C) is preferably 30 to 80%, more preferably 45 to 80%, particularly preferably 50. It is preferable to use the one of about 70%.

In the present invention, a particularly preferable foaming composition is LDPE (A-1) and a chemical foaming agent (A-
2) 50% or more foaming compound (A) and H
A combination of DPE (C) and a physical foaming agent (B), wherein the compounding ratio (weight ratio) of (A) and (C) is 20: 80-8.
0:20, preferably 30:70 to 70:30,
50% or more foaming compound (A) and LDPE (C) consisting of HDPE (A-1) and chemical foaming agent (A-2)
And a blending ratio (weight ratio) of (A) and (C) of 20:80 to 80:20,
Preferable ones are from 30:70 to 70:30.

The foamable composition of the present invention may further contain a nucleating agent. Examples of the nucleating agent include inorganic particles such as silicon oxide and boron nitride (BN) and / or a chemical foaming agent which is generally considered to also serve as a nucleating agent. The amount of the nucleating agent used is the amount of the organic polymer 10 in the composition.
0.1 to 10 parts by weight, particularly 0.2 to 5 parts by weight, and more preferably 0.3 to 3 parts by weight are preferable with respect to 0 parts by weight.

Usually, the nucleating agent is preferably used in advance (before being fed to the extruder) in a state of being mixed with the component (A) or the component (C).

The amount of the component (B) added varies depending on the type and the components (A) and (C) used and is not generally determined, but generally 100 parts by weight of the organic polymer in the composition is used. 0.005 to 2 parts by weight, preferably 0.1 to
0.5 parts by weight.

The foamable composition of the present invention may optionally contain additives such as a copper damage inhibitor, an antioxidant and a coloring agent.

According to the foaming method of the present invention, foam extrusion molding is particularly preferable. Among them, the foam composition is foam extruded on a conductor to form a foam insulating layer on the conductor to form a coaxial cable for communication. The method of manufacturing the cable is a particularly preferred embodiment.

That is, in order to form an insulating layer on the conductor, the foamable composition can be supplied onto the conductor by an extrusion molding method to form an insulating layer having a foamed structure simultaneously with molding. For example, the component (A), or a mixture of the component (C) and the component (C), is supplied to the extruder, and the component (B) is press-fitted into the barrel of the extruder through a foaming agent injection hole formed separately. Then, both are mixed to form a foamable composition, and this is foamed and extruded on a conductor to form an insulated conductor having a foamed insulating layer.
The foamed insulating layer thus formed may be further subjected to a subsequent treatment such as a crosslinking treatment or a post-foaming treatment. In addition, in the said foam manufacture, as (A) component, (A-1) component was previously (A
In addition to using the mixture of the component (-2), (A-2) may be added to (A-1) before or after the injection of (B), or at the same time in the process of producing a foam.

[0033]

EXAMPLE FIG. 1 shows a production line diagram of a high-foam insulation cable as one embodiment of the foam extrusion molding method of the present invention.

The component (A) supplied to the first extruder 4, the component (C) and a mixture of the component (C) and a nucleating agent added as necessary are melted in the extruder 4.
The component (B) is press-fitted into the extruder 4 through the pump 3 and sufficiently mixed with the melt.

The temperature and pressure in the first extruder 4 vary depending on the resin and foaming agent used and cannot be determined unconditionally, but are usually 140 to 240 ° C., 80 to 120 atm, preferably 150 to 230 ° C. , 50 to 150 atm. Specifically, for example, when using HDPE and LDPE, it is preferable to adjust the temperature to 180 to 210 ° C. and 50 to 150 atm. In addition, O as a chemical foaming agent was added to polyethylene.
150 to 170 when using (A) containing BSH
AD to polyethylene at 100 to 150 atm.
When using (A) containing CA, 200 to 230 ° C.,
It is preferable to adjust the pressure to 100 to 150 atm.

The pressure when the component (B) is pressed in is not generally determined as in the above, but is usually adjusted to 100 to 200 atm, preferably about 150 atm.

The foamable composition in which (A) or the mixture of (A) and (C), (B) and the like is thoroughly mixed in the first extruder 4 moves to the second extruder 5. Immediately before the die 6, the temperature of the foamable composition is set to a temperature slightly higher than the melting temperature of the organic polymer just before the die 6 so that the composition extruded from the die 6 does not coarsen due to coalescence of adjacent bubbles immediately after the foaming. It is preferable to adjust the temperature so that For example, when HDPE and LDPE are used, it is preferable to adjust the temperature to 130 to 140 ° C. The pressure inside the extruder 5 is preferably adjusted to 30 to 50 atm.

The conductor supplied from the conductor supply unit 1 is preferably preheated by the preheater 2 and supplied to the extruder. On the other hand, the foamable composition in the second extruder 5 is discharged through the die 6 and, at the same time, is fed around the conductor wire that has been fed through the axial core of the die 6 and is crimped to the conductor wire. At the same time it foams.

FIG. 2 is an explanatory diagram of the vicinity of the discharge port of the die 6 and the sizing die 7 of FIG. When argon is used as (B), the foamable composition foams immediately after it exits the die 6, and if it is left after foaming, it collapses. Therefore, in order to prevent excessive foaming and keep the foamed layer at a constant thickness, it is preferable to provide the sizing die 7 as close as possible to the discharge port of the die 6. When the conducting wire is an electric wire, the distance m from the exit of the die 6 to the sizing die 7 is preferably about 0.5 to 10 cm, particularly preferably about 1 to 5 cm. When m is less than 0.5 cm, the surface of the foam is roughened. On the other hand, if it exceeds 10 cm, the foam tends to be deflated and a sufficient degree of foaming may not be obtained. Before entering the sizing die 7, air may be lightly blown onto the surface of the foamed layer discharged from the die 6 to cause the foamed layer to be hardened. If you do,
The foam layer 10 thus obtained has a smooth surface and is easy to obtain a target high foam. The sizing die 7 is typically a stainless steel pipe and need not be cooled. Instead of passing through the sizing die 7, immediately after the composition is discharged, air may be blown into the foam layer to cause it to cool, and then the foam layer may be cooled.

The conductor 11 covered with the foam layer 10 that has exited the sizing die 7 is cooled with water, cold gas or the like at appropriate intervals, as shown in FIG. The distance between the outlet of the sizing die 7 and the cooler is usually in the case of wire coating,
It is 1 to 3 m.

The foam layer 10 may be directly formed on the conductive wire 11, but in order to improve the adhesion between the foam layer 10 and the conductive wire 11, a non-foamed organic layer is previously formed around the conductive wire 11. A thin film of the molecule may be prepared and a foamed layer may be formed thereon.

The present invention can also be carried out by adding a specific nucleating agent and a physical foaming agent to a non-foaming organic polymer without using the above-mentioned foaming compound of 50% or more, for example, Has a high foaming property of 75% or more,
Moreover, it is possible to obtain a foam having more excellent electrical characteristics. The obtained foam is suitable as an insulator for coaxial cables, particularly coaxial cables used at high frequencies. The following is a description of methods of making such foams.

As a nucleating agent, the increase in tan δ is 0.3.
Organic fine powder and / or inorganic fine powder of x10 ^-4 or less, preferably 0.2 x 10 ^-4 or less, having an average particle size of, for example, 50 µm or less, preferably 0.1 to 20 µm, and particularly preferably 0. .1 to 10 μm is used.

The tan δ increase amount is a value measured by the method described below. Temperature 20 ℃, frequency 1.0
Polyethylene 10 whose tangent of dielectric loss angle δ in GHz, that is, tan δ is 1.0 × 10 ⁻⁴ to 2.0 × 10 ⁻⁴
A uniform mixture is obtained by mixing 2 parts by weight of the tested nucleating agent per 0 part by weight. This mixture is extrusion-coated on a conductor to form a non-foamed insulating layer, and an outer conductor is formed thereon to obtain a test coaxial cable having a conductor outer diameter of 1 mm and an insulating layer thickness of 5 mm. On the other hand, a control coaxial cable having the same size and structure as above is obtained except that the tested nucleating agent is not mixed. For both cables, the transmission loss of each cable is measured at the same temperature and frequency as above, and a well-known calculation method from the values, that is, for example, issued by Mitsubishi Cable Industries, Ltd. Handbook, 101
It is calculated using the formula shown on page 2.

Then, the tan δ increase amount is calculated from the following equation.

Increase in tan δ = (tan δ of test coaxial cable)-(tan δ of control coaxial cable)

Examples of the nucleating agent satisfying the above conditions include BN, ZrO ₂ , MgO and the like. Above all, BN
Is preferred.

As the physical foaming agent and the non-foaming organic polymer, the above-mentioned physical foaming agent (B) and organic polymer (A-1) are used, and the above description (general description) of each is given. , Preferred embodiment, description of amount used, etc.) is also applicable here. Further, the above description of the method of manufacturing the foam body and the like also applies here.

The amount of the nucleating agent used when 50% or more of the foaming compound is not used is 0.3 to 10 parts by weight, particularly preferably 0.8 to 5 parts by weight based on 100 parts by weight of the non-foaming organic polymer. Parts by weight, more preferably 0.9-1.5
Parts by weight.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A 50% foaming compound D containing low density polyethylene (density: 0.925 g / cm ³ ) and OBSH as a chemical foaming agent was used by using a foam insulation cable production line.
FDJ-4960 (manufactured by Nippon Unicar Co., Ltd.) and high-density polyethylene (density: 0.946 g / cm ³ ) 50: 5
The mixture was melt-mixed at 0 (weight ratio) (swelling ratio of polyethylene mixture: 54), and 0.2 part by weight of argon as a physical foaming agent was injected into 100 parts by weight of polyethylene. This was extruded and foamed on a copper wire (9.6 mm) under the following extrusion conditions. Internal temperature of the first extruder (65 mm): 160 to 170 ° C. Internal temperature of the second extruder (90 mm): 150 to 135 ° C. The copper wire provided with the foam layer that exits the die hardens the surface of the foam layer. For this purpose, cooling air was blown, and then it passed through a cooling water tank and was wound up. The outer diameter of the obtained foam insulated cable was 22 mm.

Example 2 Instead of the 50% foaming compound as the component (A), low density polyethylene (density: 0.923 g / c) was used.
m ³⁾ 70% foaming compound of WN-866
A foam insulated cable was produced in the same manner as in Example 1 except that (made by Nippon Unicar) was used.

Example 3 As a physical foaming agent (B), argon and carbon dioxide gas of 50:
A foam insulated cable was produced in the same manner as in Example 2 except that the 50 (volume ratio) mixture was used.

Comparative Example 1 Low density polyethylene containing no chemical foaming agent in place of the 50% foaming compound (density: 0.925 g / c
m ³ ), and a foam insulating cable were produced in the same manner as in Example 1 except that 0.5 part by weight of silicon oxide was used as a nucleating agent with respect to 100 parts by weight of the resin.

With respect to the foam insulation cables obtained in Examples 1 to 3 and Comparative Example 1, the foaming degree of the foam layer, the average diameter of the cells, the VSWR characteristics of the foam insulation cable, the bending diameter of buckling occurrence, and the attenuation amount were measured. did. The bending diameter that causes buckling is
The diameter of the mandrill when the obtained foam insulated cable (outer diameter: 22 mm) is wrapped around the mandrill and buckling occurs for the first time is shown. The results are shown in Table 1.

[0056]

[Table 1]

Further, the degree of foaming of DFDJ-4960, which is the compound for 50% foaming used in Example 1, and WN-866, which is the compound for 70% foaming used in Examples 2 and 3, was determined as follows. It was measured. That is, using an extruder with L / D of 20, cylinder temperature: 165 ° C., temperature near die: 130 ° C., screw rotation speed: 20 r
pm, screw shape: Under normal extrusion conditions of a full flight screw, without using a physical foaming agent, etc., DFDJ-4
960 alone or WN-866 alone was foamed and extruded. The degree of foaming is 50.2% for DFDJ-4960, W
N-866 was 70.3%.

Examples 4 to 12 and Comparative Example 2 DFDJ-4960 and high density polyethylene (density: 0.
A foam insulated cable was produced according to Example 1 except that 943 g / cm ³ ) was used in the compounding ratio (weight ratio) shown in Table 2. In Comparative Example 2, 0.5 part by weight of silicon oxide was used as a nucleating agent with respect to 100 parts by weight of the resin. The degree of foaming, the appearance, and the average cell diameter of the obtained foamed layer were examined. The results are shown in Table 2.

[0059]

[Table 2]

Examples 13 to 21 Using the same foam insulation cable production line as in Example 1,
A foam insulated cable having the same structure was obtained under the same conditions. However, as the expanded polyethylene, low density polyethylene (density: 0.925g / cm ^2): as a used in the proportions shown in Table 3, also nucleating agents and high density polyethylene (0.943 g / cm ² density) The BN used was introduced into the hopper of the extruder together with the polyethylene in the form of a masterbatch. The degree of foaming of the foam layer of each cable obtained,
The appearance and cell average diameter are shown in Table 3.

[0061]

[Table 3]

[0062]

According to the present invention, by using at least 50% or more of the foaming compound (A) or a mixture thereof with a non-foaming organic polymer (C), a noble gas and / or a physical foaming agent (B) is used. By using carbon dioxide gas, a foamed product having a foaming degree of 75% or more without depleting the ozone layer or the like, which is as high as that when using CFC gas, and having a uniform and fine foaming structure. Can be obtained. A suitable insulated conductor that does not buckle when applied to the foam layer of an insulated conductor such as a foam insulated wire that requires particularly high insulation properties and may be subjected to considerably severe conditions during installation. Is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing one embodiment of a foam extrusion molding method of the present invention.

FIG. 2 is an explanatory diagram of a discharge port of the die of FIG. 1 and a vicinity of a sizing die.

FIG. 3 is an explanatory diagram of the vicinity of the sizing die and the cooling device of FIG.

[Explanation of Codes] 1 Conductor supply part 2 Preheater 3 Pump 4 First extruder 5 Second extruder 6 Die 7 Sizing die 8 Cooler 9 Conductor take-up part 10 Foam layer 11 Conductor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location C08L 23:04 (72) Inventor Takuma Takai 8 Nishinomachi, Higashimukaijima, Amagasaki-shi, Hyogo Mitsubishi Electric Cable Industries Incorporated (72) Inventor Mutsumi Wada 8 Nishinomachi, Higashi-Mukojima, Amagasaki City, Hyogo Prefecture Mitsubishi Electric Wire & Cable Co., Ltd. (72) Inventor Kan, Haru, 4-3 Ikejiri, Itami City, Hyogo Itami Mitsubishi Electric Wire Inside the factory

Claims (29)

[Claims] 1. 50% or more foaming compound (A) containing an organic polymer (A-1) and a chemical foaming agent (A-2).
And a foamable organic polymer composition containing at least one (B) selected from rare gas and carbon dioxide as a physical foaming agent. 2. The composition according to claim 1, further comprising a non-foaming organic polymer (C). 3. 50% or more foaming compound (A)
Is a foaming compound containing the chemical foaming agent (A-2) in an amount of 1.5% by weight or more based on the organic polymer (A-1). 4. The composition according to claim 1, wherein the organic polymer (A-1) is an olefin resin. 5. The composition according to claim 2, wherein the non-foaming organic polymer (C) is an olefin resin. 6. The composition according to claim 4, wherein the olefin resin is polyethylene. 7. The composition according to claim 5, wherein the olefin resin is polyethylene. 8. The composition according to claim 6, wherein the polyethylene is at least one selected from high density polyethylene and low density polyethylene. 9. The composition according to claim 7, wherein the polyethylene is at least one selected from high density polyethylene and low density polyethylene. 10. ADCA as a chemical foaming agent (A-2)
8. A composition according to claim 6 or 7 comprising and / or OBSH. 11. The composition according to claim 1, wherein the foaming compound (A) is a foaming compound of 60% or more. 12. The composition according to claim 1, wherein the foaming compound (A) is 70% or more of a foaming compound. 13. A compound (A) for foaming containing 50% or more of an organic polymer (A-1) and a chemical foaming agent (A-2) is added to at least one kind selected from rare gas and carbon dioxide gas as a physical foaming agent ( A method for producing a high-foaming foam by injecting B) to foam. 14. A compound (A) for foaming which is 50% or more.
The manufacturing method according to claim 13, wherein the non-foaming organic polymer (C) is allowed to be present together. 15. A compound (A) for foaming which is 50% or more.
Is a foaming compound containing the chemical foaming agent (A-2) in an amount of 1.5% by weight or more with respect to the organic polymer (A-1). 16. The method according to claim 13, wherein the organic polymer (A-1) is an olefin resin. 17. The production method according to claim 14, wherein the non-foaming organic polymer (C) is an olefin resin. 18. The method according to claim 16, wherein the olefin resin is polyethylene. 19. The method according to claim 17, wherein the olefin resin is polyethylene. 20. The method according to claim 18, wherein the polyethylene is at least one selected from high-density polyethylene and low-density polyethylene. 21. The method according to claim 19, wherein the polyethylene is at least one selected from high-density polyethylene and low-density polyethylene. 22. The manufacturing method according to claim 13, wherein the foaming method is foaming extrusion molding. 23. The method according to claim 22, wherein the foam extrusion molding is a foam extrusion coating for coating a conductive wire. 24. As the chemical foaming agent (A-2), ADC
The production method according to claim 18 or 19, wherein A and / or OBSH is used. 25. As the foaming compound (A), 6
The method according to claim 13 or 14, wherein 0% or more of a foaming compound is used. 26. As the foaming compound (A), 7
The method according to claim 13 or 14, wherein 0% or more of a foaming compound is used. 27. The method according to claim 13 or 14, wherein a sizing die is provided at a position 1 to 5 cm from the exit of the die. 28. Organic polymer, tan δ increase as a nucleating agent
The weight is 0.3 × 10 ^-FourThe following organic and inorganic fine powders
100 parts by weight of at least one organic polymer selected from
0.3 to 10 parts by weight, and a rare gas as a physical foaming agent.
And at least one selected from carbon dioxide
Effervescent organic polymer composition. 29. As an organic polymer and a nucleating agent, 0.3 to 10 parts by weight of tan δ per 100 parts by weight of the organic polymer.
High foaming by injecting at least one selected from rare gas and carbon dioxide as a physical foaming agent into at least one selected from organic fine powder and inorganic fine powder whose increase amount is 0.3 × 10 ⁻⁴ or less to foam. Method for producing foam.