JP2001088258A - Laminated film - Google Patents

Abstract

(57) [Summary] [Problem] Although having a synthetic resin layer containing nitrogen in a constituent unit, generation of hydrocyanic acid gas is suppressed at the time of combustion, and sufficient transparency or coloring as a packaging material or interior material is provided. To provide a suitable laminated film. The resin composition comprises (A) a layer 1 composed of a synthetic resin having nitrogen in a structural unit, and (B) a resin composition containing 0.2 to 20 parts by weight of an iron compound catalyst per 100 parts by weight of a polyolefin resin. Wherein the iron compound catalyst has an average particle size of 0.05.
It is one or more iron oxide-based compounds selected from iron oxide particles of up to 2.0 μm and hydrous ferric oxide particles, and has a specific oxidation catalytic activity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film, and more particularly, to a laminated film in which the generation rate of hydrocyanic acid during combustion is reduced.

[0002]

2. Description of the Related Art In recent years, changes in lifestyles, improvement in living standards and income levels have led to the overflow of new products and a rich material culture, but the amount of garbage discharged from households has also increased rapidly. This waste disposal problem has become a major social problem.

[0003] Among these refuse, those composed of synthetic resin account for a considerable proportion, and it has been pointed out that those composed of vinyl chloride resin may generate dioxins during incineration. Meanwhile, polyamide resin,
For synthetic resins containing nitrogen in their constituent units, such as polyurethane resins, see Morimoto, “Composition of high-molecular combustion product gas”,
Polymer, Vol. 22, No. 253, p. 192,1
973, it has been confirmed that hydrocyanic acid is generated as a combustion product gas during combustion. Therefore, it is considered that a laminated film having a polyamide resin, which is widely used as a packaging material, as a constituent layer also generates hydrocyanic acid.

On the other hand, synthetic resins containing nitrogen in their constituent units are widely used in general households and the like as interior materials such as wallpaper, decorative paper for decorative plywood, and the like. Sometimes hurt human lives. .

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and has a synthetic resin layer containing nitrogen in a structural unit, while suppressing the generation of hydrocyanic acid gas during combustion. Moreover, it is an object of the present invention to provide a laminated film having sufficient transparency or colorability as a packaging material or an interior material.

[0006]

Means for Solving the Problems The present inventors have made intensive studies.
went. As a result, the synthetic resin having nitrogen in the structural unit
Polyolefin containing iron compound catalyst in layer 1 consisting of
The above problem is solved by laminating the resin-based resin layer 2.
The inventors have found out what can be done, and have reached the present invention. That is, the present invention
According to the above, it is composed of a synthetic resin having nitrogen in a structural unit.
Layer 1, iron compound to 100 parts by weight of polyolefin resin
From a resin composition containing 0.2 to 20 parts by weight of a catalyst
A laminated film comprising at least a layer 2 comprising
The iron compound catalyst is an acid having an average particle size of 0.05 to 2.0 μm.
One or more selected from iron oxide particles and hydrous ferric oxide particles
Is an iron oxide-based compound, measured under the following test conditions.
More than 15% of carbon monoxide can be converted to carbon dioxide
Laminated film characterized by having an active activity
It is. <Test conditions> 1. Test device: pulse type catalytic reactor Reaction temperature: 250 ° C SV = 42400h^-1  2. Iron compound catalyst Pretreatment: heat treatment at 800 ° C. for 15 minutes Catalyst amount: 2.8 × 10^-4mol 3. Pulse (carbon monoxide) Pulse amount: 6.1 × 10^-7mol 4. Carrier gas: helium

[0007] More preferably, the laminated film is provided, wherein the ratio of the iron compound catalyst to the whole film is 0.1 to 5 parts by weight.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The laminated film of the present invention comprises at least a layer 1 composed of a synthetic resin having nitrogen in a constituent unit and a layer 2 composed of a composition in which an iron compound catalyst is mixed with a polyolefin resin. . That is, the iron compound catalyst having the effect of suppressing the generation of hydrocyanic acid as described later is mainly formed of a polyolefin-based resin that can be processed at a lower temperature, instead of the layer 1 made of a synthetic resin having nitrogen in a constituent unit. Layer 2. Thereby, it is possible to prevent the iron compound catalyst from discoloring due to the processing with the synthetic resin having nitrogen in the constituent unit, which is required to be processed at a relatively high temperature, and to reduce the transparency of the laminated film as a whole. In addition, the effect is not impaired in the mixing of the pigment and the coloring such as printing in a subsequent step. Hereinafter, the present invention will be described in detail.

In the present invention, the synthetic resin having nitrogen in its constituent unit used for the layer 1 includes nylon 6, nylon 66, nylon 6 / nylon 66 copolymer, nylon 6 / nylon 12 copolymer, nylon 6 / nylon. 66
/ Polyamide resin such as nylon 12 copolymer; polyacrylonitrile; (thermoplastic) polyurethane resin.

On the other hand, examples of the polyolefin synthetic resin used for the layer 2 include various polyethylenes such as low-, medium-, or high-density polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly (4-methyl). Pentene-1), an ethylene-vinyl acetate copolymer,
Ethylene-methyl methacrylate copolymer, ethylene-
Methyl acrylate copolymer, ethylene-acrylic acid copolymer, ion-crosslinked olefin copolymer (ionomer) and the like can be exemplified, but low density polyethylene, ethylene-ethylene copolymer, Those which can set the processing temperature low, such as a vinyl acetate copolymer, are more preferable.

On the other hand, the iron compound used in the present invention
The catalyst has an average particle size (when the particle shape is spindle-shaped or needle-shaped
Is the major axis diameter, if it is plate-shaped, it is the plate surface diameter, if it is granular, it is the particle size
Mean value) is 0.05 to 2.0 μm
Selected from iron oxide particles and hydrated ferric oxide particles
The above iron oxide compounds are measured under the following test conditions.
More than 15% of carbon monoxide to carbon dioxide
It has a possible activity. Have such activity
The object of the present invention has been achieved by using
Can be achieved. The activity of iron compound catalysts as oxidation catalysts
Using a pulse-type catalytic reactor commonly used in
The iron compound catalyst was treated at 800 ° C. for 15 minutes.
After that, granulated and classified to a particle size of 150 to 200 μm
To the column (made of quartz glass, diameter 3 mmφ) of the device
2.8 × 10^-4mol and fill with helium gas.
While flowing as a rear gas, the column temperature is 250
° C, SV = 42400h ^-1Under the condition of
6.1 × 10^-7mol of carbon monoxide,
Contacting carbon monoxide with the iron compound catalyst in the column,
Oxidized carbon monoxide produced from the column
Carbon dioxide was quantified by gas chromatography, and the following equation 1
It is evaluated by the conversion represented by In addition, SV is Spa
ce Velocity, the flow rate of the reaction gas is a catalyst
Is the amount divided by the volume of the^-1)
It is represented by

[0012]

(Equation 1)

Here, the iron compound catalyst is once heated to 800 ° C.
Was subjected to a catalyst activity evaluation test after being subjected to a heat treatment for 15 minutes because the waste is usually incinerated at a temperature of 800 ° C. or higher, and iron oxide particles and hydrated ferric oxide under such high temperatures. Is a reproduction of conditions in an actual incinerator because it is considered to cause a phase change. Also,
The reason for setting the measurement temperature to 250 ° C. is that at a high temperature exceeding 300 ° C., the conversion of carbon monoxide by the iron compound catalyst increases, and the difference in catalytic activity is less likely to appear. Under the condition of 250 ° C., if no oxidation catalyst is present,
It has been determined that carbon monoxide does not convert to carbon dioxide even when oxygen is present.

The present inventors have examined the correlation between the conversion rate of carbon monoxide measured by the above method and the behavior of cyanogen generation when the laminated film of the present invention was actually burned. It has been found that when an iron compound catalyst having a carbon monoxide conversion of 15% or more as measured by the above method is used, the amount of hydrocyanic acid generated is reduced. Therefore, the iron compound catalyst used in the present invention needs to have a catalytic activity such that the above conversion is 15% or more, preferably 18% or more, more preferably 20% or more. If the conversion is less than 15%, even if a large amount is used, the effect of promoting combustion is small and the object of the present invention cannot be achieved.

The iron oxide particles or the ferric hydroxide particles referred to in the present invention specifically mean the following compounds. For example, as ferrous hydroxide particles, goethite (α-FeOOH) particles, lipid closite (γ
-FeOOH) particles or δ-FeOOH particles can be used, and the particle shape may be any of a spindle shape (bamboo leaf shape), a needle shape, a plate shape, etc., but a spindle-shaped hydrous hydrous solution. Ferric particles are most preferred in terms of combustion efficiency.

The spindle-shaped hydrous ferric oxide particles are particles having an appearance in which a number of ultrafine fibers are bundled according to observation with an electron microscope, and have a major axis diameter of 0.05 to 1.5 μm and an axial ratio of (Major axis diameter / short axis diameter-the same applies hereinafter) is 1 to 18, the BET specific surface area is 30 to 250 m ² / g,
In particular, those having a major axis diameter of 0.1 to 1.0 μm, an axial ratio of 3 to 15 and a BET specific surface area of 50 to 150 m ² / g are preferred.

The needle-shaped hydrous ferric oxide particles include not only needle-shaped particles but also needle-shaped particles having the appearance of dendrites appearing from some places, and have a long axis diameter (corresponding to the average particle diameter). The same applies hereinafter.) Is 0.05 to 2.0 μm, the axial ratio is 2 to 20, and the BET specific surface area is 10 to 200.
m ² / g, especially the major axis diameter is 0.1 to 0.8 μm,
The axial ratio is 5 to 15, and the BET specific surface area is 15 to 10
Those having 0 m ² / g are preferred.

The plate-like hydrous ferric oxide particles are particles having a hexagonal plate-like or disk-like appearance according to observation with an electron microscope, and have a plate surface diameter (corresponding to an average particle size; the same applies hereinafter). .)
Is 0.02 to 1.5 μm, and the plate-like ratio (plate surface diameter / thickness-the same applies hereinafter) is about 3 to 15, particularly the plate surface diameter is 0.03 to 0.5 μm. Is preferably 5 to 10.

The hydrous ferric oxide particles of these various shapes are:
Neutralization reaction between ferrous salt aqueous solution and alkali aqueous solution such as alkali hydroxide aqueous solution and alkali carbonate aqueous solution An oxygen-containing gas such as air is passed through a suspension containing precipitates in the presence or absence of additives. By doing so, it can be produced from an aqueous solution.

The iron oxide particles include hematite (α-Fe ₂ O ₃ ) particles, magnetite (FeO _x.
Fe ₂ O ₃ , 0 <x ≦ 1) particles, maghemite (γ-F
Any of e ₂ O ₃ ) particles can be used, and the particle shapes are spindle-shaped, needle-shaped, plate-shaped, and so-called granular having a nearly isotropic shape such as spherical, octahedral, polyhedral, and amorphous. Either type may be used, but spindle-shaped iron oxide particles are most preferable in terms of combustion efficiency.

Generally, the major axis diameter of the spindle-shaped iron oxide particles and the needle-shaped iron oxide particles is 0.03 to 1.0 μm, and the axial ratio is 2 to 12 μm.
And the BET specific surface area is 5 to 200 m ² / g, particularly, the major axis diameter is 0.05 to 0.3 μm, and the axial ratio is 3 to
10, having a BET specific surface area of 20 to 100 m ² / g
Are preferred. Further, the average particle diameter of ordinary granular iron oxide particles is 0.03 to 1.0 μm, the BET specific surface area is ² to 30 m ² / g, and particularly 0.05 to 0.5 μm.
m and a BET specific surface area of 4 to 25 m ² / g is preferred.

The spindle-shaped iron oxide particles and the needle-shaped iron oxide particles are obtained by mixing the spindle-shaped hydrated ferric oxide particles and the acicular hydrated ferric oxide particles obtained from the above-mentioned aqueous solution at 250 to 700 ° C in the air. By heating while maintaining the shape to form spindle-shaped hematite particles or needle-shaped hematite particles, these hematite particles are then placed in a reducing atmosphere such as under a stream of hydrogen.
By heating the particles while maintaining the particle shape at 0 to 500 ° C. to obtain spindle-shaped magnetite particles or acicular magnetite particles, these magnetite particles can be further reduced to 200 to 500 ° C. in air.
It can be obtained by oxidizing while maintaining the particle shape at 500 ° C. to obtain spindle-shaped maghemite particles or acicular maghemite particles.

The plate-like iron oxide particles are prepared by heating a neutralized precipitate of an aqueous ferrous salt solution and an aqueous alkali solution in an autoclave to form plate-like hematite particles.
By heating the plate-like hematite particles in a reducing atmosphere such as under a stream of hydrogen at 300 to 500 ° C. while maintaining the particle shape to form plate-like magnetite particles, the plate-like magnetite particles are further reduced to 200 to 500 in air. It can be obtained by oxidizing into plate-like maghemite particles while maintaining the particle shape at ℃.

The granular iron oxide particles are formed by passing an oxygen-containing gas such as air into a suspension containing a precipitate obtained by neutralizing a ferrous salt aqueous solution with an aqueous alkali solution such as an aqueous alkali hydroxide solution and an aqueous alkali carbonate solution. By producing the granular magnetite particles by the
By heating the particles while maintaining the particle shape at ℃ to form granular maghemite particles, the maghemite particles or the previously obtained granular magnetite particles are further reduced to 500 to 90%.
It can be obtained by heating at 0 ° C. while maintaining the particle shape to obtain granular hematite particles.

The iron compound catalyst according to the present invention has a phosphorus content of 0.02 to 0.0001% by weight, preferably 0.01 to 0.0001% by weight, and more preferably 0.02 to 0.01% by weight.
05 to 0.0001 wt%. If the content exceeds 0.02 wt%, the phosphorus acts as a catalyst poison, so that the oxidizing activity for converting carbon monoxide to carbon dioxide is reduced, and the effect of suppressing the generation of hydrocyanic acid during combustion becomes difficult to obtain. The phosphorus content is preferably as low as possible, but is preferably 0.0001% by weight or more as industrially obtained.

The iron compound catalyst according to the present invention has a sulfur content of 0.3 to 0.001% by weight, preferably 0.1 to 0.1% by weight.
0.001 wt%, more preferably 0.07 to 0.0
01 wt%. If it exceeds 0.3 wt%, the sulfur acts as a catalyst poison, so that the oxidizing activity for converting carbon monoxide to carbon dioxide decreases, and the effect of suppressing the generation of hydrocyanic acid during combustion becomes difficult to obtain. Further, the sulfur content is preferably as small as possible, but it is 0.001 wt% or more as industrially obtained.

The iron compound catalyst according to the present invention has a sodium content of 0.3 to 0.001 wt%, preferably 0.2 to 0.001 wt%, more preferably 0.15 to 0.005 wt%.
0.001 wt%. If it exceeds 0.3 wt%, the sodium acts as a catalyst poison, so that the oxidizing activity for converting carbon monoxide to carbon dioxide is reduced, and the effect of suppressing the generation of hydrocyanic acid during combustion becomes difficult to obtain. Also,
The sodium content is preferably as low as possible, but is preferably 0.001 wt% or more as industrially obtained.

For this reason, in the production of the iron compound catalyst according to the present invention, it is necessary to reduce the contents of phosphorus, sulfur and sodium, which are poisons of the catalyst, to a predetermined amount or less. Usually, without using sodium hexametaphosphate used for sintering prevention treatment at the time of heating and firing, sulfate ions derived from ferrous raw materials and sodium ions derived from alkalis are subjected to purification treatment such as sufficient washing with water. It is necessary to reduce the content of phosphorus, sulfur and sodium.

In the present invention, one or more of the above-mentioned hydrated ferric oxide particles and iron oxide particles having the activity as an oxidation catalyst may be appropriately selected and used as an iron compound catalyst. .

The amount of the iron compound catalyst is 0.2 to 20 parts by weight based on 100 parts by weight of the polyolefin resin constituting the layer 1.
Parts by weight, more preferably 0.5 to 10 parts by weight. If the amount of the iron compound catalyst is less than 0.2 parts by weight, the object of the present invention cannot be sufficiently achieved. Conversely, if it exceeds 20 parts by weight, not only the effect corresponding to the compounding amount is not increased, but also the film tends to be colored. In addition,
The ratio of the iron compound catalyst in the entire laminated film is 0.1
More preferably, it is set to be about 5% by weight.

The iron compound catalyst of the present invention can be used after the particle surface is surface-treated with various surface treating agents for the purpose of improving dispersibility in a synthetic resin.

The laminate of the present invention comprises the above-described layers 1 and 2
As an essential layer, but may also include a synthetic resin layer having a gas barrier property typified by polyvinyl alcohol or a saponified ethylene-vinyl alcohol copolymer, a metal foil layer, a metal vapor-deposited layer, and the like.

In the present invention, in addition to the compositions described above, various additives depending on the purpose, such as antiblocking agents such as silica and calcium carbonate, lubricants, ultraviolet absorbers, light stabilizers, etc. Antioxidants, colorants, and plasticizers can be added in common sense amounts. Further, an iron compound catalyst may be added to layers other than the layer 2 as long as the transparency of the laminated film is not significantly reduced.

[0034] In the present invention, the iron compound catalyst exhibits a peculiar assisting effect, and as a result, generation of hydrocyanic acid is suppressed. The mechanism of these effects is not clear, but it is presumed that the following reactions occur. Iron atoms on the surface of the iron compound catalyst are stabilized by surface hydroxyl groups formed by dissociation and adsorption of water.However, during the combustion process, dehydration occurs between the surface hydroxyl groups, and coordination unsaturated iron ions and oxygen ions are generated. Occurs. Next, the coordinatively unsaturated active sites generated in this manner exhibit catalytic activity in a series of processes such as activation of oxygen by oxygen adsorption generated in the combustion process and dehydrogenation reaction from organic matter, and promote combustion. The effect is shown. Thereby, the synthetic resin having nitrogen in the constituent unit is decomposed while suppressing the generation of hydrocyanic acid.

[0035]

The present invention will be described in more detail with reference to the following examples. The measurement of the amount of hydrocyanic acid and the activity evaluation of the iron compound catalyst were performed according to the following procedures. <Analysis method of cyanide generation degree> A 20 mg sample was inserted into a quartz tube (22 mmφ × 300 mm) furnace whose surroundings were controlled at 700 ° C., and 100 m from one end of the quartz tube.
Air is supplied at a flow rate of 1 / min. The gas discharged from the other end of the glass tube is collected in a Tedlar bag for 5 minutes. The concentration of hydrocyanic acid in the collected gas is measured using a detector tube (No. 12M manufactured by Gastech Co., Ltd.).

<Evaluation of activity of iron compound catalyst> Using a pulse type catalytic reactor, the iron compound catalyst was treated at 800 ° C. for 15 minutes, then granulated and classified to a particle size of 150 to 200 μm. 2.8 × 10 ⁻⁴ mol was filled in a column (made of quartz glass, diameter 3 mmφ) of the apparatus, and while flowing helium gas as a carrier gas, under the conditions of a column temperature of 250 ° C. and SV = 42400 h ⁻¹ , 6.1 × 10 ⁻⁷ mol of carbon monoxide is injected from the sample inlet, and the carbon monoxide is brought into contact with the iron compound catalyst in the column, and the carbon monoxide discharged from the column is oxidized and formed. The amount of carbon dioxide to be produced is quantified by gas chromatography, and evaluated by the conversion represented by the above formula 1.

As the layer 1, "Emblem ONM-15" (trade name: Biaxially stretched polyamide film, 15 μm, manufactured by Unitika Ltd.) was used. The following were used as the polyolefin resin and the iron compound catalyst constituting the layer 2.・ Polyolefin resin: (Sumitomo Chemical Co., Ltd., low density polyethylene, Sumikasen L705) ・ Iron compound catalyst: Spindle-shaped goethite (Toda Kogyo Co., Ltd., average particle size: 0.25 μm, BET specific surface area: 86m)
² / g, axial ratio: 8, conversion: 23%, phosphorus content: 0.
(0004 wt%, sulfur content: 0.01 wt%, sodium content: 0.05 wt%)

[Production Example] Using a pressure kneader, 80 parts by weight of a polyolefin resin and 20 parts by weight of an iron compound catalyst were melt-kneaded and then granulated to obtain an iron compound catalyst master batch.

[Examples 1 to 4] Using an extrusion coating machine, a low-density polyethylene layer containing an iron compound catalyst was laminated on a polyamide film as a substrate. Specifically, a polyamide film that has been mixed with an iron compound catalyst masterbatch and low-density polyethylene so as to have a composition as shown in Table 1 and put into a hopper of an extruder, and that has been anchor-coated with a polyisocyanate-based resin. Extruded up. Table 1 shows the thickness of the extruded layer formed on the polyamide film and the ratio of the iron compound catalyst to the total weight of the obtained laminated film. Table 1 also shows the hydrocyanic acid generation degree of the laminated film thus obtained. All of the obtained laminated films had practically sufficient transparency.

Comparative Example 1 A low-density polyethylene was extruded onto a polyamide film that had been anchor-coated with a polyisocyanate resin to obtain a laminated film. The degree of hydrocyanic acid generation of the thus obtained laminated film was measured by the above-described procedure. Table 1 shows the results.

[0041]

[Table 1]

As is evident from Table 1, the amount of hydrocyanic acid in the combustion gas is reduced in the laminated film obtained according to the present invention as compared with Comparative Example 1 not containing the iron compound catalyst. It is.

Comparative Example 2 Granular hematite capable of converting 5.3% of carbon monoxide to carbon dioxide (manufactured by Toda Kogyo Co., Ltd., average particle size: 0.55 μm, BET specific surface area: 2.1)
m ² / g, phosphorus content: 0.01 wt%, sulfur content:
0.04 wt%, sodium content: 0.18 wt%)
Was melt-kneaded with low-density polyethylene in the same manner as in the Production Example, followed by granulation to obtain a master batch. Next, using this masterbatch, the same layer configuration and thickness configuration as in Example 3 were used.
A laminated film was obtained so that the compounding ratio of the iron compound was obtained. The hydrocyanic acid generation rate during burning of the laminated film thus obtained was measured by the above-described procedure. As a result, 3
It was confirmed that hydrocyanic acid of 00 PPM was generated, and the effect of suppressing the generation of hydrocyanic acid was insufficient.

[0044]

As described above, according to the present invention, there is provided a laminated film in which the generation of hydrocyanic acid during combustion is suppressed even though nitrogen is contained in the structural unit. Moreover, the laminated film of the present invention has sufficient transparency. Alternatively, since the base material serving as the base has sufficient transparency, it has good coloring aptitude without disturbing the effect of coloring with a pigment or printing in a subsequent step. Further, when the laminated film of the present invention is burned together with other refuse in an incinerator, the laminated film also has an effect that the amount of dioxins discharged from the incinerator can be reduced due to the auxiliary effect of the iron compound catalyst. At this time,
The iron compound catalyst ferrites with heavy metals such as zinc, copper, and cadmium existing in the incinerator. Since this ferrite has magnetism, it can be easily separated and can be effectively used. This can prevent heavy metals in the incinerator from being discharged into the environment as water-soluble salts together with residual ash. In addition, when the laminated film of the present invention is used as an interior material such as wallpaper, decorative paper for decorative plywood, etc., in the event of a fire, the occurrence of hydrocyanic acid is suppressed, resulting in harm to human life. The effect that it is hard to spread can also be expected. The laminated film of the present invention having such features is usefully used as an interior material for packaging materials, wallpaper, decorative paper for decorative plywood, and the like.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiki Matsui 1-4 Meiji-Shinkai, Otake-shi, Hiroshima Toda Kogyo Co., Ltd. Inside the Otake Plant (72) Inventor Tomoyuki Imai 1-4 Meiji-Shinkai, Otake-shi, Hiroshima Toda Kogyo F-term in Otake Plant of Shikisha (reference)

Claims (2)

[Claims] 1. A synthetic resin having nitrogen in a structural unit
Layer 1, 100 parts by weight of polyolefin resin and iron
Resin composition containing 0.2 to 20 parts by weight of compound catalyst
A laminated film comprising at least a layer 2 consisting of
The iron compound catalyst has an average particle size of 0.05 to 2.0.
selected from μm iron oxide particles and hydrous ferric oxide particles
One or more iron oxide-based compounds, measured under the following test conditions
More than 15% of carbon monoxide to carbon dioxide
Laminate fill characterized by its convertible activity
M <Test conditions> 1. Test device: pulse type catalytic reactor Reaction temperature: 250 ° C SV = 42400h^-1  2. Iron compound catalyst Pretreatment: heat treatment at 800 ° C. for 15 minutes Catalyst amount: 2.8 × 10^-4mol 3. Pulse (carbon monoxide) Pulse amount: 6.1 × 10^-7mol 4. Carrier gas: helium 2. A laminated film, wherein the ratio of the iron compound catalyst to the whole film is 0.1 to 5% by weight.