JP2001206961A - Flame-retardant film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant film capable of being readily formed into the film, capable of being readily burned without causing plugging of an incinerator and without generating a harmful gas or a harmful compound, after the use, and without remaining ash, and especially suitably usable at a radioactive material-handling site. SOLUTION: This flame-retardant film is characterized in that the film comprises 100 pts.wt. olefinic resin, and 10-50 pts.wt. one or more kinds of the flame retardants selected from the group consisting of glycine, isocyanuric acid, melamine isocyanurate and guanidine carbonate, and substantially consists of only carbon, hydrogen, oxygen and nitrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant film, and more particularly to a flame-retardant film suitably used in a radiological material handling facility.

[0002]

2. Description of the Related Art Conventionally, in places where radioactive materials are handled, such as nuclear power plants, chemical factories, laboratories, hospitals, etc., in order to prevent contamination by radiation, floors where radioactive materials are handled, especially during periodic inspections and construction work, etc. Protective films are installed on walls, ceilings, partitions, shelves, etc.

[0003] Resin films such as olefin-based resins and vinyl chloride-based resins have been used as the protective film. However, in such places, fire is often used. Required. Therefore, inorganic flame retardants such as halogen-based flame retardants, antimony oxide, aluminum hydroxide and magnesium hydroxide have been added to the resin.

[0004] The protective film is removed after a certain period of use and incinerated. However, since the ash after incineration contains radioactivity, it must be stored for a long period as a radioactive substance, so that the ash after incineration is low. Is required. or,
If halogens are contained in the protective film, toxic gas or toxic compounds will be generated in case of fire or incineration, which may affect humans, damage the incinerator, or cause environmental problems. Required not to be included.

In order to satisfy the above requirements, Japanese Patent Publication No. 7-1
No. 06621 proposes a non-ash composite film in which a flammable resin film is laminated on both sides of a flame-retardant film made of a flammable thermoplastic polymer and urea.
However, urea has a high polarity, it is difficult to disperse it uniformly in the olefin resin, and since the thermal decomposition temperature is lower than the film formation temperature of the olefin resin, it is very difficult to form a uniform film. And the resulting composite film was expensive.

[0006] Japanese Patent Application Laid-Open No. Hei 6-157820 discloses that
An olefin resin, a flame-retardant resin composition comprising a melamine cyanurate powder treated with a nonionic surfactant and a phosphorus compound are described. JP-A-6-184330 discloses an ethylene-vinyl acetate copolymer resin, There has been proposed a flame-retardant sheet comprising a melamine cyanurate and a red phosphorus compound for a radioactive substance handling place. However,
These flame-retardant resin compositions and flame-retardant sheets are clogged in an incinerator because of the addition of the phosphorus compound, which reduces the incineration function. Since ash remains, it is necessary to treat them as radioactive contaminants. There were drawbacks such as

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to form a film easily in view of the above-mentioned drawbacks, and to easily form a film after use without clogging an incinerator and generating no toxic gas or toxic compound. An object of the present invention is to provide a flame-retardant film that can be burned and has no ash residue, particularly a flame-retardant film that can be suitably used in a radiation substance handling facility. It is still another object of the present invention to provide a flame-retardant film that can be easily attached to a wide wall, floor, or the like.

[0008]

The flame-retardant film according to claim 1 comprises at least one member selected from the group consisting of 100 parts by weight of an olefin resin, glycine, isocyanuric acid, melamine cyanurate and guanidine carbonate. Flame retardant 10
To 50 parts by weight, and substantially consist of only carbon, hydrogen, oxygen and nitrogen.

The olefin resin is a (co) polymer of an olefin monomer and may have a film-forming property. Examples of the olefin resin include polyethylene and polypropylene.
Poly-1-butene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-heptene copolymer , Ethylene-1-octene copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate alkyl ester copolymer, ethylene-propylene-1-butene copolymer, ethylene-propylene diene copolymer, and the like. Polyethylene and ethylene-vinyl acetate copolymer can be suitably used.

The flame retardant is selected from the group consisting of glycine, isocyanuric acid, melamine cyanurate and guanidine carbonate, and may be used alone or in combination of two or more.

The above-mentioned melamine cyanurate is a reaction product of melamine and isocyanuric acid, and it is preferable that unreacted products of melamine and isocyanuric acid are minimized. It is preferable that the surface of the melamine cyanurate powder is treated with polyvinyl alcohol because the dispersibility in the olefin resin is improved.

When the particle size of the flame retardant increases, the dispersibility in the olefin resin decreases, the surface becomes rough, and the appearance deteriorates. Therefore, the particle size is preferably 10 μm or less, and the average particle size is preferably 5 μm or less.

When the amount of the flame retardant is small, the flame retardancy is reduced, and when the amount is large, the film forming property of the olefin resin is reduced.
５０50 parts by weight, preferably 15-45 parts by weight.

The flame-retardant film according to claim 1 comprises the olefin resin and at least one flame retardant selected from the group consisting of glycine, isocyanuric acid, melamine cyanurate and guanidine carbonate, and substantially comprises carbon. , Hydrogen, oxygen and nitrogen only.

If a compound containing an element other than carbon, hydrogen, oxygen and nitrogen, particularly a compound containing a metal element such as antimony, silicon and aluminum, is contained, ash remains during incineration, and a compound containing halogen is contained. In the event of a fire or incineration, toxic gas or toxic substances are generated, and if phosphorus-containing compounds are included, the incinerator will be damaged or ash remains during incineration, so carbon, hydrogen, oxygen and nitrogen Compounds containing elements other than the above must not be substantially added.

It should be noted that substantially not containing means that the compound does not contain such a compound as to cause the above-mentioned disadvantages, and does not include a compound present as an impurity.

As the method for producing the above-mentioned flame-retardant film, any known method may be adopted. For example, the above-mentioned olefin resin and a flame retardant are mixed, and the mixture is subjected to an inflation method, a T-die method, a calendar method, a casting method and the like. What is necessary is just to shape. In this case, it is necessary to mold at a molding temperature not higher than the thermal decomposition temperature of the flame retardant.

The thickness of the flame-retardant film is not particularly limited, and is generally 30 to 200 μm.

The flame-retardant film according to claim 4 is a flame-retardant film obtained by laminating an adhesive layer near one end of the flame-retardant film according to any one of claims 1 to 3.

As the pressure-sensitive adhesive, any conventionally known pressure-sensitive adhesive can be used, but a pressure-sensitive adhesive which does not leave ash and does not generate toxic gas or toxic substance when incinerated, ie, substantially carbon or hydrogen Pressure-sensitive adhesives comprising only oxygen and nitrogen, such as acrylic pressure-sensitive adhesives, styrene-conjugated diene copolymer elastomers (styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer and hydrogenated products thereof) Etc.) based pressure-sensitive adhesives.

The pressure-sensitive adhesive layer may be formed by directly applying a pressure-sensitive adhesive to the flame-retardant film, or by applying a double-sided pressure-sensitive adhesive tape. Alternatively, it may be formed by attaching a single-sided adhesive tape to one end of a flame-retardant film.

The pressure-sensitive adhesive layer may be formed at the end of the flame-retardant film or near one end slightly inside from the end.
The pressure-sensitive adhesive layer is preferably formed continuously, but may be formed intermittently. Further, the pressure-sensitive adhesive layer may be a single layer or a plurality of layers.

The thickness and width of the pressure-sensitive adhesive layer may be appropriately determined depending on the application, but generally, the thickness is 10 μm to 1 m.
m is preferable, and the width is preferably 1 cm to 10 cm.

According to a sixth aspect of the present invention, there is provided a flame-retardant film, wherein the pressure-sensitive adhesive layer is laminated on one end of the flame-retardant film. This is a flame-retardant film in which the remaining portion is folded so that the portion where it is projected.

Next, the method of folding will be described with reference to the drawings. 1 to 3 are sectional views showing an embodiment of the invention of claim 6. In the figure, 1 is a flame-retardant film, and 2 is a pressure-sensitive adhesive layer laminated on the end of the flame-retardant film.

In FIG. 1, the remaining portion is folded twice by folding the screen so that the portion where the pressure-sensitive adhesive layer 2 is laminated protrudes, and the end portion where the pressure-sensitive adhesive layer 2 is not laminated is the adhesive layer 2.
Are located in the opposite direction of the stacked portion.

In FIG. 2, the remaining portion is folded three times by folding folding so that the portion where the pressure-sensitive adhesive layer 2 is laminated protrudes.
Are located in the same direction of the stacked portion.

In FIG. 3, the remaining portion is folded so that the portion where the pressure-sensitive adhesive layer 2 is laminated is projected so that the pressure-sensitive adhesive layer is inside, and then the pressure-sensitive adhesive layer is outside so that the pressure-sensitive adhesive layer is outside. The folded portion is folded in two, and the end where the pressure-sensitive adhesive layer 2 is not laminated is located in the same direction as the portion where the pressure-sensitive adhesive layer 2 is laminated.

As the method of folding the flame-retardant film, any method may be employed so as to be suitable for the intended use. However, when the method is applied to a large area or to a wall, as shown in FIG. It is preferable to fold even numbers by folding screens.

When this folding is performed, a second flame-retardant fill is attached to the end of the first flame-retardant fill with an adhesive at the time of construction, and then the third and fourth flame-retardant fills are applied.・ Laminate and laminate the first flame-retardant film, and then apply the first flame-retardant film to the upper end or end of the wall, floor, etc. to be adhered with the adhesive, and open or the outermost end It can be easily constructed by pulling.

FIG. 4 is a sectional view of an essential part showing an embodiment in which an adhesive tape is used to form an adhesive layer. 4 in the figure
Is a pressure-sensitive adhesive tape, and a pressure-sensitive adhesive layer 2
Are laminated, and the pressure-sensitive adhesive layer 2 of the pressure-sensitive adhesive tape 4 is adhered to the flame-retardant film 1 so that the pressure-sensitive adhesive layer is formed in a direction opposite to the surface of the flame-retardant film 1 to which the pressure-sensitive adhesive tape 4 is adhered. Is formed.

The flame-retardant film according to claim 7 is a flame-retardant film obtained by winding the flame-retardant film according to claims 4 to 6 so that the pressure-sensitive adhesive layer is located at a side end. is there.
When winding, it is preferable that a release paper is laminated on the pressure-sensitive adhesive layer, or that a release agent layer is formed on the film surface to which the pressure-sensitive adhesive layer is in contact.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0034]

Example 1 Ethylene-vinyl acetate copolymer (vinyl acetate content 20% by weight, melt index 20) 100
Parts by weight and 100 parts by weight of melamine cyanurate powder (average particle size: 2 μm) treated with polyvinyl alcohol were supplied to an extruder, mixed, extruded, and pelletized to obtain a master batch. The melt index of the obtained master batch was 1.5.

60 parts by weight of the master batch and 40 parts by weight of linear low-density polyethylene (melt index 1.5) were extruded by an inflation method to obtain a 150 μm-thick flame-retardant film for a radioactive substance handling facility.

The resulting film had an oxygen index of 30. Further, the obtained film was vertically dropped, ignited, and the flammability was examined. As a result, the film was self-extinguishing and the ash content could not be measured.

[0037]

Example 2 The thickness was changed in the same manner as in Example 1 except that an ethylene-vinyl acetate copolymer (vinyl acetate content: 20% by weight, melt index: 20) was used instead of linear low-density polyethylene. A 100 μm flame-retardant film for a radioactive substance handling place was obtained.

The resulting film had an oxygen index of 32. Further, the obtained film was vertically dropped, ignited, and the flammability was examined. As a result, the film was self-extinguishing and the ash content could not be measured.

[0039]

Example 3 30 parts by weight of a master batch and 70 parts by weight of an ethylene-vinyl acetate copolymer (vinyl acetate content: 20% by weight, melt index: 20) were extruded by a T-die method and used for a radioactive substance handling station having a thickness of 100 μm. A flammable film was obtained.

The resulting film had an oxygen index of 28. Further, the obtained film was vertically dropped, ignited, and the flammability was examined. As a result, the film was self-extinguishing and the ash content could not be measured.

[0041]

The structure of the flame-retardant film according to claim 1 is as described above, so that it can be easily manufactured, has excellent flame retardancy, does not generate toxic gas or toxic substance after use, and has an ash content. Can be incinerated without leaving any incinerators, and the incinerator does not hurt or clog.

Therefore, it can be suitably used for applications requiring flame retardancy. In addition, since there is no need to store and control enormous costs of radioactive pollutants because there is no generation of ash, it can be used particularly suitably in radiological material handling facilities.

Since the flame-retardant film of the fourth aspect has a pressure-sensitive adhesive layer formed at one end, it can be easily attached to a place to be protected such as a wall or a floor. In addition, the flame-retardant film of claim 6 is compact because the remaining portion is folded so that the portion where the pressure-sensitive adhesive layer is laminated protrudes, so that it can be easily transported and installed. After laminating a plurality of flame-retardant films, the flame-retardant films can be easily pasted to the ends first and spread.

Since the pressure-sensitive adhesive for the flame-retardant film of claim 5 is a pressure-sensitive adhesive consisting essentially of only carbon, hydrogen, oxygen and nitrogen, there is no generation of ash even after incineration after use, which is a huge cost. Such storage control of radiation contaminants is not necessary, so that the radiation contaminants can be used particularly preferably in a radiation substance handling facility.

Furthermore, since the flame-retardant film according to the seventh aspect is wound, it is easy to store, transport and construct.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a flame-retardant film of the present invention.

FIG. 2 is a sectional view showing another embodiment of the flame retardant film of the present invention.

FIG. 3 is a sectional view showing another embodiment of the flame retardant film of the present invention.

FIG. 4 is a sectional view of a main part showing a different embodiment of the flame retardant film of the present invention.

[Explanation of symbols]

 1: Flame retardant film 2: Adhesive layer 3: Tape substrate 4: Adhesive tape

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 23/02 C08L 23/02 C09J 7/02 C09J 7/02 Z

Claims (8)

[Claims] 1. A flame retardant selected from the group consisting of 100 parts by weight of an olefin resin and one or more flame retardants selected from the group consisting of glycine, isocyanuric acid, melamine cyanurate and guanidine carbonate.
A flame-retardant film comprising 0 to 50 parts by weight, substantially consisting of only carbon, hydrogen, oxygen and nitrogen. 2. The flame-retardant film according to claim 1, wherein the melamine cyanurate is a melamine cyanurate powder having a surface treated with polyvinyl alcohol. 3. The flame-retardant film according to claim 1, wherein the particle diameter of the flame retardant is 10 μm or less. 4. The flame-retardant film according to claim 1, wherein an adhesive layer is laminated near one end. 5. The flame-retardant film according to claim 4, wherein the pressure-sensitive adhesive is a pressure-sensitive adhesive comprising substantially only carbon, hydrogen, oxygen and nitrogen. 6. The flame-retardant film according to claim 4, wherein the remaining portion is folded so that the portion where the pressure-sensitive adhesive layer is laminated projects. 7. The flame-retardant film according to claim 4, wherein the pressure-sensitive adhesive layer is wound so as to be located at a side end. 8. The method according to claim 1, which is for a radiological material handling facility.
The flame-retardant film according to any one of the above.