JPH11100456A - Flame retardant foamable sheet, flame retardant foamed sheet, and wall paper and floor material therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject foamable sheet, satisfying flame retardance, and capable of manifesting a high expansion ratio and an excellent design by chemically foaming a polyolefin resin using a specific metal hydroxide. SOLUTION: This foamed sheet comprises (A) a polyolefinic resin, (B) a platy metal hydroxide (for example, magnesium hydroxide) having 2-10 asbestos ratio (ratio of a diameter/a thickness) and <=2 μm average particle diameter, (C) a chemical foaming agent (for example, azodicarbonamide), and if necessary, (D) an inorganic filler (for example, calcium carbonate). The comprising ratio of the components is preferably 1-120 pts.wt. component B and <=100 pts.wt. component D based on 100 pts.wt. component A. From the view point of the flame retardance, the total of the compounded amounts of the components B and D is preferably >=5 pts.wt. As a result, a floor material excellent in a design, and an architectural interior material such as a wallpaper are expected to be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamable sheet made of a polyolefin resin which does not emit smoke when burned, is excellent in safety and flame retardancy, and has a high degree of design. The present invention relates to a foaming sheet for providing a novel flooring material, a wallpaper, and other building interior materials that pass a quasi-nonflammable or nonflammable class defined by the Building Standards Act as a decorative material.

[0002]

2. Description of the Related Art Fireproofing is required for architectural interior materials such as flooring materials and wallpaper from the viewpoint of fire safety, and a certain degree of fireproofing is often required by the Building Standards Law.
In addition, building interior materials are required to have high designability in order to enhance the comfort as a living space in the room. Particularly, in order to have a three-dimensional design (volume), not only flexibility but also advanced Foamable materials are advantageous. As a material that can meet such demands, a material using a vinyl chloride resin has been widely used. However, a halogen-containing resin composition such as a vinyl chloride resin generates a large amount of smoke at the time of fire or incineration. Therefore, a material containing no halogen has been demanded.

In the case of vinyl chloride resin, it is relatively easy to make it flame-retardant because it contains a large amount of chlorine having a flame-retarding effect. However, in the case of a raw material containing no halogen, a technique for non-halogen flame retardation is required. As the non-halogen flame retardant, metal hydroxides such as aluminum hydroxide and magnesium hydroxide are generally used. JP-A-5-200948 and JP-A-6-1
No. 28402 discloses an ethylene and α-olefin copolymer (hereinafter referred to as VLD) having a specific density and a specific melting property.
(Abbreviated as PE) has been proposed which is filled with a metal hydroxide or another inorganic compound. However, since it is necessary to mix a large amount of metal hydroxide, the original foaming characteristics of the resin are impaired. In fact, the expansion ratio of the materials disclosed in these publications was as small as about 2.5 times at the maximum.

It is well known that a polyolefin foam containing a large amount of a metal hydroxide has been subjected to a crosslinking gelation treatment by irradiation with ionizing radiation, peroxide or the like, and has a high expansion ratio. However, since the crosslinking reaction proceeds by generating radicals in the resin composition in both methods, the effects of the hindered phenol-based antioxidant and the like as radical scavengers are diminished.
It is necessary to increase the amount of the antioxidant. However, if the hindered phenol is excessively blended, it may be colored, so that the amount thereof is not easily adjusted.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel halogen-free, flame-retardant and high-design material that is required when used as a building interior material such as flooring and wallpaper. An object of the present invention is to provide a foamable sheet.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies on such problems and found that the particle shape of the metal hydroxide strongly affects the foaming characteristics. Further studies based on this finding have shown that, if a polyhydric resin is mixed with a metal hydroxide having a specific particle shape and a chemical blowing agent usually used for a foaming resin, high flame retardancy and foaming can be obtained. It has been found that a foam sheet having a high magnification and a rich sense of volume and excellent design properties can be obtained, and the present invention has been completed.

That is, the present invention essentially comprises (A) a polyolefin resin, and (B) an aspect ratio (diameter / thickness).
Is a metal hydroxide in the form of a plate having an average particle diameter of 2 to 10 μm or less, and (C) a chemical foaming agent, and optionally containing (D) an inorganic filler. And a foam material obtained from the foamable sheet, a floor material or wallpaper, etc., comprising the foamable sheet or foam sheet and a skin material and / or a backing material or base paper. Architectural interior materials.

As the component (A) constituting the foamable sheet of the present invention, any polyolefin resin can be used, and examples thereof include a polyethylene resin, a polypropylene resin and a polybutene resin. Examples of the polyethylene resin include an ethylene homopolymer such as high-density polyethylene, medium-density polyethylene, and low-density polyethylene, and a copolymer of ethylene and another monomer. As the copolymer, a copolymer of ethylene and α-olefin including linear low-density polyethylene (hereinafter referred to as L
LDPE and the like), ethylene-vinyl acetate copolymer resin (hereinafter abbreviated as EVA), and ethylene-acrylate copolymer resin (hereinafter abbreviated as EEA). One of these may be used alone, or a blend of two or more thereof may be used.

The α-olefin referred to herein is CH ₂ ＝
A monomer having a CRR 'skeleton (here, R and R' are each independently hydrogen or a monovalent hydrocarbon group), and has three or more carbon atoms. For example, propylene, 1-
Butene, 1-pentene, 1-hexene, 1-heptene,
Examples thereof include 1-octene and the like, and these structural isomers are also exemplified as long as they conform to the above definition of α-olefin. Further, these α-olefins may be a single compound or a plurality of them may be used in combination. In some cases, feel and flexibility are required for building interior materials such as wallpaper. From that viewpoint, it is desirable that the component (A) has low crystallinity and therefore has a low melting point. In particular, the melting endothermic peak by the differential scanning calorimeter (hereinafter the same) is 100 ° C.
Less than is preferred. Therefore, (A1) LLDPE or the like is preferable as the polyethylene resin. LL like this
Examples of the DPE include those produced by a so-called metallocene catalyst. Also, (A2) EVA and (A
3) EEA can also be suitably used from the viewpoint of flexibility. These may be used alone or a plurality of blends of (A1) to (A3) may be used, but it is necessary that the overall melting endothermic peak is less than 100 ° C. in terms of flexibility. It is. Other polyolefins may be added as needed.

When the ethylene-vinyl acetate copolymer resin is used, the vinyl acetate content in the component (A) is adjusted to 10 to 45% by weight, so that flexibility, handleability during processing, and An economical foamable sheet can be obtained.

The component (B) is a metal hydroxide for imparting flame retardancy to the foamable sheet of the present invention and a building interior material using the same. Although excellent flame retardancy is brought about by blending this component in a large amount, in order to obtain a foam having a high expansion ratio that supports the design property when blended in a large amount, the particles of component (B) must Shape and size are important. That is, it is necessary to have a plate-like particle shape having an aspect ratio (diameter / thickness) of 2 to 10 and an average particle diameter of 2 μm or less. The aspect ratio in the present invention refers to a ratio (d / t) between a representative diameter (d) passing through the center of a polygonal surface and a thickness (t) measured by observing a crystal particle under a microscope or the like. .

That is, when the average particle diameter exceeds 2 μm, the expansion ratio becomes low. Even when the average particle diameter is 2 μm or less, the aspect ratio such as spherical or irregular
If the particle size of the metal hydroxide is less than 1, the desired foam cannot be obtained. When the aspect ratio exceeds 10, it becomes difficult to disperse the plate-like metal hydroxide in the resin in a sufficient state, and it is impossible to obtain a foam having a high expansion ratio.

Note that d and t are different from the crystallite diameter measured by the half width of the X-ray diffraction peak. That is,
The particle shape and size of the component (B) surrounded by the matrix of the component (A) are important for foamability, and it is not necessary that each particle of the component (B) be composed of one crystallite. Therefore, the crystallite diameter and d and t do not necessarily have to match.

Examples of such metal hydroxides include hydroxides of magnesium hydroxide, aluminum hydroxide, barium hydroxide, calcium hydroxide, strontium hydroxide, zinc hydroxide, magnesium hydroxide and divalent metals such as nickel and zinc. And a solid solution in which the surface layer of the magnesium hydroxide particles is the solid solution. Among them, preferred are a solid solution of magnesium hydroxide, a hydroxide of a divalent metal such as nickel or zinc and magnesium hydroxide, and a solid solution in which the surface layer of magnesium hydroxide particles is the solid solution. Particles of these substances can be produced in various shapes (aspect ratios) and particle diameters by adjusting the production conditions (crystallization conditions).

The surface treatment of these metal hydroxides is excellent in dispersibility in the resin composition, and has high affinity with the component (A), so that high foaming properties can be achieved. Is preferred. Examples of such surface treatment agents include higher fatty acids or salts thereof, phosphates having long-chain alkyl groups or salts thereof, silane coupling agents, titanate coupling agents, and coupling agents such as aluminum coupling agents. Is done.

The component (C) is a pyrolysis type foaming agent called a chemical foaming agent. That is, it is thermally decomposed by the heat treatment to generate a volatile component, and the volatile component foams the component (A) melt-softened by the heat treatment. Examples of the chemical blowing agent include organic blowing agents such as azodicarbonamide (hereinafter abbreviated as ADCA), dinitrosopentamethylenetetramine, and 4,4′-oxybisbenzenesulfonylhydrazide, and inorganic blowing agents such as carbonate and bicarbonate. There are foaming agents. The foaming agent to be used is substantially heat during the production of the foamable sheet of the present invention, the lamination of the sheet to a base material such as a paper base, and other processes applied before the foaming treatment of the foamable sheet. It is preferable to select one that does not cause decomposition and that decomposes quickly when foaming.

A plurality of foaming agents may be used in combination for adjusting the foaming state such as foaming speed, foam surface, and coloring of the foam. Depending on the type of the foaming agent, it is also preferable to add an auxiliary agent for adjusting the decomposition temperature of the foaming agent. Various such auxiliaries are known. For example,
When ADCA is used as a foaming agent, examples of the organic compound include a urea-based compound, glycerin, diethylene glycol, dibutyltin maleate, and metal soap. Examples of the metal soap include calcium, barium, and zinc-based soaps. Examples of the inorganic compound include metal oxides such as zinc oxide and magnesium oxide, and salts such as zinc phosphite.

The component (D) of the present invention is an inorganic filler,
By filling a large amount of this component, it plays a role of improving the concealing power to the base, which is one of the functions of the sheet, and improving the flame retardancy by relatively reducing the amount of the flammable resin component. Furthermore, when coloring in the foaming process,
The addition of a strong hiding power such as titanium dioxide or zinc sulfide also has the effect of alleviating this coloring. Also, depending on the price of this component, a foamable sheet can be obtained at a lower cost by filling it in large quantities.

Examples of such inorganic fillers include calcium carbonate, magnesium carbonate, magnesium silicate, aluminum silicate, silica sand, zinc sulfide, titanium dioxide, barium sulfate and the like. May be used.

In the present invention, when the amount of the component (B) is small, the flame retardancy is reduced, and when the component (D) is used in combination, the foamability is also reduced. When hiding is important, the component (D) is essential. Accordingly, the preferred amounts of the components (A), (B) and (D) in the present invention are as follows. The component (B) is preferably blended in an amount of 1 to 120 parts by weight per 100 parts by weight of the component (A). High flame retardancy can be easily achieved by adding 1 part by weight or more.
In a system in which the component (D) is used in combination, a reduction in the foaming state caused by the component (D) can be suppressed. Especially 30
A blending of not less than parts by weight is preferred. On the other hand, component (B) 12
If the amount is less than 0 parts by weight, the foamability is not significantly impaired. The amount of the component (D) is preferably 100 parts by weight or less per 100 parts by weight of the component (A). Within this range, a foamable sheet having excellent foamability can be obtained. Especially,
It is preferably at most 70 parts by weight. From the perspective of concealment,
The component (D) requires 10 parts by weight or more based on 100 parts by weight of the component (A).

From the viewpoint of flame retardancy, component (B) and component (D)
The total amount of the components and the components is preferably at least 5 parts by weight. The flame retardancy of the foam sheet of the product depends on the amount of the component (A) per unit area of the foam sheet, that is, the thickness of the foam sheet. Therefore, by setting the total of the components (B) and (D) to 5 parts by weight or more, sufficient flame retardancy can be realized even when the foamable sheet thickness is 0.1 mm or more, and a foam having a higher design property can be realized. A sheet is obtained. The amount of the component (C) depends on the types and amounts of the components (A), (B), and (D) used, the temperature and time of the foaming treatment, the type and amount of the foaming aid, and the desired expansion ratio. It may be adjusted appropriately.

The means for forming a sheet containing the component (A), (B), (C) or (D) of the present invention into a sheet is not particularly limited. For example, (a) a method in which an organic solvent is used as a medium to disperse or dissolve these components is applied on a substrate and dried, and (a) a dispersion using water as a medium (hereinafter, referred to as an emulsion). Similarly, a method of applying and drying on a base material, and a method of heating and melting and kneading these components to form the composition are mentioned.

The methods (A) and (A) have an advantage that the apparatus used for applying the paste polyvinyl chloride sol, which is the mainstream of the current wallpaper production method, can be applied. However,
In the case of (a), a large amount of the organic solvent evaporates in the drying process, so that it is necessary to take measures to suppress the deterioration of the working environment. In the case of (a), the evaporation of water is relatively slow. For this reason, the thickness of the resin composition layer must be reduced from the viewpoint of securing the productivity, and thus there is a problem that the design is poor.

On the other hand, the method (c) does not have these problems, and the resin composition kneaded and manufactured by a kneading method such as an extruder, a Banbury mixer, a kneader, or a roll which is usually used for molding a resin composition is calendered. This is a preferred embodiment because the sheet can be formed by a known method such as molding, inflation molding, cast molding, or T-die molding.
In addition, EVA or E is used as all or a part of the component (A).
When a sheet is formed by the method (c) using EA, the content of vinyl acetate or acrylate is set to 45% by weight or less in the entire component (A), so that the adhesiveness to the processing machine is reduced. Can be appropriately suppressed, and a sheet can be produced with good workability. When the content is 5% by weight or more, the heat of combustion of the resin is reduced, which is preferable in terms of flame retardancy.

When the foamable sheet according to the present invention is used for flooring or wallpaper, it may be applied as a foamed sheet to a skin material, a backing material, a base paper, or the like. You may. It is preferable to use non-combustible paper treated with aluminum hydroxide or flame-retardant paper impregnated with guanidines as the base paper when used for wallpaper, but use general paper that has not been subjected to such treatment. You can also. Foaming can be carried out under normal pressure using a hot-air foaming furnace or a far-infrared heater or the like that is used in the production of ordinary wallpaper. The skin material and the backing material used for the floor material are not particularly limited as long as they are polymers having characteristics required for each member such as surface hardness, flexibility, and abrasion resistance.

Further, by printing a pattern or the like on the surface of the foamable sheet or the foamed sheet, or by embossing, it is possible to obtain a flame-retardant building interior material having a three-dimensional appearance and a very high designability. If the sheet surface is subjected to corona discharge treatment, ozone treatment or the like prior to printing, printability is improved.

Various additives and the like can be added to the foamable sheet of the present invention and a building interior material using the same, as long as the purpose of the present invention is not impaired. For example, modified polymers for improving physical properties, flame retardants other than the component (B), antioxidants, light stabilizers, crosslinking agents, antistatic agents, antibacterial agents, antifungal agents, lubricants,
Pigments and the like.

The modified polymer for improving the physical properties improves the affinity between the inorganic compounds (B) and (D) and the component (A), and improves the processability of the foamable sheet and the foaming properties. It is added for the purpose, and examples thereof include acid-modified polyolefin and polysiloxane-modified polyacrylate.

The flame retardant other than the component (B) must not contain halogen. Examples of such compounds include red phosphorus, esters and salts of various oxygen acids of phosphorus, condensed phosphates, and metal oxides.

As the antioxidant, known ones can be used, and examples thereof include hindered phenol-based, phosphite-based and sulfur-based ones.

Examples of light stabilizers include light absorbers such as salicylates, hydroxybenzoates, benzotriazoles and benzophenones, and hindered amines. Examples of the cross-linking agent include peroxides and azos. However, the amount of the cross-linking agent must be limited to a level that does not cause foaming behavior, sheet formability, or product deterioration.

Antistatic agents are effective in preventing malfunctions of computers and the like due to static electricity and in preventing dust from adhering. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and the like. Various surfactants such as surfactants are exemplified.

Antibacterial and antifungal agents are used to suppress the generation of mold and various microscopic organisms on the front and back surfaces of interior materials. Quaternary ammonium salts such as pyridinium salts, quaternary phosphonium salts and silver ions And the like.

Lubricants are used for adjusting the fluidity and sheet formability of the resin composition during melt kneading and sheet forming, and include various waxes, higher fatty acids, higher fatty acid amides, and lower alcohols of higher fatty acids. , Aromatic alcohols, esters with polyhydric alcohols, higher aliphatic alcohols, metal soaps and the like.

[0035]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[Component (A)] A1-1: LLDPE, maximum melting endothermic peak position = 97 ° C. A1-2: LLDPE, maximum melting endothermic peak position = 112 ° C. A2-1: EVA, vinyl acetate content = 15 weight %, Maximum melting endothermic peak position = 90 ° C. A2-2: EVA, vinyl acetate content = 26% by weight, maximum melting endothermic peak position = 76 ° C. A2-3: EVA, vinyl acetate content = 28% by weight, maximum melting Endothermic peak position = 71 ° C A2-4: EVA, vinyl acetate content = 46% by weight, maximum melting endothermic peak position = 58 ° C A3-1: EEA, ethyl acrylate content = 23% by weight, maximum melting endothermic peak position = 93 ° C. A1-1 is based on a metallocene catalyst, while A1-2 is based on a Ziegler catalyst.

[Component (B)] Table 1 shows the particle shape, aspect ratio, and average particle diameter of the component (B) used in Examples and Comparative Examples.

[0038]

[Table 1]

The particle shapes in Table 1 were observed using a scanning electron microscope. The plate shape had a polygonal surface and was clearly smaller than the diameter passing through the center of the polygon. The shape with the thickness was called. The term “indefinite” refers to those in which the shape cannot be specified and those in which the primary particles are spherical but strongly agglomerated. In addition, the aspect ratio of the plate-shaped object was obtained from a representative diameter and thickness passing through the center of arbitrarily selected 30 polygons by magnifying observation with a scanning electron microscope, and the average value was shown. The particle diameter is an average particle diameter measured by a microtrack.

[Component (C)] In Examples and Comparative Examples,
ADCA was used as the component (C).

[Component (D)] The following three components (D) were used in Examples and Comparative Examples.

D1: Light calcium carbonate (average particle size: 0.97 μm)
m) D2: heavy calcium carbonate (average particle diameter: 2.1 μm) D3: titanium dioxide (average particle diameter: 0.21 μm) D4: zinc sulfide (average particle diameter: 0.30 μm) [Examples 1 to 5, Comparative Examples 1 to 7] (A), (B),
The resin composition was obtained by melt-kneading the component (C) and zinc stearate as a foaming aid at the ratio shown in Table 2 using an open roll. AD content of zinc stearate
The content was 30% by weight of CA. The composition was rolled by an open roll and bonded to flame-retardant paper by heat fusion to form a resin composition layer (foamable sheet) having a thickness of 0.1 m.
m, 0.11 mm and 0.12 mm were obtained.

The foamed raw material comprising the foamed sheet and the flame-retardant paper was obtained by heating the foamable raw material at 210 ° C. for 60 seconds in a small oven (manufactured by Wellnamatis). Table 2 shows the expansion ratio determined using the following equation.

Expansion ratio = thickness of foamed sheet / thickness of foamable sheet layer The appearance (surface smoothness) of the foamed sheet was determined by visual observation according to the following criteria. Table 2 shows the results.

No surface roughness: ◎, surface almost smooth: ○, surface roughness: × The flexibility of the foamed sheet was judged from the feeling when pressed with a finger according to the following criteria, and the results were shown in the following table. It is shown in FIG.

Rich in flexibility: 、, flexibility: ○, lack of flexibility: × Next, the raw foam was heated in a small oven at 210 ° C. for 5 seconds, and embossing was immediately performed using an embossing roll. . The embossability (pattern transferability) was visually determined. The results are shown in Table 2 as follows.

Good transferability: 、, poor transferability: × The foam was pasted on a board specified in JIS A 1321 (1994) using glue, and JIS A 13
21 (1994). The smoke emission coefficients CA were all 20 or less, and the temperature curve did not exceed the standard curve within 3 minutes from the start of heating. Heating was stopped 10 minutes after the start of heating, but the flame disappeared immediately. Accordingly, Table 2 shows the results of determination based on the value of Tdθ (temperature time area: unit ° C. · min) based on the following criteria. In other words, the foamed raw material of the foamable sheet having the following thickness satisfies the flame retardant class 2 (equivalent to quasi-non-combustible when bonded to a legally incombustible gypsum board or a quasi-incombustible base material according to the Building Standards Law). Is shown.

Tdθ ≦ 100 at the foamable sheet thickness of 0.12 mm: Ｔ Tdθ ≦ 100 at the foamable sheet thickness of 0.11 mm: ○ Tdθ ≦ 100 at the foamable sheet thickness of 0.10 mm No: Tdθ ≦ 100 was not achieved even with a foamable sheet thickness of 0.10 mm: ×

[0049]

[Table 2]

In Examples 1 to 3, the aspect ratio was 2 to 10.
And an example using plate-like magnesium hydroxide having an average particle diameter of 2 μm or less. All of them were excellent in foaming characteristics (expansion ratio, appearance, flexibility), and also passed the second-class flame retardancy. On the other hand, when the particle size of the magnesium hydroxide used is large (Comparative Example 1), when the aspect ratio is small (Comparative Example 2), and when it is amorphous (Comparative Examples 3 to 5).
Had a low expansion ratio and were inferior in appearance and emboss transferability.

In the case where aluminum hydroxide is used as the component (B), if the aspect ratio and the average particle size are plate-like and satisfy the conditions of the present invention (Example 4), foaming properties and
Good flame retardancy was obtained. When the aspect ratio was small even in the form of a plate (Comparative Example 6) or in the case of an irregular shape (Comparative Example 7), the foaming properties, appearance, and embossability were poor.

Also when calcium hydroxide meeting the conditions of the present invention was used as the component (B) (Example 5), a raw foam excellent in flame retardancy and foaming characteristics was obtained.

Examples 6 to 13 and Comparative Examples 8 to 11
Example 1 and Comparative Example 4,
Used in combination with metal hydroxides 6, 7, and 8, Table 3
Was prepared in the same manner as in Example 1 with the composition shown in Table 1, and the foaming characteristics and flame retardancy were evaluated. However, in Example 10,
In Nos. 12 and 13, the foamable raw material was foamed by heating for 40 seconds.

[0054]

[Table 3]

In the examples shown in Table 2, the foamed sheet was slightly yellowed, but 10 parts by weight of titanium dioxide was added as the component (D) to 100 parts by weight of the component (A) (Example In Example 6), such coloring was hardly observed, and the hiding property of the component (D) was shown.

As the component (D), any of heavy calcium carbonate (ground calcium carbonate), light calcium carbonate (synthetic calcium carbonate), titanium dioxide and zinc sulfide did not significantly affect the foaming characteristics. However,
The total amount of the component (D) is 8 per 100 parts by weight of the component (A).
0 parts by weight (Example 12), 110 parts by weight (Example 13)
As a result, the foaming ratio, appearance, and embossability were slightly reduced, but the flame retardancy was good. On the other hand, the magnesium hydroxide of the component (B) in Example 6 was examined using a particle having a particle shape and a particle size not within the range of the present invention (Comparative Examples 8 to 10).
11) In any case, the foaming characteristics were not satisfactory.

[Examples 14 and 15] Component (B) and component (D)
In order to clarify the effects of the amounts of the components, Table 3 shows the compositions of Example 10 with the amounts of the components (B) and (D) reduced, and the evaluation results. When the component (B) was reduced to 5 parts by weight with respect to 100 parts by weight of the component (A) (Example 14), good results were obtained although the expansion ratio was slightly reduced. In addition, when the component (D) was not further added (Example 15), the flame retardancy was reduced and the thickness of the foamable sheet had to be reduced to 0.1 mm. It became.

Examples 16 to 21 The effects of the type of resin used on the flexibility of the foamed sheet were examined. That is,
With the composition shown in Table 4, foamed raw material was prepared by the same operation as in the above-mentioned examples, and its foaming characteristics and flame retardancy were evaluated. Table 4 shows the results.

[0059]

[Table 4]

The use of the component (B) in which various polyolefins satisfy the conditions of the present invention gave good foaming properties and flame retardant foam. However, when the melting endothermic peak exceeded 100 ° C. (Example 17), the flexibility was somewhat inferior.

Example 22 An expanded foam was prepared in the same manner as in Example 1 except that A2-2 was changed to A2-4, and its foaming characteristics and flame retardancy were evaluated (see Table 4). However, the thickness of the foamable sheet was set to 0.5 mm because the adhesiveness to the roll was stronger than the other examples. Expansion ratio is 8.5, appearance,
All of the flexibility, embossability and flame retardancy were ◎ as in Example 1.

Example 23 EVA emulsion (resin content: 50% by weight, vinyl acetate content in resin: 85% by weight) was mixed with 100 parts by weight of B1-1, 10 By weight of titanium dioxide, 12 parts by weight of ADCA, and 3 parts by weight of zinc stearate,
Apply to non-combustible paper treated with aluminum hydroxide, 14
The foamed material was heated at a temperature of 0 to 150 ° C. for 2 minutes. This foamable raw material was prepared. This foaming raw material is
By heating at 0 ° C. for 60 seconds, a foamed raw fabric was obtained. The same evaluation as in Example 1 was performed on this foam, and it was found that the expansion ratio was 3.1 times, the appearance was 、, the flexibility was ◎, the embossability was ○, and the flame retardancy was ◎.

[Comparative Example 12] A foam foam was prepared in the same manner as in Example 23 except that B1-1 was replaced with B1-8.
When the same evaluation was performed, the expansion ratio was 1.9 times, the appearance was ×, the flexibility was ◎, the embossability was ×, and the flame retardancy was ◎.

That is, by using a metal hydroxide meeting the conditions of the present invention, a foamable sheet having high foaming properties can be obtained even by a method of applying an emulsion.

[0065]

As described above, by chemically foaming the polyolefin resin of the present invention using a specific metal hydroxide or a specific metal hydroxide and an inorganic filler,
A foam sheet that satisfies flame retardancy, has a high expansion ratio, and has excellent design properties can be obtained. In addition, it is possible to produce a building interior material such as flooring and wallpaper having excellent design properties.

Claims (14)

[Claims] (A) a polyolefin resin, (B) a plate-like metal hydroxide having an aspect ratio (diameter / thickness ratio) of 2 to 10 and an average particle diameter of 2 μm or less, and
(C) A foamable sheet comprising a chemical foaming agent. 2. A polyolefin resin, (B) a plate-like metal hydroxide having an aspect ratio (diameter / thickness ratio) of 2 to 10 and an average particle diameter of 2 μm or less, (C)
A foamable sheet comprising a chemical foaming agent and (D) an inorganic filler. 3. The metal hydroxide of (B) is used in an amount of 1 to 120 parts by weight per 100 parts by weight of the polyolefin resin of (A).
3. The method according to claim 2, wherein the inorganic filler of (D) is contained in an amount of 100 parts by weight or less, and the total of the components (B) and (D) is 5 parts by weight or more. Foamable sheet. 4. A method according to claim 1, wherein the metal hydroxide (B) is contained in an amount of 30 to 120 parts by weight and the inorganic filler (D) is contained in an amount of 70 parts by weight or less based on 100 parts by weight of the polyolefin resin (A). The foamable sheet according to claim 2, wherein: 5. The metal hydroxide of (B) is contained in an amount of 30 to 120 parts by weight and the inorganic filler of (D) is contained in an amount of 10 to 70 parts by weight based on 100 parts by weight of the polyolefin resin (A). The foamable sheet according to any one of claims 2 to 4, wherein 6. The polyolefin resin of (A) comprises the following (A)
The foamable sheet according to any one of claims 1 to 5, wherein the foamable sheet is one or a mixture of two or more kinds selected from 1), (A2), and (A3). (A1) Copolymer of ethylene and α-olefin (A2) Ethylene-vinyl acetate copolymer resin (A3) Ethylene-acrylate copolymer resin 7. The polyolefin resin (A) is an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 10 to 45% by weight or a mixture of the ethylene-vinyl acetate copolymer resin and another polyolefin resin. The foamable sheet according to any one of claims 1 to 6, wherein the vinyl acetate content in the mixture is 10 to 45% by weight. 8. The foamable sheet according to claim 1, wherein the foamable sheet is formed by heat-melting and kneading. 9. The foamable sheet according to claim 8, wherein the content of vinyl acetate and acrylate in component (A) is 5 to 45% by weight. 10. A foamed sheet obtained from the foamable sheet according to claim 1. 11. A floor material further comprising a foam material according to claim 10 and a skin material and / or a backing material. 12. An original flooring material further comprising the foamable sheet according to claim 1 and a skin material and / or a backing material. 13. A wallpaper comprising a foamed sheet obtained from the foamable sheet according to claim 1 and a base paper. 14. A raw wallpaper comprising the foamable sheet according to claim 1 and a base paper.