WO2000012620A1 - Resin composition and molded object thereof - Google Patents

Abstract

A flame-retardant resin composition comprising an ethylene/α-olefin copolymer (A), a low-density polyethylene (B), and a flame retardant (C), wherein the amounts of components (A) and (B) are preferably 60 to 97 wt.% and 3 to 40 wt.%, respectively, and that of component (C) is preferably 50 to 200 parts by weight per 100 parts by weight of the sum of components (A) and (B). The composition can be rolled in a wide temperature range, and the resultant sheet can be wound up without stretching it from the rolls. Since the composition has a high melt tension, it has excellent suitability for foam molding and can give a foam sheet which has an expansion ratio of 2.5 to 10, is flexible, and has a satisfactory appearance. A laminate of this foam sheet with a paper base is suitable for use as a wall paper which feels good to the touch.

Description

 Description Resin composition and molded product thereof [Technical field]

 TECHNICAL FIELD The present invention relates to a polyolefin resin composition suitable for molding a foamed resin sheet, a foamed resin sheet produced therefrom, and a wall paper using the same. More specifically, the present invention relates to a resin composition having excellent roll processability and flame retardancy, a foamed resin sheet produced therefrom having flexibility and excellent appearance, and a wallpaper using the same.

[Background technology]

 The wallpaper has a structure in which a synthetic resin foam sheet is adhered to the front side on a paper base material, but until now a sheet made of vinyl chloride resin has been used as the synthetic resin foam sheet. Mainly used. Vinyl chloride resin sheets have been widely used because they have been evaluated for their good processability, flame retardancy, and low cost. However, vinyl chloride resin sheets are gradually shifting to alternative materials due to concerns about environmental pollution from combustion gases and health effects of plasticizers.

 Considering environmental and health considerations, polyolefin resin is a safe material with less of a concern, but the sheet formability of a single piece of calendar is not good, and the expansion ratio when foaming is performed. It is pointed out that the surface feel is different from that of conventional vinyl chloride resin sheets.

Japanese Patent Application Laid-Open No. 5-209498 discloses a highly flame-retardant wallpaper using an ethylene / polyolefin copolymer. Also Japanese Patent Application Laid-Open No. H10-17724 describes a wallpaper using a linear low-density polyethylene and having excellent calender roll workability.

 However, a resin composition having a wide processing temperature range during roll processing and low adhesion to a roll, a polyolefin resin foamed resin sheet having a high expansion ratio, and the use of the same. Wallpaper is required.

[Disclosure of the Invention]

 Therefore, the present inventor has studied various materials suitable for roll processing such as calendering using polyolefin resin, and it is easy to form a thin sheet with a high foaming ratio, and feels such as texture and touch. The present inventors have achieved the present invention as a result of developing a flame-retardant material which is excellent, is resistant to thermal discoloration and shrinkage, and is suitable for wallpaper materials.

That is, the resin composition according to the present invention has a density of less than 0.885 (g / cm ³ ) and a melt flow rate of 0 :! to 15 (g / 10 minutes). ethylene down-flying one Orefu fin copolymer (A), contact and density 0. 9 0 0~ 0. 9 4 0 (g / cm 3) der is, Mel walk opening one rate is 0. l to 15 (g / 10 min), and the melt tension (MT: mN) and melt flow rate (MFR) are expressed by the following relational expression.

4 0 x (MF R)-°-6 ⁷ ≤MT

≤ 2 5 0 X (MF R ) - 0 · 6 7

It relates to a composition in which a flame retardant (C) is blended with a low-density polyethylene (B) satisfying the above.

In particular, when the proportion of the above components is 60 to 97% by weight of the ethylene-hydroolefin copolymer (A) and 3 to 40% by weight of the low-density polyethylene (B) (where A) and (B) together 100% by weight And the flame retardant (C) is composed of 50 to 200 parts by weight per 100 parts by weight of the total of (A) and (B). Suitable for molding

The mixture comprising (A) and (B) has a density of 0.850 to 0.890 (g / cm ³ ) and a melt mouth rate of 0.1 to 1 5 (g / 10 minutes) and a resin composition having a melt tension at 150 ° C. of 20 to 10 O mN, a resin composition containing this mixture Is suitable for foam molding and provides a foamed resin sheet in which cells are uniformly dispersed.

 The present invention further relates to a flexible and good-looking foamed sheet obtained by subjecting the resin composition to foaming at a foaming ratio of 2.5 to 10 times, and laminating it on a paper substrate. It is related to the wallpaper.

[Best Mode for Carrying Out the Invention]

 Next, each component of the present invention will be specifically described in order. Ethylene / Hiichisai Refine Copolymer (A)

 The ethylene-olefin copolymer that can be used in the present invention is a copolymer of ethylene and monoolefin having 3 to 20 carbon atoms. Examples of hyolephine include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, etc. It is possible to use olefins having 3 to 10 carbon atoms, particularly propylene, 1-butene and 1-octene. One or more of these olefins can be used for copolymerization with ethylene.

The content of ethylene units in the copolymer is 60 to 90, preferably It is 65 to 85 mol%, and the content of monoolefin units is 10 to 40, preferably 15 to 35 mol%. The copolymer having the above composition range desirably has a crystallinity measured by X-ray diffraction of not more than 20%, and from this value, such a copolymer has low crystallinity or non-crystallinity. Of the polymer.

The density (gZ cm ³ ) of this copolymer is less than 0.885, preferably 0.850 or more and less than 0.885, more preferably 0.885 or more. And not more than 0.880. When the copolymer is within this density range, a molded article having flexibility and heat resistance, having no stickiness and a soft touch can be obtained.

 Furthermore, the melt rate is from 0.1 to 15, preferably from 0.5 to 10 (g / 10 minutes). If the melt mouth opening rate of the copolymer is within this range, not only is it easy to process with a roll or an extruder and a sheet having a smooth surface state is obtained, but also the foaming A sheet in a uniformly foamed state is obtained, and the sheet has excellent mechanical properties. Here, the Menoletoffee rate (MFR) is a value measured at 190 ° C and under a load of 2.16 kg according to ASTM D-1238.

 In the ethylene-polyolefin copolymer, the branched structure of the molecule may affect the resin composition and the molded product thereof. That is, if the g * value, which is one index for estimating the branched structure of the copolymer, exceeds 0.95, the copolymer has short-chain branches or relatively long-chain branches. It suggests that the resin composition containing such a copolymer has a low shrinkage rate of the primary molded body before foam molding, and the lamination with the paper base described later is low. This has the advantage that the laminate is less likely to curl.

On the other hand, if the g "* value is in the range of 0.2 to 0.95, It is suggested that the ethylene / ethylene copolymer has a long-chain branch, and a resin composition containing the same is excellent in moldability and foamability. Therefore, in consideration of the molding method and physical properties of the final molded article, it is desirable to select an ethylene-diolefin copolymer having an appropriate g ″ * value.

The g * value is determined by measuring the intrinsic viscosity [???????? of the ethylene-co-olefin copolymer at 135 ° C in a decalin solvent. ?] (d 1 / g) and the intrinsic viscosity of linear ethylene. hyolefin copolymer having the same weight average molecular weight as that measured by the light scattering method and having an ethylene content of 70 mol% [ 7?] It is a value expressed as a ratio to _{bl ank} (d 1 / g).

S r, * = [V] / [V] _b l ank

The g w * value was calculated according to the measurement method described in Japanese Patent Publication No. 3-14405.

The ethylene-polyolefin copolymer having such properties can be used to convert ethylene and olefin into a transition metal compound, an organic aluminum compound and / or an oxyaluminum compound, if necessary. It can be produced by copolymerization under ordinary polymerization conditions in the presence of a catalyst component combined with a third component and a carrier. For example, Ziegler-based catalysts represented by a combination of a halide or alkoxide compound of nonaluminum titanate and an organic aluminum compound, or a combination of a zirconium compound having a cyclopentene genenyl ring and an aluminum oxane. It can be obtained by the copolymerization of ethylene and polyolefin by using the catalyzed metallocene catalyst. Low-density polyethylene B) Low density polyethylenes used in the present invention has a density, 0.9 0 0 to 0.9 4 0, then rather the preferred 0. 9 0 0~ 0. 9 3 0 (g / cm 3) Der The melt flow rate is 0.1 to 15 and preferably 0.5 to 10 (gZ10). When the density and the melt flow rate are within the above ranges, the melt tension of the ethylene / forefine copolymer (A) is increased, and as a result, the sheet forming processability of the resin composition is enhanced, and the uniform thickness is obtained. A sheet with good appearance can be obtained. The melt flow rate (MFR) is a value measured at 190 ° C; 2.16 kg under ASTMD-1238.

 The low-density polyethylene used here has a melt tension (M T: mN) and a Menoletov mouthplate (M F R) satisfying the following relational expression.

^{4 0 X (MFR) - 0} - 6 7 ≤ MT

≤ 2 50 x (MFR)-°-6 ⁷

Here, both MT and MFR are values measured at 190 ° C. This relational expression shows that when a low-density polyethylene is sheet-molded, a suitable melt viscosity is imparted to the resin composition, and a melt tension suitable for sheet molding is given. It also suggests that this polyethylene is a low-density polyethylene having such an action, with moderately short or long chain branches attached to the polymer backbone.

A low-density polyethylene having a density and a melt flow rate within the above-mentioned range and satisfying the relational expression between the melt flow rate and the melt tension is an ethylene-high-density polyethylene. When a sheet composition is formed from a resin composition containing a olefin copolymer (A) and a flame retardant (C), the melt tension of the resin composition is increased, and the sheet is drawn unevenly. It does not stretch, and has the effect of uniformly dispersing bubbles during foam molding.

 Here, the melt tension (M T) is a value determined as a stress measured when a molten and extruded low-density polyethylene is stretched at a constant speed. Melt tension was actually measured using an MT measuring machine manufactured by Toyo Seiki Seisaku-sho, at a resin temperature of 190 ° C, an extrusion speed of 15 mm / min, a winding speed of Ιδπιι, and a nozzle diameter of 2. It is performed under the conditions of O 9 mm 0 and nozzle length 8 mm.

 Such a low-density polyethylene may be a so-called high-pressure polyethylene obtained by polymerizing ethylene under a high pressure using a radical catalyst, or a Ziegler catalyst or a metallocene catalyst as long as the above-mentioned physical properties are satisfied. It may be a so-called medium-to-low pressure polyethylene obtained by copolymerizing ethylene and a small amount of comonomers such as monoolefin under a medium to low pressure using a system catalyst.

 In the case of high pressure polyethylene, branching occurs along the polyethylene main chain during the polymerization of ethylene, and in the case of medium / low pressure polyethylene, branching due to coexisting comonomers is also added. It is thought that chain branching occurs, which increases the melt tension of the ethylene-diolefin copolymer and contributes to the improvement of processability. In the present invention, the high pressure method polyethylene is particularly suitable because it has a suitable branch because it has a high effect of adjusting the melt tension. Flame retardant (C)

As the flame retardant used in the present invention, an organic or inorganic compound which is generally blended with a synthetic resin and imparts flame retardancy can be used. Specifically, gold such as magnesium hydroxide and aluminum hydroxide Hydrate such as genus hydroxide, alumina, hydrotalcite, antimony oxide, metal oxides such as nickel oxide, magnesium borate, borate such as zinc borate, Mention may be made of organophosphates, ammonium phosphate monobasic, organic bromine or chlorine compounds, potassium chloride and mixtures thereof.

 These may be used alone or in combination of two or more. Of these, inorganic compounds such as metal hydroxides, hydrates, and antimony oxides are preferred, and metal hydroxides or mixtures of such metal oxides with the other inorganic compounds are particularly preferred. In order to enhance the compatibility between the flame retardant and the resin component and to uniformly disperse the flame retardant in the resin component, higher fatty acids, fatty acid amides, fatty acid esters, norafin, waxes, A dispersibility improver such as a silane coupling agent or a higher alcohol may be directly added to the resin composition, or the surface of the flame retardant may be treated therewith before blending into the resin component. Resin composition

The resin composition according to the present invention is mainly composed of the ethylene-polyolefin copolymer (A), the low-density polyethylene (B), and the flame retardant (C) described above. I have. The mixing ratio is not particularly limited, but (A) is 60 to 97% by weight, preferably 65 to 95% by weight, (B) is 3 to 40% by weight, and preferably 5 to 35% by weight. %. Here, the total of (A) and (B) is 100% by weight. Further, (C) is compounded in an amount of 50 to 200, preferably 70 to 150 parts by weight per 100 parts by weight of the total of (A) and (B). Such a component composition is desirable for enhancing the flame retardancy of the resin composition while maintaining excellent moldability and sheet physical properties. Among the above compositions, a homogeneous mixture comprising (A) and (B) has a density of 0.850 to 0.890, preferably 0.80 to 0.8. 85 (/ cm ³ ) with a melt flow rate of 0.1 to 15 and preferably 0.5 to 10 (g / 10 min) and at 150 ° C When the melt tension has a physical property in the range of 20 to 100, preferably 25 to 90 (mN), the roll processability of the resin composition is further improved, and foaming is further improved. Preferable because it improves moldability.

 This resin composition may contain other synthetic resins or rubbers or various additives within a range that does not impair the object of the present invention. Examples of additives include antioxidants, heat stabilizers, weather stabilizers, light stabilizers, antistatic agents, pigments, hydrochloric acid absorbers, dispersibility improvers, fillers, and the like.

 After mixing the ethylene / polyolefin copolymer (A), the low-density polyethylene (B), the flame retardant (C), and the additives to be added as required, the mixing ratio is as described above. Mix uniformly using a mixer such as a Banbury mixer, a Ni-da mixer, a roll or an extruder, and knead the mixture to produce the desired flame-retardant resin composition. Form into a compact.

 A resin composition having such a composition imparts flexibility and heat resistance to the molded product, and can be kneaded in a wide range of processing temperatures when rolled, and has a large sheet. It can be pulled off from the roll without being deformed easily, while enabling high expansion ratio in foam molding.

The resin composition obtained here can be molded into general films and sheets in addition to the foam sheets described below, and can be used as various products such as wallpaper and packaging materials. Can be. Foam resin sheet

 The foamed resin sheet according to the present invention can be easily produced by adding a foaming agent to the above resin composition and keeping it under foam molding temperature and pressure conditions. At that time, a method of once forming an unfoamed resin sheet from a resin composition to which a foaming agent has been added in advance, and then heating the foamed resin sheet to a temperature at which foaming can be performed to convert the foamed resin sheet into a foamed resin sheet may be adopted. Alternatively, a method of directly obtaining a foamed resin sheet from a resin composition to which a foaming agent has been added may be used.

 Usable foaming agents are appropriately selected from chemical foaming agents and physical foaming agents based on the molding method and molding temperature of the foamed resin sheet described above.

 Examples of the chemical foaming agents include azo compounds such as azodicarbonamide and azobisisobutyronitrile, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p, p, monooxybis (benzensulfonyl hydrazide). Hydrazide compounds, such as nitrozinc compounds, and nitroso compounds such as dinitrosone methylenetetramine, etc., which decompose themselves under foam molding conditions and are used for foam molding. It generates gas.

 Examples of the physical foaming agent include halogenated hydrocarbons such as carbon dioxide and difluorodichloromethane, and hydrocarbons such as butane, pentane, hexane, cyclobutane, and cyclohexane. Is gasified by itself under molding conditions and contributes to foam molding. One of the above-mentioned foaming agents may be used, or two or more of the same or different types may be selected and used in combination.

When molding foam sheets, the resin composition containing a foaming agent In the case of a method of producing a foamed resin sheet by forming an unfoamed resin sheet once using a roll or an extruder and then moving the resin sheet under foam molding conditions, physical foaming is used. The use of a chemical foaming agent is preferred over the use of a foaming agent. Among them, azodicarbonamide and the like are suitable because stable molding can be performed. In this case, the foam molding can be performed by using a heating device such as an air oven or a heating roll.

 On the other hand, when a foaming agent is press-fitted from another supply port of the extruder while the resin composition is supplied to the extruder, and the foamed resin sheet is directly taken from the die and manufactured, physical foaming is generally performed. Agents are used, especially carbon dioxide gas and chlorofluorocarbon gas. It is also possible to supply the resin composition to which the foaming agent has been added in advance to the extruder and to directly take out the foamed resin sheet from the die. In this case, it is possible to use a chemical foaming agent or a physical foaming agent. Any of the agents can be used.

 The expansion ratio of the obtained foamed resin sheet is 2.5 to 10, preferably 3 to 8 times. In the sheet obtained from the resin composition, air bubbles having a uniform diameter are uniformly dispersed, and the sheet surface is smooth and a flexible sheet is obtained. Therefore, this foamed resin sheet is suitable for use as a laminate material as in the case of a wallpaper material described later, and can also be used for various foam products such as general packaging materials and cushioning materials. it can.

The wallpaper according to the present invention has a structure in which a paper base material is laminated on one surface of the foamed resin sheet and integrated. Usually, paper having a thickness of 0.1 to 0.2 mm is used for the paper base layer in consideration of the dimensions and form stability of the wallpaper, while the foamed resin sheet layer is used for the expansion ratio. By adjusting 2.5 to 10 times, preferably 3 to 8 times, a layer having a thickness of 0.5 to 1.5 mm is obtained. The surface of the foam sheet layer is designed as a wallpaper by printing, embossing, embossing, or the like. Further, a surface protective layer can be provided on the outer surface as needed.

 The paper substrate that can be used is selected according to the intended use of the wallpaper, such as paper made from natural pulp or synthetic pulp, or paper mixed with inorganic substances. Since the above-mentioned foamed resin sheet layer has water resistance and flame retardancy by itself, it can be used for general purposes without particularly requiring the properties of a paper base material, but contains inorganic substances. Use of flame-retardant paper, for example, aluminum hydroxide paper, as the paper substrate further enhances the flame retardancy, and is therefore preferable for enhancing safety.

 In the manufacture of wallpaper, a resin sheet pre-foamed and formed on a paper base may be laminated and laminated using an adhesive between the two layers, or extruded molten polyethylene resin or the like between the layers. Can be laminated by pressure bonding. In this lamination, if the adhesive surface of the foamed resin sheet is subjected to corona discharge treatment, frame treatment, oxidation treatment or the like in advance, a strong interlayer adhesion is obtained, which is a desirable treatment method.

 As another method of producing wallpaper, a preformed unfoamed resin sheet is laminated and adhered on a paper base material, or an unfoamed resin sheet is extruded onto a paper base material and laminated. Thereafter, the laminate is foamed by being subjected to foaming conditions such as passing through a heating device such as a heating furnace and a heating roll to obtain a wallpaper in which a foamed resin sheet is laminated on a paper base material. Can also. Alternatively, it can also be produced by a method in which a resin composition in which a foaming agent is added or press-fitted onto a paper substrate is directly laminated from an extruder or a calender roll, and lamination and foaming are simultaneously performed.

This wallpaper is flame retardant and has good surface feel and appearance Therefore, it is suitable as an intelligent product. Example

 Next, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Examples 1 to 7 and Comparative Examples 1 to 6

 Table 1 shows the physical properties of the ethylene-hydrofuran copolymer (A-1 to A-5) and the low-density polyethylene (B-- :! to B-4). In the table, the high-pressure method LDPE indicates low-density polyethylene produced by the high-pressure method.

Next, ethylene / polyolefin copolymer and low-density polyethylene were mixed as resin components at the blending ratio (% by weight) shown in Tables 2 and 3, and the mixture was kneaded using an open roll. I got The density (g / cm ³ ), melt flow rate (MFR: g / 10 min), and melt tension (MT: mN) of this mixture were measured, and the results are shown in Tables 2 and 3. Indicated.

 Next, with respect to 100 parts by weight of the mixture, 100 parts by weight of magnesium hydroxide as a flame retardant and 5 parts by weight of azodicarbonamide as a foaming agent were further added. The mixture was kneaded using a resin to obtain a resin composition.

 At this time, the temperature of the open roll was changed between 110 ° C and 140 ° C to increase the adhesiveness of the sheet to the roll during this kneading work and the elongation when the sheet was pulled out from the mouth. The situation was observed. These were used as judgment items for roll workability. Based on the judgment results, the roll workability was comprehensively evaluated, and the results are shown in Tables 2 and 3.

Then, the resin composition is removed from the resin composition using an electric heating roll. — Sheet molding was performed to obtain a sheet with a thickness of 200 zm. The obtained sheet was placed in an air oven at 220 ° C. for 2 minutes to decompose the foaming agent to obtain a foamed sheet. Tables 2 and 3 show the expansion ratio of the foamed sheet, the surface state visually evaluated, and the flexibility evaluated by surface feel.

[Industrial applicability]

 Since the resin composition according to the present invention contains an ethylene-high-refined olefin copolymer, low-density polyethylene, and a flame retardant, a molded article having flexibility and flame retardancy can be obtained.

 In addition, the resin composition can be rolled in a wide temperature range, and does not strongly adhere to the roll at that time, so that the sheet can be peeled off with little stretching of the sheet when taking off. Sheets having good dimensions and appearance can be manufactured. Therefore, the production speed of the sheet is improved, and the sheet is not discolored by heat at that time.

 Further, since the resin composition has a high melt tension, it has good foam moldability, and can form a foam having a uniform cell shape. Therefore, the resin composition is a thin foam resin sheet which is soft and has good surface appearance. Can be obtained. In particular, since sheet molding with a high expansion ratio can be performed, productivity can be improved.

When this foamed resin sheet is adhered to a paper base material, it has a volume feeling and becomes a surface layer with an excellent touch such as texture and touch, so it is suitable for use as wall paper. Table 1 Type of each component Ethylene content a-olefin density MF _g 5 η * ΜΤ value

(Mol%) (g / cm ³ ) (g / 10 min) (mN) Ethylene

Fin copolymer

_{Α- 1 81 c 4 0. 860} 3. 6 1, 00

_{A- 2 81 c 4 0. 860} 1. 0 1, 00

A—3 85 c ₈ 0 .870 4, 0 1 .00

A— 4 81 c ₄ 0. 860 35 1, 00

A— 5 90 c ₈ 0. 890 4.01, 00

_{A- 6 81 c 4 0. 860} 1. 0 0, 85 low density polyethylene

 B- 1 100 High pressure LDPE 0.917 7.0 65 B-2 100 High pressure LDPE 0.917 3.6 100 B-3 100 High pressure LDPE 0.915 0.5

 Low pressure method LDPE 210 B-4 100 0.915 20 18

(Note) C ₄ indicates 1 bouten.

C _B is 1 _c

Table 1 2

O

(Note) 〇 Good, Δ Somewhat good, X bad

Table 1 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Types of Each Component

 Α— 1 100 80 1 ― A Q n

 A— 4 O U O U

 A— 5 80 80

B-2 20 20

 B-3 20 20

B-4 20 Physical properties of resin mixture

 Density 0.860 0.871 0.871 0.872 0.895 0.895

MFR 3, 6 5.4 21 16 4.0 0.2 Melt tension 12 15 9 27 36 42

ΟOne hole 7JU 丄 1ϊ

 11 o. c O O O 〇 O

120. C O O O O O O

130. C X △ X mm O O

140 ° C X X X X O 物 Foam sheet properties

 Expansion ratio 3. 6 3. 2 2. 0 2. 4 4. 5 4.5 Surface condition 〇 〇 厶 〇 柔軟 性 柔軟 性 柔軟 性 〇 Δ O Δ X X

(Note) o Good, Δ Somewhat good, X bad

Claims

The scope of the claims 1. Ethylene monofluoride having a density of less than 0.885 (g / cm ³ ) and a melt mouth opening rate of 0.1 to 15 (/ 10 min) Copolymer (A), and a density of 0.90 to 0.94 (g / cm ³ ), and a melt flow rate of 0.1 to 15 (g / 0 min), and the melt tension (MT: mN) and melt flow rate (MFR) are expressed by the following relational expression. 4 0 x (MFR) — ° · ^{6 7} ≤ Μ Τ ≤ 2 50 x (MFR)-°-6 ⁷  A resin composition comprising a low-density polyethylene (B) satisfying the above, and a flame retardant (C) blended therein.  2. The above ethylene 'olefin copolymer (A) is 60 to 97% by weight, and the low-density polyethylene (B) is 3 to 40% by weight (where (A) and (B) are combined). 100% by weight) and the flame retardant (C) comprises 50 to 200 parts by weight per 100 parts by weight of the total of (A) and (B). The resin composition according to claim 1, wherein  3. The mixture comprising the above ethylene copolymer (A) and the low-density polyethylene (B) has a density of 0.850. 0.80 g (g / cm ³ ) and the melt flow rate is 0.1-: L5 (g / 10 min) and the melt temperature at 150 ° C The resin composition according to claim 1, wherein the tension is 20 to 10 O mN. 4. The above ethylene / polyolefin copolymer (A) has an ethylene content of 60 to 90 (mol%) and a hy- olefin content of 10 to 4%. 4. The method according to claim 1, wherein the amount is 0 (mol%). A resin composition according to any of the preceding claims. The resin composition according to any one of claims 1 to 4, wherein the carbon is a carbon having 3 to 20 carbon atoms. 6. The ethylene-hydrogen olefin copolymer (A) having a crystallinity of not more than 20% as measured by X-ray diffraction. A resin composition according to any one of the above. Ethylene-a-olefins with densities less than 0.885 (g / cm ³ ) and melt mouth-rates between 0.1 and 15 (g / 10 min) The polymer (A) has a density of 0.90 to 0.94 (g / cm ³ ) and a melilet flow rate of 0.1 to 15 (g / 10 minutes). And the melt tension (MT: mN) and the melt flow rate (MFR) are 4 0 x (MFR)-°-6 ⁷ ≤ MT ≤ 250 x (MFR)-°-6 ⁷ A resin composition comprising a low-density polyethylene (B) and a flame retardant (C) satisfying the above conditions, and is formed into a sheet having an expansion ratio of 2.5 to 10 times. G. Ethylene mono-olef whose density is less than 0.885 (g / cm ³ ) and melt mouth—rate is 0.;! To 15 (g / 10 minutes) The copolymer (A) has a density of 0.90 to 0.94 (g / cm ³ ) and a melt flow rate of 0.1 to 15 (g / cm ³ ). 10 minutes), and the melt tension (M T: mN) and the melt flow rate (M F R) are expressed by the following relational expression. ^{4 0 X (MFR) - 0} · 6 7 ≤ MT ≤ 250 X (MFR)-. · ^{6 7} Low-density polyethylene (Β) and flame retardant (C) A wallpaper characterized by a paper base material laminated on one side of a foamed resin sheet having a foaming ratio of 2.5 to 10 times.