阅读说明：本技术 橡胶海绵及发泡性橡胶组合物 (Rubber sponge and foamable rubber composition ) 是由 渡部健太 于 2019-02-18 设计创作，主要内容包括：本发明公开一种橡胶海绵,其具有含有经过硫化的合成橡胶的发泡部,发泡部的平均气泡直径为10～350μm,发泡部的气泡直径的标准偏差为10～150μm。合成橡胶的含量以橡胶海绵的质量为基准可以为20～80质量％。(The invention discloses a rubber sponge, which comprises a foaming part containing vulcanized synthetic rubber, wherein the average bubble diameter of the foaming part is 10-350 mu m, and the standard deviation of the bubble diameter of the foaming part is 10-150 mu m. The content of the synthetic rubber may be 20 to 80% by mass based on the mass of the rubber sponge.)

1. A rubber sponge having a foamed part containing a vulcanized synthetic rubber,

the average cell diameter of the foaming part is 10-350 μm,

the standard deviation of the bubble diameter of the foaming part is 10-150 μm.

2. The rubber sponge of claim 1, wherein,

the content of the synthetic rubber is 20 to 80 mass% based on the mass of the rubber sponge.

3. The rubber sponge according to claim 1 or 2,

the synthetic rubber comprises an ethylene-alpha-olefin-non-conjugated diene copolymer rubber.

4. The rubber sponge according to any one of claims 1 to 3,

the rubber sponge also contains an organic filler.

5. The rubber sponge of claim 4, wherein,

the ratio of the content of the organic filler to the content of the synthetic rubber is 0.20 to 1.00.

6. The rubber sponge of claim 4 or 5, wherein,

the organic filler contains particles containing a vinyl chloride resin.

7. A foamable rubber composition comprising a synthetic rubber, an organic filler and a foaming agent,

the content of the synthetic rubber is 30 to 80% by mass based on the total mass of the components other than the foaming agent in the foamable rubber composition,

the mass ratio of the content of the organic filler to the content of the synthetic rubber is 0.20 to 1.00.

8. The foamable rubber composition according to claim 7,

the organic filler contains particles containing a vinyl chloride resin.

Technical Field

The present invention relates to a rubber sponge and a foamable rubber composition which can be used for obtaining the rubber sponge.

Background

Rubber sponges are elastic foams and are used as sealing materials, caulking materials, sound absorbing materials, heat insulating materials (heat insulating materials), cushioning materials, and rolls (materials ロール in Japanese) in the fields of construction, civil engineering and construction, electrical equipment, automobiles, vehicles, ships, and housing equipment. The rubber sponge is produced by, for example, foaming and vulcanizing a rubber composition containing a synthetic rubber such as an ethylene- α -olefin copolymer rubber and a foaming agent (for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

The rubber sponge is sometimes required to have rebound resilience (japanese original text: anti-aging resilience). Accordingly, an object of one aspect of the present invention is to provide a rubber sponge having more excellent rebound resilience.

Means for solving the problems

The present inventors have found that the uniformity of the cell diameter is related to the rebound resilience in the case of a rubber sponge containing fine cells, and have completed the present invention based on this finding.

That is, one aspect of the present invention provides a rubber sponge having a foamed part containing a vulcanized synthetic rubber, the foamed part having an average cell diameter of 10 to 350 μm and a standard deviation of the cell diameter of the foamed part of 10 to 150 μm. The rubber sponge can have more excellent rebound elasticity than the conventional rubber sponge.

Another aspect of the present invention relates to a foamable rubber composition containing a synthetic rubber, an organic filler, and a foaming agent. The content of the synthetic rubber is 20 to 80 mass% based on the mass of the foamable rubber composition, and the mass ratio of the content of the organic filler to the content of the synthetic rubber is 0.20 to 1.00. The foamable rubber composition can easily form a rubber sponge having more excellent rebound resilience than a conventional rubber sponge.

Effects of the invention

According to the present invention, a rubber sponge having more excellent rebound resilience than a conventional rubber sponge and a foamable rubber composition from which the rubber sponge can be obtained can be provided. In general, the synthetic rubber is suitably used in accordance with the use of the rubber sponge, and the magnitude of the rebound resilience of the rubber sponge may vary depending on the type of the synthetic rubber. According to the present invention, when rubber sponges containing the same type of synthetic rubber are compared, rubber sponges having relatively higher rebound resilience than conventional rubber sponges can be obtained.

Drawings

FIG. 1 is a photomicrograph of a cross-section of the rubber sponge produced in example 1.

Detailed Description

Hereinafter, several embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

The rubber sponge of one embodiment has a foamed portion containing a vulcanized synthetic rubber. The average cell diameter of the foamed part is 10 to 350 [ mu ] m, and the standard deviation of the cell diameter of the foamed part is 10 to 150 [ mu ] m. By making the average particle diameter of the foamed part and the standard deviation of the cell diameter fall within these ranges at the same time, the rubber sponge can have excellent rebound resilience. From the same viewpoint, the average cell diameter of the foamed part may be 30 to 300 μm, and the standard deviation of the cell diameter may be 20 to 125 μm. The average cell diameter of the foamed part may be 50 to 250 μm or 50 to 200 μm, and the standard deviation of the cell diameter may be 30 to 100 μm. When the average cell diameter of the foamed part is 50 μm or more, the rubber sponge can be produced more easily. Similarly, when the standard deviation of the cell diameter of the foamed part is 30 μm or more, the rubber sponge can be produced more easily.

Here, in the present specification, the cell diameter refers to the maximum width of each cell observed in a cross section of the foamed part of the rubber sponge. The maximum width of the bubble is the maximum of the distance between 2 parallel lines tangent to the outer circumference of the bubble in cross section. The average cell diameter of the foamed part and the standard deviation of the cell diameter of the foamed part are determined by a method including the following steps.

1) The cross section at 3 different positions of the portion located inside with respect to the depth of the large value among 10% or 1mm of the minimum width of the rubber sponge from the surface of the rubber sponge was observed with a solid microscope.

2) In the section plane observedIn (1), the area is measured at 6mm²The bubble diameter of all bubbles observed in the region of (a).

3) The arithmetic mean of all the measured cell diameters was defined as the average cell diameter of the foamed part, and the standard deviation of all the measured cell diameters was defined as the standard deviation of the cell diameters of the foamed part.

In the above method, the "minimum width of the rubber sponge" is the minimum value of the distance between 2 parallel lines that are tangent to the outer periphery of the obtained projected image when the rubber sponge is vertically projected onto an arbitrary plane. The position and direction of the plane on which the rubber sponge is perpendicularly projected with respect to the rubber sponge are determined in such a manner that the minimum value of the distance between the 2 parallel lines is minimized. For example, in the case of a rectangular parallelepiped rubber sponge, the length of the shortest side thereof is "the minimum width of the rubber sponge". In the case of a sheet-like rubber sponge, the thickness thereof is usually "the minimum width of the rubber sponge". When the minimum width of the rubber sponge is 10mm or less, the bubble diameter of a portion located inside with respect to a depth of 1mm from the surface is measured, and when the minimum width of the rubber sponge is greater than 10mm, the bubble diameter of a portion located inside with respect to a depth of a value of "10% of the minimum width of the rubber sponge" is measured.

The rubber sponge may have a skin layer having a higher density than the foamed part as an outermost layer. The boundary between the foamed part and the skin layer is not necessarily clear, but the average cell diameter of the foamed part and the standard deviation of the cell diameter of the foamed part can be determined by measuring the cell diameter of a portion located inside from the surface to a certain depth as in the above-described method. In other words, when the skin layer is present, a portion from the surface of the rubber sponge to a depth of a large value of 10% or 1mm of the minimum width of the rubber sponge may be regarded as the skin layer, and a portion inside the skin layer may be regarded as the foamed part. However, the average cell diameter of the foamed part and the standard deviation of the cell diameter of the foamed part can be determined by the above-described method regardless of the presence or absence of the skin layer.

The density of the rubber sponge or the foaming part can be 0.01-0.6 g/mL. The rubber sponge having a density in this range is easily used as a sufficiently lightweight material in various uses. In addition, rubber sponges with too low a density are often difficult to manufacture. Rubber sponges with too high a density have poor lightness. From the same viewpoint, the density of the rubber sponge or the foamed part may be 0.02 to 0.5g/mL or 0.03 to 0.4 g/mL.

The water absorption rate of the rubber sponge or the foamed part may be 0 to 20%, 0 to 15%, or 0 to 10% from the viewpoint of sealing property or water stopping property.

The synthetic rubber in the rubber sponge is usually vulcanized by a vulcanizing agent such as sulfur or other vulcanizing agent or crosslinking agent.

The content of the synthetic rubber in the rubber sponge may be 20 to 80% by mass based on the mass of the rubber sponge. Rubber sponges with a content of synthetic rubber in this range tend to show particularly high rebound resilience and good processability. From the same viewpoint, the content of the synthetic rubber may be 30% by mass or more, and may be 50% by mass or less, 45% by mass or less, or 42% by mass or less.

The synthetic rubber may include, for example, ethylene- α -olefin-based copolymer rubber, butyl-based rubber, butadiene rubber, styrene butadiene rubber, isoprene rubber, chloroprene rubber, acrylonitrile butadiene rubber, epichlorohydrin rubber, or a combination thereof.

The ethylene- α -olefin copolymer rubber may be, for example, an ethylene- α -olefin copolymer rubber or an ethylene- α -olefin-non-conjugated diene copolymer rubber.

The method for producing the ethylene- α -olefin copolymer rubber is not particularly limited. The ethylene- α -olefin copolymer rubber can be obtained by, for example, a method of polymerizing ethylene, α -olefin, and optionally a non-conjugated diene in the presence of a catalyst such as a so-called ziegler-natta catalyst or a metallocene catalyst.

As Ziegler Natta catalysts, combinations of organoaluminum compounds with vanadium compounds are suitable. Examples of the organoaluminum compound constituting the ziegler-natta catalyst include triethylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, isobutylaluminum chloride, ethylaluminum dichloride, isobutylaluminum dichloride, and a combination thereof. Examples of the vanadium compound constituting the Ziegler-Natta catalyst include vanadium tetrahalide, vanadium oxyhalide, vanadium triacetylacetonate, vanadium diacetylacetonate oxide (Japanese: バナジウムオキシジリアセチルアセトネート), vanadium trialkoxide, vanadium oxyhalide alkoxide (Japanese: ハロゲン: バナジウムオキシアルコキシド), and a combination thereof.

The organoaluminum compound and vanadium compound as the Ziegler Natta catalyst may be used in combination with an alcohol such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol or 2-methyl-2-propanol. Hydrogen may also be used as a chain transfer agent.

As an example of the metallocene catalyst, a transition metal complex having at least 1 cyclopentadienyl skeleton can be cited. Transition metal complexes are compounds containing a transition metal atom. The transition metal atom herein refers to a transition metal element of group 4 of the periodic table (revised 1989 of IUPAC inorganic chemical nomenclature), and examples thereof include a titanium atom, a zirconium atom, and a hafnium atom.

Examples of the α -olefin constituting the ethylene- α -olefin copolymer rubber include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. The alpha-olefin can also be propylene, 1-butene, or a combination thereof.

Examples of the non-conjugated diene constituting the ethylene- α -olefin-non-conjugated diene copolymer rubber include chain non-conjugated dienes such as 1, 4-hexadiene, 1, 6-octadiene, 2-methyl-1, 5-hexadiene, 6-methyl-1, 5-heptadiene and 7-methyl-1, 6-octadiene, cyclohexadiene, dicyclopentadiene, methyltetraindene, 5-vinylnorbornene, cyclic non-conjugated dienes such as 5-ethylidene-2-norbornene and 6-chloromethyl-5-isopropenyl-2-norbornene, 2, 3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2, 2-norbornadiene, 1, 3, 7-octatriene and 1, 4, 9-decatriene, 5-vinyl-2-norbornene, 5-octatrienes, 5- (2-propenyl) -2-norbornene, 5- (3-butenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene, 5- (5-hexenyl) -2-norbornene, 5- (5-heptenyl) -2-norbornene, 5- (7-octenyl) -2-norbornene, 5-methylene-2-norbornene, 6, 10-dimethyl-1, 5, 9-undecatriene, 5, 9-dimethyl-1, 4, 8-decatriene, 4-ethylene-8-methyl-1, 7-nonadiene, 13-ethyl-9-methyl-1, 9, 12-pentadecatriene, 5, 9, 13-trimethyl-1, 4, 8, 12-tetradecadiene, 8, 14, 16-trimethyl-1, 7, 14-hexadecatriene, and 4-ethylene-12-methyl-1, 11-pentadecadiene. The ethylene- α -olefin-non-conjugated diene copolymer rubber may contain 1 or more non-conjugated dienes selected from them as monomer units. The non-conjugated diene can also be 5-ethylidene-2-norbornene, dicyclopentadiene, or a combination thereof.

The ethylene-alpha-olefin copolymer rubber (for example, ethylene-propylene copolymer rubber) may have an intrinsic viscosity of 1.0 to 4.0dl/g or less as measured in tetralin at 135 ℃. When the intrinsic viscosity is 1.0dl/g or more, the rebound resilience of the rubber sponge tends to be further improved. When the intrinsic viscosity is not more than 4.0dl/g, the rubber composition tends to have improved roll processability. From the same viewpoint, the ethylene-alpha-olefin copolymer rubber may have an intrinsic viscosity of 1.2 to 3.0dl/g or 1.4 to 2.5dl/g as measured in tetralin at 135 ℃.

The intrinsic viscosity (unit: dl/g) is measured, for example, under the following conditions. The reduced viscosity (viscosity number) of the copolymer solution having a known concentration was measured in tetralin at 135 ℃ using an Ubbelohde viscometer. From the measurement results, the intrinsic viscosity of the copolymer was determined by the calculation method described in 491 of Polymer solution and Polymer Experimental science 11 (1982, Co., Ltd.).

The content of the α -olefin unit in the ethylene- α -olefin copolymer rubber may be 20 to 70% by mass, assuming that the total of the content of the ethylene unit and the content of the α -olefin unit is 100% by mass. When the content of the α -olefin unit is 20% by mass or more, the processability of the rubber sponge can be improved. If the content of the α -olefin unit is 70% by mass or less, the durability of the rubber sponge can be improved. From the same viewpoint, the content of the α -olefin unit may be 25 to 65% by mass, or 30 to 60% by mass.

The content of the ethylene unit in the ethylene- α -olefin copolymer rubber may be 30 to 80 mass%, 35 to 75 mass%, or 40 to 70 mass% when the total of the content of the ethylene unit and the content of the α -olefin unit is 100 mass%.

The content of the non-conjugated diene unit in the ethylene- α -olefin-non-conjugated diene copolymer rubber may be 1 to 15 mass%, 2 to 13 mass%, or 3 to 11 mass% when the total of the content of the ethylene unit, the content of the α -olefin unit, and the content of the non-conjugated diene unit is 100 mass%.

When the synthetic rubber contains 2 or more types of ethylene- α -olefin copolymer rubbers, the intrinsic viscosity, the content of ethylene units, the content of α -olefin units, and the content of non-conjugated diene units are values of the whole of a combination of 2 or more types.

The synthetic rubber may be introduced into the rubber composition as an oil extended rubber which is a mixture with a processing oil such as a paraffin oil and a naphthene oil.

The rubber sponge may also contain an organic filler. In this case, the mass ratio of the content of the organic filler to the content of the synthetic rubber may be 0.20 or more or 0.25 or more, or may be 1.00 or less or 0.90 or less, from the viewpoint of improving rebound resilience. From the same viewpoint, the content of the organic filler may be 8 mass% or more, 9 mass% or more, or 10 mass% or more, or 40 mass% or less, 35 mass% or less, or 30 mass% or less based on the mass of the rubber sponge. The organic filler may be dispersed in the foaming section. In the case where the rubber sponge has a skin layer, the organic filler may be dispersed in the foamed part and the skin layer.

The organic filler may be any material that can be dispersed in a rubber composition containing a synthetic rubber. The organic filler may be particles containing an organic polymer, or may be particles substantially formed of an organic polymer. The particles substantially made of an organic polymer mean particles containing an organic polymer in an amount of 95 mass% or more based on the mass of the particles. The organic polymer forming the particles containing the organic polymer may be, for example, a thermoplastic resin, a thermosetting resin, or a cured product thereof. Examples of the thermoplastic resin include vinyl chloride resins, polyethylene resins, polypropylene resins, and polymethyl methacrylate resins. For example, when a part or the whole of the organic filler is particles containing a vinyl chloride resin, 60 to 100 mass% of the organic filler may be particles containing a vinyl chloride resin.

The vinyl chloride resin is a vinyl chloride homopolymer or a copolymer containing vinyl chloride as a monomer unit. Examples of the monomer constituting the copolymer together with vinyl chloride include vinyl esters such as vinyl acetate and vinyl propionate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and itaconic acid, unsaturated carboxylic acid esters such as methyl acrylate, methyl methacrylate and ethyl itaconate, olefins such as ethylene and propylene, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, and fumaric acid, maleic acid, and anhydrides or esters thereof. Examples of the method for producing a vinyl chloride resin such as a vinyl chloride homopolymer include suspension polymerization, emulsion polymerization, and microsuspension polymerization. The particles containing a vinyl chloride resin may be particles produced by emulsion polymerization or microsuspension polymerization.

The average particle size of the organic filler is not particularly limited, but may be 0.1 to 30 μm, or 0.1 to 10 μm, or 0.1 to 5 μm. As the average particle diameter of the organic filler, an arithmetic average of the maximum width of the organic filler observed when the cross section of the rubber sponge is observed may be mentioned. The average particle diameter of the organic filler may be an arithmetic average of the maximum widths of the organic fillers observed when the organic fillers before being compounded in the rubber composition for forming the rubber sponge are observed by an electron microscope. Since the average particle diameter of the organic filler does not substantially change before being compounded into the rubber composition and after the rubber sponge is formed, generally, the average particle diameter of the organic filler before being compounded into the rubber composition and the average particle diameter of the organic filler in the rubber sponge do not substantially differ. When the average particle diameter of the organic filler is in the above range, a rubber sponge having a foamed part with an average cell diameter of 10 to 350 μm and a standard deviation of the cell diameter in the range of 10 to 150 μm is easily formed.

The rubber sponge may contain an inorganic filler as a reinforcing agent or filler. Examples of the reinforcing agent include carbon black and silica. Examples of the filler include calcium carbonate, calcium oxide, magnesium oxide, titanium oxide, aluminum oxide, clay, talc, mica, montmorillonite, hydrotalcite, zeolite, barium sulfate, magnesium hydroxide, aluminum hydroxide, antimony trioxide, and calcium silicate. The content of the reinforcing agent may be 0 to 100 parts by mass, 5 to 50 parts by mass, or 10 to 30 parts by mass per 100 parts by mass of the synthetic rubber. The content of the filler may be 0 to 50 parts by mass, 0 to 40 parts by mass or 0 to 30 parts by mass per 100 parts by mass of the synthetic rubber. Particularly, when the content of the reinforcing agent is 0 to 100 parts by mass relative to the content of the synthetic rubber and the content of the filler is 0 to 50 parts by mass relative to the content of the synthetic rubber, a rubber sponge having a foamed part with an average cell diameter of 10 to 350 μm and a standard deviation of the cell diameter in the range of 10 to 150 μm is easily formed.

The rubber sponge may contain processing oil. Examples of the processing oil include paraffin-based oil, naphthene-based oil, and aromatic-based oil. The content of the processing oil may be 0 to 250 parts by mass, 10 to 200 parts by mass, or 30 to 160 parts by mass with respect to 100 parts by mass of the synthetic rubber.

The rubber sponge may further contain other components such as zinc oxide, stearic acid, polyethylene glycol, calcium oxide, a foaming aid, a crosslinking agent, a crosslinking aid, an antiaging agent, sulfur, a vulcanization accelerator, an adhesive substance (polybutene, rosin, etc.), a thermoplastic resin (polyethylene, polypropylene, etc.), and the like, as required. The air bubbles in the rubber sponge may contain a gaseous component from the foaming agent.

The rubber sponge can be produced, for example, by a method including the steps of molding a foamable rubber composition containing a synthetic rubber and a foaming agent to obtain a molded body, vulcanizing the synthetic rubber in the molded body, and foaming the molded body. The vulcanization and foaming steps may be performed simultaneously or continuously.

The foaming agent contained in the foamable rubber composition may be selected from among foaming agents generally used for forming rubber foams. Examples of the blowing agent include azodicarbonamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, 4 ' -oxybis-benzenesulfonylhydrazide, sodium hydrogencarbonate, sodium carbonate, ammonium hydrogencarbonate, ammonium carbonate, ammonium nitrite, N ' -dimethyl-N, N ' -dinitroso-terephthalamide, azocyclohexanecarbonitrile, azodiaminobenzene, barium azodicarboxylate, benzenesulfonylhydrazide, toluenesulfonylhydrazide, diphenylsulfone-3, 3 ' -disulfonylhydrazide, calcium azide and 4, 4 ' -diphenyl-disulfonylazide-p-toluenesulfonylazide. The blowing agent may be azodicarbonamide. The content of the foaming agent may be 1 to 35 parts by mass or 2 to 30 parts by mass with respect to 100 parts by mass of the synthetic rubber.

The foamable rubber composition may contain a foaming aid for lowering the decomposition temperature of the foaming agent. Examples of the foaming aid include urea-based aids. The content of the foaming aid may be 1 to 20 parts by mass, 1.5 to 15 parts by mass, or 2 to 12 parts by mass based on 100 parts by mass of the synthetic rubber.

The foamable rubber composition may contain a vulcanizing agent for vulcanizing the synthetic rubber. Examples of the vulcanizing agent include sulfur, sulfur-based compounds, and organic peroxides. The sulfur may be powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, or insoluble sulfur, or the like. The content of the vulcanizing agent in the foamable rubber composition may be 0.5 to 5 parts by mass, or 0.6 to 4 parts by mass, based on 100 parts by mass of the synthetic rubber.

The foamable rubber may contain the above-mentioned components as components of the rubber sponge in addition to the synthetic rubber, the foaming agent and the vulcanizing agent. The content of each component is also the same, and the content based on the mass of the rubber sponge may be referred to as the content based on the total mass of the components other than the foaming agent in the foamable rubber composition. In particular, when the content of the synthetic rubber is 20 to 80% by mass based on the total mass of the components other than the foaming agent in the foamable rubber composition and the ratio of the content of the organic filler to the content of the synthetic rubber is 0.20 to 1.0, a rubber sponge having a foamed part with an average cell diameter of 10 to 350 μm and a standard deviation of the cell diameter in the range of 10 to 150 μm is easily formed. From the viewpoint of facilitating the formation of the rubber sponge, it is more preferable that the content of the synthetic rubber is 30 to 80% by mass based on the total mass of the components other than the foaming agent in the foamable rubber composition.

The foamable rubber composition can be obtained by kneading the respective components by a usual method such as a banbury mixer, a kneader, or a roll. The foamable rubber composition is molded by various methods such as extrusion molding to obtain a molded article. In the molding, the foamable rubber composition may be melted under a reduced pressure. When the foamable rubber composition is molded while being melted under reduced pressure, a rubber sponge having a foamed portion with a small average cell diameter and a small standard deviation of cell diameter tends to be easily formed. The gauge pressure of the reduced pressure atmosphere here may be-10 kPa or less.

When the foamable rubber composition contains a vulcanizing agent, the synthetic rubber can be vulcanized by heating the molded body, and the molded body can be foamed. The heating conditions for this purpose may be appropriately adjusted so as to appropriately promote vulcanization and foaming, and may be, for example, two or more stages of heating including heating at 90 to 130 ℃ for 10 to 60 minutes and heating at 140 to 200 ℃ for 10 to 60 minutes.

The rubber sponge of the present embodiment can be used as a sealing material, a caulking material, a sound absorbing material, a heat insulating material (heat insulating material), a cushion material, a coil material, a cushion material, a flooring material, a cloth lining material, a skin lining material, a water stopping material, a pipe cover material, an electric wire covering material, or a packaging/packing material in the fields of, for example, civil engineering and construction, electric equipment, OA equipment, air conditioning equipment, automobiles, vehicles, ships, housing equipment, bedding, furniture, nursing products, sporting goods, and the like.