JP2006001979A - Soft film and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soft film which has excellent flexibility and scratch resistance, and to provide wall paper which uses the same and has excellent stain resistance and stain removability. <P>SOLUTION: This soft film is obtained from a composition containing a specific propylene copolymer having a melting point of ≤100°C as a main component. This wall paper is obtained by laminating the soft film to a foamed resin layer of a laminate prepared by laminating a foam layer formed from a vinyl chloride resin, a polyolefin resin or a polyolefin resin composition to a substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention comprises a composition mainly composed of a propylene-based copolymer having a specific melting point, a soft film having a specific elastic modulus, and further, scratch resistance, stain resistance, and decontamination using the soft film. It relates to a wallpaper with excellent properties.

The wallpaper has a structure in which a synthetic resin sheet is bonded to the front side of a paper base material, but a sheet made of vinyl chloride resin is widely used as a synthetic resin foam sheet. Vinyl chloride resin sheets are widely used because of their good moldability, flame retardancy, and low cost. However, since the wallpaper obtained from a vinyl chloride resin is inferior in scratch resistance, stain resistance, and decontamination, methods for improving these have been studied.
Japanese Patent Application Laid-Open No. 2000-281844 discloses a wallpaper in which a foamed resin layer formed from a polyolefin resin composition containing an ethylene (co) polymer as a main component is laminated on a base material. (Patent Document 1)
Japanese Patent Application Laid-Open No. 9-193315 discloses a wallpaper in which an ethylene-vinyl acetate copolymer saponified product (EVOH) is laminated on a laminate made of a thermoplastic resin / polyolefin resin such as vinyl chloride resin. (Patent Document 2)
Japanese Patent Application Laid-Open No. 2001-260287 discloses a wallpaper in which an ethylene-vinyl alcohol copolymer resin film is laminated on a foamed resin layer. (Patent Document 3)
These wallpapers are superior in stain resistance and the like compared to vinyl chloride wallpaper, but are still insufficient in practical use, and further improvements are desired.
JP 2000-281844 A JP-A-9-193315 JP 2001-260287 A

The present inventors solved the above-mentioned problems by laminating a soft film made of a propylene-based copolymer on a specific foamed resin layer for a wallpaper excellent in scratch resistance, stain resistance, and decontamination, The present invention has been completed.

That is, the present invention
It is formed from a composition comprising 90 to 100% by weight of a propylene copolymer (a) having a melting point of 100 ° C. or less as measured by a differential scanning calorimeter (DSC) and 0 to 90% by weight of an ethylene polymer (b). A soft film characterized in that the initial elastic modulus measured by JISK6781 is 500 MPa or less,
Furthermore, the present invention provides the foamed resin layer of the laminate in which the foamed resin layer (B) formed from a vinyl chloride resin, a polyolefin resin, or a polyolefin resin composition is laminated on the substrate (A). It is a wallpaper characterized by being laminated | stacked.

The soft film of the present invention is a soft film excellent in flexibility and tear resistance as compared with a conventional polypropylene film, and excellent in balance between flexibility and strength as compared with a conventional low density polyethylene film. Film.
The wallpaper using the flexible film of the present invention has less curling and excellent scratch resistance.

The present invention relates to a soft film comprising a resin composition containing a propylene-based copolymer having a specific melting point as a main component and having a specific elastic modulus. Furthermore, the above-mentioned flexible film is laminated on the resin layer of a laminate in which a foamed resin layer (B) formed from a vinyl chloride resin, a polyolefin resin or a polyolefin resin composition is laminated on the substrate (A). It is related with the wallpaper characterized by.

Soft film The soft film of the present invention has a melting point measured by DSC method (after holding at 200 ° C. for 5 minutes, after cooling down to −20 ° C. at a rate of temperature fall of −20 ° C./min, again to 20 ° C./min to 180 ° C. Endothermic peak when observed when the temperature is raised at 100 ° C. or less, preferably 95 ° C. or less, more preferably 40 to 90 ° C., 10 to 100% by weight of the propylene copolymer (a), Preferably 20-100 wt%, more preferably 30-95 wt%, ethylene-based polymer (b) 0-90 wt%, preferably 0-80 wt%, more preferably 5-70 wt% resin composition The initial elastic modulus formed from the product and measured by JISK6781 is 500 MPa or less, preferably 480 MPa or less, more preferably 450 MPa or less.

  As the propylene-based copolymer (a), a known stereoregular catalyst can be used, but a polymer polymerized using a metallocene catalyst is particularly preferable because of less stickiness of the film. In this case, the molecular weight distribution obtained from gel permeation chromatography (GPC) is in the range of 1-3.

  The comonomer copolymerized with propylene is at least one α-olefin having 2 to 20 carbon atoms (excluding propylene) including ethylene, 1-butene and 1-pentene, preferably 1 -The main component is butene or 1-butene.

Such a propylene copolymer can be obtained, for example, using a catalyst as described in International Publication No. WO95 / 14717. Such a propylene copolymer has a comonomer constituent unit content M (mol%) determined by measurement of the melting point Tm (° C.) and 13 C-NMR spectrum of 146 exp (−0.022 M) ≧ Tm ≧ 125 exp (−0. 032M)
Those within the range are desirably used.

  The melt flow rate (hereinafter abbreviated as MFR (230 ° C.)) measured under a load of 2.16 kg at 230 ° C. according to ASTM D-1238 of the propylene copolymer (a) is 1 to 40 (g / 10 minutes), preferably in the range of 3-20 (g / 10 minutes).

  Any ethylene-based polymer (b) can be used as long as it is a copolymer mainly composed of ethylene, preferably ethylene and at least one α-olefin having 3 to 20 carbon atoms, preferably Is a copolymer (ethylene / α-olefin copolymer) with an α-olefin having 3 to 10 carbon atoms. The molecular structure may be linear or branched having long or short side chains.

  Specific examples of the α-olefin having 3 to 20 carbon atoms used as a comonomer of such an ethylene / α-olefin copolymer include propylene, 1-butene, 1-pentene, 1-hexene and 4-methylpentene. -1, 1-octene, 1-decene, 1-dodecene and combinations thereof, among which propylene, 1-butene, 1-hexene and 1-octene are preferable. Moreover, you may contain small amounts of other conomomers, for example, dienes such as 1,6-hexadiene and 1,8-octadiene, cyclic olefins such as cyclopentene, and the like.

  The density of the ethylene / α-olefin copolymer (ASTM 1505 23 ° C.) is 0.850 to 0.900 g / cm 3, preferably 0.860 to 0.897 g / cm 3, and more preferably 0.865 to 0.895 g / cm 3. cm3.

  The melt flow rate (hereinafter abbreviated as MFR (190 ° C.)) measured under a load of 2.16 kg at 190 ° C. according to ASTM D-1238 of the ethylene / α-olefin copolymer is 1 to 150 (g / 10 minutes), preferably in the range of 3 to 75 (g / 10 minutes). The molecular weight distribution (Mw / Mn) obtained by gel permeation chromatography (GPC) of the ethylene / α-olefin copolymer is 3 or less, preferably 2.5 or less, more preferably 2.3 or less.

  There is no particular limitation on the method for producing such an ethylene / α-olefin copolymer, but ethylene and α-olefin are copolymerized using a radical polymerization catalyst, a Phillips catalyst, a Ziegler-Natta catalyst, or a metallocene catalyst. Can be manufactured. In particular, a copolymer produced using a metallocene catalyst usually has a molecular weight distribution (Mw / Mn) of 3 or less and can be preferably used in the present invention.

  The composition comprising the propylene-based copolymer (a) and the ethylene-based polymer (b) includes a heat-resistant stabilizer, an antioxidant, an ultraviolet absorber, an anti-blocking agent, a slip agent, an antistatic agent, if necessary. A weathering stabilizer, an antifogging agent, a crystal nucleating agent, a base absorbent, a lubricant, a flame retardant, and the like can be added as long as the object of the present invention is not impaired.

The flexible film of the present invention is formed by a known molding method such as an inflation molding method or a T-die molding method using the composition comprising the propylene copolymer (a) and the ethylene polymer (b). Can do.
The film thickness is 5 to 1000 μm, usually 10 to 500 μm.

  The flexible film of the present invention may be stretched uniaxially or biaxially. Moreover, the laminated body with the film and metal foil which consist of other resin may be sufficient, and the soft film which consists of the propylene-type copolymer of this invention should just be used for at least 1 layer. Examples of other resins when used as a laminate include films obtained from polypropylene, polyethylene, polyamide, and polyester, stretched films thereof, and metal vapor deposited films obtained by depositing aluminum or silicon compounds on these films. As a method for producing such a laminate, a known co-extrusion method, dry lamination method, extrusion dry lamination method or vacuum deposition method can be preferably used, but is not limited thereto.

  Moreover, it is also possible to directly deposit aluminum or a silicon compound on the flexible film of the present invention or a stretched film thereof and use it as a metal deposition film.

  The flexible film of the present invention can be used for applications where flexibility is desired. For example, it can be used for vegetables, confectionery, bread, etc. because it has excellent melting, plasticity, transparency, gas permeability, and heat sealability. It can be used for packaging films such as foods and fibers, foams such as wallpaper, and skin materials for other building materials.

Wallpaper The wallpaper of the present invention comprises a propylene resin on the foamed resin layer of a laminate in which a foamed resin layer (B) formed from a vinyl chloride resin, a polyolefin resin, or a polyolefin resin composition is laminated on a substrate (A). A soft film made of a copolymer is laminated.

As the base material (A) in the wallpaper of the present invention, a paper base material is generally used. The paper substrate is selected according to the intended use for wallpaper, such as paper made from natural pulp or synthetic pulp, and paper made by mixing them with inorganic substances. When the foamed resin layer (B) (hereinafter sometimes referred to as a foamed resin sheet (layer)) has its own water resistance and flame retardancy, the paper substrate is particularly required to have such properties. Although it can be used for general purposes, the use of flame retardant paper containing an inorganic substance as the base material (A), for example, paper containing aluminum hydroxide or the like, further improves flame retardancy. preferable.
The foamed resin layer (B) which is laminated on the base material (A) and constitutes the wallpaper of the present invention is formed from a vinyl chloride resin, a polyolefin resin or a polyolefin resin composition. A vinyl chloride resin or a polyolefin resin can be used alone, but it is preferably formed from a polyolefin resin composition comprising a polyolefin resin and a flame retardant and / or an inorganic filler. More preferred is a polyolefin resin composition containing an ethylene (co) polymer as a main component. Specific examples of the ethylene (co) polymer include high-density polyethylene, high-pressure low-density polyethylene, a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, an ethylene-vinyl acetate copolymer, ethylene -Methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, etc., or a mixture thereof.
Specific examples of the ethylene (co) polymer used in the polyolefin resin composition include a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms or a mixture of other ethylene (co) polymer. preferable. Preferred α-olefins of a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms (ethylene (co) polymer) are 1-butene, 1-hexene and 1-octene. The density of the ethylene-based (co) polymer is 0.850 to 0.920 g / cm 3, preferably 0.850 to 0.900 g / cm 3, more preferably 0.855 to 0.890 g / cm 3, and MFR ( 190 ° C.) is 0.1 to 100 g / 10 min, preferably 1 to 50 g / 10 min. A method for producing such an ethylene / α-olefin copolymer is described in Japanese Patent Application Laid-Open No. 10-212382.
The polyolefin resin composition is also preferably a resin composition of an ethylene (co) polymer and a high-pressure low-density polyethylene. In that case, the ethylene (co) polymer is 50 to 90% by weight, preferably 60 to 80% by weight, 10 to 50% by weight, preferably 20 to 40% by weight of high-pressure low-density polyethylene.

  Examples of the flame retardant include metal hydrated oxides such as aluminum hydroxide and magnesium hydroxide. Examples of the inorganic filler include calcium carbonate, talc, barium sulfate, magnesium sulfate, and the like, but calcium carbonate is preferable from the balance between product quality and price. When the polyolefin resin composition contains a flame retardant and / or an inorganic filler, 30 to 200 parts by weight, preferably 50 to 180 parts by weight of the flame retardant and / or inorganic filler can be blended per 100 parts by weight of the polyolefin resin.

  By setting the resin composition in such a preferable range as the foamed resin layer (B), the adhesive strength with the flexible film of the present invention is improved, and an adhesive layer such as an adhesive is not required between these layers, and flame retardant From the viewpoint of safety and hygiene. In such a resin composition, as long as it does not impair the performance as wallpaper of the present invention, other synthetic resins and rubbers, or antioxidants, heat stabilizers, weathering stabilizers, slip agents, antiseptics as necessary. It may contain additives such as blocking agents, crystal nucleating agents, pigments, hydrochloric acid absorbents and the like.

  Further, after blending each component of the polyolefin resin composition and various additives as required, for example, with a mixer such as a Henschel mixer, a Banbury mixer, a tumbler mixer, a roll or an extruder, calender molding, T-die molding It can be used for a known sheet forming machine such as a sheet.

  A foaming resin layer is obtained by adding a foaming agent to such a resin layer and foaming it by placing it under a foaming temperature and pressure condition. As a method for producing the foamed resin layer, a method may be employed in which a non-foamed sheet is once formed from a resin composition to which a foaming agent has been added in advance, and then the temperature is raised to change to a foamed resin sheet. The method of obtaining a foamed resin sheet directly from the added resin composition may be used.

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

  Chemical foaming agents include azo compounds such as azodicarbonamide and azobisisobutyronitrile, hydrazide compounds such as benzosulfonyl hydrazide, toluenesulfonyl hydrazide, p, p'-oxybis (benzenesulfonyl hydrazide), dinitrosopentamethylenetetramine Nitroso compounds such as these, or a mixture thereof, and the like, and these decompose themselves under molding conditions to generate gas for foam molding. Moreover, you may use a foaming adjuvant with these foaming agents as needed. Examples of the foaming aid include zinc compounds such as zinc oxide and zinc stearate, and organic acids such as salicylic acid, phthalic acid, and oxalic acid.

  Examples of the gas foaming agent (physical foaming agent) include hydrocarbons such as carbon dioxide, halogenated hydrocarbons such as difluorodichloromethane, butane, pentane, hexane, cyclobutane, and cyclohexane. It itself becomes a gas and contributes to foam molding. As the gas foaming agent (physical foaming agent), carbon dioxide gas, butane gas, chlorofluorocarbon gas and the like are suitable. One type of foaming agent may be used, or a plurality of types may be used in combination.

  When forming a foamed sheet, an unfoamed resin sheet is once formed from a resin composition to which a foaming agent has been added using a roll or a T-die, and then the resin sheet is transferred to foaming conditions to produce a foamed resin sheet. In the case of this method, it is preferable to use a chemical foaming agent rather than a gas foaming agent. The foam molding can be performed by using an air oven or a heating roll.

  On the other hand, when a resin composition is supplied to an extruder and a foaming agent is press-fitted from another supply port of the extruder to form a foamed resin sheet directly from a die, a gas foaming agent (physical foaming agent) is generally used. used. Moreover, the resin composition which added the chemical foaming agent previously can be supplied to an extruder, and a foamed resin sheet can also be taken out from a die | dye similarly. The foamed resin layer (B) of the wallpaper of the present invention is obtained by adding a known foaming agent and foaming. As thickness of a foamed resin layer (B), it is 0.1-2 mm normally, Preferably it is 0.2-1 mm. The surface of the foamed sheet layer (foamed resin layer (B)) is designed as wallpaper by printing, embossing or embossing.

  The foamed resin sheet thus obtained becomes a laminate which is a part of the structure of the present invention by being laminated with the base material (A) such as the paper described above.

  The production of the laminate of the base material (A) and the foamed resin layer (B) can be performed, for example, by laminating a resin sheet previously foam-molded on a paper base material and laminating using an adhesive between both layers. Alternatively, it can be laminated by extruding a molten polyethylene resin or the like between the layers. As another method, an unfoamed resin sheet molded in advance on a paper substrate is laminated and bonded, or an unfoamed resin sheet is laminated on the paper substrate, and then the laminate is heated. It is possible to obtain a laminate in which a foamed resin sheet is laminated on a paper substrate by placing the foamed material under a foaming condition such as passing through a furnace or a heating roll. In addition, a resin composition to which a foaming agent is added can be directly laminated on a paper base material from an extruder or a calender roll.

  The method of laminating the soft film made of the propylene-based copolymer includes a dry lamination method using an adhesive between the foamed resin layers, a heat roll of the soft film and / or the foamed resin layer made of the propylene-based copolymer. A method of laminating by heating with heat or the like, or an extrusion lamination method in which a raw material resin of a soft film made of a propylene copolymer is extruded from a die and laminated with a foamed resin layer in a molten resin state can be used. In addition, the composition used for the flexible film of the present invention and the resin composition used for the foamed resin layer can be laminated by a co-extrusion method. Among these, since there are few curls also in the wallpaper after lamination | stacking, the method of laminating by an extrusion lamination method or a heat | fever can be used preferably. Alternatively, a soft film made of a propylene-based copolymer may be laminated on the unfoamed resin layer in advance, and then foamed to obtain the wallpaper of the present invention.

The thickness of the soft film layer used as the wallpaper of the present invention is 1 to 30 μm, preferably 2 to 25 μm.
[Example]
EXAMPLES Next, although an Example demonstrates this invention, this invention is not limited to this.

[Example 1]
An ethylene / 1-butene random copolymer (1-butene content 19 mol%) having an MFR (190 ° C.) of 3.6 g / 10 min and a density of 0.885 g / cm 3 is 70% by weight, and the MFR (190 ° C.) is 9 0.5 g / 10 min, 30% by weight of high-pressure low-density polyethylene having a density of 0.917 g / cm 3, 100 parts by weight of calcium carbonate having an average particle diameter of 0.8 μm with respect to 100 parts by weight, and as a blowing agent 5 parts by weight of azodicarbonamide was added, and an unfoamed resin sheet having a thickness of 130 μm was obtained at a die temperature of 140 ° C. using a T-die molding machine equipped with a 40 mmφ extruder. The obtained unfoamed resin sheet was bonded to a paper base material (plain paper) having a basis weight of 65 g / m 2 by heating to 140 ° C. Further, this was passed through a continuous foaming furnace set at 210 ° C. for 2 minutes to obtain a laminate having a foamed resin layer with a foaming ratio of 4.5 times.

Next, the soft film (thickness 20 micrometers) which consists of the following resin compositions was shape | molded with the cast film molding machine (die temperature 220 degreeC).
Propylene copolymer (a1): Propylene / 1-butene copolymer Butene content: 21%, Tm = 81 ° C., MFR (230 ° C.) = 7 g / 10 min
Ethylene polymer (b1): ethylene / 1-butene random copolymer MFR (190 ° C.) = 3.6 g / 10 min, density: 0.885 g / cm 3

Propylene-based copolymer (a1) / ethylene-based polymer (b1) = 100/0.

  Sample of wallpaper using a soft film made of the above laminate and the propylene-based copolymer with a commercial iron using a heat lamination (bonding temperature of about 120 ° C., using a fluororesin film so that the soft film does not fuse to the iron). 1 was obtained. The following evaluation was performed using this. The results are shown in Table-1. The physical properties of the soft film (thickness 50 μm) used at this time are shown in Table 2.

  Scratch resistance: The back of the wallpaper and the front were rubbed together, the polyolefin film surface was observed, and scratch resistance was evaluated.

Adhesive strength: Adhesion of gum tape to wallpaper sample (adhesion area 10 mm × 10 mm) and presence / absence of peeling of soft film when peeled.

[Example 2]
The same evaluation as in Example 1 was performed with the following resin composition for a flexible film.
Propylene copolymer (a1): Propylene / 1-butene copolymer Butene content: 21%, Tm = 81 ° C., MFR (230 ° C.) = 7 g / 10 min
Ethylene polymer (b1): ethylene / 1-butene random copolymer MFR (190 ° C.) = 3.6 g / 10 min, density: 0.885 g / cm 3

Propylene copolymer (a1) / ethylene polymer (b1) = 80/20.

[Example 3]
The same evaluation as in Example 1 was performed with the following resin composition for a flexible film.
Propylene copolymer (a1): Propylene / 1-butene copolymer Butene content: 21%, Tm = 81 ° C., MFR (230 ° C.) = 7 g / 10 min
Ethylene polymer (b1): ethylene / 1-butene random copolymer MFR (190 ° C.) = 3.6 g / 10 min, density: 0.885 g / cm 3

Propylene copolymer (a1) / ethylene polymer (b1) = 60/40.

[Comparative Example 1]
Instead of the soft film made of the propylene-based copolymer of Example 1, the following film made of random polypropylene (thickness 20 μm, laminating temperature 190 ° C.) was used for the same evaluation as in Example 1.
Random polypropylene: propylene-ethylene-butene copolymer Tm = 138 ° C., MFR (230 ° C.) = 7 g / 10 min.

The soft film of the present invention is a soft film excellent in flexibility and tear resistance as compared with a conventional polypropylene film, and excellent in balance between flexibility and strength as compared with a conventional low density polyethylene film. Film.
The wallpaper using the flexible film of the present invention has less curling and excellent scratch resistance.

Claims (4)

It is formed from a composition comprising 10 to 100% by weight of a propylene-based copolymer (a) having a melting point measured by a differential scanning calorimeter (DSC) of 100 ° C. or less and 0 to 90% by weight of an ethylene-based polymer (b). A soft film, which is a film and has an initial elastic modulus of 500 MPa or less as measured by JISK6781. The soft film according to claim 1, wherein the propylene-based copolymer (a) is a propylene-butene copolymer obtained with a metallocene catalyst. The flexible film according to claim 1 or 2, wherein the foamed resin layer of the laminate in which the foamed resin layer (B) formed from a vinyl chloride resin, a polyolefin resin, or a polyolefin resin composition is laminated on the substrate (A). A wallpaper characterized by being laminated. The wallpaper according to claim 3, wherein the foamed resin layer (B) is a polyolefin resin composition comprising an ethylene-based (co) polymer and a flame retardant and / or an inorganic filler.