Laminated films, coated films and adhesive labels

Abstract

To provide an adhesive label which has a small amount of carbon dioxide gas, has high whiteness, and leaves little adhesive remaining in an adherend when peeled, and a laminated film and a coat film used in the same.SOLUTION: A laminated film has a base material layer, and a first surface layer on one surface of the base material layer. The laminated film contains a porous stretched film containing an olefinic resin and an inorganic filler. The olefinic resin contains a propylene-based resin, and the propylene-based resin contains a biomass-derived propylene-based resin. The first surface layer has a porosity of 40% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminated film, a coated film, and an adhesive label. [Background technology]

[0002] Resin films have been widely used as printing paper for labels, wrapping paper, posters, calendars, catalogs, advertisements, etc. In particular, resin films have been in high demand as labels that can be used outdoors because of their excellent water resistance.

[0003] Labels usually have a printed layer on one side of a resin film for information or design purposes. Furthermore, a pressure-sensitive adhesive layer may be provided on the other side of the resin film, and the label may be used as an adhesive label that is attached to an adherend. Patent Document 1 discloses a resin film that can be used as a substrate for such an adhesive label.

[0004] On the other hand, as a measure against global warming, there is a demand to move away from petroleum dependence and create an environment with low carbon dioxide gas emissions. Patent Document 2 proposes a resin film that uses both petroleum-derived polyolefin and biomass-derived polyolefin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-102826 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-251006 Summary of the Invention [Problem to be solved by the invention]

[0006] When adhesive labels are peeled off from an adherend, any adhesive remaining on the adherend can easily cause stains. Furthermore, adhesive labels are required to have a high degree of whiteness so that the printed content can be displayed more clearly. There is room for further reduction in carbon dioxide gas emissions during the manufacturing process of resin films used in adhesive labels by improving the materials or film structure used.

[0007] An object of the present invention is to provide an adhesive label that emits little carbon dioxide gas, has high whiteness, and leaves little adhesive on the adherend when peeled off, and a laminate film and a coated film to be used therefor. [Means for solving the problem]

[0008] As a result of intensive research conducted by the inventors to solve the above problems, they discovered that the above problems can be solved by using a porous stretched film containing a resin component derived from biomass and adjusting the porosity of the surface layer to a relatively small value, and thus completed the present invention. That is, the present invention is as follows.

[0009] [1] A laminated film comprising a base layer and a first surface layer on one side of the base layer, The porous stretched film includes an olefin resin and an inorganic filler, the olefin-based resin includes a propylene-based resin, the propylene-based resin includes a biomass-derived propylene-based resin, The first surface layer has a porosity of 40% or less. Laminated film.

[0010] [2] The propylene-based resin further includes a petroleum-derived propylene-based resin. The laminated film according to [1] above.

[0011] [3] The olefin-based resin further contains an ethylene-based resin. The laminated film according to the above [1] or [2].

[0012] [4] The ethylene-based resin includes a biomass-derived ethylene-based resin. The laminated film according to [3] above.

[0013] [5] The ethylene-based resin includes a petroleum-derived ethylene-based resin. The laminated film according to [3] or [4] above.

[0014] [6] The porosity of the first surface layer is 0.1 to 30%. The laminated film according to any one of the above [1] to [5].

[0015] [7] A second surface layer is provided on the other surface of the base material layer, The second surface layer has a porosity of 30 to 55%. The laminated film according to any one of the above [1] to [6].

[0016] [8] The laminated film according to any one of [1] to [7] above, a coating layer on at least one surface of the laminated film, The coating layer contains a (meth)acrylic acid ester resin. Coated film.

[0017] [9] The laminated film according to any one of [1] to [7] above, a pressure-sensitive adhesive layer provided on one surface of the laminated film. Self-adhesive labels. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide an adhesive label that emits little carbon dioxide gas, has high whiteness, and leaves little adhesive on the adherend when peeled off, as well as a laminate film and a coated film to be used therefor. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing an example of a pressure-sensitive adhesive label of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The laminated film, coated film, and adhesive label of the present invention will be described in detail below. The following description is an example (typical example) of the present invention, and the present invention is not limited thereto.

[0021] In the following description, the term "(meth)acrylic" refers to both acrylic and methacrylic.

[0022] (Laminated film) The laminated film of the present invention comprises a substrate layer and a first surface layer on one side of the substrate layer. The laminated film of the present invention includes a stretched film made porous by stretching a resin film containing an olefin-based resin and an inorganic filler. The porous stretched film is stretched at least uniaxially, but from the viewpoint of increasing the porosity and mechanical strength of the film, it is more preferably a stretched film stretched biaxially.

[0023] In porous stretched films, the whiteness of the laminated film is enhanced by the numerous pores formed by inorganic fillers as nuclei. This allows for the provision of laminated films that can clearly display printed content. Furthermore, by making the film porous, the resin components in the laminated film are replaced with air, which has a zero carbon dioxide emission coefficient, or inorganic fillers, which have a lower carbon dioxide emission coefficient than resins. This means that less resin component is used per unit volume than in non-porous resin films. While a significant amount of carbon dioxide gas is emitted during the manufacturing process of resin components, reducing their use also reduces carbon dioxide gas emissions.

[0024] In the laminated film of the present invention, the olefin-based resin includes a propylene-based resin. Propylene-based resins are harder than ethylene-based resins and have the characteristic of easily forming more pores by stretching. The propylene-based resin having such characteristics can increase the porosity of the stretched film, making it easier to reduce carbon dioxide gas emissions.

[0025] Furthermore, the propylene-based resin includes a biomass-derived propylene-based resin. In the present invention, biomass refers to a biomass-derived resource. Biomass can include the plant itself as a raw material, as well as oils and sugars obtained from the plant. Because the plants used as raw materials absorb carbon dioxide gas during the growing stage, the carbon dioxide gas emission factor in the production process of biomass-derived propylene-based resin is smaller than that of petroleum-derived propylene-based resin, which does not absorb carbon dioxide gas. Therefore, the amount of carbon dioxide gas emitted per unit volume of the laminated film can be reduced, further reducing the environmental load.

[0026] As described above, according to the present invention, the amount of resin components that emit carbon dioxide gas during the manufacturing process is reduced, and the amount of petroleum-derived resin components, which have a relatively high carbon dioxide gas emission coefficient, used is small. This makes it possible to effectively reduce carbon dioxide gas emissions and provide a laminated film with a low environmental impact.

[0027] Furthermore, in the laminate film of the present invention, the porosity of the first surface layer is 40% or less. When an adhesive layer is formed on such a first surface layer and the laminate film of the present invention is used as a substrate for an adhesive label, the adhesion between the first surface layer and the adhesive layer is improved. Even when the adhesive label is peeled off after being attached to an adherend, the adhesive layer is likely to maintain adhesion to the first surface layer, and the amount of adhesive layer remaining on the adherend can be reduced. Therefore, an adhesive label that is easy to peel off and does not easily become dirty after peeling can be provided.

[0028] The laminated film may include one or more layers of the porous stretched film containing the biomass-derived propylene-based resin and a filler. From the viewpoint of reducing the environmental load, it is preferable that more layers are such porous stretched films, and it is more preferable that all layers are such porous stretched films. Each layer will be described below.

[0029] (base material layer) The substrate layer imparts stiffness or rigidity to the laminated film, and can improve transportability during printing, etc. From the viewpoint of whiteness, the substrate layer is preferably a porous stretched film containing an olefin-based resin and an inorganic filler, and from the viewpoint of reducing the environmental load, it is preferable that the olefin-based resin contains a biomass-derived propylene-based resin.

[0030] <Olefin resin> Examples of olefin-based resins include propylene-based resins, ethylene-based resins, and polymethyl-1-pentene. Among these, propylene-based resins have excellent mechanical strength, so it is preferable that the olefin-based resin contains a propylene-based resin as a main component. In this specification, the main component refers to a component whose content in the layer is 50% by mass or more.

[0031] <Propylene-based resin> Examples of propylene-based resins include propylene homopolymers such as isotactic homopolypropylene resin and syndiotactic homopolypropylene resin, propylene-based copolymers copolymerized with ethylene, propylene-based α-olefin copolymers copolymerized with propylene and α-olefins containing 4 or more carbon atoms, such as 1-butene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1-pentene, and propylene-ethylene-α-olefin copolymers. Propylene copolymers may be binary or ternary or higher multicomponent systems, and may be random, block, or reactor-blended copolymers. Specific examples include propylene homopolymer, propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-ethylene-1-butene copolymer, propylene-4-methyl-1-pentene copolymer, propylene-3-methyl-1-pentene copolymer, propylene-ethylene-3-methyl-1-pentene copolymer, etc. Among these, from the viewpoint of film stretchability, crystalline homopolypropylene resin obtained by homopolymerizing propylene is preferred, and isotactic homopolypropylene resin is more preferred.

[0032] Propylene-based resins include, depending on the manufacturing method, polypropylene produced using a Ziegler-Natta polymerization catalyst, polypropylene produced using a metallocene polymerization catalyst (single-site polymerization catalyst), olefin-based thermoplastic elastomers also known as reactor TPOs, and high melt strength polypropylene.

[0033] The melt flow rate (MFR) of the propylene-based resin in accordance with JIS K7210:2014 (temperature 230°C, load 2.16 kg) is preferably 0.2 to 20 g / 10 min, more preferably 1 to 10 g / 10 min, and even more preferably 2 to 6 g / 10 min, from the viewpoint of improving the mechanical strength of the porous stretched film.

[0034] <<Biomass-derived propylene resin>> In the present invention, one or more of the above propylene-based resins can be used for the porous stretched film, and a part or all of the propylene-based resins are biomass-derived. The biomass-derived propylene-based resin is a propylene polymer that uses biomass-derived propylene as a monomer. Part or all of the propylene used as a monomer may be biomass-derived, and part or all of ethylene or an α-olefin used as a comonomer may be biomass-derived.

[0035] From the viewpoint of improving the biomass content, the biomass-derived propylene-based resin preferably contains a propylene homopolymer containing biomass-derived propylene, and more preferably contains a homopolymer made of biomass-derived propylene.

[0036] Biomass-derived propylene, which is a raw material for propylene-based resins, can be produced by a metathesis reaction from biomass-derived ethylene and an equal amount of butene.

[0037] Biomass-derived propylene, which serves as a raw material, can be produced, for example, by fermenting biomass to produce sugars, followed by producing isopropanol through a fermentation process including a glycolytic process, and then dehydrating the isopropanol. Examples of sugars produced by fermentation include maltose, sucrose, glucose, and fructose. In the fermentation process, Clostridium bacteria or Escherichia coli or yeast into which genes derived from Clostridium bacteria have been introduced act on these sugars.

[0038] Examples of biomass include rapeseed, soybean, oil palm fruit, oil palm seed, sunflower seed, cottonseed, peanut, olive fruit, corn germ, coconut endosperm, sesame, perilla, linseed, castor, rice bran, safflower seed, and grape seed, as well as vegetable oils obtained by pressing plants.

[0039] Commercially available biomass-derived propylene resins include, for example, HC101BF (MFR: 3.2 g / 10 min), HC110BF (MFR: 3.2 g / 10 min), Bormed HE125MO (MFR: 12 g / 10 min), HF840MO (MFR: 19 g / 10 min), HG430MO (MFR: 25 g / 10 min), and HJ325MO (MFR: 50 g / 10 min) manufactured by Borealis, and Circulen HP456J (MFR: 3.4 g / 10 min), Circulen HP483R (MFR: 27 g / 10 min), Circulen HP500N (MFR: 12 g / 10 min), Circulen HP501H (MFR: 2.1 g / 10 min), and Circulen EP310M manufactured by RondelBasell. HP (MFR: 7.5g / 10min), Circulen EP540P (MFR: 15g / 10min), etc. can be used.

[0040] <<Petroleum-derived propylene resin>> Petroleum-derived propylene-based resins can also be used together with the biomass-derived propylene-based resins. Petroleum-derived propylene-based resins are propylene polymers obtained using propylene, whose raw material is petroleum, as a monomer. Petroleum-derived propylene-based resins are inexpensive and easily available. Furthermore, there are a wide variety of types, including those with increased melt viscosity due to adjusted polymerization conditions and those that have been chemically modified. Therefore, when these are used in combination with biomass-derived propylene-based resins, it is easy to adjust the formability and quality of the porous stretched film.

[0041] <<Mass ratio of biomass-derived propylene resin to petroleum-derived propylene resin>> The mass ratio of the biomass-derived propylene-based resin to the petroleum-derived propylene-based resin (biomass-derived propylene-based resin: petroleum-derived propylene-based resin) is preferably 1:99 to 99:1. From the viewpoint of increasing the biomass content and reducing carbon dioxide gas emissions, a higher content of the biomass-derived propylene-based resin is preferable. On the other hand, since biomass-derived resins are more expensive than petroleum-derived resins, a higher content of the petroleum-derived propylene-based resin is preferable from the viewpoint of reducing production costs. Therefore, the mass ratio is more preferably 5:95 to 70:30, and even more preferably 10:90 to 40:60.

[0042] <Ethylene-based resin> The olefin-based resin used in the porous stretched film preferably further contains an ethylene-based resin. The combined use of a propylene-based resin and an ethylene-based resin improves the stretchability of the film, making it easier to obtain a film with less stretching unevenness and a good appearance. Furthermore, the combined use of an ethylene-based resin, which melts more easily than a propylene-based resin, makes it easier to stretch the film in a molten state. This facilitates the formation of fibril-like pores, improves pore formability, and reduces the manufacturing cost of the porous stretched film.

[0043] When an ethylene-based resin is used in combination, if the amount of the propylene-based resin in the total resin amount of the porous stretched film is a majority, a sea-island structure in which the propylene-based resin forms the sea and the ethylene-based resin forms the islands is likely to be formed. The stress applied during stretching of the resin composition causes shear at the interface of the sea-island structure in addition to shear at the interface between the resin and the inorganic filler, making it possible to form a large number of pores with a weaker force.

[0044] Examples of ethylene-based resins include high-density polyethylene resins, medium-density polyethylene resins, high-pressure low-density polyethylene resins, and linear low-density polyethylene resins. Among these, from the viewpoint of film formability, polyethylene resins having a density of 0.950 to 0.965 g / cm are preferred. 3 High density polyethylene resin is preferred.

[0045] When an ethylene-based resin is used in combination with a propylene-based resin, it is preferable to select an ethylene-based resin having a melt flow rate close to that of the propylene-based resin, from the viewpoint of facilitating uniform kneading or facilitating the formation of a dense phase-separated structure during melt kneading. The melt flow rate (MFR) of such an ethylene-based resin according to JIS K7210:2014 (temperature 190°C, load 2.16 kg) is preferably 0.2 to 20 g / 10 min, more preferably 1 to 10 g / 10 min, and more preferably 2 to 8 g / 10 min.

[0046] <<Biomass-derived ethylene resin>> In the present invention, the ethylene-based resin contained in the porous stretched film may be either petroleum-derived or biomass-derived, but from the viewpoint of further reducing the environmental load, it is preferable to contain a biomass-derived ethylene-based resin. The biomass-derived ethylene-based resin is an ethylene polymer using ethylene derived from biomass as a raw material as a monomer.

[0047] Biomass-derived ethylene can be produced, for example, by dehydrating ethanol produced by the fermentation of biomass. The α-olefin used as a comonomer for the biomass-derived ethylene resin may be a biomass-derived α-olefin or a petroleum-derived α-olefin.

[0048] An example of a biomass-derived high-density polyethylene resin is SHC7260 (MFR: 7.2 g / 10 min, density: 0.959 g / cm) manufactured by Braskem. 3 ), SHD7255LSL (MFR; 4.5g / 10 min, density; 0.954g / cm 3 ), SGE7252 (MFR; 2.2g / 10 min, density; 0.953g / cm 3 The MFR of the above Braskem products is a measurement value in accordance with JIS K7210:2014, and the density is a measurement value in accordance with ASTM D1505 / D 792.

[0049] <<Petroleum-derived ethylene resin>> Petroleum-derived ethylene-based resins are ethylene polymers that use petroleum-derived ethylene as a monomer. Petroleum-derived ethylene-based resins are easily available and come in a wide variety of varieties, making them preferable because they allow for easy adjustment of the formability and quality of porous stretched films.

[0050] Petroleum-derived and biomass-derived ethylene resins can be produced in the same way, except that petroleum or biomass is used as the raw material. Ziegler-Natta catalysts, metallocene catalysts, etc. are generally used as polymerization catalysts for production.

[0051] <<Propylene resin to ethylene resin ratio>> The mass ratio of propylene-based resin to ethylene-based resin in the resin components constituting the porous stretched film (total amount of biomass-derived and petroleum-derived propylene-based resin:total amount of biomass-derived and petroleum-derived ethylene-based resin) is preferably 1:99 to 99:1, more preferably 10:90 to 97:3, and even more preferably 65:35 to 95:5, from the viewpoint of pore formation.

[0052] <<Ratio of biomass-derived resin components to petroleum-derived resin components>> As described above, the biomass-derived propylene-based resin may be used in combination with a petroleum-derived propylene-based resin and a biomass- and petroleum-derived ethylene-based resin, but the mass ratio of the total amount of the resin components consisting of the biomass-derived propylene-based resin and the ethylene-based resin to the total amount of the resin components consisting of the petroleum-derived propylene-based resin and the ethylene-based resin is preferably 1:99 to 99:1. The lower limit of the content of the biomass-derived resin component in this mass ratio is more preferably 5:95, and the upper limit of the content of the biomass-derived resin component in this mass ratio is more preferably 45:55. Within this range, the mass ratio of the biomass-derived resin component can be increased to increase the biomass content and effectively reduce carbon dioxide gas emissions.

[0053] From the viewpoint of achieving both biomass content and cost, the olefin-based resin used in the porous stretched film preferably contains 5 to 90 parts by mass of a biomass-derived propylene-based resin, 40 to 90 parts by mass of a petroleum-derived propylene-based resin, 0 to 20 parts by mass of a biomass-derived ethylene-based resin, and 0 to 20 parts by mass of a petroleum-derived ethylene-based resin.

[0054] In addition, the porous stretched film may contain olefin-based resins, ester-based resins, styrene-based resins, amide-based resins, (meth)acrylic resins, urethane-based resins, etc. other than the above-mentioned propylene-based resins and ethylene-based resins, as long as the effects of the present invention are not impaired.

[0055] <Inorganic filler> Inorganic fillers that can be used in porous stretched films include inorganic particles such as calcium carbonate, titanium oxide, calcined clay, talc, barium sulfate, aluminum sulfate, silica, zinc oxide, magnesium oxide, and diatomaceous earth. The incorporation of an inorganic filler facilitates the formation of pores by stretching. Among these, fine powder of calcium carbonate, clay, or diatomaceous earth is preferred because it has good pore-forming properties and is inexpensive. Fine powder of calcium carbonate is particularly preferred because it is available in a wide variety of types, making it easy to adjust the porosity and the whiteness of the porous stretched film.

[0056] From the viewpoint of easiness of pore formation, the average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more. From the viewpoint of increasing the strength of the porous stretched film, the average particle size of the inorganic filler is preferably 10 μm or less, more preferably 8 μm or less. Therefore, the average particle size of the inorganic filler is preferably 0.01 to 10 μm, more preferably 0.05 to 8 μm. The average particle size of the inorganic filler is a volume average particle size measured by a particle size distribution analyzer using laser diffraction.

[0057] The content of the inorganic filler relative to 100 parts by mass of the total resin components in the porous stretched film is preferably 3 to 233 parts by mass.

[0058] <Other additives> The porous stretched film may contain additives such as heat stabilizers (antioxidants), light stabilizers, dispersants, and lubricants, as needed. When the porous stretched film contains a heat stabilizer, it typically contains 0.001 to 1% by mass of the heat stabilizer. Examples of heat stabilizers include sterically hindered phenolic, phosphorus-based, and amine-based stabilizers. When the porous stretched film uses a light stabilizer, it typically contains 0.001 to 1% by mass of the light stabilizer. Examples of the light stabilizer include sterically hindered amine, benzotriazole, and benzophenone-based light stabilizers. The dispersant or lubricant can be used, for example, to disperse inorganic fillers. The amount of dispersant or lubricant used in the porous stretched film is typically within the range of 0.01 to 4% by mass. Examples of dispersants or lubricants include silane coupling agents, higher fatty acids such as oleic acid and stearic acid, metal soaps, polyacrylic acid, polymethacrylic acid, and salts thereof.

[0059] <Porosity> The higher the porosity of the porous stretched film, the whiter the laminated film can be imparted, and the lower the proportion of resin components in the porous stretched film, which reduces carbon dioxide gas emissions. Therefore, the porosity of the porous stretched film constituting the substrate layer is preferably 3% or more, more preferably 5% or more, and even more preferably 10% or more. From the viewpoint of imparting mechanical strength such as tear resistance, the porosity is preferably 55% or less, more preferably 45% or less, and even more preferably 42% or less. The porosity can be adjusted by the average particle size of the filler, the film composition such as the mass ratio of the propylene-based resin to the ethylene-based resin, and the stretching conditions such as the stretching temperature or stretching ratio.

[0060] The porosity can be determined from the ratio of the area occupied by pores to a certain region of the cross section of a film observed with an electron microscope. Specifically, an arbitrary portion of the film to be measured is cut out, embedded in epoxy resin, and solidified. Using a microtome, the film to be measured is cut perpendicular to the film's surface, and the cut surface is attached to an observation sample stage so that the cut surface becomes the observation surface. Gold, gold-palladium, or the like is vapor-deposited on the observation surface, and the pores in the film are observed with an electron microscope at an arbitrary magnification (e.g., 500x to 3000x magnification) and the observed region is captured as image data. The obtained image data is subjected to image processing using an image analyzer to determine the area ratio (%) of pores in a certain region of the film, which is then used as the porosity (%). In this case, the porosity can be determined by averaging the measured values ​​from observations of 10 or more arbitrary locations.

[0061] (1st surface layer) The first surface layer can improve the strength of the laminate film and increase tear resistance, etc. Furthermore, when the laminate film is used as an adhesive label, the first surface layer makes it easy to adjust the adhesion between the adhesive layer and the laminate film.

[0062] From the viewpoint of pore-forming properties and reducing environmental impact, the first surface layer is a porous stretched film containing an olefin-based resin and an inorganic filler, similar to the base layer, and the olefin-based resin preferably contains a biomass-derived propylene-based resin. The materials used in the first surface layer and the base layer, and the amounts thereof, may be the same or different.

[0063] Examples of olefin-based resins that can be used for the first surface layer include the same olefin-based resins as those used for the base layer described above, and these can be used alone or in combination. From the viewpoint of adhesion to the adhesive layer, the first surface layer preferably contains two or more propylene-based resins with different melt flow rates. For example, the first surface layer can contain a first propylene-based resin having a melt flow rate of 0.1 g / 10 min or more and less than 5.0 g / 10 min, and a second propylene-based resin having a melt flow rate of 5.0 g / 10 min or more and 20 g / 10 min or less. From the viewpoint of improving mechanical strength, the propylene-based resin used for the first surface layer is preferably a propylene-based resin having a melting point (peak temperature of the DSC curve) of 130 to 210°C. Among these, a propylene homopolymer having a melting point (peak temperature of a DSC curve) of 155 to 174°C, a melt flow rate (MFR) according to JIS K7210:2014 of 0.5 to 20 g / 10 min, and a crystallinity of 45 to 70% is more preferred.

[0064] Inorganic fillers that can be used in the first surface layer include the same inorganic fillers as those used in the base layer, as well as precipitated calcium carbonate.

[0065] From the viewpoint of improving adhesion to the pressure-sensitive adhesive layer, the average particle size of the inorganic filler used in the first surface layer is preferably 6 μm or less, more preferably 4 μm or less, and even more preferably 2 μm or less. From the viewpoint of pore-forming ability, the average particle size is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.07 μm or more.

[0066] From the viewpoint of improving adhesion to the pressure-sensitive adhesive layer, the content of the inorganic filler in the first surface layer is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less. From the viewpoint of increasing the porosity and reducing carbon dioxide gas emissions, the content is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more.

[0067] <Porosity> As described above, the porosity of the first surface layer is 40% or less. From the viewpoint of improving adhesion to the pressure-sensitive adhesive layer, the porosity is preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, and particularly preferably 20% by mass or less. From the viewpoint of reducing environmental impact, the porosity is preferably 0.1% or more, more preferably 5% or more, and even more preferably 10% or more. The porosity can be adjusted by the average particle size of the filler, the composition of the film, or the stretching conditions.

[0068] <Thickness> From the viewpoint of improving film strength, the thickness of the first surface layer is preferably 1 μm or more, more preferably 1.5 μm or more, and from the viewpoint of improving handleability, the thickness is preferably 50 μm or less, more preferably 20 μm or less.

[0069] (2nd surface layer) The laminate film of the present invention can have a second surface layer on the surface opposite to the first surface layer. The second surface layer can further improve the strength of the laminate film and further increase tear resistance, etc. Furthermore, when a printed layer made of ink is provided on the laminate film by printing, the second surface layer can easily improve adhesion to the ink.

[0070] The second surface layer can be configured in the same manner as the first surface layer. From the viewpoint of pore formation or reducing the environmental load, the second surface layer is a porous stretched film containing an olefin-based resin and an inorganic filler, and the olefin-based resin preferably contains a biomass-derived propylene-based resin. Examples of the olefin-based resin and inorganic filler that can be used in the second surface layer include the same materials as those for the first surface layer, and preferred materials are also the same as those for the first surface layer. The materials used for the first surface layer and the second surface layer may be the same or different.

[0071] From the viewpoint of improving the scratch resistance of the printed layer, the content of the inorganic filler in the second surface layer is preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, even more preferably 55% by mass or less, and particularly preferably 50% by mass or less. From the viewpoint of increasing the porosity and reducing carbon dioxide gas emissions, the content is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more.

[0072] <Porosity> From the viewpoint of improving adhesion to ink by an anchoring effect, the porosity of the second surface layer is preferably 10% or more, more preferably 20% or more, even more preferably 30% or more (or more than 30%), even more preferably 35% or more, and particularly preferably 40% or more. From the viewpoint of improving tear resistance, the porosity of the second surface layer is preferably 55% or less, more preferably 50% or less. The porosity can be adjusted by the average particle size of the filler, the composition of the film, or the stretching conditions.

[0073] <Thickness> From the viewpoint of image clarity in printing, the thickness of the second surface layer is preferably 20 μm or more, more preferably 25 μm or more, and from the viewpoint of improving handleability, the thickness is preferably 100 μm or less, more preferably 50 μm or less.

[0074] (other layers) The laminated film of the present invention may have layers other than the first and second surface layers described above depending on the application or function. For example, from the viewpoint of further increasing whiteness, a propylene-based resin film containing 8 to 55% by mass of an inorganic filler may be provided as an intermediate layer between the base layer and the first or second surface layer.

[0075] (Biomass ratio) The biomass degree of the laminated film is preferably 1 to 97%. The higher the biomass degree, the less carbon dioxide gas is emitted during the production process of the laminated film, and the smaller the environmental load. Therefore, the biomass degree is more preferably 10% or more, and even more preferably 25% or more. On the other hand, since biomass-derived raw materials are more expensive than petroleum-derived raw materials, from the viewpoint of reducing production costs, the biomass degree is preferably 90% or less, more preferably 80% or less, even more preferably 70% or less, particularly preferably 60% or less, and most preferably less than 50%.

[0076] The biomass content is calculated from the content of biomass-derived raw materials in the laminate film. Specifically, it is the mass ratio of the biomass-derived olefin resin in the entire laminate film, and is calculated from the content of the biomass-derived olefin resin. Petroleum-derived propylene-based resins or ethylene-based resins do not contain radioactive carbon (14C) with a mass number of 14, whereas biomass-derived propylene-based resins or ethylene-based resins contain a certain percentage of 14 The ratio of biomass-derived raw materials in the resin components of the laminated film can be measured. 14 It can be calculated based on the C content.

[0077] (whiteness) The laminate film of the present invention preferably has a whiteness of 95% or more, which allows printed characters, figures, etc. to look good and provides printed matter with excellent appearance. The whiteness can be measured in accordance with JIS L1015:1999.

[0078] (Application) The laminate film of the present invention can be used as printing paper or writing paper. That is, the first surface layer or the second surface layer of the laminate film can be printed or written on. Usable printing methods include ultraviolet-curable offset printing, solvent-based offset printing, electrophotography, sublimation thermal transfer, fusion thermal transfer, and direct thermal printing, as well as letterpress printing, gravure printing, and flexographic printing. Printing can be performed using either a sheet or a roll-type rotary printing method. Of these, ultraviolet-curable offset printing is preferred because the second surface layer has high adhesion to ultraviolet-curable ink.

[0079] The laminate film of the present invention can also be used as a substrate for an adhesive label. Since the first surface has high adhesion to the adhesive layer, it is preferable that the adhesive layer is provided on the first surface layer of the laminate film.

[0080] (Laminated film manufacturing method) The method for producing the laminated film of the present invention is not particularly limited, and the laminated film can be produced by molding and laminating films of each layer. The porous stretched film can be produced by molding and stretching a film from a resin composition containing an olefin-based resin and an inorganic filler.

[0081] <Film molding> Examples of methods for forming a single layer film include cast molding in which a molten resin is extruded into a sheet shape using a T-die, I-die, or the like connected to a screw-type extruder, calendar molding, roll molding, and inflation molding.

[0082] Examples of methods for forming multilayer films include coextrusion, extrusion lamination, and coating, and these methods can also be combined. In the coextrusion method, resin compositions for each layer, which have been melt-kneaded in separate extruders, are laminated and extruded in a feed block or multi-manifold, performing film formation and lamination in parallel. In the extrusion lamination method, a resin composition is extruded onto a preformed film to laminate another film. In the coating method, a resin solution, emulsion, or dispersion is applied to a film and then dried to form and laminate another film.

[0083] <Stretching> The film may be stretched before or after lamination. Because the first surface layer or the second surface layer is relatively thin, it is preferable to stretch it after laminating it on the base layer, rather than stretching it as a single layer. As described above, when the porous stretched film is a biaxially stretched layer, the porosity is increased, further reducing carbon dioxide gas emissions and increasing mechanical strength, which is preferable. Furthermore, when the porous stretched film is a uniaxially stretched film, it is preferable because it is easy to form a fibrillated surface and improving ink permeability.

[0084] Examples of stretching methods include longitudinal stretching using the difference in peripheral speed between rolls, transverse stretching using a tenter oven, sequential biaxial stretching that combines these, rolling, simultaneous biaxial stretching using a tenter oven and a pantograph, simultaneous biaxial stretching using a tenter oven and a linear motor, etc. Also usable is simultaneous biaxial stretching (inflation molding), in which molten resin is extruded into a tube using a circular die connected to a screw extruder and then air is blown into the extruded material.

[0085] When an amorphous resin is used, the stretching temperature is preferably in the range of not less than the glass transition temperature of the amorphous resin. When a crystalline resin is used, the stretching temperature is preferably in the range of not less than the glass transition temperature of the amorphous portion of the crystalline resin and not more than the melting point of the crystalline portion of the crystalline resin, and is preferably 2 to 60°C lower than the melting point. Specifically, a stretching temperature of 100 to 164°C is preferred for propylene homopolymer (melting point 155 to 167°C), and a stretching temperature of 70 to 133°C is preferred for high-density polyethylene resin (melting point 121 to 134°C).

[0086] The stretching speed is not particularly limited, but is preferably within the range of 20 to 350 m / min from the viewpoint of stable stretching.

[0087] The stretching ratio can also be appropriately determined taking into consideration the properties of the resin components used. For example, when a propylene homopolymer or a propylene copolymer is used, the lower limit of the stretching ratio when stretched in one direction is usually 1.1 times or more, preferably 2 times or more, and the upper limit is usually 10 times or less, preferably 9 times or less. On the other hand, the lower limit of the stretching ratio when stretched biaxially, in terms of areal stretching ratio, is usually 1.5 times or more, preferably 4 times or more, and the upper limit is usually 75 times or less, preferably 50 times or less. When other thermoplastic resin films are stretched in one direction, the lower limit of the stretching ratio is usually 1.2 times or more, preferably 2 times or more, and the upper limit is usually 10 times or less, preferably 5 times or less. When stretching biaxially, the lower limit of the stretching ratio when stretched in terms of areal stretching ratio is usually 1.5 times or more, preferably 4 times or more, and the upper limit is usually 20 times or less, preferably 12 times or less. Within the above stretching ratio range, the desired porosity and basis weight are easily obtained, and opacity is easily improved. Furthermore, the film is less likely to break, and stretching is more likely to be stable.

[0088] <Surface treatment> The first or second surface layer is preferably subjected to a surface treatment to activate the surface, which can improve adhesion between the first or second surface layer and the adjacent layer. Examples of the surface treatment include corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment, ozone treatment, etc., and these treatments can be combined. Among these, corona discharge treatment or flame treatment is preferred, and corona treatment is more preferred.

[0089] When corona discharge treatment is performed, the discharge amount is preferably 600 J / m 2 (10W min / m 2 ) or more, and more preferably 1,200 J / m 2 (20W min / m 2 ) or more, while preferably 12,000 J / m 2 (200W min / m 2 ) or less, and more preferably 10,800 J / m 2 (180W min / m 2 The discharge amount when flame treatment is carried out is preferably 8,000 J / m 2 or more, more preferably 20,000 J / m 2 or more, preferably 200,000 J / m 2 or less, more preferably 100,000 J / m 2 The following is the result.

[0090] (coated film) The coated film of the present invention comprises the laminate film described above and a coating layer on at least one surface of the laminate film. While the laminate film alone can be used as printing paper, the coated film has high adhesion between the coating layer and ink, resulting in improved printability. Furthermore, the laminate film can be used as a substrate and an adhesive layer provided thereon to form an adhesive label, and the coating layer of the present invention also has high adhesion to such an adhesive. Therefore, using the coated film as a substrate for an adhesive label is preferable because it enhances adhesion between the laminate film and the adhesive layer via the coating layer, making it less likely for the adhesive to remain on the adherend when the adhesive label is peeled off from the adherend.

[0091] <Coating layer> The coating layer preferably contains a (meth)acrylic acid ester resin. The (meth)acrylic acid ester resin improves adhesion between the coating layer and the pressure-sensitive adhesive layer or ink. Such a coating layer can be formed by preparing a coating liquid containing the acrylic acid ester resin for forming the coating layer and applying the coating liquid to the surface of the laminate film.

[0092] From the viewpoint of improving adhesion to the pressure-sensitive adhesive layer or ink, the (meth)acrylic acid ester resin preferably has cationic properties, more preferably has an amino group, a quaternary ammonium salt structure, or a phosphonium salt structure, and even more preferably has an amino group or a quaternary ammonium salt structure.

[0093] From the viewpoint of improving adhesion to the pressure-sensitive adhesive, the content of the (meth)acrylic acid ester resin in the coating layer is preferably 5% by mass or more, more preferably 20% by mass or more, and even more preferably 40% by mass or more. The upper limit of the content is not particularly limited, but may be 90% by mass or less, 80% by mass or less, or 70% by mass or less.

[0094] The coating layer preferably further contains an ethyleneimine-based polymer, which has a strong affinity with various printing inks, particularly ultraviolet-curable inks, and therefore tends to improve printability.

[0095] Examples of ethyleneimine-based polymers include polyethyleneimine, poly(ethyleneimine-urea), ethyleneimine adducts of polyamine polyamides, modified products or hydroxides thereof, etc. Examples of modified products include alkyl-modified products, cycloalkyl-modified products, aryl-modified products, allyl-modified products, aralkyl-modified products, benzyl-modified products, cyclopentyl-modified products, alicyclic hydrocarbon-modified products, glycidol-modified products, etc. These may be used alone or in combination of two or more.

[0096] As the ethyleneimine-based polymer, commercially available products such as Epomin (trade name) manufactured by Nippon Shokubai Co., Ltd.; Polymin SK (trade name) manufactured by BASF; and Saftomer AC-72 and AC-2000 (trade names) manufactured by Mitsubishi Chemical Corporation can also be used.

[0097] Furthermore, from the viewpoint of improving adhesion to ink, the coating layer may contain resin particles such as ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, alkali (earth) metal salt of ethylene-(meth)acrylic acid copolymer, or ethylene-(meth)acrylic acid ester-maleic anhydride copolymer. The resin particles may be derived from an emulsion. An emulsion is a liquid obtained by dispersing and emulsifying the above copolymer as fine particles in an aqueous dispersion medium. Such resin particles have a high affinity with ink.

[0098] The coating layer may contain other auxiliary components such as an antistatic agent, a crosslinking accelerator, an antiblocking agent, a pH adjuster, and an antifoaming agent, as required.

[0099] From the viewpoint of adhesion to the pressure-sensitive adhesive layer or ink, the thickness of the coating layer is preferably 0.01 μm or more, more preferably 0.02 μm or more, and even more preferably 0.03 μm or more. From the viewpoint of suppressing cohesive failure of the coating layer, the thickness of the coating layer is preferably 7 μm or less, more preferably 3 μm or less, and even more preferably 1 μm or less.

[0100] (adhesive label) The adhesive label of the present invention comprises the laminate film and an adhesive layer on one surface of the laminate film. In the adhesive label of the present invention, it is preferable that a coating layer is provided on the laminate film. That is, the adhesive label of the present invention can also comprise the coating film and an adhesive layer on the coating layer of the coating film. It is preferable that the adhesive layer is provided on the coating layer on the first surface layer side. As described above, not only is the adhesive layer and the coating layer highly adhesive, but the coating layer and the first surface layer also highly adhesive, so it is possible to provide an adhesive label that leaves little adhesive on the adherend when the adhesive label is peeled off from the adherend.

[0101] FIG. 1 shows an example of an adhesive label. As illustrated in Fig. 1, the adhesive label 30 has a coated film 20 as a substrate and an adhesive layer 31 on one side thereof. A printed layer 40 can be provided on the other side of the adhesive label 30 by printing. The coated film 20 has the coated layers 21 on both sides of a laminated film 10. The laminated film 10 has a substrate layer 11 and a first surface layer 12 and a second surface layer 13 on both sides thereof. In the adhesive label 30, the first surface layer 12 of the laminated film 10 is disposed on the adhesive layer 31 side, and the second surface layer 13 is disposed on the printed layer 40 side.

[0102] <Adhesive layer> Examples of the adhesive used in the adhesive layer include rubber-based adhesives, acrylic-based adhesives, and silicone-based adhesives.

[0103] Examples of rubber-based adhesives include polyisobutylene rubber, butyl rubber, a mixture of these, and rubber-based adhesives containing these with a tackifier. Examples of tackifiers include abietic acid rosin ester, terpene-phenol copolymer, and terpene-indene copolymer. Examples of acrylic adhesives include compounds with a glass transition point of −20° C. or lower, such as 2-ethylhexyl acrylate-n-butyl acrylate copolymer or 2-ethylhexyl acrylate-ethyl acrylate-methyl methacrylate copolymer. Examples of silicone-based adhesives include addition-curing adhesives using a platinum compound or the like as a catalyst, and peroxide-curing adhesives that are cured with benzoyl peroxide or the like. The form of the pressure-sensitive adhesive is not particularly limited, and various types of pressure-sensitive adhesives such as solution type, emulsion type, or hot melt type can be used.

[0104] The adhesive layer may be formed by directly applying the adhesive to the surface of the coated film, or by applying the adhesive to the surface of a release sheet described below to form an adhesive layer, which is then attached to the surface of the coated film. Examples of the pressure-sensitive adhesive coating device include a bar coater, blade coater, comma coater, die coater, air knife coater, gravure coater, lip coater, reverse coater, roll coater, spray coater, etc. The pressure-sensitive adhesive coating film coated by these coating devices is smoothed as necessary and dried to form a pressure-sensitive adhesive layer.

[0105] <Coating amount> The amount of adhesive to be applied is not particularly limited, but is preferably 3 to 60 g / m in terms of solid content after drying. 2 It is preferable that the density is 10 to 40 g / m 2 It is more preferable that:

[0106] <Release sheet> A release sheet may be provided on the pressure-sensitive adhesive layer, if necessary, for the purpose of protecting the surface of the pressure-sensitive adhesive layer. The release sheet may be, for example, wood-free paper, kraft paper, or sheets of these that have been calendered, resin-coated, or film-laminated, or glassine paper, coated paper, or silicone-treated resin film, etc. Among these, it is preferable to use a sheet whose surface that comes into contact with the adhesive layer has been silicone-treated, as this provides good releasability from the adhesive layer. [Example]

[0107] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the examples, "parts", "%", and the like are based on mass unless otherwise specified.

[0108] Table 1 lists the materials used in the examples and comparative examples. [Table 1]

[0109] Table 2 lists the compounding ratios of the materials in each resin composition. [Table 2]

[0110] Table 3 shows a list of the blending ratios of materials used in the coating liquid for forming the coating layer. [Table 3]

[0111] (Preparation of Coating Solution (a) for Forming Coating Layer) As shown in Table 3, an aqueous solution containing 50 parts by mass (solid content equivalent) of an acrylic ester resin (product name: Saftomer ST3200, manufactured by Mitsubishi Chemical Corporation) and 50 parts by mass (solid content equivalent) of a polyethyleneimine resin (product name: Saftomer AC72, manufactured by Mitsubishi Chemical Corporation) was prepared as a coating liquid (a) for forming a coating layer.

[0112] (Preparation of Coating Solution (b) for Forming Coating Layer) As a coating agent, an aqueous solution containing 10 parts by mass (solid content equivalent) of an acrylic ester resin (product name: Saftomer ST3200), 10 parts by mass (solid content equivalent) of a polyethyleneimine resin (product name: Saftomer AC72), and 80 parts by mass (solid content equivalent) of an ethylene methacrylic acid copolymer (product name: Aquatex AC3100, manufactured by Japan Coating Resins Co., Ltd.) was prepared as a coating liquid (b) for forming a coating layer.

[0113] (Preparation of Coating Solution (c) for Forming Coating Layer) As a coating agent, an aqueous solution containing 100 parts by mass (solid content equivalent) of polyethyleneimine resin (trade name: Saftomer AC72) was prepared as a coating liquid (c) for forming a coat layer.

[0114] Example 1 <Laminated film manufacturing> 41 parts by mass of a propylene homopolymer produced from vegetable oil (product name: HC101BF, manufactured by Borealis, MFR: 3.2 g / 10 min) and 41 parts by mass of a petroleum-derived propylene homopolymer (product name: Novatec PP FY6, manufactured by Japan Polypropylene Corporation, MFR: 2.4 g / 10 min (JIS K7210), density: 0.90 g / cm 3 ) and 41 parts by mass of a petroleum-derived propylene homopolymer (trade name: Novatec PP MA3, manufactured by Japan Polypropylene Corporation, MFR: 11 g / 10 min (JIS K7210), density: 0.90 g / cm 3 ) and 14 parts by mass of petroleum-derived maleic acid-modified polypropylene (trade name: Umex 1001, manufactured by Sanyo Chemical Industries, Ltd., acid value: 26 mg KOH / g, density: 0.90 g / cm 3 ) and 1 part by mass of petroleum-derived high-density polyethylene (trade name: Novatec HD HJ580N, manufactured by Japan Polyethylene Co., Ltd., MFR: 12 g / 10 min (JIS K7210), density: 0.96 g / cm 3 ) and 13 parts by mass of heavy calcium carbonate particles (trade name: Softon 1800, manufactured by Bihoku Funka Kogyo Co., Ltd., average particle size: 1.25 μm, density: 2.72 g / cm 3 20 parts by mass of ) was mixed with 20 parts by mass of , to prepare Resin Composition B. This was melt-kneaded in an extruder with a cylinder temperature set to 230°C, extruded into a strand shape, cooled, and then cut to obtain pellets of Resin Composition B.

[0115] Separately, 9 parts by mass of the biomass-derived propylene homopolymer (trade name: HC101BF), 85 parts by mass of a petroleum-derived propylene homopolymer (trade name: Novatec PP FY6), 16 parts by mass of a petroleum-derived propylene homopolymer (trade name: Novatec PP MA3), 1 part by mass of a petroleum-derived maleic acid-modified polypropylene (trade name: Umex 1001), 13 parts by mass of a petroleum-derived high-density polyethylene (trade name: Novatec HD HJ580N), and 6 parts by mass of heavy calcium carbonate particles (trade name: Softon 1800) were mixed to prepare a resin composition A. This was melt-kneaded in an extruder with a cylinder temperature set to 230 ° C., extruded into a strand, cooled, and cut to obtain pellets of resin composition A.

[0116] In addition, 10 parts by mass of a propylene homopolymer produced using vegetable oil as a raw material (trade name: HE125MO, manufactured by Borealis, MFR: 10 g / 10 min), 20 parts by mass of the petroleum-derived propylene homopolymer (trade name: Novatec PP FY6), 30 parts by mass of a petroleum-derived propylene homopolymer (trade name: Novatec PP MA3), 1 part by mass of a petroleum-derived maleic acid-modified polypropylene (trade name: Umex 1001), 13 parts by mass of a petroleum-derived high-density polyethylene (trade name: Novatec HD HJ580N), and 58 parts by mass of heavy calcium carbonate particles (trade name: Softon 1800) were mixed to prepare resin composition C. This was melt-kneaded in an extruder with a cylinder temperature set to 230 ° C, extruded into a strand, cooled, and cut to obtain pellets of resin composition C.

[0117] The above resin composition B was melt-kneaded in an extruder set at 250°C, and then fed to an extrusion die set at 250°C and extruded into a sheet. The extruded sheet was cooled to 60°C using a cooling device to obtain an unstretched sheet. This unstretched sheet was heated to 150°C and stretched 4.8 times in the machine direction (MD direction) using the difference in peripheral speed between a group of rolls to form a sheet for the base layer.

[0118] Next, resin compositions A and C were melt-kneaded in two extruders set at 250°C, and then melt-extruded onto both sides of the base layer sheet, thereby obtaining a three-layer sheet in which a first surface layer made of resin composition A was laminated on one side of a base layer made of resin composition B, and a second surface layer made of resin composition C was laminated on the other side.

[0119] The three-layer sheet was cooled to 60°C using a cooling device, then reheated to 150°C and stretched 9 times in the sheet width direction (TD) using a tenter, and annealed at 165°C. After cooling again to 60°C, the edge portions were slit to obtain the laminated film of Example 1. The laminated film of Example 1 had a three-layer structure (uniaxially stretched / biaxially stretched / uniaxially stretched), a total thickness of 80 μm, and the thicknesses of the layers of resin compositions A / B / C were 18 μm / 36 μm / 26 μm.

[0120] <Production of coated films> 30 W·min / m on both sides of the laminated film of Example 1 2 A corona discharge treatment was performed under the conditions of

[0043] Next, the coating solution (a) for forming a coating layer was applied using a roll coater so that the thickness after drying would be 0.03 μm. The coating film was dried in an oven at 60°C to form a coating layer, and a coated film was obtained.

[0121] (Examples 2 to 5 and 7) Pellets of resin compositions D to G were prepared in the same manner as for resin composition A, except that the blending amounts of the materials in resin composition A were changed as shown in Table 2. Resin composition J was prepared by mixing 9 parts by weight of a biomass-derived propylene homopolymer (MFR: approximately 11 g / 10 min (JIS K7210)) obtained by polymerizing propylene produced from sugarcane using a Ziegler-Natta catalyst according to a standard method, 73 parts by weight of a petroleum-derived propylene homopolymer (trade name: Novatec PP FY6), 14 parts by weight of a petroleum-derived propylene homopolymer (trade name: Novatec PP MA3), 1 part by weight of a petroleum-derived maleic acid-modified polypropylene (trade name: Umex 1001), 13 parts by weight of a petroleum-derived high-density polyethylene (trade name: Novatec HD HJ580N), and 20 parts by weight of heavy calcium carbonate particles (trade name: Softon 1800). Pellets of resin composition J were then prepared in the same manner as for resin composition A.

[0122] The laminated films and coated films of Examples 2 to 5 and 7 were produced in the same manner as in Example 1, except that the first surface layer was formed by changing resin composition A to each of resin compositions D to G and J. The layer structures of the laminated films of Examples 2 to 5 and 7 are shown in Table 4.

[0123] Example 6 Pellets of resin composition H were prepared in the same manner as for resin composition A, except that the blending amounts of each material of resin composition A were changed as shown in Table 2.

[0124] Furthermore, 32 parts by mass of the biomass-derived propylene homopolymer (trade name: HC101BF), 65 parts by mass of the biomass-derived propylene homopolymer (trade name: HE125MO), 1 part by mass of petroleum-derived maleic acid-modified polypropylene (trade name: UMEX 1001), 3 parts by mass of petroleum-derived high-density polyethylene (trade name: NOVATEC HD HJ580N), and 29 parts by mass of heavy calcium carbonate particles (trade name: SOFTON 1800) were mixed to prepare resin composition I. This was melt-kneaded in an extruder with a cylinder temperature set to 230°C, extruded into a strand, cooled, and then cut to obtain pellets of resin composition I.

[0125] The laminated film and coated film of Example 6 were produced in the same manner as in Example 1, except that the first surface layer was formed by changing resin composition A to resin composition H and the second surface layer was formed by changing resin composition C to resin composition I. The layer structure of the laminated film of Example 6 is shown in Table 4.

[0126] Example 8 <Laminated film manufacturing> Pellets of resin compositions K, N and L were prepared in the same manner as for resin composition C, except that the blending amounts of the materials in resin composition C were changed as shown in Table 2.

[0127] Pellets of resin compositions K, N, and L were melt-kneaded in three extruders set at 250° C. These were fed into a co-extrusion die, laminated inside the die to form a three-layer structure of K / N / L, and extruded from the die into a sheet.

[0128] The extruded sheet was cooled using a cooling roll to obtain an unstretched sheet. This unstretched sheet was then reheated to 150°C and stretched twice in the sheet flow direction (MD) using the speed difference between the rolls to obtain a longitudinally stretched resin film. The longitudinally stretched resin film was then cooled to 60°C, reheated to 150°C, stretched twice in the sheet width direction (TD) using a tenter, and annealed at 165°C. After cooling again to 60°C, the edge portions were slit to obtain the laminated film of Example 8. The laminated film of Example 8 had a three-layer structure (biaxially stretched / biaxially stretched / biaxially stretched), with a total thickness of 80 μm and layer thicknesses of resin compositions K / N / L of 18 μm / 36 μm / 26 μm.

[0129] <Production of coated films> A coating layer was formed on the laminated film in the same manner as in Example 1, to produce a coated film of Example 8.

[0130] Example 9 <Laminated film manufacturing> Pellets of the above resin compositions A, B, and C were melt-kneaded in three extruders set at 250° C. These were fed into a co-extrusion die, laminated inside the die to form a three-layer structure of A / B / C, and extruded from the die into a sheet.

[0131] The extruded sheet was cooled using a cooling roll to obtain an unstretched sheet. This unstretched sheet was then reheated to 150°C and stretched 4.8 times in the sheet flow direction (MD) using the speed difference between the rolls to obtain a longitudinally stretched film. The longitudinally stretched film was then cooled to 60°C, reheated to 150°C, stretched 9 times in the sheet width direction (TD) using a tenter, and annealed at 165°C. After cooling again to 60°C, the edge portions were slit to obtain the laminated film of Example 9. The laminated film of Example 9 had a three-layer structure (biaxially stretched / biaxially stretched / biaxially stretched), with a total thickness of 80 μm and layer thicknesses of resin compositions A / B / C of 18 μm / 36 μm / 26 μm.

[0132] <Production of coated films> A coating layer was formed on the laminated film in the same manner as in Example 1 to produce a coated film of Example 9.

[0133] Examples 10 and 11 The coated films of Examples 10 and 11 were produced in the same manner as in Example 2, except that the coating layer was formed by changing the coating liquid (a) for forming the coating layer to each of the coating liquids (b) and (c) for forming the coating layer.

[0134] Example 12 The mixture was a mixture of 82 parts by mass of the biomass-derived propylene homopolymer (trade name: HC101BF), 14 parts by mass of the biomass-derived propylene homopolymer (trade name: HE125MO), 1 part by mass of petroleum-derived maleic acid-modified polypropylene (trade name: Umex 1001), and biomass-derived high-density polyethylene (trade name: HDPE SHC7260, manufactured by Braskem, MFR: 7.2 g / 10 min, density: 0.959 g / cm). 36.5 parts by mass of a petroleum-derived high-density polyethylene (product name: Novatec HD HJ580N) was mixed with 6.5 parts by mass of heavy calcium carbonate particles (product name: Softon 1800) to prepare resin composition M. This was melt-kneaded in an extruder with a cylinder temperature set to 230°C, extruded into a strand, cooled, and cut to obtain pellets of resin composition M.

[0135] The laminated film and coated film of Example 12 were produced in the same manner as in Example 2, except that resin composition B was changed to resin composition M to form the base layer, and resin composition C was changed to resin composition I to form the second surface layer.

[0136] Example 13 A laminated film and a coated film of Example 13 were produced in the same manner as in Example 1, except that Resin Composition C was changed to Resin Composition A to form the second surface layer.

[0137] Example 14 The laminated film and coated film of Example 14 were produced in the same manner as in Example 1, except that resin composition A was changed to resin composition E to form the first surface layer, and resin composition C was changed to resin composition N to form the second surface layer.

[0138] (Comparative Example 1) A laminated film and a coated film of Comparative Example 1 were produced in the same manner as in Example 1, except that resin composition A was changed to resin composition C to form the first surface layer.

[0139] (Comparative Example 2) Resin composition M was melt-kneaded in an extruder set at 250°C, then fed to an extrusion die set at 250°C and extruded into a sheet. The extruded sheet was cooled to 60°C using a cooling device to obtain an unstretched sheet. This unstretched sheet was heated to 150°C and stretched 4.8 times in the machine direction (MD) using the difference in peripheral speed between rolls to form a sheet for the base layer.

[0140] The base layer sheet was cooled to 60°C using a cooling device, then reheated to 150°C, stretched 9 times in the sheet width direction (TD direction) using a tenter, and annealed at 165°C. After cooling again to 60°C, the edge portions were slit to obtain a laminated film of Comparative Example 2. The laminated film of Comparative Example 2 was a biaxially stretched film having a single-layer structure and a total thickness of 80 μm.

[0141] (Measurement of physical properties) The physical properties of the laminated film and coated film of each of the Examples and Comparative Examples were measured as follows.

[0142] <Total thickness> The total thickness (μm) of the laminated film was measured using a constant pressure thickness measuring instrument (device name: PG-01J, manufactured by Teclock Corporation) based on JIS K7130:1999 "Plastics - Films and sheets - Thickness measurement method".

[0143] <Thickness of each layer> The thickness (μm) of each layer in the multilayer structure was measured as follows. The laminate film was cooled to a temperature below -60°C using liquid nitrogen, and the sample was placed on a glass plate and cut at a right angle with a razor blade (product name: Proline Blade, manufactured by Schick Japan Co., Ltd.) to prepare a sample for cross-sectional measurement. The cross-section of the obtained sample was observed using a scanning electron microscope (instrument name: JSM-6490, manufactured by JEOL Ltd.). The boundary lines of each layer were identified based on their appearance, which differed depending on the composition, and the thickness ratio of each layer in the laminate film was calculated. The thickness of each layer was calculated by multiplying the measured total thickness by the thickness ratio of each layer.

[0144] <Porosity> An arbitrary part of the laminated film to be measured was cut out, embedded in an epoxy resin and solidified. Then, it was cut perpendicularly to the surface direction of the laminated film to be measured using a microtome, and attached to an observation sample stage so that the cut surface became the observation surface. Gold or gold-palladium etc. was vapor-deposited on the observation surface, and the cut surface of the laminated film was observed at an arbitrary magnification (for example, a magnification of 500 to 3000 times) that was easy to observe with a scanning electron microscope, and the observed region was taken in as image data. The image data was processed by an image analysis device, and the area ratio (%) of the pore part in a certain region of each layer of the laminated film was determined. The average value of the area ratio (%) obtained at any 10 or more locations was taken as the porosity (%) of each layer.

[0145] (Evaluation) The following evaluations were performed on the laminated films and coat films of each example and comparative example.

[0146] <Degree of biomass> The ratio (%) of the total mass of biomass-derived polypropylene and biomass-derived polyethylene to the total mass of all raw materials constituting the laminated film was calculated as the degree of biomass (%).

[0147] <Whiteness> The whiteness (%) of the laminated film was measured using a colorimeter in accordance with the method specified in JIS L1015:1999. As the colorimeter, a touch panel type color computer SM-T manufactured by Suga Test Instruments Co., Ltd. was used. The measured whiteness was evaluated according to the following criteria. The higher the whiteness, the clearer the printed content, and a clear display equivalent to pulp paper is possible when the whiteness is 95% or more. 〇: The whiteness is 95% or more. ×: The whiteness is less than 95%.

[0148] <Water rub resistance of UV ink> The coated film was cut into an A2 size (420 mm x 594 mm), and a design was offset-printed onto the coating layer on the second surface layer side. An offset printing machine (product name: SM102, manufactured by Heidelberg) and UV-curable sheet-fed process ink (product name: UV BC161 (black, indigo, red, yellow), manufactured by T&K TOKA) were used for printing. The design was printed in four colors: black, indigo, red, and yellow, with each color density being 100%. Specifically, UV offset four-color printing was performed at a speed of 6,000 sheets per hour in an environment with a temperature of 23°C and a relative humidity of 50%, and the ink on the printed surface was dried by passing the sheets under two metal halide lamps (manufactured by Eye Graphics, 100 W / cm). 1,000 sheets were printed continuously to obtain an offset print.

[0149] The resulting offset print was die-cut to a size of 70 mm x 110 mm, immersed in ion-exchanged water at 23°C for 24 hours, and then removed from the water. The removed print was placed in a Gakushin-type dye rub fastness tester (product name: Rub Tester Type II, manufactured by Suga Testing Instruments Co., Ltd.) and subjected to a rub test. The rub test was conducted in accordance with JIS L0849:2004 (Test method for dye fastness to rub), in which the printed surface was rubbed 100 times with a white cotton cloth (gold cloth No. 3) under a load of 215 g.

[0150] The ink area before and after the test was imaged using an image analyzer (Luzex IID, manufactured by Nireco Corporation), and the remaining area of ​​the ink area was calculated and evaluated according to the following criteria. ◎: Over 95% of the ink remains on the recording paper, an excellent level ◯: 90% or more but less than 95% of the ink remains on the recording paper, a good level △: 70% or more but less than 90% of the ink remains on the recording paper, a practical level ×: Less than 70% of the ink remains on the recording paper, to a level that is not practical.

[0151] <Adhesive remaining rate> An adhesive layer was formed on the coated film as follows to produce an adhesive label. Silicone-treated glassine paper (G7B, manufactured by Oji Tack Co., Ltd.) was used as a release sheet. A sheet with a dry basis weight of 25 g / m was applied to the silicone-treated surface of this glassine paper. 2 The adhesive was applied using a comma coater so that the adhesive layer was formed, and then dried to form an adhesive layer. The adhesive was prepared by mixing a solvent-based acrylic adhesive (Oribain BPS1109, manufactured by Toyochem Co., Ltd.), an isocyanate-based crosslinking agent (Oribain BHS8515, manufactured by Toyochem Co., Ltd.), and toluene in a ratio of 100:3:45. A coated film was laminated on the adhesive layer so that the coating layer side of the first surface layer was in contact with the adhesive layer, and the two were pressure-bonded using a pressure roller to form an adhesive layer on the coating layer.

[0152] The release sheet of the adhesive label was peeled off, and the adhesive layer side was attached to a transparent, highly smooth glass plate and rubbed with a finger three times to ensure sufficient adhesion. This glass plate was heat-treated for 24 hours in an environment at 40°C, and then immersed in water at 23°C for 24 hours. Five minutes after removing the glass plate from the water and lightly wiping off the water with a cloth, the adhesive label was manually peeled from the glass plate in a 180° direction at a speed of 300 m / min. The haze of the glass plate after peeling the adhesive label was measured in accordance with JIS K7136:2000. A haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., model name: NDH2000) was used for the measurement.

[0153] The adhesive remaining rate was determined based on the difference between the haze measured after peeling and the haze of the glass plate before the adhesive label was attached, according to the following criteria: The smaller the haze difference, the lower the adhesive remaining rate can be evaluated. ◎: Haze difference is less than 3%, excellent level Good: The haze difference is 3% or more and less than 5%, which is a good level. △: The haze difference is 5% or more and less than 10%, which is a practical level. ×: The haze difference is 10% or more, which is not practical.

[0154] Table 4 shows the evaluation results. [Table 4]

[0155] As shown in Table 4, Examples 1 to 14 have a biomass degree of 10 or more, and therefore have a low environmental impact. Furthermore, Examples 1 to 14, in which the porosity of the first surface layer is 40% or less, have a low adhesive residual rate, indicating that adhesive films are provided that are less likely to leave adhesive on the adherend. On the other hand, Comparative Example 1, in which the porosity of the first surface layer exceeds 40%, results in adhesive remaining easily even when a coating layer is provided. Comparative Example 2, which does not have a first surface layer, has a high biomass degree but a high adhesive residual rate.

[0156] Furthermore, comparing Examples 1 to 9 with Examples 10 and 11, it can be seen that the inclusion of an acrylic ester resin in the coating layer effectively reduces the amount of adhesive remaining on the adherend. The coating layer also improves adhesion to UV ink, resulting in excellent water abrasion resistance. [Explanation of symbols]

[0157] 10 Laminated film 11 Base material layer 12 1st surface layer 13 Second surface layer 20 coated film 21 Coat layer 30 adhesive labels 31 Adhesive layer 40 printing layer

Claims

1. a base layer and a first surface layer on one surface of the base layer; The porous stretched film includes an olefin resin and an inorganic filler, the olefin-based resin includes a propylene-based resin, the propylene-based resin includes a biomass-derived propylene-based resin, the first surface layer has a porosity of 40% or less, a laminated film in which the substrate layer is the porous stretched film; a coating layer on the first surface layer of the laminated film, The coating layer contains a (meth)acrylic acid ester resin. Coated film.

2. The propylene-based resin further includes a petroleum-derived propylene-based resin. The coated film according to claim 1 .

3. The olefin-based resin further contains an ethylene-based resin. The coated film according to claim 1 or 2.

4. The ethylene-based resin contains a biomass-derived ethylene-based resin. The coated film according to claim 3.

5. The ethylene-based resin contains a petroleum-derived ethylene-based resin. The coated film according to claim 3 or 4.

6. The porosity of the first surface layer is 0.1 to 30%. The coated film according to any one of claims 1 to 5.

7. a second surface layer on the other surface of the base layer; The second surface layer has a porosity of 30 to 55%. The coated film according to any one of claims 1 to 6.

8. The coated film according to any one of claims 1 to 7, a pressure-sensitive adhesive layer provided on the coating layer of the coated film. Self-adhesive labels.

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