Polypropylene film, vapor deposition polypropylene film, and laminated film

Abstract

[Problem] To provide: a polypropylene film which has excellent scratch resistance on a film surface that is subjected to vapor deposition or printing processing; a vapor deposition polypropylene film; and a laminated film. [Solution] A polypropylene film 10 comprising at least two layers including a first surface layer 20 and a second surface layer 30, wherein: the first surface layer 20 and the second surface layer 30 each contain an anti-blocking agent; and when the arithmetic average roughness of the three-dimensional surface roughness of the first surface layer 20 is represented as SRa1 (μm), the number of peaks that have a peak height of not less than 1 μm in the three-dimensional surface roughness of the second surface layer 30 is represented as SPc2 (pieces), and the pore volume of the anti-blocking agent contained in the second surface layer 30 as determined by a nitrogen adsorption method is represented as V2 (ml / g), the value of scratch resistance is not more than 2,600.

Description

Polypropylene film, vapor-deposited polypropylene film, and laminated film

[0001] The present invention relates to a polypropylene film composed of at least two layers of a first surface layer and a second surface layer, a vapor-deposited polypropylene film using the polypropylene film, and a laminated film using the vapor-deposited polypropylene film, and particularly relates to a polypropylene film, a vapor-deposited polypropylene film, and a laminated film suitable for vapor deposition and printing processes.

[0002] Generally, polypropylene films are wound in a roll shape after production, and if necessary, processes such as vapor deposition and printing are performed to impart functionality to the film surface. In this type of polypropylene film, an anti-blocking agent such as silica particles is added for improved processability. However, when an anti-blocking agent is added to the film, the film surface may be damaged when the films rub against each other during winding or the like. When vapor deposition or printing is performed on such a damaged film surface, there is a problem that the appearance deteriorates, such as becoming cloudy, and the design quality decreases. Also, in the vapor-deposited film subjected to vapor deposition, the surface of the vapor-deposited layer may be damaged when the films rub against each other during winding or the like, resulting in a problem of decreased design quality. Furthermore, when the films rub against each other during winding or the like during the printing process, the printed surface may be damaged, and similarly, there is concern about a decrease in design quality and commercial value. [[ID=​​​Furthermore, films have been proposed that improve printability by reducing the antiblocking agent on the printed surface and improve blocking resistance by increasing the antiblocking agent on the non-printed surface. For example, films in which the amount of amorphous silica added to the printed surface layer is less than the amount of amorphous silica added to the non-printed surface layer (see Patent Document 2), or films in which the amount of shaped amorphous silica added to the printed surface layer is less than the amount of amorphous silica added to the non-printed surface layer, thereby making the average roughness of the printed surface layer less than the average roughness of the non-printed surface layer (see Patent Document 3). However, with these films, it is difficult to prevent scratches on the printed surface when the printed surface and non-printed surface rub against each other during winding or other processes.

[0005] Japanese Patent Publication No. 2004-076004, Japanese Patent Publication No. 2020-151907, Japanese Patent Publication No. 2016-196159

[0006] The present invention has been made in view of the above points, and provides a polypropylene film, a vapor-deposited polypropylene film, and a laminated film that have excellent scratch resistance on the film surface subjected to vapor deposition or printing.

[0007] In other words, the first invention relates to a polypropylene film comprising at least two layers, a first surface layer and a second surface layer, wherein both the first surface layer and the second surface layer contain an antiblocking agent, and the film satisfies the scratch resistance value shown in the following formula (i) when the arithmetic mean roughness of the three-dimensional surface roughness of the first surface layer is SRa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is SPc2 (pitch).

[0008]

[0009] The second invention relates to a polypropylene film that satisfies the scratch resistance value shown in the following formula (ii) when the pore volume of the antiblocking agent contained in the second surface layer, as determined by nitrogen adsorption, is V2 (ml / g) in the first invention.

[0010]

[0011] The third invention relates to the polypropylene film according to claim 1 or 2 of the first or second invention, wherein a vapor-deposited layer is formed on the first surface layer by vapor deposition.

[0012] The fourth invention relates to a polypropylene film in which, in the first or second invention, the glossiness of the first surface layer measured in accordance with JIS Z 8741 (1997) is 110% or more.

[0013] The fifth invention relates to a polypropylene film in which the first surface layer is surface-treated, as described in the first or second invention.

[0014] The sixth invention relates to a polypropylene film in which the polypropylene film is an unstretched film, in the first or second invention.

[0015] The seventh invention relates to a polypropylene film in which, in the first or second invention, the pore volume of the antiblocking agent contained in the first surface layer, as determined by nitrogen adsorption, is 0.5 to 1.3 ml / g, and the average particle size, as measured by laser diffraction, is 2.5 to 4.5 μm.

[0016] The eighth invention relates to a vapor-deposited polypropylene film comprising at least two layers, a first surface layer and a second surface layer, both containing an antiblocking agent, wherein a vapor-deposited layer is formed on the first surface layer, and the vapor-deposited polypropylene film satisfies the value of scratch resistance shown in the following formula (iii) when the arithmetic mean height of the vapor-deposited layer is Sa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is SPc2 (number).

[0017]

[0018] The ninth invention relates to the vapor-deposited polypropylene film according to claim 7, wherein, in the eighth invention, when the pore volume determined by nitrogen adsorption of the antiblocking agent contained in the second surface layer is V2 (ml / g), the film satisfies the scratch resistance value shown in the following formula (iv).

[0019]

[0020] The tenth invention relates to a vapor-deposited polypropylene film in which, in the eighth or ninth invention, the glossiness of the vapor-deposited layer, measured in accordance with JIS Z 8741 (1997), is 720% or higher.

[0021] The eleventh invention relates to the vapor-deposited polypropylene film according to claim 8 or 9 of the eighth or ninth invention, wherein the polypropylene film is an unstretched film.

[0022] The twelfth invention relates to a vapor-deposited polypropylene film in which, in the eighth or ninth invention, the pore volume of the antiblocking agent contained in the first surface layer, as determined by nitrogen adsorption, is 0.5 to 1.3 ml / g, and the average particle size, as measured by laser diffraction, is 2.5 to 4.5 μm.

[0023] The 13th invention relates to a laminated film using a vapor-deposited polypropylene film of the 8th or 9th invention, characterized in that at least one layer of a lamination base film made of a polyester film, a polyamide film, or a polypropylene film is laminated on the vapor-deposited layer side of the vapor-deposited polypropylene film.

[0024] According to the polypropylene film of the first invention, the polypropylene film comprises at least two layers, a first surface layer and a second surface layer, wherein both the first surface layer and the second surface layer contain an antiblocking agent, and when the arithmetic mean roughness of the three-dimensional surface roughness of the first surface layer is SRa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is SPc2 (pitch), the film satisfies the scratch resistance value shown in formula (i) above. As a result, the film has excellent scratch resistance and good scratch haze, scratches on the first surface layer are reduced, and deterioration of appearance when vapor deposition or printing is performed can be suppressed, making it suitable for use as a base film for vapor deposition or a film for printing.

[0025] According to the polypropylene film of the second invention, in the first invention, when the pore volume determined by the nitrogen adsorption method of the antiblocking agent contained in the second surface layer is set to V2 (ml / g), the scratch resistance value shown in formula (ii) above is satisfied, so that scratches on the first surface layer are further reduced and deterioration of appearance when vapor deposition or printing is performed can be suppressed.

[0026] According to the polypropylene film of the third invention, in the first or second invention, a vapor-deposited layer is formed on the first surface layer by vapor deposition, and because the vapor-deposited layer is formed on the scratch-resistant first surface layer, the film has excellent design qualities when made into a vapor-deposited film.

[0027] According to the polypropylene film of the fourth invention, in the first or second invention, the glossiness of the first surface layer measured in accordance with JIS Z 8741 (1997) is 110% or more, thus it has excellent glossiness and a luxurious appearance.

[0028] According to the polypropylene film of the fifth invention, in the first or second invention, since the first surface layer is surface-treated, the adhesion between the polypropylene film and the vapor-deposited film can be improved.

[0029] According to the polypropylene film of the sixth invention, in the first or second invention, since the polypropylene film is an unstretched film, whitening is less likely to occur and the heat seal strength is increased.

[0030] According to the polypropylene film of the seventh invention, in the first or second invention, the pore volume of the antiblocking agent contained in the first surface layer, determined by nitrogen adsorption, is 0.5 to 1.3 ml / g, and the average particle size, measured by laser diffraction, is 2.5 to 4.5 μm. As a result, the film has excellent scratch resistance and good total light transmittance against scratches. When a vapor-deposited layer is formed, damage to the vapor-deposited layer is reduced, and the deterioration of the film's design due to friction between films can be suppressed. Furthermore, cracking of the vapor-deposited layer can be reduced, preventing a decrease in barrier properties.

[0031] According to the eighth invention, the vapor-deposited polypropylene film is a polypropylene film comprising at least two layers, a first surface layer and a second surface layer, both containing an antiblocking agent, wherein a vapor-deposited layer is formed on the first surface layer, and when the arithmetic mean height of the vapor-deposited layer is Sa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is SPc2 (number), the film satisfies the scratch resistance value shown in the following formula (iii). As a result, the film has excellent scratch resistance and good scratch haze, and scratches on the vapor-deposited layer are reduced, suppressing deterioration of appearance.

[0032] According to the vapor-deposited polypropylene film of the ninth invention, in the eighth invention, when the pore volume determined by the nitrogen adsorption method of the antiblocking agent contained in the second surface layer is set to V2 (ml / g), the scratch resistance value shown in formula (iv) above is satisfied, so that scratching of the vapor-deposited layer is further reduced and deterioration of appearance can be suppressed.

[0033] According to the vapor-deposited polypropylene film of the tenth invention, in the eighth or ninth invention, the glossiness of the vapor-deposited layer measured in accordance with JIS Z 8741 (1997) is 720% or higher, thus it has excellent glossiness and a high-quality appearance.

[0034] According to the vapor-deposited polypropylene film of the 11th invention, in the 8th or 9th invention, the polypropylene film is an unoriented film, and therefore exhibits excellent suitability as a vapor-deposited film.

[0035] According to the vapor-deposited polypropylene film of the 12th invention, in the 8th or 9th invention, the pore volume of the antiblocking agent contained in the first surface layer, determined by nitrogen adsorption, is 0.5 to 1.3 ml / g, and the average particle size, measured by laser diffraction, is 2.5 to 4.5 μm. As a result, the film has excellent scratch resistance and good total light transmittance against scratches, reducing scratches on the vapor-deposited layer and suppressing the deterioration of the film's design due to friction between films. Furthermore, cracking of the vapor-deposited layer can be reduced, and a decrease in barrier properties can be suppressed.

[0036] According to the laminated film of the 13th invention, a laminated film using the vapor-deposited polypropylene film of the 8th or 9th invention is made in which at least one layer of a lamination base film made of a polyester film, a polyamide film, or a polypropylene film is laminated on the vapor-deposited layer side of the vapor-deposited polypropylene film. As a result, a laminate film can be made that can suppress deterioration of the vapor-deposited layer and can be suitably used as various packaging bags and the like.

[0037] This is a schematic cross-sectional view of a polypropylene film according to the present invention. This is a schematic cross-sectional view of a vapor-deposited polypropylene film according to the present invention. This is a schematic cross-sectional view of a laminated film using a vapor-deposited polypropylene film according to the present invention.

[0038] The polypropylene film 10 according to one embodiment of the present invention shown in Figure 1 consists of at least two layers, a first surface layer 20 and a second surface layer 30, and both the first surface layer 20 and the second surface layer 30 are configured to contain an antiblocking agent. This polypropylene film 10 is preferably used as a vapor-deposited film, in which vapor deposition or printing is applied mainly to one side. Furthermore, when the polypropylene film 10 is used as a vapor-deposited film, it is preferable that it be an unoriented film. Unoriented films have reduced orientation due to suppressed stretching, which makes them less prone to whitening and increases heat seal strength. Note that the term "unoriented film" also includes cases where unavoidable stretching occurs during film formation.

[0039] The polypropylene resin used as the resin raw material for the polypropylene film 10 is appropriately selected from resins produced from appropriate starting materials such as petroleum-derived, biomass-derived, material recycling-derived, chemical recycling-derived, etc. As for the type of polypropylene resin, general polypropylene resins can be appropriately used. For example, it is selected from at least one or more of a propylene homopolymer, a propylene-α-olefin random copolymer such as a propylene-ethylene random copolymer or a propylene-ethylene-butene random copolymer, or a propylene-ethylene block copolymer. In particular, it is preferably mainly composed of a propylene-α-olefin random copolymer. The polypropylene resin can also use a mixture of one or more of the above.

[0040] In the polypropylene resin, the melt flow rate (MFR) is not particularly limited. From the perspective of the film formability, the MFR of the polypropylene resin, for example, in accordance with JIS K 7210, the value measured under the conditions of 230°C and a load of 2.16 kg is preferably 1 to 20 g / 10 min, particularly preferably 2 to 10 g / 10 min If the MFR of the polypropylene resin used is too low, the pressure of the extruder used for molding may become excessively high, and there is a risk of reduced productivity. If the MFR is too high, the melt viscosity of the resin becomes low and it is likely to break during molding, making it difficult to form a film.

[0041] The first surface layer 20 is the surface layer on one side of the polypropylene film 10 and contains an antiblocking agent. This first surface layer 20 corresponds to the vapor deposition layer having a vapor deposition surface 21 to which vapor deposition processing is applied when used as a vapor deposition film. Also, when used as a printed film, the first surface layer 20 corresponds to the printed layer having a printed surface.

[0042] The second surface layer 30 is the surface layer on the other side of the polypropylene film 10 and contains an antiblocking agent. This second surface layer 30 has a heat-sealing surface 31 that can be fused to the adherend by heat-sealing when used as a vapor deposition film.

[0043] An antiblocking agent is an additive used to improve the processability of the polypropylene film 10 by providing antiblocking properties. The type of antiblocking agent is not particularly limited, but for example, organic or inorganic particles, or both, can be used as appropriate. Organic particles can be obtained by emulsion polymerization or suspension polymerization, for example, and include polymethyl methacrylate, polystyrene, and polyamide. Inorganic particles can be obtained by silica, zeolite, talc, etc. One or more of these antiblocking agents may be used in combination. From the viewpoint of scratch resistance of the film, it is preferable to use inorganic particles such as silica or zeolite. The method of adding the antiblocking agent is not particularly limited, but it can be added by known methods, such as preparing a high-concentration masterbatch and mixing it, or by mixing it in a dry blend.

[0044] There are no particular restrictions on the amount of antiblocking agent added to each surface layer 20, 30. If the amount added is too high, it is likely to increase costs, worsen the transparency of the film, and cause the antiblocking agent to fall off after film formation. If the amount added is too low, the desired antiblocking properties may not be obtained. For this reason, for example, it is considered that an appropriate amount of antiblocking agent to be added is a concentration of 500 to 30,000 ppm, preferably 1,000 to 20,000 ppm.

[0045] In addition to the antiblocking agent, the resin raw material constituting the polypropylene film 10 may contain additives such as antioxidants, neutralizing agents, antistatic agents, antifogging agents, lubricants, nucleating agents, and colorants, as needed, within a range that does not impair the objectives of the present invention. Of these additives, it is preferable to add a nucleating agent from the viewpoint of suitability for vapor deposition processing. By incorporating a nucleating agent into the polypropylene resin, the crystallization of the resin can be promoted, thereby improving heat resistance, rigidity, and other properties.

[0046] Examples of nucleating agents that can be used include fatty acid metal salts, carboxylate metal salts, phosphate ester metal salts, rosin metal salts, talc, mica, sorbitol derivatives, and high-density polyethylene resin. High-density polyethylene is particularly preferred from the viewpoint of vapor deposition suitability. High-density polyethylene resin has a density of 0.945 to 0.975 g / cm³. ３ Preferably, 0.950 to 0.966 g / cm³ ３ This is more preferable. If the density of the high-density polyethylene resin is too low, the crystallization rate will be low, which may reduce heat resistance and other properties. If the density of the high-density polyethylene resin is too high, the impact strength of the film may decrease.

[0047] The polypropylene film 10 of the present invention may be composed of three or more layers, including layers other than the first surface layer 20 and the second surface layer 30, as needed. The polypropylene film 10 in Figure 1 is a three-layer film having an intermediate layer 40 between the first surface layer 20 and the second surface layer 30. The intermediate layer 40 is mainly composed of polypropylene resin, and the polypropylene resin is selected from at least one of the following: propylene homopolymer, propylene-ethylene random copolymer, propylene-α-olefin random copolymer such as propylene-ethylene-butene random copolymer, or propylene-ethylene block copolymer. In particular, it is preferable to mainly use a propylene-α-olefin random copolymer. In addition, polyethylene resin may be added in addition to the polypropylene resin. By using a resin with arbitrary physical properties in the intermediate layer 40, the film can be given appropriate functionality.

[0048] The thickness of the polypropylene film of the present invention is not particularly limited, but can be appropriately determined according to demand and application. For example, when vapor deposition or printing is performed, a thickness of 10 to 100 μm is preferred, and 15 to 70 μm is more preferred. If the surface layers 20 and 30 are too thin, the antiblocking agent tends to fall off when the film passes through the roll during processing, and if they are too thick, the amount of antiblocking agent added will be large, which tends to reduce the transparency of the film. The ratio of the thicknesses of each layer of the polypropylene film can be set appropriately, but whether it is two layers or three or more layers, at least the first surface layer is composed of 10 to 85% and the second surface layer of 10 to 30%. In particular, when it is composed of three layers, the first surface layer, the intermediate layer and the second surface layer, the thickness ratio is preferably 10 to 33.3% for the first surface layer, 33.4 to 80% for the intermediate layer and 10 to 33.3% for the second surface layer.

[0049] The polypropylene film 10 of the present invention is obtained by known film forming methods such as the T-die method or the inflation method. In particular, it is preferable to form and shape it by the T-die method. Film forming by the T-die method has the advantage of being able to obtain the high thickness-to-thinness accuracy required for a film. Furthermore, the polypropylene film 10 can also be used as a laminate (laminate film) by laminating it with other films. Known methods such as extrusion lamination and dry lamination can be appropriately selected for lamination with other films.

[0050] In polypropylene films in which antiblocking agents are added to each surface layer, there is a concern that the film surface may be scratched when the films rub against each other due to fine irregularities on the film surface. Therefore, in the polypropylene film 10 of the present invention, assuming that the first surface layer 20 is the surface layer that is scratched and the second surface layer 30 is the surface layer that scratches, we focused on the arithmetic mean roughness of the three-dimensional surface roughness of the first surface layer 20 and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer 30, and found a correlation between the relationship between these parameters and scratch resistance to derive an index of scratch resistance for polypropylene films 10 in which antiblocking agents are contained in each surface layer 20 and 30.

[0051] In other words, the polypropylene film 10 of the present invention satisfies the scratch resistance value shown in the following formula (i) when the arithmetic mean roughness of the three-dimensional surface roughness of the first surface layer 20 is SRa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer 30 is SPc2 (number of peaks).

[0052]

[0053] The arithmetic mean roughness (SRa1) in three-dimensional surface roughness is a parameter in the height direction. It is calculated by placing orthogonal coordinate axes X and Y on the center plane of the roughness surface, with the axis perpendicular to the center plane being the Z axis, and dividing the volume of the area enclosed by the roughness surface and the center plane by the measurement range. In three-dimensional surface roughness, a larger arithmetic mean roughness indicates that the film surface is rougher, and the surface layer that is prone to scratching tends to be less susceptible to scratching. In polypropylene film 10, the first surface layer 20 is the surface layer that is prone to scratching. Therefore, the arithmetic mean roughness SRa1 (μm) of the first surface layer 20 in three-dimensional surface roughness serves as an indicator of the scratch resistance of the surface of the first surface layer 20. It can be said that a larger arithmetic mean roughness SRa1 tends to improve the scratch resistance of the polypropylene film.

[0054] The number of peaks with a height of 1 μm or more (SPc2) in the three-dimensional surface roughness is a parameter that represents the degree of surface irregularity. On the surface of the scratching side, peaks with a height of a predetermined value (1 μm) or more are thought to be more likely to scratch the surface of the opposing film that is rubbing against it, and the more peaks there are, the more likely the surface of the opposing film is to be scratched. In the polypropylene film 10, the second surface layer 30 is the surface of the scratching side, so the number of peaks with a height of 1 μm or more (SPc2) in the three-dimensional surface roughness of the second surface layer 30 serves as an indicator of how easily the second surface layer 30 can scratch the surface of the opposing first surface layer 20, and it can be said that the smaller the value of the number of peaks with a height of 1 μm or more (SPc2), the more likely the scratch resistance of the polypropylene film 10 is to improve.

[0055] The left-hand side of equation (i) represents the scratch resistance of the polypropylene film, expressed using these two indicators. As shown in the examples described later, when the scratch resistance value expressed in equation (i) is 2100 or less, scratches on the first surface layer 20 by the second surface layer 30 of the polypropylene film 10 become less likely.

[0056] In equation (i), the arithmetic mean roughness SRa1 in the three-dimensional surface roughness, which is an indicator of the scratch resistance of the surface of the first surface layer 20, is the denominator of equation (i). Therefore, as the arithmetic mean roughness SRa1 decreases, the scratch resistance value increases, indicating that the first surface layer 20 is smoothed and becomes more susceptible to scratching by the second surface layer 30. Thus, a preferred arithmetic mean roughness SRa1 for the first surface layer 20 is 0.01 to 0.15 μm, more preferably 0.02 to 0.08 μm. If the arithmetic mean roughness SRa1 of the first surface layer 20 is too small, the roughness of the first surface layer 20 may be insufficient, making it more susceptible to scratching. If the arithmetic mean roughness SRa1 is too large, the first surface layer 20 may become too rough, potentially reducing its function as a vapor-deposited film.

[0057] Furthermore, the numerator of equation (i) uses SPc2, the number of peaks with a peak height of 1 μm or more, which is an indicator of the susceptibility to scratching by the second surface layer 30. The larger the value of SPc2, the greater the scratch resistance, indicating that the second surface layer 30 is more likely to scratch the first surface layer 20.

[0058] The number of peaks SPc2 with a peak height of 1 μm or more in the three-dimensional surface roughness, which is an indicator of the height of the irregularities of the second surface layer 30, indicates that the higher the number of peaks SPc2 with a peak height of 1 μm or more, the larger the numerator value becomes, and the easier it is to damage the first surface layer 20. Therefore, the preferred number of peaks SPc2 with a peak height of 1 μm or more in the second surface layer 30 is 3 to 200, more preferably 5 to 130. If the number of peaks SPc2 with a peak height of 1 μm or more is too low, the performance such as blocking resistance by the antiblocking agent may be insufficient. If the number of peaks SPc2 with a peak height of 1 μm or more is too high, the number of peaks becomes excessive, and the easier it is to damage the first surface layer 20.

[0059] Furthermore, the pore volume (V2) of the antiblocking agent added to the second surface layer 30 can also be used to derive an index of the scratch resistance of the polypropylene film 10 containing the antiblocking agent in each surface layer 20, 30. The pore volume (V2) of the antiblocking agent is the volume of fine pores present in the antiblocking agent, determined by the nitrogen adsorption method, and can be used as an index of the hardness of the antiblocking agent. The larger the value of the pore volume of the antiblocking agent, the softer the antiblocking agent becomes, making it less likely for scratches to occur on the film surface when it rubs against other film surfaces. Conversely, the smaller the value of the pore volume, the harder the antiblocking agent becomes, making it more likely for scratches to occur on the film surface. Since the antiblocking agent forms the ridges on the surface that cause scratches on the opposing film when rubbing against it, it is considered that the softer the antiblocking agent, the less likely it is to scratch the opposing film. From this, it can be said that the pore volume V2 (ml / g) of the antiblocking agent added to the second surface layer 30 also serves as an indicator of the scratchability of the second surface layer 30, and that the larger the value of the pore volume V2 of the antiblocking agent, the more the scratch resistance of the polypropylene film tends to improve.

[0060] In other words, the polypropylene film 10 of the present invention can achieve a further reduction in scratching of the first surface layer by satisfying the scratch resistance value shown in the following formula (ii), where SRa1 (μm) represents the arithmetic mean roughness of the three-dimensional surface roughness of the first surface layer 20, SPc2 (number) represents the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer 30, and V2 (ml / g) is the pore volume determined by the nitrogen adsorption method of the antiblocking agent contained in the second surface layer.

[0061]

[0062] In the numerator of formula (ii), the number of peaks SPc2 with a peak height of 1 μm or more, which is an index of the susceptibility to damage by the second surface layer 30, and the pore volume V2 of the antiblocking agent are used, and are represented by the relationship of (SPc2 / V2). Since (SPc2 / V2) is used in the numerator of formula (ii), the larger the value, the larger the damage resistance value, indicating that the second surface layer 30 is more likely to damage the first surface layer 20.

[0063] The number of peaks SPc2 with a peak height of 1 μm or more in the three-dimensional surface roughness, which is an index of the unevenness height of the second surface layer 30, indicates that from the relationship of (SPc2 / V2), the larger the number of peaks SPc2 with a peak height of 1 μm or more, the larger the value of (SPc2 / V2), and the more likely it is to damage the first surface layer 20. Therefore, the preferable number of peaks SPc2 with a peak height of 1 μm or more in the second surface layer 30 is 3 to 200, more preferably 5 to 130. If the number of peaks SPc2 with a peak height of 1 μm or more is too small, there is a risk that the performance such as antiblocking property by the antiblocking agent may be insufficient. If the number of peaks SPc2 with a peak height of 1 μm or more is too large, there is a risk that the number of peaks becomes excessive and it is easy to damage the first surface layer 20. In the second surface layer 30, regarding the layer thickness and the particle diameter of the antiblocking agent used, it is preferable to appropriately select from the range of about 2 to 13 μm so that the preferable number of peaks SPc2 with a peak height of 1 μm or more in the second surface layer 30 satisfies 3 to 200.

[0064] Further, the pore volume V2, which is an index of the hardness of the antiblocking agent, indicates that from the relationship of (SPc2 / V2), the larger the pore volume V2, the smaller the value of (SPc2 / V2), and the less likely it is to damage the first surface layer 20. Therefore, the preferable pore volume V2 of the antiblocking agent in the second surface layer 30 is 0.4 to 2 ml / g, more preferably 0.5 to 1.5 ml / g. If the pore volume V2 of the antiblocking agent is too small, the antiblocking agent may be too hard and may easily damage the first surface layer 20. If the pore volume V2 is too large, there is a risk that the dispersibility of the antiblocking agent may decrease.

[0065] The average particle size of the antiblocking agent, measured by laser diffraction, is set according to the thickness of each surface layer 20, 30 to which it is added. The average particle size is measured by laser diffraction in accordance with JIS Z 8825-1. For example, when the surface layer is thin, an antiblocking agent with a relatively small average particle size is suitable, while an antiblocking agent with a relatively large average particle size tends to be unsuitable. On the other hand, when the surface layer is thick, an antiblocking agent with a relatively large average particle size is suitable, while an antiblocking agent with a relatively small average particle size tends to be unsuitable. Specifically, an antiblocking agent with an average particle size suitable for the surface layer thickness is appropriately selected from the range of 1 to 15 μm, preferably 1 to 13 μm. If the average particle size of the antiblocking agent used is too small, the antiblocking performance may be insufficient, and if the average particle size is too large, shedding and deterioration of transparency are more likely to occur.

[0066] The pore volume of the antiblocking agent added to the first surface layer 20, determined by nitrogen adsorption, should preferably be 0.5 to 1.3 ml / g, and the average particle size, measured by laser diffraction, should preferably be 2.5 to 4.5 μm. If the average particle size of the antiblocking agent added to the first surface layer 20 is too large, the surface of the first surface layer 20 tends to become too rough, which may reduce the aesthetic appeal of the vapor-deposited film. If the average particle size is too small, the surface roughness of the first surface layer 20 tends to be insufficient, which may make the first surface layer 20 more susceptible to damage. Furthermore, if the pore volume of the antiblocking agent added to the first surface layer 20 is too small, that is, if the antiblocking agent is too hard, the vapor-deposited layer tends to crack more easily, which may reduce its barrier properties against oxygen and water vapor. On the other hand, if the pore volume of the antiblocking agent added to the first surface layer 20 is too large, that is, if the antiblocking agent is too soft, the dispersibility of the antiblocking agent tends to decrease, which may reduce the aesthetic appeal of the polypropylene film 10. By setting the pore volume of the antiblocking agent added to the first surface layer 20 to 0.5 to 1.3 ml / g, determined by nitrogen adsorption, and the average particle size measured by laser diffraction to 2.5 to 4.5 μm, the scratch resistance of the first surface layer is improved, and the film can be given excellent permeability. Furthermore, when used as a vapor-deposited film, scratching of the vapor-deposited layer is reduced, suppressing the deterioration of aesthetic appeal due to friction between films. In addition, cracking of the vapor-deposited layer can be reduced, suppressing the deterioration of barrier properties against oxygen and water vapor.

[0067] In the polypropylene film 10 of the present invention, scratch haze was used to evaluate scratch resistance. Scratch haze is an index that indicates the scratch resistance (scratch resistance) of the film surface when films are rubbed together, and is a value obtained from the difference between the haze of the film after rubbing and the haze of the film before rubbing. Haze is an index that represents the transparency of the film, measured in accordance with JIS K 7136 (2000), and a lower value indicates better transparency.

[0068] A high scratch haze value indicates that the film surface is more scratched and its transparency is impaired by rubbing, while a low value indicates that the film surface is less scratched and its transparency is not impaired. When the polypropylene film 10 is used as a vapor-deposited film, a low scratch haze is preferable. In the polypropylene film 10 of the present invention, the scratch haze is preferably 10% or less, more preferably 6.5% or less. If the scratch haze is too high, the film's scratch resistance is insufficient, and when used as a vapor-deposited film, the appearance may be poor, such as the film appearing cloudy. If the scratch haze is 10% or less, it can be said that scratches on the first surface layer 20 (vapor-deposited surface 21) caused by rubbing are suppressed, and thus the deterioration of the film's design due to friction between films during transportation and processing can be suppressed.

[0069] Furthermore, in the polypropylene film 10, it is preferable that the glossiness of the first surface layer 20 is 110% or higher. Glossiness is an index that indicates the sheen, glare, and degree of specular reflection of light on the film surface, and is measured in accordance with JIS Z 8741 (1997). As mentioned above, in order to give the polypropylene film good scratch resistance, it is preferable that the arithmetic mean roughness (SRa1) of the first surface layer be large. However, when it comes to a vapor-deposited film, good glossiness is considered desirable for its aesthetic appeal, and it is necessary to suppress the arithmetic mean roughness (SRa1) of the first surface layer. Therefore, by making a film that has good glossiness while possessing a certain level of scratch resistance, it is possible to obtain a polypropylene film that is a vapor-deposited film with an even more luxurious appearance.

[0070] In the polypropylene film 10, it is preferable to apply a surface treatment to the first surface layer 20, which is on the vapor deposition side 21, in order to broaden the range of applications. Examples of surface treatments include atmospheric pressure plasma treatment, flame treatment, and corona discharge treatment. By surface treating the vapor deposition side 21, the adhesion between the polypropylene film and the vapor deposition can be improved.

[0071] Figure 2 shows a vapor-deposited polypropylene film 50 according to one embodiment of the present invention. This vapor-deposited polypropylene film 50 is an example in which a polypropylene film 10 containing an antiblocking agent in a first surface layer 20 and a second surface layer 30 is used as the base film for the vapor-deposited film, and a vapor-deposited layer 60 is formed on the first surface layer 20 of the polypropylene film 10.

[0072] The vapor-deposited layer 60 is formed by vapor deposition directly onto the vapor-deposited surface 21 of the first surface layer 20, or via an anchor coat layer. By vapor deposition on the vapor-deposited surface 21, the polypropylene film 10 can be given barrier properties against water vapor, oxygen, etc. Known methods such as vacuum deposition, sputtering, and ion plating can be used as vapor deposition methods.

[0073] As the material for vapor deposition, an appropriate material such as a metal vapor deposition layer or an inorganic oxide layer can be selected. The metal vapor deposition layer is a thin film layer made of known metals such as aluminum, gold, silver, copper, and chromium, and may also be a thin film layer of oxides, sulfides, or nitrides of these metals. Furthermore, the metal vapor deposition layer may be a single layer or multiple layers of two or more different or identical types of metals. The inorganic oxide layer consists of known inorganic oxides such as aluminum oxide, silicon oxide, magnesium fluoride, and magnesium oxide, and is a thin film layer using one or more types of inorganic oxides.

[0074] In vapor-deposited polypropylene films, there is a concern that, similar to polypropylene films, the film surface may be scratched due to friction between the films caused by fine irregularities on the film surface during winding or other processes after vapor deposition on the base film. Therefore, in the vapor-deposited polypropylene film 50 of the present invention, assuming that the vapor-deposited layer 60 is the surface layer that is scratched and the second surface layer 30 is the surface layer that causes the scratching, an index for the scratch resistance of the vapor-deposited polypropylene film 50 was derived by focusing on the arithmetic mean height of the vapor-deposited layer and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer 30.

[0075] In other words, the vapor-deposited polypropylene film of the present invention satisfies the scratch resistance value shown in the following formula (iii), where Sa1 (μm) is the arithmetic mean height of the vapor-deposited layer 60 and SPc2 (number of peaks with a peak height of 1 μm or more) in the three-dimensional surface roughness of the second surface layer 30.

[0076]

[0077] The arithmetic mean height (Sa1) of the vapor-deposited layer 60 is a height parameter and represents the average of the absolute values ​​of the height differences from the average plane at each measurement point. Since the vapor-deposited layer 60 is the surface layer that is scratched, the arithmetic mean height Sa1 (μm) of the vapor-deposited layer 60 serves as an indicator of the scratch resistance of the surface of the vapor-deposited layer 60, and it can be said that the larger the arithmetic mean height Sa1, the better the scratch resistance of the polypropylene film tends to be.

[0078] As described above, the number of peaks SPc2 (number of peaks) with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer 30 is an indicator of how easily the second surface layer 30 can scratch the surface of the opposing vapor-deposited layer 60.

[0079] The left-hand side of equation (iii) represents the scratch resistance of the vapor-deposited polypropylene film, expressed using these two indicators. As shown in the examples described later, when the value of scratch resistance expressed in equation (iii) is 130 or less, scratches on the vapor-deposited layer 60 by the second surface layer 30 of the vapor-deposited polypropylene film 50 become less likely.

[0080] In equation (iii), the arithmetic mean height Sa1, which is an indicator of the scratch resistance of the surface of the vapor-deposited layer 60, is the denominator of the left side of equation (iii). This indicates that the smaller the arithmetic mean height Sa1, the greater the scratch resistance value, and the smoother the vapor-deposited layer 60 becomes, making it more susceptible to scratching by the second surface layer 30. Therefore, the preferred arithmetic mean height Sa1 of the vapor-deposited layer 60 is 0.2 to 1.5 μm, more preferably 0.3 to 0.8 μm. If the arithmetic mean height Sa1 of the vapor-deposited layer 60 is too small, the surface roughness of the vapor-deposited layer 60 may be insufficient, making it more susceptible to scratching. If the arithmetic mean height Sa1 is too large, the vapor-deposited layer 60 may become too rough, potentially reducing its function as a vapor-deposited film.

[0081] The numerator on the left side of equation (iii) is the same as that of equation (i) shown above. As the surface layer on which the vapor-deposited layer 60 is damaged, the number of peaks SPc2 with a peak height of 1 μm or more, which is an indicator of ease of scratching, is used as an indicator.

[0082] Furthermore, an index of the scratch resistance of the vapor-deposited layer 60 can also be derived from the pore volume (V2) of the antiblocking agent added to the second surface layer 30. When the arithmetic mean height of the vapor-deposited layer 60 is Sa1 (μm), the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer 30 is SPc2 (number), and the pore volume of the antiblocking agent contained in the second surface layer, determined by nitrogen adsorption method, is V2 (ml / g), satisfying the scratch resistance value shown in the following formula (iv) can further suppress scratching of the vapor-deposited layer and prevent deterioration of the appearance of the vapor-deposited polypropylene film.

[0083]

[0084] The denominator on the left side of equation (vi) is the arithmetic mean height Sa1, which is an indicator of the scratch resistance of the surface of the vapor-deposited layer 60, and is the same as in equation (iii). The numerator on the left side of equation (iv) is the same as in equation (ii) above. As the surface layer that scratches the vapor-deposited layer 60, the number of peaks SPc2 with a peak height of 1 μm or more, which is an indicator of scratch susceptibility, is used as an indicator. From the examples described later, by satisfying the scratch resistance value expressed in equation (iv) of 165 or less, scratches on the vapor-deposited layer 60 by the second surface layer 30 of the vapor-deposited polypropylene film 50 become less likely to occur.

[0085] The pore volume of the antiblocking agent added to the first surface layer 20, determined by nitrogen adsorption, should preferably be 0.5 to 1.3 ml / g, and the average particle size, measured by laser diffraction, should preferably be 2.5 to 4.5 μm. If the average particle size of the antiblocking agent added to the first surface layer 20 is too large, the surface of the first surface layer 20 tends to become too rough, resulting in an overly rough surface on the vapor-deposited layer 60, which may reduce the aesthetic appeal of the vapor-deposited film. If the average particle size is too small, the surface roughness of the first surface layer 20 tends to be insufficient, resulting in an insufficient surface roughness on the vapor-deposited layer 60, which may make the vapor-deposited layer 60 more susceptible to damage. Furthermore, damage to the vapor-deposited layer can be reduced, suppressing the deterioration of aesthetic appeal due to friction between films. In addition, if the pore volume of the antiblocking agent added to the first surface layer 20 is too small, that is, if the antiblocking agent is too hard, the vapor-deposited layer 60 tends to crack more easily, which may reduce its barrier properties against oxygen and water vapor. On the other hand, if the pore volume of the antiblocking agent added to the first surface layer 20 is too large, that is, if the antiblocking agent is too soft, the dispersibility of the antiblocking agent tends to decrease, which may reduce the aesthetic appeal of the vapor-deposited polypropylene film 50. By setting the pore volume of the antiblocking agent added to the first surface layer 20 to 0.5 to 1.3 ml / g, determined by nitrogen adsorption, and the average particle size measured by laser diffraction to 2.5 to 4.5 μm, the scratch resistance of the first surface layer is improved, and the film can be given excellent permeability. Furthermore, when used as a vapor-deposited film, scratching of the vapor-deposited layer is reduced, suppressing the deterioration of aesthetic appeal due to friction between films. In addition, cracking of the vapor-deposited layer can be reduced, suppressing the deterioration of barrier properties against oxygen and water vapor.

[0086] In the vapor-deposited polypropylene film 50 of the present invention, scratch total light transmittance was used to evaluate scratch resistance. Scratch total light transmittance is an index that indicates the scratch resistance (scratch resistance) of the film surface when films are rubbed together, and is a value obtained from the difference between the maximum total light transmittance of the film after rubbing and the maximum total light transmittance of the film before rubbing. A lower scratch total light transmittance value indicates better light transmittance after rubbing, and it is preferably 16% or less. If the scratch total light transmittance is too high, the scratch resistance of the vapor-deposited polypropylene film may be insufficient, and the appearance may be inferior. If the scratch total light transmittance is 16% or less, it can be said that scratches on the vapor-deposited layer 60 caused by rubbing are suppressed, and thus the deterioration of the film's design due to rubbing between films during transportation and processing can be suppressed.

[0087] Furthermore, in the vapor-deposited polypropylene film 50, it is preferable that the gloss of the vapor-deposited layer 60, measured in accordance with JIS Z 8741 (1997), is 720% or higher. By making the vapor-deposited polypropylene film 50 a film that has good gloss while possessing a certain level of scratch resistance, it is possible to make a vapor-deposited polypropylene film with an even more luxurious appearance.

[0088] In addition, the base film for vapor deposition on which the vapor-deposited polypropylene film 50 is formed is not particularly limited, as long as it satisfies the scratch resistance values ​​shown in formulas (iii) to (iv). It is preferable to use the polypropylene film 10 of the present invention shown in the embodiment as the base film for vapor deposition. Since the polypropylene film 10 has a first surface layer 20 having a vapor-deposited surface 21 that is resistant to scratching, deterioration of appearance when vapor deposition processing is performed to form the vapor-deposited polypropylene film 50 can be suppressed.

[0089] In the vapor-deposited polypropylene film 50, as shown in Figure 3, a laminated film 100 may be formed by laminating at least one layer of a laminating base film 110 on the vapor-deposited layer 60 side. The laminated film 100 shown in the figure consists of a two-layer structure of polypropylene film 10, with a first surface layer 20 and a second surface layer 30. As described above, the polypropylene film 10 may have a structure of three or more layers, including an intermediate layer, etc.

[0090] The base film 110 for lamination is preferably a film made of a polyester film, a polyamide film, or a polypropylene film. Examples of polyester films include biaxially oriented polyethylene terephthalate film, examples of polyamide films include biaxially oriented polyamide film, and examples of polypropylene films include biaxially oriented polypropylene film and uniaxially oriented polypropylene film. These films are suitable for use as base films for the laminated film 100 because they have excellent strength and other properties. Such a laminated film 100 can be made into a laminate film that suppresses the deterioration of the vapor-deposited layer 60, and can therefore be suitable for use as various packaging bags and the like.

[0091] [Preparation of Polypropylene Films] In preparing the polypropylene films for prototypes 1 to 33, each material described later was kneaded and melted according to a predetermined mixing ratio (weight %), co-extruded using the T-die method, cooled with a cooling roll, and then subjected to corona discharge treatment on the first surface layer to produce an unstretched polypropylene film. The films for prototypes 1, 4, 5, and 30 are two-layer films consisting of a first surface layer (deposited surface) and a second surface layer (heat-sealed surface), while the films for prototypes 2, 3, 6 to 29, and 31 to 33 are three-layer films consisting of a first surface layer (deposited surface), an intermediate layer, and a second surface layer (heat-sealed surface). The thickness of each film for prototypes 1 to 33 was 25 μm. The materials used in each layer of prototypes 1 to 33 are shown in Tables 1 to 5 below.

[0092] [Materials Used] The following resins and antiblocking agents were used as materials for each layer. For each resin material, the melt flow rate (MFR) was measured in accordance with JIS K 7210 (2014), with the polypropylene resin measured at a test temperature of 230°C and the polyethylene resin at a test temperature of 190°C.

[0093] Furthermore, the pore volume of the antiblocking agent was determined by the nitrogen adsorption method as follows. As a pretreatment, the antiblocking agent was vacuum degassed and dried at 200°C for 2 hours, and the amount of nitrogen adsorbed was measured and converted to the volume of liquid nitrogen for calculation. The amount of nitrogen adsorbed was measured using an automatic specific surface area / pore distribution analyzer ("BELSORP-miniII", manufactured by Microtrac-Bell Co., Ltd.). From the obtained amount of nitrogen adsorbed, the amount of nitrogen adsorbed at a relative pressure of 0.990 (V) was calculated using the following formula (v) to obtain the volume of liquid nitrogen (V). ｐ It was calculated by converting to ). Note that in equation (v), M ｇ The molecular weight of the adsorbate (nitrogen: 28.020), ρ ｇ (g / cm ３ ) is the density of the adsorbate (nitrogen: 0.808).

[0094]

[0095] [Resin Material] ・PP1: Propylene-ethylene-butene random copolymer, melting point 139°C, MFR (230°C, 2.16 kg): 7 g / 10 min ・PP2: Propylene-ethylene-butene random copolymer, melting point 142°C, MFR (230°C, 2.16 kg): 7 g / 10 min ・PP3: Propylene-ethylene random copolymer, melting point 135°C, MFR (230°C, 2.16 kg): 7 g / 10 min ・PP4: Propylene-ethylene random copolymer, melting point 125°C, MFR (230°C, 2.16 kg): 7 g / 10 min ・PP5: Propylene-ethylene random copolymer, melting point 147°C, MFR (230°C, 2.16 kg): 7 g / 10 min ・PP6: Propylene homopolymer, melting point 164°C, MFR (230°C, 2.16 kg): 7.5 g / 10 min ・PP7: Propylene homopolymer, melting point 166°C, MFR (230°C, 2.16 kg): 7.5 g / 10 min ・PE1: High density polyethylene, melting point 134°C, MFR (190°C, 2.16 kg): 13 g / 10 min

[0096] [Antiblocking Agent (AB Agent)] ・AB1: Amorphous silica, average particle size 3.9 μm, pore volume 0.80 ml / g ・AB2: Amorphous silica, average particle size 4.1 μm, pore volume 1.25 ml / g ・AB3: Shaped silica, average particle size 2.7 μm, pore volume 0.57 ml / g ・AB4: Amorphous silica, average particle size 3.7 μm, pore volume 1.00 ml / g

[0097] [Prototype Example 1] Prototype Example 1 is a polypropylene film that uses 98.37 wt% of PP1, 1.50 wt% of PE1, 0.06 wt% of AB1, and 0.07 wt% of AB3 in the first surface layer, 97.80 wt% of PP4, 2.00 wt% of PE1, 0.15 wt% of AB2, and 0.05 wt% of AB3 in the second surface layer, and has a layer ratio of first surface layer:second surface layer = 4:

[0098] [Prototype Example 2] Prototype Example 2 is a polypropylene film that has the same formulation of materials used in the first and second surface layers as Prototype Example 1, uses 30 wt% of PP1, 30 wt% of PP5, and 40 wt% of PP7 as the intermediate layer, and has a layer ratio of first surface layer:intermediate layer:second surface layer = 1:3:1

[0099] [Prototype Example 3] Prototype Example 3 is a polypropylene film in which the composition of the materials used for the first surface layer, intermediate layer, and second surface layer is the same as that of Prototype Example 2, and the layer ratio is first surface layer:intermediate layer:second surface layer = 1:6:1.

[0100] [Prototype Example 4] Prototype Example 4 is a polypropylene film in which the first surface layer uses 98.45% by weight of PP2, 1.50% by weight of PE1, and 0.05% by weight of AB1, and the second surface layer uses 98.40% by weight of PP2, 1.50% by weight of PE1, and 0.10% by weight of AB1, with a layer ratio of first surface layer:second surface layer = 5:1.

[0101] [Prototype Example 5] Prototype Example 5 is a polypropylene film with the same composition as Prototype Example 4, except that the PP2 in the first surface layer was changed to 98.40% by weight and AB1 to 0.10% by weight compared to the material composition used in Prototype Example 4.

[0102] [Prototype Example 6] Prototype Example 6 is a polypropylene film in which the composition of the materials used for the first and second surface layers is the same as that of Prototype Example 5, and 60% by weight of PP2 and 40% by weight of PP7 are used as the intermediate layer, with a layer ratio of first surface layer:intermediate layer:second surface layer = 1:4:1.

[0103] [Prototype Example 7] Prototype Example 7 is a polypropylene film with the same composition as Prototype Example 6, except that the PP2 in the first surface layer was changed to 98.20% by weight and AB1 to 0.30% by weight compared to the material composition of Prototype Example 6.

[0104] [Prototype Example 8] Prototype Example 8 is a polypropylene film with the same composition as Prototype Example 6, except that the antiblocking agent in the second surface layer was changed from AB1 to AB2 compared to the material composition used in Prototype Example 6.

[0105] [Prototype Example 9] Prototype Example 9 is a polypropylene film with the same composition as Prototype Example 7, except that the PP2 in the second surface layer was changed to 98.30% by weight and AB1 to 0.20% by weight compared to the material composition of Prototype Example 7.

[0106] [Prototype Example 10] Prototype Example 10 is a polypropylene film with the same composition as Prototype Example 6, except that the antiblocking agent in the second surface layer is changed from AB1 to AB4 compared to the material composition used in Prototype Example 6.

[0107] [Prototype Example 11] Prototype Example 11 is a polypropylene film with the same composition as Prototype Example 10, except that the PP2 in the first surface layer was changed to 98.20% by weight and AB1 to 0.30% by weight compared to the material composition of Prototype Example 10.

[0108] [Prototype Example 12] Prototype Example 12 is a polypropylene film with the same composition as Prototype Example 10, except that the antiblocking agent of the first surface layer is changed from AB1 to AB2 compared to the material composition of Prototype Example 10.

[0109] [Prototype Example 13] Prototype Example 13 is a polypropylene film with the same composition as Prototype Example 6, except that the PP2 in the first surface layer was changed to 97.90% by weight and AB1 to 0.60% by weight compared to the material composition of Prototype Example 6.

[0110] [Prototype Example 14] Prototype Example 14 is a polypropylene film with the same composition as Prototype Example 13, except that the PP2 in the second surface layer was changed to 98.30% by weight and AB1 to 0.20% by weight compared to the material composition of Prototype Example 13.

[0111] [Prototype Example 15] Prototype Example 15 is a polypropylene film with the same composition as Prototype Example 13, except that the PP2 in the second surface layer was changed to 98.20% by weight and AB1 to 0.30% by weight compared to the material composition of Prototype Example 13.

[0112] [Prototype Example 16] Prototype Example 16 is a polypropylene film with the same composition as Prototype Example 6, except that the antiblocking agent of the first surface layer was changed from AB1 to AB2 compared to the material composition of Prototype Example 6.

[0113] [Prototype Example 17] Prototype Example 17 is a polypropylene film with the same composition as Prototype Example 10, except that the antiblocking agent of the first surface layer is changed from AB1 to AB4 compared to the material composition of Prototype Example 10.

[0114] [Prototype Example 18] Prototype Example 18 is a polypropylene film with the same composition as Prototype Example 17, except that the antiblocking agent of the second surface layer was changed from AB4 to AB1 compared to the material composition of Prototype Example 17.

[0115] [Prototype Example 19] Prototype Example 19 is a polypropylene film with the same composition as Prototype Example 18, except that the PP2 in the first surface layer was changed to 98.35% by weight and AB4 to 0.15% by weight compared to the material composition of Prototype Example 18.

[0116] [Prototype Example 20] Prototype Example 20 is a polypropylene film with the same composition as Prototype Example 18, except that the PP2 in the first surface layer was changed to 98.20% by weight and AB4 to 0.30% by weight compared to the material composition of Prototype Example 18.

[0117] [Prototype Example 21] Prototype Example 21 is a polypropylene film with the same composition as Prototype Example 6, except that the polypropylene resin for the first surface layer is changed to 73.37% by weight of PP2 and 25.00% by weight of PP6, and the antiblocking agents are changed to 0.10% by weight of AB1 and 0.03% by weight of AB3.

[0118] [Prototype Example 22] Prototype Example 22 is a polypropylene film with the same composition as Prototype Example 21, except that the composition of the materials used in Prototype Example 21 is changed to 23.32% by weight of PP2 in the first surface layer, 75.00% by weight of PP6, and 0.08% by weight of AB3.

[0119] [Prototype Example 23] Prototype Example 23 is a polypropylene film with the same composition as Prototype Example 21, except that the PP6 in the first surface layer was changed to 98.30% by weight (PP2 to 0.00% by weight) and AB3 to 0.10% by weight compared to the material composition of Prototype Example 21.

[0120] [Prototype Example 24] Prototype Example 24 is a polypropylene film with the same composition as Prototype Example 6, except that the polypropylene resin of the first surface layer is changed to 68.40% by weight of PP2 and 30.00% by weight of PP3 compared to the material composition of Prototype Example 6.

[0121] [Prototype Example 25] Prototype Example 25 is a polypropylene film with the same composition as Prototype Example 24, except that the PP2 in the first surface layer is changed to 28.40% by weight and the PP3 to 70.00% by weight compared to the material composition of Prototype Example 24.

[0122] [Prototype Example 26] Prototype Example 26 is a polypropylene film with the same composition as Prototype Example 24, except that the amount of PP3 in the first surface layer was changed to 98.40% by weight (PP2 to 0.00% by weight) compared to the material composition of Prototype Example 24.

[0123] [Prototype Example 27] Prototype Example 27 is a polypropylene film with the same composition as Prototype Example 6, except that the PP2 in the second surface layer was changed to 98.35% by weight and AB1 to 0.15% by weight compared to the material composition of Prototype Example 6.

[0124] [Prototype Example 28] Prototype Example 28 is a polypropylene film with the same composition as Prototype Example 7, except that the PP2 in the second surface layer was changed to 98.20% by weight and AB1 to 0.30% by weight compared to the material composition of Prototype Example 7.

[0125] [Prototype Example 29] Prototype Example 29 is a polypropylene film with the same composition as Prototype Example 16, except that the PP2 in the second surface layer was changed to 98.35% by weight and AB1 to 0.15% by weight compared to the material composition of Prototype Example 16.

[0126] [Prototype Example 30] Prototype Example 30 is a polypropylene film with the same composition as Prototype Example 4, except that the PP2 in the second surface layer was changed to 98.35% by weight and AB1 to 0.15% by weight compared to the material composition of Prototype Example 4.

[0127] [Prototype Example 31] Prototype Example 31 is a polypropylene film with the same composition as Prototype Example 18, except that the PP2 in the second surface layer was changed to 98.30% by weight and AB1 to 0.20% by weight compared to the material composition of Prototype Example 18.

[0128] [Prototype Example 32] Prototype Example 32 is a polypropylene film with the same composition as Prototype Example 31, except that the antiblocking agent of the first surface layer is changed from AB4 to AB2 compared to the material composition of Prototype Example 31.

[0129] [Prototype Example 33] Prototype Example 33 is a polypropylene film with the same composition as Prototype Example 31, except that the antiblocking agent of the first surface layer is changed from AB4 to AB1 compared to the material composition of Prototype Example 31.

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] For the evaluation of the polypropylene films of prototype examples 1 to 33, the arithmetic mean roughness SRa1 (μm) of the three-dimensional surface roughness of the first surface layer, the number of peaks with a peak height of 1 μm or more SPc2 (pitch) of the three-dimensional surface roughness of the second surface layer, the pore volume V2 (ml / g) obtained by nitrogen adsorption method of the antiblocking agent contained in the second surface layer, scratch haze (%), and gloss (%) were measured. Furthermore, scratch resistance 1 (formula (i)) was calculated based on the measurement results of the arithmetic mean roughness of the first surface layer and the number of peaks with a peak height of 1 μm or more of the second surface layer, and scratch resistance 2 (formula (ii)) was calculated using the pore volume V2 (ml / g) obtained by nitrogen adsorption method of the antiblocking agent contained in the second surface layer. Note that when the second surface layer contains multiple antiblocking agents, the pore volume of the antiblocking agent was determined based on the content ratio of each antiblocking agent to the total antiblocking agent content. The results of each measurement and their evaluation are shown in Tables 6 to 10 below.

[0136] [Measurement of Three-Dimensional Surface Roughness] The arithmetic mean roughness (SRa1) of the three-dimensional surface roughness of the first surface layer and the number of peaks with a peak height of 1 μm or more (SPc2) of the three-dimensional surface roughness of the second surface layer were measured using the three-dimensional surface roughness measuring instrument "SE3500K (manufactured by Kosaka Research Institute Co., Ltd.)" and the analysis device "TDA-22 (manufactured by Kosaka Research Institute Co., Ltd.)" under the following measurement conditions. The measurement standards for each type of roughness (SRa1, SPc2) were referred to in JIS B 0601. Measurement direction: Vertical (MD) direction X measurement length: 2 mm X feed pitch: 4 μm X feed speed: 0.2 mm / s Y measurement length: 0.25 mm Y feed pitch: 5 μm Z magnification: 20000 Polarity: Positive Leveling: Least squares method Low-frequency cutoff: 0.250 mm High-frequency cutoff: 0.000 mm Phase characteristics: Gaussian Y number of lines: 51 Detector: PU-DJ2S Stylus tip radius: 2 μm Stylus apex angle: 60° Measurement force: 0.7 mN or less Particle analysis: Particle analysis (multiple levels) Output content setting: Particle numerical output Hysteresis width: 0 μm Slice level equal spacing: 0.1 μm

[0137] [Calculation of Scratch Resistance] The value of scratch resistance 1 was calculated based on formula (i) using the arithmetic mean roughness (SRa1) of the three-dimensional surface roughness of the first surface layer and the number of peaks with a peak height of 1 μm or more (SPc2) of the three-dimensional surface roughness of the second surface layer, which were obtained by measuring the three-dimensional surface roughness. Furthermore, the value of scratch resistance 2 was calculated based on formula (ii) using the arithmetic mean roughness (SRa1) of the three-dimensional surface roughness of the first surface layer, the number of peaks with a peak height of 1 μm or more (SPc2) of the three-dimensional surface roughness of the second surface layer, and the pore volume (V2) of the antiblocking agent contained in the second surface layer.

[0138] [Measurement of Scratch Haze] The haze (%) of the film before rubbing was measured using a haze meter "NDH-8000 (manufactured by Nippon Denshoku Industries Co., Ltd.)" in accordance with JIS K 7136 (2000). Next, three test pieces were prepared for each prototype example, and using a friction measuring instrument "FRICTION TESTER TR (manufactured by Toyo Seiki Seisakusho Co., Ltd.)", the second surface layer of the test piece was placed on the test table side and the first surface layer on the sliding piece side, referring to JIS K 7125 (1999). The sliding piece was slid once to rub the first and second surface layers together. The conditions were as follows: Material of the bottom surface of the sliding piece: Rubber Test speed: 100 mm / min Distance traveled: 80 mm Total mass of the sliding piece: 2.17 kg

[0139] Next, the haze of one side of the film that was rubbed was measured at six locations, and the maximum value (maximum haze) was read. Here, the haze of the film measured before rubbing was taken as H1 (%), and the average of the maximum haze of the three test pieces after rubbing was taken as H2 (%), and the scratch haze (ΔH = H2 - H1) was calculated. The obtained scratch haze value was evaluated as "Excellent (◎)" if it was 6.5% or less, "Good (○)" if it was 10% or less, and "Poor (×)" if it was greater than 10%.

[0140] [Gloss Measurement] Gloss (%) was measured in accordance with JIS Z 8741 using a gloss meter "VG-7000 (manufactured by Nippon Denshoku Industries Co., Ltd.)" at a measurement angle of 60° and in the vertical (MD) direction of the film. A gloss measurement result of 110% or higher was evaluated as "Excellent (◎)", a result of 100% or higher but less than 110% was evaluated as "Acceptable (○)", and a result of less than 100% was evaluated as "Unacceptable (×)".

[0141]

[0142]

[0143]

[0144]

[0145]

[0146] [Results and Discussion (1)] As can be seen from Tables 6 to 10, among the polypropylene films of prototypes 1 to 33, the scratch haze of films 1 to 26 was good, but the scratch haze of films 27 to 33 was poor.

[0147] In prototypes 1 to 26, which showed good scratch haze, the arithmetic mean roughness (SRa1) of the first surface layer was 0.027 to 0.070 μm, the number of peaks (SPc2) of 1 μm or larger on the second surface layer was 8 to 117, and the pore volume (V2) of the antiblocking agent (hereinafter referred to as AB agent) on the second surface layer was 0.80 to 1.25 ml / g. On the other hand, in prototypes 27 to 33, which did not yield good scratch haze, the arithmetic mean roughness (SRa1) of the first surface layer was 0.027 to 0.046 μm, the number of peaks (SPc2) of 1 μm or larger on the second surface layer was 64 to 117, and the pore volume (V2) of the AB agent on the second surface layer was 0.80 ml / g. All of these values ​​fall within the numerical ranges measured for each physical property in prototypes 1 to 26. Therefore, it is considered difficult to individually identify preferred conditions for the physical properties of the film.

[0148] Therefore, when examining the value of scratch resistance 1 (SPc2 / SRa1), which is expressed based on the arithmetic mean roughness (SRa1) of the first surface layer and the number of peaks of 1 μm or more (SPc2) of the second surface layer, the values ​​of scratch resistance 1 for prototypes 1 to 26 ranged from 186 to 1671. In contrast, for prototypes 27 to 33, the values ​​of scratch resistance 1 ranged from 2133 to 3407, all of which were higher than those for prototypes 1 to 26. Thus, it can be said that the physical property of the film expressed as (SPc2 / SRa1) is an effective indicator of the scratch resistance of the film. Furthermore, from the results of prototypes 1 to 26 and prototypes 27 to 33, it is considered that the desirable relationship for scratch resistance is (SPc2 / SRa1) ≤ 2100.

[0149] Next, we examined the scratch resistance value 2{(SPc2 / V2) / SRa1}, which is expressed based on the arithmetic mean roughness (SRa1) of the first surface layer, the number of peaks of 1 μm or more (SPc2) of the second surface layer, and the pore volume (V2) of the AB agent. In prototypes 1 to 26, the {(SPc2 / V2) / SRa1} value ranged from 172 to 2527. In contrast, in prototypes 27 to 33, the {(SPc2 / V2) / SRa1} value ranged from 2667 to 4259, all of which were higher than those of prototypes 1 to 26. Thus, it can be said that the film property expressed as {(SPc2 / V2) / SRa1} is an effective indicator of the film's scratch resistance. Furthermore, from the results of prototypes 1-26 and 27-33, it is considered that the favorable relationship for scratch resistance is {(SPc2 / V2) / SRa1} ≤ 2600.

[0150] Furthermore, among the 26 prototypes with good scratch haze, prototypes 13 to 15 had slightly insufficient gloss. Comparing prototypes 13 to 15 with the other prototypes, the arithmetic mean roughness (SRa1) of the first surface layer was higher in these prototypes. This suggests that if the arithmetic mean roughness (SRa1) of the first surface layer is too high, it may worsen the gloss. From the viewpoint of obtaining good gloss, it is considered that a preferable arithmetic mean roughness (SRa1) of the first surface layer is around 0.060 or less.

[0151] As described above, the polypropylene film of the present invention has been shown to exhibit good scratch haze when the value of scratch resistance 1, represented by (SPc2 / SRa1), is 2100 or less. Furthermore, it has been shown that the scratch haze is also good when the value of scratch resistance 2, represented by {(SPc2 / V2) / SRa1}, is 2600 or less. In particular, as can be seen from each prototype example, it is difficult to identify the conditions for obtaining good scratch resistance from the individual physical properties of the film, so it can be said that the significance of using the relationship between specific physical properties of the film as an indicator of scratch resistance performance has also been demonstrated.

[0152] [Fabrication of Vapor-Deposited Polypropylene Films] For the polypropylene films of prototype examples 1, 2, 4 to 33, vapor-deposited polypropylene films were fabricated by vapor deposition on the first surface layer. In the vapor deposition process, a resistance heating vacuum deposition apparatus (manufactured by Machine Technology Co., Ltd.) was used to deposit aluminum onto each polypropylene film so that the aluminum deposition film thickness was 350 Å and the vacuum level was 9 E-03 Pa. For the evaluation of the obtained aluminum vapor-deposited polypropylene films of prototype examples 1, 2, 4 to 33, the arithmetic mean height Sa1 (μm) of the vapor-deposited layer, the total light transmittance against scratches (%), and the gloss (%) were measured. Furthermore, scratch resistance 3 and 4 were calculated based on the measurement results of the pore volume of the antiblocking agent in the second surface layer and the number of peaks with a peak height of 1 μm or more in the second surface layer, as well as the measurement results of the arithmetic mean height of the vapor-deposited layer. The results of each measurement and their evaluation are shown in Tables 11 to 15 below.

[0153] [Measurement of Arithmetic Mean Height of Vapor Deposition Layer] The arithmetic mean height (Sa1) of the vapor deposition layer was measured using a laser microscope "VK-X 3000 (manufactured by Keyence Corporation)" under the following measurement conditions: <Measurement> Shape measurement: Surface measurement Scan mode: Laser confocal <Analysis> Surface shape correction: Waviness removal Measurement: Surface roughness measurement Measurement area: Entire area Filter: Gaussian S-filter: None F-operation: None L-filter: None End effect correction: ON

[0154] [Calculation of scratch resistance of vapor-deposited polypropylene film] Scratch resistance 3 was calculated based on formula (iii) using the arithmetic mean height (Sa1) of the vapor-deposited layer and the number of peaks with a peak height of 1 μm or more (SPc2) in the three-dimensional surface roughness of the second surface layer, which were determined by laser scope. Furthermore, the value of scratch resistance 4 was calculated based on formula (iv) using the arithmetic mean height (Sa1) of the vapor-deposited layer, the number of peaks with a peak height of 1 μm or more (SPc2) in the three-dimensional surface roughness of the second surface layer, and the pore volume (V2) of the antiblocking agent contained in the second surface layer.

[0155] [Measurement of Total Light Transmittance by Scratch] The total light transmittance (%) of the vapor-deposited polypropylene film before rubbing was measured using a haze meter "NDH-8000 (manufactured by Nippon Denshoku Industries Co., Ltd.)". Next, three test pieces were prepared for each prototype example, and using a friction measuring instrument "FRICTION TESTER TR (manufactured by Toyo Seiki Seisakusho Co., Ltd.)", the second surface layer of the test piece was placed on the test table side and the vapor-deposited layer on the sliding piece side, referring to JIS K 7125 (1999). The sliding piece was slid once to rub the vapor-deposited layer and the second surface layer together. The conditions were as follows: Material of the bottom surface of the sliding piece: Rubber Test speed: 100 mm / min Distance traveled: 80 mm Total mass of the sliding piece: 2.17 kg

[0156] Next, the total light transmittance of the vapor-deposited polypropylene film on one side of the rubbed surface was measured at six locations, and the maximum value (maximum total light transmittance) was read. Here, the total light transmittance of the vapor-deposited polypropylene film measured before rubbing was defined as T1 (%), and the average of the maximum total light transmittances of the three test pieces after rubbing was defined as T2 (%), and the scratch total light transmittance (ΔT = T2 - T1) was calculated. The obtained scratch total light transmittance value was evaluated as "Excellent (◎)" if it was 16% or less, and as "Unacceptable (×)" if it was greater than 16%.

[0157] [Measurement of Glossiness of Vapor-Deposited Polypropylene Film] Glossiness (%) was measured using a gloss meter "VG-7000 (manufactured by Nippon Denshoku Industries Co., Ltd.)" at a measurement angle of 60° and in the film measurement direction: vertical (MD) direction. A glossiness measurement result of 720% or higher was evaluated as "Excellent (◎)", a result of 700% or higher but less than 720% was evaluated as "Acceptable (○)", and a result of less than 700% was evaluated as "Unacceptable (×)".

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[0159]

[0160]

[0161]

[0162]

[0163] [Results and Discussion (2)] As can be seen from Tables 11-15, among the vapor-deposited polypropylene films of prototypes 1, 2, 4-33, the scratch total light transmittance of films 1, 2, 4-8, 10-14, and 16-26 was good, but the scratch total light transmittance of films 9, 15, and 27-33 was poor.

[0164] In prototypes 1, 2, 4-8, 10-14, and 16-26, which showed good scratch total light transmittance, the arithmetic mean height (Sa1) of the first surface layer was 0.37-0.72 μm, the number of peaks (SPc2) of 1 μm or more on the second surface layer was 8-117, and the pore volume (V2) of the AB agent on the second surface layer was 0.80-1.25 ml / g. On the other hand, in prototypes 9, 15, and 27-33, which did not obtain good scratch total light transmittance, the arithmetic mean height (Sa1) of the first surface layer was 0.037-0.046 μm, the number of peaks (SPc2) of 1 μm or more on the second surface layer was 64-117, and the pore volume (V2) of the AB agent on the second surface layer was 0.80 ml / g. All of these values ​​fall within the numerical ranges measured for each of the physical properties in prototypes 1, 2, 4-8, 10-14, and 16-26.

[0165] Therefore, when examining the value of scratch resistance 3 (SPc2 / Sa1) expressed based on the arithmetic mean height (Sa1) of the vapor-deposited layer and the number of peaks of 1 μm or more (SPc2) of the second surface layer, the values ​​of scratch resistance 3 were 13 to 128 for prototype examples 1, 2, 4-8, 10-14, and 16-26. In contrast, for prototype examples 9, 15, and 27-33, the values ​​of scratch resistance 3 were 136 to 221, all of which were higher than those for prototype examples 1, 2, 4-8, 10-14, and 16-26. Thus, it can be said that the physical property of the film expressed as (SPc2 / Sa1) is an effective indicator of the scratch resistance of the film. Based on the results from prototypes 1, 2, 4-8, 10-14, 16-26 and prototypes 9, 15, 27-33, it is considered that the preferred relationship for scratch resistance is (SPc2 / Sa1) ≤ 130.

[0166] Next, we examined the scratch resistance value 4 {(SPc2 / V2) / Sa1}, which is expressed based on the arithmetic mean height (Sa1) of the vapor-deposited layer, the number of peaks of 1 μm or more in the second surface layer (SPc2), and the pore volume (V2) of the AB agent. In prototype examples 1, 2, 4-8, 10-14, and 16-26, the scratch resistance value 4 was 12-160. In contrast, in prototype examples 9, 15, and 27-33, the scratch resistance value 4 was 170-276, all of which were higher than those in prototype examples 1, 2, 4-8, 10-14, and 16-26. Thus, it can be said that the physical property of the vapor-deposited film expressed as {(SPc2 / V2) / Sa1} is an effective indicator of the scratch resistance of the film. Based on the results from prototypes 1, 2, 4-8, 10-14, 16-26 and prototypes 9, 15, 27-33, it is considered that a favorable relationship for the scratch resistance of the vapor-deposited film is {(SPc2 / V2) / Sa1} ≤ 165.

[0167] Furthermore, among prototypes 1, 2, 4-8, 10-14, and 16-26, which showed good scratch total light transmittance, prototypes 13 and 14 had slightly insufficient gloss. Comparing prototypes 13 and 14 with the other prototypes, the arithmetic mean height (Sa1) of the first surface layer was higher in these prototypes. This suggests that if the arithmetic mean height (Sa1) of the first surface layer is too high, it may worsen the gloss. Therefore, from the viewpoint of obtaining good gloss, it is considered that the preferable arithmetic mean height (Sa1) of the first surface layer is around 0.70 or less.

[0168] As described above, it has been shown that the vapor-deposited polypropylene film of the present invention achieves good scratch total light transmittance by satisfying the condition that the scratch resistance value 3, represented by (SPc2 / Sa1), is 130 or less. Furthermore, it has been shown that the scratch total light transmittance is good by satisfying the condition that the scratch resistance value 4, represented by {(SPc2 / V2) / Sa1}, is 165 or less. In addition, similar to the polypropylene film of the present invention, it is difficult to identify the conditions for obtaining good scratch resistance from the individual physical properties of the vapor-deposited polypropylene film, so it can be said that the significance of using the relationship between specific physical properties of the film as an indicator of scratch resistance performance has also been demonstrated.

[0169] [Fabrication of Laminated Films] Laminated films were fabricated for the aluminum-metallized polypropylene films of prototype examples 1, 2, 4-8, 10-14, and 16-26. The laminated films were made by applying a two-component curing polyester adhesive at approximately 4 g / m² to the corona-treated surface of a polyester film (Futamura Chemical Co., Ltd.; FE2001#12). ２ The material was applied and then bonded to the aluminum vapor-deposited surface of each prototype using the dry lamination method. Visual inspection of the laminated films of each prototype revealed that there were no wrinkles or other defects, and all were of good quality.

[0170] As illustrated and explained above, the polypropylene film of the present invention can be provided with excellent scratch resistance by satisfying the requirement that the scratch resistance value calculated from the arithmetic mean roughness (SRa1) (μm) of the three-dimensional surface roughness of the first surface layer is 2100 or less. Furthermore, the polypropylene film of the present invention can be provided with even better scratch resistance by further satisfying the requirement that the scratch resistance value calculated from the arithmetic mean roughness (SRa1) (μm) of the three-dimensional surface roughness of the first surface layer, the number of peaks (SPc2) (number of peaks) with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer, and the pore volume (V2) (ml / g) of the antiblocking agent contained in the second surface layer is 2600 or less. Therefore, even if the first surface layer and the second surface layer are rubbed together by winding or the like, scratching of the surface of the first surface layer is suppressed, and surface treatments such as vapor deposition can be appropriately applied. Accordingly, the polypropylene film of the present invention can be suitably used as a base film for vapor deposition.

[0171] Furthermore, the vapor-deposited polypropylene film of the present invention can be provided with excellent scratch resistance by satisfying the requirement that the scratch resistance value calculated from the arithmetic mean height (Sa1) (μm) of the vapor-deposited layer and the number of peaks (SPc2) (number of peaks) with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is 130 or less. Moreover, the vapor-deposited polypropylene film of the present invention can be provided with even better scratch resistance by further satisfying the requirement that the scratch resistance value calculated from the arithmetic mean height (Sa1) (μm) of the vapor-deposited layer and the number of peaks (SPc2) (number of peaks) with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer and the pore volume (V2) (ml / g) obtained by nitrogen adsorption method of the antiblocking agent contained in the second surface layer is 165 or less.Therefore, even if the vapor-deposited layer and the second surface layer are rubbed together by winding or the like, scratching of the surface of the vapor-deposited layer is suppressed, and the deterioration of the design quality of the film due to friction between films can be suppressed.

[0172] As described above, the polypropylene film of the present invention has excellent scratch resistance on one of its processed surfaces, allowing for smooth vapor deposition and printing processes. Furthermore, by suppressing the susceptibility of the other surface to scratching, the scratch resistance of the processed film can also be improved. Therefore, it is promising as a replacement for conventional base films for vapor deposition and printing films. In addition, the vapor-deposited polypropylene film of the present invention has excellent scratch resistance on the surface of the vapor-deposited layer, and the susceptibility of the other surface to scratching is suppressed, which effectively prevents a decrease in the aesthetic appeal of the vapor-deposited film. Therefore, by constructing a laminated film using the vapor-deposited polypropylene film, it is possible to create a laminate film that can suppress the deterioration of the vapor-deposited layer, making it promising as a replacement for laminated films used in various packaging bags and the like.

[0173] 10 Polypropylene film 20 First surface layer 21 Vapor-deposited surface 30 Second surface layer 31 Heat-seal surface 40 Intermediate layer 50 Vapor-deposited polypropylene film 60 Vapor-deposited layer 100 Laminated film 110 Laminating base film

Claims

1. A polypropylene film comprising at least two layers, a first surface layer and a second surface layer, wherein both the first surface layer and the second surface layer contain an antiblocking agent, and the film satisfies the scratch resistance value shown in the following formula (i) when the arithmetic mean roughness of the three-dimensional surface roughness of the first surface layer is SRa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is SPc2 (pitch).

2. The polypropylene film according to claim 1, wherein the pore volume of the antiblocking agent contained in the second surface layer, determined by nitrogen adsorption, is V2 (ml / g), and the film satisfies the scratch resistance value shown in the following formula (ii).

3. The polypropylene film according to claim 1 or 2, wherein a vapor-deposited layer is formed on the first surface layer by vapor deposition.

4. The polypropylene film according to claim 1 or 2, wherein the gloss of the first surface layer, measured in accordance with JIS Z 8741 (1997), is 110% or more.

5. The polypropylene film according to claim 1 or 2, wherein the first surface layer is subjected to a surface treatment.

6. The polypropylene film according to claim 1 or 2, wherein the polypropylene film is an unstretched film.

7. The polypropylene film according to claim 1 or 2, wherein the pore volume of the antiblocking agent contained in the first surface layer, as determined by nitrogen adsorption, is 0.5 to 1.3 ml / g, and the average particle size, as measured by laser diffraction, is 2.5 to 4.5 μm.

8. A vapor-deposited polypropylene film comprising at least two layers, a first surface layer and a second surface layer, both containing an antiblocking agent, wherein a vapor-deposited layer is formed on the first surface layer, and the vapor-deposited polypropylene film satisfies the scratch resistance value shown in the following formula (iii) when the arithmetic mean height of the vapor-deposited layer is Sa1 (μm) and the number of peaks with a peak height of 1 μm or more in the three-dimensional surface roughness of the second surface layer is SPc2 (number).

9. The vapor-deposited polypropylene film according to claim 8, wherein the pore volume of the antiblocking agent contained in the second surface layer, determined by nitrogen adsorption, is V2 (ml / g), and the film satisfies the scratch resistance value shown in the following formula (iv).

10. The vapor-deposited polypropylene film according to claim 8 or 9, wherein the gloss of the vapor-deposited layer, as measured in accordance with JIS Z 8741 (1997), is 720% or higher.

11. The vapor-deposited polypropylene film according to claim 8 or 9, wherein the polypropylene film is an unstretched film.

12. The vapor-deposited polypropylene film according to claim 8 or 9, wherein the pore volume of the antiblocking agent contained in the first surface layer, as determined by nitrogen adsorption, is 0.5 to 1.3 ml / g, and the average particle size, as measured by laser diffraction, is 2.5 to 4.5 μm.

13. A laminated film using the vapor-deposited polypropylene film according to claim 8 or 9, characterized in that at least one layer of a lamination base film made of a polyester film, a polyamide film, or a polypropylene film is laminated on the vapor-deposited layer side of the vapor-deposited polypropylene film.

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