Long-fiber nonwoven fabric for printing substrate and printing substrate made using the same

Abstract

To provide a long fiber nonwoven fabric that has a smooth surface and excellent printing processability.SOLUTION: A long fiber nonwoven fabric for printing base material is formed of fibers mainly made of thermoplastic resin. Apparent density of the long fiber nonwoven fabric for printing base material is 0.40 g / cm3 or more and 0.90 g / cm3 or less. On a cross section of the long fiber nonwoven fabric, a ratio between a maximum height Za (μm) from a maximum convex part on one surface to a maximum concave part on the surface and a maximum height Zb (μm) from a maximum convex part on the other surface to a maximum concave part of the other surface (Za / Zb, where, Za<Zb) is a relation represented by a following formula (1). The range of Za is 9 μm or more and 30 μm or less. 0.50≤Za / Zb≤1.00...(1)SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a long-fiber nonwoven fabric for use as a printing substrate, which is suitable for use as a printing substrate. [Background technology]

[0002] The most commonly used conventional printing media are pulp paper and paper-made nonwoven fabrics made from pulp and polyester resin. While these printing media are excellent in terms of price and printing properties, there are many applications in which they cannot be used due to factors such as strength, waterproofness, and weather resistance. For this reason, printing media have been proposed that can be used as outdoor signs and posters by applying a resin coating to the surface of a substrate made only of polyester resin (see, for example, Patent Document 1). On the other hand, packaging materials with excellent mechanical strength have been proposed by applying reverse printing to long-fiber nonwoven fabric made of polyester resin and laminating a film on the printed surface (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-230499 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-183970 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the technology disclosed in Patent Document 1, although a resin coating is applied, the surface roughness is small, at 5 to 150 μm, and there are still some unevenness, which poses a problem of uneven ink application during printing.

[0005] In the case of the technology disclosed in Patent Document 2, a non-woven fabric having a partially thermally bonded portion formed by a thermal embossing device is thermally bonded with a pair of flat rolls to form a smooth surface, and reverse printing is performed. However, there is a problem that the appearance of the ink after reverse printing is different between the partially thermally bonded portion and the other portions.

[0006] Therefore, an object of the present invention is to provide a long fiber non-woven fabric for a printing substrate that has a smooth surface and excellent printing processability.

Means for Solving the Problems

[0007] As a result of intensive studies to achieve the above object, the inventor has found that by thermally bonding with a thermal roll having a flat surface, the surface of the non-woven fabric becomes smooth and excellent in printing processability, and a long fiber non-woven fabric for a printing substrate suitable for a printing substrate can be obtained. Furthermore, it has also been found that this long fiber non-woven fabric for a printing substrate is not only smooth on the surface, but also has less fiber fuzzing and fiber shedding, and is excellent in mechanical strength and handling properties.

[0008] The present invention has been completed based on this finding, and according to the present invention, the following inventions are provided.

[0009] The long fiber non-woven fabric for a printing substrate of the present invention is a long fiber non-woven fabric for a printing substrate composed of fibers mainly composed of a thermoplastic resin, and the apparent density of the long fiber non-woven fabric for a printing substrate is 0.40 g / cm 3 or more and 0.90 g / cm 3 or less. In the cross-section of the long fiber non-woven fabric for a printing substrate, the ratio (Za / Zb, provided that Za < Zb) of the maximum height Za (μm) from the maximum convex portion on one surface to the maximum concave portion on the one surface and the maximum height Zb (μm) from the maximum convex portion on the other surface to the maximum concave portion on the other surface is in the relationship represented by the following formula (1), and the range of Za is 9 μm or more and 30 μm or less 0.50 ≦ Za / Zb ≦ 1.00 ···(1).

[0010] According to a preferred embodiment of the long-fiber nonwoven fabric for a printing substrate of the present invention, the range of Zb (μm) is 10 μm or more and 50 μm or less.

[0011] According to a preferred embodiment of the long-fiber nonwoven fabric for a printing substrate of the present invention, the fibers are conjugated fibers in which a low-melting polymer having a melting point lower than that of the high-melting polymer is disposed around the high-melting polymer.

[0012] According to a preferred embodiment of the long-fiber nonwoven fabric for a printing substrate of the present invention, the basis weight of the long-fiber nonwoven fabric for a printing substrate is 30 g / m 2 More than 120g / m 2 The following is the result.

[0013] According to a preferred embodiment of the long-fiber nonwoven fabric for a printing substrate of the present invention, the Young's modulus in the MD direction of the long-fiber nonwoven fabric for a printing substrate is 1200 MPa or more and 2200 MPa or less.

[0014] According to a preferred embodiment of the long-fiber nonwoven fabric for a printing substrate of the present invention, the Young's modulus in the CD direction of the long-fiber nonwoven fabric for a printing substrate is 300 MPa or more and 1000 MPa or less.

[0015] Furthermore, the printing substrate of the present invention is preferably a printing substrate made using the long-fiber nonwoven fabric for printing substrates, and has a resin layer provided on at least one surface of the long-fiber nonwoven fabric for printing substrates, and the thickness of the resin layer is 5 μm or more and 80 μm or less. [Effects of the Invention]

[0016] The long-fiber nonwoven fabric for printing substrates of the present invention maintains hardness and moderate breathability, and is superior in handleability. In addition, since the nonwoven fabric has little fuzz and a smooth surface, it has excellent printability and does not cause uneven color development of ink during printing. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a cross section of a long-fiber nonwoven fabric for a printing substrate according to one embodiment of the present invention. [Mode for Carrying Out the Invention]

[0018] The long fiber nonwoven fabric for a printing substrate of the present invention is a long fiber nonwoven fabric for a printing substrate composed of fibers mainly composed of a thermoplastic resin, and the apparent density of the long fiber nonwoven fabric for a printing substrate is 0.40 g / cm 3 or more and 0.90 g / cm 3 or less. In the cross section of the long fiber nonwoven fabric for a printing substrate, the ratio (Za / Zb, provided that Za < Zb) of the maximum height Za (μm) from the maximum convex portion on one surface to the maximum concave portion on the one surface and the maximum height Zb (μm) from the surface of the maximum convex portion on the other surface to the maximum concave portion on the other surface is in the relationship represented by the following formula (1), and the range of Za is 9 μm or more and 30 μm or less 0.50 ≦ Za / Zb ≦ 1.00 ···(1) Hereinafter, the components will be described in detail, but the present invention is not limited to the scope described below as long as the gist thereof is not exceeded.

[0019] [Fibers mainly composed of a thermoplastic resin] First, examples of the thermoplastic resin for the long fiber nonwoven fabric for a printing substrate of the present invention include polyester, polyamide, polyolefin, or mixtures or copolymers thereof. Among them, polyester is preferably used because it is excellent in durability such as mechanical strength, heat resistance, water resistance, and chemical resistance.

[0020] Polyester is a high molecular polymer having an acid component and an alcohol component as monomers. In the present invention, as the acid component, aromatic carboxylic acids such as phthalic acid (ortho form), isophthalic acid, and terephthalic acid, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanecarboxylic acid can be used. Further, as the alcohol component, ethylene glycol, diethylene glycol, polyethylene glycol, and the like can be used.

[0021] Specific examples of the polyester include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate, polylactic acid, polybutylene succinate, etc. Of the polyesters used as high-melting-point polymers described below, polyethylene terephthalate (PET) is most preferably used because it has a higher melting point, excellent heat resistance, and excellent rigidity.

[0022] Additives such as crystal nucleating agents, matting agents, pigments, mildew inhibitors, antibacterial agents, flame retardants, metal oxides, aliphatic bisamides and / or alkyl-substituted aliphatic monoamides, and hydrophilic agents can be added to these polyester raw materials, provided that the effects of the present invention are not impaired. Metal oxides such as titanium oxide, among others, improve spinnability by reducing surface friction of the fibers and preventing fusion between the fibers. They also improve the fusion properties of long-fiber nonwoven fabrics for printing substrates by increasing thermal conductivity during fusion molding of long-fiber nonwoven fabrics with heated rolls. Furthermore, aliphatic bisamides such as ethylene bisstearamide and / or alkyl-substituted aliphatic monoamides improve the releasability between the heated roll and the nonwoven fabric web, thereby improving transportability.

[0023] The long-fiber nonwoven fabric for printing substrates of the present invention is made of fibers whose main component is the thermoplastic resin. The "main component" here means a component that accounts for 50% by mass or more of the fiber components.

[0024] The fibers according to the present invention are preferably conjugated fibers in which a low-melting-point polymer having a melting point lower than that of a high-melting-point polymer is disposed around the high-melting-point polymer. This type of conjugated fiber facilitates strong fusion bonding within the long-fiber nonwoven fabric, thereby suppressing fuzzing on the surface of the long-fiber nonwoven fabric for printing substrates and easily achieving a smooth surface. Furthermore, in addition to the fibers constituting the long-fiber nonwoven fabric for printing substrates being strongly fused to each other, the number of fusion points between the fibers in the long-fiber nonwoven fabric for printing substrates can be increased compared to fibers blended with fibers having different melting points, thereby improving mechanical strength.

[0025] The difference between the melting points of the high-melting-point polymer and the low-melting-point polymer (hereinafter sometimes simply referred to as the melting point difference) is preferably 10°C or more and 140°C or less. In other words, a low-melting-point polymer having a melting point lower than the melting point of the high-melting-point polymer by 10°C or more and 140°C or less is preferred. By making the difference in melting points 10°C or more, more preferably 20°C or more, and even more preferably 30°C or more, the fusion properties between the fibers can be improved. Furthermore, by making the difference 140°C or less, more preferably 120°C or less, and even more preferably 100°C or less, it is possible to prevent the low-melting-point polymer component from fusing to the heated roll during fusion, which would result in a decrease in productivity.

[0026] The melting point of the high-melting-point polymer in the present invention is preferably in the range of 160°C or higher and 320°C or lower. By setting the melting point to preferably 160°C or higher, more preferably 170°C or higher, and even more preferably 180°C or higher, it is possible to obtain a long-fiber nonwoven fabric for a printing substrate that has excellent shape stability and can maintain its shape even when subjected to processing that involves heat, when used as a printing substrate. Furthermore, by setting the melting point to 320°C or lower, more preferably 300°C or lower, and even more preferably 280°C or lower, it is possible to prevent a large consumption of thermal energy for melting during the production of a long-fiber nonwoven fabric for a printing substrate, which would otherwise reduce productivity.

[0027] On the other hand, the melting point of the low-melting-point polymer in the conjugate fiber is preferably in the range of 150°C or higher and 310°C or lower, while ensuring the above-mentioned difference in melting points. By setting the melting point at 150°C or higher, more preferably 160°C or higher, and even more preferably 170°C or higher, it is possible to obtain a long-fiber nonwoven fabric for a printing substrate that has excellent shape stability and can maintain its shape even when subjected to processing that involves heat when used as a printing substrate. Furthermore, by setting the melting point at 310°C or lower, more preferably 290°C or lower, and even more preferably 270°C or lower, it is possible to easily obtain a long-fiber nonwoven fabric for a printing substrate that has excellent fusion properties and mechanical strength when produced.

[0028] In the present invention, the melting point of a thermoplastic resin is measured using a differential scanning calorimeter (for example, a "DSC-2" model manufactured by PerkinElmer) at a heating rate of 20°C / min over a temperature range of 30°C to 350°C, and the temperature at which the obtained melting endothermic curve gives an extreme value is taken as the melting point of the thermoplastic resin. For resins whose melting endothermic curve does not give an extreme value in the differential scanning calorimeter, the resin is heated on a hot plate, and the temperature at which the resin melts under microscope observation is taken as the melting point.

[0029] When the thermoplastic resin is polyester, examples of the combination of a high-melting polyester polymer and a low-melting polyester polymer (hereinafter sometimes referred to in the order of high-melting polyester polymer / low-melting polyester polymer) include PET / PBT, PET / PTT, PET / polylactic acid, and PET / copolymerized PET, among which the combination of PET / copolymerized PET is preferred due to its excellent spinnability. Furthermore, isophthalic acid-copolymerized PET is preferably used as the copolymerization component of copolymerized PET due to its particularly excellent spinnability.

[0030] Examples of the composite form of the composite fiber include a concentric sheath-core type, an eccentric sheath-core type, and an islands-in-the-sea type. Of these, the concentric sheath-core type is preferred because it allows the fibers to be fused uniformly and firmly. Furthermore, the cross-sectional shape of the composite fiber may be a circular cross-section, a flat cross-section, a polygonal cross-section, a multi-lobal cross-section, a hollow cross-section, etc. Of these, a circular cross-sectional shape is a preferred embodiment of the composite fiber.

[0031] Furthermore, the ratio of the high-melting-point polyester polymer to the low-melting-point polyester polymer in the fibers primarily composed of thermoplastic resin is preferably in the range of 90:10 to 60:40 by mass, more preferably 85:15 to 70:30. By adjusting the content of the high-melting-point polyester polymer to 60% by mass or more and 90% by mass or less, the durability of the long-fiber nonwoven fabric for printing substrates can be improved. On the other hand, by adjusting the content of the low-melting-point polyester polymer to 10% by mass or more and 40% by mass or less, the fibers constituting the long-fiber nonwoven fabric for printing substrates are firmly fused together, resulting in a long-fiber nonwoven fabric for printing substrates with excellent mechanical strength.

[0032] The average single fiber diameter of the fibers according to the present invention is preferably in the range of 10.0 μm or more and 26.0 μm or less. By setting the average single fiber diameter to 10.0 μm or more, preferably 10.5 μm or more, and more preferably 11.0 μm or more, a long-fiber nonwoven fabric for a printing substrate with excellent mechanical strength can be obtained. On the other hand, by setting the average single fiber diameter to 26.0 μm or less, preferably 25.0 μm or less, and more preferably 24.0 μm or less, the uniformity of the long-fiber nonwoven fabric for a printing substrate can be improved, resulting in a long-fiber nonwoven fabric for a printing substrate with a dense surface. For example, when used as a printing substrate, surface unevenness can be reduced.

[0033] In the present invention, the average single fiber diameter (μm) of the long-fiber nonwoven fabric for a printing substrate is determined by the following method. (i) Ten small sample pieces are randomly taken from the long fiber nonwoven fabric for printing substrate. (ii) The surface of the collected small sample is photographed using a scanning electron microscope or the like at a magnification of 500 to 2000 times, allowing the thickness of the fibers to be measured. (iii) From the photographs of each small sample, ten fibers (a total of 100 fibers) were randomly selected and their thickness was measured. Assuming that the cross section of the fibers is circular, the thickness was taken as the fiber diameter. (iv) The average single fiber diameter is calculated by rounding off the arithmetic mean value to one decimal place.

[0034] [Long-fiber nonwoven fabric for printing substrate] The long-fiber nonwoven fabric for printing substrates of the present invention is made of fibers whose main component is the thermoplastic resin. Here, the term "long-fiber nonwoven fabric" as used herein refers to nonwoven fabrics such as spunbonded nonwoven fabrics and meltblown nonwoven fabrics manufactured by the manufacturing methods described below, and does not include nonwoven fabrics (short-fiber nonwoven fabrics) made solely of fibers cut to a certain length (e.g., 100 mm).

[0035] The apparent density of the long-fiber nonwoven fabric for printing substrate of the present invention is 0.40 g / cm 3 More than 0.90g / cm 3 The apparent density is 0.40 g / cm 3 or more, preferably 0.42 g / cm 3 More preferably, 0.45 g / cm 3 By adjusting the apparent density to 0.90 g / cm or more, a long-fiber nonwoven fabric for a printing substrate having excellent mechanical strength and durability can be obtained. 3 or less, preferably 0.80 g / cm 3 or less, more preferably 0.70 g / cm 3 By setting the thickness below this, it is possible to provide a certain level of breathability, and when used as a printing substrate, for example, ink will easily penetrate into the interior of the nonwoven fabric.

[0036] In the present invention, the apparent density (g / cm 3Adopt the value obtained by the following formula from the basis weight and thickness values of the long-fiber non-woven fabric for a printing substrate measured by the method described below. Apparent density (g / cm 3 ) = basis weight (g / m 2 ) / thickness (mm) / 1000.

[0037] In the cross-section of the long-fiber non-woven fabric for a printing substrate of the present invention, the ratio of the maximum height Za (μm) from the maximum convex part on one surface to the maximum concave part on the same surface to the maximum height Zb (μm) from the maximum convex part on the other surface to the maximum concave part on the other surface (Za / Zb, provided that Za < Zb) satisfies the relationship represented by the following formula (1). 0.50 ≤ Za / Zb ≤ 1.00 ···(1) That is, the ratio (Za / Zb) is 0.50 or more and 1.00 or less. When Za / Zb is 0.50 or more, preferably 0.53 or more, more preferably 0.55 or more, there is no surface difference between the front and back. For example, when used as a printing substrate, printing can be performed on both sides, and a long-fiber non-woven fabric for a printing substrate with excellent handling properties is obtained. Also, when Za / Zb is 1.00 or less, preferably 0.98 or less, more preferably 0.95 or less, it is possible to suppress the fiber surface from becoming a sheet form like a film, and obtain a long-fiber non-woven fabric for a printing substrate having appropriate air permeability.

[0038] Furthermore, in the cross section of the long-fiber nonwoven fabric for printing substrates of the present invention, while satisfying the relationship expressed by the above-mentioned formula (1), the maximum height Za (μm) from the largest convex portion on one surface to the largest concave portion on the same surface is in the range of 9.0 μm to 30.0 μm. By setting Za to 9.0 μm or more, preferably 9.5 μm or more, and more preferably 10.0 μm or more, the constituent fibers of the long-fiber nonwoven fabric for printing substrates can better maintain their fiber shape and can be prevented from completely melting and becoming a film-like sheet. On the other hand, by setting Za to 30.0 μm or less, preferably 28.0 μm or less, and more preferably 25.0 μm or less, it is possible to suppress fiber fuzzing on the surface of the nonwoven fabric, resulting in a long-fiber nonwoven fabric for printing substrates with excellent handleability and print processability.

[0039] On the other hand, the long-fiber nonwoven fabric for printing substrates of the present invention preferably has a maximum height Zb (μm) in its cross section from the largest convex portion on the other surface to the largest concave portion on the other surface in the range of 10.0 μm to 50.0 μm. By setting Zb to 10.0 μm or more, preferably 12.0 μm or more, and more preferably 15.0 μm or more, the constituent fibers of the long-fiber nonwoven fabric for printing substrates can better maintain their fiber shape and can be prevented from completely melting and becoming a film-like sheet, resulting in a long-fiber nonwoven fabric for printing substrates with appropriate breathability. On the other hand, by setting Zb to 50.0 μm or less, preferably 48.0 μm or less, and more preferably 45.0 μm or less, fiber fuzzing on the surface of the nonwoven fabric can be suppressed, resulting in a long-fiber nonwoven fabric for printing substrates with excellent handleability and print processability.

[0040] In the present invention, the values ​​of the maximum height Za (μm) and the maximum height Zb (μm) are determined as follows. (i) On any surface of a long-fiber nonwoven fabric for printing substrate, the intersection of the center line in the MD direction (a line connecting points equidistant from both ends of the long-fiber nonwoven fabric for printing substrate) and the center line in the CD direction is defined as the center point. (ii) Draw a straight line passing through the center point and parallel to the CD direction. (iii) Starting from two points on the line 0.5 cm apart from the center point, draw a line 1.0 cm long along the MD direction, and then draw a line connecting the endpoints. (iv) Cut out the area enclosed by the 1.0 cm x 1.0 cm square formed in (i) to (iii) with a razor blade. (v) In the same manner, five 1.0 cm x 1.0 cm measurement samples are taken from any location within the long-fiber nonwoven fabric for printing substrate at equal intervals in the CD direction of the long-fiber nonwoven fabric for printing substrate. (vi) Using a scanning electron microscope (SEM) (for example, "VHX-D500" manufactured by Keyence Corporation), the cross section of the measurement sample is observed and photographed at a magnification of 700 times. (vii) As shown in the example of Figure 1, first, draw a straight line A (6a, 6b) parallel to the center line (8) of the cross section of the long-fiber nonwoven fabric for printing substrate so as to pass through the top (2, 4) of the cross section of the long-fiber nonwoven fabric (1) in the photographed cross-sectional image, and then draw a straight line B (7a, 7b) parallel to the straight line A so as to pass through the bottom (3, 5) of the cross section of the long-fiber nonwoven fabric for printing substrate in the cross-sectional image. (viii) From the distance between line A (6a, 6b) and line B (7a, 7b), the maximum height Za (μm) and the maximum height Zb (μm) are measured, and the ratio Za / Zb is calculated from the measurement results. (ix) The arithmetic mean values ​​of the maximum height Za (μm), maximum height Zb (μm), and Za / Zb obtained from each measurement sample are calculated, and the maximum height Za (μm) and maximum height Zb (μm) are rounded to one decimal place, and the value obtained by rounding to three decimal places is used for Za / Zb.

[0041] In the present invention, the MD direction refers to the sheet conveying direction when producing a long-fiber nonwoven fabric for printing substrates, i.e., the winding direction of the nonwoven fabric roll, and the CD direction refers to the direction perpendicular to the sheet conveying direction, i.e., the winding direction of the nonwoven fabric roll. Furthermore, when the long-fiber nonwoven fabric for printing substrates is not in a rolled state because it has been cut, for example, the MD direction and CD direction are determined by the following procedure. (a) Within the surface of the long-fiber nonwoven fabric for printing substrate, select one direction at your discretion and take a test piece 25 cm long and 1.5 cm wide along that direction. (b) Similarly, collect test pieces 25 cm long and 1.5 cm wide at angles rotated 30 degrees, 60 degrees, and 90 degrees from the direction in which the sample was taken. (c) For each test piece in each direction, the Young's modulus of each test piece is measured based on the method for measuring the Young's modulus of a long-fiber nonwoven fabric for a printing substrate, which will be described later. (d) The direction in which the measured value is highest is the MD direction of the long-fiber nonwoven fabric for printing substrate, and the direction perpendicular to this is the CD direction. If there are two or more directions in which the Young's modulus is highest, the direction perpendicular to these directions is the MD direction of the long-fiber nonwoven fabric for printing substrate. If there are two or more directions in which the Young's modulus is highest and the Young's modulus in the directions perpendicular to these directions is also equal, for example, if the Young's modulus in all four directions is equal, then one of the four directions is the MD direction, and the direction perpendicular to this is the CD direction.

[0042] The basis weight of the long fiber nonwoven fabric for printing substrate in the present invention is 30 g / m 2 More than 120g / m 2 The weight of the long-fiber nonwoven fabric for printing substrate is preferably 30 g / m or less. 2 or more, preferably 40 g / m 2 More preferably, 50 g / m 2 By adjusting the weight of the nonwoven fabric to 120 g / m or more, a nonwoven fabric having excellent mechanical strength can be obtained. 2 or less, preferably 115 g / m 2 or less, more preferably 110 g / m 2 By satisfying the following conditions, a long-fiber nonwoven fabric for a printing substrate that is lightweight and has excellent handling properties can be obtained.

[0043] In the present invention, the basis weight of the long-fiber nonwoven fabric for printing substrate is a value measured by the following procedure in accordance with JIS L1913:2010 "6.2 Mass per unit area." (i) Take three 25cm x 25cm test pieces per meter of sample width. (ii) Weigh the mass (g) of each at standard conditions. (iii) The average value is 1 m 2 Mass per unit (g / m 2 )

[0044] The thickness of the long-fiber nonwoven fabric for a printing substrate in the present invention is preferably 0.05 mm or more and 0.30 mm or less. By setting the thickness within this range, the long-fiber nonwoven fabric for a printing substrate has excellent handleability.

[0045] In the present invention, the thickness of the long-fiber nonwoven fabric for a printing substrate is measured by the following procedure. (i) Using a thickness meter (for example, "TECLOCK" (registered trademark) SM-114 manufactured by TECLOCK Corporation), the thickness of the long-fiber nonwoven fabric for printing substrate is measured at 10 cm intervals in the CD direction. (ii) The thickness (mm) of the long-fiber nonwoven fabric for printing substrate shall be determined by rounding off the above arithmetic mean value to two decimal places.

[0046] In the present invention, the Young's modulus in the MD direction of the long-fiber nonwoven fabric for a printing substrate is preferably 1200 MPa or more and 2200 MPa or less. By having a Young's modulus in the MD direction of preferably 1200 MPa or more, more preferably 1250 MPa or more, and even more preferably 1300 MPa or more, the long-fiber nonwoven fabric for a printing substrate retains appropriate rigidity and can be made into a long-fiber nonwoven fabric for a printing substrate with excellent handleability. Furthermore, by having a Young's modulus in the MD direction of preferably 2200 MPa or less, more preferably 2150 MPa or less, and even more preferably 2100 MPa or less, the long-fiber nonwoven fabric for a printing substrate has good conformability.

[0047] On the other hand, in the present invention, the Young's modulus in the CD direction of the long-fiber nonwoven fabric for a printing substrate is preferably 300 MPa or more and 1000 MPa or less. A CD Young's modulus of 300 MPa or more, more preferably 350 MPa or more, and even more preferably 400 MPa or more will result in a long-fiber nonwoven fabric for a printing substrate with appropriate rigidity and excellent handleability. Furthermore, a CD Young's modulus of preferably 1000 MPa or less, more preferably 950 MPa or less, and even more preferably 900 MPa or less will result in a long-fiber nonwoven fabric for a printing substrate with good conformability.

[0048] In the present invention, the Young's modulus in the MD direction or the Young's modulus in the CD direction of a long-fiber nonwoven fabric for a printing substrate is a value measured by the following procedure based on 5.3.1 of JIS L1906:2000 "Testing methods for general long-fiber nonwoven fabrics." (i) Five samples measuring 25 cm x 1.5 cm in width are taken from the nonwoven fabric at equal intervals in the CD direction (when determining the Young's modulus in the CD direction, take them at equal intervals in the MD direction). (ii) Measurements were taken in both the MD and CD directions under the conditions of a grip distance of 18 cm and a pulling speed of 10 cm / min. (iii) The initial tensile resistance (the value at 100% elongation at the initial slope) was read from the obtained strength-strain curve, and the value rounded to the first decimal place was divided by the sample width (5 cm) and the thickness of the nonwoven fabric obtained above. The value rounded to the first decimal place was used as the Young's modulus in the MD and CD directions of the long-fiber nonwoven fabric for printing substrate.

[0049] The air permeability of the long-fiber nonwoven fabric for printing substrate of the present invention is 3 cm 3 / (cm 2 ·Seconds) or more than 50cm 3 / (cm 2 By doing so, the long-fiber nonwoven fabric for a printing substrate becomes partially film-like, and when used as a printing substrate, it is possible to prevent a decrease in the impregnation of the ink resin and to obtain a long-fiber nonwoven fabric for a printing substrate having excellent mechanical strength.

[0050] The air permeability of long-fiber nonwoven fabrics for printing substrates will be measured as follows based on JIS L1913:2010 "Test methods for general nonwoven fabrics" 6.8 "Air permeability (JIS method)" 6.8.1 "Fragile method". (i) Ten test pieces measuring 150 mm long x 150 mm wide are taken at equal intervals in the CD direction of the long fiber nonwoven fabric for printing substrate. (ii) After attaching the test specimen to one end of the cylinder of the testing machine, adjust the intake fan and air hole so that the inclined barometer indicates a pressure of 125 Pa using the lower limit resistor, and measure the pressure indicated by the vertical barometer at that time. (iii) From the measured pressure and the type of air hole used, calculate the volume of air (cm3) passing through the test piece using the conversion table attached to the tester. 3 / (cm 2 · seconds) (iv) The average value obtained from the air permeability of 10 test pieces is rounded to the nearest whole number to obtain the air permeability (cm 3 / (cm 2 · seconds).

[0051] The long-fiber nonwoven fabric for printing substrates of the present invention has a flat surface, little fuzz, and a moderate density, and is excellent in mechanical strength. It also has excellent processability, preventing strike-through and uneven coating when a resin layer is applied, and is therefore suitable for use as a printing substrate as described below.

[0052] [Method of manufacturing long-fiber nonwoven fabric for printing substrate] Next, the long-fiber nonwoven fabric for printing substrates of the present invention and its manufacturing method will be described. The long-fiber nonwoven fabric of the present invention is preferably manufactured by sequentially carrying out the following steps (a) to (c). (a) A process in which a thermoplastic resin is melt-extruded from a spinneret, and then pulled and stretched by an ejector to form fibers. (b) A process in which the arrangement of the fibers is controlled by a fiber spreader plate and the fibers are deposited on a moving net conveyor to form a fiber web. (c) heat-bonding the resulting fibrous web; Each of the above steps will be described in more detail below.

[0053] (a) Fiber formation process First, a thermoplastic resin is melt-extruded through a spinneret. In particular, when the fibers constituting the long-fiber nonwoven fabric for printing substrates are to be conjugated fibers in which a low-melting polymer having a melting point lower than that of a high-melting polymer is disposed around the high-melting polymer, the high-melting polymer and the low-melting polymer are melted at temperatures above their melting points but not exceeding (70°C above the melting point), and a low-melting polymer having a melting point 10°C to 140°C lower than that of the high-melting polymer is disposed around the high-melting polymer. The conjugated fibers are then spun through fine holes in a spinneret having a temperature above the melting point but not exceeding (70°C above the melting point), and then pulled and drawn by an ejector at a spinning speed of 3000 m / min to 6000 m / min to spin fibers with a circular cross-section.

[0054] (b) forming a fibrous web The fibers spun by the above steps are preferably subsequently sucked by an ejector, ejected from a fiber-spreading plate having a slit at the bottom of the ejector, and deposited on a moving net conveyor to form a fiber web.

[0055] (c) A step of thermally bonding the fiber web In the method of producing a long-fiber nonwoven fabric for a printing substrate of the present invention, it is also a preferred embodiment that the fiber web collected on the net conveyer is temporarily bonded and then further thermally bonded.

[0056] First, the temporary bonding is preferably performed by fusing the collected fiber web with a pair of upper and lower flat rolls, or by placing a flat roll on a net conveyor and fusing the web between the net conveyor and the flat roll.

[0057] A pair of upper and lower flat rolls for temporary bonding or a flat roll on a net conveyor refers to a metal roll or an elastic roll with a smooth surface. Furthermore, a pair of upper and lower flat rolls can be formed by pairing a metal roll with another metal roll or a metal roll with an elastic roll. Here, an elastic roll refers to a roll made of a material that is more elastic than a metal roll. Examples of elastic rolls include so-called paper rolls such as paper, cotton, and aramid paper, as well as resin rolls made of urethane resins, epoxy resins, silicone resins, polyester resins, hard rubber, and mixtures thereof.

[0058] The temperature for temporary bonding is preferably 65°C to 120°C lower than the melting point of the thermoplastic resin (in the case of a composite fiber in which a low-melting polymer having a melting point lower than that of a high-melting polymer is disposed around the high-melting polymer, the melting point of the low-melting polymer). By setting the temperature in this manner, it is possible to improve conveyability without excessively fusing the fibers together.

[0059] The linear pressure for temporary bonding is preferably 45 N / cm or more and 1960 N / cm or less. By setting the linear pressure for temporary bonding to 45 N / cm or more, the mechanical strength required for transporting the fiber web to the next process can be imparted. On the other hand, by setting the linear pressure for temporary bonding to 1960 N / cm or less, excessive fusion between the fibers can be prevented.

[0060] Next, the temporarily bonded fiber web is subjected to a second thermal bonding using a pair of upper and lower flat rolls. The pair of upper and lower flat rolls refers to metal rolls or elastic rolls with smooth surfaces, and a pair of metal rolls or a pair of metal rolls and elastic rolls can be used. Among these, a combination of metal rolls and metal rolls is preferred because it allows for excellent smoothness and a long-fiber nonwoven fabric with little variation in thickness in the width direction. A combination of metal rolls and metal rolls can make the surface of the long-fiber nonwoven fabric for printing substrate highly uniform and free of fluff.

[0061] The temperature for the second heat bonding is preferably 5°C to 60°C lower than the melting point of the thermoplastic resin (in the case of composite fibers in which a low-melting polymer having a melting point lower than that of a high-melting polymer is disposed around the high-melting polymer, the melting point of the low-melting polymer). Setting the temperature in this manner can prevent excessive fusion between the fibers and the long-fiber nonwoven fabric for printing substrates from partially transforming into a film-like sheet. It can also prevent the low-melting polymer component from fusing to the roll used during heat bonding, resulting in a decrease in productivity.

[0062] The linear pressure in the second thermal bonding is preferably 98 N / cm or more and 1960 N / cm or less. By using a linear pressure for thermal bonding of 98 N / cm or more, a long-fiber nonwoven fabric for printing substrates with excellent mechanical strength can be obtained. By using a linear pressure for thermal bonding of 1960 N / cm or less, excessive fusion between the fibers can be prevented.

[0063] In the method for producing a long-fiber nonwoven fabric for a printing substrate of the present invention, the temporary bonding and the second thermal bonding may be carried out continuously on one production line, or the fabric may be wound up once after temporary bonding and then unwound again for the second thermal bonding. Among these, the preferred embodiment is to carry out the temporary bonding and the second thermal bonding continuously on one production line, as this provides excellent productivity.

[0064] [Printing base material] The printing substrate of the present invention is a printing substrate made from the long-fiber nonwoven fabric for printing substrates, and preferably has a resin layer provided on at least one surface of the long-fiber nonwoven fabric for printing substrates. By providing a resin layer, the printing substrate can have higher hiding power.

[0065] When a resin layer is applied to the long-fiber nonwoven fabric for printing substrates of the present invention, the thickness of the resin layer is preferably 5 μm or more and 80 μm or less. By making the resin layer thickness 5 μm or more, preferably 8 μm or more, a printing substrate with appropriate hiding power can be obtained. Furthermore, by making the resin layer thickness 80 μm or less, preferably 70 μm or less, the weight of the printing substrate can be reduced, resulting in excellent handleability.

[0066] When applying a resin layer to the long-fiber nonwoven fabric for printing substrate of the present invention, the application amount of the resin layer per unit area weight is 20 g / m 2 More than 60g / m 2 The coating amount of the resin layer is preferably 20 g / m or less. 2 or more, preferably 25 g / m 2 By setting the coating amount of the resin layer at 60 g / m or more, a printing substrate having appropriate hiding power can be obtained. 2 Less than 55 g / m 2 By setting the weight as a printing substrate to the following value, the weight of the printing substrate becomes light and the handling property becomes excellent.

[0067] The resin solution used when applying a resin layer to the long-fiber nonwoven fabric for printing substrate of the present invention must be able to impart hiding properties to the long-fiber nonwoven fabric for printing substrate, and for example, a solvent-based or water-soluble white pigment resin to which a fine white powder such as titanium oxide, calcium carbonate, magnesium carbonate, or clay has been added is preferably used.

[0068] The resin layer can be applied to the long-fiber nonwoven fabric for printing substrate of the present invention by a coating method such as gravure coating, gravure offset coating, flexography, roll coating, comma coating, or knife coating.

[0069] Other additives may also be used as long as they do not impair the object of the present invention. For example, water repellents, antistatic agents, penetrants, etc. These finishing agents are mixed with the resin solution and applied to the long-fiber nonwoven fabric for printing substrates. [Example]

[0070] Next, the long-fiber nonwoven fabric for printing substrates of the present invention will be specifically described based on examples. However, the present invention is not limited to these examples. In addition, in measuring each physical property, unless otherwise specified, the measurement was performed based on the above-mentioned method.

[0071] [Measurement method] (1) Melting point of polyester (℃) Measurement was carried out using a PerkinElmer differential scanning calorimeter "DSC-2" at a temperature rise rate of 20°C / min, and the temperature at which the extreme value was obtained in the obtained melting endothermic curve was taken as the melting point.

[0072] (2) Intrinsic viscosity (IV) of polyester The intrinsic viscosity (IV) of polyester was measured by dissolving 8 g of sample in 100 mL of orthochlorophenol and measuring the relative viscosity η using an Ostwald viscometer at 25°C. r was calculated using the following formula: η r =η / η0=(t×d) / (t0×d0) (where η is the viscosity of the polymer solution, η0 is the viscosity of orthochlorophenol, t is the solution drop time (seconds), and d is the solution density (g / cm 3 ), t0 is the fall time of orthochlorophenol (seconds), and d0 is the density of orthochlorophenol (g / cm 3 ) respectively. Next, the relative viscosity η r The intrinsic viscosity (IV) was calculated using the following formula: Intrinsic viscosity (IV)=0.0242η r +0.2634.

[0073] (3) Average single fiber diameter (μm) The average single fiber diameter of the fibers according to the present invention was calculated by the above-mentioned method using a scanning electron microscope "VHX-D500" manufactured by Keyence Corporation.

[0074] (4) Weight of long-fiber nonwoven fabric for printing substrate (g / m 2 ) The basis weight of the long-fiber nonwoven fabric for printing substrate was calculated by the method described above.

[0075] (5) Thickness of long-fiber nonwoven fabric for printing substrate (mm) The thickness of the long-fiber nonwoven fabric for printing substrate was evaluated by the above-mentioned method using a thickness meter "TECLOCK" (registered trademark) SM-114 manufactured by TECLOCK Corporation.

[0076] (6) Air permeability of long-fiber nonwoven fabric for printing substrate (cm 3 / (cm 2 ·sec)) The air permeability of the long-fiber nonwoven fabric for printing substrate was evaluated using the tester "FX3300-III" manufactured by Swiss Textest, using the method described above.

[0077] (7) Density of long-fiber nonwoven fabric for printing substrate (g / cm 3 ) The density of the long-fiber nonwoven fabric for printing substrate was calculated by the method described above.

[0078] (8) Maximum heights Za, Zb, and Za / Zb in the cross section of the long-fiber nonwoven fabric for printing substrate The maximum heights Za, Zb, and Za / Zb in the cross section of the long-fiber nonwoven fabric for printing substrate were calculated using the method described above.

[0079] (9) Young's modulus of long-fiber nonwoven fabric for printing substrate The Young's modulus of the long-fiber nonwoven fabric for printing substrate was calculated by the method described above.

[0080] (10) Color development of printing substrate The printing machine was a Hewlett-Packard latex printer "Latex570," and the ink was genuine "Lx ink" compatible with the machine, and the printing process was carried out on the printing substrate. The color development of the ink was then visually checked by 20 healthy men and women and rated on a four-point scale, with the most common rating being the color development of the printing substrate. In the event of a tie, the higher rating was considered to be the color development of the printing substrate. A: The color is vibrant and even. B: Some unevenness is observed, but the color is vivid. C: Some unevenness is observed, and the color is whitish in places (base material). D: Unevenness is observed, the color is faint, and the white base material is visible.

[0081] (11) Printing processability of printing substrate In the evaluation of the color development of the printing substrate (10), the printability of the printing substrate was evaluated on a four-point scale by visual inspection by 20 healthy men and women, and the most common evaluation was regarded as the printability of the printing substrate. In the event of a tie, the higher evaluation was regarded as the printability of the printing substrate. A: No curling at the edges and no wrinkles observed. B: No curling at the edges, but 1 to 5 wrinkles observed. C: Curling at the edges is observed and wrinkles are observed in six or more places. D: Six or more wrinkles are observed and large curls are observed at the edges.

[0082] [Resin used] Next, the resins used in the examples and comparative examples will be described in detail. High-melting point polymer: Polyethylene terephthalate (referred to as PET in Table 1) with an intrinsic viscosity (IV) of 0.65 and a melting point of 260°C, dried to a moisture content of 50 mass ppm or less. Low-melting point polymer: Copolymerized polyethylene terephthalate (referred to as co-PET in Table 1) that has been dried to a moisture content of 50 mass ppm or less, has an intrinsic viscosity (IV) of 0.64, an isophthalic acid copolymerization rate of 11 mol%, and a melting point of 230°C.

[0083] [Example 1] The high-melting point polymer and low-melting point polymer were melted at temperatures of 295°C and 280°C, respectively. The high-melting point polymer was used as the core component, and the low-melting point polymer was used as the sheath component. The high-melting point polymer was then spun through fine holes at a spinneret temperature of 295°C in a core:sheath mass ratio of 80:20. Fibers with a circular cross-section were then spun using an ejector at a spinning speed of 4900 m / min. The fiber arrangement was controlled using a fiber spreader plate, and the fibers were deposited on a moving net conveyor. A fiber web consisting of fibers with an average single fiber diameter of 10.6 μm was collected. The collected fiber web was temporarily bonded using a pair of calender rolls made of metal flat rolls, both at a temperature of 150°C and a linear pressure of 455 N / cm. Subsequently, the web was thermally bonded using a pair of calender rolls made of metal flat rolls, both at a temperature of 195°C and a linear pressure of 455 N / cm, to obtain a long-fiber nonwoven fabric for printing substrates. The basis weight of this long-fiber nonwoven fabric for printing substrate is 90 g / m 2 , thickness is 0.20mm, density is 0.45g / cm 3 , ventilation volume is 10cm 3 / (cm 2 The Young's modulus in the MD direction was 2040 MPa, the Young's modulus in the CD direction was 781 MPa, Za was 14.5 μm, Zb was 15.1 μm, and Za / Zb was 0.96. The results are shown in Table 1.

[0084] [Example 2] The calender roll temperature during thermal bonding after temporary bonding was increased from 195°C to 200°C, and the basis weight of the long-fiber nonwoven fabric for printing substrate was increased to 90 g / m 2 from 100g / m 2 A long-fiber nonwoven fabric for a printing substrate was obtained in the same manner as in Example 1, except that the weight per unit area of ​​the long-fiber nonwoven fabric for a printing substrate was 100 g / m 2 , thickness is 0.23 mm, density is 0.43 g / cm 3 , ventilation volume is 6cm3 / (cm 2 The Young's modulus in the MD direction was 2090 MPa, the Young's modulus in the CD direction was 862 MPa, Za was 17.1 μm, Zb was 20.7 μm, and Za / Zb was 0.83. The results are shown in Table 1.

[0085] [Example 3] Temporary bonding was not performed, and the temperatures of the calendar rolls consisting of a pair of metal flat rolls during thermal bonding were 200°C for the upper flat roll and 170°C for the lower flat roll (denoted as "200 / 170" in Table 1), the linear pressure was 490 N / cm, and the basis weight of the long-fiber nonwoven fabric for printing substrate was 90 g / m 2 from 110g / m 2 A long-fiber nonwoven fabric for a printing substrate was obtained in the same manner as in Example 1, except that the weight per unit area of ​​the long-fiber nonwoven fabric for a printing substrate was 110 g / m 2 , thickness is 0.26 mm, density is 0.42 g / cm 3 , ventilation volume is 21cm 3 / (cm 2 The Young's modulus in the MD direction was 1253 MPa, the Young's modulus in the CD direction was 804 MPa, Za was 27.1 μm, Zb was 48.5 μm, and Za / Zb was 0.56. The results are shown in Table 1.

[0086] [Example 4] The linear pressure during temporary bonding was changed from 455 N / cm to 45 N / cm, the temperature of both flat rolls was changed from 150°C to 130°C, and the temperature of both flat rolls during thermal bonding was changed from 195°C to 180°C. The basis weight of the long-fiber nonwoven fabric for printing substrate was changed to 50 g / m 2 A long-fiber nonwoven fabric for a printing substrate was obtained in the same manner as in Example 1, except that the weight per unit area of ​​the long-fiber nonwoven fabric for a printing substrate was 50 g / m 2 , thickness is 0.08 mm, density is 0.63 g / cm 3 , ventilation volume 25cm 3 / (cm 2 The Young's modulus in the MD direction was 1435 MPa, the Young's modulus in the CD direction was 492 MPa, Za was 10.2 μm, Zb was 15.3 μm, and Za / Zb was 0.67. The results are shown in Table 1.

[0087] [Example 5] The basis weight of the long fiber nonwoven fabric for printing substrate is 50 g / m 2 from 70 g / m 2 A long-fiber nonwoven fabric for a printing substrate was obtained in the same manner as in Example 4, except that the basis weight of this long-fiber nonwoven fabric for a printing substrate was 70 g / m 2 , thickness 0.11 mm, density 0.64 g / cm 3 , ventilation volume is 11cm 3 / (cm 2 The Young's modulus in the MD direction was 2036 MPa, the Young's modulus in the CD direction was 939 MPa, Za was 16.3 μm, Zb was 20.6 μm, and Za / Zb was 0.79. The results are shown in Table 1.

[0088] [Example 6] The basis weight of the long fiber nonwoven fabric for printing substrate is 50 g / m 2 from 35g / m 2 A long-fiber nonwoven fabric for a printing substrate was obtained in the same manner as in Example 4, except that the weight per unit area of ​​the long-fiber nonwoven fabric for a printing substrate was 35 g / m 2 , thickness is 0.06 mm, density is 0.58 g / cm 3 , ventilation volume is 40cm 3 / (cm 2 The Young's modulus in the MD direction was 1216 MPa, the Young's modulus in the CD direction was 361 MPa, Za was 9.1 μm, Zb was 10.2 μm, and Za / Zb was 0.89. The results are shown in Table 1.

[0089] [Comparative Example 1] A continuous fiber nonwoven fabric was obtained in the same manner as in Example 1, except for the following changes in the production process of Example 1. - The fiber webs collected were made up of fibers with an average single fiber diameter of 10.6 μm, but the change was made to collect fiber webs made up of fibers with an average single fiber diameter of 18.6 μm. The adhesive process was carried out continuously following the temporary bonding process, but a change was made to include a process between the temporary bonding process and the thermal bonding process in which the sheet obtained in the temporary bonding process is wound up once, cooled to room temperature, and sent to a calendar roll consisting of a pair of metal flat rolls for thermal bonding. During the thermal bonding process, the conditions were that the temperature of both flat rolls was 195°C and the linear pressure was 455N / cm, but this was changed to the conditions that the temperature of both flat rolls was 190°C and the linear pressure was 500N / cm. - Long fiber nonwoven fabric for printing substrate with a basis weight of 90g / m 2 from 130 g / m 2 The point that was changed to. The basis weight of the obtained long fiber nonwoven fabric for printing substrate was 130 g / m 2 , thickness is 0.33 mm, density is 0.39 g / cm 3 , ventilation volume is 2cm 3 / (cm 2 The Young's modulus in the MD direction was 1701 MPa, the Young's modulus in the CD direction was 710 MPa, Za was 32.4 μm, Zb was 81.5 μm, and Za / Zb was 0.40. The results are shown in Table 1.

[0090] Comparative Example 2 The following points were noted: temporary bonding was not performed; in the thermal bonding process, the temperature of both flat rolls was 195°C and the linear pressure was 455N / cm; however, the temperature of both flat rolls was changed to 190°C and the linear pressure was changed to 455N / cm; and the basis weight of the long-fiber nonwoven fabric for printing substrate was changed to 90g / m 2 from 80g / m 2 A long-fiber nonwoven fabric for a printing substrate was obtained in the same manner as in Example 1, except that the weight per unit area of ​​the long-fiber nonwoven fabric for a printing substrate was 80 g / m 2 , thickness is 0.10 mm, density is 0.80 g / cm 3 , ventilation volume is 2cm 3 / (cm 2 The Young's modulus in the MD direction was 2455 MPa, the Young's modulus in the CD direction was 962 MPa, Za was 7.2 μm, Zb was 9.3 μm, and Za / Zb was 0.77. The results are shown in Table 1.

[0091] [Table 1]

[0092] The properties of the obtained nonwoven fabrics are shown in Table 1. The long-fiber nonwoven fabrics for printing substrates of Examples 1 to 6 all had a density of 0.40 g / cm 3 More than 0.90g / cm 3 The following long-fiber nonwoven fabrics for printing substrates had Za of 9 μm or more and 30 μm or less, and Za / Zb of 0.50 or more and 1.00 or less, and maintained hardness and moderate breathability, with little fuzz and a smooth surface. On the other hand, Comparative Example 1 was inferior in that the sheet was thick and had noticeable fuzz on the surface. Comparative Example 2 had a film-like surface, with low breathability and high rigidity, which were inferior.

[0093] [Example 7] The long-fiber nonwoven fabric for printing substrate of Example 1 was coated with a white resin layer of 27 g / m 2 The resulting printing substrate was coated with the resin to a thickness of 8 μm. The color development of the resulting printing substrate was rated A, with no problems, and the printing processability was also rated A. The results are shown in Table 2.

[0094] [Example 8] The long-fiber nonwoven fabric for printing substrate of Example 3 was coated with a white resin layer at 47 g / m 2 The resulting printed substrate was coated with the resin to a thickness of 78 μm. The color development of the resulting printed substrate was graded B due to some unevenness, but the printability was graded A with no problems. The results are shown in Table 2.

[0095] [Comparative Example 3] The long-fiber nonwoven fabric for printing substrate of Comparative Example 1 was coated with a white resin layer of 72 g / m 2 The resulting printed substrate was coated with the resin to a thickness of 102 μm. The color development of the resulting printed substrate was graded B because some unevenness was observed, and the printability was graded C because the edges were curled and wrinkles were found in seven places. The results are shown in Table 2.

[0096] [Table 2]

[0097] The properties of the obtained printing substrates and printed matter are as shown in Table 2. In Examples 7 and 8, the resin layer thickness was 5 μm or more and 80 μm or less, and there were no problems with printability, making them suitable printing substrates and printed matter. On the other hand, in Comparative Example 3, the resin layer thickness was 81 μm or more, making it heavy as a substrate and inferior in terms of handleability. In addition, the color development and processability during printing were also insufficient and inferior. [Explanation of symbols]

[0098] 1: Long-fiber nonwoven fabric for printing substrate 2, 4: The top of the cross section of the long-fiber nonwoven fabric for printing substrate 3, 5: Bottom of the cross section of the long-fiber nonwoven fabric for printing substrate 6: Line A 7: Straight line B 8: Center line of the cross section of the long-fiber nonwoven fabric for printing substrate

Claims

1. A long-fiber nonwoven fabric for a printing substrate, which is made of fibers containing a thermoplastic resin as a main component, and the long-fiber nonwoven fabric for a printing substrate has an apparent density of 0.40 g / cm ３ 0.90g / cm or more ３ a long-fiber nonwoven fabric for a printing substrate, wherein in a cross section of the long-fiber nonwoven fabric for a printing substrate, the ratio of the maximum height Za (μm) from the largest convex portion on one surface to the largest concave portion on the one surface to the maximum height Zb (μm) from the largest convex portion on the other surface to the largest concave portion on the other surface (Za / Zb, provided that Za<Zb) satisfies the relationship expressed by the following formula (1), and the range of Za is 9 μm or more and 30 μm or less. 0.50≦Za / Zb≦1.00 (1)

2. The long-fiber nonwoven fabric for a printing substrate according to claim 1 , wherein the Zb (μm) ranges from 10 μm to 50 μm.

3. 3. The long-fiber nonwoven fabric for printing substrates according to claim 1, wherein the fibers are conjugated fibers in which a low-melting polymer having a melting point lower than that of a high-melting polymer is disposed around the high-melting polymer.

4. The weight of the long fiber nonwoven fabric for printing substrate is 30 g / m ２ 120g / m or more ２ The long-fiber nonwoven fabric for printing substrates according to any one of claims 1 to 3, wherein:

5. The long-fiber nonwoven fabric for a printing substrate according to any one of claims 1 to 4, wherein the Young's modulus in the MD direction of the long-fiber nonwoven fabric for a printing substrate is 1200 MPa or more and 2200 MPa or less.

6. 6. The long-fiber nonwoven fabric for a printing substrate according to claim 1, wherein the Young's modulus in the CD direction of the long-fiber nonwoven fabric for a printing substrate is 300 MPa or more and 1000 MPa or less.

7. A printing substrate made using the long-fiber nonwoven fabric for printing substrates according to any one of claims 1 to 6, wherein a resin layer is provided on at least one surface of the long-fiber nonwoven fabric for printing substrates, and the thickness of the resin layer is 5 μm or more and 80 μm or less.

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