JP2019131922A - One-side glossy kraft paper and manufacturing method of the same - Google Patents

Abstract

To provide one-side glossy kraft paper having an appearance and a natural uneven texture of Japanese paper and having good workability and strength at the time of packaging and a method for producing the same.SOLUTION: The present invention comprises pulp fibers as a main component, one side is a glossy surface, the other side is a non-glossy surface, and the pulp contains hardwood bleached kraft pulp, coniferous bleached kraft pulp and coniferous unbleached kraft pulp. The total content of hardwood bleached kraft pulp and softwood bleached kraft pulp in the pulp is 95% by mass or more, the Bekk smoothness of the glossy surface is 85 seconds or more and 200 seconds or less, and the Beck smoothness of the non-glossy surface is 5 seconds or more and 20 seconds or less, smoothness difference between the glossy surface and the non-glossy surface is 80 seconds or more, and Parker print surf smoothness of the glossy surface is 1.6 μm or more and 5.5 μm or less, and Parker print surf smoothness of the non-glossy surface is 5.5 μm or more and 10.0 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to glossy kraft paper and a method for producing the same.

  In recent years, Japanese paper and paper having a texture of Japanese paper are used for various purposes. This is because, as the number of overseas tourists has increased rapidly, there has been a demand for ordinary paper that has a Japanese character. However, since Japanese paper is difficult to mass-produce due to problems with raw materials and manufacturing means, in view of such problems, paper such as large bill paper, cloud dragon paper, hooks, etc., called patterned paper with a Japanese paper-like texture Exists.

  Usually, a patterned paper having a Japanese paper-like texture as described above is manufactured using a raw material in which rayon fibers are mixed with pulp fibers. Specifically, a patterned paper having a two-layer structure is formed by adhering a pattern layer made of rayon fibers to a base layer made of rayon fibers and pulp fibers with a binder containing polyvinyl alcohol as a component. However, in such a patterned paper, since polyvinyl alcohol is water-soluble, the fibers of the patterned layer are loosened and become prone to fluffing and breaking when wet with water. Therefore, there has been a problem that it cannot be used in an environment where it gets wet with water.

  Therefore, in order to compensate for the above-described drawbacks, the first conventional technique discloses a pattern processed paper that forms a pattern by aggregating chemical fibers without using polyvinyl alcohol (see Patent Document 1). In the first prior art, the patterned paper is obtained by papermaking a raw material obtained by adding an aggregate containing chemical fibers to pulp fibers. Next, in the second conventional technique, a water-repellent high-humidity Japanese paper sheet is disclosed in which base paper composed of hemp fibers and other fiber materials is laminated as a constituent material (see Patent Document 2).

  In the third prior art, fingered sensitive paper having finger sensitivities with different front and back surfaces of the paper is disclosed. Using a dandy roll as a means for varying the fiber density during paper making, a so-called concavo-convex pattern is formed to produce fingered sensitivity (see Patent Document 3). In the fourth conventional technique, a technique for forming a concavo-convex pattern on the paper surface by using a papermaking net having a predetermined wire diameter on one side of the papermaking mesh used during papermaking is disclosed (see Patent Document 4). Further, Patent Document 5 discloses a technique for agglomerating a microcapsule-type foaming agent after fixing to a pulp to form an aggregated ground pattern, and then forming the ground pattern on a paper material to form an uneven pattern. (See Patent Document 5).

JP 2011-94253 A JP 2010-13753 A JP 2010-163718 A JP 11-315500 A Japanese Patent Publication No. 6-94640

However, in the first prior art, the adhesiveness of the pattern portion formed by the aggregate is not sufficient, and the pattern may be peeled off or defibrated during use. In the second prior art, it is considered that a Japanese paper-like appearance can be obtained by using relatively long hemp fibers among the fiber materials for paper use. It is difficult to get. Furthermore, in the second prior art, since it has a multi-layer structure and the thickness of the base material itself is increased, it is suitable for building materials, but may not be suitable for use in wrapping paper or handbags. is there. Further, in the third prior art, the operating means of the manufacturing equipment that brings out fingered sensibility is complicated and has a disadvantage in terms of cost, and the unevenness of the obtained fingered sensation sheet can be obtained by scoring. Therefore, there is a risk of an artificial texture pattern. Moreover, since the same unevenness | corrugation is expressed on both front and back surfaces, the visibility of the contents is increased, and the density is particularly reduced only at that portion, so that there is a possibility that breakage may occur. In the fourth prior art, there is a possibility that a natural texture cannot be obtained because it is a means for imparting an uneven pattern to the wet paper in the wet paper state. Furthermore, when the basis weight of the paper is 50 g / m ² or more required in applications such as wrapping paper and handbags, it is difficult to develop sufficient unevenness, and a Japanese paper-like texture on the appearance can be obtained. There is a risk of not. further. In the fifth prior art, microcapsules or the like may fall off when cutting or using paper, and may not be suitable for wrapping paper such as food, and a Japanese paper-like texture is obtained in appearance and feel. There is a risk of not being able to.

  In addition, wrapping paper and handbags are required to have strength to provide workability during packaging and durability during use.

  The present invention has been made based on the circumstances as described above, and produces a glossy kraft paper with a good workability and strength at the time of packaging, and a method for producing the same, while creating an appearance and a natural texture of Japanese paper. The purpose is to provide.

  The inventors of the present invention, as a result of intensive investigations on means for obtaining a texture of Japanese paper-like unevenness in appearance and feel, while using pulp fibers originally used for papermaking, as a result of the paper originally required to be uniform As a means of intentionally destroying the formation and further obtaining a Japanese paper-like appearance, it was found that the object of the present invention can be achieved by combining a plurality of pulp fibers and a specific drying means, and the present invention was completed.

The invention made in order to solve the above-mentioned problems is mainly composed of pulp fibers, one surface is a glossy surface, the other surface is a non-glossy surface, and the pulp is hardwood kraft pulp, softwood kraft pulp and Containing untreated kraft pulp, the total content of hardwood kraft pulp and coniferous kraft pulp in the pulp is 95% by mass or more, and measured according to JIS-P8119 (1998) of the glossy surface. The Beck smoothness is 85 seconds or more and 200 seconds or less, the Beck smoothness of the non-glossy surface is 5 seconds or more and 20 seconds or less, and the smoothness difference between the glossy surface and the non-glossy surface is 80 seconds. The Parker print surf smoothness measured according to JIS-8151 (2004) of the glossy surface is 1.6 μm or more and 5.5 μm or less. Car Print Surf smoothness is at 5.5μm or more 10.0μm or less, the total number of 0.05 m ² or more dart measured using an image analysis apparatus, 1,500 / ^{m 2} or more 3000 / ^{m 2} or less And a glossy kraft paper having a total area of dirt of 100 mm ² / m ² or more and 300 mm ² / m ² or less.
Here, the “glossy surface” refers to a surface having gloss. "Non-glossy surface" refers to a surface that does not have gloss.

Single glossy kraft paper is mainly composed of pulp fiber, one side is glossy side, the other side is non-glossy surface, and the above pulp is hardwood kraft pulp, coniferous kraft pulp and coniferous kraft pulp Contained, the total content of hardwood kraft pulp and the above-mentioned softwood kraft pulp in the above pulp is 95% by mass or more, so that the ground pattern caused by the coniferous pulp is intentionally produced, and the Japanese paper-like unevenness of the ground pattern is produced. A glossy kraft paper having good workability and strength during packaging can be obtained. In addition, by containing the soft kraft pulp, the surface of the single gloss kraft paper is used as a raw material for Japanese paper. A pattern can appear.
Further, the Beck smoothness measured in accordance with JIS-P8119 (1998) of the glossy surface is 85 seconds or more and 200 seconds or less, and the Beck smoothness of the non-glossy surface is 5 seconds or more and 20 seconds or less. And the difference in Beck smoothness between the glossy surface and the non-glossy surface is 80 seconds or more, and the Parker print surf smoothness measured according to JIS-8151 (2004) of the glossy surface is 1.6 μm. More than 5.5 μm, Parker print surf smoothness of the non-glossy surface is 5.5 μm or more and 10.0 μm or less, and the total number of dirt of 0.05 m ² or more measured using an image analyzer is The difference in smoothness between the glossy surface and the non-glossy surface can be obtained when the total area of the dart is 1500 mm / m ² or more and 3000 pieces / m ² or less and the total area of the dirt is 100 mm ² / m ² or more and 300 mm ² / m ² or less. Enlarge Not in appearance only it is possible to strike a texture of Japanese paper tone of unbleached in feel.

Both Beck smoothness and Parker print surf smoothness are devices that evaluate smoothness from the air flow rate (air leak), and the number of nips, nip pressure, roll temperature, roll material, roll hardness, etc. can be set as appropriate. In particular, smoothing treatment with a super calender and thermal calender suppresses the change in density, and as a means of adjusting only the surface property, the raw pulp in the present invention contains a large amount of lignin and is relatively unexposed to hard coniferous trees. It has an effect that does not impair the feel of kraft pulp and can be suitably used. The Beck smoothness specified in JIS-P8119 (1998) is about 98 (kN / m) / (g / m2) ² between the glass standard surface of the optical flat finish and the rubber pressing plate. It is expressed in terms of the time required for 10 ml of air to pass through a relatively wide 10 cm ² glass standard surface and flow into a vessel maintained at about 370 ml of mercury under reduced pressure. Parker print surf smoothness is a value measured at a clamping pressure of 0.5 MPa using a hard type backing, and according to the knowledge of the present inventors, the printing plate is more microscopic than Beck smoothness. In the present invention, the smoothness at the time of printing when printing pressure is applied by various printing presses can be evaluated by measuring the object under pressure. Exposed on the surface It has a close relationship with the surface state of that softwood unbleached kraft pulp. Therefore, it is possible to evaluate the printability as a wrapping paper and handbag which is the main use of the present invention with Beck smoothness, and with the Parker Print Surf smoothness, it is possible to evaluate the texture and fingering sensitivity of the Japanese paper of the present invention, Furthermore, the texture of Japanese paper on the appearance can be evaluated by the total number of dirt and the area of the dirt.

  The freeness of the hardwood kraft pulp is 500 ml or less, the freeness of the softwood kraft pulp and the softwood kraft pulp is 660 ml or more, the content of the hardwood kraft pulp, the softwood kraft pulp, The total content of the above-mentioned softwood kraft pulp is 55:45 to 65:35 by mass ratio, and the content of the above-mentioned softwood kraft pulp and the content of the above-mentioned softwood kraft pulp is a mass ratio. In the case of 87.5: 12.5-92.9: 7.1, it is used as a raw material for Japanese paper as it is unexposed in white base paper. It can express the content of ganpi) bast fibers. In particular, the freeness of untreated kraft pulp that has not progressed to fibrillation is 660 ml or more, so that the unbleached kraft pulp is fixed in broad-leaved sara kraft pulp or softwood bleached kraft pulp and hardly loses out. Toned kraft paper.

  When the difference in freeness between the hardwood kraft pulp and the softwood kraft pulp is 100 ml or more, it becomes easy to bring out the flatness of the glossy surface, the printing suitability is improved, and the bast fiber-like content is expressed. It becomes easy.

  The mass-weighted average fiber length measured according to JIS-P8226-2 (2011) in the single gloss kraft paper is 1.6 mm or more and 2.0 mm or less, and is measured using an ultrasonic propagation velocity measuring instrument. When the fiber orientation ratio is 1.20 or more and 1.50 or less, it is possible to improve the processability in wrapping paper and handbag use, and the paper quality such as tension, tearing, and curl resistance.

Further, another invention made to solve the above-mentioned problems is a paper making process of a raw pulp containing hardwood straw kraft pulp, softwood straw kraft pulp and conifer wood kraft pulp, and paper made in the paper making process Forming a glossy surface by drying one surface of the raw material pulp with a Yankee dryer, the total content of the hardwood kraft pulp and the softwood kraft pulp in the raw pulp is 95% by mass or more, The Beck smoothness measured in accordance with JIS-P8119 (1998) is 85 seconds to 200 seconds, the Beck smoothness of the non-glossy surface is 5 seconds to 20 seconds, and the glossy surface. And the Parker print server which has a difference in smoothness of the non-glossy surface of 80 seconds or more and is measured according to JIS-8151 (2004) of the glossy surface. 0.05m smoothness is at 1.6μm or 5.5μm or less, Parker Print Surf smoothness of the non-gloss surface, and a 5.5μm or 10.0μm or less, as measured using an image analyzer ^The method for producing single glossy kraft paper, wherein the total number of darts of ² or more is 1500 / m ² or more and 3000 / m ² or less, and the total area of the darts is 100 mm ² / m ² or more and 300 mm ² / m ² or less It is.

  The production method of the single glossy kraft paper has the above-described configuration, so that it does not require a large amount of capital investment and complicated processes, and using existing equipment, the appearance and natural uneven texture that Japanese paper has It is possible to produce glazed kraft paper with good workability and strength during packaging.

  ADVANTAGE OF THE INVENTION According to this invention, while giving the external appearance and natural uneven | corrugated texture which Japanese paper is equipped with, the glossiness kraft paper with favorable workability | operativity and intensity | strength at the time of packaging can be provided.

  Hereinafter, a single glossy kraft paper and a manufacturing method thereof according to an embodiment of the present invention will be described in detail.

<Single gloss craft paper>
The single glossy kraft paper has pulp fibers as a main component, and one surface (back surface) is a glossy surface and the other surface (front surface) is a non-glossy surface. Moreover, the said pulp contains a hardwood cocoon kraft pulp, a coniferous cocoon kraft pulp, and a softwood unsettled kraft pulp.

  The single glossy kraft paper fills the gap between the soft cocoon kraft pulp that is rigid and has a long fiber length due to the residual lignin, the soft cocoon kraft pulp that is relatively soft but has a long fiber length, and the above softwood kraft pulp. In order to ensure the printability required for packaging paper applications, hardwood kraft pulp is combined and mixed to create a ground pattern caused by coniferous pulp intentionally. Paper can be obtained. In addition, by containing the soft kraft pulp, the surface of the single gloss kraft paper is used as a raw material for Japanese paper. A pattern can appear.

[Pulp fiber]
Pulp fibers as a raw material constitute the main component of single gloss kraft paper. The main component means a component having the highest content on a mass basis. The pulp fibers used for the single glossy kraft paper include hardwood kraft pulp, coniferous kraft pulp and softwood virgin kraft pulp.

  The lower limit of the total content of hardwood kraft pulp and softwood kraft pulp in the pulp is 95% by mass. The total content of the hardwood kraft pulp and the softwood kraft pulp in the pulp is 95% by mass or more, so that a ground pattern caused by the coniferous pulp is intentionally produced, and the ground pattern has Japanese paper-like unevenness. Single glossy kraft paper with good workability and strength during packaging can be obtained.

  The content of the hardwood kraft pulp and the total content of the softwood kraft pulp and the softwood kraft pulp are preferably 55:45 to 65:35 in mass ratio. Moreover, it is preferable that content of the said coniferous kraft pulp and content of the said coniferous kraft pulp are 87.5: 12.5-92.9: 7.1 by mass ratio. When the above mass ratio is in the above range, it is used as a raw material for Japanese paper as it is unexposed in white base paper, containing bast fibers like koji, mitsumama or ganpi Can be expressed.

  The content of hardwood kraft pulp with respect to the total content of hardwood kraft pulp, coniferous kraft pulp and softwood uncured kraft pulp is preferably 57% by mass or more and 62% by mass or less, and coniferous kraft kraft pulp with respect to the total content. The content of is preferably 35% by mass or more and 41% by mass or less, and the content of softwood kraft pulp with respect to the total content is preferably 3% by mass or more and 5% by mass or less. The content of hardwood kraft pulp, softwood kraft pulp and softwood kraft pulp is in the above range, so that the appearance and natural uneven texture that Japanese paper has is better and the workability at the time of packaging and Can provide glossy kraft paper with good strength.

(Hardwood kraft pulp)
The raw pulp of the single gloss kraft paper contains a large amount of hardwood kraft pulp (LBKP) which is excellent in dimensional stability.

  The upper limit of the freeness of hardwood kraft pulp is preferably 500 ml, more preferably 480 ml. When the freeness exceeds 500 ml, it is difficult to prevent the softwood non-saracraft pulp from falling off, and the flatness of the glossy surface may be impaired.

  The whiteness of the pulp is measured according to JIS-P8148 (2001). The lower limit of the whiteness of the broad-leaved kraft pulp is preferably 70% or more and 80% or less from the viewpoint that the appearance of unbleached pulp fibers in the bleached pulp fibers becomes clear in appearance.

(Coniferous bleached kraft pulp)
Softwood bleached kraft pulp (NBKP) has a longer fiber length than hardwood kraft kraft pulp and is strong and supple.

  The lower limit of the freeness of the softwood bleached kraft pulp is preferably 660 ml, more preferably 680 ml. When the freeness is 660 ml or more, the texture, tensile strength, and tear strength of the wrapping paper and handbags that are the main uses of the present invention can be ensured, and in combination with the coexistence of unbleached kraft pulp, the texture of Japanese paper Can be produced. In addition, the freeness of untreated softwood kraft pulp is not less than 660 ml, so that unbleached kraft pulp is fixed in broad-leaved Sarak kraft pulp and softwood bleached kraft pulp, and almost no drop occurs. Toned kraft paper. Furthermore, as the difference in freeness between the hardwood kraft pulp and the softwood bleached kraft pulp, the viewpoints of ensuring the surface properties, printability and paper quality strength for wrapping paper and handbags as required by each Japanese paper Therefore, 100 ml or more that can obtain a synergistic effect without inhibiting each other's effect is preferable.

  The lower limit of the whiteness of the softwood bleached kraft pulp is preferably 66% or more and 70% or less from the viewpoint that the appearance of unbleached pulp fibers in the bleached pulp fibers becomes clear in appearance.

(Unbleached kraft pulp of conifers)
Softwood kraft pulp has a relatively high strength, especially softwood unbleached kraft pulp (NUKP) from which not much lignin and sterol ester compounds have been removed has a higher strength due to the action of lignin remaining in the pulp, In addition, the sterol ester compound remaining in the pulp provides the pulp fiber with excellent lubricity and moderate rigidity and breakage resistance. For this reason, the use of softwood unbleached kraft pulp as a raw material pulp can impart high strength and suitable workability to the single gloss kraft paper. Further, the unbleached kraft pulp is entangled with the coexistence with other pulp fibers in the paper layer, and from the viewpoint of obtaining a Japanese paper-like texture, the concentration at the initial stage of beating is preferably 5 to 15% by mass. The concentration is preferably 2 to 8% by mass. When softwood kraft pulp is beaten at a high concentration, it is refined by friction between fibers rather than by cutting with a blade. For this reason, fibrillation is beaten predominately than shortening, and shortening can be achieved while maintaining a wide average fiber width like bast fibers of cocoon, mitsu or scab. When the raw material concentration is low, fibrils are difficult to be generated because shortening fiber works preferentially, and the generated fibrils are also dropped due to the cutting force applied by the blade.

  As a minimum of the above-mentioned freeness of softwood unbleached kraft pulp, 660 ml is preferred and 680 ml is more preferred. When the freeness of the disaggregated pulp is 660 ml or more, it is easy to express the existence of softwood unbleached kraft pulp, and it is easy to create a Japanese paper-like texture. In addition, the difference in freeness between the above hardwood kraft pulp and the above-mentioned unbleached kraft pulp is that the paper layer contains bast fibers such as cocoon, mitsu or ganpi. From the viewpoint of producing fingered sensibility, 100 ml or more is preferable.

  The whiteness of the unbleached kraft pulp is preferably 23% or more and 32% or less from the viewpoint of bringing about the appearance of bast fibers of apparent cocoons, mitsutsu and scabs.

The “kappa number” is a value measured in accordance with JIS-P-8211 (2011) and serves as an index of the lignin amount of unbleached pulp. The copper value of unbleached kraft pulp is preferably 14 or more and 18 or less. If the kappa number of unbleached kraft pulp is less than the above lower limit, the appearance of unbleached pulp may be weakened and the texture of Japanese paper may be impaired. In addition, when the kappa number exceeds the above upper limit, the content of bast fibers in cocoons, mitsu and ganpi can be emphasized, but coexistence with other pulp in the paper layer can be obtained. This makes it difficult to cause the unbleached pulp to fall off or to be exposed, which impairs the appearance and makes it unsuitable for wrapping paper or handbag use.

(Other raw pulp)
The raw material pulp is generally used as a papermaking raw material, such as waste paper pulp, mechanical pulp, and non-wood pulp, as long as it does not impair the texture of Japanese paper that is the object of the present invention. One kind or two or more kinds of raw material pulp can be mixed and used.

[Coagulant]
In the single gloss kraft paper, it is preferable to add a coagulant to suppress fluctuations in pulp-derived inorganic particles and fine pulp fibers, and it is particularly preferable to add a cationic polymer. Examples of the coagulant include diallyldimethylammonium chloride polymer, polyethyleneimine modified product, 2- (methacryloyloxy) ethyltrimethylammonium chloride polymer, polyethyleneimine, diallyldimethylammonium chloride / acrylamide copolymer, polyamine polymer, acrylamide. Examples include copolymers. Among these, a diallyldimethylammonium chloride / acrylamide copolymer is preferable from the viewpoint of corresponding to the anionic property of unbleached kraft pulp containing a large amount of lignin. Moreover, as a mass average molecular weight of a coagulant | flocculant, a 500,000 to 5 million compound can be used conveniently.

  The lower limit of the solid content of the coagulant in the pulp slurry with respect to the pulp fibers is preferably 0.3 kg / pulp t, more preferably 0.5 kg / pulp t. Moreover, as an upper limit of content with respect to the pulp fiber of the coagulant | flocculant in the said pulp slurry, 2.0 kg / pulp t is preferable and 1.8 kg / pulp t is more preferable. When the content of the coagulant with respect to the pulp fiber is in the above range, flocking is avoided, moderate agglomeration of unexposed kraft pulp of softwood is brought about, and further, it is easy to secure the paper quality strength for wrapping paper and handbag use.

[Other additives]
In the base paper of the glossy kraft paper, known papermaking additives other than the coagulant may be added. Such an internal additive is not particularly limited, and various chemicals can be used alone or in combination. For example, flocculant, sulfuric acid band, bentonite, silica, sizing agent, dry paper strength agent, wet paper strength agent, bulking agent, filler, dye, fluorescent whitening agent, pH adjuster, antifoaming agent, UV protection agent, anti-fading Paper-making chemicals such as an agent, a pitch control agent, and a slime control agent can be used. Among these, a flocculant; polyacrylamide polymer, polyvinyl alcohol polymer, cationic starch, various modified starches, urea / formalin resin, melamine / holgan resin, etc. Strength enhancer; Internal wet paper strength enhancer such as polyamide polyamine epichlorohydrin resin; Internal addition of rosin sizing agent, AKD sizing agent, ASA sizing agent, petroleum sizing agent, neutral rosin sizing agent, etc. Sizing agent; and the like.

(Beck smoothness)
The Beck smoothness is a value measured according to JIS-P8119 (1999). The Beck smoothness is a device for obtaining smoothness from the air flow rate in the same manner as Parker print surf smoothness described later, and evaluates macro smoothness in a relatively wide surface. In the single glossy kraft paper, the so-called waviness of the surface can be evaluated by the Beck smoothness. In this way, by placing both the Parker print surf smoothness and the evaluation values of the Beck smoothness within a predetermined range, the surface flatness of the glossy paper on a microscopic surface and a certain wide surface can be obtained. The texture of Japanese paper tone by containing unbleached kraft pulp can be evaluated.

  The lower limit of the Beck smoothness on the glossy side of the single gloss kraft paper is 85 seconds, and preferably 95 seconds. When the glossy side Beck smoothness is less than 85 seconds, the surface flatness is impaired due to the presence of rigid softwood unbleached kraft pulp, which may impair the printability required for wrapping paper and handbags. On the other hand, the upper limit is preferably 200 seconds and more preferably 180 seconds. When the glossy side Beck smoothness exceeds 200 seconds, the flatness of the glossy surface becomes excessive and the fingered feeling is inferior, which may cause a problem that the texture of Japanese paper intended by the present invention is impaired.

  The lower limit of the Beck smoothness on the non-glossy side (back side) of the single glossy kraft paper is 5 seconds, and preferably 7 seconds. When the Beck smoothness on the glossy surface side is less than 5 seconds, there is a possibility that rigid softwood unbleached kraft pulp may be exposed or dropped. On the other hand, the upper limit is preferably 20 seconds, and more preferably 18 seconds. When drying with a Yankee dryer, it is necessary to take measures such as combining a multi-cylinder dryer in order to increase the Beck smoothness on the non-glossy surface side to 20 seconds or more. As a result, the texture of the Japanese paper may be impaired.

  The lower limit of the Beck smoothness difference between the glossy surface and the non-glossy surface is 80 seconds, and more preferably 85 seconds. When the Beck smoothness difference is less than 80 seconds, there is a possibility that the texture of Japanese paper is impaired along with the texture of matt glossy kraft paper.

(Parker print surf smoothness)
Parker print surf smoothness (hereinafter also referred to as “PPS smoothness”) measured in the examples described later is Parker print surf smoothness (μm) measured according to Appendix A of JIS-P8151 (2004). is there. Parker print surf smoothness is a device that obtains smoothness from the air flow rate in the same way as Beck smoothness, but it is possible to measure the smoothness under pressure by applying pressure to the measuring head. . In the present invention, by setting the measurement pressure to 0.5 Mpa and hard backing, it is suitable for quantifying the feeling close to a so-called finger feeling, and the measured value has a Japanese paper-like unevenness and smoothness. It seems to represent quite accurately. That is, when the Parker print surf smoothness is high, the measurement surface of the glossy kraft paper has Japanese paper-like irregularities, and the texture of the Japanese paper-like irregularities can be felt from the touch. On the other hand, when the Parker print surf smoothness is low, the measurement surface is flat, the fixing property of the ink on the surface of the single glossy kraft paper is excellent, and problems such as printing blur are unlikely to occur.

  The lower limit of the Parker print surf smoothness of the glossy surface of the single glossy kraft paper is 1.6 μm, and preferably 2.2 μm. The upper limit of the Parker print surf smoothness of the glossy surface is 5.5 μm, and more preferably 5.3 μm. When the Parker print surf smoothness of the glossy surface is within the above range, an appropriate ink fixing property can be obtained while producing a texture of Japanese paper-like unevenness, and the printability is improved.

  The lower limit of the Parker print surf smoothness of the non-glossy surface of the single glossy kraft paper is 5.5 μm, and preferably 5.7 μm. The upper limit of the Parker print surf smoothness of the non-glossy surface is 10.0 μm, preferably 9.8 μm. When the Parker print surf smoothness of the non-glossy surface is in the above range, Japanese paper-like irregularities can be satisfactorily expressed not only in appearance but also in touch while maintaining printability.

(Dirt)
The lower limit of the total number of 0.05 m ² or more dart of the piece gloss kraft paper is measured using an image analyzer, a 1400 / ^{m 2,} preferably 1,500 / ^{m 2.} The upper limit of the total number of dirts is 3000 / m ² , preferably 2800 / m ² . The lower limit of the total area of dirt of the piece gloss kraft paper is 100 mm ² / ^{m 2,} preferably 90mm ² / ^{m 2.} Moreover, as an upper limit of the total area of the dirt of the glossy kraft paper, it is 300 mm ² / m ² , and preferably 280 mm ² / m ² . According to the knowledge of the present inventors, in order to ensure a Japanese paper-like appearance and uneven texture, a predetermined amount of unbleached pulp fiber is required on the surface of the kraft paper, and an image analysis device is used as an appearance evaluation method. It has been found that it is preferable to set the above numerical range in the index measured in this manner.

(Mass weighted average fiber length)
The mass weighted average fiber length is measured according to JIS-P8226-2 (2011). The mass-weighted average fiber length of the single gloss kraft paper is preferably 1.6 mm or more and 2.0 mm. When the mass weighted average fiber length is in the above range, the dimensional stability is improved.

(Fiber orientation ratio)
The fiber orientation ratio is a measure of the degree of fiber orientation (arrangement), and the pulp fiber flows out onto the wire of the paper machine and dehydrates in the process of forming a paper layer (pulp fiber on the paper machine). In the direction of flow). The fiber orientation ratio indicates that the larger the numerical value, the stronger the degree of arrangement. In the present invention, an ultrasonic method is employed, and an ultrasonic propagation velocity measuring device is used to measure the longitudinal ultrasonic propagation velocity (VMD) and the transverse ultrasonic propagation velocity (VCD), and the ratio (VMD / VCD). ) Is a fiber orientation ratio, and the randomness of the fiber orientation is evaluated. Since fiber swelling and shrinkage during moisture absorption and dehumidification is performed in the transverse (CD) direction of the fiber, the fiber orientation ratio and the transverse direction representing the degree of dimensional change of the paper when sucking water are shown. Regarding the relationship with the elongation in water, when the fiber orientation ratio is high, the lateral elongation in water is large, and when the fiber orientation ratio is low, the lateral elongation in water is small, and both act directly. This fiber orientation ratio is determined by the paper making conditions in the machine, and a desired fiber orientation ratio can be obtained by adjusting the machine speed, the ratio of the fiber suspension jet inflow speed to the wire speed (J / W ratio), etc. Optimization is mentioned.
Here, the “longitudinal direction” means a paper making direction (MD), and the “horizontal direction” means a direction perpendicular to the longitudinal direction (CD: Cross Direction).

  The fiber orientation ratio measured using the ultrasonic transmission velocity measuring instrument for the single glossy kraft paper is preferably 1.20 or more and 1.50 or less. When the fiber orientation ratio is in the above range, workability and strength during packaging can be further improved.

(Specific tensile strength of single glossy kraft paper)
The specific tensile strength in the machine direction of the single glossy kraft paper according to JIS-P8113 (2006) is 0.048 (kN / m) / (g / m ² ) or more and 0.065 (kN / m). / (G / m ² ) or less is preferable, and the specific tensile strength in the transverse direction perpendicular to the longitudinal direction is 0.037 (kN / m) / (g / m ² ) or more and 0.053 (kN / m). / (G / m ² ) or less is preferable. When the specific tensile strength of the single glossy kraft paper is in the above range, the paper strength as a wrapping paper or hand-paper can be further improved, which is the main use of the single glossy kraft paper.

(Specific tear strength of single gloss kraft paper)
The specific tear strength in the longitudinal direction of the fiber according to JIS-P8116 (2000) of the single glossy kraft paper is 8.25 (mN) / (g / m ² ) or more and 8.93 (mN) / (g / m ² ) or less is preferable, and the specific tear strength in the transverse direction perpendicular to the longitudinal direction is 9.93 (mN) / (g / m ² ) or more and 10.98 (mN) / (g / m ² ) or less. Is preferred. When the specific tear strength of the single glossy kraft paper is within the above range, it is possible to further improve the breakage and processing suitability of wrapping paper and handbags, which are the main uses of the single glossy kraft paper.

(Whiteness of single glossy kraft paper)
The whiteness is a value measured according to JIS-P8148 (2001). The single glossy kraft paper exhibits a kraft paper surface with a mixture of bleached pulp and unbleached pulp fibers, so that a measured value lower than the appearance whiteness can be obtained, but it represents a moderate whiteness of Japanese paper. Therefore, the whiteness of the glossy kraft paper is preferably 68% or more and 72% or less.

(Basis weight)
The lower limit of the basis weight of the piece gloss kraft paper, preferably ^{30g / m 2, 40g / m} 2 is more preferable. When the basis weight is less than 30 g / m ^2, there is a possibility that the paper quality strength as wrapping paper or handbag paper cannot be satisfied. As said upper limit, 150 g / m < ² > is preferable. If the basis weight of single gloss kraft paper exceeds 150 g / m ² , it is not preferable from the viewpoint of weight reduction.

  According to the single-glazed kraft paper, it is possible to obtain a single-glazed kraft paper having an appearance and a natural uneven texture of Japanese paper and having good workability and strength during packaging.

<Manufacturing method of single gloss kraft paper>
The process for producing the single glossy kraft paper includes a step of making raw pulp containing hardwood kraft pulp, coniferous kraft pulp and softwood kraft pulp, and one side of the paper made in the paper making step using a Yankee dryer. And a step of forming a glossy surface by drying.

In the paper making process, the pulp slurry is dewatered (paper making). The single glossy kraft paper is made from unleaved coniferous kraft pulp, coniferous kraft kraft pulp, and broadleaf cocoon kraft pulp. As described above, the total content of the hardwood kraft pulp and the softwood kraft pulp in the raw pulp is 95% by mass or more.

  Next, the mixed paper is sent to the head box of the paper machine, and is jetted from the head box onto the wire, and paper is made at a speed of 100 to 800 m / min. As the paper machine, for example, a long paper machine, a twin wire paper machine, a cap former paper machine, a Yankee paper machine, etc. can be used as appropriate, but even with a twin wire paper machine where the formation tends to deteriorate, the effect of the present invention can be achieved. Can be demonstrated significantly. Examples of twin wire paper machines include gap formers and on-top formers. Among these paper machines, a gap former type paper machine, more preferably an on-top type gap former paper machine is preferable. In the production method of the single glossy kraft paper, as a means for producing a texture of a Japanese paper tone while forming a suitable ground pattern, as a form of gap former from the viewpoint of forming a suitable ground pattern unevenness, It is preferable that the mold gap former is further made with a J / W ratio of 100 or more.

  Next, one side of the pulp (paper-made pulp) obtained by dehydrating the pulp slurry is dried with a Yankee dryer. The texture of the Japanese paper-like unevenness, which is the object of the present invention, is preferably dried with a Yankee dryer, and it becomes possible to change the flatness of one side and the other side during drying with a Yankee dryer. It is possible to form irregularities that create a tone. The glossy kraft paper has a glossy surface in contact with the Yankee dryer. More specifically, the glossy surface of mono-glazed kraft paper is obtained by pressing wet paper against the Yankee dryer with a so-called blanket and copying the mirror surface of the cylinder surface of the Yankee dryer onto the wet paper. In the drying process with a Yankee dryer, the surface temperature of the dryer is in pressure contact with the mirror surface of the Yankee dryer within a range of 100 ° C. to 150 ° C. Further, the non-contact surface with the Yankee dryer is formed as a non-glossy surface. On the non-glossy surface side, the Beck smoothness and the Parker print surf smoothness are adjusted by adjusting the pressure of the touch roll that presses the blanket material or the blanket against the Yankee dryer.

As described above, the glossy surface of the obtained glossy kraft paper has a Beck smoothness of 85 seconds to 200 seconds, the Beck smoothness of the non-glossy surface is 5 seconds to 20 seconds, and the gloss. The smoothness difference between the surface and the non-glossy surface is 80 seconds or more. Moreover, the Parker print surf smoothness of the glossy surface of the single gloss kraft paper is 2.0 μm or more and 5.5 μm or less, and the Parker print surf smoothness of the non-glossy surface is 5.5 μm or more and 10.0 μm or less. It is. Furthermore, the total number of 0.05 m ² or more dart the strip gloss kraft paper is measured using an image analysis apparatus is 3,000 1,500 / ^{m 2} or more pieces / ^{m 2} or less, and the total area of the dart 100mm ² / m ² or more and 300 mm ² / m ² or less.

  According to the production method of the single glossy kraft paper, it does not require a large amount of capital investment and complicated processes, and it uses the existing equipment to bring out the appearance and natural uneven texture that Japanese paper has, and at the time of packaging It is possible to produce glazed kraft paper with good workability and strength.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and can be implemented in a mode in which various changes and improvements are made in addition to the above-described mode.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

  The measuring method of the physical-property value of an Example and a comparative example is as follows.

[Freeness of each pulp (mL)]
Hardwood cocoon kraft pulp, softwood cocoon kraft pulp and softwood unfinished kraft pulp are disaggregated according to JIS-P8220-1 (2012) pulp disaggregation method, and this disaggregated pulp is defined as JIS-P811-2. (2012) Canadian standard freeness test method.

[Kappa number of unleavened conifer kraft pulp]
The copper value of unleavened conifer kraft pulp was measured according to JIS-P-8211 (2011).

[Beck smoothness (seconds)]
It was measured according to “Measurement method of Beck smoothness” described in JIS-P8119 (1998).

[Parker Print Surf Smoothness (μm)]
Using a PPS roughness measuring machine manufactured by Kumagai Riki Kogyo Co., Ltd., with soft backing and clamping pressure of 0.5 MPa, according to “Measurement method of Parker print surf smoothness” described in JIS-P8151 (2004) It was measured.

[Basis weight (g / m ² )]
It was measured according to “Paper and paperboard—basis weight measurement method” described in JIS-P8142 (1998).

[Dirt]
The number and total area of the dirt were measured using a scan mark 800 which is an image analysis system manufactured by Nomura Corporation.

[Fiber orientation ratio]
The fiber orientation ratio was measured using an optical orientation tester manufactured by Toyo Seiki Seisakusho.

[Specific tensile strength]
It measured based on JIS-P8113 (2006).

[Specific tear strength]
It measured based on JIS-P8116 (2000).

[Whiteness]
It measured based on JIS-P8148 (2001).

[Example 1]
(1) A pulp slurry containing 58% by mass of hardwood kraft pulp, 38% by mass of softwood kraft pulp, and 4% by mass of softwood kraft pulp is prepared. The softwood unbleached kraft pulp was beaten at a concentration of 3.5%.
(2) In 100 parts of pulp slurry, diallyldimethylammonium chloride / acrylamide copolymer as a coagulant [mass average molecular weight 2 million] (“A2400” manufactured by Somaru): 1.4 kg / pulp t, and others A rosin sizing agent, a dry paper strength agent (polyacrylamide (RP236Y manufactured by Harima)), starch, a sulfate band (aluminum sulfate), a dye, and the like were appropriately added.
(3) The pulp slurry was made by a wire part using a long web paper machine.
(4) Next, using a Yankee dryer, the wire surface was made a glossy surface (back surface), and the glossy kraft paper of Example 1 was obtained.
(5) The physical properties of the single gloss kraft paper of Example 1 are as follows.
(Raw pulp)
Hardwood kraft pulp: Freeness 470mL Whiteness 85%
Coniferous kraft pulp: Freeness 700mL Whiteness 78%
Softwood kraft pulp: Freeness 750mL, Whiteness 30%
Copper number 16
(Glossy kraft paper)
Basis weight: 120 g / m ²
Mass weighted average fiber length: 1.74 (mm)
Fiber orientation ratio: 1.27
Beck smoothness: glossy surface (back surface) 103 seconds, non-glossy surface (front surface) 12 seconds, smoothness difference 91 seconds Parker print surf smoothness: glossy surface (back surface) 3.8 μm, non-glossy surface (front surface) 8.4 μm
Dirt: 0.05 m ² or more of the total number 1623 (number ^{/ m} 2), total area ¹²² (mm 2 ^{/ m} 2)
Specific tensile strength: 0.055 (mN) / (g / m ² ) in the machine direction
: Lateral direction 0.039 (mN) / (g / m ² )
Specific tear strength: 8.82 (mN) / (g / m ² ) in the longitudinal direction
: Lateral direction 10.65 (mN) / (g / m ² )
Whiteness: 70.4%

[Examples 2 to 18 and Comparative Examples 1 to 6]
The glossy kraft paper of Examples 2 to 18 and Comparative 1 to Comparative Example 6 is obtained in the same manner as in Example 1 except that the types, contents and physical properties of the raw materials are as shown in Table 1. It was.
Moreover, the following raw materials were used as the coagulant.
(A) Diallyldimethylammonium chloride polymer [mass average molecular weight 300,000]: “Himax SC-100” manufactured by Hymo
(B) Modified polyethyleneimine [mass average molecular weight 500,000]: “Himax SC-924” manufactured by Hymo Co., Ltd.
(C) Diallyldimethylammonium chloride / acrylamide copolymer [mass average molecular weight 2 million]: “A2400” manufactured by Somar
(D) Polyamine polymer [mass average molecular weight 5 million]: “Himoloc FR740” manufactured by HAimo
(E) Acrylamide copolymer [mass average molecular weight 8 million]: “Nalco 61610” manufactured by Nalco
In addition, “-” in the following Table 1 indicates that the corresponding component was not used.

[Evaluation]
(sensory evaluation)
Sensory evaluation was performed on the obtained glossy kraft paper (size 210 × 297 mm: A4) with respect to the texture and texture of Japanese paper in Examples and Comparative Examples by the following method.
Japanese paper tone was judged visually, and the texture of the unevenness of the Japanese paper was judged by touch.
The evaluation criteria were as follows. Sensory evaluation by 10 adult men and women was judged according to the following evaluation criteria. The evaluation results are shown in Table 2 below.

(1) Appearance evaluation of Japanese paper style: Glossy surface A: Appearance is not inferior to Japanese paper in appearance, and can be judged as equivalent to Japanese paper.
○: Japanese paper-like pattern is expressed.
Δ: Japanese paper-like pattern is not sufficiently expressed.
X: The appearance is not Japanese paper.
(2) Texture: glossy surface)
(Double-circle): The touch and surface property are equivalent to Japanese paper.
○: It has finger feeling and has a texture close to that of Japanese paper.
(Triangle | delta): Although it has finger sensitivity, the texture of Japanese paper is not enough.
X: The texture of Japanese paper is not felt.

[Evaluation]
(Packaging workability evaluation)
Using an automatic bag making machine (model number: 136T + 504TH, manufactured by Neurong Kogyo Co., Ltd.), a square bottom bag was processed from single glossy kraft paper and evaluated based on the following evaluation criteria.
(1) Processing speed A: The processing state is uniform as a whole, and can be processed at a speed equivalent to that of conventional single glossy kraft paper.
○: Although the processing state is slightly inferior, it can be processed at a speed equivalent to that of conventional single glossy kraft paper.
(Triangle | delta): Since the tendency for a processing state to fall is seen, it is necessary to reduce a processing speed compared with the conventional glossy kraft paper. Waves are observed in the glued part.
X: The processing state is not uniform, and no improvement is seen even if the processing speed is greatly reduced.
(2) Bag making suitability Using the above-mentioned automatic bag making machine, processing a square bottom bag from single glossy kraft paper, examining the state of square cracks at the folded portion of the square bottom bag, and based on the following evaluation criteria And evaluated.
(Double-circle): In the processed square bottom bag, the frequency of occurrence of square cracks is less than that of conventional single glossy kraft paper.
○: In the processed square bottom bag, the frequency of occurrence of square cracks is the same as that of conventional single glossy kraft paper.
Δ: In the processed square-bottomed bag, the frequency of occurrence of angular cracking is the same as that of conventional glossy kraft paper, but when multiple corners are observed in one bag, or the frequency of angular cracking is the same as that of conventional glossy kraft paper Less than double and the size of one bag is light.
X: In the processed square bottom bag, the frequency of occurrence of square cracks is more than double that of conventional single gloss kraft paper.
(3) Square bottom bag making property Using the above-described automatic bag making machine, square bottom bags were produced from single-glazed kraft paper, and the obtained square bottom bags were evaluated based on the following evaluation criteria.
(Double-circle): The obtained square bottom bag has moderate waist | lumbar | floor and a softness | flexibility, and its bonding property is good, and it can perform the packaging operation | work of a to-be packaged object very smoothly.
○: Good slipperiness between the article to be packaged and the inner surface of the square bottom bag is obtained, and the packaging operation can be performed smoothly.
X: As a square bottom bag, it lacks moderate waist and flexibility, and the packaging work cannot be performed smoothly.

  As shown in Table 2 above, it was shown that Examples 1 to 18 of the glossy kraft paper were good both in visual appearance evaluation of Japanese paper tone and texture evaluation by touch. Examples 1 to 18 were also good in terms of processing speed, bag-making suitability, and square-bottom bag-making ability, which are packaging workability evaluations. Meanwhile, the total content of hardwood kraft pulp and the above softwood kraft pulp in pulp, Beck smoothness, Parker print surf smoothness, the total number of darts and the total area of the darts is the one glossy kraft paper Comparative Example 1 to Comparative Example 6 that do not have the requirements are either of Japanese paper-like appearance evaluation and sensory evaluation, which are sensory evaluations, and processing workability, which is packaging workability evaluation, bag-making suitability, and square-bottom bag-making characteristics. It was inferior in either. In Examples 1 to 18, it was shown that the specific tensile strength and specific tear strength all showed good values and the strength was excellent.

  The glossy kraft paper of the present invention can be suitably used as a wrapping paper for gifts such as Japanese confectionery, a handbag, etc. as a patterned paper having a Japanese paper-like texture.

Claims (5)

With pulp fiber as the main component,
One side is glossy, the other side is non-glossy,
The pulp contains hardwood straw kraft pulp, softwood straw kraft pulp and softwood unripe kraft pulp, the total content of hardwood straw kraft pulp and the softwood straw kraft pulp in the pulp is 95% by mass or more,
The Beck smoothness measured according to JIS-P8119 (1998) of the glossy surface is 85 seconds or more and 200 seconds or less, and the Beck smoothness of the non-glossy surface is 5 seconds or more and 20 seconds or less, And the smoothness difference between the glossy surface and the non-glossy surface is 80 seconds or more,
Parker print surf smoothness measured according to JIS-8151 (2004) of the glossy surface is 1.6 μm or more and 5.5 μm or less, and Parker print surf smoothness of the non-glossy surface is 5.5 μm or more. 10.0 μm or less,
Total 0.05 m ² or more dart measured using an image analysis apparatus, 1,500 / ^{m 2} or more 3000 / ^{m 2} or less, and the total area of the dart 100 mm ² / ^{m 2} or more 300 mm ² / m ² pieces gloss kraft paper or less. The freeness of the hardwood kraft pulp is 500 ml or less,
Freeness of the above-mentioned coniferous kraft pulp and coniferous kraft pulp is not less than 660 cml,
The content of the hardwood kraft kraft pulp and the total content of the coniferous kraft kraft pulp and the softwood kraft pulp are 55:45 to 65:35 by mass ratio,
2. The piece according to claim 1, wherein the content of the coniferous kraft pulp and the content of the coniferous kraft pulp are 87.5: 12.5 to 92.9: 7.1 in mass ratio. Glossy kraft paper.   The glossy kraft paper according to claim 1 or 2, wherein a difference in freeness between the hardwood kraft pulp and the softwood kraft pulp is 100 ml or more. The mass weighted average fiber length measured according to JIS-P8226-2 (2011) is 1.6 mm or more and 2.0 mm or less,
The glossy kraft paper according to claim 1, wherein the fiber orientation ratio measured using an ultrasonic propagation velocity measuring instrument is 1.20 or more and 1.50 or less. Making a raw pulp containing hardwood kraft pulp, softwood kraft pulp and softwood kraft pulp,
A step of drying one side of the paper made in the paper making process with a Yankee dryer to form a glossy surface,
The total content of the hardwood cocoon kraft pulp and the softwood cocoon kraft pulp in the raw material pulp is 95% by mass or more,
The Beck smoothness measured according to JIS-P8119 (1998) of the glossy surface is 85 seconds or more and 200 seconds or less, and the Beck smoothness of the non-glossy surface is 5 seconds or more and 20 seconds or less, And the smoothness difference between the glossy surface and the non-glossy surface is 80 seconds or more,
The Parker print surf smoothness measured according to JIS-8151 (2004) of the glossy surface is 1.6 μm or more and 5.5 μm or less, and the Parker print surf smoothness of the non-glossy surface is 5.5 μm. Is 10.0 μm or less,
Total 0.05 m ² or more dart measured using an image analysis apparatus, 1,500 / ^{m 2} or more 3000 / ^{m 2} or less, and the total area of the dart 100 mm ² / ^{m 2} or more 300 mm ² / A method for producing single gloss kraft paper which is m ² or less.