Paper

Abstract

To provide environmentally friendly paper with excellent strength and surface properties.SOLUTION: Paper contains pulp and juice residue from squeezed apples and / or citrus fruits, and the juice residue has an average particle size (Dv(50)) of 10 μm or more and 1,000 μm or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to paper.

Background Art

[0002] In the process of manufacturing fruit juice, a large amount of juice residues are generated, and effective utilization of these juice residues has been explored. For example, regarding apple juice residues, there are feeds with a deodorizing effect on animal manure mixed with apple juice residues (Patent Document 1), re-squeezed juice residues to obtain reclaimed squeezed cake feed without leaving an apple odor in dairy products, etc. (Patent Document 2), mixing apple juice residues with an auxiliary material composed of plant long fiber scraps, extracting more apple juice by applying high pressure to the mixture, and drying and fermenting the mixture after secondary pressing to obtain livestock feed (Patent Document 3). Also, Patent Document 4 proposes an edible sheet containing juice residues. Thus, technical proposals regarding the utilization of juice residues mainly involve uses such as feeds with low added value and utilization as edible foods such as food, and do not relate to paper.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide paper that is environmentally considerate and excellent in strength and surface properties.

Means for Solving the Problem

[0005] The means for solving the above problems are as follows. 1. A paper containing pulp and the juice residue of either apple, citrus fruits, or both, wherein the average particle size (Dv(50)) of the juice residue is 10 μm or more and 1000 μm or less. 2. The paper according to 1, characterized in that the juice residue is contained in an amount of 3% by mass or more and 50% by mass or less based on the entire paper.

Effect of the Invention

[0006] The paper of the present invention uses the juice residue as a raw material and can reduce the amount of waste, so it can reduce the environmental load. The paper of the present invention is superior in strength compared to paper that does not contain the juice residue. Further, by containing the juice residue having a specific particle size, it is possible to obtain a paper with less dirt due to the residue and excellent surface properties.

Best Mode for Carrying Out the Invention

[0007] The present invention relates to a paper containing pulp and the juice residue of either apple, citrus fruits, or both.

[0008] · Pulp As the pulp, chemical pulps of wood such as softwood kraft pulp (NBKP), softwood unbleached kraft pulp (NUKP), hardwood kraft pulp (LBKP), hardwood unbleached kraft pulp (LUKP), sulfite pulp (SP), etc., mechanical pulps of wood such as ground pulp (GP), refiner ground pulp (RGP), stone ground pulp (SGP), chemiground pulp (CGP), semi-chemical pulp (SCP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), etc., non-wood pulps obtained from kenaf, bagasse, bamboo, hemp, straw, etc., waste paper as a raw material, and waste paper pulp obtained by removing the ink contained in waste paper in a deinking process, etc., known pulps can be appropriately blended and used.

[0009] Since the paper of the present invention is excellent in strength, a large amount of waste paper pulp can be blended. In addition, blending waste paper pulp, which is a recyclable material, is also preferable from the environmental point of view. The paper of the present invention preferably contains 50% by weight or more of waste paper pulp based on the total amount of pulp, more preferably 70% by weight or more, still more preferably 80% by weight or more, and can also be 90% by weight or more, and even 100% by weight. As the waste paper pulp, waste paper pulp obtained by dissociating unprinted waste paper such as cardboard waste paper, upper white, special white, medium white, and white waste, waste paper printed on high-quality paper, coated high-quality paper, medium-quality paper, coated medium-quality paper, and recycled paper, and written waste paper, papers such as discarded confidential documents, waste paper of magazines, and pulp (DIP) obtained by deinking newsprint waste paper after dissociation can be used.

[0010] · Juice residue The paper of the present invention contains, as a papermaking raw material, the juice residue of either apples, citrus fruits, or both. As the juice residue, the residue after juicing apples or citrus fruits by a known method can be used after drying and pulverization. A washing step may be performed before or after pulverization. The present invention uses, as the juice residue, those having an average particle diameter (Dv(50)) of 10 μm or more and 1000 μm or less. By setting the average particle diameter (Dv(50)) of the juice residue within this range, it is possible to obtain a paper that achieves both the effect of improving the paper strength by the juice residue and the aesthetics of the paper surface (less impurities). The average particle diameter (Dv(50)) of the juice residue can be measured, for example, with a laser diffraction particle size analyzer (manufactured by Malvern Panalytical Ltd., Mastersizer 3000). This average particle diameter (Dv(50)) is more preferably 20 μm or more, still more preferably 25 μm or more, and more preferably 250 μm or less, still more preferably 100 μm or less.

[0011] In the paper of the present invention, when the average fiber length (length weighted) of the juice residue is measured with a fiber length distribution measuring device (L&W Fiber Tester Plus CODE912 manufactured by ABB), it is preferably 0.10 mm or more and 1 mm or less, more preferably 0.15 mm or more and 0.80 mm or less, and even more preferably 0.20 mm or more and 0.50 mm or less. Also, the average fiber width (length weighted) is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 80 μm or less, and even more preferably 20 μm or more and 50 μm or less. By setting the average fiber length and average fiber width of the juice residue within the above ranges, the amount of fiber lumps confirmed as contaminants on the paper surface is reduced, the appearance of the paper is improved, and the fibers derived from the juice residue can contribute to the expression of paper strength. In addition, in the juice residue, the fine rate, which is the ratio of fines (fine fibers with a fiber length of less than 0.2 mm), is preferably 80% or more, more preferably 85% or more, and most preferably 95% or more. By setting the fine rate within the above range, the number of fiber bonding points in the paper increases, so that a high-strength paper can be obtained. The fine rate is a value that can be calculated by a fiber length distribution measuring device, and is the ratio (%) of the cumulative length of fibers with a fiber length of 0.2 mm or less to the cumulative length of all fibers.

[0012] In the paper of the present invention, the blending amount of the juice residue is not particularly limited, but is preferably 3% by mass or more and 50% by mass or less based on the total amount of the paper. When the blending amount of the juice residue is within this range, it is easy to obtain a paper having excellent strength as compared with the case where the juice residue is not contained. The blending amount of the juice residue is more preferably 5% by mass or more, even more preferably 10% by mass or more, and more preferably 45% by mass or less based on the total amount of the paper.

[0013] The paper of the present invention can contain known fillers and papermaking aids as required. As the filler, known fillers such as inorganic fillers like talc, kaolin, calcined kaolin, clay, heavy calcium carbonate, light calcium carbonate, white carbon, zeolite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, barium sulfate, calcium sulfate, etc., and organic fillers like urea-formalin resin, polystyrene resin, phenol resin, micro hollow particles, etc. can be used.

[0014] As paper-making aids, various internal sizing agents such as rosin, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), etc., various retention improvers of nonionic, cationic, and amphoteric types, drainage improvers, paper strength improvers, various starches, polyacrylamide, urea resin, melamine resin, epoxy resin, polyamide resin, polyamine resin, polyethyleneimine, plant gum, polyvinyl alcohol, latex, polyethylene oxide, hydrophilic cross-linked polymer particle dispersions and their derivatives or modified products, etc., basic aluminum compounds such as sulfuric acid band, aluminum chloride, sodium aluminate, basic aluminum chloride, basic polyaluminum hydroxide, etc., water-soluble aluminum compounds such as alumina sol that is easily decomposable in water, polyvalent metal compounds such as ferrous sulfate, ferric sulfate, etc., silica sol, defoaming agents, coloring dyes, coloring pigments, pH adjusters, pitch control agents, slime control agents, etc. can be exemplified, and they can be appropriately selected and used as needed.

[0015] The basis weight of the paper of the present invention is not particularly limited, but for example, it can be 10 g / m 2 or more and 1100 g / m 2 or less. The basis weight can be selected according to its use. For example, when used as single-layer paper, it can be 10 g / m 2 or more and 500 g / m 2 or less, more preferably 30 g / m 2 or more and 300 g / m 2 or less and can be appropriately set within this range. Also, in the case of a multi-layer board paper having two or more paper layers, one layer may be within the above range, but the total of all layers is 10 g / m 21100 g / m or more 2 It can be appropriately set within the following range. For example, when used as a liner for cardboard, it can be 70 g / m 2 or more and 550 g / m 2 or less.

[0016] Although the mechanism is unclear, the paper containing the juice residue of the present invention is superior in strength compared to the paper not containing the juice residue. The tensile strength of the paper of the present invention is preferably improved by 5% or more, more preferably 10% or more, further preferably 20% or more, still more preferably 30% or more, even more preferably 40% or more, and even more preferably 50% or more compared to similar papers except that they do not contain the juice residue.

[0017] Since the paper containing the juice residue of the present invention contains the juice residue, impurities increase. Therefore, the juice residue of the present invention is added to the paper stock after being pulverized and refined as described above. If there are coarse impurities, there is a risk of problems such as the aesthetics of the printed matter being impaired and the discrimination of printed characters becoming difficult. The paper containing the juice residue of the present invention preferably has 100,000 or fewer impurities with a diameter of 250 μm or more per m 2 and more preferably 50,000 or fewer per m 2 . Also, the number of fine impurities less than 100 μm is preferably 150,000 or more per m 2 and more preferably 200,000 or more per m 2 . By setting it within the above range, it is less likely to hinder the discrimination of printed matter such as characters, and a paper with a natural color and texture can be obtained. The impurities in the paper can be measured by an impurity measuring device (manufactured by Nippon Paper Unitech Co., Ltd.) or the like. Also, the area and number of impurities can be obtained by setting the surface of the paper on the reading side of the scanner, capturing an image of 10 cm × 10 cm at a resolution of 400 dpi, and analyzing it with the attached software.

[0018] The use of the paper of the present invention is not particularly limited. For example, it can be printing paper, book paper, information paper, newsprint, kraft paper, kraft extended paper, crepe paper, fine paper, tissue paper, toilet paper, packaging paper, cardboard (liner for corrugated board, medium liner, cardboard for paper containers, cardboard for box making, cardboard for laminated paper, etc.), gardening and agricultural materials (gardening sheets, agricultural sheets, seedbed sheets, fruit bags, etc.). Since the paper of the present invention contains juice residues, it can be used for applications related to fruits, such as gardening and agricultural materials used for fruit cultivation, and packaging materials used for fruit storage and transportation, etc., to give a more environmentally friendly impression. In addition, since the paper of the present invention has excellent surface properties, dirt during printing is less noticeable, and it can be made into a printed matter with excellent aesthetics. Therefore, it is suitable for printing paper, book paper, information paper, and newsprint on which characters and patterns are printed and drawn for use, and can also be suitably used for applications such as notebooks, business cards, and fancy paper.

[0019] The method for manufacturing (papermaking) the paper and the type of paper machine are not particularly limited. Known manufacturing (papermaking) methods and paper machines using a fourdrinier paper machine, twin-wire paper machine, cylinder paper machine, gap former, hybrid former (on-top former), etc., and paper machines with combined papermaking can be selected. Also, the pH during papermaking can be in any of the acidic region (acidic papermaking), pseudo-neutral region (pseudo-neutral papermaking), neutral region (neutral papermaking), and alkaline region (alkaline papermaking). After papermaking in the acidic region, an alkaline agent may be applied to the surface of the paper layer.

[0020] After papermaking, a surface treatment agent can be applied and externally added as necessary. When applying a surface treatment agent, known surface treatment chemicals such as water-soluble polymer substances and surface sizing agents can be used alone or in appropriate combinations according to the required quality of the paper. The type of size press for applying the surface treatment agent is not particularly limited, and a known device such as a two-roll size press, gate roll coater, or sim coater can be appropriately used to externally add the surface treatment agent. The calendar may be bypassed or processed within the normal operating range.

Examples

[0021] Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the following examples only. The papers obtained in the following examples and comparative examples were measured by the following methods. The results are shown in Table 1. · Average particle size The squeezed residue dispersed in water to a solid content concentration of 0.1% was measured with a laser diffraction particle size analyzer (Master Sizer 3000, manufactured by Malvern Panalytical). · Average fiber length · Average fiber width · Fine rate Measured with a fiber length distribution measuring device (L&W Fiber Tester Plus CODE912, manufactured by ABB).

[0022] · Basis weight Measured with reference to JIS P 8124. · Thickness Measured with reference to JIS P 8118. · Density Calculated from the basis weight and thickness. · Kawabata smoothness Measured in accordance with JIS P 8155. · Tensile strength Measured in accordance with JIS P 8113. · Breaking length Measured in accordance with JIS P 8113. Impurities: The number of dirt and the dirt area were measured using an impurity measuring device (Easy Scan, manufactured by Nippon Paper Unitech). The number of dirt refers to the number of dirt per 1 m 2 and the dirt area refers to the total dirt area (mm 2 ) per 1 m 2 .

[0023] (Example 1) Hardwood kraft pulp (LBKP with a drainage degree of about 630 ml; manufactured by Nippon Paper Industries Co., Ltd.) was added with water to a solid content concentration of 0.6% by weight to obtain an LBKP slurry. Also, apple powder (manufactured by appcycle, average particle diameter (Dv(50)) 66.6 μm) was added with water to a solid content concentration of 5% by weight and stirred using a three-one motor to obtain an apple powder slurry. A mixture of the LBKP slurry and the apple powder slurry with a total solid content weight ratio of 55:45 was used as the raw material. This was hand-sheeted using a round hand sheet machine to a basis weight of 64 g / m 2 and then dewatered using a press device, and further tension dried at 50 °C using a blow dryer to produce a sheet. The content rate of the juice residue in the sheet was calculated by calculation. Specifically, since the yield during hand-sheeting using a round hand sheet machine for LBKP was 100% and all the LBKP input was contained in the sheet, the difference between the weight of the sheet and the weight of the LBKP input was calculated as the juice residue (sheet - LBKP input amount = juice residue).

[0024] (Example 2) A sheet was produced in the same manner as in Example 1, except that a mixture of the LBKP slurry and the apple powder slurry with a total solid content weight ratio of 32:68 was used as the raw material. (Example 3) The apple powder once dispersed in water was filtered using ADVANTEC No. 2 filter paper, water was added to a filter cake solid content concentration of 4% by weight, and stirred using a three-one motor to obtain a washed apple powder slurry (average particle diameter (Dv(50)) 59.7 μm). A sheet was produced in the same manner as in Example 1, except that a mixture of the LBKP slurry and the washed apple powder slurry with a total solid content weight ratio of 73:27 was used as the raw material.

[0025] (Comparative Example 1) A sheet was produced in the same manner as in Example 1, except that only the LBKP slurry was used as the raw material. (Comparative Example 2) Grape powder (manufactured by appcycle, average particle diameter (Dv(50)) 49.6 μm) was added with water so that the solid content concentration became 5% by weight and stirred using a three-one motor to obtain a grape powder slurry. Paper was produced in the same manner as in Example 1, except that the LBKP slurry and the grape powder slurry were mixed so that the total solid content weight ratio was 66:34 and used as raw materials. (Comparative Example 3) Apple juice residue dry matter that was not pulverized (manufactured by appcycle) was added with water so that the solid content concentration became 5% by weight and stirred using a three-one motor to obtain an uncrushed apple slurry. Paper was produced in the same manner as in Example 1, except that the LBKP slurry and the uncrushed apple slurry were mixed so that the total solid content weight ratio was 68:32 and used as raw materials. Note that since this juice residue was too large, the average particle diameter (measurement range 0.01 to 3500 μm), average fiber length, etc. could not be measured.

[0026]

Table 1

[0027]

Table 2

[0028] The papers obtained in Examples 1 to 3 were superior in strength compared to the paper obtained in Comparative Example 1. Also, the papers obtained in Examples 1 and 3 had appropriate coarseness and a natural texture, but did not impair printability. The papers obtained in Comparative Examples 2 and 3 were inferior in strength compared to the paper obtained in Comparative Example 1. Also, the paper obtained in Comparative Example 3 was so rough on its surface that printing was difficult.

Claims

1. Paper containing pulp and the juice residue of either apple, citrus fruit, or both, wherein the average particle size (Dv(50)) of the juice residue is 10 μm or more and 1000 μm or less.

2. The paper according to claim 1, characterized in that the paper contains 3% by mass or more and 50% by mass or less of the juice residue based on the total paper.

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