JP7323113B1 - Paperboard - Google Patents
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- JP7323113B1 JP7323113B1 JP2022206271A JP2022206271A JP7323113B1 JP 7323113 B1 JP7323113 B1 JP 7323113B1 JP 2022206271 A JP2022206271 A JP 2022206271A JP 2022206271 A JP2022206271 A JP 2022206271A JP 7323113 B1 JP7323113 B1 JP 7323113B1
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- 239000011087 paperboard Substances 0.000 title claims abstract description 114
- 239000010410 layer Substances 0.000 claims abstract description 154
- 239000002344 surface layer Substances 0.000 claims abstract description 64
- 229920001131 Pulp (paper) Polymers 0.000 claims abstract description 60
- 239000010893 paper waste Substances 0.000 claims abstract description 57
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 35
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 34
- 239000002655 kraft paper Substances 0.000 claims abstract description 29
- 238000004513 sizing Methods 0.000 claims abstract description 27
- 239000011436 cob Substances 0.000 claims abstract description 21
- 239000011122 softwood Substances 0.000 claims abstract description 18
- 238000005259 measurement Methods 0.000 claims abstract description 9
- 230000006835 compression Effects 0.000 claims description 29
- 238000007906 compression Methods 0.000 claims description 29
- 239000000835 fiber Substances 0.000 claims description 14
- 238000011084 recovery Methods 0.000 claims description 12
- 239000011121 hardwood Substances 0.000 claims description 9
- 239000002699 waste material Substances 0.000 claims description 8
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 238000005336 cracking Methods 0.000 abstract description 8
- 238000010521 absorption reaction Methods 0.000 abstract description 4
- 239000000123 paper Substances 0.000 description 45
- 238000000034 method Methods 0.000 description 8
- 239000011111 cardboard Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 239000003623 enhancer Substances 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- 229920002401 polyacrylamide Polymers 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000013054 paper strength agent Substances 0.000 description 6
- 230000009172 bursting Effects 0.000 description 5
- 239000011247 coating layer Substances 0.000 description 5
- RSWGJHLUYNHPMX-UHFFFAOYSA-N Abietic-Saeure Natural products C12CCC(C(C)C)=CC2=CCC2C1(C)CCCC2(C)C(O)=O RSWGJHLUYNHPMX-UHFFFAOYSA-N 0.000 description 4
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- KHPCPRHQVVSZAH-HUOMCSJISA-N Rosin Natural products O(C/C=C/c1ccccc1)[C@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 KHPCPRHQVVSZAH-HUOMCSJISA-N 0.000 description 4
- 229920002472 Starch Polymers 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 239000005871 repellent Substances 0.000 description 4
- 230000002940 repellent Effects 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 239000008107 starch Substances 0.000 description 4
- 235000019698 starch Nutrition 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- KHPCPRHQVVSZAH-UHFFFAOYSA-N trans-cinnamyl beta-D-glucopyranoside Natural products OC1C(O)C(O)C(CO)OC1OCC=CC1=CC=CC=C1 KHPCPRHQVVSZAH-UHFFFAOYSA-N 0.000 description 4
- -1 alkyl ketene dimer Chemical compound 0.000 description 3
- 239000004927 clay Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000005995 Aluminium silicate Substances 0.000 description 2
- 241000218631 Coniferophyta Species 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 2
- 235000012211 aluminium silicate Nutrition 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- 125000002091 cationic group Chemical group 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- 241000609240 Ambelania acida Species 0.000 description 1
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- SGHZXLIDFTYFHQ-UHFFFAOYSA-L Brilliant Blue Chemical compound [Na+].[Na+].C=1C=C(C(=C2C=CC(C=C2)=[N+](CC)CC=2C=C(C=CC=2)S([O-])(=O)=O)C=2C(=CC=CC=2)S([O-])(=O)=O)C=CC=1N(CC)CC1=CC=CC(S([O-])(=O)=O)=C1 SGHZXLIDFTYFHQ-UHFFFAOYSA-L 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 244000025254 Cannabis sativa Species 0.000 description 1
- 235000012766 Cannabis sativa ssp. sativa var. sativa Nutrition 0.000 description 1
- 235000012765 Cannabis sativa ssp. sativa var. spontanea Nutrition 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 240000000797 Hibiscus cannabinus Species 0.000 description 1
- 229910001374 Invar Inorganic materials 0.000 description 1
- 229920000881 Modified starch Polymers 0.000 description 1
- 239000004368 Modified starch Substances 0.000 description 1
- 244000082204 Phyllostachys viridis Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229920002522 Wood fibre Polymers 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000010905 bagasse Substances 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000000481 breast Anatomy 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 235000009120 camo Nutrition 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 239000010897 cardboard waste Substances 0.000 description 1
- 229920006317 cationic polymer Polymers 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 235000005607 chanvre indien Nutrition 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000011487 hemp Substances 0.000 description 1
- 238000007602 hot air drying Methods 0.000 description 1
- 229910052900 illite Inorganic materials 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000011256 inorganic filler Substances 0.000 description 1
- 229910003475 inorganic filler Inorganic materials 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 235000019426 modified starch Nutrition 0.000 description 1
- VGIBGUSAECPPNB-UHFFFAOYSA-L nonaaluminum;magnesium;tripotassium;1,3-dioxido-2,4,5-trioxa-1,3-disilabicyclo[1.1.1]pentane;iron(2+);oxygen(2-);fluoride;hydroxide Chemical compound [OH-].[O-2].[O-2].[O-2].[O-2].[O-2].[F-].[Mg+2].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[K+].[K+].[K+].[Fe+2].O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2 VGIBGUSAECPPNB-UHFFFAOYSA-L 0.000 description 1
- 239000012766 organic filler Substances 0.000 description 1
- 239000001254 oxidized starch Substances 0.000 description 1
- 235000013808 oxidized starch Nutrition 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920005990 polystyrene resin Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 150000004671 saturated fatty acids Chemical class 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000012748 slip agent Substances 0.000 description 1
- 229910001388 sodium aluminate Inorganic materials 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000010902 straw Substances 0.000 description 1
- 229940014800 succinic anhydride Drugs 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 239000004034 viscosity adjusting agent Substances 0.000 description 1
- 238000011179 visual inspection Methods 0.000 description 1
- 239000002025 wood fiber Substances 0.000 description 1
- UGZADUVQMDAIAO-UHFFFAOYSA-L zinc hydroxide Chemical compound [OH-].[OH-].[Zn+2] UGZADUVQMDAIAO-UHFFFAOYSA-L 0.000 description 1
- 229940007718 zinc hydroxide Drugs 0.000 description 1
- 229910021511 zinc hydroxide Inorganic materials 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
- D21H11/14—Secondary fibres
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/64—Paper recycling
Landscapes
- Paper (AREA)
Abstract
【課題】折り曲げ加工を行った際に罫線割れが発生しにくく、印刷品質に優れた高坪量の板紙を提供すること。【解決手段】少なくとも表層、表中層、裏中層及び裏層を備え、４層以上６層以下の層を有し、前記表層が、針葉樹未晒クラフトパルプを５０～１００質量％含み、前記表中層及び裏中層が段ボール古紙パルプを９５質量％以下含み、且つ裏層が段ボール古紙パルプを９０質量％未満含み、全層が、内添サイズ剤を含有し、全パルプ１００質量部に対する全内添サイズ剤の含有量が０．２～１．０質量部であり、総坪量が３３０ｇ／ｍ２以上であり、前記表層と前記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、前記表層と前記裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下である板紙。【選択図】図１The present invention provides a paperboard with a high basis weight which is less prone to crease cracking when it is folded and which is excellent in print quality. SOLUTION: At least a surface layer, a front/middle layer, a back/middle layer and a back layer are provided, and the layer has 4 to 6 layers, the surface layer contains 50 to 100% by mass of softwood unbleached kraft pulp, And the back middle layer contains 95% by mass or less of corrugated waste paper pulp, and the back layer contains less than 90% by mass of corrugated waste paper pulp, all layers contain an internal sizing agent, and the total internal size for 100 parts by mass of the total pulp The content of the agent is 0.2 to 1.0 parts by mass, the total basis weight is 330 g/m2 or more, and the Cobb water absorbency of the surface layer and the back layer is 5 g/m2 or more and 50 g/m2 at a measurement time of 2 minutes. m2 or less, and the absolute value of the difference in Cobb water absorption between the surface layer and the back layer is 10 g/m2 or less. [Selection drawing] Fig. 1
Description
本発明は、板紙に関し、特に段ボール用のライナや製函、積層合紙等に好適に使用することのできる板紙に関する。 TECHNICAL FIELD The present invention relates to paperboard, and more particularly to paperboard that can be suitably used as a liner for corrugated board, box making, laminated interleaving paper, and the like.
段ボールは、波形に成形した中芯の片面あるいは両面にライナをコルゲーターで貼り合わせて製造される。
段ボールは、軽量で安価であるため、種々の物品の梱包に使用されている。段ボールは、運搬時等に梱包物が内側から衝突する、あるいは、保管時等に外部から衝撃を受ける場合がある。そのため、段ボール用ライナには、その用途に応じて、衝撃を受けても破れないように、高い破裂強さが要求される場合がある。破裂強さが要求される板紙は、一般的に、原料パルプとして、バージンパルプ、バージンパルプ１００％の段ボール由来の古紙パルプのいずれか、またはこれらの混合物が使用されている。このような原料パルプを使用した板紙は、強度が高く、罫線割れ（段ボール原紙に付与された罫線（浅い溝）から発生する破損線）が生じ難く、段ボール用ライナに適したものである。
Corrugated board is manufactured by laminating a liner on one or both sides of a corrugated core with a corrugator.
Corrugated cardboard is used for packaging various articles because it is lightweight and inexpensive. Corrugated cardboard may be hit from the inside by the packed items during transportation, or may be subjected to external impact during storage. Therefore, a corrugated board liner is sometimes required to have a high burst strength so that it does not break even when subjected to an impact, depending on its use. Paperboards that require bursting strength generally use either virgin pulp, 100% virgin pulp waste paper pulp derived from corrugated board, or a mixture thereof as raw material pulp. Paperboard using such a raw material pulp has high strength and is less prone to crease cracks (broken lines generated from creases (shallow grooves) given to corrugated board), and is suitable for corrugated board liners.
しかし、バージンパルプは、原料コストが高い。バージンパルプ１００％の段ボール由来の古紙パルプも、古紙パルプを含む段ボール由来の古紙パルプ等の他の古紙パルプが混入しないように専用の回収ルートで回収する必要があるため高コストであり、また、その発生量も少ない。そのため、原料パルプとして、バージンパルプ、バージンパルプ１００％の段ボール由来の古紙パルプを多く含む板紙を、段ボール製造や、製函、合紙製造に使用した場合、高コストとなる。 However, virgin pulp has a high raw material cost. Waste paper pulp derived from corrugated board containing 100% virgin pulp is also expensive because it needs to be collected through a dedicated collection route so that other waste paper pulp such as waste paper pulp derived from corrugated board containing waste paper pulp is not mixed. The amount of occurrence is also small. Therefore, when virgin pulp or 100% virgin pulp corrugated cardboard-derived waste paper pulp is used as raw material pulp in a large amount, the cost is high when used for corrugated board production, box making, and interleaving paper production.
原料コストを低減するために、古紙パルプの配合率を高くした板紙が提案されている。
特許文献１には、全パルプに占める古紙パルプの配合率が７０質量％以上であり、坪量が３５０ｇ／ｍ２以上であり、透気抵抗度が２５秒以上である板紙が提案されており、その実施例において古紙パルプとして段ボール古紙パルプを使用している。
特許文献２には、４層以上６層以下の層を有する板紙であって、表層の針葉樹未晒クラフトパルプの含有量が９０質量％以上であり、表下層、中層及び裏層が段ボール古紙パルプを含有し、裏層の全パルプ成分に対する上記段ボール古紙パルプの含有量が９０質量％以上であり、全層が内添サイズ剤を含有し、全層における内添サイズ剤の合計含有量が固形分換算で２．５０ｋｇ／パルプｔ以上６．００ｋｇ／パルプｔ以下であり、総坪量が３３０ｇ／ｍ２以上４００ｇ／ｍ２以下であり、上記表層及び上記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、上記表層と、上記裏層とのコッブ吸水度の差が１０ｇ／ｍ２以下である板紙が提案されている。
In order to reduce raw material costs, paperboards with a high content of waste paper pulp have been proposed.
Patent Document 1 proposes a paperboard in which the ratio of waste paper pulp to the total pulp is 70% by mass or more, the basis weight is 350 g/m 2 or more, and the air resistance is 25 seconds or more. , in which corrugated board waste paper pulp is used as the waste paper pulp in the examples.
Patent Document 2 discloses a paperboard having 4 or more layers and 6 or less layers, in which the content of unbleached softwood kraft pulp in the surface layer is 90% by mass or more, and the lower surface layer, middle layer, and back layer are corrugated paper pulp. The content of the corrugated waste paper pulp to the total pulp component of the back layer is 90% by mass or more, all layers contain an internal sizing agent, and the total content of the internal sizing agent in all layers is solid It is 2.50 kg/pulp t or more and 6.00 kg/pulp t or less in terms of minutes, the total basis weight is 330 g/m 2 or more and 400 g/m 2 or less, and the Cobb of the surface layer and the back layer at a measurement time of 2 minutes A paperboard having a water absorbency of 5 g/m 2 or more and 50 g/m 2 or less and a difference in Cobb water absorbency between the surface layer and the back layer of 10 g/m 2 or less has been proposed.
特許文献１、２は、いずれも古紙パルプとして段ボール古紙パルプを用いている。これは、段ボール古紙パルプは、他の古紙パルプと比較して、繊維長が長く、リグニン含有率と澱粉含有率が高く、インキ含有率が低い傾向にあるため、他の古紙パルプと比較して強度を維持しやすいためである。
特許文献１、２に記載の板紙は、強度に優れているが、特に高坪量の場合に、段ボールを箱とするために折り曲げ加工する際に罫線割れが生じやすいこと、パルプ配合によってはクッション性が劣るため印刷版との密着性が低下し、段ボール表面に図柄等を印刷したときの印刷品質に劣ることが判明した。
本発明は、このような事情に鑑みてなされたものであり、折り曲げ加工を行った際に罫線割れが発生しにくく、印刷品質に優れた高坪量の板紙を提供することを課題とする。
Both Patent Documents 1 and 2 use cardboard waste paper pulp as the waste paper pulp. This is because corrugated waste paper pulp tends to have longer fiber lengths, higher lignin and starch contents, and lower ink contents than other waste paper pulps. This is because it is easy to maintain strength.
The paperboards described in Patent Documents 1 and 2 are excellent in strength, but especially in the case of a high basis weight, crease cracks are likely to occur when corrugated cardboard is folded into a box. It was found that the adhesion to the printing plate was lowered due to the inferior properties, and the printing quality was inferior when a pattern or the like was printed on the surface of the corrugated cardboard.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a paperboard with a high basis weight that is less prone to cracking of creases during folding and has excellent print quality.
上記課題を解決するための手段は、以下の通りである。
１．少なくとも表層、表中層、裏中層及び裏層を備え、４層以上６層以下の層を有し、
前記表層が、針葉樹未晒クラフトパルプを５０～１００質量％含み、
前記表中層と前記裏中層が段ボール古紙パルプを９５質量％以下含み、且つ前記裏層が段ボール古紙パルプを９０質量％未満含み、
全層が、内添サイズ剤を含有し、全パルプ１００質量部に対する全内添サイズ剤の含有量が０．２～１．０質量部であり、
総坪量が３３０ｇ／ｍ２以上であり、
前記表層と前記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、前記表層と前記裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下である板紙。
２．圧縮エネルギーが、２０～１５０ｍＮ・ｃｍ／ｃｍ２である１．に記載の板紙。
３．圧縮回復率が、７０％以上である１．または２．に記載の板紙。
４．前記表層以外の層が、いずれも雑誌古紙パルプ、台紙古紙パルプ、針葉樹クラフトパルプ、広葉樹クラフトパルプからなる群から選ばれる１種以上を含むことを特徴とする１．または２．に記載の板紙。
５．前記表層以外の層が、平均繊維長１．０５ｍｍ以下の古紙パルプを含むことを特徴とする１．または２．に記載の板紙。
６．少なくとも表層、表中層、裏中層及び裏層を備え、４層以上６層以下の層を有し、
前記表層が、針葉樹未晒クラフトパルプを５０～１００質量％含み、
全層が、内添サイズ剤を含有し、全パルプ１００質量部に対する全内添サイズ剤の含有量が０．２～１．０質量部であり、
総坪量が３３０ｇ／ｍ２以上であり、
前記表層と前記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、前記表層と前記裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下であり、
圧縮エネルギーが２０～１５０ｍＮ・ｃｍ／ｃｍ２であり、及び／又は、圧縮回復率が７０％以上である板紙。
７．前記表層以外の層が、いずれも雑誌古紙パルプ、台紙古紙パルプ、針葉樹クラフトパルプ、広葉樹クラフトパルプからなる群から選ばれる１種以上と、段ボール古紙パルプとを含むことを特徴とする６．に記載の板紙。
８．前記表層以外の層が、平均繊維長１．０５ｍｍ以下の古紙パルプを含むことを特徴とする６．または７．に記載の板紙。
Means for solving the above problems are as follows.
1. At least a surface layer, a front middle layer, a back middle layer and a back layer, having 4 to 6 layers,
The surface layer contains 50 to 100% by mass of unbleached softwood kraft pulp,
The front and middle layers and the back middle layer contain 95% by mass or less of recycled cardboard pulp, and the back layer contains less than 90% by mass of recycled cardboard pulp,
All layers contain an internal sizing agent, and the content of the total internal sizing agent is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of all pulp,
A total basis weight of 330 g/m 2 or more,
The Cobb water absorbency of the surface layer and the back layer at a measurement time of 2 minutes is 5 g / m 2 or more and 50 g / m 2 or less, and the absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is 10 g / m Paperboard that is 2 or less.
2. 1. Compression energy is 20 to 150 mN ·cm/cm 2 . The paperboard described in .
3. Compression recovery rate is 70% or more1. or 2. The paperboard described in .
4. 1. Layers other than the surface layer contain at least one selected from the group consisting of recycled magazine pulp, recycled board pulp, softwood kraft pulp, and hardwood kraft pulp. or 2. The paperboard described in .
5. 1. The layer other than the surface layer contains waste paper pulp having an average fiber length of 1.05 mm or less. or 2. The paperboard described in .
6. At least a surface layer, a front middle layer, a back middle layer and a back layer, having 4 to 6 layers,
The surface layer contains 50 to 100% by mass of unbleached softwood kraft pulp,
All layers contain an internal sizing agent, and the content of the total internal sizing agent is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of all pulp,
A total basis weight of 330 g/m 2 or more,
The Cobb water absorbency of the surface layer and the back layer at a measurement time of 2 minutes is 5 g / m 2 or more and 50 g / m 2 or less, and the absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is 10 g / m is 2 or less,
A paperboard having a compression energy of 20 to 150 mN ·cm/cm 2 and/or a compression recovery rate of 70% or more.
7. 6. The layers other than the surface layer contain at least one selected from the group consisting of recycled magazine pulp, recycled board pulp, softwood kraft pulp, and hardwood kraft pulp, and recycled corrugated board pulp. The paperboard described in .
8. 6. The layer other than the surface layer contains waste paper pulp having an average fiber length of 1.05 mm or less. or7. The paperboard described in .
本発明の板紙は、折り曲げ加工をした際に罫線割れが生じにくく、箱とした際にも強度を高く保つことができる。本発明の板紙は、印刷品質に優れており、絵柄やカラー印刷を施す用途に適している。本発明の板紙は、仮に罫線割れが生じたとしても罫線割れ部分等から水が染み込みにくいため、段ボールとした際に内容物が濡れることを防止することができる。 The paperboard of the present invention is less prone to crease cracking when folded, and can maintain high strength even when used as a box. The paperboard of the present invention is excellent in print quality and is suitable for applications where pattern and color printing are applied. Even if the paperboard of the present invention has cracks in the ruled lines, it is difficult for water to permeate through the cracks in the ruled lines.
本発明の板紙の第１態様は、少なくとも表層、表中層、裏中層及び裏層を備える４層以上６層以下の層を有し、
前記表層が、針葉樹未晒クラフトパルプを５０～１００質量％含み、
前記表中層及び裏中層が段ボール古紙パルプを９５質量％以下含み、且つ裏層が段ボール古紙パルプを９０質量％未満含み、
全層が、内添サイズ剤を含有し、全パルプ１００質量部に対する全内添サイズ剤の含有量が０．２～１．０質量部であって
総坪量が３３０ｇ／ｍ２以上であり、
前記表層と前記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、前記表層と前記裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下である。
A first aspect of the paperboard of the present invention has at least 4 layers or more and 6 layers or less comprising at least a surface layer, a front middle layer, a back middle layer and a back layer,
The surface layer contains 50 to 100% by mass of unbleached softwood kraft pulp,
The front and middle layers and the back middle layer contain 95% by mass or less of corrugated waste paper pulp, and the back layer contains less than 90% by mass of corrugated waste paper pulp,
All layers contain an internal sizing agent, the content of the total internal sizing agent is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of the total pulp, and the total basis weight is 330 g/m 2 or more. ,
The Cobb water absorbency of the surface layer and the back layer at a measurement time of 2 minutes is 5 g / m 2 or more and 50 g / m 2 or less, and the absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is 10 g / m 2 or less.
本発明の板紙の第２態様は、少なくとも表層、表中層、裏中層及び裏層を備え、４層以上６層以下の層を有し、
前記表層が、針葉樹未晒クラフトパルプを５０～１００質量％含み、
全層が、内添サイズ剤を含有し、全パルプ１００質量部に対する全内添サイズ剤の含有量が０．２～１．０質量部であり、
総坪量が３３０ｇ／ｍ２以上であり、
前記表層と前記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、前記表層と前記裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下であり、
圧縮エネルギーが２０～１５０ｍＮ・ｃｍ／ｃｍ２であり、及び／又は、圧縮回復率が７０％以上である。
以下、第１態様の板紙と第２態様の板紙をまとめて、本発明の板紙ともいう。
なお、本明細書において、「Ａ～Ｂ」（Ａ、Ｂは数値）との表記は、Ａ、Ｂの値を含む数値範囲、すなわち、Ａ以上Ｂ以下を意味する。
A second aspect of the paperboard of the present invention comprises at least a surface layer, a front middle layer, a back middle layer and a back layer, and has 4 to 6 layers,
The surface layer contains 50 to 100% by mass of unbleached softwood kraft pulp,
All layers contain an internal sizing agent, and the content of the total internal sizing agent is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of all pulp,
A total basis weight of 330 g/m 2 or more,
The Cobb water absorbency of the surface layer and the back layer at a measurement time of 2 minutes is 5 g / m 2 or more and 50 g / m 2 or less, and the absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is 10 g / m is 2 or less,
It has a compression energy of 20 to 150 mN ·cm/cm 2 and/or a compression recovery rate of 70% or more.
Hereinafter, the paperboard of the first aspect and the paperboard of the second aspect are collectively referred to as the paperboard of the present invention.
In this specification, the notation "A to B" (A and B are numerical values) means a numerical range including the values of A and B, that is, from A to B.
本発明の板紙は、少なくとも表層、表中層、裏中層及び裏層を備え、４層以上６層以下の層を有する。なお、裏層とは、抄紙時における下面であり、かつ多層抄き抄紙機において最初にワイヤーパートへ原料が供給されて形成される層を指し、表層とは裏層の反対側、つまり抄紙時における上面であり、かつ多層抄き抄紙機において最後にワイヤーパートへ原料が供給されて形成される層を意味する。 The paperboard of the present invention comprises at least a surface layer, a front/middle layer, a back/middle layer and a back layer, and has 4 to 6 layers. In addition, the back layer is the lower surface during papermaking, and refers to the layer formed by first supplying the raw material to the wire part in the multi-layer paper machine. is the upper surface of the multi-layer paper machine, and means the layer formed by finally supplying the raw material to the wire part in the multi-layer paper machine.
本発明の板紙は、表層が、針葉樹未晒クラフトパルプを５０～１００質量％含む。これにより、本発明の板紙は、破裂強さに優れるとともに、表層での罫線割れを防止することができる。表層における針葉樹未晒クラフトパルプの配合量は、６０質量％以上が好ましく、８０質量％以上がより好ましく、９０質量％以上がさらに好ましく、９５質量％以上がよりさらに好ましく、１００質量％であることが最も好ましい。表層は、針葉樹未晒クラフトパルプの他に、針葉樹晒クラフトパルプ、広葉樹未晒クラフトパルプ、広葉樹晒クラフトパルプ、古紙パルプ等を含むことができるが、表層が含むパルプとして、クラフトパルプ（晒クラフトパルプと未晒クラフトパルプをまとめて、クラフトパルプともいう）を８０質量％以上含むことが好ましく、９０質量％以上含むことがより好ましく、９５質量％以上含むことがさらに好ましい。 In the paperboard of the present invention, the surface layer contains 50 to 100% by mass of softwood unbleached kraft pulp. As a result, the paperboard of the present invention has excellent bursting strength and can prevent crease cracks in the surface layer. The blending amount of softwood unbleached kraft pulp in the surface layer is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass. is most preferred. In addition to unbleached softwood kraft pulp, the surface layer can contain bleached softwood kraft pulp, unbleached hardwood kraft pulp, bleached hardwood kraft pulp, and waste paper pulp. and unbleached kraft pulp, collectively referred to as kraft pulp) is preferably contained in an amount of 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.
本発明の第１態様である板紙は、表中層と裏中層が段ボール古紙パルプを９５質量％以下含み、且つ裏層が段ボール古紙パルプを９０質量％未満含む。以下、表中層、裏中層、裏層をまとめて他の層ともいう。段ボール古紙パルプは、他の古紙パルプと比較して強度を維持しやすいため、従来、古紙パルプを用いた板紙では高配合されていた。しかし、表中層及び裏中層が段ボール古紙パルプを９５質量％を超えて含む、裏層が段ボール古紙パルプを９０質量％以上含む、のいずれか、または両方を満足する板紙は、硬くクッション性が低いため、罫線割れが起こりやすく、また、印刷版との密着性が低く印刷適性に劣っている。本発明の第１態様である板紙は、表中層と裏中層が段ボール古紙パルプを９５質量％以下含み、且つ裏層が段ボール古紙パルプを９０質量％未満含むことにより、強度を維持しながらもクッション性を向上することができ、これにより、罫線割れを防ぐことができるとともに、印刷適性に優れている。 In the paperboard of the first aspect of the present invention, the front and middle layers and the back and middle layers contain 95% by mass or less of corrugated waste paper pulp, and the back layer contains less than 90% by mass of corrugated waste paper pulp. Hereinafter, the front/middle layer, the back/middle layer, and the back layer are collectively referred to as other layers. Since corrugated waste paper pulp maintains strength more easily than other waste paper pulps, conventional paperboards using waste paper pulp have been highly blended. However, paperboard that satisfies either or both of the fact that the front and middle layers and the back middle layer contain more than 95% by mass of recycled corrugated board pulp, or that the back layer contains more than 90% by mass of recycled corrugated board pulp, is hard and has low cushioning properties. Therefore, cracking of ruled lines is likely to occur, and adhesion to the printing plate is low, resulting in poor printability. In the paperboard of the first aspect of the present invention, the front and middle layers and the back middle layer contain 95% by mass or less of corrugated waste paper pulp, and the back layer contains less than 90% by mass of corrugated waste paper pulp, thereby maintaining strength and cushioning. It is possible to improve the durability, thereby preventing cracking of the ruled lines, and having excellent printability.
他の層が含む段ボール古紙パルプ以外のパルプは特に制限されず、針葉樹クラフトパルプ、広葉樹クラフトパルプ、段ボール古紙パルプ以外の古紙パルプ、砕木パルプ（ＧＰ）、リファイナーグラウンドパルプ（ＲＧＰ）、ケミカルパルプ（ＣＰ）、サーモメカニカルパルプ（ＴＭＰ）、ケミサーモメカニカルパルプ（ＣＴＭＰ）等の木材繊維由来の各種パルプ、ケナフ、バガス、竹、麻、ワラなどから得られた非木材パルプ等の１種または２種以上を含むことができる。段ボール古紙パルプは、繊維の角質化が進んでいるため固く、表層を外側に折り曲げた際に、表層の罫線割れを誘発する傾向にあるが、針葉樹クラフトパルプや広葉樹クラフトパルプなどのバージンパルプは繊維がしなやかなため、配合する事で紙自体の強度が向上すると共に、表層を外側に折り曲げても、表層の罫線割れをより効果的に防ぐことができる。 Pulp other than corrugated waste paper pulp contained in other layers is not particularly limited, and includes softwood kraft pulp, hardwood kraft pulp, waste paper pulp other than corrugated waste paper pulp, ground wood pulp (GP), refiner ground pulp (RGP), chemical pulp (CP ), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP) and other wood fiber-derived pulps, and non-wood pulp obtained from kenaf, bagasse, bamboo, hemp, straw, etc. can include Corrugated waste paper pulp is hard because the fibers are highly keratinized, and when the surface layer is folded outward, it tends to induce crease cracks on the surface layer. Since it is flexible, the strength of the paper itself is improved by blending it, and even if the surface layer is folded outward, cracking of the ruled lines of the surface layer can be prevented more effectively.
段ボール古紙パルプ以外の古紙パルプ（以下、他の古紙パルプともいう）としては、上白、特白、中白、白損等の未印刷古紙を離解した古紙パルプ、上質紙、上質コート紙、中質紙、中質コート紙、更紙等に印刷された古紙、および筆記された古紙、廃棄機密文書等の紙類、雑誌古紙、新聞古紙を離解後脱墨したパルプ（ＤＩＰ）等の１種または２種以上を混合して使用することができる。他の古紙パルプとしては、平均繊維長１．０５ｍｍ以下のものが好ましい。上記したように、段ボール古紙パルプは、他の古紙パルプと比較して繊維長が長い。平均繊維長が１．０５ｍｍ以下の他の古紙パルプを含むことにより、他の層の強度が低下し、表層を外側に折り曲げた際に、他の層が内側に座屈しやすくなり、表層の罫線割れをより効果的に防ぐことができる。他の古紙パルプの平均繊維長は、０．７ｍｍ以上が好ましく、０．８ｍｍ以上がより好ましく、０．９ｍｍ以上がさらに好ましい。なお、本発明において平均繊維長は、長さ加重平均繊維長を意味し、例えば、ＡＢＢ株式会社製ファイバーテスターやバルメット株式会社製フラクショネータ等の画像解析装置や光学顕微鏡、電子顕微鏡を用いて繊維を観察することにより測定できる。 Waste paper pulp other than corrugated waste paper pulp (hereinafter also referred to as other waste paper pulp) includes waste paper pulp obtained by disaggregating unprinted waste paper such as fine white, special white, medium white, and white loss, high quality paper, high quality coated paper, medium A type of pulp (DIP) made by de-inking de-inking of waste paper such as waste paper, medium-quality coated paper, waste paper printed on raw paper, waste paper written on, waste confidential documents, etc., waste magazine paper, and waste newspaper. Alternatively, two or more types can be mixed and used. As other waste paper pulp, those having an average fiber length of 1.05 mm or less are preferable. As described above, corrugated waste paper pulp has a longer fiber length than other waste paper pulps. By containing other waste paper pulp with an average fiber length of 1.05 mm or less, the strength of the other layers is reduced, and when the surface layer is folded outward, the other layers tend to buckle inward, and the creases of the surface layer Cracks can be prevented more effectively. The average fiber length of other waste paper pulp is preferably 0.7 mm or longer, more preferably 0.8 mm or longer, and even more preferably 0.9 mm or longer. In the present invention, the average fiber length means the length-weighted average fiber length. It can be measured by observing the fiber.
他の層は、これらの中で、雑誌古紙パルプ、台紙古紙パルプ、針葉樹クラフトパルプ、広葉樹クラフトパルプからなる群から選ばれる１種以上を含むことが好ましく、この群から選ばれる１種以上のパルプと段ボール古紙パルプのみを含むことがより好ましい。 Among these, the other layer preferably contains at least one selected from the group consisting of recycled magazine pulp, recycled board pulp, softwood kraft pulp, and hardwood kraft pulp, and at least one pulp selected from this group. and more preferably contain only corrugated waste paper pulp.
本発明の第１態様である板紙において、表中層と裏中層は、パルプ全体に対して段ボール古紙パルプを９５質量％以下含めばよく、９５質量％未満が好ましい。また、その下限値は特に制限されないが、コストと強度のバランスの点から、２０質量％以上が好ましく、３０質量％以上がより好ましく、４０質量％以上がさらに好ましい。
本発明の第１態様である板紙において、裏層は、パルプ全体に対して段ボール古紙パルプを９０質量％未満含めばよく、８９質量％以下が好ましい。また、その下限値は特に制限されないが、コストと強度のバランスの点から、２０質量％以上が好ましく、３０質量％以上がより好ましく、４０質量％以上がさらに好ましい。
In the paperboard of the first aspect of the present invention, the front and middle layers and the back and middle layers may contain 95% by mass or less of corrugated waste paper pulp, preferably less than 95% by mass, based on the entire pulp. Although the lower limit is not particularly limited, it is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, from the viewpoint of the balance between cost and strength.
In the paperboard of the first aspect of the present invention, the backing layer may contain less than 90% by mass of corrugated waste paper pulp, preferably 89% by mass or less, of the entire pulp. Although the lower limit is not particularly limited, it is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, from the viewpoint of the balance between cost and strength.
本発明の第２態様である板紙において、クッション性、罫線割れの防止、印刷適性の点から、表中層と裏中層は、パルプ全体に対して段ボール古紙パルプを９５質量％以下含むことが好ましく、９５質量％未満含むことがより好ましい。また、その下限値は特に制限されないが、コストと強度のバランスの点から、２０質量％以上が好ましく、３０質量％以上がより好ましく、４０質量％以上がさらに好ましい。
本発明の第２態様である板紙において、クッション性、罫線割れの防止、印刷適性の点から、裏層は、パルプ全体に対して段ボール古紙パルプを９０質量％未満含むことが好ましく、８９質量％以下含むことがより好ましい。また、その下限値は特に制限されないが、コストと強度のバランスの点から、２０質量％以上が好ましく、３０質量％以上がより好ましく、４０質量％以上がさらに好ましい。
In the paperboard of the second aspect of the present invention, the front and middle layers and the back and middle layers preferably contain 95% by mass or less of corrugated waste paper pulp based on the entire pulp, from the viewpoints of cushioning properties, prevention of cracking of ruled lines, and printability. It is more preferable to contain less than 95% by mass. Although the lower limit is not particularly limited, it is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, from the viewpoint of the balance between cost and strength.
In the paperboard of the second aspect of the present invention, the back layer preferably contains less than 90% by mass of corrugated waste paper pulp relative to the entire pulp, and 89% by mass, from the viewpoints of cushioning properties, prevention of creasing of ruled lines, and printability. More preferably, it includes: Although the lower limit is not particularly limited, it is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, from the viewpoint of the balance between cost and strength.
本発明の板紙において他の層は、パルプ全体に対して、雑誌古紙パルプ、台紙古紙パルプ、針葉樹クラフトパルプ、広葉樹クラフトパルプからなる群から選ばれる１種以上を１０質量％以上含むことが好ましく、２０質量％以上含むことがより好ましく、３０質量％以上含むことがさらに好ましく、４０質量％以上含むことがよりさらに好ましい。
本発明の板紙において、表層以外の他の層のそれぞれにおけるパルプの組成は、同一でもよく、異なっていてもよい。ただし、裏層は、最表面に位置するため強度が要求される。そのため、裏層は、その他の層の中で、段ボール古紙パルプの配合量が最も少ないことが好ましく、また、針葉樹クラフトパルプ、広葉樹クラフトパルプの１種以上を含むことが好ましい。
In the paperboard of the present invention, the other layer preferably contains at least 10% by mass of at least one selected from the group consisting of waste magazine pulp, waste board pulp, softwood kraft pulp, and hardwood kraft pulp, based on the entire pulp. More preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more.
In the paperboard of the present invention, the composition of the pulp in each layer other than the surface layer may be the same or different. However, since the back layer is located on the outermost surface, strength is required. Therefore, the back layer preferably contains the least amount of waste corrugated paper pulp among the other layers, and preferably contains at least one of softwood kraft pulp and hardwood kraft pulp.
本発明の板紙の各層には、それぞれ必要に応じて、ポリアクリルアミド（ＰＡＭ）や変性でん粉等の内添紙力増強剤、ロジン系サイズ剤、中性ロジン系サイズ剤、ロジンエマルジョン系サイズ剤、α－カルボキシルメチル飽和脂肪酸、アルキルケテンダイマー（ＡＫＤ）、アルケニル無水コハク酸（ＡＳＡ）、カチオンポリマー系サイズ剤等の内添サイズ剤、硫酸バンド、塩化アルミニウム、アルミン酸ソーダ、塩基性アルミニウム化合物、水溶性アルミニウム化合物、多価金属化合物、シリカゾル等の公知の内添薬品を内添することができる。 In each layer of the paperboard of the present invention, if necessary, an internal paper strength enhancer such as polyacrylamide (PAM) or modified starch, a rosin-based sizing agent, a neutral rosin-based sizing agent, a rosin emulsion-based sizing agent, α-Carboxylmethyl saturated fatty acid, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), internal sizing agents such as cationic polymer sizing agents, aluminum sulfate, aluminum chloride, sodium aluminate, basic aluminum compounds, water Known internal additives such as polyvalent aluminum compounds, polyvalent metal compounds, silica sol, etc. can be internally added.
本発明の板紙は、全層が、内添サイズ剤を含有し、かつ板紙が含む全パルプ１００質量部に対する板紙が含む全内添サイズ剤の含有量が０．２～１．０質量部である。これにより、板紙の端部吸水度を小さくすることができ、板紙の側端部や、仮に罫線割れが生じた場合に罫線割れ部分からの水の染み込みを防止することができる。本発明の板紙は、端部吸水度（２分）が１５０ｇ／ｍ２以下であることが好ましく、１３０ｇ／ｍ２以下がより好ましく、１１０ｇ／ｍ２以下がさらに好ましく、９０ｇ／ｍ２以下がよりさらに好ましい。この端部吸水度（２分）の値は小さいほど好ましいが、本発明の板紙においてはその下限値は４０ｇ／ｍ２程度である。全層が内添サイズ剤を含有する場合、各層の内添サイズ剤の配合率は同一であってもよく、異なっていても良いが、最表面に位置する表層と裏層の配合率が、それ以外の層の配合率よりも高いことが好ましい。 In the paperboard of the present invention, all layers contain an internal sizing agent, and the content of the total internal sizing agent contained in the paperboard is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of the total pulp contained in the paperboard. be. This makes it possible to reduce the water absorbency of the edge portions of the paperboard, and prevent water from permeating from the side edges of the paperboard or, if a crease occurs, from the cracked portion of the crease. The paperboard of the present invention preferably has an edge water absorbency (2 min) of 150 g/m 2 or less, more preferably 130 g/m 2 or less, still more preferably 110 g/m 2 or less, and 90 g/m 2 or less. Even more preferable. The smaller the edge water absorbency (2 minutes), the better, but the lower limit of the paperboard of the present invention is about 40 g/m 2 . When all layers contain an internal sizing agent, the blending ratio of the internal sizing agent in each layer may be the same or different. It is preferably higher than the compounding ratio of other layers.
本発明の板紙は、板紙が含む全パルプ１００質量部に対して内添紙力増強剤を０．３質量部以上含むことが好ましく、０．４質量部以上含むことがより好ましい。内添紙力増強剤の配合率の上限は特に限定されないが、例えば、全パルプ１００質量部に対して１．５質量部以下とすることができる。内添紙力増強剤を１．５質量部より多く配合しても、効果が飽和してそれ以上の紙力増強はほとんど望めず、高コストとなる。内添紙力増強剤を配合する場合、紙力増強効果が高いため、ポリアクリルアミドを用いることが好ましい。ポリアクリルアミドとしては、アニオン性、カチオン性、両性のいずれも使用することができる。なお、本発明の板紙の各層における内添紙力増強剤の配合率は、同一であってもよく、異なっていてもよく、内添紙力増強剤を含まない紙層があってもよい。 The paperboard of the present invention preferably contains 0.3 parts by mass or more, more preferably 0.4 parts by mass or more, of the internal paper strength enhancer with respect to 100 parts by mass of the total pulp contained in the paperboard. The upper limit of the mixing ratio of the internal paper strength enhancer is not particularly limited, but can be, for example, 1.5 parts by mass or less with respect to 100 parts by mass of the total pulp. Even if more than 1.5 parts by mass of the internal paper strength enhancer is blended, the effect is saturated and no further paper strength enhancement can be expected, resulting in high cost. When the internal paper strength enhancer is blended, it is preferable to use polyacrylamide because of its high paper strength enhancement effect. Any of anionic, cationic and amphoteric polyacrylamides can be used. The blending ratio of the internal paper strength enhancer in each layer of the paperboard of the present invention may be the same or different, and there may be a paper layer that does not contain the internal paper strength enhancer.
本発明の板紙の各層には、それぞれ必要に応じて、公知の填料を内添させることができる。填料としては、例えば、カオリン、焼成カオリン、デラミネーティッドカオリン、クレー、焼成クレー、デラミネーティッドクレー、イライト、重質炭酸カルシウム、軽質炭酸カルシウム、軽質炭酸カルシウム－シリカ複合物、炭酸マグネシウム、炭酸バリウム、二酸化チタン、酸化亜鉛、酸化珪素、非晶質シリカ、水酸化アルミニウム、水酸化カルシウム、水酸化マグネシウム、水酸化亜鉛等の無機填料、及び尿素－ホルマリン樹脂、ポリスチレン樹脂、フェノール樹脂等の有機填料等が挙げられ、１種または２種以上を使用することができる。なお、本発明の板紙の各紙層における填料の配合率は、同一であってもよく、また、異なるものであってもよい。 Each layer of the paperboard of the present invention can be internally added with a known filler as required. Examples of fillers include kaolin, calcined kaolin, delaminated kaolin, clay, calcined clay, delaminated clay, illite, ground calcium carbonate, light calcium carbonate, light calcium carbonate-silica composite, magnesium carbonate, and barium carbonate. , titanium dioxide, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide and other inorganic fillers, and urea-formalin resin, polystyrene resin, phenolic resin and other organic fillers. etc., and one or more of them can be used. The blending ratio of the filler in each paper layer of the paperboard of the present invention may be the same or different.
本発明の板紙は、板紙の強度向上や印刷適性付与等を目的として、表面に塗工層を有することができる。塗工層は、その目的に応じて、表面紙力剤、表面サイズ剤、撥水剤、顔料、バインダー樹脂、防滑剤、防腐剤、消泡剤、粘度調整剤、罫割防止剤等の公知の表面処理薬品の１種、または２種以上を含むことができる。
本発明の板紙は、強度向上の点から、表面紙力剤を含む塗工層を有することが好ましい。表面紙力剤は、ポリアクリルアミド系、ポリビニルアルコール系、酸化澱粉、カチオン化澱粉、両性澱粉等の澱粉系、カルボキシメチルセルロース等のセルロース系等を用いることができるが、ポリアクリルアミド系が好ましい。表面紙力剤の塗工量は、片面あたり固形分で０．０５ｇ／ｍ２以上であることが好ましく、０．１ｇ／ｍ２以上であることがより好ましい。
また、耐候性の向上を目的として、塗工層は、表面サイズ剤、撥水剤を含むことが好ましい。表面サイズ剤としては、上記した内添用と同様のものが挙げられ、撥水剤としては、フッ素系樹脂、ポリアミド系樹脂、ワックスエマルジョン等が挙げられる。
The paperboard of the present invention may have a coating layer on its surface for the purpose of improving the strength of the paperboard and imparting printability. Depending on the purpose, the coating layer may contain known agents such as surface paper strength agents, surface sizing agents, water repellent agents, pigments, binder resins, anti-slip agents, preservatives, antifoaming agents, viscosity modifiers, and anti-crease agents. can contain one or more of the surface treatment chemicals.
From the viewpoint of improving strength, the paperboard of the present invention preferably has a coating layer containing a surface strength agent. The surface paper strength agent may be polyacrylamide-based, polyvinyl alcohol-based, starch-based such as oxidized starch, cationic starch or amphoteric starch, or cellulose-based such as carboxymethylcellulose, etc., but polyacrylamide-based is preferred. The coating amount of the surface paper strength agent is preferably 0.05 g/m 2 or more, more preferably 0.1 g/m 2 or more in terms of solid content per side.
For the purpose of improving weather resistance, the coating layer preferably contains a surface sizing agent and a water repellent agent. Examples of the surface sizing agent include the same ones as those for internal use, and examples of the water repellent include fluorine-based resins, polyamide-based resins, wax emulsions, and the like.
本発明の板紙は、総坪量が３３０ｇ／ｍ２以上である。板紙は、折り曲げた際に内側は圧縮され、外側は伸長する。そのため、板紙は、高坪量となるほど（厚くなるほど）、折り曲げた際の内側と外側での変形量の差が大きくなり、折り曲げ加工の際に罫線割れが生じやすくなる。本発明の板紙は、この罫線割れが生じにくいため、高坪量の板紙に適しており、総坪量は３４０ｇ／ｍ２以上が好ましく、３６０ｇ／ｍ２以上がより好ましく、３８０ｇ／ｍ２以上がさらに好ましい。本発明の板紙において、坪量の上限は、抄紙機で製造可能な範囲で特に制限されないが、例えば、６００ｇ／ｍ２以下であり、５５０ｇ／ｍ２以下が好ましく、５００ｇ／ｍ２以下がより好ましい。 The paperboard of the present invention has a total basis weight of 330 g/m 2 or more. Paperboard is compressed on the inside and stretched on the outside when folded. Therefore, the higher the basis weight of the paperboard (the thicker the paperboard), the greater the difference in the amount of deformation between the inner side and the outer side when the paperboard is folded. The paperboard of the present invention is suitable for paperboard with a high basis weight because the crease cracks are less likely to occur . is more preferred. In the paperboard of the present invention , the upper limit of the basis weight is not particularly limited as long as it can be produced by a paper machine. preferable.
裏層の坪量は、板紙全体の坪量に対して１５質量％以上５０質量％以下であることが好ましく、１７質量％以上であることより好ましく、４８質量％以下であることがより好ましく、４６質量％以下であることがさらに好ましい。また、本発明の板紙が有する４～６層の紙層の中で、裏層の坪量が最も大きいことが好ましい。
表層の坪量は、板紙全体の坪量に対して１０質量％以上２５質量％以下であることが好ましく、１２質量％以上であることがより好ましく、２３質量％以下であることがより好ましい。
The basis weight of the backing layer is preferably 15% by mass or more and 50% by mass or less, more preferably 17% by mass or more, and more preferably 48% by mass or less, relative to the basis weight of the entire paperboard. It is more preferably 46% by mass or less. In addition, it is preferable that the back layer has the largest basis weight among the 4 to 6 paper layers of the paperboard of the present invention.
The basis weight of the surface layer is preferably 10% by mass or more and 25% by mass or less, more preferably 12% by mass or more, and more preferably 23% by mass or less of the total basis weight of the paperboard.
本発明の板紙は、表層と裏層のＪＩＳ－Ｐ８１４０（１９９８）に準拠して、計測時間を２分として測定されるコッブ吸水度が、いずれも５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、表層と裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下である。
表層と裏層のこのコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下である板紙は、水分や湿気といった使用環境による影響を受けにくく物性変動が小さく、また破裂強さや引張強さを維持することができる。表層と裏層とのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下である板紙は、湿気や水分によって紙層間の剥離が起こりにくく、紙層間剥離によって破裂強さをはじめとした板紙強度が低下することを防ぐことができる。表層と裏層のこのコッブ吸水度は、１０ｇ／ｍ２以上が好ましく、１５ｇ／ｍ２以上がより好ましく、２０ｇ／ｍ２以上がさらに好ましく、また、４５ｇ／ｍ２以下が好ましく、４０ｇ／ｍ２以下がより好ましく、３５ｇ／ｍ２以下がさらに好ましい。表層と裏層とのコッブ吸水度の差の絶対値は、８ｇ／ｍ２以下が好ましく、６ｇ／ｍ２以下がより好ましく、４ｇ／ｍ２以下がさらに好ましい。
In the paperboard of the present invention, both the surface layer and the back layer have a Cobb water absorbency of 5 g/m 2 or more and 50 g/m 2 or less, measured with a measurement time of 2 minutes in accordance with JIS-P8140 (1998). , the absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is 10 g/m 2 or less.
Paperboard with a Cobb water absorbency of 5 g/m 2 or more and 50 g/m 2 or less in the surface layer and back layer is less susceptible to the effects of moisture and moisture in the usage environment, and its physical properties fluctuate less, and it also maintains burst strength and tensile strength. can do. Paperboard with an absolute value of the difference in Cobb water absorption between the surface layer and the back layer of 10 g/m 2 or less is less prone to peeling between paper layers due to moisture and moisture. can be prevented from declining. The Cobb water absorbency of the surface layer and the back layer is preferably 10 g/m 2 or more, more preferably 15 g/m 2 or more, still more preferably 20 g/m 2 or more, and preferably 45 g/m 2 or less. 2 or less is more preferable, and 35 g/m 2 or less is even more preferable. The absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is preferably 8 g/m 2 or less, more preferably 6 g/m 2 or less, and even more preferably 4 g/m 2 or less.
本発明の板紙は、罫線割れが起こりにくい。本発明の板紙は、２３℃・５０％の調湿下で評価した罫割れ率が５５％以下であることが好ましい。この罫割れ率は、５０％以下がより好ましく、４５％以下がさらに好ましく、４０％以下がよりさらに好ましく、３５％以下がよりさらに好ましく、３０％以下がよりさらに好ましい。罫割れ率は、低いことが好ましいが、本発明の板紙での下限値は５％程度である。 The paperboard of the present invention is less susceptible to crease cracking. The paperboard of the present invention preferably has a crease rate of 55% or less when evaluated under a humidity condition of 23° C. and 50%. The crease rate is more preferably 50% or less, more preferably 45% or less, even more preferably 40% or less, even more preferably 35% or less, and even more preferably 30% or less. The crease rate is preferably low, but the lower limit of the paperboard of the present invention is about 5%.
本発明の第１態様である板紙は、クッション性に優れており、印刷版と密着することができるため、印刷適性に優れている。また、本発明の第１態様である板紙は、クッション性に優れていることにより、折り曲げた際に内側が潰れて座屈しやすく外側の伸びが抑えられるため、罫線割れが起こりにくい。本発明の第１態様である板紙は、圧縮エネルギーが２０～１５０ｍＮ・ｃｍ／ｃｍ２であることが好ましい。圧縮エネルギーは、圧縮時に要したエネルギーを表し、その値が大きければ圧縮されやすいことを示す。圧縮エネルギーは、１２０ｍＮ・ｃｍ／ｃｍ２以下がより好ましく、９０ｍＮ・ｃｍ／ｃｍ２以下がさらに好ましい。本発明の第１態様である板紙は、圧縮回復率が７０％以上であることが好ましい。圧縮回復率は、圧縮された状態から元に戻る際の回復性を示しており、１００％に近いほど回復性があることを示す。圧縮回復率は、７２％以上がより好ましく、７４％以上がさらに好ましく、７６％以上がよりさらに好ましい。
The paperboard of the first aspect of the present invention has excellent cushioning properties and can adhere to a printing plate, and thus has excellent printability. In addition, since the paperboard of the first aspect of the present invention has excellent cushioning properties, the inner side of the paperboard is easily crushed and buckled when folded, and the outer elongation is suppressed. The paperboard of the first aspect of the present invention preferably has a compression energy of 20 to 150 mN ·cm/cm 2 . The compression energy represents the energy required for compression, and the greater the value, the easier the compression. The compression energy is more preferably 120 mN ·cm/cm 2 or less, and even more preferably 90 mN ·cm/cm 2 or less. The paperboard of the first aspect of the present invention preferably has a compression recovery rate of 70% or more. The compression recovery rate indicates the recoverability when returning from a compressed state, and the closer to 100%, the higher the recoverability. The compression recovery rate is more preferably 72% or higher, even more preferably 74% or higher, and even more preferably 76% or higher.
本発明の第２態様である板紙は、圧縮エネルギーが２０～１５０ｍＮ・ｃｍ／ｃｍ２であり、及び／又は、圧縮回復率が７０％以上であり、圧縮エネルギーが２０～１５０ｍＮ・ｃｍ／ｃｍ２、且つ圧縮回復率が７０％以上であることが好ましい。本発明の第２態様である板紙は、圧縮エネルギーが１２０ｍＮ・ｃｍ／ｃｍ２以下が好ましく、９０ｍＮ・ｃｍ／ｃｍ２以下がより好ましい。本発明の第２態様である板紙は、圧縮回復率が７２％以上が好ましく、７４％以上がより好ましく、７６％以上がさらに好ましい。
The paperboard of the second aspect of the present invention has a compression energy of 20 to 150 mN ·cm/cm 2 and/or a compression recovery rate of 70% or more, and a compression energy of 20 to 150 mN ·cm/cm 2 . and a compression recovery rate of 70% or more. The paperboard of the second aspect of the present invention preferably has a compression energy of 120 mN ·cm/cm 2 or less, more preferably 90 mN ·cm/cm 2 or less. The paperboard of the second aspect of the present invention preferably has a compression recovery rate of 72% or more, more preferably 74% or more, and even more preferably 76% or more.
本発明の板紙の用途は特に制限されず、例えば、段ボール用ライナ、中しん原紙、紙器用板紙、製函用の板紙、積層合紙用の板紙等に好適に利用することができる。これらの中で、段ボール用ライナが特に好ましい。 The use of the paperboard of the present invention is not particularly limited, and for example, it can be suitably used as a liner for corrugated board, a base paper for corrugating medium, a paperboard for paper containers, a paperboard for making boxes, a paperboard for laminated interleaving paper, and the like. Among these, corrugated board liners are particularly preferred.
本発明の板紙は、４～６層の紙層を有するが、長網抄紙機、ツインワイヤー抄紙機、円網抄紙機、ギャップフォーマー、ハイブリッドフォーマー（オントップフォーマー）等を組み合わせた抄き合わせの抄紙機等を用いた公知の製造（抄紙）方法、抄紙機が選択可能であり、各層に応じた紙料を調製して抄紙する。また、抄紙時のｐＨは酸性領域（酸性抄紙）、疑似中性領域（疑似中性抄紙）、中性領域（中性抄紙）、アルカリ性領域（アルカリ性抄紙）のいずれでもよく、酸性領域で抄紙した後、紙層の表面にアルカリ性薬剤を塗布してもよい。 The paperboard of the present invention has 4 to 6 paper layers, and can be made by combining fourdrinier paper machines, twin wire paper machines, cylinder paper machines, gap formers, hybrid formers (on-top formers), and the like. A known production (papermaking) method using a combination paper machine or the like, or a papermaking machine can be selected, and a stock suitable for each layer is prepared to make paper. The pH during papermaking may be in the acidic region (acidic papermaking), quasi-neutral region (quasi-neutral papermaking), neutral region (neutral papermaking), or alkaline region (alkaline papermaking). After that, an alkaline chemical may be applied to the surface of the paper layer.
また、ワイヤーパートは、シェーキング装置を使用することが好ましい。シェーキング装置とは、ワイヤーパートのブレストロールを紙料の流れ方向と垂直な方向（マシン幅方向とも呼ぶ。）に摺動させる装置である。シェーキング装置を使用することにより、坪量が均一化する（地合が向上する）ため、破壊の起点となる、他の部分と比較して薄い箇所が減少するため、破裂強さが向上する。 Moreover, it is preferable to use a shaking device for the wire part. The shaking device is a device that slides the breast roll of the wire part in the direction perpendicular to the flow direction of the stock (also called the machine width direction). By using a shaking device, the grammage is uniformed (improved formation), so the thin parts that are the starting points of breakage are reduced compared to other parts, so the bursting strength is improved. .
さらに、各層の抄造条件を調整することにより、板紙の強度を向上させることもできる。例えば、ヘッドボックスから射出されるジェット液（紙料）の速度（Ｊ）と、ワイヤーの速度（Ｗ）との比であるＪ／Ｗ比（＝Ｊ／Ｗ×１００）を１００％未満とすることにより、ジェット液がワイヤーに引っ張られてパルプが抄紙方向（流れ方向）に配向させることができる。そして、パルプが縦方向（長手方向）に配向した板紙は、比破裂強さが向上する傾向がある。Ｊ／Ｗ比は、８１％以上９９％以下であることが好ましく、８４％以上９８％以下であることがより好ましい。また、各層の坪量配分を変更して表層および／または裏層の坪量を増加させること、各層の紙力増強剤配合率を調整して表層および／または裏層への紙力増強剤配合を中層より多くすること等により、強度を向上させることができる。 Furthermore, the strength of the paperboard can be improved by adjusting the papermaking conditions for each layer. For example, the J/W ratio (= J/W x 100), which is the ratio of the speed (J) of the jet liquid (paper stock) injected from the headbox and the speed (W) of the wire, is less than 100%. As a result, the jet liquid is pulled by the wire and the pulp can be oriented in the papermaking direction (flow direction). Paperboard in which the pulp is oriented in the machine direction (longitudinal direction) tends to have an improved specific burst strength. The J/W ratio is preferably 81% or more and 99% or less, more preferably 84% or more and 98% or less. In addition, changing the basis weight distribution of each layer to increase the basis weight of the surface layer and / or the back layer, adjusting the paper strength agent blending ratio of each layer and adding the paper strength agent to the surface layer and / or back layer is greater than that of the middle layer, the strength can be improved.
ワイヤーパート以降の製造（抄紙）方法、抄紙機についても、要求される板紙の強度および生産効率を損なわない範囲で特に限定されず、通常の抄紙機に使用されているものを用いることができる。
抄紙機のプレスパート工程におけるプレスの形式は、例えばストレートスルー型プレス、リバース型プレス、インバープレス、ツインバープレス、ピックアッププレス、ユニプレス、トライニッププレス、トライベントプレス、シュープレス、ミニシュープレス等、特に限定されるものではないが、公知のプレス装置を用いることができる。また、プレス条件についても特に限定はなく、通常の操業範囲で適宜設定できるが、プレス時間を長くすることで繊維がより水素結合しやすくなり、板紙の強度が向上することから、生産効率を損なわない範囲で低速抄造することが好ましい。
The manufacturing (papermaking) method after the wire part and the papermaking machine are not particularly limited as long as the required strength and production efficiency of the paperboard are not impaired, and those used in ordinary papermaking machines can be used.
The type of press in the press part process of a paper machine is, for example, straight-through type press, reverse type press, invar press, twin bar press, pickup press, unipress, tri-nip press, tri-vent press, shoe press, mini shoe press, etc. Although not limited, a known press device can be used. There are no particular restrictions on the press conditions, and they can be set as appropriate within the normal operation range. It is preferable to carry out low-speed papermaking within the range of
抄紙機のドライパート工程におけるドライヤー（乾燥装置）の形式についても、生産効率および板紙の強度を損なわない範囲であれば特に限定されるものではなく、通常の抄紙機に使用されている熱風乾燥方式、多筒式シリンダー乾燥方式等、公知の乾燥装置が使用でき、乾燥装置の設置数についても１台でもよく、プレドライヤー、アフタードライヤーの２台以上設置してもよい。また、乾燥条件についても特に限定はなく、通常の操業範囲で適宜設定できる。 The type of dryer (drying device) in the dry part process of the paper machine is not particularly limited as long as it does not impair the production efficiency and the strength of the paperboard, and the hot air drying method used in ordinary paper machines. , a multi-cylinder cylinder drying method, and the like can be used, and the number of drying devices installed may be one, or two or more of a pre-dryer and an after-dryer may be installed. Also, the drying conditions are not particularly limited, and can be appropriately set within a normal operating range.
また、塗工層を設ける場合、抄紙した後に、表面紙力剤、表面サイズ剤、撥水剤等の表面処理薬品を含む塗工液を塗工する。塗工液を塗布する方法は特に限定はなく、ツーロールサイズプレス、ゲートロールコーター、シムサイザー、スプレー等の公知の装置を適宜用いることができる。カレンダーは、バイパスしてもよく、通常の操業範囲内で処理してもよい。 When a coating layer is provided, a coating solution containing surface treatment chemicals such as a surface strength agent, a surface sizing agent, and a water repellent is applied after paper making. The method of applying the coating liquid is not particularly limited, and known devices such as a two-roll size press, a gate roll coater, a shim sizer, and a sprayer can be used as appropriate. The calender may be bypassed or processed within normal operating limits.
以下に、実施例によって本発明を更に詳細に説明するが、本発明はこれによって限定されるものではない。
・実施例、比較例
各層に使用したパルプを表１～４に示す。段ボール古紙パルプの平均繊維長は１．０７ｍｍ、雑誌古紙パルプの平均繊維長は０．９９ｍｍであった。パルプの機械的処理は、表層はダブルコニファイナー、他の層はダブルディスクリファイナーを使用した。ダブルコニファイナーおよびダブルディスクリファイナー出口における濾水度（ＣＳＦ）を、機械的処理直後の濾水度（ＣＳＦ）として各表に示す。各層において、内添紙力増強剤（ＰＡＭ）と内添サイズ剤（ロジン系）を、対パルプで各表に示す量で加えて紙料とした。
各層の紙料を、多層抄き板紙抄紙機を用いて抄き合わせ、表層、中層（２層または４層）、裏層のＪ／Ｗ比をいずれも９０％とし、ワイヤーパートにおいては裏層抄造時にシェーキング装置を作動させて、板紙を得た。
EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited by these examples.
Examples and Comparative Examples The pulps used for each layer are shown in Tables 1 to 4. The average fiber length of the corrugated waste paper pulp was 1.07 mm, and the average fiber length of the magazine waste paper pulp was 0.99 mm. For the mechanical treatment of the pulp, a double conifer was used for the surface layer, and a double disc refiner was used for the other layers. The freeness (CSF) at the outlet of the double conifer and double disc refiner is shown in each table as freeness (CSF) immediately after mechanical treatment. In each layer, an internal paper strength agent (PAM) and an internal sizing agent (rosin type) were added in the amounts shown in each table based on the pulp to prepare a stock.
The stock of each layer is combined using a multi-layer paperboard machine, and the J / W ratio of the surface layer, middle layer (2 layers or 4 layers), and back layer is all 90%, and in the wire part, the back layer A paperboard was obtained by operating the shaking device during papermaking.
［物性測定］
実施例および比較例の板紙について、以下の方法で測定した。結果を表１～４に示す。
（坪量）
ＪＩＳ Ｐ ８１２４に準拠し測定した。
（紙厚）
ＪＩＳ Ｐ ８１１８に準拠し測定した。
（密度）
ＪＩＳ Ｐ ８１１８及びＪＩＳ Ｐ ８１２４に準拠し測定した坪量と厚さから求めた。
[Physical property measurement]
The paperboards of Examples and Comparative Examples were measured by the following methods. The results are shown in Tables 1-4.
(basis weight)
Measured according to JIS P 8124.
(paper thickness)
Measured according to JIS P 8118.
(density)
It was obtained from the basis weight and thickness measured according to JIS P 8118 and JIS P 8124.
（破裂強さ、比破裂強さ）
ＪＩＳ Ｐ ８１３１に準拠し、板紙の表層側から加圧し破裂強さを測定し、これを坪量で除して比破裂強さを算出した。
（コッブ吸水度）
ＪＩＳ Ｐ ８１４０に準拠し測定した。具体的には、１００ｍｌの蒸留水を紙面に接触させ、２分経過後に吸収された水の単位面積あたりの重量を測定した。
（端部吸水度）
板紙サンプルを５ｃｍ角の正方形にカットし、表面と裏面にポリエチレンテープを貼り（紙の端部しか水を吸わないようにする）、０．０５％のブリリアントブルー水溶液に２分間浸漬し、浸漬前後の重量差から算出した。
(Burst strength, specific burst strength)
According to JIS P 8131, pressure was applied from the surface layer side of the paperboard to measure the bursting strength, which was then divided by the basis weight to calculate the specific bursting strength.
(Cobb water absorption)
Measured according to JIS P 8140. Specifically, 100 ml of distilled water was brought into contact with the surface of the paper, and the weight per unit area of the water absorbed after 2 minutes was measured.
(End water absorption)
A paperboard sample was cut into a square of 5 cm square, polyethylene tape was attached to the front and back (so that only the edges of the paper absorb water), and immersed in a 0.05% brilliant blue aqueous solution for 2 minutes before and after immersion. It was calculated from the weight difference between
（罫割れ）
５ｃｍ角の正方形にカットした板紙サンプルをスクリューサーボプレス（有限会社武藤設計社、ＭＳＶ－１０－２００Ｓ）を用いて速度１７５ｍｍ／ｍｉｎ、圧力５．０ｋＮ、加圧時間０．３ｓで、表層側が外側、かつ、折れ線が板紙のＣＤ方向となるように２つ折りにした後、サンプルの表層について割れている箇所の長さを実測し、サンプル全長（５ｃｍ）で除して罫割れ率を求めた。
また、実施例１、１７、比較例１、３で得られた板紙について、罫割れ試験後の折り曲げ部分側面の画像を図１、２に示す。
(Crease)
A paperboard sample cut into a square of 5 cm square was pressed with a screw servo press (MSV-10-200S, Muto Sekkei Co., Ltd.) at a speed of 175 mm/min, a pressure of 5.0 kN, and a pressurization time of 0.3 s, with the surface side facing outward. Also, after folding in two so that the crease line is in the CD direction of the paperboard, the length of the cracked portion on the surface layer of the sample was measured and divided by the total sample length (5 cm) to obtain the crease rate.
1 and 2 show images of the sides of the folded portions of the paperboards obtained in Examples 1 and 17 and Comparative Examples 1 and 3 after the creasing test.
（圧縮エネルギー、圧縮回復率）
板紙サンプルを縦５０ｍｍ、横１００ｍｍ幅の長方形にカットし、同形状のものを厚さが１ｍｍ程度となるように２枚積層し、ＫＥＳ圧縮試験機（カトーテック社製）にて、２ｃｍ２の円形平面を持つ鋼板間を用いて、スピード５０ｓｅｃ／ｍｍの速度で最大応力５ｋＰａまで圧縮し、圧縮エネルギーと圧縮回復率を測定した。
(compression energy, compression recovery rate)
A paperboard sample is cut into a rectangle with a width of 50 mm and a width of 100 mm, and two sheets of the same shape are laminated so that the thickness is about 1 mm. Using steel plates having a circular flat surface, compression was performed at a speed of 50 sec/mm to a maximum stress of 5 kPa, and compression energy and compression recovery rate were measured.
（印字濃度）
作製した板紙の表層に、フレキソ印刷機（アイジーティーテスティングシステム株式会社製、印刷適性試験機Ｆ１）を使用して、シアンのベタ印字（大きさ：縦２ｃｍ×横３ｃｍ）を行った。１日後に分光型測色計（エックスライト社製、ｅＸａｃｔ）を用いて印字後の濃度を測定した。
本条件においては、１．２以上が好ましい印字後のマクベス濃度である。
（印字光沢度）
ＪＩＳ Ｚ ８７４１に準じて、上記のフレキソ印刷後のシアンのベタ部板紙表層の光沢度（光入射角７５度）を光沢度計（村上色彩技術研究所製、Ｔｒｕｅ ＧＬＯＳＳ ＧＭ－２６ＰＲＯ）を用いて印字後の光沢度を測定した。
本条件においては、１２．８％以上が好ましい印字後の光沢度である。
（印刷品質：目視）
上記のフレキソ印刷後のサンプルの印刷品質（印刷ムラ）を、目視にて以下の基準で評価した。
○：印刷面にムラがほとんどなく、均一な画像が得られている。
△：印刷面にムラが若干あり、画像が不均一である。
×：印刷面にムラがあり、画像が非常に不均一である。
(Print density)
Solid cyan printing (size: 2 cm long x 3 cm wide) was performed on the surface layer of the produced paperboard using a flexographic printing machine (printability tester F1 manufactured by IGT Testing Systems Co., Ltd.). One day later, the density after printing was measured using a spectrophotometer (eXact, manufactured by X-Rite).
Under these conditions, the Macbeth density after printing is preferably 1.2 or more.
(Print glossiness)
According to JIS Z 8741, the glossiness (light incident angle 75 degrees) of the cyan solid paperboard surface layer after the above flexographic printing was measured using a glossmeter (Murakami Color Research Laboratory, True GLOSS GM-26PRO). Glossiness after printing was measured.
Under these conditions, the glossiness after printing is preferably 12.8% or more.
(Print quality: visual inspection)
The print quality (print unevenness) of the samples after the flexographic printing was visually evaluated according to the following criteria.
Good: A uniform image is obtained with almost no unevenness on the printed surface.
Δ: The printed surface is slightly uneven, and the image is uneven.
x: There is unevenness on the printed surface, and the image is very nonuniform.
本発明の板紙は、罫割れ率が低く、印刷品質に優れていた。図１に示すように、実施例１、１７で得られた本発明の板紙は、紙層間が剥離して裏層側に座屈しており、これにより表層の伸びが抑えられたためであると推測される。
比較例で得られた板紙は、罫割れ率が高く、また、印刷品質に劣っていた。図２に示すように、比較例１で得られた板紙は、紙層が強く裏層側への座屈が生じなかったため、折曲げ加工により表層が伸ばされて、罫線割れが生じた。また、比較例３で得られた板紙は、裏層側に座屈しているが、そもそも表層の強度が不足していたため、罫線割れが生じた。
The paperboard of the present invention had a low crease rate and excellent print quality. As shown in FIG. 1, in the paperboards of the present invention obtained in Examples 1 and 17, the paper layers separated and buckled toward the back layer, which is presumed to be due to the suppression of elongation of the surface layer. be done.
The paperboard obtained in the comparative example had a high crease rate and poor print quality. As shown in FIG. 2, the paperboard obtained in Comparative Example 1 had a strong paper layer and did not buckle toward the back layer side, so that the surface layer was stretched by the folding process, resulting in crease cracks. Moreover, the paperboard obtained in Comparative Example 3 buckled toward the back layer side, but the strength of the surface layer was insufficient in the first place, and crease cracks occurred.
Claims (5)
前記表層が、針葉樹未晒クラフトパルプを５０～１００質量％含み、
前記表中層と前記裏中層と前記裏層が、段ボール古紙パルプを含み、
前記表中層と前記裏中層がパルプ全体に対して段ボール古紙パルプを９５質量％以下含み、且つ前記裏層がパルプ全体に対して段ボール古紙パルプを９０質量％未満含み、
全層が、内添サイズ剤を含有し、全パルプ１００質量部に対する全内添サイズ剤の含有量が０．２～１．０質量部であり、
総坪量が３３０ｇ／ｍ２以上であり、
前記表層と前記裏層の計測時間２分におけるコッブ吸水度が５ｇ／ｍ２以上５０ｇ／ｍ２以下であり、前記表層と前記裏層とのこのコッブ吸水度の差の絶対値が１０ｇ／ｍ２以下である板紙。 At least a surface layer, a front middle layer, a back middle layer and a back layer, having 4 to 6 layers,
The surface layer contains 50 to 100% by mass of unbleached softwood kraft pulp,
wherein the front and middle layers, the back middle layer and the back layer contain corrugated waste paper pulp,
The front and middle layers and the back middle layer contain 95% by mass or less of corrugated waste paper pulp relative to the entire pulp, and the back layer contains less than 90% by mass of corrugated waste paper pulp relative to the whole pulp ,
All layers contain an internal sizing agent, and the content of the total internal sizing agent is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of all pulp,
A total basis weight of 330 g/m 2 or more,
The Cobb water absorbency of the surface layer and the back layer at a measurement time of 2 minutes is 5 g / m 2 or more and 50 g / m 2 or less, and the absolute value of the difference in Cobb water absorbency between the surface layer and the back layer is 10 g / m Paperboard that is 2 or less.
3. The paperboard according to claim 1, wherein the layers other than the surface layer contain waste paper pulp having an average fiber length of 1.05 mm or less.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022206271A JP7323113B1 (en) | 2022-12-23 | 2022-12-23 | Paperboard |
| PCT/JP2023/044972 WO2024135546A1 (en) | 2022-12-23 | 2023-12-15 | Cardboard |
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| JP2022206271A JP7323113B1 (en) | 2022-12-23 | 2022-12-23 | Paperboard |
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Cited By (1)
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| WO2024190422A1 (en) * | 2023-03-13 | 2024-09-19 | 日本製紙株式会社 | Paperboard and method for manufacturing same |
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Also Published As
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| WO2024135546A1 (en) | 2024-06-27 |
| JP2024090387A (en) | 2024-07-04 |
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