JP6189287B2 - White paperboard and printed matter, printing box or packaging container using it - Google Patents

Description

  The present invention relates to white paperboard and a packaging container using the same, and more specifically, it is composed of two or more layers, and can control moderate rigidity and whiteness, thereby improving the formation. The present invention relates to a white paperboard and a printed matter, a printing box or a packaging container manufactured using the white paperboard.

  White paperboard is a multi-layer paperboard with two or more layers, with bleached pulp mainly blended in the front and back layers, and pulp and wastepaper in the middle layer (intermediate layers other than the front and back layers, the same applies hereinafter). It is roughly divided into Manila balls, and white balls that mainly contain bleached pulp on the surface and mainly old paper in the middle and back layers.

  Manila balls are used for printed items such as calendars, cards, book covers, picture books, postcards, and cosmetic boxes, soap boxes, gift cases, cigarette cartons, caramel boxes, etc. White balls are used for food. Used for packaging containers for miscellaneous goods, detergents, etc. In either case, in order to improve printability, smoothness, and concealability, a paint containing a filler is generally applied.

  Conventionally, the beating freeness of the surface layer of the white paperboard or the lower layer (the layer immediately below the surface layer) is 250 to 500 cc, and the content of the pigment contained in the layer is 10% by weight or more with respect to the pulp. , Concealment of white paperboard (conceals the color of the used paper mixed in the middle layer), visual smoothness, printability, surface strength, crease cracking measures (the ruled line part when white paperboard is used as a box should not break) (Patent document 1: Japanese Patent No. 3008313).

  In the case of the invention of Patent Document 1, the surface layer contains a pigment of 10% by weight or more. In such a case, the amount of the pulp is relatively reduced, and the pulp fiber is the main factor in developing the paper strength. As a result, the filler inhibits the hydrogen bonding of the paper, resulting in a rapid decrease in paper strength. In general, paper strength has strength such as tensile strength and stiffness such as bending stiffness, but these reductions in paper strength cause paper breakage at the time of paper manufacture and printing, thereby deteriorating operational efficiency. Workability deteriorates due to paper dust generation during printing.

  In addition, by reducing the ash content in the back layer of white paperboard consisting of three or more layers to an average value of 12% or less and a maximum value of 14% or less, the backlash during storage and transportation of white paperboard is improved. There is a thing which intends to do (patent document 2: Unexamined-Japanese-Patent No. 10-96199).

  However, the invention of Patent Document 2 specifies only the ash content of the back layer, and specializes in the improvement of the back fluff, and can control moderate rigidity, and the formation and whiteness. The directionality is different from that of the present invention in which white paper with improved slab is obtained.

Japanese Patent No. 3008313 Japanese Patent Laid-Open No. 10-96199

  As described above, conventionally, no white paperboard capable of improving the formation of whiteboard paper and controlling the stiffness and whiteness has been proposed. Therefore, an object of the present invention is to provide such a white paperboard, that is, a white paperboard whose paper layer formation is improved and whose rigidity and whiteness can be controlled.

The invention according to claim 1 for solving the above-mentioned problem is that, in a white paperboard made of multilayers composed of three or more layers, 1.0 to 9.0% based on pulp fibers in each of the front layer and the back layer and a formulated to contain an inorganic filler, middle in formulated to contain from 2.0 to 15.0% of an inorganic filler relative to the pulp fibers, Ri formed to fit the paper making the surface layer and the middle layer and the backing layer the inorganic filler is a white paperboard Ru precipitated calcium carbonate der of rosette type.

The invention according to claim 2 for solving the above-obtained white paperboard or we described above, printed material, a printed box or packing container.

  The present invention is as described above, and an inorganic filler such as light calcium carbonate and heavy calcium carbonate is added to each of the front and back layers of white paperboard composed of a plurality of layers of three or more layers in an amount of 1.0 to 9 in terms of pulp. Since it is blended so as to contain 0.0%, there is an effect that the entanglement with the mixed pulp becomes good and the formation of the surface layer and the back layer is improved (if the pulp is close to 100%, the entanglement between the pulps is It becomes too much and the formation deteriorates.) In addition, by improving the formation in this way, there is an effect of improving the smoothness in the surface layer and the back layer.

  Further, by containing 2.0 to 15.0% inorganic filler in the middle layer, it is possible to obtain an appropriate waist and whiteness of white paperboard. In other words, normally, the middle layer is blended with waste paper pulp and recycled broke in the factory (paper equivalent to damaged paper generated during production in the factory) for the purpose of cost reduction, etc., and the printability is improved on the surface and back layers. Therefore, virgin pulp is often blended, but the middle layer may have low whiteness due to the quality of the blended pulp. Accordingly, the layer structure becomes uniform, so that the color of the middle layer can be concealed (the concealment effect).

  Further, by replacing the pulp with a specific filler, it is possible to moderately improve the stiffness of the paper, and therefore, there is an effect that processability such as boxing suitability can be improved.

  The white paperboard according to the present invention is a multi-layered paper comprising three or more layers, and is blended so that each of the surface layer and the back layer contains 1.0 to 9.0% inorganic filler with respect to the pulp fiber. And it mix | blends so that 2.0-15.0% of inorganic filler may be contained in a middle layer with respect to a pulp fiber, and it manufactures by combining a surface layer, a middle layer, and a back layer.

  Fillers of the present invention include light calcium carbonate, heavy calcium carbonate, clay, calcined kaolin, deramikaolin, white carbon, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, calcium carbonate / One of inorganic fillers such as silica composite, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide and sepiolite is used, or a plurality of them are used in combination. In addition, a recycled filler obtained by incinerating sludge generated in a process of recycling used paper or a process of manufacturing paper can also be used.

  As the filler of the present invention, light calcium carbonate is particularly recommended. The crystal form of light calcium carbonate may be either calcite or aragonite, and the shape may be any of acicular, columnar, spindle, spherical, cubic, and rosetta types. Of these, Rosetta-type calcite light calcium carbonate is particularly preferable. The rosetta type refers to a shape in which spindle-shaped light calcium carbonate primary particles are aggregated in a corrugated shape, and is characterized by a high specific surface area and oil absorption. The average particle diameter of calcium carbonate is about 0.1 to 20 μm, preferably 0.5 to 10 μm, and more preferably 1 to 5 μm.

  The base paper of white paperboard is made by a multi-layer machine with two or more layers, and the pulp used is blended with bleached or unbleached wood pulp and mechanical pulp in consideration of printability on the front and back layers. Since the filler content of these pulps is about 0.5%, considering the yield, the filler should be adjusted so that the content of each inorganic filler in the front and back layers is 1.0 to 9.0%. Blend. For example, about a surface layer and a back layer, it is made to contain 1.0-9.0% by adding a fresh inorganic filler with respect to a bleached pulp with few fillers.

  In order to reduce costs, the middle layer including the front and lower layers is mixed with waste paper pulp such as magazine waste paper and cardboard waste paper and circulation broke equivalent to waste paper generated in the factory in addition to the above pulp. Filler content of the bleached pulp is about 0.5%, filler content of the waste paper pulp is 10% or more (varies depending on the type of used paper and collection), and the filler content in the circulation broke is 2.0-20.0. % (Generally, the circulation broke includes filler-coated waste paper, uncoated base paper, or a mixture thereof, but the filler in the circulation broke in one factory is the same as the filler described in this application.) In consideration of this and the yield, the middle layer is blended so that the content of the inorganic filler is 2.0 to 15.0%. For example, in the middle layer, since a fresh inorganic filler is added to a circulating broke having a large amount of filler, the content of the inorganic filler is higher than that of the front layer and the back layer.

After making white paperboard with a multi-layer machine, use normal coating equipment (curtain coater, blade coater, air knife coater, etc.) and add normal color (light calcium carbonate, heavy calcium carbonate, clay, plastic pigment) The other liquid mixture) is applied on one or both sides by single coating (single coating) or double coating (twice coating) in a coating amount range of 20 to 40 g / m ^2. producing amount 160g ^{/ m 2} ~420g ^/ m 2 about the white board.

  The white paperboard base paper according to the present invention is made with a multi-layered machine such as a long net, circular net, or ultraformer, and then coated with a coating containing an inorganic pigment on one or both sides as necessary.

[Example]
EXAMPLES Hereinafter, although this invention is further demonstrated based on an Example, it cannot be overemphasized that this invention is not limited to those Examples. Examples 1 to 5, Reference Examples 1 to 2 (Table 1) and Comparative Examples 1 to 12 (Table 2) shown below are all three-layer papermaking. In addition, the numerical value which shows a mixing | blending is a numerical value based on the weight of solid content.

<Evaluation and test methods>
Basis weight: JIS P 8124
Thickness and density: JIS P 8118
Formation: Light is applied obliquely to the surface of the paper, and the uniformity of the fibers on the surface and the unevenness of the paper surface are confirmed visually. (◎, ○ pass, △, × fail)
Stiffness: JIS P 8143 (15.0-20.0 is suitable)
Smoothness: JIS P 8155 ISO (750 and above are suitable for both front and back)
Whiteness: JIS P 8148 (80.5-84.5 is suitable for both front and back)
In-layer peel strength: JAPAN TAPPI
No. 19-2 Same as B method.
(56 or more is appropriate)

<Examples 1-5, Reference Examples 1-2 >
Various changes in the content of the inorganic filler in the surface layer and the back layer are made within the range of 1.0 to 9.0%, so that the content of the inorganic filler in the middle layer is 2.0 to 15.0%. Then, after white paper board was made by three-layer paper making by the paper making method, white paper made by coating the color on both sides with a double coating to a total of 20 g / m ² , It was set as Examples 1-5 and Reference Examples 1-2 . In the middle layer, 50% of the same type of broken paper broke (filler content: about 10%) generated in the factory was blended.

<Comparative Examples 1-11>
The content of the inorganic filler in the surface layer and the back layer is variously changed so as to be out of the range of 1.0 to 9.0%, and the content of the inorganic filler in the middle layer is 2.0 to 15. Except for blending so as to be out of the range of 0%, white paperboard produced by papermaking and coating in the same manner as in Examples was designated as Comparative Examples 1-11.

<Comparative Example 12>
A white paperboard produced in the same manner as in Example 1 except that no broke broke was added to the middle layer was used as Comparative Example 12.

<Table 1>

<Table 2>

As is clear from the results in Table 1, in Examples 1 to 5 that satisfy all the requirements in the present invention, the formation and smoothness were good, and the stiffness and whiteness were also appropriate values. On the other hand, as is clear from the results in Table 2, in Comparative Examples 1 to 4 and 7 to 11 in which the content of the inorganic filler in either the front layer or the back layer or both is less than 1.0%, the surface or Not only the amount of pulp on the back side increased too much, but the formation of the front and back sides deteriorated, but the stiffness also tended to decrease. If the stiffness is lowered, it adversely affects the suitability for subsequent box processing (when white paperboard is formed into a box, it adversely affects ruled lines).

  Moreover, in the case of Comparative Examples 5 and 7 to 9 in which the content of the inorganic filler in either the front layer or the back layer or both exceeds 9.0%, the amount of the inorganic filler is excessively increased. Stiffness has decreased. Furthermore, the whiteness exceeded the desired value. In Comparative Examples 5, 6, and 8 in which the content of the inorganic filler in the middle layer exceeded the range of 2.0 to 15.0%, the in-layer peel strength of the middle layer became weak, and the box processing suitability deteriorated. In Comparative Examples 5, 6, and 8, the stiffness decreased. In the case of Comparative Example 12 in which the content of the inorganic filler in the middle layer is less than 2.0%, the proportion of the pulp in the middle layer is excessively increased, the formation of the middle layer is deteriorated, and the formation of the surface layer and the back layer is It got worse.

From the above results, the content of the inorganic filler in the surface layer and the back layer is set in the range of 1.0 to 9.0%, and the content of the inorganic filler in the middle layer is 2.0 to 15.0%. is set within a range of manufacturing, white board paper mineral filler is according to the present invention Ru precipitated calcium carbonate der Rosetta type, texture, and smoothness, it is also effective at any point of stiffness and whiteness I was able to confirm. The packaging box manufactured using the white paperboard according to the present invention has a good appearance and has an appropriate rigidity.

  Although the present invention has been described in some detail with its most preferred embodiments, it will be apparent that a wide variety of embodiments can be constructed without departing from the spirit and scope of the invention. Accordingly, the invention is not limited to that particular embodiment, except as limited in the appended claims.

Claims (2)

In white paperboard made of multi-layered paper consisting of 3 or more layers, each surface layer and back layer are blended so as to contain 1.0 to 9.0% inorganic filler with respect to pulp fibers, and the middle layer is made into pulp fibers. 2.0 to 15.0% of the formulated to contain an inorganic filler, Ri formed to fit the paper making the surface layer and the middle layer and the backing layer, wherein the inorganic filler is Ru precipitated calcium carbonate der of rosette type white board for . A printed matter, a printing box, or a packaging container obtained from the white paperboard according to claim 1 .