JP6109787B2 - Pattern paper - Google Patents

Description

  The present invention relates to a pattern paper having a texture similar to that of Japanese paper having a feeling of unevenness.

  Embossing is widely performed for the purpose of imparting design properties to paper. This embossing process can be performed by using a wet embossing method in which felt is pressed against wet paper on a paper machine or shaped with a roll engraved with a pattern. The dry embossing method for shaping is typical.

  As such paper, Patent Document 1 discloses that, in order to produce a large amount of embossed pattern paper having the same texture as Japanese paper at a low cost, a specific pulp is blended in a specific ratio and freeness is regulated. Pattern paper with a texture similar to that of Japanese paper has been proposed. Further, in Patent Document 2, after fixing a microcapsule type foaming material to pulp, the flocs are formed by agglomeration, and the flocs are incorporated into paper stock or combined, and then the obtained paper is heated. Then, a pattern paper having a concavo-convex pattern has been proposed by foaming a microcapsule type foaming agent contained in a floc. Patent Document 3 proposes that a water droplet pattern paper is obtained by dropping water droplets over the entire width of the wire width in the wire portion of the paper machine.

  Such pattern paper is handwritten with a pencil, a ballpoint pen, and the like, and writing brush paintings and watercolors with ink and watercolor paints are also popular. When drawing with ink or watercolor paint, it is desired that the paper has a texture similar to that of Japanese paper with low smoothness and unevenness unlike writing with a pencil or ballpoint pen.

JP-A-6-264400 JP-A-60-59198 JP-A-6-272198

  An object of the present invention is to provide a pattern paper having a texture similar to that of Japanese paper having a feeling of unevenness.

  In order to solve the above problems, the pattern paper of the present invention is a pattern paper composed of two or more layers mainly composed of pulp, and at least one of the outermost layers has a surface Beck smoothness of 8 seconds. The agglomerated pulp layer is the following: the pulp contained in the agglomerated pulp layer is agglomerated pulp agglomerated with a polyacrylamide resin having a weight average molecular weight of 8 million or more, and 30% by mass or more of the agglomerated pulp is a conifer. Pulp.

  Moreover, in the pattern paper of this invention, content of the said polyacrylamide resin whose weight average molecular weight is 8 million or more is 0.08-1.0 mass% with respect to the pulp in the said aggregated pulp layer. Is preferred.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the pattern paper which has the same texture as the Japanese paper with the unevenness | corrugation suitable for drawing with ink or a watercolor paint.

It is typical sectional drawing of the pattern paper of this invention. Fig.1 (a) shows the structural example of the pattern paper which laminated | stacked two layers of the aggregation pulp layers. FIG.1 (b) shows the structural example which provided one layer each of the aggregation pulp layer and arbitrary paper layers. FIG.1 (c) shows the structural example which provided the aggregated pulp layer on both surfaces of arbitrary paper layers.

  The patterned paper of the present invention is a patterned paper composed of two or more layers containing pulp as a main component, and at least one of the outermost layers is an aggregated pulp layer having irregularities on the surface. The contained pulp is an agglomerated pulp that has been agglomerated with a polyacrylamide resin having a weight average molecular weight of 8 million or more (hereinafter sometimes referred to as “ultra-polymer polyacrylamide resin”), and 30 mass of the agglomerated pulp. % Or more is softwood pulp, and the Beck smoothness of the surface of the aggregated pulp layer is 8 seconds or less.

  A configuration example of the pattern paper of the present invention is shown in FIG. In the figure, 1 is an agglomerated pulp layer and 2 is an arbitrary paper layer. The configuration of the arbitrary paper layer is not particularly limited, and various known paper layers used in multilayer paper can be used. In the figure, the thickness of each layer does not represent an actual ratio.

  The configuration example shown in FIG. 1A is a configuration example of a pattern paper in which two agglomerated pulp layers are laminated. The two agglomerated pulp layers may be layers made of the same papermaking raw material slurry, or may be layers made of papermaking raw material slurries with different contents of ultra-high molecular weight polyacrylamide resin and pulp composition. Good. Further, the filler may be contained only in one aggregated pulp layer, and the filler may not be contained in the other aggregated pulp layer. In such a configuration, both the smoothness of both sides of the pattern paper can be set to 8 seconds or less, and the pattern paper has a texture similar to that of Japanese paper with a concavo-convex feeling suitable for drawing with ink or watercolor paint on both sides. It can be.

  Next, the configuration example shown in FIG. 1B is a configuration example in which one agglomerated pulp layer and one arbitrary paper layer are provided. With such a configuration, it is possible to obtain a pattern paper having one side having a texture similar to that of Japanese paper having an uneven feeling suitable for drawing with ink or watercolor paint. Here, the configuration of an arbitrary paper layer is not particularly limited, and various known paper layers used in multilayer paper can be used as long as the effects of the present invention are not impaired. Further, depending on the application, it is possible to further provide a pigment coating layer on the surface of an arbitrary paper layer. In addition, although the arbitrary paper layer has shown the structure of 1 layer in the figure, it is good also as a structure of 2 layers or more.

  Next, the configuration example shown in FIG. 1C is a configuration example in which one aggregated pulp layer is provided on each side of an arbitrary paper layer. Here, the configuration of an arbitrary paper layer is not particularly limited, and various known paper layers used in multilayer paper can be used as long as the effects of the present invention are not impaired. With such a configuration, like the pattern paper illustrated in FIG. 1 (a), a pattern paper having a texture similar to that of Japanese paper having an unevenness suitable for drawing with ink or watercolor paint on both sides is used. Furthermore, since an arbitrary paper layer is provided as an intermediate layer interposed between the two agglomerated pulp layers, the pulp used for all layers may not be agglomerated pulp. It is also possible to adjust physical property values such as basis weight, thickness, opacity, and various strengths of the pattern paper with an arbitrary paper layer as an intermediate layer. In addition, although the arbitrary paper layer has shown the structure of 1 layer in the figure, it is good also as a structure of 2 layers or more.

  In the pattern paper of the present invention, the pulp used in each layer is not particularly limited, and softwood bleached kraft pulp (NBKP), softwood bleached sulfite pulp (NBSP), hardwood bleached kraft pulp (LBKP), hardwood bleached sulfite Wood bleached chemical pulp represented by pulp (LBSP) can be used. If necessary, mechanical pulp such as GP (crushed wood pulp), TMP (thermomechanical pulp), BCTMP (bleached chemothermomechanical pulp), or used paper pulp can be appropriately blended. Furthermore, in addition to wood pulp, non-wood pulp such as cocoons, cocoons, and abaca, synthetic pulp, synthetic fibers, and the like can be appropriately blended. The freeness of pulp is not particularly limited, but Canadian standard freeness (freeness) (JIS P 811-2: 2012 "Pulp-Freeness test method-Part 2: Canadian standard freeness method") ) And preferably 450 to 700 ml CSF.

  In the pattern paper of the present invention, the pulp to be blended into the agglomerated pulp layer uses agglomerated pulp that has been agglomerated with an ultra-high molecular weight polyacrylamide resin, and 30% by mass or more of the pulp component of this agglomerated pulp is derived from conifers. Pulp (conifer pulp). Preferably, 50% by mass or more, more preferably 70% by mass or more, and most preferably 100% by mass (that is, the total amount of pulp) is conifer-derived pulp. The softwood-derived pulp is preferably softwood bleached kraft pulp (NBKP) or softwood bleached sulfite pulp (NBSP). The fibers of softwood pulp such as NBKP, NBSP, etc. are easy to give the surface of the pattern paper unevenness due to its length and rigidity, and the texture has the same texture as the Japanese paper with the surface unevenness by aggregating this Can be paper. If the content of the coniferous pulp in the total pulp components is less than 30% by mass, the surface roughness of the aggregated pulp layer cannot be satisfied. Moreover, since NBSP is softer than NBKP, it is preferable to use NBSP when a soft texture is required. Other pulps such as GP (crushed wood pulp), TMP (thermomechanical pulp), and BCTMP (bleached chemithermomechanical pulp) can be used. Furthermore, in addition to wood pulp, non-wood pulp such as cocoons, cocoons, and abaca, synthetic pulp, synthetic fibers, and the like can also be used. Moreover, the hardwood derived pulp (hardwood pulp), such as a hardwood bleached kraft pulp (LBKP) and a hardwood bleached sulfite pulp (LBSP), can also be mix | blended as needed. This is because by adjusting the blending amount of the hardwood pulp (L pulp) and the softwood pulp (N pulp), the unevenness of the pattern paper surface can be adjusted to a desired one.

  The freeness of the pulp subjected to the flocculation treatment is not particularly limited, but the Canadian standard freeness (freeness) (JIS P 8121-2: 2012 “pulp-freeness test method—Part 2: Canadian standard filter) It is preferable that the water content is 500 to 750 ml CSF before the agglomeration treatment. More preferably, it is 550-700 ml. By setting the freeness within this range, the smoothness of the surface of the pattern paper can be made relatively low while maintaining a constant paper strength, and the texture becomes uneven, giving it the same texture as Japanese paper. It can be made easier. Further, since the void ratio between the fibers becomes high, the ink and the watercolor paint can easily permeate the paper surface, and the drawing aptitude can be improved. When the freeness is less than 500 ml CSF, the smoothness of the surface of the pattern paper tends to be high, and it may be difficult to obtain an uneven surface. If the freeness exceeds 750 ml CSF, the strength of the pattern paper may be impaired, and the surface strength of the coagulated pulp layer may be too weak.

  In the present invention, the pulp to be contained in the agglomerated pulp layer is agglomerated pulp that is agglomerated with a polyacrylamide resin having a weight average molecular weight of 8 million or more. The aggregation treatment is preferably performed with a polyacrylamide resin having a weight average molecular weight of 10 million or more, 11 million or more, or 12 million or more, and more preferably a weight average molecular weight of 13 million or more, or 15 million or more. The upper limit of the weight average molecular weight of the polyacrylamide-based resin is not particularly limited, but is preferably 20 million or less from the viewpoint of not causing process stains in the papermaking system. Polyacrylamide-based resins are general papermaking chemicals as yield improvers and paper strength agents, and it is known that cohesion tends to be strong when the molecular weight is high. When an ultra high molecular weight polyacrylamide resin is used in a general paper making system, the strength of the cohesive force may damage the formation of the paper. Therefore, although it is difficult to use an ultra-high molecular weight polyacrylamide resin as a general paper-making chemical, in the present invention, it is used for the purpose of agglomerating the pulp to obtain an uneven feeling on the surface of the aggregated pulp layer. Molecular polyacrylamide resins can be suitably used. Then, by using an ultra-high molecular weight polyacrylamide resin and aggregating a pulp containing 30% by mass or more of a coniferous pulp, it is possible to obtain a desired unevenness on the surface of the pattern paper. If the polyacrylamide resin used here has a weight average molecular weight of less than 8 million, the pulp is insufficiently aggregated, and the desired unevenness may not be obtained on the surface of the pattern paper. The weight average molecular weight of the polyacrylamide resin can be determined by a viscosity method (extreme viscosity).

  As the ultra high molecular weight polyacrylamide resin, an anionic, cationic or amphoteric polyacrylamide resin can be used. The method for aggregating the pulp is not particularly limited, but the pulp and the ultra high molecular weight polyacrylamide resin are mixed in advance to adjust the agglomerated pulp slurry, and the agglomerated pulp slurry is filled with a filler, a sizing agent, There is a method of mixing a papermaking raw material slurry with another slurry containing a papermaking chemical such as a sulfuric acid band. In this case, a cationic ultra-high molecular weight polyacrylamide resin can be suitably used in that pulp aggregation easily occurs. Another method is to add a papermaking chemical such as filler, sizing agent, and sulfuric acid band to the pulp slurry to adjust the slurry, and then add the ultra high molecular weight polyacrylamide resin to this slurry to agglomerate the pulp. It can also be processed into a papermaking raw material slurry. In this case, although it depends on the potential of the slurry to which the ultra high molecular weight polyacrylamide resin is added, if it is a slurry type using aluminum sulfate (sulfuric acid band) or aluminum chloride (PAC), an anionic ultra high molecular weight polyacrylamide type It is easier to agglomerate the pulp when the agglomeration treatment is performed using the resin. In the two illustrated methods, the ultrahigh molecular weight polyacrylamide resin is added to the slurry prepared by adding papermaking chemicals to the pulp slurry rather than the former method of mixing the agglomerated pulp slurry with other slurries. This method has a higher pulp agglomeration effect and tends to cause unevenness on the surface of the pattern paper. Accordingly, an anionic polyacrylamide resin is preferred as the polyacrylamide resin used in the present invention. Moreover, it is preferable to add an anionic polyacrylamide resin lastly after adding various additives.

  In the present invention, 0.08 to 1.0% by mass, preferably 0.10 to 0.80% by mass, in terms of solid content, with respect to the pulp containing the ultrahigh molecular weight polyacrylamide resin in the aggregated pulp layer. %, More preferably 0.2 to 0.6% by mass. By adopting such a configuration, it is possible to obtain a patterned paper having a texture similar to that of Japanese paper having a feeling of unevenness, with pulp being agglomerated by an ultra-high molecular weight polyacrylamide resin, low smoothness. When the content of the ultra-high molecular weight polyacrylamide resin is less than 0.08% by mass with respect to the pulp, the aggregation of the pulp becomes weak, and there is a possibility that the unevenness of the intended pattern paper cannot be obtained. On the other hand, if it exceeds 1.0% by mass, process operability of papermaking deteriorates because process stains occur, and foreign matters are likely to be mixed into the pattern paper.

  Each paper layer of the pattern paper of the present invention includes, in addition to the above-described ultra-high molecular weight polyacrylamide resin, a sulfuric acid band, a filler, a sizing agent, and a paper strength agent in each layer as long as the effects of the present invention are not impaired. Further, various papermaking materials (additives) such as a yield improver, a coloring dye, and a coloring pigment can be contained. For example, 0.1 to 1 part of sizing agent, 1 to 5 parts of sulfuric acid band, and 0.5 to 3 parts of paper strength agent can be added to the aggregated pulp layer with respect to 100 parts of pulp slurry. . In addition, it is preferable to add these various additives before adding the anionic polyacrylamide resin. Furthermore, for example, 0.2 to 5 parts of paper strength agent and 0.1 to 1 part of sizing agent can be added to 100 parts of pulp slurry in layers other than the aggregated pulp layer.

  The pattern paper making method of the present invention is not particularly limited, and conventionally known paper machines such as a circular paper machine, a short paper machine, a long paper machine, and a combination paper machine of these paper machines are used. Can be made. About the lamination | stacking method of each layer, you may make together or may bond. In the case of papermaking, a paper strength agent such as interlayer starch may be sprayed to prevent delamination of each layer of papermaking.

  The patterned paper of the present invention has a Beck smoothness of at least one side of 8 seconds or less. Preferably it is 6 seconds or less. By setting the Beck smoothness to 8 seconds or less, it is possible to obtain a pattern paper having a texture similar to that of Japanese paper having an uneven feeling suitable for drawing with ink or watercolor paint. If the Beck smoothness exceeds 8 seconds, it cannot be a patterned paper having the same texture as Japanese paper. As described above, in the patterned paper of the present invention, the pulp is agglomerated by the ultra-high molecular weight polyacrylamide resin, so that the surface of the patterned paper is uneven, and the Beck smoothness can be easily set to 8 seconds or less. . Further, when calendering the pattern paper after paper making, the Beck smoothness may be processed so as not to exceed 8 seconds. For example, the linear pressure may be lowered for processing.

In the patterned paper of the present invention, various auxiliaries can be applied to the surface of the patterned paper with a size press device as necessary. For example, paper strength agents such as starch, polyvinyl alcohol, and polyacrylamide can be applied with a size press to impart surface strength, and styrene acrylic resins, alkyl ketene dimers, etc., for the purpose of improving size. A surface sizing agent may be applied. Furthermore, an ink fixing agent may be applied to impart ink jet recording suitability. For example, a 1 to 10% aqueous solution of a paper strength agent can be applied to the surface of the aggregated pulp layer at 20 to 80 cc / m ² per both sides of the paper.

The rice paper of the pattern paper of the present invention is not particularly limited, but is preferably 50 g / m ² or more. Preferably 60~1000g / ^{m 2,} particularly preferably from 100 to 600 / ^{m 2.} If the rice tsubo is less than 50 g / m ² , there is a risk of see-through when drawing with ink or watercolor paint. In addition, it is preferable that the aggregate weight of the aggregated pulp layer is 20 g / m ² or more. More preferably, it is 25-120 g / m < ² >, for example, 30-100 g / m < ² >. If the aggregate weight of the aggregated pulp layer is less than 20 g / m ² , the texture of the Japanese paper with the unevenness may be impaired.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Further, “parts” and “%” in the examples respectively represent parts by mass or mass% in terms of solid content unless otherwise specified.

Example 1
<Preparation of paper stock for agglomerated pulp layer>
A pulp consisting of 70 parts of NBKP and 30 parts of LBKP (freeness 600 ml CSF) is dispersed in water to obtain a pulp slurry, and 0.3 parts of a rosin emulsion sizing agent (trade name: AL1200 / manufactured by Seiko PMC) as a sizing agent. 2 parts of sulfuric acid band and 1 part of cationized starch (trade name: Neotac 110M / manufactured by Nippon Shokuhin Kako Co., Ltd.) as a paper strength agent were added and stirred, respectively, and then an anionic polyacrylamide having a weight average molecular weight of 12 million (trade name) : Hymolock SS-100 / manufactured by Hymo Co., Ltd.) 0.5 parts was added and the pulp was subjected to agglomeration treatment to obtain a paper stock for the agglomerated pulp layer.
<Preparation of stock for intermediate layer>
Pulp consisting of 80 parts of LBKP and 20 parts of NBKP (freeness 560 ml CSF) is dispersed in water to form a pulp slurry, and 1 part of grafted starch (trade name: DG4204 / manufactured by Seiko PMC Co., Ltd.) is used as a paper strength agent in the pulp slurry. As above, rosin-based emulsion sizing agent (trade name: AL1200 / manufactured by Seiko PMC Co., Ltd.) (0.3 parts) was added and stirred to obtain an intermediate layer stock.
<Making paper pattern>
The resulting aggregated pulp layer stock and intermediate layer stock were used to form a structure in which the agglomerated pulp layer / intermediate layer / aggregated pulp layer were sequentially laminated on a circular paper machine. A wet paper was made by laminating, dehydrated by a press, and dried. Thereafter, an 8% aqueous solution of polyacrylamide-based paper strength agent (trade name: ST5000 / manufactured by Seiko PMC Co., Ltd.) was applied with 50 cc / m ^{2 on} both sides of the paper with a two-roll size press, and then dried with a cylinder dryer. A pattern paper having a weight of 285 g / m ² was obtained. The basis weight of each layer was 95 g / m ² .

(Example 2)
In Example 1, the addition amount of anionic polyacrylamide having a weight average molecular weight of 12 million (trade name: Hymolock SS-100 / manufactured by Hymo Co., Ltd.) in the preparation of the aggregate pulp layer stock was changed to 0.1 part. Except for the above, a pattern paper was obtained in the same manner as in Example 1.

(Example 3)
In Example 1, the addition amount of anionic polyacrylamide having a weight average molecular weight of 12 million (trade name: Hymolock SS-100 / manufactured by Hymo Co., Ltd.) in the preparation of the aggregate pulp layer stock was changed to 1.0 part. Except for the above, a pattern paper was obtained in the same manner as in Example 1.

Example 4
In Example 1, a pattern paper was obtained in the same manner as in Example 1 except that the pulp in the preparation of the stock for the aggregated pulp layer was changed to a pulp (freeness 600 ml CSF) consisting of 100 parts of NBKP.

(Example 5)
In Example 1, a pattern paper was obtained in the same manner as in Example 1 except that the pulp in the preparation of the stock for the aggregated pulp layer was changed to pulp (freeness 600 ml CSF) consisting of 40 parts of NBKP and 60 parts of LBKP.

(Example 6)
In Example 1, 0.5 part of anionic polyacrylamide (trade name: Hymolock SS-100 / manufactured by Hymo Co., Ltd.) having a weight average molecular weight of 12 million in the preparation of the stock for the aggregated pulp layer and a weight average molecular weight of 1400 are used. Pattern paper was obtained in the same manner as in Example 1 except that 0.5 part of anionic polyacrylamide (trade name: Hymolock V-330 / manufactured by Hymo Co.) was used.

(Example 7)
In Example 1, 0.5 part of anionic polyacrylamide (trade name: Hymolock SS-100 / manufactured by Hymo Co.) having a weight average molecular weight of 12 million in the preparation of a paper material for an agglomerated pulp layer was used. Pattern paper was obtained in the same manner as in Example 1 except that 0.5 part of anionic polyacrylamide (trade name: Hymo Lock FA-230 / manufactured by Hymo Co.) was used.

(Example 8)
In Example 1, the addition amount of anionic polyacrylamide (trade name: Hymolock SS-100 / manufactured by Hymo Co., Ltd.) having a weight average molecular weight of 12 million in the preparation of the stock for the aggregated pulp layer was changed to 0.08 parts. Except for the above, a pattern paper was obtained in the same manner as in Example 1.

(Comparative Example 1)
In Example 1, a pattern paper was obtained in the same manner as in Example 1 except that the pulp in the preparation of the stock for the agglomerated pulp layer was changed to pulp (freeness 600 ml CSF) consisting of 25 parts of NBKP and 75 parts of LBKP.

(Comparative Example 2)
In Comparative Example 1, the addition amount of anionic polyacrylamide (trade name: Hymolock SS-100 / manufactured by Hymo Co., Ltd.) having a weight average molecular weight of 12 million in the preparation of the aggregated pulp layer stock was changed to 1.0 part. Except for the above, a pattern paper was obtained in the same manner as in Example 1.

(Comparative Example 3)
In Example 1, the addition amount of anionic polyacrylamide (trade name: Hymolock SS-100 / manufactured by Hymo Co., Ltd.) having a weight average molecular weight of 12 million in the preparation of the stock for the aggregated pulp layer was changed to 0.05 parts. Except for the above, a pattern paper was obtained in the same manner as in Example 1.

(Comparative Example 4)
In Example 1, 0.3 part of an anionic polyacrylamide (trade name: Hymolock SS-100 / manufactured by Hymo Co.) having a weight average molecular weight of 12 million in the preparation of the stock for the aggregated pulp layer and a weight average molecular weight of 500 are used. Pattern paper was obtained in the same manner as in Example 1 except that the amount was changed to 1.0 part of anionic polyacrylamide (trade name: Hymo Lock MJ-500 / manufactured by Hymo Co., Ltd.).

(Comparative Example 5)
In Example 7, the same procedure as in Example 7 was followed, except that 0.07 part of 10 million anionic polyacrylamide (trade name: Hymolock FA-230 / manufactured by Hymo Co.) in the preparation of the stock for the aggregated pulp layer was used. I got a pattern paper.

  Table 1 shows the evaluation results of the pattern paper obtained in each example and comparative example. The evaluation was performed by the following method.

<Beck smoothness>
Measured according to JIS P 8119: 1998.

<Texture>
The surface of the pattern paper was judged by hand touch and vision, and was evaluated in five stages. Among the five stages, 5 was given the impression of roughness (rough feeling) and closest to the texture of Japanese paper, and 1 was given the least unevenness (rough feeling) and different from the texture of Japanese paper. In 5 stages, those with a rating of 2-5 were considered acceptable and those with a rating of 1 were rejected.

  As shown in Table 1, the pattern paper obtained in Examples 1 to 8 was close to the texture of Japanese paper. On the other hand, the pattern paper obtained in each comparative example had high Beck smoothness, which was greatly different from the texture of Japanese paper.

Claims (2)

  A patterned paper composed of two or more layers containing pulp as a main component, wherein at least one of the outermost layers is an aggregated pulp layer having a surface Beck smoothness of 8 seconds or less, and is included in the aggregated pulp layer The patterned paper is characterized in that the pulp is an agglomerated pulp agglomerated by a polyacrylamide resin having a weight average molecular weight of 8 million or more, and 30% by mass or more of the pulp component of the agglomerated pulp is a softwood pulp.   The content of the polyacrylamide resin having a weight average molecular weight of 8 million or more is 0.08 to 1.0 mass% with respect to the pulp in the aggregated pulp layer. Pattern paper.