JP4707454B2 - Newspaper and newspaper production method - Google Patents

Description

  The present invention relates to newsprint capable of printing visual advertisements and the like and a method for producing newsprint.

  In recent years, there has been a demand for newspapers capable of printing visual advertisements (hereinafter also simply referred to as visual printing) for the purpose of, for example, increasing advertising revenue.

  In order to enable visual printing, newsprint paper has high whiteness so that it can be printed vividly, and has good adhesion to the paper plate so that it can be printed finely. I need it. In addition, since there is no drying process in the printing process of newspaper, it is also necessary that the ink is quickly absorbed by the paper (quick drying).

  Here, if only the quick-drying property and adhesiveness of newsprint are improved, for example, mechanical pulp is made into a high blending of 80 to 100% by mass as used in current newsprint (for example, patents). (Refer to Document 1.)

  However, the whiteness (JIS P 8148) decreases when the mechanical pulp is highly blended. As described in Patent Document 1, the whiteness when mechanical pulp is highly blended is at most about 50 to 60%. In order to enable printing that can be convinced by advertisers, whiteness of at least 70% or more is required.

Therefore, it is necessary to reduce the blending of mechanical pulp and blend bleaching pulp. However, when bleaching pulp is blended by reducing blending of mechanical pulp, naturally, quick-drying and adhesiveness decrease, and in addition, opacity decreases. Such a problem also arises.
Japanese Patent No. 2889159

  SUMMARY OF THE INVENTION The main problem to be solved by the present invention is to provide a newspaper and a method for producing the same that have high whiteness and are excellent in quick-drying, adhesion, and opacity.

  The present invention that has solved this problem is as follows.

[Invention of Claim 1]
2 0-60% by weight is at least either one of the machine pulp and deinked waste paper pulp, and the 40 to 80 wt% of the total pulp ingredients the mechanical pulp and the deinking waste paper pulp in the total pulp ingredients Raw material pulp that is bleached pulp other than
In the inlet with a concentration control function, the basis weight is 60 to 65 g / m ² , and one or both of the surface layers when substantially divided into four layers are filled with lipophilic fine particles mainly composed of calcium carbonate, and ash (JIS P 8251) 17~25% and Do Ri, as ash intermediate layer than the surface layer is lowered, and as newsprint produced becomes pH 6-9, and papermaking, sizing agents After applying 0.1 to 1.5 g / m ² ,
It was flattened to a density of 0.66 to 0.90 g / cm ³ by a steel rubber method.
A method for producing newsprint.
[Invention of Claim 2]
2 0-60% by weight is at least either one of the machine pulp and deinked waste paper pulp, and the 40 to 80 wt% of the total pulp ingredients the mechanical pulp and the deinking waste paper pulp in the total pulp ingredients Raw material pulp that is bleached pulp other than
One or both surface layers in a case where the basis weight is 60 to 65 g / m ² , which is substantially equally divided into four layers, are filled with lipophilic fine particles mainly composed of calcium carbonate, and ash (JIS P 8251) 17 25% and Do Ri, as ash intermediate layer than the surface layer is lowered, and as newsprint produced becomes pH 6-9, and papermaking, sizing agents 0.1~1.5g After applying / m ²
Flattened to a density of 0.66 to 0.90 g / cm ³ ;
Newspaper that is characterized by that.

  According to the present invention, it is a newsprint and a method for producing the same that are excellent in quick drying, adhesion, and opacity while having high whiteness.

Next, an embodiment of the present invention will be described.
In producing the newsprint of this embodiment, first, a raw material pulp having the following composition is made.
That is, the blend of the raw material pulp is 20 to 60% by mass, preferably 30 to 50% by mass, more preferably 30 to 40% of all pulp components, and at least one of mechanical pulp and deinked waste paper pulp (DIP). On the other hand (hereinafter, also simply referred to as mechanical pulp / deinked pulp), 40 to 80% by mass, preferably 50 to 70% by mass, and more preferably 60 to 70% by mass of the total pulp components are bleached pulp. .

  Setting the blend of mechanical pulp / deinked pulp to 20% by mass or more and blending of bleached pulp to 80% by mass or less ensures quick drying, adhesion and opacity necessary for visual printing. Because. On the other hand, when the blending of mechanical pulp / deinked pulp is 60% by mass or less and the blending of bleached pulp is 40% by mass or more, the minimum whiteness necessary for visual printing (JIS P 8148), This is because the whiteness is 70% or more.

  In addition, at least one of mechanical pulp and deinked waste paper pulp means that only mechanical pulp is blended, only deinked waste paper pulp is blended, and both mechanical pulp and deinked waste paper pulp are blended. In this case, it is intended to include both.

  The kind of mechanical pulp is not particularly limited. For example, ground (pulverized wood) pulp (GP) produced by pressing wood (logs) against a grindstone surface that rotates rapidly in a grinder, and grinding the wood while applying water in the shower, softening wood chips with steam After that, thermomechanical pulp (TMP), other refiner ground pulp (RGP), stone ground pulp (SGP), pressure type stone ground pulp (FMP) which is defibrated with a pressure type refiner and further refined with a normal pressure type refiner. PGP), pressurized groundwood pulp (PGW), chemithermomechanical pulp (CTMP), bleach chemithermomechanical pulp (BCTMP), chemical mechanical pulp (CGP), and the like.

  However, it is preferable that the mechanical pulp is a pressurized groundwood pulp (PGW). In general, mechanical pulp is less likely to be fibrinated than kraft pulp (KP) and the like, and since the ratio of fine fibers and bundled fibers is large, the binding strength of the fibers is weak. However, for example, pressure-type ground wood pulp (PGW) obtained by grinding under a pressure of 2 to 3 atm in a closed state has a pulp temperature of around 120 ° C. during grinding, and the lignin stuck between fibers is softened. Therefore, there is little mechanical damage of the fiber. As a result, the fibers are longer than other mechanical pulps, and the pulp strength is increased, so that the paper strength is excellent.

  Deinked waste paper pulp (DIP) is pulp obtained by deinking waste paper, and the waste paper used as a raw material is not particularly limited. Examples of the raw material waste paper include newspaper printed waste paper, medium quality waste paper, unsorted waste paper, and the like.

  The type of bleached pulp is not particularly limited. However, it is preferable to use hardwood bleached pulp from the viewpoint of bulky paper quality and opacity, printability, and drying on a rotary press. From the viewpoint of environmental impact, chlorine-free bleached pulp should be used. It is preferred to use.

  In the raw material pulp blended as described above, one or both of the surface layers (front and back layers) when substantially divided into four layers in the thickness direction are filled with lipophilic fine particles and ash (JIS P). 8251) Paper is made so as to be 17 to 25%, preferably 17 to 21%, and more preferably 19 to 21%. Examples of the filler having lipophilicity include calcium carbonate, hydrated silicic acid, kaolin, clay, calcined kaolin, satin white, titanium oxide, talc, aluminum hydroxide and the like. Of these pigments, calcium carbonate and hydrated silicic acid are particularly preferred.

  When oleophilic fine particles are used as the filling amount, the ink is quickly absorbed, so that quick drying is improved. In addition, the filling amount of the filling amount is conventionally about 10% of ash (JIS P 8128), but if it is a high amount of 17% or more as in this embodiment, the quick drying property is remarkably improved. . Therefore, according to this embodiment, the reduction in quick drying due to the reduction in the blending of mechanical pulp and the blending of bleached pulp is offset.

  However, when the filling amount is high, the raw material cost increases. Therefore, in this embodiment, only the surface layer in the case where the layer is substantially equally divided into four layers with respect to the thickness direction, that is, only the portion that absorbs ink is highly formulated, and the intermediate layer is not highly formulated. Thereby, an increase in cost is suppressed.

  On the other hand, since the fine particles have the effect of clogging between the fibers and improving the opacity, if the filling amount is embedded in the surface layer and in a high blending as described above, a large opacity improvement effect is obtained, The reduction in opacity due to the reduction of mechanical pulp blending and bleaching pulp blending will be offset.

  In this embodiment, the type of fine particles that can be used is not particularly limited. For example, calcium carbonate, hollow organic pigment, delaminated clay, talc, clay (white clay), titanium dioxide, aluminum hydroxide, barium sulfate, diatomaceous earth, satin white, titanium oxide, zinc oxide, calcium sulfate, silica, active Examples thereof include mineral pigments such as clay, lake, calcined kaolin, alumina, magnesium carbonate, magnesium oxide, chlorite, white carbon, bentonite, zeolite, sericite, and smectite.

  However, it is preferable to use calcium carbonate as the main raw material (filling amount with the highest mass ratio), more preferably 50% by mass (comprising mass ratio) or more, and 90% by mass (comprising mass ratio). ) Or more is particularly preferable.

  As calcium carbonate, light calcium carbonate (PCC, sedimentation type) produced by a chemical method such as carbon dioxide gasification method (manufactured by blowing carbon dioxide into lime milk) or carbonate solution compounding method, limestone mechanically Heavy calcium carbonate (GCC, pulverized mold) produced by air classification or elutriation after pulverization can be exemplified. Among these, light calcium carbonate is suitable for improving opacity and whiteness. On the other hand, heavy calcium carbonate can be obtained at low cost because limestone, which is a raw material, is produced in large quantities in Japan.

  The particle size of the fine particles is preferably 20 μm or less, and more preferably 10 to 20 μm. The reason why the thickness is preferably 20 μm or less is that, in bulky paper having a low density, a problem that the strength of the paper quality is lowered and printing equipment such as a plate cylinder is easily stained as paper dust. If it is less than 10 μm, the yield of fine particles in the paper is poor, and the diffused light reflectivity that contributes to the opacity is low, so that the effect is hardly exhibited.

  The machine for papermaking raw material pulp is not particularly limited. However, in a normal paper machine, it is difficult to make the ash content of the surface layer high, and there is a possibility that the content is lower than that of the intermediate layer. Therefore, it is preferable to use an inlet with a density adjusting function as a paper machine. Here, the inlet with the concentration adjusting function is an inlet that can adjust the concentration of the material discharged in the width direction by directly or indirectly applying the dilution water to the papermaking material in the head box. A module jet head box manufactured by Heavy Industries, Ltd. can be exemplified.

  The ash content can be adjusted by adjusting the lip opening of the inlet with the above-mentioned concentration control function, as well as by adjusting the concentration and amount of white water used to dilute the raw pulp, and adjusting the flocculant by adjusting the cation demand in the white water You can also.

  As described above, according to the present embodiment, although it is possible to reduce the blending of mechanical pulp and deinked pulp and increase the blending of bleached pulp, the newspaper is excellent in quick-drying and opacity. However, in order to realize these, since the filling amount of the surface layer is made high, there is a possibility that paper strength may be reduced and paper dust may be generated, for example, the plate may be soiled.

Therefore, in this embodiment, first, in order to prevent a decrease in paper strength, the basis weight, while was conventionally 40~48g / m ^2, the 60~65g / m ^2, preferably 63-64. to 5 g / m ^2, more preferably 63.5~64.5g / m ^2, increasing.

In order to prevent the occurrence of paper dust, the sizing agent is 0.1 to 1.5 g / m ² , preferably 0.5 to 1.2 g / m ² , more preferably 0.8 to 1.0 g / m ² . Apply m ² . By these, the problem by having high filling amount does not arise. In addition, since calcium carbonate as a filling amount (fine particles) has high hardness, there is a risk of plate wear during offset printing. However, such wear is reduced by the above size treatment.

  In this embodiment, the specific method of size processing is not particularly limited. For example, by passing paper between two press rolls and applying size press liquid (size agent) on both sides of the paper, three pairs of rolls (fountain roll, metering roll, applicator roll from outside) The size press liquid is supplied between the fountain roll and the metering roll, transferred from the metalling roll to the applicator roll, and the size press liquid layer on the applicator roll and the paper are nipped with the other applicator roll. An example is a method of coating by contact with pressure. In addition, for example, a tab size press, a calendar size press, and the like can be exemplified. In these methods, the starch concentration and viscosity to be used can be adjusted as appropriate.

  In this embodiment, the type of size press liquid that can be used is not particularly limited. For example, starch, oxidized starch, esterified starch, etherified starch, cationized starch, modified starch such as oxygen-modified, cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, polyvinyl alcohol (PVA), carboxyl-modified polyvinyl alcohol, aceto Selected from modified alcohols such as acetylated polyvinyl alcohol, styrene butadiene copolymer, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polyacrylate ester, polyacrylamide, etc. Examples thereof include an aqueous solution containing an adhesive, an aqueous latex, and the like. Moreover, auxiliary agents, such as a dispersing agent, a flow modifier, an antifoamer, a dye, a lubricant, a water-resistant agent, and a crosslinking agent, can also be blended with this size press liquid.

However, even with the above, another problem caused by reducing the blending of mechanical pulp and deinked pulp and increasing the blending of bleached pulp, that is, the problem of adhesion remains. Therefore, in this embodiment, the flattening process of back and forth in a size press process after papermaking, so that the density 0.66~0.90g / cm ^3, preferably a 0.72~0.84g / cm ³ Thus, it is carried out so that it is more preferably 0.76 to 0.80 g / cm ³ . As a result, the cushioning property of the paper is improved, and the decrease in adhesion due to the decrease in the blending of mechanical pulp and deinked pulp and the increase in the blending of bleached pulp can be offset.

The method of this planarization process is not specifically limited. However, in the steel steel method (the pair of nip roll surfaces are both made of metal), it may be difficult to achieve a density of 0.66 g / cm ³ or more. Therefore, this flattening treatment is preferably performed by a steel rubber method (one of a pair of nip roll surfaces is made of metal and the other is made of a material having elasticity such as rubber). The flattening treatment of the steel rubber method can be performed by one or two sets, or a multi-stage combination of material rolls with one side made of metal and the other made of rubber or other elastic material. When there is a difference between the two, the combination of the elastic rolls on one rough surface so as to contact more than the opposite surface is suitable for obtaining flatness equal to the front and back surfaces while maintaining the cushioning property of the paper.

(Other)
The production method of the present embodiment can be carried out so that the produced newspapers have a pH of 6-9, preferably a pH of 7-7. The reason why the pH is 6 or more is that if the pH is less than 6, there is a problem that calcium carbonate internally added as a filler is eluted, and the inside of the paper machine system is soiled. On the other hand, the reason why the pH is 9 or less is that the effect of the sizing agent added as a papermaking chemical is hardly exhibited, and the yield of the filler is reduced.

  As an example of the papermaking method, first, after adjusting the paper stock in the paper stock adjustment process, the paper stock is sprinkled in the wire part process, the sprinkled paper stock is dehydrated in the press part process, and the pre-dryer part process Dry with Next, a coating liquid is applied to the surface of the base paper dried in the predryer part process in the size press part process, and the base paper is further dried in the afterdryer part process. Next, the coated surface coated with the base paper coating solution in the calendar part process is smoothed. Next, a base paper having a smooth coated surface is wound on a reel in a reel part process, adjusted to a predetermined width and length in a winder part process, and newsprint paper is produced.

  Table 1 shows test examples for clarifying the effects of the present invention. In addition, as the filling amount, a material having affinity for the offset ink was used.

[Ink drying property] The recording area immediately after printing was rubbed with gauze, and the degree of stain due to spreading of the ink was visually evaluated according to the following evaluation criteria.
A: There is no dirt and the drying property is excellent.
○: There is almost no dirt and the drying property is good.
X: There are many dirts and dryness is inferior.

[Paper dust] Newspaper paper was cut with a cutter, and the occurrence of paper dust at that time was visually evaluated.
A: Excellent with almost no generation of paper dust.
○: Some generation of paper dust, but no problem.
X: The generation of paper dust is inferior.

[Ash content] Ash content was measured in accordance with JIS P 8251. As a means of almost equal differentiation, it was divided into approximately 4 equal parts using a “sheet splitter” manufactured by Kumagaya Riki Kogyo Co., Ltd. and subjected to the test.

[Paper Release] Using a RI printing tester (manufactured by Meisei Seisakusho), the ink of tack value 10 was used to visually determine the state of white spots.
A: There are no white spots.
○: Almost no white spots.
X: White spots are remarkably generated.

  The present invention can be applied as newsprint paper capable of printing visual advertisements and the like and a method for producing newsprint paper.

Claims (2)

2 0-60% by weight is at least either one of the machine pulp and deinked waste paper pulp, and the 40 to 80 wt% of the total pulp ingredients the mechanical pulp and the deinking waste paper pulp in the total pulp ingredients Raw material pulp that is bleached pulp other than
In the inlet with a concentration control function, the basis weight is 60 to 65 g / m ² , and one or both of the surface layers when substantially divided into four layers are filled with lipophilic fine particles mainly composed of calcium carbonate, and ash (JIS P 8251) 17~25% and Do Ri, as ash intermediate layer than the surface layer is lowered, and as newsprint produced becomes pH 6-9, and papermaking, sizing agents After applying 0.1 to 1.5 g / m ² ,
It was flattened to a density of 0.66 to 0.90 g / cm ³ by a steel rubber method.
A method for producing newsprint. 2 0-60% by weight is at least either one of the machine pulp and deinked waste paper pulp, and the 40 to 80 wt% of the total pulp ingredients the mechanical pulp and the deinking waste paper pulp in the total pulp ingredients Raw material pulp that is bleached pulp other than
One or both surface layers in a case where the basis weight is 60 to 65 g / m ² , which is substantially equally divided into four layers, are filled with lipophilic fine particles mainly composed of calcium carbonate, and ash (JIS P 8251) 17 25% and Do Ri, as ash intermediate layer than the surface layer is lowered, and as newsprint produced becomes pH 6-9, and papermaking, sizing agents 0.1~1.5g After applying / m ²
Flattened to a density of 0.66 to 0.90 g / cm ³ ;
Newspaper that is characterized by that.