JP2002173888A - Printing paper and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing paper causing no feathering phenomenon when printed with an ink-jet printer, also usable as a copying paper with high mechanical strength, containing deinked pulp regenerated from waste paper including newspaper and magazines, and to provide a method for producing the printing paper. SOLUTION: This method for producing a printing paper using deinked pulp which is produced through a plurality of steps essentially comprising the step of disaggregating waste paper and the step of using a surfactant-based deinking agent; wherein at least one step among all of the steps is characterized by comprising conducting a papermaking by adding finely fibrillated cellulose to stock pulp compounded with deinked pulp deinked by addition of a sizing agent. The other objective printing paper is provided by the above method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording paper manufactured from deinked pulp made from used paper such as newspapers and magazines and a method for manufacturing the same. The present invention relates to a usable recording sheet and a method for manufacturing the recording sheet.

[0002]

2. Description of the Related Art Deinked pulp is used as a raw material for papermaking together with wood pulp from the viewpoint of resource saving and measures against municipal waste treatment, and is widely used in the fields of newspapers and magazines. In general, the method for producing deinked pulp is to separate the ink and the pulp by washing or flotation, etc., after the waste paper disintegration process, the deinking process such as kneading in the presence of a deinking agent and alkali, etc. ), Followed by washing and bleaching as necessary. For example, waste paper on which newspapers or magazines are printed is disintegrated with an alkaline chemical or the like using a disintegrator such as a pulper, and alkali soaking (alkali immersion) is further performed by adding an alkaline chemical, hydrogen peroxide or a surfactant.
At the same time, the pulp fibers are swollen by using mechanical stirring force, the ink and the pulp are separated, and then the ink is separated from the pulp by washing or flotation to produce deinked pulp. In Japan, the recovery rate of used paper as a raw material for paper is about 50%, but with the aim of using more recycled paper,
The use of waste paper pulp is increasing in general paper as well as in recording paper such as copy paper. In recent years, personal computers have spread not only in offices but also in homes, and accordingly, the spread of inkjet printers has been remarkable. As the output paper of the inkjet printer, there is a special coated paper, but a copy paper is also used. However, when ink jet recording is performed on copy paper containing deinked pulp, characters become difficult to read due to feathering (whisker-like bleeding of ink),
When variable data such as a barcode is recorded, there is a problem that it is difficult to read the barcode or the like. In order to solve this, when making paper using pulp slurry containing pulp containing deinked pulp, add a large amount of internal sizing agent, or use a size press device or the like on the surface of the paper made. For example, a surface sizing agent is applied, but a satisfactory product has not been obtained.

Further, deinked pulp deteriorates due to deterioration due to repeated wet and dry processes, and aging due to the effects of humidity, temperature, atmospheric oxygen and ultraviolet rays, and the like. Since the recording paper is inferior in strength as compared with the case where the raw material pulp is only virgin, various troubles occur. For example, when used in a laser beam printer or a copier, which is widely used as an output of a personal computer, paper powder is generated due to low surface strength, which adversely affects the printer. As a method for improving the surface strength, a surface treatment agent such as starch or polyvinyl alcohol may be applied to the surface, but with these methods, there is a limit in improving the surface strength,
In addition, troubles such as adhesion of coating components to the drum occur, and this is not a sufficient measure.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a newspaper / magazine which does not cause feathering when recorded by an ink jet printer and has excellent strength and can be used as a co-paper for copying. It is an object of the present invention to provide a recording paper containing deinked pulp recycled from waste paper such as paper, and a method for producing the same.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found the following method. That is, in a method for producing a deinked pulp comprising a plurality of steps including at least a disintegration step of waste paper and a deinking step using a surfactant-based deinking agent, the method includes any one or more of the plurality of steps. The present invention has been accomplished by adding fine fibrillated cellulose to a raw material pulp containing deinked pulp produced by a method of deinking treatment by adding a sizing agent, followed by papermaking. The paper containing the deinked pulp obtained by this method has no or significantly improved feathering when recorded using an ink jet method, especially an aqueous ink, and has excellent surface strength and other laser beam printers. And a paper that could be used with a copier.

The production of deinked pulp comprises the steps of defibration, deinking, washing and bleaching, and is carried out by combining these steps according to the type of waste paper and the purpose of use of the deinked pulp. When disintegrating waste paper with a pulper, an alkaline chemical is added to increase the water absorption of the waste paper, and the fibers are rubbed by mechanical agitation to separate the waste paper into individual fibers and the ink is separated from the fibers. -Peel off. Further, a surfactant-based deinking agent is added together with an alkaline chemical to promote separation and peeling of the ink from the fiber, and subsequently, the ink separated from the fiber by a washing method or a flotation method is discharged out of the system. In the deinked pulp manufactured by this method, a deinking agent mainly composed of a surfactant is firmly bonded to the fiber surface or penetrates into the fiber. The surfactant cannot be completely washed away with the washing degree of. When blending the deinked pulp thus obtained and making paper,
Even if the sizing agent is internally added as usual, or applied (externally added) to the paper surface using a size press, etc., the sizing agent does not adhere sufficiently to the fibers, and the amount of the sizing agent increases. However, the amount of adhesion does not increase beyond a certain level. Therefore, when recording is performed on the recording paper thus obtained by the ink jet method using the water-based ink, feathering is considered to occur because ink bleeding partially becomes extremely large.

On the other hand, in the present invention, when producing deinked pulp, the pulp is treated with a sizing agent in advance, so that the sizing agent is sufficiently fixed on the fiber surface. In particular, if the surfactant-based deinking agent is deinked by adding the deinking agent before entering the fiber, that is, after adding the sizing agent in the defibration process, the sizing agent will have a surfactant in the deinking agent. It is expected that sufficient sizing agent will settle on the surface of the selected deinked pulp since it is hardly affected by the agent.

[0008] The fine fibrillated cellulose added to the raw pulp is mechanically, physically,
It is made fine by chemical treatment. For example, when the pulp slurry is refined and observed with an optical microscope, when the water retention value is 210 to 250%, the fiber width is 20 to 30 μm.
m of pulp fiber is partially destroyed, and fibrils with a fiber width of 3 to 5 μm increase, and these fibers are in a shape in which several to several tens of fibers are partially bound or entangled. When the fibers are observed with a scanning microscope, fine fibers having a fiber width of 0.5 μm or less are also observed. It is presumed that such a fine fiber width of the fine fibrillated cellulose contributes to an increase in the fiber surface area and an increase in the number of networks between fibers, and serves to strengthen the inter-fiber bonds of the pulp, thereby improving the strength.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, it is preferable to add a sizing agent before adding a surfactant-based deinking agent, and more preferably, in disintegrating waste paper with a pulper.
It is better to disintegrate with a solution in which a sizing agent is added together with a small amount of an alkaline chemical. It is preferable that the amount of the alkaline chemical added is as small as possible.

The sizing agents usable in the present invention include known alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), rosin, styrene, acrylic, styrene / acrylic and olefinic sizing agents. Use of a sizing agent is possible, and there is no particular limitation to these. Although the ionicity of the sizing agent to be added can be either anionic or cationic, it is preferable to use a cationic sizing agent rather than an anionic agent when considering attachment of the sizing agent to pulp fibers. .

The amount of the sizing agent to be added is preferably 0.1 to 5.0% by weight, more preferably 0.2 to 2.5% by weight, based on 100 parts by weight of the deinked pulp. 0.1% by weight of sizing agent added to 100 parts by weight of deinked pulp
In the following cases, feathering tends to increase and recording quality tends to be poor when recording is performed by an ink jet printer using an aqueous ink on recording paper made by mixing the pulp and virgin chemical pulp. On the other hand, the amount of the sizing agent was 5.0% by weight based on 100 parts by weight of the deinked pulp.
When the treatment is carried out by adding a larger amount, the effect of improving feathering is not particularly changed, and the cost is significantly increased.

The surfactant-based deinking agent of the present invention includes:
Anionic surfactants such as carboxylic acid type, sulfate ester type, sulfonic acid type and phosphate ester type, nonionic surfactants such as ether type, ester type and fatty acid alkylol amide type, amphoteric type such as amino acid type and betaine type Surfactants can be used. These can be used alone or in combination.

As the alkaline chemical of the present invention, known chemicals such as caustic soda, soda ash, sodium bicarbonate, and sodium silicate are used, but caustic soda is preferably used in consideration of handling and cost. In addition, when an alkaline chemical is used in the defibration step, the addition amount is preferably as small as possible because the effect of the cationic polymer used may be reduced in some cases, and is preferably 1.0% by weight or less based on waste paper pulp. .

In the present invention, the addition of the fine fibrillated cellulose is preferably added to the deinked pulp before mixing the deinked pulp with the virgin pulp. The fine fibrillated cellulose used in the present invention has an average fiber length of 0.0
Those having a thickness of 1 to 0.4 mm are preferred. If it is less than 0.01 mm, the fine fibrillated cellulose is too small, and the ratio of the fine fibrillated cellulose flowing out of the papermaking net at the time of papermaking becomes large, and the effect is reduced. If the length is longer than 0.4 mm, the specific surface area is reduced, and the effect is also reduced.

The fine fibrillated cellulose used in the present invention preferably has an average fiber length of 0.01 to 0.4 mm. If it is less than 0.01 mm, the fine fibrillated cellulose is too small, and the ratio of the fine fibrillated cellulose flowing out of the papermaking net at the time of papermaking becomes large, and the effect is reduced. 0.4m
When the length is longer than m, the specific surface area is reduced, and the effect is similarly reduced.

Various methods have been known as methods for producing microfibrillated cellulose in the present invention. Regardless of the method, the average fiber length is from 0.01 to 0.01.
If it becomes 0.4 mm, it can be used.
For example, a method using various beaters such as beaters, refiners, etc.
A method in which a small-diameter orifice is passed at a high speed with a pressure difference of 0 psi and then collides and rapidly decelerates to perform a cutting action. The impeller is rotated by a drive shaft with a bell to impact the fiber material. Applying mechanical shearing force to cellulose fiber, such as a method of applying, a method of performing fine pulverization by a dry method using a rotor and a hammer disposed in a housing, a method using a medium stirring wet pulverizer, a method using a pulverizer such as a vibration mill, a sand mill, and the like Thus, a method of producing fine fibrillated cellulose can be mentioned. Further, not only a mechanical treatment but also a method using a combination of a chemical treatment such as an acid hydrolysis treatment, an alkali treatment, a liquid ammonia treatment, an enzyme treatment, and a steam treatment and a mechanical treatment has been proposed.

As a raw material of the fine fibrillated cellulose in the present invention, hardwood bleached kraft pulp (LBK)
P), softwood bleached kraft pulp (NBKP), hardwood bleached sulphite pulp (LBSP), softwood bleached sulphite pulp (NBSP) and other chemical pulp, groundwood pulp (GP) and thermomechanical pulp (TMP) etc. And non-wood pulp such as cotton pulp, hemp, bagasse, kenaf, esparto, kozo, mitsumata, and goose.

In the present invention, the added amount of the fine fibrillated cellulose is 0.5 to 0.5% based on the absolute dry weight of the whole pulp.
A range of 15% by weight is preferred. When the addition amount of the fine fibrillated cellulose is less than 0.5% by weight based on the absolute dry weight of the whole pulp, the effect of the addition is hardly seen. On the other hand, if the added amount of the fine fibrillated cellulose is more than 15% by weight, the paper becomes liable to be dewatered when papermaking is performed using this raw material and dewatering from the wire is difficult.

As the raw material pulp for the recording paper in the present invention, conventionally used pulp can be used in addition to deinked pulp. For example, LBKP, NBKP, LB
Wood pulp such as chemical pulp such as SP and NBSP and mechanical pulp such as GP and TMP can be used. Furthermore, cotton pulp, hemp, bagasse, kenaf, esparto, mulberry,
Non-wood pulp such as mitsumata and goosepicks can also be used.

Further, a filler and other chemicals such as a sizing agent can be internally added to the recording paper as required. The filler internally added to the recording paper of the present invention is not particularly limited, and can be appropriately selected from known fillers and used. Examples of such a filler include talc, kaolin, illite, clay, calcium carbonate, titanium dioxide and the like. The filler is usually used in an amount of 3 to 20% by weight as a filler in paper.

The internal sizing agent used for recording paper in the present invention is not particularly limited, and may be appropriately selected from known internal sizing agents used for printing paper and ink jet recording paper. it can. Preferred internal sizing agents include, for example, hydrophobic modified rosin emulsion sizing agents. Usually, the amount of the internal sizing agent used is 0.1 to 0.7 with respect to the absolute dry weight of the pulp.
%, But is not particularly limited.

Further, in addition to the above, a defoaming agent, a pH adjuster, a dye or a color pigment for adjusting the hue, a fluorescent dye for improving the luminous whiteness, and the like may be added to the recording paper, if necessary. Further, it can be internally added.

The recording paper of the present invention can be coated with a sizing solution containing a known sizing agent, binder and the like, if necessary. As means for coating, known coating devices such as various blade coaters, roll coaters, air knife coaters, bar coaters, curtain coaters, gravure coaters, gate roll coaters and the like can be used, and can be provided on one or both surfaces. Although it is possible, from the viewpoint of operability and cost, it is preferable to use a size press coating method capable of coating both surfaces simultaneously on-machine. Further, as the surface finish, various calenders such as a machine calender, a soft calender, and a super calender can be used alone or in combination.

[0024]

EXAMPLES The specific structure of the recording sheet of the present invention will be described below with reference to examples, and the characteristics of the recording sheet will be described in comparison with comparative examples. However, the present invention is not limited to this example. is not. In the examples, “%” indicates “% by weight”, and “parts” indicates “parts by weight”. Example 1 Deinking pulp preparation process 1: Used newspaper was put into a test pulper and diluted to a pulp concentration of 5%, and a cationic styrene-based sizing agent (Arakawa Chemical Industry) (Trade name: PM360) 2.5% and NaOH
0.1% was added to disintegrate. Thereafter, the mixture was stirred for 30 minutes and dehydrated to a concentration of 18%. Water was added to the mixture to dilute it to 2%, and a surfactant-based deinking agent (DI-767, manufactured by Kao Corporation) was added to the pulp at 1.0%. The mixture was subjected to a flotation treatment for minutes, and dehydrated to a concentration of 18%. Add more water and 2
%, NaOH 2.0%, NaSiO ₃ 4.0%,
After adding 3.0% of H ₂ O _{2, the} mixture was mixed with a steam mixer and bleached at a temperature of 70 ° C. for 3 hours. Then wash and dehydrate 1
8% of deinked pulp was obtained.

Deinked pulp 7 obtained in deinking pulp preparation step 1
0 parts, Hardwood bleached kraft pulp with beating degree of 380 ml (L
-BKP) 5 parts of fine fibrillated cellulose having a number average fiber length of 0.15 mm in a pulp slurry consisting of 30 parts,
7 parts of talc, 1.5 parts of sulfuric acid band, 0.4 part of sizing agent,
Hand paper was prepared by adding 0.02 parts of a retention aid. After drying, using a two-roll size press, the coating liquid 1 was applied on both sides so that the coating amount was 4 g / m ^{2 as a} solid content, and a recording paper having a basis weight of 74 g / m ² was obtained. (Coating liquid 1) Water-soluble polymer: oxidized starch MS # 3600 (manufactured by Nippon Shokuhin Kako Co., Ltd.) 100 parts Surface sizing agent: Polymalon 482 (manufactured by Arakawa Chemical) 0.4 part Antifoaming agent: Nopco 8034L (manufactured by San Nopco) Example 2 Example ² A recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Example 1 except that the addition amount of the microfibrillated cellulose was changed to 0.5 part. Example 3 Recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Example 1 except that the amount of the fine fibrillated cellulose was changed to 15 parts. Example 4 The basis weight was 7 in the same manner as in Example 1 except that the cationic styrene sizing agent in the deinking pulp preparation step 1 was changed to 0.1%.
4 g / m ² of recording paper was obtained. Example 5 A basis weight of 7 was obtained in the same manner as in Example 1 except that the cationic styrene sizing agent in the deinking pulp preparation step 1 was changed to 5.0%.
4 g / m ² of recording paper was obtained. Example 6 An anionic styrene / acrylic sizing agent (Arakawa Chemical Industries, trade name: P)
M-1343), and a recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Example 1 except that the addition amount was 0.2%. Example 7 The sizing agent in the deinking pulp preparation process 1 was an anionic styrene / acrylic sizing agent (trade name: P, manufactured by Arakawa Chemical Industries, Ltd.)
M-1343), and a recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Example 1 except that the addition amount was changed to 2.5%. Example 8 A recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Example 1 except that the sizing agent in the deinking pulp preparation step 1 was changed to a rosin-based sizing agent and the addition amount was changed to 2.5%. Was. Example 9 Deinking pulp preparation step 2: Used newspaper was put into a test pulper, diluted to a pulp concentration of 5%, and NaOH
0.1% was added to disintegrate. Thereafter, the mixture was stirred for 30 minutes and dehydrated to a concentration of 18%. Water was added to this to dilute to 2%, a cationic styrene-based sizing agent (trade name: PM-360, manufactured by Arakawa Chemical Industries) was added, and a surfactant-based deinking agent (DI-767, Kao Corporation) )) Was added, and flotation treatment was performed for 6 minutes using a test flotator, followed by dehydration to a concentration of 18%. Further dilute to 2% by adding water, NaOH 2.0%, NaSi
After adding 4.0% of O _{3 and} 3.0% of H ₂ O _2, they were mixed with a steam mixer and bleached at a temperature of 70 ° C. for 3 hours. Thereafter, washing and dewatering were performed to obtain an 18% deinked pulp.

Deinked pulp 7 obtained in deinking pulp preparation step 2
0 parts, Hardwood bleached kraft pulp with beating degree of 380 ml (L
BKP) 30 parts of a pulp slurry, 5 parts of finely fibrillated cellulose, 7 parts of talc, 1.5 parts of sulfuric acid band.
, 0.4 parts of a sizing agent and 0.02 parts of a retention aid were added to perform hand-making. After drying, using a two-roll size press, the coating liquid 1 was applied on both sides so that the coating amount was 4 g / m ^{2 as a} solid content, and a recording paper having a basis weight of 74 g / m ² was obtained. Comparative Example 1 A basis weight of 7 was obtained in the same manner as in Example 1 except that microfibrillated cellulose was not added (the amount added was 0%).
4 g / m ² of recording paper was obtained. Comparative Example 2 A recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Example 1 except that the sizing agent in the deinking pulp preparation step 1 was not added (the amount added was 0%). Comparative Example 3 A recording paper having a basis weight of 74 g / m ² was obtained in the same manner as in Comparative Example 2, except that the sizing agent of the coating liquid 1 was changed to 0.8 part. Comparative Example 4 Hand pulp slurry was prepared by adding 7 parts of talc, 1.5 parts of sulfuric acid band, 0.4 part of sizing agent and 0.02 part of retention aid to a pulp slurry composed of 100 parts of L-BKP having a beating degree of 380 ml. Was. After drying, using a two-roll size press, the coating liquid 1 was applied on both sides so that the coating amount was 4 g / m ^{2 as a} solid content, and a recording paper having a basis weight of 74 g / m ² was obtained. An ink jet recording test and a strength test of the recording papers obtained in Examples 1 to 5 were performed by the following methods. The results are as summarized in Table 1.

[0027]

[Table 1]

(1) Inkjet recording test The recording test was performed using an inkjet printer (BJC-430).
J: trade name, manufactured by Canon Inc.), and a predetermined pattern was recorded, and evaluated according to the following criteria. a, Ink-like bleeding of ink (feathering) Bleeding of whisker-like ink was visually evaluated.

○ No whisker-like bleeding, △ Slight whisker-like bleeding, × Lots of whisker-like bleeding, b, Ink drying property Immediately after recording, the image area was rubbed with a finger, and the degree of dirt was visually evaluated. .

○ No dirt △ Slight dirt × Extremely dirt (2) Strength test a, Surface strength test The method of using a wax in the surface strength test method of paper and paperboard described in JIS P8129 was used. The highest number of waxes that did not damage the paper surface when the wax was peeled was taken as the surface strength. b, Folding strength test MI of paper and paperboard described in JIS P 8115
The bending strength test method using a T tester was followed. The load applied to the test piece was 0.5 kgf.

[0031]

As described above, the present invention has been described in detail. However, according to the method for producing a deinked pulp according to the present invention, the recordability in ink-jet recording is higher than that of the conventional method. Was obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D21H 27/00 D21H 27/00 Z G03G 7/00 101 G03G 7/00 101Z 101P F-term (Reference) 2H086 BA01 BA21 BA31 4L055 AA11 AA20 AC09 AG63 AH11 AH12 EA16 EA32 FA15 GA08 GA09

Claims (4)

[Claims] 1. A method of manufacturing a recording paper using deinked pulp, which is manufactured through a plurality of steps including at least a waste paper disintegration step and a deinking step using a surfactant-based deinking agent. Manufacture of recording paper characterized by adding fine fibrillated cellulose to raw material pulp containing deinked pulp that has been deinked by adding a sizing agent to at least one of the processes, and then making paper. Method. 2. The method according to claim 1, wherein a sizing agent is added in the waste paper disintegration step. 3. The method according to claim 1, wherein 0.5 to 15% of the fine fibrillated cellulose is added to the whole pulp. 4. A recording sheet manufactured by the manufacturing method according to claim 1.