JPH11247089A - Production of paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing paper, capable of simultaneously improving the yield and water leakiness of the paper in a paper material system containing mechanical pulp and/or deinked pulp in a large amount in a neutral to alkaline region. SOLUTION: This method for producing paper has a characteristic comprising adding a cationic coagulant, a phenolic compound and a nonionic flocculant in this order to a paper material consisting mainly of a loading material and pulp containing mechanical pulp and/or deinked pulp in an amount of 30-100 wt.% based on the total amount of the pulp and having a solid content of 0.1-1.5 wt.% and a pH of 6-10. The ratio of the cationic coagulant to the phenolic compound is 25:75 to 75:25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making paper in a neutral or alkaline region such as medium paper, lower grade paper, newsprint and the like containing mechanical pulp and / or deinked pulp to which a filler is internally added.

[0002]

2. Description of the Related Art It is required to add a filler as much as possible to paper in order to save wood resources, save pulp usage, and improve paper quality such as printability. Also,
In recent years, the speed of paper machines has been increased, and more efficient production of paper has been demanded. That is, the improvement of the yield and drainage on the wire of a paper machine is an important issue. Furthermore, even in the case of medium-grade paper and low-grade paper containing a large amount of mechanical pulp and / or deinked pulp, it is required to add a filler as much as possible from the viewpoint of printability. Conventionally, such medium- and low-grade papers have been made in the acidic region, but in recent years there has been a demand for the addition of a large amount of filler in the neutral or alkaline region.

In a conventional method for improving the yield in a general papermaking process, a single polymer system in which a polyacrylamide having a relatively high molecular weight and a low cationic charge density is added subsequent to the addition of a sulfate band has been used. Following the addition of relatively low molecular weight and high charge density polydiallyldimethylammonium chloride to respond to recent paper machine speedups, paper weight reductions, and the minimization of runaway raw materials for environmental protection. Dual polymer system in which polyacrylamide having high molecular weight and low cation or low anion charge density is added, relatively high molecular weight and low cation as disclosed in JP-A-62-191598 and JP-A-1-92498. A microparticle system in which bentonite or colloidal silica, which is a swelling viscosity mineral having a high anionic charge density, is added following addition of charge density polyacrylamide or cationic starch, US Pat. 8-504
A nonionic retention system in which polyethylene oxide or polyethylene glycol-grafted polyacrylamide is added subsequent to the addition of a phenol formaldehyde resin disclosed in Japanese Patent Publication No. 900 is used.

However, in paper stock containing mechanical pulp, anionic fine particles are used because dissolved polymers such as hemicellulose, dissolved lignin, resin acids, and fatty acids derived from mechanical pulp are present in a large amount in the papermaking system. Microparticle systems have no effect. Further, in the case of the dual polymer system, the use of a cationic coagulant improves the freeness compared to the single polymer system, but does not significantly improve the yield. In the case of the nonionic retention system, the yield is higher than that of the single polymer system due to the high cohesion ability,
Freeness was comparable to a single polymer system because the specific surface area of the fiber itself could not be reduced.

[0005] As described above, in the above-mentioned method, the improvement of the yield and drainage is not sufficient for a paper pulp containing a large amount of mechanical pulp and / or deinked pulp in the neutral and alkaline areas. In the dewatering process on the wire of the paper machine, a substantial portion of the filler has passed through the wire, increasing wire wear and shortening the wire life, loading and draining circulating white water. This causes problems such as an increase in the load on the device.

[0006]

In a stock containing a large amount of mechanical pulp and / or deinked pulp in the neutral to alkaline range, the yield and the drainage are improved because a large amount of anionic dissolved matter is present. It's not easy. An object of the present invention is to simultaneously improve the yield and drainage in such a system.

[0007]

Means for Solving the Problems The present inventors have proposed a method for preparing a pulp comprising a mechanical pulp and / or a pulp containing 30 to 100% by weight of deinked pulp and a filler, by using a cationic coagulant,
When the phenolic compound and the nonionic flocculant are added in this order, and the ratio of the cationic coagulant to the phenolic compound is in the range of 25:75 to 75:25, both the yield and the drainage are significantly increased. It was found to be improved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for preparing mechanical pulp and / or deinked pulp from 30 to 100 parts by weight based on the total pulp component.
It is composed of pulp containing filler by weight and filler, and has a solid content of 0.1 to
1.5 weight%, to a neutral and alkaline range stock having a pH of 6 to 10, a cationic coagulant, a phenolic compound and a nonionic coagulant are added in this order, and the cationic coagulant and phenol are added. 25: 7
A papermaking method characterized by being in the range of 5 to 75:25.

At this time, when the order of adding the cationic coagulant and the phenolic compound is changed, the yield is improved, but the drainage is not so much improved, so the order of adding the chemicals is important.

[0010] The cationic coagulant used in the present invention is not particularly limited as long as it is an electrolyte exhibiting cationic properties. However, polydiallyldimethylammonium chloride (pDADMAC) or a derivative thereof, diallyldimethylammonium chloride and others are used. Is most preferred. Further, cationic polyacrylamide, polyethyleneimine, polyamine or the like may be used alone or p
You may use together with DADMAC. The cationic coagulant is usually added at 0.005 to 0.5% by weight based on the stock.

The phenolic compound used in the present invention is preferably a phenol formaldehyde resin (PFR). As the nonionic coagulant, polyacrylamide (PAM) in which polyethylene oxide (PEO) or polyethylene glycol (PEG) is graft-polymerized is desirable.
The range of 100,000 to 12,000,000 is desirable.

These three chemicals are added in the order of cationic coagulant, phenolic compound and nonionic coagulant when the solid content of the stock is diluted to 0.1 to 1.5% by weight. There is a need to. When the solid content of the stock exceeds 1.5%, sufficient mixing is not performed, and the stock partially agglomerates, resulting in poor formation. On the other hand, when the solid content of the stock is less than 0.1% by weight, the chemical does not effectively fix to the paper, so that the yield and drainage are not significantly improved. Even if the order of adding the three chemicals is changed or two or more chemicals are mixed, the desired effect cannot be obtained.

As the deinked pulp (DIP) used in the present invention, there is no particular problem as long as it is a normal deinked pulp made of high quality paper, medium quality paper, lower grade paper, newsprint and the like as waste paper. As mechanical pulp, groundwood pulp (GP), refiner pulp groundwood pulp (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTM)
P), chemical ground pulp (CGP), semi-chemical pulp (SCP) and the like. The mechanical pulp and the deinked pulp need to be 30 to 100% by weight of the total pulp component, but the rest is made of chemical pulp such as kraft pulp (KP) or sulfite pulp (SP) or synthetic fiber. It is blended as appropriate.

The filler used in the present invention includes heavy calcium carbonate, light calcium carbonate, talc, clay, kaolin, titanium dioxide, synthetic silica, aluminum hydroxide and the like which are usually used as fillers for internal addition to paper. Inorganic matter,
Synthetic polymer fine particles such as polystyrene resin and urea-formaldehyde resin are exemplified, and these may be used in combination of two or more. The amount of filler added is 1 to 30% by weight of the total stock
Is desirable. If necessary, a paper strength enhancer, a sizing agent, a dye, a fluorescent whitening agent, an antifoaming agent, a pitch control agent, a slime control agent and the like can be added to the stock.

[0015]

According to the Tappi Engineer, the drainage water improves as the specific surface area of the pulp slurry decreases.
ring Conference 1996. In general, if the ionic strength of a papermaking system is increased or a polymer electrolyte is added, the electric double layer on the surface of the solid suspended and dispersed in the pulp slurry will be compressed, and the van der Since the Waals force exceeds the force due to the repulsion of the Coulomb force, solidification and solidification of solid particles occur, and the specific surface area decreases. Further, when a high molecular weight coagulant is added, cross-linking and aggregation occur, and the specific surface area of the pulp slurry further decreases. In other words, the more agglomerated the pulp slurry is, the more the specific surface area of the pulp slurry is reduced, and a higher drainage is obtained. In the present invention, by adding a cationic polymer electrolyte to the pulp slurry,
The cationic polyelectrolyte is adsorbed on the surface of the solid particles, and solidification of the solid particles occurs. Thereafter, by addition of the phenolic compound, the phenolic compound is anionic since the phenolic hydroxyl group is partially dissociated at pH 7 to 9, which is a general neutral and alkaline papermaking pH,
The previously added cationic polymer electrolyte is strongly adsorbed to the site adsorbed on the solid surface. Thereafter, when a nonionic flocculant is added, the phenolic compound and the nonionic flocculant strongly adsorbed on the solid surface of the pulp suspension cause cross-linking and flocculation due to hydrogen bonding with the phenolic hydroxyl group and the ether portion of the ethylene glycol monomer unit, resulting in strong flocculation And consequently the freeness is improved.

When the phenolic compound is excessively added when the phenolic compound is added subsequent to the addition of the cationic polymer electrolyte, the phenolic compound is adsorbed on a large amount of the cationic polymer electrolyte adsorbed on the solid surface, and the electric power is reduced. Since the compression of the overlay does not occur as expected, the degree of coagulation is weak and the freeness does not improve. Conversely, if the addition amount of the phenolic compound is relatively lower than the addition amount of the cationic polymer electrolyte, most of the phenolic hydroxyl groups of the phenolic compound will be adsorbed to the cation site of the cationic polymer electrolyte. Since it cannot form hydrogen bonds with the nonionic flocculant added afterwards, it is thought that the degree of flocculation is reduced and consequently the freeness is not improved, which is suitable for cationic polyelectrolytes and phenolic compounds. It is considered that there is a large addition ratio.

[0017]

EXAMPLES [Example 1] The measurement of the yield of fillers and fine fibers was performed according to TAPPI T261 pm-79 using a dynamic drainage jar (DDJ). The stirring speed at the time of the DDJ test was 1,000 rpm,
This was performed using a 200 mesh wire. The stock is D
60% IP, 20% bleached TMP, 10% bleached GP, N
BKP is 10%, PCC as filler is 1 to pulp
0.5% of 0% was used. This stock was added to DDJ, and after stirring for 15 seconds, a sulfuric acid band was added at a concentration of 0.5% to the absolutely dry stock and stirred for 15 seconds.
The total addition amount of DAMAC (trade name: Alcofix, manufactured by Allied Colloids) and PFR (manufactured by Sumitomo Seika Co., Ltd.) is 0.25% to 0.2%.
First, pDADMA so that the / PFR ratio becomes 1: 1.
C was added and stirred for 15 seconds, and then PFR was added. Finally, 0.015% of PEO (PEO-27, manufactured by Sumitomo Seika Co., Ltd.) was added, stirred for 15 seconds, and filtered for 1 minute.
The solids concentration of this filtrate was measured, and the yield of filler and fine fibers was calculated.

To measure the freeness, 600 ml of the stock used in the measurement of the filler and fine fiber yield was taken out, diluted to 1,000 ml, the pulp concentration was set to 0.3%, and the fine yield was measured. Similarly, 1,000 rpm
After stirring for 15 seconds, a sulfuric acid band was added at a concentration of 0.5% with respect to the absolutely dry paper stock, followed by stirring for 15 seconds, and pDAMAC.
First, pDADMAC is added and stirred for 15 seconds so that the total added amount of PDADMAC and PFR is 0.25% to 0.2% and the ratio of pDADMAC to PFR is 50:50, and then PFR is added. And finally add PEO to 0.015
% And stirred for 15 seconds, and the freeness of the pulp was measured according to T227 om-85.

[Embodiment 2] Under the same conditions as in Embodiment 1, p
The ratio of DADMAC to PFR was 75:25.

[Embodiment 3] Under the same conditions as in Embodiment 1, p
The ratio of DADMAC to PFR was 25:75.

Comparative Example 1 Under the same conditions as in Example 1, p
The ratio between DADMAC and PFR was 100: 0.

Comparative Example 2 Under the same conditions as in Example 1, p
The ratio of DADMAC to PFR was 0: 100.

Comparative Example 3 Under the same conditions as in Example 1, P
The order of addition of FR and pDADMAC was reversed.

[0024]

[Table 1]

According to Table 1, a cationic coagulant, a phenolic compound and a nonionic coagulant are added in this order to neutral or alkaline paper stock mainly composed of mechanical pulp and deinked pulp, and When the ratio of the cationic coagulant to the phenolic compound is in the range of 25:75 to 75:25, the yield and drainage are improved.

[0026]

According to the papermaking method of the present invention, both the retention and drainage are greatly improved.

Claims (4)

[Claims] 1. A pulp containing mechanical pulp and / or deinked pulp in an amount of 30 to 100% by weight based on all pulp components and a filler as a main component, and a solid content of 0.1 to 1.5% by weight.
The cationic coagulant, the phenolic compound and the nonionic coagulant are added in this order to the stock having a pH of 6 to 10, and the ratio of the cationic coagulant to the phenolic compound is 25:75 to 75. : A papermaking method characterized by being in the range of 25. 2. The papermaking method according to claim 1, wherein the cationic coagulant is polydiallyldimethylammonium chloride. 3. The papermaking method according to claim 1, wherein the phenolic compound is a phenol formaldehyde resin (PFR). 4. The papermaking method according to claim 1, wherein the nonionic flocculant is polyethylene oxide.