JPH11247091A - Production of paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing paper, capable of improving the yield 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 characteristics comprising adding a polyalkyldimethylvinylbenzylammonium chloride to a paper material comprising 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 and subsequently further adding a high mol.wt. cationic polyacrylamide to the paper material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for papermaking in the neutral and alkaline areas of medium-grade paper, lower-grade paper and newsprint containing mechanical pulp and / or deinked pulp with a filler. .

[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 yield on the wire of the paper machine,
Improvement of drainage is an important issue. Further, 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 in view of printability and the like. Conventionally, such medium- and low-grade papers have been made in the acidic range, but in recent years, it has been required to add a large amount of filler in the neutral or alkaline range.

Conventional methods for improving yield have used 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. Following the addition of polydiallyldimethylammonium chloride, which has a relatively low molecular weight and a high charge density, in order to respond to the recent increase in speed of paper machines, weight reduction of paper, and minimization of runoff materials for environmental protection, Dual polymer systems in which polyacrylamide having a high molecular weight and a low cation or low anion charge density is added, JP-A-62-191598 and JP-A-1-92498
As shown in the above, a microparticle system is used in which polyacrylamide or cationic starch with a relatively high molecular weight and low cationic charge density is added, followed by addition of bentonite or colloidal silica, which is a swelling viscosity mineral with high anionic charge density. I have been.

[0004] However, when a paper stock containing a large amount of mechanical pulp is used, the anionic property is high due to the presence of a large amount of dissolved polymers such as hemicellulose, dissolved lignin, resin acids and fatty acids in the mechanical pulp in the papermaking system. The microparticle system using the fine particles of the above is ineffective. When a dual polymer system is used for stock containing mechanical pulp, the use of a cationic coagulant improves the freeness of the single polymer system but does not significantly increase the yield.

[0005] As described above, in the above-mentioned method, the improvement of the yield was not sufficient for a stock containing a large amount of mechanical pulp and / or deinked pulp in the neutral to alkaline range. For this reason, in the dewatering process on the wire of the paper machine, a considerable portion of the filler has passed through the wire, and the wire-wear is increased and the wire life is shortened. And the load of drainage increases.

[0006]

SUMMARY OF THE INVENTION In a stock containing a large amount of mechanical pulp and / or deinked pulp in the neutral to alkaline range, it is difficult to improve the yield because a large amount of anionic dissolved matter is present. It's not easy. An object of the present invention is to improve the yield in such a system.

[0007]

SUMMARY OF THE INVENTION The present inventors have developed a polyalkyl dimethyl pulp containing a pulp containing 30 to 100% by weight of mechanical pulp and / or deinked pulp based on the total pulp component and a filler. It has been found that fine yield is greatly improved by adding vinyl benzylammonium chloride and then adding a relatively high molecular weight cationic polyacrylamide for papermaking.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a pulp containing mechanical pulp and / or deinked pulp in an amount of 30 to 100% by weight, based on the total pulp components, and a filler.
5% by weight of the stock in the neutral and alkaline regions having a pH of 6 to 10 and the addition of polyalkyldimethylvinylbenzylammonium chloride followed by the addition of a relatively high molecular weight cationic polyacrylamide Papermaking method.

The polyalkyldimethylvinylbenzylammonium chloride used in the present invention preferably has an alkyl chain having 10 or more carbon atoms.
These are known to have excellent bactericidal properties, and also exhibit an effect as a certain slime control agent. The polyalkyldimethylvinylbenzylammonium chloride is usually used in an amount of 0.005 to 0.5 with respect to the stock.
It is added at 5% by weight.

The cationic polyacrylamide used in the present invention is a commonly used retention aid,
Polyacrylamide having a relatively high molecular weight and a low charge density is desirable, and the molecular weight is desirably in the range of 8,000,000 to 12,000,000.

These two chemicals are added with polyalkyldimethylvinylbenzylammonium chloride and cationic polyacrylamide when the solid content of the stock is diluted to 0.1 to 1.5% by weight. You. 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 chemicals are not effectively fixed to the stock, so that the yield and drainage are not significantly improved.

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 kinds. 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.

[0014]

[Function] In the case of making paper stock including mechanical pulp and deinked pulp, since a large amount of anionic polymers such as hemicellulose, dissolved lignin, resin acid and fatty acid are present,
In the case of acidic papermaking, a sulfate band is used, and by neutralizing the anionic charges of these anionic polymers,
The effect of cationic polyacrylamide, which is a general yield improver, is enhanced. However, in the case of neutral papermaking, since the cationicity of the sulfate band is lost, a cationic high charge density polymer having a quaternary ammonium salt such as polydiallyldimethylammonium chloride is added, and the anionic polymer Neutralizes anionicity, but this reaction is known to occur with a relatively high molecular weight anionic polymer, a stoichiometric 1: 1 reaction between positive and negative charges. However, it was found that an ion-association reaction between a relatively low molecular weight hydrophobic anion component and polydiallyldimethylammonium chloride is unlikely to occur in Bull.
Chem. Soc. Jpn. , 52, 425. In the present invention, polyalkyldimethylbenzylammonium chloride, which is a hydrophobic polymer having a quaternary ammonium salt, is used in place of polydiallyldimethylammonium chloride, which has been used as a conventional coagulant, so that a positive charge can be obtained. Both the anion of a relatively high molecular weight anionic polymer and a relatively low molecular weight hydrophobic anion component such as resin acids and fatty acids due to the addition of an association reaction due to hydrophobic interaction as well as an ion association reaction of the negative charge and the negative charge It can neutralize the charge and maximize the effect of cationic polyacrylamide retention aid,
As a result, it is considered that the fine yield is improved.

[0015]

EXAMPLES [Synthesis 1] 1.7 g of dodecyldimethylvinylbenzylammonium chloride was dissolved in 50 ml of ion-exchanged water, and the dissolved air in the solution was replaced with nitrogen in a 200 ml three-necked flask for 30 minutes. Initiator 2,2-azobis (2-methylpropionamidine) dihydrochloride was added and polymerized at room temperature for 24 hours. After completion of the reaction, excess ethyl acetate was added to reprecipitate the target substance and purification was performed to obtain polydodecyldimethylvinylbenzylammonium chloride.

[Example 1] The measurement of the yield of filler 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 was used at 10%, and as a filler, 0.5% at which PCC was blended at 10% with respect to wood pulp was used. This paper 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 absolute paper stock and stirred for 15 seconds, and the polydodecyldimethylvinylbenzylammonium synthesized in Synthesis 1 was used. Chloride was added and stirred for 15 seconds, and then cationic polyacrylamide (trade name: DR-1)
500, manufactured by Hymo Co., Ltd.)
The mixture was stirred for 5 seconds and filtered for 1 minute. The solid content concentration of the filtrate was measured, and the yield of filler and fine fibers was calculated. The results are shown in Table 1.

Comparative Example 1 A DDJ test was conducted under the same conditions as in Example 1 except that polydiallyldimethylammonium chloride was used instead of polydodecyldimethylvinylbenzylammonium chloride. The results are shown in Table 1.

[0018]

[Table 1]

From Table 1, it can be seen that, in neutral and alkaline furnishes, mainly mechanical pulp and deinked pulp, the addition of polydodecyl dimethylvinylbenzylammonium chloride was followed by the addition of relatively high molecular weight cationic poly By adding acrylamide, the yield of fillers and fine fibers is improved.

[0020]

According to the papermaking method of the present invention, the yield in a stock system containing a large amount of mechanical pulp and / or deinked pulp in the neutral and alkaline ranges can be improved.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takanori Miyanishi 5-21-1, Oji, Kita-ku, Tokyo Nippon Paper Industries Central Research Laboratory

Claims (2)

[Claims] 1. A pulp containing mechanical pulp and / or deinked pulp in an amount of 30 to 100% by weight, based on the total pulp components, and a filler.
A papermaking method comprising adding a polyalkyldimethylvinylbenzylammonium chloride to a stock having H6 to 10 and then adding a high molecular weight cationic polyacrylamide. 2. The papermaking method according to claim 1, wherein the polyalkyldimethylvinylbenzylammonium chloride is polydodecyldimethylvinylbenzylammonium chloride.