JP3186139B2 - Paper manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing paper,
More specifically, the present invention relates to a method for producing paper using an additive that improves the yield of fine fibers and filler.

[0002]

2. Description of the Related Art In a paper manufacturing process, there is a strong demand for improving the yield and drainage of fine fibers and fillers in a pulp slurry in a paper making process in order to increase the productivity. Further, in papermaking, closed use of papermaking water has been promoted for the purpose of circulating water to reduce the amount of water discharged to the outside of the system and reducing the amount of fresh water to be newly replenished. Since this closed process treats the used water and reuses it, it is important to minimize the fine fibers and filler remaining in the white water without yielding in the paper during the papermaking process. Innovative measures have been taken to increase the yield of fine fibers and fillers.

Hitherto, as means for improving the yield of such fine fibers and fillers, high molecular weight compounds such as high molecular weight anionic polyacrylamide or high molecular weight cationic polyacrylamide, polyamide epichlorohydrin resin, polyethyleneimine, and high Mannich A method of adding a highly cationic polymer such as modified polyacrylamide is known. Recently, a method of mixing and adding a relatively low molecular weight anionic polyacrylamide and a cationic polyacrylamide (Japanese Patent Laid-Open No. 58-60 / 1983)
No. 094, JP-A-63-12792) are also known. Further, for example, an example in which an amphoteric polyacrylamide having high cationicity is used in combination with an aluminum compound (Japanese Patent Application Laid-Open No. 62-125006), and an example in which a cationic polymer compound is used in combination with basic polyaluminum chloride (Japanese Patent Application Laid-Open No. 55-12220) Is known.

[0004]

However, none of these methods has yet yielded satisfactory yield effects of fine fibers and fillers. Therefore, an object of the present invention is to provide a method for producing paper that can significantly improve the yield of fine fibers and fillers.

[0005]

SUMMARY OF THE INVENTION The present invention, in order to solve the above problems, and many organic and anionic groups both cationic and anionic groups in the molecule than the cationic groups the
The anionic group is at least one of itaconic acid and salts thereof.
Different polyacrylamide is and bi polyacrylamide-based polymer obtained by having a seed polymerization component, a cationic and the amphoteric polyacrylamide polymer over
The present invention also provides a method for producing paper, which comprises making a paper using an amide polymer, an aluminum compound, and a cationized starch.

[0006] At this time, A aluminum compound polyaluminum chloride, it is also preferably alumina sol, further cationic and different polyacrylamide polymer and the amphoteric polyacrylamide-based polymer is at least a cationic monomer, anionic monomer It is also preferable to use a copolymer having a polymer and an acrylamide-based monomer as a polymerization component.

Hereinafter, the present invention will be described in detail. Amphoteric polyacrylamide-based polymers having both cationic group and anionic group used in the present invention, it is rather multi number there anion groups of the anionic group and a cationic group,
The anionic group is at least one of itaconic acid and its salts.
Can also be obtained by having one kind in the polymerization component .

Examples of the amphoteric polyacrylamide-based polymer include modified amphoteric polyacrylamide-based polymers such as Hoffman-modified amphoteric polyacrylamide-based polymer and Mannich-modified amphoteric polyacrylamide-based polymer.
And a copolymerizable amphoteric polyacrylamide-based polymer having at least a cationic monomer, an anionic monomer, and an acrylamide-based monomer in a polymerization component. A copolymerizable amphoteric polyacrylamide-based polymer is particularly preferable.

[0009] modified type amphoteric polyacrylamide-based port Rimmer used in the present invention include, but Hoffman modified or Mannich-modified polyacrylamide polymers as described above and the like can be mentioned, et al is, they reduce the itaconic acid and salts thereof
Both can be obtained by Hoffman-modified or Mannich-modified polyacrylamide-based polymer having one kind as a polymerization component . At least one of this itaconic acid and its salts
The polymerization method for obtaining a polyacrylamide-based polymer having a seed polymerization component, eg if itaconic acid and salts thereof
At least one, and a method of copolymerizing acrylamide as polymerization components.

[0010] Itaconic acid and its
To obtain a polyacrylamide-based polymer having at least one the polymerization component of the salts, as the anionic monomer used, Lee itaconic acid and salts thereof, such as sodium salts, potassium salts, and ammonium salts and the like, singly or in Two or more can be used in combination. Also,
Yield effect of fine fibers and fillers with other anionic monomers
Can be used in combination within a range that does not impair the performance. Other anions
The sex monomer, A acrylic acid, such as methacrylic acid alpha, beta-unsaturated monocarboxylic acids, maleic acid, fumaric acid, alpha such as citraconic acid, beta-dicarboxylic acid, styrene sulfonic acid, such as vinyl sulfonic acid Unsaturated sulfonic acids and salts thereof, for example, sodium salts, potassium salts, ammonium salts, and the like can be mentioned, and these can be used alone or in combination of two or more. The usage ratio of these anionic monomers is 1 to 30 mol%, preferably 2 to 20 mol%, based on all monomers.

[0011]

In the case of Hoffman modification or Mannich modification, the modification ratio is 1 to 30%, preferably 1 to 20% of the carbamoyl group of the anionic polyacrylamide copolymer.
It is. Here, the Mannich modification rate indicates the number of mole% of formaldehyde and amines used for the amide group in the acrylamide copolymer. The Hoffman modification ratio indicates mol% of sodium hypochlorite and an alcohol or amine containing a cationic group used for an amide group of an acrylamide polymer. Hoffman and Mannich denaturation methods include:
Conventionally known methods can be used. Representative examples of the amines used in the above-mentioned Mannich reaction include aliphatic secondary amines such as dimethylamine and diethylamine. May be.
Further, alcohols containing a cationic group used in the Hoffman reaction include N- (2-hydroxyethyl) N,
N, N-trimethylammonium halide, N- (2-
(Hydroxyethyl) N-benzyl-N, N-dimethylammonium halide; and the amines containing a cationic group include 3-aminopropyldimethylamine. These can be used alone or in combination of two or more.

Examples of the cationic monomer used for obtaining the copolymerizable amphoteric polyacrylamide-based polymer include compounds represented by the following general formulas (I), (II) and (III). Although used alone, two or more of them can be used in each of the general formulas and in the general formulas. In addition, diallylamine, vinylpyridine, vinylimidazole and the like may be used alone or in combination,
Further, a compound belonging to the above general formula may be used alone or in combination.

Formula [I]

Embedded image

(Where A is oxygen or NH, and n is 2
R1 is H or a methyl group, R2, R3, R
4, R5 and R6 are the same or different lower alkyl groups, X
-And Y- represent the same or different counter ions such as chlorine ion and bromine ion, respectively. )

Formula [II]

Embedded image

(Where A is oxygen or NH, and n is 2
R7 represents H or a methyl group; R8 and R9 represent the same or different lower alkyl groups. )

General formula [III]

Embedded image

(Where A is oxygen or NH, and n is 2
R4 is H or a methyl group, R11, R1
2, R13 represents the same or different lower alkyl group, benzyl group, and Z- represents a counter ion such as a chloride ion or a bromine ion. )

Examples of the cationic monomer corresponding to the above general formula [I] include 2-hydroxy-N, N, N, N ',
N'-pentamethyl-N '-(3- (meth) acryloylaminopropyl) 1,3-propanediammonium dichloride, 2-hydroxy-N-benzyl-N, N-
Diethyl-N ', N'-dimethyl-N'-(2- (meth) acryloyloxyethyl) -1,3-propanediammonium dibromide.

The cationic monomers belonging to the above general formula [II] include N, N-dimethylaminoethyl (meth)
Acrylate, N, N-dimethylaminopropyl (meth) acrylamide and the like can be mentioned.

Further, as the cationic monomer belonging to the above general formula [III], the cationic monomer represented by the above general formula [II] can be converted into a suitable quaternizing agent such as alkyl halide, dialkyl carbonate, It is obtained by quaternization with alkyl tosylate, alkyl mesylate, dialkyl sulfate, benzyl halide, and the like. For example, N-ethyl-N, N-dimethyl- (2- (meth) acryloyloxyethyl) ammonium bromide, N- Benzyl-N, N-dimethyl- (3- (meth) acryloylaminopropyl) ammonium chloride and the like.

Furthermore, if the cationic monomer belonging to the general formula [II] is quaternized with the above-mentioned quaternizing agent and then subjected to a polymerization reaction with acrylamides and anionic monomers, etc. Alternatively, quaternization can be performed using the quaternizing agent during or after the polymerization reaction of acrylamides, anionic monomers, and the cationic monomers belonging to the general formula [II]. In this case all 4
Although it may be graded, it goes without saying that a part may be graded.

In the present invention, the above general formula [I],
In addition to the cationic monomers represented by [II] and [III], other cationic monomers can be used.

[0025] As the anionic monomer used in obtaining a copolymer type amphoteric polyacrylamide-based polymer used in the present invention, i itaconic acid and salts thereof, such as sodium salts, potassium salts, and ammonium salts and the like, which May be used alone or in combination of two or more . Itaconic acid is preferred, especially. In addition, other anionic monomers
Use together as long as the yield effect of fine fibers and fillers is not impaired.
Can also be. Other anionic monomer, A chestnut <br/> Le acids, alpha, such as methacrylic acid, beta-unsaturated monocarboxylic acids, maleic acid, fumaric acid, such as citraconic acid alpha, beta
-Unsaturated sulfonic acids such as dicarboxylic acid, styrene sulfonic acid, vinyl sulfonic acid and the like, and salts thereof, for example, sodium salt, potassium salt, ammonium salt and the like, and these can be used alone or in combination of two or more.

The acrylamides used for obtaining the copolymerizable amphoteric polyacrylamide polymer used in the present invention include acrylamide, methacrylamide, and N-acrylamide.
-Ethylacrylamide, N-methylacrylamide,
N-substituted lower alkyl acrylamides such as N, N-dimethylacrylamide and N-isopropylacrylamide, and the like, and these can be used alone or in combination of two or more. In addition, nonionic monomers such as acrylonitrile and (meth) acrylic acid lower alkyl esters (eg, methyl, ethyl, propyl) can be used alone or in combination of two or more.

The above-mentioned cationic monomer is used in an amount of 0.5 to 20 mol% based on all monomers, preferably 1.0 to 10 mol%.
Mol%. If the amount is less than 0.5 mol%, the self-fixing property (adsorption power) of the resulting amphoteric acrylamide polymer to pulp is not sufficient, and the effect of improving the yield of fine fibers and fillers may be reduced, and exceeds 20 mol%. In some cases, the combined use of an aluminum compound and a cationic polymer may not provide a sufficient effect of improving the yield of fine fibers and filler.

The anionic monomer is used in an amount of 1 to 30 mol%, preferably 2 to 20 mol%, based on all monomers. When this is less than 1 mol% or more than 30 mol%, a sufficient effect of improving the yield of fine fibers and fillers in combination with the aluminum compound and the cationic polymer may not be obtained.

[0029] The molar ratio of the cationic monomer and an anionic monomer (the ratio of the number of each of the cationic and anionic groups in the mixed monomer) is good Mashiku 1: 1 to 1:
20. It is preferable in terms of yield effect of fine fibers and fillers which anionic and cationic groups contained in the resulting copolymer is in earthenware pots by the greater the A anion group. A two <br/> on groups, the number of cationic groups is determined by counting the respective ionic groups of the monomers used.

The amphoteric polyacrylamide polymer used in the present invention has an average molecular weight of 50,000 to 3,000,000,
Preferably it is 100,000 to 1.5 million. The average molecular weight can be determined, for example, from the viscosity-molecular weight curve of polyacrylamide in FIG.

[0031] Cationic and different polyacrylic and the amphoteric polyacrylamide polymer over used in the present invention
Examples of the amide polymer include a cationic polyacrylamide polymer and a highly cationic polyacrylamide. Among these, a cationic polyacrylamide-based polymer is preferable, and the average molecular weight determined by the above method is particularly preferably 1.5 to 10,000,000.
The number of anionic groups and cationic groups, that is, whether the polymer can be anionic or cationic, is determined by the degree of cationization and the degree of anionization according to, for example, the colloid titration method (Ryoichi Chitate, published by Nankodo in 1969). it can be determined by measuring in the. present invention, the above-mentioned cationic and said amphoteric polyacrylamide polymer over
A cationized starch is used together with a polyacrylamide polymer different from the above.

[0032]

[0033]

The above-mentioned cationic polyacrylamide-based polymer is obtained by copolymerizing a cationic monomer and acrylamide, or by subjecting polyacrylamide to Hoffmann rearrangement or Mannich modification. The Huffman denaturation, Mannich denaturation method, denaturation rate and the like are the same as those described above.

The aluminum compounds usable in the present invention include polyaluminum chloride, alumina sol, polyaluminum silicate, aluminum silicate sol, and polyaluminum hydroxide, with polyaluminum chloride and alumina sol being particularly preferred. These aluminum compounds are used alone or in combination of two or more.

The polyaluminum chloride is represented by the general formula [IV], and usually has n = 5 to 15 and m = about 15 to 35, and examples thereof include the following compounds.

Formula [IV]

Embedded image

[0038]

Embedded image

As commercially available products of polyaluminum chloride,
PAC250A (manufactured by Taki Kagaku), Nikkei back (Nippon Light Metal Co., Ltd.), and alumina sol is 3-300
Millimicron feather-like alumina hydrate. Commercially available products include alumina sol 100, 200, and 520 (manufactured by Nissan Chemical Industries, Ltd.). Commercially available aluminum polysilicate aluminum silicate is PASS (Nippon Light Metal ( Co., Ltd.), and any of them can be used.

The amphoteric polyacrylamide-based polymer used in the present invention, cationic and different polyacrylamide polymer and the amphoteric polyacrylamide polymer over,
The cationized starch and the aluminum compound are used by being added to the pulp slurry in the papermaking process, and the addition ratio is 0.01 to 2% with respect to the pulp dry weight, respectively.
Preferably 0.02 to 1%, 0.001 to 2%, preferably 0.005 to 1%, also 0.001 to 2%,
Preferably it is 0.005 to 1%, and 0.01 to 3%, preferably 0.02 to 2%.

Mixing chests,
Examples include a machine chest, a head box, a vicinity of a fan pump, a vicinity of a screen, and a white water pit. Generally, a machine chest, a head box, a vicinity of a fan pump, and a vicinity of a screen are appropriate.

[0042] No particular limitation is imposed on the addition order, mosquitoes Chi <br/> on starch, amphoteric polyacrylamide polymers, aluminum compounds, different polyacrylamide-based poly cationic and the amphoteric polyacrylamide polymer over <br/> method sequentially adding M a, these two, three, a method of adding four simultaneously, these 4, 3, may be either a method of adding after previously mixing two .

In a papermaking system using the additive comprising the above-mentioned mixture according to the present invention, other papermaking additives may be added. Examples of papermaking additives that can be used in combination include rosin sizing agents such as solution rosin sizing agents, rosin emulsion sizing agents, neutral sizing agents such as alkyl ketene dimers, alkenyl succinic anhydrides, cationic styrene polymers, and cationized starch. Paper strength agent, antifoaming agent, dye, sulfuric acid band and the like.

The above-mentioned additives according to the present invention can be used in the paper making of all papers or paperboards in the acidic or neutral range. Specifically, printing writing paper, coated base paper, PPC paper, heat-sensitive paper It can be used for paperboard such as information paper such as paper base paper, wrapping paper such as pure white roll paper, Ryoso kraft paper, liner, canned liner, core base paper, paper tube base paper, white board base paper, and gypsum board base paper. .

In making the above various papers or paperboards, pulp raw materials include bleached or unbleached chemical pulp such as kraft pulp or sulfite pulp, and the like.
Any bleached or unbleached high-yield pulp such as groundwood pulp, mechanical pulp, or thermomechanical pulp, and used paper pulp such as used newspaper, used corrugated paper, or used deinked paper can be used.

Additives such as fillers and dyes may be used as necessary to exhibit the physical properties required for each paper type. Examples of the filler include clay, talc, kaolin, titanium oxide, heavy or light calcium carbonate, and these may be used alone or in combination.

[0047]

[Action] different Polyacrylic the anionic group of the amphoteric polyacrylamide-based polymer is an aluminum compound and a cationic or One the amphoteric poly acrylamide-based polymer over
Amide shows the interaction with the cationic groups of the polymer and cationic starch, differs from the fine fibers and is thought to improve the yield of filler, One or more aluminum compounds and cationic the amphoteric poly acrylamide-based polymers over poly
It is believed that the use of an acrylamide-based polymer and a cationized starch in combination significantly enhances this interaction, but details are not clear. It should be noted that the present invention is not subject to any disadvantageous restrictions due to this idea.

[0048]

EXAMPLES Next, examples of the present invention will be described, but the present invention is not limited to only these examples. In addition,
Hereinafter, percentages mean percent by weight unless otherwise specified. Further, for convenience, monomers are represented by abbreviations as follows. DM: N, N-dimethylaminoethyl methacrylate DPA-Me: N, N, N-trimethyl-N- (3-acryloylaminopropyl) ammonium chloride DMBz: N-benzyl-N, N-dimethyl-N- (2
-Acryloyloxyethyl) ammonium chloride BQ: 2-hydroxy-N, N, N, N ', N'-pentamethyl-N'-(3-methacryloylaminopropyl) 1,3-propanediammonium chloride DP: N, N -Dimethylaminopropyl methacrylamide AAm: Acrylamide IA: Itaconic acid AA; Acrylic acid MA: Methacrylic acid In carrying out the paper production methods of the present example and comparative example,
An amphoteric polyacrylamide-based polymer aqueous solution was prepared as follows.

Preparation of Polyacrylamide Polymer (Amphoteric) Aqueous Solution A In a 1-liter four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 355 g of water, 132.2 g of 50% aqueous acrylamide solution, N , N-dimethylaminoethyl methacrylamide 3.14 g, itaconic acid 6.51 g, 2% aqueous sodium hypophosphite solution 6.45
g, and then a 5% aqueous solution of ammonium persulfate.
After adding 01 g, the temperature was raised to 80 ° C. under nitrogen gas introduction, and the mixture was reacted for 5 hours. The aqueous polymer solution thus obtained has a nonvolatile content of 15% and a Brookfield viscosity of 6900 cp at 25 ° C.
s, 506 g of a clear aqueous solution having a pH of 4.3. This is designated as amphoteric polyacrylamide-based polymer aqueous solution A.
Table 1 shows these measured values and the composition of the polymer.

Production of polyacrylamide-based polymer (amphoteric) aqueous solutions B to E and polyacrylamide-based polymers a and b under the conditions that an amphoteric polyacrylamide-based polymer aqueous solution A was obtained by mixing the constituent monomer components shown in Table 1. The polymerization reaction is carried out according to the amphoteric polyacrylamide polymer aqueous solution B ~
E. Polyacrylamide-based polymer aqueous solutions a and b were obtained. Table 1 shows the results of the measurement of these in the same manner as above.
Shown in In addition, in order to obtain the same viscosity, the amount of the chain transfer agent was appropriately changed.

[0051]

[Table 1]

In the table, the viscosity is a value measured at 25 ° C. by a Brookfield viscometer, and the molecular weight is an average molecular weight obtained from a polyacrylamide viscosity-molecular weight curve shown in FIG.

Example 1 and Reference Examples The polyacrylamide-based polymer (amphoteric) aqueous solutions A to E obtained above, aluminum compounds shown in Table 2, cationic and polyacrylamide-based polymer (amphoteric) aqueous solutions A to
According addition rate showing a polyacrylamide-based polymer different from the polymer over the E in Table 2, subjected to paper making hand under the following conditions using a Noble and Wood Co. paper machine, it was measured for transmittance white water at the same time. Pulp: bleached kraft pulp Hardwood / Conifer = 8/2 Canadian Standard Freeness (CSF): 35
5 ml Additives and order of addition The following substances were added to the above pulp in the following order.
The percentages are based on pulp. (1) Calcium carbonate (Tamapearl 121S, manufactured by Okutama Industry Co., Ltd.) 15% (2) Cationized starch (Hicut 132, Rhone Poulin Japan Co., Ltd.)
(3) Polyacrylamide-based polymer (amphoteric) A to E (4) Alkyl ketene dimer-based sizing agent (Harcon 6)
03, Dick Hercules Ltd. Co.) 0.08% (5) different polyacrylamide and aluminum compound (6) cationic and amphoteric polymers polyacrylic amide polymer solution A~E
De polymer papermaking pH: 8.0 Dry: drum dryer (80 ° C., 100 sec) In Table 2, No. 6 (as a cationic polymer
No. "using PA-Epi"). 9 (Polymer aqueous solution
No. "B" is used), No. 10 (polymer water
Using "C" as the solution); 12 (Polymer
-The one using "E" as the aqueous solution) shows a reference example.

In Table 2, abbreviations indicate the following. PAM: Cationic polyacrylamide-based polymer (Hiretene 103, manufactured by Dick Hercules KK) PA-Epi: Polyamide polyamine epichlorohydrin resin (Saimen 557H, manufactured by Dick Hercules KK) PAC: Polyaluminum chloride (250A, Taki AS: alumina sol (alumina sol-200, manufactured by Nissan Chemical Co., Ltd.) PASS: aluminum polysulfate silicate (manufactured by Nippon Light Metal Co., Ltd.) The hand-made paper obtained above was subjected to 65% relative humidity. After conditioning for 24 hours at 20 ° C., the filler content in the paper was measured. Table 2 shows the results.

[0055]

[Table 2]

The measuring method of the above measurement items was in accordance with the following method. White water transmittance: TAPPI PAPERMAKERS
Modified Hercules Dynam described in CONFERENCEP 171 (1985)
An apparatus similar to the ic Drainage Tester (a pulp slurry is poured into a container having a diameter of about 7.5 cm, air is sent from the lower part under stirring so as not to form a mat, and stirring and air supply are stopped, and at the same time filtration is performed. ), 500 ml of the pulp slurry was poured into a container, and 50 ml of the filtrate was collected.
The transmittance (%) at nm was measured and used as an index of the first pass retention. That is, the higher the transmittance,
This indicates that the filtrate is clear and that the yield of fine fibers and filler is high. Filler content: JIS P8128

Comparative Example 1 In Example 1 described above, the addition ratio of each additive in Table 2 was shown in Table 3
The hand-making was performed in the same manner as in Example 1, and the transmittance of the white water and the filler content were measured in the same manner as in Example 1. The results are shown in Table 3. In Table 3, abbreviations are the same as those in Table 2.

[0058]

[Table 3]

[0059] is different from the reference example polyacrylamide polymer (amphoteric) solution A~E obtained above, aluminum compounds shown in Table 4, cationic and amphoteric polyacrylic amide polymer solution A~E polymers and cationic starch Table 4 shows the polymers
In accordance with the addition ratio shown in Table 1, hand-making was performed using a paper machine manufactured by Noble and Wood Co., Ltd. under the following conditions, and at the same time, the transmittance of white water was measured. Pulp: bleached kraft hardwood / softwood = 8/2 Canadian Standard Freeness (CSF): 40
2 ml Additives and order of addition The following substances were added to the above pulp in the following order.
The percentages are based on pulp. (1) Sulfuric acid band 1% (2) Talc (ND talc, manufactured by Nippon Talc Co., Ltd.) 1
0% (3) Polyacrylamide-based polymer (amphoteric) aqueous solution A
To E (4) rosin emulsion sizing agent (OT500J,
Dick Hercules Ltd. Co.) 0.2% (5) different polymers papermaking pH is with the aluminum compound (6) cationic and amphoteric polyacrylic amide polymer solution A~E polymers and cationic starch: 5.0 Dry : Drum dryer (100 ° C., 50 seconds) The handmade paper obtained above was conditioned at 65% relative humidity and 20 ° C. for 24 hours, and the filler content in the paper was measured. Table 4 shows the results. The measurement conditions were the same as in Example 1.
Is the same as

[0060]

[Table 4]

Comparative Example 2 In Example 2 above, the addition ratio of each additive in Table 4 was shown in Table 4.
The hand-making was performed in the same manner as in Example 1, and the transmittance of white water and the filler content were measured in the same manner as in Example 1, and the results are shown in Table 5. In Table 5, abbreviations are the same as those in Table 4.

[0062]

[Table 5]

[0063]

As described above, a cationic group,
Have a both of anionic group anionic group is a cationic group
More and the anionic group is itaconic acid and its salts
Is obtained by having at least one of
And bi polyacrylamide polymers that, cationic and different ports from the above amphoteric polyacrylamide polymer over
Itaconic and polyacrylamide-based polymers, by paper making using the cationic starch and the aluminum compound, a high yield effect of conventional obtained not fine fibers and fillers are obtained, especially amphoteric polyacrylamide-based polymer
Anionic group using at least one of acids and salts thereof
These effects become more remarkable by increasing .

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between viscosity and molecular weight of an aqueous solution of polyacrylamide.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiromi Hashimoto 17-2 Yawata Kaigandori, Ichihara City, Chiba Prefecture Inside the laboratory of Dick Hercules Co., Ltd. (56) References JP-A-63-12792 (JP, A) 58-91897 (JP, A) JP-A-63-275795 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21H 17/00-27/42

Claims (4)

(57) [Claims] 1. A and many organic and anionic groups both cationic and anionic groups in the molecule than the cationic groups the
The anionic group is at least one of itaconic acid and salts thereof.
Different polyacrylamide is and bi polyacrylamide-based polymer obtained by having a seed polymerization component, a cationic and the amphoteric polyacrylamide polymer over
A paper manufacturing method comprising making a paper using a metal- based polymer, an aluminum compound, and a cationized starch. 2. The amphoteric polyacrylamide-based polymer is a copolymer having at least a cationic monomer, itaconic acid and an acrylamide-based monomer in a polymerization component.
Process for the preparation of 1 Symbol placement of paper. 3. A process for producing paper according to claim 1 or 2 aluminum compound is polyaluminum chloride. Preparation of paper according to any one of claims 4] to aluminum compound claims 1 to alumina sol 3.