JP2002004192A - Method for papermaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for papermaking by which excellent paper strength and drainage effects are obtained in a wide pH range, especially high pH range required owing to he deterioration of water quality for papermaking because of the use of waste paper, deinked pulp or a closed papermaking system. SOLUTION: This method for papermaking comprises adding (A) an amphoteric highly branched acrylamide-based polymer prepared by copolymerizing a cross-linking vinyl monomer as an essential constituent monomer and (B) a condensed hydrated aluminum salt to a papermaking raw material pulp slurry and forming the paper according to a conventional method. The amphoteric highly branched acrylamide-based polymer (A) is a polymer obtained by copolymerizing (a) the cross-linking vinyl monomer with (b) a cationic vinyl monomer, (c) an anionic vinyl monomer and (d) (meth)acrylamide as principal components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking method, and more particularly, to a zwitterionic hyperbranched acrylamide polymer (A) obtained by copolymerizing a raw pulp slurry of papermaking with a crosslinkable vinyl monomer as an essential constituent monomer. And the condensed hydrated aluminum salt (B), the use of waste paper or deinked pulp and the deterioration of the quality of papermaking water due to the closeness of the papermaking process, etc., make the papermaking conditions even more severe and in a wide pH range. In particular, the present invention provides a papermaking method exhibiting excellent paper strength and drainage effect even in a high pH region.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for energy saving and resource saving. For this reason, the usage ratio of waste paper or deinked pulp has increased, and the papermaking process has been closed. Therefore, in the papermaking industry, problems such as deterioration of papermaking conditions, especially accumulation of harmful substances, accumulation of sulfates, deterioration of papermaking conditions due to the increase in fine fibers, and an increase in pH due to calcium carbonate contained in waste paper. In addition, there is an increasing demand for speeding up of a paper machine for improving productivity and demand for quality improvement with diversification of paper. 2. Description of the Related Art Conventionally, various papermaking chemicals have been used in the papermaking process of paper, paperboard, and the like. For example, synthetic starches such as cationic starch, pregelatinized starch, etherified starch, modified starch such as oxidized starch, acrylamide polymers and derivatives thereof, polyamide polyamine epichlorohydrin resins, melamine and urea formaldehyde resins are used. ing.

[0003] Although the above-mentioned modified starch is inexpensive, it has to be used in a large amount because of its poor paper strength enhancing effect on the amount used. The effect is also poor. That is, the modified starch has problems in performance and workability, and synthetic polymers are mainly used as papermaking additives.

A typical example of the above-mentioned synthetic polymer-based additive is an acrylamide-based polymer.
Modified types such as anionic acrylamide polymers hydrolyzed with alkali, cation-modified acrylamide polymers by Hoffman decomposition reaction, and cation-modified acrylamide polymers by Mannich reaction, (meth) acrylamide and anionic vinyl monomer and / or cation A copolymer type obtained by copolymerizing a hydrophilic vinyl monomer is known.

However, in order to cope with severe papermaking conditions as described above, the use of a conventionally known acrylamide-based polymer alone has limitations in paper strength and drainage effect. Therefore, papermaking methods and papermaking additives using a plurality of papermaking additives have been proposed. For example, a method in which an anionic acrylamide-based polymer is used in combination with a cation-modified acrylamide-based polymer by a Hoffman decomposition reaction (Japanese Patent Laid-Open No.
No. 26501), a method in which an anionic polyacrylamide is used in combination with a cationic Mannich-modified polyacrylamide (Japanese Patent Application Laid-Open No. 63-12792), a method in which an anionic polyacrylamide polymer and a cationic acrylamide polymer are used in combination. JP-A-54-68407, JP-A-58-60094, JP-A-59-10
No. 6598), a method in which a zwitterionic acrylamide polymer is used in combination with a zwitterionic acrylamide polymer (JP-B-63-63678, JP-A-5-7899).
No. 7), a method in which two or more kinds of polymers are used in combination, such as a method of mixing an amphoteric crosslinked acrylamide-based polymer and a modified polyacrylamide with an aqueous solution (Japanese Patent Application Laid-Open No. 9-78486). Using a combination of an aluminum-based polymer and an aluminum-based polymer (Japanese Patent Publication 6-11)
No. 956), a method in which a specific cationic acrylamide polymer having a cationic group is used in combination with colloidal silicic acid (Japanese Patent No. 2515495), a method in which an amphoteric acrylamide polymer is used in combination with a basic polyaluminum hydroxide (Japanese Patent No. 2515495). JP-A-7-53958), a method of using an amphoteric polymer compound and alumina sol in combination (Japanese Patent Application Laid-Open No. 62-206).
No. 099) has been proposed in combination with an organic polymer and an inorganic polymer. Further, a method using a zwitterionic acrylamide-based polymer to which aluminum ions are previously bonded (Japanese Patent Application Laid-Open No. 8-188982,
Japanese Patent Application Laid-Open No. Hei 8-226092) has been proposed.

Further, a paper-strengthening agent which is a acrylamide-based polymer having a bifunctional, trifunctional or tetrafunctional crosslinkable vinyl monomer introduced therein and has a relatively high molecular weight and a highly branched structure (Japanese Patent Application Laid-Open No. 63-50597, JP-A-4-14-1
No. 8190, JP-A-5-140893, JP-A-7-82689, and JP-A-7-97790), but for papermaking, which exerts further paper strength and drainage effect. There is a need for additives and papermaking methods.

[0007]

As described above, as papermaking water quality deteriorates due to the use of waste paper or deinked pulp and the closing of the papermaking process, the papermaking conditions become more and more severe, and the pH range is particularly wide. The present invention has been completed as a result of intensive studies with a technical problem of providing a papermaking method which improves the excellent paper strength and drainage in the pH range.

[0008]

That is, the present invention relates to a papermaking method having the following constitution.

The invention of claim 1 is to provide a zwitterionic hyperbranched acrylamide-based polymer (A) obtained by copolymerizing a crosslinkable vinyl monomer as an essential constituent monomer in a papermaking pulp slurry and a condensed hydrated aluminum salt ( B) and papermaking according to a conventional method.

According to a second aspect of the present invention, in the first aspect, the amphoteric hyperbranched acrylamide polymer (A) comprises 0.001 to 10 mol% of a crosslinkable vinyl monomer (a) and a cationic vinyl monomer (b). ) Paper making obtained by copolymerizing 0.5 to 20 mol% of anionic vinyl monomer (c) 0.2 to 20 mol% and (meth) acrylamide (d) 50 to 99 mol% as main components. It consists of a method.

The invention according to claim 3 is the method according to claim 1 or 2, wherein the anionic vinyl monomer (c) constituting the amphoteric hyperbranched acrylamide polymer (A) is an α, β-unsaturated dicarboxylic acid. It has a configuration of a papermaking method described in a certain description.

According to a fourth aspect of the present invention, in the first to third aspects, the condensed hydrated aluminum salt (B) is at least one selected from the group consisting of polyaluminum chloride, polyaluminum hydroxide and alumina sol. It consists of a papermaking method.

[0013] That is, according to the constitution of the present invention, the papermaking conditions become more and more severe due to the use of waste paper or deinked pulp and the lowering of the quality of papermaking water due to the closing of the papermaking process, and
An object of the present invention is to provide a papermaking method for improving paper strength and drainage in a wide pH range, particularly in a high pH range.

Hereinafter, the technical configuration of the present invention will be described in detail. In the present invention, the amphoteric hyperbranched acrylamide polymer (A) (hereinafter referred to as “amphoteric hyperbranched acrylamide polymer”) obtained by copolymerizing a crosslinkable vinyl monomer as an essential constituent monomer, Crosslinkable vinyl monomer (a), cationic vinyl monomer (b),
It is obtained by copolymerizing a monomer mixture containing anionic vinyl monomer (c) and (meth) acrylamide (d) as main components.

In the amphoteric hyperbranched acrylamide polymer, the crosslinkable vinyl monomer of the component (a) includes, for example, N-substituted acrylamide such as N, N-dimethylacrylamide and N-methylolacrylamide, and methylenebis (meth) acrylamide. (Meth) acrylamides such as ethylene bis (meth) acrylamide, di (meth) acrylates such as ethylene glycol di (meth) acrylate and diethylene glycol di (meth) acrylate, and divinyl esters such as divinyl adipate and divinyl sebacate , Epoxy acrylates, urethane acrylates, bifunctional vinyl monomers such as divinylbenzene, 1,3,5-triacryloylhexahydro-S-triazine, triallyl isocyanurate, triallylto Mellitate, triallyl amine, N, N-di trifunctional monomer allyl acrylamide, tetramethylolmethane tetraacrylate,
Examples include tetrafunctional monomers such as tetraallyl pyromellitate. Among them, N-methylolacrylamide, methylenebisacrylamide, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, 1,3,5-triacryloylhexahydro-S-triazine, tetramethylolmethanetetraacrylate, N, N-dimethylacrylamide Is preferred. These crosslinkable vinyl monomers can be used alone or in combination of two or more.

In the amphoteric hyperbranched acrylamide copolymer, the cationic vinyl monomer of component (b) includes, for example, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate,
Vinyl monomers having a tertiary amino group such as dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, allylamine, diallylamine and salts of inorganic or organic acids such as hydrochloric acid, sulfuric acid, nitric acid, sulfamic acid, and the like; and A tertiary amino group-containing vinyl monomer is reacted with a quaternizing agent such as benzyl chloride, methyl chloride, dimethyl sulfate, epichlorohydrin, glycidyltrimethylammonium chloride, or 3-chloro-2-hydroxypropyltrimethylammonium chloride.
And a vinyl monomer containing a secondary ammonium salt. These cationic vinyl monomers may be used alone or
More than one species can be used in combination.

In the amphoteric hyperbranched acrylamide-based polymer, the anionic vinyl monomer of the component (c) includes, for example, α, β- such as acrylic acid and methacrylic acid.
Α, β-unsaturated dicarboxylic acids such as unsaturated monocarboxylic acid, itaconic acid, maleic acid and maleic anhydride, α, β-unsaturated tricarboxylic acids such as aconitic acid, (meth) allylsulfonic acid, 2-acrylamide- Examples thereof include sulfo group-containing vinyl monomers such as 2-methylpropanesulfonic acid and salts thereof, and these anionic vinyl monomers can be used alone or in combination of two or more. Among these anionic vinyl monomers, α, β-unsaturated dicarboxylic acids such as itaconic acid and maleic acid, and salts thereof are preferred.

The molar ratio of the components (a) to (d) constituting the amphoteric hyperbranched acrylamide copolymer of the present invention is as follows:
(a) component 0.001 to 10 mol%, (b) component 0.5 to 20
Mol%, component (c) 0.2 to 20 mol%, and component (d) 50 to
99 mol%, preferably 0.01 to 8 mol% of component (a), 1 to 15 mol% of component (b), 0.5 to 15 mol% of component (c) and 62 to 98 mol% of component (d) It is.

When the amount of the component (a) is less than 0.001 mol%, the effect of the present invention is not improved. When the amount exceeds 10 mol%, gelation occurs.

Further, as long as the effects of the present invention are not impaired,
Other vinyl monomers such as styrene, styrene derivatives such as α-methylstyrene, vinyl acetate, acrylonitrile, allyl alcohol, (meth) acrylate having a hydroxyl group, methyl (meth) acrylate,
It is possible to copolymerize alkyl (meth) acrylates such as ethyl (meth) acrylate and other various monomers.

The weight-average molecular weight of the amphoteric hyperbranched acrylamide copolymer (A) of the present invention does not need to be particularly restricted, but is preferably 1 from the viewpoint of paper strength enhancing effect and drainage effect. 10,000 to 10 million, preferably 100,000 to
The range is 3 million.

As the method for producing the amphoteric hyperbranched acrylamide polymer (A) in the present invention, various conventionally known methods can be employed. For example, a stirrer,
(A) Component, (b) component, (c) component, (d) component and water were charged into a reaction vessel equipped with a thermometer, a reflux condenser, and a nitrogen gas inlet tube, and hydrogen peroxide was used as a polymerization initiator. Redox initiators such as peroxides such as ammonium persulfate, potassium persulfate and hydroperoxide, or a combination of these peroxides and a reducing agent such as bisulfite, or 2,2-azobis (2-amidinopropane) Add a water-soluble azo initiator such as hydrochloride, etc., and if necessary, add isopropyl alcohol, allyl alcohol, sodium allyl sulfonate, sodium methallyl sulfonate, sodium hypophosphite, mercaptoethanol, thioglycolic acid, etc. Using a polymerization regulator or a chain transfer agent as appropriate,
It is obtained by reacting at a temperature of 40 to 95 ° C for 1 to 5 hours.

In carrying out the present invention, the amount of the amphoteric hyperbranched acrylamide polymer (A) to be used may be arbitrarily changed according to the purpose and the degree of expected effect. 0.01 based on dry weight
By adding an amount corresponding to 〜5%, preferably 0.1 to 2% and making the paper as usual, the paper strength enhancing effect and drainage can be improved.

Examples of the condensed hydrated aluminum salt (B) in the present invention include polyaluminum chloride, polyaluminum hydroxide and alumina sol.
The species can be used alone or in combination of two or more.

The main component of the polyaluminum chloride is represented by the general formula [Al ₂ (OH) _n Cl _6-n ] _m (where n <
5, m <10), and are commercially available as an aqueous solution or powder, but any of them can be suitably used.

The polyaluminum hydroxide is [Al
(OH)] _n AlCl ₃ (where n <30), and is distinguished from the polyaluminum chloride by having high basicity.

The alumina sol generally has a particle size of 5 to 200 μm.
An alumina colloid solution comprising an aggregate of feather-like particles having a specific surface area of 200 m ² / g or more can be suitably used.

In the practice of the present invention, the amount of the condensed hydrated aluminum salt (B) used is 0.01% by weight of aluminum oxide (Al ₂ O ₃ ) based on the dry weight of the raw pulp.
% To 4%, preferably 0.05 to 1%, and papermaking is carried out in the usual manner, thereby improving the paper strength and drainage. The condensed hydrated aluminum salt (B) exhibits a remarkable effect when used in combination with the zwitterionic hyperbranched acrylamide polymer (A) used in combination, and it is hardly effective alone. Therefore, it is desirable that the amount of addition be minimized.

The addition of the zwitterionic hyperbranched acrylamide polymer (A) and the condensed hydrated aluminum salt (B) to the pulp slurry of the papermaking raw material may be carried out by adding either the component (A) or the component (B). It is desirable to add the other component after adding and thoroughly mixing with the pulp slurry, preferably adding the component (B) first and then thoroughly mixing the pulp slurry with the component (A). Thereby, the effect of the present invention can be sufficiently exhibited.
When the components (A) and (B) are preliminarily mixed and the mixed solution is added to the pulp slurry, it is difficult to sufficiently exert the effects of the present invention.

The papermaking method of the present invention can be applied to various kinds of paper, paperboard, for example, corrugated cardboard, especially using waste paper or deinked pulp.
Gypsum board base paper, information recording paper, newsprint, packaging paper,
The purpose of the present invention is to enhance the paper strength of paper tube base paper, printed writing paper, coated paper, white paperboard and the like, and to improve drainage.

In the paper making method of the present invention, a rosin-based sizing agent, a neutral sizing agent, a cationized starch-based paper strength agent, a dye, an antifoaming agent, a sulfate band, various fillers, and the like are used as necessary. Can be done.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically with reference to Preparation Examples, Examples, and Comparative Examples, but the present invention is not limited to these Examples. In each example, parts and%
All are by weight unless otherwise specified.

Preparation of Papermaking Additives <Preparation of Zwitterionic Hyperbranched Acrylamide Polymer (A)> Preparation Example 1 A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with methylene. Bisacrylamide 0.147g
(0.05 mol%), dimethylaminoethyl methacrylate 20.9 g (7 mol%), itaconic acid 7.4 g (3 mol%)
Mol%), 403.8 g of a 40% aqueous acrylamide solution
(89.95 mol%) and 676 g of ion-exchanged water were added, the pH was adjusted to 3.5 with sulfuric acid, the temperature was raised to 50 ° C. while passing nitrogen gas, and 2.5 g of a 10% aqueous ammonium persulfate solution was added. 1.25g% aqueous sodium bisulfite solution
Was added and reacted at 50 to 80 ° C. for 3 hours to obtain a zwitterionic hyperbranched acrylamide polymer. Table 1 shows the properties.
Shown in

Preparation Examples 2 to 9 Preparation Examples 1 to 9 were carried out in the same manner as in Preparation Example 1 except that the types of components (a) to (d) and the amounts used were changed as shown in Table 1. The zwitterionic hyperbranched acrylamide polymers of Examples 2 to 9 were obtained. The properties are shown in Table 1.

<Preparation of Zwitterionic Acrylamide Polymer> Comparative Preparation Example 1 In Preparation Example 1, except that the types of the components (a) to (d) and the amounts used were changed as shown in Table 1. The zwitterionic acrylamide polymer of Comparative Preparation Example 1 was obtained in the same manner as in Preparation Example 1. The properties are shown in Table 1.

Comparative Preparation Example 2 In the same reaction vessel as in Preparation Example 1, 12.4 g (4 mol%) of dimethylaminoethyl methacrylate, 7.7 g (3 mol%) of itaconic acid, 40% aqueous acrylamide solution 3
After charging 25 g (93 mol%) and 655 g of ion-exchanged water, the pH was adjusted to 3.5 with sulfuric acid, the temperature was raised to 50 ° C. while passing nitrogen gas, 2.5 g of a 10% aqueous ammonium persulfate solution, 2.5 g, 10% 1.25 g of sodium bisulfite aqueous solution
Was added and reacted at 50 to 80 ° C. for 3 hours to obtain 1000 g of a zwitterionic acrylamide polymer. Next, concentration 2
9.93 g of an aqueous aluminum sulfate solution (1.32 parts based on 100 parts of the total monomers) diluted to 0% was dropped into the stirred polymer to obtain a zwitterionic acrylamide polymer of Comparative Preparation Example 2. The properties are shown in Table 1.

[0037]

[Table 1] In Table 1, MBA: methylenebisacrylamide TAF: 1,3,5-triacloylhexahydro-S-
Triazine DMAA: dimethylacrylamide, MAA: N-methylolacrylamide IA: itaconic acid, AA: acrylic acid, Mn: maleic anhydride DM: dimethylaminoethyl methacrylate DMC: methyl methacryloyloxy trimethylammonium chloride DMAPA: dimethylaminopropyl acrylamide DMB: methacryloyl Oxyethyldimethylbenzylammonium chloride band: Aluminum sulfate (primary reagent)

Evaluation method of paper quality and drainage: (1) Paper strength effect test Break length: Measured in accordance with JIS P8113. Specific burst strength: Measured according to JIS P8112. Internal bond: TAPPI practical test method UM-4
03 was measured.

(2) Drainage Effect Test (CSF) Measured with a Canadian standard type freeness tester according to JIS P8121.

[0040]

[Example 1] [Preparation of papermaking] Polyaluminum chloride (PAC-250A: manufactured by Taki Kagaku Co., Ltd.) was added to a 2% pulp slurry of corrugated cardboard / miscellaneous paper (97/3). Preparation Example 1 after adding 0.2% to the dry weight of pulp in terms of ₂ O ₃ minutes and mixing uniformly.
The aqueous solution of the amphoteric hyperbranched acrylamide polymer obtained in the above was added at a solid content of 0.3% based on the dry weight of the pulp and mixed well. Next, the basis weight of rice is 150 g / m
^The prepared pulp slurry corresponding to No. ² was subjected to papermaking using a TAPPI standard sheet machine as usual (papermaking pH 6.
3) After squeezing and dehydrating at 3.5 kg / cm ² pressure for 5 minutes,
After drying in a dryer at 05 ° C. for 3 minutes and conditioning the humidity (24 hours at 23 ° C.), the paper quality was tested. Table 2 shows the results. -Test of drainage (CSF) From the prepared pulp slurry to which the above-mentioned chemicals were added before papermaking, a prepared pulp slurry equivalent to 3 g was taken out by absolute drying, diluted with water to 1000 ml, and then diluted as usual. Freeness (CSF) was measured on a Canadian standard freeness tester. Table 2 shows the results.

Examples 2 to 11 The same procedures as in Example 1 were carried out except that polyaluminum chloride and the amphoteric hyperbranched acrylamide polymer obtained in Preparation Example 1 were changed as shown in Table 2. Similarly, the preparation of various types of paper and the test of drainage were performed. Table 2 shows the paper quality and drainage (CSF).

[0042]

[Table 2]

Comparative Examples 1 to 9 The same procedures as in Example 1 were carried out except that polyaluminum chloride and the amphoteric hyperbranched acrylamide polymer obtained in Preparation Example 1 were changed as shown in Table 3. Similarly, the preparation of various types of paper and the test of drainage were performed. Table 3 shows the paper quality and drainage (CSF).

[0044]

[Table 3]

[Example 12] Preparation of paper-made paper A 2% pulp slurry of miscellaneous paper / flyer (50/50)
Polyaluminum chloride (PAC-250A: manufactured by Taki Kagaku Co., Ltd.) was added in an amount of 0.1% based on the dry weight of pulp in terms of Al ₂ O _3, and the mixture was uniformly mixed. An aqueous solution of an amphoteric hyperbranched acrylamide polymer was added at a solid content of 0.3% based on the dry weight of the pulp and mixed well. Next, the paper basis weight of rice is 105 g / m ²
The prepared pulp slurry corresponding to the above was paper-made using a TAPPI standard sheet machine in the usual manner (papermaking pH 7.
4) After pressing and dewatering at 3.5 kg / cm ² pressure for 5 minutes,
After drying in a dryer at 05 ° C. for 3 minutes and conditioning the humidity (24 hours at 23 ° C.), the paper quality was tested. Table 4 shows the results. -Test of drainage (CSF) From the prepared pulp slurry to which the above-mentioned chemicals were added before papermaking, a prepared pulp slurry equivalent to 3 g was taken out by absolute drying, diluted with water to 1000 ml, and then diluted as usual. Freeness (CSF) was measured on a Canadian standard freeness tester. Table 4 shows the results.

Examples 13 to 17 and Comparative Examples 10 to 12
In Example 12, the preparation and filtration of various papers were performed in the same manner as in Example 12 except that the polyaluminum chloride and the zwitterionic hyperbranched acrylamide polymer obtained in Preparation Example 1 were changed as shown in Table 4. An aqueous test was performed. Table 4 shows the paper quality and drainage (CSF).

[0047]

[Table 4] In Tables 2, 3 and 4, PAC: polyaluminum chloride (PAC250A; manufactured by Taki Kagaku Co., Ltd.) Paho: polyaluminum hydroxide (Paho # 2S;
AS: alumina sol (alumina sol-100; manufactured by Nissan Chemical Industries, Ltd.) Band: aluminum sulfate (first-class reagent) The addition rate of aluminum hydrate (b) is calculated as Al ₂ O ₃ Represents

[0048]

According to the papermaking method of the present invention, the use of waste paper or deinked pulp can be carried out by adding a specific zwitterionic hyperbranched acrylamide polymer and a condensed hydrated aluminum salt to a papermaking raw material pulp slurry. Provide a papermaking method that exhibits excellent paper strength and drainage effect in increasingly severe papermaking conditions and with a wide pH range, particularly in a high pH range, due to the deterioration of papermaking water quality due to the close papermaking process. is there.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 1/02 C08L 1/02 33/26 33/26 D21H 17/38 D21H 17/38 17/66 17 / 66 F term (reference) 4J002 AB01W AH00W BG13X DD076 DE146 GK04 4J100 AJ02R AJ08R AJ09R AL08Q AL10S AL62S AM15P AM19S AM21Q AM21S AM23R AM24S AN03Q AN14Q BA03S BA31Q BA56R CA06 CA23 FA13 AG17 AG13 AG55

Claims (4)

[Claims] 1. A papermaking raw material pulp slurry comprising: a zwitterionic hyperbranched acrylamide polymer (A) obtained by copolymerizing a crosslinkable vinyl monomer as an essential constituent monomer; and a condensed hydrated aluminum salt (B). A papermaking method characterized by adding paper and making the paper according to a conventional method. 2. The method according to claim 1, wherein the amphoteric hyperbranched acrylamide polymer (A) is a crosslinkable vinyl monomer (a) in an amount of 0.001 to 10%.
Mol%, 0.5 to 20 mol% of a cationic vinyl monomer (b), 0.2 to 20 mol% of an anionic vinyl monomer (c), and 50 to 99 mol% of (meth) acrylamide (d). 2. The composition according to claim 1, which is obtained by polymerization.
Papermaking method described in 1. 3. An anionic vinyl monomer (c) constituting a zwitterionic hyperbranched acrylamide polymer (A),
The papermaking method according to claim 1, wherein the papermaking method is an α, β-unsaturated dicarboxylic acid. 4. The papermaking method according to claim 1, wherein the condensed hydrated aluminum salt (B) is at least one selected from the group consisting of polyaluminum chloride, polyaluminum hydroxide and alumina sol.