JP2003193396A - Pretreatment of paper-making stock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a polyethyleneimine-based pitch-controlling agent that is easily reaction-controllable with low decrease in the cation equivalence, when the polyethyleneimine-based antiflocculant having high charge density that can cope with the recent paper-making stock including increased contents of mechanical pulp and used paper because a so-called antiflocculant having the action to control the electric charge on the pitch particle surfaces has been used for inhibiting pitch coagulation, but the contents of mechanical pulp and used paper recently increase and conventional antiflocculants meet some difficulty to cope with. <P>SOLUTION: A polyalkyleneimine or a mixture thereof with a polyamine is allowed to react with a polycatinic substance having a specific structure and the resultant modified polyalkyleneimine is used as an antiflocculant for this purpose. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment method for papermaking raw materials. More specifically, the present invention relates to a method for pretreating a papermaking raw material that effectively suppresses and prevents pitch defects in the paper manufacturing process.

[0002]

2. Description of the Related Art Generally, what is called pitch in the pulp and paper manufacturing process is a natural resin or gum substance released from wood, pulp and paper, and an additive used in the pulp and paper manufacturing process. It is a water-insoluble adhesive substance that is mainly composed of organic substances and is derived from chemicals. Pitch is dispersed in the form of colloid in the pulp and paper manufacturing process, especially in white water, but due to some external action such as large shearing force, abrupt change of pH, excessive addition of sulfuric acid band, etc. It is believed that the colloidal state is destroyed, aggregated, and enlarged. Agglomerated and huge pitch adheres to pulp and paper due to its adhesiveness, and also adheres to manufacturing equipment such as fan pumps, pipes, chests, wires, felts and rolls, and then peels off to pulp and paper. Re-adhesion causes deterioration of quality due to paper stains and defects, and breakage of paper due to paper breakage, resulting in pitch problems such as deterioration in production and workability. In recent years, as the amount of chemicals used has increased due to the diversification of paper and the water used in the process has become closed, pitch obstacles are more frequent and more complicated than ever before.

For example, in Japanese Patent Laid-Open No. 4-241184, a dimethyldiallylammonium chloride / acrylic acid / (in some cases, alkyl acrylates) copolymer is used as a papermaking wet end for suppressing natural pitch troubles. Is disclosed. Further, in the bleaching step alkali extraction of pulp production, as a method of removing the pitch in the pulp derived from the raw wood, the pulp slurry is a copolymer of a water-soluble unsaturated carboxylic acid and a hydrophobic monomer as follows. It is disclosed that it is added before entering the alkali extraction tower (Japanese Patent Laid-Open No. 11-256490). However, a decisively effective measure has not yet been proposed, particularly regarding a method of suppressing stains derived from a papermaking raw material mainly composed of mechanical pulp. That is, since a large amount of anionic substances derived from raw wood are mixed in mechanical pulp, conventional acrylic or diallylammonium cationic polymers cannot be sufficiently treated to electrically neutralize them. Therefore, the amount of cation required after the treatment does not decrease, and when a papermaking raw material containing this pulp is used for papermaking, paper cutting during operation and defects such as papermaking are affected.

[0004]

In order to prevent the agglomeration of pitch, a so-called coagulant having a charge adjusting action on the pitch particle surface is used as a pitch control agent, and the higher the cation, the higher the effect. In that respect, polyethyleneimine, which is a very high cation, has an excellent antifouling effect, but is also expensive. In order to solve this problem, polyethyleneimine crosslinked products using epichlorohydrin and the like are often used. However, these crosslinking agents have a lower cation density by the amount added, and the effect is also lowered. The purpose of the present invention is to solve the problem of cation density reduction by using a condensation-type polycationic substance having terminal reactivity as a cross-linking agent, and to synthesize a polyethyleneimine-modified product having cost merit.

[0005]

The inventor of the present invention has made extensive studies in order to solve the above-mentioned problems and, as a result, has reached the following invention. That is, the invention of claim 1 of the present invention is characterized in that a polyalkyleneimine modified product having a structural unit represented by the following general formula (1) and / or (2) is added to a papermaking raw material before papermaking. The present invention relates to a pretreatment method for papermaking raw materials.

[Chemical 1]

[Chemical 2] However, n in the formulas (1) and (2) is an integer of 0 or more,
R1 to R9 are hydrogen, an alkyl group having 1 to 3 carbon atoms, or a benzyl group.

According to a second aspect of the present invention, the modified polyalkyleneimine comprises a polyalkyleneimine or a mixture of polyalkyleneimine and polyamine, and a polycationic substance represented by the following general formulas (3) and / or (4). The method for pretreatment of a papermaking raw material according to claim 1, wherein the pretreatment method comprises a reaction product.

[Chemical 3]

[Chemical 4] However, n in the formulas (3) and (4) is an integer of 0 or more,
R10 to R18 are hydrogen or an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group or a benzyl group, and X is a halogen atom.

The invention of claim 3 is the method for pretreating a raw material for papermaking according to claim 1, wherein the modified polyalkyleneimine is crosslinked by the polycationic substance (3).

According to a fourth aspect of the present invention, the polycationic substance comprises one or more amines selected from ammonia, an aliphatic primary amine, an aliphatic secondary amine and an aliphatic tertiary amine, and epihalohydrin. It is a polycondensate, The pretreatment method of the papermaking raw material of Claim 1 or 2 characterized by the above-mentioned.

According to a fifth aspect of the present invention, the polycationic substance is epihalohydrin A (mol), ammonia,
When B (mol) is one or more amines selected from primary amine, secondary amine, and tertiary amine, A / B
The polycondensation product reacted in the range of 0.25 to 1.2 is the pretreatment method for the paper-making raw material according to claim 4.

According to the invention of claim 6, the amino group in the polyalkyleneimine or the mixture of the polyalkyleneimine and the polyamine is C (mol), the above general formula (3) and / or
Alternatively, when the halohydrin group and / or the epoxy group in the polycationic substance represented by (4) is D (mol),
The method for pretreatment of a raw material for papermaking according to claim 1 or 2, wherein the reaction is carried out in the range of C / D = 5 to 300 (mol%).

The invention of claim 7 is the method for pretreatment of a raw material for papermaking according to claim 1, wherein the polyalkyleneimine is polyethyleneimine.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The modified polyalkyleneimine of the present invention is obtained by modifying polyalkyleneimine by a crosslinking reaction or a graft reaction with a specific polycationic substance. Hereinafter, these modified polyalkyleneimines and the modification method thereof will be described in detail. The polycationic substance used for modification is ammonia, an aliphatic primary
It can be produced by reacting one or more amines selected from tertiary amines (hereinafter referred to as primary amines) with epihalohydrin. The method for producing the polycationic substance in the present invention is not particularly limited, and for example, epihalohydrin is added dropwise to one or more amines selected from ammonia, primary amines, secondary amines, and tertiary amines for reaction. can do. In the present invention, epihalohydrin is charged into a reactor and selected from ammonia, primary amine, secondary amine, and tertiary amine.
It is preferable to react by dropping one or more amines.

The polycationic substance used in the present invention has a molar ratio of one or more amines selected from ammonia, primary amines, secondary amines and tertiary amines to epihalohydrin in a desired polyalkylene. It is appropriately selected depending on the properties, structure, molecular weight and the like of the imine-modified product, but it is generally in the range of 0.25 to 1.20. When the molar ratio of one or more amines selected from ammonia, primary amine, secondary amine, and tertiary amine to epihalohydrin is 0.25 or less, epihalohydrin remains. 1 selected from ammonia, primary amine, secondary amine, and tertiary amine for epihalohydrin
When the molar ratio of one or more amines is 1.20 or more, it is obtained by a reaction of epihalohydrin and one or more amines selected from ammonia, primary amine, secondary amine, and tertiary amine. The content of the halohydrin group at the end of the polyacation substance in the product decreases, and it becomes difficult to react with the polyalkyleneimine or the polyalkyleneimine and polyamine mixture.

The polycationic substance used in the present invention has a cross-linking action represented by the general formula (3) and is reactive at both ends, and a one-end reactive substance represented by the general formula (4). Some have a graft reaction action. The former, which has a cross-linking action, is ammonia for epihalohydrin,
The molar ratio of one or more amines selected from primary amine, secondary amine, and tertiary amine is about 0.25 to
When the reaction is carried out in the range of 0.9, the production ratio of the polycationic substance represented by the general formula (3) is high, and the latter one having a grafting action is ammonia to epihalohydrin,
The molar ratio of one or more amines selected from primary amines, secondary amines, and tertiary amines is about 0.8-1.
When the reaction is carried out in the range of 2, the production ratio of the polycationic substance represented by the general formula (4) becomes high.

The method for producing a modified product produced by the reaction of the polyalkyleneimine (C) or the mixture of polyalkyleneimine and polyamine with the polycationic substance represented by the general formula (3) and / or (4) in the present invention. Is not particularly limited, and can be produced, for example, by adding the cationic substance represented by the general formula (3) and / or (4) to polyalkyleneimine or a mixture of polyalkyleneimine and polyamine and reacting them. Alternatively, the reaction can be carried out by adding polyalkyleneimine or a mixture of polyalkyleneimine and polyamine to the cationic substance represented by the general formula (3) and / or (4).

The method of controlling the reaction is not particularly limited and includes, for example, polyalkyleneimine as a raw material or a mixture of polyalkyleneimine and polyamine as a raw material, or a polycation represented by the above general formula (3) and / or (4). The reaction rate can be reduced by previously diluting a mixture of substances with ion-exchanged water or the like to cause a reaction. Alternatively,
It is also possible to control the reaction rate while diluting during the reaction. In addition, in order to obtain a reaction product having a desired product viscosity, acids such as sulfuric acid and hydrochloric acid may be added during the reaction to stop the reaction.

Generally epihalohydrin and ammonia,
Aliphatic primary amine to tertiary amine can easily react to obtain a polycationic substance. Such amines are ammonia, aliphatic monovalent amines and aliphatic polyamines. Examples of the aliphatic monovalent amine include monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, and n.
-Butylamine or isobutylamine.
Aliphatic polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylenehexamine, hexamethylenediamine and the like. Particularly preferred among these monovalent or polyamines are:
It is monomethylamine, dimethylamine, trimethylamine, ethylenediamine or pentaethylenehexamine.

The temperature range in which the reaction of epihalohydrin and amines is carried out is appropriately selected depending on the properties, structure, molecular weight and the like of the polyalkyleneimine modified product desired in the subsequent modification reaction, but it is generally 10 to 90 ° C. Preferably 2
It is in the range of 0 to 60 ° C. When the reaction temperature is 20 ° C or lower, the reaction rate is slow and not practical, and when it is 60 ° C or higher, the polyhalogenated terminal halohydrin group or epoxy go obtained by the reaction of epihalohydrin with ammonia or monovalent aliphatic or polyamine is hydrolyzed. As a result, the reactivity between the polyalkyleneimine or the polyalkyleneimine and the polyamine mixture is lost.

Further, the temperature range in which the reaction of the polyalkyleneimine or the polyalkyleneimine and the polyamine mixture and (D) the polycationic substance represented by the general formula (3) and / or (4) is carried out is within a desired range. The alkyleneimine modified product is appropriately selected depending on the properties, structure, molecular weight, etc., but is generally 10 to 90 ° C., preferably 20 to 90 ° C.
It is in the range of 70 ° C. Further, in order to improve the reactivity with the polycationic substance, the reaction can be carried out by adding an alkali catalyst such as sodium hydroxide in a molar ratio of 1.0 or less to epihalohydrin.

The molar ratio during the modification reaction is within the following range. That is, the amino group in the polyalkyleneimine or the mixture of polyalkyleneimine and polyamine is C (mol unit), and the halohydrin group in the polycationic substance represented by the general formula (3) and / or (4) If the epoxy group is D (molar unit), C
/ D = reacts in the range of 5 to 300 (mol%). For example, when the molecular weight of polyalkyleneimine is as high as tens of thousands to hundreds of thousands, especially when the polycationic substance represented by the above general formula (3) is mixed in at a high ratio, the crosslinking reaction proceeds too much and It becomes insoluble in water. Therefore, the filling mol% is usually 5 to 50 mol%, preferably 5
~ 30 mol%. On the other hand, when the molecular weight of the polyalkyleneimine is low such as 1,000 to 10,000, the mol% to be incorporated is usually 50 to 300 mol%, preferably 70 to 150 mol%.

The mixing ratio of the polyalkylimine and the polyamine mixture is not particularly limited and may be appropriately selected depending on the properties, structure, molecular weight and the like of the desired polyalkyleneimine modified product. 0 to 50% by weight, preferably 0 to 30% by weight
Is the range.

The major characteristic of the modified polyalkyleneimine according to the present invention is that the function is improved by partially crosslinking or grafting the polyalkyleneimine or polyamine with a polycationic substance to increase the molecular weight and make the polymer three-dimensional. . The characteristics of the modified polyalkyleneimine according to the present invention have succeeded in further increasing the cohesive force and the like without impairing the conventional properties of the polyalkyleneimine. That is, the polyalkyleneimine has primary to tertiary amino groups centering on the primary amino group in the molecule, but dissociation disappears in a high pH pulp dispersion liquid such as a neutral papermaking raw material, and the effect decreases. However, the above general formula (3)
In the polycationic substance represented by (4) and / or (4), a quaternary amino group exists, and the modified quaternary amino group is introduced, so that the range of use is expanded. Therefore, not only the acid papermaking but also the neutral and alkaline papermaking can exert a remarkable effect. In particular, it is possible to efficiently reduce the required amount of cations due to the high cation density even in a papermaking raw material containing mechanical pulp mixed with a large amount of anionic substances, and as a result, paper breaks during operation, papermaking It is possible to reduce defects and paper tears.

The amount of the polyalkyleneimine-modified product used in the present invention added to the papermaking raw material varies depending on the cation requirement of the papermaking raw material, but is approximately 100 to 5000 ppm as the polymer content per dry paper raw material. Yes, preferably 100 to 2000 ppm, more preferably 100
-1000 ppm. The addition amount of the cationic water-soluble high molecular weight polymer is determined by measuring the amount of cation required for the papermaking raw material using PCD-03 type manufactured by Mutek Co., Ltd. For example, the polymer of the present invention is added to the used papermaking raw material,
After stirring treatment, filter paper No. The raw material is filtered by 41, and the cation required amount and turbidity of the filtrate are measured. The place where the turbidity decreases the most is estimated to be an appropriate amount to add, but it cannot be accurately determined unless it is applied to the paper manufacturing site.

As a place of addition, it is more preferable to add the pulp directly to the raw material pulp which causes the most stains, rather than a mixing chest in which various pulps are mixed, and a remarkable effect is exhibited. Examples of the adding place include the raw material pulp chest intended for the treatment directly or at the raw material pulp chest piping outlet, but may be the machine chess after mixing.

The antifouling treatment of the present invention also improves the yield rate on the wire. That is, the coating material, which is the main raw material pulp, contains calcium carbonate for coating. The calcium carbonate for coating contains 70 to 80% by weight of particles of 2 μm or less, and the content of particles of 2 μm or less of the grade for internal addition (that is, for filling the inside of the sheet) is 25 to 60% by weight. There are many fine particles overall. These particles have a high zeta potential because they enhance the dispersibility of the coating liquid. Therefore, the conventional situation is that the yield rate on the wire is low. However, since the zeta potential on the surface of the particles is neutralized to a certain extent by the treatment of the present invention and the anion component in the raw material is also neutralized, the treatment is directed to improve the retention rate.

There are no particular restrictions on the type of waste paper or mechanical pulp to which the method of the present invention is applied, and examples of the waste paper include coat broke, newspaper waste paper, magazine waste paper. Also,
Examples of mechanical pulp include groundwood pulp, refiner groundwood pulp, pressurized groundwood pulp, thermomechanical pulp, and chemithermomechanical pulp.

[0027]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

(Synthesis Example 1) 146.6 g of epichlorohydrin and 29.6 g of ion-exchanged water were charged in a 4-neck separable flask equipped with a thermometer, a stirrer and a dropping funnel,
40% of 123.8 g of a 50 wt% aqueous solution of dimethylamine
Add dropwise at ~ 45 ° C over 2 hours, then at 45 ° C for 1 hour after completion of the addition.
After reacting for 2 hours, 29.6 g of ion-exchanged water was added. As a result of colloid titration, the reaction rate of dimethylamine was 100.0%. As a result of neutralization titration of amine, the content of tertiary amine was 0.4330%, and the amount of residual epichlorohydrin measured by gas chromatography was 0% (polycationic substance-1). Separately, in a 4-neck separable flask equipped with a thermometer, a stirrer, and a dropping funnel, 87.5 g of 54% 3-chloro-2-hydroxypropyltrimethylammonium chloride was added.
And 44.2 g of a 20% aqueous sodium hydroxide solution were added, and 3
The mixture is stirred for 0 minutes and neutralized by adding 8.3 g of 36% hydrochloric acid. 172 g of epichlorohydrin was charged therein, 167.6 g of a 50 wt% aqueous solution of dimethylamine was added dropwise at 40 to 45 ° C. over 2 hours, and after completion of the addition, reaction was carried out at 45 ° C. for 1 hour. As a result of colloid titration, the reaction rate of dimethylamine was 100.0%. As a result of neutralization titration of amine, the content of tertiary amine was 0.4330%, and the amount of residual epichlorohydrin measured by gas chromatography was 0% (polycationic substance-
2).

(Synthesis Example 2) Next, in a separable flask equipped with a thermometer and a stirrer, polyethyleneimine P-200 (molecular weight 10,000) manufactured by Nippon Shokubai Co., Ltd., 100 was added.
% Product of 23.3 g and ion-exchanged water of 60 g, and after stirring, 26.9 g of the polycationic substance-1 of Synthesis Example 1 was added and reacted at room temperature for 45 minutes, and when a viscosity increase of the reaction product was observed. The reaction was stopped by adding 4.5 g of 75% sulfuric acid, and 35.4 g of ion-exchanged water was added to adjust the concentration to 28%.

When the molecular weight of this reaction product was measured by gel permeation chromatography, the following chart was obtained (FIG. 1). The cation equivalent value in colloid titration was 15.2 meq / g. In addition, the solution viscosity at a polymer concentration of 28% was measured. This sample is referred to as prototype-1.

The viscosity of the aqueous solution was measured using a Brookfield rotary viscometer. (Weight average molecular weight) The weight average molecular weight was measured by gel permeation chromatography and calculated as a polyacrylamide-equivalent molecular weight. The columns used are TOSOH and TSKge
1, the calculation was performed by GMPW by excluding the polymer below the exclusion limit of the column. The results are shown in Table 1.

(Synthesis Example 3) In a separable flask equipped with a thermometer and a stirrer, 26% of polyethyleneimine SP-1050 (molecular weight 70,000), 50% product manufactured by Nippon Shokubai Co., Ltd.
After adding 6.7 g and 66.7 g of ion-exchanged water and stirring, 9.6 g of the polycationic substance-1 of Synthesis Example 1 was added, and the mixture was heated to 60 ° C.
And reacted for 4 hours. After the reaction, 16.0 g of ion-exchanged water was added to make the final concentration 39%. The molecular weight and the cation equivalent value were measured in the same manner as in Synthesis Example 3. Prototype of this sample-2
And The results are shown in Table 1.

(Synthesis Example 4) 295.6 g of 50% 50% polyethyleneimine P-1050 manufactured by Nippon Shokubai Co., Ltd. and 73.89 g of ion-exchanged water were added to a separable flask equipped with a thermometer and a stirrer and stirred. 11.81 g of the polycationic substance-1 of Synthesis Example 1 was added and reacted at 60 ° C. for 30 minutes. After the reaction, 10.7 g of ion-exchanged water and 8 g of 75% sulfuric acid were added to make the final concentration 39%. The molecular weight and the cation equivalent value were measured in the same manner as in Synthesis Example 3. This sample is referred to as prototype-3. The results are shown in Table 1.

(Synthesis Example 5) In a separable flask equipped with a thermometer and a stirrer, polyethylene imine P-1050 manufactured by Nippon Shokubai Co., Ltd., 50% product, 105.9 g and 100% was added.
Pentaethylenehexamine 2.8g and ion-exchanged water 3
After adding 0.64 g and stirring, 4.0 g of the polycationic substance-1 of Synthesis Example 1 was added, and the mixture was reacted at room temperature for 6 hours. After the reaction, 2.21 g of ion-exchanged water and 4.5 g of 75% sulfuric acid were added to make the final concentration 39%. The molecular weight and the cation equivalent value were measured in the same manner as in Synthesis Example 3. Prototype of this sample-4
And The results are shown in Table 1.

(Synthesis Example 6) In a separable flask equipped with a thermometer and a stirrer, 4.0 g of the polycationic substance-2 of Synthesis Example 1 was added to 100 g of 50% polyethyleneimine P-1050 manufactured by Nippon Shokubai Co., Ltd. The reaction was carried out at room temperature for 6 hours. After the reaction, 8.6 g of ion-exchanged water and 75% sulfuric acid 4.
0 g was added to a final concentration of 45%. The molecular weight and the cation equivalent value were measured in the same manner as in Synthesis Example 3. This sample is referred to as prototype-5. The results are shown in Table 1.

[0036]

[Figure 1]

[0037]

[Table 1]

[0038]

[Examples 1 to 5] Thermo-mechanical pulp, waste magazine paper,
Medium quality paper raw material consisting of LBKP (pH 6.85, turbidity 95
0 FAU, total ss 3.50%, ash content 0.11%, cation requirement 0.67 meq / L, zeta potential -1
3 mV) each, 100 mL, and set on a stirrer,
Samples 1 to 5 in Table 1 are paired with ss and 25, respectively.
0,500 ppm was added, and the mixture was stirred at 200 rpm for 60 seconds, and a commercially available amphoteric paper strength enhancer was added, and the mixture was stirred at 200 rpm for 30 seconds. Then, Whatman made N
O. The total amount was filtered with a 41 (90 nm) filter paper, and the cation requirement of the filtrate was measured with a PCD-03 model manufactured by Mutek Co., Ltd., and the turbidity was measured with a HACH, DE2000P turbidimeter. The results are shown in Table 2.

[0039]

[Comparative Examples 1 and 2] As a comparison, a dimethylamine / epichlorohydrin / polyamine reaction product (molecular weight 16500, cation equivalent 7.31 meq / as polycondensation cation)
g, Comparative-A), and a homopolymer of a methyl chloride quaternary product of dimethylaminoethyl methacrylate as a comparative polymer (molecular weight 300,000, cation equivalent, 4.95 meq).
/ G, comparison-B) was used and the test was conducted in the same manner as in the example. The results are shown in Table 2.

[0040]

[Table 2] Cation demand; meq / g, filtrate turbidity; F
AU

Claims (7)

[Claims] 1. A pretreatment of a papermaking raw material, which comprises adding a polyalkyleneimine modified product having a structural unit represented by the following general formula (1) and / or (2) to a papermaking raw material before papermaking. Method. [Chemical 1] [Chemical 2] A method for pretreating a papermaking raw material, comprising adding a modified polyalkyleneimine product to a papermaking raw material before papermaking. However, n in the formulas (1) and (2) is an integer of 0 or more, and R
1 to R9 are hydrogen, an alkyl group having 1 to 3 carbon atoms or a benzyl group. 2. The modified polyalkyleneimine is a polyalkyleneimine or a mixture of polyalkyleneimine and polyamine, and the following general formulas (3) and / or (4).
The pretreatment method for a papermaking raw material according to claim 1, which is a reaction product with a polycationic substance represented by: [Chemical 3] [Chemical 4] N in the formulas (3) and (4) is an integer of 0 or more, and R10
To R18 are hydrogen or an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group or a benzyl group, and X is a halogen atom. 3. The pretreatment method for a papermaking raw material according to claim 1, wherein the modified polyalkyleneimine is crosslinked with the polycationic substance (3). 4. The polycationic substance is a polycondensation product of epihalohydrin with one or more amines selected from ammonia, aliphatic primary amines, aliphatic secondary amines, and aliphatic tertiary amines. The pretreatment method for a papermaking raw material according to claim 1 or 2, characterized in that. 5. The polycationic substance has epihalohydrin as A (mol) and one or more amines selected from ammonia, primary amine, secondary amine and tertiary amine as B (mol). Then, A / B = 0.25-1.
The pretreatment method for a papermaking raw material according to claim 4, wherein the precondensation product is a polycondensate reacted in the range of 2. 6. An amino group in polyalkyleneimine or a mixture of polyalkyleneimine and polyamine is converted to C
(Mole), C / D = 5 to 300, where D (mol) is the halohydrin group and / or epoxy group in the polycationic substance represented by the general formula (3) and / or (4).
The reaction is carried out in the range of (mol%).
Alternatively, the pretreatment method for a papermaking raw material according to 2). 7. The method for pretreating a papermaking raw material according to claim 1, wherein the polyalkyleneimine is polyethyleneimine.