JPS62104998A - Papermaking additive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an additive for paper manufacturing, which is excellent in increasing paper strength, and furthermore, in a papermaking system that uses both filler and sizing agent, it is effective in reducing the amount of filler. It increases the yield and the yield of the sizing agent.

[Technical background of the invention and its problems]

Until recently, acidic papermaking using sulfuric acid was the mainstream in the papermaking process, but acidic papermaking has caused serious problems such as deterioration of the paper, corrosion of paper machines, and wastewater treatment due to the quasi-disruption of the papermaking process. In place of this, papermaking in the neutral to alkaline range is attracting attention.

With this shift in papermaking, it has become possible to use inexpensive alkaline fillers such as calcium carbonate, which could not be used in acidic papermaking. Therefore, there is a need for an excellent retention agent for paper strength agents, fillers, and sizing agents that can be used in neutral to alkaline papermaking.

Acrylamide poly(1-) has been known as a material with excellent paper strength effect. The method for imparting ionicity to this acrylamide polymer is described by Hofman.
Examples include those based on an n-rearrangement reaction, those based on a Mannlch reaction, and those based on copolymerization of a cationic monomer and an anio-yi monomer. Among these, polyacrylamide-based Hofmann rearrangement reactants have been studied in various ways due to their excellent performance, but their stability has not yet been improved and they cannot avoid performance deterioration over time. Also! The cationic nature of the 1lIannLch reactant decreases under neutral or alkaline papermaking conditions, and it cannot exhibit sufficient effects.

Furthermore, although copolymers have an excellent paper strength enhancement effect, they are inferior in water dehydration properties and size retention effects. If an attempt is made to increase the ionicity of the copolymer in order to improve this drawback, there is a disadvantage in that the cost increases.

The present inventors disclosed water WI in JP-A-60-94697.
@Kanaone monomer and/or salts thereof, α,
β-unsaturated dicargonic acids and/or their salts,
We have invented a paper strength agent comprising a water-soluble copolymer obtained as an essential monomer component of acrylamide and/or methacrylamide. Also, special request in 1986
-183128, dimethylaminopropyl (meth)acrylamide or its quaternized product, itaconic acid or its salt, and acrylamide are obtained as essential monomer components as a papermaking additive useful in papermaking in the neutral to alkaline range. We have invented a water-soluble copolymer that can be used as a water-soluble copolymer.

However, even in the above invention, it cannot be said that all the drawbacks of the above copolymer have been solved.

In contrast to these synthetic paper strength enhancers, starch-based paper strength enhancers are also popular.1 For example, they are used as internal additives or coated on size presses to improve the surface strength of printing paper, and they are also used in paperboards. It is also used internally to improve strength.

A feature of starch-based paper strength enhancers is that they are cheaper than synthetic ones. Starch used as an internal additive to increase paper strength is generally chemically treated to become cationic! death,
It is increasing its own yield rate. However, chemically treated cationized starch cannot be said to be as effective as polyacrylamide-based paper strength enhancers.

[Summary of the invention]

The present inventors have conducted intensive studies on backing paper additives that have an excellent paper strength enhancement effect and are particularly effective in retaining F water, fillers, and sizing agents. Monomers and/or their salts (B
), α, β-unsaturated dicargenic acids and/or their salts (C1 and acrylamide and/or methacrylamide (DJ'), a water-soluble polymer that is an essential component of DJ', has particularly excellent performance, and is also an inexpensive water-soluble polymer. The present inventors have discovered that when a polymeric material is used, it is less expensive than a copolymer and has significantly increased industrial utility.

Here, water-soluble polymeric substances (typical examples include starches, polyvinyl alcohols (hereinafter abbreviated as PVAs), celluloses, gums, etc.

Starches are not particularly limited, and include raw starches such as potato starch and corn starch, dextrin, oxidized starch, soaldehyde starch, alkylney fJIi starch, cationized starch, phosphate starch, urea phosphate starch, and the like. .

All PVAs can be used as long as they are water-soluble.

The type of ionicity does not matter.

A representative example of cellulose is Cal? Examples include oxymethylcellulose, hydroxyethylcellulose, and cationized cellulose.

Gums include guar gum, locust bean gum, and their derivatives (phosphorylated, hydroxyethylated,
Cal? (modification treatment such as oxymethylation).

Typical water-soluble cationic monomers as component (f9) include trimethylaminoethyl (meth)acrylate, noethylaminoethyl (meth)acrylate, trimethylaminopropyl (meth)acrylamide, and diethylaminopropyl (meth)acrylate. Vinyl monomers containing tertiary amine groups such as acrylamide and salts of these monomers with inorganic or organic acids such as sulfuric acid or acetic acid.

Or a vinyl monomer entirely containing a quaternary ammonium salt obtained by reacting the tertiary amine group-containing vinyl monomer with a quaternizing agent such as methyl chloride, dimethyl sulfuric acid or epichlorohydrin? -1 Bisquaternary ammonium (meth) obtained by reaction of the tertiary amino group-containing vinyl monomer with a quaternizing agent such as 3-chloro-2-hydroxylapropyltrimethylammonium chloride
Examples include acrylamide. Among these monomers, amide-type cationic monomers are superior to ester-type cationic monomers because amide-type cationic monomers are susceptible to hydrolysis and retain their cationic properties even in neutral or alkaline conditions. This is thought to be due to the presence of

Component (C) is α,β-unsaturated decaldic acid. Typical salts thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid, and their sodium salts, potassium salts, and ammonium salts. Can be mentioned. In particular, itaconic acid and its salts show the most excellent effects.

Components (monomers) include acrylamide and methacrylamide; acrylamide is preferred from an economic standpoint, but both may be used in combination.

In the present invention, the amount of the water-soluble polymeric substance (A) is 5 to 50 weight f1.
%, and the sum total of each monomer of components (B), (C1 and ■) is 50 to 95% by weight. When the amount of water-soluble polymeric substance (A) is less than 5 times and 11 times.

The water resistance and size yield effect decreases @Also, water-soluble polymeric substances (when the amount of Al is 50I or more).

In addition, in the case of polymers that age, such as starches, the paper strength enhancing effect decreases, and the viscosity properties of water-soluble polymers decrease.

The proportions of each monomer in the comonomer consisting of the components (Bl, (C1 and CD+) are 0.1 to 20 mol, 0.1 to 15 mol, and 99.
It is 8 to 65 molti. Component (B) among these three components
The higher the monomer ratio, the higher the retention effect of fillers and sizing agents, and the more the paper strength enhancement effect tends to be poor. This is due to the fact that the higher the ratio of the component (Bl monomer) that becomes a cation site, the easier it is to adsorb and aggregate fillers and sizing agents, and as a result, each exhibits a high yield effect, but on the other hand, hydrogen bonds with the hydroxyl groups of cellulose It is thought that paper strength decreases because the proportion of amide groups, which are thought to exhibit a strength-enhancing effect, decreases.

Paper-making additives are required to have a paper strength enhancement effect, water resistance, filler and sizing agent retention effects, and it is important to balance each of these performances. The composition that exhibits excellent effects in both of these performances has a component (B) monomer of 0.1 to 20%.
Component (C) monomer is in the range of 0.1 to 15 mol, and component (Dl monomer) is in the range of 99.8 to 68 mol. In addition to these three components.

α, β-unsaturated monocarcinic acids such as acrylic acid and methacrylic acid, their salts (such as styrene, acrylonitrile, ethyl acrylate, methyl methacrylate, etc.) to the extent that they do not impair the water solubility of the ill 31 combination. The use of monomers such as hydrophobic monomers, (iii) monomers containing sulfonic acid groups such as vinyl sulfonic acid and styrene sulfonic acid, and their salts does not hinder the present invention @Brookfield of the water-soluble polymer of the present invention The viscosity (hereinafter abbreviated as viscosity) is 300 when the concentration is 10% by weight.
~100. OOOcps (25°C, Brookfield viscometer used...hereinafter abbreviated as B-type viscometer),
Particularly preferably 800 to 20. It is OOOcps.

If the molecular weight is extremely low (low viscosity), the yield effect will be poor; if the molecular weight is extremely high (high viscosity), the yield effect will be excellent, but the paper strength will be reduced due to excessive agglomeration. No adverse effect on.

Polymerization which requires the water-soluble polymeric substance (8), component (B), (C1 and (D) monomers) is carried out by a conventional method.

That is, (1) a ceric salt, a hydrogen peroxide type, an ammonium persulfate type redox type initiator, or benzoyl peroxide as a polymerization initiator.

Examples include a method using a radical polymerization initiator such as ammonium persulfate, and a method of irradiating with a number ray, a single ray, an ultraviolet ray, etc.

Polymers obtained by these polymerization methods are considered to be so-called graft polymers. That is, water-soluble polymer*(A
It is considered that a polymer consisting of component (B), (Q and (]:1 monomer) is grafted onto J.
, a copolymer consisting of monomers (C) and (D) alone, or a water-soluble polymer substance and component (B), (
The reason why it is superior to a blend of copolymers consisting of monomers C) and (D) in terms of increasing paper strength and improving retention of fillers and sizing agents is not clear, but It is thought that the synergistic effect of the copolymer was expressed by the grafting.

Next, the present invention will be specifically explained using examples and application examples.

Unless otherwise specified, all references to weight are percentages by weight. In addition, the abbreviations of drugs are as follows.

AAm...Acrylamide DM...Dimethylaminoethyl methacrylate DPA
...Zomethylaminoglovir acrylamide BQ ・
・-2-Hydroxy-N, N, N, N', N'-p
antamethyl -N'-(3-[(1-oxo
-2-propenyl)amlno)propyl)
-1,3-propanediaminiumdic
hloride MA...maleic acid IA...itaconic acid fi'A...fumaric acid M...acrylic acid APS...ammonium persulfate S) I...sodium hypophosphite. Each measurement in the adverse case was carried out according to the following method.

Specific burst strength...JI8 P-8112 specific compressive strength
・・JIS P-8!26DDT-Tappl J
ournal Volume 56, No. 1O (1973) No. 4
r DynamL described on page 6.

Pardesura! using a device similar to Drainage Jar J. J 800mg'! Pour into a jar with a diameter of about 7.5 mm, open the bottom cock while stirring at 800 rpm, let the 10 meh wire mesh t-F retreat, and measure the time until the liquid state becomes constant. It can be used for evaluation. Here, the F liquid amount is 200-
The time it took to reach this point was measured.

Steckigt sizing degree: JIS P-8122 Filler content: JIS-8128 ash content 'Ik1.
Multiply by 78, Ca Of! Converted to k f Ca COs l.

Try-Pick: Printing was performed using an RI printing tester (manufactured by Kirikai Dojo), the peeling condition was observed with the naked eye, and the results were rated as "dry pick resistance, excellent 5 to poor 1".

Wet pick...Using an R1 printing tester, moisten the surface with a water supply roll, print, and observe the paper peeling condition with the naked eye. Wet pick resistance is excellent 5 to poor 1.
A judgment was made.

T, M, -Paper maksra conference
ncs (1985).

Modlfed He described in 9, 171)
rules Dynamic Drainage Te
Equipment similar to atar (a structure in which pulp slurry is poured into a jar with a diameter of approximately 7.5 mm, Alt'i is fed from the bottom to prevent mat'ir formation under stirring, and the stirring and air supply are stopped and filtered at the same time) Pour into 300ml 1f Jar of No. 9 Lupus slurry using a
Trana-mlgsion at enemy's 620nm (
T, M, ) f Measure. First Pa5sR@
T, M, as Parametersr of tantloH
I used it.

In other words, if T and M are high, the F solution is clear, indicating a high yield.

Example 1 A 5.51% cationized starch (corn starch was cationized with a tertiary cationizing agent and nitrogen-containing 10% .251.20 at 90℃
After kneading for a minute, cool to 25°C and use a B-type viscometer (
As a result of measurement at 60rprn), the viscosity was 360
It was cps. ) Gelatinization liquid 41.74.9 was added.

Furthermore, 0M2.35.9, IA O, 78f! , 50
Aqueous solution of 39.661 g of water, 8 g of water, and 1112.24.9 i of 21 S) I water were charged, and then the pH was adjusted to 4.1 with an aqueous solution of 15 sulfuric acid. The constituent monomer allocation is D
M5 mol, IA 2 mol, AAm 93 mol. Further, the ratio of the total weight of DM, IA, and AAm to the weight of cationized starch was 10:1.

The temperature was raised to 60°C under the introduction of nitrogen gas, and 5% APS water #1 was added.
0.68.9'i of liquid was added to start polymerization. Then 75℃
1.5 hours after the start of polymerization, add 5% APS aqueous solution 0.
．． 34.91- was added and further kept at 75°C for 1.5 hours to complete the polymerization reaction, resulting in a non-volatile content of 15.1%.
, an aqueous solution having a viscosity of 6800 EPA at 25°C was obtained. This is referred to as water-soluble polymer A-1.

Examples 2 to 4 Except for the composition of the ingredients as shown in Table 1 and the total monomer/cationized starch weight ratio,
The same operation as in Example 1 was performed.

However, the crushing of the Sf (and 15-thiosulfuric acid water IW solution) was changed each time to obtain an appropriate viscosity and -.The property values of the water-soluble polymers obtained in each example are summarized in the same table. .

Table 1 Examples 5 to 16 and Comparative Example 1 According to the composition of the constituent monomer components as shown in Table 2, the total monomer/cationized starch weight ratio 'kl O:
The same operation as in Example 1 was performed except that the temperature was changed to 3. However, the amount of AP8 and SR Okobi 154I sulfuric acid aqueous solution was changed each time to obtain an appropriate viscosity. The property values of the water-soluble polymers obtained in each example are summarized in the same table.

Examples 17 to 19 The same operation as in Example 5 was performed except that the water-soluble polymeric substance and constituent monomers shown in the third light were used. The property values of the water-soluble polymers obtained in each example are summarized in a scale.

The viscosity of the oxidized starch used was determined by heating at 90°C for 20 minutes, cooling it to 50°C, and measuring it with a B-type viscometer (60 rpm).
) was measured at 310 cps and 6°.

In addition, urea phosphate starch was used as Nylgum A-160 (Matsuya (1 Kogyo C stock)'t), and cal-xymethylcellulose (CMC) was used as Secl'n 7A (Daiichi Kogyo Seiyaku Co., Ltd.). .

Example 20 In a four-loaf flask similar to Example 1, 7.0% polyvinyl alcohol (degree of saponification 98.21, weight average molecular weight 73) was added.
900) 191.11 was added. The temperature was raised to 60°C, and 8°2g of 5*APS was added thereto. 60
After holding for 5 minutes at °C, further 0M2.83.9, IA
), 51.5 Q 96 AAm water soluble [81,05,9
'i then add 15 sulfuric acid aqueous solution 2. OIi'e added. The proportion of constituents is DM 2.5 mol, IA
1.8 molar ratio, AAm 95.7 molar ratio. Further, the ratio of the total weight of DM, IA, and AAm to the cationized starch weight was 10:3. After heating the sulfuric acid aqueous solution, the temperature was raised and the reaction was carried out at 75°C for 2.5 hours, and the non-volatile content was 1.
A water bath liquid having a viscosity of 9.7% and a viscosity (25° C.) of 4,300 eps was obtained. This is referred to as a fully water-soluble polymer D-4.

Examples 21 to 22 Urea phosphate starch (Nylgum A-160
) was used, but the same operations as in Examples 15 and 16 were performed. The property values of the water-soluble polymers obtained in each example are shown in the same table.

Table 4 Example 23 5% Nylgum in a four-loaf flask similar to Example 1.
1138.8Nk of A160 water solution was added. Nitrogen gas t-
After blowing for 30 minutes, 50% AAm aqueous solution 3946
．． 9, IA 0.59 g, DPA 2.815,
92.7.9 ft of water was added to each and the pH was adjusted to 3.9 with INHNO. Then cerium ammonium nitrate 0
．． 24 F (dissolved in IN) INO 510,1) was added, and the pH was further adjusted to 1,1 with IN) fNo. This reaction was heated to [' and kept at 40°C for 60 minutes, then 15%
F at aOH! '1 total 4.1. The water bath liquid thus obtained had a nonvolatile content of 8.6% and a viscosity of 920 cps.

This is referred to as water-soluble polymer F.

The proportions of the constituent monomers are DPA: 6 mol, 11 mol.
．． 5 molar ratio, AAm 92.5 molar ratio, DPA, IA.

The weight ratio of the total weight of AAm to Nylgum A-160 is 1°:3.

Example 24 Put 335.7 J of water into a four-bottle flask similar to Example 1, blow in nitrogen gas for 10 minutes, and then add 12.6 J of water to the flask.
% hypochlorous acid) IJum 2.52. ! i'e, stir evenly and post-mortem guar gum Fixture name: EMCOGXM
C8AA-trisrystal(&) ) 4.67 tit- was added, and the pH was adjusted to 10.3 with 5 To NaOH. 10
After stirring for a minute at room temperature, the pH was adjusted to 3.1 with H2So4 at 7°C. Then 50% AAm aqueous solution 25
．． 56N, IAo, 77I! , DPA 1.85.9 and water 10.0#, into which nitrogen gas had been blown beforehand, was added, stirred at room temperature for 40 minutes, heated to 55°C over 10 minutes, and heated to 55°C for 1 hour. Allowed time to react.

The aqueous solution thus obtained had a nonvolatile content of 5.2 cm and a viscosity of 2400 cpa. This will be referred to as fully water-soluble polymer G.

The proportion of constituent monomers is 6 moles of DPA.

IA 1 mol%, AAm 93 mol%, DPA
, I.A.

The total weight ratio of AAm to guar gum is 10:3.

Comparative Example 2 DM 4.72.9 in a four-loaf flask similar to Example 1
, IA), 56#, 50 To AAm water soluble R79,3
6,9, water 214.0#, 21SH water soluble Q 4.489
After t-preparation, adjust the pH to 4,
Adjusted to 4. The proportion of constituent monomers is based on DM5 molar ratio,
The IA ratio is 2 mol and 93 mol. The temperature was raised in the same manner as in Example 1.

Addition of APS was carried out. However, 5 * The amount of APS added was 1.37.9N for the first time and 0.68N for the second time.
And nine. The nonvolatile content of the aqueous solution thus obtained is 15.
3, and the viscosity was 7400 (!pa). This is referred to as water-soluble polymer H.

Application Examples 1 to 15 and Comparative Application Examples 1 to 8 Canadian Standard Freeness (
Hereinafter, they will be abbreviated as C, S, and F. ) is 407- in a 2.5% concentration slurry of beaten pulp IJ-, sulfuric acid band't O,
5 g (based on pulp dry weight, the same applies hereinafter), and then used for the synthesis of the water-soluble polymers obtained in Examples 1 to 4 and Comparative Example 2 and A-1 to A-4. Cationized starch, cationized starch and water-soluble polymer 1A-
A mixture of powders listed in Table 5 was added as a paper strength agent in the same proportion as 3.

After stirring for 2 minutes, dilute the cell des slurry to a concentration of 25% and stirring for another 1 minute. 6.5), then heated at 110℃ using a drum dryer.
After drying for 90 seconds, the basis weight is 85±21/m
Two types of handmade paper, 2 and 172 ± 3117 m” were obtained. Also, using this o, 25% pulp slurry,
DDT was measured and reactor water properties were investigated. The obtained handmade paper stock was conditioned for 24 hours at 20°C and 65% RH, and then the paper stock with the former basis weight had a specific bursting strength of gold, and the paper stock with the latter basis weight had a specific compression strength. All strengths were measured. The results are shown in Table 5.b The water-soluble polymer of the present invention is superior to cationized starch alone, polyacrylamide copolymer alone, and a blend of cationized starch and polyacrylamide copolymer, especially in terms of reactor water resistance. Admitted.

Application Examples, 16 to 24 and Comparative Applications 1.5% of sulfuric acid band ft was added to a 2.5% concentration slurry of beaten pulp of C, S, ・F) 372- obtained from %9-column waste paper. , "New Four 100J (Rosin Emarzo, manufactured by Dick Bercules Co., Ltd.) 0.
Then, 0.4% of each of the water-soluble polymers obtained in Examples 8 to 16 was added as a paper strength agent. (As a comparative application example, the same cationized starch i1.0 as in Example 1 was used.
% addition9) After that, in the same manner as Application Examples 1 to 12 and Comparative Application Examples 1 to 8, the 1 basis weight was 78 ± 31/m" and 1
A handmade paper of 60±5/m" was obtained. The water resistance was also measured.

In addition, - at the time of paper making was 4.5. After that, 78±
The specific burst strength and Steckigt sizing of a stock of 3 P/m" and the specific compressive strength of a stock with a basis weight of 160±511/m2 were completely measured.

The results are summarized in Table 6.

It has been found that the water-soluble polymer of the present invention has better water retention and sizing agent retention effects than cationized starch. It was also found that the water-soluble polymer E-2 synthesized using the cationizing agent BQ' was superior to the water-soluble polymer synthesized using the cationic agent DM.

Application examples 26 to 35 and comparative application examples 10 Application examples 16 to 2
5 and comparative application example 9, sulfuric acid 27220.5%
The water-soluble polymers obtained in Examples 8 to 16 were each added in an amount of 0.4% as a paper strength agent, and as a comparative application example, the same cationized starch i as in Example 1 was added at 1.0%.
% added. ) After that, in the same manner as Application Examples 16 to 25 and Comparative Application Example 9, Tsuboho is 85 ± 217 m" and 1
A handmade paper with a thickness of 73±29/m" was obtained. In addition, water resistance was measured.

In addition, - at the time of paper making was 6.5.

The effects were measured in the same manner as Application Examples 16 to 25 and Comparative Application Example 9. The results are summarized in Table 7.

From Table 7, it was confirmed that the water-soluble polymer of the present invention has a water-repellent effect and a paper strength enhancing effect superior to that of cationized starch. It was also found that the water-soluble polymer E-2 synthesized using the cationizing agent BQ was superior to the water-soluble polymer synthesized using the cationic agent DM.

Table 7 Application Examples 36 to 46 and Comparative Application Examples 11 to 13 Nogurude (LBKP/NBKP-75/25, C, ・S
, ·Fo, 371-) 20% calcium carbonate in 2.5% aqueous dispersion, Invention 5-7, 17-20% 21.2
The water-soluble polymers obtained in 3 to 25 and Comparative Example 1 were
As a comparative application example, the cationized starch used in Example 1 was added as a paper strength agent in amounts of 0.8 and 1.2, respectively. Then Burcon W (Dick Bercules)
1% of an alkyl ketene dimer sizing agent) ko manufactured by Co., Ltd. was added. This pulp slurry was diluted to 0.25%,
The paper was made using a hand paper making machine made by Nople & Wood (pH 8.4), and then the pH was 100% using a drum dryer.
℃, dry for 90 seconds! A handmade paper with a t65±21/m" was obtained. The obtained paper stock was conditioned for 24 hours at 20° C. and 65% Rf, and then subjected to each measurement. Shown in the table.

From Table 8, it was confirmed that the water-soluble polymer of the present invention had better water-retaining properties and sizing agent retention effects than cationized starch. In addition, as anionic monomers,
From acrylic acid, an α,β-unsaturated monocarzenic acid,
It was found that maleic acid, fumaric acid, and itaconic acid, which are α,β-unsaturated dicarbons, are superior. Itaconic acid was particularly excellent.

Procedural amendment (voluntary) +n+net
March 17th, 2015 Michibe Uga, Commissioner of the Japan Patent Office 1 Indication of the case 1985 Patent riI'i No. 244077 2 Name of the invention Paper-making additive 3 Relationship to famous case for amendment Special amendment Applicant Address: 103 Tokyo 7-20, 11 Kibashi 3-chome, Chuo-ku, Tokyo Dick Vercules Co., Ltd. Representative: Kawai - line 4 Agent: 103 Chuo-ku, Tokyo [1-117-20, 3-chome, Honbashi, Omemoto Ink Chemical Industry Co., Ltd.] Column 6 of “Detailed Description of the Invention” of Book 411 Contents of amendment (1) Line 17 of page 3 of the specification is amended as follows.

"Due to the reaction, cationic monomer and 7-ion j (2)
The second line of page 13 of the specification is amended as follows.

fFA... fumaric acid j (3) Page 19, line 6 of the specification should be amended as follows.

``In addition, the viscosity of the oxidized starch used is 20wt$ and 90℃
, 20 minutes j (4) Correct "waste paper" in line 2 on page 28 of the specification to r waste paper J.

(5) Page 30, line 3 of the specification and Page 31, lines 2-3 "The cationizing agent BQJ, “Correct to cationic monomer BQJ.

(6) "Cationizing agent DMJ" on page 30, lines 4 to 5 of the specification and page 31, lines 3 to 4 has been corrected to "cationic monomer 〇MJ."

(7) Add the following sentence from line 5 on page 33 of the specification.

"Also, as a cationic monomer, DPA, which is an amide type cationic monomer, was found to be superior to DM, which is an ester type cationic monomer. (8) Page 27 of the specification. Table 5 is amended as follows.

Claims (6)

[Claims] (1) Water-soluble polymeric substance (A), water-soluble cationic monomer and/or their salts (B), α,β-unsaturated dicarboxylic acid and/or their salts (C), and acrylamide and/or methacrylamide (D
) is an essential component of a papermaking additive consisting of a water-soluble polymer. (2) The water-soluble polymer substance (A) is 5 to 50% by weight, and the total amount of each monomer of components (B), (C), and (D) is 50% by weight.
The papermaking additive according to claim 1, characterized in that the amount is 95% by weight. (3) The proportion of each monomer in the comonomer consisting of each monomer of components (B), (C) and (D) is 0.1 to 20 mol%, 0.1 to 15 mol% and 99%, respectively.
．． The papermaking additive according to claim 1, characterized in that the content is 8 to 65 mol%. (4) The papermaking additive according to claim 1, wherein the water-soluble polymeric substance (A) is starch, polyvinyl alcohol, cellulose, or gum. (5) Component (B) monomer is dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylamide or 2-Hydroxy-N,N,N
, N', N'-pentamethyl-N'-[3-
[(1-oxo-2-propenyl)amino]
propyl]-1,3-propanediamin
2. The papermaking additive according to claim 1, wherein the additive is .ium dichloride. (6) The papermaking additive according to claim 1, wherein the component (C) monomer is itaconic acid or a salt thereof.