JPS5891897A - Papermaking method - 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 Misfire J describes a method for making paper, specifically, adding a specific acrylamide thread water-soluble amphoteric copolymer and sulfuric acid band to an aqueous slurry of pulp in a specific order, and then adding this to an aqueous slurry of pulp. Regarding the papermaking method.

Paper is made by adding various paper-making chemicals such as paper strength agents, sizing agents, fixing agents, etc. to an aqueous slurry of pulp, and after drying, it is wound onto a roll and manufactured. Moreover, it can be finished as a coated paper by applying various coating solutions containing adhesives, pigments, etc. to one or both sides of the paper depending on the required TLC. Does the use of paper strength agents improve paper strength? It is important to give the paper, but what about the time of paper making? It is also an important factor in reducing paper quality, white water, and wastewater load. The paper strength agent has a great influence on the aqueous P of the pulp slurry and the transient yield (one-pass redenation) in the wire 7, and due to these improvements, the sheed amplifier of the paper fineness becomes l:If hQ. , Paper machine inlet water usage rat, Soy? The control of the dehydration behavior in -J- can be fully expanded, and the formation of the paper can be improved easily. In addition, by using paper strength agents, the pulp 1. IA
PL-2 Paper strength agents, dyes, and other additives may be reduced in some cases, and in this case, the number of ridges in raw material recovery equipment such as additives and polytisf filters can be reduced, and the subsequent drainage] You can reduce COD or SS damage in the second stage. In this way, in the paper manufacturing industry, paper strength agents not only provide excellent paper strength to paper making, but also can be expected to have effects such as improving paper-making properties and reducing the burden of white water and wastewater. It is desired to develop a paper strength agent that can exhibit such excellent properties and a paper making method that utilizes it.

゛ In the Paper Making 1 -Wow, LJL] Wrapped in 2] In about 2, a paper writing product selected in the paper 8 and the finishing process for the two ears, the roll -connected, and the finished process. It is unavoidable that paper that cannot be made into paper (referred to as completely waste paper in the industry) will be generated. Normally, it is re-disintegrated and used again as a pulp source, filler source, etc. However, if the re-disintegration of the waste paper is insufficient at that time, the quality of the paper obtained using it will be uneven. This is required for all types of paper such as industrial paper, wrapping paper, etc.Therefore, there is also a growing trend in the industry to improve the redisintegrability of the above-mentioned waste paper.

Conventionally, as a paper strength agent, acrylamide 1r is used as an amphoteric 1 (it is known that it is a combination).
When a polyacrylamide [14-class tertiary) group is introduced (Hoffmann reaction), the water decomposition reaction of the acid amine F group is also shown. A polymer is obtained and the +44
Coalescence has been proposed as a paper strength agent. However, when this polymer is stored as an aqueous solution, the amino groups formed are extremely unstable, and most of them disappear within a few days at room temperature, resulting in paper strength effects. There is a drawback that it reduces it by half. Even when used after production, it has almost no effect on improving papermaking properties or reducing the load on white water and wastewater.
Furthermore, the redisintegration properties of paper (broken paper) obtained using this are poor. Furthermore, an amphoteric copolymer obtained by copolymerizing acrylamide, acrylic acid, and methacrylic acid dialkylamine ethyl ester or a salt thereof has been proposed as a paper strength agent that can be used in a wide pH range. However, for some reason, the amino group introduced through the Nisder bond tube as seen in the copolymer is not as strong as the primary amino group due to the above reaction, but it is still polymerized by hydrolysis. It has the disadvantage that it easily separates from the coalescence, and therefore it is difficult to stably impart the desired paper strength to Vc paper, especially when the pH of the papermaking yarn is neutral or alkaline. . Moreover, this amphoteric copolymer does not show any effect on improving paper-making properties or reducing the load on white water and wastewater.

In addition, Vc paper is obtained by subjecting the acrylamide-acrylic acid copolymer, which is used as a paper strength, to a Mannich reaction.
Amphoteric copolymers generally have insufficient paper strength effects, are poor in improving paper-making properties, reducing white water and wastewater loads, and have poor redisintegration properties of broken paper.

Conventionally, in the paper making of marigami, two different internal chemicals were added, such as anionic polyacrylamide and polyamide polyamine epichlorohydrin resin (Japanese Patent Publication No. 45-31
No. 690), anionic polyacrylamide and Boarman reaction product of polyacrylamide (see JP-A No. 690)
49-26501)) It has been proposed to use them in combination. However, the combined use of bending chemicals has the disadvantage that the pH range for use is limited to the acidic side, and in addition, the strength on the M side is large, and the redisintegration property of the paper is deteriorated in an aqueous medium. There it is. In addition, the latter has the disadvantage that the effect of improving paper-making properties is poor, and the paper strength of the formed paper is still unsatisfactory.

No polymer has yet been developed that can exhibit satisfactory performance as a paper strength agent when used alone or in combination. The present inventors also independently attempted to use an amphoteric copolymer consisting of acrylamide, acrylic acid, and a specific acrylamide derivative represented by the general formula [I] described later as a paper strength agent; With use, the paper strength of sand-formed paper (1) was sufficient, but the improvement in paper properties and the effect of reducing white water and wastewater load were at a very advanced level, and the redisintegration properties of broken paper were slightly inferior. Atsuko.

7- In view of the above-mentioned current situation, the non-inventors continued to make a series of efforts to create a specific water bathing compound compound in-house additive drug.
This? When using m-acid band and 61 finishing addition in a specific order, Vco can significantly improve paper-making properties and also provide sufficient paper strength for forming paper. It has been found that a well-balanced paper making method that meets the needs of the industry can be established, which can also significantly improve the properties. The present invention has been developed based on this new knowledge.

That is, the present invention provides a water-sprayable amphoteric copolymer having the following constituents (all d) in an aqueous slurry of pulp, (
A method for making paper VC, characterized in that fL acid band and the following (al or dl) are used as constituent monomers, and paper is made after sequentially adding the same or different water-soluble ampholytic copolymer as mentioned above.

<a) At least one persimmon selected from arp-unsaturated monocarboxylic acids and alkali salts thereof (hereinafter referred to as component a) 1 to 20 mol%, 8-(bl General formula [wherein n is 2.3 or 4, R1 is a hydrogen atom or a methyl group, and K R2 and R'l are dog fil -17'
r represents an alkyl group having 1 to 4 carbon atoms, or a 6-membered heterocyclic group th together with the nitrogen atom to which they are bonded;
10 to 50 mol % of at least one cationic monomer (b-1) selected from acrylamide derivatives, acid addition salts thereof and quaternary salts thereof represented by is 1.2" or 3, R4 is a hydrogen atom or a methyl group, and K R5 and R6 are largely the same or similar □
acrylic acid esters, acid addition salts thereof, and quaternary salts thereof; 1 to 20 mol % of a mixture (hereinafter referred to as component) with 50 to 90 mol % of at least one selected cationic monomer (b-2), (C) acrylamide (hereinafter referred to as component C) 40 to 90 mol %;
98 mol % and (d) 0 to 30 mol % of other nonionic columnar particles (hereinafter referred to as ``di'') that can co-NPr with (a) to c) above.

The method of the present invention can be applied over a wide range of pH ranging from alkaline to acidic.
It can be easily produced in a pH range of 4 to 9, for example. Moreover, according to this implementation, the P aqueous properties and one-pass retention of pulp slurry containing internal chemicals on the paper machine can be improved,
Paper-making properties can be significantly improved to 1, including the reduction of white water and wastewater load, and excellent paper strength can be imparted to paper, and in addition, the redisintegration properties of waste paper are also extremely good. It can be done.

In the present invention, as described above, it is essential to use a specific water-soluble amphoteric copolymer system in which the sulfuric acid band and the co-Ka 7 to d components are used as t#I monomers in a specific order.

The component a, which is the constituent monomer of the copolymer L, is as follows:
For example, α, β-unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and alkali metal salts thereof, such as salts with caustic nose, caustic potash, etc., and alkali salts such as Asimonicum salts can be used.

tNjl? , minutes consist of the above b-1 and b-2. b
As the -1 component, the compound represented by the above general formula [I], its acid addition salt and its quaternary salt can be used alone or in combination of two or more. In the acrylamide derivative represented by the general formula [1], examples of the alkyl group represented by R'l and R3 include methyl, ethyl, propyl,
An example is a butyl group. Examples of the 6-membered hetero IN group that R2 and R3 can form together with the nitrogen atoms to which they are bonded include, for example, morpholino,
All examples include piperidino and piperazino groups.

Preferred specific examples of the acrylamide derivatives used as b-IVt are as follows.

Dimethylaminoethyl acrylamide, dimethylaminopropylacrylamide, dimethylaminobutylacrylamide, diethylaminoethyl acrylamide, diethylaminopropylacrylamide, diethylaminobutylacrylamide, dipropylaminoethylacrylamide, diethylaminoethylacrylamide, and methacrylamide derivatives corresponding thereto.

As component b-2, a compound represented by the above general formula [formula], an acid addition salt thereof, and a quaternary salt thereof can be used alone or in combination of two or more. In the acrylic ester represented by the general formula C, preferred specific examples of R6 and R6 as 12-acrylic esters are as follows.

Dimethylaminomethyl acrylate, diethylaminomethyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, 3-dimethylaminopropyl acrylate, acrylic acid 2
-Aminoalkyl esters of acrylic acid such as dimethylaminoisopropyl and the corresponding aminoalkyl esters of methacrylic acid.

gtI General formula C131 The following is an acid addition salt of a compound represented by [old], for example, an aqueous salt added with an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, or an organic acid such as formic acid, acetic acid, propionic acid, oxalic acid, etc. Examples include acid addition salts. ′! As the quaternary salt of the above-mentioned compound a, ordinary quaternary salts obtained by known quaternization methods can also be used. 4I!
[Quaternized R used in the conversion], except for those with crosslinking properties, include ordinary ones such as alkyl halides such as ethyl bromide, butyl bromide, benzyl bromide, methyl chloride, benzyl chloride, and methyl iodide. Alternatively, inorganic acid esters such as aralkyl halides, dimethyl a-acid, diethyl sulfate, dimethyl sulfite, and dimethyl phosphate can be used. Amphoteric copolymers obtained by using a crosslinking quaternizing agent such as epichlorohydrin are not preferred because their use results in poor paper-making properties and rather impairs the redisintegration properties of broken paper.

Of course, the quaternization by quaternization removal may be performed on the compound of formula [l) or the formula [older compound or a salt thereof] in advance of the production of the copolymer used in the present invention, or It is also possible to produce a copolymer and then conduct the reaction on the compound of formula [l] or formula [old] contained in the copolymer.

In addition, dfj'y is a component that can be incorporated into the copolymer of the present invention depending on the I&L requirements, and specifically includes vinyl esters such as vinyl acetate and vinyl globionate; styrene; Vinyl aromatic hydrocarbons such as a-methylstyrene and vinyltoluene; a, β-unsaturated monocarboxylic acid nitriles such as acrylonitrile and methacrylonitrile: methyl acrylate, methyl methacrylate, ethyl acrylate, goutyl acrylate, C1-8 alkyl esters of acrylic acid or methacrylic acid such as butyl methacrylate and 2-ethylhexyl acrylate; nonionic monomers such as methacrylamide and diaseptone acrylamide;

The blending ratio of the Doi af to d components is 1 to 20 mol%, preferably 2 to 8 mol%, and 1 to 20 mol% of the b component, preferably 2 to 15 mol%, in the resulting copolymer.
The range is such that the C component is 40 to 98 mol%, and the C component is 65 to 96 mol%, and the di content is 0 to 30 mol%. If the loss fraction is less than 1 mol%, the resulting copolymer will be close to a cationic polymer, and conversely, if the b modification is less than 1 mol%, the resulting copolymer will be anionic. Close to polymer,
In either case, it becomes difficult to fully exhibit the desired properties as a paper strength agent, which is undesirable. What is the copolymer obtained when the fraction a or component b exceeds 20 mol%? Even if it is used as a paper strength agent, it imparts excellent paper strength to the paper, but the release properties and the redisintegration properties of broken paper may be inferior, which is still undesirable. Furthermore, regarding the b component, b -1 share and b -
The ratio of b-1 to the total amount of the two components should be 0.1 to 0.5, that is, 10 to 50 mol%, and if it is less than the above range, paper strength and paper making properties will deteriorate. If it is insufficient, and conversely if it is too much, the redisintegration properties of the broken paper will be poor. The above IEC+ component, which is used depending on the required vc, is used in mackerel in an amount of 30 mol% or less on the premise that the resulting copolymer exhibits hydroxyl properties.

The water-soluble amphoteric copolymer used in the method of the present invention can be obtained by copolymerizing a predetermined combination of components a to d. The copolymerization reaction of the above components a to d can be carried out by any of the conventionally known methods.

For example, a water-soluble radical-generating catalyst such as Iω hydrogen oxide, potassium persulfate, or ammonium persulfate is added to a Fiff monomer mixture at a concentration of 0.05 to 5%, and the monomer concentration is 5 to 50% in an aqueous medium. %, and stirred at 50-95°C for 1-10 hours. At this time, various hydroxyl chemicals, such as f'f sodium bicarbonate,
Alternatively, as in the conventional method, it is possible to appropriately use a buffer such as dibasic sodium phosphate, a reducing agent such as dimethylamine or sodium thiosulfate, or a chain transfer reduction agent such as isoglobil alcohol or allyl alcohol.

In this way, a copolymer 'e IIK can be obtained which is an effective material for paper scraping in non-explosion IK. The copolymer is an amphoteric polymer having a cationic group and an anionic group in its molecule based on the use of the above components a and b. The viscosity of the aqueous solution is 1
00~1000000CPS (25℃),
Especially when the above viscosity is 500 to 100,000 CPS (25°C)
) copolymers are most suitable.

As mentioned above, the present invention is based on Pulbusura IJ-[the specific amphoteric copolymer, a sulfate band, and then the amphoteric copolymer is added, and then the amphoteric copolymer is added, that is, the amphoteric copolymer is added after it is added. There is a number T', and thereby the remarkable effect intended by the present invention can be achieved. In particular, according to the method of the invention, if the same amphoteric copolymer as described above is added in a conventional manner only before or after the sulfuric acid band [! It is possible to impart good paper strength to the paper even when it is used. In addition, g+1 of the sulfuric acid band and each amphoteric copolymer added later, 10,000 of any of them were added to the pulp slurry at the same time as the sulfuric acid band.
C may be added, and this is also applicable to the present invention. Of course, as long as the order of addition is maintained, there is no limit to the location where each chemical is added. In addition, the amphoteric copolymers added before and after the sulfuric acid band may be the same or different, as long as they have all the components a to d mentioned above. It may be necessary.

The addition of the l-oriented copolymer to the pulp used in the unexploded F-moon force method VC is based on the type of dog's teat combination that is added separately to the VC+jh, the purpose of the resulting paper, the type of pulp used, etc. Lt 7 is limited depending on VC, but usually about 0.01 to 3% on a dry weight basis, preferably about 0 ()
It is best to set it at 5 to 2%, and the phase such as 11J O,
(A range of 15 to 5% is appropriate.The amount of sulfuric acid band used is not limited as it depends on the type of pulp, water for paper making, extraction number L+ of the copolymer, amount used, etc.) but
In general, dry Azogi beef has an i! content of about 0.1 to 5% for pulp. r
It is appropriate to use 11 pig iron.

The pulps that are obvious for the unexploded IJ-1 method are ordinary pulps (also known as crand pals), thermometical pulps, sulfide pulps, semi-chemical pulps, clarine pulps, various 8-component pulps, disintegrated waste paper, etc. ? Any of these can be used, and these are 2-5%
It is used as an aqueous slurry of culm.

' Also, in the present invention, sizing agents such as reinforced rosin soap, reinforced rosin emulsion, alkylcutene dimer emulsion, sock emulsion, alkenyl cobalt 9e stone, alkenyl succinic anhydride emulsion, etc. Materials such as clay, talc, titanium oxide, and carbonic acid, as well as dyes such as direct dyes, basic dyes, and color pigments, retention improvers, okisui-based + a + top polishing, slime control polishing, and erasing a Various types of cutting agents such as QJ, pitch control agents, and pH adjusters can be added.

Thus, according to the papermaking method of the present invention, the P aqueous nature of the papermaking valve slurry and the wire walk of various preparation raw materials mυ are heated in all directions, and white water and wastewater loads are reduced. It can be reduced. Therefore, modern papermaking equipment, which is becoming faster and closer to closed JF20, can be utilized extremely effectively. Moreover, according to the method of the present invention, excellent effects can be exhibited in terms of paper strength development of several papers and redisintegration properties of waste papers. According to Juku et al., the paper web obtained by the paper making method of the present invention is excellent in primary processing properties and can be effectively used as a base paper for various coated papers.

Note that the application of papermaking method 1 of the present invention is not limited to a specific paper machine type, and conventionally known examples include wire-mesh or circular-mesh paper machines, paper machines that combine these, and twin-wire paper machines. It is possible to apply L-I to various paper machines such as Vc.

Below, we will give examples of the production of a water-M oriented copolymer used in the invention and a copolymer for comparison, then we will give examples and comparative examples of the present invention, and we will discuss the characteristics of Vfr. .

Production Example 1 Acrylamide 75.0% was placed in a Yotsuro flask equipped with a stirrer, an ILR+1 degree meter, and a nitrogen gas inlet tube. J', dimethylaminoethyl methacrylate 19.7y, 98% sulfuric acid 8.2
y, 4.5 y of acrylic acid, 4.2 y of type 48 caustic soda, and 5'65 y of deionized water, and heated to 50° C. while stirring and passing nitrogen gas. Then, when 0.17y of ammonium persulfate and 0.04P of sodium bisulfite were added, the internal width reached 90° C1 above the polymerized IvIIVC. 3 hour direction width Vc maintenance vortex [7 tano also deionized water 3
33yf: Added and diluted, non-volatile content 10%, viscosity 6300
CPS (injected at 25°C, pH 4.4, an aqueous solution of both copolymers was obtained. This is referred to as paper strength agent A.

The types and/or usage amounts of components a to d are shown in Table 1. Agents A'B-K) were obtained. Table 6 also lists the composition and properties of the paper strength agent A.

The abbreviations of the content classifications in Table 1 above indicate those of the large method.

AA...Acrylic acid MAA °...Methacrylic acid b-11...N-(3-dimethylaminopropyl)acrylamide b-12°゛N-(3-dimethylaminopropyl)methacrylamide b-13... Trimethyl (3-acrylamidopropyl) ammonium chloride b-21...dimethylaminoethyl methacrylate b-22...diethylaminoethyl methacrylate b-23°゛Trimethylmethacryloyloxyethylammonium chloride AM...acrylamide AN...acrylonitrile Table 2 Production Example 2 Acrylamide+: 9887, 80% Acrylic Aqueous Solution 6
．． 3y, 48% caustic soda 4.6y and deionized water 56y
0y was charged, and the mixture was heated to 45° C. while stirring while passing through a nitrogen stream. Then ammonium acid 0.18
Y and anhydrous sodium bisulfite 0. (When added to 18-1, the polymerization reaction started immediately and the temperature inside the fan reached 90℃.After that, after stirring for 3 hours, 333y'''C of de-ionized water was diluted and the non-volatile content was 10%. Combined water EG liquid CYl)K
10. (100cPs) k? 4sl. ,n;
/”LK48% caustic soda 1.3y, 50% dimethylamine water bath Europe 188y and 37% Polmarine 11.4y
After adding y and reacting at 45°C for 1 hour, it was diluted with deionized water to give a nonvolatile content of 10%, pH 9.8, viscosity 4.40
A water-soluble amphoteric copolymer e and 1r of 0 CPS were obtained. This paper is called L (relative soft).

Production Example 3 A 10% aqueous solution of polyacrylamide (1.7 million yen) (412 (10 yk l) cooled at 5° CVC,
VC12% Sodium salt aqueous solution 18.6P, 48%
Mixture Arr & 16op consisting of seasonal Nuda 4.6y and water
It was added dropwise over a 30-minute session and maintained at Vc for 1 hour. During this time, the isthmus was kept at 2()°C. Then, the pH was adjusted to 4.5 KM with hydrochloric acid. In this way, a 6% hydroxyl solution (viscosity: 150 CPS) of an amphoteric acrylamide polymer containing 9.5 mol % of amide 7 groups (NHa) and 8.2 mol % of carboxyl groups was obtained. This is called Mine force cutting M (comparison).

Production example 4 Acrylamide 87.7y, acrylic acid 9.9y.

9.2 y of 48% caustic soda and 557 y of deionized water
After the entire charge was made, the mixture was heated to 45° C. under stirring while passing through a gas stream. Then 4 r/lt, m ammonium 0.
When 18y and 0.08yi of anhydrous sodium bisulfite were added, the Vc polymerization reaction immediately started and the internal slurry reached 9()℃. After keeping it temporarily for 3 hours, it was diluted with 333 ml of deionized water to give a solution with a nonvolatile content of 10%, a pH of 6.5, and a viscosity of 4300 CPS.
I got the water solubility of Kyoa union. This is referred to as paper strength agent N (IP, soft).

27- Production Example 5 Aqueous solution of commercially available polyamide polyamine epichlorohydrin resin (non-volatile content 10%, pH 4.5, viscosity 80 CP)
S) Complete preparation. This is defined as paper strength agent 0 (comparison).

Example pulp (L-BKP, beating degree 500m1C8F)
Talc'fr1 for 1 pulp in 1% aqueous slurry of
Tatsubi Standard Sheet-
The paper was made to have a paper strength of 150 ± 1y/rI11" using a thin paper. As the similar paper strength agent in E, select paper strength B, C, G or J in it1, and use the same or different paper strength. ?111 and after the addition of the sulfuric acid pad, respectively, were added using the buttons shown in Table 3 below.
After dehydrating with Ef for 5 minutes and drying at 100°C for 1 minute, it was conditioned at 20°C and 165% R11 for 24 hours.

Comparative Example 1 28 = In place of the paper strength agent used in Example 1 above, use any one of ntJ paper strength A, D to F, Hjl and -0 and carry out the same procedure, or use a 2-equivalent ratio. Use soft paper to sharpen straight acid.
Add h @iJ Do the same for each paper stock except adding only K? Obtained. The types, amounts and methods of use of the above paper strength agents are shown in Table 3 below.

-31- Each paper ladle obtained in the above-mentioned Taniko Example and Comparative Example was measured by the Uchida 9 strength and re-boat disassembly method. Regarding the above-mentioned valley fruit erosion examples and some comparative examples, the paper strength reduction ratio of one yarn of those ash grains, raw material yield, water resistance, and white water C
OD was measured according to the following method. The results obtained are all shown in Table 4 below.

Test method〉 Internal bond strength: Approximately manufactured by Tani Riiso Co., Ltd., internal bond
Tester L Internal bon(l test
Er.

Based on Tappi RC308HC.

Dissolve the re-encampment: An 1 [1 Seiiso (i < f: ) Dissolution is completed based on the month 5P8209 using the disengagement iso 1^1 in γ
Measure everything.

Paper strength reduction rate based on the Nikerdahl nitrogen analysis method.

Yield: Calculated using the following formula.

82-P Aqueous: According to Canadian Standard 7 Lines Destar.

118P8121) White water COD: For paper mill water, cumulative acid consumption by filtration of potassium manganate at 100'C (JIS K-+1102).

Claims (1)

[Claims] ■ The following (a) to d) are added to the pulp aqueous slurry.
A water-soluble amphoteric copolymer, a sulfuric acid band, and the following (at or d) '! A method for making paper, which is characterized in that paper is made after sequentially adding a water-soluble amphoteric copolymer which is the same as or different from the above as a monomer. (al 1 to 20 mol% of at least one selected from α, β-unsaturated monocarboxylic acids and alkali salts thereof, (b) General formula [where n is 2.3 or 4, R1 is a hydrogen atom or a methyl group] Arrangement K R2 and R3 are largely the same, and 1 is different from the alkyl group having 1 to 4 carbon atoms, or the nitrogen atom to which the box or the like is bonded. At least one cationic monomer selected from the represented acrylamide derivatives, acid addition salts thereof, and quaternary salts thereof (b-1) (7,) 1 g to 5 () mol%
In the general formula c, m is 1.2 or 3, R4 is a hydrogen atom or a methyl group, and K R' and R6 are largely the same or different and represent an alkyl group having 1 to 4 carbon atoms. At least one cationic monomer selected from acrylic acid esters, acid addition salts thereof and quaternary salts thereof, represented by [representing a 6-membered heterocyclic group] together with the nitrogen atom to which the or the like is bonded. Mixtures 1-2 with 50-90 mol% of (b-2)
0 mol%, (C) acrylamide 40-98 mol%, and (
d) Copolymerization with (a) or C) above;
and other 7-ionic monomers from 0 to 30 mol%.