CA2010690A1 - Amphoteric polyelectrolite and method for production thereof - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An amphoteric polyelectrolite represented by the general formula:

Description

AMPHO~ERIC POLYELECTROLITE 9 AND METHOD FOR PRODUCTION THEREOF

BACK~ROUND OF THE INVENTION
Field o~ the Invention:
This invention relates to a novel amphoteric polyelectrolite and a method for the production thereof.
The objects in which the amphoteric polyelectrolite of this in~ention finds utility include antistatic agent for synthetic ~ibers, synthetic resin film, and shaped article~
of synthetic resin; electroconductive agent for electrostatic recording papers and electrophotographic recording papers; yield impro~er for paper sheet filler;
paper strength enhancer; sizing agent; polymeric ~locculant and dehydrater for sewage and refuse disposal; dehydrater for ~arious colored waste waters including ~tained waste water; sequestrating resin for heavy metals and ion-exchange resin; component for such cosmetic goods as hair spray; rust preventiv~; fungicide; mildewproo~ing agent; and antifoggant~ for example.
Dsscr.iption of the Prior Art:
The amphoteric polyelectrolite which have been known to the art inolude:
(1) Products obtained by Mannich reaction and the like (Japanese Patent Laid-Open SHO 58t1983)-4,898 and Japanese Patent Laid-Open SHO 58(1983)-104,299), (2) Products obtained by Hoffman reaction (Japanese Patent Laid-Open SHO 55(1980)-6,556), (3) Products containing a quanternary ammonium group or a tertiary amine group a~ a cationic group in the molecular unit thereof (Japanese Patent Laid-Open-SHO 49(1974)-6,078 and Japanese Patent Laid~Open SHO 62(1987)-205,112), and the amphoteric polyelectrolite obtained by aminoalkylating reaction include:

Z()~69~

(4) Products aquated by aminoalkylating an acrylic ba~e polymer and neutralizing the residual acid thereof with an amine (Japanese Patent Publication SH0 55(1980)-35,422), ~nd (5) Productq obtained by aminoalkylating an acryl type base polymer with 1.0 to 1.1 equivalent weights, based on 1 equivalent weight of the acid of the base polymer, of an alkylene amine and possessing the average value of n of the suspended aminoalkyl group in the range of 1 to 1.2 (U.S.
Patent No. 3,372,149), for example.
Amphoterio polyele¢trolite have been heretofore obtained by these known techni~ues. Those produced by employing Mannich reaction and Hoffman decomposition reaction are not stable because of gelation, for exampleO
An amphoteric polyelectrolite containing mainly a quaternary ammonium group as a cationic component has been proposed as a paper strength enhancer. Though the u3ability of thi~
amphoteric polyelectrolite as a flocculant i3 mentioned in the pertinent patent specification, the polyelectrolyte i3 short of fulfilling the performanoe expected of the ~locculant. Moreover, the cationic monomer used therefor is expensive~ When a amphoteric polyelectrolite is produced by the known technique resorting to aminoalkylation7 it iq unstable and vulnerable to gelation.
Heretofore, the disposal of various plant effluents and the disposal of sewage and excrements have given ri~e to sludge of polymeric flocced and sedimented particle~ and excess sludge. As a dehydrater for the sludge of thi~ type, an organic flucculant has come to Pind utility. In the method~ for flocculation and dehydration of sludge, the method which resorts to exclusive addition of a cationic organic macromolecular flocculant and the method which resorts to simultaneous addition of a cationic organic polymeric flocculant and an anionic organic polymeric flocculant have been famous.
The method which relies on the sole addition of a cationic organic polymeric flocculant, however, is not fully ef~ective in disposing thoroughly of the sludge an~ ~rl~ ging about a satisfactory result in terms o~ cake content and speed of filtration, for example.
Further, in case o~ the method relying on combined use of a cationic organic polymeric flocculant and an anionic organic polymeric flocculant, though it possibly allows improvement in cake content and speed of filtration, it has a disadvantage that the operation thereo~
necessitates installation of a plurality of flocculant dissolYing tanks and flocculant reacting tanks, the equipment therefor is expensive, and the disposal of sludge calls for hea~y consumption of additives and boosts the cost of chemicals.
In recent years, a method has been proposed which uses a cationic organic macromolecular ~locculant and an anionic organic macromolecular flocculant as di3solved jointly in a solution with the pH of the solution controllQd as disclosed in Japanese Patent Publication SHO 60(1985)-43,800 and Japanese Patent Laid-Open SHO 58(1983)-216,706.
In the case of thi~ method, however, there is impo~ed a restriction on the kind of the cationic organic polymeric flocculant to be effectively usable for this method. Then, in the case of an amphoteric organic polymeric ~locculant using as a cationic component thereof a monomer oontaining a tertiary amine or a quaternary salt as disclosed in Japanese Patent Laid-Open SHO 62(1987)-205,112, a restriction is imposed on the balance of composition of the flocculant.
When an organic polymeric flocculant containing both a cationic and an anionic cumponent i~ u3ed a~ an organic sludge dehydrater 9 the dehydrated cake content is smaller than when a cationic ar an anionic flocculant is u3ed alone as di~closed in Japanese Patent Publication SHO 60(1985~-43,800, Japane~e Patent Laid-Open SHO 58(1983)-216,706, and Japanese Patent Laid-Open SHO 63(1988)--205,112. The use found for this flocculant, however, is limited.

2~ ;90 In the case of an amphoteric organic macromolecular flocculant ha~ing as a cationic component thereof a monomer containing a tertiary amine, since the balance of composition is limited, the value of equi~alent weight of cation, that of anion, and the equivalent weight ratio of cation/anion have their own limits. An amphoterioc organic sludge dehydrater which combines ability of flocculation and ability of dehydration remains yet to be developed.
An object of this invention, therefore, is to provide a no~el amphoteric polyelectrolite and a method for the production thereof.
SUMMARY OF THE INVENTION
The objects described above are accomplished by a amphoteric polyelectrolite represented by the general formula I:

~-CHz- f - ]a [- CH~ b L CH2 O(CH21H_I)nH~ntHY) ~4 R5 wherein n i9 an integer in ~he range of 1 to 5, providing the average value o~ n i9 not le~s than 2, a, b, and c are proportions ~uch that the sum; a ~ b ~ c is 1, or a ~ b is 1, R1, R2, ~3 and R4 are independently hydrogen atom or an alkyl group3 R5 is hydrogen atom, an alkyl group, or an alkyl group substituted with a ~-hydroxy group, HY is a monobasic acid, and Z i an amide group represented by the general formula II:

-CoNR6R7 (II) wherein R6 and R7 are independently hydrogen atom or an alkyl group, a hydroxyalkyl group represented by the general formula m:

L06~
--COzfH-FHOH (m) wehrein R8 and R9 are independently hydrogen atom or an alkyl group, or a nitrile ~roup represented by the general formula N:
-CN (IV) These objects are further accornplished by a method for the produotion of an amphoteric polyelectrolite possessing an aminoalkyl group and a carboxyl group, which method comprises either polymerizing in water at least one anionic monomer (i) sele~ted from the group consisting of acrylic acid and methacrylic acid or copolymerizing the anionic monomer (i) with a nonionic monomer (ii)7 causing an alkylene imine of an amount of not less than 1.2 mol~ per mol of the anionic monomer (i) to react on the resultant vinylic carboxylic acid polymer (iii) thereby aminoalkylating the polymer (iii), and sub~equently acidifying the aminoalkylated polymer with a monobasi¢ acid.
These objects are also a¢complished by an amphoterio polyeleotrolite having aminoalkyl ~roup and a carboxyl group and repre~ented by the general formula V:

[ CH2 - f ]d [-CH2- f, ~ CH2 f ]~ [ CH~_ C-l C-O COOH A B
(CH2fH-N)nH n(HY) (v) wherein n is an integer in the range of 1 to 5, d, e, f, and g are proportions such that the sum, d ~ e + ~ + g, is 1, or d + e ~ f is 1, R1, R2, R3, R4 and R10 are independently hydrogen atom or an alkyl group, R5 is hydrogen atom, an alkyl group, or an alkyl group substituted zo~9o with a ~-hydroxy group, HY is a monobassic acid, A is an ester group represented by the general formula Vl:
-C02R 1 1 ( Vl ) wherein R11 is an alkyl group, an aromatic group, or an alicyclic group, an unsubstituted or a p-substituted phenyl group represented by the general formula ~:

~R12 (V~

wherein R12 is hydrogen atom, an alkyl group, or a hydroxy group, or a nitrile group represented by the general formula lV :
CN (IV) B is an amide group represented by the general formula 11:
-CoNR6R7 (Il) wherein R6 and R7 are independently hyrogen atom or an alkyl group, a hydroxyalkyl group represented by the general formula m:
-CO21H-fHOH

wherein ~8 and R9 are independen~ly hydrogen atom or an alkyl group, or a nitrile group represented by the general formula N:
-CN (~) These objects are accomplished by a method for the production of an amphoteric polyelectrolite having an aminoalkyl group and a carboxyl group, which method comprises either emulsion polymerizing in water at least one anionic monomer (i) selected from the group consisting of acrylic acid and methacrylic acid and a nonionic monomer (iv) corresponding to A in the general formula V to be added for the purpose of emulsification or -effecting in water the emulsion polymerization in the presence of a nonionic monomer (v) corresponding to B in the general formula V, Z0~L069~) causing an alkylene imine to react on the resultant vinylic carboxylic acid polymer emulsion (vi) thereby aminoalkylating the polymer emulsion, and subsequently acidifying the aminoalkylated polymer emul~ion with a monobasic acid.
These object~ are further accomplished by a water-in-oil type amphoteric copolymer emul~lon oontaining an amphoteric polylelectrolite represented by the general t`ormula ~:
R1 R2 ~3 [-C~2- I-]a [ CH2- f - ]b [ CH2- I-]c C-O COOH Z
(vm) O(CH2fH-N)nH n(HY) wherein n is an integer in the range oY 1 to S, providing the average value of n is not less than 2, a, b, and c are proportions ~uch that the ~um, a + b ~ c iq 1 or a ~ b is 1, R1, R2, R3, and R4 are .independently hydrogen atom or an alkyl group, R5 is hydrogen atom, an alkyl gr-oup, or an alkyl group substituted with a ~-hydroxy group, HY i~ a monobasic acid, and Z i9 an amide group represented by the general formula 11:
-CoR6R7 ~II) wherein R6 and R7 are independently hydrogen atom or an alkyl group, hydroxyalkyl group represented by the general formula m:

--C02fH-CHOH (~

wherein R8 and R9 are independently hydrogen atom or an alkyl group, a nitrile group represented by the general formula N
-CN ~N) ~ L069~
or an ester group represented by the general formula ~:
-CO2R10 (~) wherein R10 is an alkyl group, an aromatic group, or an alioyclic group.
These objects are also accomplished by a method for the production of a water-in-oil type amphoteric polyelectrolite emulsion having an aminoalkyl group and a carboxyl group, which method comprises emulsifying either at least one anionic monomer (i) selected from the group consiqting of acrylic acid and methacrylic acid or a mixture of the anionic monomer ti) with a nonionic monomer (ii) in water-in-oil form in the presence of water, a surfaotant, and a hydrophobic organic solvent, causing an alkylene imine to react on ~he resultant water-in-oil form vinylic carboxylic acid emulsion (vii) resulting from the polymerization or copolymerization by the use of a radical polymerization catalyst thereby aminoalk~lating the emulsion, and subsequently acidifying the amlnoalkylated emulsion wiSh a monoba~ic acid.
The amphoteric polyelectrolite o~ this lnventior finds utility for antistatic agent for synthetic fibers, synthetic resin film~ and shaped articles of synthetic resin; electroconduotive agent for electrostatic recording papers and electrophotographic recording papers; yield improver for paper sheet filler; paper strength enhancer;
sizing agen~; macromolecular flocculant and dehydrater for sewage and re~use disposal3 dehydrater for various colored waste waters including stained waste water; sequestrating resin for heavy metals and ion-exchange resin; component for such cosmetic goods as hair spray; rust preventive;
fungicide; mildewproofing agent; and antifoggant, for example.
EXPLANATION OF THE PREFERRED EMBODIMENT
First, the amphoteric polyelectrolite represented by the general formula I will be described below. The subscript, n, is an integer in the range of 1 to 5, ;~0~ 90 preferably 1 to 3, providing that the average value of n precede 2 and preferably falls in the range of 2 to 3. The proportions of a, b, and c are such that the 3um a ~ b + c is 1 or a ~ b is 1 and the ratio a : b : c is in the range of 0.2-0.999: 0,001-0.2:0-0.6, preferably 0.4-0.99:0.01-0.1:0-0.5 R1, R2, ~3, and R4 are independingly hydrogen atom or an alkyl group. The number of carbon atoms of the alkyl group is preferable to fall in the range of 1 to 2. R5 i~
hydrogen atom, an alkyl group, or an alkyl group substituted with a ~-hydroxy group. The number of carbon atoms of the alkyl group is preferable to fall in the range of 1 to 2.
NY is a monobasic acid.
Z is an amide group represented by the general formula II, -CoNR6R7? a hydroxyalkyl group represented by the general formula ~, --C02fH-CHOH

,or a nitrile group represented by the general formula ~, -CN. R6, ~7, R8, and R9 are independently hydrogen atom or an alkyl group. The number of carbon atoms of the alkyl group is preferable to fall in the range of 1 to 2.
The amphoteric polyelectrolite represented by the general formula I is produced by either polymerizing in water at least one anionic monomer (i) selected from the group consisting of acrylic aoid and methacrylic acid or copolymerizing the anionic monomer (i) with a nonionic monomer (ii), causing an alkylene imine of an amoun't of not leqs than 1.2 mols per mol of the anionic monomer (i) to react on the resultant vinylic carboxylic acid polymer (iii) thereby aminoalkylating the polymer (iii3, and subsequently acidifying the aminoalkylated polymer with a monobasic acid.
The anionic monomer (i) is preferable to be acrylic acid or methacrylic acid~ The nonionic monomer (ii) is required to be selected in consideration of the )69~
characteristic of acid dissociation. The acid dissociation indexes of acrylic acid and methacrylic acid at 25C are 4.3 and 4.7 respectively. Though acrylic acid or a salt thereof in water of a pH value of not more than 4.3 or meth~crylic acid or a salt thereo~ in water of a pH value of not more than 4.7 assumes ionic form, the proportion of its ion sharply decreases below the indicated pH value. The monomers both are in ~ubstantially undissociated form in water of a pH value of not more than 3.5. Xn the case of an anionic monomer possessing a sulfonic acid group of a small dissociation acid index, since the amount of ion ~eeds present is large even in a low pH region approximately in the range of 2 to 3, the outstanding effect of this invention cannot be attained by using this monomer.
The nonionic monomer ~ii) may be any nonionic monomer copolymerizable with the monomer (i) mentioned above. For example 7 a vinylic monomer possessing an amide group represented by the general formula X can be used.

R3-C-C -N /R7 tX) Il \R
o In the general formula X, ~37 R6, and R7 are independently hydrogen atom or an alkyl group as described aboveO The vinylic monomers of the general formula X
include acrylamide, methacrylamide, N,N-dimethyl acrylamide, N,N-dimethyl methacrylamide, N,N-diethyl acrylamide, and N,N-diethyl methacrylamide, for example.
A vinylic monomer possessing a hydroxyalkyl group repre~ented by the general formula XI is also usable.

In the general formula XI~ R3, R8, and R9 are independently hydrogen atom or an alkyl group. The vinylic monomers of the general formula XI include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, CH2 2(~10690 Il Il ~8 R9 (XI) and hydroxypropyl methacrylate, ~or example. Acrylonitrile and methacrylonitrile may be also cited.
It should be noted that the nonionic monomer (ii) is used herein ~or the purpose of adjusting the molecular weight and ion equi~alent weight of the macromolecular ampholyte. Generally, it is preferable to account for a proportion in the range of 0 to 60 mol%, preferably 0 to 50 mol%, in the vinylic carboxylic acid polymer (iii).
In the production of the amphoteric polyelectrolite by the method of this invention, the amount o~ the anionic monomer (i) and that of the nonionic monomer (ii) to be used in the polymerization of the vinylic carboxylic acid polymer (iii) must be fixed so that the produced amphoteric polyelectrolite may acquire a cation equivalent weight value, Cv, in the range o~ 0.8 to 7.0 me~/g, an anion equivalent weight value, Av, in the range o~ 0.1 to 4.0 meq/g, and a Cv/Av ratio in the ran~e of 1.0 to 25Ø
Further, preparatory to the aminoalkylation, it is necessary to fix the amounts of the vinylic carboxylic aci~
polymer (iii) and the alkylene imine to be used for the aminoalkylation.
If the cation equivalent weight value, Cv, is less than 0.8 meq/g, the produced amphoteric polyelectrolite manifests its characteristics only with difficultyO If the cation equivalent weight value, Cv, exceeds 7.0 meq/g, the produced amphoteric polyelectrolite does not ea~ily manifest its characteristics. If the anion equivalent weight value, Av, is less than 0.1 meq/g9 the produced amphoteric polyelectrolite manifests its characteristiQs only with difficulty. Conversely, if the anion equivalent weight value, Av, exceeds 4.0 meq/g, there arises a disadvantage 9~
that the produced amphoteric polyelectrolite tends to quffer a decrease in its solubility in water.
If the Cv/Av ratio is less than 1.0 and the anion equivalent weight value is unduly large proportionately, there ensues a disadvantage that the effect of the cationic group i9 degraded. If the Cv/Av ratio exceeds 25 and the proportion of the anionic group is unduly small ? the produced amphoteric polymer cannot be expeoted to manifest its action sufficiently.
Preparatory to the initia~ion of the polymerization in this invention, the total amount of` the anionic monomer (i), the nonionic monomer (ii), and the vinylic carboxylic acid polymer (iii~ (hereinafter re~erred to as "total amount of monomersl'3 in the aqueous solution is pre~erable ~o account for a concentration approximately in the range of 10 to 80% by weight. If this concentration i~ less than 10% by weight, there is a disad~antage that the productivity of the polymerization is inferior. Conversely, if this concentration exceeds 80% by weight, there iq a disadvantage that the polymerization produoes a large amount of heat and the temperature of the polymerization system rises excessively.
During the production of the vinylic carboxylic acid polymer (iii) by the polymeri~ation in water of at least one anionic monomer (i) selected from the group con~isting of acrylic acid and methacrylio acid or the copolymerization of the anionic monomer (i) with the nonionic monomer (ii), it is permissible to use, when necessary, a radical polymerization initiator of the redox type or the azo type, for example. The redox type polymerization initiator~
include combinations between such oxidizing agents as ammonium persulfate, potassium persulfate, hydrogen peroxide, and cumene hydroperoxide and such reducing agents a~ formaldehyde sodium ~ulfoxylate, thioglycolic acid, L-ascorbic acid, dimethylaminopropionitrile, sodium hdyrogen sulfite, ~-mercapto ethanol, and divalent iron salts, for 069~
example. The azo type polymerization initiators usable herein include azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis(2,4-dimethylvaleronitrile), and 4,4'-azobis(4-cyanopentanoic acid) 7 for example. It is permissible to use a redox type polymerization initiator and an azo type polymerization initiator in combination. The amount of the polymerization initiator is in the range of 0.001 to 10 ~ by weight, preferably 0.01 to 5 % by weight, based on the total amount of monomers.
The polymerization may be carried out in an adiabatic qystem, with the initial polymerization temperature kept approximately in the range of 10 to 4~C.
The sheet polymerization method may be used in properly modified form, with the polymeri~ation temperature externally controlled at a fixed level approximately in the range of 30 to 100C, preferably 40 to 80C .
Though the polymerization time i~ variable with the concentration of monomers, the polymerization temperature~
the polymerization degree aimed at~ and the like, it i~
generally in the range of 10 minutes to 10 hours, preferably 1 to 7 hours.
The aminoalkylation reaction can be carried out by cau~ing an alkylene imine to react on the vinylic carboxylic acid copolymer (iii). Preferably, the aminoalkylation reaction is carried out at a temperaturs not exceeding about 65C~ preferably falling approximately in the range of 35 to 55C.
The aminoalkylation is effected by causing reaction of the acid group of the vinyl type carboxylic acid polymer (iii) with the alkylene imine as indicated below. The reaction with 1,2-alkylene imine, for example, i~ indicated by the following general formula.

6~C~
-C -OH ~ H2C- CH-R4 l N

-C -O-CH2- CH-R4 _ f _o_fH - IH2 o NH or O R NH

In the formula, R4 is hydrogen atom or an alkyl group and R5 is hydrogen atom, an alkyl group, or an alkyl group sub~tituted with a ~-hydroxy group.
The alkylene imine for exchanging the free carboxyl group of the vinylic polymer for an aminoe3ter group is a 1,2-alkylene imine (aziridine). Among other 1,2-alkylene imines, 1,2-propylene imine and ethylene imine prove to be particularly desirable because of their ready availabilîty and relatively low prices. Optionally, n-alkyl-~ub~tituted or unsubstituted l,3~alkylene imine~ ~azetidine) are u~able because their imine~ 9 in forming an aminoester group 9 exhibit chemical reactivity and other properties similar to those o~ 1,2-imin0s. Such compounds u~able herein include 2-methyl aziridine, 2-ethyl aziridine, 2-n-propyl aziridine 9 2 i~opropyl aziridine, 2-n-butyl aziridine, 2-isobutyl aziridine; 2-sec-bu~yl aziridine, 2-(1-methylbutyl) aziridine, 2(2-methylbutyl) aziridine, 2-(3~methylbutyl) aziridine, 2-n-pentyl aziridine, 2-(methylpentyl) aziridina, 2-(methylpentyl) aziridine, 2-(4-methylpentyl) aziridine, 2(3-ethylpentyl) aziridine, 2-(2-isopropylpentyl) aziridine, 2-n-hexyl aziridine, 2-n-(heptylaziridine), 2-n-octyl aziridine, 2,3-dimethyl aziridine 9 2,3-di(2-methylbutyl) aziridine, 2-ethyl-3-n~hexyl aziridine, 3-n-octyl-3-propyl aziridine, 2-hydroxyethyl aziridine, and azetidine~
corresponding thereto such as, for example, 2-methyl azetidine, 2-ethyl azetidine, 2-n-propyl azetidine, 2,4-2~06~30 dimethyl azetidine, 2,4-dioctyl azetidine, and 2,3-di(2-methylbutyl) azetidine, for example.
Ths acidification of a suspended aminoalkyl group i5 effected with a monobasic acid, which is used in an amount in the range of 50 to 100 mol% (preferably 60 to 90 mol~), based on the amount of the added alkylene imine. The addition of the monobasic acid to the reaction system i~
carried out either collectively or peacemeal during the course of the aminoalkylation. The monobasic acid is selected from among hydrochloric aicd, nitric acid, etc.
Specifically to effect the aminoalkylation, the vinylic carboxylic acid polymer (iii) and the alkylene imine added thereto in an amount of 50 mol~., based on the mol equivalent of the aninonic monomer (ii) contained in the polymer (iii) are stirred for a period in t~e range of 5 to 60 minutes. Then ? the resultant mixture and a neutral acid added thereto in an amount proportionate to the amount of the alkylene imine added are stirred continuously for a period in the range of 5 to 60 minutes. To the stirred mixture, the remaining part of the alkylene imine is gradually added over a period in the range of 5 to 60 minutes. Thereafter, the resultant mlxture and the remaining part of the neutral acid added thereto are stirred for a period in the range of 5 to 60 minutes. During the course of the reaction, the reaction temperature must be kept at a level in the range of 30 to 65C, preferably 35 to 55C.
If the reaction temperature exceeds 65C, the reaction mixture is gelled during the course of the reaction and the product of the reaction is opacified with suspended insoluble particles. Conversely, if the temperature is le~
than 30C, the reaction itself becomes meaningless because the reaction time is elongated infinitely.
In the production of the amphoteric polyelectrolite by the method of this invention, not only the cation equivalent weight value and the anion equivalent weight 20~69~
value mentioned above but also the molecular weight i~
preferable to be suitably controlled. The composition of the component monomers~ the polymerization time, and the like are preferable to be suitably set so that thi~
molecular weight a~ expressed by the molecular weight of the vinylic carboxylic acid polymer (iii) may be in the range of 10,000 to 1,000,000, preferably 100,000 to 800,000~
By carrying out the polymerization in water and ths reaction under the conditlons mentioned above, there is obtained an aqueous solution of the amphoteric polyelectrolite.
The amphoteric polyelectrolite represented by the general formula VIII is in the Eorm of water-in-oil type amphoteric copolymer emulsion. This emulsion is produced by emulsifying in water-in-oil form either the anionic monomer (i) or the mixture of the anionic monomer with the nonionic monomer ~ii) in the presence of water, a surfactant, and a hydrophobic organic sol~ent, then polymerizing or copolymerizing the emulsi~ied monomer or monomers through the agency of a radical polymerization cataly~t thereby producing a water--in-oil form vinyl type carboxyllc acid emulsion (vii), causing the alkylene imine to reactor on the carboxylic acid emulsion thereby aminoalkylating it, and subsequently acidi~ying the aminoalkylated emulsion with the monobasic acid.
The anionic monomer (i) i9 used as already described. The anionic monomer (i), however, is preferable to be used as neutralized with a b~ae such as, for example, sodium hydroxide, potassium hydroxide, or ammonia. The neutralization ratio of the anionic monomer (i) in this case i3 in the range of 5 to 100 mol%, preferably 20 to 95 mol%.
The compounds which are usable as the nonionic monomer (ii) include, in addition to the compound~
represented by the aforementioned general formulas X and XI
and acrylonitrile and mechacrylonitrile, the compounds repre~ented by the following general formula XII.

R~-C - C -O-R10 (XII) wherein R3 ishydrogen atom or an alkyl group and R10 is an alkyl group, an aromatic group, or an alicyclic group, providing that the number of carbon atoms of the alkyl group is in the range of 1 to 6, the number of carbon atom~ of the aromatic group in the range of 6 to 9, pre~erably 6 to 8, and the number of carbon atoms of the alicyclic group in the range of 4 to 8, preferably ~ to 7. The compound~ o~ the general formula XII include methyl acr~late, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, cyolohexyl methacrylate, and phenyl methacrylate, for example.
The nonionic monomer (ii) i~ used herein for the purpose of adjusting the molecular weight and ion equivalent weight of the water-in-oil type amphoteric ¢opolymer emul~ion.
For the water-in-oil type amphoteric type copolymer emulsion to be produced b~ the method of this invention, the amounts of the anionic monomer (i) and the nonionic monomer (ii) to be u~ed during in the polymerization of the water~
in-oil form vinylic carboxylic acid polymer emulsion (iv) must be fixed so that the produced copolymer emulsion may acquire a cation equivalent weight value, Cv, in the range o~ 0.8 to 10.0 meq/g, and an anion equivalent weight ~alue, Av, in the range of 0.1 to 6.0 meq/g.
When at least one anionic monomer (i) ~elected from the group consiqting of acrylic acid and methacrylic acid or a mixture of the anionic monomer (i) with a nonionic monomer (ii) is to be emulsified in water-in-oil form in the presence of water, a surfactant, and a hydrophobic organic 2~ 69() solvent, the surfaotant may be a nonionic surfactant in popular use. The nonionic surfactants which are usable herain include sorbitan monooleate, sorbitan monostrearate, sorbitan monolaurate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbin monolaurate, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, glycerol monostearate, and glycerol monooleate, ~or example. These nonionic surfactants may be used either singly or in the form o~ a mixture of two or more members~
Optionally, the nonionic surfactant may be used in combination with an anionic and a cationic surfactant of ordinary grade.
The hydrophobic organic solvents which are usable herein include hydrophobic aliphatic and aromatic hydrocarbons, ~egetable and animal oils, and modified products of such oils, for example. Typical examples are normal paraffin, isoparaffin, cyclohexane, toluene, xylene, kerosine, mineral oils, and lamp oil, eto.
The total amount of the anionic monomer (i) and the nonionic monomer (ii~ to be used herein ls preferable to account ~or a corcentration in the range of 20 to 80~ by weight, based on the amount of water. The concentration o~
the sur~actant to be used is preferable to be in the range of 5 to 30% by weight~ based on the amount of the hydrophobic organic solvent. The ratio of the hydrophobic organic solvent to the water is in the range of 1 : 10 to 10 :1, preferably 1 : 5 to 3 : 1.
When the water-in-oil form monomer emulsion obtained by emulsifying in water-in-oil form at least one anionic monomer (i) selected from the group consisting of acrylic acid and methacrylic acid or a mixture of the anionic monomer (i) with a nonionic monomer ~ii) in the presence of water, a surfactant, and a hydrophobic organic solvent i9 to be polymerized or copolymerized, a redox type or azo type radical polymerization initiator may be used as occasion ZO~)69~:D
demands. The kinds of the redox type and azo type radical polymerization initiator and the amount of addition of the radical polymerization initiator are as already described.
It is also permissible to add to the polymerization system a well-known chain transfer agent such as isopropyl alcohol, erythorubic acid, or 2-mercapto ethanol.
The polymerization temperature is preferable to be externally controlled, during the initial phase of the polymerization, in the range of 10 to 60C, preferably 20 to 60C and, during the normal phase of the polymeri~ation, in the range of 30 to 100C, preferably 40 to 80C.
Though the polymerization time is variable with the concentration of monomers, the polymerization temperature~
and the polymerization degree aimed at, for example 9 it is generally in the range of 10 minutes to 10 hours, preferably 1 to 7 hours.
The reaction of aminoalkylation can be effected by causing an alkylene imine to react on the water-in-oil form vinylic carboxylic acid polymer emulsion (iv).
Preparatory to the aminoalkylatlon, it is necessary to fix the amounts of the water-in-oil form vin~lic carboxylic aoid polymer emulsion (iv) and the alkylene imine to be used.
If the cation equivalent weight value, C~, is less than 0.8 meq/g, the produced amphoteric macromolecule manifests its characteristics only with difficulty. If the cation equivalent weight value, Cv, exceed~ 10.0 meq/g, the produced amphoteric polyelectrolite does not easily manifest its characteristics. If the anion equivalent value, Av, is less than 0~1 meq/g, the produced amphoteric macromolecule manifests its characteristics with difficulty. If the anion equivalent weight value, Av, exceeds 6.0 meq/g, there is disadvantage that the produced amphoteric polyelectrolite tends to exhibit inferior ~olubility in water.
The acid group of the water-in-oil form vinylic carboxylic acid polymer emulsion (iii) is cau~ed to react 201~90 with the alkylene imine in the conventional manner indicated below for the aminoalkylation. The reaction with a 1,2-alkylene imine is performed as already described. Typical examples of the alkylene imine and the amount of the alkylene imine to be used are as already de~cribed. The reaction of aminoalkylation i9 per~ormed as already described.
For the water-in-oil form amphoteric copolymer emulsion to be obtained by the method o~ this invention, it is preferable to control suitably t;he molecular weight thereof in addition to the cation equivalent weight and the anion equivalent weight value mentioned above. With intrinsic viscosity as an index to molecular weight, the composition of the component monomers, the polymerization conditions, etc. are preferable to be suitably set so that the produced water-in-oil form amphoteric copolymer emul~ion may aquire intrinsic viscosity [~] in the range of 0.1 to 25, preferably 1 to 15.
Now, the amphoteric polyelectrolite repre~ented by the general formula V will be described. The subscript n i9 an integer in the range o~ 1 to 5, preferably 2 to 3. The proportions d, e, f, and g are such that the sum, d + e ~
P ~ g? or d + e -t f is 1, is 1 and the ratio, d : e : f :
g~ is 0.2-0.999: 0.001-0.2~ 0.01-0.2: 0-0.8, pre~erably 0.4-0.99: 0.01 0.1: 0.1-0.2: 0-0.7. R1, R2, R3 and R10 are independently hydrogen atom or an alkyl group, providing that the number of carbon atoms of the alkyl group i~ in the range of 1 to 2. R5 is a hydrogen atom, ~n alkyl group, or an alkyl group substituted with a ~-hydroxy group, providing that the number of carbon atoms of the alkyl group i~ in the range of 1 to 6, preferably 1 to 3. HY is a monobasic acid. A is an ester group represented by the general formula VI, -C02R11 wherein R~ an alkyl group, an aromatic group, or an alicyclic group, providing that the number of carbon atoms of the alkyl group is in the range of 1 to 6, preferably 1 to 3, the number of carbon atoms of the aromatic group in the range of 6 to 9, preferably 6 to 8, and the number of carbon atoms oP the alicyclic group in the range of 4 to 8, preferably 5 to 7, an unsubstituted or p-substituted phenyl group represente~ by the general formula ~m _~R12 (~) wherein R12 is hydrogen atom, an alkyl group, or an hydroxide hydroxyl group, providing that the number of carbon atoms of the alkyl group is in the range o~ 1 to 2, or a nitrile group represented by the general formula IY. B
stands for an ester group represented by the general formula III or a nitrile group represented by the general formula IV.
The ampho~eric polyelectrolite represented by the general formula V is produced by either e.mulsion polymerizing in water at least one anionio monomer (i) selected from the group consisting of acrylio aoid and methacrylic acid and a nonionic monomer (iv) aorre~ponding to A in the general ~ormula V to be added to the anionic monomer (i) for the purpose of emulsification with the anionic monomer or e~fecting this emulsion polyemerization in water in the presence of a nonionic monomer (v) corresponding to B in the general ~ormula V 9 aminoalkylating the resultant vinylic carboxylic acid polymer emulsion (vi) ~by the reaction thereof with an alkylene imine, and subsequently acidifying the aminoalkylated polymer emulsion with a monobasic acid.
The anionic monomer (i) to be used herein is as already described.
The nonionic monomer (iv) may be any nonionic monomer which is emulsifiable and, at the same time, copolymerizable with the aforementioned monomer (i). The nonionic monomers which are usable herein include vinylic monomers pos~e~ing an ester group repre~ented by the general formula Xll. Typical examples are as alr2eQ ~ ~ d.
Further, vinyl compounds posses~ing an unsubstituted or p-substituted phenyl represented by the general formula ~ m:

R~C~R12 ( X 111 ) wherein R3 and R12 have the meanings defined above, are also usable~ Typical examples are styrene, p-methylstyrene~ and p-vinylphenol. Acrylonitrile may be cited as another example.
The nonionic monomer (v) is used herein for the purpose of enabling the vinylic carboxylic acid polymer emulsion (vi) to be obtained as an emulsion po~se~sing low viscosity and allowing an increase in molecular weight.
Generally it is added in an amount of not more than 20 mol%, based on the amount of the vinylic carboxylic acid polymer emulsion (vi). If this amount exceeds 20 mol%, there ari~es a disadvantage that the produced amphoteric polyelectrolite exhibits inferior solubility in water.
As the nonionic monomer (v), any o~ the nonionic monomers which are copolymeriæable with the aforementioned monomers ~i) and (iv) can be used. These nonionic monomers include the vinylic monomers possessing an amide group a~
represented by the general formula X and the vinylic monomers possessing a hydroxyalkyl group a repre~ented by the general formula XI, for example. Typical examples o~
these monomers are as already cited. Besides, acrylonitrile and methacrylonitrile are also usable.
The nonionic monomer (v) is used for the purpose of adjusting the molecular weight and ion equivalent weight of the amphoteric polyelectrolite. Generally, it is preferable to be u~ed in an amount of not more than 70 mol~ based on the amount of the vinyl type caboxylic acid polymer emulsion (vi) .
For the amphoteric polyelectrolite to be produced by the method of this invention, it is necessary to fix the -~2-20~)6~0 amounts of the anionic monomer (i) and the nonionic monomers ~iv) and ~v) to be used in the polymerization of the vinylic carboxylic acid polymer emulsion (vi) so that the produced amphoteric polyelectrolite may acquire a cation equivalent weight value, Cv, in the range o~ 0.8 to 10.0 meq/g and an anion equivalent weight value, Av, in the range of 0.1 to 6.0 meq/g. The amounts of monomers [the total amount of the anionic monomer (i) and the nonionic monomers (iv) and (v) (hereinafter referred to as "total amount of monomers")] are preferable to account for a concentration approximately in the range of 10 to 80% by weight. If the concentration i~
less than 10~ by weight, there arises a di~advantage that the polymerization betrays poor productivityO Conversely, if the concentration exceeds 80~ by weight, there ensure at disadvantage that the polymerization generates a large volume of heat and the polymerization system suffers from undue rise of temperature.
In emulsion polymerizing in water at least one anionic monomer (i) selected from the group consisting of acrylic acid and methacrylio acid and a nonionic monomer (iv) correqponding to A in the general ~ormula V to be added for the purpose of emulsification with the anionic monomer or in effecting the emulsion polymeri~ation in the presence of a hydrophilic nonionic monomer (v) corresponding to B of the general formula V, it is permissible to use a surfactant Por the purpose of ensuring thorough di~persion of the monomers (i), (iv), and (v). Though the surfactant to be used is not ~pecifically defined, it is preferable to possess relatively high hydrophylicity enough for the formation of an 0/W ~orm emulsion in consequence of the emulsification. The surfactants which are usable herein for this purpose include nonionic surfactants such polyoxyethylene nonylphenyl ether and polyoxyethylenestearyl ether, anionic surfactants such as sodium lauryl sulfate and polyoxyethylene nonylphenyl ether sodium sulfate, and cationic surfactants such as stearyl amine acetate and 2C~1069~
stearyl trimethyl ammonium chloride, for example. The amount of the surfactant to be used is in the range of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the total amount of monomers.
In the production of the vinylic carboxylic acid polymer emulsion (vi), it is permissible to use a redox type or azo type radical polymerization initiator, as occasion demands. The kinds of the polymerization initiator and the amount of the polymerization initiator to be used are as already described.
The polymerization temperature i~ required to be controlled externally, during the initial phase of the polymerization, in the range of 10 to 40C, preferably 20 to 40C, and, during the normal course of the polymerization, in the range of 30 to 100C, preferably 40 to 80C.
Though the polymerization time is variable with the concentration of the monomers, the pol~merization temperature, and the polymerization degree aimed at, for example, ik is generally in the range of 10 minute~ to 10 hours, pre~erably 1 to 7 hours.
Preparatory to the reaction of aminoalkylation, it i~ necessary to ~ix the amounts of the vinylic oarboxylic acid polymer emulsion (Yi) and the alkylene imine.
I~ the cation equivalent weight value, Cv, is les~
than 0.8 meq/g, the produced amphoteric polyelectrolite does not manifest its characteristics easily. Conversely, if the cation equivalent weight value, Cv, exceeds 10.0 meq/g, the characteristics expected of the produced amphoteric polyelectrolite do not easily manifest themselves~ If the anion equivalent weight value, Av, is less than 0.1 meq/g, the produced amphoteric polyelectrolite mani~ests its characteristics only with difficulty. I~ this ~alue exceeds 6.0 meq/g, there is a disadvantage that the produced amphoteric polyelectrolite tends to exhibit inferior solubility in water.

Z~06go The aminoalkylation can be carried out by causing the vinylic carboxylic acid copolymer emulsion (vi) to be acted upon by an alkylene imine.
Specifically, the aminoalkylation i~ conventional manner as described above between the carboxylic acid group of the vinylic carboxylic acid polymer emulsion (vi) and the alkylene imine~ The typical examples of the alkylene imine and the amount of the alkylene imine to be used are a~
already described~ The conditions ~or the aminoalkyl~tion are also as described above.
In the production of the amphoteric polyeleotrolite by the method o~ this invention, it is pre~erable to control suitably the molecular weight thereof in addition to the cation equivalent weight value and the anion equivalsnt weight value mentioned above. With intrinsic viscosity a~
an index to molecular weight, the composition of the component monomers, the polymerization conditions, etc. are pre~erable to be suitably set so that the produced amphoteric polyelectrolite may acquire intrinsic viscosity ~] in the range oY 0.1 to 25, preferably 1 to 15.
By carrying out the polymerization and reaction in water under the conditions described above, the amphoteric polyelectrolite can be produced~
Now, the present invention will be described more specifically below with reference to working examples. It should be noted, however, that the present invention is not limited in any sense by these examples.
In the following Examples and Controls, the abbreviation are as follows:
AA~ acrylic acid AAm: acrylamide HEA: 2-hydroxyethyl acrylate AN: acrylonitrile MAm: methacrylamide AI: alkylene imine EI: ethylene imine )6~1 PI: propylene imine St: styrene MA: methyl acrylate BA: butyl acrylate MMA: methyl methacrylate MAA: methacrylic acid Referential Examples 1 to 6 [Production of vinylic carboxylic acid polymer (iii)~
A varying vinylic carboxylic acid polymer (iii) was obtained by placing in a reactor a mixture compri~ing monomers of amounts forming an indicated weight ratio and totalling a proportion of 20% by weight, di~placing the air en~rapped in the reactor with nitrogen ga~, and e~fecting polymerization of the monomer mixture by keeping the monomer mixture at 50C and adding thereto 0.2% by weight each, based on the total amount of monomers, of ammonium per~ulfate (APS) and sodium hydrogen sul~ite (SB).

Tablel _--~
Referential Compo3ition ratio of monomers E~ample ., _ , , ~
1 AAtAAm = 100/0 2 AA/AAm = 80/20 _ _ _ 3 AA/AAm = 60/40 4 AA/HEA = 60/40 AAlAAmlAN = 6313515 6 AA/MAm = 60/40 . __. ____ Exampl~ 1 In a reactor, 1,000 g of the vinylic carboxylic acid polymer ~ynthesized in Referential Example 1 wa9 placed, heated to 50C, kept at this temperature throughout the whole course o~ reaction and, after dropwise addition of 59.7 g of ethylene imine thereto, ~tirred with the added 2~0~g~
ethylene imine for 30 minutes. The amount of the ethylene imine thus added dropwise to the polymer accounted for 50 mol%, based on the mol equivalent of the carboxylic acid in the charged vinylic carboxylic acid polymer. Then, the resultant reaction mixture was stirred for 30 minutes with 143 g of an aqueous 61 wt% nitric acid solution, i.e. an amount proportionate to the amount of the dropwise added ethylene imine. The ensuant mixture was stirred for 30 minutes with the balance, or 140.3 g, of ethylene imine.
The resulting mixture, after dropwise addition thereto of 193 g of an aqueous 61 wt% nitric acid solution, was stirred with the aqueous solution for 30 minutes, to obtain an amphoteric polyelectrolite. The reaction conditions involved herein and the appearance of the reaction product were as shown in Table 2.
Examples 2 to 9 The procedure of Example 1 was repeated, except that the conditions indlcated in Table 2 were used instead. The physical properties of the reaction product~ were as ~hown in Table 2.
Controls 1 to 5 The procedure of Example 1 was repeated, except that the conditions indicated in Table 2 were used instead. The physical properties of the reaction products were as shown in Table 2.
The cation equivalent weight values, the anion equivalent weight values, and the average values of n indicated in Table 2 were determined by the following methods (which similarly apply hereinafter).
(1~ Cation equivalent weight value Thi~ property was determined by placing 95 ml of distilled water in a beaker, adding thereto 5 ml of a solution of 1,000 ppm of a given sample, adju~ting the pH
value of the resultant solution to 7.0 by addition of either 1% HCl or 1% NaOH, qtirring the solution for about 1 minute, then adding two or three drops of toluidine blue indicator 069~
solution, and titrating the ~olution with N/400 PVSK
(polyvinyl sulfate potassium solution) at intervals of 2 ml.
The time at which an interval of at least 10 seconds elapsed after the color of the sample water had changed from blue to reddish purple was taken as the end point of thi~ titration.
Cation equivalent weight value (CY) (meq/g) =
(Amount of titrant [ml] for sample - amount of titrant [ml] for blank) x F/2 x (concentration o~
effective component (ppm) in sample) The term "effective component" as used herein refer~
to the component remaining after removal of neutralizing acid from the solids of the sample.
(2) Anion equivalent weight value This property was determined by placing 50 ml of distilled water in a beaker, adding thereto about 0.3 g of accurately weighed sample, stirring the resultant solution, and titrating this solution with a N/10 NaOH solution to obtain the scale reading of electrocondcutivity. l'he ~cale reading of titration oorresponding to the last (the point at which neutralization of the whole acid present was completed) of several points of in~lection was taken for reporting.
Anion equivalent weight value (Av) (meq/g) =
0.1 x F x (Amount of titrant [mll for N/10 NaOH) -(number of m.mols of neutralizing acid used in accurately weighed sample [meq]/(concentration of amount of effective component [ppml in ~ample) (3) Average value of n Average value of n - Cr/Ar wherein Cr is number of m.mols of alkylene imine (meq/g) in effective component of polyelectrolyte and Ar i~ number of m.mol~ of anionic monomer (i) (meq/g) in ef~ective component of polyelectrolyte minu~ anion equivalent weight value (meq/g).

- ~ c~ c`~ c`~ ci c'~ ~> ~ l ~ l o ~ ~ l c~ - l ~ -- - - - - - - - ~-- - --o ~ c~ ~p c~ ~ ~-~ -~ t~- c~- u-~l co ~ --- - - - -- -- - - - ~ - - -~
~ ~ u~. o u~ o~ ~o ~o o 3 ~ o .~ ~ _ _ _. _ __ _ ___ ~ ~)~ ~ ~ ~, ~ ~ ~ ~ ~ ~r ~
1 ~
,0 ~ U~ U~ U~ ~O O 10 10 U~ O c- r t- t- t-',~0~- _ _. _ .- __ _ ___ _ n ~ ~ ~
~3 ~3 g a~ aao3 ~ co a o P~ ~o to Si O ~ ~; a~ _ ~3 ~ ~ ~ t o t-- t~ N 1- CD tO tO O O
~ _ O _ ~ _ ~ _ O ~ --~ ~ _ ~

~ 1~ 1~ ~ ~y ~ ~ 1~1 1~ ,i~3 1~--1~ ~Y 5:
~ ~1 ~ ~

z~o~9o Referential Example 7 [Method for production of water-in-oil form vinylic carboxylic acid polymer emulsion (vii)]
In a four-neck flask fitted with a ~tirrer, a thermometer, a condenser9 a dropping funnel, and a nitrogen gas inlet tube, 100 g of Isoper M (isoparaffin solvent produced by ~xxon Chemical) wa~ placed and 11.6 g of sorbitan monooleate was dissolved therein and the resultant mixture was emulsified by gradual adclition thereto o~ a mixed solution prepared as an aqueous monomer solution by the combination of 80 g of acrylic acid, 20 g o~ acrylamide, 52.9 g of aQueous 28 wt% ammonia solution, and 33.9 g of deionized water. After the internal gas of the reaction system had been thoroughly displaced with nitrogen gas, the reaction mixture was heated to 60C and, in the pre~ence of 0.7 g of azobis(dimethyl valeronitrile) added thereto ag a catalyst, was heated at 60C and, at the same time, stirred for 4 hours. Consequently, there was obtained a water-in-oil form vinylic carboxylic acid polymer emulsion.
Referential Examples 8 to 11 Water-in-oil form vinyl type carboxylio acid polymer emulsions were obtained by ~ollowing the procedure of Referential Example 1, except that varying hydrophoblc organio solvent, surfactants, and monomer compositions indicated in Table 3 were used instead.
Referentlal Examples 12 and 13 Aqueous solution form vinylic carboxylic acid polymers were obtained by polymerizing in water monomers of amounts forming weight ratios indicated in Table 3 and totalling a proportion of 33~ by weight.

Z ~ ~0 69 T~ble3 _ ~
Refer~ntial Weight ratio Hydrophobic Example of n~onomersorgani~ solvent Surfactant . _ , ~
8 AA/AAm = 100/0isoparaf~m sorbitan mono~tear1te . ~
9 AA/AAm = 60/40n-parafflm sorbitan monolauro.te _ ~ __ _~
AA/HEA = 60/40 kerosen glyc~rol monost~arate ~ __ ~ _~
11 AA/MAm = 60/40 tolu~ne sorbitan mono~tearate +
polyoxyethelene nonyl phenyl ether _ ~ _. _~
12 AA/AAm = 80/20 _~ . .~ _ 13 A~UAAm =100/0 _ ~ __ ~ ~_ Example 10 In a reactor, 200 g of the water-in-oil form vinylic carboxylic acid polymer emulsion synthesi2ed in Referential Example 7 was placed, heated to 50C and kept at thi~
temperature throughout the course of reaction ancl, a~ter dropwise addition thereto of 16.0 g of ethylene imine, stirred with the added ethylene imine for 30 minute~. Then, the resultant mixture and 38.4 g of an aqueous 61 wt% nitric acid solution added thereto were stirred for 30 minutes.
Subsequently, the resulting reaction mixture and 50.8 g of ethylene imine added dropwise thereto were stirred for 30 minutes. Then, the ensuing stirred mixture and 73.9 g of an aqueous 61 wt% nitric acid solution added thereto were stirred for 30 minutes. Consequently 5 ~here was obtained a water-in-oil form amphoteric copolymer emulsion. The reaction conditions and the physical properties of the reaction product were as shown in Table 4.
Examples 11 to 17 The procedure of Example 10 was repeated, except that the conditions shown in Table 4 were used instead. The Z~ 90 physical properties of the reaction product were as shown in Table 4.
Controls 6 and 7 Reactions were carried out by following the procedure of Example 10, except that the aqueous solution form vinylic carboxylic acid polymers obtained in Referential Examples 12 and 13 were respectively used instead. The physical properties of the reaction products were as shown in Table 4.
The intrinsic viscosity was determined by the following method (which applies similarly hereinafter).
(3) Intrinsic viscosity (dl/g) In 100 parts by volume of water 9 0.2 part by weight of a sample polymer was dissolved and adjus~ed to p~ 4 with hydrochloric acid. In a conical flask fitted with a ground stopper, 50 ml of the resutlant solution was placed and gently stirred with 50 ml of 2N-NaN03 ~or thorough solution.
Then, the resultant solution was diluted with 1N-NaN03 to concentrations o~ 0.02%, 0,OL~%, 0.06%, and 0.08%, diluted solutions were adjusted to pH 4.
In a constant temperature bath adjusted to 30C ~
0.1C and fitted with a Canon Fenske viscosimeter, tO ml of a sample was placed in the visco~imeter and allowed to flow down spontaneously. The time required for the sample to pass through the distance between the vertically separated marks on the measuring bul~ was measured. This procedure was repeated at least three times to determine the intrinsic viscosity as the average. A blank test was performed with an aqueous solution of 1N-NaN03.
This prooedure was performed on each o~ the 0.02 to 0.08~ solutions mentioned above.
The reduced viscosity was calculated as follows.
Relative viscosity ~rel = t/to Specific viscosity ~sp = (t - to)/to = ~rel ~
Reduced viscosity ~sp/c -3~-Z0~9~
wherein to i5 the time for downward flow of 1N-NaN03, t is the time for downward flow of sample solution, ~rel is the relative viscosity, ~sp is the specific viscosity, and c is the concentration of sample solution.
On a graph having the horizontal axis graduated for sample conc~ntration and the vertical axis for reduced ~iscosity, the numerical values obtained by the measurement described above were plotted and straight line~ were drawn across the points. The reading of the vertical axis against whiah the sample concentration was O was taken as the intrinsic viscosity of the sample.
to = the time required for 1N-NaN03 t - the time required for the sample soln.
c = the concentration of the sample soln.

21D1~6 _ __ _ _ . _ . _ _ _ c ~ `~ c~ u~ ~ ~ a:) u~ ~ r ,- o ~-~= j L5- -I
~ ¢~ o ~o O c~, O ~o o ~o ~o ~r ~ _ . . ~ .
~ cn c~, ~ ~ c~ a~ c~ ~

_ 3~C~ _ _ . _ _ _ _ _ ~ ~ r o o o o r r r o r Z ~ _ _ _ _~ _ _ _ __ .~ _ ~. _ _ __ _ _ ~ __ ~3 ' o~ ~ a~ ,, ~D, r o~ ~ a~ ~rO

_ _._ _ __ . _ _ _ _.
¢ ~ ~ ~ ~ ~ ~ ~ ~ ~ a _ _ _ _ _ _ _ ~ _ ~ ' ~ i r ~ e j ~
~.~
1 _ L~ - I ~ L~ L L L~ ~ L 1 Z~06go Referential Example 14 ~Production of vinylic carboxylic acid polymer emulsion (~
In a four-neck flask fitted with a stirrer, a thermometer~ a condenser, a dropping funnel, and a nitro~en gas inlet tube, 820 g o~ deionized water and 0.8 g of sodium lauryl sulfate were stirred for thorough solution. To the resultant solution, Z5.6 g of acrylic acid (AA), 3.2 g of acrylamide ~AAm), and 3.2 g of styrene (St) were added. The reaction mixture was kept stirred and the internal gas of the reaction system was thoroughly displaced with nitrogen gas. After the nitrogen displacement, the reaation mixture was heated to 50C and 0.288 g of ammonium persulfate (APS) and 0~288 g of sodium hydrogen sulfite were added as catalyst thereto. Immediately, 102.4 g of acrylic acid (AA), 12.8 g of acrylamide (AAm), and 12.8 g of styrene (St) were added dropwlse through the dropping funnel to the reaction mixture over a period of 2 hours, with the temperature kept at 50C. The resultant mixture was left aging for 2 hours. Consequently, there was obtained a vinylic carboxylic acid polymer emulsion. The visco~ity of this polymer emulsion was 2850 cps. When this polymer emulsion was neutrali~ed with sodium hydroxide to effect thorough ~olution of the emulsion and the solids content of the resultant solution was adjusted to 1% by weight, the viscosity of the solution was 130 cps.
Referential Examples 15-19 ~ inylic carboxylic acid polymer emulsions (vi) were obtainad by following the procedure of Referen~ial Example 14, except that the composition of monomers was varied as indicated in Table 5.

2~
Table~
.... ~ , _ ~ __~___ _ . .
Vi~cos~y Viscosityof Re~erential Weightratioo~monomer (2~C,CPS) l%solution ____ 1~ AAlAAmlSt = 80/15/5 3,500 140 _.
16 AAlAAmlBA = 80/10/10 3,100 120 17 AA/HEA/MMA = 60/30/10 3,600 113 __. ___ 18 AAIMAlVSt=65l30l5 6,200 83 _ ~______ 19 AA/HAm/MA = 80/10/10 2,800 105 _ ~
AAJAAm = 100/0 35,000 75 ~__ ___ 21 AA/AAm = 80/20 28,000 80 ~ ~ ,____ Example 18 In a reactor, 500 g of the vinylic carboxylic acid polymer emulsion (vi) synthesized in Referentia~ Example 14 was placed and heated 50C and kept at this temperature throughout the entire course of reaction and, after dropwise addition of 19.1 g of ethylene imine thereto, was stirred with the added ethylene imine for 30 minutes. The resultant mixture and 45.9 g of an aqueous 61 wt~ nitric acid solution added thereto were stirred for 30 minutes. Subsequently, the ensuant mixture and 88.6 g of an aqueous 61 wt% nitric acid solution ad~ed thereto were stirred for 30 minutes.
Consequently, there was obtained an amphoteric polyelectrolite. The reaction conditions and the physical properties of the reaction product were ~s shown in Table 6.
Examples 19 to 26 The procedure of Example 18 was repeated, except that the conditions indicated in Table 6 were used instead.
The physical properties of the reaction products were as shown in Table 6.
Controls 8 and 9 IL069~
The procedure of Example 18 was repeated, except that the vinylic carboxylic acid polymers (vi) synthesized in Referential Examples 20 and 21 were respectively used instead. The physical properties of the reaction products were as shown in Table 6.

lL0~9C~

I _ ~1 ,W ~ ~ ¦ ~ ¦ d ¦ ~ ¦ ~ I O co d .1 I O
_ _ _ _______ __ _ ~o ~ CO ~O O, ~0 ~0 O ~0 O ~ U~ O
b _ _ _ _ _ _ _ _ __ _ _ ~ ~ _~ a~, ,. ~ , ~, ,~ ~ u~ ~ ~ ~
_ _ _ _ ___ ____ __.

~ ~ o o o, o o r o o o o, o ~o 3 ~ ~ o~ co c~n ~ , o G~ ~ o~
:~ _ __ _ _ .._ _ _ _ _ ~ ~ L~ ~ ~ ~3 ~ ~:d ~3 P~ E~ ~ g _ _, _ l ____ ~ _ ~m ;~ ~
c -3~-zo~o~9~
Examples 27 to 35 The amphoteric polymer dehydraters abtained in Examples 1 to 9 were tested for flocculation property on a mixed raw sludge (having a solids content o~ 2.2% by weight) from a sewage disposal plant. The results were as shown in Table 7.
Controls 10 to 12 DAM (N,N-dimethylaminoethyl methacrylate) type polymer dehydraters indicated in Table 7 were tested for flocculation property on a mixed raw sludge (having a solids content of 2.2% by weight) from a sewage disposal plant.
The results were as shown in Table 7.
Control 13 The amphoteric polymer dehydrater obtained in Example 10 was tested for flocculation property on a mixed raw sludge (having a solids content of 2.2% by weight) from a sewage disposal plant. The results were as shown in Table 7.
Control 14 The amphoteric DAM (N,N-dimethylaminoethyl methacrylate) type polymer dehydrater indicated in Table 7 was tested for flocculation property on a mixed raw sludge (having a solids content of 2.2% by weight) from a sewage disposal plant. The results were as shown in Table 7.
~Flocculation te3t]
In a beaker having an inner volume of 300 ml, 150 ml of sludge was placed and a stated amount of an aqueous 0.2 wt% solution of a polymer dehydrater indicated in Table 7 was added thereto. After the addition, the sludge and the dehydrater were stirred at 150 rpm for 2 minutes with a jar tester. The flocs of sludge consequently obtained were passed through a 100-mesh nylon filter cloth under 400 mmHg in a vacuum filtrating device (leaf tester) to determine the average specific resistance of filter cake as an index to water-filtrating property. The cake resulting from the vacuum filtration was nipped between two filter cloths 2~0~g~
having a surface area of the square of 10 cm, pressed under 0.~ kg/cm2 for 10 minutes, and then tested for water content.
The amount of the amphoteric polymer dehydrate added to the sludge was 15% by weight as effective component, based on the amount of the solids of the sludge slurry.
The water content of the dehdyrated cake wa~
calculated from the weight of the cake after the dehydration with the pre~s and the weight of the sludge solids remaining after 2 hours' drying at 110C.
The average specific resistance, a, of the cake indicates that the desirability of water filtering property increases in proportion as the average specific resistance decreases.
The average specific resistance~ a, of the cake was found by plotting the found functions of ~/V and V on a graph and calculating Routh's filtration constant K and filtration constant.
The average specific re~i~tance, a, of the ¢ake and the resistance coefficient of the filter material were calculated by plotting the function~ of H/V and V on a graph paper and calculating Routh's filtration constant K and filtration constant C.
The Routh'~ theoretical formulas convering th~
constant pressure filtration are as follows:
v2 + 2VC = K~
K - 2 P qc A2 k/a~
C = A km k /a a = 2 P qc A2 k~K~
km = C a/A k V: amount of filtrate (m3) ~: time of filtration (s) K: Routhls filtration constant (m3/s) C: Routh's filtration constant (m3) p: pressure difference ~kgw/m3) A: filtration area (m2) ~O~
~: viscosity of filtrate (kg~m . s) (assured to be 0.001 kg/m s) a: specific resistance of cake (m/kg) km: resistance coefficient of filter material (1/m) k: amount of filtrate per unit m~ss of dried cake (m3/kg) = 0.00~ - m s/p . 3 m: mass ratio of wet cake dry cake s: sludge concentration (mass ratio of solids to sludge) p: density of filtrate (kg~m3) (= 1000 kg/m3) qc. coefficient for conversion of qravity (kg ~ m/kgw ~2) I ~ 1~ 1~ ~ ~ ~ ~ Z 106 0 L~ SX s so o ~ ~ ~o ~x ~o ~x Sx o x I

m ¦~ ¦~ m _ L m _ m ¦_ _ ¦_ ~ ~ _ ¦

~i 2 m m o _ r m m m ¦_ _ ¦_ m o:~ j o m 6 ~ o ~ o o o o o o ~ ' ~ ~ ' s .

_ 42 --

Claims (24)

1. An amphoteric polyelectrolite represented by the general formula I:

(I) wherein n is an integer in the range of 1 to 5, providing that the average value of n is not less than 2, a, b, and c stand for proportions such that the sum, a + b + c, is l or the sum, a + b, is l, R1, R2, R3, and R4 are independently hydrogen atom or an alkyl group, R5 is hydrogen atom, an alkyl group, or an alkyl group substituted with a .omega.-hydroxy group, HY is a monobasic acid, Z is an amide group represented by the general formula II:
-CONR6R7 (II) wherein R6 and R7 are independently hydrogen atom or an alkyl group, a hydroxyalkyl group represented by the general formula III:

(III) wherein R8 and R9 are independently hydrogen atom or an alkyl group, or a nitrile group represented by the general formula IV:
-CN (IV)

2. An amphoteric polyelectrolite according to claim 1, which possesses a cation equivalent weight value (Cv) in the range of 0.8 to 7.0 meq/g, an anion equivalent weight value (Av) in the range of 0.1 to 4.0 meq/g, and a Cv/Av ratio in the range of 1.0 to 25Ø

3. A method for the production of an amphoteric polyelectrolite represented by the general formula I and possessing an aminoalkyl group and a carboxyl group, which method comprises either polymerizing in water at least one anionic monomer (i) selected from the group consisting of acrylic acid and methacrylic acid or copolymerizing said anionic monomer (i) with a nonionic monomer (ii), allowing the resultant vinylic carboxylic acid polymer (iii) to be reacted upon by not less than 1.2 mols, per mol of said anionic monomer (i), of an alkylene imine thereby aminoalkylating said vinylic polymer (iii), and subsequently acidifying the aminoalkylated vinylic carboxylic acid polymer (iii) with a monoasic acid.

4. A method according to claim 3, wherein said nonionic monomer (ii) accounts for a proportion in the range of 0 to 50 mol%, based on the amount of said vinylic carboxylic acid polymer (iii).

5. A method according to claim 4, wherein said nonionic monomer (ii) is at least one member selected from the group consisting of vinyl monomers possessing an amide group and represented by the general formula X:

(X) wherein R3, R6, and R7 have the same meanings as defined above, vinyl monomers possessing a hydroxyalkyl group and represented by the general formula XI:

(XI) wherein R3, R8, and R9 have the same meanings as defined above, and (meth)acrylonitriles.

6. A method according to claim 3, wherein said polymerization is carried out at a temperature in the range of 30° to 100°C.

7. A method according to claim 3, wherein said alkylene imine is represented by the general formula, wherein R4 and R5 have the same meanings as defined above.

8. A method according to claim 3, wherein said vinylic carboxylic acid polymer (iii) has a molecular weight in the range of 10,000 to 1,000,000.

9. An amphoteric polyelectrolite possessing an aminoalkyl group and a carboxyl group and represented by the general formula V:

(V) wherein n is an integer in the range of 1 to 5, d, e, f, and g are proportions such that the sum, d, e + f + g, is 1 or the sum, d + e + f, is 1, R1, R2, R3, R4, and R10 are independently hydrogen atom or an alkyl group, R5 is hydrogen atom, an alkyl group, or an alkyl group substituted with a .omega.-hydroxy group, HY is a monobasic acid, A is an ester represented by the general formula VI:
-CO2R11 (VI) wherein R11 is an alkyl group, an aromatic group, or an alicyclic group, an unsubstituted or a p-substituted phenyl group represented by the general formula VII:

(VII) wherein R12 is hydrogen atom, an alkyl group, or a hydroxy group, or a nitryl group represented by the general formula IV:
-CN (IV) B is an amide group represented by the general formaula II:
-CONR6R7 (II) wherein R6 and R7 are independently hydrogen atom or an alkyl group, a hydroxyalkyl group represented by the general formula III:

(III) wherein R8 and R9 are independently hydrogen atom or an alkyl group, or an aminoalkyl group represented by the general formula IV:
-CN (IV)

10. A macromolecular ampholyte according to claim 9, which possesses a cation equivalent weight value (Cv) in the range of 0.8 to 10.0 meq/g and an anion equivalent weight value (Av) in the range of 0.1 to 6.0 meq/g.

11. A method for the production of an amphoteric polyelectrolite possessing an aminoalkyl group and a carboxyl group, which method comprises either emulsion polymerizing in water at least one anionic monomer (i) elected from the group consisting of acrylic acid and methacrylic acid and a nonionic monomer (iv) corresponding to A in the general formula V and added for the purpose of emulsification or effecting said emulsion polymerization in water in the presence of a nonionic monomer (v) corresponding to B of said general formula V, allowing the resultant vinylic carboxylic acid polymer emulsion (vi) to be reacted upon by an alkylene imine thereby aminoalkylating said vinylic carboxylic acid polymer emulsion, and subsequently acidifying said aminoalkylated polymer emulsion with a monobasic acid.

12. A method according to claim 11, wherein said nonionic monomer (ii) is at least one member selected from the group consisting of vinyl monomers possessing an amide group and represented by the general formula X:

(X) wherein R3, R6, and R7 have the same meanings a defined above, vinyl monomers possessing a hydroxyalkyl group and represented by the general formula XI:

(XI) wherein R3, R8, and R9 have the same meanings as defined above, (meth)acrylonitriles, vinyl monomers possessing an ester group and represented by the general formula XII:

(XII) wherein R3 and R10 have the same meanings as defined above, and vinyl monomers possessing an unsubstituted or p-substituted phenyl group and represented by the general formula XIII:

(XIII) wherein R3 and R12 have the same meanings as defined above

13. A method according to claim 11, wherein said polymerization is carried out at a temperature in the range of 30° to 100°C.

14. A method according to claim 11, wherein said alkylene imine is represented by the general formula, wherein R4 and R5 have the same meanings as defined above.

15. A method according to claim 11, wherein said nonionic monomer (ii) accounts for a proportion in the range of 0 to 70 mol%, based on the amount of said vinylic carboxylic acid polymer emulsion (vi).

16. A method according to claim 11, wherein said amphoteric polyelectrolite possesses an intrinsic viscosity [n] in the range of 1 to 25.

17. A water-in-oil form amphoterioc copolymer emulsion containing an amphoteric polyelectrolite represented by the general formula VIII:

(VIII) wherein n is an integer in the range of 1 to 5, a, b, and c are proportions such that the sum, a + b + c, is 1 or the sum, a + b, is 1, R1, R2, R3, and R4 are independently is hydrogen atom or an alkyl group, R5 is hydrogen atom, an alkyl group, or an alkyl group substituted with a .omega.-hydroxy group, HY is monobasic acid, Z is an amide group represented by the general formula II:
-CONR6R7 (II) wherein R6 and R7 are independently hydrogen atom or an alkyl group, a hydroxyalkyl group represented by the general formula III:

(III) wherein R8 and R9 are independently hydrogen atom or an alkyl group, a nitrile group represented by the general formula IV:
-CN (IV) or an ester group represented by the general formula IX:
-CO2R10 (IX) wherein R10 is an alkyl group, an aromatic group, or an alicyclic group.

18. An emulsion according to claim 17, wherein said amphoteric polyelectrolite possesses a cation equivalent weight value (Cv) in the range of 0.8 to 10.0 meq/g and an anion equivalent weight value (Av) in the range of 0.1 to 6.0 meq/g.

19. A method for the production of a water-in-oil form amphoteroc polyelectrolite emulsion possessing an aminoalkyl group and a carboxyl group, which method comprises emulsifying either at least one anionic monomer (i) selected from the group consisting of acrylic acid and methacrylic acid or a mixture of said anionic monomer (i) with a nonionic monomer (ii) in water-in-oil form in the presence of water, a surfactant, and a hydrophobic organic solvent, then polymerizing or copolymerizing the emulsified monomer or monomer mixture with a radical polymerization catalyst thereby forming a water-in-oil form vinylic carboxylic acid emulsion (vii), then aminoalkylating said emulsion with an alkylene imine, and subsequently acidifying the aminoalkylated emulsion with a monobasic acid.

20. A method according to claim 19, wherein said nonionic monomer (ii) accounts for a proportion in the range of 0 to 70 mol%, based on the amount of said vinylic carboxylic acid monomer (iii).

21. A method according to claim 19, wherein said nonionic monomer (ii) is at least one member selected from the group consisting of vinyl monomers possessing an amide group and represented by the general formula X:

(X) wherein R3, R6, and R7 have the same meanings as defined above), vinyl monomer possessing a hydroxyalkyl group and represented by the general formula XI:

(XI) wherein R3, R8, R9 have the same meanings as defined above vinyl monomers possessing a hydroxyalkyl group, (meth)acrylonitrile, and vinyl monomers possessing an ester group and represented by the general formula XII:

(XII) wherein R3 and R10 have the same meaning defined above.

22. A method according to claim 18, wherein said polymerization is carried out at a temperature in the range of 30° to 100°C.

23. A method according to claim 18, wherein said alkylene imine is represented by the general formula, wherein R4 and R5 have the same meanings as defined above.

24. A method according to claim 18, wherein said water-in-oil form amphoteric copolymer emulsion possesses an intrinsic viscosity [n] in the range of 0.1 to 25.