CA2092775A1

CA2092775A1 - Alkenylaminoalkenylenephosphonic esters and process for the preparation of copolymers comprising alkenylaminoalkenylenephosphonates and ethylenically unsaturated compounds

Info

Publication number: CA2092775A1
Application number: CA002092775A
Authority: CA
Inventors: Matthias Krull; Christoph Naumann
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1992-03-28
Filing date: 1993-03-26
Publication date: 1993-09-29
Also published as: EP0563730A3; EP0563730A2; NO931136L; NO931136D0; JPH0649082A

Abstract

Abstract of the Disclosure:

Alkenylaminoalkylenephosphonic esters and process for the preparation of copolymers comprising alkenylamino-alkylenephosphonates and ethylenically unsaturated compounds The present invention relates to alkenylaminoalkylene-phosphonic esters of the formula (1) (1) where R1 to R5, Z, X, a and b have the meanings specified in the description, with the exception of the compounds of the formulae (H2C=CH-CH2)2N CH[PO3(C2H5)2]2 and (H2C=CH-CH2)2N-CHR4-PO3X2, and also processes for their preparation.

The invention also relates to a process for preparing copolymers comprising from 0.1 to 99% by weight, prefer-ably from 1 to 50% by weight, of at least one monomer unit of the formula (2)

Description

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HOECHST AKTIENGESELLSCHAFT HOE 92/F 079 Dr.Kl/rh Alkenylaminoalkylenephosphonic esters and process for the preparation o~ copolymers comprising alkenylamino-alkylenephosphonates and ethylenically unsaturated compounds Copolymers of unsaturated phosphonic acids and unsatur-ated monocarboxylic and dicarboxylic acids are proposed in US-A-5 126 418 as alkaline earth metal and heavy metal complexing agents, as antiscalants in the petroleum industry, and as builders, cobuilder and peroxide stabilizers and also granulation auxiliaries for bleach-ing activators in detergents. Such copol~mers combine the properties o~ polycarboxylates and phosphonates.
:
Phosphonomethylated polyvinylamines are known from DE-A-3 926 059, which are prepared by phosphono~
methylation of polymers containing N-vinylamide groups or vinylamine groups and are used as additives in detergents and as water treatment agents (~equestering agents).
.~
JP-A2-54/135 724 describes a procsss for preparing aminomethylenephosphonic esters and also their acid hydrolysis, for example the Yynthesis of tetrethyl N-diallylaminomethylenediphosphonate and of the corres-;~ ponding acid.

The homopolymerization and copolymerization of diallyl-aminomethylenephosphonic acids with ethylenicallyunsaturated monomer~ to form high molecular weight (co)polymers is described in JP-A2-50/72 987. In the polymerization of diallylammonium salts, polymers that , ~ are onIy slightly branched and that contain piperidinium groups are obtained (Lancaster et al., Polym. Lett. 1976, `~ 14, 54~).
:
: .
(Co)polymerizable phosphonic acid derivatives can be obtained for ~xample by the Mannich reaction of k ~

- 2 ~
(di)allylamine with aldehyde~ and phosphorous acid in concentrated mineral acid solution (K. Noedritzer, R.R.
Irani; J. Org. Chem. 1966, 31, 1603). The amine is reacted with formaldehyde and phosphorous acid in the presence of at least equimolar amounts of a mineral acid.
In the subsequent neutralization of the reaction solution at least equimolar amounts of salts are corre~pondingly formed, which are separated by comp:Lex operations for specific applications, for example prevention of scale in cooling waters and also for modern detergents, and finally have to be disposed of. If hydrochloric acid is used the formation of carcinogenic halogenated dimethyl ethers, which occur as by-products, is moreover a serious disadvantage.

The need therefore exi.sted to provide a proce~s for preparing ~ao)polymerizable alkenyl~minoalkylene-phosphonic acid derivatives which produces little~ if any, inorganic salt and in which the formation of car-cinogenic halogenated dimethyl ethers i5 avoided.

We have surprisingly found that the esters of alkenyl-aminoalkylenephosphonic acids can be prepared without the aforementioned disadvantages occurring. These esters are suitably copol~merizable with ethylenically unsaturated compounds.

The present invention relates to alkenylaminoalkylene-phosphonic esters of the formula 1 R1 ~R2)bR3 (H2C = C ~ Z)a - N --- C - PO3X2 I

,;

: :

i 2 ~

where R' is hydrogen or methyl, R2 is hydrogen, C1-C22-alkyl, preferably Cl-C~-alkyl, C3-C6-alkenyl, preferably propenyl, aryl, preferably phenyl or a group of the formulae -C(R3)(R4)-Po3X2 and -C(O)Rs, R3 is hydrogen, C~C22-alkyl J preferably Cl-C6~alkyl, or aryl, preferably phenyl, R4 is hydrogen, C1-C22-alkyl, preferably Cl-C6-alkyl, aryl, preferably phenyl, or a group of the formula : -PO3X2 ~
Rs is C1-C22-alkyl, preferably Cl-C4 alkyl, or aryl, : preferably phenyl, :~ Z is Cl-C3-alkyl, ;.
a is 1 or 2, b i8 0 or 1, a + b is 2, and X is Cl-C4-alkyl, or aryl, preferably phenyl, :~. with the exception of the compound~ of the formulae ~ (H2C-CH-C~2)2N-CH[PO3 ~ C2~5 ) 2 ] 2 a~d (H2C-C~-C~2)2~-CHR-~PO3x2-s~ ' ~he present invention also relates to a proce~s for preparing copolymer~ ~omprising ; from 0.1 to 99.9% by weight, preferably from 1 to 50% by `~ weight, of at least one monomer unit of the formula 2 R1 (R )bR
( 2 ) (H2C = C ~ Z)a ~ N --- C - PO3MY

: R7 ~ where :~; 25 Rl is hydrogen or methyl, R6 is hydrogen, Cl-C22-alkyl, preferably C1-~6-alkyl, C3-C6-alkenyl, preferably propenyl, aryl, preferably phenyl, or a group of the formulae -C~R3)(R4)-Po3MY
-~; and -C(O)Rs, 30 R3 is hydrogen, C1-C22-alkyl, pre~erably Cl-C6-alkyl, or .~ aryl, preferably phenyl, : ~ R7 is hydrogen, C,-C22-alkyl, preferably C~-C6-alkyl, ~:

2 ~

aryl, preferably phenyl, or a group of the formula -PO3MY, Rs is C~-C2~-alkyl, preferably C,-C4-alkyl, or aryl, preferably phenyl, Z is Cl-C3-alkyl, a is 1 or 2, b is 0 or 1, a + b is 2, Y is hydrogen, C,-C~-alkyl, or aryl, preferably phenyl, and M is, independently in each instAnce, hydrogen or a cation, preferably sodium, potas~ium, or ammonium and from 99.9 to Ool~ by weight, preferably from 99 to 50~ by weight, of at least one monomer unit from the group comprising ethylenically unsaturated carboxylic acids, sulfonic acids and their derivativeq, and also other ethylenically unsaturated compounds, wherein alkenyl-aminoalkylenephosphonic esters of ~he formula 1 and monomers from the group comprising ethylenically unsatu-rated carboxylic acids, sulfonic acids and their deriva-~: 20 tives and also other ethylenically unsaturated compounds are polymerized in aqueous medium or organic medium at a : pH of less than 5, and if necessary the remaining : phosphonic ester groups of the copolymers obtained are ~- hydrolyzed.

The preparation of the alkenylaminoalkylenephosphonic esters of the formula l according to the invention is . described hereinafter.

If the compounds of the formula 1 are monophosphonic esters (R4 different from PO3X2), these esters are obtained by reacting an aldehyde or ketone of the formula R3-C(o)-R4, preferably formaldehyde, with a diester of phosphorous acid and an amine of the formula 3 R1 (R2)b I
;~ (H2C = C-Z~a-N-H (3) ;..
,,,,, .. ~ . . . . . - - , - . - -- , . -where R1, R2, z, a and b are as defined above. Suitable diesters of phosphorous acid ar~ for example dialkyl esters with Cl-Cs-alkyl, such as the dimethyl ester and the diethyl ester, diphenyl ester and alkyl aryl esters.
In the preparation of the monophosphonic esters of the formula 1 (R4 different from PO3X2) the diester of phos-phorous acid and the aldehyde or ketone of the formula R3-C[o)-R4 are normally placed in thle reaction ve~sel first and the corresponding amine is then added so that the exothermic reaction proceeds in a controlled manner.
Alternativsly, however, the diester of phosphorous acid and the amine may be placed in the reaction vessel first, following which the aldehyde or ketone of the formula R3-C(o)-R4 is slowly added.

It has been found that from 0.5 to 1.5 mol, preferably from 0.3 to 1.2 mol, of aldehyde or ketone of the formula R3-C~o)-R4 and from 0.5 to 1.5 mol, preferably from 0.8 to 1.2 mol, of diester of phosphorous acid per mole of the secondary amine axe reacted with one another. It is part.icularly preferred to react the individual components with one another in equimolar amounts.
With primary amines~ double the amounts of aldehyde or ketone of the formula R3-C(o)-R4 and of the diester of phosphorou~ acid are correspondingly used. ~he reaction temperatures are in the range from 20 to 200C, prefer-ably from 50 to 150C.

If the compounds of the formula 1 are l,l-diphosphonic esters (R4 the same as -PO3X2), these esters are obtained by reacting diesters of phosphorous acid with an alkyl ester of orthoformic acid and an amine of the formula 3.
Suitable alkyl estexs of orthoformic acid are Cl-C4-alkyl esters, for example ethyl orthoformate.
In the preparation of these l,l-diphosphonic acid esters advantageously from 0.5 to 2 mol, preferably from 1.0 to 1.3 mol, of alkyl ester of orthoformic acid and from .l 1.5 to 3.0 mol, preferably 2.0 to 2.5 mol, of diester of phosphorous acid are reacted per mole of the rslevant ,'.

. ~ . ., .. . ~ -. .
-~: :

~ 3 primary or secondary amine at temperatures in the range from 50 to 150C, the alcohol formed being distilled off, and the addition of the amine to the mixture of diester and alkyl ester of orthoformic acid normally being 5 effected in a controlled manner. It is particularly preferred to react the individual components in the molar ratio 1:2:1.

The aforementioned processes for preparing compounds of the formula 1 have the advantage that no inorganic salts, such as sodium chloride, occur, and the ~ormation of carcinogenic halogenated dimethyl ethers is avoidPdl As compounds of the formula 1 there may be mentioned in particular allylaminobis~methylenephosphonic) acid tetraethyl ester, methallylaminobis(methylenepho~phonic) acid tetraethyl ester, diallylaminomethylen2phosphonic acid dimethyl ester, diallylaminomethylenephosphonic acid diethyl ester, diallylaminomethane~ diphosphonic acid : ~ tetraethyl ester, diallylaminomethane-1,1-diphoæphonic : acid tetramethyl ester, diallylaminomethane-l,l-diphos-phonic acid tetrapropyl ester, and N-methylallylamino-methane~ diphosphonic acid tetraethyl ester.

Th~ salt-~ree compounds o~ the formula 1 may be used without further purification or drying in the preparation of the aforementioned copolymers comprising monomers of the formula 2 and monomers of the group comprising ethylenically unsaturated carboxylic acids, ~ulfonic acids and their derivatives, and also other ethylenically ~: unsaturated compounds.

If, however, drying i~ necessary, the water present can be removed by suitable methods, such as distillation or ;. the addition of drying agents.
, . . .
¦ Both novel and known alkenylaminoalkylenephosphonic esters may be used as starting compounds for the prepa ration of copolymers by the process according to the .~

. :
.i ~. - - . . ~

- 7 ~
invention. The known compounds include diallylamino-methane~ diphosphonic acid tetraethyl ester and the diallylaminomethanephosphonic acid dies~ers named in the still unpublished German patent application with the file No. P 4100760.3.

Suitable comonomers are ethylenically unsaturated carboxylic acids and their derivative~, for example acrylic acid, methacrylic acidr crotonic acid, maleic acid, maleic anhydride, fumaric acicl, itaconic acid, itaconic anhydride, methyl acrylate, ethyl acrylate, methyl methacrylate, butyl methacrylate~ dimethyl-aminoethyl acrylate, dimethylaminoethyl methacrylate, monoethyl maleate, diethyl maleate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl meth-acrylate, hydroxypropyl methacrylate, methacrylamido-propyldimethylammonium chloride, dimethylaminopropyl acrylamide~ acrylonitrile and methacrylonitrile.
~; Also suitable are ethylenically unsaturated sulfonic acids such as vinyl~ulfonic aaid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, acrylic acid (3-sulfopropyl)ester, methacrylic acid (3-sulfo-propyl) ester, and 2-acrylamido-2-methylpropane~ulfonic ~ acld.
- Other suitable compounds include neutral unsaturated compounds such as N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, vinyl acetate, vinyl propionate, vinyl butyrate, styrene, olefins having 2 to 10 carbon atoms, such as ethylene, propylene, isobutylene, hexene, diisobutene, and vinyl alkyl ethers, such as methyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, hexyl vinyl ether and octyl vinyl ether.
The aforementioned starting substances may be used as ~` individual substance6 or in the form of mixtures.

The copolymers may be prepared by bulk, solution, preci-pitation, suspension or (inverse)emulsion polymerization.
~he preferred preparation process is solution .~

.:
;, ;, : , ~ ~ ~ 2 ~ ~ ~
polymerization, further details of which will be discussed hereinafter.
The copolymerization normally takes place in the presence of initiators that form free radicals under the poly-merization conditions, for example in the presence ofperoxides, hydroperoxides, psrsulfates, azo compounds ox redox catalysts.
Suitable solvents are aqueous media and organic media.
The aqueous media comprise mixtures of water and water-miscible organic solvents, such as alcohols, cyclicesters or, preferably, only water. The organic media comprise water-miscible or wa~er-immiscible organic solvents, which also include aromatic hydrocarbons such as toluene and xylene and paraffins. Solution poly-merization is carried out at a total monomer concen-tration of from 1 to 80% by weight/ preferably from 10 to 60% by weight, The temperatures are from 0 to 120C, preferably from 10 to 100C.

The starting materials may be added to the solvent separately or together. The addition of the free radlcal chain initiator, i~ necessary dissolved in a ~uitable solvent, may take place at the same time as, or after the addition of the starting materials. In order to improve the solubility in water of the alkenylaminoalkylene-phosphonic esters employed, it i~ advisable to add short-chain aliphatic alcohols such as ethanol or isopropanol.
In addition it may be advantageous, in order to improve the solubility of the compound of the formula 1 and furthermore to prevent oxidation, to add acids, prefer-ably in equimolar amounts, to the aqueous medium beforethe actual polymerization, in which connection the pH of the aqueous medium should be less than 5, and preferably less than 3. Suitable acids are mineral acids, for example hydxochloric acid, sulfuric acid, phospboric acid, and also organic acids, such as alkanecarboxylic acids, for example formic acid and acetic acid, and aromatic carboxylic and ~ulfonic acid~, for example benzoic and p-toluenesulfonic acid.
; ;
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, .

'~; ' ' ' ~ : ' 9- ~$~7~
If copolymers with free phosphonic acid groups of the formula -PO3H2 are to be obtained, t~len the copolymeriza-tion may be carried out in strongly acidic solution with the addition of the aforementioned acids, or the phosphonic ester groups of the copolymers obtained by the process according to the invention are hydrolyzed by heating in strongly acidic solution, at a p~ of less than

3. In a special variant of the process the hydrolysis of the phosphonic ester groups may be effected by treating the copolymers with copolymers containing free phosphoni~
acid groups, with the addition of water, and distilling off the alcohol that is formed. In addition to the aforementioned acids the ethylenically unsaturated carboxylic acids or sulf onic acids used as starting materials may also act as proton donor~, so that if desired the addition of acids can be omitted. In this connection, it has been found that, under the acid reaction conditions, hydrolysis of the alkenylamino-alkylenephosphonic esters occurs in parallel to the polymerization, and the formation of ethyl chloride can be excluded. Pref erred monomers in this reaction are acrylic acid, methacrylic acid, maleic acid and 2-acryl-amido-2-methyl-propanesulfonic acid.
., In the copolymerization of phosphonic e~ters of the formula 1 with comonomers carrying acidic groups in aqueous solution, the ester groups are hydrolyzed during the polymerization, as can be shown by 3lP-NMR spectros-copy. For example, the 3lP-NMR sp~ctrum of a copolymer of acrylic acid and diallylaminomethane-l,1-diphosphonic ~ 30 acid tetraethyl ester (Example 8) exhibits a broad signal `` between 8 and 9 ppm, whereas the diallylaminomethane-1,1-- diphosphonic acid tetraethyl ester that is used exhibits a substantially sharper signal at 19.8 ppm.

; The 31P-NMR spectrum of the pyrrolidine-1,1-methanedi-phosphonic acid prepared for the purposes of comparison (Comparative Example 2)~ which constitutes a structural element of the polymer according to Example 4, also ~`
''"

.; .: ,1 .::
.~
.,,;, ~ ~ .

lo~ 7~
exhibits a signal at 8.25 ppm.

According to the process of the invention, copolymer can be prepared by reacting oil~soluble alkenylamino-alkylenephosphonic esters with oleophilic ethylenically un~aturated comonomers in organic solvents in the presence of free-radical chain i.nitiator~ ~uch as AIBN or organic peroxides, followed by hydrolysis of the copoly-mer~ thereby obtained by adding minera.1 acids at a pH of less than 3.

The molecular weight of the copol~mers prepared depends on the intended use, but in principle is not subject to any restrictions. Pre~erably, copolymers are prepared having low and mean molecular weights in the range ~rom 1000 to 500,000. Thi~ can also be achieved by adding from : 15 0.001 to 30~ by weight of regulators such as thiogly~_olic acid, ethanethiol, dodecanethiol, phosphorous acid, hypo-phosphorous acid, sodium hydrogen sulite~ or water~
soluble salts of transition metals such as copper, iron, manganese and nickel to the reaction mixture before or during the addition of the catalyst. The preferred intrinsic viscosity K (determined according to Ubbelohde) of the polymers i9, for example if the polymers are used as antiscalants, from 10 to 100, in particular from 10 to 50.

The copolymers prepared by the process according to the invention have a broad range of application and can be used in many sectors, with utilization of their advan-tageous properties. The copolymers are preferably used as anti~calants, for example in the cleaning of machinery, bottle cleaning, steam generation, cooling water treat-ment and in oil conveyance, as complexing and/or sequestering agents, for example in water treatment, in the production of leather and in textile and paper blèaching, and as builders and cobuilders in detergents.

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. . . ;

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7~ j Examples The percentage figures are, unless otherwise speci~ied, by weight. The water used in the examples is deionized.
The intrinsic viscosity values K were determined accord-ing to Ubbelohde at 25C in water at a polymer concentra-tion of 5~ ~y weight. 3lP-NMR spectra were recorded with a 121-MHz spectrometer in D2O with 3-(trimethylsilyl)propionic acid d4-sodium salt and in CDCl3 with tetramethyl silane as internal standard.

~he polymerizations were carried out in 1 1 5 necked flasks with plane-ground cover~. The 1asks are each equipped with an anchor stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel. The solutions added to the flasks for the polymeriæation were flushed with nitrogen.

Example 1 Preparation of allylaminobis(methylenephosphonic) acid ; tetraethyl ester 14.3 g (0.25 mol) of allylamine were added at 80C during ; 20 the course of hal~ an hour to a mixture of 15 g (0.5 mol) of paraformaldehyde and 69 g (0.5 mol) of diethyl phosphite. ~he reaction wa~ complete after stirring for half an hour at 85C. The crude product, which contained 9% of water, was dried by adding Na2SO4. It was used without further purification for the polymerization.
H-NMR (DMS~-d6)~ ~ = 1.23 (t, 12H); 3.05 (d, 4H); 3.38 (d, 2H); 4.0 (m, 8~); 5.2 ~m, 4H); 5.58-5.g5 ppm (m, lH).
31P-NMR (D2O): ~ = 27-55 ppm-Example 2 ,, Preparation of diallylaminomethylenephosphonic acid diethyl ester 30 g (1 mol) of paraformaldehyde were slowly added at 60C to a well-stirred mixture of 138.1 g (1 mol) of diethyl phosphite and 97.2 g (1 mol) of diallylamine. The reaction was complete after 30 minutes' stirring at 85C.
The crude~ product ~(comprieing approximately 90% of :.

:., ~ - .

g~

diallylaminomethylenephosphonic acid diethyl ester and 6~
of water) can be purified by distillation (bp35 ~r ~
139-143C).
1H-NMR (DMSO-d6): ~ = 1.23 (t, 12H)i 2078 (d, 2H); 3.18 (d, 4~); 4.0 (m, 4H); 5.2 (m, 4H); 5.58-5.95 ppm (m, 2EI).
3'P-NMR ~CDCl3): ~ = 25.9 ppm.

Example 3 Preparation of diallylaminomethane-1,1-diphosphonic acid tetraethyl ester

4.85 g (O.05 mol) of diallylamine, 8.9 g tO.06 mol) o~
; ethyl orthoformate, and 13.8 g (0.1 mol) of diethyl phosphite were heated to 150C with the addition of O.2 ml of boron trifluoride etherate. The ethanol fonmed (8.2 ml) wa9 distilled off over about 2 hours~
The crude product thus obtained was taken up in toluene, dried over sodium sulfate, and the toluene was removed under reduced pressure. The product was then purified by fractional vacuum distillation. 8.1 g (42% of theory) of N,N-diallylaminomethane~ diphosphonic aaid tetraethy~
ester having a boiling point of 118-121C (0.04 mbar) were obtained.
31P-NMR (D2O~: ~ = 19.8 ppm-Example 4 Copolymer of acrylic acid and 15% of allylamino-bis(methylenephosphonic) acid tetraethyl ester 7.5 g (0.021 mol) of allylaminomethyl~ne-bis(phosphonic) acid diethyl ester according to Example 1 were dissolved in a mixture of 80 g of water and 40 g of isopropanol and heated to 75C while passing a stream of nitrogen through the mixture. A catalyst solution comprising 42.5 g (0.6 mol) of acrylic acid and 1.5 g of (~H4)2S2O~ in 30 g of water was added dropwise ~ynchronously from 2 dropping funnels at thi~ temperature. After the end of the exo-; thermic reaction phase the reaction mixture was stirred for 4 hours at 80C. The resulting polymer had an intrinsic viscosity K of 22.

. . ~ . . . ~

, ~ , . -.

~ ~ 9 2 7 r~ ~

Example 5 Copolymer of acrylic acid and diallylaminomethylene-phosphonic acid diethyl ester 7.5 g (0.030 mol~ of the distilled diallylaminomethylene phosphonic acid diethyl ester according to Example 2 were copolymerized as described in Example 4 with 42.5 g (0.6 mol) of acrylic acid. The resulting pol~mer had an intrinsic viscosity K of 20.

Example 6 Copolymer of acrylic acid and diallylaminomethylenephos-phonic acid diethyl ester in the presence of ~Cl 22.5 g (0.091 mol) of diallylamino methylenephosphonic acid diethyl ester (crude product) according to Example 2 were dissolved in a mixture of 240 g of water and 120 g of isopropanol with the addition of 40 g (0.364 mol) of 33% hydrochloric acid and heated to 75C while passing a stream of nitrogen through the mixture. A catalyst solution aomprising 4.5 y of (N~4)~S2O8 in 90 g of water, and 120 g (1.8 mol) o~ acrylic acid was added dropwi~e synchronously from 2 dropping funnel~ at this tempera-ture. After the end of the exothermic reaction phase the reaction mixture was stirred for 2 hours at 80C. ~he .
~; resulting polymer had an intrinsic viscosity K of 23.
After distilling off isopropanol the reaction mixtur~ was refluxed ~or 1 hour to hydrolyze the phosphonate esters.

Example 7 Copolymer of acrylic acid and diallylaminomethane~
diphosphonic acid tetraethyl ester 10.0 g (0.026 mol) of diallylaminomethane~ diphos-phonic acid tetraethyl ester are copolymerized, as described in Example 4, with 40.0 g tO.56 mol) of acrylic acid.

Example 8 Copolymer of acrylic acid and diallylamillomethane-1,1-diphosphonic acid tetraethyl ester in the presence of ~Cl ; 10 g tO.026 mol) of diallylaminomethane~ diphosphonic .

~` ~ ~ :'. ' , .. ~ :

acid tetraethyl ester are copolymerized with 40 g (O.56 mol) of acrylic acid as described in Example 6, with the addition of 2.89 g (0.026 mol) of 33% hydro-chloric acid.
After distilling off the isopropanol the reaction mixture was refluxed for 1 hour to hydrolyze the phosphonate esters.

Example 9 Copolymer of 2-acrylamido-2-methylpropanesulfonic acid and diallylaminomethylenephosphonic acid diethyl ester A third of a monomer solution comprising 7.5 g (0O03 mol) of diallylaminomethylenephosphonic acid diethyl e~ter and 42.5 g (0.2 mol) of 2-acrylamido-2-methylpropanesulfonic acid in 120 g of water was placed in the reaction flask and heated to 80C whil~ pa~sing a stream o~ nit;rogen through the reaction mixture. The remainder of the monomer solution and also a catalyst solution comprising 1.5 g of (NH4)2S2O8 in 30 g of water were added dropwise~
synchronously within 2 hours at this temperature~ The ; 20 reaction mixture was refluxed for 2 hours. The resulting polymer had a X value of 47.

Comparative Example 1 Preparation of diallylaminomethane~ dipho~phonic acid ~similar to JP-A2 54/135724) The diallylaminomethane-l,1-diphosphonic acid was prepared by hydrolysis of the corresponding distilled tetraethyl ester with concentrated HCl.

Comparative Example 2 ' Preparation of pyrrolidine-1,1-methanediphosphonic acid 71.1 g (1 mol) of pyrrolidine, 170.4 g (1.2 mol) of ethyl orthoformate, and 289.8 g (2.1 mol) of diethyl phosphite were heated for 4 hours at 150C and the ethanol formed was distilled off. The unreacted substances were then removed by distillation under a high vacuum. 286 g of the biphosphonate obtained were refluxed for 6 hours with 1 1 of concentrated hydrochloric acid. The excess ~ .
..
~, . .

- 15 - 2~2~
hydrochloric acid was then removed under reduced pressur~.
142 g (58~ of theory) of pyrrolidine~ methanedi-phosphonic acid were obtained as a colorles~ powder.
3lP-NMR ~D2O): ~ = 8.25 ppm Comparative Example 3 Copolymer of acrylic acid and diallyl~ninomethylena-phosphonic acid Diallyl~ninomethylenephosphonic acid was prepared by reacting diallylamine with formaldehyde and phosphorous acid in equimolar amount6 (K. ~oedritzer, I.I. Irani J. Org. Chem. 1966, 31, 1603-1607). Sulfuric acid w~s used instead of hy~rochloric acid as mineral acid and, a~ter the reaction, was neutralized with sodium hydroxide. The phosphonic acid was separated from the salt by extracting the reaction product, concentrated by heating to dryness, with ethanol. 10.0 g (0.05 mol) of diallylaminomethylenephosphonic acid were copolymerized with 40.0 g (0.56 mol) of acrylic acid as described in Example 4.
20 3lP-NMR spectroscopic investigations on diallylamino-monophosphonate ~:;
Example 2 25.9 ppm ~; Example 6 17.2 ppm, 10.5 ppm, 9.2 ppm;
rel. intensity 3:1:0.1 ' after 1 hour's boi}ing 17.3 ppm, 10.7 ppm, 9.2 ppm;
rel. intensity 3:1:0.3 Comp. Ex. 3 8.6 ppm 3~P-NMR spectroscopic investigations on diallylamino-l,l-diphosphonate Example 3 19.8 ppm Example 7 20.1-~0.3 ppm, 14.2-15.5 ppm;
rel. intensity 3:1 ~' ~

~::
.

2~2~ l ~J

Example 8 16.9-17.1 ppm, 16.1-16.3 ppm, 12.9-13.4 ppm, rel. intensity 2:1:2 " after 1 hour's boiling 8.8-9.0 ppm Comp. Ex. 1 7.7 ppm Comp. Ex. 2 8.25 ppm : These measurements point to a continuing hydrolysis of the phosphonate esters (Example~ 6, 7 and 8) during the 10 polymerization and in the thermal post-treatment.

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Claims

We claim:

1. An alkenylaminoalkylenephosphonic ester of the formula 1 (1) where R1 is hydrogen or methyl, R2 is hydrogen, C1-C22-alkyl, preferably C1-C6-alkyl, C3-C6-alkenyl, preferably propenyl, aryl, prefer-ably phenyl or a group of the formulae C(R3)(R4)-PO3X2 and -C(O)R5, R3 is hydrogen, C1-C22-alkyl, preferably C1-C6-alkyl, or aryl, preferably phenyl, R4 is hydrogen, C1-C22-alkylll, preferably C1-C6-alkyl, aryl, preferably phenyl, or a group of the formula -PO3X2, R5 is C1-C22-alkyl, preferably C1-C4-alkyl, or aryl, preferably phenyl, Z is C1-C3-alkyl, a is 1 or 2, b is 0 or 1, a + b is 2, and X is C1-C4-alkyl, or aryl, preferably phenyl, with the exception of the compounds of the formulae (H2C=CH-CH2)2N-CHR4PO3X2 and (H2C=CH-CH2)2N-CH[PO3-(C2H5)2]2.

2. A process for preparing monophosphonic esters as claimed in claim 1, wherein a mixture of aldehyde or ketone of the formula R3-C(O)-R4 (A), diester of phosphorous acid (B) and secondary amine of the formula 3 (3) where R1, R2, Z, a and b are as defined above, is reacted at temperatures in the range from 20 to 200°C, the components A:B:C being present in the mixture in a molar ratio of 0.5-1.5:0.5-1.5:1 at the start of the reaction.

3. A process for preparing monophosphonic esters as claimed in claim 1, wherein a mixture of aldehyde or ketone of the formula R3-C(O)-R4 (A), diester of phosphorous acid (B) and primary amine of the formula 3 (D) is reacted at temperatures in the range from 20 to 200°C, the components A:B:D being present in the mixture in a molar ratio of 1.0-3.0:1.0-3.0:1 at the start of the reaction.

4. A process for preparing 1,1-diphosphonic esters as claimed in claim 1, wherein a mixture of diester of phosphorous acid (B), alkyl ester of orthoformic acid (E) and primary or secondary amine of the formula 3 (D,C) is reacted at temperatures in the range from 50 to 150°C, the components B:E:D or B:E:C being present in the mixture in a molar ratio of 1.5-3.0:0.5-2.0:1 at the start of the reaction.

5. A process for preparing copolymers comprising 0.1-99.9% by weight, preferably 1-50% by weight, of at least one monomer unit of the formula 2 (2) where R1 is hydrogen or methyl, R5 is hydrogen, C1-C22-alkyl, preferably C1-C6-alkyl, C3-C6-alkenyl, preferably propenyl, aryl, prefer-ably phenyl, or a group of the formulae -C(R3)(R4)-PO3MY and -C(O)R5, R3 is hydrogen, C1-C22-alkyl, preferably C1-C6-alkyl, or aryl, preferably phenyl, R7 is hydrogen, C1-C22-alkyl, preferably C1-C6-alkyl, aryl, preferably phenyl, or a group of the formula -PO3MY, R5 is C1-C22-alkyl, preferably C1-C4-alkyl, or aryl, preferably phenyl, Z is C1-C3-alkyl, a is 1 or 2, b is 0 or 1, a + b is 2, Y is hydrogen, C1-C4-alkyl, or aryl, preferably phenyl, and M is, independently in each instance, hydrogen or a cation, preferably sodium, potassium, or ammonium and from 99.9 to 0.1% by weight, preferably from 99 to 50% by weight, of at least one monomer unit from the group comprising ethylenically unsaturated car-boxylic acids, sulfonic acids and their derivatives, and also other ethylenically unsaturated compounds, wherein alkenylaminoalkylenephosphonic esters of the formula 1 and monomers from the group comprising ethylenically unsaturated carboxylic acids, sulfonic acids and their derivatives and also other ethylenically unsaturated compounds are polymerized in aqueous medium or organic medium at a pH of less than 5, and if necessary the remaining phosphonic acid ester groups of the copolymers obtained are hydrolyzed.

6. The process as claimed in claim 5, wherein the solution polymerization takes place in a mixture of water and/or organic solvents in the presence of a free radical-forming initiator, with the addition of equimolar amounts of mineral acid, at a temperature of from 0 to 120°C, preferably from 10 to 100°C, and at a total monomer concentration of from 1 to 80% by weight, preferably from 10 to 60% by weight.

7. The process as claimed in claim 5 or 6, wherein compounds of the formula 1 and ethylenically unsatu-rated carboxylic acids and/or sulfonic acids are copolymerized in a mixture of water and organic solvents, if necessary with the addition of mineral acids, in the presence of a free radical-forming initiator, and if necessary the remaining phosphonic ester groups of the copolymers obtained are then hydrolyzed by heating in a concentrated mineral acid solution.

8. The process as claimed in claim 5 or 6, wherein oil-soluble compounds of the formula 1 are copolymerized with oleophilic ethylenically unsaturated compounds in organic solvents with free-radical chain initiators and the remaining phosphonic ester groups of the copolymers obtained are then hydrolyzed by adding mineral acids at a pH of less than 5.

9. The process as claimed in any of claims 5 to 8, wherein the remaining phosphonic acid ester groups of the copolymers obtained are hydrolyzed by adding copolymers containing phosphonic acid groups, with the addition of water and distillation of the alcohol that is formed.

10. The use of copolymers prepared as claimed in any of claims 5 to 8 as antiscalants in the cleaning of machinery, bottle cleaning, steam generation, cool-ing water treatment and in oil conveyance, as complexing and/or sequestering agents in water treatment, in the production of leather and in textile and paper bleaching, and as builders and cobuilders in detergents.