CA1123450A - Process for the preparation of polyfunctional isocyanates from polymeric n-halogen amides - Google Patents
Process for the preparation of polyfunctional isocyanates from polymeric n-halogen amidesInfo
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- CA1123450A CA1123450A CA328,524A CA328524A CA1123450A CA 1123450 A CA1123450 A CA 1123450A CA 328524 A CA328524 A CA 328524A CA 1123450 A CA1123450 A CA 1123450A
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- acrylate
- chloramide
- tertiary amine
- methacrylamide
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F8/00—Chemical modification by after-treatment
- C08F8/30—Introducing nitrogen atoms or nitrogen-containing groups
- C08F8/32—Introducing nitrogen atoms or nitrogen-containing groups by reaction with amines
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- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
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Abstract
PROCESS FOR THE PREPARATION OF POLYFUNCTIONAL
ISOCYANATES FROM POLYMERIC N-HALOGEN AMIDES
ABSTRACT OF THE DISCLOSURE
A process for the preparation of polyfunctional isocyanate derivatives of the homo- or inter-polymers of acrylamide or methacrylamide, wherein a suitable N-chloramide derivative of the homo- or inter-polymer of the acrylamide or methacrylamide is reacted with a tertiary amine having a pKa value above 7 in the presence of an inert solvent.
ISOCYANATES FROM POLYMERIC N-HALOGEN AMIDES
ABSTRACT OF THE DISCLOSURE
A process for the preparation of polyfunctional isocyanate derivatives of the homo- or inter-polymers of acrylamide or methacrylamide, wherein a suitable N-chloramide derivative of the homo- or inter-polymer of the acrylamide or methacrylamide is reacted with a tertiary amine having a pKa value above 7 in the presence of an inert solvent.
Description
- llZ3~
BACKGROUND OF THE INVENTION
U. S. Patent 3,929,749 and Wright et al, Journal of ~ ~-Applied Polymer Science, 20, 3305-3311 (1976) describe the reaction of polymers containing amide groups with excess aqueous alkali hypochlorite in the presence of an inert solvent at temperatures from O to 15C to form isocyanates.
This process has drawbacks since, because of the presence of water, it is unavoidable that a portion of the isocyanate formed is hydrolytically decomposed during the processing of the reaction mixture. The corresponding amines are formed by the Hofmann reaction, through the unstable carbamic acid intermediate. These amines further react with addition-al isocyanates to form urea compounds, resulting in a -~
further lowing of the theoretical isocyanate yield. Thus, as shown in Example 15 of U. S. Patent 3,929,744, 5.2%
by weight of isocyanate groups are present when a polymer containing amide groups is reacted with sodium hypochlorite, ~ `
whereas only 3.25% by weight of isocyanate groups are measured after isolation of the isocyanate by removal of water by azeotropic distillation. Further, in the prior art system, the addition of deemulsifiers to the mixed ; aqueous-organic reaction mixture does not result in rapid separation of an aqueous phase and an organic isocyanate containing phase. Therefor, in this procedure, an isocyanate loss must also be accepted. The long separation times, which in the most favorable cases are at least several hours, and sometimes several days, are also a disadvantage in the processing system.
3~5~
DESCRIPTIO~ OF THE INVENTION
The present invention is directed to a process for the preparation of polyfunctional isocyanates prepared by : :
reacting a N-chloramide derivative of homopolymers or inter-polymers of acrylamide or methacrylamide with a tertiary amine having a PKa value of more than 7, in the presence of an inert solvent, at a temperature between about 20 to about 180C.
The ~chloramide derivatives utilized in the pro-cess of the invention are formed by chlorination of the appropriate amide group containing polymers. Suitable amide group containing polymers are acrylamide or methacrylamide homopolymers and acrylamide or methacrylamide interpolymers containing about 5 to 100 mole % acryl- or methacryl-amide, and free of functional groups which would interfere with ~-chloramide formation or the N-chloramide-amine reaction. A
group of suitable polymers are disclosed in U. S. Patent 3,929,744. Examples of suitable polymers include polyacryl- i~-amide, polymethacrylamide, as well as interpolymers or `
acrylamide or methacrylamide with at least one copolymeriz-able monomer, for example, styrene, methylstyrene, dimethyl-styrene, p-chlorostyrene, o-chlorostyrene and alkylacrylates, such as methyl acrylate, methylmethacrylate, ethyl acrylate, ~`.'7.'' ethyl methacrylate, butyl acrylate, hexylacrylate, decyl ~
acrylate, dodecyl acrylate, and the llke, as well as cross- .:
linked products of the aforementioned polymers and in-terpolymers prepared ~or example by mean6 o~
.' ~'.`'' ' `
: ':
.
~lZ;~45~
known crosslinking techniques, for example, usin~ divinyl crosslinking agents such as divinyl benzene or divinyl ether, for example, by employing about 1 to about 10 mole %
of a divinyl crosslinking agent. The molecular weight of the amide group containing polymers can vary widely.
Preferably, the average molecular weight of the uncrossed linked polymers is from about 1,000 to about 10,000. Most preferably, polymers with an average molecular weight from about 5,000 to, about 10,000 are employed.
Chlorination of amide groups is generally well known.
Chlorination of the amide-group-containing homo- and inter- ;~
polymers is preferably carried out by means of chlorine in an aqueous-mineral acid suspension preferably at tempera-tures of from about 0 to about 40C. For example, dilute, `~ ;
aqueous hydrochloric acid, sulfuric acid, or phosphoric acid are suitable as the aqueous, dilute mineral acid. In one process, one starts out with a neutral, aqueous suspension ~- -of the amide group containing polymers, and the hydrogen chloride formed during chlorination as by-product dissolves ~ ;
in the reaction mixture and the chlorination thus takes place in a dilute aqueous-hydrochloric medium. Preferably, such a process is started with dilute hydrochloric, or dilute sulfuric acid-aqueous suspensions of the amide group containing polymer. Chlorination proceeds exothermically and is preferably carried out at temperatures from about 0 to about 30C The use of temperatures higher than about 40C is disadvantageous because measurable quantities of carboxyl groups are formed by hydrolysis at higher temperatures. ;
3 - ---~
llZ34~
Chlorination can be ca,rried out at normal ambient pressure, as well as at an elevated pressure, The required reaction ', time declines with inçreasing pressure,` but for economic reasons, the pre,f,erred pressure'range is between about 1 and about 6 atm~ abs~ Since chlorination takes place in a ' heterogeneous system, a good mixing of the suspension is re~uired. The'reaction mixture should be sufficiently , dilute so that it can be'stirrred, or mixed in some other way, without difficulties. The preferred reaction batch ' çoncentr~tion is about 100 to 200 g of amide'group containing ~, polymer per liter of water or aqueous mineral acid. When - , the`above described PXocess conditions are maintained, '"
chlorination is complete after about 1~4 to 2 hours. ; , Depending upon the composit;on of the am;de group containing ~, pQlymers employed~ about 30 to 95% of the amide groups ~ ~
are converted to N-chloramide groups under these conditions. '' After completion of chlorination reaction, the modified polymer is the only sol~d substance in the suspension. ', , It can be sepa~ated verY easily by filtration or centrifuglng.
Selection of a suitable base is of critical importance ~ ,`
for the success of the process of the`invention. In accordance ~ith the ~nVent~Qn~ tertiary amines with a certain basicity ~' are employed~ The basicity constant PKa is used as a measure of the basicity. Tertiary amines suitable for use in the ''- ' pxocess of the'invent~on have to have a minimum basicity ' corresponding to a PKa value of more than 7, Suitable tertia,ry amines are aliphatic, cycloaliphatic and aromatic ~':
~ 4 - `~
. ` ,~ `'`"~ .
. ~ , .
amines, such as (the pertinent PKa values, in each case at 25C, are given in parentheses): Trimethylamine (9.80), triethylamine (10.74), tributylamine (9.89), 2.4.6-trimethylpyridine (7.45 - 7.63), tri-n-propylamine (10.74), ethyldimethylamine (10.06), propyldimethylamine (10.16), isopropyldimethylamine (10.38), methyldimethylamine (10.43), butyldimethylamine (10.31), 2.3.4.5-tetramethylpyridine ~7.78), and 2.3.4.5.6-pentamethylpyridine (8.75). Preferred tertiary amines are trimethylamine, triethylamine, tri-n- ~ -I0 propylamine and tri-n-butylamine. PKa values of various amines can be found in the conventional chemical handbooks.
In the case of aliphatic tertiary amines, special reference is made to L. Spialter et al., The Acyclic, Aliphatic Tertiary Amines, The McMillan Co., New York (1965), and, as to substituted pyridines, to Klingsberg, Heterocyclic Compounds Pyridine and Derivatives, part 2, Interscience Publishers, Inc., New York (1961).
The basicity of the tertiary amine used is of signifi-cance for the progress of the reaction, i.e. when polymers with the same N-chloramide content are used, the isocyanate yield is lower, the lower the pK value of the tertiary amine.
The tertiary amine is employed in the process of the invention in quantities of at least about one mole equivalent per mole of N-chloramide constituent in the polymer. ;The preferred equivalence ratio of N-chloramide constituent .. . . , . ~, ., ............................... ,- - - -~- .
: , , ~ . . .. .
~ ~1234~
to tertiary amine is 1 : 1 to 1 : 4. Greater quantities of tertiary amine can be used without being harmful, but should be avoided for economic reasons.
. .
Care must be taken in the selection of the inert organic solvent so that, under the given reaction conditions, ; it will react neither with the N--chloramide group, with the ~
isocyanate group or with the tertiary amine employed. ~ :
Suitable solvents are, for example, methylene chloride, l.l-dichloroethylene, chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene, pentane, hexane, ~ cyclohexane, heptane, octane, benzene, toluene, ethylbenzene, :.
; chlorobenzene, xylene, dichlorobenzene, d.ethyl ether, ,;
, tetrahydrofuran, dioxane, acetic methyl ester, acetic -butyl ester, and propionic methyl ester. Preferred inert 15~ solvents are toluene, xylene, chlorobenzene, acetic butyl ester, chloroform, tetrachloroethylene, carbon :~
tetrachloride, cyclohexane and dioxane. ~: ~
The preferred concentration of the reaction batch . ~ ` -is about 100 to about 200 g of polymer with N-chloramide content per liter of solvent, but lower, as well as higher ~- :
concentrations can also be used.
.
In the process of the invention, the reaction temperatures can range from about 20 to about 180C. Essentially, the :
reaction temperature depends upon the type of polymer used, its N-chloramide content, and the basicity of the tertiary amine. In the case of some starting materials the reaction ' ''' - . . , . ; ,, , -~Z3450 `:
will start spontaneously at room temperature, in some cases even very vigorously. Generally, the reaction is carried out at the boiling temperature of the solvent used. The preferred reaction temperatures are in the range of from about 65 to about 135C.
The reaction times in the process of the invention are reasonably short, generally only a few mlnutes. However, longer reaction times, e.g. a reaction time of an hour, can also be used without being harmful.
In order to carry out the process of the invention it is expedient to disperse the polymer containing the N- ;;
chloramide groups in the solvent and then to add the required minimum quantity of tertiary amine. In some cases, the reaction starts immediately, in other cases heating to the desired reaction temperature is necessary. If necessary, heating is continued for a desired time. After completion of the reaction, and cooling of the reaction mixture, the ~ ~
reaction mixture is worked up in a conventional manner to ~ `
obtain the product polyisocyanate in a useful form; for example the hydrochloride of the tertiary amine formed during the reaction is removed and the polymeric isocyanate ;-<~ -containing filtrate is concentrated under vaccum.
The filtrate containing the polymeric isocyanate can, `
of course, also be used directly in reactions, e.g. with compounds containing hydroxyl groups. ~-;:
There follows a number of Examples which are to be considered illustrative rather than limiting. All parts and percentages are by weight unless otherwise specified.
- All temperatures are degrees Centigrade unless otherwise specified.
EX~'IPLE 1 10 g of a copolymer of 10 parts methacrylamide, 50 parts methylmethacrylate and 40 parts butylacrylate were dispersed in 100 g 5% hydrochloric acid. Subsequently, chlorine was passed through the dispersion for 4 hrs. at 15 to 20C. After stripping of the excess chlorine with nitrogen, the polymeric N-chloramide was filtered with ;~-suction, washed with distilled water until neutral and dried at 35C under a vacuum (30 mbar).
10.2 g of polymeric N-chloramide with an active `~
15~ chlorine content of 3.1% were isolated, i.e. 77% of the amIde~ ~;
- ; groups of the polymer had been converted to chloramide.
. .
EXA~PLE 2 10 g of a copolymer of 20 parts methacrylamide, 40 parts methylmethacrylate and 40 parts butyl acrylate in 100 ~-g 5% hydrochloric acid were chlorinated at 20C for 30 ~
, minutes under a chlorine pressure of 4 bar. The N-chloramide ~ ~
:`
was isolated as in Example 1. 10.35 g of polymeric N-chloramide with an active chlorine content of 6.4~ were '~
~llZ3~o obtained, i.e. 8~/o of the amide groups were chlorinated.
:
10 g of polymeric N-halogen amide with an active chlorine content of 3.1% prepared by chlorination of a copolymer of 10 parts methacrylamide, 50 parts methylmethacrylate and 40 parts butyl acrylate were suspended in 100 ml toluene.
After the addition of 3 g of triethylamine, the mixture was quickly heated to 100C and left at this temperature for 30 min. Then, excess triethylamine and 20 ml toluene were distilled off. After cooling, the precipitated triethylamine hydrochloride and other undissolved con- `
stituents were removed and the filtrate concentrated under a vacuum. 9.5 g of resin with an isocyanate content of 3.4%
remained.
.
Example 3 was repeated, except that instead of toluene, the same quantities of chlorobenzene, dioxane and acetic butyl ester were used in each case. The quantities of polymeric isocyanate that were isolated, as well as their NCO contents have been compiled in Table 1.
'' ~' ,:
Table 1 Reaction Medium Quantity by weight of NCO Content polYmeric isocYanate (~6) .' chlorobenzene 9.3 g 3.35 dioxane 9.5 g 3.2 acetic butyl ester 9.25 g 3.5 _ g _ : :
1~234~ ~
10 g of polymeric N-halogen amide, prepared by - chlorination of a copolymer of 20 parts methacrylamide, 40 parts methylmethacrylate and 40 parts butyl acrylate, with an active chlorine content of 6.4%, in toluene as in ;~
Example 3, was converted to polymeric isocyanate with the addition of 5 g triethylamine. 9.25 g of a resin with an NCO content of 4.7% were obtained.
As described in the preceding examples, additional polymeric N-chloramides, in toluene, were converted to polymeric isocyanates with triethylamine.
Table 2 shows the composition of the polymers, the chlorine content of the polymeric N-halogen amides, as well as the NCO content of the resulting polymeric isocyanates.
EXAMPLE 7 ~ -10 g of polymeric N-halogen amide, prepared by chlorination of a copolymer of 20 parts acrylamide and 80 parts methylmethacrylate, with an active chlorine content of 7.7%, in toluene, were converted (as in Example 3) to a polymeric isocyanate with the addition of 5 g triethylamine.
4.8 g of polyisocyanate with an NCO content of 4.7%
were isolated.
,, -- 10 -- `
~1~34~;~
.
O-- ~ U~ ~D
t, o\O
~ ~ U~ Ln ,~ o Z _ _ a a~
_ _ Q) ~,~ ~ o o .,, ,~
E~
~,-~ ,, ~,~
~ o o o Ql ~Z .
E~ O ~ ~ :
C~ o ~' ~
_ a~ ~
o ~ ~ o ~ - ' ,, ~ ,, o . ~, . ,~
. -~ , o .,, ~.
,, ~o ~ ~ ~u o ~ ~
o ~ u ~ U
U
~ >1 ~ ~ ~
S~ ' ~ U ~ ~ ~ ~ ~ .:
~ E~
~1 oP o~ op op o~O op o~O "
O oo oo o oo ' ':' :: ;~
. , . .
4S~
~.
10 g of the polymeric N-halogen amide in Example 3 were suspended in 50 ml toluene, and a solution of 3 g trimethylamine in 50 ml toluene added thereto. The mixture was quickly heated to reflux temperature (110C). Gaseous excess trimethylamine escaped during heating up. The mixture was kept boiling for one hour, then cooled, tri- -methylamine hydrochloride removed by suction and the filtrate concentrated under a vacuum. 9.3 g of resin, with an NCO
.~ ~, ..
; content of 4.5~ were obtained as residue.
~.
10 g of polymeric, cross-linked N-halogen amide with an active chlorine content of 17%, prepared by chlorination of a polymethacrylamide cross-linked with 5% divinyl benzene, were suspended in 100 ml of toluene and, after addition of 20 g of triethylamine, treated for 30 minutes at 110C.
Cooling was followed by filtering with suction and washing of the residue with chloroform to remove the triethylamine -hydrochloride. 7.5 g of a white powder with an NCO content ~ ~;
of 9.8~ remained.
A mixture of 10 g of polymeric, cross-linked N-halogen amide of Example 6, 26 g tripropylamine and 100 ml chlorobenzene ;~
was heated for 10 min. to 130C. This was followed by suction ;
filtering, washing with chlorobenzene and drying of the :, .
~L~Z3~S0 residue. 7.7 g of polymeric, cross-linked isocyanate with an NCO content of 9.6~ were obtained.
WHAT IS CLAIMED IS:
~ 3 ;~:
BACKGROUND OF THE INVENTION
U. S. Patent 3,929,749 and Wright et al, Journal of ~ ~-Applied Polymer Science, 20, 3305-3311 (1976) describe the reaction of polymers containing amide groups with excess aqueous alkali hypochlorite in the presence of an inert solvent at temperatures from O to 15C to form isocyanates.
This process has drawbacks since, because of the presence of water, it is unavoidable that a portion of the isocyanate formed is hydrolytically decomposed during the processing of the reaction mixture. The corresponding amines are formed by the Hofmann reaction, through the unstable carbamic acid intermediate. These amines further react with addition-al isocyanates to form urea compounds, resulting in a -~
further lowing of the theoretical isocyanate yield. Thus, as shown in Example 15 of U. S. Patent 3,929,744, 5.2%
by weight of isocyanate groups are present when a polymer containing amide groups is reacted with sodium hypochlorite, ~ `
whereas only 3.25% by weight of isocyanate groups are measured after isolation of the isocyanate by removal of water by azeotropic distillation. Further, in the prior art system, the addition of deemulsifiers to the mixed ; aqueous-organic reaction mixture does not result in rapid separation of an aqueous phase and an organic isocyanate containing phase. Therefor, in this procedure, an isocyanate loss must also be accepted. The long separation times, which in the most favorable cases are at least several hours, and sometimes several days, are also a disadvantage in the processing system.
3~5~
DESCRIPTIO~ OF THE INVENTION
The present invention is directed to a process for the preparation of polyfunctional isocyanates prepared by : :
reacting a N-chloramide derivative of homopolymers or inter-polymers of acrylamide or methacrylamide with a tertiary amine having a PKa value of more than 7, in the presence of an inert solvent, at a temperature between about 20 to about 180C.
The ~chloramide derivatives utilized in the pro-cess of the invention are formed by chlorination of the appropriate amide group containing polymers. Suitable amide group containing polymers are acrylamide or methacrylamide homopolymers and acrylamide or methacrylamide interpolymers containing about 5 to 100 mole % acryl- or methacryl-amide, and free of functional groups which would interfere with ~-chloramide formation or the N-chloramide-amine reaction. A
group of suitable polymers are disclosed in U. S. Patent 3,929,744. Examples of suitable polymers include polyacryl- i~-amide, polymethacrylamide, as well as interpolymers or `
acrylamide or methacrylamide with at least one copolymeriz-able monomer, for example, styrene, methylstyrene, dimethyl-styrene, p-chlorostyrene, o-chlorostyrene and alkylacrylates, such as methyl acrylate, methylmethacrylate, ethyl acrylate, ~`.'7.'' ethyl methacrylate, butyl acrylate, hexylacrylate, decyl ~
acrylate, dodecyl acrylate, and the llke, as well as cross- .:
linked products of the aforementioned polymers and in-terpolymers prepared ~or example by mean6 o~
.' ~'.`'' ' `
: ':
.
~lZ;~45~
known crosslinking techniques, for example, usin~ divinyl crosslinking agents such as divinyl benzene or divinyl ether, for example, by employing about 1 to about 10 mole %
of a divinyl crosslinking agent. The molecular weight of the amide group containing polymers can vary widely.
Preferably, the average molecular weight of the uncrossed linked polymers is from about 1,000 to about 10,000. Most preferably, polymers with an average molecular weight from about 5,000 to, about 10,000 are employed.
Chlorination of amide groups is generally well known.
Chlorination of the amide-group-containing homo- and inter- ;~
polymers is preferably carried out by means of chlorine in an aqueous-mineral acid suspension preferably at tempera-tures of from about 0 to about 40C. For example, dilute, `~ ;
aqueous hydrochloric acid, sulfuric acid, or phosphoric acid are suitable as the aqueous, dilute mineral acid. In one process, one starts out with a neutral, aqueous suspension ~- -of the amide group containing polymers, and the hydrogen chloride formed during chlorination as by-product dissolves ~ ;
in the reaction mixture and the chlorination thus takes place in a dilute aqueous-hydrochloric medium. Preferably, such a process is started with dilute hydrochloric, or dilute sulfuric acid-aqueous suspensions of the amide group containing polymer. Chlorination proceeds exothermically and is preferably carried out at temperatures from about 0 to about 30C The use of temperatures higher than about 40C is disadvantageous because measurable quantities of carboxyl groups are formed by hydrolysis at higher temperatures. ;
3 - ---~
llZ34~
Chlorination can be ca,rried out at normal ambient pressure, as well as at an elevated pressure, The required reaction ', time declines with inçreasing pressure,` but for economic reasons, the pre,f,erred pressure'range is between about 1 and about 6 atm~ abs~ Since chlorination takes place in a ' heterogeneous system, a good mixing of the suspension is re~uired. The'reaction mixture should be sufficiently , dilute so that it can be'stirrred, or mixed in some other way, without difficulties. The preferred reaction batch ' çoncentr~tion is about 100 to 200 g of amide'group containing ~, polymer per liter of water or aqueous mineral acid. When - , the`above described PXocess conditions are maintained, '"
chlorination is complete after about 1~4 to 2 hours. ; , Depending upon the composit;on of the am;de group containing ~, pQlymers employed~ about 30 to 95% of the amide groups ~ ~
are converted to N-chloramide groups under these conditions. '' After completion of chlorination reaction, the modified polymer is the only sol~d substance in the suspension. ', , It can be sepa~ated verY easily by filtration or centrifuglng.
Selection of a suitable base is of critical importance ~ ,`
for the success of the process of the`invention. In accordance ~ith the ~nVent~Qn~ tertiary amines with a certain basicity ~' are employed~ The basicity constant PKa is used as a measure of the basicity. Tertiary amines suitable for use in the ''- ' pxocess of the'invent~on have to have a minimum basicity ' corresponding to a PKa value of more than 7, Suitable tertia,ry amines are aliphatic, cycloaliphatic and aromatic ~':
~ 4 - `~
. ` ,~ `'`"~ .
. ~ , .
amines, such as (the pertinent PKa values, in each case at 25C, are given in parentheses): Trimethylamine (9.80), triethylamine (10.74), tributylamine (9.89), 2.4.6-trimethylpyridine (7.45 - 7.63), tri-n-propylamine (10.74), ethyldimethylamine (10.06), propyldimethylamine (10.16), isopropyldimethylamine (10.38), methyldimethylamine (10.43), butyldimethylamine (10.31), 2.3.4.5-tetramethylpyridine ~7.78), and 2.3.4.5.6-pentamethylpyridine (8.75). Preferred tertiary amines are trimethylamine, triethylamine, tri-n- ~ -I0 propylamine and tri-n-butylamine. PKa values of various amines can be found in the conventional chemical handbooks.
In the case of aliphatic tertiary amines, special reference is made to L. Spialter et al., The Acyclic, Aliphatic Tertiary Amines, The McMillan Co., New York (1965), and, as to substituted pyridines, to Klingsberg, Heterocyclic Compounds Pyridine and Derivatives, part 2, Interscience Publishers, Inc., New York (1961).
The basicity of the tertiary amine used is of signifi-cance for the progress of the reaction, i.e. when polymers with the same N-chloramide content are used, the isocyanate yield is lower, the lower the pK value of the tertiary amine.
The tertiary amine is employed in the process of the invention in quantities of at least about one mole equivalent per mole of N-chloramide constituent in the polymer. ;The preferred equivalence ratio of N-chloramide constituent .. . . , . ~, ., ............................... ,- - - -~- .
: , , ~ . . .. .
~ ~1234~
to tertiary amine is 1 : 1 to 1 : 4. Greater quantities of tertiary amine can be used without being harmful, but should be avoided for economic reasons.
. .
Care must be taken in the selection of the inert organic solvent so that, under the given reaction conditions, ; it will react neither with the N--chloramide group, with the ~
isocyanate group or with the tertiary amine employed. ~ :
Suitable solvents are, for example, methylene chloride, l.l-dichloroethylene, chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene, pentane, hexane, ~ cyclohexane, heptane, octane, benzene, toluene, ethylbenzene, :.
; chlorobenzene, xylene, dichlorobenzene, d.ethyl ether, ,;
, tetrahydrofuran, dioxane, acetic methyl ester, acetic -butyl ester, and propionic methyl ester. Preferred inert 15~ solvents are toluene, xylene, chlorobenzene, acetic butyl ester, chloroform, tetrachloroethylene, carbon :~
tetrachloride, cyclohexane and dioxane. ~: ~
The preferred concentration of the reaction batch . ~ ` -is about 100 to about 200 g of polymer with N-chloramide content per liter of solvent, but lower, as well as higher ~- :
concentrations can also be used.
.
In the process of the invention, the reaction temperatures can range from about 20 to about 180C. Essentially, the :
reaction temperature depends upon the type of polymer used, its N-chloramide content, and the basicity of the tertiary amine. In the case of some starting materials the reaction ' ''' - . . , . ; ,, , -~Z3450 `:
will start spontaneously at room temperature, in some cases even very vigorously. Generally, the reaction is carried out at the boiling temperature of the solvent used. The preferred reaction temperatures are in the range of from about 65 to about 135C.
The reaction times in the process of the invention are reasonably short, generally only a few mlnutes. However, longer reaction times, e.g. a reaction time of an hour, can also be used without being harmful.
In order to carry out the process of the invention it is expedient to disperse the polymer containing the N- ;;
chloramide groups in the solvent and then to add the required minimum quantity of tertiary amine. In some cases, the reaction starts immediately, in other cases heating to the desired reaction temperature is necessary. If necessary, heating is continued for a desired time. After completion of the reaction, and cooling of the reaction mixture, the ~ ~
reaction mixture is worked up in a conventional manner to ~ `
obtain the product polyisocyanate in a useful form; for example the hydrochloride of the tertiary amine formed during the reaction is removed and the polymeric isocyanate ;-<~ -containing filtrate is concentrated under vaccum.
The filtrate containing the polymeric isocyanate can, `
of course, also be used directly in reactions, e.g. with compounds containing hydroxyl groups. ~-;:
There follows a number of Examples which are to be considered illustrative rather than limiting. All parts and percentages are by weight unless otherwise specified.
- All temperatures are degrees Centigrade unless otherwise specified.
EX~'IPLE 1 10 g of a copolymer of 10 parts methacrylamide, 50 parts methylmethacrylate and 40 parts butylacrylate were dispersed in 100 g 5% hydrochloric acid. Subsequently, chlorine was passed through the dispersion for 4 hrs. at 15 to 20C. After stripping of the excess chlorine with nitrogen, the polymeric N-chloramide was filtered with ;~-suction, washed with distilled water until neutral and dried at 35C under a vacuum (30 mbar).
10.2 g of polymeric N-chloramide with an active `~
15~ chlorine content of 3.1% were isolated, i.e. 77% of the amIde~ ~;
- ; groups of the polymer had been converted to chloramide.
. .
EXA~PLE 2 10 g of a copolymer of 20 parts methacrylamide, 40 parts methylmethacrylate and 40 parts butyl acrylate in 100 ~-g 5% hydrochloric acid were chlorinated at 20C for 30 ~
, minutes under a chlorine pressure of 4 bar. The N-chloramide ~ ~
:`
was isolated as in Example 1. 10.35 g of polymeric N-chloramide with an active chlorine content of 6.4~ were '~
~llZ3~o obtained, i.e. 8~/o of the amide groups were chlorinated.
:
10 g of polymeric N-halogen amide with an active chlorine content of 3.1% prepared by chlorination of a copolymer of 10 parts methacrylamide, 50 parts methylmethacrylate and 40 parts butyl acrylate were suspended in 100 ml toluene.
After the addition of 3 g of triethylamine, the mixture was quickly heated to 100C and left at this temperature for 30 min. Then, excess triethylamine and 20 ml toluene were distilled off. After cooling, the precipitated triethylamine hydrochloride and other undissolved con- `
stituents were removed and the filtrate concentrated under a vacuum. 9.5 g of resin with an isocyanate content of 3.4%
remained.
.
Example 3 was repeated, except that instead of toluene, the same quantities of chlorobenzene, dioxane and acetic butyl ester were used in each case. The quantities of polymeric isocyanate that were isolated, as well as their NCO contents have been compiled in Table 1.
'' ~' ,:
Table 1 Reaction Medium Quantity by weight of NCO Content polYmeric isocYanate (~6) .' chlorobenzene 9.3 g 3.35 dioxane 9.5 g 3.2 acetic butyl ester 9.25 g 3.5 _ g _ : :
1~234~ ~
10 g of polymeric N-halogen amide, prepared by - chlorination of a copolymer of 20 parts methacrylamide, 40 parts methylmethacrylate and 40 parts butyl acrylate, with an active chlorine content of 6.4%, in toluene as in ;~
Example 3, was converted to polymeric isocyanate with the addition of 5 g triethylamine. 9.25 g of a resin with an NCO content of 4.7% were obtained.
As described in the preceding examples, additional polymeric N-chloramides, in toluene, were converted to polymeric isocyanates with triethylamine.
Table 2 shows the composition of the polymers, the chlorine content of the polymeric N-halogen amides, as well as the NCO content of the resulting polymeric isocyanates.
EXAMPLE 7 ~ -10 g of polymeric N-halogen amide, prepared by chlorination of a copolymer of 20 parts acrylamide and 80 parts methylmethacrylate, with an active chlorine content of 7.7%, in toluene, were converted (as in Example 3) to a polymeric isocyanate with the addition of 5 g triethylamine.
4.8 g of polyisocyanate with an NCO content of 4.7%
were isolated.
,, -- 10 -- `
~1~34~;~
.
O-- ~ U~ ~D
t, o\O
~ ~ U~ Ln ,~ o Z _ _ a a~
_ _ Q) ~,~ ~ o o .,, ,~
E~
~,-~ ,, ~,~
~ o o o Ql ~Z .
E~ O ~ ~ :
C~ o ~' ~
_ a~ ~
o ~ ~ o ~ - ' ,, ~ ,, o . ~, . ,~
. -~ , o .,, ~.
,, ~o ~ ~ ~u o ~ ~
o ~ u ~ U
U
~ >1 ~ ~ ~
S~ ' ~ U ~ ~ ~ ~ ~ .:
~ E~
~1 oP o~ op op o~O op o~O "
O oo oo o oo ' ':' :: ;~
. , . .
4S~
~.
10 g of the polymeric N-halogen amide in Example 3 were suspended in 50 ml toluene, and a solution of 3 g trimethylamine in 50 ml toluene added thereto. The mixture was quickly heated to reflux temperature (110C). Gaseous excess trimethylamine escaped during heating up. The mixture was kept boiling for one hour, then cooled, tri- -methylamine hydrochloride removed by suction and the filtrate concentrated under a vacuum. 9.3 g of resin, with an NCO
.~ ~, ..
; content of 4.5~ were obtained as residue.
~.
10 g of polymeric, cross-linked N-halogen amide with an active chlorine content of 17%, prepared by chlorination of a polymethacrylamide cross-linked with 5% divinyl benzene, were suspended in 100 ml of toluene and, after addition of 20 g of triethylamine, treated for 30 minutes at 110C.
Cooling was followed by filtering with suction and washing of the residue with chloroform to remove the triethylamine -hydrochloride. 7.5 g of a white powder with an NCO content ~ ~;
of 9.8~ remained.
A mixture of 10 g of polymeric, cross-linked N-halogen amide of Example 6, 26 g tripropylamine and 100 ml chlorobenzene ;~
was heated for 10 min. to 130C. This was followed by suction ;
filtering, washing with chlorobenzene and drying of the :, .
~L~Z3~S0 residue. 7.7 g of polymeric, cross-linked isocyanate with an NCO content of 9.6~ were obtained.
WHAT IS CLAIMED IS:
~ 3 ;~:
Claims (9)
1. A method for the preparation of polyfunctional isocyanates which comprises reacting an N-chloramide group containing derivative of an acrylamide or methacrylamide homopolymer or interpolymer with a tertiary amine having a pKa value of more than 7, in the presence of an inert solvent, at a temperature of from about 20°C to about 180°C.
2. The method as in claim 1 wherein the inert solvent is selected from the group of aliphatic, cycloaliphatic and aromatic hydrocarbons, aliphatic, cycloaliphatic and aromatic halohydrocarbons, carboxylic esters and ethers.
3. The method as in claims 1 or 2 wherein the tertiary amine is selected from the group of trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine or 2,4,6-trimethylpyridine.
4. The method as in claim 1 where the equivalence ratio of N-chloramide group containing polymers to tertiary amine is between about 1:1 and about 1:4.
5. The method as in claim 1 where the reaction temperature is between about 65°C to about 135°C.
6. The method as in claims 4 or 5 wherein the tertiary amine is selected from the group of trimethylamine, triethyl-amine, tri-n-propylamine, tri-n-butylamine or 2,4,6-trimethyl-pyridine.
7. The method as in claim 1 wherein the N-chloramide derivative is an interpolymer of methacrylamide and acryl-amide, or of methacrylamide or acrylamide and styrene, methyl-styrene, dimethylstyrene, chlorostryrene and/or an alkyl acrylate.
8. The method as in claim 7 wherein the alkyl acrylate is methyl acrylate, methyl methacrylate, ethyl acrylate, ethylmethyl acrylate, butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, or dodecyl methacrylate.
9. The method as in claim 7 wherein the N-chloramide derivative is cross-linked by means of divinyl benzene or divinyl ether.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2841713A DE2841713C2 (en) | 1978-09-25 | 1978-09-25 | (meth)acrylamide! polymer polyfunctional isocyanate derivs. - obtd. by reacting N-chloramide deriv. of the polymer with tert. amine, giving prod. free from alkaline or urea gps. |
| DEP2841713.2 | 1978-09-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1123450A true CA1123450A (en) | 1982-05-11 |
Family
ID=6050404
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA328,524A Expired CA1123450A (en) | 1978-09-25 | 1979-05-28 | Process for the preparation of polyfunctional isocyanates from polymeric n-halogen amides |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5545790A (en) |
| BE (1) | BE878978A (en) |
| CA (1) | CA1123450A (en) |
| DE (1) | DE2841713C2 (en) |
| SU (1) | SU876061A3 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2932765C2 (en) * | 1979-08-13 | 1986-09-18 | Akzo Gmbh, 5600 Wuppertal | Use of alkali and urea group-free polyfunctional isocyanates for the production of paints |
| JPH0629296B2 (en) * | 1985-05-28 | 1994-04-20 | 日本ペイント株式会社 | Blocked acylisocyanate group-containing polymer and process for producing the same |
| JPS62146060U (en) * | 1986-03-07 | 1987-09-14 |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3483242A (en) | 1966-11-14 | 1969-12-09 | Allied Chem | Process for the preparation of isocyanates |
| DE2338755A1 (en) | 1973-07-31 | 1975-02-13 | B Ulrich Dr Kaczmar | Snake-cage polymer contg. N-chloro-substd. polymeric amides - for use as oxidn. and chlorination agents |
| US3929744A (en) | 1974-10-31 | 1975-12-30 | Cook Paint & Varnish Co | Polymeric isocyanates and process for making same |
| JPS51122188A (en) | 1975-04-12 | 1976-10-26 | Ryoichi Senjiyu | Method of aminating polyacrylamide |
| US4195142A (en) | 1977-06-24 | 1980-03-25 | Gaf Corporation | Modified tertiary amide polymers |
-
1978
- 1978-09-25 DE DE2841713A patent/DE2841713C2/en not_active Expired
-
1979
- 1979-05-28 CA CA328,524A patent/CA1123450A/en not_active Expired
- 1979-09-24 SU SU792822052A patent/SU876061A3/en active
- 1979-09-25 BE BE0/197293A patent/BE878978A/en not_active IP Right Cessation
- 1979-09-25 JP JP12215279A patent/JPS5545790A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| SU876061A3 (en) | 1981-10-23 |
| DE2841713A1 (en) | 1980-04-10 |
| BE878978A (en) | 1980-01-16 |
| JPS5545790A (en) | 1980-03-31 |
| DE2841713C2 (en) | 1986-10-16 |
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