Film-forming and thermocurable vinyl alcohol-substituted acrylamide copolymers and process for production thereof

A film-forming and thermocurable vinyl alcohol-substituted acrylamide copolymer consisting essentially of PA1 (1) 0 to 20 mole% of a unit of the formula ##STR1## wherein R represents a group selected from the class consisting of alkyl groups with 1 to 7 carbon atoms and aryl groups with 6 to 7 carbon atoms, and n is 0 or 1, PA1 (2) 30 to 70 mole% of a unit of the formula ##STR2## wherein n is as defined above, (3) 0 TO 20 MOLE% OF A UNIT OF THE FORMULA ##STR3## wherein R' represents a hydrogen atom or a lower alkyl group, and R is as defined above, and PA1 (4) 30 to 70 mole% of a unit of the formula ##STR4## wherein R' is as defined above, R" represents a group selected from the class consisting of alkyl groups with 1 to 18 carbon atoms, cycloalkyl groups with 5 to 6 carbon atoms, hydroxyalkyl groups with 2 to 4 carbon atoms and aryl groups with 6 to 7 carbon atoms, and R"' represents a group selected from the class consisting of a hydrogen atom and the group R", the amount of each unit being based on the total amount in moles of units (1) to (4); and a process for production thereof. The above polymers are especially useful as a paint vehicle to provide coated films of various useful properties such as anti-haze property.

This invention relates to novel film-forming and thermocurable vinyl 
alcohol-substituted acrylamide copolymers which can be used, for example, 
as vehicles for paints to provide coated films having superior properties, 
and to a process for producing these copolymers. The invention also 
relates to a coating composition containing said copolymer as a resin 
vehicle. 
More specifically, the invention relates to a copolymer which has far 
better water resistance and alkali resistance than the most analogous 
known copolymer, can be formed into a coating composition utilizing an 
alcohol-type solvent thus obviating the need to use toxic solvents, and 
which permits the controlling of the hardness and flexibility of coated 
films prepared from such a coating composition. 
In particular, the invention provides a film-forming and thermocurable 
vinyl alcohol-substituted acrylamide copolymer consisting essentially of 
(1) 0 TO 20 MOLE% OF A UNIT OF THE FORMULA 
##STR5## 
wherein R represents a group selected from the class consisting of alkyl 
groups with 1 to 7 carbon atoms and aryl groups with 6 to 7 carbon atoms, 
and n is 0 to 1, 
(2) 30 to 70 mole% of a unit of the formula 
##STR6## 
wherein n is as defined above, 
(3) 0 to 20 mole% of a unit of the formula 
##STR7## 
wherein R' represents a hydrogen atom or a lower alkyl group, and R is as 
defined above, and 
(4) 30 to 70 mole% of a unit of the formula 
##STR8## 
wherein R' is the same as defined above, R" represents a group selected 
from the class consisting of alkyl groups with 1 to 18 carbon atoms, 
cycloalkyl group with 5 to 6 carbon atoms, hydroxyalkyl groups with 2 to 4 
carbon atoms and aryl group with 6 to 7 carbon atoms, and R''' represents 
a group selected from the group consisting of a hydrogen atom and the 
groups R", 
the amount of each unit being based on the total amount in mole of units 
(1) to (4). 
"Kobunshi Kagaku", Vol. 16, pages 437-440, 1959 describes the 
copolymerization of acrylamide and vinyl acetate. This article describes a 
process similar to process (C) of the present invention to be described 
except that the alcohol reactant is not used and a copolymer of vinyl 
acetate and acrylamide is hydrolyzed in the presence of a basic compound 
such as potassium hydroxide. It is reported that the resulting product is 
a four-component copolymer containing acrylamide, acrylic acid, vinyl 
acetate and vinyl alcohol. Copolymers containing a substantial amount of 
an acrylic acid unit have poor water resistance. Furthermore, the article 
gives no statement about the properties of the resulting copolymer. 
Japanese Patent Publication No. 26827/67 (published on Dec. 19, 1967) 
discloses a saponification product of a copolymer with an acrylamide 
content of 0.4 to 17 mole% which is obtained by saponifying 75 to 95 mole% 
of acetic acid groups contained in a copolymer of vinyl acetate and 
acrylamide, and is useful as a textile finishing agent, especially a 
textile size used in weaving. This copolymer is distinguished from the 
copolymer of this invention in that it corresponds to a copolymer of the 
invention in which R" and R''' in unit (4) are both hydrogen atoms. The 
copolymer of this patent has much lower water resistance and alkali 
resistance than the copolymer of this invention, as can be seen also from 
its utility. 
For many years, the present inventors worked on the development of 
film-forming and thermocurable vinyl alcohol-substituted acrylamide 
copolymers having unique and excellent properties. The work lead to the 
successful development of a modified copolymer consisting of the units 
described hereinabove which has not been described in the literature, and 
to the discovery that this novel copolymer finds a wide range of 
applications in the field of coating techniques. 
The novel modified copolymer can be used, for example, as an anti-haze 
agent, a paint vehicle, a surface treating agent for leather, a base agent 
for extraction of oil in water, a primer for adhesion of metal to 
plastics, and an anionic flocculant. When it is used as an anti-haze 
agent, or as a surface coating agent for metal or glass, an aqueous or 
organic solvent solution of the modified copolymer is coated on the 
surface of glass, a mirror or metal, and dried to provide a coating having 
an anti-haze effect. By heat-treating the resulting coating, the copolymer 
partially undergoes cross-linking, lactamization or lactonization, and the 
coating attains superior water resistance. 
The hardness and flexibility of the coating can be changed as desired by 
suitably selecting the types and amounts of the constituent units of the 
copolymer. Hence, the modified copolymer is useful in a wide range of 
applications. 
It is an object of this invention to provide a new type of film-forming and 
thermocurable vinyl alcohol-substituted acrylamide copolymer. 
Another object of the invention is to provide a process for producing said 
copolymer. 
The above and other objects of the invention along with its advantages will 
become more apparent from the following description. 
The copolymer of the invention consists essentially of the following units 
(1) to (4): 
##STR9## 
wherein R and n are as defined above, 
##STR10## 
wherein n is as defined above, 
##STR11## 
wherein R and R' are defined above, and 
##STR12## 
wherein R', R" and R''' are as defined above. 
The amounts based on the total amount in mole of units (1) to (4) are: 
0 to 20 mole%, preferably 0 to 10 mole%, of unit (1), 
(30 to 70 mole%, preferably 35 to 65 mole%, of unit (2), 
0 to 20 mole%, preferably 0 to 10 mole%, of unit (3) and 
30 to 70 mole%, preferably 35 to 65 mole%, of unit (4). 
Preferred copolymers are those in which units (2) and (4) form combinations 
of the formula 
##STR13## 
wherein R', R", R'", and n are as defined hereinabove, and the content of 
the combination unit is at least about 30 mole%, preferably about 40 to 
about 100 mole%, based on the total amount in moles of units (1) to (4). 
The amount of the combined unit can be determined from the C.sup.13 NMR 
spectra of the copolymer of this invention and the copolymer used as a 
starting material for it. 
The copolymer of the invention has a number average molecular weight (in 
dimethyl formamide), M.sub.n, of preferably about 500 to about 100,000, 
more preferably about 1000 to about 50,000, as measured by a vapor 
pressure molecular weight measuring device. 
The copolymer of this invention can be produced by various processes. In 
particular, the following processes (A) to (C) can be exemplified. 
[I] Process (A) 
A copolymer consisting essentially of a unit of the formula 
##STR14## 
wherein R represents a group selected from the class consisting of alkyl 
groups with 1 to 7 carbon atoms and acryl groups with 6 or 7 carbon atoms, 
and n is 0 or 1, 
and a unit of the formula 
##STR15## 
wherein R' represents a hydrogen atom or a lower alkyl group, and R is as 
defined, 
is reacted with an amine selected from primary and secondary amines of the 
formula 
EQU NH.sub.2 R" 
and 
EQU NHR"R'" 
wherein R" represents a group selected from the class consisting of alkyl 
groups with 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, 
cycloalkyl groups with 5 to 6 carbon atoms, hydroxyalkyl groups with 2 to 
4 carbon atoms and aryl groups with 6 to 7 carbon atoms, and R'" is a 
group selected from the class consisting of a hydrogen atom and the groups 
R". 
As a result of the above reaction, the unit (1) is converted partly or 
wholly into a unit of the following formula 
##STR16## 
wherein n is as defined hereinabove and the unit (3) is converted partly 
or wholly into a unit of the formula 
##STR17## 
wherein R', R" and R'" are as defined hereinabove. 
The copolymer consisting essentially of units (1) and (3), used as a 
starting material in process (A), can be obtained by known methods 
disclosed, for example, in Japanese Patent Publication No. 9950/70 
(published on Apr. 10, 1970), German OLS No. 2641922 (laid open on Mar. 
24, 1977), and Japanese Laid-Open Patent Publications Nos. 44282/75 (laid 
open on Apr. 21, 1975) and 36181/77 (laid open on Mar. 19, 1977). 
According to the methods disclosed in the two Japanese Laid-Open Patent 
Publications cited above, the starting copolymer consisting essentially of 
units (1) and (3) can be prepared by copolymerizing an unsaturated 
carboxylic acid ester (1') for forming unit (1) 
##STR18## 
wherein R and n are as defined with regard to unit (1), with an 
acrylic-type carboxylic acid ester (3') for forming unit (3) 
##STR19## 
wherein R is as defined with regard to unit (3), in the presence of a 
catalyst composed mainly of an organo-aluminum compound of the formula 
EQU AlY.sub.m X.sub.3-m 
wherein Y represents an alkyl group, X represents a halogen atom, and 
0&lt;m&lt;3. 
The starting copolymer may also be a highly random copolymer obtained by an 
ordinary free radical copolymerization method which comprises 
copolymerizing 1 mole of the aforesaid unsaturated ester of a carboxylic 
acid and 0.05 to 2 moles of the aforesaid acrylic-type carboxylic acid 
ester in the presence of a radical polymerization catalyst while feeding 
them continuously. 
Of these starting copolymers, those produced by the methods suggested in 
the above-cited Japanese Laid-Open Patent Publications Nos. 44282/75 and 
36181/77 are especially preferred for process (A) because the unsaturated 
carboxylic acid ester unit (1) and the acrylic-type carboxylic acid unit 
(3) are aligned highly alternately, and these copolymers are of straight 
chain, thus serving to form modified copolymers containing the combined 
units described hereinabove. 
Examples of preferred unsaturated esters of formula (1') are unsaturated 
esters of carboxylic acids with 3 to 10 carbon atoms. Specific examples 
include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, 
vinyl caproate, vinyl valerate, vinyl benzoate, allyl acetate, allyl 
propionate, allyl benzoate, isopropenyl formate, isopropenyl acetate, 
isopropenyl propionate, methallyl acetate, methallyl propionate, 1-butenyl 
acetate, and 1-butenyl propionate. They may be used either singly or as 
mixtures. 
It is preferred to use in the process of this invention a copolymer 
containing a unit of an organic carboxylic acid ester of an unsaturated 
alcohol with 2 to 4 carbon atoms as the unsaturated carboxylic acid ester 
unit. More preferably, the alcohol moiety of the unsaturated carboxylic 
acid ester unit is vinyl alcohol or allyl alcohol. 
Preferred acrylic-type carboxylic acid esters of formula (3') are those 
containing 4 to 10 carbon atoms, especially 4 to 8 carbon atons. Specific 
examples include acrylic acid esters such as methyl acrylate, ethyl 
acrylate, propyl acrylate, butyl acrylate, phenyl acrylate and benzyl 
acrylate; methacrylic acid esters such as methyl methacrylate, ethyl 
methacrylate, propyl methacrylate, butyl methacrylate, phenyl 
methacrylate, benzyl methacrylate, and tolyl methacrylate; 
.alpha.-substituted acrylic acid esters such as methyl 
.alpha.-phenylacrylate, ethyl .alpha.-phenylacrylate and ethyl 
.alpha.-ethylacrylate; .beta.-substituted acrylic acid esters such as 
methyl crotonate and ethyl crotonate. Of these, the acrylic acid esters 
and methacrylic acid esters are preferred. These compounds can be used 
either singly or as admixtures. 
In the copolymerization of the unsaturated carboxylic acid ester of formula 
(1') with the acrylic-type carboxylic acid ester of formula (3'), a small 
amount of a third monomer copolymerizable with the ester (1') and/or the 
ester (3') may be added. Examples of the third monomer are .alpha.-olefins 
such as ethylene, propylene, 1-butene or 4-methyl-1-pentene, dienes such 
as butadiene or isoprene, aromatic olefins such as styrene or 
.alpha.-methylstyrene, and polar vinyl compounds such as vinyl chloride, 
acrylamide, acrylonitrile or methacrylonitrile. The purpose of adding the 
third monomer is to improve various properties required of the modified 
copolymer, such as higher flexibility, water resistance and rigidity 
according to its use. The amount of the third monomer should be small to 
such an extent that in the copolymer obtained by copolymerizing the 
unsaturated carboxylic acid ester of formula (1') with the acrylic-type 
carboxylic acid ester of formula (3'), the proportion of unit (1) should 
be limited to 30 to 70 mole%, preferably 35 to 65 mole%, and the 
proportion of unit (3), to 30 to 70 mole%, preferably 35 to 65 mole%. If 
the amount of the third component is larger than the specified limit, the 
proportions of units (2) and (4) in the resulting modified copolymer fall 
outside the ranges described and claimed in the present application, and 
such a modified copolymer can no longer form coatings of superior quality. 
According to the process (A), the starting copolymer consisting essentially 
of 30 to 70 mole%, preferably 35 to 65 mole%, of unit (1) and 30 to 70 
mole%, preferably 35 to 65 mole%, of unit (3), the amounts being based on 
the total amount of units (1) and (3) is reacted with the amine of the 
formula NH.sub.2 R" or NHR"R'''. 
Examples of the primary amine are alkylamines with 1 to 18 carbon atoms 
such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, 
pentylamine, hexylamine, octylamine, dodecylamine, tetradecylamine, 
pentadecylamine and octadecylamine; cycloalkylamine containing 5 and 6 
carbon atoms such as cyclohexylamine; acrylamines with 6 and 7 carbon 
atoms such as aniline, toluidine or benzylamine; and alkanolamines with 2 
to 4 carbon atoms such as ethanolamine or propanolamine. Examples of the 
secondary amine are dialkylamines with 1 to 18 carbon atoms such as 
dimethylamine, diethylamine, dipropylamine, diisopropylamine, 
dibutylamine, dipentylamine, dihexylamine or dioctylamine; arylamines or 
heterocyclic amines such as diphenylamine, ditolylamine, dibenzylamine, 
piperidine or piperazine; and dialkanolamines with 4 to 8 carbon atoms 
such as diethanolamine or dipropanolamine. 
In process (A), the reaction between the starting copolymer and the amine 
can be performed in the presence or absence of a reaction solvent. 
Usually, the reaction is carried out using an amine in an amount 
sufficient to act as a solvent. If desired, a solvent may be separately 
used. Such reaction solvents include aromatic hydrocarbons such as 
benzene, toluene or xylene; alcohols such as methanol, ethanol or 
propanol; and ethers such as diethyl ether, ethylene glycol dimethyl ether 
or tetrahydrofuran. 
The reaction can be performed easily with stirring while maintaining the 
temperature at usually 0.degree. to about 300.degree. C., preferably about 
20.degree. to about 250.degree. C. under sufficient pressures to maintain 
the reaction system in the liquid phase. Usually, the pressure is 
atmospheric pressure to about 20 kg/cm.sup.2. 
When no other solvent is used, and the amine as a reactant is used in an 
amount sufficient to serve also as a solvent, the starting copolymer is 
usually insoluble or only slightly soluble in the reaction system, but 
with the progress of the amidation reaction, the resulting modified 
polymer dissolves in the reaction system. The final modified polymer can 
be recovered in a customary manner by evaporating off the excess of the 
amine, the by-product alcohol and amide and optionally the solvent from 
the reaction mixture, and separating the precipitated modified copolymer, 
washing it and drying it; or by placing the reaction mixture in a solvent 
incapable of dissolving the final modified copolymer to precipitate the 
copolymer, and separating, washing and drying the separated copolymer. 
Thus, as a result of process (A), unit (1) is converted partly or wholly to 
unit (2), and unit (3) is converted partly or wholly to unit (4). Hence, a 
modified copolymer consisting substantially of units (2) and (4) can be 
formed. By properly controlling the reaction temperature, the reaction 
time, the concentration of the amine, and the concentration of the 
starting copolymer, and thus converting the constituent units of the 
starting copolymer partly into the unsaturated alcohol unit (2) and the 
acrylamide unit (4), there can be obtained a three-component modified 
copolymer composed of the unsaturated alcohol unit (2), the acrylamide 
unit (4) and the acrylic acid-type carboxylic acid ester unit (3), another 
three-component modified copolymer composed of the unsaturated alcohol 
unit (2), the acrylamide unit (4) and the unsaturated carboxylic acid 
ester unit (1) and a four-component modified copolymer composed of the 
unsaturated alcohol unit (2), the acrylamide unit (4), the unsaturated 
carboxylic acid ester unit (1) and the acrylic-type carboxylic acid ester 
unit (3). 
[II] Process (B) 
A copolymer consisting essentially of a unit of the formula 
##STR20## 
wherein n is 0 or 1, and a unit of the formula 
##STR21## 
wherein R' represents a hydrogen atom or a lower alkyl group, and R 
represents a group selected from the class consisting of alkyl groups with 
1 to 7 carbon atoms and aryl groups with 6 to 7 carbon atoms, 
is reacted with an amine selected from primary and secondary amines of the 
formulae 
EQU NH.sub.2 R" 
and 
EQU NHR"R''' 
wherein R" represents a group selected from the class consisting of alkyl 
groups with 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, 
cycloalkyl groups with 5 to 6 carbon atoms, cycloalkyl groups with 2 to 4 
carbon atoms and aryl groups with 6 to 7 carbon atoms and R''' represents 
a group selected from the class consisting of a hydrogen atom and the 
groups R". 
As a result of this reaction, the unit (3) is converted partly or wholly 
into unit (4) of the formula 
##STR22## 
wherein R', R" and R''' are as defined hereinabove. 
The starting copolymer consisting essentially of units (2) and (3) can be 
prepared by known methods disclosed, for example, in Japanese Laid-Open 
Patent Publications Nos. 44282/75 (laid open on Apr. 21, 1975), 36181/77 
(laid open on Mar. 19, 1977), 63990/77 (laid open on May 26, 1977), and 
63991/77 (laid open on May 26, 1977). 
One typical method comprises reacting the starting copolymer formed from 
the unsaturated carboxylic acid ester of formula (1') and the acrylic-type 
carboxylic acid ester of formula (3') with an alcohol in the presence of a 
basic compound (see the above-cited Japanese Laid-Open Publications Nos. 
63990/77 and 63991/77). This method will be more specifically described 
below. 
The alcohol includes, for example, methanol, ethanol, propanol, butanol, 
amyl alcohol, and cyclohexanol, but methanol is commonly employed. 
Generally, the alcohol is used in a large excess to cause it to serve also 
as a reaction solvent. In addition to the alcohol, another solvent may be 
used. Examples of the other solvent are hydrocarbons such as pentane, 
hexane, benzene, toluene or xylene; ketones such as acetone, methyl ethyl 
ketone, methyl isobutyl ketone or diethyl ketone; and halogenated 
hydrocarbons such as methylene chloride and chloroform. 
The reaction between the copolymer and the alcohol is carried out in the 
presence of a basic compound. Examples of the basic compound are alkali 
metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium 
hydroxide; alkali metal oxides such as lithium oxide, sodium oxide and 
potassium oxide; alkaline earth metal hydroxides such as calcium hydroxide 
and barium hydroxide; alkali metal alkoxides such as lithium methoxide, 
lithium ethoxide, lithium propoxide, lithium butoxide, sodium methoxide, 
sodium ethoxide, sodium propoxide, sodium butoxide; potassium methoxide, 
potassium ethoxide, potassium propoxide and potassium butoxide; organic 
alkali metal compounds such as butyl lithium and phenyl lithium; organic 
basic compounds such as ethylamine, diethylamine, triethylamine, 
propylamine, dipropylamine, pyridine and quinoline; and ammonia. Of these, 
the alkali metal hydroxides or alkoxides are preferred. 
The basic compound is used after directly dissolving it in an alcohol, or 
dissolving a small amount of it in water and then mixing the aqueous 
solution with an alcohol. In the latter case, the amount of water should 
be minimized because excessive water results in the comsumption of the 
basic compound by saponification. 
The amount of the basic compound is 0.01 to 10% by weight, preferably 0.05 
to 5% by weight, based on the copolymer. 
The aforesaid reaction is carried out by stirring a mixture consisting of 
the copolymer composed of units (1) and (3), the basic compound, the 
alcohol and optionally a solvent at a temperature of 20.degree. to 
200.degree. C., preferably 30.degree. to 100.degree. C., under sufficient 
pressures to maintain the reaction system in the liquid phase. It is 
preferred that at this time, the starting copolymer containing units (1) 
and (3) be dissolved in the reaction system. When an alcohol such as 
methanol, ethanol or propanol is used in an amount sufficient to cause it 
serve also as a solvent, the starting copolymer dissolves in the reaction 
system, but as the alcoholysis reaction proceeds, the product precipitates 
as an insoluble resin powder. The desired modified copolymer can be 
obtained by separating the precipitate by filtration and washing and 
drying it in a customary manner. When a solvent capable of dissolving the 
modified copolymer is used as a reaction solvent, the crude product is 
separated by evaporating off the solvent, and then washed with another 
solvent, followed by drying it to afford the desired copolymer containing 
units (2) and (3). 
Preferred starting copolymers are those obtained by the aforesaid methods 
which are of straight chain and in which units (2) and (3) are aligned 
highly alternately, because they serve to form the combined units (2) and 
(4) or (4) and (2) described hereinabove. 
Examples of the unsaturated carboxylic acid ester of formula (1') and the 
acrylic-type carboxylic acid ester of formula (2') used in producing the 
starting copolymer for process (B) are those already exemplified 
hereinabove with regard to process (A). 
According to the process (B), the starting copolymer consisting essentially 
of 30 to 70 mole%, preferably 35 to 65 mole%, of unit (2) and 30 to 70 
mole%, preferably 35 to 65 mole%, of unit (3), the amounts being based on 
the total amount of the units (2) and (3) is reacted with the amine of 
formula NH.sub.2 R" or NHR"R'''. Examples of the amine are the same as 
those already given hereinabove with regard to process (A). 
In process (B) also, the reaction of the starting copolymer with the amine 
can be carried out in the presence or absence of a reaction solvent. 
Usually, the reaction is carried out using the amine in an amount 
sufficient to cause it to serve also as a solvent. If desired, a reaction 
solvent may be separately used. Examples of such other solvent are those 
given hereinabove with regard to process (A). 
The reaction can be easily performed with stirring at a temperature of 
usually about -70.degree. C. to about 300.degree. C., preferably about 
-30.degree. C. to about 200.degree. C. under sufficient pressures to 
maintain the reaction system in the liquid phase. The pressure is about 
atmospheric pressure to about 10 kg/cm.sup.2. The reaction product can be 
separated and collected from the reaction mixture in the same way as 
described hereinabove with regard to process (A). 
Thus, by process (B), unit (3) is converted partly or wholly to unit (4). 
When unit (3) is partly converted to unit (4), a modified copolymer 
composed of the unsaturated alcohol unit (2), the acrylic-type carboxylic 
acid ester unit (3) and the acrylamide unit (4) can be formed. When the 
entire unit (3) is converted to unit (4), a modified copolymer composed of 
units (2) and (4) can be formed. 
Thus, process (B) affords a modified copolymer consisting essentially of 30 
to 70 mole%, preferably 35 to 65 mole%, of unit (2), 0 to 20 mole%, 
preferably 0 to 10 mole%, of unit (3), and 30 to 70 mole%, preferably 35 
to 65 mole%, of unit (4). 
[III] Process (C) 
A copolymer consisting essentially of a unit of the formula 
##STR23## 
wherein R represents a group selected from the class consisting of alkyl 
groups with 1 to 7 carbon atoms and aryl groups with 6 to 7 carbon atoms, 
and n is 0 or 1, 
and a unit of the formula 
##STR24## 
wherein R' represents a hydrogen atom or a lower alkyl group, R" 
represents a group selected from the class consisting of alkyl groups with 
1 to 18 carbon atoms, cycloalkyl groups with 5 to 6 carbon atoms, 
hydroxyalkyl groups with 2 to 4 carbon atoms and aryl groups with 6 to 7 
carbon atoms, and R''' represents a group selected from the class 
consisting of a hydrogen atom and the groups R", 
is reacted with an alcohol in the presence of a basic compound. 
As a result of this reaction, unit (1) is converted partly or wholly into 
unit (2) of the formula 
##STR25## 
wherein n is as defined hereinabove. 
The starting copolymer consisting essentially of units (1) and (4) for use 
in process (C) can be produced, for example in accordance with the method 
disclosed in Japanese Laid-Open Patent Publication No. 63991/77, by the 
free radical copolymerization of an unsaturated ester of a carboxylic acid 
of formula (1') for forming unit (1) 
##STR26## 
wherein R and n are the same as defined hereinabove with regard to unit 
(1), 
with an N-substituted acrylamide of formula (4') to form unit (4) 
##STR27## 
wherein R', R" and R''' are as defined above with regard to unit (4). 
Example of the unsaturated carboxylic acid ester (1') are the same as those 
already given hereinabove with regard to process (A). Examples of the 
N-substituted acrylamide of formula (4') include N-methyl acrylamide, 
N-ethyl acrylamide, N-propyl acrylamide, N-isopropyl acrylamide, N-butyl 
acrylamide, N-n-hexyl acrylamide, N-n-octyl acrylamide, N-n-decyl 
acrylamide, N-n-dodecyl acrylamide, N-n-pentadecyl acrylamide, 
N-n-octadecyl acrylamide, N-cyclohexyl acrylamide, N-phenyl acrylamide, 
N-p-tolyl acrylamide, N-benzyl acrylamide, N,N-dimethyl acrylamide, 
N,N-dipropyl acrylamide, N,N-diisopropyl acrylamide, N,N-dibutyl 
acrylamide, N,N-di-n-hexyl acrylamide, N,N-dicyclohexyl acrylamide, 
N,N-diphenyl acrylamide, N,N-dibenzyl acrylamide, N-methyl methacrylamide, 
N-ethyl methacrylamide, N-n-propyl methacrylamide, N-n-butyl 
methacrylamide, N-n-hexyl methacrylamide, N-n-dodecyl methacrylamide, 
N-n-pentadecyl methacrylamide, N-n-octadecyl methacrylamide, N-cyclohexyl 
methacrylamide, N-phenyl methacrylamide, N-benzyl methacrylamide, 
N,N-dimethyl methacrylamide, N,N-di-n-propyl methacrylamide, 
N,N-di-n-butyl methacrylamide, N,N-dicyclohexyl methacrylamide, 
N,N-diphenyl methacrylamide, N-methyl-.alpha.-ethyl acrylamide, 
N-ethyl-.alpha.-ethyl acrylamide, N-n-propyl-.alpha.-ethyl acrylamide, 
N-n-butyl-.alpha.-ethyl acrylamide, N,N-dimethyl-.alpha.-ethyl acrylamide, 
N,N-diethyl-.alpha.-ethyl acrylamide, N,N-dipropyl-.alpha.-ethyl 
acrylamide, N,N-dibutyl-.alpha.-ethyl acrylamide, N-methyl-.beta.-methyl 
acrylamide, N-ethyl-.beta.-methyl acrylamide, N-n-propyl-.beta.-methyl 
acrylamide, N-n-butyl-.beta.-methyl acrylamide, N,N-dimethyl-.beta.-methyl 
acrylamide, N,N-diethyl-.beta.-methyl acrylamide, 
N,N-di-n-propyl-.beta.-methyl acrylamide, and N,N-di-n-butyl-.beta.-methyl 
acrylamide. 
The acrylamide component in the copolymer may be one, or a mixture of at 
least two, of these acrylamide compounds. The use of acrylamides or 
methacrylamides with 3 to 21 carbon atoms is preferred. 
In the free radical copolymerization of the unsaturated carboxylic acid 
ester of formula (1') with the N-substituted acrylamide of formula (4'), a 
small amount of a third monomer copolymerizable with components (1') 
and/or (4') may be used. Examples of the third monomer are free radical 
polymerizable olefins such as ethylene or styrene and polar vinyl 
compounds such as vinyl chloride, vinylidene chloride, acrylonitrile and 
methacrylononitrile. The purpose of adding the third monomer is to impart 
higher flexibility, water resistance and rigidity, etc. to the modified 
copolymer composed mainly of units (2) and (4) obtained by process (C). 
The amount of the third monomer should be small to such an extent that in 
the resulting copolymer, the proportion of each of the units (1) and (4) 
is 30 to 70 mole%, preferably 35 to 65 mole%. If the amount is larger than 
the specified range, the proportions of the components (1') and (4') fall 
outside the range described and claimed in the present application, and 
the resulting modified copolymer can no longer give films having superior 
properties. 
According to process (C), the starting copolymer consisting essentially of 
30 to 70 mole%, preferably 35 to 65 mole%, of unit (1) and 30 to 70 mole%, 
preferably 35 to 65 mole%, of unit (4) is reacted with an alcohol in the 
presence of a basic compound. 
Examples of usable alcohols are methanol, ethanol, propanol, butanol, amyl 
alcohol, and cyclohexanol. Usually, methanol is used. Generally, the 
alcohol is used in a large excess in order to cause it to act also as a 
reaction solvent. Other solvents may be used together with the alcohol. 
Examples of the other solvent are hydrocarbons such as pentane, hexane, 
benzene, toluene and xylene; ketones such as acetone, methyl ethyl ketone, 
methyl isobutyl ketone and diethyl ketone; and halogenated hydrocarbons 
such as methylene chloride and chloroform. 
The reaction between the copolymer and the alcohol is carried out in the 
presence of a basic compound. Examples of the basic compound that can be 
used are alkali metal hydroxides such as lithium hydroxide, sodium 
hydroxide and potassium hydroxide; alkali metal oxides such as lithium 
oxide, sodium oxide and potassium oxide; alkaline earth metal hydroxides 
such as calcium hydroxide and barium hydroxide; alkali metal alkoxides 
such as lithium methoxide, lithium ethoxide, lithium propoxide, lithium 
butoxide, sodium methoxide, sodium ethoxide, sodium propoxide, sodium 
butoxide, potassium methoxide, potassium ethoxide, potassium propoxide and 
potassium butoxide; organic alkali metal compounds such as butyl lithium 
and phenyl lithium; organic basic compounds such as ethylamine, 
diethylamine, triethylamine, propylamine, dipropylamine, pyridine and 
quinoline; and ammonia. Of these, the alkali metal hydroxides and 
alkoxides are preferred. 
The basic compound is used after directly dissolving it in an alcohol; or 
dissolving it in a small amount of water and mixing the aqueous solution 
with alcohol. In the latter case, the amount of water should be minimized 
since excessive water results in the consumption of the basic compound by 
saponification. The amount of the basic compound used is 0.01 to 10% by 
weight, preferably 0.05 to 5% by weight, based on the copolymer. 
The reaction is performed by stirring a mixture composed of the copolymer 
consisting of units (1) and (4), the basic compound, the alcohol and 
optionally another solvent at a temperature of 20.degree. to 200.degree. 
C., preferably 30.degree. to 100.degree. C., under sufficient pressures to 
maintain the reaction system in the liquid phase. At this time, it is 
preferred that the copolymer containing units (1) and (4) be dissolved in 
the reaction system. This reaction proceeds while the product remains 
dissolved in the alcohol solution. The desired product can therefore be 
recovered, for example, by (1) a re-precipitation method which comprises 
pouring the reaction mixture in a large excess of a poor solvent for it 
(e.g., ketones such as acetone or methyl ethyl ketone; esters such as 
methyl acetate and ethyl acetate; and hydrocarbons such as toluene, 
benzene and hexane); (2) a method which comprises pouring the poor solvent 
into the reaction mixture after the reaction, to precipitate the product; 
(3) a method which comprises precipitating the product as an insoluble 
resin powder with the progress of the reaction by using a mixture of the 
poor solvent and alcohol; or (4) a method which comprises removing the 
solvent by distillation, etc. after the reaction. 
When the resulting modified copolymer is intended for use as a paint or 
antihaze agent, the reaction solution can be directly used. 
Thus, process (C) can afford a modified copolymer consisting of the 
unsaturated carboxylic acid ester unit (1), the unsaturated alcohol unit 
(2) and the N-substituted acrylamide unit (4) when unit (1) is partly 
converted to unit (2); or a modified copolymer consisting of units (2) and 
(4) when unit (1) is wholly converted to unit (2). In this way, according 
to process (C), a modified copolymer can be produced which consists of 0 
to 20 mole%, preferably 0 to 10 mole%, of unit (1), 30 to 70 mole%, 
preferably 35 to 65 mole%, of unit (2), and 30 to 70 mole%, preferably 35 
to 65 mole%, of unit (4). 
According to this invention, processes such as the processes (A) to (C) 
described in detail hereinabove can afford a noval film-forming and 
thermocurable vinyl alcohol-substituted acrylamide copolymer consisting 
essentially of 
(1) 0 to 20 mole%, preferably 0 to 10 mole%, of a unit of the formula 
##STR28## 
wherein R represents a group selected from the class consisting of alkyl 
groups with 1 to 7 carbon atoms and aryl groups with 6 to 7 carbon atoms, 
and n is 0 or 1. 
(2) 30 to 70 mole%, preferably 35 to 65 mole%, of a unit of the formula 
##STR29## 
wherein n is as defined above, 
(3) 0 to 20 mole%, preferably 0 to 10 mole%, of a unit of the formula 
##STR30## 
wherein R' represents a hydrogen atom or a lower alkyl group, and R is as 
defined above, 
and 
(4) 30 to 70 mole%, preferably 35 to 65 mole%, of a unit of the formula 
##STR31## 
wherein R' is as defined above, R" represents a group selected from the 
class consisting of alkyl groups with 1 to 18 carbon atoms, cycloalkyl 
groups with 5 to 6 carbon atoms, hydroxyalkyl groups with 2 to 4 carbon 
atoms and aryl groups with 6 to 7 carbon atoms, and R''' represents a 
group selected from the class consisting of a hydrogen atom and the groups 
R", 
the amounts of each unit being based on the total amount of units (1) to 
(4). 
The properties of the modified copolymer can be varied over a wide range 
according to the types of units (1) to (4), their combinations and 
proportions, etc. For example, the copolymer is water-soluble when the 
number of carbon atoms of the unsaturated alcohol unit (2) is small as in 
vinyl alcohol, and the amide group of the acrylamide component (4) 
contains a hydrophilic functional group as in N-2-hydroxyethyl acrylamide. 
On the other hand, when the number of carbon atoms of the unsaturated 
alcohol component (2) is large and the amide group of the acrylamide 
component (4) is substituted with a hydrocarbon group having a large 
number of carbon atoms, the copolymer of this invention is insoluble in 
water but has hydrophilicity showing wettability with water as its 
surface. 
Because of these properties, the copolymers of this invention can be used 
in various applications, for example, as an anti-haze agent, a paint 
vehicle, a leather surface treating agent, a basic ingredient of a 
composition for extracting oil in water, a primer for adhesion of metal to 
plastics, and an anionic flocculating agent. 
Coated films having superior resistance to water and alkalies can be 
prepared from the copolymer of this invention. If the copolymer is 
water-soluble, it is dissolved in water or a mixture of it with a polar 
solvent such as alcohols (e.g., methanol, ethanol, or isopropanol), coated 
on a substrate and then cured by heating at a temperature of about 
120.degree. to about 400.degree. C. for 0.1 to 30 minutes. This results in 
a molecular structure containing a cyclized structure expressed, for 
example, by the following formulae 
##STR32## 
thus attaining superior resistance to water and alkalies. 
If the copolymer is water-insoluble, it is dissolved in an alcoholic 
solvent, such as methanol, ethanol, isopropanol, n-propanol, isobutanol, 
t-butanol, mixtures of these, or a mixture of such an alcohol with water, 
and by the same procedure as above, a coated film having superior 
resistance to water and alkalies can be formed. 
When the copolymer of this invention is used as an anti-haze agent, an 
aqueous or organic solvent solution of the copolymer is coated on the 
surface of glass, a mirror or metal, and dried to provide a coating having 
an anti-haze effect. By heat-treating the resulting coating, the copolymer 
partially undergoes cross-linking, lactamization or lactonization, and 
thus attains superior water resistance. For use as anti-haze agents, 
straight-chain copolymers consisting essentially of 70 to 30 mole% of the 
unsaturated alcohol unit (2), 30 to 70 mole% of the 
N-substituted-acrylamide unit (4) and 0 to 20 mole% of the acrylic-type 
carboxylic acid ester unit (3) with 4 to 8 carbon atoms and having a 
number average molecular weight (Mn) of 500 to 100,000, especially 1,000 
to 50,000, are preferred. Especially preferred copolymers are 
straight-chain copolymers consisting of 65 to 35 mole% of the unsaturated 
alcohol unit (2), 35 to 65 mole% of the acrylamide unit (4) and 0 to 10 
mole% of the acrylic-type carboxylic acid ester unit (3) and having a 
number average molecular weight of 500 to 100,000, especially 1,000 to 
50,000. It is more preferred to use straight-chain copolymers contaning 
vinyl alcohol or allyl alcohol as the unsaturated alcohol unit (2), an 
N-substituted-acrylamide or methacrylamide as the acrylamide unit (4) and 
an acrylic or methacrylic acid ester as the carboxylic acid ester unit (3) 
and having a number average molecular weight of 500 to 100,000, especially 
1,000 to 50,000.

The following examples illustrate the present invention in more detail. 
EXAMPLE 1 
A 10-liter separable flask equipped with a stirring device, a condenser, a 
thermometer and two metering pumps was used as a polymerization reactor. 
It was purged with nitrogen prior to polymerization. 
Methyl benzoate (111.9 ml; 900 mmoles) was mixed with 6570 ml of n-hexane, 
and the mixture was cooled to below 5.degree. C. by using a ice water 
bath. With stirring, 46.3 ml (450 mmoles) of ethyl aluminum dichloride was 
added to the solution slowly. The mixture was maintained for an additional 
30 minutes at this temperature to form a complex of methyl benzoate and 
ethyl aluminum dichloride. With stirring at this temperature, a mixture of 
1331 ml (15.5 moles) of vinyl acetate and 1067 ml (12.4 moles) of methyl 
acrylate and a mixture of 41.9 ml (225 mmoles) of t-butyl peroxy isopropyl 
carbonate and 1600 ml of n-hexane were continuously fed at a given rate 
for 5 hours by the two metering pumps, thereby to perform 
copolymerization. The resulting copolymer precipitated as a slurry in the 
reaction system, and its amount increased with the passage of the 
polymerization time. After the feeding of the mixtures, the contents of 
the flask were maintained for an additional 2 hours with stirring, and an 
n-hexane solution containing a small amount of isopropanol was added. The 
copolymer was recovered by performing filtration and washing with n-hexane 
twice, and then dried overnight in vacuo at room temperature. The amount 
of the vinyl acetate/methyl acrylate copolymer obtained was 2150 g. The 
copolymer had a methyl acrylate unit content of 50 mole% as determined by 
NMR spectroscopy, and an intrinsic viscosity, measured at 30.degree. C. in 
toluene, of 0.49. 
A 1-liter autoclave equipped with a stirring device, a pressure gauge and a 
needle valve was charged with 50 g of the resulting vinyl acetate/methyl 
acrylate copolymer, and 500 ml of n-butylamine. They were reacted at 
120.degree. C. for 28 hours. 
The reaction mixture was obtained as a uniform solution. When the resulting 
reaction solution was poured into a large amount of acetone, a solid 
precipitated. The solid was pulverized in acetone using a mixer, washed 
with acetone, recovered by filtration, and dried overnight at room 
temperature under reduced pressure. The results of elemental analysis of 
the resulting product well agreed, as shown in Table 1, with those 
obtained under the assumption that the entire vinyl acetate unit in the 
starting vinyl acetate/methyl acrylate copolymer was converted to the 
vinyl alcohol unit and the entire methyl acrylate unit, to a butyl 
acrylamide unit. The copolymer was soluble in water, methanol, ethanol, 
and isopropanol. The infrared absorption spectrum of a cast film prepared 
on sodium chloride crystal plate from a solution of the copolymer in 
isopropanol showed an absorption based on hydroxy at 3250 cm.sup.-1 and an 
absorption based on the substituted amide at 1640 cm.sup.-1, and the 
intensity of an absorption at 1740 cm.sup.-1 based on the ester bond was 
very weak. This led to the confirmation that the vinyl acetate unit in the 
starting copolymer was converted to the vinyl alcohol unit, and the metal 
acrylate unit, to the n-butyl acrylamide. 
EXAMPLES 2 to 4 
The same 1-liter autoclave as described in Example 1 was charged with 50 g 
of the starting vinyl acetate/methyl acrylate copolymer prepared in 
Example 1, and each of the amines shown in Table 1 was added in an amount 
of 500 ml instead of the n-butylamine in an atmosphere of nitrogen. The 
mixture was maintained at the temperatures and for the times indicated in 
Table 1 with stirring, and then cooled to room temperature. 
The data of the recovered polymers are shown in Table 1. 
EXAMPLES 5 TO 10 
A 2-liter separable flask equipped with a stirring device, a condenser and 
a thermometer was charged with 100 g of the vinyl acetate/methyl acrylate 
copolymer prepared in Example 1, and 1000 ml of each of the amines shown 
in Table 1 was added in an atmosphere of nitrogen. The mixture was 
maintained at the temperatures and for the times indicated in Table 1 with 
stirring, and then cooled to room temperature. In the reaction mixture 
after the reaction, the starting vinyl acetate/methyl acrylate copolymer 
did not remain as a solid, but was a uniform solution. When the reaction 
mixture was poured into a large amount of acetone, a solid precipitated. 
The solid was pulverized in acetone using a mixer, washed with acetone, 
recovered by filtration, and dried overnight under reduced pressure. The 
elemental analysis values of the resulting product, as shown in Table 1, 
were close to those obtained under the assumption that the entire vinyl 
acetate unit in the starting copolymer was converted to the vinyl alcohol 
unit and the entire methyl acrylate unit, to the acrylamide unit having 
the same substituent as the amine used. 
The copolymers obtained in Examples 5 to 8 were each dissolved in 
isopropanol, and cast films were prepared from the solutions on a sodium 
chloride crystal plate. The copolymers obtained in Examples 9 and 10 were 
dissolved in water, and cast films were prepared from the aqueous 
solutions on a KRS 5 (mixed crystals of thallium bromide and thallium 
iodide) plate. The infrared absorption spectra of these films were 
determined. In any of these spectra, an absorption at 1640 cm.sup.-1 based 
on the substituted amide was detected, and the intensity of the absorption 
of 1740 cm.sup.-1 based on the ester bond became very weak. This led to 
the confirmation that the vinyl acetate unit in the starting copolymer was 
converted to the vinyl alcohol unit, and the methyl acrylate unit, to the 
acrylamide unit having the same substituent as the amine used. 
An aqueous solution of each of the copolymers obtained in Examples 9 and 10 
containing a vinyl alcohol unit and a N-substituted acrylamide unit was 
coated on a cleaned glass sheet, dried in the air, and heat-treated at 
120.degree. C. for 3 minutes to form a film of the copolymer. The glass 
sheets thus obtained were cooled to below 0.degree. C. in a refrigerator, 
and then the temperature was returned to room temperature. No haze was 
observed in these glass sheets, and it was confirmed that the copolymers 
containing the vinyl alcohol unit and the N-substituted acrylamide unit 
had an anti-haze effect. 
Ten grams of each of the copolymers obtained in the foregoing Examples in 
which the N-substituent of the N-substituted acrylamide units were n-butyl 
(Example 1), n-hexyl (Example 5), n-dodecyl (Example 6), cyclohexyl 
(Example 7), allyl (Example 2), phenyl (Example 4), and benzyl (Example 
8), respectively was dissolved in 100 ml of isopropanol to form a uniform 
clear solution of the respective polymer. 
The copolymer solution was coated on a sheet of polytetrafluoroethylene, 
dried in the air, and heat-treated at 180.degree. C. for 15 minutes to 
prepare a transparent film having a thickness of 5 to 10.mu.. The infrared 
absorption spectra of the resulting films were determined. It was found 
that in any of these, the intensities of the absorptions at 3250 cm.sup.-1 
based on hydroxy and at 1640 cm.sup.-1 based on the N-substituted amide 
group which had been seen in the copolymers were much weakened, and a new 
absorption based on the carbonyl group of an N-substituted pyrrolidone 
ring was detected at 1660 cm.sup.-1. This fact led to the confirmation 
that in any of these copolymers, the adjacent vinyl alcohol unit and the 
N-substituted acrylamide unit underwent a dehydrocyclization reaction to 
form a lactam ring structure. 
The decomposition temperature of each of the films of these polymers having 
a lactam ring structure was measured by a thermobalance. It was found that 
in any of the samples tested, the temperature at which a weight loss began 
was at least 330.degree. C., and all of them had superior thermal 
stability. 
Furthermore, these films having a lactam ring structure were dipped 
overnight at room temperature in acetone, ethyl acetate, n-hexane, 
benzene, toluene, kerosene, and a thinner lacquer, respectively, and the 
states of the films after dipping were observed. It was found that no 
change occurred as a result of dipping, and these polymers having a lactam 
ring structure had superior resistance to organic solvents. 
Furthermore, the same copolymer solutions as set forth above were each 
coated on a glass sheet, an aluminum plate, an iron plate, a tin plate and 
a stainless steel plate, respectively, dried in the air, and heat-treated 
at 190.degree. C. for 15 minutes. Transparent films of polymers having a 
lactam ring structure were obtained. Then, the coated substrates were each 
cooled to -20.degree. C., and then the temperature returned to room 
temperature. No crack or peeling of the coated films was observed. Using 
an Erichsen tester in accordance with JIS B-7729, the coated products 
(excepting the coated glass sheet) were subjected to an Erichsen test in 
accordance with JIS Z-2247, and all showed as Erichsen value of more than 
10 mm. This led to the confirmation that the films of polymers containing 
an N-substituted lactam ring structure have superior flexibility and 
superior adhesion to substrates. 
Furthermore, these films were tested for surface hardness using a pencil 
scratch tester in accordance with JIS K-5401. It was found that the pencil 
hardness was 3 to 4H for the film of a polymer having an 
N-n-butyl-pyrrolidone ring structure (Example 1), 2 to 3H for the film of 
a polymer having an N-n-hexylpyrrolidone ring structure (Example 5), 2 to 
3H for the film of a polymer having an N-n-dodecylpyrrolidone structure 
(Example 6), 6H for the film of a polymer having an 
N-cyclohexylpyrrolidone ring structure (Example 7), 4 to 5H for the film 
of a polymer having an N-allylpyrrolidone ring structure (Example 2), 6H 
for the film of a polymer having an N-phenylpyrrolidone ring structure 
(Example 4), and 4 to 5H for the film of a polymer having a 
N-benzylpyrrolidone ring structure (Example 8). It was found therefore 
that the films of the polymers having a lactam ring structure have 
superior surface hardness. 
These films were also tested for their resistances to water, acids and 
alkalies in the following manner. 
Water resistance: Dipped in boiling water for 2 hours. 
Acid resistance: Dipped for 2 hours in a 5% aqueous solution of 
hydrochloric acid at 40.degree. C. 
Alkali resistance: Dipped for 2 hours in a 3% aqueous solution of sodium 
hydroxide at room temperature. 
After these tests, the surface appearances of these films showed no change 
at all. 
COMATIVE EXAMPLE 1 
A 1-liter autoclave equipped with a stirring device, a pressure gauge, a 
safety valve and a needle valve was charged with 50 g of the vinyl 
acetate/methyl acrylate copolymer obtained in Example 1, and then 500 ml 
of liquid ammonia collected by a "distillation charging method" by which 
ammonia was passed from an ammonia bomb through a pressure controller into 
a receptacle cooled with a dry ice methanol bath was introduced from the 
receptacle into the autoclave through the needle valve by a "distillation 
charging method". Then, the autoclave filled with the starting copolymer 
and ammonia was maintained at 30.degree. C. for 20 hours with stirring to 
react the two materials. The reaction pressure was maintained at about 12 
kg/cm.sup.2 from the initial to the last stage of the reaction. After the 
reaction, the unreacted ammonia was slowly removed from the needle valve, 
and then the autoclave was opened. A transparent viscous reaction product 
was obtained at the bottom of the autoclave. A part of the reaction 
product was withdrawn, and dried at 40.degree. C. under reduced pressure 
to afford a white solid mass. The solid mass was pulverized in a mortar in 
an atmosphere of nitrogen to afford a white powder. On the other hand, a 
small amount of water was added to the remaining reaction product at the 
bottom of the autoclave. The reaction product dissolved in water and could 
be recovered as an aqueous solution. When the aqueous solution was poured 
into a large excess of isopropanol, the reaction product precipitated as a 
white powder. It was recovered by filtration, and dried at 40.degree. C. 
under reduced pressure to afford a white powdery solid having a uniform 
particle diameter. The total amount of the resulting solid was 33.0 g. 
This weight was close to the amount (33.5 g) which was calculated under 
the assumption that the entire vinyl acetate unit of the starting 
copolymer was converted to a vinyl alcohol unit, and the entire methyl 
acrylate unit, to an acrylamide unit. 
A part of the resulting powder was again dissolved in water. The resulting 
clear aqueous solution was cast on a KRS-5 (mixed crystals of thallium 
bromide and thallium iodide) plate to form a film. The infrared absorption 
spectrum of the film showed an absorption at 3300 cm.sup.-1 based on 
hydroxy and an absorption at 1650 cm.sup.-1 based on amide. This led to 
the confirmation that the vinyl acetate unit in the starting copolymer was 
converted to the vinyl alcohol unit, and the methyl acrylate unit, to the 
acrylamide unit. The elemental analysis values of the modified copolymer 
were found as follows: C, 52.0%, H, 8.0%; O, 28.1%; N, 11.9%. These values 
were very close to the calculated values (C, 52.2%;, H, 7.9%; O, 27.8%; N 
12.2%) which were obtained under the assumption that the entire vinyl 
acetate unit of the starting copolymer were converted to the vinyl alcohol 
unit, and the entire methyl acrylate unit, to the acrylamide unit. 
The film was tested for its resistance to water and alkalies in the same 
way as in Example 1. The coated film peeled off, and was partly dissolved. 
EXAMPLE 11 
The same separable flask as in Example 1 was used as a polymerization 
reactor except that only one metering pump was used. 
The flask was purged with nitrogen, and charged with 4000 ml of acetone, 
1000 ml of isopropanol, 3492 ml (37.9 moles) of vinyl acetate and 188 ml 
(2.1 moles) of methyl acrylate, in this order. With stirring, the mixture 
was heated to 50.degree. C. When this temperature was reached, 14.3 ml of 
an n-hexane solution containing 90 mmoles of t-butyl peroxypivalate was 
added, and the copolymerization was started. Thirty minutes after the 
initiation of the polymerization, 188 ml (2.1 moles) of methyl acrylate 
was added continuously as a given rate over the course of 30 minutes. 
Immediately after the addition, the polymerization reactor was dipped in 
an ice water bath, and then, the reaction mixture having the copolymer 
product dissolved in it was poured into a large excess of n-hexane to 
precipitate the resulting copolymer. The n-hexane used as a precipitant 
was removed by decantation. The product was washed twice with fresh 
n-hexane, and decantation was performed twice. The product was dried 
overnight at room temperature under reduced pressure. The amount of the 
vinyl acetate/methyl acrylate copolymer so obtained was 605 g. The content 
of the methyl acrylate unit was found to be 51 mole% by NMR spectroscopy. 
The copolymer had an intrinsic viscosity, measured in toluene at 
30.degree. C., of 0.16. 
The same 2-liter separable flask as shown in Example 5 was charged with 100 
g of the vinyl acetate/methyl acrylate copolymer so obtained, and then 
1,000 ml of n-butylamine was added in an atmosphere of nitrogen. The 
mixture was maintained at 80.degree. C. for 28 hours with stirring while 
refluxing n-butylamine. Then, the product was cooled to room temperature. 
The resulting reaction mixture was a slightly yellowish uniform clear 
solution. When the solution was worked up in the same way as in Example 1, 
96.6 g of a white powdery solid was obtained. 
The infrared absorption spectrum of the solid was determined in the same 
way as in Example 1. Same as in the case of the copolymer obtained in 
Example 1, an absorption at 3250 cm.sup.-1 based on hydroxy and an 
absorption at 1640 cm.sup.-1 based on the substituted amide were detected, 
and the intensity of an absorption at 1740 cm.sup.-1 based on the ester 
bond was very weak. 
The other properties of the copolymer were measured, and the results are 
shown in Table 1. 
EXAMPLE 12 
Using the same apparatus as used in Example 1, vinyl acetate and methyl 
acrylate were copolymerized in the same way as in Example 11 except that 
5,000 ml of acetone was used as a solvent, the amounts of the vinyl 
acetate and methyl acrylate to be charged before the initiation of the 
polymerization were changed to 4364 ml (47.3 moles) and 238 ml (2.6 
moles), respectively, and the amount of methyl acrylate to be added 
continuously by a metering pump over the course of 30 minutes after a 
lapse of 30 minutes from the initiation of the polymerization was changed 
to 239 ml (2.6 moles). The amount of the copolymer obtained was 1,300 g. 
The copolymer had a methyl acrylate unit content of 31 mole% by NMR 
spectroscopy and an intrinsic viscosity, measured at 30.degree. C. in 
toluene, of 0.25. 
Using the same 2-liter separable flask as described in Example 5, 100 g of 
the resulting vinyl acetate/methyl acrylate copolymer was reacted with 
n-hexylamine under the same condition as in Example 5. The reaction 
product was post-treated in the same way as in Example 5 to afford 88.7 g 
of a white powdery solid. 
The infrared absorption spectrum of the copolymer measured in the same way 
as in Example 1 showed an absorption at 3250 cm.sup.-1 based on hydroxy 
and an absorption at 1640 cm.sup.-1 based on the substituted amine, and 
the absorption at 1740 cm.sup.-1 ascribable to an ester bond was scarcely 
detected. 
The results of the other measurements are shown in Table 1. 
EXAMPLE 13 
Using the same apparatus as in Example 11, vinyl acetate and methyl 
acrylate were copolymerized in the same way as in Example 11 except that 
the amounts of vinyl acetate and methyl acrylate fed to the system before 
the initiation of polymerization were changed to 1875 ml (20.7 moles) and 
805 ml (8.9 moles), respectively, and the amount of methyl acrylate to be 
added by means of a metering pump continuously over the course of 30 
minutes after a lapse of 30 minutes from the initiation of polymerization 
was changed to 450 ml (5.0 moles). The amount of the copolymer obtained 
was 1325 g. The copolymer had a methyl acrylate unit content of 69 mole% 
as determined by NMR spectroscopy, and an intrinsic viscosity, measured at 
30.degree. C. in toluene, of 0.23. 
Then, 100 g of the vinyl acetate/methyl acrylate copolymer was reacted with 
cyclohexylamine under the same conditions as in Example 7 using the same 
2-liter separable flask as shown in Example 5. The reaction product was 
worked up in the same way as in Example 7 to afford 134.0 g of a white 
powdery solid. 
The infrared absorption spectrum of the copolymer showed an absorption at 
3250 cm.sup.-1 based on hydroxy and an absorption at 1640 cm.sup.-1 based 
on substituted amine, and the intensity of the absorption at 1740 
cm.sup.-1 ascribable to the ester bond was weakened markedly as compared 
with the starting copolymer. 
The results of the other measurements are shown in Table 1. 
EXAMPLE 14 
Allyl acetate and methyl acrylate were copolymerized in the same way as in 
Example 1 using the same apparatus as in Example 1 except that 1644 ml 
(15.4 mmoles) of allyl acetate was used instead of the vinyl acetate. The 
product was then worked up in the same way as in Example 1. The amount of 
the resulting allyl acetate/methyl acrylate copolymer was 1690 g. The 
copolymer had a methyl acrylate unit content, determined by NMR 
spectroscopy, of 59 mole%, an an intrinsic viscosity, as measured at 
30.degree. C. in toluene, of 0.61. 
Then, 100 g of the allyl acetate/methyl acrylate copolymer was reacted with 
ethanolamine under the same conditions as in Example 9 using the same 
2-liter separable flask as shown in Example 9. The product was worked up 
in the same way as in Example 9 to afford 103.8 g of a powdery solid. 
The infrared absorption spectrum of the copolymer measured in the same way 
as in Example 9 showed absorptions ascribable to hydroxy and substituted 
amide as in Example 9, and the intensity of absorption of the ester bond 
was markedly smaller than that of the starting copolymer. 
The results of the other measurements are shown in Table 1. 
EXAMPLE 15 
Vinyl acetate and ethyl acrylate were copolymerized in the same way as in 
Example 1 using the same apparatus as in Example 1 except that 1344 ml 
(12.4 moles) of ethyl acrylate was used instead of the methyl acrylate. 
The product was worked up in the same way as in Example 1. The amount of 
the resulting vinyl acetate/ethyl acrylate copolymer was 1935 g. The 
copolymer had an ethyl acrylate unit content, as determined by NMR 
spectroscopy, of 57 mole%, and an intrinsic viscosity, as measured at 
30.degree. C. in toluene, of 0.55. 
Then, 100 g of the resulting vinyl acetate/ethyl acrylate copolymer was 
reacted with cyclohexylamine under the same conditions as in Example 7 
using the same 2-liter separable flask as shown in Example 5. The product 
was worked up in the same way as in Example 7 to afford 110.4 g of a white 
powdery solid. 
The infrared absorption spectrum of the copolymer was measured in the same 
way as in Example 7. Absorptions ascribable to the hydroxy and the 
substituted amide were detected same as in Example 7, and the intensity of 
the absorption ascribable to the ester bond was markedly smaller than that 
of the starting copolymer. 
The results of the other measurements are shown in Table 1. 
EXAMPLE 16 
Vinyl acetate and methyl methacrylate were copolymerized using the same 
apparatus as used in Example 1 in the same way as in Example 1 except that 
1315 ml (12.4 moles) of methyl methacrylate was used instead of the methyl 
acrylate. The product was worked up in the same way as in Example 1. The 
amount of the resulting vinyl acetate/methyl methacrylate copolymer was 
1480 g. The copoloymer had a methyl methacrylate unit content, as 
determined by NMR spectroscopy, of 66 mole%, and an intrinsic viscosity, 
determined in toluene at 30.degree. C., of 0.45. 
Then, 100 g of the vinyl acetate/methyl methacrylate copolymer was reacted 
with ethanolamine under the same conditions as in Example 9 using the same 
2-liter separable flask as used in Example 9. The product was worked up in 
the same way as in Example 9 to afford 101.5 g of a powdery solid. 
The infrared absorption spectrum of the copolymer, measured in the same way 
as in Example 9, showed an absorption at 3250 cm.sup.-1 based on hydroxy 
and an absorption at 1640 cm.sup.-1 based on substituted amide, and the 
intensity of the absorption at 1740 cm.sup.-1 based on the ester bond was 
far smaller than that of the starting copolymer. 
The results of the other measurements are shown in Table 1. 
Table 1 
__________________________________________________________________________ 
Reaction 
conditions 
Starting copolymer Tempera- 
Unit (1) Unit (3) Amine ture Time 
Example 
(mole %) (mole %) (amount in grams) 
(.degree. C) 
(hrs.) 
__________________________________________________________________________ 
1 Vinyl acetate 
50 Methyl acrylate 
50 n-Butylamine 
50 
120 28 
2 Vinyl acetate 
50 Methyl acrylate 
50 Allylamine 
50 
120 28 
3 Vinyl acetate 
50 Methyl acrylate 
50 Diethylamine 
50 
120 28 
4 Vinyl acetate 
50 Methyl acrylate 
50 Aniline 50 
220 42 
5 Vinyl acetate 
50 Methyl acrylate 
50 n-Hexylamine 
100 
135 28 
6 Vinyl acetate 
50 Methyl acrylate 
50 n-Dodecylamine 
100 
220 28 
7 Vinyl acetate 
50 Methyl acrylate 
50 Cyclohexylamine 
100 
145 28 
8 Vinyl acetate 
50 Methyl acrylate 
50 Benzylamine 
100 
185 28 
9 Vinyl acetate 
50 Methyl acrylate 
50 Ethanolamine 
100 
170 28 
10 Vinyl acetate 
50 Methyl acrylate 
50 Diethanolamine 
100 
220 42 
11 Vinyl acetate 
49 Methyl acrylate 
51 n-Butylamine 
100 
80 28 
12 Vinyl acetate 
69 Methyl acrylate 
31 n-Hexylamine 
100 
135 28 
13 Vinyl acetate 
31 Methyl acrylate 
69 Cyclohexylamine 
100 
145 28 
14 Allyl acetate 
41 Methyl acrylate 
59 Ethanolamine 
100 
170 28 
15 Vinyl acetate 
43 Ethyl acrylate 
57 Cyclohexylamine 
100 
145 28 
16 Vinyl acetate 
34 Methyl methacrylate 
66 Diethanolamine 
100 
170 28 
Copolymer formed 
Contents of units Number 
Amount Elemental analysis (%) 
(mole %) (2)+(4) or 
average 
yielded Found Calculated (*) 
Unit 
Unit 
Unit 
Unit 
(4)+(2) 
molecular 
Example 
(g) C H O N C H O N (1) 
(2) 
(3) 
(4) 
(%) weight 
__________________________________________________________________________ 
1 46.9 63.0 
10.2 
18.6 
8.1 
63.1 
10.0 
18.7 
8.2 
0 50 0 50 above 90 
10,100 
2 43.0 62.0 
8.3 
20.7 
8.7 
61.9 
8.4 
20.6 
9.0 
0 50 2 48 " 9,200 
3 47.5 63.2 
9.8 
18.9 
7.9 
63.1 
10.0 
18.7 
8.2 
0 50 2 48 " 10,200 
4 53.6 69.5 
7.0 
16.5 
7.0 
69.1 
6.9 
16.7 
7.3 
1 49 2 48 " 11,300 
5 115.0 
66.2 
10.8 
16.2 
6.8 
66.3 
10.6 
16.1 
7.0 
0 50 1 49 " 11,600 
6 159.8 
72.6 
11.8 
11.0 
4.6 
72.0 
11.7 
11.3 
4.9 
1 49 3 47 " 16,600 
7 112.3 
67.3 
9.5 
16.3 
6.9 
67.0 
9.7 
16.2 
7.1 
0 50 2 48 " 11,700 
8 115.7 
70.3 
7.4 
15.7 
6.6 
70.2 
7.4 
15.6 
6.8 
0 50 1 49 " 12,100 
9 93.0 56.2 
8.2 
30.3 
8.9 
52.8 
8.2 
30.2 
8.8 
0 50 0 50 " 9,600 
10 116.0 
53.4 
8.1 
31.7 
6.8 
53.2 
8.4 
31.5 
6.9 
0 50 1 49 " 12,000 
11 96.6 63.4 
9.9 
18.7 
8.0 
63.2 
10.0 
18.5 
8.3 
0 49 2 49 ca. 55 
5,100 
12 88.7 63.3 
10.4 
21.1 
5.2 
63.6 
10.3 
20.7 
5.4 
0 69 1 30 ca. 35 
6,300 
13 134.0 
68.5 
9.7 
13.9 
7.9 
68.7 
9.8 
13.4 
8.1 
0 31 2 67 ca. 35 
6,500 
14 103.8 
54.9 
8.5 
28.0 
8.6 
54.7 
8.5 
27.7 
9.0 
0 41 3 56 ca. 80 
12,100 
15 110.4 
67.5 
9.6 
15.6 
7.3 
67.7 
9.7 
15.1 
7.5 
0 43 2 55 ca. 85 
21,500 
16 101.5 
55.4 
8.7 
26.8 
9.1 
55.6 
8.7 
26.5 
9.2 
0 34 1 65 ca. 70 
18,700 
__________________________________________________________________________ 
*Calculated values obtained under the assumption that the entire unit (1) 
was converted to unit (2), and the entire unit (3), to unit (4). 
EXAMPLE 17 
An equimolar mixture of vinyl acetate and methyl acrylate and an n-hexane 
solution of t-butyl peroxy isopropyl carbonate were continuously fed with 
stirring to an n-hexane solution containing a complex of ethylaluminum 
dichloride and methyl benzoate at 20.degree. C. over the course of 5 
hours. The reaction mixture was further polymerized for 15 hours to form a 
straight-chain copolymer of vinyl acetate/methyl acrylate having a methyl 
acrylate unit content of 50 mole% and a number average molecular weight of 
10,000. The copolymer was treated in methanol in the presence of sodium 
methoxide as a catalyst at about 50.degree. C. for about 5 hours to form a 
copolymer to be used as a starting material. From the yielded amount, 
elemental analysis values and infrared absorption spectrum of the starting 
copolymer, it was confirmed that this copolymer resulted from the 
conversion of the starting vinyl acetate unit of the vinyl acetate/methyl 
acrylate copolymer into a vinyl alcohol unit by alcoholysis. 
In a 500 ml three-necked flask equipped with a stirrer, a condenser and a 
distillation device, 20 g of the resulting starting copolymer was 
suspended in 200 ml of n-butylamine, and the suspension was stirred. The 
starting copolymer was seen to dissolve gradually in n-butylamine, and a 
reaction was seen to take place between them. When the temperature of the 
reaction system was raised to about 70.degree. C. in order to increase the 
rate of the reaction, methanol could be removed through the distillation 
device. By performing the reaction for about 8 hours, a somewhat viscous 
clear uniform solution was formed. After the reaction, the solution was 
poured into a large excess of diethyl ether. The reaction product 
precipitated as a white powder. It was collected by filtration, and dried 
at 40.degree. C. under reduced pressure to recover a white powdery solid 
having a uniform particle diameter. The amount yielded of the solid was 
24.8 g which amount was close to the theoretical amount (26.2 g) which was 
calculated under the assumption that the entire methyl acrylate unit of 
the starting copolymer composed of the vinyl alcohol unit and the methyl 
acrylate unit was converted to an N-n-butyl acrylamide unit. 
A part of the n-butylamine solution after the reaction was coated on a 
sodium chloride plate, and dried at 70.degree. C. under reduced pressure 
to form a cast film. The infrared absorption spectrum of this film showed 
an absorption at 1655 cm.sup.-1 based on the monoalkyl-substituted amide 
group. The elemental analysis values of the reaction product were: C, 
63.3%; H, 9.8%; O, 18.5%; N, 8.4%. This led to the confirmation that a 
straight-chain copolymer composed of a vinyl alcohol unit and an N-n-butyl 
acrylamide unit was formed as a result of the complete conversion of the 
methyl acrylate unit in the starting copolymer into the N-n-butyl 
acrylamide unit, and that the resulting copolymer was composed of 50 mole% 
of the vinyl alcohol unit and 50 mole% of the N-n-butyl acrylamide unit. 
EXAMPLES 18 TO 25 
Twenty grams of the same vinyl alcohol/methyl acrylate copolymer as used in 
Example 17 was used as a starting material, and reacted in the same way as 
in Example 17 except that each of the amines show in Table 2 was used 
instead of the n-butylamine. The reaction proceeded while exhibiting 
almost the same behavior, and a viscous clear uniform amine solution was 
obtained. The solution was treated in the same way as in Example 17 to 
obtain a white solid powder. The infrared absorption spectrum of the white 
powder showed an absorption at 1655 cm.sup.-1 based on the 
monoalkyl-substituted amide group. The results of other measurements are 
shown in Table 2. 
Table 2 
__________________________________________________________________________ 
Example 17 18 19 20 21 22 23 24 25 
__________________________________________________________________________ 
Amine n-Butyl- 
n-Hexyl 
n-Dodecyl- 
Benzyl- 
Cyclo- 
Aniline 
.beta.-Amino- 
Di-n- 
Di- 
amine 
amine 
amine amine 
hexyl- ethyl butyl- 
ethanol- 
amine alcohol 
amine 
amine 
(amount) 200 ml 
200 ml 
200 g 200 ml 
200 ml 
200 ml 
200 ml 
200 
200 ml 
Reaction conditions 
Temperature (.degree. C.) 
70 135 150 150 145 70 170 70 170 
Time (hrs.) 
8 8 8 8 8 8 8 8 8 
Amount yielded 
24.8 29.2 40.5 29.6 28.9 27.8 21.0 31.6 29.0 
(g) 
Elemental analysis 
C (%) 63.3 66.2 72.0 70.4 64.0 69.8 52.1 69.0 52.2 
Co- H (%) 9.8 10.7 11.7 7.4 10.4 7.3 8.5 11.4 8.6 
polymer 
O (%) 18.5 16.1 11.3 15.8 18.8 17.1 30.6 14.2 33.5 
formed 
N (%) 8.4 7.0 4.9 6.4 6.7 5.9 8.8 5.5 6.7 
Unit (2) (%) 
50 50 50 50 50 50 50 50 50 
Unit (3) (%) 
0 0 1 3 3 9 1 6 2 
Unit (4) (%) 
50 50 49 47 47 41 49 44 48 
(2)+(4) or 
above 90 
above 90 
above 90 
above 90 
above 90 
above 90 
above 90 
above 
above 90 
(4)+(2) (%) 
Number average 
10,000 
11,600 
16,500 
11,000 
16,500 
11,000 
9,200 12,500 
11,900 
molecular weight 
__________________________________________________________________________ 
EXAMPLES 26 TO 28 
Each of the copolymers shown in Table 3 was used instead of the vinyl 
acetate/methyl acrylate copolymer used in the alcoholysis in Example 17, 
and was subjected to alcoholysis in the same way as in Example 17 under 
different alcoholysis conditions using sodium methoxide as a catalyst. 
The resulting starting copolymer (20 g) was reacted with cyclohexylamine in 
an autoclave in the same way as in Example 17. A similar clear viscous 
reaction product was obtained. It could be recovered as a white powder by 
the re-precipitation method using isopropanol. 
The infrared absorption spectrum and NMR spectrum of the product measured 
in the same way as in Example 17 showed absorptions at 1650 cm.sup.-1 
which indicated the presence of an acrylamide unit. 
The results are shown in Table 3. 
Table 3 
__________________________________________________________________________ 
Example 17 26 27 28 
__________________________________________________________________________ 
Composition 
Vinyl acetate 
Vinyl acetate 
Vinyl acetate 
Allyl acetate 
(mole %) (50) (49) (49) (37) 
Start- Methyl Methyl Methyl Methyl 
ing acrylate 
acrylate 
methacrylate 
acrylate 
co- (50) (51) (51) (63) 
polymer 
Number 
average 
molecular 10,000 15,000 9,000 18,000 
weight 
Alcoholysis 
Alcohol used 
Methanol 
Ethanol Methanol 
Methanol 
Temperature 
(.degree. C.) 
50 60 50 50 
Time (hrs.) 
5 5 5 5 
Amount 
yielded (g) 
24.8 25.9 28.6 28.5 
Elemental 
analysis 
C (%) 63.3 66.9 67.6 67.7 
Co- H (%) 9.8 9.3 9.4 11.4 
polymer 
O (%) 18.5 16.3 16.5 14.5 
formed 
N (%) 8.4 7.5 6.5 6.4 
Unit (1) (%) 
0 0 0 0 
Unit (2) (%) 
50 49 49 37 
Unit (3) (%) 
0 2 3 6 
Unit (4) (%) 
50 49 48 57 
(2) + (4) or 
(4) + (2) (%) 
above 90 
above 90 
above 90 
ca. 75 
Number average 
molecular 10,000 17,000 10,200 22,500 
weight 
__________________________________________________________________________ 
EXAMPLE 29 
A 2-liter separable flask equipped with a stirring device, a condenser, a 
thermometer and three metering pumps was used as a polymerization reactor, 
and charged with 200 ml of methanol, 25.8 g (0.3 mole) of vinyl acetate, 
and 10.7 g (0.08 mole) of N-t-butyl acrylamide in an atmosphere of 
nitrogen. With stirring, the temperature of the reaction system was raised 
to 50.degree. C. When the temperature of the reaction system reached 
50.degree. C., 3.48 g (0.02 mole) of t-butyl peroxypivalate was added, and 
the copolymerization was started. The copolymerization was continued while 
continuously feeding 172.2 g (2.0 moles) of vinyl acetate from a first 
metering pump for 2 hours at a rate of 1 mole/hr, a solution of 366.3 g 
(2.88 moles) of N-t-butyl acrylamide in 800 ml of methanol from a second 
metering pump for 2 hours and 20 minutes so that the rate of N-butyl 
acrylamide fed was 1 mole/hr, and a solution of 6.97 g (0.04 mole) of 
t-butyl peroxypivalate in 200 ml of methanol from a third metering pump 
for 2.5 hours so that the feed rate of the t-butyl peroxypivalate became 
0.01 mole/hr. The copolymerization proceeded while maintaining a 
homogeneous system. After the copolymerization for 2.5 hours, the 
polymerization reaction mixture was poured into a large amount of water. 
The resulting copolymer precipitated and came afloat on the surface of the 
water. The copolymer was collected, washed thoroughly with water, 
pulverized by a mixer into a powder, collected by filtration, and dried at 
40.degree. C. in vacuo. The amount of the vinyl acetate/N-t-butyl 
acrylamide copolymer so obtained was 465 g. NMR spectroscopy in 
deuterochloroform showed that the N-t-butyl acrylamide unit content of the 
copolymer was 51 mole%. 
One hundred grams of the resulting vinyl acetate/N-t-butyl acrylamide 
copolymer was dissolved in 900 ml of methanol in a 2-liter separable flask 
equipped with a stirrer, a condenser and a thermometer. Then, 100 ml of a 
methanol solution containing 0.2 g of sodium methoxide was added to the 
resulting solution. The temperature of the system was raised to 65.degree. 
C., and the reaction was performed for 5 hours with stirring. During the 
above reaction, there was no change in the homogeneous condition of the 
reaction system. The occurrence of reaction was noted however from the 
fact that methyl acetate formed by the reaction distilled from the 
condenser together with methanol used as solvent. After the reaction, the 
reaction mixture was poured into a large amount of acetone. The reaction 
product precipitated as a powder. The powder was collected by filtration, 
washed fully with water, and dried at room temperature in vacuo. The 
amount of the reaction product so obtained was 79.9 g which was very close 
to the theoretical amount (80.3 g) calculated under the assumption that 
the entire vinyl acetate unit of the vinyl acetate/N-t-butyl acrylamide 
copolymer used was converted to a vinyl alcohol unit. 
The elemental analysis values found of this reaction product were C, 63.4%; 
H, 9.8%; O, 18.8%; N, 7.9%, which were in good agreement with the 
calculated values (C, 63.2%; H, 10.0%; O, 18.5%; N, 8.3%) which were 
obtained under the assumption that the entire vinyl acetate unit of the 
vinyl acetate/N-t-butyl acrylamide copolymer was converted to a vinyl 
alcohol unit. 
The infrared absorption spectrum of the reaction product was determined 
using a cast film prepared from its methanol solution. It was found that 
the absorption at about 1740 cm.sup.-1 ascribable to the ester carbonyl 
group of the vinyl acetate unit was no longer observed, and an absorption 
based on hydroxy was detected at about 3400 cm.sup.-1. This led to the 
confirmation that the vinyl acetate unit of the vinyl acetate/N-t-butyl 
acrylamide copolymer was converted to a vinyl alcohol unit. 
EXAMPLES 30 to 32 
Vinyl acetate and N-substituted acrylamide were copolymerized in the same 
way as in Example 29 except that each of the compounds indicated in Table 
4 was used as an N-substituted acrylamide to be initially charged into the 
polymerization reactor, and the N-substituted acrylamide to be 
additionally fed with the progress of the reaction was a solution of 2.88 
moles of the N-substituted acrylamide in 800 ml of methanol. 
The copolymer obtained was analyzed by NMR spectroscopy in the same way as 
in Example 29 to determine its N-substituted acrylamide content. 
One hundred grams of each of the copolymers obtained in the above manner 
was reacted with methanol in the same way as in Example 29 using sodium 
methoxide as a catalyst, and worked up to form a final product. The 
results are shown in Table 4. 
The infrared absorption spectra of these products were determined in the 
same way as in Example 29. It was found that the intensity of the 
absorption at about 1740 cm.sup.-1 based on the ester carbonyl group of 
the vinyl acetate unit was very much weakened, and an absorption based on 
hydroxy was detected at about 3400 cm.sup.-1. This led to the confirmation 
that the vinyl acetate unit of the starting copolymer was converted to a 
vinyl alcohol unit. 
Table 4 
______________________________________ 
Example 29 30 31 32** 
______________________________________ 
N-substituted 
N-t- N-t- N-cyclo- 
N-phenyl 
acrylamide butyl octyl hexyl acryl 
acryl- acryl- 
acryl- amide 
Pro- Amount fed amide amide amide 
duction 
at the start 
of the of reaction (g) 
10.7 14.7 12.3 17.7 
start- (mole) 0.08 0.08 0.08 0.12 
ing Amount 
co- added during 
polymer 
the reaction (g) 
366.3 527.9 441.3 423.9 
Amount 
yielded (g) 465 576 506 499 
Content of 
N-substituted 
51 49 49 50 
acrylamide 
(mole %) 
Amount 
yielded (g) 79.9 83.5 82.4 81.0 
Elemental 
analysis 
(found) 
C (%) 63.4 68.6 67.2 69.4 
H (%) 9.8 10.8 9.8 6.9 
O (%) 18.8 14.6 16.1 17.0 
N (%) 7.9 6.0 6.9 7.3 
Elemental 
Co- analysis 
polymer 
(calculated)* 
formed C (%) 63.2 68.7 67.0 69.1 
H (%) 10.0 11.1 9.7 6.9 
O (%) 18.5 14.1 16.2 16.7 
N (%) 8.3 6.2 7.1 7.3 
Unit (1) (%) 
4 5 3 4 
Unit (2) (%) 
45 46 45 46 
Unit (4) (%) 
51 49 52 50 
(2) + (4) or 
(4) + (2) (%) 
ca. 85 ca. 80 
ca. 80 ca. 85 
Number 
average 18,800 22,600 
17,500 15,000 
molecular 
weight 
______________________________________ 
*Calculated under the assumption that the entire vinyl acetate unit (1) o 
the starting copolymer was converted to the vinyl alcohol unit (2). 
**In the production of the starting copolymer, the amount of vinyl acetat 
to be initially charged into the polymerization reactor was 34.4 g (0.4 
mole). 
EXAMPLE 33 
One hundred grams of the vinyl acetate/N-t-butyl acrylamide copolymer 
obtained in Example 29 was worked up in the same way as in Example 29 
except that 900 ml of ethylene glycol was used instead of methanol, 100 ml 
of an ethylene glycol solution of 0.2 g of sodium hydroxide was used 
instead of the methanol solution of sodium methoxide, and the reaction 
temperature was changed to 150.degree. C. There was obtained 79.6 g of a 
reaction product. 
The infrared absorption spectrum of the product was substantially the same 
as that obtained in Example 29. This led to the confirmation that the 
vinyl acetate unit of the vinyl acetate/N-t-butyl acrylamide copolymer was 
converted to a vinyl alcohol unit. 
The results of other measurements including elemental analysis values and 
the contents of the constituents are shown in Table 5. 
EXAMPLE 34 
One hundred grams of the vinyl acetate/N-t-butyl acrylamide copolymer 
synthesized in Example 29 was placed in a 2-liter autoclave equipped with 
a stirrer, a thermometer, a pressure gauge, a safety valve and two needle 
valves, and then 1,000 ml of isopropanol was fed into it. Liquid ammonia 
(50 ml) collected by a "distillation charging method" into a dry 
ice-methanol-cooled receptacle from an ammonia bomb through a pressure 
controlling device was fed into the autoclave in the cooled state from the 
receptacle through the needle valves by a "distillation charging method". 
The autoclave was then heated to 120.degree. C., and the contents were 
maintained for 8 hours at this temperature with stirring. The pressure was 
about 6 kg/cm.sup.2 from the initial to the last stages of the reaction. 
After the reaction, the autoclave was cooled to room temperature, and the 
ammonia was driven off by opening the needle valves. The ammonia was 
completely removed by passing nitrogen gas into the autoclave through one 
of the needle valves and discharging it from the other. The reaction 
mixture obtained was treated in the same way as in Example 29 to afford 
80.8 g of a powdery product. 
The infrared absorption spectrum of this product showed that the intensity 
of the absorption at about 1740 cm.sup.-1 based on the ester carbonyl 
group of the vinyl acetate unit was very much weakened, and an absorption 
based on hydroxy was detected at about 3400 cm.sup.-1. This led to the 
confirmation that the vinyl acetate unit of the starting vinyl 
acetate/N-t-butyl acrylamide copolymer was converted to a vinyl alcohol 
unit. 
The results of other measurements are shown in Table 5. 
Table 5 
______________________________________ 
Sample 29 30 34 
______________________________________ 
Alcoholysis 
Alcohol Methanol Ethylene Isopropanol 
glycol 
Catalyst Sodium Sodium Ammonia 
methoxide hydroxide 
Elemental analysis (%) 
C 63.4 63.3 63.0 
H 9.8 10.1 9.6 
O 18.8 18.4 19.3 
N 7.9 8.2 8.0 
Unit (1) (%) 
4 8 2 
Unit (2) (%) 
45 41 47 
Unit (4) (%) 
51 51 51 
(2) + (4) 
or (4) + (2) (%) 
ca. 85 ca. 85 ca. 85 
Number average 
18,000 18,600 18,700 
molecular weight 
______________________________________