Acetoacetyl group-containing polyvinyl alcohol resin powder composition, and production method therefor
View Patent ↗Acetoacetyl group-containing polyvinyl alcohol resin powder composition containing a C1 to C3 alcohol in an amount of 0.5 to 4 wt % is produced by allowing a powdery polyvinyl alcohol resin to react with diketene, washing the resulting acetoacetyl group-containing polyvinyl alcohol resin particles with the C1 to C3 alcohol to remove an unreacted portion of the diketene, and drying the intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition at a temperature of 40° C. to 120° C. at a pressure of not higher than 20 kPa after the washing. The acetoacetyl group-containing polyvinyl alcohol resin powder composition thus produced is highly soluble in water.
1. An acetoacetyl group-containing polyvinyl alcohol resin (AA-PVA) powder composition comprising:
acetoacetyl group-containing polyvinyl alcohol resin particles consisting of a structural unit represented by the following formula (1), a vinyl alcohol structural unit and a vinyl acetate structural unit:
and
a C1 to C3 alcohol in an amount of 0.5 to 4 wt. % of the powder composition.
2. The acetoacetyl group-containing polyvinyl alcohol resin powder composition according to claim 1 , wherein the C1 to C3 alcohol is methanol.
3. A method of producing the acetoacetyl group-containing polyvinyl alcohol resin powder composition according to claim 1 , the method comprising:
preparing acetoacetyl group-containing polyvinyl alcohol resin particles through a reaction of a powdery polyvinyl alcohol resin with diketene;
washing the acetoacetyl group-containing polyvinyl alcohol resin particles with a C1 to C3 alcohol to remove an unreacted portion of the diketene and thereby to form an intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition; and
drying the intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition at a temperature of 40° C. to 120° C. at a pressure of not higher than 20 kPa so as to control an alcohol content of the intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition obtained by washing the AA-PVA particles at 0.5 to 4 wt. % after the washing to form the acetoacetyl group-containing polyvinyl alcohol resin powder composition.
4. A method of producing the acetoacetyl group-containing polyvinyl alcohol resin powder composition according to claim 2 , the method comprising:
preparing acetoacetyl group-containing polyvinyl alcohol resin particles through a reaction of a powdery polyvinyl alcohol resin with diketene;
washing the acetoacetyl group-containing polyvinyl alcohol resin particles with a C1 to C3 alcohol to remove an unreacted portion of the diketene and thereby to form an intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition; and
drying the intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition at a temperature of 40° C. to 120° C. at a pressure of not higher than 20 kPa so as to control an alcohol content of the intermediate acetoacetyl group-containing polyvinyl alcohol resin particles composition obtained by washing the AA-PVA particles at 0.5 to 4 wt. % after the washing to form the acetoacetyl group-containing polyvinyl alcohol resin powder composition.
5. The method of producing the acetoacetyl group-containing polyvinyl alcohol resin powder composition according to claim 3 , wherein a drying period is in a range of 30 to 120 minutes.
6. The method of producing the acetoacetyl group-containing polyvinyl alcohol resin powder composition according to claim 4 , wherein a drying period is in a range of 30 to 120 minutes.