The present invention provides a polyvinyl acetal resin that has an excellent dispersing property and enables the production of a formed article having high mechanical strength. Provided is a polyvinyl acetal resin having a water absorption per unit area of 2 mg/cm.sup.2 or greater and 50 mg/cm.sup.2 or less when formed into a film having a thickness of 10 .Math.m.

The present invention provides a polyvinyl acetal resin that has an excellent dispersing property and enables the production of a formed article having high mechanical strength. Provided is a polyvinyl acetal resin having a water absorption per unit area of 2 mg/cm.sup.2 or greater and 50 mg/cm.sup.2 or less when formed into a film having a thickness of 10 .Math.m.

A composition comprising; a) at least one homopolymer or copolymer of vinyl acetate; and b) at least one softener.

A composition comprising; a) at least one homopolymer or copolymer of vinyl acetate; and b) at least one softener.

The present invention relates to resin particles including a residue unit represented by the following general formula (1) and having a volume average particle diameter equal to or more than 5 μm and equal to or less than 2000 μm, and a method for producing thereof. Furthermore the present invention relates to a fluororesin comprising a residue unit represented by a general formula (1) and having a weight average molecular weight Mw in a range of 5×10.sup.4 to 3×10.sup.5, and a yellow index of a heat-melted molded product (thickness 3 mm) after 24 h at 280° C. of equal to or less than 6, and a method for producing thereof. ##STR00001## In the formula (1), Rf.sub.1, Rf.sub.2, Rf.sub.3, and Rf.sub.4 are each independently one of the groups consisting of a fluorine atom, a linear perfluoroalkyl group having 1 to 7 carbon atoms, a branched perfluoroalkyl group having 3 to 7 carbon atoms, or a cyclic perfluoroalkyl group having 3 to 7 carbon atoms. The perfluoroalkyl group may have an ethereal oxygen atom. Further, Rf.sub.1, Rf.sub.2, Rf.sub.3, and Rf.sub.4 may be linked to one another to form a ring having 4 or more and 8 or less carbon atoms, and the ring may include an ethereal oxygen atom.

The present invention relates to resin particles including a residue unit represented by the following general formula (1) and having a volume average particle diameter equal to or more than 5 μm and equal to or less than 2000 μm, and a method for producing thereof. Furthermore the present invention relates to a fluororesin comprising a residue unit represented by a general formula (1) and having a weight average molecular weight Mw in a range of 5×10.sup.4 to 3×10.sup.5, and a yellow index of a heat-melted molded product (thickness 3 mm) after 24 h at 280° C. of equal to or less than 6, and a method for producing thereof. ##STR00001## In the formula (1), Rf.sub.1, Rf.sub.2, Rf.sub.3, and Rf.sub.4 are each independently one of the groups consisting of a fluorine atom, a linear perfluoroalkyl group having 1 to 7 carbon atoms, a branched perfluoroalkyl group having 3 to 7 carbon atoms, or a cyclic perfluoroalkyl group having 3 to 7 carbon atoms. The perfluoroalkyl group may have an ethereal oxygen atom. Further, Rf.sub.1, Rf.sub.2, Rf.sub.3, and Rf.sub.4 may be linked to one another to form a ring having 4 or more and 8 or less carbon atoms, and the ring may include an ethereal oxygen atom.

The present invention provides a vinyl alcohol-amino acid ester copolymer that is excellent in properties such as cell culture properties, biocompatibility, antibacterial properties, and solubility in organic solvents, and is applicable to the medical field, the biomaterial field, and the agricultural field (medical and life science fields). Provided is a vinyl alcohol-amino acid ester copolymer including a unit represented by the following formula (1) and a unit represented by the following formula (2):

##STR00001##

where, in the formula (2), R.sup.1 represents a hydrocarbon group that may optionally have a substituent, R.sup.2 and R.sup.3 each independently represent a hydrogen atom or a hydrocarbon group, and R.sup.1 and R.sup.2, or R.sup.2 and R.sup.3, may optionally be bonded together to form a cyclic structure.

The present invention provides a vinyl alcohol-amino acid ester copolymer that is excellent in properties such as cell culture properties, biocompatibility, antibacterial properties, and solubility in organic solvents, and is applicable to the medical field, the biomaterial field, and the agricultural field (medical and life science fields). Provided is a vinyl alcohol-amino acid ester copolymer including a unit represented by the following formula (1) and a unit represented by the following formula (2):

##STR00001##

where, in the formula (2), R.sup.1 represents a hydrocarbon group that may optionally have a substituent, R.sup.2 and R.sup.3 each independently represent a hydrogen atom or a hydrocarbon group, and R.sup.1 and R.sup.2, or R.sup.2 and R.sup.3, may optionally be bonded together to form a cyclic structure.

A composition comprising; a) at least one homopolymer or copolymer of vinyl acetate; and b) at least one softener.

A composition comprising; a) at least one homopolymer or copolymer of vinyl acetate; and b) at least one softener.