Polyvinyl alcohol resin composition and films
View Patent ↗A PVA resin composition is provided which is excellent in melt-formability and free from emanation of odor in a melt-forming process, and is capable of providing a product free from residual odor, a highly transparent film and a laminate film having higher interlayer adhesive strength. The resin composition comprises: (A) a polyvinyl alcohol resin having a 1,2-diol structural unit represented by the following formula (1): and having a saponification degree of 80 to 97.9 mol %; and (B) an alkylene oxide adduct of a polyvalent alcohol containing 5 to 9 moles of an alkylene oxide per 1 mole of the polyvalent alcohol.
1. A resin composition comprising:
(A) a polyvinyl alcohol resin having a 1,2-diol structural unit represented by the following formula (1):
and having a saponification degree of 80 to 97.9 mol %; and
(B) an alkylene oxide adduct of a polyvalent alcohol containing 6 to 9 moles of an alkylene oxide per 1 mole of the polyvalent alcohol,
wherein the alkylene oxide adduct of a polyvalent alcohol (B) has a hydroxyl value of 200 to 1500 mg KOH/g.
2. A resin composition as set forth in claim 1 , wherein the polyvinyl alcohol resin (A) is a polyvinyl alcohol resin prepared by saponifying a copolymer of a vinyl ester monomer and a 3,4-diacyloxy-1-butene.
3. A resin composition as set forth in claim 1 , wherein the 1,2-diol structural unit represented by the formula (1) is present in a proportion of 2 to 15 mol % in the polyvinyl alcohol resin (A).
4. A resin composition as set forth in claim 1 , wherein the polyvalent alcohol for the alkylene oxide adduct of a polyvalent alcohol (B) has a carbon number of 2 to 20.
5. A resin composition as set forth in claim 1 , wherein the polyvalent alcohol for the alkylene oxide adduct of a polyvalent alcohol (B) has a valence of 2 to 15.
6. A resin composition as set forth in claim 1 , wherein the polyvalent alcohol for the alkylene oxide adduct of a polyvalent alcohol (B) is glycerol.
7. A resin composition as set forth in claim 1 , wherein the alkylene oxide for the alkylene oxide adduct of a polyvalent alcohol (B) is ethylene oxide.
8. A resin composition as set forth in claim 1 , wherein the polyvinyl alcohol resin (A) and the alkylene oxide adduct of a polyvalent alcohol (B) are present in a weight ratio of (A)/(B)=80/20 to 97/3.
9. A resin composition as set forth in claim 1 , which has a melt flow rate (MFR) of 10 to 100 g/10 min as measured at 190° C. with a load of 2160 g.
10. A film composed of a resin composition comprising:
(A) a polyvinyl alcohol resin having a 1,2-diol structural unit represented by the following formula (1):
and having a saponification degree of 80 to 97.9 mol %; and
(B) an alkylene oxide adduct of a polyvalent alcohol containing 6 to 9 moles of an alkylene oxide per 1 mole of the polyvalent alcohol,
wherein the alkylene oxide adduct of a polyvalent alcohol (B) has a hydroxyl value of 200 to 1500 mg KOH/g.
11. A laminate film comprising a plurality of layers, at least one of which is composed of a resin composition comprising:
(A) a polyvinyl alcohol resin having a 1,2-diol structural unit represented by the following formula (1):
and having a saponification degree of 80 to 97.9 mol %; and
(B) an alkylene oxide adduct of a polyvalent alcohol containing 6 to 9 moles of an alkylene oxide per 1 mole of the polyvalent alcohol,
wherein the alkylene oxide adduct of a polyvalent alcohol (B) has a hydroxyl value of 200 to 1500 mg KOH/g.
12. A resin composition as set forth in claim 1 , wherein the resin composition is a resin composition for film.