Resin composition, film, bag product and production process of resin composition
View Patent ↗An object of the present invention is to provide a resin composition improved in film formability and/or mechanical property, particularly tensile elastic modulus or tearing strength, of the film. The present invention provides a resin composition including at least (A) an aliphatic polyester-based resin and (C) a starch, the aliphatic polyester-based resin (A) forming a matrix phase and the starch (C) forming a dispersed phase, wherein the average particle diameter of the dispersed phase is 1 μm or less.
1. A resin composition, comprising:
(A) an aliphatic polyester-comprising resin comprising mainly an aliphatic polyester comprising a diol unit and a dicarboxylic acid unit as constituent units, and containing substantially no aromatic group; and
(B) an aliphatic-aromatic polyester based resin;
(C) a starch, and
(D) a plasticizer suitable for plasticizing starch;
wherein the aliphatic polyester-comprising resin (A) forms a matrix phase and the starch (C) forms a dispersed phase, and
wherein an average particle diameter of the dispersed phase is 0.5 μm or less and the content of the starch (C) is from 30 mass % to 60 mass % based on the entire resin composition (100 mass %), and
wherein the plasticizer (D) accounts for from 17 mass % to 55 mass % based on the starch (C).
2. The composition of claim 1 , wherein the aliphatic polyester-comprising resin (A) is at least one selected from the group consisting of a polybutylene succinate-comprising resin and a polybutylene succinate adipate-comprising resin.
3. The composition of claim 1 , wherein the aliphatic polyester aliphatic polyester-comprising resin (A) does not include ether groups.
4. The composition of claim 1 , wherein the resin composition comprises 70% by mass or more of the aliphatic polyester resin aliphatic polyester-comprising resin (A) based on the total mass of the resin composition.
5. The composition of claim 1 , wherein the resin composition comprises 90% by mass or more of the aliphatic polyester resin aliphatic polyester-comprising resin (A) based on the total mass of the resin composition.
6. The composition of claim 1 , further comprising:
(B) a thermoplastic resin other than an aliphatic polyester-comprising resin,
wherein the thermoplastic aliphatic-aromatic polyester based resin (B) forms a dispersed phase distinct from the dispersed phase of the starch (C).
7. The composition of claim 6 , wherein the aliphatic-aromatic polyester based resin (B) polyester-comprising resin comprises a diol unit and a dicarboxylic acid unit as constituent units.
8. The composition of claim 6 , wherein the aliphatic-aromatic polyester based resin (B) polyester-comprising resin is a polybutylene adipate terephthalate-comprising resin.
9. The composition of claim 1 , wherein a content of a cyclic dimer comprised in the aliphatic polyester-comprising resin (A) is from 1,000 to 10,000 ppm by mass, based on the aliphatic polyester-comprising resin (A).
10. The composition of claim 9 , wherein the content of a cyclic dimer comprised in the resin composition is from 1,000 to 9,000 ppm by mass, based on the entire resin composition.
11. The composition of claim 1 , further comprising:
(B) a thermoplastic resin other than the aliphatic polyester-comprising resin (A), wherein the aliphatic-aromatic polyester based resin (B) thermoplastic resin (B) accounts for 1 to 100 parts by mass per 100 parts by mass of the aliphatic polyester-comprising resin (A), and the plasticizer (D) accounts for from 10 to 55 mass % based on the starch (C).
12. The composition of claim 1 , further comprising
(B) a thermoplastic resin other than the aliphatic polyester-comprising resin (A), wherein the aliphatic polyester-comprising resin (A) is a polybutylene succinate-comprising resin,
the aliphatic-aromatic polyester based resin (B) thermoplastic resin (B) other than the aliphatic polyester-based resin (A) is a polybutylene adipate terephthalate comprising resin or a polybutylene succinate terephthalate-comprising resin,
the plasticizer (D) for starch is glycerin, and
mass ratios of respective components to the entire resin composition are from 30 to 45 mass % of the polybutylene succinate-comprising resin, from 15 to 25 mass % of the polybutylene adipate terephthalate comprising resin or the polybutylene succinate terephthalate-comprising resin, from 30 to 45 mass % of the starch (C), and from 4 to 8 mass % of the glycerin.
13. A film, obtained by molding the composition of claim 1 , wherein a tensile elastic modulus in accordance with JIS K7127 is 200 MPa or more and an Elmendorf tearing strength in accordance with JIS K7128 is 100 N/mm or more.
14. The film of claim 13 , wherein the film is molded by inflation molding.
15. A bag product, comprising the film of claim 13 .