A Coating Composition Comprising a High MN Polyester and a Low MN Polyester
AssigneePPG Coatings (Suzhou) Co., Ltd.
InventorsFeng Han, Cunyi Fan, Shimin Wang
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Abstract
A coating composition comprising: (a) a first polyester material having a number-average molecular weight (Mn) of 500 to 5,500 Daltons, and (b) a second polyester material having a number-average molecular weight (Mn) of 6,000 to 100,000 Daltons. The coating composition is useful for, among other things, coating food and/or beverage containers.
Claims15
A coating composition comprising;
- (a) a first polyester material having a number-average molecular weight (Mn) of 500 to 5,500 Daltons, and
- (b) a second polyester material having a number-average molecular weight (Mn) of 6,000 to 100,000 Daltons.
A coating composition according to any preceding claim, wherein the first polyester material may be present in the coating compositions in amounts from 1 wt % to 50 wt % based on the total solid weight of the coating composition.
A coating composition according to any preceding claim, wherein the second polyester material may be present in the coating compositions in amounts from 10 wt % to 50 wt % based on the total solid weight of the coating composition.
A coating composition according to any preceding claim, wherein the coating composition further comprises a crosslinking agent.
A coating composition comprising;
- (a) a first polyester material having a number-average molecular weight (Mn) of 500 to 5,500 Daltons, and
- (b) a second polyester material,
- wherein the second polyester material (b) comprises the reaction product of
- (i) 1,2-propanediol,
- (ii) terephthalic acid, and
- (iii) a molecular weight increasing agent,
- characterised in that the high molecular weight polyester material has a number-average molecular weight (Mn) of at least 6,100 Da and a glass transition temperature (Tg) of at least about 80° C.
A two layer coating system for a food and/or beverage container comprising an undercoat layer and an overcoat layer, wherein the undercoat layer comprises;
- (a) a first polyester material having a number-average molecular weight (Mn) of 500 to 5,500 Daltons, and
- (b) a second polyester material having a number-average molecular weight (Mn) of 6,000 to 100,000 Daltons.
Dependencies are inferred from the claim text.