Copolymerized saturated polyester resin and coating composition containing same

Patent metadata

Field	Value
Publication number	US-11401371-B2
Application number	US-201916966084-A
Country	US
Kind code	B2
Filing date	Jan 31, 2019
Priority date	Feb 7, 2018
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

A copolymerized saturated polyester resin is formed by polycondensation of an acid component and an alcohol component. The acid component contains (a-1) 90 to 99% by mole of an aromatic dicarboxylic acid or a C1-2 alkyl ester thereof and (a-2) 0.5 to 2% by mole of a trifunctional or higher functional carboxylic acid or an anhydride thereof. The alcohol component contains (b-1) 45 to 80% by mole of an alicyclic polyhydric alcohol and (b-2) 20 to 55% by mole of an aliphatic polyhydric alcohol having a C1-3 alkyl side chain. A coating composition containing the copolymerized saturated polyester resin shows excellent corrosion resistance and chemical resistance. A coating film formed from the coating composition shows excellent processability and resin solubility, and is useful for coating a can and pre-coated metal.

First claim

The invention claimed is:

1. A copolymerized saturated polyester resin, which is formed by polycondensation of an acid component and an alcohol component, and has a glass transition temperature of 60 to 120° C., an intrinsic viscosity of 0.4 to 0.7 dl/g, and a number average molecular weight of 12,000 to 20,000 g/mol,
wherein the acid component comprises (a-1) 90 to 99% by mole of an aromatic dicarboxylic acid or a C 1-2 alkyl ester thereof and (a-2) 0.5 to 2% by mole of a trifunctional or higher functional carboxylic acid or an anhydride thereof, each based on total amount of the acid component,
wherein the alcohol component comprises (b-1) 45 to 80% by mole of an alicyclic polyhydric alcohol and (b-2) 30 to 55% by mole of an aliphatic polyhydric alcohol having a C 1-3 alkyl side chain, each based on total amount of the alcohol component,
wherein the alcohol component (b-1) is (i) tricyclodecane dimethanol, (ii) a mixture of tricyclodecane dimethanol and cyclohexane dimethanol, (iii) a mixture of tricyclodecane dimethanol and isosorbide, or (iv) a mixture of tricyclodecane dimethanol, cyclohexane dimethanol, and isosorbide; and
wherein the alcohol component (b-2) is 2 methyl-1,3-propanediol.

2. The copolymerized saturated polyester resin of claim 1 , wherein the acid component (a-1) is selected from the group consisting of isophthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, C 1-2 alkyl ester thereof, and a combination thereof; and
the acid component (a-2) is selected from trimellitic acid, an anhydride thereof, and a combination thereof.

3. The copolymerized saturated polyester resin of claim 1 , which has a polydispersity index of 2.0 to 4.0.

4. A coating composition, which comprises the copolymerized saturated polyester resin of claim 1 .

5. The coating composition of claim 4 , which further comprises a curing agent, wherein the curing agent is selected from the group consisting of a phenol-formaldehyde resin, a polyfunctional polyisocyanate compound, a melamine-formaldehyde resin, a benzoguanamine resin, and a combination thereof.

Assignees

• Sk Chemicals Co Ltd

Inventors

• Kim Hyung-Gon
• Sim Jong-Ki
• Kim Soon-Ki

Classifications

• C08G63/189

  containing a naphthalene ring · CPC title

• C09D7/63

  organic · CPC title

• C09D167/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C09D167/06 takes precedence) · CPC title

• C08G2150/90

  Compositions for anticorrosive coatings · CPC title

• C08G63/20

  Polyesters having been prepared in the presence of compounds having one reactive group or more than two reactive groups · CPC title