Polycarbonate coatings for metal packaging

Patent metadata

Field	Value
Publication number	US-9303184-B2
Application number	US-201314062968-A
Country	US
Kind code	B2
Filing date	Oct 25, 2013
Priority date	Oct 31, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A liquid polycarbonate coating composition including an aliphatic polycarbonate resin and a cross linking compound, said aliphatic polycarbonate resin being derived from, in the presence of a catalyst, an aliphatic polyol which comprises (a) from 50 to 100% by weight of the aliphatic polyol, one or more cycloaliphatic polyols that consist essentially of primary hydroxyl groups and (b) from 0 to 50% by weight of the aliphatic polyol, one or more linear aliphatic polyols, is provided. A method of coating a substrate with the liquid polycarbonate coating composition and the resulting articles are also provided.

First claim

What is claimed is:

1. A liquid polycarbonate coating composition comprising an aliphatic polycarbonate resin and a cross linking compound, said aliphatic polycarbonate resin being derived from, in the presence of a catalyst, an aliphatic polyol which consists of
(a) from 70 to 100% by weight of the aliphatic polyol, one or more cycloaliphatic polyols and
(b) from 0 to 30% by weight of the aliphatic polyol, one or more linear aliphatic polyols;
wherein the aliphatic polyol comprises no more than 2.5% of polyols which comprise secondary hydroxyl groups, by weight based on the aliphatic polyol; and
wherein the aliphatic polycarbonate resin has a number average molecular weight (Mn) of from 2000 to 10,000 and the liquid polycarbonate coating is an amorphous thermosetting composition.

2. The coating composition of claim 1 wherein the aliphatic polyol consists of
(a) from 85 to 100% by weight of the aliphatic polyol, one or more cycloaliphatic polyols and
(b) from 0 to 15% by weight of the aliphatic polyol, one or more linear aliphatic polyols;
wherein the aliphatic polyols comprises no more than 2.5% of polyols which comprise secondary hydroxyl groups, buy weight based on the aliphatic polyol.

3. The coating composition of claim 1 wherein the cross linking compound comprises one or more of melamines, formaldheydes, phenolics, isocyanates, isocyanurates, hydroxyalylamides and mixtures thereof.

4. The coating composition of claim 1 wherein the cycloaliphatic primary polyols are selected from the group consisting of 1,4-cyclohexane dimethanol, cis/trans-1,3-cyclohexane dimethanol, cis/trans-1,4-cyclohexane dimethanol, 1,2,4-cyclohexanetrimethanol, 1,3,5-cyclohexanetrimethanol, 1,2,4,5-cyclohexanetetramethanol, and combinations thereof.

5. The coating composition of claim 1 wherein the linear aliphatic polyols are selected from the group consisting of neopentyl glycol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, nonaethylene glycol, decaethylene glycol, 1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4,4-tetramethyl-1,6-hexanediol, thiodiethanol, 2,4-diethyl-1,5-pentanediol, norbornene dimethanol, hydroxypivalyl hydroxypivalate, 1,10-decanediol, trimethylolethane, trimethylolpropane, pentaerythritol, and combinations thereof.

6. The coating composition of claim 1 further comprising one or more polymers selected from the group consisting of polyesters, epoxy resins, epoxy ester resins, acrylic resins, vinyl resins, solution vinyl resins, polyolefins, polyolefin dispersions and mixtures thereof.

7. A method of coating a substrate comprising:
(i) preparing a liquid polycarbonate coating composition comprising an aliphatic polycarbonate resin and a cross linking compound, said aliphatic polycarbonate resin being derived from, in the presence of a catalyst, an aliphatic polyol which consists of (a) from 70 to 100% by weight of the aliphatic polyol, one or more cycloaliphatic polyols and (b) from 0 to 30% by weight of the aliphatic polyol, one or more linear aliphatic polyols;
wherein the aliphatic polyols comprises no more than 2.5% of polyols which comprise secondary hydroxyl groups, buy weight based on the aliphatic polyol; and
wherein the aliphatic polycarbonate resin has a number average molecular weight (Mn) of from 2000 to 10,000 and the liquid polycarbonate coating is an amorphous thermosetting composition;
(ii) applying the liquid polycarbonate coating composition onto a substrate; and
(iii) curing the coating composition.

8. The method of claim 7 wherein the substrate is plastic, wood, metal, concrete, glass, a composite material, urethane elastomer, or a painted surface.

9. A coated article made by the process of claim 7 .

10. The coated article of claim 9 wherein the article is a beverage or food container and the coating is in between the substrate and the beverage or food.

11. The coating composition of claim 1 wherein the aliphatic polyol comprises no more than 1% of polyols which comprise secondary hydroxyl groups, by weight based on the aliphatic polyol.

12. The coating composition of claim 1 wherein the aliphatic polyol comprises no polyols which comprise secondary hydroxyl groups.

Assignees

• Dow Global Technologies Llc

Inventors

• Kainz Bernhard
• Moore Jonathan D
• Sonnenschein Mark F
• Wendt Benjamin L

Classifications

• C08L69/00

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title

• B65D85/70

  for materials not otherwise provided for · CPC title

• C08G64/305

  and alcohols · CPC title

• C09D169/00 Primary

  Coating compositions based on polycarbonates; Coating compositions based on derivatives of polycarbonates · CPC title

• Y10T428/31507

  Of polycarbonate · CPC title