Pigmented coating compositions having low solvent content

Patent metadata

Field	Value
Publication number	US-2022089902-A1
Application number	US-202017030913-A
Country	US
Kind code	A1
Filing date	Sep 24, 2020
Priority date	Sep 24, 2020
Publication date	Mar 24, 2022
Grant date	—

Abstract

A coating composition can include an aliphatic polyisocyanate and a polyaspartate combined at an equivalent ratio of from 0.9 to 1.8, the aliphatic polyisocyanate having an NCO % of from 6 wt % to 25 wt % based on ISO 11909:2007. The coating composition can also include a pigment at a pigment to binder ratio of from 0.05 to 1.3 and a drying agent in an amount of from 0.5 wt % to 5 wt % based on a total weight of the coating composition. The coating composition can have a total solvent content of less than or equal to 250 g/L.

First claim

What is claimed is:

1 . A coating composition, comprising:
an aliphatic polyisocyanate and a polyaspartate combined at an equivalent ratio of from 0.9 to 1.8, the aliphatic polyisocyanate having an NCO % of from 6 wt % to 25 wt % based on ISO 11909:2007; a pigment at a pigment to binder ratio of from 0.05 to 1.3; and a drying agent in an amount of from 0.5 wt % to 5 wt % based on a total weight of the coating composition, wherein the coating composition has a total solvent content of less than or equal to 250 g/L.

2 . The coating composition of claim 1 , wherein the aliphatic polyisocyanate comprises an HDI polyisocyanate, a PDI polyisocyanate, or a combination thereof.

3 . The coating composition of claim 1 , wherein the aliphatic polyisocyanate comprises a trimer, an allophanate, or a combination thereof.

4 . The coating composition of claim 1 , wherein the aliphatic polyisocyanate has a number average isocyanate functionality of from 2.3 to 3.7 based on gel permeation chromatography.

5 . The coating composition of claim 1 , wherein the aliphatic polyisocyanate has a weight average molecular weight of from 400 g/mol to 2500 g/mol based on gel permeation chromatography.

6 . The coating composition of claim 1 , wherein the pigment is present at a pigment to binder ratio of from 0.1 to 1.0.

7 . The coating composition of claim 1 , wherein the drying agent comprises a molecular sieve.

8 . The coating composition of claim 7 , wherein the molecular sieve has a water absorption capacity of from 20 to 35 g water/g molecular sieve at 25° C. and 40% R.H.

9 . The coating composition of claim 7 , wherein the molecular sieve has a pore size of from 1 Å to 12 Å.

10 . The coating composition of claim 1 , further comprising a metal additive in an amount of from 0.01 wt % to 0.1 wt % based on a total weight of the coating composition.

11 . The coating composition of claim 10 , wherein the metal additive comprises a tin compound.

12 . The coating composition of claim 11 , wherein the tin compound is dibutyltin dilaurate.

13 . The coating composition of claim 10 , wherein the metal additive comprises a metal having a +4 oxidation state.

14 . The coating composition of claim 1 , wherein the coating composition has an initial viscosity of from 55 KU to 90 KU at 23° C. based on ISO 3219:2003,

15 . The coating composition of claim 1 , wherein the coating composition has a viscosity of less than or equal to 120 KU at 23° C. based on ISO 3219:2003 for at least 1.5 hours after mixing.

16 . The coating composition of claim 1 , wherein the coating composition has a weight solids content of from 91 wt % to 99 wt % based on a total weight of the coating composition.

17 . A coated substrate, comprising:
a substrate having the coating composition of claim 1 applied to a surface portion thereof, wherein the coating composition is applied at a coating thickness of from 1 mil to 16 mil.

18 . The coated substrate of claim 17 , wherein the substrate comprises metal, plastic, wood, cement, concrete, glass, or a combination thereof.

19 . A method of manufacturing a coating composition, comprising:
combining an aliphatic polyisocyanate and a polyaspartate at an equivalent ratio of from 0.9 to 1.8, wherein the aliphatic polyisocyanate has an NCO % of from 6 wt % to 25 wt % based on ISO 11909:2007, wherein the coating composition has a total solvent content of less than or equal to 250 g/L, and wherein the coating composition further comprises: a pigment at a pigment to binder ratio of from 0.05 to 1.3; and a drying agent in an amount of from 0.5 wt % to 5 wt % based on a total weight of the coating composition.

20 . The method of claim 19 , further comprising diluting the coating composition with a solvent.

Assignees

• Covestro Llc

Inventors

• Wang Daniel P
• Best Kurt E

Classifications

• C09D5/00 Primary

  Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced {(electrically insulating plastics, resins or waxes H01B3/30)}; Filling pastes · CPC title

• C08K2003/2241

  Titanium dioxide · CPC title

• C09D7/61

  inorganic · CPC title

• C08K3/013

  Fillers, pigments or reinforcing additives · CPC title

• C08G18/246

  containing also tin-carbon bonds · CPC title