Sprayable polyurethane based protective coating

Patent metadata

Field	Value
Publication number	US-9988554-B2
Application number	US-201414916220-A
Country	US
Kind code	B2
Filing date	Sep 29, 2014
Priority date	Oct 2, 2013
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A sprayable polyurethane based reaction system for forming a protective coating in industrial containers includes a first component and a second component, each having a viscosity less than 1500 cP at 25° C. A difference between the viscosities of the first component and the second component within a temperature range of 60° C. and 80° C. is from −150 cP to 150 cP. The first component is a reaction product of a polyol component that includes a first butylene oxide propylene oxide copolymer polyol having a polyoxybutylene content of at least 50 wt % and an isocyanate component that includes at least one polyisocyanate. The second component has a second butylene oxide propylene oxide copolymer polyol having a polyoxybutylene content of at least 50 wt %. At least one selected from a group of the polyol component and the second component includes a primary hydroxyl containing polyol.

First claim

The invention claimed is:

1. A sprayable polyurethane based reaction system for forming a protective coating in industrial containers, the reaction system comprising:
a first component that is a reaction product of a polyol component and an isocyanate component, the polyol component including a first butylene oxide-propylene oxide copolymer polyol having a polyoxybutylene content of at least 50 wt % based on a total weight of the first butylene oxide-propylene oxide copolymer polyol and the first butylene oxide-propylene oxide copolymer polyol being a polyether polyol, the isocyanate component including at least one polyisocyanate, and a viscosity of the first component being less than 1500 cP at 25° C.; and
a second component that includes a second butylene oxide-propylene oxide copolymer polyol having a polyoxybutylene content of at least 50 wt %, based on a total weight of the second butylene oxide-propylene oxide copolymer polyol and the second butylene oxide-propylene oxide copolymer polyol being a polyether polyol, a viscosity of the second component being less than 1500 cP at 25° C., and a difference between the viscosities of the first component and the second component within a temperature range of 60° C. and 80° C. being from −150 cP to 150 cP,
wherein at least one selected from a group of the polyol component and the second component includes a primary hydroxyl containing polyol, and a reaction product of the first component and the second component has a tensile strength of at least 1500 psi and a percent elongation at break of at least 400.

2. The reaction system as claimed in claim 1 , wherein:
the first butylene oxide-propylene oxide copolymer polyol and the second butylene oxide-propylene oxide copolymer polyol each independently have a functionality from 1.6 to 3.5 and a number average molecular weight from 1500 to 3000, and
the primary hydroxyl containing polyol has a functionality from 1.6 to 3.5 and a number average molecular weight from 200 to 10,000.

3. The reaction system as claimed in claim 1 , wherein the viscosities of the first component and the second component at 60° C. are each less than 220 cP and the viscosities of the first component and the second component at 80° C. are each less than 110 cP.

4. The reaction system as claimed in claim 1 , wherein the polyol component includes the primary hydroxyl container polyol and the amount by weight percentage of the first butylene oxide-propylene oxide copolymer polyol in the polyol component is greater than the amount by weight percentage of the primary hydroxyl containing polyol in the polyol component.

5. The reaction system as claimed in claim 1 , wherein the second component includes the primary hydroxyl container polyol and the amount by weight percentage of the second butylene oxide-propylene oxide copolymer polyol in the second component is greater than the amount by weight percentage of the primary hydroxyl containing polyol in the second component.

6. The reaction system as claimed in claim 1 , wherein the volume ratio of the first component to the second component is from 0.95:1.05 to 1.05:0.95 within the temperature range of 60° C. and 80° C.

7. The reaction system as claimed in claim 1 , wherein the second component includes a curative component that has at least one amine based curing agent, the curative component accounting for 5 wt % to 50 wt % of a total weight of the second component.

8. The reaction system as claimed in claim 1 , wherein at least one selected from the group of units derived from the primary hydroxyl containing polyol in the first component and the primary hydroxyl containing polyol in the second component account for 5 wt % to 30 wt % of a combined total weight of the first and second components.

9. A protective coating formed from the reaction system according to claim 1 , the protective coating having a tensile strength of at least 1500 psi and a percent elongation at break of at least 400.

10. The protective coating as claimed in claim 9 , wherein:
the protective coating has a second tensile strength of at least 500 psi and a second percent elongation at break of at least 300 after exposure for seven days at 25° C. to a 37 wt % solution of hydrogen chloride in water,
the protective coating maintains the tensile strength of at least 1500 psi and the percent elongation at break of at least 400 after exposure for seven days at 25° C. to a 30 wt % solution of sulfuric acid in water, and
the protective coating has a third tensile strength of at least 500 psi and a second percent elongation at break of at least 100 after exposure for seven days at 25° C. exposure to diesel fuel.

Assignees

• Dow Global Technologies Llc

Inventors

• Watkins Avery L
• Facello James

Classifications

• C08G18/10 Primary

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G18/4825

  Polyethers containing two hydroxy groups (C08G18/4833 - C08G18/5096 take precedence) · CPC title

• C08G18/246

  containing also tin-carbon bonds · CPC title

• C08G18/6208

  Hydrogenated polymers of conjugated dienes · CPC title

• C08G18/4854

  Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group · CPC title