Omniphobic Polyurea

Patent Title: MOISTURE-CURABLE OMNIPHOBIC COATINGS

Number/Link: US2019/0031909

Applicant/Assignee: US Navy

Publication Date: 31 January 2019

“Gist”: Polyurea topcoat containing both silane and perfluoro groups

Why it is interesting: According to this invention, a coating having both hydrophobic and oleophobic properties can be prepared by reacting an alkoxysilane-terminated polyurea with a perfluoromaterial having at least one alkoxy- or hydroxyl group. In an example a coating is prepared by reacting a polyurea based on HDI trimer and N-butyl-3-aminoppropyltrimethoxysilane with triethoxy(perfluoro-octyl)silane. The coating showed contact angles of more than 140 degrees vs water and more than 90 degrees vs hexadecane.

omniphobicpolyurea

Reaction system according to the invention

Low Viscosity Polyester Polyols

Patent Title: LOW VISCOSITY POLYOLS FOR POLYURETHANE APPLICATIONS

Number/Link: WO2019/010018

Applicant/Assignee: Stepan

Publication Date: 10 January 2019

“Gist”: Polyester polyol containing lactide

Why it is interesting:  The invention relates to low viscosity polyester polyols for use in crosslinked polyurethane coating compositions. The polyols are prepared from a polycarboxylic acid, one or more polyols and 5-35% lactide. In an example adipic acid is reacted with lactide, neopentyl glycol and trimethylolpropane. Coatings made from these polyols are said to have improved hardness and solvent resistance and a low VOC content.

lactide

Lactide

Polyurethane for Oil Well Refracking

Patent Title: METHODS AND MATERIALS FOR REFRACTURING A PARTIALLY DEPLETED OIL AND GAS WELL

Number/Link: US2018/0346786

Applicant/Assignee:  Covestro

Publication Date: 6 December 2018

“Gist”: Use of low-reactive, low-viscosity PU systems for oil well sealing

Why it is interesting: It is known that partially depleted fracking wells can be “re-fractured” to increase production. Prior to this operation former perforations in the well casing need to be sealed to prevent furthering of existing fractures, by using a chemical “diverting agent”.  According to this invention, the diverting agent can be a polyurethane system with a long potlife and relatively low viscosity, which is prepared from an unblocked hexamethylene diisocyanate and a polypropyleneoxide triol which is miscible with the isocyanate. In the examples an allophanate-modified HDI is used together with a 450-molecular weight PO triol and a delayed-action tert amine catalyst. The system does not de-mix and has a gel time ranging from 30 to more than 1000 minutes.

refracking

Sealing of fracking well