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

 

 

m-Xylylene Diisocyanate for Polythiourethanes

 

Patent Title: ISOCYANATE COMPOSITION FOR OPTICAL LENSES AND PROCESS FOR PREPARING THE SAME

 Number/Link: US2018/0334531

Applicant/Assignee:  SKC

Publication date: 22 November 2018

Gist”:  m-XDI is prepared from purified m-xylylene diamine and used for improved optical materials

Why it is interesting: Polythiourethanes have a high refractive index, a high transparency and a relatively high impact resistance and their use in optical lenses is well known. In this invention, polythiourethanes are prepared by using ‘pure’ (i.e. 99 to 100%) m-XDI as the isocyanate. The m-XDI is prepared from m-xylylene diamine from which impurities (esp. o-XDA, p-XDA and monoamines) are removed by distillation or crystallization.  Polythiourethanes prepared from 100% m-XDI are said to show improved optical properties such as refractive index, transparency, dispersion (Abbe number), yellowness, cloudiness etc.

XDI

Polyurethanes Emission Control – EBook

Emissions of volatile organic compounds (VOC) from polyurethane systems and materials can contribute to safety, health and environmental issues and are subject to ever more stringent laws and regulations.

This report reviews the different strategies and technologies to reduce or eliminate emissions from polyurethane systems as disclosed in the recent patent literature.
The following groups of compounds are discussed:

  • Monomeric isocyanates
  • Aldehydes
  • Amines
  • Silicones
  • Antioxidants
  • Flame retardants
  • Cyclic oligomers
  • “Odours”

Order the report HERE  or download a SINGLE READER license from my shop HERE.
Contact me for other license agreements.

Calixarene-Based Self-Healing Polyurethane Coatings

Patent Title: CALIXARENE-TYPE PHOTOCURABLE POLYURETHANE RESIN AND SELF-REPAIRING COATING PREPARED THEREFROM

 Number/Link: WO2018/205208  (Chinese)

Applicant/Assignee:  Jiangnan Univ.

Publication date: 15 November 2018

Gist”: A coumarine-containing prepolymer is reacted with calixarene

Why it is interesting: UV-curable and self-healing polyurethanes containing coumarine groups have been discussed before in this blog. In the current invention, an isocyanate-ended prepolymer is partially capped with coumarine groups.  The remaing NCO groups are then reacted with a calixarene to form a core-shell type material that can be used in UV curable coatings with improved hardness and self-healing characteristics.

Calixarene-based polyurethane according to the invention

Polyurethane-Graphene Composite

Patent Title: POLYURETHANE FILM COMPRISING GRAPHENE AND PREPARATION PROCESS THEREOF.

 Number/Link: WO/2018/202747

Applicant/Assignee:  Directa Plus

Publication date: 8 November 2018

Gist”: A PU film containing graphene nano-platelets

Why it is interesting: The invention is about polyurethane-graphene nanocomposites useful as films in textiles for clothing and medical applications. The films are prepared by incorporating into a (commercially available) PU resin, 1-30% (w/w) of graphene nano platelets together with 0.1-5% of (pref.) silica particles as a blocking agent and a solvent to adjust viscosity.  The composition is cured on a flat support as a film of 10 to 100µm thick. It is said that the PU films can a.o. have improved breathability, thermal conductivity, electrical conductivity and antibacterial activity.

Graphene

Graphene (Wikipedia)