Hybrid Polyisocyanurates for Composites and Coatings

Patent Title: DUAL-CURING ISOCYANURATE POLYMERS

 Number/Link:WO2018/087395 WO2018/087396  WO2018/087399 (German)

Applicant/Assignee:  Covestro

Publication date: 17 May 2018

Gist”:  Di-isocyanate trimer is reacted with hydroxymethacrylates and polyacrylates in the presence of a trimerization catalyst. 

Why it is interesting: According to these inventions a reaction system with two curing modes can be prepared by mixing high functionality oligomeric isocyanate, ethylenically unsaturated compounds, unsaturated compounds containing isocyanate-reactive groups, timerization catalyst and a free-radical initiator at an NCO index of 100 to 200. The system shows a relatively low viscosity and can e.g. be used in fiber-reinforced composites and coatings. In the examples HDI trimer is reacted with hexanedioldimethacrylate and hydroxypropylmethacrylate in the presence of potassium acetate and a peroxybenzoic acid.

HDI isocyanurate

HDI-trimer


Photocrosslinkable Polyurethane Coatings and Adhesives

Patent Title: PHOTORESPONSIVE POLYURETHANES

 Number/Link: WO2018/039453

Applicant/Assignee:  Univ of Akron

Publication date: 1-March-2018

Gist”: PU coatings or adhesives with built-in coumarin or phenacyl groups 

Why it is interesting: According to this invention, polyurethane coating- and adhesive systems with two ‘levels of strength’ can be made by incorporating photoresponsive groups like coumarin into the PU backbone.  The coumarin groups will dimerize when irradiated with UV light of about 340nm and can be cleaved again with light of about 250nm. Alkoxyphenacyl groups can also be built into the PU backbone, allowing photocleavage with UV light of 250-350nm. The use of coumarin in (self-healing) coatings is not new and has been discussed before in this blog, so I doubt that this is patentable.

coumarin monomer

Hydroxy functional coumarin monomer

Fingerprint Resistant Coatings

Patent Title: COATINGS COMBINING OIL-ABSORBING AND OIL-REPELLING COMPONENTS FOR INCREASED SMUDGE RESISTANCE

 Number/Link: WO2018/032356

Applicant/Assignee:  HRL Laboratorories

Publication date: 15 February 2018

Gist”: Phase separated polyurethanes with oleophilic dispersed phase and oleophobic continuous phase (or vice versa) behave as anti-smudge materials.

Why it is interesting: Anti-smudge coatings are of great interest for smartphones and other touch screen devices and are currently made from oleophobic materials, i.e. materials showing a small contact angle vs. oils. According to this invention improved anti-smudge properties can be achieved by using a material having discrete inclusions in a continuous matrix. The matrix material needs to be oleophilic, while the inclusions are oleophobic (or vice versa) and the inclusions need to be smaller than 50nm so not to scatter visible light.  A coating like this can be prepared from a segmented polyurethane comprising (e.g.) a polybutadiene soft phase and a perfluoro/isocyanate/TMP hard phase. It is said that the oleophobic phase will repel the oil while the oelephilic phase will absorb it, leaving a smudge-free surface.
Question remains what happens when the oily phase gets saturated..

smudgecoating

Schematic representation of the invention

Polyurethanes from Alpha Glucan

Patent Title: POLYURETHANE POLYMERS COMPRISING POLYSACCHARIDES

 Number/Link: WO2018/017789

Applicant/Assignee:  Du Pont

Publication date: 25 january 2018

Gist”: Polyurethanes containing poly alpha 1,3-glucan

Why it is interesting: The invention is related to the preparation of different types of polyurethanes comprising poly alpha 1,3-glucan, which is a polymeric D-glucose having alpha 1,3 glycosidic bonds (as opposed to most natural glucose polymers which show α or β 1,4 glycoside linkages). Alpha 1,3 glucan can be prepared by enzymatic polymerization using sucrose and a glycosyltransferase. The glucan can be mixed with polyols and reacted with isocyanates to prepare polyurethanes.  Many examples are given ranging from PUDs, films, flexible foams to TPUs.

glucan

Poly alpha 1,3-glucan

 

Coated Fracking Proppants

Patent Title: AMIDE BASED COATING

 Number/Link: WO2017/213855

Applicant/Assignee:  Dow

Publication date: 14 December 2017

Gist”: Proppant particles are coated with polyamide based on isocyanate and carboxylic acids

Why it is interesting: Proppant particles are used in the hydraulic fracturing process to force open rock fissures to extract gas and oil – as discussed before in this blog. According to this invention the proppant particles are coated with a reacting mixture of a polyisocyanate (e.g. polymeric MDI) and polycarboxilic acids (e.g. a blend of citric acid and an acid-terminated polyether triol). Under the high pressure and temperature of the fracture, the coating will bond the proppant particles together, thus preventing flow-back of the proppant and the blocking of the well. The coating can contain additives to capture heavy metals like radium and sulfides like hydrogensulfide to reduce contamination of the fracture fluid.

citricacid

Citric acid