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

Fluorinated Thermoplastic Polyurethanes

Patent Title: SHOE UPPERS & CASE FOR PORTABLE DEVICES

 Number/Link: WO2018/007359  WO2018007360

Applicant/Assignee:  Solvay

Publication date:  11 January 2018

Gist”:  F-TPUs are prepared by incorporating perfluoro diols

Why it is interesting: The current inventions are about fluorinated TPU and its applications. The F-TPUs are prepared by replacing part of the polyol with hydroxyl-ended fluorinated polyethers. In the examples fluorinated polyether diols are used in different ratios to conventional polyester-, PTMEG-, CAPA- and polycarbonate diols and reacted with MDI or HDI and BDO or HDO as chain extenders. The F-TPUs can be used as uppers for footwear and as cases for smartphones and are said to have improved stain resistance and – surprisingly- a soft feel to the touch.

case

F-TPU smartphone case

 

Hydrolysable Ureas

Patent Title: DYNAMIC UREA BONDS WITH FAST HYDROLYTIC KINETICS FOR POLYMERS

Number/Link: WO2017/155958

Applicant/Assignee: Univ. Illinois

Publication Date: 14 September 2017

“Gist”: Hindered urea bonds with fast hydrolysis kinetics are prepared from aromatic-sbstituted diamines and diisocyanates

Why it is interesting: Polyurethanes containing thermally reversible hindered urea bonds (HUBs) have been discussed before in this blog. In the current case the HUBs are prepared from aromatic (e.g aryl-) substituted amines and are said to show fast, pH-independent, hydrolysis kinetics. The HUBs can be built into linear or crosslinked polyurethanes or other polymers like polyamides, polycarbonates etc.  The resulting materials are useful for medical applications like drug delivery, water-degradable packaging, self-healing materials and the like.

HUB hysdrolysis

Hydrolysis reaction of phenyl-N-tetrabutyl-N-ethyl urea

 

PCM Containing PU Gels

Title: Temperature Regulating Polyurethane Gels

Number/Link: US2017/0210961

Applicant/Assignee: Technogel

Publication Date: 27 july 2017

“Gist”: Fatty acid ester PCMs are incorporated into Technogel-type gels without encapsulation

Why it is interesting: Polyurethane gels have been discussed before in this blog. The current invention is about “Technogel-type”  gels, made at low NCO-index and high functionality, that contain phase change materials (PCMs). The PCMs are esters of fatty acids that can be blended in molten state with the low EO polyol to form a clear solution, which is then reacted with isocyanate to form the gel. Despite not being encapsulated or forming a separate phase, the PCMs can reversibly melt and crsytallize while in the fluid phase of the gel. In the examples blends of lauryl laurate (C12-C12) and myristyl myristate (C14-C14) are used as PCM such that the phase change temperature is about 22-38°C.  The gels are said to be useful for ‘close to body’ comfort applications especially for use in matresses to improve sleeping comfort.

Lauryl laurate

 

TPU Shrink Wrap

Title: TPU SHRINK MATERIAL

Number/Link: WO2017/108920

Applicant/Assignee: BASF

Publication Date: 29-jun-2017

“Gist”: Shape memory TPU is used as shrink wrap

Why it is interesting: A thermoplastic polyurethane with a shape-memory is prepared from a diisocyanate, a chain extender and a polyol comprising an ‘aromatic polyester block’, especially a polyethylenetherephthalate block. The composition is chosen such that the TPU has a melting point between 160 and 230ºC and another phase transition between 30 and 80ºC (the “switching temperature”). Films of this material are then stretched at a temperature higher than the switching temperature but below melt temperature and then cooled in stretched state. The stretched films are said to be useful as shrink wrap, especially for foodstuffs. No examples are given.
A surprising application for TPU but hardly a surprising TPU invention i.m.o.

Shrink-wrapped Helicopters (Wikipedia)