Polyurethane Oil Gel

Patent Title: OIL GEL, PRESSURE RESISTANT MATERIAL USING SAME FOR PROTECTING ELECTRONIC DEVICES AND OIL GEL-FORMING AGENT

 Number/Link: WO2018135494  (Japanese)

Applicant/Assignee:  Sec Corp.

Publication date: 26 July 2018

Gist”: A gel from a paraffinic  oil and a compatible linear PU is used as a pressure resistant material for deep-sea applications

Why it is interesting: The invention relates to a PU-oil gel that is used as a kind of “potting compound” to protect subsea electronics at “abyssal depths” , i.e. at pressures of 5.6 MPa (about 550m deep). The gel is prepared by reacting a hydrophobic diol and a hydrophobic diisocyanate in the presence of 10-50% (w/w) on the total composition of a paraffinic oil. In the examples an OH-ended, saturated polyisoprene is used as diol together with norbornanediisocyanate.

NBDI

2,5-norbornane diisocyanate

TPU with Reduced Blooming

Patent Title: POLYOLS WITH REDUCED CYCLIC OLIGOMER CONTENT AND THERMOPLASTIC POLYURETHANE COMPOSITIONS THEREOF

 Number/Link: WO2017040505

Applicant/Assignee: Lubrizol

Publication date: 9-mar-2017

Gist”: Enzymes are used to remove cyclo-oligomers from polyster polyols

Why it is interesting: It is known that the “blooming” of polyester TPUs (i.e. the fomation of a white surface haze) is caused by the migration of cyclic polyester oligomers to the surface of the TPU. Conventionally these unreactive cyclo-oligomers are removed by e.g extraction, or their formation is prevented by careful choice of diol and diacid as mentioned before in this blog. According to this invention the cyclic polyesters can be removed by treating the polyol with an enzyme. Enzymes of the lipase or cutinase type are immobilized by attachement to an inert and insoluble material and then heated together with the polyol at 70 to 90ºC to ‘cut’ the polyester rings. After treatment of the polyol the immobilized enzyme can be filtrated.

A cyclic diester

Novel Polyurethane Gels

Patent Title: POLYURETHANE BASED GEL COMPOSITION

 Number/Link: W016/036786

Applicant/Assignee: Dow

Publication date: 10-03-2016

Gist”: PU gels are made from MDI prepolymer, high EO polyol and some diamine at low NCO index.

Why it is interesting: Polyurethane gels are well known and are sometimes used in comfort cushioning as layers or dispersed as particles in e.g. viscoelastic matresses. According to this invention plasticizer-free gels can be made by reacting a slightly branched, low NCO prepolymer ( based on 2,4′ and 4,4′ MDI and a high EO polyol), with a large amount of high EO polyol (triol or higher) and some amine-ended low mole-weight diol.
Although the material is said to be ‘plasticizer-free’not all of the polyol will be reacted at low NCO index.  However, because of its high polarity, the unreacted polyol will probably not leach.

A Polyurethane Gel

A Polyurethane Gel