PU-FPOSS Coating Compositions

Title: ICE ADHESION REDUCING PREPOLYMERS AND POLYMERS

Number/Link: US20170204291

Applicant/Assignee: Boeing

Publication Date: 20 July 2017  (published as PCT)

“Gist”: Ice repellent polyurethane coatings are prepared by incorporating F-POSS prepolymers

Why it is interesting: The invention is about coated surfaces that show reduced ice formation and/or adhesion. This is accomplished by incorporating fluorinated polyhedral oligomeric silsesquioxanes (F-POSS) into the composition. OH-functional F-POSS is prepared as per the scheme below, which is then reacted with polyisocyanates to prepare an NCO-functional F-POSS prepolymer.  The prepolymer can then be used in PU coating compositions, or reacted with amino-functional PDMS compounds and used as an additive in coating compositions.
It is believed that the F-POSS particles interfere with H-bond formation of ice to the coated surface.  Ice repellent surfaces are particularly useful for aircraft, wind turbines, cooling equipment an the like.

Synthesis of OH-functional trifluoropropyl POSS

Infrared Curable 2K PU Adhesives

Patent Title: LATENT TWO-PART POLYURETHANE ADHESIVES CURABLE WITH INFRARED RADIATION

 Number/Link: WO2016/205251 and related cases: WO..5252, WO…5254 and WO..5255

Applicant/Assignee: Dow

Publication date: all published on 22 dec 2016

Gist”: Two-component PU adhesive using 3 different delayed-action catalysts

Why it is interesting: Two component adhesive systems need a sufficiently long ‘open time’ preferably combined with a fast cure once activated, e.g. by heat. Heat curing using infrared radiation allows for ‘spot curing’ , i.e. curing only predetermined parts of the adhesive such that the assembly can be handled and can be cured completely in a subsequent step.  This process is fast and saves energy.  The current invention is about IR curable adhesives containing 3 different types of latent catalysts: a latent room temperature organometallic catalyst based on Sn, Zn or Bi added to the polyol component, a phenol-blocked cyclic amidine and a carboxylic acid blocked cyclic amidine.  The two latter catalysts can either be included in the polyol or in the isocyanate component. The catalysts used in the examples are dioctyltinthioglycolate, phenol blocked 1,8-diazabicycloundec-7-ene and a carboxilic acid blocked 1,8-diazabicycloundec-7-ene.

1,8-diazabicycloundec-7-ene

1,8-diazabicycloundec-7-ene

Reactive Polyurethane Plasticizer

Patent Title: REACTIVE POLYURETHANE PLASTICIZERS AND ADHESIVES MADE THEREFROM

 Number/Link: W02016179131

Applicant/Assignee: Dow

Publication date: 10-11-2016

Gist”: An EO/PO monol is reacted with an excess of 4,4′-MDI

Why it is interesting: The invention is about reactive PU plasticizers which are said to be especially useful for polyurethane moisture curing adhesives used in automotive glass bonding. As opposed to conventional plasticizers they will supposedly not migrate and therefore not degrade adhesive properties over time or cause window fogging. The reactive plasticizers are prepared by reacting a slight excess of 4,4′-MDI with and EO/PO monol of MW between 500 and 2000 Da and an EO:PO ratio of about 1:1, such that the resulting in NCO content is between 0.1 and 1%.  Obviously at such low NCO values most of the MDI will have reacted twice with monol, and the resulting non-reactive plasticizer may (in my opinion) well migrate depending on the composition of both monol and adhesive.

4,4'-MDI

4,4′-MDI

 

PU-Acrylate/Epoxy IPN for 3D Printing

Patent Title: PHOTOCURABLE COMPOSITIONS FOR THREE-DIMENSIONAL PRINTING

 Number/Link:  WO 2016/153711

Applicant/Assignee: Dow

Publication date: 29-09-2016

Gist”: Acrylate-capped PU prepolymer is copolymerized with epoxides using UV radiation

Why it is interesting: This case is about UV-curable compositions to make flexible materials using additive manufacturing, especially stereolithography.  A prepolymer of an isocyanate and a ‘flexible’ polyol is capped with a hydroxy-functional acrylate, then mixed with a multifunctional epoxy, a multifunctional acrylate ‘monomer’ (a crosslinker also acting as reactive diluent) and two photoinitiators:  one radical and one cationic.  In the example a 6 to 8000 Mole weight diol is capped with TDI and then with hydroxyethyl acrylate.  The prepolymer is then mixed with 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 1,6-hexanedioldiacrylate and two photoinitiators.  After UV curing the materials had a shore A hardness between about 60 and 80 and an elongation at break between about 70 and 200.

3,4-Epoxycyclohexylmethyl-3,4- epoxycyclohexane carboxylate

3,4-Epoxycyclohexylmethyl-3,4-
epoxycyclohexane carboxylate

Polyurethane Prepolymer with Very Low Monomeric Isocyanate Content

Patent Title: ULTRALOW MONOMER POLYURETHANES

 Number/Link: WO 2016/142513

Applicant/Assignee: Henkel

Publication date: 15-09-2016

Gist”: An NCO-ended prepolymer is reacted with a bis(alkoxysilylalkyl)amine

Why it is interesting: This invention is about laminating adhesives with a ‘primary aromatic amine migration limit’ of less than 10ppb, in accordance with the EU regulation for food packaging laminates. The low monomeric content is achieved by first making a NCO-ended prepolymer, which is then reacted with an monofunctional ‘H-acidic’ compound, preferably a bis(alkoxysilylalkyl)amine.  In an example a mixture of diols (OHv 108 to 236) was  reacted with 2.4-TDI down to an NCO value of 3.85%. Then 4,4′ MDI, trimethylolpropane and a triiso based on TDI were added to an NCO value of 2.2%.  Finally the prepolymer was reacted with bis(3-(triethoxysilyl)proplyl)amine at an NCO/NH ratio of 7:1.  Final NCO value was 2% with 0.05% (w/w) free 2,4-TDI and less than 0.01% free 4,4′-MDI. The prepolymer is said to be useful in 1K and 2K adhesive compositions and is said to have better adhesion properties and reactivity compared to NCO-free adhesives like sile silane-terminated PU adhesives.

Bis(3-(triethoxysilyl)propyl)amine

Bis(3-(triethoxysilyl)propyl)amine