Translucent Rigid Foams

Patent Title: TRANSLUCENT POLYURETHANE FOAMS

 Number/Link: WO2018/178139  WO2018/177987  (German)

Applicant/Assignee:  Covestro

Publication date: 4 October 2018

Gist”: Rigid foam formulation is mixed without air to delay nucleation

Why it is interesting: The invention is about translucent rigid foams which are said to be useful as wall and roof elements such as light strips, light domes and the like.  The foams are based on (pref.) trimerized aliphatic diisocyanates and are blown with water.  The composition is degassed and then mixed without inclusion of air to delay nucleation. The resulting foams have a course cell structure and thick cell struts which apparently allows light to pass through.

 

Desmodur N3900

Asymmetric trimer of HDI (iminooxadiazinedione)

Carbamate Blown Rigid Foams

Patent Title: A METHOD FOR PRODUCING AN OPEN CELL RIGID POLYURETHANE FOAM

 Number/Link: WO2018096101  WO2018096102

Applicant/Assignee:  Covestro

Publication date: 31 may 2018

Gist”: An open cell rigid foam is prepared using an amine-CO2 adduct and water as blowing agents

Why it is interesting: According to this invention an open cell rigid spray foam can be prepared from a conventional rigid foam formulation and a blowing agent consisting of 4-12 parts (pref.) on 100 parts of polyol of an adduct of a primary or secondary amine and carbon dioxide, together with 15 to 50 parts of water.  The properties of the resulting open cell, low density foam are said to be largely independent of ambient conditions and spray thickness. The foams are useful for thermal insulation applications in construction.

carbamate

Carbamate of N,N-dimethylaminopropylamine

 

Solid-Solid PU PCM

Patent Title: PHASE-CHANGE MATERIAL FOR STORING THERMAL ENERGY, MANUFACTURING METHOD AND USES OF SUCH A MATERIAL

 Number/Link:  WO2017/198933 (French)

Applicant/Assignee:  UNIV CERGY-PONTOIS

Publication date: 23 november 2017

Gist”: A crosslinked PEG-HMDI elastomer can be used as phase change material.

Why it is interesting: Phase change materials, used to dampen temperature cycles in buildings, are well known. Most organic phase change materials (e.g. paraffines) show solid-liquid phase transitions and therefore need to be macro- or micro-encapsulated. This invention is about polyurethane PCMs with a solid to solid phase transition, and therefore need not be encapsulated. The PU PCM is prepared by reacting a polyethylene glycol with a diisocyanate like HMDI together with a crosslinker like glycerol. The solid elastomer is then ground into powder which can be used in construction materials like plaster or cement. The transition temperature and the latent heat of the PCM is controlled through the mole weight of the PEG (e.g. 1000 to 2000 Da) and the degree of crosslinking.
Solid-solid PU PCMs are not new, see WO2011/089061 (Huntsman), which (in my opinion) presents a more elegant and flexible solution to the problem.

Phase_Change_Materials

Temperature damping by PCM (Wikimedia Commons)

 

Formic Acid Blown EPIC Foams

Patent Title: ISOCYANATE-BASED TEMPERATURE-RESISTANT FOAMS WITH HIGH FLAME RESISTANCE

 Number/Link: WO2016/131874

Applicant/Assignee: BASF, Covestro

Publication date: 25-08-2016

Gist”:  One shot rigid isocyanate-epoxy foams blown with formic acid

Why it is interesting: This is the first in a series of (at least) 3 patent applications apparently resulting from a cooperation between BASF and Covestro on epoxy-isocyanate (“EPIC”) foams.  The other applications are WO2016/131878 and WO2016/131880 published on the same date. More publications may follow.
The current invention is about temperature-resistant foams with reportedly very high mechanical properties prepared form a one-shot system comprising a (pref.) high functional MDI, a (pref.) bisphenol-A or bisphenol-F polyglycidylether, at least one reactive amine catalyst and a blowing agent comprising formic acid. The ratio of iso to epoxy groups is (pref.) 3:1 to 15:1. The resulting materials are post-cured at 200°C. The foams contain no, or very little, urethane or urea groups and are said to be especially useful in laminates a.o.  In the examples foams with densities of 25-35 kg/m³ with a thermal conductivity as low as 20 mW/mK are shown.

Bisphenol-F diglycidylether

Bisphenol-F diglycidylether

1K Dual Cure Polyurethane Adhesive

Patent Title: DUAL CURE 1K PU ADHESIVE FORMULATIONS USING MATRIX ENCAPSULATED POLYAMINES

 Number/Link: W02016022346

Applicant/Assignee: Dow

Publication date: 11-02-2016

Gist”: Encapsulated polyamines are added to a moisture curing adhesive

Why it is interesting: One component (1K) PU adhesives are either NCO-ended prepolymers cured by atmospheric moisture, or OH-ended prepolymers containing encapuslated or blocked isocyanates and which are cured by heat.  According to this invention a 1K adhesive curable by both moisture and heat can be made by incorporating an encapuslated polyamine into a 1K mositure curing prepolymer. The amine is solid at room temperature (e.g. 1,12-dodecanediamine) and is mixed with a (semi-)crystalline termoplastic with a well defined melting point, e.g. a polyacrylate or polyolefine before being added to the adhesive. Dual cure 1K adhesives allow for heat-curing the adhesive at critical spots to providing stability to an assembly.  The adhesives are said to be especially useful for the automotive industry.

1,12-dodecanediamine

1,12-dodecanediamine