m-Xylylene Diisocyanate for Polythiourethanes

 

Patent Title: ISOCYANATE COMPOSITION FOR OPTICAL LENSES AND PROCESS FOR PREPARING THE SAME

 Number/Link: US2018/0334531

Applicant/Assignee:  SKC

Publication date: 22 November 2018

Gist”:  m-XDI is prepared from purified m-xylylene diamine and used for improved optical materials

Why it is interesting: Polythiourethanes have a high refractive index, a high transparency and a relatively high impact resistance and their use in optical lenses is well known. In this invention, polythiourethanes are prepared by using ‘pure’ (i.e. 99 to 100%) m-XDI as the isocyanate. The m-XDI is prepared from m-xylylene diamine from which impurities (esp. o-XDA, p-XDA and monoamines) are removed by distillation or crystallization.  Polythiourethanes prepared from 100% m-XDI are said to show improved optical properties such as refractive index, transparency, dispersion (Abbe number), yellowness, cloudiness etc.

XDI

Polyurethane-Graphene Composite

Patent Title: POLYURETHANE FILM COMPRISING GRAPHENE AND PREPARATION PROCESS THEREOF.

 Number/Link: WO/2018/202747

Applicant/Assignee:  Directa Plus

Publication date: 8 November 2018

Gist”: A PU film containing graphene nano-platelets

Why it is interesting: The invention is about polyurethane-graphene nanocomposites useful as films in textiles for clothing and medical applications. The films are prepared by incorporating into a (commercially available) PU resin, 1-30% (w/w) of graphene nano platelets together with 0.1-5% of (pref.) silica particles as a blocking agent and a solvent to adjust viscosity.  The composition is cured on a flat support as a film of 10 to 100µm thick. It is said that the PU films can a.o. have improved breathability, thermal conductivity, electrical conductivity and antibacterial activity.

Graphene

Graphene (Wikipedia)

 

 

PU Elastomers with Extremely High Elongation

Patent Title:  Polyurethane Elastomer with High Ultimate Elongation

 Number/Link: US2018/0312623

Applicant/Assignee:  UNIV PENNSYLVANIA

Publication date: 1 November 2018

Gist”: Low hardblock polyurethane-polyurea elastomers are prepared from low unsat diols, HDI and a bulky diamine chain extender

Why it is interesting: The current invention relates to PU  elastomers which are said “to  have the highest reported elongation-at-break among known polyurethane elastomers“. The materials are prepared from an NCO-ended prepolymer consisting of a low unsaturated, low dispersity diol and a symmetric diisocyanate (i.e. no 4,4′-MDI), which is reacted with a “bulky” diamine chain extender. In the examples Acclaim 4200 (polyether diol with OHv 28) is used together with HDI and 2-methyl-1,5-pentanediamine. The elastomer showed an elongation at break of more than 2000%.
Because these materials have a low- and non-aromatic hardblock content, it is my opinion that they show creep rather than elasticity.

methylpentandiamine

2-methyl-1,5-pentanediamine

  • Pages

  • Categories

  • Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 1,090 other followers

  • Follow Innovation in PU on Twitter

%d bloggers like this: