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

Polyurethanes from Bisphenol-Based Polyols

Patent Title:  OLIGOMERIC POLYOL COMPOSITIONS

 Number/Link:WO2018/190891

Applicant/Assignee:  Presidium USA

Publication date: 18 October 2018
Gist”: Polyurethanes from high functionality  bisphenol-based polyols

Why it is interesting: The invention relates to high functionality (and high viscosity) polyols that consist of bisphenol moieties and aliphatic polyol moieties and that can be prepared by reacting a bisphenol-based polycarbonate with a short-chain, high functionality polyol in the presence of a suitable catalyst or promotor.  In the examples a bisphenol-A based polycarbonate powder is reacted with propoxylated pentaerythritol and a tetra – OH – functional tert-amine that acts as a promotor.  The polyols are said to be useful for high stiffness polyurethanes that show improved heat distortion and a relatively low reaction exotherm.

multranol

Catalytic tetrol used in the invention

 

TPUs from Block Polyester Polyols

Patent Title: THERMOPLASTIC POLYURETHANE HAVING HIGH TEAR PROPAGATION STRENGTH  & PROCESS FOR PRODUCING TRANSPARENT HARD THERMOPLASTIC POLYURETHANES

 Number/Link: WO2018/115460  WO2018/115464

Applicant/Assignee:  BASF

Publication date: 28 June 2018

Gist”:  Polyester polyols containing a “hard block” of polyethyleneterephthalate are used in the preparation of TPU 

Why it is interesting: According to this invention thermoplastic polyurethanes with a high hardness at a relatively low hardblock level (<75%), or a high tear strength at relatively low Tg (<5°C) can be prepared from a polyester polyol that is a block copolymer containing 10-50% of an aromatic polyester block, the rest being aliphatic polyester. In the examples diols are prepared from PET together with adipic acid and BDO or DEG. The diols are reacted with MDI or HDI and a chain extender like BDO or HDO.

PET

Poly(ethyeleneterephthalate)