All posts in category Elastomers

Polyester Polyol with PDMS Backbone

Title: POLYESTER POLYOL, POLYURETHANE OBTAINED USING THE SAME, PROCESS FOR PRODUCTION THEREOF, AND MOLDED POLYURETHANE

Number/Link: US2014/0246621

Applicant/Assignee: Mitsubishi Chemical

Publication date: 4-09-2014 (priority PCT)

“Gist”: A polyester polyol is prepared from a caboxylic acid-modified PDMS and a polyether diol.

Why it is interesting: A polyester polyol is prepared form a linear polydimethylsiloxane end-capped with carboxylic acid groups and having a molecular weight between about 500 and 4000 together with a polytetramethyleneether glycol with MW of 500 to 2000, such that the PDMS content is about 40% . The use of this polyol in polyurethane elastomers results in modified surface characteristics like reduced tackiness. The invention mentions fibers and films as potential applications, but this could be an interesting polyol for many other applications as well. Interesting idea but probably not new. Only one claim appears to have survived the filing process.

Representation of the polyester polyol according to the invention

Classic PU Patent of the Month: ICI on Non-Isocyanate Polyurethanes (1961)

Title: Polyurethanes

Number/Link: GB944310

Applicant/Assignee: Imperial Chemical Industries

Publication date: 11-12-1963

“Gist”: Non-isocyanate polyurethanes by transurethanization of bis-carbamates and polyols.

Why it is interesting: Because of the growing concern over isocyanate toxicity and related changes in legislation, research and development of non-isocyanate polyurethane (NIPU) systems has increased sharply over the last few years. The idea, and most of the chemistry of NIPU is by no means new. In this patent, filed by ICI in 1961, NIPU is prepared by transesterification of bis-carbamates and polyols with a functionality of 2 or more. The materials are said to be especially useful for coatings and as TPU for fiber production. According to the patent, the advantages of this reaction system over the use of isocyanates are the reduction of the toxicity hazard, less moisture sensitivity and no need to carefully control reaction conditions and reactant proportions. In an example N,N’-methylene-bis-urethane was reacted with 1,4-butanediol catalyzed by DBTDL resulting in a TPU which could be melt-drawn into fibers. (Note that, in this case, ‘urethane’ is the common name for ethylcarbamate).

ICI logo anno 1961

1 Comment

by Gerhard Bleys on September 1, 2014 • Permalink

Posted in Classic PU Patent of the month, Elastomers, Thermoplastics

Tagged aliphatic isocyanates, carbamate, Environment, isocyanate-free, NIPU, TPU, transurethanization

Posted by Gerhard Bleys on September 1, 2014

https://purpatents.com/2014/09/01/classic-pu-patent-of-the-month-ici-on-non-isocyanate-polyurethanes-1961/

Hydrophobic and Clear Thermoplastic Polyurethane

Title: CLEAR HYDROPHOBIC TPU

Number/Link: WO2014/121174

Applicant/Assignee: Lubrizol

Publication date: 7-08-2014

“Gist”: A hydrophobic, clear and low density TPU is prepared from 4,4’MDI, a dimer acid-based polyol and a mixture of “non-stacking” chain extenders.

Why it is interesting: Most commercial TPUs are hydrophilic to a certain extend and because of phase separation and partial crystallization are often transparent but not clear. The current invention teaches a highly hydrophobic and clear TPU made form 4,4′ MDI, a polyester polyol produced by reacting a C36 dimerized fatty acid (“dimer acid”) with 1,6-hexanediol and a chain extender mixture consisting of 1,12-dodecanediol and 2-butyl,2-ethyl propanediol or 1,4-cyclohexanedimethanol (all preferred). Hardblock content in the examples is between 25 and about 45% resulting in a shore A hardness range of about 75 to 95. No thermal data are given.
While this is no doubt an interesting material, I expect this to be a single phase glass with a relatively low Tg and therefore less useful for structural applications.

Example of a C36 dimer acid

Innovation in Polyurethanes

All posts in category Elastomers

Polyester Polyol with PDMS Backbone

Classic PU Patent of the Month: ICI on Non-Isocyanate Polyurethanes (1961)

Hydrophobic and Clear Thermoplastic Polyurethane

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